Document mBBLqgOa9ZJJ8omaJKn07Nmad

jlu- r\ - ojsenamg i-'Oitcy Ex. 16, al l (111) Page ] of7 CSQ Centre) Policy -Him kiln. Controls -Long Term Plan - Report to Congress Draft-Policy on Blending Vxtftnnal lj,S, `U7V'W)^err|^/ Dhd'-.a^e &;r Jnatlon Sysfcsjr fdPCES; RecentAddMons | Cpntad U I PM Version Search NPDES E23 EPA Horne > OW Home > OWM Home > NPDES Home > Combined Sewer Overflows > Blending of Effluent at Publicly Owned Sewage Treatment Facilities MM Tv'if ; Blending of Effluent at Publicly Owned Sewage Treatment Facilities Guidance Documents aiemorr'.nda Demographics Wet V/eaiher Dischargee Combined Sewer Overflows Homo EPA is requesting public comments on a proposed policy addressing the practice of blending at publicly owned sewage treatment facilities during periods of high flow caused by rainfall or snowmelt This proposed policy is available for comment until January 9, 2004. The public is invited to review the proposed policy and submit comments. Detailed instructions for making comments are included in the Federal Register notice below Proposid_BMQdjng_Fplcy pdf Format) Federal Register Notice [pdf Format) - Press Statement Comment Questions and Answers ' Click on the image below for more information. "The Water Environment Federation (WEF) is pleased that EPA is providing national guidance on blending at municipal wastewater treatment plants during wet weather Blending is a longstanding, sensible practice used to manage high flow events at wastewater treatment plants while maintaining compliance with NPDES permit limits, EPA's guidance will support local governments in planning and operating wastewater facilities which provide environmentally sound and cost effective treatment during a variety ofconditions, leading to Improvements in water quality." Larry JaworsM, President, Water Environment Federation WEEfressEeteaseonBleadtoa Ken Kirk, Executive Director of the Association of Metropolitan Sewerage Agencies (AMSA), applauds the release of the national blending guidance, calling it "an excellent example of environmental policymaking that protects both the nation's waters and public health. The guidance also is cost effective and fakes into full account the practical realities that the nation's publicly owned treatment works face on a daily basis. Clarification of this blending issue is extremely important to the nation's publicly owned treatment works and AMSA looks forward to working with EPA on this issue throughout the notice and comment period." - AMSARress BMas_eonBiendjng Recer FAQs Public Reguli Itainir Links Conte' w The do site a Witt What is Blending? During periods of high rainfall or snowmelt, sewage treatment facilities often experience significantly higher flows due to either tie design of the system (older cities often have combined sanitary and storm sewer systems) or the condition of the pipes (deteriorating pipes in older systems car, allow significant amounts of stormwater or ground water to enter into the system). To cope with high flows during storm events, some sewage treatment facilities provide primary treatment for all flows coming into the facility and biological treatment (also called secondary treatment) for flows up to the http://cfpub.epa.gov/npdes/cso/blending.cfm 17cv1906 Sierra Club v. EPA - 6/22 Production 11/4/2003 ED 001523 00002939-00001 fiPA - Blending Policy Ex. 16, at 2 (112) Page 2 of 7 capacity of the i biological 1 treatment units. Primary treatment unis can handle significant variations in flow I concentration of pollutants, whereas biological units are more jlHBHpHHH|^HH|HHHHHHHHHH sensitive and can be negative!y sMSMMMS9S99SsSHSHS9i affected by such changes. 'A/hen the flows into the facility exceed the capacity of the biologtca1 treatment units, excess flows are diverted around the biological units and then recombined or "blended" with the flows that have been treated by the biological units. This blended effluent is usually disinfected and discharged. It is important to note that the proposed policy only applies in situations where the effluent discharged meets all permit limits. Common Questions and Answers Why is EPA Taking this Action? Why Allow Blending? What Are the Benefits? How Can Biological,Treatment Units be Damaged By Wet Weather Rows?? What Happens Wien a Blended Discharge Does Mot Meet Permit limits? WhaiRegyiremente Dp, the Proposed Blending Policy Place on Local Sewage Treatment Facilities? Is this Proposed Policy Protective of Homan Health and the Environment? Do Permits Protect Against Pathogens, Such as Cryptosporidium and fisMi? ~ ' ' Does the_ProRosecl Policy Provide Incentives to Minimize the Use of Blending and Maximize jfie Use of Biological Treatment*7 Will This Policy Discourage (ylunicipaljlies from Investing in their .Sewer Collection Systems? Is Blending Currently,Used,by Local Sewage Treatment Facilities? Is 1be.Proposed,Policy Co nsistent,wfihJt'eX-teaJl Water_Act fCWAj? !s_EPA.Coridycling Any Research on Blending? http://cfpub.epa.gov/iapdes/cso/blendlng.cfm 17cv1906 Sierra Club v. EPA - 6/22 Production 11/4/2003 ED 001523 00002939-00002 <L.rn - menaing Policy Ex. 16, at 3 (113) Page i of 7 Why is EPA Taking this Action? A number of state NPDES authorities, municipal officials, and others have requested clarification of EPA's NPDES regulations as they relate to blending scenarios. EPA is seeking public comment on a proposed policy that aims to. Clarify how the NPDES regulations apply to wet weather blending scenarios Recognize management approaches for high flows due to wet weather that are both environmentally protective and cost effective Improve regulatory coverage by: o ensuring that blending is addressed in the permitting process o specifying, in permits, conditions under which blended discharges are allowed o enhancing monitoring requirements and collection of other information on potential effects of the blended discharge o encouraging states that have not already done so to adopt EPA's 1988 water quality criteria for pathogens The final discharge from any sewage treatment facility must continue to meet the term of the NPDES permit. This proposed policy applies only in situations where the final discharge continues to meet NPDES permit limits. EPA developed the proposed blending policy to provide clear, nationally consistent guidance to the interpretation of the NPDES regulations as they related to the practice of blending. In the past, blending by sewage treatment facilities had been addressed in a variety of ways by state permitting authorities, EPA regional offices, and others. Because of the lack of clear guidance, many questions were raised by municipal officials, state and EPA permit writers, and others. The proposed policy seeks to establish clear guidance and to ensure that if blending is used by a municipal sewage treatment facility it is used in a way that is fully protective of human health and the environment. Why Allow Blending? What are the Benefits? Reducing tile frequency and volume of sewage collection system overflows and backups into homes and other buildings and improving the structural integrity of systems have been major goals of EPA's NPDES program since the early 1990s An important component of these efforts has been to increase the delivery of wet weather flows to the treatment facility. Bienoing of effluents at sewage treatment facilities during periods of high flow associated with wet weather is a common engineering practiceaaoss the country `naiamsac .to.-Pc4aqttoiolcgrcai..oroa.tai.erdUj?jTs from ctomsqe and to prevent overflows and backups elsewhere In the system. EPA's picposed policy seeks to set clear parameters for blending to ensure that if is protective of human health and the environment. As stated earlier, the blending policy applies only when the final discharge meets _atijemi[t limits. Blending that would cause the discharge of pollutants http://cfpub.epa.go v/npdes/cso/blending.efm 17cv1906 Sierra Club v. EPA - 6/22 Production 11/4/2003 ED 001523 00002939-00003 bFA - Blending Policy Ex. 16, at 4 (114) Page 4 of7 not in compliance with the terms of the MPDES permit is and would remain illegal. Discharges of raw sewage are a significant tnreai to both human health and the environment, ft has been a long-term goal of EPA and its state and local partners to eliminate all discharges of raw sewage to the environment. Over the past 30 years, municipal, state, and federal agencies have invested billions of dollars toward achieving this goal. The use of blending as an option for managing wel weather flows coming into a sewage treatment facility can help to reduce overflows of raw sewage from elsewhere in the system. Blending allows a.much big.faeL.volume of incoming wastewater to receive TreaFmeni and disinfection thereby..reducing or possibly. eliminating.mych more hangful.o.verflows of untreated-sewage, ' The proposed blending policy seeks to set parameters and conditions for the practice of blending. Under the proposed policy, sewage treatment facilities would need to evaluate their systems and implement management practices minimizing the need for blending and preventing overflows from occurring In addition, enhanced monitoring would be required and would allow permit writers to assess any potential impact of blended discharges on the particular waterbody and make adjustments in permit limits as needed. How Can Biological Treatment Units be Damaged By Wet Weather Flows? Most sewage treatment plants use a series of steps to treat wastewater which include; preliminary treatment or screening to remove large solids; primary clarification to remove floating and settleable solids; biological treatment units (also referred to' as secondary treatment units) to remove biodegradable organic pollutants and suspended solids. Many treatment facilities also provide disinfection to kill pathogens and achieve water quality standards. Some facilities also provide advanced treatment which are designed to remove additional constituents and meet water quality standards. Biological treatment units utilize a natural process to biodegrade pollutants using a stable population of microorganisms This means that biological treatment units generally cannot be designed to accommodate wide variations in flow volumes and strength. Wet weather flows can cause malfunctions in the system Excessive flows into the biological units can actually washout the microorganisms necessary for treatment and may result in additional pollutants being discharged to the environment. In addition, the diluted nature of wet weather flows (more rainwater, less sewage) can have negative effects on the functioning of the biological unites it can taka weeks or months for a biological treatment unit to recover from such an event. What Happens When a Blended Discharge Does Not Meet Permit Limits? This proposed policy would not alter permit limits or the conditions that apply to publicly owned sewage treatment facilities. Discharges not in compliance with permit limits would remain illegal and would continue to be subject to the full range of enforcement options outlined in the Clean Water Act, including fines of up to $27,500 per day. What Requirements Do the Proposed Blending Policy Place on Local Sewage Treatment Facilities? The proposed policy includes the following management principles: http://cfpub.epa.gov/npdes/cso/blending.cfm 17cv1906 Sierra Club v. EPA - 6/22 Production 11 /4/2003 ED 001523 00002939-00004 fcPA - Blending Policy Ex. 16, at 5 (115) Page 5 of 7 a Blended discharges must meet permit limits that are based on secondary treatment standards or any more stringent (imitations necessary to attain water quality standards, including appropriate pathogen-indicator limitations. - Permits must include monitoring requirements for blended discharges to evaluate compliance with permit limits. In addition, the permit should require monitoring to assess potential wafer quality impacts and to evaluate the effectiveness of the treatment process on key pollutants, including pathogens; and to characterize the level of key pollutants in ambient waters. The policy indicates that discharges of blended flows to sensitive waters should not be authorized wherever physically possible and economically achievable. 2s this Proposed Policy Protective of Human Health and the Environment? EPA believes that allowing blending under the limited terms outlined in the proposed policy would be protective of human health and the environment. The use of btsndincuas a technique for manaairtcLwal weatber-flo.ws at sewage treatment facilities could reduce overflows of raw sewage fram-pther parts'oftfie'treatment system.' ~ ~ ~ "" The Agency's efforts to control combined sewer overflows (CSOs) and sanitary sewer overflows (SSOs) are not affected by this proposed guidance. The Agency continues to work with states and affected communities to implement the 1994 CSO Policy, including implementation of the nine minimum technology-based controls and adoption of long-term control plans. EPA and the states are addressing overflows from sanitary sewer systems using the principles outlined in EPA's April 27,2000, Compliance and Enforcement Strategy Addressing Combined Sewer Overflows and Sanitary Sewer Overflows, Do Permits Protect Against Pathogens, Such as Cryptosporidium and GiardicR Many NPDES permits provide a level of protection against these pathogens EPA's 1988 water quality criteria for pathogens provides a relevant tool for establishing water quality-based effluent limitations for infrequent blended discharges. The 1988 criteria serves as an indicator (not a direct measure) for a wide range of pathogens in wastewater, including viruses and parasites, that can produce acute gastrointestinal disease symptoms. The data supporting the 1986 bacteria water quality criteria were obtained from a series of epidemiological studies that examined the relationship between swimmingassociated illness (namely, acute gastrointestinal illness) and the microbiological quality of the wafers used by recreational bathers. Hence, we believe the 1986 criteria is a relevant indicator for protecting against gastrointestinal disease associated with potential exposure to ambient waters. This proposed policy encourages states that have not already done so to adopt water quality standards based on ERA'S 1986 pathogen criteria and to include appropriate limits in permits. Does the Proposed Policy Provide Incentives to Minimize the Use of Blending and Maximize the Use of Biological Treatment? The proposed policy provides a number of safeguards that seek to minimize the use of blending and maximize the use of biological treatment. The bUp;//efpub.epa.gov/npdes/cso/blending.elm 17cv1906 Sierra Club v. EPA - 6/22 Production 11/4/2003 ED 001523 00002939-00005 or a - mending Policy Ex. 16, at 6 (116) Page 6 of 7 proposed policy would ensure appropriate management of high flow events by: Limiting the use of blending to times when the capacity of biological units is fully utilized Ensuring monitoring of blended effluents and ambient monitoring in the wafers that receive blended discharges Requiring appropriate operation and maintenance of the collection system to reduce high flows Recognizing management approaches for high flows due to wet weather that are both environmentally protective and cost-effective Blending is only an accepted oractic.e..wh.ea.wet.weather flows exceed the SpacityTpf^iijSiQl^iiSEBSitE^tainitsjLod&teSg^Qits^al^iJi^. The proposed policy does not allow sewage treatment facilities to blentTduring dry weather. Dry weather flows should not exceed the capacity of theTFioIogical treatment units. Any diversion from biological treatment during dry weather conditions will be subject to the existing bypass provisions of the regulations. Will This Policy Discourage Municipalities from Investing in their Sewer Collection Systems? ERA believe that this policy will o.QLaIeAtocalipfrastMCturejiiye.stroe,tit decisionsTlVfuriFcipilitiisacross the country face significant problems with {Reir wastewater infrastructure, including problems caused by storm events. EPA estimates the national needs for additional municipal investment in wastewater infrastructure include about $50.6 billion for combined sewer overflow control, $88.5 billion far sanitary sewer overflow control, and $57.2 billion for wastewater treatment plants. This policy does not alter federal requirements for overflows from collection systems that will continue to drive municipal investment in infrastructure. However, the policy does outline.a ........................ " ' ' ither.lowtba.tjsj Is Blending Currently Used by Local Sewage Treatment Facilities? Information from municipalities and states indicates that blending is a widespread practice. In 2001, the Association of Metropolitan Sewerage Agencies (AMSA) conducted a survey on blending. AMSA received 122 responses (representing 47% of the organization's . membership). Of these, 59 respondents (48%) blended during some peak flow conditions. Of the 48% of the facilities that blended: 70% of the plants were originally designed to blend 31% of permits for these facilities recognized blending 33% of these communities are served by combined sewers Is the Proposed Policy Consistent with Hie Clean Water Act (CWA)? Yes The Clean Water Act requires that discharges from sewage treatment facilities achieve effluent limitations based on secondary treatment, as well as any more stringent limitations necessary to meet water qualify standards. The secondary treatment regulations define performance standards for minimum levels of effluent quality . Likewise, more stringent limits are sometimes necessary to meet water quality standards. Jp.aitte/jfase, limits almost alwav.s... apply at the "end-of-the-pipe." The regulations do gotsgecify ffii type of treatmentprocess to be used tojnee^secondiry treatment" http ://cfpub. epa.gov/npdes/cso/bIeadi ng.cfm 17cv1906 Sierra Club v. EPA - 6/22 Production 11/4/2003 ED 001523 00002939-00006 ruucy Ex. 16, at 7 (117) Page 7 of 7 requirements, nor do t^qKre^gcleJh^jJse^nonbioIogical.feicii.ities. The reguIationsWfeqiTlre proper operation of any treatment process " Is EPA Conducting Any Research on Blending? EPA working with the Water Environment Research Foundation (WERF) that wifi examine blended effluent quality and its impact on ambient waters, this project is seeking answers to the following questions: What changes occur in the qualify of the wastewater arriving at the sewage treatment facility and the corresponding changes in the final discharge? What ambient water quality changes occur during each wet weather event? Is there an impact from blended discharges on water qualify? During a storm event, what is the relevant impact to overall stream water qualify from a sewage treatment facility practicing blending and all other sources which are contributing pollutants? What effects do different management techniques used fay sewage treatment facilities have on the level of pathogens in the final discharge? Ogee of Water | pffice.of Wastewater Management J Dgclgitrier | Search EPA ERA Home | Rriyjt^artd_SecuiyHQliseJ Confact fJs last updated on November 04,2003 10 22 AM URL, Mtp7/ttfpub.epa.gov/npdes/csoA>!ef)cling,cfm http://cfpukepa.gov/npdes/cso/blending.cfra 17cv1906 Sierra Club v. EPA - 6/22 Production J1/4/2003 ED 001523 00002939-00007 Att. 1 Post-ILOC Timeline (Based on New Evidence) ! j' \ i :'.!i 5i i. --1-- 1.... |....1---...-I-- J....I....t... ... f-...1........1--- 1....i-...J.... ... 1... L i 4- - i...-... *....*.... 1-.. J-- i ` i 9/1/13 9/16/13 10/1/13 10/16/13 10/31/13 11/15/13 11/30/13 12/15/13 12/30/13 $ Nonacquiescence decision 0 EPA Internal discussion and distribution 0 EPA FOIft non-disclosures V Punlic statements 2014 -I--1--- __t__ i__ i__ i__ _l__ I__ 1................ J___|__ 1__ |__ L_ 2015 2016 ,1... 1 ...1___I----1----1__ 1_ 2017 17cv1906 Sierra Club v. EPA - 6/22 Production ED 001523 00002940-00001