Document 7M78L9zVakR3GK8OwkbjbOZRg

GEPA United States Environmental Protection Agency Office of Research and Development Washington, DC 20460 bffice of Air Quality Planning and Standards Research Triangle Park NC 2771 1 Technology Transfer EPAl625/R-92/003 August 1992 Seminar Publication Organic Air Emissions from Waste Management FaciIities EPAJ625/R-92/003 August 1992 Seminar Publication Organic Air Emissions from Waste Management Facilities Center for Environmental Research Information Office of Research and Development Office of Air Quality Planning and Standards U.S. Environmental Protection Agency Cincinnati, Ohio 45268 @ Printed on Recyckd Papa Disclaimer The information in this document has been funded wholly by the United Sates Environmental Protection Agency. It has been subject to the Agency's peer and administrative review, and it has been approved for publication as an EPA document. Mention of trade names or commercial products does not constitute endorsement or recommendation for use. Contents Page Disclaimer ........................................................................................................................................................ .. II Figures ............................................................................................................................................................ iv Acknowledgments........................................................................................................................................... ix Inlroduction...................................................................................................................................................... x Workshop Schedule........................................................................................................................................ xi Chapter 1 Air Pollution Overview....................................................................................................... 1 Chapter 2 Emission Sources and Controls ........................................................................................ 11 Chapter 3 Process Vents Standards-Subpan AA ............................................................................ 27 Chapter 4 Equipment Leak StandardsSubpart BB ........................................................................ 35 Chapter 5 RCRA Phase I1 Air Regulations...................................................................................... 47 Chapter 6 RCRA Overview ............................................................................................................... 51 Chapter 7 Implementation of RCRA Air Regulations ...................................................................... 59 Chapter 8 Case Study: Measuring and Estimating Emissions .......................................................... 65 Chapter 9 Benzene Waste Operations NESH.................................................................................. 75 Chapter 10 Case Study: Application of Benzene Waste Operations NESHAF'to Wastewater Treament Systems............................................................ Chapter 11 Case Study: Process Vent Rule Applicability and Compliance....................................... Chapter 12 Case Study: Equipment Leaks Testing-EPA Method 21 ............................................... 81 89 95 Appendices: A Federal Register Excerpt-Revised Method 21 ............................................................................ B Published Response Factors (From EPA 340/1-88-015) .............................................................. C Bibliography-Equipment Leak Monitoring ................................................................................ 105 109 115 iii Figures Page 1.1 . Ozone in the atmosphere................................................................................................................... 1 1.2 . Troposphericozone formation.......................................................................................................... 2 1.3 . photsohgorawpihngoflulnugngdafrmomage1p9o-ysesiabrl-yoldduaecctoidoeznotnveicetixmpoinsuLreo.s...A....n..g...e..l.e..s........................................... 3 1 4. Areas exceeding the ozoneNAAQS................................................................................................. 3 1.5 . Sourcesof nationwide VOC emissions............................................................................................. 4 1.6 . Top fourteen VOC/HAP chemicals................................................................................................... 5 1.7 . HazarQus waste management.......................................................................................................... 6 1.8 . Phases I and I1 RCRA air standardsoverlaid onto hazardous waste management. ......................... 7 1.9 . Overlap of statutory coverage for air emission sources.................................................................... 7 1.10 . Storage tanks under several "regulatoryumbrellas." ........................................................................ 8 2.1 . Fate of organics: emissions. effluent,biodegradation. sludge........................................................ 12 2.2 . Typical fmed-mof tank.................................................................................................................... 13 2.3 . Covered tanks (working losses)...................................................................................................... 14 2-4. Covered tanks(breathing losses).................................................................................................... 14 2.5 . External floatingroof tank.............................................................................................................. .2.6 Emission sources for distillation..................................................................................................... .2.7 Emissions from solvent extraction.................................................................................................. .2.8 Individual drains.............................................................................................................................. 14 15 15 16 2.9 . Typical junction box........................................................................................................................ 16 2.10 . Oil-water separator.......................................................................................................................... 16 2.11 . Schematic diagram of an air stripping system................................................................................ 17 2.12 . 2.13 . Steam srripper for ethylene dichloriddvinylchloride..................................................................... Preliminary treatment prior M sm.ppi.ng.......................................................................................... 17 17 2.14 . Belt filter press................................................................................................................................ 18 2.15 . Flow path of thin-film evaporator................................................................................................... 18 2.16 . Splash loading vs.submerged loading............................................................................................ 19 2.17 . Land treatment emission mechanisms............................................................................................ 20 2.18 . Emissions from a closed landfill..................................................................................................... 20 2.19 . Carbon Canistets.............................................................................................................................. 21 iv Figures (continued) 2.20 . Two-stage adsorption system.......................................................................................................... 21 2.21 . Schematic diagram of a contact condenser..................................................................................... 21 2.22 . Schematicdiagram of a shell-and-tubesurfacecondenser............................................................. 22 2.23 . Packed tower for gas absorption..................................................................................................... 22 2.24 . Steam-assistedelevatedflare system.............................................................................................. 23 2.25 . 2.26 . 3-1 TCEhxaeatarmlmypnal.lecio1n.-xcaiixndei..zraestrmo...r.p.....p.....i...n....g.................................................................................................................................................................................................................................................................................................................................................. 24 24 28 3.2 . Example %steam stripping........................................................................................................... 28 3.3 . Number of units............................................................................................................................... 29 3-4. Annual emissions from a typical facility........................................................................................ 29 3.5 . Facility bubble for emision rate @..........I....)............................................................................... 30 3.6 . Example 3-control options for a facility....................................................................................... 31 3.7 . Example 3 ( c o n t i n u e d ~ n ! doptions for a facility................................................................... 31 3.8 . 3.9 . 4.1 . CASulpompshe.mcda-a.vbreiylni.-ttaysp.y.p.s..ht.e..c.m.a....b.....d.....i...t...y....d.....e....c....i...s...i....o....n......t....r...e...e.................................................................................................................................................................................................................................................................................. 32 32 36 4.2 . Centrifugalpump construction........................................................................................................ 37 4.3 . Labyrinth shaft seal for compressors.............................................................................................. 37 4-4. Rising stem gate valve.................................................................................................................... 37 4.5 . Spring-loadedrelief valve............................................................................................................... 38 4.6 . Leak area in flanged joint. ............................................................................................................... 38 4.7 . Steam stripper.................................................................................................................................. 38 4.8 . Sealless pumps can be designated for no detectable emissions...................................................... 40 4.9 . Schematic diagramsof two leakless pumps.................................................................................... 41 4.10 . Double mechanical seal with barrier fluid controls emissions....................................................... 42 4.11 . Handwheel-operated pinch valve.................................................................................................... 43 4.12 . A bolted-bonnetbellows seal globe valve...................................................................................... 43 4.13 . Rupture disk.................................................................................................................................... 43 4.14 . Closed-loop sampling system (to avoid losses from sampling)..................................................... 43 .4.15 Open-ended lines............................................................................................................................. 44 5.1 . National VOC emissions-stationary sources................................................................................ 48 6.1 . Hazardous waste characteristics...................................................................................................... 53 6.2 . Hazardous waste generator statistics-number of generators by generator size........................... 53 6.3 . Hazardous waste generator statistics-waste quantity by generator size...................................... 54 8.1 . Vent sampling.................................................................................................................................. 66 8.2 . Isolation flux chamber and supportingequipment.......................................................................... 66 8.3 . Concentration-profiletechnology.................................................................................................... 67 8-4. Transect technology......................................................................................................................... 68 V Figures (continued) 8.5 . Mass balance approach..................................................................................................................... 68 8.6. Open liquid surfaces-modeling approach..................................................................................... 69 8.7 . Effect of volatility on emissions from a surface impoundment...................................................... 70 8.8 . Effect of residence time on emissions from an impoundment....................................................... 70 8.9 . Fate of organics: emissions. effluent. biodegradation. sludge........................................................ 71 8.10. Typical model inputs (liquid surfaces)............................................................................................ 71 8.11 . Model inputs for an aerated lagoon................................................................................................. 72 8.12 . Air porosity vs.totalporosity.......................................................................................................... 72 8.13 . Land treatment emission mechanisms............................................................................................ 72 8.14 . Typical model inputs (prous solids).............................................................................................. 73 .8.15 Model inputs for land treatment...................................................................................................... 73 8.16 . Model inputs for a covered landfill................................................................................................. 73 9.1 . Benzene waste operations NESHAP reporting requirements......................................................... 78 ........10.1 . Wastewater treatment system showing benzene concentrations and flow rates: Example 1 82 10.2 . Wastewater treatment system showing benzene concentrations and flow rates: Example 2........83 .10.3 Wastewater treatment system showing benzene concentrationsand flow rates: Example 3........83 10.3a . Wastewater Example 3: StroelauttmioenntAs.y..s..t.e..m....s..h..o..w...i.n..g...b...e.n...z.e..n..e...c..o..n..c..e..n..t.r..a..t.i.o..n..s..a..n...d...f.l.o...w....r.a..t.e..s.:......................... 84 10.3b . Wastewater Example 3: mtmen Solution tBs.y..s..t.e..m.....s.h..o..w....i.n..g...b..e..n..z..e..n..e...c..o..n..c..e..n..t.r.a..t.i..o..n..s..a..n...d...f.l.o..w.....r.a..t.e..s.:........................ 84 .10.4 ABC Oil Refinery wastewater treatment system-case study problem. (wAnanstueawlaatveerrsaegeeambe.n)z..e..n..e...c..o..n..c..e..n..t.r..a.t..i.o..n...a..n..d...a..n...n..u..a..l..b..e..n..z..e..n..e...q..u..a..n..t.i..t.y...s..h..o..w...n...f..o..r..e..a..c..h............. 85 10.5 . 11.1 . FAaBcCi.li.tOyiXl RYeZfincearsye wastewater treatment system+ase study solution......................................... study.................................................................................................................. 87 90 .11.2 Case study of Facility XYZ wastewater treatment plant 0with "DES permit.................91 12.1 . Flow schematic of one type of flame-ionization analyzer.............................................................. 96 12.2 . Photograph of the front of one type of flame-ionization analyzer................................................. 97 12.3 . Lamp inside analyzer and window on surfaceof lamp.................................................................. 97 12-4. Photoionization lamp on the end of an umbilical cord................................................................... 98 12.5 . Catalytic combustion analyzer........................................................................................................ 98 vi Tables Page 1.1 . StandardsDevelopmentUnder Section 3004(n) ............................................................................... 4 1.2 . Clean Air Act .................................................................................................................................... 6 13. . CERCLNSARA (Superfund) ........................................................................................................... 7 2.1 . MajorFactors AffectingEmissions ................................................................................................ 12 3.1 . Questions on Details........................................................................................................................ 27 3.2 . Units Affected ................................................................................................................................. 28 3.3 . How theRegulations Work ............................................................................................................. 30 4.1 . Highlights ........................................................................................................................................ 35 4.2 . Topics .............................................................................................................................................. 35 4.3 . Equipment Coveredby SubpartBB ................................................................................................ 36 4 4. Applicabilityof OrganicContent Analytical Methods ................................................................... 39 4.5 . Applicabilityof Organic Analytical Detectors ............................................................................... 39 4.6 . LightlHeavyLiquid Determination................................................................................................. 39 4.7 . Leak Detection Monitoringwith Method 21 .................................................................................. 40 4.8 . Control Requirements. Subpart BB Equipment Leak Rules. Summary ......................................... 42 4.9 . EquipmentLeak Model Units ......................................................................................................... 44 4.10 . EquipmentLeak Impacts................................................................................................................. 44 4.11 . General Records Required .............................................................................................................. 44 4.12 . Information Required in Semiannual Reports (264.1065) .............................................................. 45 4.13 . EquipmentLeak Rules .................................................................................................................... 45 4.14 . Types of Equipment Leak Standards .............................................................................................. 45 6.1 . RCRA Hazardous Waste Program-Title 40. Code ofFederal Regularions................................. 52 6-2. HSWA Schedule for SubmittingPart B Permit Applications ........................................................ 55 9.1 . Background of Benzene Waste Operations NESHAP .................................................................... 75 9.2 . Total Annual Benzene in Waste (TAB) .......................................................................................... 76 9.3 . Process Wastewater Exclusions ...................................................................................................... 76 9 4. " n a t i v e Standards for WWTS ................................................................................................... 77 9.5 . Benzene Waste OperationsNESHAp--General Control Requirements........................................ 77 9.6 . Initial Determinationof TAB .......................................................................................................... 78 9.7 . Certificationof Compliance............................................................................................................ 78 10.1 . Case Study Problem ........................................................................................................................ 85 10.2 . Case Study solution ........................................................................................................................ 86 11.1 . Process Vent Emission Rate (ER) and Operating Hour (OH) Data ............................................... 92 vii Tables (continued) 11.2. RTSevDieFwOopferRatCioRnAs-CAaisreEmSistsuidoyns...S..t..a..n..d.a..r..d...f..o..r..p..r..o..c..e..s.S...V...e..n...t.s..f...h...n....H..a..z..a..r..d..o..u..s...W..a..s.t..e................. 93 12.1 . Overview ......................................................................................................................................... 95 12.2 . Catalytic Combusion Analyzer Exposed to 10.OOO ppm Methanol Vapors ................................. 100 12.3 . Flameionization Analyzer Used to Detect Orthochlorotoluene Vapors ...................................... 100 12-4. Catalytic Combusion Analyzer Used to Detect TehachlorceIhane Vapors ................................. 100 12.5 . Response Factors at Various Concentrations. Example 1 ............................................................ 100 12.6 . Response Factors at Various Concentrations. Example 2 ............................................................ 100 12.7 . Response Factors at Variws Concentrations. Example 3 ............................................................ 100 12.8 . Instrument Variations. Example 4 ................................................................................................. 101 12.9 . Instrument Variations. Example 5................................................................................................. 101 12.10 . Health and Safety Considerations ................................................................................................. 102 12.11 . Comparison of Available Insauments........................................................................................... 103 viii Acknowledgments This seminar publication was prepared by Research Triangle Institute @TI) under contract to the Office of Air Quality Planning and Standards (OAQPS). It contains the presentationsof the speakers at the seminar series conducted from August 1990to March 1991. The seminars were sponsored jointly by OAQPS and the Office of Research and Development (ORD). Many persons were involved in the development of these seminars and the presentations. They include: EPA, OAQPS K. C. Hustvedt Robert B. Lucas Susan R. Wyatt EPA, Offme of Solid Waste Ginger Freedman Frank McAIister James Michael A.T. Kearney, Inc. Mitchell Baer RTl Marvin R. Branscombe David W. Coy F. Graham Fitzsimons. Robert G. Hetes Paul R. Peterson Terrence K. Pierson Robert A. Zerbnia PEER Consultants,P.C. Donovan S.Duvall Andrew W. Weisman Justice A. Manning, the Center for Environmental Research Information, ORD, coordinated the workshops with assistance from PEER Consultants, P.C. Peer review was provided by several persons at RTI and OAQPS. Special appreciation is expressed to Bob Zerbnia who worked tirelessly with CERI in bringing this document to completion. Bob Zerbnia and Bob Lucas provided a final review. * Formerly RTI; currently EC/R ix Introduction The organic chemicals contained in wastesprocessed during waste management operations can volatilize into the atmosphere and cause toxic or carcinogenic effects or contribute to ozone formation. Because air emissions from waste management operations pose a threat to human health and the. environment, regulations were developed to control organic air emissions from these operations. In June of 1990, the Environmental Protection Agency @PA) promulgated standards under the authority of Section 3004 of the Hazardous and Solid Waste Amendments to the Resource Conservation and Recovery Act (RCRA). The standards limit organic air emissions as a class from process vents and equipment leaks at hazardous waste treatment, storage, and disposal facilities requiring a permit under Subtitle C of RCRA. Additional RCRA standards are under development. On July 22,1991, EPA pmposed, under RCRA authority, organic air emission standards for tanks, surface impoundments, and containersat hazardous waste treatment, storage, and disposal facilities (56 FR 33491). In March of 1990, the EPA promulgated standards under the authority of Section 112 of the Clean Air Act (CAA) that limit emissions of benzene from benzene waste operations. To improve the understanding of the recently proposed and promulgated air rules that apply to waste management operations and to ensure that EPA, state, and local permit writers and enforcement personnel and the regulated community receive consistent guidance related to implementation, compliance, and enforcement activities, EPA conducted a series of workshops focusing on these rules. Presentations and case studies focus on waste management sources of air emissions, control technologies,and the RCRA and CAA regulations. This workshop was sponsoredjointly by EPA's Office of Air Quality Planning and Standards and the Officeof Research and Development, with support from the Office of Solid Waste and Emergency Response. Technical support for the workshops was provided by Research Triangle Institute; logistical support for the workshops was provided by PEER Consultants, P.C. At the end of each chapter is a select list of questions either submitted by the attendees or asked of the speakers at the conclusion of their presentations. Answers based on the best information available at the time were given onsite and summarized here. X Workshop Schedule Boston, MA August 28-30, 1990 Elizabeth, NJ September 11-13. 1990 Chicago, IL October 23-25, 1990 Atlanta GA November 13-15, 1990 Dallas, TX December 11-13, 1990 Sacramento, CA January 15-17, 1991 Seattle, WA January 22-24, 1991 Kansas City, MO February 12-14, 1991 Philadelphia, PA February 26-28, 1991 Denver, CO March 26-28, 1991 Sincethe regulatory scene is dynamic, some statementsin this publicationmay be dated.As can be seen from the above dates, these workshops were completed over a year ago. Information was accurate then. If questions arise conceming TSDFs from reading material in this publication, the reader should contact: Air Questiom Bob Lucas (919) 541-0884 RCRA Permitting Questions Frank McAlister (202) 260-2223 xi Chapter 1 Air Pollution Overview Abstract Ozone A broad overview of the need to control organic air emissionsis provided in tbis introductory chapter. Human health and environmental problems cansed by organic air emissions or problems to which organic air emissions contribute are discussed. Major problems discussed are those resulting from tropospheric ozone formation and exposure to air toxics. Other problems discussed include stratospheric ozone depletion, global climate change, and acid rain. The statutory mechanisms under which organic air emissions are regulated are discussed, with emphasis on the Clean Air Act and the Resource Conservation and Recovery Act (RCRA). The specific rules that apply to waste management operations and that are the focus of the workshop are introduced. These are the rules devel- oped by the U.S. Environmental Protection Agency (EPA) under RCRA Section3004(n) that apply to RCRA-permitted hazardous waste treatment, storage, and disposal facilities (TSDFs) and the rule promulgated under Section 112 of the Clean Air Act that limits emissions from benzene waste operations. Overview Organic gaseous emissions are the focus of this chapter because the air emissionsstandardsthat are the subject of this workshop are those being developed by the Office of Ai Quality Planning and Standards(OAQPS) to address organic emissions from several waste management sources.However, other types of emissions also occur from waste management sources, such as inorganic gaseous emissions (e.g., metals) and pdculate emissions,thatare subjectto regulation through other programs. For example, the Office of Solid Waste (OSW) has proposed standards for emissions from industrial boilers and furnaces that include requirements for metals. General requirements exist that limit blowing dust (particulates) from landfills and waste piles at hazardous waste treatment, storage,and disposal facilities (TSDFs). The EPA also has developed a Hazardous Waste TSDF - Fugitive Particu- late Matter Air Em`sswns Guidance Document (EPA450/389-019) that deals with controlling these emissions. Why are we concerned about organic gaseous emissions? Two major concerns are ozone and air toxics. Ozone in the atmosphere is illustrated in Figure 1-1. Ozone is both a blessing and a curse, in relation to human health and environmental effects. It exists naturally in the upper atmosphere (the stratosphere) and in the lower atmosphere (the troposphere). Ozone is a blessing in the stratosphere; it protects us from the sun's radiation. However,in the lower atmosphere, exposureto ozoneresults in negativehealth effectson humans and other adverseenvironmentalimpacts. The way ozone is formed in the lower atmosphere. is depicted very simplisticallyin Figure 1-2. The primary ingredients are nitrogen oxides, organic compounds, and solar radiation. Emission of nitrogen oxides come primarily from combustion sources. Major stationary sources of NOx,are coal-firedpower plants. Transportationsources(automobiles, trucks, buses) are also big NO sources. Organic compounds come from a variety of source;, includingwaste management operations. In the presence of sunlight, nitrogen oxide and organic compounds go through a series of complex chemical reactions,and two principalby-productsare formed. One is ozone, identified by the symbol 0,.and the other is an aerosol that, K , . .....................................................s..t.r.a.t.o...s.p..h..~..r.ic.o.?..O..n.e.:...:.:...::...::...:.s..t.r_.a.tosre Stratosphericozone ("goodozone") providesprotectionI"the sun's radiation Troposphericozone ("bad ozone') is detrimentalto human health and welfare Figure 1-1. Ozone in the atmosphere. 1 among other things, restricts visibility. The combination of these is referred to as photochemical smog. Human exposure to ozone can affect the respiratory system. Impacts include inflammationof thelungs, impaired breathing,reduced breathing capacity, coughing, chest pain, nausea, and general initation of the respiratory passages. The results of long-term ozone exposure can include increased suswptibility to respiram infections, permanent damage to lung tissues, and severe restrictions on breathing capacity. Certain subpopula- tion groups, such as the very young, the elderly, and those with preexisting respiratory conditions, are more sensitive to exposure to ozone thanthe normal, healthy, adult population. However, healthy, young individuals can also be subject to negative health impacts if exposed to ozone during exercise. Studies have been conducted to determine the existence and extent of the human health impacts of ozone. For example, in a study in 1988of several hundred deceased persons in Los Angeles, allbelieved to be accident victims and otherwise healthy, about half were found to have lesions in their lungs, characteristicof the early stagesof lung disease (Figure 1-3). Welfareeffectsare associated with ozone exposure. Ma- terial damage due to oxidation may occur. Synthetic and rubber compounds, for example, have a much shorter useful life in an ozone-laden environment Reduction in crop fields, lower forest growth rate, and premature leaf droppage also may occur. EPA recently estimated that between $2 billion and $3 billion worth of annual damage to commercial crops and forests was due to zone exposure. Visibility impairment can also be considered a welfare impact of photochemical smog. EPA is charged under the Clean Air Act (CAA) to establish national ambient air quality standards for pollutants including ozone. One measure of how extensive the ozone problem is in the United States is to compare air quality monitoring data with the health-ba9 ambient air quality standard. The national ambient air quality standard (NAAQS) for ozone was set at 0.12 ppm (an hourly average not to be exceeded more than once annually). Historical monitoring data indicate that the national ambientair quality standardhas been exceeded routinely in more than 60 areas nationwide. Over 100 million people live in these areas. Recent data indicate some improvement from these figures, but the ambi- ent air quality standard for ozone is still being exceeded in many areas that contain a significant portion of the total population of the United States.Furthermore, some areas may not attain the ambientair quality standard for many years. The CAA amendments of 1990 contain provisions that address "nonattainment" areas;that is,areas not attaining the ambient air quality standards for several "criteria" pollutants, including ozone. Under this new law, areas with extreme ozone nonattainment problems have 20 years to attain the ozone ambient air quality standard. More stringent standards for ozone have been called for-pariicularlywith regard tosensitivepopulationsfor whom 0.12 ppm may not be low enough. 2 L Solar Radiation A map of the United States highlighting areas exceeding the ambient ozone standard, based on data collected in 1986 and 1988, is shown in Figure 1-4. Although the largest urban areas, such as the Los Angeles area, Chicago, Houston, and the northeast comdor, are the "hot spots" for ozone, many other areas across the United States also have an ozone problem. In addition,due to the transport of ozoneprecursors, the ozone NAAQS is exceeded in areas of the country far e Emissions Organic Compounds Flaum 1-2. Tropospheric ozone fonnstlon. 2 Flgura 1-3. Photograph of lung from 19-year-oldaccldent vlctlm In Loa Angeles showlng lung damage possibly due to ozone exposure. removed from urban centers. Some of the national parks, for example, have been observed to exceed the ozone ambient air quality standard occasionally. The relative contribution of various source categories to total nationwide emissions of volatile organic compounds (VOCs) is shown in Figure 1-5. In EF'A terminology, a V O C is an organic compound that is believed to participatein ozone formation. As shown, hazardous waste TSDFs are a significant source, contributing an estimated 8 percent of total VOC emissions. Air Toxics I n general, air toxics are air pollutants that cause cancer or other human health effects.Onehundred ninety compounds are specifically identified in the CAA amendments of 1990as air toxics that EF'A must investigate and potentially regulate. A significant number of those 190 are organic compounds. Many point and area sources of air toxic emissions exist. These include large point sources such as chemical plants, pelroleum refineries, and power plants. Smaller and more widespread sources, such as dry cleaners, can alsobe sources of air toxic emissions. Waste management sources also contribute to air toxics and are widespread. A recent count of TSDFs by the EPA OSW indicated about 2.600 IO 3,000 potentially permitted TSDFs. Each air pollutant produces characteristic health effects, which can occur due to acute (short-term) exposureor chronic (long-term) exposure. Exposure to air toxics affect neurologi- 3 Industrial Processes 2% ,Surfam Coating 14% Petroleum Marketing 10% I TSDF 8% 2% Flgun 1-5. Sources of nationwide VOC emlsslons. cal, respiratory, and reproductive systems. Some air toxics, such as benzene. also mav cause cancer. Two EPA measures 6of health cffccts &c used identify or quantify the impacls of carcinogenic air toxics. One is individual risk, expressed as a statistical probability, that indicates an individuai's increased risk of contracting cancer when exposed to a particular concentration of a pollutant over a 70-year lifetime. The other measure is an indication of population risk expressed as the number of cancer incidences per year expected nationwide due to exposure to that pollutant. Recently,major U.S. industriesbegan reporting the amount of toxic chemicals released to the air, land, and water as required by the Superfund Amendments and Reauthorization Act (SARA), Section 313. Industry reported that in 1987 about 2.4 billion pounds of toxic pollutants were emitted to the air. Air toxics are estimated by EF'A to account for between 1,600 and 3,000 cancer deaths per year, and the average urban individual lifetime risk of contracting cancer due to exposure to air toxics is estimated to be as high as 1 in 1,OOO. example, is the most emitted compound but is less toxic than benzene. a carcinoeen linked to leukemia. I Laws That Address Organic Air Emissions Several major environmental laws address organic air emissions. These include the CAA, which is specifically designed to address major air pollution problems in the United States; the RCRA, as amended by the Hazardous and Solid Waste Amendments: and the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), as amended by SARA. Most of the new air standardsdescribed in this workshop arebeing developed under RCRA. Section 3004(n) directs the EPA Administrator to establish standards for the monitoring and control of air emissions from treatment, storage, and disposal facilities, as necessary, to protect public health and welfare. The standards developed under RCRA 3004(n) areto be implemented through the RCRA permit system established for hazardous waste management units. For trcalmcnl, Storage, and disposal facilitics,a Prcliminary estimate indicatesa national population risk of about 140 ~ ~ 1,-1,. l ~Standards Development Under Sectlon 300qn) cancer incidences per year and a m&imum individual risk of 2 in 100 possibly caused by air toxic emissions from these facilities. The top 14 VOCs and air toxics (also referred to as Phase I Phase I1 Total organics Process vents and equipment leak6 - Promulgated6/21/90 (55 FR 25454) Total organics "hazardous air pollutants'' (HAPS)) on a mass emission basis * Tanks, surlam impoundments, mntalners are shown in Figure 1-6. Mass of emissions alone, however, does not indicate the relative severity of the problems associated with air toxics. The toxicity of each compound and the degree of exposure that occurs (e.g.. time and concentration) are equally important and must be considered. Toluene, for Phase ill and miScellaneouSunits - Proposal package In OMB Individualconstituentstandards,as needed, - to supplement Phase I and Phase II standards Early Work Group stage 4 Toluene 0 Formaldehyde Methylenechloride Methylchloroform Ethylene m-Xylene Benzene o-Xylene Perchloroethylene p-Xylene Chlorobenzene Aceticacid Trichlorotrifluoroethane Trichloroethylene Figure 14. Top fourteen VOClHAP chemlcals. As illustrated in Tablel-1, the EPA is developing the RCRA 3004(n) air standards in three phases. Organic emissions from process vents associated with specificnoncombustion waste treatment processes (e.g., stream snipping and thii-film evaporation units) as well as equipment leaks from pumps, valves, and pipe fittings are addressed in Phase I. Final standards for these sources were promulgated June 21, 1990 (refer to Subparts AA and BB in the Code of Federal Regulations (CFR), Title 40, Paris 264 and 265 (40 CFR 264 and 265)). Organic emissions from tanks, surface impoundments, containers, and miscellaneous units are addressed in Phase 11. Standards for these sources were proposed in July 1991 as a new Subpart CC in 40 CFR Parts 264 and 265. Current analyses indicate that a potential residual risk problem may remain after implementation of the Phase I and Phase I1 standards for organics. Therefore, emissions of individual chemical constituentsas necessary to bring the residual maximum individual risk 4 within an acceptable range under RCRA (104to lob)will be addressed in Phase 111.Proposal of standards, as needed, under Phase I11 is planned to be concurrent with promulgation of the Phase I1 standards. The Corrective Action Program is also under RCRA. Under the Corrective Action Program, solid waste management units have to go through a site-specific facility evaluation. Site-specific evaluation and risk assessment also include consideration of air emissions. In addition, the land disposal restrictions (LDR) promulgated under RCRA affect air emissions. The LDR prohibit the depositing of hazardous waste on or into land disposal sources such as landfills, surface impoundments, and waste piles unless certain treatment require menu are met. Treatment of wastes to meet the LDR can result in air emissions if the treatment process is not properly controlled, and the RCRA 3004(n) air standards work in concert with the LDR to prevent this potential cross-media pollution. units before disposal. Waste may be stored or treated, for example, in tanks and containers. Containers include 55gallon drums, dumpsters, tank trucks, and railcars. Waste treatment tomeet therequirementsof theLDRmay takeplace early in the waste management process, or just prior to dis- posal. Further, the management of hazardous waste may take place at the generator site (onsite) or at a commercial TSDF (offsite). If a waste is managed offsite,it may also be handled at a storage and transfer station before being transported to another location for final treatment and disposal. In Figure 1-8,coverageof the Phase I and Phase I1RCRA air standards is overlaid onto the hazardous waste manage ment units illustrated in Figure 1-7. In the Phase I standards, process vent organic air emissions from treatment units specifically identified in the standards are limited, and equipment leak emissions from other waste management units are limited also. Coverage of the RCRA air standards would be expanded by the Phase I1 standards to address organic air emissions from tanks, surface impoundments, and containers. As is discussed in more detail in later workshop chapters, the Phase I1 standards are designed to contain (or suppress) potential organic emissions from escaping prior to treatment. According to the standards, operators would be required, for example, to cover open tanits unless the concentration of organic waste contained in a tank could be demonstrated tobe below a specified value. Because control requirements are niggered by the organic content of the waste, these standards are "waste-based"rules. Waste treatment is not required,according to the Phase I1RCRA air standards, but is required by the LDR. The benzene waste national emissions standards for hazardous air pollutauts (NESHAP),also discussed in this workshop, q u i r e s containment-type controls prior to treatment similar to the Phase I1 RCRA air standards. Unlike the Phase I1 standards, however, treatment requirements for benzene-containing wastes are included in the benzene waste NESHAP. CIean Air Act Other programs under RCRA, such as one that estab- Major regulatory programs established under the CAA lishes location standards for the siting of new facilities, also that are used to address organic air emissions, including ozone require consideration of air emissions. precursors and air toxics, are shown in Table 1-2. An overview of hazardous waste management is shown As referenced earlier, NAAQS are established by EPA in Figure 1-7. Once a hazardous waste is generated, it may go for "criteria" pollutants. and the states then set standards to through a series of different processes and waste management attain and maintain them. Ozone is a criteria pollutant, and 5 Waste Oeneration Waste Handling and Treatment Waste Disposal Land Disposal Units 90-Day Tanks : : Figum 1-7. Hazardous waste management. Tanks 8 SurfaceImpoundments ! volatile organic compounds are regulated by the states as ozone pmursors on a source-by-sourcebasis. The new source performance standards (NSPS),set under Section 111 of the CAA,are designed to address emissions of the criteria pollutants from new, modified, or reconstructed stationary sources. "Designated pollutants" may also be addressed by NSPS. A designated pollutant is a noncriteria pollutant that is identified by EPA for regulation under Section 11l(d), based on health or welfare impacts. Examples of designated pollutants are toral reduced sulfur (TRS)and sulfuric acid mist. NESHAP are set under Section 112 of the Clean Air Act to h i t emissions of pollutants identified as hazardous from both existingandnew stationary sources. Section 112waschanged substantially by the 1990 CAA amendments. The "old" Sec- Table 1-2. Clean Alr Act tion 112required EPA fvst to list apollutant as hazardous and then to establish standards to protect public health "with an ample margin of safety."In the new Section 112, EPA must establish technology-based standards for sources of 190 hazardous pollutants listed in the new law. At a later time, more stringent standards are required if risk assessments indicate that the technology-based standards are not adequately protective. A NESHAP for benzene waste operationswas completed recently and is the last NESHAP set under the "old" Section 112. It was promulgated in March 1990 and is codified in 40 CFR 61. Subpart FF. It applies to chemical plants, petroleum refiieries, coke by-product recovery facilities, and certain treatment, storage, and disposal facilities. The compliance deadline for existing facilities to install the controls that are required by this standard is March 7,1992. The benzene waste NESHAP is described more fully in later chapters. * National AmMent Air Quality Standards (NAAQS) - Criteria pollutants - PM, SO,. CO, NO,, 0,. Pb - New Source PerformanceStandards (NSPS) - Criteria pollutants - Designated pollutants (9.g.. TRS) - National Emission Standards for Hazardous Air Pollutants (NESHAP) CERCLA (Superfund) The cleanup of inactive contaminated sites is mandated in CERCLA. As shown in Table 1-3,several aspects of CERCLA are important in the control of organic air emissions. A sitespecific risk analysis must be conducted prior to a removal and remediation action under Superfund,and this site-specific analysis must include a consideration of air emissions that may result from the cleanup. For example, ground-water 6 Waste Generation Waste Handling and Waste Disposal Land Disposal Units Tanks 3. Surface Impoundments Flgun 1-8. Phases I and IIRCRA air standards overlald onto hazardous waste management. shipping to remove an organic contaminant could result in a potential cross-media problem if air emissions created by the treatment process were not controlled. In addition. removal and remediation actions must comply with those existing laws that are applicable or relevant and appropriate requirements (ARARs).As will be discussed later, the Phase I RCRA air standards may be ARARs for some cleanup operations under Superfund. Finally, the toxic release inventory required by SARA Title 313 is also an important tool for addressingair toxics. In avery broad sense,thisinventory is helping to improveEPA's knowledge of the sources of toxic air pollutants. SARA Title 313 was one of the databases that EPA reviewed recently in Tabla 13. CERCLNSARA (Superfund) trying to identify sources of the 190toxic air pollutants listed under the CAA of 1990. Some overlap exists in statutory coverageof air emission sources by the various laws as shown in Figure 1-9. In some situations, this overlapping coverage will result in the same source being subject to regulations with different control requirements. When this occurs, it likely will be because the applicableregulations were developed under laws with different mandates. For example, NSPS under the CAAare.technol- Clean Air Act - NSPS - NESHAP -- 3004(n) Waste treatment standards * Site-specific risk analysis required for removal and remediation actions * Removal and remediation actions must comply with federal and state laws that are applicable or relevant and appropriate (ARARS) Toxic release inventory required by SARA Title 313 - Control requirements consistent and complimentary to me extent passible Compliance must be demonstrated with all applicable rules Flgure 1-9. Overlap of statutory coverage for alr emlsslon sources. 7 ogy-based standards,and the RCRA 3004(n) air standardsare risk-based. Where different standardsapply, compliance musi be demonshated with all applicable rules. However, when possible, FPA will make the control requirements of rules thal apply to the same sources consistent and complementary. An exampleof this overlappingcoveragerelated to waste management is storage tanks. As illustrated in Figure 1-10, storagetanksmay be covered by three separaterules. Tanks in which benzene-containing waste is stored at chemical plants, petroleum refineries,cokeby-product plants, andcertain TSDF are.covered by the benzene waste NESHAP (40 CFR Part 61, Subpart FF). New, modified, or reconstructed tanks containing volatile organic liquids (VOLs) and those above certain size limits are.covered by the NSPS for VOL storage (40 CFR part 60,Subpart Kb). Finally, the RCRA Phase I1 air standards will apply to tanks in which organic hazardous waste is managed. Dependingon the particular physical characteristics of the tank,the waste being stored, and theage of the tank, the same tank could be covered by the benzene waste NESHAP, the VOL storage NSPS, and the RCRA Phase I1air standards. The ramifications of this overlap for owner/operators are minimal, however, because, if an owner/operator is complying with the control requirements of any one of the standards, he or she will be in compliance with the conml requirements of all three. Questions and Answers Question-Regarding the location of ozone problems in the lower atmosphere,where do the problems occur in terms of emission sources or locations? Is the transport of VOC a factor? Answer-This oxidizing type of pollution is generally found in urban areas. It results from chemical reaction of NO, and HC in sunlight and produces O,, PAN, and other complex compounds. The pollution is expressed asozone and referred to asphotochemical oxidants. Because it is a secondary pollutant, transport is a concern. Ozone is a regional problem with impacts occurring up to 250 km from the source. Quesfion-If ozone is depleted in the upper atmosphere,why is it not depleted in the lower atmosphere? Answer-Ozone is short-lived in the lower atmosphere. The concentration follows a daily cycle with peaks around nwn decreasing to near zero levels after midnight, as the intensity of solar radiation diminishes. Ozone in the upper atmosphere (- 30 km) is formed by photodissociation of oxygen. Conclusions Organic air emissions contribute to major air pollution problems, including ozoneformation in the lower atmosphere and air toxics. Waste management operations are a significant sourceof organic air emissions and are being regulated under several federal laws. The applicability and specific requirements of the various regulations issued and under development will bediscussed in subsequent chapters of this course. Question-Regarding the ozone NAAQS, does a link exist between the concentration of 0.12 ppm and when health effects take place? Answer-The ozone NAAQS is a health-based standard, but debate exists on the level that provides an adequate margin of safety. Question-1s a copy of the hazardouspollutant list available? Dostandards exist for these compounds; existing limits aJ aVOL Storage NSPS on emission rates from facilities? Answer-No standards exist on emission rates; some emission measurements are available. RCRA 3004(n) Phase II Question-Why are we concentratingon benzene from among the entire list of 190hazardous air pollutants? J Answer-A court order has been issued on the benzene regulations. Question-Can you summarize when RCRA and when CAA has jurisdiction? How do the new CAA amendments overlap with the RCRA process vent rules? Flgun 1-10. Answer-Both say protect and the CAA says "be consistent" Storage Tanks with RCRA rules. Guidance for VOC control is being -JUissued in the process vent alternative control technology; RCRA-exemptWWTS maximum achievablecontrol technology (MACT) standards (technology based for HAPS) Storage tanks under several `"regulatoryumbrella.." will be developed. Title 5 permits still may be needed for RCRA vents. Q u e s f i o d o u l d you be more specific as to what impacts Quesrion-Regarding maximum individual cancer risk,is it organic air emissionshave on global climate change and onsite,offsite,%-hour exposure,lietime, or nationwide? acid rain, and the specific organics that cause these Is the risk for TSDF s o m s evaluated separately from impacts? What are the "greenhouse gases"? the risk from production processes? Answer-% greenhouse gasesareCO,, $0, CH,, NO,, and Answer-The risk is evaluated at the fenceline. It represents CFCs; concentrationsare increasing. the nationwidemaximum individualcancer riskresulting from lifetime exposure. 9 Chapter 2 Emission Sources and Controls Abstract The major sources of air emissions at waste management facilities, how these emissions occur, and their control are the focus of this chapter, The major sources that are discussedin detail include surface impoundments, the very broad and diverse category of tanks and ancillary equipment, containers, and other major land disposal sources. As each source is described, controls that are inherent to that source or commonly found on that particular source are presented. In addition, details are provided ou the hasic mechanisms by which emissions occur and the major factors that affect the emissions. After the discussion of sources and their inherent controls, air pollution control devices that may be gener- ally applicable to any enclosed or vented source (Le., add- on coutrols) are described. The discussion of control de- vices focuses on their applicability, control performance, and the maior factors affecting oerformauce. Organic land disposal restrictions (LDR). The major focus is on the fmt three categories because they are the most directly impacted by the air emission regulations covered in this work- shop. Surface Impoundments A surface impoundment is "a natural topographical de- pression, man-made excavation, or dked area formed primarily of earthen materials (although it may be lined with manmade materials)which is designed to hold an accumulationof liquid wastes or wastes containing free liquids and which is not an injection well. Examples of surface impoundment$are .holding, storage, settling, and aeration pits, ponds, and la- mans.'* Impoundments a~~ ponds and lagoons that are U s e d PrimklY for managing aqUeous wastes and sludges. They are certainly land disposal sources, but they are discussed sepmtelY becauseOf continued useafter LDR is in cussion describes processes that remove or destroy the organics in the waste, which may eliminate the need to control subsequent waste processing steps. Emission Sources and Controls The types of sources found at waste management facili- ties, inherent conwls that are typically part of the construction and operation of the sources, and emission mechanisms are covered in this chapter. As each source is discussed, covers and enclosures that are specifically applicable to the source are described, as well as simple work practices that reduce emissions. Other emission controls that are broadly applicable to many of the individual sources are discussed collectivelyin the second part of this chapter. These controls includetraditionalairpollution conwl devices,processes that remove the organics before the waste is placed in units with a high emission potential, and waste incineration. A surface impoundment is below grade, usually has berms with sloping sides to contain wastes, and has a liquid surface that is exposed to the atmosphere. It may be operated as a flowthrough system with liquid flowing in at one point and out at thesame time at another point,or the liquid may be pumped out or evapomed, leaving behind a sludge. Surface impoundments are commonly part of wastewater treatment processes and are used for storage, equalization of different waste streams, neutralization, biodegradation, or other processes. Surface impoundmentshave a very high emission potential for volatile organics for several reasons.These impoundmerits have largeexposed surfaceareasthatrange in size up to several acres. In addition, the residence time of the waste in the impoundment is on the order of days, weeks, or months, which results in the loss of most of the volatiles. Sources of Air Emissions The discussion of emission sources is divided into four categories: surface impoundments,the very broad and diverse group of tanks and ancillary equipment, containers, and land disposal sources that are expected to be most affected by the Several of the factors that affect emissions from im- poundments are listed in Table 2-1. These same factors are applicable to emissions from open tanks. The constituent's volatility has a direct effecton emissions from impoundments and other sources with exposed liquid surfaces. Highly volatile compoundssuch asbenzene arereadily emitted from open 11 Table 2-1. YajM Factors Affecting EmlMlOnS - Constluent volatlllty Resldence tlme . ~umcearea Turbulenca (sentlon, agllatlon) Windsped and temperature Extent of competingmechanisms (such as biodegradation) sources, whereas relatively nonvolatile compounds such as phenol tend to stay in the water. The residence time in the impoundment has an obvious effect on emissions: longer residence times result in higher emissions. If the waste is in the impoundment long enough, even relatively nonvolatile compounds are evaporated. For impoundments with relatively short residence times, a higher percentage of the organic may be removed with the effluent and emitted later in other units in the treatment sequence. Many impoundments and tanks are agitated for mixing, air stripping, or biodegradation. Agitation and aeration in- crease. emissions by creating turbulent zones and increase contact between the waste and air. A highly turbulent area and water spray around the agitators used in mechanically aerated units exists. Essentially all of the highly volatile compounds can be emitted when the impoundment is mechanically agi- tated. Approximately half of the impoundments used to treat hazardous waste are aerated or agitated. As is illustrated in Figure 2-1, emissions from impound- ments occur from wind blowing across the exposed surface of the waste. Organics can also be removed by biodegradation, adsorption onto sludge, or removed with the effluent. Emission models have been developed to estimate the extent of each of these different removal mechanisms. The models developed for open liquid surfaces are applicable to both impoundments and open tanks. These models can accountforrelatively calm surfacesor the emissionsfrom the turbulence created by amtion or agitation. The emissions are modeled as two mass transfer steps in series: (1) diffusion through the liquid, and (2) mass transfer from the surface of the liquid to the air. The approach can account for removal in flowthrough systems and removal in units designed for dis- Emissions Wind -+ TTT -0 out Figure 2-1. Falo of otganka: emlsslons, emuent, blodegradatlon, sludge. p o d or evaporation.The extent of biodegradation, if any, can also be estimated. One of the controls demonstrated for impoundments is an air-supported structure, which uses fans to maintain a positive pressure to inflate the structure. For effective control, the air vented from the structure must be. sent to a control device, such as a carbon adsorber. Air-supported structures have been used as enclosures for conveyors, open top tanks,and storage piles, as well as impoundments. An air-supported structure and control device has been installed on a 1-acre aerated lagoon that is used for biodegra- dation at a pharmaceutical manufacturing facility. The cova material is a PVC-coated polyester with a Tedlar backing. Agitators are used inside the structure to provide oxygen and to keep carbon and biomass suspended. In this application, the exhaust from the structure is vented to a carbon adsorber. Very few leaks were found around the structure; consequently, the control efficiencyis determined primarily by how well the control device works. This plant's experience with the air-supported structure has found that corrosion can be accelerated inside the structure and that special worker safety precautions are needed. Floating membrane covers areanother control option and have been demonstrated on various types of impoundments, including water reservoirsin the westem parts of the United States. For proper operation as a control technique for organic compounds, the membrane must provide a seal at the edge of the impoundment and provisions made to remove rainwater. If gas is generated under the cover, vents and a control device may be needed. In addition, if sludge accumulates, some means for periodic sludge removal may be required, such as a sludge pump. Emission control depends primarily on the type of membrane, its thickness, and the individual organic compounds in the waste. Theoretical estimates based on diffusion through the membrane indicate worst-case.control efficienciesof 50 to over 95 percent. Laboratory studies indicate that the cover is an efficient control for some organic compounds, and, for specific compounds that permeate the membrane, the control efficiency is lower. The floating membrane cover has been demonstrated on an impoundment that is used as an anaerobic digester. The impoundment is about 7 acres in size with a depth of approximately 14 feet. The membrane material is 100-mil highdensity polyethylene. The cover is anchored over a concrete ring wall that extends above grade level around the perimeter of the impoundment. The membrane extends over the concrete wall and is covered with backfil to anchor and seal it. Punctures or tears in the membrane can be patched. This installation has been in operation for4 years, and the company supplying the membrane offered a 20-year warranty on the life of the material. Tanks The most diverse group of sources falls into the category of tanks, which is broadly defined. If the unit is not a land disposal source, it is probably a tank. A tank is defined as "a stationary device, designed to contain an accumulation of 12 hazardouswaste which is constroctedprimarily of nonearthen materials (e.g., wood, concrete, steel, plastic) which provide smcturalsupport." A tank system is defmed as a tank and its ancillary equipment, and ancillary equipment includes such devices as piping, fittings, flanges, pumps, and valves. Thecategory of tanksand tanksystemsincludes a discussion of those units that are easily identified as tanks, such as fvceed-roof storage tanks. It alsoincludes wastewater treatment tanks that are typically open: units that perform separation processes, such as columns used for distillation, absorption, and solvent extraction: units used for dewatering: and devices used for waste fmtion.The discussion of tanks is divided into four groups: (1) those used primarily for managing organic liquids, (2) those. used foraqueous wastes, (3) those used for sludges, and (4) the miscellaneous equipment items associated with tanks. Organic Liquids Organic liquids are usually managed in covered or enclosed tanks,including those with fixed roofs. those with f l a g roofs, and p s u r e tanks.Fixed-mf tanks are the most common type of storage tank found at hazardous waste facilities. Emissions occurthrough the tank`s vent, which may beopen to the atmosphere, equipped with a pressure-vacuum relief valve, or vented to a pollution control device. The fixed roof may have several openings in addition to the vent, such as a manhole for tank entry. a hatch used for measuring the liquid level, or an overflow pipe (Figure 2-2). The pressure-vacuum relief valve is also called a conservation vent, which permits small changes in the liquid level without pushing out the tank`s vapors. If the tank has a conservation vent 01is vented to a control device, the other openingson the tankmust bekept closed and sealed for the emission controls to be effective. Emissions from fixed-roof tanksoccur primarily by working losses and, to a lesser extent, by breathing losses. The quantity emitted is most directly affected by the rate at which vapors are pushed from the tank and the volatility of the tank's contents. These emissions are increased by heating or aeration. Working losses occur when waste is pumped into the tank and vapors are pushed out by the rising level of liquid (Figure 2-3). Breathing losses occur when the volume of vapor in the tank is increased because of changes in temperature or pressure (Figure 2-4). Equations developed by the American Petroleum Institute (API) are used to estimate emissions for organic liquids. The basic form of the equation, which can be used for other types of wastes, estimates the volume of vapor pushed out from the amount of liquid pumped in. The concentration of organics in the vapor can be measured or estimated. One error in using the API tank equations for aqueous wastes is to estimate the concentration in the vapor from the mole fraction of the compound in the liquid, which significantly underestimates concenlration. Henry's law constant should be used for dilute aqueous wastes. Breathing losses are usually very low compared to working lossesand can often be neglected. Note that if the tank is operated at a constant liquid level, as some separators and collection tanks are, very little vapor i s displaced and working losses are small. As an emission control option, fixed-roof tanks can be retrofitted to open tanks, or a fixed-roof tank can he used to replace an open tank or impoundment. Compared to an open tank, a fixed-roof tankcan provide additional control of 86 to 99 percent, depending on the waste volatility and the operating characteristics of the open tank.If the fixed-roof tank is constructed to withstand pressures of 2.5 psig, an additional control of 20 to 45 percent can be obtained. (Most tanks are not designed and constructed to withstand this pressure.) Floating roof tanks are common at petroleum refineries and gasoline marketing facilities for the storage of volatile liquids. The floating roof can be installed internallyin a fixedroof tank or externally without a fixed roof. The roof floats on the liquid and moves with changes in the liquid level, thus controlling working losses. Emissions from a properly maintained floating roof are very low and occur from standing losses and withdrawal losses. The equipment associated with an external floating roof tank is shown in Figure 2-5. Standing losses occur at the deck seals and at openings for fittings in the floating roof. With- PresisureNacuum V Flgun 2-2. Typical fixed-roof tank. 13 Volume of Displaced Vapors Working Losses Due to Loading T + New Liquid Level t Original Liquid Level t uid In Flgun 23. Covered tanks (working i o ~ e s ) . Breathing Losses Due to Ambient Pressure and Temperature t FluctaUons VaMr s&3 Increases Flgun 2-4. Cowredtanks (brosthlng losses). drawal losses occur from the evaporation of volatiles on the wetted wall as liquid is removed from the tank and the mf descends. If retrofitted to a hazardous waste tank,the floating roof materials must be compatible with the waste, and floating roofs cannot be used in hazardous waste treatment ranks with surface mixers or aeration equipment. The emission reductions achieved by a floating roof relative to a fixed roof have been evaluated for volatile organicliquidsby using empirical models. Depending on the type of deck and seal system selected, emission reductions of 93 to 97 percent can be obtained. For the smaller size tanks and varieties of wastes found at hazardous waste facilities, reductions of 74 to 82 percent can be obtainedrelativeto a fixed m f . Convertingan open top tank to a floating roof tank is estimated to reduce emissionsby 96 to 99 percent. Pressure tanks are designed to operate safely et internal pressures above atmospheric pressure. Consequently, these tanks can often be operated as closed systems and do not emit organics at normal storage conditions 01during routine loading and withdrawal. Pressure-relief valves on the W k s open only in the event of improper operation or an emergency to relieve excess pressure. They are most common for the storage of gases; however, they can also be used to store liquids. Another type of tank is that used for the distillalion of organic liquids, which is common at solvent recyclers. In distillation, the more volatile components are separated from the waste by heating and transferring them to the vapor phase. which is removed through the overhead system. Distillation can be performed in a simple heated pot as a batch operation or in a column as a continuous operation. The device may be operated at atmospheric pressure, under vacuum, or under pressure. Emissions occur from the condenserldecantervent, vents on collection tanks,and the vacuum system if vacuum is used (Figure 2-6). Figure 2-5. External floating roof tank. 14 Vent uresent in the wastewater when it is fmt g-enerated is emitted In the collection system. Waste In Flgum 2-8. EmlMlon sources for dlstlllstlon. Some of the different ways that the wastewater is drained from a specificprocess into the sewer line are shown in Figure 2-8. The open, unsealed drain is the greatest source of emissions from the free fall of the wastewater and vapors from the sewer. The closed draii essentially eliminates these emissions. In a batch still, the waste material is heated and volatiles are removed to some predetermined cutoff point, such as the concentration of organics in the condensate or the concentration remaining in the waste. Individual sewer l i e s from different processes flow through junction boxes before entering the hunk or main sewer lines that handlecombined flows from different process areas. The purpose of thejunction box is to combine flows, to permit ready access to the sewer line for cleaning and inspec- Emission models for distillationcolumns or other separa- tion,and to isolate vapors from the different individual sewer tion devices are not available because the emissions depend lines. A typical junction box that is fitted with a gas-tight on the types of wastes, the specific organic compounds, and cover and a vent is shown in Figure 2-9. The device alsohas a thedesign and operating details. However, the emissionsfrom water seal to prevent the flow of airthrough lines that may be distillation and other separation devices are usually vented partially fflled with water. This device is operated at a con- from a point source and can be measured. In addition, the stantliquid level; consequently,emissionsfromworking losses operator should have the basic design and performance calcu- should be relatively low. lations that can provide insight into emission potential, or material balance calculations that indicate the fate of volatile Oil-waterseparatorsat petroleum refmeries are also part compounds. of collection systems that may require control under the benzene waste NESHAP.These devices separate oil, water, Solvent extraction is another type of separation process and sludge f"the wastewater (Figure 2-10). that has been used for organic liquids. It involves dissolving the volatile organics in a solvent The solvent is physically separated from the waste and then recovered for recycle by distilling off the volatiles. This process has also been demonstrated for removing benzene from petroleum refinery sludge. The most common type of oil-water separator at petroleum refineries is the AFI' separator. The separator is a large rectangular tank with an oil skimmerand the main bay, which provides a zone for separation. The separator relies on the different densities of oil, water, and solids: oil and solids Although 80 to 100percent of the target organics can be lighter than water float on top of the aqueous phase and removed from the waste by the solvent, the overall control heavier sludges sink to the bottom. Oil is skimmed from the efficiency is probably less. Major emission points associated surface, and heavy sludge is periodically removed from the with solvent extraction are those involved in the distillation bottom of the separator. process used to recover the solvent (Figure 2-7). As discussed earlier, these emission points include the vent on the condenser/decanter and any collection tanks associated with the unit. Another type of separator in use at refineries is the corrugated-plateinterceptor (CPI).This unit consists of 12to 48 parallel carugatedplates mounted at an angle. Wastewater flows downward between the plates with the lighter oil drop- Aqueous Wastes (Wastewater) Wastewater collection systems are of interest because some are affected by the N E S W for benzene waste operations. The collection system includes individual drains, sewers,andjunction boxes. Emissions occurwhen thewastewater lets coalescing and floating to the surface. The oil droplets move up the plates to form a floating layer that is skimmed from the surface of the tank. These oil-water separatorscan be controlled by covering or by covering and venting emissions to a control device. is in direct contact with the air or from air sweeping lhrough Wastewater is usually treated in large open tanks, and the the collection system from a chimney effect. Our modeling emission mechanisms are similar to those described for sur- efforts indicate that 20 to 40 percent of the benzene that is face impoundments. Generally, these tankshave smaller ex- posed surface areas and much shorter residence times than impoundments. This results in somewhat lower emissions from a single tank compared to a single impoundment; how- l 4 ever, usually several of these tanks in series provide multiple b Waste Resldual Out opportunities for volatiles to be emitted. Emissions Eok'~fraactend ~ s Examples of wastewater treatment tanks include large open tanks used for equalization of wastewater streams from Solvent different processes and tanks that are often aerated or agitated to provide mixing, to suspend biomass, or to provide oxygen. Many wastewater treatment processes are performed in open tanks, such as equalization,neuaalization, solids settling,and Flgum 2-7. Emissions from solvent exbscllon. Rsoelcvyecnlef biodegradation. 15 =ifDrain pip .?lDrrain Open, Unsealed Flgura 2-8. lndlvldual dralns. P-Leg seal I Closed Drain Steam stripping also is used to treat aqueous wastes with concentrationson the orderof hundreds of parts per million or higher. Steam is injected directly into the wastewater, the overhead vapors are condensed, organics are separated from the condensed water, and the decanted water is returned to the feed stream. Emissions occur from the vent on the condenser1 decanter and from collection tank vents. 1Water Flgura 2-9. Typical junctlon box. Another type of tank used to treat aqueous wastes is an air stripper (Figure 2-11), which may be a spray tower, packed column, or simply an aerated tank. It is most com- monly used to remove parts per million or lower levels of volatiles from dilute aqueous wastes. Many air strippers with lower emissions simply are vented directly to the atmosphere, while others are controlled by carbon adsorption or incineration if organic concentrations warrant. Condensers on air strippersaregenerally ineffectivebecause of low vapor phase concentrations and high volumetric flow rates. Emissions 4 Forebay OIIY~4stwater Emissions Oil Water Sludge A schematic of an actual steam stripping system is shown in Figure 2-12 and illustrates the use of a heat exchanger to preheat the feed (to recover energy) and to cool the boaoms stream from the stripper before additional wastewater treatment. This particular system has a high level of organic recovery because both a primary and much colder secondary condenser are used. Emission control should be excellent becausenoncondensibles are vented to a vapor incinerator. For continuous steam strippers, pretreatment (Figure 213) may sometimes be required to adjust pH or to remove solids, which can foul the column packing or trays and cause plugging problems. Any separate organic phase that can be decanted from the wastewater is removed prior to stripping. Sludges Fixation is another process that is often performed in tanks to solidify or stabilize sludges. The basic steps include mixing in a fixative agent, such as lime or fly ash, curing to allow solidification, and disposal. Mixing occurs most often in tanks, containers, or pug mills, which are relatively easy to enclose to control emissions. About half of the hazardous waste that is solidified is cured in tanks or containers, and the other half is cured in large open sources such as trenches or landfills. Most of the volatiles are emitted during mixing when agitation is provided while adding the fixative agent. Exothermic reactions produce heat and increase volatilization, as in the addition of quick lime or calcium oxide to aqueous sludges. These emissions can be controlled by installing covers or enclosures that are vented to a control device. Flgure 2-10. Oil-water separator. 16 Vent in storage Overhead Vapofs Vented I A Feed 4 L TITI 1Control Device Liquid Distributor Air Control Device Residue Packed (e.&, Spent Carbon) Column Air Stripper Pump -Air Flgun 2-11. Schematlc diagram of an alr strlpplng system. Another common pmcess used for managing sludges is dewatering, which is performed by various types of filter presses, rotary vacuum filters, and centrifugal filters.A plate and-frame press is an assembly of alternate solid plates, which are grooved or perforated to permit drainage, and hollow frames, in which the dewatered sludgecollects during filtration. A fdter medium, usually a fabric, covers both faces of each plate. As the slurry passes through the filter fabric to the plates, a cake of solids slowly builds up. The filtration continues until the pressure drop across the filter reaches a preset limit. The plates are then separated and the cake drops from the fdter press into a collection bin under the press. The belt fdter press (Figure 2-14) squeezes the sludge between two systems of belts. Sludge is fed onto the lower belt, and, asthe belt moves into the press, the upper belt meets it and squeezes the sludge. The fibate squeezed from the sludge is usually collected in a sump under the fdter and removed for furtherbreatment or discharge. Solidsare scraped off the belts as they separateand collect in a bin or are taken by conveyor to a storage or disposal area. As the belts continue their rotation, they are usually cleaned by being passed through a belt washing system of high-pressure spray nozzles. Other types of dewatering units are rotary in nature and use a vacuum, gravity, or cenhifugal force to remove water from the sludge.For larger scale operations, sludge is scraped from the unit continuously and discharged through a chute to a container or conveyor belt. These dewatering devices are not usually enclosed sys- tems and provide several opportunitiesf a volatileorganics to be emitted. For the plate-and-frame press, emissions occur when the press is opened to remove and transportthe accumu- lated sludge. During filtration, a small amount of liquid may leak from the press and accumulate in the drip pan under- neath. The belt press providesa moving exposed surface area that facilitatesdryingand evaporation of volatiles. The filtrate drains freely and is often collected in an open sump. Both the filtrate and sludge are sources of emissions. Similarly, the sludge and filtrate. handling systems for rotary vacuum and centrifugal filters are emission sources for any volatiles that are present in the original slurry. In addition, the vacuum pump may discharge volatilas. Emissions from dewatering devices can be controlled by building an enclosurearound the unit and venting it to a control device. ,Condensers, Exchanger Steam Stripper incinerator Y EDC Figure 2-12. Steam stripper for ethylene dlchlorlde/vinyl chiorlde. Oganics Sludge Figure 2-13. Preliminary treatment prior to stripping. 17 Sludge Loading f Sludge Discharge Draining Zone Press Zone Shear Zone e \A ir -/ Figure 2-14. B ~ I IHller press. Thin-filmevoporutors(TFEs)pigure2-15) arealso used to treat sludges. The primary advantage of this treatment technique is that it can remove volatiles from viscous sludges ad A thin layerof waste is overa moving or wiped surface that is heated to organics. Emissions occur from vents on condensers, decanters, and collection tanks, or from the vacuum system if one is used. The vertical thin-fdm evaporator looks like a distillation column. In the TFE, the vapors with volatile organics are removed overhead to a condenser, and the treated waste is discharged from thebottom. Ancillary Equipment $'To Condeiiserl Outlet Decanter The ancillary equipment associated with tank systems includes pumps, valves, pressure-reliefdevices,compressors, sampling connections, and open-ended lines, which can b e come emission sourceswhen they leak. Controlsincludedual mechanical seals with a barrier fluid (forpumps and compressors), sealless pumps, diaphragm or sealed-bellows valves, rupture disks for pressure-relief devices, closed-loop sampling, and caps for open-ended lines. In addition to the equip- ment controls for these types of sowes, emissions can be controlled by establishing a leak detection and repair (LDAR) program. This program includessurveying these components for leaks, using a portable organic vapor detector to locate leaks, and making repairs, adjustments, or replacements as needed. Heating Medium Modular Heating Bodies Containers Containers are defined as any portable device in which a material is stored, transported, treated, disposed of, or otherwise handled. Examples of typical containers are drums, dumpsters or roll-off bins, and tank trucks. Emissions occur from loading these containers, from uncovered containers during storage or transport,and from spills. Drums can be sourcesof emissions from the evaporation of leaksand spills,and poor housekeepingpracticescan make spill detection and cleanup difficult. If the drums are well maintained on a diked pad, emissions from spills or ruptures can be identified by routine inspection proceduresand promptly cleaned up. Dumpsters or roll-off bins can be. a source of emissions if they are left uncovered with the surface of the waste exposed to the atmosphere. ProdudOutlet Figure 2-15. Flow path of thin-Hlm evapralor. Emissionsfrom containersFigure 2-16) occur when they are loaded, and emissions are greatest when splash filling is 18 Splash Loading (Tends to Saturate Vapors) Product/ Flgure 2-16. Splash loading vs. submerged loading. Submerged Loading Vapor Emissions ,Fill Pipe Hatch Cover Ivapors fl I PalgoTank I W J- 1.1 I 'Product used. When splash filling, the vapors displaced from the After covering and compacting,emissions occur by diffusion, container by loading can quickly become saturatedwith vola- barometric pumping, and gas venting (Figure 2-18). tiles from the splashing. Submerged fill uses an influent pipe that is below the surface, which reduces splashing and the degree of saturation of the displaced vapors. A study of submerged filling of tank trucks indicated that emissions were reduced by 65 percent relative to splash filling. Other basic controls for containers include using simple covers during Wastepiles are. defined as noncontainerized accumula- tions of solid. nonflowing hazardous waste used for treatment or storage. The emission mechanisms for wastepiles are similar to those f a land treatment:rapid volatiliization from the exposed surface followed by mass transfer through the waste. storage or transport and routine housekeeping practices with Models have been developed for exposed soil surfaces daily inspectionsand prompt cleanup of spills. such as land treatment and wastepiles and for covered land- LandDisposal Sources fills. In the model for exposed soil surfaces that contain organics, volatiles in the oil and water are assumed to be in Landfills, wastepiles. and land treatment are the sources equilibrium with airin the void spaces. Some organics may be expected to be most directly affected by the LDR. These are. adsorbed onto the soil particles, and, in some cases, bicdegra- open areasources from which the volatile organic compounds dation may destroy the organics.Emissions occur by diffusion are.emitted fairly quickly, and the emissionscan be controlled to the surface, where organics are removed by the wind. For by covers and enclosures. However, the technologies de- the covered portion of landfills. the modeling includes diffu- scribed under LDR will likely take care of the volatile organics, and in the end they should not be significant sources of emissions. A land rreatmenr facility is defied as a facility at which hazardous waste is applied onto or incorporated into the soil surface; such facilities are disposal facilities if the waste will remain after closure. Land treatment is also known as land farming, land application, land spreading, and soil incorpora- tion. Volatiles are rapidly emitted from the surface of landtreatedwaste (Figure2-17).Over time, volatiles diffusethrough the waste to the surface, where they are swept away by the sion through the cap and losses from barometric pumping, which is caused by changes in ambient pressure. These land disposal sources can be controlled by install- ing a flexible membrane cover, enclosing the sourcein a rigid structure, or using an air-supported structure as discussed earlier for surfaceimpoundments. A better emission control is not to place wastes containing volatiles in these sources (for example, treat the wastes to remove the organics before disposal). Emission Controls wind. In land treatment, the waste can be applied to the soil and mixed by tilling, or the wastes may be sprayed directly onto the soil and subsequently mixed with the soil by tilling. Volatilesare rapidly removed from the waste during spraying. Several air pollution control devices can be applied to many of the sources that have been discussed once they are covered or enclosed and vented. The traditional ones that are discussed briefly here are carbon adsorption, condensation, absorption, and vapor combustion. rondfirrs are composed of activeandcovered cells. Wastes are often segregated based on waste compatibility and compaction requirements. The wastes are then covered with a layer of soil and compacted, and another layer of waste is added or a new cell is started. If any volatiles are left in the waste when it finally reaches the landfill, they are rapidly emitted from the surface of e x p d waste in active cells. Carbon Adsorption In adsorption, organics are selectively collected on the surface of a porous solid. Activated carbon is a common adsorbent because of its high internal surface area: 1gram of carbon can have a surface area equal to that of a football field and can typically adsorb up to half its weight in organics. The adsorber will remove essentially all of the target volatiles 19 . . . . .Wind Volatilization 0. ' Diffusion ThmughPores .* Flgun 2-17. Land treatment smlsslon mechanlsms. from the vented vapors until breakthrough, which is when the volatiles are fust detected in the cleaned vapor leaving the bed. Carbon adsorbers can achieve control efficiencies of at least 95 percent, and control levels of 97 to 99 percent have been demonstrated in many applications. The two common types of adsorbersare carbon canisters and regenerable fixed beds. Carbon canisters (Figure 2-19) are used for low vent flows, usually less than 100 ft3/min, and are not regenerated onsite. They are usually discarded or returned to the supplier. The canisters are fairly compact units and can easily be removed and fresh canisters installed. Fixed-bed carbon adsorbers that can be regenerated (Figure 2-20) are used for controlling continuous vent streams with flows exceeding 100,OOO ft'/min and can handle a wide range of organic Diffusion through the Cap concentrations. A common procedure is to have dual beds with one desorbing while the other is adsorbing. The carbon capacity for organics is affected by the concentration of organics in the vapor. Carbon manufacturers generally have equilibrium data for specific compounds and their specific carbons. The bed design is important and must be deep enough to prevent rapid breakthrough,yet not sodeep as to causeexcessivepressuredrop. The flowrate is important in the bed design and in determiningcarbon capacityrequirements. Humidity has an adverse effect when water occupies some of the adsorption sites. For a relative humidity of 50 percent or more, dehumidification or dilution may be neces- Convective Loss I" tBarometric Pumping through the Vent. - Landhlled Waste Flgure 2-18. Emlsslons I"a closed Iandflll. 20 For Vent Flaws Less Than 100 CFM e Cannot Be Regeneratedin Canister Activated Catbon Flours 2-19. Carbon cenl8ters. Condensation Condenserswork bycwhgtheventedvaporstothedew point and removing the organicsas a liquid. The efficiencyof a condenserisdeterminedby the vapor phase concentrationof the specific organics and the condenser temperature. Two common types of condensers are contact condensers and surface condensers. The contact condenser (Figure 2-21) is cheap and efficient. However, the cooling liquid that directly contacts the vented vaporscan presenta disposalproblem. For example,if the coolant is water that is sent to wastewater treatment, the volatiles may be emitted in open tanks.The shell and tube condenser (Figure 2-22) does not allow contact between the vented vapors and the cooling medium. In this type of condenser, a concennated organic liquid can be recovered for recycleor other use. Absorption In absorption,the organics in the vent gas are dissolvedin a liquid (Figure 2-23). The contact between the absorbing sary to lower the relative humidity. The bed's operating temperature affects capacity, and some compounds such as aldehydes and ketones may generate heat in adsorbers. For these special cases, some means of removing the excess heat may be necessary. For effective emission controlby adsorption, one of two actions is necessary: either to monitor for breakthrough or to replace thecarbonperiodicallybefore breakthrough occurs.In addition, any emissions from the disposal or regeneration of the carbonshould be controlled. Controllingemissionsfrom a vent stream is of little value if the collected organics are emitted later in the wastewater associated with regeneration. Vapor Inlet LiquidOutlet (Water and VOCs) Flgum 2-21. Schematic diagram of e contact condenser. I Closed Steam Desorbing , Vent tmosphere , J. To Condenser and sparator Flgum 2-20. Two-stage adsorpllon system. liquid and the vent gas is accomplished in spray towas, scrubbers. or uacked or late columns. Some common solvents that ma; be useful-for volatile organics include wa& mineral oils, or other nonvolatile petroleum oils. Absorption effiiienciesof 60to 96percent havebeen reportedfor organics. For example, methylene chloride removal from vented vapors has been measured at 87 percent using water as the absorbing liquid. The material removed from the absorber may present a disposal or separation problem. For example, organics must be removed from the water or nonvolatile oil without losine them as emissions during the solvent recovery or treaGe4 prOCeS.9. Vapor Combustion Vapor combustion is anothercontrol techniquefor vented vapors. The destruction of organics can be accomolished in flares, thermal oxidizers, suEh as incinerators, doilers, or process heaters, and in catalyticoxidizers. 21 Codant Inlet Coding Tower or Refrigeralion Unit VaporOullet Vapor Inlet 1 Coolant Outlet t Condensed VOC (to Decanter or Receiving Tank) Flgun 2-22 Schemellc dlagnm of a shell-and-tube surface condeneer. Flares are an open combustion process in which the oxygen is suppliedby the air surroundingthe flame. Flaresare operated either at ground level (usually with enclosed multiple burner heads) or they are elevated. Elevated ilaresoften use steam injection to improve combustion by increasing mixing or turbulence and pulling in additionalcombustion air. Properly operated flares can achieve destruction efficiencies of at least 98 percent. Figure 2-24 is a schematic of the basic componentsof a flaresystem. The EPA has developedregulations forthe design and operation of flaresthat include tipexit velocitiesfor differenttypes of flaresand different gas sMam heating values. Thermal vapor incinerators can also achieve destruction efficiencies of at least 98 percent if the conditions of an adequatelyhigh temperature, good mixing, sufficientoxygen, and an adequateresidence timearemet. These vapor incinera- tors can be designed to handle vent rates of 200 to 500.000 cfm. An auxiliary fuel may be required to maintain the combustion conditions if the vent gas has less than 50 Btdscf. Figure 2-25 shows the components of a vapor incinerator. A heat recovery unit, such asa steam generator, may be used to recover some of the energy from a thermal incinerator. Catalytic incinerators provide oxidation at temperatures lower than those required by thermal incinerators. Design considerations are important because the catalyst may be adversely affected by high temperatures, high concentrations of organics, fouling from particulate matter or polymers, and deactivationby halogens or certain metals. The basic components of a catalyticoxidizer (Figure 2-26) are similar to those of a thermal unit except that a catalystbed is used. The energy requirements of a catalytic oxidizer are lower than those of a thermal unit because of the lower operating temperatures. -Absorbing Liquid In CleanedGas Out to Final Control Devim I Absorbing Liquidwith Organics Out To Disposalor Organic Solvent Recovery Flgure 2-23. Packed tower for gas absorptlon. 22 E- Pilot Burners Gas Collection Header Transfer Line 1 JI Drain Flgun 2-24. St.am-asslsled elevated flare system. Stream Line f ignition Devim Air Line Gas Line The organics in vented vawrs can also be destroyed with a high levelof efficiencyin boilers aprocess heaters:In these devices, vaporswith halogensor sulfurare avoided becauseof potentialcorrosionproblems.These devkesrecover the heat- ing value of the vent stream,and they offer the advantage of using existingequipment to control emissions. Organic Removal Organic removal or pretreatment is a control option that is applicable to a variety of waste types. These processes include steam or air stripping, thin-fdm evaporation, solvent extraction, and distillation. These processes are capable of removing all Of the 'Ohtile " ~ u n d s from the waste.The removal of the volatiles near the point of generation can avoid the need to install controls on subse quentprocess units and may facilitaterecyclingthe recovered organics back to the process. The control efficiency that can be obtained by organic depends On many factors' such as the percent removed from the waste, the emissions from the removal sys- tem, and the uncontrolled emissions from treatment units before the removal device was installed. Generallv. overall control efficiencies of 98 to over 99 percent can be achieved. waste lflclfleratlon wasteincinerationis also an emissioncontrol that can be used instead of processing the waste in units with a high emissionpotential, This technologyhas been as an alternative to land disposal in the development of the land disoosalrestrictions for certain wastes.Destruction efficienciesof99.99 percent or higher havebeen demonstrated in properly operated waste incinerators. Summary majoIrnssouumrcmesaroyf, otargnaknsicanadirseumrfaiscseioinmspaotuhnadzmaerdnotsuasrweatshtee stomge, and disposal facilities. Based on work in Ihedevelopmentof the waste wastewater systemsare a major soUTCoef benzene emissions from wastesthat containbenzene, Emissions occur from the surface of open area sources, and high percentagesof the vohtiles are lostasemissionsin these sources. For enclosed sources, the displacement of containing volatiles from the enclosed vapor space is theemissionmechanism. For both types of sources,heating or 23 Auxiliary Fuel Bumer (Discrete) Stack Air- Mixing Section V Combustion Section Heat Recovery Figun 2-25. Thermal Incinerator. aeration increases emissions. Emissions also occur from the evaporation of leaks and spills. Emission models have been developed for open area sources, including both the liquid surface of impoundments and tanks and the solid surfaces associated with land treatment and landfills. Both types of models can account for the biodegradation of specific compounds, and the effect of turbulence from agitationcan beincluded for liquid surfaces.For enclosed sources, models are available to estimate the vapor displacement rate and the concentration of volatiles in the vapor. For emission control, open area sources and containers can be covered or enclosed. Control devices can be installed to collect and remove organics from vented vapors, which is especially important if the sources are heated or aerated. Organic removal by pretreatment and waste incineration are also emission control options, and their use may preclude the need to apply covers or control devices to subsequent Ireatment units. Simple work practices, such as leak detection and repair or inspections and cleanup of spills, help to control emissions from equipment leaksand spills. Pumps and valves that are designed not to leak offer another potential control option for these sources. 4 r Figun 2-26. Calalytic oxidlrer. 24 Heal Recovery Bibliography U.S. Environmental Protection Agency, CERI. "Handbook ControlTechnologies for HazardousAir Pollutants." EPN 625/6-86/014. NTIS PB91-228809/AS. Cincinnati, OH. September 1986. U.S. EnvironmentalProtectionAgency, Control Technology Center. "Industrial Wastewater Volatile Organic Compound Emissions-Background Information for BACT/ LAER Determinations." EPA-450/3-90-004. January 1990. U.S. Environmental hotection Agency, OAQPS. "Altemative Control Technology Document-Organic Waste Process Vents." EPA-45013-914KI7. December 1990. efficiency may be limited by a minimum outlet concentration of 20 ppm. Thedesm~~iioanndremovalefficiency(DRE)forhazardous waste combustion is based on the principal organic hazardous constituents. These compounds are present in relatively high concentrations, and the measured DRE is often limited by detection limits in the exhaust. Question-How significantare equipment leaks as sourcesof emissions? Answer-The uncontrolled emissions can be as significant as those from open area sources, especially when the facility has a large number of equipment items (such as pumps, valves,and flanges) that handlevolatile organicemissions. U.S. Environmental Protection Agency, OAQPS. "Hazardous Waste Treatment, Storage, and Disposal Facilities (TSD+Air Emission Models." EPA450/3-87-026. No- vember 1989. Question-Are emissions from landfills, land treatment, and wastepiles significant,and will these sou~cesbe regulated for organic emissions? U.S. Environmental Protection Agency, OAQPS, ``Hazard- Answer4uxrently. no plans to regulate these sources under ws Waste Treatment, Storage, and Disposal Facilities Section 3004(n) of RCRA exist. Our available data and (TSDSBackground Information for Promulgated Or- considerationof the effectsof theland disposalrestrictions ganic Emission Standards for Process Vents and Equip- suggestthattheseoperations arenot significant sources of ment Leaks." EF'A450/3-89-009, July 1990. organic emissions. U S . Environmental Protection Agency, OAQPS. "Hazardous Waste TSDF-Background Information Document for ProposedRCRA Air Emission Standards." EPA-450/ 3-89-23. (Wiil be availableto thepublic u p pmposal of the standard.) U.S. Environmental Protection Agency, OAQPS. "Hazardous Waste TSDF-Technical Guidance Document for RCRA Air Emission Standards for Process Vents and Equipment Leaks."EPA450/3-89-21. July 1990. U.S. EnvironmentalProtection Agency, O R D M R L . . "Preliminary Assessment of Hazardous Waste Pretreatment as an A i Pollution Control Technique." EPA-600/2-86028. NTIS PB86-172095/AS. March 1986. US. Environmental Protection Agency, OAQPS. "VOC Emissions from Petroleum Refmery Wastewater Systems-Background Information for Proposed Standards." EPA-450/3-85-001a. February 1985. Questions and Answers Ouestlorr-What isthedifferenceinthecombustionof gaseous emissions at 95 to 98 percent efficiency versus the combustionof hazardouswasteat 99.99percentefficiency? Answer-Vapor incinerators are often used on vapor streams thathaverelativelylowconcentrationsE. PA studiesindicate that destruction efficiencies on the order of 98 percent or higher canbe achieved on the= vapor streams. For vapor streams with very low concentrations, the destruction Question-When carbon is used for emission control, what happens to the organics that are removed when the carbon is regenerated? Answer-The fate of the organics dependson the regeneration process. If theregeneration is performed in a furnace, the organics in the gases and vapors removed f " the carbon usuallyare destroyedby thermaloxidation.If steamis used for regeneration, the organics are either recovered by condensation, emitted through the condenser vent, or emitted from the wastewater (condensed steam from regeneration) when it is treated. Question-Are primary condenserspaa of the production unit or are they control devices? Condensers areefficient from primary control,but oftendo notget high efficienciesasan emission contml. Is EPA promoting their use? Answer--Primary condensers are part of theprcduction unit and are not considered as a control device to meet the standards. For example, in many recovery operations, volatile components are separated in the vapor phase and then recovered by condensation in the primary condenser. The EPA is not promoting the use of condensers; most of therulesquire that thecondenserbedesignedandoperated to achieve a control efficiency of at least 95 percent. Consequently, condensers may not be acceptablecontrols in many applications, such as the control of vapor streams withverylowconcentons orsmeamsthatwouldrequire unreasonably low temperatures to achieve 95 percent control. 25 Chapter 3 Process Vents Standards Subpart AA Abstract The objective of t h i presentation on the RCRA process vent rules is to provide a basic understanding of the new RCRA air emision standards for process vents so that those persons required to comply with, implement,or enforce the rules can do so effectively and in a timely manner. The presentation clearly explains the process vent rule applicability criteria, which include facility authorization under RCRA, hazardous waste management unit type, and waste organic concentration. Technical requirementsfor emhion conbols and the facility "bubble" concept for emission rate limits are explained. Recordkeeping and reporting requirements are discussed also. The process vent standards in 40 CFR 264 and 265, Subpart AA, limit organic air emissions at hazardous waste treatment, storage, and disposal facilities (TSDF) requiring a permit under Subtitle C of the Resource Conservation and Recovery Act (RCRA). The standards were promulgated on June 21,1990 (55 FR 25454), under the authority of Section 3004(n) of the Hazardous and Solid Waste Amendments (HSWA) to the RCRA. The Subpart AA standards are applicable to process vents associated with distillation, fractionation, thin-film evaporation, solvent extraction, and air and steam stripping operations that manage hazardous wastes with 10 parts per million by weight (ppmw) or greater total organic concentration. The RCRA air rules for process vents require that ownerd operators of TSDFs subject to the provisions of Subpart AA: (1) reduce total organic emissions from all affected process vents at the facility to below 1.4 kgh (3 IWh) and 2.8 Mg/yr (3.1 todyr), or (2) install and operate a control device@) that reduces total organic emissions from all affected process vents at the facility by 95 weight percent. The process vent rules do not require use of any specific types ofequipment or add-on control devices. Condensers, carbon adsorbers, incinerators, and flares are demonstrated emission control technologies for the regulated processes, although the choice of control is not limited to these. To ensure that control devices perform according to their design, the rules for process vents require that specific control device operating parameters be monitored continuously and the monitoring information be recorded in the facility operating record. Process Vents This chapter covers the organic airemission standards for process vents. These rules were promulgated on June 21, 1990.The purpose of the chapter is to answer some of the most wmmon questions the US.Environmental Protection Agency (EF'A) has received on the rules. lhis chaptershould answer the followingquestiom(Table 3-1): "Who is affectedby the rule, why did EPA develop the rule, and how many facilities are subject to the rule?" In addition, detailsof the regulation including types of regulated units, the effective date, control device requirements, recordkeeping, and reporting will be discussed. Table 3-1. Queetlonson ~etslla What units are regulated? How does the regulation Work? When do IIMregulations become elfedve? What are the requirements for control devices? What remrds must be maintained? What reports must be filed? Who is affected?On the broadest level,anyone who has a facility subject toPart 270 of the Resource, Conservation,and Recovery Act (RCRA).That covers anyone with a Subtitle C facility, whether the facility has a fmal permit or is still in interim status. In promulgating this rule, EPA modified Section 261.6 of the RCRA regulations and brought in previously exempt recycling units at RCRA-pmitted facilities. If you have a RCRA permit and you have a recycling unit that up to this point has not been subject to any RCRAmles, it may now be subject to the RCRA air rules, Subparts AA and BB. Six types of unit operations arewvered by the d e (Table 3-2): steamshippas,distillation,fractionation,thin-filmevapcration, solvent extraction, and air strippers. Unless the unit involves one of these six types of unit operations, it is not regulated by Subpart AA. Other than recycling, all RCRA exemptions remain in effect. etoduction units are not regulated by RCRA and are not affected by this rule (40 CFR 261.4(c)). The wastewater treatment exemption applies to units that are regulated under 27 --~ stemstrippen Dktlllation -* Fracdlonadion min-Rlm waporation - sdventexuacum AirsUippem J[Overhead WaInste z the Clean Water Act (CWA) (40 CFR 264.1(g)(6), 265.1(~)(10),and 270J(c)(2)(v)). Subtitle D or municipal waste units are not covered under these rules. Units handling domestic sewageareexempted from the rules because sewage is not considered a solid waste (40 CFR 261.4(aK1)). Closed- loop reclamation refers to another exclusion from the solid waste deffition that ispresented in 40CFR 261A(a)(8) of the EtAuent out Air In RCRA rules. Secondary materials that are being reclaimed in accordance with the RCRA rule are not considered solid Figure 3-1. Example 1 4 1 r strlpplng. waste and therefore are not subjectto RCRA. Section 261A is specific as to what is considered a closed-loop reclamation: covered under the rules, the process vent case study is very thereclamation process must be connected directly by piping helpful. to the production process, only tank storage is allowed, the materials have to be reclaimed within 12 months, and reclamation cannot involve combustion processes. A process that qualifies for this closed-loop reclamation exclusion is not regulated by the SubpartAA rules discussed here. Subpart AA was developed to protect human health and the environment In addition, as mentioned previously, EPA developed this rulein recognition of the fact that the Officeof Solid Waste (OSW) was also developing rules on land dis- posal restrictions and that air emissions would need to be The applicability discussion started at the facility level, controlled from someof the technologiesused to comply with moved to the process level, and is now at the vent level. the land disposal restrictions rule. Subpart AA is a waste-based rule, and the waste must contain 10 ppm or gr" total organics by weight before an indi- The number of units in the United States is shown in , vidual unit must be controlled under this rule. The 10ppmw must be determined on a time-weighted annual average basii, which means that, at some point in the year, greater than 10 ppmw waste could be managed in the unit and still the unit would not be affected by the rule if the waste managed in the unit had an organic concentration of less than 10 ppmw on a Figure 3-3. These data were collected by the OSW in 1987. Batch distillation is the most common, with 185units, and the numbers decrease to onIy IO air s t r i p p s shown as regufafed under RCRA in 1986. Again, the rule covers recycling units that are located at facilities with a RCRA permit so these n u m b from 1986 will increase as previously unregulated timeweighted annual averagebasis. Inaddition,emissionsdo not have to be vented from the affected unit. If the emissions units are brought into the RCRA system. The annual emis- sions for three different size model plants is presented in are vented through a tank that is associated with the unit, the emissions are still covered by this rule. Typical associated Figure 34. In the development of the rule, EPA looked at three different sizefacilities based on annual operating hours tanks with affected process vents include condensers, hot wells, and distillate receivers. Example 1 (Figure 3-1). air stripping, is one of the six Condenser vapors a unit operationscovered by the rule. If the waste going into this air stripper is greater than 10ppmw in organic concentration on a time-weighted annual average basis, then the overhead vaporsfrom this air stripper would be covered by the rule. The tank that sits in front of the air stripper, the feed tank,is not regulated by the process vent rule. The emissions from this tank are a result of the breathing and working losses. Example 2, steam stripping, is another one of the six unit 231 WaInSte operations covered by the rule (Figure 3-2). In this case, the Feed Tank emissions pass through a condenser and are vented through a distillatereceiver. This distillatereceiver is considered a tank Accumulator Tank associated with the steam stripper and therefore the emissions are regulated under the rule. The other three tanks,the accu- mulator tank,the effluent storage tank,and the feed tank,are similar to the feed tank in the fmt example. Emissions from thesethreeranksare not regulated by the process vent rule. If yon need to get a better understanding of which vents are Figure 3-2. Example Z-steam strlpplng. 28 Flgun 3-3. Number of unlts. Distillation ation Evaporation Exuae Wippers Strippers lion Source: 1987 TSDR Survey and the sizeof the units. With six diffmnt operationscovered by the le, quite a range of emissions exists. For a large facility, emissions range from about 1 ton per year up to Inslightly more than XI tons per year. Medium facilitiesrange from around ton per year up to 5-lntons per year. Small facilities,which are primarily batch distillation units, all have less than 1 tonper year of emissions. The five steps involved in how the regulation works at a single facility are listed in Table 3-3. The fmt step is to identify all the units that fall under the rule. Six t y p of unit operations are covered, and the units must be treating a hazardous waste with an organic concentra- tion of 10 ppmw or greater on a timeweighted annual basis. Once a unit is identified as falling under the rule, the owner/ operator must determine the maximum hourly and annual emission rates from the vents. Therule specifies methodsthat can be used for direct measurement, such as Method 18 for organicconcentrationand Method 2 for velocity and volumetric flow rate. In addition, the rule has provisions for use of "knowledge" to determine emission rates. If you have previously tested the stack on the process vent and can certify that the operation and the waste have not changed, then the previous test results would be acceptable. In some cases, the manufacturer may be able to certifyemission rates on certain units. Once a maximum hourly and annual emission rate for each vent has been determined, the individual rates mustbe summed to get a facility rate. The total facility process vent emissionsratemustbecomparedtotheLimitsof3lb/hand3.1 tort&. If the facility is over either limit, the owner/operator must either reduce emissions down to the limit or reduce total facility process vent emissionsby 95 percent. The rule specifies that the reduction must be obtained by using a control device. In Example 3,shown in Figures 3-5, 3-6,and 3-7.three process vents havebeen identified;the.facility emissionrateis obtained by summing the individual emission rates. In this case,thethreeemissionratesare10,I.and55.foratotalof66 tort&. To reach compliance with the rule, the facility must eitherbring emissions below the emission rate limit orreduce the total by 95 percent. In this case, a 95 percent reduction works out to be 3.3 ton/yr, which is slightly greater than the 3.1-ton/yr emission rate limit. The facility can reach compliance by achieving 95 percent control on each of the three vents. The facility could usethreedifferentcontroldevices,or it could tie all three into a single control device that would achieve95 percent. A second option shown here involves the facility providing 88 percent control on Process Vent #I, leaving the second vent uncontrolled, and achievingan emission reduction of 98 percent on the largest emitting vent, #3. S 10.0 5.0 0.0 It Large Facility Medium Fadlity Small Fadlity Model Plants-Annual Emissions Estimates I Flgun 3-4. Annual emluions from a typical tsclllly. 29 Table 3-3. How the RogulatlonsWork --- Mentlfyaffected process vents Determlm emission rates Sum individualraw -* Compare to emissionrate llmlk Reduce emkslons below limits or 05% One additionalpoint: certain control devices have the performance standards in the rules. The performance standard for combustion devices is 95 percent destruction efficiency. A facility using a combustion deviceon Vent #1 would not be in compliancewith a control efficiencyof 88percent The rules became effective December 21, 1990. How- ever, the compliancedate depends on the classificationof the facility. Interim status facilitieshave up to 18months after the effective date to install control equipment. The 18 months is not a blanket extension; facilities will need to submit an implementation schedule to the permit writer for approval. Facilities that already have a final permit are shielded from the Phase I air standards; this means that they do not have to comply with the standards until their permit is reissued. The different situations that occur under the RCRA permitting program are discussed in the RCRA implementation chapters of this workshop. The rule does not specify the use of a specific control device. However, there are individual performance requirements for certain devices. In addition,there is a provision that equipment must be properly designed, o p t e d , and main- tained and continuously monitored. The regulation specifies what parameters must be monitored for particular control devices. As an example, if you are using a vapor incinerator, you have to monitor the temperature in the combustioncham- ber downstream of the combustion zone. If you are using a catalyticincinerator, you have to monitor temperature both at the inlet and the outlet of the catalyst bed. In addition,the owner/optor is required to do a daily check of the control device to ensureproper operation. Vapor recovery systems include condensers and carbon adsorbers, and the rule specifies that each device has to achieve at least 95 weight percent recovery efficiency. The primary condenser on a distillation column is considered a primary recovery devicerather thana control device and does not count toward the 95 weight percent reduction. For com- bustion devices such as incinerators, process heaters, and boilers, the rule requiresa destructionefficiency of 95 weight percent or greateror the useof a combustiondevice that has a minimum residence time of half a second at a minimum temperature of 760'C. In addition, EPA's work on vapor incineratorsdetermined that, for air streamswith low concen!rations of organics, 95 percent reduction is not always possible. For those situations, the rule includes an alternative provision by which you can demonsmte that the incinerator exhaustconcentrationhas been reduced to 20 ppm by volume total organics and be in compliance with the process vent rules. Flaresare another option as a controldevice. The performance requirements for flares specify that they can have no visible emissions as demonstrated by using Methcd 22. A tlame must be presentat all times, and a heat-sensingmonitoring devicewith continuousrecorder to indicatethe continuous ignition of the pilot flame must be used. In addition, the flare requirements have specifications for net heating value on the gas being combusted and the permissible exit velocity. The owner/operator must inspect readings from each monitoring device daily, and, if there is a problem, the rules require that the owner/operator immediately implement corrective measures to get the control device operating correctly again. The equipment that connects the process vent to the control device is called the closed-vent system (Figure 3-8). The next chapter on equipment leakswill cover leak monitor- \ L PVZ n ERFaciliv 3: EERpvi i=l =ERFaciliv ERpvl + ERpvZ + ERpv3 Flgun 3-5. Facllity bubble for emlsslon rate (ER). 30 ERpvl + ERpVZ + ERpv3 ERFacility=10+1+55=66 Flgun 34. Example 3-control optlons for a tscillly. ERFacility = 66 66 (1-.95) = 3.3 3.3 Mgurvs. 3.1 Mglyr Option 1- 95% Control on All Three Vents Option2-88% Control on pvl and 98% Control on pv3 Flgun 3-7. Example 3 (continuad)-wntrol options for a facility. ing required of closed-vent systems. In this figure, emissions from this process vent pass through the closed vent system to the control device. Records must be maintained to demonstrate compliance. The records must be kept onsite. at the facility and consist of two main types: facility compliancedocuments and control device records. For facility compliance documents, records must be kept of the waste stream determinations, which are particularly importantif you areclaiming that a unit is exempt from conmls because it receives waste with an average concentration less than 10 ppmw. Emission rate determina- tions, the second type of records,are the stack testsand other materials that document emissions from a particular unit and also total emissions from the facility. Facilities that are installing a control device must keep the implementation schedule in the operating record. In addition, design and operational information must be maintained in the operating record. Control device exceedance records must also be maintained. The rules specify the conditionsthat defme an exceedance (Le., when the control device is not operating correctly). As an example, an incinerator designed to operateat 760C is exceeding the rules when it is operating at <76OoC.Any time the owner/operator fmds an exceedance, the owner/operator must record that exceedanceand keep it as part of the records. In addition, facilities that elect to use alternative controls must keep additional information regarding thecontrol device onsite. Facilities with a final permit that incorporatesthese rules arerequired to submit semi-annual reports if any exceedances 31 1Closed-vent System * Ducls. p i p . connectors, and blowerswhich lransportvapors or gases from equipment to a control &vim `Carbon Adsorption System Figure 3-8. Closed-vent system. Figure 3-9. Summary+ppllcablllty decislon Ime. last longer than 24 hours. Note that all exceedances must be recorded in the operating record. However, only exceedances that go uncorrectedfor more than 24 hours must be reported. A facility with no exceedances during a 6-month period does not file any report. Interim status facilities are not required to report. The rule with an applicability decision me is summa- rized in Figure 3-9. The fust decision point is a determination of whether the facility is subject to Subtitle C of RCRA. If so, are any units affected, i.e., any of the six specific unit operations that are regulated under rules of RCRA? If so,do these units treat hazardous waste with greater than 10ppmw in the total organics on a time-weighted annual basis? Finally, are any of these units exempt under the rules of RCRA? If they are not exempt units. the rule applies, and the facility must meet the emission rate limits. The limits require that all organic emissions from affected process vents be reduced to below 3 lb/h and 3.1 tom.As an alternative, the facility can reduce the total organic emissions from all affected process vents by 95 percent after the primary recovery. Bibliography "Hazardous Waste Treatment, Storage, and Disposal Facilities; Air Emission Standards for Volatile Organics Control." Federal Register, Vol52, pp 3748-3770. February 5, 1987. "Hazardous Waste Treatment, Storage, and Disposal Facilities-Organic AirEmissionStandards forprocess Vents and Equipment Leaks." Federal Register, Vol 55, pp 25454-25519. June 21,1990. U.S. Environmental hotection Agency. "Air Stripping of Contaminated Water Sources - Air Emissions and Con- trols." Control Technology Center. Research Triangle Park, NC. Publication No. EF'A450/3-87-017. August 1987. U.S. Environmental Protection Agency. "DistillationOperations in SyntheticOrganicChemicalManufacturing-Background Information for hoposed Standards."EPA Publication No. EPA-450/3-83-005a. December 1983. U.S. Environmental Protection Agency, Air Pollution Train- ing Institute, RTF', NC 27711."APT1Course 415 Control of Gaseous Emissions." EpA-450/2-81-005. December 1981. U.S. Environmental hotection Agency, Officeof A i Quality Planning and Standards. "Alternative Control Tech- nology Document - Organic Waste hocess Vents.'' To be published in December 1990. 32 US.Environmental Protection Agency, Office of Air Qual- Question-What is a primary recovery? ity Planning and Standards. "Hazardous Waste Treat- Answer-Vapor recovery or collection devices that are ment, Storage, and Disposal Facilities (TSDF) -Back- inherentlypart of theprocess, e.g., aprimarycondenseron ground Information for Promulgated Organic Emission asolventdistillationunit. Primaryrecovery devicesarenot Standardsfor Process Vents and EquipmentLeaks." EPA- considered control devices under the Subpart AA rules. 450/3-89-009, July 1990. U.S.Environmental Protection Agency, Office of Air Qual- -ity Planning and Standards."Hazardous Waste TSDF Technical Guidance Document for RCRA Air Emission Standardsfor ProcessVents and EquipmentLeaks." EPA- 450/3-89-21. July 1990. U.S.Environmental Protection Agency, Office of Air Quality Planning and Standards. "OAQPS Control Cost Manual, 4th Edition." EPA450/3-90-006. Research Triangle Park, NC 27711. January 1990. U.S.Environmental Protection Agency, Office of Air Quality Planning and Standards."RCRA TSDFAir Emissions - Background Technical Memoranda for Propsed Standards." EPA-450/3-86-009. October 1990. U.S. Environmental Protection Agency, Office of Research and Development, Hazardous Waste Engineering Research Laboratory. "Air Strippers and Their Emissions Control at Superfund Sites." Publication No. EPA-600/ D-88-153, NTIS PB88-239082. Cincinnati, OH. August 1988. U.S.Environmental Protection Agency, Office of Research and Development, Hazardous Waste Engineering Research Laboratory. "Preliminary Assessment of Hazard- ous Waste Pretreatmentas an AuPollution Control Technique."Publication No. EPA-60012-86-028, NTIS PB86- 172095/AS. March 1986. US.Environmental Protection Agency, Office of Research and Development, Industrial Effects Research Labora- tory. "ProcessDesign Manual for Stripping of Organics." Cincinnati,OH. Publication No. EPA-600D-84-139. Au- gust 1984 Question-B y semiannualreportingof exceedances, doesthis mean an exceedance is a total of 24 hours in 6 months or mustanexceedancelastmorethanh~ourstobereported? Ifanexceedancemustlastlongerthan24hours,thencould not afacility havea4-hourormoreexceedanceeveryday? Whatistherelationofanexceedancetotheannualemissions limit? Answer-An exceedance must last more than 24 hours to be reported.Exceedancesof shorterdurationmustberecorded andmaybethebasisforenforcementactionuponaRCRA inspection. Exceedances provide an indication that the controlequipmentisnotproperly operatedandmainrained as required under the rules. Exceedances and the annual emission rate limit are different provisions; the emission rate limit is an emission cap that is not to be exceeded. Exceedancesindicate that thecontrol device is operating outside design limits. Question-Do the Subpart AA requirements apply to incinerators? Answer-No. Incineration is not one of the unit operations specified in the rule. Questiorr-Wouldsoilventingunits andairstrippersatgasoline cleanup sites be brought under the rules by the toxicity characteristicleachingprocedure (TCLP)ruleforbenzene? Answer-Ifthesiterequires aRCRApermitandtheairstripper is managing a hazardous waste with 10ppmw or greater organics, then the air stripper would be covered. Soil venting units are not covered by the rule because they are not one of the unit operations specified in the rules. Questions and Answers Q u e s t i o n a a n a vapor recovery system be operated at less than 95 percent efficiency if the emission rate limits are met? Answer-Yes. The performance requirements for control devices must be met only when the facility exceeds the emission rate limits and is requiredtoredwe totalprocess vent emissions by 95 percent. Questiorr-The process vent rules require control for sources exceeding the emission rate limits at 95 percent control efficiency. Are there any requirements under the RCRA rulesforcaptureefficiency. sinceoverallcontrolefficiency is the productofcapture andremoval/destmctionefficiency of the control device? Are there any test methods to determinecapture efficiency? Answer-The closed vent system requirementsin the Subpart AA rulesresult in lwpercent capture efficiency. Method 21 leak detection monitoring must be conducted on the closed vent system. 33 Chapter 4 Eq-ui-pment Leak Standards Subpart BB The organic air emission standards for equipment leaks at hazardous waste treatment, storage, and disposal facilities (TSDFs) codified in Subpart BB of 40 CFR 264 and 265 are covered in this chapter. The session is designed to provide a basic understanding of tbe equipment leak rules toaid Resource Conservation and Recovery Act (RCRA) permit writers and enforcement personnel in determining compliance and to aid facility owners and operators in achieving compliance. A review of the background of the equipment leak rules ispresented first,followed by a detailed presentation of the applicability of the rules. The control requirements are briefly summarized with references to the standards for details. Waste stream determinations for the purposes of applicability are covered in detail and the recordkeeping and reporting requirements are summarized with references to tbe standard for details of the recordkeeping requirements. the maintenance of records. Therefore, the recordkeeping aspects of these rules are very important. The chapter is organized into seven sections as shown in Table 4-2. Background These rules were promulgated June 21,1990. The effective date was December 21, 1990 (i.e., 6 months following promulgation). Facility owners and operators should have completed the fvst leak detection and repair work by the effective date, if they have equipment that is subject to these rules. These standards were adopted in large part from Clean Air Act (CAA) standards that were promulgated for equip ment leaks in other industries, such as the synthetic organic chemical manufacturing industry, the petroleum refining industry, and the coke by-product industry.For example,Clean Subpart BB-Equipment Leak Rules Resource Conservation and Recovew Act (RCRA) organic air emission standarcis for equipmeit I& were'promulgatedto protecthuman health and the environmentthrough reduction of equipment leak emissions at hazardous waste heaunent, storage,and disposal facilities(TSDF).These rules were ummuleated as SubDart BB of Parts 264 and 265 of the Code'of Fe&ral Regukons (CFR). The purpose of this chapter is to provide a basic understanding of Subpart BB equipment leak rules, which were promulgakd undetauthority of Section 3004(n) of RCRA. Table4-1. * * The highlights of this chapter are presented in Table 4-1: First,these standards affectequipment that comesinto contact with hazardous organic waste. Second,hazardouswaste treatment, storage, and disposal facilities may have hundreds or even thousandsof potential sources or equipment components such as pumps, valves, and flanges to which the rules could apply. Third, the standards include requirements for leak detection and repair for certain equipment; for other potential emission sources specified equipment is required to reduce leak emissions. The last point, which is related to recordkeep- ing,is that compliancewith these rules is demonstratedthrough Table 4-2. Hlghlightd Standardsgenerally affect equipmentwnmcting organic wastes Facilitiesmay have hundredsof these potential sourcas Standards include leakdetectionand repair (LDAR) -.-.and c_wrl r i l b r l mniiirn.ment Complianca is demonstratedthrough the maintenanca of rewrds Topics Background Applicability Waste stream determination Control requirements Rewrdkeeping requirements Reporting requirements Summary 35 Air Act standards were promulgated as 40 CFR 60,Subpart W, for NSPS and 40CFR 61, Subpart V,for NESHAP. In general, the language of these standards was revised to make them apply to waste management facilitiesand to formatthem according to RCRA specifications. For example, the words "process operations" were changed to "waste. management units," and the words " p m m s fluids"we.re.changed to "waste." In addition to these word changes, requirements were added for inspection and monitoring that would make the rules selfimplementing under the RCRA program. The Parts 264 and 265 rules for equipment leaksare identical except that reporting is not required for those facilitiescovered by the Pan 265 rules (is., interim status facilities). Applicability An applicability decision treefor the rule is shown in the workshop manual (Figure 4-1). In the fmt block at the top of the diagram is the question, "Is this a RCRA facility?" That is, is it a new or existing hazardous waste trealment, storage,and disposal facility that requires a subtitle C permit? If it is, proceed to the next question, which is, "Are certain types of `equipment' present at the facility?" The equipment covered Facility? I yes Exempt from Subpalt BE by this rule is shown in Table 4-3. If "equipment" is present in the facility, "Is the waste material at the facility hazardous waste that contains at least 10%organics by weight?" If the answer is yes, p e e d to the next question regarding the type of m i c e in which the equipment is used. "Is the equipment operated under vacuum?" If it is operated under vacuum, then it is exempt: the Subpart BB rules do not apply. If it is operated at atmosphericconditions or positive pressure, go to the final question, "Is the unit an exempt unit?" In the workshop presentation on process vents, RCRA exempt units are identified; that same list of units is exempt from the Subpart BB rules. If the facility, wastes, and equipment meet all the criteria shown in the applicability diagram, then Subpart BB does apply to the equipment in the facility. A list of the types of equipment affected by the r u l e s pumps, valves, compressors, sampling connections, open- ended lies, pressurerelief devices,and flanges-is presented in Table 4-3. The following figures are diagrams that help to show why these equipment pieces are potential sources of emissions for which these rulesapply. The fust is a schematic diagram of a centrifugalpump (pipure 4-2). The impeller that moves the fluid through the p- um-p is at one end of the pump. Penetrating that impeller housing is a shaft that provides the motive power for the impeller. A seal or packing along the shaft prevents leakage to the outside of the wastes that are in the pump impeller section. When that seal breaks down or doesnot operate properly, the fluidsfrom inside the pump can move along the pump shaft and become exposed to the atmosphere at the point where a potential leak area is indicated in the figure. JI Compressors (Figure 4-3) are similar to pumps. The differenceis that the fluid on which they operate generally is a gas. The gaseous fluid is on the inside. Pressure is exerted inside the compressor, which tends to force waste materials along the shaft and through the seal area. Once the gas is exposed to the atmosphere, it becomes a leak. A diagram of a gate valve is shown in Figure 4 4 . The waste fluid passes through the valve when the gate is open. The fluid can leak along the valve shaft; once it penetrates the packing gland area and becomes exposed to the atmosphere, a leak or air emission exists. Ilves A flow control valve shaft moves constantly to change the flow rate through the valve. This shaft movement up and down creates constant wear on the seal,and the area where the shaft becomes exposed to the atmosphere is a potential leak site. Flow control valves, as a result, have a higher potential for leakage than manual on/off valves. 1 No Flgum 4-1. Appllcablllty. Applies Table 4-3. -- -* Equlpment Cowred by Subpart BB Pumps Valves Compressors Sampling ConneCtionssystems Open-endedvalves or lines Pressure-reliel devices Flanges and other mnnectors 36 Potentiel Typical Pump Section Flgure 4-2. Cenlrlfugsl pump construction. Section through Impeller and Volute along Mean Flow Surface Adiagramof apressurerelief valveisshowninFigure4- 5. The pressure relief is provided for a process that is located upstream of the device; the pressure is produced by the fluid inside the processor waste management unit In this case, the pressure is exerted upward and may cause the sealing disc to move and potentially produce a leak if the disc is not reseated properly. For flanges, leaks can occur at the area where two pieces of pipe interface (Figure 4-6). Leaks tend to develop at the gasket because of vibration, bad assembly, or damage to the gaskets at the time they were installed when the pipe was put in place. The most common sitefor equipmentcoveredby Subpart BB at a TSDF is in the waste destruction, recycling, and recovery operations. Example operations include: incineration, distillation,solventextraction, steam stripping,and storage tanks for reclaimed organics. But these are not the only places that the types of equipment subjectto these rulescan be found. If concentrated organic wastes are in tanks or containers, the auxiliary/anciUary equipment related to that tank or container management may also be affectedby these rules. Steam strippers(Figure4-7) commonly are.used on relatively diluteaqueouswastes. Soa questionmight be,"Why is this a type of device where you would find equipmentaffected by these rules?" When the waste materials are shipped, the organic vapor phase passes overhead into an accumulator tank.When the organic materialcomes outof the accumulator tank and passes through the pumps and valves, the stripping system at these points may be contacting waste materialswith high enough organic content to be subject to these rules. Waste Stream Determinations The waste stream determination is that portion of the applicability diagram that helps you decide whether the waste materials that contact the equipment are of sufficient organic content to make the equipment subject to the rules. The organic content of the hazardous waste must be at least 10 percent by weight This is not an average organic concentra- Potential Leak Area Packing Nut Packing Gland Packing Gas Pressure Flgure 4-3. Lebyrlnth ahaH seal for compreasors. Flgura 4-4. RIslng stem gale valve. 37 Emissions (Simmering, improper Reseating. Pressure Relief) A Process Side Figure 4-5. Springloaded relief valve. Potential / LeakArea Leaks Caused by improperlyChosen Gaskets Damaged Gaskets Poor Assembly Vibrations Flgure 4-6. Leak ere8 In flanged Joint. Primaw Condenser Process Vent . Waste In Storage and Feed Tank Figure 4-7. Steam strlpper. Storage Tank ..- -m Bottoms Receiver E&X'I". !81 yir 38 tion. If at any time the equipment is expected to contain M come into contact with a hazardous waste that could have 10 percent or greater organic content, that equipment is subjectto the equipment leak rules if it meets the other applicability Criteria. The second aspect of waste sueam determinations is the type of "service" in which the equipment is used. Is it a gas or a liquid at the operating conditions, and, if it is a liquid, is it a light or heavy liquid? Table 4-5. Appllcablllty of Organlc Analytical Detectors Method Flame Ionization Compounds Moat Applicable All Photoionization Aromatics Hall eleclrolytic conductivity device Halogenated The waste organic content determinations can be based on prior knowledge that the waste is lower than the 10percent limit or by direct measurement or chemical analysis. Examples of types of acceptable knowledge are: (1) documentation that no organics are used in the process, (2) information from an identical process if the waste materials that are handled in the process for which you are making the certification are the same, (3) analyses done previously on the waste managed in the unit when no changes to the waste materials have been made since that analysis was done. If questions exist about whether the level of knowledge is adequate, the Regional Administrator can require a direct measurement to demonstratethat the waste is less than 10percent organic. Some analytical methods that can be used to make an organic concentration determination are listed in Table 4-4. First, representative samples must be taken; guidance on how to do that is available in the EPA document SW846, Test Methodsfor Evaluating Solid WasrePhysicallChemical Methods. An analytical technique that is appropriate for the types of waste being managed must be chosen. Some alternative ways of making those determinations are found in the table. If a gas chromatographic method is selected, the appropriate detector for the types of compounds that are expected to be in the waste must be selected (Table 4-5). Some detectors are more appropriate than others. For instance, if you are Table 4-4. Appllcablllty of Organlc Content Analytlcal Method. Method ASTM E 2M)-85 (General GC analysis) Compounds Most Applicable Multiple compounds ASTM D 2267-88 (Aromatics by GC) Benzene,toluene. C8, and heavier aromatics Nondispersive infrared Mass spectrometer Any compoundwith C-H bond All working with halogenated solvents, the CI, F, I, Br, and carbon content of the material must be measured because the halogens also count toward the total organic compound cmcentration determination. Therefore, you must add both the carhon and halogen portions of the waste compounds. The next question to be answered in determining the applicability of the equipment leak standardsis, "In what type of service is the equipment used?" At this point, the waste exceeds 10 percent organic content by weight The next question is, "Is the fluid a gas at operating conditions?" An example of a gas service situation is an overhead stream from a distillation unit prior to the condenser. If the waste stream is not a gas at operating conditions, a determination must be made as to whether it is a light liquid or a heavy liquid. The light liquid determination is made in several steps (Table 4-6). First, if the waste stream is a liquid at the operating temperature, the next step is to determine whether compounds are present in the waste that have vapor pressures greater than 0.3 kilopascals at ZOOC. If compounds of that type are in the waste, the concentration of those compounds with vapor pressures exceeding 0.3 kilopascals must be determined. If the total concentration of those compounds with vapor pressures greater than 0.3 kilopascals is 20 percent M more, then the waste streamis a light liquid.If it does notmeet these criteria, then the liquid is a heavy liquid. Any liquid that is more volatile than kerosene would probably be a light liquid. An example of a heavy liquid is No. 6 fuel oil. Control Requirements In this segment, control requirements and the standards used to achieve control of the equipment leak emissions are described and discussed. Method9060(SW-846) (Total organic carbon [TOCI) Organiccarbon greater than 1 ma/L Table 4-6. LlghVHeavyLlquld Determlnatlon Method8240 (SW-US) (Volatiles by gas chromatograph/mass spectrometer [GClMS]) ASTM E 168-88 (Infrared [IR] analysis) ASTM E 169-87 (Ultraviolet[UWanalysis) Generally used to measure Appendix Vlll compounds in wastewaters. sludges and soils Single- or double-component systems Single- or double-component systems A light liquid: - Is a liquidat operatingtemperatures - Containscompound@)with vapor pressure 9 . 3 kPa (0.04 psia) at 20C (68OF) - Total concentrationof pure componentswith vapor pressure >C.3 kPa at 20C is greater than ?3% * All liquids not light liquids are heavy liquids. 39 The first type or format of standards to be discussed is the response factor of the instrument to each of the com- based on work practices. Work practices are based on leak pounds that may be leaking from that equipment must be detection and repair (LDAR) programs. Depending on the determined. A certification or demonstration must be made sourcetype, an LDAR program requires leak detection moni- for EPA that the leak detection equipment (analyzer) used is toring and/or inspection by use of an instrument or by visual capable of responding to all the organic compounds that could means or by sense of smell. Once a leak has been detected, be leaking from the equipment. For additional information, repair must be initiated and completed within a specific time review the chapter on Method 21 in this workbook. frame. A flameionizationanalyzer can be used to monitor for leaks or a soap bubble solution can be used on nonmoving equipment or equipment that is not at elevated temperatures Once a leak has been detected, repair to the equipment must be started within 5 calender days. Repairs must be that would cause the liquid to evaporate. The formation of completed within 15days of detecting the leak. bubbles is an indication that the valve leaks and needs repair. The second type or format of standard that applies to Usually, leak detection monitoring by Method 21 (Table 4-7) requires the use of a totalorganic analyzer to locate leaks from valves, flanges, and pumps. For purposes of this stan- dard, leaks are defined asmeasuring a concentration of 1 0 , ppm or greater based on a reference compound. The Subpart some of the emission sources regulated under Subpart BB is an emission limit standard. This standard is based on use of equipment that has been designed not to leak. No waste must ~contact the equipment's extemal activating mechanisms. For instance, in a pump, the drive shaft must be isolated from the ' BB rule specifies that the reference compounds for this stan- waste for it to qualify for compliance with the emission limit dard are methane or n-hexane. In leak detection monitoring, standard. Compliance is based on demonstrating that no d e tectable emissions (Le., >5GU ppm) are present, which is done with a leak-detection monitoring device using Method 21. Table 4-7. Leak Delectlon Yonltorlng with Method 21 Compliance must be demonstrated at least annually and more often if the Regional Administrator believes a problem exists. Portabletotal organic analyzer Is used to locate leaks from vaives. Hanges,and pumps Two types of pumps that would qualify under the emis- sion limit rules are a magnetically coupled pump and a canned * A leak Is defined as 10,000ppm. based on a reference motor pump (Figure 4-8). Thecanned motor pump is designed - compound The Subparl BB reference compound is methane or nhexane so that a containment can is located around the pump impeller shaft. A magnetic field is induced on the outside of the containment can. The field causes the impeller shaft to rotate without any direct contact between the waste and the drive * A responsefactor must be determined for each comound shaft for the pump. A schematic diagrams of two additional to be measured leakless pumps is shown in Figure 4-9. Bearirms Outer Coupling / Motor Volute Outlet 0-Rino / Mo- to-r Conlainme'nt Can I Inner Coupling inlet Impeller Bearing Motor Rotor/PumpShall a. Magnetically Coupled Cenbitugal Pump Flgure 4-8. Sealless pumps can be deslgnated for no detectable emlsslons. 40 b. Canned Motor Centrifugal Pump Gear Magnets c. Magnetically CoupledGear Pump `Cam Inlet Diaphragms d. Hydraulically Backed Diaphragm Metering Pump Figure 4-9. Schemallc dlagram of two leakless pumps. The third type of standard that may apply to emissions sources affected by this rule is an equipment standard. The equipment standard specifies the type of equipment that must be used to comply with the rules, for example, dual mechani- cal seals on pumps, the use of a closed-vent system and control device, or, in the case of sampling connections, closed- loop sampling. Visual inspections must be made of equipment that is subject to the equipment standard provisions, and if equipment is vented to a control device, noemissions must be detectable from the vent system to the conuol device. Any leaks detected must be repaired within I5 days. The control requirements under the Subpart BB equipment leak rules for various types of equipment are summaried in Table4-8. The left-most column in Table 4-8 lists the type of source. The second column gives the type of service in which that source is used (Le., light liquid, heavy liquid, or gas). The next three columns list types of standards that could apply forcertain types of equipment. Because alternatives are available for certain types of equipment, the primary control method is indicated in the figure by a box. You may also comply with the standard for pumps in light liquid service by using either of the altemative types of controls. The asterisk (*) in the box indicates that leak detection monitoring is required for those sources; for example, for pumps in heavy liquid service, leak monitoring is required if evidence of a leak is found. So a visual inspection must be made and, if liquids are seen leaking from the pump. monitoring for leaks must be done. Information for pressure-relief devices and flanges and other connectors is also summarized in Table 4-8. To demonstrate compliance with the standard for pressure-relief devices in gaseous service, the emission limit is no detectable emissions. For compressors, sampling connection systems, and openended lines, equipment standardsconstitute the primary means of complying. Notice that for sampling connections systems, the use of certain types of equipment is the only means of complying. The following figures demonstrate various equipment controls. A pump shaftwith dual mechanical sealsis shown in Figure 4-10. Two sets of seals are on the pump shaft; a barrier fluid is circulated from a reservoir between those two pump seals and is discharged at the opposite end. The rules specify requirements for managing this liquid. It can be sent to a control device or vented into a degassing reservoir connected to a control device. An alarm must be on the system to indicatewhen organic fluidshave peneuated into this circulating barrier fluid. A type of valve that could be used to comply with the nodetectable emissions limit is shown in Figure 4-11. A diaphragm-type material lines the inside of the valve and prevents any possibility of waste materials moving along the stem and escaping the valve at the point at which the stem is exposed to the atmosphere. Figure 4-12 is a schematicof a sealed-bellows valve. The bellows prevents contact between the waste material and the valve stem. For pressure-relief purposes, rupture discs (Figure 4-13) are placed over the potential leak source. Rupture discs are designed to rupture at certain pressures. The discs must be replaced after a pressure-relief event has occurred so that the valve can be returned to the condition of no detectable emissions. Closed-loop sampling systems (Figure 4-14) must be designed so that no possibility exists for the purged waste material stream to become exposed to the atmosphere and produce organic emissions. The purged material must be returned to the process line or waste management unit or disposed of by incineration or some other method that eliminates the possibility of organic emissions. For open-endedlines (Figure4-15),a cap or plug must be put on the opening to prevent leaks from the open end. 41 Table 4-8. Control Requlremante, Subpart BB Equlpment Leak Rules, Summary Source %Nice Emisslon Limit Equipment SDecification Light liquid No detectable emissions ( 4 Dual seals. closed vent Valve Pressure relief device Flange/ connector Compressor Heavy liquid Gas 8 lighl liquid No detectable emissions Heavy liquid Gas UNo detectable emissions Ught 8 heavy liquids Gas & light 8 heavy liquids Gas No detectable emissions (or) Sampling connection Gas 8 ilght &heavy liquids openended line Gas & ilght 8 heavy liquids 0Monitoring is requiredif evidence of a leak is found. indkates the primary control method Ciosed vent 71 I Iwith barrier fluid or closedvent I IClosed-purge system or dosed "ent Work Practice I IMonthly monitoring Possible Leak into Sealing Fluid Sealing-Liquid Inlet I Sealing-Liquid Outlet I Fluid End Inner Seal Assembly Outer Seal Assembly Flgum 4-10, Double mechanical m a l with bawler fluid control8 emlsslons. 42 Flow U Shut U Figure 4-11. Handwheel-operated plnch valw. Body Bonnet Sample Container Figure 4-14. Closed-loop sampling Byetom (to avoid loeeee from sampling). Figure 4-12. A bolted-bonnet bellows seal glob. valve. To Atmosphere 4 4 Process Side Figure 4-13. Rupture disk. To estimate equipment leak impacts for the background information document,model unitswere developed. The model unit parameters, A, B, and C, that were used to estimate national impacts for equipment leaks during development of the standardsare listed in Table 4-9. Model Unit A, the largest model facility, is characteristic of the numbers of equipment components that would be found in a large recycling facility; B represents a small recycling facility or waste incinerator; and C represents a small tank farm. The national impact estimates listed by model unit and the nationwide estimatesaregiven in Table 4-10. The national emissions from equipment leaks from these types of facilities were estimated to be about 26,ooO metric tons or megagrams per year. The rules were estimated to be able to achieve an emission reduction of about 73 percent at an annual cost of nearly $33 million. One of the components of this cost is the salary of the persons who do the leak-detection work, but annual cost also includes the cost of materials forrepairing the leaking pumps and valves and for the leak detection work necessary for compliance with the standards. RecordkeepingRequirements Compliance with the Subpart BB rules is demonstrated through the maintenance of records; thus recordkeeping is a very important aspect of the rules. 43 Open-EndedLine (Leaks throughValve) Flgun 4-15. Opm-.nd.d Iims. Cap When Not in Use The sectionsof the regulation that describe the details of the life of the facility to indicate how that determination was recordkeepingrequirementsare listed in Table4-11. Note that made. the last one, Information for Determining Exemptions, is critical. If a claim is made that the equipment in a facility is Reporting Requirements not subject to the rules, that information must be retained. The reporting requirements for these rules (i.e., Subpart Records must be retained fadifferent periods of time under BB) are similar to those for Subpart AA. the rules. Some records must be retained for only 3 years: the results of monthly leak monitoring, repair, detectable emis- A record of control device exceedances must be kepc sion monitoring work that is done, and any closed-vent con- situations that go uncorrected for greater than 74. hours must trol device operating data that have to be available to show be reported (Table 4-12). For pumps, valves, and compressors that those devices have complied with the o p t i n g require- in light liquid service, and valves in gaseous and light liquid ments. Other records must be maintained for the life of the service, repairs that have not been completed within 15 days facility. An example is the design basis for a control device asrequiredby the standards must berem as an exceedance. that demonstrates that the device is able to meet a 95 percent If no exceedances have occurred, filing a report is not neces- control efficiency.m e design basis must be kept on record for sary. Facilities subject to the interim status provisions of Part 265 are not required to report: however, they must maintain the exceedancerecords in the facility operating records. Tsbh 4-9. Equipment Leak Yodel Units Model Unit Pumps A 15 Valves 364 Sampling Connections 26 Openended Lines 105 Pressure relief Devices 9 Summary To summarize, the equipment leak rules apply to equipment at new or existing hazardous waste treatment, storage, and disposal facilities that require a Subtitle C permit (Table 4-13). Some recycling units at hazardous waste facilities were previously exempt but are now covered. Equipment coming into contact with a hazardous waste that contains at least 10 E5 C3 121 72 9 35 5 21 Table 4-10. Equipment Leak impact. Model Emission6 Unit (Mglyr) Emission Redunions (Wyr) % Captal co6st)s' A 41.1 30.4 74 68,300 B 13.7 10.2 74 __C ___-8.3--_-6-.2----7-4-- Nation- 26.200 wide 19.000 72.5 Costs are in 1986 dollars. 27,000 18.700 127 miiiim 3 Table 4-11. General Records Required 2 Annual costs. ($) 31,000 * Equipment-sped& identificationinformation(Section 264.1064[b]) - Closedventsystem and m l r o i devim information .fSeclion 264.1064Iell ~ .I - informationon equipment rmt subject to monthly LDAR (Section 264 lO64[g]) * Marking of leaking equipment (Secbon 264 10641cj) - informationon leaking equipment (Section 264.1064[d]) 11,m 8,100 * Wrier fluid system wnsor information(Section 264.1064~l) 32.9 million e inlormationfor determiningexemptions (Section 264.1064[k]) 44 Tabla 4-12. Information Requlred InSemlannual Reports (264.1065) * Control deviceexmedances unwrrectedfor .24 hoursdates, duration, cause, corrective measures - Pumpsin LC ~ e ~ i cvealv. es in WLL service, compressws not repaired in 15 days - No report required if no exceedanms - Facilities subject to interim status provisions. Part 265, are not required to report -Table 4-13. Equlpment Leak Rules Equipmentat new or existing TSDF requiring RCRA Subtitle C permit -* Equipmentcontainingor contactingwastes with at least 10% organic * Control requirementsvary by type of seriice-gas. light - liquid, heavy liquid Recordkeepingrequirementsto demonstratewmpliance - Samiannualreportingof exceedancas Bibliography "Hazardous Waste Treatment, Storage, and Disposal Facilities; Air Emission Standards for Volatile Organics Control." Federal Register, Vol 52, pp 3748-3770. Febmary 5, 1987. "Hazardous Waste Treatment, Storage, and Disposal Facilities4rganic Air Emission Standards for Process Vents and Equipment Leaks." Federal Register, Vol 55, pp 25454-25519. June 21,1990. US.Environmental Protection Agency. "Fugitive Emission Sources of Organic Compounds-Additional Information on Emissions, Emission Reductions, and Cost" Research TrianglePark, NC. EPA-450/3-82-010.April 1982. US.Environmental Protection Agency, AiPollution Train- ing Institute. "APT1 Course Sk417 Controlling VOC Emissions from Leaking hocess Equipment" EPA 450/ 2-82-015. Research Triangle Park, NC. August 1982. U.S.Environmental Protection Agency, Office of Air Qual- ity Planning and Standards. "Hazardous Waste Treatment, Storage, and Disposal Facilities (TSDWBackground Information for Promulgated Organic Emission Standardsfor Prccess Vents and EquipmentLeaks."EPA450/3-89-009. July 1990. percent organic by weight is affected by this rule. The control requirements VarY by the type of Service in which the WUiP mentis used: gas, light liquid, or heavy liquid. Recordkeeping is the means by which the operators can demonsmte compliance; semiannual reports of exceedances are required if exceedanceshave occurred within the 6-month period preceding that reporting time. The types of standards that are available for complying with Subpart BB for each murce are summarized in Table 414. As shown in the table, alternative compliance methods are available for pumps, valves, compressors, and pressure-relief devices. For sampling connection systems, flanges, and other connectors, only one means of compliance is appropriate. US.Environmental Protection Agency, Office of Air Qual- ity Planning and Standards. "Hazardous Waste TSDFTechnical GuidanceDocument for RCRA ~i~ Emission Standards for Proms Vents and EquipmentLeaks." P A 450/3-89-21. JUIY 1990. US.Environmental Protection Agency, Office of Air Qual- ity Planning and Standards. "RCRA TSDF Air Emissions-Background Technical Memoranda for Proposed Standards." EPA450/3-86-009.October 1986. U.S. EnvironmentalProtection Agency, Ofice of Solidwaste, SW846 "Test Methods for Evaluating Solid Waste Pbysical/Chemical Methods." EPA-53O/SW-84-631. September 1986. TabIe4-14. Types of Equipment teak Standards Sources Equipment Work Practice Pumps Valves Compressors Sampling connection systems Open-ended valves or lines Pressure-relief devices Flanges and other connectors (01) (or) (or) (or) Questionsand Answers Question-Is the process vent applicability criterion a waste concentntion of 10 ppm versus the 10 percent organics concentration for equipment leaks? Why the difference? Answer-The criteria are correct as stated in the question and the reason is related to the emission potential of the wasin the two situations. Fluids in which the organic concentration was less than IO percent were not found to have as significantan emission potential in leaks from the types of equipment covered by the Subpart BB rules as discharges from vents on processes where wastes with lower organic concentrationswere managed. Therulesare described as waste-based, meaning applicability is conditional upon theorganiccontentofthe wastesandtheir emission potential from the sources regulatpd. 45 Question-What is the differencebetween leak definitionsof Question-Is equipment that is used for the management of l0,oOO ppm and 500 ppm in the equipment leak rules? recycled (product) materials subject to the Subpart BB What must happen between 10,oOO and 500ppm? equipment leak rules? Answer-For certain types of equipment in certain types of Answer-If the materialis a recycled `product"as opposedto service (gadlight liquidheavy liquid), leak detection waste,then the equipmentit comes intocontactwith is not monitoring with an instrument that meets the criteria of subject to the parts 264 and 265, Subpart BB equipment EPA Reference Method 21 is required. When a leakrules.Dependingonthefacility in whichthe`product" concentrationof10,oOOppmorgreaterisfoundatasource, is handled, the equipment could be subject to equipment a leak is determined to be present. The presence of a leak leak rules issued under the authorityof the Clean Air Act, requiresthefacilityopatortoattempttocompletearepair however. Someexamplesoffacilitytypeswherethiscould of the leak within a certain period of time afteridentifying happen include petroleum refineries, coke by-product theleak.Detectionoftheleakis notaviolationoftherules, plants,andsyntheticorganicchemicalmanufacturingplants. but failure to repair or attempt to repair within a certain The point at which a waste becomes a recycled ``product'' time period would be a violation. may notbeclear.Suchdistinctionsmay havetobemadeon Forother equipment,controlsareapplied to meet therules a case-by-casebasis. that are designed to achievea condition of "no detectable emissions."Thedemonstrationof no detectableemissions presentisacompliancetastusing aleakdetectioninsmment that indicates no concentrations greater than 500 ppm abovebackgroundconcentrationsneartheequipment.The compliancetest mustbe repeatedat leastannuallyto show that the controlscontinue to have no detectableemissions. The rules have been violated if concentrationsmore than 500ppm abovebackground aremeasured. Questio+What provisions are stipulated for inaccessible equipment? Can elevated pipes with tlanges be ignored until replacement or until evidence of a leak is seen? Answer-Elevatedpipefgescannotbeignored. TheSubpart BB rules require that flangesbe monitoredby Method 21 withii 5 days of findingevidence of a potential leak via visual,audible,orolfactorymeans, orby anyotherdetection method. First attemptat repair is required within 5 days if a leak is found and repairs must be completed within 15 Queslion-Are flangeson a valve consideredpart of the valve days. Difficult-to-monitor valves and unsafe-to-monitor or are they separate sources?Should monitoringbe done valves may be monitored less frequently than others with the valve in an open or closed position? dependingm thecircumstances. Difficult-tc"nitorvalves Answer-Each flange on the valve is considered a separate source under the SubpartBB rules. So three total sources are associated with the valve, a flange on each end of the fluidflowpath and thevalve stemareawhere thestem exits must be monitored at least once a year, but valves placed inoperation afterJune21,1990,arenotgrantedthisrelief. Unsafe-tomonitor valves must be monitoredasfrequently as practicableduring safe-to-monitortimes. the body of the valve. Monitoring of the valve sources should be done during normal operations (either open or Questio-Are any changes anticipated in the leak definition closed). concentrationof 10,000ppmlmedontheplannedproposal of a 500-ppm value for process leaks under theHazardous Q u e s t i o ~ I s t h e p r e s s u r e ~ ~ u(uPm/V)ventonastoragetank considered a "pressurerelief device" for purposes of the Organic N E W (HOW (atrefineries, syntheticorganic chemical manufacturingplants)? Subpart BB rules, and, if so,does the operator need to Answer-The 500-ppm leak defmition is one of many new monitor the PN vent after each time organic liquid is requirementsin the HON regulatorynegotiationpackage. loaded into the tank? Thepackagehasnotyet beenproposedorpromulgatedbut Answer-No,thepressurdvacuum ventonastoragetankisnot consideredapressure-reliefdeviceand, therefore,does not require monitoring. willbeanactionundexthe1990CleanAirActAmendments. No plans have been madeat this timetorevisethe Subpart BB rules. 46 Chapter 5 RCRA Phase II Air Regulations Abstract Under the Resource Conservation and Recovery Act (RCRA) Phase XI rulemaking, the U.S. EPA is developing new standards and amendments that would control more treatment, storage, and disposal facility (TSDF) waste management units and add new requirements and imple- mentation changes to the existing RCRA air emission standards under Subpart A A (TSDF treatment unit Pro- cess vents) and Subpart BB (TSDFequipment leaks). A new Subpart CC would he added to 40 CFR 264 and 265 requiring t4at organic emission controls be applied to TSDF tanks, surface impoundments, containers, and cer- tain units based on the volatile organic concentration of the waste managed in the unit. In addi- tion, compliance with the air emission control require- ments relevant to tanks and containers under Subparts AA, BB, and CC would be included as a condition to maintain a permit exemption for 90-day accumulation tanks and containers. Also, the US. EPA would amend 40 CFR 270.4 torequire the owner or operator of an existing permitkd TSDF to the RCRA ai,. standards for interim status facilities (40 CFR 265 Sub- parts AA, BB, and CC) until the facility's permit is modi- fied or renewed. Finally, to be consistentwith Subpart CC, the U.S. EPA would add to Subparts A.4 and BB require- ments for managing spent carbon removed from carbon adsnrbers. RCRA Phase II Air Regulations under authority ofResource G~nservatiOnand RecOVerY Act (RCRA) Section 3004(n), EPA is developing nationwide standards to control air emissions from hazardous waste Wat- ment, storage,and disposal facilities(TSDF). These standards arebeing developed in a series of phases. For the first phase of this RCRA regulatory program, EPA promulgated in 40 CFR 264 and 265 air emission standards for TSDF process vents (Subpart AA) and TSDF equipment leaks (Subpart BB). For the second phase, EPA proposed on July 22. 1991 (56 FR 33490). rules that would (1) create a new Subpart CC to control air emissions from more TSDF waste management units; (2) create two new EPA test methods for implementing the Subpart CC standards;(3)extend the relevant air emission control requirements specifiedin Subpans AA, BB, and CC to 90-day accumulation tanks and containers; and (4) add new requirements and implementation changes to the existing Subpans andBB Thepurposeof *is chapteris to summarize the regulatory actions EPA proposed for the RCRA Phase I1 air rules. Organic emissions from TSDF contribute to ambient ozone formation, affect public health (e.g., increase cancer risk to humans), and contribute to stratospheric ozone depletion.Like the Subpans AA and BB standards, the Phase 11 rulemaking is intended to control totalorganic emissions from TSDF. This rulemaking would significantly reduce TSDF organic emissions beyond the levels controlled by the Sub- pans kA and BB standards(Figure 5-1). The Subpart CC standards would establish air emission control requirements for additional categories of waste man- agement units at TsDF subject to permitting requirements under RCRA Subtitle C. Applying the same implementation aspupbrpoaarcthccUsewdoufoldr the subpans AA and BB be added to part 26`6 and a rub a new new subpart cc Would also be added to part 265. part 264 applies to ccpermitted TsDF, a ~ 1 P m 2 6 5applies to interim StatusTSDF. The Specific subpan requirements in 264 and 265 are. identical with one exception; no reporting requirements exist in Subpart cc for interim status TSDF. The subpart cc standardswould be applicable to three broad categoriesof management units at TSDFsubject to RcRA Subtitle requirements: tanks,surface impoundments, and containers. In addition, the Phase 11 rulemaking would require TSDFwaste management units that are not specifically defmed under the RCRA regulations (referred to as "miscellaneous units") to comply with the appropriate emission control requirements specified in Sub- partcc as wellas subansAA and BB. The Subpart CC standardsare based on a control strategy that reduces air emissions from those TSDF hazardous waste streams identified to have a significant organic emission potential asdetermined by the amount of volatile organicsin a given waste slream. Organic emission controls are then applied on each unit managing these waste streams from the point where the waste is generated through treatment to remove or destroy the organics in the waste stream in accordance with other RCRA rules (e.g., incinerator standards in Part264, Subpart0,or the land disposal restriction treatment standards in Part 268). The TSDF owner or operator could demonstrate compliance of an affected TSDF waste management unit with the Subpart CC standards in one of three ways: (1) install and 47 IndustrialProcesses 2% ,.-.-.-isc. Solvent Uses *.+- .-e HazardousWaste TSDF ...:...... :............ :... Phase 2 98% Petroleum Marketing 14% Pelroleum Refinin ------------------- mical Manufaclure Flgure 5.1. Misc. Sources 20% National VOC emisslong-statlonsry sources. Phase 1 2% operate on the unit the organic emission controls specified in the rule: (2) determinethat the waste managed in the unit at all times has a volatile organic concentration less than 500 parts per million by weight (ppmw): or (3) certify that the waste managed in the unit complies with organic-specific land disposal restriction treatment standards in Part 268. The specific control requirements for those affected units managing waste with a volatile organic concentration of 500 ppmw or more depend on the type of unit. For tanks, the basic control requirement would be to cover the tank and vent it through a closed-vent system to a control device that removes or destroys the organics in the vent stream by 95 percent. As an altemative to using the control device, a floating roof could be used. Also,a control device would not be required for certain tanks that contain wastes having organic vapor pressures below specified limits and manage the wastes in a "quiescent" manner (i.e., a waste is not aerated, agitated, or mechanically mixed). Subpart X to require that the permit conditions for a miscellaneous unit include compliance with appropriate emission control requirements specified in Subparts AA, BB, and CC. This means, for example, if a miscellaneous unit is determined to resemble a surface impoundment, the control requirements for surface impoundmentsapply to the unit. As part of the Phase I1rulemaking,EPA is proposing two new test methods for use in implementing and enforcing the Subpart CC standards. These methods would be used to determine which waste streams have a significant organic emission potential, and therefore need to be controlled. Both methods are based on relatively simpleand easy-to-useprotocols that do not require measuring specific organic compounds. Also, both methods would be added to two sets of EPA test method references: Appendix A to the New Source Performance Standards in 40 CFR 60 and "Test Methods for Evaluating Solid Waste, PhysicaVChemical Methods" (SW846). The controlrequirementsfor surfaceimpoundmentswould The first test method could be used by a TSDF owner or be to cover the unit and vent it through a closed-vent system to operator to determine if a waste stream has a volatile organic a control device that removes or destroys the organics in the concentration less thanthe 500-ppmw actionlevel specifiedin vent stream by 95 percent. As with tanks, if the waste in the the Subpart CC standards. This method, Reference Method surface impoundment is managed in a "quiescent" manner, a 25D in Appendix A or Test Method 5100in SW-846, involves control device would not be required and a floatingmembrane collecting representative samples, heating the sample and cover could be used. purging it with nitrogen, measuring the carbon and chloride content, and then using a formula to calculate the volatile Containers would need to be tightly covered except when waste is being added to or removed from the container. organic concentration value for comparison to 500 ppmw. Pumpable waste would need to be added by submergedfill. If The second test method could be used by an owner or the container is used for certain treatment processes, such as operator to determine if the organic vapor pressure of a waste waste fixation, then the container would need to be placed in is below the vapor pressure limit specified in the Subpart CC an enclosure that is vented to a control device during the standards so that a control device would not be required for a periods when the container is open. tank. This method, Reference Method 25E in Appendix A or Test Method 5110in SW-846,involvescollecting representa- Under existingRCRA regulations in Part 264, SubpartX, miscellaneous units are permitted on a case-by-case basis. tive samples,analyzing the headspace vapor for propane, and then using a formula to calculate the organic vapor pressure. Each permit contains terms and provisions to protect public health and the environment based on the similarity of the unit Three amendments to existing RCRA air rules would be to the other types of waste management unit categories regu- added by the Phase I1 rulemaking. One amendment would lated under RCRA. The Phase I1 rulemaking would amend 48 affect hazardous waste generators accumulating waste in 90- Summarizing the Phase I1 rulemaking as proposed, air day tanksand containers. A second amendment would change emission standards would be established for TSDF tanks, the implementation practice for RCRA air rules under Sub- surface impoundments, containers, and miscellaneous units. parts AA, BB, and CC. The thud amendment would add new Specificorganic emission controlswould be required on those requirements for managing spent activated carbon removed units managing wastes with a volatile organic concentration from carbon adsorber control devices used to comply with of 500 ppmw or more. To implement these standards, EPA is Subparts AA and BB. proposing two new test methods. Also, existing RCRA air Under current RCRA regulations, tanks and containers accumulating waste for 90days or less at the site where the waste is generated do not need a RCRA permit provided the waste generator complies with certain conditions specifiedin 40 CFR 262. As part of the Phase I1 rulemaking, EPA would amend the RCRA rules to add an additional condition that a hazardous waste generator must meet in order for 90-day accumulator tanks and containers to remain exempt from needing a RCRA permit This condition would require com- rules wouldbe amended. To maintainaRCRA permit exemp tion for a 90-day accumulation tank or container, relevant air emission controls specified in Subparts AA, BB, and CC would need to be used. Control requirements under Subparts AA, BB, and CC in Part 265 would need to be implemented at permitted TSDF until the facility's permit is modified or renewed. Subparts AA and BB would be amended to include the same spent activated carbon management requirements specified in Subpart CC. pliance with the emission control requirements relevant to tanks and containers specified in Subparts CC, AA, and BB. To maintain a pennit exemption for a 9O-day accumulation Questionsand Answers tank,for example, the waste generator would need to install the controls as specified in Subpart CC if the waste in the tank has a volatile organic concentration of 500 ppmw or more. Also,specific requirements under Subparts AA and BB may apply depending on the particular circumstances. Implementation of RCRA air rules would be changed by Question-Would the proposed SubpartCC standardsrequire testingofeverywastemanagedataTSDFinatank,surface impoundment, or container? Answer-No. Waste determinations would be required only when an owner or operator chooses to demonstrate that the Phase I1 rulemaking. Current EPA practice is to require controlsarenorneededonauN~~use~wastemanaged that interim status TSDF comply with a new RCRA rule by in theunit hasa volatileorganicconcentrationlessthan500 the rule's effective date, but allow a permitted TSDF to ppmw, or the owner or operator chooses to place a waste comply with the new rule when the facility's permit is modi- with an organic vapor pressure below the specified limits fied or renewed. The Phase I1 rulemaking would amend the RCRA rules to require compliance with Subparts AA, BB, and CC by the rule's effective date regardless of the TSDF inatank notusing acontroldevice.FunhermMe,theowner or operator would be allowed to perform the waste determinations using either direct measurement or permit status. This means a TSDF with a permit issued before knowledge of the waste. Direct measurementof the waste the effective date would comply with the Part 265 standards until the facility's permit is modified or reissued. A TSDF volatile organic concentration 01organic vapor pressure would be performed using the FPA test methods included with a permit issued or renewed after the effectivedate would intheRCRAPhaseIIrulemaking.Knowledgeofthewaste comply with the Part 264 standards. would need to be supported by documentation that shows Requirements for management of spent carbonremoved from carbon adsorber control devices would be added to Subparts AA and BB by the Phase I1rulemaking. For carbon that the waste volatile organic concentration or organic vapor pressure is below the specified limit under all conditions. adsorben to remain effective control devices, the activated carbon eventually needs to be replaced with fresh carbon. Question-Is the 500-ppmw action level specified in the Because the spent carbon is saturated with organics, the proposed SubpartCCstandardsfordeterminingtheneedto benefits of controlling the emissions from the waste manage- apply emission controls to a unit an average value? ment unit would be lost if the organics adsorbed on the spent carbon are released to the atmosphere when the carbon is regenerated or disposedof. The Subpart CC standards include speciiic requirements for managing spent carbon removed from carbon adsorbers used to comply with the rule. For consistency, Subparts AA and BB would be amended to include the same requirements. These requirements specify that the TSDF owner or operator certify that the spent carbon removed from the carbon adsorber is either (1) regeneratedor reactivatedby a process that usesorganic emission controlsor (2) destroyed in a hazardous waste incinerator. Answer-No.The 5Wppmwactionlevelisamaximumvolatile organicconcentrationnottobeexceededatany time.EPA intends that only those units be exempted from using emission controls for which the owner or operator is reasonably certain that the volatile organic concentration of the waste managed in the unit consistently remains below 5OOppmw.If the owneroroperatorcannotdetermine confidently that the volatile organic concentration of the waste placed in a unit will remain below 500 ppmw at all times,then theowneroroperatorshouldinstalltherequired emission controls. 49 Quesrion-Forthe purposeofdeterminingif thevolatileorganic concentration of a waste is below the 500-ppmw action level, who is responsible for performing the waste determinatio-the hazardouswastegeneratorortheTSDF waste would still berequired to usecontrolsin accordance with the appropriate requirements of the Subpart CC standards. operator? Queslion-How long a period would TSDF owners and Answer-The proposed Subpart CC standards would require operatorshavetocomplywith therequirementsasproposed that the waste determination be based on the waste for the Subpart CC standards? compositionbefore thewaste isexposed totheambientair. Whenawastegeneratoris alsotheTSDFowneroroperator (e.g., the TSDF is located at the waste generation site), performing a waste determination before the waste is exposed to the ambient air can be readily accomplished sincetheTSDFowneroroperatorhascustodyofthewaste from the point of generation. However, for the situations where the waste generator is not the TSDF owner or operator(e.g., thewasteisgeneratedatone siteandshipped to a commercial TSDF), the TSDF owner or operator would not have custody of the waste until it is delivered to Answer-The TSDFowners and operators would be required to be in compliance with the SubpartCC standards by the rule's effective date, which would be 6 months after the promulgation date of the finalrule. Facilities required to install control equipment would be allowed up to an additional 18monthsbeyondtheeffectivedatetocomplete the design and installation of the equipment provided the owner or operatorhaspreparedan implementationschedule by the effective date showingwhen these controls will be installed. the TSDF. In this case, the TSDF owner or operatormay not have access to the waste before it is exposed to the ambientair.Consequently,the hazardous waste generator must perform the waste determination if waste is to be placed in TSDF units not equipped with the specified emission controls. Queslio-How would the proposed amendment requiring compliance with RCRA air rules by the rule's effective dateregardlessof aTSDF'spermitstatus(i.e.,removalof "pe~it-as-a-shield"policyfor RCRA air rules) affectthe implementationof theSubpartAA andBB rulesatexisting permittedTSDF? QuesfioGWouldpollution prevention techniquesheallowed under the proposed Subpart CC standards? Answer-Yes. The proposed Subpart CC standards would allow a TSDF owner or operator to reduce the volatile organic concentration for a specific waste to a level less than 500 ppmw through pollution prevention and other engineering techniques. For example, ifa waste is treated usingameansotherthanby dilutionorevaporationintothe atmospheresothatthe volatileorganicconcentrationof the wasteis lessthan500ppmw,thenemissioncontrolswould not be required on the subsequent downstream tanks, surface impwndments.containers,andmiscellaneousunits that manage this waste. However, the unit used to treat the Answer-Currently. a TSDFthat has beenissued a finalpermit prior to the promulgation date of the Subpart AA and BB standardsisnotsubjecttotheSubpartAAandBBstandards undereitherPart264or265rulesuntilthefacility'spermit is modified or reissued. Upon promulgation of the RCRA Phase I1 air rules,owners and operatorsof thesepermitted TSDFs would be required to be in compliance with the SubpartAAandBB rulesunderpart265within6months. Facilitiesthatwouldberequired toinstallcontrolequipment wouldbeallowed uptoanadditional18monthstocomplete the design and installation of the equipment. This is the sameperiodof timenow allowed forownersandoperators ofinterim statusTSDFtocomolvwiththesubuart AAand .I BB rules. 50 Chapter 6 RCRA Overview Abstract General information and background on the structure and operations of the solid and hazardous waste management programs are provided in this chapter. Its objectives are to Introducelsummarize the Resource Conservation and Recovery Act (RCRA); Discuss the RCRA Subtitle C hazardous waste program and its regulations; and Discuss the relationship of the air standards to other rules. RCRA Overview Federal regulations and standards dealing with the ongoing management of solid and hazardous wastes are founded in theResourceConservation and Recovery Act (RCRA) passed in 1976. The goals of the legislation are to Protect human health and the environment, Reduce waste and conserve energy and natural resources, and Reduce or eliminate the generation of hazardous waste as expeditiously as possible. The RCRA program is continually evolving as new regulations and standards are developed and promulgated. For example, the Hazardous and Solid Waste Amendments (HSWA) of 1984further refined hazardous waste regulations (e.g., introducing the land disposal restrictions). Regulations regarding the management of hazardous wastes associated with abandoned disposal sites are found in the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLAhommonly known as Superfund-and the Superfund Amendments and Reauthorization Act (SARA). There are four major programs within RCRA Solid Waste Management under Subtitle D; Hazardous Waste under Subtitle C; Underground Storage under Subtitle I:and Medical Waste- a 2-year demonstration program under SubtitleJ. all hazardous waste was managed in an environmentally sound manner. The remainder was transported, treated, stored, or disposed of in a way that potentially threatens human health and the environment. Since that time, the amount of hazardous waste produced has risen steadily. The Subtitle C program developed under RCRA (Sections 3001-3019 of the act) is designed to ensure. that the mismanagement of hazardous wastes does not continue. This is done by creating a federal "cradle-to-grave" system to manage hazardous waste (including provisions for cleaning up releases) and to set forth statutory and regulatory -requirements for Identifying hazardous waste; Generating hazardous waste; -* Transporting hazardous waste; Owners and operators of facilities that treat, store, or - dispose of hazardous wastes; Issuing operating permits to owners or operators of treatment, storage, and disposal facilities (TSDFs) and providing for corrective action for hazardous waste releases; * Enforcing the Subtitle C program; and * Transferring the responsibilities of the Subtitle C program from the federal government to the states. The Subtitle C regulations are grouped under Title 40, Chapter I, of theCode ofFederal Regulations(CFR). Chapter I is divided into numerous parts. Each part is further divided into subparts. Partsof 40 CFR are identified by the word "Part" followed by a number in Arabic numerals, for example, the TSDF air standards fall under 40CFR Part 264 (often written as 40 CFR 264, without "Part" included), Subparts AA, BB, and CC. The parUr in Chapter I of Title 40that deal with hazardous waste are listed in Table 6-1. The improper management of hazardous waste is probably one of the mast serious endironmental problems in the United States. In 1979,EPA estimated that only 10percent of Waste Definitions Materials that are solid wastes and the subset of these that are defined as hazardous wastes are identified in 40 CFR 261. Specific exclusions to the definitions of solid and hazardous 51 waste also are identified in Part 261. For example, domestic waste in RCRA. The second criterion is that the properties sewage is a solid waste but is excluded from the defmition of defining the characteristicbe measurable by standardized and a hazardous waste. available testing protocols. The hazardous waste definition is divided into four categories: Characteristic wastesdescriM as wastes that exhibit hazardous properties such as ignitability, comsivity. reactivity, or toxicity; Listed wastes-such as wastes from specificand nonspecific generation sources, and discarded and off-specification commercial chemical products; Mixture rule wastes(1) a mixture of nonhazardous waste and a characteristic hazardous waste unless the mixture no longer exhibits any hazardous characteristic, or (2) a mixture of a nonhazardous waste and one or more - listed hazardous waste; and Derived from rule wastes--any solid wastes generated from the treatment, storage, or disposal of a hazardous waste, including any sludge, spill residue, ash, emission control dust, or leachate (but not including precipitation runoff). Air emissions arenot defined as hazardous waste because they do not meet the definition of a solid waste (Le., solid, liquid, or containerized gas). The criteria for identifying characteristics of hazardous wastes and for listing hazardous waste are described in part 261. The first criterion is that the characteristicbe capable of being defined in terms of physical, chemical, or other properties that cause the waste to meet the definition of hazardous Table 6-1. RCRA HazardousWaste Program-Tltle 40, C d e of Federal Regulations 40 CFR Pan Title 260 Hazardous waste management system: general 261 Identificationand listing of hazardouswaste 262 Standardsapplicableto generationof hazardouswaste 263 Standardsapplicableto transportersof hazardouswaste Characteristic hazardous wastes exhibit one or more of the following: ignitability,reactivity,comivity,and toxicity, which are portrayed in Figure 6 1 The definition of each propxty ties into test results of waste properties and/or con- stituents. The toxicity test was amended this year to reflect specific concentrations of some 40 organic and inorganic waste constituents in a waste extract derived using the Toxicity Characteristic Leaching Procedures (TCLP), which be came effective September 29,1990. Listed hazardous wastes are divided into four groups: * Nonspecific industry sources such as degreasing opera- . tions and electroplating; Hazardous wastes gemrated from specific sources such as petroleum refming; * Wastes representing discarded and/or off-specification commercialchemical productsand manufacturingchemical intermediates (whether usable or off-specification); and Wastesfrom spillresidues,contaminated soils,andcleanup materials. Wastes are also characterized into RCRA waste codes. "Characteristic wastes" are labeled as D codes which are shown on Figure 6-1. "Listed wastes" encompass four groups of alphanumeric code published in 40 CFR 261, Subpart D. Hazardouswastesgenerated from nonspecificindustrysources such as degreasing operations and electroplating are listed as codes beginning with the letter "F," e.g., Fool,spent haloge nated degreasing solvents. Hazardouswastes from specific generation sourcessuch as petroleum refining are assigned codes beginning with the letter "K," e.g., K04g. oil emulsion solids from petroleum refining. Waste codes beginning with "F"' or "U" represent waste commercialchemicalproducts and manufacturingchemical intermediates (whether usable or off-specification), e.g., m37,container residue-dieldrin and U196 spill residuepyridine. 264 Standards for owners and operators of hazardous waste treatment. storage. and disposal facilities 265 Interim status standards for owners and omrators of hazardous waste treatment, storage, and disposal halities 266 Standards for the management of specific hazardous wastes and specific types of hazardous waste land disposal facilities 267 Interim status standards for owners and operators of new hazardous waste land disposalfacilities 268 Land disposal restrictions 270 EPA-administered permit programs: the hazardous waste permit prcgram 271 Requirementsforauthonzalonof statehazardcuswaste programs 124 Procedures for decisionmakina Generators Title 40 CFR Part 262 defines a hazardous waste generatorasany Facility owner or operator or person who fust creates a hazardous waste; * Person who fust makes the waste subject to Subtitle C regulations, e.g., mixes hazardous wastes of different De+"ent of Transportation (DOT) shipping descrip tions by placing them into a single container. The regulations require all solid waste generators to determine whether any of their waste is hazardous. Once determined hazardous. thegenerator may fall into one of three .categories depending on the volume of waste generawl: Large-quantity generator-generates >l,oOO k g h o of hazardous waste; 52 Characteristic RCRA Code Ignitable DO01 Comsive DO02 Reactive DO03 'Toxicity Characteristic Leaching Procedure(effective 9/29/90) Figura 51. Hazardous wasla characteristics. Toxic' DO04 - DO43 Smd-qmtitY generator-generates 'loo kg/mO and . <1,000 kglmo of hazardous waste: and ~ ~ ~ dexemi pt stmdli-qua~ntity~ gen~erato~r--ge~ner- ates 4 0 0 kglmo of hazardous waste (or 1 kg of acutely hazardous waste). Generators must comply with specificregulationsinclud- ing obtaining an EPA identification number specific for haz- ardouswaste generators. premsportrquuements (e.g., con- tainer Storage, labeling, inspection), manifest r q U i m " for shipping @art of the waste system), biennial reporting and recordkeeping requirements, and conditions for which accumulation is required without the need for a RCRA hazardous waste " w e m e n t facility permit. The length of time waste may be accumulated without requiring a storage permit is of the total hazardous waste generated. The majority of the small-quantity generators are automotive repair fms, con- smction f i s . dry cleaners, Photographic pmessors, and laboratories. Transporters EPA and the DOT jointly developed regulations govem- ing the transportationof hazardous waste. The regulations in Part 263 incorporate, by reference, peninent parts of DOT'S rules on labeling, marking, packaging, placarding, and other requirements for reporting hazardous waste discharges or spills during transportation. In summary, Part 263 requires that transporters subject u) regulations on obtaining an EPA identificationnumber, complying with the manifest system, and handling hazardous waste discharges. It should be 90days for large-quantity generators; -180 270 days for small-quantity generators depending on transportation circumstances; and No limit for conditionally exempt small-quantity generators. The overwhelming majority of hazardous wastes areproduced by large-quantity generators, Le., those f m s that generatemore than 1.000kglmo of hazardous wastes. It has been estimated that there are about 71,000 large-quantity generators of hazardous waste in the United States (Figure 6-2). These generators accounted for more than 99 percent of the 275 million Mgly of hazardous waste produced and managed under RCRA in 1985. Although small-quantity generators (those that generate >lo0 kglmo and <1,000 kglmo of hazardous waste) represent a large proportion of the number of hazardous waste generators nationally (more than 26,OW, they account for only a very small fraction of the hazardous wastes generated as shown in Figure 6-3. A b u t 25 percent of the country's hazardous waste generators are small-quantity generators;but these generators contribute less than one-half of the 1percent eLarge-Quanity Generators (75%) (71,000) Small-Quantiiy Generators (25%) (26,000) source~: ~of solid wa~ste,nprr ~ andJufne 1w6l. Figure 5 2 . Hazardous waste ganerator stallsllcs-number of WneratMs by generain sha. 53 ~ Large-Quantify Generators (99%) (273 Million M/Ur) SmalCOuantity Generators (1%) - Waste analysis plans; Personnel training programs; . Contingency plans; Manifest systems for waste shipped or received from offsite; Closure and post-closure plans (if a land disposal unit); and Financial responsibility for closure, post-closure, and liability. Source: EPA OSWER. The Hazardous Waste System, June 1987. Technical standards for interim status facilities address specific types of hazardous waste management units. These include containers. tanks, surface impoundments, wastepiles, landfills, land treatment units, incinerators, thermal treatment units, and chemical, physical, and biological treatment units. Flgum 63. Hazardouswaste generator statlatlcc-waste quantity by generator slze. As with interim status standards, the components of the RCRA permit for TSDF fall into two areas: General Facility Standards and Technical Standards for specific waste man- agement unit types. noted that any transporter holding hazardous waste for more The RCRA permit requires complice with general stan- than 10days is required to obtain a RCRA storage permit. dards on facility security, inspection, personnel training, and Permitting and Interim Status Standards other programs. Other permit requirements common to all TSDFs address waste analysis, contingency procedures, train- TSDFs are the last link in the cradle-to-grave hazardous ing, closure, etc. waste management system. Subtitle C requires all TSDFs that handle hazardous waste to obtain an operating permit and comply with the treatment, storage, and disposal regulations of Part 265 before fully permitted and Part 264 once permitted. Depending upon the type of hazardous waste management processes proposed for the facility, the permit will specify technical requirements for containers, tanks,and other waste management units. Unit-specific standards exist for containers, tanks, surface impoundments, wastepiles, land- RCRA permits are required for any facility that treats, fills, land treatment, incinerators, and miscellaneous units. stoles, or disposes of hazardous waste. Parties are exempt -from permitting if They generate the waste and accumulate it for a limited amount of time (e.g., for less than 90 days if large- - quantitygenerators); The waste is being managed in an emergency situation;or To obtain a RCRA permit, the following steps must be taken: First, the TSDF owner/operator submits a detailed .RCRA Part B permit application. EPA then Reviews the application for completeness and technical adequacy; Prepares a draft permit: An imminent and substantial danger exists that requires immediate waste management. Issues a public notice to local newspapers and radio stations Interim status facilities are those that have not yet been permitted. To qualify, the TSDF must be in existence when the permit regulations become effective. The TSDF owner/ operator must notify the authorized agency of its existence and submit a Part A permit application describing (1) the - notifying the public that a draft permit has been prepared; or - notifying the public that the permit has been denied. waste types managed and their annual quantities, and (2) the waste management process(es) in use at the TSDF. It shouldbe emphasized that interim status is only temporary.It is availableonly until a TSDFis granted a final permit Allows 45 days for receipt of public comment on the - decision; Holds a public hearing if requested; and decision. Issues a final permit decision and responds to comments Interim status TSDFs are regulated under 40 CFR Part received. 265. These are self-implementing regulations that contain The public or any interested party has the opportunity to both administrative and technical standards. The administra- appeal a permit decision before the permit becomes effective. tive standards include rules for developing and implementing 54 Interim status facilities regulated in Part 265 have or will be submitting Part B permit applications to obtain RCRA operating permits. HSWA established a schedule for final permitting decisions for interim status facilities. The HSWA schedule for submittingPart B permit applicationsand for the Agency to reach a permit decision is shown in Table 6-2. Table 6-2. HSWA Schedule for Submining Part B Permlt Appllcatlons Waste Management Process Land disposal facilities Fadiitiesw i h incinerators Oher-storage/ lreabnent and miscellaneous units (Subpart X) Application Due November 1985 November 1986 November 1988 Agency Dedsion November 1988 November 1989 November 1992 Standards Under Development EPA chose to develop this porrion of its TSDFrulemaking first to prevent uncontrolled air emissions from land disposal restriction (LDR) treatment technologies since these technologies were likely to have increased use. In addition, EPA already had control technology information to support t h w regulations, and thus earlier development of these rules was possible. This is principally because effective controls now in place under the Clean Air Act (CAA)to control emissions from the same types of emission points in chemical production facilities and petroleum refineries m be applied to reduce the health risk posed by air emissions from uncontrolled distillation, fractionation, thin-film evaporation, solvent extraction, and stripping processes and equipment leaks at TSDFs. The EPA has limited the applicability of tcday's final standards to those types of process vents for which control techniques are well developed, i.e., those associated with processes designed to drive the organics from the waste, such as distillation, fractionAtion, thin-film evaporation, solvent extraction,and stripping operations. Land Disposal Restrictions HSWA mandated a phased approach to prohibit the land disposal of all untreated hazardous wastes by 1990. In Part 268, EF'A has promulgated treatment standards for each hazardouswaste codewhich must be complied with to allow land disposalof the waste treatment residue. Otherwise, * A TSDF owner/operator must have an approved petition that demonstrates that there will be no migration of hazardous constituents from the disposal unit as long as the waste remains hazardous (a case-by-casedecision); * A TSDF owner/operator must have an approved petition that demonsuatesthat a specific waste cannotbe treated to the RCRA-specified level or by the specified method: * EPA must determine that the national treatment capacity is inadequate; or The TSDF owner/operator's disposal unit is a surface impoundment that will be dredged.annual1y. The restrictions were divided into the following phases: solvents and dioxins, California list, fmt scheduled wastes, second scheduled wastes, and thud scheduled wastes. The third and fmal scheduled waste restrictions became effective May 8, 1990. Any newly listed waste (i.e., after 1984) must have a land disposalrestriction determinationperformed within 6 months of the listing. Sate Authority Part 271 provides the procedures that state hazardous waste management agencies must follow in order to receive authority to administer a hazardous waste program in place of the federal RCRA program administered by EPA. To receive authority, state hazardous waste programs must be substantively equivalent and equally or more stringent than the federal program. The LDRs are already in place, so there is a need to begin some level of emission control as soon as possible. The restrictions will reduce emissions from land disposal units in most cases, since the designated best demonstrated available technology (BDAT) has the samegoal of reducing organics in waste. However, BDAT units, other than incineration, will have process vents and equipment leaks that will remain air emission sources. The technologies used in lieu of land disposal include the distillatiodseparation processes subject to the Phase I rules. Publication of the June 21, 1990, fmal rules for air emissions from hazardous waste management unit process vents associatedwith distillation,fractionation,thin-film e v a p ration, solvent extraction, and air and steam stripping processes and from leaks in equipment and piping containing or contacting hazardous waste marked the completion of this first phase. Phase I1 standards address organic emissions from TSDF tanks, surface impoundments, and containers. These stan- dards would subs&ntialIy reduce emissions of ozone precursors as well as toxic constituents. The regulation of total organics as a class is relatively straightforwardbecause it can be accomplished by a single standard, whereas the control of individual toxic constituents will require multiple standards. Implementation of the Phase I1 standards would achieve substantial organic emission reductions while EPA analyzes the residual emissions as part of the third phase of the program. A third phase would involve analyses of individual toxic constituents that compose the TSDF organic emissions. The EPA has initiated an effort to improve the database used for the Phase I1 TSDF impact analyses. If additional controls are needed to reduce specific toxic constituent emissions, the number of constituents requiring the development of standards is expected to be significantly fewer than if a constituent-by-constituent approach were used as the only means of regulating TSDF air emissions. The EPA believes that the control of organics as a class followed by controls for indi- 55 vidual toxic constituents, if necessary, will result in comprehensive standards that are protective of human health and the environment. Relationshipof Air Standardsto Other Rules Three regulatory programs may have an effect on the Phase I rules or be affected by the Phase I rules. These are RCRA's hazardous waste toxicity characteristic, LDRs, and corrective action along with CERCLA. Hazardous Waste ToxicityCharacteristic One of the procedures by which EPA defines wastes as hazardous is through hazardous waste characteristics (ignitable, corrosive, reactive, and toxic). This procedure involves identifying properties or characteristics of wastes, which, if exhibited by a waste, indicate that the waste will pose hazards to human health and the environment if its management is not controlled. Final rules became effective on September 29, 1990, to modify and significantly expand the existing characteristic of toxicity. Sections 40 CFR 264.24 and 40 CFR Part 261, Appendix 11,were amended by adding 25 organic constituents to the Toxicity Characteristic list of constituentsand replacing the Extraction Procedure (EP) with the TCLP. These changes identify large quantities of currently nonhazardous wastewater and additional quantities of sludges and solids as hazardous waste. Consequently, additional waste types and quantities would be subject to the control requirements of the TSDF air standards. Land Disposal Restrictions Under Section 3004(m) The LDRs, developed under Section 3004(m) of the HSWA, require that hazardous waste be treated to reduce concentrations of specific chemicals or hazardous properties to certain levels 01be treated using technologies before the waste may be disposed on land. Affected land disposal units include surface impoundments, wastepiles, landfills, and land treatment units. The EPA anticipates that LDR will substantially reduce the potential for air emissions from these land disposal sources. The first set of restrictions, for certain dioxins and solvent-containing hazardous wastes, was promulgated on November 7, 1986 (40 CFR 268.30-268.31); the second set of restrictions, the Califomia list, was promulgated on July 8. 1987 (40 CFR 268.32). Standards were developed for wastes having RCRA waste codes in three phases, hence the name "Thirds." The "First Thiid" was promulgated on August 7.1988 (40 CFR 268.33); the "Second Third" on June 23, 1989 (40 CFR 268.34); and the "Third Third" on May 8. 1990. The treatment technologiesevaluated under theLDRs for nonwastewater spent solvents include distillation and other SeparationProcesses subject to the requirements of the Phase I rules. The proposed Phase 11TSDF air standards are designed to protect human health and the. environment by reducing air emissions from technologies expected to be used to treat wastes prior to land disposal. The basis for the proposed Phase 11standards is to imPlement control measures that would keep the organics in the hazardous waste stream until the waste is aeated or disposed of in such a manner that the organics are destroyed, removed, or otherwiseprevented from being released to the atmosphere. Because all hazardous waste must ultimately be disposed of, air emission standards are needed that control the release of organic emissions to the atmosphere during the management of the waste from the point of generation through the various treatment processes to the point of disposal. Thus, the LDRs in combination with air emission standards provide an integrated approach to air pollution control at TSDFs. CorrectiveAction Under Section 3004(u) Under the authority of RCRA Section 3004(u), EPA is developing regulations to address releases of hazardous waste or hazardous constituents from solid waste management units (SWMU) that pose a threat to human health and the enviroument. Because this authority applies to contamination of soil, water, and air media, organic air emissions from SWMU at some TSDFs would be addressed by the corrective action program. The regulations under development would establish health-based media-specific trigger levels measured at the TSDF boundary for determining whether further remedial studies are required. Health-based cleanup standards would then be set for air emission or contamination levels that exceed acceptable health-based levels. When such contamination or exposure is determined either through monitoring or modeling techniques, corrective action would be required to reduce such emissions. Corrective actions and standards are handled on a site-specific basis. There are no uniform standards. Any corrective action using one of the six treatment/ separation technologies would be required to comply with Phase I rules, Subpart AA and/or Subpart BB. Likewise, any wastes removed from the site as part of a corrective action containing wastes >IO ppmw organics and managed in one of the six technologies would also be subject to the Phase I rules. CERCLA The Comprehensive Emergency Response, Compensation, and Liability Act (CERCLA), as amended by the Superfund Amendments and Reauthorization Act of 1986 (SARA), 42 U.S.C. 9601et seq., authorizes EPA to undertake removal and remedial actions to clean up hazardous substance releases. Removal actions typically are short-term or t e m p rary measures taken to minimize exposure or danger to humans and the environment from the release of a hazardous substance. Remedial actionsare longer term activities that are consistent with a permanent remedy for a release. Remedial actions arerequired by CERCLA Section 121(d)(2) to comply with the requirements of federal and more stringent state public health and environmental laws that are applicable or relevant and auaropriate requirements (ARAR)to the specific CERCLA sit&-Thi Natioial Contingency Plan (NCP) provides that CER(1L.A removal actions should comnlv with the ~ ~ r - ,~~~ ~~ ~~ ~ ~ federal MAR `ato the greatestextent practicable considering the exigencies of the circumstances" (40 CFR 300.65(f)). The equipment le& standards may be considered ARAR for cer- tain onsiteremedial and removal actions, A requirement under a federal or state environmental law may either be "applicahle" or "relevant and appropriate," but not both, to a remedial or removal action conducted at a CERCLA site, ~ ` ~ ~ ~ l i ~ ~ bas dl ef~ined in 40 56 CFR 300.6, are those federal requirements that would be legally applicable either directly or as incorporated by a federally authorized state program to a particular activity if the activity was not undertaken as a remedial or removal action pursuant to CERCLA. "Relevant and appropriate r e quirements" are those federal requirements that, while not applicable, aredesigned to apply to an environmental problem similar to one encountered at a particular CERCLA site and, therefore, it is appropriate to apply these requirements to a remedial or removal action performed at the CERCLA site. Some waste management activities used for remedial and removal actions to clean up hazardous organic substances require use of the distillatiodseparation operations regulated under 40 CFR 264, Subpart AA. For example, hazardous organic liquid wastes and ground and surface waters contaminated with hazardous wastes may be treated onsite using air stripping processes. Therefore, the organic emission control requirements of the Subpart AA rules may be "applicable"for onsite remedial and removal action activities that use distillation, fractionation, thin-film evaporation, solvent extraction, or air or steam stripping operations that treat substances identified or listed under RCRA as hazardous wastes and that have a total organic concentration of 10ppmw or greater. In addition, offsite storage, treatment, and disposal of all wastes classified under RCRA as hazardous waste must be performed ata TSDF pemiued under RCRA Subtitle C. Thus, CERCLA wastes that are defined as hazardous under RCRA that contain more than 10 ppmw of total organics and that are shipped offsite for management in distillation, fractionation, thin-film evaporation, solvent extraction, and air or steam stripping operations would be subject to the final standards as would any similar RCRA hazardous waste. The new Subpart AA control requirements for process vents may also be "relevant and appropriate" to onsite CERCLA removal and remedial actions that use distillation, fractionation, thin-film evaporation, solvent extraction, and air or steam stripping operations to manage substances that contain organics not covered by this rule (e.g., organics less than 10ppmw or organics from nonhazardous wastes). The final rules do not include control requirements for process vents on operations not associated with organics distillation/separation but typically associated with CERCLA remedial or removal actions such as soil excavation, in situ soil vapor extraction, in situ steam stripping of soil, soil washing, stabilization, bioremediation (in situ or otherwise), dechlorination, and low-temperature thermal desorption. The organic emission control requirements of Subpart BB for TSDF equipment leaks may also be considered as an ARAR for the equipment components(e.g.. pumps and valves) installed at CERCLA cleanup sites that contain or contact substances containing 10 percent by weight or more total organics. Although the final standards would not be ARAR for all types of remedial and removal actions that are potential sources of organic air emissions, other existing RCRA or CAA regulations may qualify as ARM for many of these activities. For example, Subpart 0 of 40 CFR 264 establishes standards of performance limiting organic emissions from thermal destruction processes (Le., hazardous waste incinerators). Other Existing RCRA Air Standards In addition to the promulgation of Phase I air emission standards, the EPA has promulgated several standards under RCRA that reduce air emissions from TSDFs. These include standards for particulate emissions from land disposal units, particulates, metals, chloride,and cartan monoxideemissions from incinerators and boilers and industrial furnaces, general air protection standards for miscellaneous waste management units, unspecified emissions from interim status thermal treatment units, and the 1990emission siandardsfor process vents and equipment leaks at TSDFs. Nonparticulate air emissions from waste management units such as tanks, containers, and impoundments are currently not regulated. Thus, it is EPA's charge under Section 3004(n) of HSWA to develop such standards as determined necessary. Land Disposal Units-Particulates Several existing provisions in 40 CFR 264 (40 CFR 264251[fl, 264.301b1,and 264.273[fl)require the implementation of general design and operating practices at permitted wastepiles, landfills, and land treatment operations to limit the release of particulate air emissions. The EPA has prepared a technical guidance document to aid in the implementation of these particulate rules; the document (Hazardous Waste TSDF-Fugitive Particulate Matfer Air Emissions Guidance Document, EPA450/3-89-019) provides information on the sources of and control technology for particulate air emissions at TSDFs. Miscellaneous Units 40 CFR 264, Subpart X,contains provisions that require prevention of air releases that may have adverse effects on human health and the environment at miscellaneous hazardous waste management units. Miscellaneous units are those units that are not containers, tanks, surface impoundments, wastepiles, land treatment units, landfills, incinerators, boil- ers, industrial furnaces, underground injection wells, or units eligible for a research, development, and demonstration permit. Miscellaneous units would include detonation units and salt domes. Incinerators Air standards also have been promulgated for the control of air emissions from permitted hazardous waste incinerators (40 CFR 264, Subpart 0).These standards require that incherators be operated to achieve a destruction and removal efficiency (DRE) of at least 99.99 percent for those principal organic hazardous constituenu listed in the facility permit. Higher efficiencies are required when the incinerator is buming certain specified waste types, e.g., polychlorinated biphe nyls. These standards also limit air emission of organics. hydrochloric acid, and particulates from incinerator stacks. EPA proposed revised standards in April 1990 that also require risk-based emission limits on metal chloride species and products of incomplete combustion using carbon monoxide as an indicator. 57 Thermal Treatment Interim sliltus standards for thermal treatment units other than incinerators (such as wet air oxidation) are found in 40 CFK 265, Subpart P. These standards apply to facilities that thermally treat hazardouswaste in devicesother than enclosed devices using controlled flame combustion. The standards require monitoring of visible emissions and operating conditions of the combustion devices and prohibit open burning except for open burning and detonation of waste explosives. Boilers and Industrial Furnaces The EPA also has promulgated standards covering the burning of hazardous waste in boilers and industrial furnaces (December 31, 1990 published in the Federal Register). These standards would require suchburning to achievea DRE of 99.99 percent for each principal organic hazardous constituent identified in the facility permit. The proposed standards also have provisions for exempting the burning of lowrisk wastes when the risk posed to the most exposed individual is less than 1 in lO0,OOO. For noncarcinogenic compounds, exemptions may be allowed if the resulting air concentrationsdo not exceed the referenceconcentration (RK)of individual hazardous compounds. The proposed standards would also limit emissions of carbon monoxide, metals, and hydrochloric acid from boilers and furnaces burning hazardous wastes. Bibliography 1. RCRA Orientation Program. US.Environmental Pro- tection Agency, Office of Solid Waste, Prepared by the University of Michigan Press. 1990. 2. 45 FR 33084. Hazardous Waste Management System; Identification and Listing of Hazardous Waste. May 19, 1990. 3. 55 FR 11798. Hazardous Waste Management System; Identificationand Listing of Hazardous Waste; Toxicity Characteristics Revisions. March 29, 1990. 4. Solid Waste Disposal Act, Title 11-Solid Waste. Disposal, Subtitlec-Hazardous Waste Management, Sec- tion 3005(c&Permits for Treatment, Storage,or Dis- posal of Hazardous Waste: Permit Issuance. 5. Solid Waste Disposal Act, Title I I 4 o l i d Waste Disposal, Subtitlec-Hazardous Waste Management,Section 3004(m)-Standards Applicable to Owners and Operators of Hazardous Waste Treatment,Storage,and Disposal Facilities: Treatment Standards for Wastes Subject to Land Disposal Prohibition. 6. Research TriangleInstitute,SourceAssessmentModelchemical universe. 7. US.Environmental Protection Agency. SummaryReport on RCRA Activities for May 1986. Officeof Solid Waste. Washington, DC.June 16, 1986. p. 4. 8. US. Environmental Protection Agency. The Hazardous Waste System. Office of Solid Waste and Emergency Response. Washington, DC. June 1987. p. 14. 9. Reference 7, p. 4. 10. Abt Associates, Inc. National Small Quantity Hazard- ous Waste Generators Survey. Prepared for the US. Environmental Protection Agency, Office of Solid Waste. Washington, DC. February 1985. p. 2. 11. Westat, Inc. National Survey of HazardousWasteGenerators and Treatment, Storage, and Disposal Facilities Regulated under RCRA in 1981. PrepareU for the U.S. Environmental Protection Agency, Office of Solid Waste. April 1984. p. 65. 12. Reference 11, p. 69. 13. Reference 7, p. 4. 58 Chapter 7 Implementation of RCRA Air Regulations The Treatment, Storage, and Disposal Facility (TSDF) Air Emissions Standards, Subparts AA (Process Vents) and BB (Equipment Leaks)are self implementing. The rules became effective 6 months after the promulgation date, or December 21, 1990. Some facilities will have up to an additional 18 months to install control devices. The actual effective date for specific facilities depends on the type of facility with regard to its permit status. Phase 11,currently undergoing Office of Management and Budget (OMB) review, will also have an impact on the implementation of Phase I. The self-implementing nature of the regulations minimizes the need for interaction between the permitting agency and the permit applicant or permittee. The need for interaction is reduced because the regulations are very specific. The regulations have specific requirements that a facility must meet in ader to be in compliance. First, facilitiesmust make applicability determinations, and the regulations include specific procedures for determining whether a facility is affected by the regulations. If the rules are applicable to a facility, the regulations specify how to estimate emissions. Whether control devices are needed to control air emissions is determined by the facility emissions. If the facility exceeds the facility emission rate limits of 3.0 lbh or 3.1 ton/ yr, then control devices are required to control the emissions. If control devices are required, performance and operations standards for those control devices would apply. Therefore, meeting the requirements that have been specified in the regulations would ensure compliance with the regulation as a whole. Because of these specific requirements, the need for engineering or professional judgment in interpreting the regulations and in applying them to a specific facility is reduced. To further ease the implementation of the Resource, Recovery, and Conservation Act (RCRA) air rules, the requirements for interim status facilities under Part 265 and for permitted facilities under Part 264 are essentially the same, with the exception that no reporting requirements for interim status facilities are required. The air rules have been passed pursuant to 3004(n) of the Hazardous and Solid Waste Amendments of 1984 (HSWA), are therefore considered HSWA rules, and will follow an HSWA implementation schedule. This means that the rules become effective immediately in all states and that the U S . EPA would implement and enforce these rules in all states. The EPA would continue to do so in nonauthorized states, but at such a time as HSWA-authorized states have revised their programs to reflect the new air emissions standards and these changes have been approved by EPA, then the authority for implementation and for enforcement would be delegated to that state. HSWA-authorized statesarerequired to adoptthe HSWA provisions or the TSDF air standards to maintain their authorization status. Authorized states had a statutory deadline IO adopt the Phase I air regulations by July 1, 1990, to maintain their authorization status. If a statutoq change is required to reflect the new Phase I air standards, an additional year is available and July 1, 1991, became the deadline. In some cases the schedule can be extended for up to 6 months for extenuating circumstances. The states may have or adopt the equivalent standards as a matter of state law and administer and enforce these as state law prior to approval of the HSWA modification authorization. Delays in the permitting process are likely because of the inclusion of these air standard requirements into the permits, an additional layer of complexity in the permitting process. Delays were likely for thosepermits scheduled for issuance in early 1991. This can occur for three major reasons: (1) if the detailed module approach is used,some delays may occw in developing permit language that specifically and adequately addresses the Phase I air standards; (2) if information or data received from the applicant are either incomplete or of poor quality and insufficient for permitting decision; and (3) procedural delays, if the permit has gone through public notice without the inclusion of the air standards. For these facilities, an additional public notice covering only the Phase I air standards is required. The whole permit does not need to be opened, only that portion covering the Phase 1standards. The best way to minimize delays in the permitting process is to first set up a dialogue between the applicant and the permitting agency to determine what information is required for the permit and what is the quality of that information, and to call for any Part B information as early as possible in the process. To further minimize delays, language associated with the Phase I air standards should be incorporated into the draft permit as soon as possible. When to expect facilities to develop and submit informa- tion depends upon when the rules become effective for spe- cific facilities. The cffectivedate of the Phase I air standards is December 21, 1990. The actual effective date for a specific facility may be as early as December 21, 1990,or may be later depending upon its permitting status. Information can be 59 expected as early as December 21, 1990, for facilities immediately affected by the regulation. The effective date of the regulations for specific facilities depends upon the permit status classification of that facility. For the purposes of discussing the classification of the effective date for a specific facility, facilities have been divided into five categories: (1) interim status facilities, (2) permitted facilities, (3) facilities or units that become newly subject to the RCRA rules (either through a newly listed or newly identified waste), (4) a newly constructed facility or unit, and (5) a unit that becomes newly subject to the Phase I air standards (where a change has been made in the waste stream concentrations so that they now exceed the waste classification limits). Interim status facilities became subject to the air rules on the effective date, December 21, 1990. Any part of the permit applications that has been submitted before December 21, 1990, or those submitted subsequent to this date must be modified to include the Phase I air standards. Facilities are required to install emission control devices, if needed, by the effective date, December 21, 1990. If they are not able to install those control devices, an extension period of up to 18 months from that effective date is available. The 18-month extension period is not a blanket extension and any delays must be justified. All control devices must be installed as early as possible, and all must be installed by June 21, 1992. Permitted facilities-those that have received their final permits before the effective date of the regulations(December 21, 1990)-are effectively shielded from the Phase I air standards through the permit-as-a-shield policy. This means that the rules do not apply to these facilities, and they do not have to comply with the requirements. The standards can be applied and added to the permit when the permit is reissued, modified, or reviewed under the land disposal review. The Phase I rules provide cause for the agency to modify any permits under the permit modification procedures outlined in Part 270.41. If the Agency initiates a permit modification, headquarters policy is that the Phase I air standards can be applied to the facility as a whole. However, if an owner/operator- or facility-initiatedpermit modification is requested, the Phase I air standards would apply only to those units subject to that permit modification. The rules should not be applied to that facility as a whole. However, the rules may be applied to the facility as a whole if the permit modification procedures outlined in Part 270.41 are followed. For hose facilities that become newly subjectto RCRAthrough a newly listed or newly identifiedwaste-the air rules would apply 6 months after the listing of that waste, or the effective date of the test by which the waste was identified. These facilities would then become interim status facilities and follow the interim status rules under Part 265. They would therefore have up to an additional 18 months from the listing date of that waste to install control devices. If control devices are not installedby the effective date of that regulation for that facility, the operating record must contain either an implementation schedule that describes when installation control devices will occur or documentation that the emission rate limit of 3.0 Ib/h or 3.1 ton/yr has not been exceeded and control devices are not needed. This must be in the operating record at the time of the effective date for that facility. For newly constructed facilities, the law requires that permits issued after December 21, 1990, must include the Phase I air emission standards in the permit. The law also requires that any facility must receive final permit prior to the initiation of construction. Any applications submitted prior to December 21,1990, must be modified and resubmitted. In all cases, controls must be in place and operating upon slarlup. No extension is allowed for the installation of controls. For new units at existing facilities, if the unit is at a permitted facility, a permit modification is required to address the air emission standards. The air standards would apply to that unit on the date that the permit modification is approved. For new units at interim status facilities, a revised Part A application is required to justify the need for an additional unit, and the air staudards would apply on the date that the revised Part A is approved. In all cases, controls must be installed and operating upon startup of new units. For newly constructed facilities and new units at existing facilities, no extensions are allowed for the installation of controls. They must all be installed and operating on the startup of that facility or unit. The waste stream of a facility may change, so that the concentration of the waste now exceeds the waste classification limit, 10ppm by weight for the Subpart AA process vent standards or 10 percent for the equipment leak Subpart BB standards. The air rules would apply on the date that the facility begins to exceed the waste classification limits. In all cases, all vents associated with wastes 10 ppm or greater by weight are considered affected regardless of whether facility emissions are above or below the emission rate limit. If control devices are needed, they must be installed and operating on the effective date, the date that the facility begins to exceed the limit. No extensions are permitted for the installation of control devices allowed for these facilities. Therefore, if facility owners/operators believe that change has occurred in the waste stream, they should be conservative in making their determinations. If a facility begins to exceed the waste classification limit, and controls to comply with the regulations have not been installed, they would be considered out of compliance. The waste classification limit for Subpart AA, IO ppmw is an annual average, not an instantaneous concentration limit. Therefore, the facility owners/operators must determine whether or not they foresee a chance of the facility's exceeding the waste classification, in order to have sufficient time to install control devices. By contrast, the Subpart BB equipment leak standardsare instantaneousconcentration limits. The instant that equipment comes in contact with wastes exceeding 10 ppm, they are considered to be affected by the regulation; controls, if needed, mnst be installed and operating and a leak detection and repair (LDAR) program must be in place. To demonstrate compliance with the regulations, facility owners/operators must first determine that they are affected by the regulations, that theirs is a Subtitle C facility (either having or needing a RCRA permit), that they manage waste in one of the six technologies designated in the standards for 60 process vents (Subpart AA), and/or that they exceed the waste classification limits. The determination of applicability must be made by the effective date for facilities immediately affected by the regulations (December 21, 1990). They must document these determinations in the operating record by the effective date. Information that must be in the operating record at the effectivedate includes the waste determinations of organic concentrationsof all waste streams;whether or not they exceed the waste classification limits of 10 ppmw for Subpart AA or 10 percent for Subpart B B and, for process vents, any emissions estimates either from actual measurement or monitoring data or from engineering calculations. The facility must also make a determination as to whether or not control devices are needed at their facility, i.e., if the facility exceeds the emission rate limit of 3 Ib/h or 3.1 ton/yr. If either emissionrate is exceeded,control devices areneeded, and documentation must exist stating that control device efficiency will be met-by existing operating records, data associated with existing control devices, or any documentation or engineering calculations that indicate devices to be installed will achieve 95 percent control efficiency or reduce emissions to below the facility emission rate limits. Certain requirements and data associated with equipment leaks must be in the operating record by the effective date (as early as December 21, 1990). In addition to the applicability determinations, any Method 21 monitoring results and any leak detection repair records associated with the equipment leak rules must be documented. On the effectivedate, facilities can be considered to be in one of three states: They can be in full compliance, having ma& their applicability determination of what facility or the units at their facility are affected by the regulations, made emissions estimatesto determinewhethercontroldevices are needed, and, if needed, have these control devices installed by the time of the effective date, December 21,1990. If emission control devices are required and have not been installed by the effective date, the facility must have an implementation schedule in their operating record. This will be covered in greater detail later in this chapter. A facility owner/operator can document that the emission rate limit is not exceeded, i.e., that the total facility emissions from the affected process vents do not exceed the 3 Ib/h or 3.1 ton/yr, and, therefore, control devices are not required. In all cases these requirements must be met by a facility at the time of the effective date in order for it to remain in compliance. No extension period is allowed for these requirements. If installation of control eauipment has not been completed by the effective date, a; &tension is possible if included in the implementation schedule is the statement that these control devices will be installed within 18 months from the effective date, as early as June 21, 1990. Further exten- sions are not possible beyond this date. The Phase I air standards require information for Part B permit applications above that already required for a normal RCRA permit. This information would reflect the Phase I air standards. The information required for Part B applications follows that described above for facility documentation of compliance. The facility must include any documentation associated with applicability determinations. Affected facilities are, for the equipment leak standards, those managing wastes greater than 10 percent, and, for the process vents standards, those using one of the six designated technologies and also handling wastes greater than 10ppmw. Once affected by the process vent rules, determination that the process vent emission rate limit is or will be met must also be included. If the facility emissions from affected process vents are below 3 Ib/h and 3.1 ton&, conml devices are not needed.If control devices are needed (emissions above 3.0 Ib/h or 3.1 todyr). controls would reduce emissions below the 3-lb/h, 3.l-ton/yr limit or, if the limit cannot be met, achieve 95 percent control efficiency. For the Subpart BB rules, each piece of equipment must have a designation of service. Equipment designation is important because the actual requirements or standards of Subpart BB depend upon and vary according to the classification of that piece of equipment, be it in gaseous, light liquid, or heavy liquid service. Additionally, for equipment leak rules, records and reports associated with a leak detection and repair program must be submitted. Determiningemission rates and control device design can be done in several ways: a verification must be made that acceptable methods to calculate emissions and control device designs have been followed. The regulations d e f i e appropriate test methods and are described in the rules. Further, if test methods are not used, proper engineering design or judgment should be used. Finally, if controls have not been installed at the time of the effective date, an implementation schedule must be submitted with the Part B application and must include an explanation as to why the units were not installed by the effective date and the dates by which each unit will be up and operating. If control devices have not been installed by the time of the effective date, procedures must be followed so that the facility remains in compliance. An extension period of up to 18months is possible. This extension period is available only to interim status facilities and newly regulated facilities. The extensions do not apply to either new facilities or facilities that become newly subject to the standards due to waste stream changes resulting in exceedance of the waste classification limit. This 18-month period is not a blanket or automatic extension. The rules specify that the equipment must be installed by the time of the effective date, as early as December 21,1990. If the control devices have not been installed, an explanation of why they were not installed by the effective date must be included. The rules allow for an extension if documentation exists stating that the installation of these control devices could not reasonably have been expected to have been completed earlier. Two reasons are acceptable for not having installed control devices by the effective date. They are 1. vendor constraints, or documentation that vendors could not deliver and install control devices at any date earlier, and 61 2. delay of installation until normal scheduled routine shut- tribute about IO percent of the total organics from stationq down of a unit. sources nationwide. if they were allowed to continue to oper- ate without having to comply with the Phase I d e s , these Delaying installation until normal routine shutdown is accept- emissions would continue to occur, and delayed health and able only if documentation exists stating that doing so would environmental benefits associated with those reduced emis- actually reduce the overall emissions from that unit. This sions would occur. Also, Congress clearly intended to have would apply to those many control devices,units, or technolo- these regulations implemented as early as possible and uni- gies for which the greatest emission potential occurs during formly, as stated in the preamble language. shutdown and startup of the unit. An unscheduled shutdown may increase the emission potential from the unit so much Accumulation is the first step in the hazardous waste that waiting until normal shutdown would actually reduce management process and occurs prior to any air emission emissionsand would justify a delay. Economic constraints are control. Air emission potential is probably the highest during not considered to be a legitimate reason for delay of installa- accumulation. The possibility exists of losing most, if not all, tion of controls, though this may be negotiated on a case-by- of the volatiles before any controls or standards can be applied case basis. to that waste stream, which reduces the regulatory benefits of the Phase I rules. An implementation schedule is required to be in the operating record by the effective date. This schedule shows The changes that have been proposed under Phase I will the dates by which the design and construction for each unit become effective6 months after the promulgation of Phase 11, will be completed. The dates and schedule must be specific which is anticipated to occur by mid-1992. for each unit at the facility. The 18-monthextension period is not a blanket extension; delays for each unit must be justified and documented. What does the removal of a permit as a shield mean? Those facilities that had their original operating permit before December 21, 1990, were effectively shielded from the regu- In all cases, the implementation schedule should show lations and did not have to comply. By removing the permit as that the installation of all control devices should be completed a shield, those facilities that were originally exempt from the within 18months of the effective date, by June 21, 1992, for Phase I rules would become subject to the interim status rules those immediately affected. No furtherextensions are allowed under Part 265. Because they are going to be following the for the installation of controls beyond this date. interim status rules, they will have up to an additional 18 months to install control devices. The interim status rules The rules allow for changes in the extension period if would apply directly to that facility until a permit is either documentation exists stating that a schedule change could not modified or reissued. In essence, the facility would be operatreasonably be avoided because of vendor constraints (e.g., ing under dual status. The permit rules under Part 264 would delivery was not able to be completed by such time). This apply to all other units, while the interim status Part 265 rules exception should be supported and documented with vendor would apply diectly to those units at that facility that are information (e.g.. purchase orders). Extensions for this or any affected by the Phase I regulations. reawn are not allowed beyond the %month period. In all cases the implementation schedule must be in the facility operating record by the effective date, as early as December 21, 1990, for those immediately affected by the regulations. No extension is allowed for the presence of the implementation schedule in the operating record. Phase I1 would also change the rules governing accumulation tanks and containers. The requirements have been changed so that Subparts I and J regulations would require compliance with the Subpart AA process vent standards, Subpart BB equipment leak standards, and the new Subpart CC tanks and containers requirements under Phase II in order Measures exist in Phase I1 that will have an impact on the implementation of the Phase I air standards. The implementation of the Phase I1 rules will be essentially the same as that for them to maintain their permit exempt status. Phase I1is not going to affect either small-quantity generators or satellite accumulation exemptions. discussed under Phase I. Provisions included in Phase I1 that t In summary, the rules are self implementing, with spe- would have an impact on the implementation of Phase I include the elimination of the permit as a shield and the inclusion of accumulation tanks and containers into the Subpart AA and BB standards. The removal of the permit as a shield is being allowed primarily because the rules arc self implementing; that is, they are very specific for facilities making applicability determinations and determinations of the need for control devices. If control devices are needed, stan- cific requirements and procedures for facilities to follow to detcrmine the applicability of the rules to their facilitiesand, if they are applicable, how to make estimates of emissions to determine the need for control devices and whether a facility excecds the waste emission rate limit. Specific design and operating standards for control devices are available, if they are needed. For the equipment leak rules, specificprocedures and leak detection and repair (LDAR) programs must be dards for design and operation are included in the rule. Standards for interim status and permitted facilities are essentially the same. The Office of Air Quality Planning and Standards (OAQPS) has had success in taking this approach with other instituted to comply with the Subpart BB standards. The selfimplementing nature of the rules minimizes the need for interaction between the permitting agency and the permit applicant. The Phase I rules became effective on December regulations and has that experience to draw from. Also, hu- 21, 1990, but the effective date for individual facilities d e man health and environmental benefits arc associated with the pends upon the classification of the facility with regard to its reduced emissions that would occur as a result of the Phase I permit status. Interim status facilities arc immediately afair standards. Given that many TSDFs arc estimated to con- 62 fected by the regulations. Other facilities, such as new units or Question-What willtriggerthereopening ofapermitforthese newly regulated facilities, would become subject on later rules? dates, and permitted facilities are initially exempt from the Answer-Any openingof thepermit(administrative,technical) regulations. wouldopentheunitssubject to therulesassociated withthe The Phase I rules are considered to be HSWA rules, passed pursuant to 3004(n) of HSWA and therefore will permit change. On the basis of excessive residual risk, omnibus can be used to open a permit under 270.41. follow an HSWA implementation schedule. The rules are effective immediately in all states, implementedand enforced by EPA. When HSWA-authorized states modify their programs to address the Phase I air standardsand these modifica- tions are approved by EF'A, enforcement and implementation authority will be delegated to those authorized states. EF'A will continue to enforce and implement the rules in nonauthorized states. Finally, provisions in Phase I1 will have an impact on the implementation of the Phase I rules. This Question-In the process vent presentation, the statement was made that permittedfacilitiesare shielded from Phase I air standards. Does this shieldingof permitted facilitiesapply toboth theprocess ventrequirementsand to theequipment leak requirements? Answer-Yes, until the permit is reissued, modified, or Phase I1 is promulgated. includes the removal of uermit as a shield for those facilities that are Originally exempt by having their final Operating permit issued prior to December 21,1990. After Phase 11they will become subject to the interim status facility for those units. To maintain their permit exempt status, accumulation tanks and containers will also be reuuired to comulv with the ~~ ~~ ~ ~~~ ~ Question-Do statesautomaticallyget authorizationfor Phase I if the state is previouslyauthorized? Answer-No. The state must adopt changeshew regulations and have the modificationapproved. Subpart AA and BB standards aloig with the n&CC stan- dards proposed under Phase 11. Question-Would the proposed SubpartCCstandardsrequire testingofevery wastemanagedat aTSDFin a tank,surface impoundment,or containers? Questions and Answers Answer-No. Waste determinations would only be required when an owner or operator chooses to demonstrate that Question-Must theapplicantsubmitdeterminationsofprocess vents and equipment not subject to control requirements? controlsarenotneededon aunitbecause thewastemanaged unit hasavolatileorganicconcentrationlessthan 5oo ppmw, or theOwneror chooses to place a Answer-The determinationmust be in the operating record; it with an organic vapor pressure below the specifiedlimits is not submitted with the permit application. inatank notusingacontroldevice.Furthermore. theowner or ouerator would be allowed to uerform the waste Question--Are only theregions authorized to imp1ementhe air regulations? If so, does the state permit writer have omnibus authority with respect to air emissions? detehinations using either direci measurement or knowledge ofthe waste. kt measurementofthe volatile organic concentrationor organic vapor pressure would be performed using the EPA test methods included Answer-Only EPA is currently authorized to implement the in theRCRAPhaseIIrulemakine. Knowledeeofthe waste airregulations; however,onceauthorized stat&adoptionof regulations is approved, they can implement. Omnibus is left to the states aspolicy. The supportrole dependson the would need to be supported by &cumentagon that shows that the waste volatile organic concentration or organic vapor pressure is below the specified limit under all state and its relationship with the region. conditions. Question-Ifamanufacturing facilityhasboth finalandinterim status units, does the rule apply? Answer-The rule applies to interim status units; final permit units are shielded. Question-If the permit is opened for an unrelated purpose, does the facility come under the rules? Answeraffice of Solid Waste-Headquarters says the rules would apply only to those units affected by the permit reopening if the ownerloperator initiated the permit modification.If EPA initiated the opening of the permit, the rules may be applied to all units. Question-Is the 500 ppmw action level specified in the proposedSubpartCCstandardsfor determiningtheneedto apply emission controls to a unit an average value? Answer-No. The 500 ppmw action level is a maximum volatile organic concentration not to be exceeded at any time. EPA staff intends that only those units be exempted from using emission controls for which the owner or operator is reasonably certain that the volatile organic concenmtionofthe wastemanagedin theunitconsistently remainsbelow 500 ppmw. If theowner or operatorcannot determineconfidentlythatthevolatileorganicconcentration of the waste placed in a unit will remain helow 500 ppmw at all times, then the owner or operator should install the required emission controls. 63 Question-For thepurposeof determiningif thevolatileorganic concentration of a waste is below the 500 ppmw action level, who is responsible for performing the waste determinatioII-the hazardouswastea-eneratorortheTSDF operator? Answer-The propsed cc standards require that the waste determination must be based on the waste compositionbeforethewaste isexposedto theambientair. WhenawastegeneratorisalsotheTSDFowneroroperata (e.g., the TSDF is located at the waste generation site), performing a determination before the is exposed to the ambient air can be readily accomp[ished sinwtheTSDFowneroroperatorhas custody of the waste from the point of generation. However, for the situations where the waste generator is not the T ~ D Fowner or operator(e.g.,the wasteisgeneraledatonesiteandshipped to a commercial TSDF), the TSDF Owner or would not have custody of the waste until it is delivered to the TSDF. In this case, the TSDF owner or operator may not have access to the waste before it is exposed to the ambientair. Consequently, the hazardous waste generator must perform the waste determination if waste is to be placed in TSDF units not equipped with the specified emission controls. Question-Would pollutionprevention techniquesbe allowed under the proposed Subpart CC standards? Answer-Yes. The proposed Subpart CC standards would allow a TSDF owner or operator to reduce the volatile organic concentration for a specific waste to a level less than 500 ppmw through pollution prevention and other engineering techniques. For example, if a waste is treated usingameansotherthanby dilutionorevaporation intothe atmospheresothatthevolatileorganicconcentrationofthe waste is less than 500ppmw, emission controls would not be required on the subsequent downstream tanks, surface impoundments, containers, and miscellaneous units that manage this waste. However, the unit used to treat the waste would stillbe required to usecontrols in accordance with the appropriate requirements of the Subpart CC standards. Question-How long a period would TSDF owners and ofopretrhaetoSrsuhbapvaerttocccomsptalnywdiatr&ht?herequirementsasproposed Answer-The TSDF Owners and would be required to be in compliance with the Subpart CC standards by the rule's effective date which would be 6 months after the promulgation date of the final rule. Facilities required to install equipment be allowed up to an additional 18monthsbeyond theeffectivedatetocomplete the design and installation of the equipment provided the Owneror operatorhaspreparedanimplementationschedule bi.nysttha.le.leeaf..fective date showing when these controls will be Question-How would the proposed amendment requiring compliance with RCRA air rules by the rule's effective date regardless of a TSDF's permit status (i.e., removal of "permit-as-a-shield"policy forRCRA air rules) affectthe implementationoftheSubparlAAandBB rulesatexisting permitted TSDF? Answer--Presently,aTSDFthathasbeenissuedafinalpermit prior to the promulgation date of the Subpart AA and BB skmdardsisnot subjecttothe SubpartAAandBBstandards undereitherPart264 or265rulesuntil thefacility'spermit is modified or reissued. Upon promulgation of theRCRA Phase I1 air rules,owners and operators of these permitted TSDFs would be required to be in compliance with the SubpartAAandBBrulesunderPart265 within6months. Facilitiesthatwould be required toinslallcontrolequipment wouldbealloweduptoanadditional18monthstocomplete the design and installation of the equipment. This is the sameperiod oftimenowallowed forownersandoperators ofinterimstatusTSDFtocomplywith theSubpartAAand BB rules. 64 Chapter 8 Case Study: Measuring and Estimating Emissions This chapter is provided primarily as information that may be of interest and not as guidance for implementing the rules that are the topic of the workshop. None of the rules covered in the workshop require that the owner/operator of an affected source measure or estimate emissions. Under the Phase II rule for process vents (Subpart AA), the owner/ operator of the source has the option of measuring emissions from process vents. If the source has not been constructed, emissions must be estimated either by using emission models or by analogy to an existing sourcewhere emission measurements have been made. For enclosed vented sources, emission measurements are the preferred choice because.they can be determined with a high degree of accuracy. On the other hand, open area sources are very difficult to measure and may be candidates for emission modeling. Some of the techniques to be discussed for open area sources may be very inaccurate. In such cases, emission models may provide estimates that are equally or more accurate than attempts to measure the emissions. Emission models may also be useful, and much less expensive than measurements, when only an upper bound estimate of emissions is needed. For cases where significant variability exists in the way a unit is operated or the quantity and composition of the waste, emission models can be used to account for the variability and the effect on emissions. Attempts to measure emissions from highly variable sources could require numerous measurements and significant costs, often for results that are highly uncertain. Consequently, cost and available time are often important considerations in deciding whether to measure or estimate emissions. Emission Measurements The discussion of emission measurements is divided into direct measurements of mass emission rates, indirect measurements that involve a back calculation, and engineering calculations, which involve the use of mass balances. Direct Measurements Two types of direct measurement techniques are vent sampling and the isolation flux chamber. Vent sampling requires that the volumetric flow rate of vapors in the vent be measured along with the vapor phase concentration of the organic of interest. Concentration can be analyzed on site with a gas chromatograph, or samples can be collected in Tedlar bags, stainless steel canisters, or glass for transport to a laboratory for analysis. If the concentration is too low for analysis, the sample can be concentrated by collection on an adsorbent, such as Tenax or activated carbon, and then desorbed for analysis. The basic items for vent sampling are shown inFigure 8-1. A sample is taken from the vent through a sampling probe and a filter to remove particulate matter, then routed to a sample container or online analyzer. If the process varies over time or if it is a batch operation, representative samples must be obtained over the cycle or during the variations in processing. For steady-state continuous operations,vent sampling can provide very accurate measurements of emissions. Even with process variations or cyclic operation, vent sampling can provide accurate results if care is taken to obtain measurements of flow and concentration that are representative of the operation over time. Vent sampling has been used for various types of waste management units, such as vented landfills, vented treatment systems,vented buildings, storage tanks, etc. Obviously vent sampling can be used Cor any source in which the unit is vented through an enclosed pipe, and the accuracy of the results depends primarily on the accuracy of the measurement of flow and concentration. The isolation flux chamber shown in Figure 8-2 was developed to measure the flux rate of organics from open area sources such as surface impoundments and land treatment facilities. The device is placed over a portion of the open source. A clean, dry sweep of inert gas is introduced into the Plexiglas chamber at a metered rate and is mixed with the vapor in the chamber, either by an impeller or by the design (e.g., multiple outlets for the sweep gas). The mixture of sweep gas and vapors is withdrawn from the chamber and analyzed for organics, either onsite or at an offsite laboratory if samples are collected in containers. For large area sources, multiple samples are taken at multiple locations to charactcrize emissions from the entire source. During its operation, the pressure inside the chamber must be kept at zero. If a positive pressure exists from the sweep gas, emissions may be suppressed, if a negative pres- 65 Vent 222 mv., T Probe Ib= CCaalliibbrraattiioonn VVaallvvee Particulate F. ilte.r o.r. Separation Devica -Sampling Pump II & SamDle Container or On-Line Analyzer1 1 Recorder Figure 8-1 Vent sampling. Temperature SensorlRecorder Impeller Carrie1 Gas Stainless Steel or Figure 8-2 leoiatlonflux chamber and supporting equipment. sure exists, emissions may be increased by the removal of more organics from the surface. Another factor to consider is the sampling of sufficient locations, especially for sources where the emission rate may vary because of differences in concentration in the waste as a function of location. The flux chamber has been evaluated on several different types of sources, such as active landfills, land treatment, impoundments, and vents. Its utility for vents is limited to the case where a very low (almost immeasurably low) flow rate from the vent exists. In this case, the flux chamber niay be a reasonable approach to measure the emissions that are occurring primarily by diffusion. If the source is heterogeneous with variation in composition with respect to location, many samples may be required. Some individuals have commented that the flux chamber has some shortcomings for measuring emissions from area sources. For example, when the flux chamber is placed over a source outdoors, the chamber alters the emission mechanisms that existed before the chamber was installed. For impoundments, the chamber disrupts the wind that was blowing across the exposed surface and creating the emissions. GG Indirect Measurements Indirect measurements involve measuring concentrations of specificorganics in the ambient air,and then back-calculating what the emission rate from the source would be to give the measured air cowmaation. One such technique is called the concentration profde technology. The sampling device shown in Finure 8-3 consists of six m u l i n e urobes that are mounted vekcally and placed at logarithmiciliy spaced intervals. A single mast 4 m in height is placed downwind of the s o w e in the plume centerline. The concentration, wind speed, and temperature are measured at each of the probe heights to generateprofiles for each. These profiles are used tocalculate the vertical flux rate from the source. The sampling equipment can be placed on a trailer or on a boat for measurements on impoundments. The concentration profile technique has been used lo make measurements on both surface impoundments and land treatment facilities. The technique does not work (it is not applicable) when quiescent or unstable wind conditions exist, such as shifting of direction. The site must be relatively homogeneous; the technique will not work well if emissions or waste composition vary with respect to location. The transect technology illustrated in Figure 8-4 is also known asplume mapping. Thisdeviceusesboth a vertical and horizontal array of samplingp r o b that areplaced downwind of the source in the plume centerline. The probes are used to measure the ambientair concentration in a cross section of the plume. Four probes are mounted on 1.5-m masts and three on the 3.5-mcenter mast. Background measurements are made upwind of the sourceto correct for the contributionfrom other sources. The device also has insmments to measure wind speed, wind direction, and temperalure. The measured con- centrationsare spatiallyintegrated and a Gaussian dispersion model is used to back-calculatethe emission rate the sourcethatwould be needed to give the concentra- tion. The transect technique has been used on several types of area sources, such as active landfills, surface impoundments, land treatment facilities, and drum storage areas. As with the concentrationprofile technology, this technique does not work when calm wind conditionsexist or when the wind conditions are unstahle. It is less susceptible to changing meteorological conditions than the concentration profile technique, and it is more suitable to heterogeneous sites provided sufficient sam- pling stations are used across the plume. Mass Balance The mass balance approach shown schematicallyin Figure 8-5 focuses on measuring what enters and leaves a unit, and then calculating what is emitted by difference. For example, the flow and concentration can be measured for the waste that enters an open tank and for the treated waste as it leaves. Potential air emissions (in the simplest application of this approach) are calculated from the difference between what enters and what leaves. If no competingremoval mechanisms are in the unit, this approach can provide accurate results. Even if competing mechanisms exist, the approach can be used to place an upper bound on the emissions. Wind Indicator tI Figure &3 Concentration-profile iechnol-y. 67 U Flgum 64 Transect technology. If biodegradation or adsorption are occurring in the unit, attempts should be made to quantify the fraction of the organic that is removed by these mechanisms. This removal can then be used to correct the mass balance to obtain a more accurate estimate of emissions. The mass balance approach works best on sources that are operated at steady-state conditions with little variation in flow rate or composition. However, unsteady-state operationscan also be evaluated with this technique if a sufficient number of samples are taken. The mass balance approach has been evaluated on several types of waste management units, such as wastewater treatment tanks, solventrecovery processes, and surface impoundments. The accuracy of this approach dependson the accuracy of the individual measurements of flow rate and concentration, and on the size of the differences between what enters _ jWaste In Air Emissions 4 Biodegradation. Adsorption, and Other Mechanisms Waste out the unit and what leaves by the various mechanisms. If biodegradation or other competing mechanisms are significant for a specific organic constituent, this approach may, at best,provide an upper bound estimate of emissions. Summary In summary, advantages and disadvantagesexist for performing the emission measurements. The measurements provide a feel for site-specific results from the facility or unit of interest, the methods have been evaluated and standardized, and they can provide reasonable precision. On the other hand, the results can be very inaccurate,and they are affectedby the site conditions (such as wind speed) and the way the unit is operated. Consequently, the measurements provide results for only one point in time, and the emissions over the long term may be different from the short-term results. The measurements can also be very costly and often require a significant amount of time to get usable results. The sensitivity varies, and often detection limit problems arise for the measurement of concentration in the air. Therefore, emission models in many cases can provideequally satisfactory(orbetter) results at a fraction of the cost. Estimating Emissions The discussion of the mathematical models used for estimating emissions is divided into an overview to provide background information, models that are used for open liquid surfaces, and models used for wastes applied to soil or other porous solids. Figure a 5 Mass balance approach. 68 Overview Models have proven to be useful in estimating emissions in many applications. For example, models have been used to evaluate emission estimatesor measurements that others have made and are also helpful in assessing the emission potential of sources that are to be constructed. In cases of large open area sources,measurements are often impractical and modeling is the most practical option to estimate emissions. Emission modeling has other uses, such as understanding what factors affect emissions and to what extent. F a example, sensitivity analyses using the models can provide insight into the major operating parameters, how the variability in these parameters affects emissions, and how to place reasonable bounds on the estimates.These models have also been used to perform one of the several steps (the emission estimates) in an environmental and health impacts analysis. Although the models are quite versatile, limitations exist in the use of the models. The typical system that is being modeled is always more complex than the relatively simple models that we use to describe it. There are invariably some questions about the uncertainties associated with the use of the model for a specific site and their effect on accuracy. For example, are all of the assumptions that are used in the model applicable for the specific case for which the model is being used? If not, are the model results still close enough? Another limitation in using the models is the availability of the input parameters needed to run the model. The models are relatively simple and require only a few inputs: however, if these basic inputs are not available, the models will not provide accurate emission estimates. Perhaps the most important concept in understanding emissions from wastes is that of volatility, which is the concentration in the vapor divided by the concentration in the waste atequilibrium.For example, if we have a diluteaqueous waste containing benzene and place it in a half-filled, tightly capped vial, roughly 20 percent of the benzene will be in the vapor phase above the waste and 80percent will remain in the waste. If the waste containsphenol instead of benzene, less than 0.002 percent of the phenol appears in the vapor space. Consequently, benzene in water is highly volatile, whereas phenol in water is relatively nonvolatile. In contrast, some volatiles in mixtures of similar compounds exhibit a lower volatility than when they arepresent in water. If the sample in the vial contained benzene in oil at the same concentration as benzene in water from the previous example, the amount of benzene in the vapor space is over 100 times less. are emitted. The potential emissions are bounded on the upper end by the quantity of waste and the concentrationof volatiles in the waste. The emission models give us a feel for the fraction of a particular volatile compound that is likely to be emitted, and the product of waste quantity, concentration, and fraction emitted provides an estimate of emissions. A critical point to remember in assessing emissionpotential or in using the models is that the concentration that is needed is the concentration entering the source (for example, at the point of generation before exposure to the atmosphere). Measuring the concentration in the impoundment or open tank after most of the volatiles have been emitted is of little value. Models for Open Liquid Surfaces The emissions from open liquid surfaces that are characteristic of surface impoundments and open wastewater m t ment tanks are modeled as two mass transfer steps that occur in series (Figure 8-6). The first step involves the transfer of the organic through the liquid phase to the surface, followed by the transfer of the organic from the surface to the air. These steps are referred to as liquid-phase and gas-phase mass transfer, respectively. For highly volatile compounds, the rate of transfer to the air is very rapid relative to the rate of mass transfer through the liquid; for these compounds, the rate of volatilization is controlled by the. liquid phase rate. Other compounds such as phenol are not very volatile and the rate of mass transferis controlled by the gas-phase rate. As shown in Figure 8-7,volatility has an importanteffect on the tendency of a compound to be emitkd. The graph shows that the fraction of organic compounds emitted increases with volatility up to a point. In the example, the fraction emitted eventually levels off as a function of volatility; at this point, the rate of emissions of the more volatile compounds is controlled by the liquid-phase rate and is not affected by the volatility. The residence time also has an important effect on emissions as illustrated in Figure 8-8. As the residence time increases to several weeks, even the relatively nonvolatile compounds such as phenol will be emitted. The rate of mass transfer through the liquid phase is affected by the specific compound`s diffusivity in the liquid (usually water), by the wind speed, and by the ratio of fetch/ depth. (Fetch is the distance across the exposed surfaceof the source in the direction that the wind is blowing.) The gasphase mass transfer is affected by the constituent's volatility, its diffusivity in air, the wind speed. and the diameter of the source. If the surface is highly turbulent from mechanical We do not have equilibrium data for the wide variety of compounds and types of wastes; consequently, theoretical relationships are used in the emission models. For aqueous wastes, volatility is assessed by Henry's law constant, which is estimated from the pure component vapor pressure divided by its solubility in water. For organic liquids, the volatility used in the emission models is usually estimated from the pure component vapor pressure and the mole fraction in the waste. To aid in the discussion of emissions and modeling, the term "emission potential" is often used and is most easily pictured for open area sources in which most of the volatiles Two mechanismsin series -- Through liquid to surface From surface to air Rate-controllingstep - Liquid phase - Gasphase ... Other removal mechanisms - With efnuent - Biodegradation - Sludge From Surface to Air .. Figure 8-6 Open liquid surfaces-modeling approach. 69 t -t t Phdnol -Volatility t Benzene Flgun a7 Effect of volatilily on em18alona hom a surface Impoundment. 1.o 0.9 0.6 3._ 0.7 wE 0.6 $c 0.5 L? 0.4 0.3 0.2 0.1 I Benzene 0 I I I II 1 4 10 46 90 150 365550 Residence Time (Days, Logarithmic Scale) Flgun 8-0. E M t of nsidence time on emlaalona from an impoundment. aeration, additional parameters are needed. For example, the additional factorsaffectingemissions from turbulent surfaces include the horsepower supplied to the aerators, impeller diameter and speed, and the fraction of the total area that is turbulent. The fraction that is turbulent has a direct effect on emissions because the rate of emissions is much higher for the turbulent portion. As illustrated in Figure 8-9, the modeling must also consider the presence of mechanisms other than volatilization that may contribute to the disappearance of an organic compound. The models that will be discussed evaluate removal with the effluent from the unit, biodegradation within the unit, and adsorption onto and removal with the sludge. A biodegradation model has been incorporated into the emission models for those units that are designed to promote 70 Wind + Emissions Waste: Constituents Properties Concentration Ouanlilies Oil Content Process: Area Depth Agitation Aeration Flow Type Site: Wind Speed Temperature Flgure 8-9. Fate of organics: emissions, effluent, blodegradatlon, sludge. + Emission Estimate Flgure 8-10. Typical model Inputs (Ilquldsurfaces). biodegradation. After review and consultation, the models were revised to incorporate Monod kinetics to describe the rate of biodegradation. In Monod kinetics, the rate is fust order with respect to (directly proportional to) the constituent concentration for very dilute concentrations. At very high concentrations, the rate of biodegradation becomes independent of concentration (zero order). The rate is also proportional to the concentration of biomass in the system. Data are available for the Monod parameters for over 90 compoundsfrom various biodegradation testsin the literature. For other compounds, techniques have been devised to estimate the Monod parameters for the model. The fust choice is to use parameters that have been measured for the specific compoundsand the system of interest. A second choice would be to use values for the same compounds in other systems, such as the literature values in the emission modeling database. A third choice is to use values for compounds that are srmcturally similarto the compound of interest Finally, some empiricalrelationshipshave been developed to providerough estimates of the biodegradation parameters based on the compound's octanol-water partition coefficient. Several specialized forms of the models have been developed for specific applications. For example, the most commonly used form of the model is based on well-mixed conditions occurring in the tank or impoundment. However, some wastewater treatment tanks are designed forplug flow instead of well-mixed flow. Models are available for both types of flow systems. Some tanks or impoundments have a layer of oil floating on the surface of thewater. For this case, an oilfilm model was developed. This specializedapplicationof the model assumes that the gas-phaserate controls the overallrate of mass transfer.and the volatileorganicsof interestare in the oil layer. A model was also develoGd for diffusedair systems based on the assumption that the rising air bubbles reach equilibrium with the organics in the liquid. Finally, models are available for disposal impoundments (no flow out) in which the waste is placed and the liquid is allowed to evaporate. For this model, the time sincedisposal must be specified to estimate emissions. The typical inputs that must be specified to use the models for open liquid surfaces (shown in Figure 8-10) includecertain featuresof the waste, the unit itself,and ambient conditions. For the waste, the individual constituents must be known, their physical properties, concentrations, waste quan- tity, and the oil content if a separate oil layer forms. For the process unit (such as the aerated lagoon shown in Figure 8- 11). the input parameters include the surfacearea, depth, type of flow, biomass concentration, and certain aeration or agitation parameters if the unit is aerated. The typical wind speed and ambient temperature are also needed as inputs to the models. Models for Porous Solids The models developed for porous solids include putting the waste on top of a soil layer or incorporatingit into the soil. For the fist case, the modeling assumes that a thin layer of waste is spread on the soil surface and that the gas-phase rate of mass transfer is rate controlling. After the waste is mixed with the soil. the modeling assumes that the air in the soiland the organics in the soivwaste mixture are in equilibrium. In addition, the emission mechanism that is modeled is the diffusionof the organic through air voids to the surface,where the organics are emitted. One of the most common questions that has arisen about these models is the differencebetween air porosity and total porosity, which is illustrated in Figure 8-12. Air porosity is the fraction of the soiVwaste matrix that is air. Total porosity is that fraction of the soil/wastematrix that is not solid,Mthe sum of the fractions that are made up of air, water, and oil. The different pathways for organic compounds in land treatment are illustrated in Figure 8-13. The model for land treatment incorporates options for either oily or aqueous wastes (this affects how volatility is estimated) and accounts for biodegradation within the soil. The major mechanism for mass transfer is diffusionthrough the air voids. Absorption by oil or water and adsorption onto soil particles are ncglected as altemateremoval mechanisms. The biodegradation model used for land treatment and landfills is a simple first-order model and not the Monod model developedfor wastewater treatment. The primary basis is informationobtained on the biodegradation of benzene and toluene in petroleum refinery sludges that are land treated. These data were used with the biodegradation data for benzene and toluene in water to extrapolate to other compounds for which the aqueous data were available. Consequently,the predicted biodegradation in soil is morc uncertain than esti- 71 --t Wind s"i *mArep Waste Out If*\ Biomass Concentration Figure 0.11. Model inputs for en aerated lagoon. Vapors Move in Air 44 4 flgure 8-12. Air porosity vs. total porosity. Wind . mates of biodegradation in water because of the scarcity of data. The typical inputs that are needed for the porous solids model are shown in Figure 8-14 and include characteristicsof the waste, the land disposal source, and ambient conditions. The features of the waste that are needed include the constituents, their properties, concentrations, waste quantity, porosity, and oil content (if present). For the source (such as the land treatment plot shown in Figure 8-15), the surface area, depth of application of the waste, porosity, and the time since the waste was applied or disposed of are the items needed to run the models. The typical wind speed and ambient temperature must also be specified. For the covered landfdl shown in Figure 8-16, the cap thickness and its porosity must also be known. Volatilization .. Diffusion Through Pores Figure 8-13. land treatment emission mechanisms. 72 UI Iwaste: Constiluents Properties Concentration Quantities Porosity Application Time Oil Content Temperature Application Method \Waste LoadingArea Porosity P+Emission Model Emission Estimate Figure 8-14. Typical model inputs (porous solids). Figure 8-15. Model inputs for land treatment. ;:ii waste Figure 8-16. Model Inputs for a covered landflll. 73 Cap Porosity Waste Porosity Questions and Answers Question-Is EPA recommending or endorsing the use of the indirect sampling techniques to measure emissions? assumes thattheconditionsarefavorableforbiodegradation. If the waste contains compounds that will inhibit biodegradation, the emission model can be run with no biodegradation (set the biomass equal to zero). Answer-No. The information is being provided to let people know that they exist. However, an important part of the Question-Are the emission models conservative? discussiondealswiththeirlimitations.includinginaccuracy, Answer-The models were intended to provide unbiased cost, and measurements that represent emissions for a estimatesoflong-termemissions.Actualemissionsforany single point in time. In many cases, mass balance or given unitmaybehigherorlowerthanthemodelpredictions. emission modeling can provide more accurate long-term By incorporatingbiodegradation,the modelsarelesslikely estimates of emissions at a fraction of the cost of the tooverestimateemissionsfrom biologically activesystems. indirect samplingtechniques. Question-Theschematicofthefl~chambershowsanimpeller for mixing. Is this a standard item for all flux chambers? Answer-No. Mixing is important; however, it can be accomplished without the impeller by having multiple outletsfor the sweepgastoenterthechamberandmix with the vapors. Question-Do the biodegradation models account for the presence of toxic metals or organics in some wastes that may inhibitbiodegradation? Answer-No. The models arebased onlaboratory studies that involved abiodegradationsystemthatwasfullyacclimated to the waste. Consequently, the biodegradation model Question-Are the measurements and estimates for Henry's law constantbased on a single pure componentdissolved indistilledwater?If so,is this areasonableapproachforthe many constituents and waste matrices that make up hazardous waste? Answer-The data for Henry's law constant are as described. The preferred approach would be to have direct measurementsofaconstituent'svolatilityfrom asampleof the waste. These measurements have not been made on very many wastes. Some measurements are based on a single compound in distilled water, and these are used for specific compounds when available. In the absence of measurements,the estimating techniqueofvaporpressure divided by solubility in water provides a reasonable approximationof volatility. 74 Chapter 9 Benzene Waste Operations NESHAP NOTE: Since the time the workshops were given, EPA has determined that clarifications to the Benzene Waste Operations NESHAP are required. Revisions to the rule were proposed March 5, 1992 (57 FR 8017). Thus interpretations given during the workshop may have changed. For the latest interpretation, contact Bob Lucas, Emissions Standards Division, OAQPS (919) 541-0884. Benzene is listed as a hazardous air pollutant by EPA because it is a known human carcinogen. National emission standards for hazardous air pollutants (NESHAP) are established by EPA in accordance with Section 112 of the Clean Air Act (CAA). On March 7, 1990, EPA promulgated the benzene waste operations NESHAP (Table 9-1). This rule was one of the last NESHAP promulgated under the "old Section 112" (Le., Section 112 as in effect prior to the CAA Amendments enacted November 15, 1990). The 1990 CAA Amendments change the approach EPA will use to develop future air standards for hazardous air pollutants. As applied to the development of the benzene waste operations NESHAP, the old Section 112 directed EPA to establish national standards to controlbenzene emissionswith an "ample margin of safety" from those sources that present significant risks to human health. To comply with this directive, EPA adopted a risk-reduction policy that strives to achieve a level of emission reduction that (1) limits to no greater than approximately 1in 10,ooO (also expressed as 1x lo4) the estimated additional cancer risk to the individual living in the location that receives the maximum exposure to benzene emissionsfrom waste operations(referred to as "maximum individual risk"), and (2) minimizes the number of people nationwide exposed to estimated additional cancer risks of greater than 1 in 1million (also expressed as 1 x lo6). A four-step regulatoly approach is used as the basis for the requirements specified in the benzene waste operations NESHAP. This approach consists of (1) identifying the facili- ties where benzene emissions from waste operations pose a health risk to the people living around the facility: (2) identifying those waste streams that cause the benzene emission problem: (3) treating the identified waste streams to remove Table`9-1. Background of Benzene Waste Operations NESHAP * Benzene waste rule one of last under "oldSection 1 1 2 Rules promulgatedMarch 7, 1990 (45FR 8292) . Impacts of standards - Reduce benzene emissions from 6,000to 450 Mglyr - Reduce maximum risk from 2 x I O 3 to 5 x I O 6 - Reduce annual cancer incidence from 0.6 lo 0.05 or destroy the benzene: and (4) using organic emission controls on all units in which the waste stream is managed prior to and during treatment. The EPA performed an analysis to identify those indusuial categories where benzene emissions from waste operations potentially could present a significant risk to human health. This analysis indicated that large quantitiesof benzene can be contained in the wastes generated by chemical manufacturing plants, petroleum refineries, and coke by-product recovery plants. Waste operations at these facilities or at offsite hazardous waste treatment, storage,and disposal facilities (TSDF) receiving wastes from these facilities are potential sources of significant benzene emissions to the atmosphere. Therefore, the benzene waste operations NESHAP is applicable to four specific induswial categories--chemical manufacturing plants, petroleum refineries, coke by-product plants, and offsite TSDF that receive wastes from any of these three industries. Note that if a TSDF receives all of its benzene-containingwastes from industries other than chemical manufacturing plants, petroleum refincries, or coke byproduct plants, the rule is not applicable to the TSDF. Some individual facilities in the affected industrial categories manage wastes that contain little or no benzene. To avoid requiring these facilities with low benzene emission potential to be subject to the treatment and control standards under the benzene waste operations NESHAP, a cutoff level related to the facility's benzene emission potentlal is specified in the rule. This cutoff level identifies which facilities in the four affected industrial categories have the potential for presenting significantrisks to human health as a result of benzene emissions from waste operations and, consequently, need to treat and control ben7me-coutaining waste streams. The cutoff level is based on the totalannual quantity of benzene in the waste managed at a facility (referrcd to here as the "facilitywide TAB). The EPA determined that those facilities in the affected industrial categories with a facility-wideTAB of 10 Mdyr or more nced to control certain waste strcams containing benzene in ordcr to achieve the EPA risk policy goals. Thc definition of "waste" used for the benzene waste operations NESHAP is the same definition used for other CAA standards(specificallythe volatile organic liquid (VOL) storageNew SourcePerformance Standard [NSPS]in 40 CFR 75 60 Subpart Kb). Note that this definition is not the m e definition of waste used for the Resource Conservation and Recovery Act (RCRA) rules. The waste definition used for the benzene waste operations NESHAP is very broad and generally includes all waste materials generated at a facility except for those waste materials specifically excluded under the applicability section of the rule. As specified in this section, the benzene waste operations NESHAP does not apply to (1) wastes in the form of gases and vapors, and (2) wastes managed in segregated stormwater sewer systems (i.e., a sewer system used exclusivelyfor collecting rainfall runoff at a facility). Once a liquid or solid waste stream exits the process unit that generates the waste, that waste stream is regulated by this rule even if the material eventually is recycled or recovered. The EPA specified that the facility-wide TAB be calculated by summing the annual quantity of benzene in all aqueous waste streams managed at a facility (Table 9-2). An aqueous waste, for purposes of implementing the rule, is a waste with a water content of 10 percent or more (or that at any time is mixed with water or other wastes and the resulting mixture has a water content of 10 percent or greater). The facility-wide TAB calculation procedure is based on EPA's assessment that benzene in aqueous wastes (e.g., process wastewater, tank drawdown, landfill leachate) are the dominant source of benzene emissions from wastes operations. However, it is important to note that even though the facilitywide TAB calculationdoes not include organic wastes(wastes with a water content less than 10percent that are never mixed with water), benzene emissions from organic wastes contrib ute to the overall health risks, and the impacts of the rule were estimated based on the assumption that these wastes would also be controlled. Therefore, if the facility-wide TAB is 10 Mglyr or more, then all benzene-containing waste streams at the facility regardless of a stream's water content are subject to treatment and control requirements under the rule. The water content of a waste stream is relevant only to identifying whether the waste stream is to be included in the calculation of the facility-wide TAB. For the purpose of calculating the facility-wide TAB, an owner or operator can determine the waste stream quantities and benzene contents by direct measurement or by his or her knowledge of the process or operation that generates the waste. The waste stream quantity and benzene content are required under the rule to be determined at lhc point of waste generation. The general definition of point of waste generation as used for the rule is the location where a waste exits the Table 9-2. Total Annual Benzenein Waste (TAB) production process or waste managementunit that generatesit or the point the waste enters the first downstream waste management unit provided the waste has not been exposed to the atmosphere or mixed with other wastes. Determining the waste benzene quantity at this location ensures that all potentially significant sources of benzene emissions from waste operations at these facilities are regulated by the rule. Note that in applying the rule, there are exceptions to this general definition for a few special situations (e.g., coke by-product recovery plants regulated by 40 CFR 61 Subpart L and petroleum refinery sour water plants). The benzene waste operations NESHAP requires that certain waste streams containing benzene be mated by a means other than dilution to remove or destroy benzene, and each waste management unit that manages the waste prior to and during treatment must use emission controls. In general, the waste streams that require control are those streams that have an annual average benzene concentration of 10parts per million by weight (ppmw) or more as determined at the point of waste generation. In other words, all waste streams with an annual average benzene concentration less than 10 ppmw are exempt from the treatment and control requirements. Under the rule, certain process wastewater streams are exempt from the treatment and control requirements (Table 93). Process wastewater is a specifically defined in the rule as water that contacts benzene within the manufacturing process unit. Specific examples of waste streams that are not process wastewater are listed in the rule. A process wastewater stream is exempt if it meets one of two flow conditionsregardless of the benzene content of the stream. Fist, if the flow rate of a process wastewater stream is less than 0.02 Umin, it is exempt from the treatment and control requirements. Second, if the total mass flow late of a process wastewater stream is less than 10Mg/yr, it is exempt from the treatment and control requiremenls. As an alternative to these flow-rate exclusions, the owner or operator can choose to meet an alternative standard for all process wastewater streams at an affected facility. This altemative standard excludes process wastewater streams with an annual average benzene concentration of 10 ppmw or more from the treatment and control requiremenu provided sufficient process wastewater streams are treated (in accordance with the requirements of the rule) to reduce the total amount of benzene in all process wastewaters at a facility to 1 Mg/yr. The benzene waste operations NESHAP requires that affected waste streams with an annual average benzene concentration of 10 ppmw or more be treated to remove or destroy benzene. These treatment requiremenu are specified in terms of performance standards. The rule requires that each TAB=C (QiG) i-1 0 = annualwaste quantity C = annualaverage benzene concentration n = number of affected waste streams with ~ 1 0 %water content Table 9-3. Process Wastewater Exclusions Waste streams= than 0.02Umin or 10 Mg/yr Waste streams > l o ppmw benzene if processwastewater TAB less than 1 Mg/yr for combinationof: TAB in untreatedstreams at pointof generation TAB in treated streams at exit to treatment unit 76 affected individual waste stream be treated to (1) remove to a control device that removes or destroys the organics in the benzene from the waste stream to a level less than 10 ppmw vent stream by 95 percent. The affected waste management on a flow-weighted annual average basis; (2) remove or units are tanks, surface impoundments, containers, oil-water destroy thc quantity of benzene in the waste by 99 percent on separators,and individual drain systems. The specific control a mass basis; or (3) comply with the treatment standards of requirements for each type of waste management unit are other relevant EPA standards (Le., RCRA waste combustion summarized below. rules, RCRA land disposal restrictions, benzene-specific ef- fluent guidelines and stan&&). ~ i l ~of thei w~aste~ to comply with he is prohibited, H ~ ever, mixing of waste to facilitate treatment is allowed as described below. Tanks arerequired to be covered with a fixedroof, which ri~esmveon-vteesd through a closed-vent system to a control device that or destroys the organics in the vent Stream by 95 percent. As an alternative to using a fixed roof vented to a control device, an internal or extemal floating roof can be At affected facilities having many wastewater streams used. containing benzene such as petroleum refineries, owners and Table 9-5, operators often prefer to combine wastewater streams to facilitate treatment in a single process. For this situation, there Benzene waste Control Requirements NESHAP--General are special treatmentreq&ements specified in the rule. These requirementsapply to a wastewater treatment system in which * Apply controls prior to and during treatment wastewater streams having annual average benzene concentrations of 10 ppmw or more are mixed with wastewaters Cover or enclose wasw managementunit having annual averagebenzeneconcentrationsbelow 10ppmw (Table 94). A wastewater treatment system is specifically defined in the rule as a unit that ultimately discharges in accordance with a National Pollutant Discharge Elimination * Generally, convey emissionsthrough dosed-ventsystem to control device * Control devices remove or destroy 295% of organics System ("DES) permit. All waste management units mak- ing up the wastewater treatment system handling these mixed wastewater streams are required to use controls except for those units that meet two conditions. The first condition is the annual average benzene concentration of the waste entering the unit is less than 10ppmw. The second condition is the total annual benzene quantity in the wastewaters first entering all affected uncontrolled units constituting wastewater treatment systems facility-wide is less than 1 Mglyr. Determination of this total annual benzene quantity does not include wastewaters entering an enhanced biodegration unit. Application of these special treatment requirements for wastewater treatment systemscan be complex. For additional information about this Surface impoundments are required to be covered and vented through a closed-vent system to a control device that removes or destroys the organics in the vent stream by 95 percent. Containers are required to be tightly covered except when waste is being added to or removed from the container. Waste that is transferred (Le., pumped) into a container must be added by submerged fill. If the container is used for certain treatment processes such as waste fixation, the container needs to be placed in an enclosure that is vented to a control device during the periods when the container is open. provision of the ruld, the reader is referred to the case study in this workbook titled "Application of Benzene Waste Operations NESHAP to Wastewater Treatment Systems." The benzene waste operations NESHAP requires that controls be applied to certain waste management units managing benzene-containing waste prior to and during treatment Oil-waterseparators are required to be covered and vented to a control device that removes or destroysthe organics in the vent stream by 95 percent. As an alternative. an owner or operator may elect to use a floating roof or comply with the requirements specifiedin the Petroleum Refinery Wastewater System NSPS (40 CFR 60 Subpart QQQ). (Table 9-5). In general, the basic control requirements are to cover the unit and vent the unit through a closed-vent system Individual drain systems are required to have covers installed and a closed-vent system that routes all organic vapors from the drain system to a control device. As an Table 9-4. Alternative Standards for WWTS If wastes with 210 ppmw benzene mixed with wastes 4 0 - PPmw benzenein VJ"W Special Provisionsapply All units in W W S must be wnlrolled until both: alternative,an owner or operator may elect to comply with the requirements specified in 40 CFR 60 Subpart QQQ and, in addition, control box junction emissions by equipping the junction box with a system to prevent the flow of organic vapors from the junction box vent pipe during normal operation (e.g., water seals on the inlet sewer line connectionsto the junction box) or connecting the vent pipe to a closed-vent system and control device (e.g., a carbon canister). - The wastes entering an uncontrolledunit are 4 0 The benzene waste omrations NESHAP reuuires the * TAB enbering enhanced biodegradationis excluded from the 1-Mglyr determination -___- facill'ty-wideTAB is less than 1 Mgyr there are n o further reporting requuements (Figure 9-1). If the facility-wideTAB IS less than 10 Mdyr but greater than or equal to 1 Mg/yr, the owncr or operator is required to submit an annual report 77 updating the facility-wide TAB determination.If the facilitywide TAB is 10 Mg/yr or more, then the owner or operator is required to submit certification of compliance documenting the installation and proper operation of all equipment necessary to comply with the treatment and control requirements of the rule (Table 9-7). Table 9-6. lnltlal Determination of TAB - Existingfacilities report June 7, 1990 ing quarterly and annual reports documenting inspection and incidences of upset for the treatment processes and control devices. Table 9-7. Certification of Compliance . Submitted by March 7, 1992, or by date of new source startup * Certifies installationof required equipment Updates allowed as new informationobtained Certifies completion of initial testing and inspections New sources report at startup * Report to include: - TAB for wastes with 10% water - Identificationof streams to be controlled - Defails on basis for benzene waste streams not controlled To ensure that the treatment processes and emission control equipment are properly operated and maintained, the rule requires the owner or operator to install instrumentation to monitor the treatment process and control device operation continuously and to conduct monthly effluent testing for treatment processes. Emission control equipmentcovers must be visually checked at least quarterly to ensure that equipment is being used properly (e&, covers are closed and latched except when workers require access to a tank or container) and that equipment is being maintained in good condition (e.g., no holes or gaps have developed in covers). Annual leak detection monitoring using EPA Reference Method 21 is required for closed-vent systems to ensure all fittings remain leak-tight. As a means of verifying compliance, recordkeeping and reporting requirements are specified in the rule. The owner or operator is required to record certain information documenting all waste determination results, treatment and control equipment design, and inspection and monitoringresults. This information must be maintained in onsite facility files for at least 2 years and must be readily available for review by EPA enforcement personnel during onsite compliance inspections. Certain information must be reported to EPA regularly includ- Facilities I No Further Reporting 1 Mglyr to t o Mg/yr I Certification: Annual and In summary, the benzene waste operations NESHAP is applicable to chemical manufacturingplants, petroleum refineries, coke by-productrecovery plants, and offsite TSDF that rcceive wastes from any of these three indusaial categories.If the facility-wideTAB is 10 Mg/yr or more, the facility owner or operator is required to treat certain benzene-containing waste streams having an annual average benzene concentration of 10 ppmw or more. Tanks, surface impoundments, containers, oil-water separators, and individual drain systems used to manage the waste prior to and during waste treatment must be controlled by covering all openings and venting the unit through a closed-vent system to a control device that removes or destroys the organics in the vent stream by 95 percent. For some of the waste management unit categories, attemative controls may be used. Questions and Answers Question-Does the rule require controls for any wastes that contain benzene when the benzene in the wastes does not originate from petroleum refineries, chemical plants, or coke by-product recovery plants? Answer-No. Additional clarification has been provided in a Federal Register notice (55 FR 37230). Question-Does the rule apply to publicly owned treatment works (POTW) and municipal solid waste landfills (MSWLF')? Answer-For most cases, therule does not apply to POTW or to MSWLF. When the coverage of the proposed rule was clarified in a Federal Register notice (54 FR 51423) on Dcccmbcr 15,1989,POTWandMSWLFwerenotincluded. AnadditionalclarificationhasbeenpublishedintheFederal Regisrer followingpromulgationoflherule(55FR 37230). There are two special cases in which the rule could apply: (1) whcn these facilities are also acommercial hazardous wastc facility with a permit under Subtitle C of RCRA, or (2) whcn these facilities accept affected waste streams from chemical plants, petroleum refineries, or coke byproductrecovery plants.It isthe generator's responsibility toobtain an agreementfromtheoffsiteueatmentordispo~l facility LOensure compliancewith the benzene waste rule for trcatment of the ben7,ne waste. Flgure 9-1 Benzene waste operatlons NESHAP reporting requirements. 78 Question-When must commercialhazardous waste facilities Question-Are process wastewaters that qualify for the low control wastes that contain benzene? flow cutoff (0.02 L/min or 10 Mglyr) in Section 61.342 ~ ~ ~ ~ haz~ardous~waste<faciliti~es ~ ~ ~(c)(3) i~ncludeid in deaterminling the TAB for the facility? under Subtitle C ofRCRA must apply controls when they Answer-Yes, all benzene-containing wastes managed at a receive benzene waste from chemical plants, petroleum facility are included in determiningthe facility's TAB. refineries,orcokeby-pmductrecoveryplants,andthtoetal annual benzene in these indushes is in55 FX37230.) water (TAB)in thewastesreceivedfrom 10 ~ g / ymrore~. (s~ee the c ~ ~ f i c a t i addition,commercia ~ z a r d o u s o nQuesftaiocnil-iItsy the benzene in wastewater discharged counted in the determination of TAB? from a facilities must comply with the controlrequirements for a Answer-The quantityof benzene in the wastewaterdischarge specificwastestreamifthatwastestreamhasbeenidentified isnot countedunlessthedischargeisthepointof generation by the generator as requiring control under the rule. forthe waste.Facilitiesshouldavoiddoublecounting, such as adding the quantity at the point of generation in the Question-Are aqueouswastesthataregeneratedinfrequently, process to the quantity that is eventually discharged. accidentally, or intermittently included in the calculation of TAB? Question-Is the determination of flow-weighted annual Answer-Yes. If aqueous benzene wastes are generated infrequently,the initial report should includethe facility's average water content (for comparison to a value of 10 percent) based on percent by volume or by weight? estimate of the quantityand concentration for thesewastes Answer-Aqueous wastes are those that contain 10percent or based on measurements, historical data, or engineering more water by volume as total water. This has been analysis.Ifanew orunexpectedaqueouswasleisgenerated, clarified in a Federal Register notice (55 FX 37230). this waste must be added to the initial report and included in the facility's determination of TAB. Wastes that are generated infrequently or intermittently are subject to Question-When are controls required for new sources? controlundertheruleiftheTAB andbenzeneconcentration Answer-Applicability determinationsare made on a facility criteria are exceeded. basis (cntire geographical plant site). A new facility must be in compliancewith the regulation at startup. Benzene- Question-What is the basis for the term "annual" in the determination of TAB? containing wastes managed in a new unit at an existing facilityabovethe IO-MglyrTABcutoffmustbecontrolled by March 7,1992. Answer-This determination is based on anv 12 consecutive monthsofopcration. lfthc waste hasnolbccngcncraicd for a full the facility should ib best cstilnate Question-Do 311 chcniicol p k " , pC~olCUlllrCfinCriC5, coke thc hasis for M ~~ annual ~~ ~~~~~ rn~roiccml iiiiantitv ~ .I.f i h t , WWIP _i c " generated periodically every few years, the estimate of TAB should be based on the quantityproduced during the by-product rwovery plmts, and commcrci31 hazardous waste facilities have to submit an initial report of their determination of TAB, even if they do not use or produce year with the highest generated auantitv. benzene or manage wastes that contain benzene? Answer-Yes. All facilitiesin thesefouraffectedindustriesare Question-Areorganic wastesthatcontain less than 10percent waterandare discharged10thewastewatersystemincluded in the calculation of TAB? For example, drainings from low pointsinlinesorpumpsthat handleanorganicproduct (or even pure benzene) may enter the sewer system. subject to at least a one-time reporting requirement of TAB. If the plant does not use or produce benzene, if it is present only in small quantities,or if no wastes containing benzene are managed, the initial report should state this clearly. Whether waste streams should be controlled is determined by the TAB and benzene concentration data Answer-Although the discharge of organic products to the presented in the report. sewer was not anticipated in the development of the regulation, they should be included in the calculation of TAB because once they enter the wastewater treatment system and are mixed with wastewater, they become aqueous wastes (10 percent or more water). Theoretically, the benzenein the organicwaste should be counted toward Question-What waste streams must be included in the initial report of TAB determinations (due June 5, 1990). what accuracyisrequired,canitbeamended,andshouldcontrols be identificd? the TAB if the organic waste is mixed with the water or Answer-These questions arose because some facilities have other waste and the resulting mixture has a water content hundreds of waste streams,many of which have not been of 10percentormore. Becausethis wouldbedifficult, two mcasured for benzene quantity or concentration,and their other options are to (1) include the benzene in the organic data collection effort may not be completed within the 90- waste at its point of generation or (2) measure the benzene day pcriod. A clarification has been published in the in the combined waste at the oil-water separator and Federal Register (55FR 37230).Thepurpose of the initial include any benzene lost prior to the separator. report is to identify facilities subject to the control requirements,to identify whichstreamsmustbecontrolled. 79 and to provide the basis for exemption of streams. There are situations where knowledge of the waste could be the basisfor theestimates. Knowledgeof wastecouldbebased on engineering analyses, material balances, similarity of streams,purchaserecords,etc.Forexample, wastes thatdo not contactmaterialscontainingbenzenedo need not to be listed.When new or moreaccurate informationis obtained ortheprocessisredesigned,aresubmittal ofthereport may be appropriate.Controlsdo not need to be identified in the initial report; however, controls must be in place by the March 7,1992, compliance date. Question-If a facility hardpipes several waste streams to a single point or location, are they required to measure each individual waste stream at the point of generation or can they measure the flow and concentration of the combined stream? When are controls required for mixed wastes? Answer-the ruledoesnotrequiremeaswementatthepointof generation. Consequently, the facility can measure the combined streamand,coupled with otherknowledgeofthe individual processes or streams, estimate the flow and concentrationofindividualstreamsatthepointofgeneration to calculate the TAB. Process wastewater, which is defined in the rule and specifically excludes certain wastes, may be excluded from the control requirements under certain conditions, even if it is a mixturethat containsindividual streams with lOppm ormore.Therequirementfortheprocesswastewater exclusion is that the TAB in process wastewater be less than 1 Mg/yr for the sum of (1) the TAB in untreated streams at the point of generation and (2) the TAB in untreated streams at the exit to the treatment unit. There is also an altemative standard that addresses the mixingofwastestreams in a wastewater treatmentsystem. The wastewater treatmentunitshandling the mixture must be controlled until both (1) the waste entering an uncontrolledunitislessthan lOppmand(2) theTABfmt enteringan uncontrolledunitislessthan 1Mg/yr.TheTAB enteringan enhancedbiodegradation unitisexcludedfrom this I-Mg/yrdetermination.In otherwords,controlswould notberequiredon theenhanced biodegradationunitunless the tcnzene concentration entering the unit is 10 ppm or higher. Question-Arecontrols for intermediateproducttanksandday tanks required under the rule? Answer-No. The rule does not require controls for tanks that manageproductsor intermediates. Therule appliesonly to tanks that manage wastes containing benzene. However, benzene wastes could be generated from these tanks (as from water drawdown),and these wastes could be subject to control under the rule. Question-Does the rule require water seals on the junction box vent? Answer-No. This has been clarified in a Federal Register notice (55 FR 37230) to indicate that water seals are required on the junction box and not on the vent. The purpose is to isolate the junction box to prevent wind or induced air drafts from sweeping through the wastewater collection system. Question-Must the three samplesrequired in Section 61.355 (c)(2)(i) bc collected at different times or can they be collected at the same time? Answer-The rule does not specify a time between samples. Thc applicable requirement is that the samples be rcprescntative of the waste that is being analyzed. 80 Chapter 10 Case Study: Application of Benzene Waste Operations NESHAP to Wastewater Treatment Systems NOTE Since the time the workshops were given, EPA has determined that clarifications to the Benzene Waste Operations NESHAP are required. Revisions to the rule were proposed March 5, 1992 (57 FR 8017). Thus interpretations given during the workshop may have changed. For the latest interpretation, contact Bob Lucas, Emissions Standards Division, OAQPS (919) 541-0884. Overview Examples of the application Of the National Standard for Benzene Waste Operations (40 cFR61 Subpart FF) to wastewater treatment systems areprovided in this case study. The standards for wastewater treatment systems that manage and treat aggregated or mixed waste streams are reviewed usine some simole examules. A case studv oroblem is then presented to illus&te the aiplication of the &dard to a "real world" wastewater treatment system at a petroleum refinery. Standards for Wastewater Treatment Systems The Benzene Waste Operations NESHAF' requires owners and operators of affected facilities at which the total annual benzene quantity from the facility waste is equal to or greater than 10 Mg/yr to remove or destroy benzene contained in certain waste streams using a treatment process or wastewater treatment system. Section 61.348 of the rule establishes the treatment standards for treatment processes or wastewater treatment systems. These standards require that if an owneror operator chooses to aggregate or mix waste streams to facilitate treatment io a wastewater treatment system, the waste streams must be treated in a wastewater treatment system that meets special requirements. Each waste management unit that comprises the wastewater treatment systems at the facility must use the appropriate emission coutrols as specified under Sections 61.343 through 61.347 until both of the following conditions are met: 1. The waste entering an uncontrolled unit is less than 10 ppmw benzene; and 2. The total facility-wide wastewater treatment system annual benzene quantity first entering any uncontrolled unit is less than 1 Mg/yr. Application of Basic Standards The application of the hasic standards is illustrated in Figure 10-1. The drainage system, the oil/water separator, and the dissolved air flotation (DAF) unit shown in Figure 10-1 require controls because they receive waste with benzene concentrations of 10 ppmw or higher, me next three units require controls because even though the benzene concentration is below ppmw, the flow rate of benzene (i.e,, the annual benzene quantity)entering the units is greater than Mg/yr, Enhanced Biodegradation Units One minor exclusion to the 1 Mg/yr benzene quantity limit is: The benzene quantity entering an "enhanced biodegradation" unit from the total annual benzene quantity inventory for the wastewater treatment system is excluded if the enhanced biodegradation unit is the first exemptunit. Section 61.348(b)(2)(ii)(B) provides guidelines regarding operating conditions for what is defined as an "enhanced biodegradation" unit. These guidelines basically describe the operation of a conventional activated sludge wastewater treatment process. Activated sludge systems with benzene concentrations of 10ppmw or higher in any influent stream will still require controls, hut, if the benzene concentration is less than 10 ppmw, the annual benzene quantity entering an activated sludge system does not count towards the 1 Mg/yr control limit. Therefore, if we replace the surface impoundment in Figure 10-1with an activated sludge system (refer to Figure 10-Z), no controls are required after the equalization basin. Multiple Wastewater Treatment Systems The 1 Mg/yr of benzene control limit pertains to the total annual benzene quantityof the facility'swastewater treatment system and not to the annual benzene quantity of a single waste stream. For example, referring to Figure 10-3, Equalization Basin #I has an annual benzene quantity of 0.8 Mg/yr while the groundwater waste stream entering Equalization Basin #2 has an annual benzene quantity of 0.6 Mg/yr. In a single train system, these equalization basins would not require controls. However the cumulative or total annual benzene quantities for the uncontrolled units in this dual train facility is 1.4 Mg/yr, which exceeds the 1.0 Mg/yr control limit Therefore, one of the equalization basins in Figure 10-3 81 Drainage System Legend - Indicates Unit Not Requiring Controls under 40 CFR 61 Subpart FF Indicates Unit Requiring Controlsbecause , i ~Be~nze~ne~ConcentrationExceeds 10 ppm - Indicates Unit Requiring Controlsbecause Mass Flow Rate of Benzene Exceeds 1 Mg/yr T 0.001Mg/yrj j Discharge 0.014 Mg/yr Figure 10.1. Wastewater treatment system showing benzene concentrations and flow rates: Example 1. Polishing W must be controlled. No requirement is provided in the rule that determines which basin is controlled since controlling either basin reduces the total annual benzene quantity in the uncontrolled units to less than 1Mglyr. Therefore, to comply with the rule, the facility owner or operator can choose which of the equalizationbasins is controlledas is shown in Figures 103a and 10-3b.Note that if Equalization Basin #2 is selected to be controlled, the groundwater drainage system must also be controlled. Case Study Problem: Application of Benzene Waste Operations NESHAPto Wastewater TreatmentSystems The ABC Oil Company operates a refinery that is determined to have a facility total annual benzene (TAB) quantity greater than 10 Mg/yr, and is therefore required to treat and control certain benzene-containingwaste streams at the refinery to comply with the National Emission Standard for Ben- zene Waste Operations (40 CFR 61 Subpart FF). Individual process wastewater streams, product tank drawdown streams, and landfill leachate streams generated by refinery processes are collected in the refinery's drain systems for the purpose of managing these wastewatersin a central wastewater treatment system. Wastewaters that have an annual average benzene concentrations above IO ppmw are mixed with wastewaters that have an annual average benzene concentrationsbelow 10 ppmw in the refinery drain systems. Wastewater containing hydrogen sulfides is first treated in a sour water stripper to remove the hydrogen sulfides before the wastewater is mixed with other wastewaters. A flow diagram of the ABC Oil Refinery wastewater treatment system is shown in Figure 10-4.The annual average benzene concentration and annual benzene quantity for each wastewater stream are identified on the figure. To comply with the treatment standards under Section 61.348 of the rule, the refinery managerhas decided to treat the benzene-containing wastewater streamsusing the refinery's existingwastewater treatment system. The refinery manager has asked you to determine which units comprising the wastewater treatment system are required to use controls in accordance with the rule. Refer to Table 10-1 for the problem and Table 10-2 for the solution. Under Section 61.348(b) of the Benzene Waste Operations NESHAP,special requirements apply to a wastewater treatment system in which wastewater streams having annual average benzene concentrations of 10 ppmw or more are mixed with wastewaters having annual average benzene concentrations below 10 ppmw. The waste management units handling these mixed wastewater streams are required to use controls except for those units that meet two conditions: (1) the annual average benzene concentration of the waste entering the unit is less than 10ppmw; (2) the total annualbenzene (TAB) quantity in the wastewaters first entering all affected uncontrolled units comprising wastewater treatment systems facility-wide is less than 1 Mglyr. The wastewater treament system configuration used for the case study problem is shown in Figure 10-4. The same configuration showing the case study solution is shown in Figure 10-5. A discussion of the reasons why each unit shown in the figures is or is not required to use controls is presented below. 82 Drainage System Legend Indicates Unit Not Requiring Controls - under40 CFR 61 Subpart FF m - Indicates Unit Requiring Controls because Benzene Concentration Exceeds 10 ppm - Indicates Unit Requiring Controls because Mass Flow Rate of Benzene Exceeds 1 Mg/yr Discharge 0.014Mgiyr Figure 10-2. Wastewater treatment system showing benzene concentratlons and flow rates: Example 2. Drainage System ........................................... /- I @ Ifi16Mglyr; 8Mgiyrl-1 Process : 10 ppmw. 5 OilMlater 5 ppmw Ulmnliltas . Separator ;- .. .......... ....................... .I 0.6 ppmw 17 0.8Mgiyr; DAF 0.5 PPmW Equalization Unit Basin X1 0.5 Mg/yr; Basin #2 0.5 Mgiyr; 0.07 Mgiyr; 0.008 Mgiyr; 0.003 ppmw Sludge Clarifier Return Sludge: 0.008Mgiyr; 0.01 ppmw Disclarge Figure 10-3. Waslewater treatment system showing benzene concentratlons and llow rates: Example 3. 83 Return Sludge 0.008 Mglyr; 0.01 ppmw 0 - Indicates Unit Not Requiring Controls under 40 CFR 61 Subpart FF e.Indicates Unit Requiring Conlrols because Benzene Concentration Exceeds 10 ppm "- Indicates Unit Requiring Controls because Benzene Mass Flow Rate Exceeds 1MgIyr - Indicates Unit Requiring Controls because Facility-Wide Uncontrolled Benzene Quantity Exceeds IMgIyl Figure 103a. Wastewater treatment system showing benzene concentrations and flow rates: Example 3; Solution A, Drainage System 0.008 Mglyr; 0.01 ppmw 0- Indicates Unit Not Requiring Controls under40 CFR 61 Subpart FF - Indicates Unit Requiring Controls because Benzene Concentration Exceeds 10 ppm "- Indicates Unit Requiring Controls because Benzene Mass Flow Rate Exceeds IMglyr - Indicates Unit Requiring Controls because Facility-Wide Uncontrolled Benzene Quantity Exceeds 1Mglyr Figure 10-3b. Wastewater treatment system showing benzene concentrations and flow rates: Example 3; Solution 6. 84 Figure 10-4. ABC Oil Retlnely wastewater treatment system-use study problem. (Annual average benzene concentration end annual benzene quantity shown for each wastewaler stream.) Table 10-1. Case Study Problem Drain Systems Possible answers for each waste management unit are: A. No controls required. 8. Controls required: Annual average benzene concentration entering the unit is 10 ppmw or more. C. Controls required: Annual benzene quantity entering the unit is 1 Mglyr or more. D. controls required: Total annual benzene (TAB) quantity first entering unwntrolled waste management unik comprising the refinerywastewater treatment system is 1 Mglyr or more. For each waste management unit shown on Figure 10-4, circle the letter or leners corresponding to all wrrecl answers for lhe unit (more than one answer may be correct for a particular unit). Waste Manegemant Unlt 1. Drain Systems 2. Sour Water Stripper 3. Oilwater Separator Answer ABCD ABCD ABCD 4. DAF Unit 5. Primary Clarifier 6. Equalization Basin ABCD ABCD ABCD The refinery drain systems combine wastewaters having annual average benzene concentrationsabove 10ppmw with wastewaters having annual average benzene concentrations below 10 ppmw. .This results in three mixed wastewater streams: a stream having an annual average benzene concen- mhon of 100 ppmw and annualbenzenequantityofsol ~ g / yr,a meam having an annual average benzene concentration of g ppmw and benzene quantity of 0.8 ~ g /an~d a~ ; stream having an annual average benzene concentration of 2 ppmw and annual benzene quantity of 1.2Mg/yr. At this point in the `One Of the management units are controlled under the rule, so the TAB quantity for the refinery wastewater treatmentsystem is 303 Mg/yr (calculation of this value is discussed below under the oil/water separator unit). Control requirements for drain systems are specified in Sec- tion 61.346of the rule. Thus, the drain systemsarerequired to use controls because the conditions specified in answers "b," "c,"and "d" are not met. Sour Water Stripper 7. Actiated Sludge Tank 8. Secondary Clarifier 9. Trickling Filter IO. Clarifier 11. Polishing Pond ABCD ABCD A ABCD ABCD For the purpose of implementing the Benzene Waste OperationsNESHAP,EPA has specified that, for a sour water stripper unit, the determination of the flow-weighted annual average benzene concentration shall be made at the exit to the unit. A "sour water stripper'' must be controlled to meet the 85 Table 10-2. Case Study Solullon Possibleanswers for each waste managementunit are A. No controls required. B. Controls required:Annual average benzeneconcentration entering the unit is 10 ppmw or more. C. Controls required: Annual benzenequantity entering the unit is 1 Mglyr or more. D. Controls required:Tola1 annual benzene (TAB) quantity first entering uncontrolledwaste management unitscomprisingthe refinerywastewater treatment system is 1 Mglyr or more. For each waste management m i l mown on lhe figure. the correct answers are circled below. Waste Management Unit Answer 1. Drain Systems 2. Sour Water Stripper A @@@ ABCD 3. OilNaler Separator 4. DAF Unit 5. Primary Clarifier 6. Equalization Basin 7. Activated Sludge Tank 8. Secondary Clarilier 9. Trickling Filter I O . Clarifier 11. Polishing Pond @B ~~ CD definition in the rule, Le., it must be "operated in such a manner that the offgases are sent to a sulfur recovery unit, processing unit, incinerator, flare, or other combustion device." Consequently,none of the listed answers are appropriainte`.cCbo,"n``tcr,o.,lsoaIr"edr,e"quired. but not because of the reasons listed OilMater Separator The annual average benzene concentration of the waste entering the oil/water separator is greater than 10ppmw (100 ppmw). The annual benzene quantity in the waste entering the unit is greater than 1Mg/yr (301 Mg/yr). Thus, neither of the two conditions required for an exemption from controls is met. At this point in the analysis for an actual facility, you would conclude that the oivwater separator requires controls because it does not meet either condition, and then move on to the next downstream unit. However, for the purpose of this case study problem, we will also determine the TAB quantity first entering the uncontrolled waste management units comprising the refinery wastewater treatment system from the inlet to the oil/water separator. The TAB quantity is calculated by summing the individual waste stream annual benzene quantities for each location where a waste stream first enters an affected uncontrolled waste management unit that is included in the facility wastewater treatment system. Assuming that Unit 3 and the remaining units (Le., Units 4 through 11) are uncontrolled, the TAB quantity is then calculated by summing the annual benzene quantity in three wastewater streams: (1) the stream flowing directly from the drain system to the oil/water separator (301 Mg/yr): (2) the stream flowing directly from the drain system to the trickling filter (0.8 Mglyr); and (3) the stream flowing directly from the drain system to the clarifier (1.2 Mg/yr). The TAB quantity is calculated to be 303 Mgyr which is well above the 1 M&r limit. Thus, the oil/water separator is required to use controls because the conditions specified in answers "c,"and "d" are not met. DAF Unit The annual average benzene concentration of the waste entering the DAF unit is equal to 10 ppmw. Remember that the rule requires the annual average benzene concentration of the waste entering the unit to be less than 10 ppmw as one of the conditions to be met for the exemption from controls. The annual benzene quantity of the waste entering the unit is greater than 1Mg/yr (23 Mg/yr). Assuming at this step in the analysis that Unit 4 and the remaining units (i.e., Units 5 through 11) are uncontrolled, the TAB quantity that would be managed in the uncontrolled waste management units is calculated to be 25 Mg/yr. Thus, the DAF unit is required to use controls because the conditions specified in answers "c," and "d" are not met. Primary Clarifier The annual average benzene concentration of the waste. entering the primary clarifier unit is less than 10 ppmw (3 ppmw). However, the annual benzene quantity of the waste entering the unit is greater than 1Mg/yr (7 Mglyr). Assuming at this step in the analysis that Unit 5 and the remaining units (i.e., Units 6 through 11) are uncontrolled, the TAB quantity that would be managed in the uncontrolled waste management units is calculated to be 9 Mg/yr. Thus, the primary clarifier is required to use controls because the conditions specified in answers "c,"and "d"are not met. Equalization Basin The equalizationbasin only receives wastewater from the primary clarifier. Consequently, the annual average benzene concentration of the waste entering the unit remains less than 10ppmw (2.5 ppmw). However, the annual benzene quantity of the waste entering the unit still is greater than 1 Mdyr (6 Mg/yr). Assuming at this step in the analysis that Unit 6 and the remaining units (is., Units 7 through 11)are uncontrolled, the TAB quantity that would be managed in the uncontrolled waste managementunits is calculatedto be 8 Mg/yr. Thus, the equalization basin is required to use controls because the conditions specified in answers "c," and "d" are not met. Activated Sludge Tank The activated sludge tank is considered to be an "enhanced biodegradation unit" in accordance with Section 61.348(b)(2)(ii)(B) of the rule. This section specifies that the annual benzene quantity managed or treated in an enhanced biodegradation unit is not included in the calculation of the TAB quantity if the enhanced biodegradation unit is the first uncontrolled unit in which the waste is managed or treated. This means that for the purpose of calculating the TAB quantity, the annual benzene quantity entering the enhanced biodegradation unit is set to 0 Mg/yr if the annual average 86 3 301 Mgyr 23 Mglyr 100 ppmw 3 10 ppmw b OIhVaMr ___) Separqor 4 DAF Unit . Relinery Processes Process Wastewater Tank Drawdown Landfill Leachate 1_' I2PPm;; Controls Required On Unit No Controls Required On Unit Must Be Controlledto Meet Rule Definition(see text) Figure 10-5. ABC Oil Reflnery wastewaler treatment s y s t e m 4 a s e study solution. I 11 Polishing -0.75 Mgyr 0.2 ppmw Discharge benzene concentration of the waste entering the unit is less than 10ppmw. For the case study problem, the annual average benzene concentration of the waste. entering the activated sludge tank is 2 ppmw. Even though the actual annual benzene quantity of the waste entering the unit is greater than 1 Mg/yr (5 Mg/yr), the TAB quantity condition that the upstream units must meet in order to he exempted from using controls is not applicable to the activated sludge tank because it is an enhanced biodegradation unit in which the annual average benzene concentration of the waste entering the unit is less than 10 ppmw. Therefore, the activated sludge unit is not required to use conhols (answer "a"). Secondary Clarifier The secondary clarifier only receives wastewater from the activated sludge tank. As discussed above, the activated sludge unit is an enhanced biodegradation unit which is exempt from having to use controls. For the purpose of calculating the TAB quantity, the annual benzene quantity entering the activated sludge tank is set to 0 Mg/yr. Consequently, it must follow that the wastewaterstream entering the secondary clarifier is also set to 0 Mg/yr. Even though the annual benzene quantity of the waste entering the secondary clarifier is equal to 1 Mg/yr, the TAB quantity condition is not applicable to this unit because all of the waste managed in the secondary clarifier is received from an uncontrolled enhanced biodegradation unit. Thus, the secondary clarifier is not required to use controls (answer "a"). Trickling Filter The trickling filter is not considered to be an "enhanced biodegradation unit" because it is a supported growth process rather than a suspended growth process, and it does not recycle biomass. Therefore, the trickling filter must meet both the benzene concentration and TAB quantity conditions to be exempt from having to use controls. The annual average benzene concentration of the waste entering the trickling filter is less than 10 ppmw (8 ppmw). Also, the annual benzene quantity of the waste entering the unit is less than 1Mg/yr (0.8 Mg/yr). Thus, whether or not the trickling filter is required to use controls depends on the TAB quantity first entering the uncontrolled waste managementunits comprisingthe refinery wastewater treatment system. The TAB quantity is calculated based on the annual benzene entering Units 9, 10, and 11 and the decision as to which o lthese units will be controlled. As discussedunder the activated sludge tank unit, Unit 7 does not require controls and, for the purpose of calculating the TAB quantity, the annual benzene quantity entering the activated sludge tank is 87 set to 0 Mg/yr. Assumingthat Units 9 and 10are uncontrolled, the TAB quantity is calculated to be 2.0 Mglyr by summing the annual benzene quantity entering the trickling filter (0.8 M&r) plus the annual benzene quantity entering the clarifier directly from the drain system (1.2 Mglyr). Assuming that Units 9 and 11 are uncontrolled, the TAB quantity is calculated to be 1.55 Mglyr by summing the annual benzene quantity entering the trickling filter (0.8 Mglyr) plus the annual benzene quantity entering the polishing pond from the clarifier (0.75 Mglyraetermination of this value is discussed under the polishing pond unit). For either assumption, the TAB quantity is calculated to be greater than 1 Mglyr. Thus, for the particular set of benzene quantities selected for the case study problem, the trickling filter is required to use controls because the condition specified in answer "d" is not met. Clarifier The annual average benzene concentration of the waste entering the clarifier is less than 10 ppmw (2 ppmw). However, the annual benzene quantity of the waste entering the unit is greater than 1 Mg/yr (1.4 Mg/yr) as a result of the mixing of the waste stream from the hickling filter with a waste stream directly from the drain systems.Knowing at this step in the analysis that Unit 7 is uncontrolled and assuming that Units 10 and 11 are uncontrolled, the TAB quantity that would be managed in uncontrolled waste managementunits is calculated to be 1.4 Mg/yr (the sum of the annual benzene quantities entering the activated sludge tank, which is set to 0 Mglyr, plus the clarifier). Thus, the clarifier is required to use controls because the conditions specified in answers "c" and "d" are not met. Polishing Pond Two wastewater streams also mixed together prior to entering the polishing pond; one stream from the secondary clarifier and one stream from the clarifier. The annual average benzene concentration of the waste entering the polishing pond is less than 10 ppmw. The annual benzene quantity in the wastewater stream from the clarifier is 0.75 Mg/yr. The annual benzene quantity in the wastewater stream from the secondary clarifier is 0.3 Mg/yr. However, for the purpose of determining compliance with !he rule, the annual benzene quantity for the wastewater stream entering the secondary clarifier is set to 0 Mdyr (refer to the discussion for the secondary clarifier unit). Consequently,it must follow that the wastewater stream exiting the secondary clarifier is also set to 0 Mg/yr. Even though the totalannual benzene quantity of the wastewater streams entering the polishing pond is actually 1.05Mglyr, the TAB quantity of the waste entering the unit is calculated to be 0.75 Mg/yr for the purpose of determining compliancewith the rule. Thus, the TAB quantityof the waste entering the polishing pond is less than 1 Mg/yr, and the unit is not required to use controls (answer "a"). 88 Chapter 11 Case Study: Process Vent Rule Applicability and Compliance Process Vent Case Study-Review of RCRA Air Emission Standard for Process Vents HazardousWaste TSDF Operations Situation The XYZ Manufacturing Company operates various manufacturing processes that generate approximately 1,OOO tons of hazardous waste per year. This qualifies the XYZ Manufacturing Company as a large quantity generator under RCRA. The facility is a RCRA TSDF operating under interim status and has an on-site wastewater treatment system with a National Pollution Discharge Elimination System W D E S ) permit. As the owner/oprator of the facility, you are required to 1) determine the applicability of the RCRA air rules for process vents (Le., 40 CFR 265, Subpart AA) to the hazardous waste management unit emission sourcesat the facility, 2) determine compliancestatus of current process vent emissions and emission controls in relation to the control requirements in 40 CFR 265, Subpart AA, 3) determine what action can be taken to comply with the regulation, if the emission reductions are required under the process vents standards. Determinations 1. Determine which process vents are subject to the require menb of Subpart AA and why. For each process vent identified in Figures 11-1 and 11-2, circle all of the following statements that are correct (Note: Some vents will have more than one applicable statement;all relevant and appropriate choices should be circled.) a. Vent is a process vent associated with one of the unit operations specified in the rule that manages a hazardous waste with an organic concentration greater than 10 ppmw and therefore is subject to the requirements of Subpart AA. b. Vent is not a process vent as defined in the rule and therefore is not subject to the requirements of Subpart AA. The operation/process associated with the vent is not one of the unit operations specif2i6e5d.1i0n3S0(ubb)p),art AA applicability (Section -or The passage of gases (i.e., vent emissions) into the atmosphere is not process-related. For example, emissions are caused by tank loading and unloading (working losses) rather than the process or unit operation. Comments a. Theprocess vent rules apply only to those waste management units or unit opemtions that are specified in the rules. Affected unit operations include: distillation, fractionation, thin-filmevaporation, solvent extraction, steam stripping and air stripping. Vents on control devices (e.g., condensers and carbon adsorbers) and on tanks serving the affected unit oprations (e.g., distillate receivers, bottoms receivers, surge control tanks, decant separator tanks, or hot wells) are also subject to the standardsif emission from the process are vented through them (e.g., uncondensed overhead vapors from a distillation operation). b. A process vent means any open-ended pipe or stack that is vented to the atmosphere either directly, through a vacuum-producing system, or through a tank or air poilution control device. Emissions (i.e., gases or fumes) must be process-related,such as evaporation produced by heating or caused by mechanical means such as a vacuumproducing system. 89 0 VentIDNo Vent p' Condenser ----.Gas Phase Liquid Phase (See Figure 11-2) To WWT (see Figure 11-2) Note: Organic Concentrationof all Streams (Unless Otherwise Noted):1,000 - 900,000ppmw Organic Concentrationof Wastewater Treatment (WWT) Plant Streams: <9 ppmw Figure 11-1. Facility XYZ case study. c. Vent is not subject to the requirements of Subpart AA because the waste managed in the unit has an organic concentration of less than 10 wmw. c. The process vent rules apply to affected units managing hazardous waste with a total organic concentration of 10 ppmw or greater on an annual average basis. Units managing wastes with an annual average of less than 10 ppmw are not subject to the rules. 90 HazardousWastewater (From Figure 11-1) Flwculation ++I Sludge Holding -Tank Plate and 1 I Filter Cake To Land Disposal Kev Aeration 9m -I I I Stripper L L------Air .. ,.TO..\ .e' NPDES *. *.pischarge,*' .-e* Vent ID No. Note:Organic Concentrationof Wastewater Treatment(WWT) Plant Streams: < 9 ppmw Q Vent Figure 11-2. Case study of Facility XYZ wastewater treatment plant (WWT) with NPDES permlt. d. Vent is not subject to the requirements of Sub- part AA because the operation/process unit associated with the vent is not subject to RCRA Subtitle C or is exempt from RCRA permitting. Vent No. Answers 1 a,b,c,d Vent No. Answers 10 a,b,c,d 2 ahcd 11 a,b,c,d 3 ahcd 12 a,bc,d 4 a,b,c,d 13 a,b,c,d 5 a,bc,d 14 a,b,c,d 6 a,b,c,d 15 a,b,c,d I a,b,c,d 16 a,b,c,d 8 a,b,c,d 17 a,b,c,d 9 a,b,c,d d. If the unit is exempt from RCRA Subtitle C, it is not subject to the requirements of Subpart AA. Examples of types of RCRA exempt units are listed below: Units such as product (not hazardous waste) distillation columns generating organic hazardous waste still bottoms are not subject to the standards while the wastes are in the product distillation column unit. Elemenmy neutralization and wastewater meatment tanks as defined by 40 CFR 260.10. Units managing Subtitle D wastes or nonhazardous wastes. Generators that accumulate hazardous waste in tanks and containers for 90 days or less. 91 2. Calculate the total facility process vent emission rate W). case 1: Total facility ER is equal to the sum of the emission rates for all individual process vents located at the facility that are subject to the requirements of Subpart AA. n Case 2 3. Based on the total facility process vent emission rate (ER) calculated above (from summing appropriate individual quantities given in Table 11-1). identify which course of action, from among those listed below, is appropriate: After identifying all affected process vents, you must determine whether the total facility affected process vent emission rate is below the emission rate limits (see operating data under #2 and compliance criteria given below.) a No emission reduction required. b. Reduce emissions from each individual process vent by 95%. c. Reduce total facility process vent emissions by 95%. d. Control one or more vents to get below the emission rate limits. e. Reduce operating hours to get below the emis- sion rate limits. Recommended Control Action Case 1: Case 2 If the total facility process vent emission rate for hourly or yearly emissions exceeds the limits in the regulation, action must be taken to reduce emissions helow the limits. If the emission rate limits cannot be attained, total facility process vent emissions must be reduced, by 95%or more through use of a control device. Emlssion Rate Limits (Compliance Criteria) Total facility process vent emission rate must be below the following emission rate limits: Short Term - 4 . 4 kg/h (3 Ibh) AND Long Term - < 2.8 Mdyr (3.1 short tons/yr) Table 11-1. ProcessVent Emission Rete (ER) and Operating Hour (OH) Data Case 1: Vent Id # 1 ER(1bhr) 9.3 OH(hr/yr) 4160 ER(ton/yr)19.3 2 6.1 4160 12.7 3 0.07 8760 0.31 4 0.49 2000 0.49 5 0.16 8760 0.7 6 1.0 2000 1.0 7 0.20 8760 0.88 8 0.12 2000 0.12 9 1.2 2000 1.2 10 0.13 8760 0.57 11 0.06 2000 0.06 12 6.1 4160 12.7 13 8.9 2000 8.9 14 1.2 2000 1.2 15 0.13 2000 0.13 16 0.84 4160 1.7 17 1.5 2000 1.5 Case 2: Vent I d # 1 ER(Ibhr) 8.1 OH(hr/yr) 4160 ER(ton/yr)16.8 2 5.2 4160 10.8 3 0.11 8760 0.48 4 1.0 4000 2.0 5 0.18 8760 0.79 6 0.8 4000 1.5 7 0.08 8760 0.35 8 0.11 2000 0.11 9 1.0 2000 1.0 10 0.15 8760 0.66 11 0.05 2000 0.05 12 4.5 4160 9.3 13 9.0 2000 9.0 14 1.1 2000 1.1 15 0.15 2000 0.15 16 1.7 4160 3.5 17 2.2 2000 2.2 A solution to the case study on RCRA air emission standards for process vents is presented in Table 11-2, and a discussion follows. 92 Table 11-2. Review of RCRA Air Emlsslon Standard tor Process Vents from Hazardous Waste TSDF Operatlons--Cese Study Solution 1 Vent Answer 14 2-b 3-b 44 5-b 6-3 7-b,d &a 94 10-b 11-b 12-b.d 13-b.d 1&,d l&b,d 1k.d 17-b.c,d 2 Case 1 n ER Hourly= i=1 n ER Annual = E%, i=1 case 2: n =049+ 1 0 + 0 12 + 1 2 = a 4 9 + 1 0 + 0 12 + 1 2 = i=1 n ER Annual = E%", = 2 0 + 1 5 + 0 11 + 1 0 = i=1 generating an organic hazardous waste, the still bottoms. However, under 40 CFR 261.4(c), a hazardous waste that is generated in a manufacturing process unit is not subject to regulation under Parts 262 through 265, 268, 270, 271, and 124until it exits the unit in which it was generated, unless the hazardous waste remains in the unit more than 90 days after the unit ceases to be operated for manufacturing. Therefore, because the unit is not subject to RCRA permitting, the vent on this unit is not subject to the Subpart AA process vent rules. Vent No. 2 6. The vent on this decanter tank is not subject to the Subpart AA rules because the vent is not a process vent associated with one of the affected unit operations, i.e., distillation, fractionation, thin-film evaporation, solvent extraction, or air or steam stripping. Vent No. 3: 6. The vent on this surge tank is not covered by the Subpart AA. Although this tank is associatedwith (or a part of) one of the affected unit operations, the vent on this tank does not meet the definition of a process vent as specified in the rule. This is because the emissions from the tank are not process-related. Emissions from one of the affected unit operationsare not vented through this tank; emissionsare working and breathing losses. 3 Case 1 Total Hourly Faulity Emission = 281 lbshr Total Hourly Facility Emission Cutoff= 3 Ibsthr 2 81 < 3: Total Hourly Faulity Emission b l o w cutoff Total Annual Facility Emission = 2 81 tonslhr Total Annual Faulity Emission Cutoff = 3 1 short tonlyr 2 81 c 3 1, Total Annual Faulity Emission below cutoff Vent No. 4: a.This vent is subject to Subpart AA. The vent on this distillate receiver is a process vent associated with a distillation column, one of the affected unit operations. Overhead gases from the distillation column are sent to a condenser;the condensedorganic (liquid) and the uncondensed vapors 90 to the distillate receiver where the uncondensed gases are vented to the atmosphere. The emissions from this vent are related directly to the distillation operation. Case 2 Total Hourly Facility Emission = 2.91 Ibsihr Total Hourly Facility Emission Cutoff= 3 lbslhr 2 91 c 3, Total Hourly Facility Emission below cutoff Total Annual Facility Emission = 4 61 tonslyr Total Annual Facility Emission Cutoff I 3 1 short tonlyr 4 61 D 3 1, Total Annual Facility Emission above cutoff Vent No. 5: 6. The vent on this storage tank, which holds the hazardous waste after a portion of the waste has been extracted, is not covered by the Subpart AA rules. Although this tank is associated with (or a part of) one of the affected unit operations, the vent on this tank does not meet the definitionof a process vent as contained in the rule. Emissions from the tank are not process-related. As shown in Figure 11- 1, the solvent extraction operation is basically a liquid-liquid extraction operation: no gases or vapors are generated nor is any heat applied to the waste stream as is the case in distillation. Emissions from the tank are not process-related but are working and breathing losses. If the hazardous waste stream was heated in the process unit to enhance extraction and the heated waste was stored in this tank at a temperature greater than ambient, the argument could be made that the emissions from the tank were indeed process-related. Therefore, the vent, in the case where heat is applied, would be a process vent associated with an affected unit operation and come under the authority of Subpart AA. Discussion of Solutionsto the Process Vent Rule (Subpart An) Case Study Applicability Determinations Vent No. 1: d. This is a production unit, i.e., distillation unit, that is part of the manufacturing operations. This unit is Vent No. 6 a. This vent is subject to Subpart AA The exhaust gases from the vacuum pump serving the batch still are considered a process vent associated with a distillation unit, one of the affected unit operations.Overhead gases from the batch stillpass through the condenser: the pumpdrawing a vacuum on the condenserand distillate receiver is exhausting uncondensed gases from the distillation operation to the aimosphere. The emissionsfrom this vent are related directly to the distillation operation. 93 Vent No. 7 b,.d. The vent on this storage tank,which holds the liquid distillate recovered from the batch still operation, is not subject to Subpart AA. The vent on this tank does not meet the definition of a process vent as specified in the rule; emissions from this vent are not process-related. In addition, under 40 CFR 261.3 (c)(Z)(i), the definition of hazardous waste, materials that are reclaimed from solid waste and that are used beneficially, are not solid wastes and hence are not hazardous wastes unless the reclaimed material is burned for energyrecovery or used in a manner constituting disposal. In this example, the distillate reclaimed in the distillation operation is returned to or reused in the manufacturing operation; therefore, the material stored in this tank is no longer a hazardous waste, and as a result the tank is not subject to regulation under RCRA Subtitle C. Vent No. 8: a This vent is subject to Subpart AA. The exhaust gases from the carbon adsorber serving the condenser on the thin-film evaporator (TFE) are considered a process vent associated with the TFE,one of the specified unit operations. Overhead gases from the TFE pass through the condenser; a portion of the uncondensed gases are duected to the carbon adsorber which emits any unadsorbed gases to the atmosphere. Emission from the control device are directly related to the TFE operations. Vent No. 9: a This vent is subject to Subpart AA. The vent on this distillate receiver is a process vent associatedwith the thin-film evaporator (TFE), one of the unit operations affected by the process vent rules. Overhead gases from the TFE are sent to a condenser; the condensed distillate (liquid) and a portion of the uncondensed vapors from the TFE go to the distillate receiver where the uncondensed gases arevented to the atmosphere. The emission from this vent are related directly to the TFE operation. Vent No. 1 0 b. The vent on this storage tank, which holds the liquid distillate recovered from the thin-film evaporator, is not subject to Subpart AA. The vent does not meet the definition of a p m e s s vent as specified in the rules; emissions from the vent are not process-related.The losses from the tank would be working and breathing losses. RCRA Subtitle C hazardous waste management standards provided the unit is pan of a wastewatertreatment facilitythat is subject to regulation under either Section 402 or Section 307@) of the Clean Water Act. Accordingly, any hazardous waste tank system that is used to store or treat wastewater that is managed at an on-site wastewater treatment facility with a National Pollution Discharge Elimination System (NF'DES) permit or that discharges to a Publicly Owned Treatment Works (F'OTW is exempt from the RCRA regulations. In this example, the facility has an "DES wastewater permit as indicated on Figure 11-2. The clarifier unit is a tank treating wastewater (i.e., the aqueous layer from the decanter) that is managed on-site; thereforethis tank is exemptfrom theRCRA regulations. Vent No. 13: b,d. The vent on the enclosed plate and frame filter press is not subject to Subpart AA. This unit does not involve one of the unit operations specified in the rule. Also, the filter press which meets the RCRA definition of a tank can be considered a RCRA exempt wastewater treatment tank (See Vent No. 12.) Vent No. 14: c, d. This vent is not subject to Subpart AA. Although the vent on the decanter is a process vent associated with one of the specified unit operations (i.e., a steam stripper), the organic concentration of the waste managed in the unit is less than the applicability criteria of 10 ppmw on an annual averagebasis. In addition, the steam strippingcolumn, which meets the RCRA definition of a tank, can be considered a RCRA exempt wastewater treatment tank (See Vent No. 12.) Vent No. 15: b,.d. The vent on this storage tank is not covered by Subpart AA because the vent is not a process vent associated with one of the affected unit operations. In addition, under 40CFR 262.34 generatorsthat accumulatehazardous wastes in tanks for 90 days or less are not subject to RCRA permitting requirementsfor these tanks, provided they comply with the'provisions of 40 CFR 262.34. As noted Figure 11-1, this is considered a generator's 90-day accumulation tank and therefore is exempt from the RCRA rules. (Note: EPA intends to modify this exemption at a later date.) Vent No. 11: b. The vent or exhaust gas from the boiler used to burn the hazardouswaste is not subject to SubpartAA, the process vent rules. This boiler is not one of the unit operations specified in the rule, Le., distillation, fractionation, thin-film evaporation, solvent extraction. and air and steam stripping. Also, the boiler is not being used as a control device to reduce emissions from an affected process vent. The boiler, however, would likely be subject to other RCRA regulation such as the recently promulgated final rule regulating the buming of hazardous waste in boilers and industrial fumaces (56 FR 7134, February 21,1991). Vent No. 1 2 b,.d. The vent on the clarifier unit is not subject to Subpart AA. This unit (i.e., a tank) is not one of the unit operations specified in the rule; nor are emissionsfrom an affected process unit vented through this tank &e., the clarifier). In addition, under 40 CFR 264.1(g)(6), 265.1(~)(10)a, nd 270.l(c)(2)(v) wastewater treatment units are not subject to Vent No. 16: c,d. The vent on this air stripper is not subject to the RCRA process vent rules. Although the vent (or air stripper exhaust) is a process vent associated with one of the specified unit operations, the organic concentration of the waste managed in the unit is less than the applicabilitycriteria of 10ppmw on an annual averagebasis, as noted in Figure 112. In addition, the air stripping column, which meets the RCRA definition of a tank, can be considered a RCRA exempt wastewater treatment tank (See Vent No. 12.) Vent No. 17: b.c.d. The vent on the enclosed plate and frame filter press is not subject to Subpart AA. This unit does not involve one of the unit operations specified in the rules. Also, the organic concentration of the waste managed in the unit is less than the applicability criteria of 10 ppmw. In addition, the filter press, which is a tank under RCRA, can be considered a RCRA exempt wastewater treatment tank (See Vent No. 12.) 94 Chapter 12 Case Study: Equipment Leaks Testing-EPA Method 21 As indicated in Table 12-1, this chapter is organized into four areas. First the Method 21 requirements are describcd, both for the instruments that are used for leak detection and for the person operating the instrument. The second segment of the chapter describes the various types of instrumcnts that can be used for leak detection and how they operate. Includcd are highlights of an 1I-minute training videotape describing preuse checks to be performed on the instrumentsbefore they are taken into the field, a discussion of instrument calibration and how response factors are used to select the correct instru- ment for particular monitoring situations.The third part of the chapter discusses field monitoring problems. This includes highlightsfrom a videotape lesson that describes some typical problems related to field monitoring work, e.g., how to orient the sampling probe and what happens if it is not done correctly. The fourth and last segment comparcs instrumcntsthat can be used for this type of work. Table 12-1. Overview Method 21 Instruments and their operation Field monitoring concerns Coml)arison of available instruments Method 21 Requirements As directed by Subpart BB, Method 21 is used only to determinewhcthcr or not equipment subject to the rules leaks. Method 21 is not used for quantification of the emissions in terms of pounds per hour or grams per second. Measurements of concentrations are made, and if they exceed the leak definition, that equipment is determined lo hc leaking and must be repaired. The method was promulgated in Appendix A of Part 60 of the Code of Federal Regulalions and most recently revised on June 22, 1990 (see Appendix A to this chapter for revised method). The method specifications require that the instruments used for leak detection be capable of responding to spccific organic compounds. That is, compounds likely to be prcscnt in the facility to be tested must he known in ordcr to sclcct an instrument capable of responding to them. The method also requires that the scale on the instrumcnt be readable to 2-1/2 percent of the leak concentration defini- tion. For Subpart BB, that leak concentration definition is 10.000 ppm. That means the scale must he readable to the nearest 500ppm (+250 ppm). The sample gas flow rate for the instruments used must he in the range of 0.1 to 3 L/min. The revision in June 1990 reduccd the minimum flow from 0.5 Lpm to 0.1 Lpm toallow somephotoionization type analyzers that did not previously meet the criteria to qualify. The instruments that are used have to be rated intrinsically safe. Intrinsically safe means that they can be used in an explosiveenvironment without riskof setting off an explosion that will destroy the instrument and the user. To usc an instrument in a specific monitoring situation, the response factor of that instrument for the compounds that may be leaking has to be less than IO. Response factors will be discusscd in more dctail later in this section. The response time of the instruments must he less than 30 seconds. This is important because thc facilities in which leaks are monitored often contain hundreds of valves. The method requires hat the sampling probcs be kept in the vicinity of a potentially leaking source for up to twice the response time of the instrument in order to determine if a leak is present. If you have an instrumcnt that rcsponds in 30 seconds instead of one that responds in 5 scconds, that may significantly prolong the inspection work that you are doing. The calibration precision, Le., the repeatability of the mcasurcments. must he equal to or less than 10percent of the calibration gas concentration.Calibrationgas concentration is the leak definition concentration (10,000 ppm) so the precision of the instrument has to be repeatable within 1,000ppm. The calibration precision of the instrument, i.e., the repeatability of the measurements, has to he checked at least once evcry 3 months. Response factors are needed for each compound that may he prcscnt in a leak. Response times for the instrumentsmust he checked when you purchase the instrument and then any timc that modifications that could affect sample flow are made to thc instrument. For instance, changing the sampling probc by making it longer may change response time. Adding a glass wool plug at the end of the prohe to keep particulate mattcr out of the sampling probe may also affect sample flow ratc. Whcn such changes are made, the sample flow rate must 95 be rechecked and response time to make sure they comply Figure 12-2 is a photograph of the front of one type of with the ranges specified by the method. flame-ionizationanalyzer. Instruments and Their Operation The second type of instrument that could be used is a Instrument Descriptions photoionization analyzer. In this instrument, the organic vapors that are drawn into the sampling probe are exposed to a Instruments generally used for this type of work and pre- source of ultraviolet light. That ultraviolet light causes the use checks and calibrations arediscussed in this segment.The .organic compounds present in the sample gas mixture to definition of response factor is presented and a numbcr of ionizc. When those ions are formed, they generate a current examples are given to show how response factors are uscd to that is amplified and produces a meter reading proportionalto select the correcl type of instrument. thc organic vapor concentration. Different organic compounds Four types of portable organic analyzers can be used for this work Flame-ionization, catalytic combustion, photoionization, and infrared. Although infrared devices can be used, they arena typically used in this work. ionizc at diffcrcnt voltages. Lamps purchased for use in the photoionization analyzers are available in several voltages. The lamp voltage should be selected on the basis of the compounds anticipated to be present. For example, this type of analyzcr does not respond to hexane or methane and A flow schematic of one type of flame-ionization analyzer is shown in Figure 12-1. The sample gas is drawn in through the sampling probe where particle filter prevents contamination of the sampling probe and intemal plumbing with particulates. The sample passcs through a flow indicator into the detector chamber. Hydrogen comes from an internal pararfinic type organic compounds at the lamp voltages typically available. It does respond very well to oxygenated or halogcnatcd compounds such as ketones, aldehydes, or chlori- nated solvcnts, but certain of these compounds ionize more rcadily than others. Thus, in some situations this instrument is bcttcr than othcrs for detccting organic vapor emissions. fuel tank, passing through some pressure regulators, and mixes with the sample gas stream, and the mixture is com- busted in the detector chamber. On each side of the detector chamber are sintered metal flamearrestors that are part of the inhinsically safedesign of the instrument.They prevent flame in the combustion chamber from escaping and igniting an explosion in an area where an explosive gas mixture may be Appcndix B of the attachment to this session includes a table that has response factors; the table also lists ionization potentials for some organic compounds. This table can be used to dcterminc what voltage ultraviolet light to select. In addition, the instrument manufacturer should have further information on which to base a selection. present. The lamp inside the analyzer and the window on the surfacc of that lamp that needs to be cleaned after it has been The combustion reaction in the detection chamber pro- exposcd to organic compoundsfor a period of time are shown duces positive ions. The ion current is amplificd to gct a mctcr in Figurc 12-3. Dcposils will build up on the window which reading that is proportional to the organic conccntration in Lhc sample gas stream. Sintered Hz supply L~~ HPrZesssuuprpelyIndicatorValve Pressure Regulator High Pressure Regulator Exhaust Capillary Restrictor +I Sample I Pump I i I I I Filter I Line I I Fitting Sample Indicator Hz Tank Pressure Indicator K iHydrogen Fuel Tank Refill Valve Filter and Flow Restrictor I Sample I In II I Pick-UD Fixture I I Figure 12-1. Flow schematic of one type of flame-ionization analyzer. 96 The third type, the catalytic combustion analyzer (Figure 12-5). is similar to the flame-ionization type detector in that the sample gas drawn into the instrument is combusted (oxidized) by a heated catalyst wire inside the instrument that promotes the combustion reaction. When combustion takes place, the resistance of the catalyst-coated wire changes, and the rcsistance change is detected in the metering circuit. That change in resistance is proportional to the concentration of the organic materials that are present in the sample gas stream. One difference between the catalytic combustion analyzer and the flame-ionization analyzer is that no hydrogen gas is supplicd or required. The combustion reaction is pro- moted through the presence of oxygen that is drawn with the sample gas stream. No hydrogen tank is inside this device as shown in Figure 12-5. This box is somewhat more compact than the flameionization type device. Figure 12-2. Photograph of the front of one type of flameionization analyzer. will have to be cleaned to maintain the instrument's sensitivity. It can be cleancd with the lamp in place. This instrument is somewhat morc compact than the flame-ionization type analyzer. In this particular case, the photoionization lamp is located in the box that contains the meter. Another design is shown in Figure 12-4 in which the photoionization lamp is located on the end of an umbilical cord. In this case, the lamp is outside the box that contains the meter. Daily Use Prechecks This section describes some of the steps that should be taken bcfore the instrument is brought into the field. The precheck list shown here is specifically for a flame-ionization detector; the list may vary for other types of instruments. Prechecks require only a modest amount of time. Time invested in conducting a precheck is well spent, since work should not he attempted if the instrument is not functioning properly or if it will fail soon after you begin. The following instrument prechecks are recommended as a means of ensur- ing adequate instrument performance during leak surveys: Hydrogen Supply Confirmsufficient hydrogen ispresent to fuel instrument. (Note: Insufficient hydrogen pressure can result in erro- -ncous readings.) Read prcssure gauge Flgure 12-3. Lamp inside analyzer and window on surlace of lamp. 97 Flgure 12-4. Photolonlzatlon lamp on the end of an umbilical cord. Battery Confirm battery is adequately charged. (Note: Failure to adequately charge battery could lead to a deep discharge necessilating installation of new batteries.) * Disconnect battery from external charger and connect instrument gauge to instrument. Watch for proper gauge response. Take a spare fully charged battery to the inspection site. Flame Arrestor Confirm the presence of the flame arrestors before each use to prevent hydrogen flame exposure to outside air. (Note: Precheck is critical in preventing potential explosive conditions.) Visually verify flame arrestors are in the proper location. Amplifier Confirm amplifier electronic linearity. (Note: Lack of amplifier electroniclinearity will result in erroneousreadings.) +I. S. (Intrinsically Safe) Battery Pack 0023-7354 Vibration her 0002-0054 eaction Chamber Flgure 12-5. Catalytic combustion analyzer. 98 Turn on amplifier system allowing 10-minute warmup. If linearity is adcquate, move the calibration knob to yield a reading of 10.000 ppm with high calibration scale and 10 ppm with the low switch. If linearity is not adequate, adjust internal calibration. rcadily. If neccssary, the calibration knob is adjusted to give the calibration gas concentration. Instrument Recordkccping of instrument's response time. Prefilter and Probe Check prefilter and probe for contamination.(Note: Contamination of probe or prefilter could affect instrument performance.) Visually examine the probe for deposits of material on the filter or organic deposit of moisture on the probe. Probe and Sample Gas Handling System Confirm that no leaks are in the sample gas handling system. (Note: Leaks could bias the insuumcnt's response low and even reduce the unit's capability to draw fugitive gas into the probe.) Turn pump on and briefly block the sample gas line at various locations and listen for starved pump sound. If not heard, air leak must be found and eliminated. Sample Flow Rate Measure the sample gas flow rate into the probe and conduct a lcak check to confirm no infillration at the lop of the rotameter. (Note: Leak could bias flow readings low.) * Attach a calibratcd rotameter or a soap bubble flowmeter to the probe and record flow rate in a bound notebook. - . .Samole Valve to Gas Chromatoaraoh (GC,) Colimn or Scrubbina Column ~ ~ ~~ Confirm closure of valves that direct sample gas to GC column or activated charcoal scrubbing column that are not used in fugitive emissions testing. (Note: Opening these valves will cause the VOC readings to suddcnly decrease to negligible levcls.) * Visually check valve buttons u) verify they are not depressed. Instrument Method 21 requires daily calibration of the instrument. (Note: The readings after calibration are only a gcncral indication of the lcak concentration unless you have calibrated with the prccise gas or gas mixture being detected.) Calibration should be done with instrumcnt under a hood using either a gas cylindcr standard or a volatilized liquid mixture. Fill a 5-litcr Tedlarbag with calibration gas, then disconnect bag from the regulator and connect to the instrument probe. Due to short response time of mi&, gauge should deflect within scvcral sccondsand quickly reach the anticipated concentration At least quarterly, observe and record the response time of the instrument. The procedure mentioncd directly above in calibrating should be repeated at least three times and the time rcquired to reach 90 percent of the calibration concentration recorded in a bound notebook. The Subpart BB rules require that calibration be done either with 10.000 ppm of methane in air or normal hexane in air. Although not required by the method, calibration should be done at 500 ppm, which for some of the equipment is the conccntration lcvcl below which no detectable emissions are dcmonstratcd (thc readings must be less than 500 ppm above background). Flame-ionization detectors and catalytic combustion analyzers should be calibrated with methane or hexane in air. Thc photoionization analyzers do not respond well to paraffinic type compounds, but, specifically, photoionization analyzers cannot be calibrated with methane and hexane; thcy must be calibrated with some other gas. Photoionization analyzers are often calibrated with butadiene or benzene or some othcr compound that may be present in the mixtures for which leak monitoring would be attempted. If a photoionization analyzer is selected, a conversion factormust be dcvcloped to show the relationshipbetween the calibration of that instrument with whatever compound is sclcctcd for the calibration and the readings that would be obtained if it wcre calibrated with methane and hexane. Photoionization analyzers generally will not read beyond the 1,000-to 2,000-ppm range of organic concentration.So, if a photoionization analyzer is selected for a leak detection survcy, a dilution probe or some means must be used of supplying a known amount of air to mix with the sample gas strcam whcn it is drawn into the instrument. That dilution probc will rcduce theconcentration into the measurablerange. By knowing thc dilution ratio for that probe and instrument, the truc reading may be dctcrmined. Response Factors Response factors in Method 21 are defined as the actual conccntration of a known gas sample divided by the meter reading that is produced for that known gas sample on the instrumcnt aftcr thc instrument has been calibrated with the sclcctcd calibration gas. Thc next several tables show how to use rcsponse factors to hclp choose the instrumcnt to be used in a specific leak monitoring situation. The first example (Table 12-2) is a catalyticcombustion analyzer exposed to a known concentration of 10,000 ppm of mcthanol vapors that have been made up as a standard. After this instrument has been calibrated with incthanc or hexane, a meter reading of 5,000 ppm is produccd when the instrument is exposed to the 10,000-ppm concentration of methanol.So actual concentration dividedby mctcr rcading givcs a rcsponse factoroC2. Method 21 requires 99 Table 12-2. Catalytlc Combustlon Analyzer Exposed to 10.000 ppm Methanol Vapors Instrument + Organic vapor -----, *Actual concentration Meter reading Reswnse factor + + Catalytic wmbustion Methonal 10,WO ppm 5,000ppm 2 Table 12-5. -Response Factors at Varlous Concentratlons, Example 1 Instrument Catalytic wmbustion Organic vapor + Methonal Actual concentration + Response factors (ppm) that the response factor for the compounds for which you are altempting to find leaks be less than 10. Thus, this instrument would be acceptable for finding methanol leaks. The second example (Table 12-3) is a flame-ionization analyzer used to detect orthochlorotoluene vapors made up in an actual concentration of 3,000 ppm. The meter, after the instrument has been calibrated with methane or hexane, produced a reading of 6,000. Actual concentration divided by meter reading is 0.5, obviously well below 10. This instru- ment is sensitiveto orthochlorotoluenevapors, more sensitive to them than it is to methane. It is actually giving a higher reading than the true concentration. -Table 12-3. Flame-Ionization Analyzer Used to Detect OrthochlorotolueneVapors Instrument 4 Flame ionization Organic vapor 0-Chlorotoluene Actual wncentration + 3,028 ppm Meter reading Response factor d + 6,056 ppm 0.5 instrument would be acceptable to measure concentrationsof laking vapors of methanol. In Table 12-6, orthochlorotoluene standards in the concentration range of 200 to 3,100 ppm were made. The response factors decrease slightly with increasing concentration. Two points are illustrated with this example; one is that the response factors vary with concentration. The second is that situations may exist in which obtaining a mixture of a particular compound at l0,oOO ppm is not possible. The mixture may be made up in concentration levels that can be achievcd in the laboratory, over a concentration range, and then a statistical method may be used to project what the response factor would be at 10,000ppm. Table 12-6. Response Factors at Various Concentrations, Example 2 In the third example, Table 12-4,a catalytic combustion analyzer is being used for detection of tetrachloroethane vapors that are present in an actual concentration of 6,000 ppm. The instrument reading of 430 shows the instrument is not very sensitive to tetrachloroethane.The response factor is 14, so the instrument would not be acceptable for monitoring leaks of tetrachloroethane. Instrument -----, organic vapor d ActualwncentratlOn + (ppm) Flame ionization 0-Chlorotoluene Response factors Table 12-4. CatalyticCombustion Analyzer Used to Detect Tetrachloroethane Vapors Instrument <Organic vapor -Actual concentration Meter reading -- Response factor L + Catalytic wmbustion I ,1,2~~-TetrachlorOethane 5,980 ppm 427ppm 14 In the next examole. Table 12-7. the catalvticcombustion analyzcr with tetrachiorckthanevapors is in &econcentration range of 210 to 1,453 ppm. The response factors at 210 and 572PPm are around 8. Above 1,000 ihe response factors have incrcased to 11. So at 10,OOO ppm, you would project from this information that it would not be an acceptable insmment to use for detecting tetrachloroethaneleaks. The next three examples show that response factors can +-vary with organic vapor concentration, so the response factor determinations must be made at the leak derinition level. Table 12-7. Response Factors at Various Concentratlons, Example 3 lnsuument Catalytic combustion Organic vapor 1.I.2,2-Tetrachioroethane In the example shown in Table 12-5, methanol standards were made up over a concentration range of 50 to 20,000ppm, and the response factors determined varied between 1.3 and 2.5. Some scatter exists, but the response is increased with Actual concentration d (ppm) 1453 p lResponse factors 11.0 increasing concentration. All of these data show that the 1453 11.0 .~ 100 Published response factor tables that are in Appendix B give response factors at 1O.OOO ppm. A set of tables gives response factors at 500 ppm as well. The calibration gas selected,whether it is methane or hexane, may affect the value of the response factor for a particular compound. shows that extreme reading differences could occur between two supposedly identical units. A reason may exist for this difference; for example, in this catalytic combustion unit, the catalyst coated wire was damaged from exposure to high organic vapor concentrations. Response factors are used only to select the correct type of instrument for a particular monitoring situation. Response factors are not used to adjust meter readings obtained during leak tests. Once the instrument selection is made, the readings are taken exactly as they Off the Illeter' Only lime the meter readings would have to be adjusted is be when the calibration gas used is different from the ones indicated by the rules. The method allows use of the published response factors as a basis for demonstrating that the instrument selected is acceptable. One problem with using published response fac- tors is that data are not available for all organic compounds. Only about 300 for which data are available to the public actually havebeen tested. So, if working with compounds that are not on the list of 300, response factors must he determined experimentally. Another reason for the experimental determi- nations is that variations exist between instruments of the same twe. In the next example a flame ionization analyzer is being ;led to detect cyclohexanol vapors in the range bf 200 to 1,200 ppm. Some slight differences in response factors between the two units are evident. The trend would indicate that at l0,oOO ppm the response factors would be less than IO --(Tahle 12-8). Table 12-8. Instrument Varlatlons. Example A Instrument Organic vapor Flame ionization Cyclohexanol Actual concentration Response factors (Ppm) Unit #1 Unit #2 Field Monitoring Problems Thissegment of the chapteris related actual field use of the instrument, I,, conducting field several problems need to me consideredin order to identify leaks reliably. Such problems in field monitoring procedures, including limited (voc)quantities, and volatileorganiccompound conditions, are discussed be- low. Limited Capture Bcfore discussing problems in field monitoring procedures as they relate to capture, the differences between gas flow undcr positive pressure versus gas flow under negative pressure must be understood. The portable VOC analyzer works undcr negative pressure. Because of its negative pressure characteristics, the sample gas capture and distance of effectiveness is nearly zero, several diameters away from the urobe entrance. Leaks leaving the leaking eauimnent are under positive pressure. The ch&acteristic eifeck of the positive pressure result in limited dispersion and gradual deceleration causing the leak to persist out as a narrow jet. Because of the effects of negative and positive pressure mentioned above, limited capture is related to instrument sample gas flow rates and probe orientation to the VOC "plume." Limited capture can result in nondetection of some leaks. Instruments with low gas sampling rates are especially sensitive to the capture problems. For this reason. leaks are -easy to miss unless the following steps are taken: Locate the probe fairly close to the leak itself. * Orient the probe so that the positive pressure characteris- tics of the leak benefit the capture (injects material into the probe and does not act as a cross draft which would make capture poor). In the next example (Table 12-9).two catalytic combus- tion instruments, supposedly identical, were used to detect concentrations of meta-xylene over the range of 200 to 7,000 -ppm. One unit gives response factors in the range of 1.5 to 2; the other unit gives readings in the range of 3.5 to 37.9. This Tabla 12-9. Instrument Varlatlons, Example 5 Instrument Catalytic ambustion Organic vapor Meta-xylene Actual concentration d Response faclors (ppm) Unit #I Unit #2 Extreme VOC Quantity Extreme VOC quantity problems can result because the instrumcnt is too good at capture, thus taking in a high conccntration of VOC material. In the case of a flame ioniza- tion detector (FID), the unit may not operate properly because the dctcctor flame may go out due to lack of adequate oxygen to support combustion, or condensation may occur of nonvolatile componcnts in sample line, flame arrestor leading to the mixer burner, or exhaust flame arrestor. Photoionization detectors, however, present a somewhat different problem. Flemc-out is not the problem under consideration, but rather deposits of some of the nonvolatile compounds on the lamp surface. This can result in loss of instrument sensitivity and inability to read anything even though the probe may be sitting in a high concentration leak. For these reasons, emphasis must be placed not only on getting closc to (heleak and proper orientation,but alsoon not staying near the leak for very long. As soon as a leak is indimled, the instrument should be withdrawn. The instru- 101 men1 should not be at a high concentration for a very long time. A mistake of this nature will shut the instrument down for a day and will necessitate a thorough cleaning, which could take hours. For best results, the instrumentprobe should be moved as slowly as possible around the potential leaking area due to the limited capture problems that can make leaks disappear. However, because of the potential for extrcme VOC quantities, the probe should be withdrawn immediately if a high concentration is found. Table 12-10. Health and Safety Considerations inhalation hazards Keep portable organic analyzer on at all times to indicate localized areas where pollutantshave accumulated Use relatively long probe so user does not have to be exposed to leak plume Electrical and explosion hazards Adverse Weather In addition to procedures that minimize problems because of limited capture and extreme VOC intake, instrument problems that can be created by adverse weather conditions must be considered. Portable VOC analyzers should not be used in the rain. Droplets inadvertently drawn into the probe can cause minor damage to the various types of scnsors (e&, flame ionization units-watcr can partially plug flamc arrcstors; photoionization detectorsdroplcts can coat the optical surfaces). Even after the rain is over, some care is necessary in checking for leaks. Taking in water from small pools can damage the instrument. Exercise caution when downwind of small steam vents or other sources of moisture. A sudden change in wind direction can cause intake of fine droplets and damage. Use only instruments rated intrinsicallysafe for Class 1, Division 1, and Class 2, Division 1 conditions Use only instrumentrecorderswhich satisfy the above requirements Do not touch rotatingshafts with metallic probes or other parts Do not use cigarette lightersto check instrumentresponse Burn hazards Avoid hot surfaces adjacent to equipment being screened Walking and climbing hazards Avoid exposed rotating equipment Avoid equipment more than 2 meters above secure pialformsor surfaces Climb ladders properly Safety Follow plant safcty procedures. Avoid hot surraces,rotating equipment, and valves that may be reached only by standing on a fixcd caged ladder. Do not use portable ladders and avoid valves in high locations unless a safe and convenient access exists. In addition, only those portable analyzers and equipment that have been rated as intrinsically safe should be taken into these areas. , In conclusion, several problems may be encountered in field monitoring procedures that cause or prevent the adequate determination of leaks including limited capture, cxlremc VOC quantities, and weather conditions. To minimize thcse problems, locate the probe close to equipment bccause of capture limitations,vary probe oricntation to find Icaks, withdraw the probe if the gauge suddenly spikes above the action level, avoid any droplet intake into equipment duc to rain or spray, and work safely during the fugitive VOC scrcening. Health and safety considerations during field monitoring are shown in Table 12-10. These precautions should be observed in addition to following general plant safety guidelines. Comparison of Available instruments With respect to Method 21 requircmcnts, thc major comparison point to consider is whethcr the response factor is acceptable for a particular instrument applied to detecting a particular compound. Perhaps a choice exists of two or three different types of devices for a particular monitoringsituation. After determining that response factors are within acceptable ranges for more than one type of instrument,go on to the next set of criteria. Ease of Use The casc of use points are response time, configuration, calibration, and reliability. The method allows you to use instrumcnts with response times up to 30 seconds, but if you have a large facility with many sources, you should look for an instrument that has shorter response times. Otherwise, much time can be spent around the pumps and valves that are not leaking because the method requires continuing to search for a lcak up to twice the length of the response time for the insuumcnt. With rcspect to configuration, placement of the meter in rclation to the sampling probe is important. This point is discusscd morc in a lakr section. Instrument Costs Most people tend to focus on the purchase price of the instrumcnt initially, but factorsalsoexist that affect the cost of the instrument over its operating life. For instance, ultraviolet light replacement in the case of the photoionization analyzer is an important operating cost. In the flame-ionization detector case, the hydrogen supply must be replaced. A hydrogen tank must bc available to recharge the instrument tank (Table 12-11). Comparison Summary Available instrument types are compared in Table 12-11. Across the top of the table are the four types of analyzers that can be used for leak detection work. Down the side are the considcrations to be made if a choice among these types is possiblc. For response times, both the photoionization and flamc-ionizationanalyzersare indicated to be fast responding, catalytic combustionmedium, and infrared slow.These all are 102 Table 12-11. Comparison of Avallable Instruments* Criteria Ease of Use Response time Weight (portability) Contamination susceptibility Configuration Maximum concentrationcapability Flame ionization Fast Heavy LOW Excellent Excellent Analyzer type Photoionization Catalytic combustion Fast Light Moderate Adequate Adequate Medium Light LOW Adequate Excellent Infrared slow Heavy Moderate Adequate Excellent costs Capital Operating Moderate Moderate Moderate Moderate LOW Moderate Moderate Moderate Other Concerns Ruggedness Maximum hold feature Good No Good Yes Good No Good No Calibration Good Good Good Good Capture capability Excellent Adequate Moderate Moderate ' A variety of models are available; the comparisonsare subjective and based on excerience with a limited number of models. within the 30-secondresponsetime requirementof the method, but for the flame ionization and photoionization types fast may mean 5 seconds, and for infrared slow may mean 25 seconds. Flame-ionization analyzers are typically equipped with lead acid batteries and a hydrogen tank that makes them relatively heavy. The catalytic and photoionization instruments are relatively light. The photoionization analyzer and infrared analyzers are moderately susceptible to contamination. The window is a potential problem in both that may require more frequent attention, although it may not be a major difficulty in keeping the instruments in operating condition. Configuration refers to the issue of where the sampling probe is in relation to the meter that must be read while doing the survey. Designs that locate the meter directly behind or at the end of the probe are easier to use. The method requires the probe tip to be placed close to the equipment that is being surveyed. Position the meter and probe so that both can be seen at the same time. With respect to maximum concentration capability, only the photoionization analyzer is rated differently. Because photoionization analyzers are not capable of directly reading concentrations that exceed 1,000 to 2,000 ppm, a dilution probe must be used with this instrument if looking for leaks at 10,OOO ppm The cost information presented here was obtaincd from telephone quotes. The flame-ionkation type analyzer generally is available for $4,000 to $7,000. The photoionization analyzers are available for $4,000 to $6,000. These instruments come equipped with other convenient features that may not be essential to the leak detection work but may cause the cost to vary. Cost of the catalytic combustion analyzers is in the $2,000 to $4,000 range. They are shown as being a relatively low-costdevice, but reasons may exist for their not being as good forleak detection as the other types. A moderate cost for infrared is indicated in Table 12-11. However, the one quote received for an infrared device was $16,000,which would not be moderate. Apparently some are available for less than that. No diffcrcnce is shown in operaling costs. Consider the portions of the instrument that may fail or need replacement, such as the lamps, the hydrogen supply, and batteries. Instrument manufacturers are probably the best source for information about these operatingcosts for their particular instrument. All instrumentsare rated similarlyfor ruggednessor how they stand up to abuse in the field. The maximum hold feature may be important for instruments that have the sampling probe and meter in two different locations. An analyzer that locks in the maximum concentration that the meter achieves while in the middle of a survey can be helpful. One photoionization analyzer has this feature. All instruments are rated similarly for calibration. Capture capability is really a reference to the flow rates of the instruments. The flame-ionization analyzer is rated as excellent because it is at the high end of that flow rate range allowed by the method. Photoionization is indicated as adequate because it is at the low end of the acceptable flow range. Low flow rates do not capture the leaking vapors as well. 103 Questions and Answers Question-What factors should be considered in choosing a lamp for a photoionization detector? Answer-Photaionization lampsthatoperateatdifferentvoltage levelsareavailableforpurchase. Thefirstconsiderationin choosing the lamp is the ionization potential of the compounds for which measurements will be needed. The lampselectedshouldbecapableof ionizinganycompound likely to be present, i.e., the compound with the highest ionizationpotential. Published tablesareavailable that list compoundionizationpotentials.Theinformationmay also be obtained from the instrument or lamp suppliers.Lamp voltages in the 9- to 11-electronvolt range are common. The higher voltage lamps are more sensitive to a broad rangeoforganic compounds,but have shorterservice lives than the lower voltage lamps. Therefore, more frequent replacementand higheroperatingcostsfortheinstruments can be anticipated with the higher voltage lamps. Question-How canphotoionizationanalyzersbe used forleak monitoringif they cannot read concentrationshigher than 1,000 to 2,000 ppm? Answer-photoionization analyzer scanbeused todemonstrate thatequipment designatedfor no detectableemissionshas no detectableemissions,Le., no measuredconcentrationof emissions 500 ppm or greater than background level. If photoionization analyzers are to be used to monitor equipment for leaks that are defined by concentrationsof 10.000ppm or greater, a dilution probe must be used with the insuument. The dilution probe mixesa known volume of air with the sampledgas stream to ensurethat a samplcd gas stream concentration of 10,000ppm will be diluted to a concentration within the capability of the instrument to measure when the combined stream enters the detection chamber. The measured concentration reported by the instrumentmetermustbemultiplied by thedilution ratio to give the concentration of the sampled gas stream. For example,if thedilution ratio forthe dilutionprobeis 6parts ofair to 1partof sampledgas, ameterreadingof 1,000ppm meansthat theconcentrationoforganicsin thesampledgas stream is 6,000 ppm. Question-Wastes may contain a large number of organic compounds; how do you determine whether a particular instrument will adequately respond to the combination of vapors that may leak from equipment? Answer-Acceding to Method 21, the instrument response factor for each compound that is to be measurcd must be lessthan 10.Withamixtureofafewcompounds,checking the published response factors and verifying their compliance is not difficult. Some limited study suggests thattheresponsefactorforamixtureissimply theweighted averageresponse factor of the multiplecomponentswhen the compounds are similar, such as the two forms of tetrachloroethane(l,1,2,2and 1,1,1.2).Forothermixtures involvingcompoundswith substantiallydifferentmolecular structuresandvolatility characteristics,this may notbethe case. Also, the relative concentrations of vapors present abovea mixtureoforganicscouldbe substantiallydifferent than the relative concentrations of those compounds in 1eakingliquids.sothecorrectweightedaveragetousemay not be obvious. A possible solution to the problem would betoprepareamixtureofknown concentrationstosimulate thewaste,and thenexperimentallydeterminetheresponse factor for vapors of the mixture. If the response factor for themixtureisless than 10,theinsr"entmaybeused.For amixture composedofavery largenumberof compounds, this may notbepractica1,Perhapsamixturethatrepresents 90percentofthecompoundspresentinthewaste wouldbe a suitable basis for response factor determination. The acceptability of the latter approach would need to be discussed with EF'A officials before adopting it. QuestionXan analyzers that use combustion to detect the presence of organic vapors be safely used in potentially explosive atmospheres? Answer-Both flameionizationand catalyticcombustiontype analyzers have flamespresent in their detectionchambers when organic vaporsare present. Certain models of these devices are rated intrinsically safe and can be used in explosiveatmospheressafely.Theintrinsicallysafemodels are constructed with flame arrestors to prevent the propagation of flame into the explosive atmosphere. In Mcthod 21, the instruments used are required to be intrinsically safe as defined by the applicable standards such as the National Electric Code by the National Fire Prevention Association. They must at a minimum be safe for Class 1, Division 1conditions,and Class 2, Division 1 conditions as defined by the above code. Quesfion-When an instrumentresponscfactorforaparticular compound is 9.5, which means the actual concentration bcing measured is 9.5 times higher than indicated by the mctcr, can sevcre leaks be missed? Answer-Leaks, when they occur, tend to generate very high concentrations. The concentrations are generally much higherthan the 10,000-ppmleakdefinition, typicallyin the 100,000- to 500,000-ppm range. Given this behavior, instrument response factors up to 10 would still yield an indication that a leak is present. 104 Appendix A Federal Register Excerpt Revised Method 21 105 Federal Register, Vo1.55, No. 121, Friday, June 22, 1990, Rules and Regulations, Pages 2S602-25604 ENVIRONMENTAL PROTECTION AGENCY [AD-FRL-3727-31 40 CFR Part 60 Standardsof Performance forNewStationary Sources; Test Methods AGENCY: Environmental Protection Agency (EPA). ACTION: Final rule. Supplementary Information 1. The Rulemaking Scction 2.4 is bcing revised to remove a description of the lcak determination procedure, which is already given, and more properly belongs in section 4.3.2. The example of an acceptable increase in surfaceconcentration versus local concentration is incorrect, and is being removed, as all existing regulatory subparts state that any reading less than 500 ppm constitutes "no detectable emissions." The definition is now expressed in terms of the instrument readability specification. Section 3,1.1(b) is being revised because it is important to call attcntion to the possibility that the leak definition concentration may be beyond the linear response range of some instrumene for some VOC. This potential problem is not identified by the existing calibration procedure, which specifies a single upscalc VOC calibration gas. An argumentcould be made that a multipoint calibration should, therefore, be required. However, adding that requirement would increase the method's performance burden and cost. Summary Method 21 applies to the determination of volatile organic compounds (VOC) leaks from process equipment such as valves, flanges and connections,pumps and compressors,and pressure relief devices. Since Method 21 was promulgated in 1983, several deficiencies in the method that could lead to inconsistencies in the determination of VOC leaks from such devices have come to the attention of EPA in the form of questions as to the proper application of the method. On May 30, 1989, EPA proposed appropriate additions and revisions to Method 21 to alleviate any deficiencies (54 FR 22920). This action promulgates those additions and revisions. Dates Effective Date. June 22, 1990.Judicial Review. Under section 307(b)(l) of the Clean Air Act, judicial review of the actions taken by this notice is available only by the filing of a petition for review in the US. Court of Appeals for the District of ColumbiaCircuit within 60days of today's publication of this notice. Undcr section 307(b)(2) of the Clean Air Act, the requirements that are the subject of today's notice may not bc challenged later in civil or criminal proceedings brought by EPA to enforce these requuemcnts. Addresses Docket. A docket, numbcr A-88-29, containing information considered by EPA in development of the promnlgatcd rulemaking is available for public inspection between 8 a.m. and 4 p.m., Monday through Friday, at EPA's Air Dockct Section (LE-131), room M-1500, First Floor, Waterside Mall, 401 M Street SW., Washington, DC 20460. A reasonable fce may be charged for copying. For Further Information Contact Scction 3.1,1(c) is being,revised in consideration of existing regulatory subparts, where the intention is for the readability to be to the nearest 500 ppm. Since the leak definition in existing subparts is 10,000 ppm, the nearest 500 ppm represen!s +2.5 pcrccnt, not +5 percent. Section 3.1.1(d) is beingreviscd topreventany flow intermption from occurring, such as could occur if a manually operated device was used for a pump. The minimum flow rate spccification or 0.50 liter per minute is reduced to 0.10 liter per minute to prevent the exclusion of some instruments that do mcet the rcsponse time specification and could be acceptable if this change was made. the flow rate specification has bccn qualified as to where, and under what conditions, it applics in order to prevent misunderstandings that it might apply at the instrumcnt detector, or with no flow restriction in the probc. The upper flow limit specification of3.0 litcrs per minute is rctaincd because some upper limit on flow rate is required to prevent dilution of any laking VOC to a concentration bclow the definition of a leak. Scction 3/1/1(e) is being revised in consideration of commcnts that have becn made to EPA that existing wording is not clcar and should be more specific. In addition, it has been reported that inexperienced sampling personnel have becn obscrvcd to use a portable flamc ionization analyzer with the exhaust flame arrestor not replaccd after removal for cleaning. Scction 3.1.1(1) is being added to emphasize that the instrumcnt is meant to samplc a discrete area. Some probes have bccn obscrvcd to havc a relatively large inlet area. The addition is ncccssary so as to provide as much consistency in the idcntificalinn of leaks as is reasonably possible. All measuremcnui made by EPA in support of its VOC-leaks regulatory development activitics have been made with probes not over 1/4 in. in outside diamcter. William Grimley or Roger T. Shigehara, Emission Mcasurcment Branch (MD-19), Technical Support Division, US. Environmcntal Protection Agency, Research Triangle Park, North Carolina 27711, telcphone (919) 541-2237. Scction 3.1.2Ca) is bcing rcviscd to include a procedure that is necdcd for chosc instances where an instrument is not avaiablc that meets the response criteria when calibrated with the spccilied (in rcgulation) VOC calibration gas. The new prcce- dure should mcct the spirit of existing VOC-leak regulations. 106 Finally, Section 3.1.2(b) is being revised by replacing the word "configuration"with all of the items of sampling equipment that might be between the probe tip and the detector during testing. This rulemaking does not impose emission measurement requirements beyond those specified in the current regulations, nor does it change any emission standard. Rather, the rulemaking would simply add methods for the achievement of emission testing requirements that would apply irrespective of this rulemaking. 11. Public Participation The proposed amendment to 40 CFR part 60 that contained proposed revisions and additions to Methcd 21 was published in the Federal Register on May 30, 1989 (54 FR 22920). Public comments were solicited at the time of proposal. To provide interested persons the opportunity for oral presentation of data, views, or arguments concerning the proposed action, a public hearing was scheduled for July 14, 1989 beginning at 10 a.m., but was not held because no one requested to speak. The public comment period was from May 30, 1989 to August 14, 1989. Two comment letters were received that contained comments concerning the proposed methods. The comments were supportive of the proposed additions and revisions, with one exception. That commcnt has been carefully considered, but no changes were made to the proposed rulemaking. 111. Comments and Changes to the Proposed Standards Two comment letters were received from synthetic organic chemical manufacturerson the proposed methods. All but one of the comments therein were statements to the effect that the commenter agreed with the proposed additions and revisions. The one exception stated that the commenter did not agree that an electrically driven pump should be required in section 3.1.1(d). The EPA believes it is necessary to specify,thatan electrically driven pump be used in order to eliminate any potential for imprecise results due to variations or interruptions in sample flow arising from the use of a hand operated squeezepump. It may be possible for a given person to use a hand operated pump satisfactorily, but EPA believes that technique is too prone to operator fatigue over the course of an extensive leak survey to permit its use in a reference method, and is, therefore, not making any change in the requirement for an electrically driven pump. IV. Admlnistrative The docket is an organized and complete File of all the information considered by EPA in the development of this rulemaking. The docket is a dynamic file, since material is added throughout the rulemaking development. The docketing system is intended to allow members of the public and industries involved to identify readily and locate documents SO that they can effectively participate in the rulemaking process. Along with the statement of basis and purpose of the proposed and promulgated standards, and EPA responses to significant comments, the contents of the docket, except for interagency review materials, will serve as the record in case of judicial review [CleanAir Act, section 307(d)(7)(A)]. Undcr Executive Order 12291, EPA is required to judge whether a regulation is a "major rule" and, therefore, subject to the requiremcnts of a regulatory impact analysis. The Agency has determined that this regulation would result in none of the adverse economic effectsset forth in section 1 of the Order as grounds for finding a regulation to be a "major rule." The rulemaking does not impose emission measurement requirements beyond those specifiedin the currentregulations, but instead, provides methods for performing emission measurementrequirements that would apply irrespective of this rulemaking. The Agency has, therefore, concluded that this regulation is not a "major rule" under Executive Order 12291. The Regulatory Flexibility Act @FA) of 1980 requires the identificationof potentially adverse impacts of Federal regulations upon small business entities. The Act specifically requires the completion of an RFA in those instances where small business impacts are possible. Because these standards impose no adverse economic impacts, an RFA has not been conducted. Pursuant to the provisionsof 5 U.S.C.605@), I hereby certify that the promulgalcd rule will not have any economic impact on small entitics, bccause the rule does not add either to the existing requirement for flow rate measurements, or increase their associated pcrformance cost. This regulation was submitted to the Office of Management and Budget (OMB) for review as required by ExecutiveOrder 12291. Any written comments from OMB and any written EPA responses are in the docket. List of Subjects in 40 CFR Part 60 Air pollution control, Intergovemmental relations, Synthetic Organic Chemicals Manufacturing Industry, Reporting and record keeping requirements. Datcd: June 7, 1990. William K. Reilly, Adminisiralor, Method 21, appendix A of 40 CFR part 60 is amended as follows: 1. The Authority for 40 CFR part 60 continues to read as follows: Authority:Scctions 101,111,114,116,and301oftheClean Air Act, as amcnded (42 U.S.C. 7401, 7411, 7414, 7416, 7601). Appendix A [Amended] 2. By revising section 2.4 to read as follows: 2.4 No Detectable Emission. Any VOC concentration at a potential leak source (adjusted for local VOC ambient concentration) that is less than a value corresponding to the instrument readability specification of section 3.1.1(c) indicatcs that a lcak is not present. 107 3. By revising section 3.1.1 (b), (c), (d), and (e) and adding (0 to read as follows: 3.1.1 Specifications. * ** * * (b) Both the linear responserange and the measurablerange of the instrument for each of the VOC to be measured, and for the VOC calibration gas that is used for calibration, shall encompass the leak definition concentration specified in the regulation. A dilution probe assembly may be used to bring the VOC concentration within both ranges: however, the specificationsfor instrument response time and sample probe diameter shall still be met. (c) The scale of the insmment meter shall be readable to k2.5 percent of the specified leak definition concentration when performing a no detectable emission survey. (d) The instrument shall be equipped with an electrically driven pump to insure that a sampleis provided to the detector at a constant flow rate. The nominal sample flow rate, as measured at the sample probe tip, shall be 0.10 to 3.0 liters per minute when the probe is fitted with a glass wool plug or filter that may be used to prevent plugging of the instrumcnt. (e) The insmment shall be intrinsically safe as defined by the applicable U.S.A. standards (e.g., National Elecuic Code by the NationalFire Prevention Asscciation) for opcration in any explosive atmospheres that may be encountered in itsuse. The instrument shall, at a minimum, be intrinsically safe for Class I, Division 1 conditions, and Chss 2, Division 1 conditions, as defined by the example Code. The instrument shall not be operated with any safety device, such as an exhaust flame arrestor, rcmoved. (0 The instrument shall be equipped with a probe or probe extcnsion for sampling not to exceed 1/4 in. in outside diamekr, with a single end opening for admission of sample. 4. By revising scction 3.1.2 (a) and (b) to read as follows: 3.1.2 Performance Criteria. fa) The instrument response factors for each of the VOC to be measured shall be less than IO. When no instrument is available that meets this specification when calibrated with the reference VOC specified in the applicable regulation, the available instrument may be calibrated with one of the VOC to be measured, or any other VOC, so long as the instrument then has a rcsponse factor of less than 10for each of the VOC to be measured. (b) The instrumcnt response time shall be equal to or less than 30 scconds. Thc instrument pump, dilution probe (if any), sample probc, and probe filter, that will be used during tcsting, shall all be in place during the response time determination. [FRDoc. 90-13845 Filed 6-21-90; 8:45am] 108 Appendix B Published Response Factors (From EPA 340/1-88-015) Table 6-1. Response Factors lor TECO Model 580 PhotolonIzatlon Type Organic Vapor Analyzers 10.0 ev Compound Acetone Acetophenone Acrolein Ammonia Aniline Benzene 1.3-Butadiene Carbon disulfide Chlorobenzene Cyclohexane 1,2-Dichloroethane Diethylamine Dimethyl sulfide Ethyl benzene Ethylene oxide Ethyl ether Hexane Hydrogene sulfide Isopropanol Methyl ethyl ketone Methyl isocyanate Methyl mercaptan Methyl methacrylate Nitric oxide Ortho chloro toluene Ortho xylene Pyridine Styrene Sec butyl bromide Tetrachloroethene Tetrachloroethylene Tetrahydrofuran Toluene Trichloroethylene * N.D. =not detected - Ionization Potential (ev) 9.58 N.D.' N.D. 10.15 7.70 9.25 9.07 io.0 9.07 9.98 N.D. N.D. 8.69 8.75 10.57 9.53 10.18 10.45 10.16 9.53 10.57 9.4 N.D. 9.25 8.83 8.56 9.32 N.D. 9.98 9.32 N.D. 9.54 8.82 N.D. Response Factor 1.7 4.2 25.0 24.5 0.6 0.7 10 2.3 0.5 2.1 50.0 2.0 1.3 1.7 33.8 1.5 11.3 7.3 19.8 1.6 12.5 1.3 4.2 44.9 0.5 0.8 0.6 3.3 1.7 1.6 1.9 3.7 0.5 1.3 109 Table 8-2. Compound Response Factors for the Hun Systems, Inc., Model ISPI-101 Photoionization Analyzer Actual Concentration Instrument Concentration Acetal Carbon disulfids Carbon arachloride Chloroform Diketene Perchloromethyl mercaptan Toluene Tetrachloroethane.1,1.2.2Trichloroehane,1.1- Trichlomtrifluoroethane,i,1,2. 1000 5000 10000 1000 10000 500 1000 1woo 1000 5000 10000 1000 5000 10000 5000 1000 1000 5000 10000 1000 5000 10000 5000 10000 925 7200 13200 1990 12900 784 1070 6070 756 2550 5250 148 318 460 103 1180 736 1170 1880 1020 6170 9430 155 430 Response Factor 1.1 0.69 0.76 0.50 0.78 0.64 0.94 1.6 1.3 2.0 1.9 6.8 16.0 22.0 48.0 0.85 1.4 4.3 5.3 0.98 0.81 1.1 32.0 23.0 110 Table 8-3. Response Factors for Foxboro OVA-108 and Bacharach TLV Sniffer at 10,000 ppmv Response Response Factor Response Factor ComDound -OVA-I08 TLV Sniffer __._ Acetic acid 1.64 Acetic anhydride 1.39 Acetone 0.80 Acetonitrile 0.95 Acetyl chloride 2.04 Acetylene 0.39 B Acrylic acid 4.59 B Acrylonitrile 0.97 3.49 I Allene 0.64 15.00 Allyl alcohol 0.96 X Amylene 0.44 1.03 Anisole 0.92 3.91 Benzene 0.29 1.07 Bromobenzene 0.40 1.19 Butadiene,l,3- 0.57 10.90 Butane, n 1.44 I 4.11 Butanol, sec- 0.76 1.25 Butanol, tert 0.53 2.17 Butene.1- 0.56 5.84 Butyl acetate 0.66 1.38 Butyl acrylate, n- 0.70 2.57 I Bury1ether, n 2.60 3.58 I Butyl ether, sec 0.35 1.15 Butylamine, n 0.69 2.02 Butylamine. sec 0.70 1.56 Butylamine, ten- 0.63 1.95 Butyrandehyde.n- 1.29 2.30 Butyronitrile 0.52 1.47 I Carbon disulfide B 3.92 Chloroacetaldehyde 9.10 5.07 Chlorobenzene 0.38 0.88 Chloroethane 5.38 I 3.90 P Chloroform 9.28 B Chloropropene,1- 0.67 0.87 Chloropropene.3- 0.80 1.24 Chlorotoluene. m- 0.48 0.91 Chlorotoluene,o- 0.48 1.06 Chlorotoluene, p- 0.56 1.17 I Crotonaidehyde 1.25 B Cumene 1.87 B Cyclohexane 0.47 0.70 Cyclohexanone 1.50 7.04 Cyclohexene 0.49 2.17 Cyclohexylamine 0.57 1.38 Diacetyl 1.54 3.28 Dichioro-l-propene.2.3- 0.75 1.75 Dichlorcethane.1,1- 0.78 1.86 Dichloroethane,1,2- 0.95 2.15 Dichloroethylene.cis1.2- 1.27 1.63 Dichloroethylene,trans1,2- 1.11 1.66 Dichloromethane 2.81 3.85 Dichloropropane.l.2- 1.03 1.54 Diisobutylene 0.35 1.41 Dimethoxy ethane.1.2- 1.22 1.52 Dimethylformamide,n.n- 4.19 5.29 Dimethylhydrazine1,I- 1.03 2.70 Dioxane 1.48 1.31 Epichlorohydrin 1.69 2.03 Ethane 0.65 0.69 I Ethanol 1.78 X Etboxy ethanol, 2- 1.55 1.82 Ethyl acetate 0.86 1.43 Ethyl acrylate 0.77 X Ethyl chloroacetate 1.99 1.59 Ethyl ether 0.97 1.14 Compound Response Factor OVA-108 ~ Ethylbenzene Ethylene Ethylene oxide Ethylenediamine Formic acid Glycidol Heptane Hexane, nHexene,l- Hydroxyacetone lsobutane Isobutylene lsoprene Isopropanol Isopropyl acetate Isopropylchloride lsovaleraldehyde Mesityl oxide Methacrolein Methanol Melhoxy-ethanol.2- Methyl acetate Methyl acetylene Methyl chloride Methyl ethyl ketone Methyl formate Metayl methacrylate Methyl-2-pentanol.4Methyl-Z-pentone,4Methyl-3-butyn-2-01,2 Methylcyclohexane Methylcyclohexene Methylstyrene,aNitroethane Nitromethane Nitropropane Nonane-n Octane Pentane Pimline,2Propane Propionaldehyde Propionic acid Propyl alcohol Propy1benzene.n- Propylene Propylene oxide Pyridine Styrene Tetrachloroethane,t,i,1l,2 Tetrachloroethane.l11,'2,2 Tetrachloroethylene -Toluene Trichioroethane,1,1.1 Trichloroethane.1,1 ,2Trichloroethylene Trichloropropane,1,2.3Triethylamine Vinyl chloride Vinylidene chloride Xylene, pXylene, mXylene, o- 0.73 0.71 2.46 1.73 14.20 6.88 0.41 I 0.41 0.49 6.90 0.41 3.13 0.59 0.91 0.71 0.68 0.64 1.09 1.20 4.39 P 2.25 1.74 0.61 1.44 0.64 3.11 0.99 1.66 0.56 0.59 0.48 0.44 13.90 1.40 3.52 1.05 1.54 1.03 0.52 0.43 0.55 I 1.14 1.30 0.93 0.51 0.77 0.83 0.47 4.22 4.83 D 7.89 2.97 0.39 0.00 1.25 0.95 0.96 0.51 0.84 1.12 2.12 0.40 0.43 Response Factor TLV Sniffer 4.74 D 1.56 2.40 3.26 B 5.55 0.73 0.69 4.69 D 15.20 0.55 B X 1.39 1.31 0.98 2.19 D 3.14 3.49 D 2.01 3.13 1.85 6.79 1.84 1.12 1.94 2.42 2.00 1.63 X 0.84 2.79 B 3.45 7.60 2.02 11.10 2.11 0.83 1.18 0.60 P 1.71 5.08 D 1.74 B 1.74 I 1.15 1.16 B 6.91 25.40 B 2.68 D 2.40 3.69 3.93 1.99 1.48 1.06 2.41 7.87 I Inverse Estimation Method D PossibleOutliers in Data N Narrow Range of Data X No Data Availablc B lO,O(x) ppvm Response Unachievable P Suspcct Poinls Eliminated 111 Response Factor Test Results The calculated response factors are presented in Table determine concentrations at 2500 ppm, for example, would be B-4. This table is organized by compound name, with the inaccurate, and the operalor would be best advised to redeler- response factors presented for the test instruments. Qualifiers mine a response factor specifically for the new conditions or for the data are noted. use a published value at the correct level. Those compounds for which a large response factors was determined (e.g., five and greater) indicate a problem, and these values should not be used. The response factor is a multiplier, and errors in field measurements caused by changes in calibration response, battery condition, parallax errors in reading the panel meters, elc., would be unduly compounded. Response factors were determined specifically for 500 ppm and should be used as a l&o leak indicator. The response factors do not remain constant as the concentrations change from 500 ppm. Use of these response factors to Operators of portable leak detection devices should be thoroughly familiar with their instrumentation. Even under the best of circumstances, no two analyzers will perform exactly the same, and the knowledge of how changes in instrument paramctcrs aCfect accuracy become paramount. Other external quality conuols, such as a checklist periodically noting battery condition, fuel pressure, post-survey calibration checks, etc., will bolster the validity of the data.An audit program testing bolh the operator and the analyzer should be a requirement whenever a situation warranting an exacting determination of a lugitive emission is encountered. Source: MelhDdPI Evalualbn Iw Ihs HON(90-ME-07).September 30.1990, OfficeOf Air Quality Planning and Standards. U.S. Environmental ProtectionAgency. ResearchTriangle Park. NC 2771 1. 112 Table E-4. ResponseFactors Summation Table Manufacturer Foxboro Foxboro Analyzer OVA-108 OVA-128 Serial Number 20868 - 41092 Compound/Calculaled Response Factor Vinyl chloride Benzene Acetonitrile' Hexane lswctane Methyl ethyl ketone Methyl isobutyl ketone Carbon tetrachloride' Chloroform Benzyl chloride 1,CDioxane Toluene Carbon Disulfide' Methanol. 1.I,2-Trichloroethane 1,l.l-Triihloroethane Ethylene dichloride Tetrachloroethlylene Ethylbenzene Methyl tert-butyl ketone orlho-Xylene para-Xylene meta-Xylene Acetophenone" Styrene oxide" Nitrobenzene'.' Chloroacetylchloride 1.1,2.2-Tetrachloroethane Ethylene glycol"' 2-Methox yethanol"' Isophwone"' 1,2- Epoxybutane Trichloroethylene Chlorobenzene Acetaldehyde' 1.2 - Propyleneimine Propyleneoxide Vinylidene chloride 1.3 - Dichloropropene Acrolein' Allyl chloride Cumene" Vinyl acetate Methyl methacrylate Ethyl acrylate Styrene Aniline". Epichlorohydrin Propionaldehyde' Hexachlorobutadiene'" Methylene chloride Propylene dichloride 2-Nitropropane Triethylamine lodomethane' Bromoform' 2.03 0.56 1.20 1.42 1.05 1.78 1.65 12.07 2.06 1.43 3.74 0.87 33.87 13.24 1.19 1.w 1.37 1.77 0.77 1.23 0.95 0.89 0.89 2.71 2.61 16.41 1.66 1.64 24.81 9.61 28.80 2.67 2.26 0.62 8.41 1.75 2.02 2.73 2.03 6.25 2.77 2.05 3.63 2.02 2.49 1.10 14.44 2.30 4.01 16.28 1.67 1.49 1.86 0.47 8.06 5.90 2.11 0.54 1.24 1.49 1.05 1.84 1.69 15.99 2.38 1.42 4.27 0.67 53.06 17.34 1.27 1.16 1.59 2.09 0.76 1.25 0.95 0.88 0.89 2.62 2.49 16.52 1.93 1.69 39.39 9.87 40.71 2.54 2.60 0.60 9.96 1.52 2.14 2.97 2.08 6.69 2.73 1.82 3.36 2.16 2.64 1.08 20.45 2.41 4.27 22.99 1.72 1.48 1.91 0.49 8.76 6.71 Foxboro OVA- 128 41102 2.11 0.50 1.27 1.33 0.89 1.59 1.40 13.72 1.91 1.21 3.60 0.76 N/R N/R 1.11 1.03 1.41 1.72 0.66 1.03 0.80 0.74 0.75 2.43 2.06 N/R 1.66 1.66 N/R N/R N/R 2.16 2.14 0.54 7.95 1.53 1.78 2.61 1.93 5.64 2.51 1.55 2.80 1.81 2.18 0.93 22.68 2.07 3.95 18.06 1.41 1.26 1.60 0.48 7.35 5.68 Health DP 111 _10_01 1.76 0.38 1.27 0.93 0.56 1.19 0.98 11.11 1.38 0.95 3.21 0.57 57.06 21.73 0.79 0.70 1.19 1.20 0.51 0.72 0.6 0.54 0.54 2.92 2.61 26.01 1.28 1.14 33.13 7.91 29.69 1.89 1.25 0.38 5.36 1.33 1.26 1.79 1.23 3.71 1.56 0.79 1.48 0.92 1.16 0.57 14.71 1.27 2.53 14.56 0.84 0.84 1.w 0.35 4.59 _5.1_2 HNU HW-101 _See _Text 2.18 1.oo N/R 1.49 0.98 2.92 1.46 3.06 3.35 1.34 1.66 1.25 0.71 4.59 1.33 1.85 1.42 0.74 1.08 1.69 1.09 0.93 0.% 3.07 3.03 19.98 3.21 1.52 10.91 2.80 17.76 2.68 1.09 1.06 6.07 2.31 3.09 1.70 1.18 2.73 1.46 1.87 2.07 1.84 1.09 1.36 15.23 1.95 4.79 19.34 2.06 I.37 3.29 0.73 0.72 _ _0.62 113 Foxboro Miran 162 322214 Recal-A OK-B 200 OK-B 200 OK-A Reca-8 OK-A Recal-B OK-B 200 OK-A OK-B 100 OK-A OK-A Recal-A OK-A Reca-A OK-A Reca-A OK-A Real-A Real-B Recal-A Real-A ReMCA ReCal-A Real-B Real-A Reca-E Real-A Reca-B Real-A Real-B Reca-E OK-A Real-A OK-B 400 Real-B OK-B 200 Real-A Real-B Real-8 Real-B Real-A Real-A OK-B 250 Recal-B OK-B 200 Real-A Real-E Real-B Real-B OK-A Real-E Real-E Reca-E Real-A Real-A (continued) Table 8-4. Continued Manufacturer Analyzer Serial Number Foxboro OVA-108 20868 CompoundJCalculaledResponse Factor Foxboro OVA-128 4 1092 Foxbom OVA-128 41102 Health DP 111 1001 HNU HW-IO1 See Text Foxtoro Miran 162 322214 Aclylic acid"' 10.51 10.81 9.63 8.61 Methyl hydrazine" 5.47 5.50 5.74 5.44 Dimethyl formamide' 6.42 6.38 7.20 7.09 1.I-Dimethylhydrazine 2.68 2.84 3.00 2.89 Acrylonitrile 1.55 1.58 1.56 1.47 1.5Butadiene 2.41 2.69 2.37 1.68 Carbonyl sulfide' 103.95 NIR NIR N/R Chloromethyl-methyl ether' 7.77 9.76 7.52 4.28 50% Chloropyrenelxylene 1.46 1.47 1.27 0.77 Dichloroethyl ether." 22.12 25.10 24.48 16.88 Ethyl chloride 1.68 1.84 1.65 1.10 Ethylene dibromide 2.03 2.22 2.03 I.36 Ethylene oxide' 2.40 2.77 2.40 1.81 Formalin 18.83 31.39 27.66 16.50 (37% formaIdehyde/H20) Methyl bromide 3.71 3.83 3.46 2.43 Methyl chloride 1.97 2.38 1.97 1.27 Vinyl bromide 2.14 2.41 2.33 1.68 ortho-Cresol Soli&Not Tested meta-CresoI'.. 75.60 115.20 NIR NIR para-Cresol N/R N/R NIR NIR Phenol (90% carboxylic acid) 16.38 44.89 47.01 NIR 1.2,4-Trichlorobenzene 12.55 16.71 N/R 18.66 Ethylidene dichloride Not available in pure form from vendors 2-Butoxyethanol"' 19.37 26.11 24.69 13.93 2-Eth yoxyethanol' 3.55 4.09 3.50 2.02 1,4-Dichlorobenzene Solid-Not Tested Maleic anhydride Soli&Not tested -~ - -N/R = No response or OIL = Off-Line Low instrument response detectedlhigh response factor calculated. If - Unstable response and tailing of instrument strip chart record over time noted. .ff - Volatility problem with compound .8.91 3.93 5.73 2.29 3.04 2.15 3.14 1.65 1.37 8.79 2.38 0.98 6.61 4.04 1.47 1.77 1.37 NIR NIR 71.06 16.56 9.23 1.70 Real-B Real-B Recal-A Real-B OK-B 100 OK-A Real-B Real-B Real-A OK-A Real-A OK-B 100 Real-A Real-A OK-A Real-B Recal-B Reoll-A Real-B Recal-B Reca-B Real-B Real-B Real-B Miran 182 OK-A = OK-B = Real-A = Real-B = Compound listed in Miran fixed library allabove 500 ppm. Compound liste din Miran fixed library below 500 ppm. yet gave satisfactory results when tested at 500 ppm; the library range is also listed. Compound listed In Miran fixed library; most under 100 ppm but gave unsatisfactoryresults when tested at 500 ppm; required recalibrationof Miran 102 for 500 ppm range. Compound not listed in Miran fixed library and needs complete user listing. peak identification.and calibrationof analyzer for 500 ppm. 114 Appendix C Bibliography Equipment Leak Monitoring 1. Blacksmith, J.R. et al. Frequency of Leak Occurrence for Fittings in Synthetic Organic Chemical Plant Process Units. US. Environmental Protection Agency. Office of Environmental Engineering and Technology, Research Triangle Park, NC. Publication No. EPA 600/2-81-003. 2. Dubose, D.A. and Harris, G.E. Project Summary. Response Factors of VOC Analyzers at a Meter Reading OF 10,000 PPMV for Selected Organic Compounds. U.S. Environmental Protection Agency. Industrial Environmental Research Laboratory. Research Triangle Park, NC. Publication No. EPA-600/S2-81-051. Septcmbcr 1981. 3. Dubose, D.A., Brown, G.E., and Harris, G.E. "Response of Portable VOC Instruments 10Chemical Mixtures." U.S. Environmental Protection Agency. PublicationEPA/ 600-2-81-110.June 1981. 4. Hanzevack, K.M. "Fugitive Hydrocarbon Emissions - Measurement and Data Analysis Methods. Proceedings: Symposiumiworkshopon Petroleum Refinery Emissions," U.S. Environmental Protection Agency. Publication EPA600/2-78-199. September 1978. 5. Harvey, C.M., and Nelson, A.C., Jr., "VOC Fugitive Emission Data-High Density Polyethylene ProcessUnit." US. EnvironmentalProtection Agency. Publication EPA600/2-81-109. June 1981. 6. US. Environmental Protection Agency, "Control of Volatile Organic Compound Leaks from Petroleum Refinery Equipment." Publication No. EPA-450/2-78-036. Research Triangle Park, NC. June 1978. 7. Langley, G.J. et. al. "Analysis of SOCMI VOC Fugitive Emissions Data.U.S. Environmental Protection Agency. Publication No. EPA-600/2-81-111. June 1981. 8. Langley, G.J. and R.G. Wetherold. "Project Summary, Evaluation of Maintenance for Fugitive VOC Emissions Control." US.Environmental Protection Agency. Publication No. EPA-600/S2-81-080. July 1981. 9. Menzies, K.T., and Fasano, R.E., "Evaluation of Potential VOC Screening Instruments." US. Environmental Protection Agency. Publication No. EPA-600/7-82-063. November 1982. 10. Richards, J., and Hellwig, H. Portable Instrument User's Manual Cor Monitoring VOC Sources. US. Environmental Protection Agency. Publication No. 340/1-86-015. June 1988. 11. U.S. EnvironmentalProtection Agency, "Controlof Volatile Organic Compound Leaks from Synthetic Organic Chemicaland Polymer ManufacturingEquipment,Guideline Serics."US. EnvironmentalProtection Agency. P u b lication No. EPA 450/3-83-006. March 1984. 12. US. Environmental Protection Agency. Measurementof Volatile OrganicCompounds,GuidelineSeries.US. EPA Publication No. EPA-450/278-041. Revised September 1979. 13. Wetherold, R.G., Provost, L.P.,and Smith, C.D. Assessmcnt of Atmospheric Emissions from Petroleum Refining: Volume 3, Appendix B. US. EnvironmentalProteclion Agency. PublicationEPA 600/2-80-075c.April 1980. 115 U.S. GOVERNMENT PRINTING OFFICE1992-648-003160076