Document N78aJrBnxQEkKR4eDRX40Q3D

Pretreatment Audit Report City of Rock Springs WY-0022357 Rock Springs, Wyoming August 21, 2024 to August 22, 2024 Prepared by: Al Garcia, Pretreatment Coordinator U.S. Environmental Protection Agency, Region 8 Wastewater Section (8WD-CWW) 1595 Wynkoop Denver, CO 80202 303.312.6382 garcia.al@epa.gov 1 City of Rock Springs Pretreatment Audit Report WY-0022357 August 21, 2024 to August 22, 2024 Report Review and Signature Drafter Name Al Garcia Reviewer Name Stephanie Passarelli Supervisor Signature/Name MICHAEL BOEGLIN Digitally signed by MICHAEL BOEGLIN Date: 2024.12.12 08:37:32 -07'00' Michael Boeglin Address/Phone Number U.S. EPA Region 8 1595 Wynkoop Street 8WD-CWW Denver, Colorado 80202 303-312-6382 Address/Phone Number U.S. EPA Region 8 1595 Wynkoop Street 8ENF-W-NP Denver, Colorado 80202 303-312-6803 Address/Phone Number U.S. EPA Region 8 1595 Wynkoop Street 8WD-CWW Denver, Colorado 80202 303-312-6250 Date 11/29/2024 Date 12/04/2024 Date 12/12/2024 2 City of Rock Springs Pretreatment Audit Report WY-0022357 August 21, 2024 to August 22, 2024 Pretreatment Audit Summary Table City of Rock Springs Pretreatment Audit Report WY-0022357 August 21, 2024 to August 22, 2024 Pretreatment Audit Findings Pretreatment Requirement and Corrective Action Section 8.0 - Control Mechanism (Permit) Evaluation and Permit Specific Issues 1. Based on the EPA's review, the City's permit template complies with the permit conditions found in 40 C.F.R. 403.12(g)(3) of the Pretreatment Regulations and incorporated in the City's municipal ordinance at section 6.11, with the following exception: The requirement to conduct representative sampling is absent in the permit template. Pretreatment Requirements 40 C.F.R. 403.12(g)(3) Rock Springs Municipal Ordinance: Section 6.11 Corrective Action Item Update the permit template to include the requirement to conduct representative sampling for monitoring related to permit compliance. Section 10.0 - Control Authority Compliance Monitoring 2. As required in 40 C.F.R. 403.8(f)(2), the POTW shall "develop and implement procedures to ensure compliance with the requirements of a Pretreatment Program." The development and implementation of Pretreatment Requirements a sampling plan or procedures ensures the POTW is 40 C.F.R. 403.8(f)(2) appropriately and consistently performing sampling or monitoring events, as well as providing 40 C.F.R. 403.8(f)(2)(vii) enforceable data that is representative of the Corrective Action Item discharge conditions at the facility. The sampling Update the sampling plans and SIU-specific plan should include the following: protocols to include appropriate QA/QC such x purpose and objective of the sampling program, as equipment blanks, trip blanks, sample x specific sampling protocols at each facility duplicates, matrix spikes, control standards to sampling location to ensure representative ensure the sampling and analytical techniques sampling, and are in control and comply with 40 C.F.R. 136. x appropriate QA/QC procedures to ensure legally defensible data. In addition, the Pretreatment Regulations at 40 C.F.R. 403.8(f)(2)(vii) require the City to ensure "Sample taking and analysis and the collection of Recommended The EPA recommends the City incorporate digital photos in the SIU-specific sampling protocols. other information shall be performed with sufficient care to produce evidence admissible in enforcement 3 City of Rock Springs Pretreatment Audit Report WY-0022357 August 21, 2024 to August 22, 2024 proceedings or in judicial actions." The City has developed a SOP for NPDES sampling that provides an overview of its sampling program. The City has also developed SIU-specific sampling protocols for each SIU to ensure consistent sampling that is representative for the production day at each SIU. Based on the EPA's review, the City's SIUspecific sampling protocols did not specify how City staff should account for any digital photos captured as part of the sampling events, and they did not incorporate QA/QC such as equipment blanks, trip blanks, sample duplicates, matrix spikes, control standards to ensure the sampling and analytical techniques are in control and compliance with 40 CFR 136. Section 13.0 - Best Management Practices - Sector Control Programs 3. The Dental Amalgam Rule, found in 40 C.F.R. Part 441, was promulgated as a final rule with new source dental facilities required to be in compliance with the Pretreatment Standards as of July 14, 2017, and existing source dental facilities required to be in compliance as of June 14, 2020. Compliance with the rule requires the installation of an ISO1143 amalgam separator or equivalent device, and compliance with the following two BMPs: x Prohibition on the use of oxidizing or chlorinecontaining line cleaners; and x Ensuring all amalgam process wastewater including chair-side traps, screens, vacuum pump filters, dental tools, cuspidors or collection devices are treated through the amalgam separator. In addition, the new and existing dental facilities are required in 40 C.F.R. 441.50 of the Dental Amalgam Rule to provide a report that characterizes the dental facility and certifies compliance. The new source dental facilities are required to be in compliance upon discharge and submit a one-time compliance report within 90 days of startup. The City has identified 15 dental facilities in its industrial waste survey and has received one-time compliance reports within the deadline required by the Rule. Based on the EPA's review of the one-time Pretreatment Requirements 40 C.F.R. 441 40 C.F.R. 441.50 Corrective Action Item Ensure the reports submitted from Health West Rock Springs Dental, White Mountain Dental, Erramouspe Dental and Aspen Dental are complete and provide adequate information to determine compliance with the Dental Amalgam Rule. 4 City of Rock Springs Pretreatment Audit Report WY-0022357 August 21, 2024 to August 22, 2024 compliance records, the following reports are not complete, as required in 40 C.F.R. 441.50 of the Dental Amalgam Rule: x Health West Rock Springs Dental, Section C - maintenance information of amalgam separator not included. x White Mountain Dental, Section C - maintenance information of amalgam separator not included. x Erramouspe Dental, Section A - new source or existing source not checked. (discharged prior to July 14, 2017) x Aspen Dental, Section A - Section A - new source or existing source not checked. (discharged prior to July 14, 2017) 5 City of Rock Springs Pretreatment Audit Report WY-0022357 August 21, 2024 to August 22, 2024 Table of Contents 1.0 Introduction.............................................................................................................. 9 2.0 Publicly Owned Treatment Works (POTW) Information ..................................... 10 2.1 NPDES Permit.................................................................................................... 14 3.0 Resources ............................................................................................................... 17 3.1 Resources Regulatory Background .................................................................... 17 3.2 Evaluation of the City's Resources and Funding ............................................... 17 3.3 Examples of Available Pretreatment Training/Resources ................................. 17 4.0 Municipal Ordinance and Intergovernmental Agreements.................................... 18 4.1 Legal Authority Background.............................................................................. 18 4.2 City of Rock Springs Municipal Ordinance ....................................................... 20 4.3 Inter-Jurisdictional or Governmental Agreements (IGA) .................................. 20 4.3.1 IGA Regulatory Background ...................................................................... 20 4.3.2 Evaluation of the City's IGAs with Outside Contributing Jurisdictions .... 20 5.0 Local Limits ........................................................................................................... 21 5.1 Local Limits Regulatory Background ................................................................ 21 5.2 Local Limits Requirements Established in the City's NPDES Permits ............. 22 5.3 The EPA Evaluation of the City's Local Limits ................................................ 23 5.3.1 Technically-based Local Limits.................................................................. 23 5.3.2 Numeric Ordinance Limits ......................................................................... 24 5.3.3 Dilution Prohibition .................................................................................... 24 5.4 Local Limits Technical Evaluation-Regulatory Background............................. 24 5.5 Technical Evaluation of the City's Local Limits ............................................... 26 5.6 Permit or Site-Specific Limits............................................................................ 26 6.0 Pretreatment Operating Procedures ....................................................................... 27 6.1 Regulatory Background...................................................................................... 27 6.2 Standard Operating Procedures (SOPs) ............................................................. 28 6.3 Templates ........................................................................................................... 29 6.4 Records and Data Management.......................................................................... 29 6.4.1 Regulatory Background .............................................................................. 29 6.4.2 Recordkeeping and Data Management ....................................................... 30 6 City of Rock Springs Pretreatment Audit Report WY-0022357 August 21, 2024 to August 22, 2024 6.5 Receipt of Discharge Monitoring Reports and Notifications............................. 30 6.6 Management of Confidential Records................................................................ 30 7.0 Industrial User Inventory and Characterization..................................................... 31 7.1 Regulatory Background...................................................................................... 31 7.2 Industrial User Identification and Characterization Procedure .......................... 32 7.3 Industrial User Database of the City's Service Area.......................................... 32 8.0 Control Mechanism (Permit) Evaluation and Permit Specific Issues.................... 33 8.1 Regulatory Background...................................................................................... 33 8.2 The EPA's Evaluation of the City's Permitting Legal Authority ...................... 35 8.3 Permit Template Overview ................................................................................ 36 8.4 Specific Permit Record Findings ....................................................................... 36 8.4.1 Permit Records Overview ........................................................................... 36 8.4.2 Memorial Hospital ...................................................................................... 37 8.4.3 Tri-Hydro RS1 ............................................................................................ 37 8.4.4 Tri-Hydro RS8 ............................................................................................ 37 9.0 Significant Industrial User Facility Inspections..................................................... 37 9.1 Regulatory Background...................................................................................... 37 9.2 Right of Entry..................................................................................................... 38 9.3 Facility Inspection Records - Background ........................................................ 39 9.4 Evaluation of the City's Inspection Reports/Records ........................................ 41 9.5 Notification of Applicable Pretreatment Standards ........................................... 41 10.0 Control Authority Compliance Monitoring ........................................................... 41 10.1 Regulatory Background...................................................................................... 41 10.2 Sampling Plan and Protocols.............................................................................. 42 10.2.1 Site-Specific Sampling Protocols ............................................................... 42 10.2.2 Quality Assurance/Quality Control (QA/QC) ............................................ 43 10.3 The EPA Evaluation of the City's Control Authority Monitoring..................... 43 10.3.1 SOPs............................................................................................................ 43 10.3.2 City's Control Authority Monitoring.......................................................... 43 11.0 Enforcement........................................................................................................... 44 11.1 Regulatory Background...................................................................................... 44 7 City of Rock Springs Pretreatment Audit Report WY-0022357 August 21, 2024 to August 22, 2024 11.2 Enforcement Legal Authority............................................................................. 44 11.3 Enforcement Response Plan............................................................................... 45 11.4 Compliance Evaluation ...................................................................................... 45 11.5 SNC Calculations and Public Participation........................................................ 45 12.0 Trucked and Hauled Waste.................................................................................... 45 12.1 Regulatory Background...................................................................................... 45 12.2 Legal Authority .................................................................................................. 46 12.3 Trucked and Hauled Waste Disposal Location and Control Mechanisms......... 47 13.0 Best Management Practices - Sector Control Programs ....................................... 47 13.1 Regulatory Background...................................................................................... 47 13.2 Authority in Rules and Regulations ................................................................... 48 13.3 Dental Amalgam BMP Sector Control Program................................................ 48 13.4 FOG Sector Control Program............................................................................. 49 14.0 PFAS Roadmap and Implementation .................................................................... 49 Figures Figure 1 -City of Rock Springs Service Area .................................................................. 15 Figure 2 - City of Rock Springs POTW Process Diagram............................................... 16 Tables Table 1 - Rock Springs Local Limits-Municipal Ordinance, 2.3(A)(1)......................... 23 Table 2 - City of Rock Springs Numeric Ordinance limits.............................................. 24 8 City of Rock Springs Pretreatment Audit Report WY-0022357 August 21, 2024 to August 22, 2024 1.0 Introduction The U.S. Environmental Protection Agency, Region 8 (EPA) conducted an audit of the Pretreatment program, administered by the City of Rock Springs, WY (City) from August 21, 2024 to August 22, 2024. The Pretreatment audit started on August 21, 2024 at 1:00 p.m. with an opening interview. The closing conference was held on August 22, 2024 at 1:00 p.m. during which the EPA presented the preliminary observations, conclusions, and findings from the audit. Participants in the audit included: City of Rock Springs, CO Justin Stewart Nick Seals Jason Anson Paul Kauchich Pretreatment Coordinator Water Reclamation Facility Superintendent Water Reclamation Facility Chief Operator Director of Engineering, Operations and Public (closing conference only) Services EPA Al Garcia Region 8 Pretreatment Coordinator The primary purpose of the EPA audit was to evaluate the Pretreatment program administered and implemented by the City. In addition, the audit served as a forum for the EPA and the City to discuss issues related to the implementation of the Pretreatment program, including PFAS requirements in the City's NPDES permit and for the EPA to provide outreach and training to the City. The EPA Pretreatment audit consisted of an evaluation of the following: x The City's legal authority codified in its municipal ordinance; Article 7-4 - Plumbing and Sewer Code, 7-420 -- Pretreatment. x Development and implementation of the City's local limits. x The City's resources to implement the Pretreatment program in its service area. x Implementation policies and templates developed by the City. x Review and evaluation of the Pretreatment programmatic activities and records maintained for the permitted Significant Industrial Users (SIUs). x Discussion of the Pretreatment Regulations and implementation. The following sections of the report highlight the findings, corrective actions, and recommended actions of the audit. The action items to correct program deficiencies and meet regulatory requirements are identified in the Pretreatment Audit Summary Table, beginning on page 3 of this report. Specific actions to clarify and strengthen program implementation are provided as recommendations within the body of the audit report. 9 City of Rock Springs Pretreatment Audit Report WY-0022357 August 21, 2024 to August 22, 2024 2.0 Publicly Owned Treatment Works (POTW) Information The City owns and operates a Publicly Owned Treatment Works (POTW) located at 2300 Sunset Dr, Rock Springs, WY 82901. The POTW serves the boundary of the City of Rock Springs and two outside contributing jurisdictions, White Mountain Water and Sewer District and Clearview Improvement and Sewer District. The service area for the POTW is shown in Figure 1 and the POTW process diagram is shown in Figure 2. A site visit of the POTW was not performed during the audit. The narrative description of the City's wastewater treatment plant operation and processes was gathered from the City's 2019 permit application to the WYDEQ. Preliminary Treatment: Headworks Building Influent wastewater is conveyed from the city collections system to the Headworks Building. It first moves through a Andritz Aquascreen which is made up of quarter inch orifice plates. At this point paper, rags and any large solids are removed from the process and augered to a dumpster for removal. There is a bypass channel which contains a manual bar screen that allows maintenance to be performed on the Aquascreen. The wastewater then travels through a Smith and Loveless Pista Grit chamber. Grit is removed and pumped to a Wemco grit classifier where the grit is washed and sent to a dumpster for removal. Excess water and organics removed from the grit classifier are returned to the treatment process. There are manual gates in the channel that allow for bypass of the grit system when maintenance is required. Following the grit system is the location where influent composite samples are collected using a flow based Hach Autosampler which collects data from the influent flow meter. The wastewater then flows through a Parshall Flume where influent flow values are calculated and totalized with the use of a 10 MGD flow meter. Main Pump House Wastewater is gravity fed from the Headworks Building to the Main Pump House. The Main Pump House consists of five Smith and Loveless centrifugal pumps. Each pump is capable of pumping 2,650 gpm and are powered by 40 horsepower motors. Each treatment train is fed by two pumps in the Main Pump House. Generally, only one pump per train runs per day. There is a fifth pump for future and emergency use that discharges to Oxidation Ditch 2. The Main Pump House also receives Sidestream and drying pad flows. Wastewater is pumped through 16-inch Khrone flow meters and is recorded as force main 1, force main 2 or force main 3. Force main 3 is not in use and meant for future expansion but ready when needed. This building has the capability to divert flows to one or both oxidation ditches. RV Dump Station: Located outside of the main gate is a 24-hour RV dump station. The flow from the RV dump station is conveyed to the Sidestream Building. Sidestream Building: The Sidestream Building or Warehouse takes flows from the RV dump, the clarifier scum 10 City of Rock Springs Pretreatment Audit Report WY-0022357 August 21, 2024 to August 22, 2024 box, and the Admin and Garage building. The Sidestream Building pumps wastewater to the main pump house with the use of two centrifugal pumps. Grease Receiving Station: The treatment plant accepts grease and septic wastes from businesses located within 10 miles of the Corporate City Limits of Rock Springs. The grease receiving station is located at Bitter Creek Lift Station located in the treatment plant. There is an area for haulers to dump their load into a sump, which is then conveyed into a wet well. Once wastes are discharged to the station, they are pumped to either the Headworks Building or Aerobic Digesters with the use of two Seepex progressive cavity pumps. Generally septic wastes are pumped to the Headworks building and grease loads are pumped to the Aerobic Digesters. The holding wet well is equipped with an automatic spray and washdown system using reclaimed water to prevent buildup of wastes. Secondary Treatment: Oxidation Ditch 1 Oxidation ditch 1 is a 2.1 MG basin consisting of two 1.05 MG channels. The waste stream enters a diversion box from the Main Pump House traveling through Force Main 1. Return activated sludge is also introduced at this point. The diversion box contains two manual gates which allow for the wastewater to be sent to either channel. Under normal conditions, influent flow is discharged to channel 1. Channel 1 consists of three mechanical surface aerators known as Orbal Rotors. Channel 1 is equipped with Hach ORP monitoring equipment, and an oxidation-reduction potential value of +50mv to -50mv is maintained to promote anoxic conditions. After a hydraulic retention time of about 17.5 hours, the mixed liquor will then flow to channel 2 through a manual gate located at the center of the oxidation ditch. Channel 2 also contains 3 Orbal Rotors. Hach dissolved oxygen monitoring equipment is installed in channel 2 and a value of at least 2.0 mg/l is maintained to promote aerobic conditions. Flow exits the oxidation ditch through the outfall located on the northwest side of channel 2, after a hydraulic retention time of about 17.5 hours. Oxidation Ditch 2 Oxidation Ditch 2 is a 1.95 MG basin containing 3 channels. Flow is pumped from the Main Pump House through either force main 2 or force main 3. It can be discharged to any channel, but under normal operations flow will be discharged to channel 1. Channel 1 is a 0.972 MG basin consisting of 3 Orbal Rotors for aeration. Return sludge flow is also discharged to this channel on the west side of the channel. Channel 1 has Hach ORP monitoring equipment installed and an oxidation-reduction potential value of +50mv to 50mv is maintained to promote anoxic conditions. After a hydraulic retention time of about 16.7 hours in channel 1, the mixed liquor will then flow to channel 2. Channel 2 has a volume of 0.629 MG and a hydraulic retention time of about 10.8 hours. In this channel, dissolved oxygen and ORP levels are dependent on the operational settings of channel 1 and channel 3. Channel 2 has three Orbal Rotors used for aeration. From channel 2, the mixed liquor flows to channel 3 which has a volume of 0.340 MG. Channel 3 has Hach dissolved oxygen monitoring equipment and a dissolved oxygen value of 2.0 mg/l or greater is maintained to promote aerobic conditions. Channel 3 also consists 11 City of Rock Springs Pretreatment Audit Report WY-0022357 August 21, 2024 to August 22, 2024 of three Orbal Rotors and carries a hydraulic retention time of about 5.8 hours. The outfall of Oxidation Ditch 2 is in the center of the oxidation ditch. Within the outfall is a recycle pump designed to move flow from the outfall back to channel 1 with the purpose of enhancing the denitrification process. Flow from each oxidation ditch is gravity fed to a diversion box located between the solids handling building and final clarifiers. The diversion box has a series of manual gates which can be adjusted to allow for flow to enter either clarifier from either oxidation ditch. Under normal conditions, flow from Oxidation Ditch 1 and Oxidation Ditch 2 are kept separate and are discharged into their own individual clarifier. Clarifiers: There are two 0.52 MG clarifiers located at the treatment plant. Flow moves up through the center and is distributed throughout the clarifier. Settleable solids are allowed to settle out and accumulate at the bottom of the clarifier and after a detention time for solids of around 0.8 hours they are pumped out and returned to the oxidation ditch for further treatment. Clear water effluent flows over the top of the clarifier weirs and is discharged to a pipe that conveys it to the UV building for disinfection. A Tow-Bro/Skimmer arm combination moves constantly around the clarifier. At the bottom of the clarifier the Tow-Bro collects and pumps solids back to the oxidation ditches. This is achieved with the use of five Wemco Hidrostal pumps that have a maximum output of 800 gpm per pump. At the top-level scum and floating solids are removed and sent back to a solids separator where they can be removed from the process. There is also a water line installed at the top level that is fed by the Reclaimed Water Station. Its purpose is to help with the removal of any excessive floating solids or scum. Disinfection: The effluent from the clarifiers is conveyed to the UV Building for final disinfection. Disinfection is achieved with the use of a 10 MGD Trojan UV3000+ disinfection system. It consists of two channels each containing two separate banks per channel. The banks are made up of 40 bulbs and it generally only takes one bank per channel to reach desired disinfection. There is a Hach flow proportioned autosampler located at the discharge side of the Trojan UV disinfection system. This is the location where plant final effluent composite samples are taken. From there the water flows through a 12" Parshall Flume where plant effluent flow rates are measured. Tertiary Treatment: From April to October each year the tertiary treatment plant is in operation. The plant consists of two separate Trident water filtration filters designed to further remove solids. Disinfected plant effluent is filtered and then chlorinated with a 12.5% solution of sodium hypochlorite. Water is stored onsite in a 0.5 MG holding tank before being pumped to storage facilities at the City Cemetery and Sweetwater County Crossroads West Park. Both facilities use this water for irrigation. In 2018 the City Cemetery used 39 MG and the Sweetwater County Crossroads West Park used 10 MG. 12 City of Rock Springs Pretreatment Audit Report WY-0022357 August 21, 2024 to August 22, 2024 Reclaimed Water Station: The reclaimed water building takes a portion of disinfected plant effluent and pumps it to various areas of the treatment plant for reuse. Before the water is sent out it is filtered and lightly chlorinated with a 6% sodium hypochlorite solution. On average the reclaimed water station pumps about 0.087 MGD. Areas where this water is in use include the Andritz Aquascreen, the RV dump station, the gravity belt thickener, and several hose locations used for plant washdown. Reclaimed water used for the Aquascreen cleaning in the Headworks Building is totalized with influent flow reading for the treatment plant. The same goes for reclaimed water used in the clarifiers as it will also affect the plant effluent flow total. Solids Handling: Waste holding tank Solids are removed from the bottom of the clarifiers and returned to the oxidation ditches. A portion of this flow is diverted to the Waste Holding Tank daily. The Waste Holding Tank consists of a mixer and two Hibbon Blowers used to maintain aerobic conditions within the tank. In cases where it is not necessary to thicken the waste activated sludge, the Waste Holding Tank may be bypassed and return activated sludge flow can be pumped directly to the Aerobic Digesters. Gravity belt thickener Activated sludge that has been wasted to the Waste Holding Tank will then be pumped to an Ashbrook Gravity Belt Thickener by use of two Wemco Hidrostal pumps. Each pump has a max output of 500 GPM depending on head pressure. Before reaching the gravity belt thickener the waste activated sludge is mixed with a cationic polymer to aid in the dewatering process. The waste activated sludge is thickened to a range of 2-6 percent total solids and pumped directly to the digester with the use of two Seepex progressive cavity pumps. Aerobic Digesters This plant is equipped with two Aerobic Digesters, each having a volume of 0.352 MG. Thickened waste activated sludge is fed to each digester evenly at 1,000 gallons per side. Once the thickened waste activated sludge enters the digester it will stay there for a minimum of 40 days. The temperature of each digester is maintained at or above 20 degrees Celsius. The digesters are aerated at different levels throughout the day to promote aerobic, and at times anoxic conditions. Aeration is achieved using five Aerzen blowers. Two blowers are available per side with a fifth blower having the capability of aerating either digester. Centrifuge When digested solids have reached class B biosolids requirements, they are pumped to the GEA Centrifuge by use of two Seepex progressive cavity pumps. The Centrifuge, with the aid of cationic polymer, will then dewater the digested sludge. The Centrifuge can be operated to dewater sludge to a range of 18-22 percent total solids. The dewatered sludge is augered to a hopper where it will fall to a dump truck. From there it is hauled to the Sludge Drying Pad. 13 City of Rock Springs Pretreatment Audit Report WY-0022357 August 21, 2024 to August 22, 2024 Sludge drying pad Digested waste activated sludge is sent to the drying pad, wind rowed and dried with the use of a Brown Bear Aerator. Dried sludge is moved off the pad and stored in two large storage beds. The drying pad contains drains for stormwater runoff. The water from these drains is returned to the Main Pump House for further treatment. Sludge drying beds There are 11 sludge drying beds located on site with a total volume of 0.495 MG. These beds are used as a backup when equipment failures in the solids drying process are encountered. 2.1 NPDES Permit The City's NPDES permit #WY-0022357, issued by the Wyoming Department of Environmental Quality (WYDEQ), contains provisions for an EPA-approved Pretreatment program in Part III.C. The permit was issued and effective on April 1, 2020 and will expire on March 31, 2025. 14 City of Rock Springs Pretreatment Audit Report WY-0022357 August 21, 2024 to August 22, 2024 POTW Figure 1 -City of Rock Springs Service Area 15 City of Rock Springs Pretreatment Audit Report WY-0022357 August 21, 2024 to August 22, 2024 Figure 2 - City of Rock Springs POTW Process Diagram 16 City of Rock Springs Pretreatment Audit Report WY-0022357 August 21, 2024 to August 22, 2024 3.0 Resources 3.1 Resources Regulatory Background The Pretreatment Regulations found in 40 C.F.R. 403.8(f)(1-6) include POTW Pretreatment requirements and procedures to implement an approved Pretreatment program. These requirements and procedures include the legal authority and the implementation procedures of the Pretreatment program (permitting, inspections, sampling, industrial waste survey, receipt of IU reporting and notification, record-keeping, slug discharge control, data evaluation and enforcement for non-compliance). In addition, the Pretreatment Regulations found in 40 C.F.R. 403.8(f)(3) state that the POTW shall have sufficient resources and qualified personnel to carry out the authorities and implementation procedures of the Pretreatment program. A Pretreatment program, in compliance with the criteria listed in the Pretreatment Regulations, requires adequate and qualified staffing to implement the Pretreatment program in its service area. The resources required for each implementation activity depend largely on the size of the service area, number of IUs/SIUs/sector control programs, and Pretreatment program policies. A compliant program also requires a consistent funding mechanism to ensure the program is adequately funded and equipped to fully implement the program. 3.2 Evaluation of the City's Resources and Funding According to the FY23 Pretreatment annual report, the City's resource commitment to the Pretreatment program is 1.25 FTE. The 1.25 FTE includes the Pretreatment Coordinator as a 1.0 FTE Pretreatment Specialist and a 0.25 FTE from the Wastewater Reclamation Facility (WRF) Supervisor. The Pretreatment Coordinator and the WRF Supervisor implement all programmatic activities such as the industrial user inventory/characterization, permitting, field activities such as inspections/sampling, compliance evaluation and enforcement. The Pretreatment program is provided support from the Collections Department personnel during sampling and some inspection activities. The City reported in the FY23 Annual Report that its Pretreatment program is budgeted $261,000 and is funded by Sewer Use Fees that are generated from residential and nonresidential users in the service area, permit fees, and trucked/waste hauler billing. The City appears to be well equipped to implement the field activities of the Pretreatment program and has portable automatic samplers, sampling equipment, confined space entry equipment, and personal protective equipment. Based on EPA's review of the City's implementation of its Pretreatment program, it appears that the City's current resources and budget is adequate to implement all programmatic activities of the Pretreatment program, in compliance with 40 C.F.R. 403.8(f)(3). 3.3 Examples of Available Pretreatment Training/Resources The EPA recommends the City participate in available Pretreatment training opportunities 17 City of Rock Springs Pretreatment Audit Report WY-0022357 August 21, 2024 to August 22, 2024 to acquire the necessary training to ensure its personnel is qualified to implement the Pretreatment program. This is not a comprehensive list of all Pretreatment related training/resources available. The City is encouraged to seek out training and resources that will support its Pretreatment program implementation. The EPA is also available to the City for Pretreatment training opportunities. The Region 8 Pretreatment workshop provided by Region 8 Pretreatment Association provides training sessions directly related to Pretreatment implementation, updates to upcoming regulations and policies, and networking opportunities. In addition, there is a Pretreatment Coordinators discussion forum to post questions regarding implementation and gather perspectives from peers within programs throughout the U.S. The discussion forum can be found at the following weblink: https://groups.io/g/Pretreatment/topics The EPA provides "Pretreatment 101" webinar training designed to provide consistent national training to local and state Pretreatment programs. The webinar series is located at https://www.epa.gov/npdes/national-pretreatment-program-training-and-webinars. Archived presentations may be downloaded, and a schedule of future training opportunities is located at the website. 4.0 Municipal Ordinance and Intergovernmental Agreements 4.1 Legal Authority Background 40 C.F.R. 403.8(f)(1) of the Pretreatment Regulations states: "The POTW shall operate pursuant to legal authority enforceable in Federal, State, or local courts, which authorizes or enables the POTW to apply and to enforce the requirements of sections 307 (b) and (c), and 402(b)(8) of the Clean Water Act (Act) and any regulations implementing those sections. Such authority may be contained in a statute, ordinance, or series of contracts or joint powers agreements which the POTW is authorized to enact, enter into or implement, and which are authorized by State law. At a minimum, this legal authority shall enable the POTW to: i. Deny or condition new or increased contributions of pollutants, or changes in the nature of pollutants, to the POTW by Industrial Users where such contributions do not meet applicable Pretreatment Standards and Requirements or where such contributions would cause the POTW to violate its NPDES permit. ii. Require compliance with applicable Pretreatment Standards and Requirements by Industrial Users. iii. Control through Permit, order, or similar means, the contribution to the POTW by each Industrial User to ensure compliance with applicable Pretreatment Standards and Requirements. In the case of Industrial Users identified as significant under 403.3(v), this control shall be achieved through individual permits or equivalent individual control mechanisms issued to each such User... 18 City of Rock Springs Pretreatment Audit Report WY-0022357 August 21, 2024 to August 22, 2024 iv. Require (A) the development of a compliance schedule by each Industrial User for the installation of technology required to meet applicable Pretreatment Standards and Requirements and (B) the submission of all notices and self-monitoring reports from Industrial Users as are necessary to assess and assure compliance by Industrial Users with Pretreatment Standards and Requirements, including but not limited to the reports required in 403.12. v. Carry out all inspection, surveillance and monitoring procedures necessary to determine, independent of information supplied by Industrial Users, compliance or noncompliance with applicable Pretreatment Standards and Requirements by Industrial Users. Representatives of the POTW shall be authorized to enter any premises of any Industrial User in which a Discharge source or treatment system is located or in which records are required to be kept under 403.12(o) to assure compliance with Pretreatment Standards. Such authority shall be at least as extensive as the authority provided under section 308 of the Act. vi. (A) Obtain remedies for noncompliance by any Industrial User with any Pretreatment Standard and Requirement. All POTW's shall be able to seek injunctive relief for noncompliance by Industrial Users with Pretreatment Standards and Requirements. All POTWs shall also have authority to seek or assess civil or criminal penalties in at least the amount of $1,000 a day for each violation by Industrial Users of Pretreatment Standards and Requirements. (B) Pretreatment requirements which will be enforced through the remedies set forth in paragraph (f)(1)(vi)(A) of this section, will include but not be limited to, the duty to allow or carry out inspections, entry, or monitoring activities; any rules, regulations, or orders issued by the POTW; any requirements set forth in control mechanisms issued by the POTW; or any reporting requirements imposed by the POTW or these regulations in this part. The POTW shall have authority and procedures (after informal notice to the discharger) immediately and effectively to halt or prevent any discharge of pollutants to the POTW which reasonably appears to present an imminent endangerment to the health or welfare of persons. The POTW shall also have authority and procedures (which shall include notice to the affected industrial users and an opportunity to respond) to halt or prevent any discharge to the POTW which presents or may present an endangerment to the environment, or which threatens to interfere with the operation of the POTW. The Approval Authority shall have authority to seek judicial relief and may also use administrative penalty authority when the POTW has sought a monetary penalty which the Approval Authority believes to be insufficient. vii. Comply with the confidentiality requirements set forth in 403.14." The provisions in 40 C.F.R. 403.8(f)(1)(i-vii) do not provide local Pretreatment programs with legal authority, but they do establish the minimum requirements for the local municipality to implement the Pretreatment program. A POTW's legal authority is derived from State law. Therefore, State law must confer the minimum legal authority required by the Pretreatment Regulations on a POTW. To apply the regulatory authority provided by State law, it is necessary for the POTW to establish local regulations to legally implement and enforce pretreatment requirements. A 19 City of Rock Springs Pretreatment Audit Report WY-0022357 August 21, 2024 to August 22, 2024 POTW's legal authority is typically established in a sewer use ordinance as part of the municipality's code, or in the case of a sanitation district, its Rules and Regulations. The EPA's 2007 Model Pretreatment Ordinance provides a template for POTWs that are required to develop pretreatment programs and can be found at the following website: https://www3.epa.gov/npdes/pubs/pretreatment_model_suo.pdf 4.2 City of Rock Springs Municipal Ordinance The EPA approved the City's Pretreatment program, including its legal authority and local limits on September 1, 1989. The City provided its Pretreatment legal authority found in Article 7-4, Plumbing and Sewer Code, Section 7-420, Pretreatment of the municipal ordinance for the EPA to review. The City also provided its Sector Control policies for Grease Interceptors, Mobile Food Vendors and Sand/Oil Interceptors, based on implementation of the best management practices authority established in the Pretreatment ordinance. Based on the EPA's review, the Pretreatment Regulations incorporated in Article 7-4, Plumbing and Sewer Code, Section 7-420, Pretreatment of the municipal ordinance provide the City the framework to implement the Pretreatment Regulations in the POTW's service area. 4.3 Inter-Jurisdictional or Governmental Agreements (IGA) 4.3.1 IGA Regulatory Background A POTW's authority to implement and enforce its approved Pretreatment program is directly related to its regulatory jurisdiction. The POTW's authority is established in ordinance or Rules and Regulations, which are in effect for its service area. Local entities with connectors, or outside jurisdictions to the service area that contribute wastewater, must establish legally binding mechanisms to ensure that all IUs in these outside contributing jurisdictions are subject to enforceable Pretreatment standards and requirements, as required in 403.8(f)(1). 40 C.F.R. 403.8(f)(1)(i) states, "The POTW shall operate pursuant to legal authority enforceable in Federal, State or local courts, which authorizes or enables the POTW to apply and to enforce the requirements of sections 307 (b) and (c), and 402(b)(8) of the Act and any regulations implementing those sections. Such authority may be contained in a statute, ordinance, or series of contracts or joint powers agreements which the POTW is authorized to enact, enter into or implement, and which are authorized by State law." [Emphasis added] The local entity that implements the Pretreatment program must either obtain this authority for itself through an IGA or ensure that the outside contributing jurisdiction has both the authority and the obligation to implement and enforce the Pretreatment Standards and Requirements against every IU that discharges to the POTW. 4.3.2 Evaluation of the City's IGAs with Outside Contributing Jurisdictions The City has two outside contributing jurisdictions discharging to the City's POTW, White 20 City of Rock Springs Pretreatment Audit Report WY-0022357 August 21, 2024 to August 22, 2024 Mountain Water and Sewer District and Clearview Improvement and Service District. The EPA reviewed the IGAs for both outside contributing jurisdictions during the audit. The IGA with the White Mountain Water and Sewer District was established on September 15, 2009 and delegates the City full authority to implement the Pretreatment program in Section 8. The IGA with the Clearview Improvement and Service District was established on June 4, 2019 and delegates the City full authority to implement the Pretreatment program in Section 10. Based on the EPA's review of the IGAs, the City has established the authority to implement the Pretreatment Regulations to every IU discharging to its POTW. 5.0 Local Limits 5.1 Local Limits Regulatory Background 40 C.F.R. 403.8(f)(4) of the Pretreatment Regulations require POTWs that are developing pretreatment programs to develop and enforce specific limits on prohibited discharges or demonstrate that the limits are not necessary. 40 C.F.R. 403.5(c)(1) states, "Each POTW developing a POTW Pretreatment Program pursuant to 403.8 shall develop and enforce specific limits to implement the prohibitions listed in paragraphs (a)(1) and (b) of this section [general and specific prohibitions]. Each POTW with an approved pretreatment program shall continue to develop these limits as necessary and effectively enforce such limits." [Clarification and emphasis added]. The National Pretreatment Program consists of three types of national pretreatment standards established by regulation that apply to industrial users. These include prohibited discharge standards, categorical standards, and local limits. Prohibited discharge and categorical standards are developed by the EPA to establish nationwide Pretreatment Standards. Prohibited discharge standards, comprised of general and specific prohibitions found in 40 C.F.R. 403.5(a) and (b) of the Pretreatment Regulations, apply to all IUs regardless of the size or type of operation. Categorical standards are uniform, technologybased standards that apply to specific process wastewater discharges from industrial categories. These categorical standards are found at 40 C.F.R. Parts 405 through 471. The EPA's promulgation of categorical standards does not relieve a POTW from its obligation to evaluate the need for and to develop local limits to meet the general and specific prohibitions in the Pretreatment Regulations. Because specific prohibitions and categorical standards provide only general protection against pass through and interference, local limits based on POTW-specific conditions may be necessary. Local limits are developed by POTWs to enforce the specific and general prohibitions, as well as any state and local regulations. An EPA-approved Pretreatment program is required to develop local limits that are protective of the POTW, the collection system, and the POTW's site-specific standards. These site-specific standards may be NPDES permit effluent limits, biosolids limits, environmental criterion, worker health and safety standards or other local standards. The EPA recommends that POTWs establish their local limits based on the maximum allowable headworks loading (MAHL) calculated for each pollutant of concern. The 21 City of Rock Springs Pretreatment Audit Report WY-0022357 August 21, 2024 to August 22, 2024 MAHL approach enables the POTW to calculate local limits considering the portion of the MAHL that is controllable (non-domestic discharges from IUs) from the uncontrollable portion (domestic sources, background concentrations, etc.). A pollutant's MAHL is determined by first calculating its Allowable Headworks Loading (AHL) for each POTW's site-specific standard or environmental criterion. Local limit development uses a massbalance approach to determine the AHLs for a POTW based on the environmental and treatment plant criteria. An AHL is the estimated maximum loading of a pollutant that can be received at a POTW's headworks, that should not cause a POTW to violate a treatment plant limit or environmental criterion. An AHL is developed to prevent interference or pass through. An AHL is calculated for each applicable POTW site-specific standard: pass through, sludge contamination, air quality standards, and the various forms of interference (i.e. biological treatment inhibition, sludge digestion inhibition). The AHLs for each pollutant of concern (POC) are calculated based on the various suitable environmental criteria, plant flow rates, and plant removal efficiency. After calculating a series of AHLs for each POC, the lowest AHL is chosen as the MAHL. MAHLs estimate the maximum combined loadings that can be received at the POTW's headworks from all sources. Maximum allowable industrial loadings (MAIL), developed by the POTW, represent the amount of pollutant loadings the POTW can receive from controlled sources (i.e., industrial users, some commercial sources, and some hauled waste) that the POTW chooses to control through local limits. Local limits can take many forms based on how MAILs are allocated by the POTW. The designation and implementation of these MAILs, including the allocation of loadings to SIUs, are left to each POTW. The POTW should provide a reasonable method of allocating the MAIL to the SIUs while ensuring the implementation procedures do not exceed the calculated MAHL. Typically, the POTWs allocate the MAIL as a uniform concentration-based or a mass limit to each SIU. The local limits should be based on the following: x Sampling of the service area to develop a representative data set collected for local limits (e.g., influent, effluent, biosolids, commercial, residential, industrial, trucked/hauled waste), x Evaluation of the current POTW standards/criteria (including, but not limited to: NPDES permit limits/conditions, water quality standards, biosolids standards), x Identification of the POTW removal efficiency and pollutant partitioning, x Evaluation of data to ensure it is current and representative of current conditions, x Identification of pollutants of concern, x Calculations of loadings and determination of MAHL, x Development of local limits and allocation methods. 5.2 Local Limits Requirements Established in the City's NPDES Permits The City's NPDES permit effective from April 1, 2020 through March 31, 2025 include 22 City of Rock Springs Pretreatment Audit Report WY-0022357 August 21, 2024 to August 22, 2024 local limit requirements in Part III.C.j.1.a. 5.3 The EPA Evaluation of the City's Local Limits 5.3.1 Technically-based Local Limits The City's current local limits were approved by the EPA on May 15, 2015. The 2015 local limits were developed by the City using SIU regulated flows located at the permitted monitoring points and are applicable to SIUs. The City's local limits are incorporated in in 2.3(A)(1) of the municipal ordinance. "No permitted Industrial User shall discharge or cause to be discharged wastewater that exceeds the following limits." Table 1 - Rock Springs Local Limits-Municipal Ordinance, 2.3(A)(1) Pollutant Symbol Daily Maximum (mg/L) Arsenic, Total As 0.25 Cadmium, Total Cd 0.012 Chromium, Total Cr 4.92 Copper, Total Cu 0.54 Lead, Total Pb 0.88 Mercury, Total Hg 0.016 Molybdenum, Total Mo 0.79 Nickel, Total Ni 3.14 Selenium, Total Se 0.15 Silver, Total Ag 0.59 Zinc, Total Zn 3.65 Chloride Cl 1,738 (1) (1) If a permitted industrial User (IU) exceeds 1,500 mg/L Chloride, the IU shall be required to identify source(s) of Chloride in its waste stream and develop options for reducing the concentration. 23 City of Rock Springs Pretreatment Audit Report WY-0022357 August 21, 2024 to August 22, 2024 5.3.2 Numeric Ordinance Limits In addition to the established technically-based limits in the municipal ordinance, the City has incorporated the following numeric limits in the municipal ordinance: Table 2 - City of Rock Springs Numeric Ordinance limits Pollutant Municipal ordinance Citation Daily Maximum (mg/L) Total Benzene, Toluene, Ethylbenzene, Xylenes (BTEX) 2.3(B) 0.75 Benzene 2.3(B) 0.05 Total Petroleum Hydrocarbons 2.1(B)(6) 103 Lower Explosive Limit (LEL) 2.1(B)(16) 5% Oil and Grease 2.1(B)(18) 200 Total Dissolved Solids (TDS) 2.1(C) (2) (2) A permitted Industrial User that discharges Total Dissolved Solids in excess of 1,083 mg/L shall be required to identify source(s) of TDS in its wastestream and develop options for reducing the concentration. 5.3.3 Dilution Prohibition The City has incorporated a prohibition on dilution in 2.5 of the municipal ordinance to ensure the IUs are appropriately managing their regulated wastestreams to meet compliance with an applicable Pretreatment Standard or Requirement: "No User shall ever increase the use of process water, or in any way attempt to dilute a discharge, as a partial or complete substitute for adequate treatment to achieve compliance with a discharge limitation unless expressly authorized by an applicable Pretreatment Standard or Requirement. The Control Authority may impose mass limitations on Users who are using dilution to meet applicable Pretreatment Standards or Requirements or in other cases when the imposition of mass limitations is appropriate." The dilution prohibition language in 2.5 meets the requirement in 40 C.F.R. Part 403.6(d) of the Pretreatment Regulations. 5.4 Local Limits Technical Evaluation-Regulatory Background 40 C.F.R. 122.44(j)(2)(ii) of the NPDES regulations require POTWs to provide a written technical evaluation of the need to revise local limits following permit issuance or reissuance. The technical evaluation is a detailed re-evaluation of data, criteria, conditions, 24 City of Rock Springs Pretreatment Audit Report WY-0022357 August 21, 2024 to August 22, 2024 and assumptions on which local limits are based to determine whether any significant changes affecting the local limits have occurred. Chapter 7 of the Local Limits Development Guidance Manual, EPA-833-R-04-002A, July 2004 provides guidance on completing the technical evaluation of local limits. The Annual Pretreatment Reports submitted to the EPA provide the POTW with an opportunity to perform reviews for exceedances of the established MAHL for the POCs, on an annual basis. The POTW compares both the maximum and average influent data for the reporting year against the MAHL to determine if there were any exceedances. In addition, the POTW is required to report biosolids data to determine if there were any changes or concerns with the biosolids loadings. An exceedance of the established MAHL may be indicative of a change in the service area, changes to the POTW operations or changes to domestic or non-domestic loadings and may indicate a need to recalculate the local limits. However, the annual review may not have addressed conditions that can change over time, such as operating conditions, environmental criteria/standards, data, or assumptions that may make local limits no longer appropriate, protective or legally defensible. As a follow-up to MAHL exceedances listed on the annual report and as required during a permit reissuance, a POTW should compare its current conditions and requirements with those that existed when the local limits were developed. The EPA recommends that POTWs determine if re-calculating existing local limits, or developing MAHLs for new pollutants of concern, is necessary in response to the following criteria: 1. Removal Efficiencies a. Modification to the POTW or new POTW brought online. b. Changes in POTW processes or operations that have affected the POTW removal efficiencies. 2. Total POTW or IU Loading a. Significant changes to flow to the POTW. b. Significant changes to loadings to the POTW due to new IUs, changes in loadings at existing IUs or significant growth in the service area. c. Significant changes in loadings from SIUs in the service area. 3. Limiting Criteria a. New or revised NPDES permit limits. b. New or revised biosolids standards. c. Changes in EPA or State Criteria (acute and chronic water quality standards for the receiving waters, reuse water quality criteria) at the time of local limit development to existing criteria. 4. Sludge Characteristics or Method of Disposal a. Changes in loadings to biosolids. b. Changes in biosolids disposal methods. 5. Background Concentrations of Pollutants in Receiving Water 25 City of Rock Springs Pretreatment Audit Report WY-0022357 August 21, 2024 to August 22, 2024 5.5 Technical Evaluation of the City's Local Limits The City's NPDES permit issued by the WYDEQ includes the following requirements for a technical evaluation of the local limits: "The Permittee shall establish and enforce specific local limits to implement the provisions of 40 CFR Section 403.5(a) and (b), as required by 40 CFR Section 403.5(c). The Permittee shall continue to develop these limits as necessary and effectively enforce such limits. In accordance with EPA policy and with the requirements of 40 CFR sections 403.8(f)(4) and 403.5(c), the Permittee shall determine if technically based local limits are necessary to implement the general and specific prohibitions of 40 CFR sections 403.5(a) and (b). This evaluation should be conducted in accordance with the latest revision of the "EPA Region VIII Strategy for Developing Technically Based Local Limits", and after review of EPA's "Local Limits Development Guidance" July 2004. Where the Permittee determines that revised or new local limits are necessary, the Permittee shall submit the proposed local limits to the Approval Authority in an approvable form in accordance with 40 CFR Section 403.18." The NPDES permit issued by the WYDEQ will expire on March 31, 2025. The reissued permit will require a technical evaluation of the City's 2015 local limits to incorporate current data, current standards, construction, or rehab updates to the POTW that result in different removal efficiency, growth in the service area and to incorporate SIU changes in the service area. The City will be required to submit the technical evaluation to the EPA within 12 months of permit reissuance, as a condition of the reissued NPDES permit and update local limits. The EPA recommends the City develop a service area sampling plan to develop a dataset for loadings in the service to capture current conditions and that is representative of potential seasonal variations. The EPA requires a minimum of 10 data points in the datasets to ensure adequate data to calculate local limits. In addition, the City should ensure it gathers a representative dataset of INF-EFF of new or projected POTW construction updates that may impact the POTW's removal efficiency. The City should evaluate the incorporation of adopted ordinance numeric limits during the local limits update and determine the justification for these adopted limits. EPA will provide the City EPA guidance for BTEX/benzene, oil/grease and TPH. 5.6 Permit or Site-Specific Limits Local municipalities implementing the Pretreatment program should have the ability to establish site or permit-specific limits as deemed necessary to be protective of the POTW. This is a beneficial authority because situations or projects may occur in the service area that the municipality may want to provide control to protect the POTW. However, the current limits in the ordinance may not address the pollutant of concern. 26 City of Rock Springs Pretreatment Audit Report WY-0022357 August 21, 2024 to August 22, 2024 The EPA considers the development of any local limit, whether codified in the municipal ordinance/rules and regulations or developed on a site-specific situation (i.e., permitsspecific limit) to be a program modification under 40 C.F.R 403.18 (53 FR 40579, Final Rule, General Pretreatment Regulations for Existing and New Sources, October 17, 1988). The development of any local limit is required to follow the approval and public notice provisions, both at the local level and by submitting to the EPA. 40 C.F.R 403.5(c)(3) of the Pretreatment Regulations states, "Specific effluent limits shall not be developed and enforced without individual notice to persons or groups who have requested such notice and an opportunity to respond." The EPA recommends that POTWs conduct public participation in the local limits process (whether codified in the municipal ordinances/rules and regulations or new limits developed in a permit) as openly as possible. This may involve notifying the SIUs/IUs and other affected parties of the proposed limits or announcing a 30-day public comment period. This would allow sufficient time for the public to participate, which is a fundamental goal of the Clean Water Act in Section 101(e). The City has established the ability to develop site or permit-specific limits in 2.3(A)(2) of its municipal ordinance: "The City may, at its sole discretion, implement local limits through allocation of the Maximum Allowable Industrial Load (MAIL) to permitted Industrial Users. The MAIL is the total load available to be allocated to permitted Industrial Users and corresponds to the uniform concentration local limits shown in the table above. The MAILs that correspond to the Daily Maximum Limits are hereby incorporated by reference." Based on the EPA's review of the Pretreatment records, the City has not established sitespecific limits in the SIU permits. 6.0 Pretreatment Operating Procedures 6.1 Regulatory Background 40 C.F.R. 403.8(f)(2) of the Pretreatment Regulations states, "The POTW shall develop and implement procedures to ensure compliance with the requirements of a Pretreatment Program." [emphasis added] The Pretreatment Regulations identify these minimum procedures in 40 C.F.R. 403.8(f)(2)(i-viii) to include the following implementation activities, summarized below: x Identify and locate all possible IUs that might be subject to the Pretreatment program, x Obtain information describing the character and volume of wastes discharged by IUs, x Notify IUs of all applicable Pretreatment standards and other applicable State or Federal standards or requirements, x Review self-monitoring reports and other notices submitted by IUs, x Randomly sample and analyze effluents from IUs, x Evaluate whether each SIU needs a slug discharge control plan, 27 City of Rock Springs Pretreatment Audit Report WY-0022357 August 21, 2024 to August 22, 2024 x Investigate instances of noncompliance with Pretreatment standards and requirements, x Comply with public participation requirements. The requirements listed in 40 C.F.R. 403.8(f)(2) include the development of procedures. Adequate and updated standard operating procedures (SOPs) provide the following benefits to a Pretreatment program: x Develop the baseline knowledge of the Pretreatment Regulations and establish the framework for program implementation, x Adequately implement the authorities established in the municipal ordinance and ensure consistency in program implementation, x Retain institutional and historical knowledge developed within the POTW's program, and x Provide a valuable training resource for new or inexperienced staff members. Ultimately, the benefits of valid SOPs to the Pretreatment program are increased efficiency, along with improved data comparability, credibility, and legal defensibility. In addition, the development of written SOPs and templates allow the EPA to determine if the procedures adequately implement the legal authority developed in the municipal ordinance/rules and regulations as required in 40 C.F.R. 403.8(f): "A POTW Pretreatment program must be based on the following legal authority and include the following procedures. These authorities and procedures shall at all times be fully and effectively exercised and implemented." 6.2 Standard Operating Procedures (SOPs) The EPA evaluated the City's procedures and templates during the audit to ensure these meet the requirements listed in 40 C.F.R. 403.8(f)(2). As previously discussed, developing SOPs are beneficial for the City's Pretreatment program but most importantly, to ensure adequate implementation of the authorities established in the municipal ordinance and ensure consistency in program implementation. The EPA considers the Industrial User Inventory and Characterization, Sampling Plan/QA-QC, and the Enforcement Response Plan to be a priority and required SOPs to ensure consistent implementation of the City's legal authority. EPA evaluated these priority SOPs and provided comments in the following sections within this audit report: x Industrial User Inventory and Characterization Procedures (discussed in 7.0), x Sampling Plan, Site-Specific Sampling Protocol, Quality Assurance and Quality Control (discussed in 10.0), and x Enforcement Response Plan and Data Compliance Evaluation (discussed in 11.0). In addition to the above-mentioned SOPs, the City has developed an IU Inventory Guidance, a narrative SNC tracking spreadsheet, and checklists for evaluating selfmonitoring compliance reports and compliance monitoring results. The EPA recommends the City evaluate the need to develop Pretreatment procedures, as necessary. 28 City of Rock Springs Pretreatment Audit Report WY-0022357 August 21, 2024 to August 22, 2024 6.3 Templates Templates and checklists are also critical to a Pretreatment program to ensure consistent and appropriate implementation of the Pretreatment regulations. The City has developed a permit application for discharging facilities and an SIU permit template. The permit application appears to provide adequate information and data for the City to develop an appropriate control mechanism. The evaluation of the permit template is included in 8.4 of this audit report. 6.4 Records and Data Management 6.4.1 Regulatory Background The recordkeeping requirements of the Pretreatment program are established in 40 C.F.R. 403.12(o)(1-3): "(1) Any Industrial User and POTW subject to the reporting requirements established in this section shall maintain records of all information resulting from any monitoring activities required by this section, including documentation associated with Best Management Practices. Such records shall include for all samples: (i) The date, exact place, method, and time of sampling and the names of the person or persons taking the samples. (ii) The dates analyses were performed. (iii) Who performed the analyses. (iv) The analytical techniques/methods use; and (v) The results of such analyses. (2) Any Industrial User or POTW subject to the reporting requirements established in this section (including documentation associated with Best Management Practices) shall be required to retain for a minimum of 3 years, any records of monitoring activities and results (whether or not such monitoring activities are required by this section) and shall make such records available for inspection and copying by the Director and the Regional Administrator (and POTW in the case of an Industrial User). This period of retention shall be extended during the course of any unresolved litigation regarding the Industrial User or POTW or when requested by the Director or the Regional Administrator. (3) Any POTW to which reports are submitted by an Industrial User pursuant to paragraphs (b), [baseline monitoring reports] (d), [90-day compliance reports] (e), [categorical industrial user monitoring reports] and (h) [significant industrial user monitoring reports] of this section shall retain such reports for a minimum of 3 years and shall make such reports available for inspection and copying by the Director and the Regional Administrator. This period of retention shall be extended during the course of any unresolved litigation regarding the discharge of pollutants by the Industrial User or the operation of the POTW Pretreatment Program or when requested by the Director or the Regional Administrator." 29 City of Rock Springs Pretreatment Audit Report WY-0022357 August 21, 2024 to August 22, 2024 6.4.2 Recordkeeping and Data Management Based on information gathered during the audit, the SIU permit and IU records are located in the Pretreatment Coordinator/Specialist's office and are maintained for at least three years, and much longer. The SIUs are chronologically organized and include the relevant records such as permit, permit rationale, control plans, inspections, enforcement actions, correspondence, etc. 6.5 Receipt of Discharge Monitoring Reports and Notifications The Pretreatment regulations in 40 C.F.R. 403.8(f)(2)(vii) require a POTW to "Investigate instances of noncompliance with Pretreatment Standards and Requirements, as indicated in the reports and notices required under 403.12 [IU compliance reports], or indicated by analysis, inspection, and surveillance activities [control authority monitoring]." This requires the POTW to ensure adequate receipt and tracking of self-monitoring reports and notifications, have procedures to evaluate the data and information contained within these reports and notices, and determine compliance with the Pretreatment standards (e.g., permit limits and conditions). The SIU self-monitoring reports, notifications and other reports submitted are date stamped by hand as received. The City ensures the reports/notifications are complete, received by the due date and evaluates compliance, based on its review of the information in the reports and notifications. The City documents its compliance evaluation in a self-monitoring report (SMR) compliance checklist. 6.6 Management of Confidential Records 40 C.F.R. 403.14 of the Pretreatment Regulations establishes the public availability of the Pretreatment records and the provisions to establish confidential business information (CBI). The City has incorporated the public availability and confidentiality requirements in Section 8.1 of the municipal ordinance: "Information and data on a User obtained from reports, surveys, wastewater discharge permit applications, Individual or General Wastewater Discharge permits, and monitoring programs, and from the Control Authority's inspection and sampling activities, shall be available to the public without restriction, unless the User specifically requests, and is able to demonstrate to the satisfaction of the Control Authority, that the release of such information would divulge information, processes, or methods of production entitled to protection as trade secrets under applicable State law. Any such request must be asserted at the time of submission of the information or data. When requested and demonstrated by the User furnishing a report that such information should be held confidential, the portions of a report which might disclose trade secrets or secret processes shall not be made available for inspection by the public, but shall be made available immediately upon request to governmental agencies for uses related to the NPDES program or pretreatment program, and in enforcement proceedings involving the person furnishing the report. Wastewater constituents and characteristics and other effluent data, as defined at 40 CFR 2.302 shall not be recognized as confidential information and shall be available to the public without restriction. " 30 City of Rock Springs Pretreatment Audit Report WY-0022357 August 21, 2024 to August 22, 2024 According to information gathered during the audit, the City has not received confidential business information. 7.0 Industrial User Inventory and Characterization 7.1 Regulatory Background The Pretreatment Regulations state in 40 C.F.R. 403.8(f)(2)(i-iii) that a POTW shall develop and implement procedures to ensure compliance with requirements of a Pretreatment Program. [These requirements are summarized after the regulation language in bold and italics font]. i. "Identify and locate all possible Industrial Users which might be subject to the POTW Pretreatment Program. Any compilation, index or inventory of Industrial Users made under this paragraph shall be made available to the Regional Administrator or Director upon request." This requires a POTW to develop and maintain an inventory of IUs in the service area. ii. "Identify the character and volume of pollutants contributed to the POTW by the Industrial Users identified under paragraph (f)(2)(i) of this section. This information shall be made available to the Regional Administrator or Director upon request." This requires a POTW to characterize the IUs in the inventory of the service area. iii. "Notify Industrial Users identified under paragraph (f)(2)(i) of this section, of applicable Pretreatment Standards and any applicable requirements under sections 204(b) and 405 of the Act and subtitles C and D of the Resource Conservation and Recovery Act. Within 30 days of approval pursuant to 40 C.F.R. 403.8(f)(6), of a list of significant industrial users, notify each significant industrial user of its status as such and of all requirements applicable to it as a result of such status." These procedures must include the notification of IUs of applicable Pretreatment Standards and other applicable requirements. The Pretreatment Regulations at 40 C.F.R. 403.8(f)(6) state, "The POTW shall prepare and maintain a list of its non-domestic or Industrial Users meeting the criteria in 403.3(v)(1). The list shall identify the criteria in 403.3(v)(1) applicable to each Industrial User and, where applicable, shall also indicate whether the POTW has made a determination pursuant to 403.3(v)(2) that such Industrial User should not be considered a Significant Industrial User. The initial list shall be submitted to the Approval Authority pursuant to 403.9 or as a non-substantial modification pursuant to 403.18(d)." Approved Pretreatment programs are required by the Pretreatment Regulations to understand their service area and outside contributing jurisdictions, by developing and maintaining an inventory of IUs. In addition, the Pretreatment Regulations require a Pretreatment program to characterize the IUs listed on the inventory and notify the IU of their status under the Pretreatment program. For example, the following characterizations may apply to an IU, based on information received from questionnaires, drive-by or facility inspections: x The IU is not characterized as significant, based on volume and characteristic of 31 City of Rock Springs Pretreatment Audit Report WY-0022357 August 21, 2024 to August 22, 2024 the discharged wastewater. x The IU is characterized as significant and issued a permit. x The IU is not characterized as significant, but loadings need to be controlled using BMPs in a source control program. x The IU is generating wastewaters that are significant but is characterized as a zero- discharging facility. The Industrial Waste Inventory and Characterization or industrial waste survey (IWS)/ IU inventory procedures are an important component to an effective Pretreatment program because this is a POTW's first exposure to the IUs, allows the POTW to determine if an IU is significant, notify the IU of its status under the Pretreatment regulations, and determine the appropriate type of control mechanisms for these facilities to protect the POTW and collection system. 7.2 Industrial User Identification and Characterization Procedure 40 C.F.R. 403.8(f)(2) of the Pretreatment Regulations require the City to "develop and implement procedures" that "enable the POTW" to comply with these Pretreatment Program requirements found in 40 C.F.R. 403.8(f)(2)(i-iii). The City developed an IU Inventory Guidance to comply with the Federal Pretreatment Regulations. The guidance provides procedures the City uses to identify IUs in collaboration with the Planning and Building departments, as well as various inspection programmatic activities. The IU Inventory guidance also describes the methods the City uses to characterize, classify IUs and notify them of applicable Pretreatment Standards To implement the IU Inventory guidance, the City participates in the Utility Review meetings to be aware of business changes and additions to the service area and the City signs off on business license applications to ensure the Pretreatment requirements and conditions are included in the new facility or changes to existing IUs. This provides the City the ability to evaluate IUs and provide notification of Pretreatment requirements. The City sends out an IWS to IUs every other year to capture current conditions and maintain the IU inventory. The EPA recommends the City determine IUs or sectors of IUs that have the potential to impact the POTW, such as machine shops or metal working IUs that may change their process to include unit operations subject to the Metal Finishing Categorical Pretreatment Standards found in 40 CFR 433. The City may not need to gather survey information from every IU and should prioritize these IU sectors or specific IUs to require more frequency survey information is gathered to update/maintain the IU inventory and characterization of IUs. In addition, the EPA recommends the City also collaborate with the Fire Department because they are in the facilities in the service area and may provide additional information regarding potential for significant process/wastewater generation or spill/slug potential in the service area. 7.3 Industrial User Database of the City's Service Area 40 C.F.R. 403.8(f)(2)(i-iii) of the Pretreatment regulations require the City to identify and locate all IUs in its service area, identify the character and volume of pollutants contributed by these IUs based on current information, and notify these IUs of applicable 32 City of Rock Springs Pretreatment Audit Report WY-0022357 August 21, 2024 to August 22, 2024 Pretreatment Standards and Requirements. The City provided a current IU inventory of the IUs in its service area for EPA to review. Based on EPA's review, the City's IU inventory is maintained in a database and consists of 812 IUs. The IU inventory appears to be current of the POTW's service area and includes contact information and includes codes for characterizing the IUs in the inventory. The EPA currently provides "Pretreatment 101" webinar training, and a training for "Industrial User Inventory and Characterization Procedures," provided in September 2010, is archived at the following website: https://www.epa.gov/npdes/national-pretreatment-program-events-training-andpublications#pretreat101 8.0 Control Mechanism (Permit) Evaluation and Permit Specific Issues 8.1 Regulatory Background POTWs are required to issue control mechanisms to IUs identified through IU Inventory and Characterization procedures as SIUs. Individual permits or general control mechanisms authorize the discharge of wastewater to a POTW upon condition that the discharger complies with the permit limitations and conditions. An SIU permit is effective for only a limited period and should be revocable by the issuing authority at any time for just cause. In addition, the POTW's legal authority will typically include a provision that forbids the discharge of industrial wastewater from a SIU without a current permit. The Pretreatment Regulations establish the required permit conditions in 40 C.F.R. 403.8(f)(1)(iii)(B)(1-6) that include the following minimum elements: 1. Statement of duration (in no case more than five years); 2. Statement of non-transferability without, at a minimum, prior notification to the POTW and provision of a copy of the existing control mechanism to the new owner or operator; 3. Effluent limits, including Best Management Practices, based on applicable general Pretreatment Standards, categorical Pretreatment Standards, local limits, and State and local law; 4. Self-monitoring, sampling, reporting, notification and recordkeeping requirements, including an identification of the pollutants to be monitored, sampling location, sampling frequency, and sample type, based on the applicable general Pretreatment Standards, categorical Pretreatment Standards, local limits, and State and local law; 5. Statement of applicable civil and criminal penalties for violation of Pretreatment Standards and requirements, and any applicable compliance schedule. Such schedules may not extend the compliance date beyond applicable federal deadlines; 6. Requirements to control Slug Discharges, if determined by the POTW to be necessary. The reporting and notification requirements in permit condition #4 above are found in 40 C.F.R. 403.12 of the Pretreatment Regulations and include the following: 33 City of Rock Springs Pretreatment Audit Report WY-0022357 August 21, 2024 to August 22, 2024 x Baseline Monitoring Reports - 403.12(b) x Compliance Schedule Progress Reports - 403.12(c) x 90-Day Compliance Reports - 403.12(d) x CIU Periodic Compliance Reports - 403.12(e) x Notice of Potential Problems, including Slug Loading - 403.12(f) x Notification of Changes Affecting Slug Discharge Potential - 403.8(f)(2)(vi) x 24-Hour Non-Compliance Notification - 403.12(g) x SIU Periodic Compliance Reports - 403.12(h) x Notification of Changed Discharge - 403.12(j) x Notification of Hazardous Waste Discharge - 403.12(p) x Notification of Bypass - 403.17 Under general principles of administrative law, permit applicants and other interested parties may challenge the POTW's permit decisions, including the permit limitations and conditions and the POTW's authority to issue the permit. The POTW must ensure that it has the requisite legal authority to impose Pretreatment Standards and Requirements in SIU permits and that it exercises its authority in a consistent and non-arbitrary manner. The local ordinance must clearly provide the POTW with the following authorities to support the permit requirements found in 40 C.F.R. 403.8(f)(1)(iii): x Authority to regulate all Industrial Users contributing wastewater to the POTW. x Authority to require and issue permits, orders, or other control mechanisms, including: o Authority to require Industrial Users to submit all data that the POTW deems relevant to permit decisions and provisions for public access to data. o Authority to enter, inspect, and sample to verify information supplied by the Industrial User as well as to assess the Industrial User's compliance status. o Authority to incorporate local limits, including BMPs (if applicable). o Authority to incorporate federal and state Pretreatment Standards and Requirements. o Authority to require self-monitoring, record keeping, reporting, and notifications by the permittee. o Authority to develop other appropriate permit conditions. x Authority to enforce sewer use ordinance and discharge permit violations. x Authority to require the development of a slug discharge control plan. The POTW is required to establish the legal authority to require an IU to complete and file a permit application, with current information, to receive an initial or reissued permit. A permit application enables the POTW to obtain the information necessary to characterize the facility, to evaluate the quality and quantity of wastewater discharged, or projected to be discharged for a new facility, and to determine the applicable Pretreatment Standards and controls. The permit application serves as the formal request from the IU to discharge to the POTW and is required to be signed by a responsible corporate officer of the IU, as defined in 40 C.F.R. 403.12(l) of the Pretreatment Regulations. In addition to the permit application, the POTW should evaluate, if available, historic IU effluent data, compliance reports, previous inspection reports, Safety Data Sheets, etc. 34 City of Rock Springs Pretreatment Audit Report WY-0022357 August 21, 2024 to August 22, 2024 Throughout the permit drafting process, the POTW should carefully and thoroughly document each step in a permit rationale or statement of basis. A statement of basis is a document that provides a justification of the permit conditions and limits based on a characterization of the IU, its wastewater discharge, and the applicable Pretreatment Standards and Requirements. The statement of basis should include a description of the facility's production, process(es), wastewater generation/management, and discharge locations to adequately characterize the facility. The statement of basis should also identify the appropriate Federal, State, and Local Pretreatment Standards, based on the IU's characterization; and should provide justification for permit conditions and requirements, such as pollutants of concern, monitoring/reporting frequencies, representative sampling types, notification requirements, slug discharge control, operation and maintenance requirements, etc. The statement of basis facilitates defending any challenges that the permit terms and conditions were developed arbitrarily or capriciously and provides the required documentation in the permit record of any relief from otherwise applicable requirements (i.e., pollutants not expected to be present, equivalent limits, decisions on general control mechanisms, decisions on Non-Significant Categorical Industrial User (NSCIU) classification, and decisions on reduced monitoring requirements). In addition, the statement of basis can serve as a resident document to preserve institutional knowledge and continuity for new or different staff members. The EPA updated the IU Permitting Guidance Manual, 833-R-12-0001A in September 2012. This guidance manual supports the implementation of the permit conditions found in 40 C.F. R. 403.8(f)(1)(iii)(B)(1-6) of the Pretreatment Regulations. The guidance manual is intended to provide both new and experienced permit writers with conceptual support and specific examples to strengthen their permit development expertise. The guidance manual references technical guidance developed by the EPA regarding local limits, enforcing Pretreatment Standards and Requirements, controlling hauled waste, information regarding compliance inspections and sampling, and BMPs. The IU Permitting Guidance Manual can be found at the following website: https://www.epa.gov/sites/production/files/201510/documents/industrial_user_permitting_manual_full.pdf 8.2 The EPA's Evaluation of the City's Permitting Legal Authority The EPA evaluated the City's municipal ordinance to ensure it provides an adequate framework to require permit coverage, to deny or condition non-domestic wastewater contributions and to establish adequate permit conditions. x Section 4.2(A) -establishes the requirement for SIUs and CIUs to obtain a wastewater discharge permit. x Section 4.2(B) -establishes the requirement for other IUs to obtain a wastewater discharge permit, as necessary to comply with the ordinance. x Section 4.4 - contains the permit application contents. x Sections 4.6 -- establishes the authority for the City to deny or conditions 35 City of Rock Springs Pretreatment Audit Report WY-0022357 August 21, 2024 to August 22, 2024 wastewaters discharged to the public sewers. x Section 5.3 - establishes the permit conditions to prevent Passthrough or Interference and to protect the POTW, worker health and safety, biosolids and the receiving stream water quality. 8.3 Permit Template Overview The EPA evaluated the City's permit template to ensure the City is incorporating the required permit conditions found in 40 C.F.R. 403.8(f)(1)(iii)(B)(1-6) of the Pretreatment required Regulations and Section 5.3 of the City's municipal ordinance. 8.4 Specific Permit Record Findings The City has identified three IUs in the service area that is determined to be significant industrial users (SIU) and that has been issued a permit under the Pretreatment program. Findings from the EPA's review of the Pretreatment records, including the facility inspection report, statement of basis, permit, compliance evaluation, and enforcement records are listed below: 8.4.1 Permit Records Overview 1. The Pretreatment Regulations at 40 C.F.R. 403.8(f)(2)(ii) require the City to "Identify the character and volume of pollutants contributed to the POTW." The SIU inspection reports include minimal descriptions of the facility's unit operations. Facility inspection report provide adequate detail regarding the SIU's chemical storage/handling/transfer, process/unit operations, wastestream generation from these unit operations, wastestream management or wastewater treatment, sampling procedures to provide a current characterization, including an evaluation of slug discharge potential and process or treatment plant changes. This information is important to capture current conditions and determine if control such as an SIU permit or BMPs are necessary or if modifications to existing control mechanism or control plans such as slug discharge control plans or spill plans are necessary. a. The EPA recommends the City gather digital photos during SIU inspections to provide current photos of areas relevant to the Pretreatment permit, including but not limited to floor drains, unit operations, raw material/chemical storage, applicable chemical handling equipment, wastestreams, treatment. 2. The Pretreatment Regulations at 40 C.F.R. 403.8(f)(2)(iii) require the City to "Notify Industrial Users identified under paragraph (f)(2)(i) of this section, of applicable Pretreatment Standards..." Based on the EPA's review of the Pretreatment records, the City provides adequate notice to the SIU or IU of applicable Pretreatment Standards. 3. Permit Template: Based on the EPA's review, the City's permit template complies with the permit conditions found in the Pretreatment Regulations and incorporated in the City's municipal ordinance, with the following exception: 36 City of Rock Springs Pretreatment Audit Report WY-0022357 August 21, 2024 to August 22, 2024 [The EPA's observations and findings are included in the 2024-09-19 - Rock Springs Permit Template Review and summarized below.] a. Requirement to conduct representative sampling absent in the permit template [40 CFR 403.12(g)(3) and section 6.11 of the City's municipal ordinance]. The City needs to update its permit template to include the requirement to conduct representative sampling for monitoring related to permit compliance. 4. Self-Monitoring Reports: Based on the EPA's review of the Pretreatment records, it appears that the City is adequately evaluating self-monitoring reports for compliance, including date/time stamping the reports to ensure they meet the due date required in the permit. 5. The Pretreatment records appear to be very well organized and current. The City uses an SMR and sample results compliance checklists to track due dates for the self-monitoring reports and determine compliance with the permit conditions. These checklists are useful tools for the City to ensure consistent compliance evaluation. 6. Based on the EPA's review of the Pretreatment records, it appears the City is adequately conducting SNC calculations of the numeric criteria and determination of the narrative SNC criteria in the Pretreatment records. 8.4.2 Memorial Hospital 1. No corrective action items identified. 8.4.3 Tri-Hydro RS1 1. The City terminated the permit on December 14, 2023. The Pretreatment records for this IU included appropriate documentation related to the permit termination. 2. No corrective action items identified. 8.4.4 Tri-Hydro RS8 1. The City terminated the permit on December 14, 2023. The Pretreatment records for this IU included appropriate documentation related to the permit termination. 2. No corrective action items identified. 9.0 Significant Industrial User Facility Inspections 9.1 Regulatory Background The General Pretreatment Regulations at 40 C.F.R. 403.8(f)(1)(v) states that the POTW shall have the legal authority to: "Carry out all inspection, surveillance and monitoring procedures necessary to determine, independent of information supplied by Industrial Users, compliance or noncompliance 37 City of Rock Springs Pretreatment Audit Report WY-0022357 August 21, 2024 to August 22, 2024 with applicable Pretreatment Standards and Requirements by Industrial Users. Representatives of the POTW shall be authorized to enter any premises of any Industrial User in which a Discharge source or treatment system is located or in which records are required to be kept under 403.12(o) to assure compliance with Pretreatment Standards. Such authority shall be at least as extensive as the authority provided under section 308 of the Act;" 40 C.F.R. 403.8(f)(2)(v) of the Pretreatment Regulations requires the POTW to inspect its SIUs at least once per year. 40 C.F.R. 403.8(f)(2)(ii) require the City to "Identify the character and volume of pollutants contributed to the POTW." 40 C.F.R. 403.8(f)(2)(vii) establishes the standard of evidence collection during sampling or inspection activities: "Investigate instances of noncompliance with Pretreatment Standards and Requirements, as indicated in the reports and notices required under 403.12, or indicated by analysis, inspection, and surveillance activities described in paragraph (f)(2)(v) of this section. Sample taking and analysis and the collection of other information shall be performed with sufficient care to produce evidence admissible in enforcement proceedings or in judicial actions." Typically, an inspector is the only representative from the POTW that regularly appears at the IU's facility and significantly represents the POTW's role as a responsible public agency, observing the actions and evaluating the performance of the regulated industry. 9.2 Right of Entry The City has established the authority for right of entry in 7.1 of the municipal ordinance: "7.1 Right of Entry Inspection and Sampling. The Control Authority shall have the right to enter the premises of any User to determine whether the User is complying with all requirements of this ordinance and any Individual or General Wastewater Discharge permit or order issued hereunder. Users shall allow the Control Authority ready access to all parts of the premises for the purposes of inspection, sampling, records examination and copying, and the performance of any additional duties. A. Where a User has security measures in force which require proper identification and clearance before entry into its premises, the User shall make necessary arrangements with its security guards so that, upon presentation of suitable identification, the Control Authority shall be permitted to enter without delay for the purposes of performing specific responsibilities. B. The Control Authority shall have the right to set up on the User's property, or require installation of, such devices as are necessary to conduct sampling and/or metering of the User's operations. 1. The monitoring facilities should normally be situated on the User's premises, but the City may, when such a location would be impractical or cause undue hardship on the User, allow the facility to be constructed in the public street or sidewalk area and located so that, it will not be obstructed by landscaping or parked vehicles. 2. Whether constructed on public or private property, the sampling and monitoring 38 City of Rock Springs Pretreatment Audit Report WY-0022357 August 21, 2024 to August 22, 2024 facilities shall be provided in accordance with the City's requirements and all applicable local construction standards and specifications. Construction shall be completed within 60 days following written notification by the City. C. The Control Authority may require the User to install monitoring equipment as necessary. The facility's sampling and monitoring equipment shall be maintained at all times in a safe and proper operating condition by the User at its own expense. All devices used to measure wastewater flow and quality shall be calibrated every quarter to ensure their accuracy. D. Any temporary or permanent obstruction to safe and easy access to the facility to be inspected and/or sampled shall be promptly removed by the User at the written or verbal request of the Control Authority and shall not be replaced. The costs of clearing such access shall be paid by the User. E. The Control Authority may use Digital Photography during an inspection to documents conditions found on a site and, or as evidence. F. Unreasonable delays in allowing the Control Authority access to the User's premises shall be a violation of this ordinance. " In addition, the City has established the authority to search warrant authority directly into its ordinance in section 7.2: "7.2 Search Warrants. If the Control Authority has been refused access to a building, structure, or property, or any part thereof, and is able to demonstrate probable cause to believe that there may be a violation of this ordinance, or that there is a need to inspect and/or sample as part of a routine inspection and sampling program of the City of Rock Springs designed to verify compliance with this ordinance or any permit or order issued hereunder, or to protect the overall public health, safety and welfare of the community, the Control Authority may seek issuance of a search warrant from the City of Rock Springs Court and or the District Court of Sweetwater County in the State of Wyoming." The municipal ordinance adequately establishes the right of entry authority for the City, as required in 40 C.F.R. 403.8(f)(1)(v) of the Pretreatment Regulations. 9.3 Facility Inspection Records - Background 40 C.F.R. 403.8(f)(2)(vii) of the Pretreatment Regulations requires the POTW to meet the criterion for evidence collection "with sufficient care to produce evidence admissible in enforcement proceedings or in judicial actions." This is performed during facility inspections by adequate documentation in the inspection report of the observations, surveillance, inspections, sampling performed, and analysis gathered during facility inspections. A complete and well-developed inspection report that provides a current characterization of the facility will benefit the POTW's Pretreatment program for programmatic decisions such as categorical determinations, slug discharge/spill potential, changes at the facility that may affect the current permit conditions, sampling frequencies, etc. As discussed in 2.11.2 of the Industrial User Inspection and Sampling Manual for 39 City of Rock Springs Pretreatment Audit Report WY-0022357 August 21, 2024 to August 22, 2024 POTWs, EPA-831B17001, January 2017, the inspection report generated from the facility inspections should accomplish the following three objectives: 1) organize and coordinate all information in a comprehensive, usable manner for use by the POTW's compliance personnel; 2) identify areas that may require follow-up activity; and 3) provide significant background information on the facility that can be reviewed prior to conducting subsequent inspections at the facility. The quality of this documentation will, to a large degree, determine how effective these follow-up activities will be at the facility. The information in the inspection report must be presented in a clear, concise, and well-organized manner. The Industrial User Inspection and Sampling Manual for POTWs describes the information necessary to characterize a facility in 2.10.3 and 2.12. The manual also discusses the records to review at a facility to help determine the facility's compliance in 2.10.8. It is important for Pretreatment programs to capture the following information during facility inspections to characterize the facility, and document facility changes to ensure the SIU's permit addresses current conditions: x Chemical storage areas, including potential spill concerns during chemical receiving and transfer/handling. x Process tanks or processing areas - detailed descriptions of the process including tank contents, capacities. x Wastestream generation from the process areas and disposal/discharge practices - frequency of discharge rinse water tanks, whether spent chemical solutions tanks discharged to the POTW or hauled off site, proximity to floor/trench drains, slug discharge control and spill containment measures, etc. x Wastestream management (treatment, recycling, hauling off site, evaporation, etc.). x Waste treatment system. x Wastestream or hazardous waste storage areas, including potential spill concerns. x Discharge monitoring points. o Evaluation of the sampling/monitoring protocols to determine if these are appropriate to provide representative data of the wastewaters regulated by the permit. A facility inspection of a permitted SIU should include a review of relevant records used to support compliance with the permit conditions and that may not be reported in the selfmonitoring compliance reports such as pH and continuous flow monitoring records, tank change out logs, analytical reports, waste manifests, operation and maintenance logs, etc. A detailed facility inspection report with descriptions of tank contents, capacities, generated wastestreams, plumbing, and management of the wastestreams will benefit the POTW to establish the baseline for the year and to determine if any changes will impact the permit conditions/limits or associated documents such as the slug discharge control plan, spill plan, treatment system operation manual or sampling protocol. During the Pretreatment audit, the EPA discussed inspection procedures with the City, including EPA's procedures. The EPA performs facility inspections by gathering verbal information in an opening conference, then performing a walkthrough to visually confirm the information gathered during the opening interview. The EPA structures its information gathering by following the raw materials/chemical supply through the unit operations and 40 City of Rock Springs Pretreatment Audit Report WY-0022357 August 21, 2024 to August 22, 2024 ultimately to the finished product or service. A closing conference is performed to gather follow-up information, review records, and to provide preliminary conclusions to the facility. 9.4 Evaluation of the City's Inspection Reports/Records The EPA evaluated the inspection reports and other records related to the facility inspection for the SIU annual facility inspection. As discussed in 8.4.1(1) of this audit report, the SIU inspection reports provide adequate characterization of the facility and includes information regarding the facility's chemical storage/handling, process, (sources, flow volume and types of discharges) wastewater generation, slug discharge potential, waste treatment methods, sampling procedures, and review of records in the annual inspection report. The inspection reports should also include digital photos to further support information gathered during the inspection. The EPA recommends the City gather digital photos during SIU inspections to provide current photos of areas relevant to the Pretreatment permit, including but not limited to floor drains, unit operations, raw material/chemical storage, applicable chemical handling equipment, wastestreams, treatment. 9.5 Notification of Applicable Pretreatment Standards The Pretreatment Regulations at 40 C.F.R. 403.8(f)(2)(iii) require the City to notify IUs of applicable Pretreatment Standards and Requirements. As discussed in 8.4.1(1) of this audit report, it appears the City is providing adequate notification to the SIUs regarding the applicable Pretreatment Standards and applicable corrective action items as a follow-up to the facility inspections. 10.0 Control Authority Compliance Monitoring 10.1 Regulatory Background 40 C.F.R. 403.8(f)(1)(v) of the Pretreatment Regulations requires the POTW to have the legal authority to "Carry out all inspection, surveillance, and monitoring procedures necessary to determine, independent of information supplied by Industrial Users, compliance or noncompliance with applicable Pretreatment Standards and requirements." Further, 40 C.F.R. 403.8(f)(2)(v) require a POTW to "Randomly sample and analyze the effluent from Industrial Users and conduct surveillance activities in order to identify, independent of information supplied by Industrial Users, occasional and continuing noncompliance with Pretreatment Standards. Inspect and sample the effluent from each Significant Industrial User at least once a year." The standard to which POTWs are held for purposes of evidence collection during a Control Authority monitoring event is outlined in 40 C.F.R. 403.8(f)(2)(vii): "Sample taking and analysis and the collection of other information shall be performed with sufficient care to produce evidence which is admissible in enforcement proceedings or judicial actions." 41 City of Rock Springs Pretreatment Audit Report WY-0022357 August 21, 2024 to August 22, 2024 In addition, a POTW is required to ensure the Control Authority monitoring events are based on representative conditions at the monitoring point, to ensure that these sampling events are legally defensible and of the same quality as required for self-monitoring events. 40 C.F.R. 403.12(g)(3) of the Pretreatment Regulations require, "The reports ...must be based upon data obtained through appropriate sampling and analysis performed during the period covered by the report, which data are representative of conditions occurring during the reporting period." An enforceable sample must be representative of the nature and character of the discharges during the reporting period and is required to be representative in composition to that in the larger volume of wastewater being discharged. A POTW is required to implement a Control Authority monitoring program that meets the compliance monitoring requirements of the Pretreatment Regulations, provides representative data for compliance determinations, and that would be legally defensible in court, if such an enforcement action is taken by the POTW. In addition, representative and legally defensible data helps the POTW support other program objectives such as local limits evaluation, and permit development or reissuance. 10.2 Sampling Plan and Protocols As required in 40 C.F.R. 403.8(f)(2), the POTW shall "develop and implement procedures to ensure compliance with the requirements of a Pretreatment Program." The development and implementation of a sampling plan or procedures ensures the POTW is appropriately and consistently performing sampling or monitoring events, as well as providing enforceable data that is representative of the discharge conditions at the facility. The sampling plan should include the following: x purpose and objective of the sampling program, x specific sampling protocols at each facility sampling location to ensure representative sampling, and x appropriate QA/QC procedures to ensure legally defensible data. 10.2.1 Site-Specific Sampling Protocols The sampling protocols must include specific procedures used at each facility to ensure adequate and representative sampling protocols. The development of the sampling protocols will ensure the sampling events are performed in accordance with appropriate standards and procedures and produce quality data that is legally defensible. At a minimum, the specific sampling protocols at each sampling location should include the following: x Sampling locations - should include all monitoring points included in the SIU's permit, including the use of digital photos for each monitoring point. x Type of sample - the POTW is required to ensure the sampling event is representative of the SIU's discharge, as required by 40 C.F.R. 403.12(g)(3). The type of sample will be dependent on the parameter to be sampled and discharge characteristics. The type of sample could include specifications for use of automatic 42 City of Rock Springs Pretreatment Audit Report WY-0022357 August 21, 2024 to August 22, 2024 samplers (including programming to provide representative sampling) or manual sampling techniques. x Type of Flow Measurement - if applicable x Parameters for Analysis - based on the SIU's permit x Sample Volume x Type of Sample Containers x Sample Preservation Techniques x Sample Identification and Chain of Custody Procedures x QA/QC Procedures 10.2.2 Quality Assurance/Quality Control (QA/QC) QA and QC are tools which are necessary in a sampling program to maintain a level of quality, such as legally defensible data, in the measurement, documentation, and interpretation of sampling data. The QA/QC procedures are used to obtain data that are both precise (degree of closeness between two or more samples) and accurate (degree of closeness between the results obtained from the sample analysis and the true value that should have been obtained). Proper implementation of QA/QC procedures will result in an increase in the POTW's confidence in the validity of the reported analytical data. The QA/QC procedures used to ensure data collected is valid and legally defensible include, but are not limited to the following: x equipment maintenance/calibration, x proper sampling bottles, proper sampling techniques that are adequate and representative of the discharge from the facility, x field blanks, equipment blanks, method blanks, standards, blind duplicates, and x ensuring sampling personnel are adequately trained. 10.3 The EPA Evaluation of the City's Control Authority Monitoring 10.3.1 SOPs The City has developed a SOP for NPDES sampling that provides an overview of its sampling program. The City has also developed SIU-specific sampling protocols for each SIU to ensure consistent sampling that is representative for the production day at each SIU. The City should incorporate digital photos in the SIU-specific sampling protocols. Based on the EPA's review, the SIU-specific sampling protocols developed by the City need to incorporate QA/QC l such as equipment blanks, trip blanks, sample duplicates, matrix spikes, control standards to ensure the sampling and analytical techniques are in control and compliance with 40 CFR 136. 10.3.2 City's Control Authority Monitoring Based on the EPA's review of the Pretreatment records, the City samples the permitted SIUs at least once per year and meets the Control Authority monitoring frequency required in 40 C.F.R. 403.8(f)(2)(v). 43 City of Rock Springs Pretreatment Audit Report WY-0022357 August 21, 2024 to August 22, 2024 11.0 Enforcement 11.1 Regulatory Background The EPA establishes the regulatory requirement to develop and implement an Enforcement Response Plan (ERP) in 40 C.F.R. 403.8(f)(5)(i-iv) of the Pretreatment Regulations. The regulations state: "The POTW shall develop and implement an enforcement response plan. This plan shall contain detailed procedures indicating how a POTW will investigate and respond to instances of industrial user noncompliance. The plan shall, at a minimum: (i) Describe how the POTW will investigate instances of noncompliance. (ii) Describe the types of escalating enforcement responses the POTW will take in response to all anticipated types of industrial user violations and the time periods within which responses will take place. (iii) Identify (by title) the official(s) responsible for each type of response. (iv) Adequately reflect the POTW's primary responsibility to enforce all applicable pretreatment requirements and standards." The development and implementation of an ERP is an important component of an effective Pretreatment Program. Although a successful Pretreatment program should provide outreach to facilities in the service area regarding the applicability of the Pretreatment Standards and compliance with these standards, in many situations, enforcement is the necessary driving force that makes the Pretreatment program functional. The ERP establishes a framework for POTWs to formalize procedures for investigating and responding to instances of IU noncompliance and to ensure that POTWs enforce against IUs objectively, consistently, and equitably. A well-developed ERP should help the POTW decide what resources are needed to enforce the Pretreatment Standards/Requirements and assist in dealing with IU violations. In addition, the ERP will provide notice to the IUs regarding the POTW's responsibility to respond to violations of Pretreatment Standards/Requirements. 11.2 Enforcement Legal Authority The EPA evaluated the City's enforcement authority and remedies found in its municipal ordinance. 1. Enforcement Response Plan incorporated in 14.1 2. Civil/Criminal penalties established in 11.2 and 11.3. 3. Injunctive relief provisions established in 11.1. 4. Authority to enforce against falsification/tampering established in 11.3(E). 5. Notice of violations authority established in 10.1. 6. Compliance orders authority established in 10.4. 7. Consent Orders authority established in 10.2. 8. Cease and Desist Order authority established in 10.5. 44 City of Rock Springs Pretreatment Audit Report WY-0022357 August 21, 2024 to August 22, 2024 9. Administrative penalty authority established in 10.6. 10. Show cause hearing provisions in 10.3. 11. Suspensions of service provisions in 10.7. 12. Search Warrant provisions established in 7.2. 13. Permit termination provisions established in 5.5 and 10.8. 14. Publication of IUs in significant noncompliance in 9.1. 11.3 Enforcement Response Plan The City submitted its Enforcement Response Plan (ERP) to the EPA for review, prior to the audit. Based on the EPA's review, the City's ERP meets the requirements established in the Pretreatment regulations at 40 C.F.R. 403.8(f)(5)(i-iv) and incorporated in the municipal ordinance: 11.4 Compliance Evaluation Based on EPA's review described in 8.4.1(4) of this audit report, it appears that the City is consistently evaluating compliance in the self-monitoring reports or notices of violation. 11.5 SNC Calculations and Public Participation 40 C.F.R. 403.8(f)(2)(viii) of the Pretreatment Regulations require a POTW to comply with the public participation requirements in the enforcement of National Pretreatment Standards. These procedures shall include a provision for at least annual public notification in a newspaper of general circulation, that provides meaningful public notice within the jurisdictions served by the POTW, of IUs which, at any time during the previous 12 months, were in SNC with applicable Pretreatment requirements. The SNC determinations are both calculation of numeric Pretreatment Standards, as listed in 40 C.F.R. 403.8(f)(2)(viii)(A-D) and determination of violations of the narrative Pretreatment Standards, as listed in 40 C.F.R. 403.8(f)(2)(viii)(E-H). Based on EPA's review of the Pretreatment records, the City is calculating numeric SNC and determining narrative SNC as necessary. 12.0 Trucked and Hauled Waste 12.1 Regulatory Background In addition to receiving wastes through the collection system, many POTWs accept trucked and hauled wastes. As stated in 40 C.F.R. 403.1(b)(1), pollutants from nondomestic sources that are transported to the POTW by truck or rail are also subject to the Pretreatment Regulations. They may also be subject to categorical Pretreatment Standards. Therefore, hauled wastes from CIUs or hauled waste that otherwise qualifies the discharger as an IU must be regulated in accordance with the requirements of the Pretreatment Regulations, including any applicable requirements for permitting and inspecting the generating facility. Hauled wastes, like wastes received through the collection system, have the potential to negatively affect the POTW, making regulatory control of the wastes necessary. 45 City of Rock Springs Pretreatment Audit Report WY-0022357 August 21, 2024 to August 22, 2024 Most wastewaters hauled or trucked to a POTW are domestic septage, typically from homes outside the POTW's service area, but compatible in nature. Because such discharges are predominantly compatible wastes, treatment at a POTW is the most appropriate disposal method. The biosolids regulations at 40 C.F.R. 503.9(f) define domestic septage as the liquid or solid material removed from a septic tank, cesspool, portable toilet, Type III marine sanitation device, or similar system that holds only domestic sewage. Domestic septage does not include liquid or solid material removed from any system that receives either commercial wastewater or industrial wastewater, and it does not include grease removed from a restaurant grease trap. The POTW cannot know for certain the nature and concentration of the trucked wastes and the impact on the POTW without implementing some type of control or surveillance program. Unlike discharges from IUs directly connected to the POTW, the makeup of a load of hauled waste is virtually unknown without some type of monitoring, be it visual or analytical. Even compatible loads of domestic septage can cause problems for a POTW due to high strength or discharge rate. Domestic septage can be partially digested, higher in metals concentrations than normal domestic wastes, or contain small amounts of household contaminants (e.g., cleaners). Similarly, disinfectants used in portable toilets have the potential to affect POTW operations. Receipt of hauled hazardous waste (as defined in Resource Conservation and Recovery Act (RCRA)) might not only affect POTW operations but also could subject the POTW to additional reporting requirements. The Domestic Sewage Exclusion, specified in 40 C.F.R. 261.4(a)(1)(ii), provides that hazardous wastes mixed with domestic sewage and under control of the Pretreatment program are exempt from the RCRA waste regulations. However, hazardous wastes received by truck or rail (or dedicated pipe) at the treatment plant are not exempt from the regulations. POTWs that accept hazardous wastes from those sources are subject to permit by rule status under RCRA [40 C.F.R. 270.60(c)] provided that certain requirements are met. The POTW must be in compliance with all its NPDES permit requirements and the waste must comply with all federal, state, and local pretreatment requirements. 12.2 Legal Authority The City has adopted the Federal specific discharge prohibitions for trucked and hauled wastes found in 40 C.F.R. 403.5(b)(8) of the Pretreatment Regulations. This is incorporated by the City in 2.1(B)(8) of the municipal ordinance: "Trucked or hauled pollutants, except at discharge points designated by Control Authority in accordance with Section 3.9 of this ordinance." The municipal ordinance further establishes requirements for trucked/hauled waste in section 3.8: A. Hauled waste may be introduced into the POTW only at locations designated by the Control Authority, and at such times as are established by the Control Authority. Such waste shall not violate Section 2 of this Ordinance, or any other requirements of this 46 City of Rock Springs Pretreatment Audit Report WY-0022357 August 21, 2024 to August 22, 2024 Ordinance and any others established by the City of Rock Springs. The Control Authority may require waste haulers to obtain Individual or General Wastewater Discharge permits. B. All hauled waste is subject to the truck and hauled waste manifest sector control program. 12.3 Trucked and Hauled Waste Disposal Location and Control Mechanisms The City accepts septic, oil and grease and RV wastes. The City has constructed a dedicated RV disposal station located outside of its front entrance designed for small volumes of domestic waste from resident-owned RVs. Septic Waste and oil and grease waste pumped out of septic tanks and grease interceptors by commercial companies are required to enter the POTW, submit manifests and dispose of the waste at the appropriate location within the POTW. According to information received during the audit, a wastewater operator observes the waste discharged. The hauled waste disposal site is open Monday through Friday from 7:30 a.m. to 3:30 p.m. The POTW receives domestic waste throughout the day and oil and grease waste primarily from 12:30 p.m. to 3:30 p.m. The hauled waste is contained in a 10,000-gallon wet well. The domestic waste in this wet well is pumped to the headworks and the oil and grease is pumped to the digesters. Currently, nine waste hauling companies service sources within 10 miles of the City's incorporated boundary and haul waste to the City's POTW. Most of these companies only have one truck. The City permits the hauled waste companies to ensure they comply with the trucked/hauled waste provisions in the City's municipal ordinance. According to information gathered during the audit, The City appears to have adequate control of the dedicated RV dump station and septic/oil and grease waste discharged at the POTW. 13.0 Best Management Practices - Sector Control Programs 13.1 Regulatory Background BMPs are defined in 40 C.F.R. 403.3(e) as "schedules of activities, prohibitions of practices, maintenance procedures, and other management practices to implement the prohibitions listed in 40 C.F.R. 403.5(a)(1) [General Prohibitions] and (b) [Specific Prohibitions]. BMPs also include treatment requirements, operating procedures, and practices to control plant site runoff, spillage or leaks, sludge or waste disposal, or drainage from raw materials storage." 40 C.F.R. 403.5(c)(4) states, "POTWs may develop Best Management Practices (BMPs) to implement paragraphs (c)(1) [develop limits to implement the general/specific prohibitions] and (c)(2) [develop and enforce specific effluent limits for industrial users that contribute pollutants that may result in Interference and Pass-Through] of this section. Such BMPs shall be considered local limits and Pretreatment Standards for the purposes of this part and section 307(d) of the Act." The regulations establish that BMPs are 47 City of Rock Springs Pretreatment Audit Report WY-0022357 August 21, 2024 to August 22, 2024 enforceable Pretreatment Standards. 13.2 Authority in Rules and Regulations The City established the authority to implement BMPs in its municipal ordinance as follows: x BMP definition in 1.5(D). BMPs are also established as Pretreatment Standards in the BMP definition. x Authority to implement BMPs in 2.3(D). x BMPs in Sector Control Programs in 3.6. x BMPs established as a permit condition in 5.3(A)(3). x BMP recordkeeping requirements in 6.13. x BMPs established as an SNC criterion in 9.1(F). 13.3 Dental Amalgam BMP Sector Control Program The Dental Amalgam Rule, found in 40 C.F.R. Part 441, was promulgated as a final rule with new source dental facilities required to be in compliance with the Pretreatment Standards as of July 14, 2017, and existing source dental facilities required to be in compliance as of June 14, 2020. Compliance with the rule requires the installation of an ISO1143 amalgam separator or equivalent device, and compliance with the following two BMPs: x Prohibition on the use of oxidizing or chlorine-containing line cleaners; and x Ensuring all amalgam process wastewater including chair-side traps, screens, vacuum pump filters, dental tools, cuspidors or collection devices are treated through the amalgam separator. In addition, the new and existing dental facilities are required in 40 C.F.R. 441.50 of the Dental Amalgam Rule to provide a report that characterizes the dental facility and certifies compliance. The new source dental facilities are required to be in compliance upon discharge and submit a one-time compliance report within 90 days of startup. The City has identified 15 dental facilities in its industrial waste survey and has received one-time compliance reports within the deadline required by the Rule. Based on the EPA's review of the one-time compliance records, the following reports are not complete, as required in 40 C.F.R. 441.50 of the Dental Amalgam Rule: x Health West Rock Springs Dental, Section C - maintenance information of amalgam separator not included. x White Mountain Dental, Section C - maintenance information of amalgam separator not included. x Erramouspe Dental, Section A - new source or existing source not checked. (discharged prior to July 14, 2017) x Aspen Dental, Section A - Section A - new source or existing source not checked. (discharged prior to July 14, 2017) 48 City of Rock Springs Pretreatment Audit Report WY-0022357 August 21, 2024 to August 22, 2024 The City is required to ensure these reports are complete and provide adequate information to determine compliance with the Dental Amalgam Rule. 13.4 FOG Sector Control Program As stated in section 4.2 of this audit report, the City has developed Sector Control policies for Grease Interceptors, Mobile Food Vendors and Sand/Oil Interceptors, based on implementation of the best management practices authority established in section 3.6 of the Pretreatment ordinance. The policies were adopted by resolution and establish treatment technology installation, sizing of the treatment as well as operation and maintenance requirements for the grease or sand/oil interceptors, depending on the type of source in the City's service area. The City inspects the grease interceptors of the food service establishments and the sand/oil interceptors from the regulated sources in the service area every other year. 14.0 PFAS Roadmap and Implementation Harmful per- and poly-fluoroalkyl substances (PFAS) are an urgent public health and environmental issue facing communities across the United States. PFAS have been manufactured and used in a variety of industries in the United States and around the globe since the 1940s, and they are still being used today. Because of the duration and breadth of use, PFAS can be found in surface water, groundwater, soil, and air--from remote rural areas to densely-populated urban centers. A growing body of scientific evidence shows that exposure at certain levels to specific PFAS can adversely impact human health and other living things. Despite these concerns, PFAS are still used in a wide range of consumer products and industrial applications. Every level of government--federal, Tribal, state, and local--needs to exercise increased and sustained leadership to accelerate progress to clean up PFAS contamination, prevent new contamination, and make game-changing breakthroughs in the scientific understanding of PFAS. 14.1 2021 EPA PFAS Strategic Roadmap On October 18, 2021, the EPA developed the Agency's PFAS Strategic Roadmap -- laying out a whole-of-agency approach to addressing PFAS. The roadmap sets timelines by which EPA plans to take specific actions and commits to policies designed to safeguard public health, protect the environment, and hold polluters accountable. The PFAS Strategic Roadmap may be found at the following link: https://www.epa.gov/pfas/pfas-strategicroadmap-epas-commitments-action-2021-2024 The EPA's integrated approach to PFAS is focused on three central directives: 1. Research. Invest in research, development, and innovation to increase understanding of PFAS exposures and toxicities, human health and ecological effects, and effective interventions that incorporate the best available science. 2. Restrict. Pursue a comprehensive approach to proactively prevent PFAS from entering air, land, and water at levels that can adversely impact human health and the environment. 49 City of Rock Springs Pretreatment Audit Report WY-0022357 August 21, 2024 to August 22, 2024 3. Remediate. Broaden and accelerate the cleanup of PFAS contamination to protect human health and ecological systems. The EPA's approach is shaped by the unique challenges to addressing PFAS contamination. The EPA cannot solve the problem of "forever chemicals" by tackling one route of exposure or one use at a time. Rather, the EPA understood that it needed to take a lifecycle approach to PFAS to make meaningful progress. PFAS pollution is not a legacy issue--these chemicals remain in use in U.S. commerce. The risks posed by PFAS demand that the Agency attack the problem on multiple fronts at the same time. In the 2021 PFAS Roadmap, the EPA is leveraging the full range of statutory authorities to confront the human health and ecological risks of PFAS: x Water - Clean Act (CWA) x Solid Waste - Resource Conservation and Recovery Act (RCRA) x Land - Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) x Air - Clean Air Act (CAA) x Chemical Safety and Pollution Prevention - Toxic Substances Control Act (TSCA) For purposes of this audit, the EPA is addressing the initiatives used in the Office of Water under the Safe Drinking Water Act, the Clean Water Act, the NPDES Permitting program and associated programs under the NPDES regulatory umbrella. The specific PFAS Roadmap commitments and updates may be found at the following link: https://www.epa.gov/pfas/pfas-strategic-roadmap-epas-commitments-action-20212024#ow 14.1.1 Office of Water 14.1.1.1 Undertake nationwide monitoring for PFAS in drinking water The Safe Drinking Water Act (SDWA) establishes a data-driven and risk-based process to assess drinking water contaminants of emerging concern. Under SDWA, the EPA requires water systems to conduct sampling for unregulated contaminants every five years. The fifth Unregulated Contaminant Monitoring Rule (UCMR 5) was published on December 27, 2021. UCMR 5 requires sample collection for 30 chemical contaminants between 2023 and 2025 from drinking water systems using analytical methods developed by EPA and consensus organizations. This action provides the EPA and other interested parties with scientifically valid data on the national occurrence of these contaminants in drinking water. Going forward, the EPA will continue to prioritize additional PFAS for inclusion in UCMR 6 and beyond, as techniques to measure these additional substances in drinking water are developed and validated. 14.1.1.2 Establish a national primary drinking water regulation for PFOA and PFOS 50 City of Rock Springs Pretreatment Audit Report WY-0022357 August 21, 2024 to August 22, 2024 Under the SDWA, the EPA has the authority to set enforceable National Primary Drinking Water Regulations (NPDWRs) for drinking water contaminants and require monitoring of public water supplies. To date, the EPA has regulated more than 90 drinking water contaminants but has not established national drinking water regulations for any PFAS. In March 2021, the EPA published the Fourth Regulatory Determinations, including a final determination to regulate Perfluorooctanoic acid (PFOA) and Perfluorooctane sulfonic acid (PFOS) in drinking water. On March 14, 2023, the EPA announced the proposed National Primary Drinking Water Regulation (NPDWR) for six PFAS including perfluorooctanoic acid (PFOA), perfluorooctane sulfonic acid (PFOS), perfluorononanoic acid (PFNA), hexafluoropropylene oxide dimer acid (HFPO-DA, commonly known as GenX Chemicals), perfluorohexane sulfonic acid (PFHxS), and perfluorobutane sulfonic acid (PFBS). The proposed PFAS NPDWR does not require any actions until it is finalized. EPA anticipates finalizing the regulation by the end of 2023. The EPA expects that if fully implemented, the rule will prevent thousands of deaths and reduce tens of thousands of serious PFAS-attributable illnesses. 14.1.1.3 Publish the final toxiMWR assessment for GenX and five additional PFAS On June 15, 2022, the EPA issued final health advisories (HAs) for these two per- and polyfluoroalkyl substances (PFAS): 1) hexafluoropropylene oxide (HFPO) dimer acid and its ammonium salt (referred to as "GenX chemicals"); and 2) perfluorobutane sulfonic acid and its potassium salt (PFBS). In chemical and product manufacturing, GenX chemicals are considered a replacement for perfluorooctanoic acid (PFOA), and PFBS is considered a replacement for perfluorooctane sulfonic acid (PFOS). GenX chemicals have been found in surface water, groundwater, drinking water, rainwater, and air emissions. GenX chemicals are known to impact human health and ecosystems. Scientists have observed liver and kidney toxicity, immune effects, hematological effects, reproductive and developmental effects, and cancer in animals exposed to GenX chemicals. The Office of Research and Development is also currently developing toxiMWR assessments for five other PFAS--PFBA, PFHxA, PFHxS, PFNA, and PFDA. 14.1.1.4 Publish health advisories for GenX and PFBS PFAS contamination has impacted drinking water quality across the country, including in underserved rural areas and communities of color. SDWA authorizes EPA to develop nonenforceable and non-regulatory drinking water health advisories to help Tribes, states, and local governments inform the public and determine whether local actions are needed to address public health impacts in these communities. Health advisories offer a margin of protection by defining a level of drinking water concentration at or below which lifetime exposure is not anticipated to lead to adverse health effects. They include information on health effects, analytical methodologies, and treatment technologies and are designed to protect all lifestages. On June 15, 2022, the EPA issued interim updated drinking water health advisories for PFOA and PFOS that replace those EPA issued in 2016. In addition, EPA published health 51 City of Rock Springs Pretreatment Audit Report WY-0022357 August 21, 2024 to August 22, 2024 advisories for GenX and PFBS chemicals. These updated health advisories levels, which are based on new science, will remain in place until the EPA establishes a National Primary Drinking Water Regulation. (As identified above the proposed National Primary Drinking Water Regulations were proposed on March 14, 2023. 14.1.1.5 Restrict PFAS discharges from industrial sources through a multi-faceted Effluent Limitations Guidelines program Effluent Limitations Guidelines (ELGs) are a powerful tool to limit pollutants from entering the nation's waters. ELGs establish national technology-based regulatory limits on the level of specified pollutants in wastewater discharged into surface waters and into municipal sewage treatment facilities. EPA has been conducting a PFAS multi-industry study to inform the extent and nature of PFAS discharges. Based on this study, EPA is taking a proactive approach to restrict PFAS discharges from multiple industrial categories. EPA plans to make significant progress in its ELG regulatory work by the end of 2024. EPA has established timelines for action--whether it is data collection or rulemaking--on the nine industrial categories in the proposed PFAS Action Act of 2021, as well as other industrial categories such as landfills. EPA's multi-faceted approach entails: x Undertake rulemaking to restrict PFAS discharges from industrial categories where EPA has the data to do so, including the guidelines for organic chemicals, plastics and synthetic fibers (OCPSF), metal finishing, and electroplating. Proposed rule is expected in the Fall 2024 for OCPSF and Summer 2025 for metal finishing and electroplating. x Launch detailed studies on facilities where EPA has preliminary data on PFAS discharges, but the data are currently insufficient to support a potential rulemaking. These include electrical and electronic components, textile mills, and landfills. EPA expects these studies to be complete by Fall 2022 to inform decision making about a future rulemaking by the end of 2023. x Initiate data reviews for industrial categories for which there is little known information on PFAS discharges, including leather tanning and finishing, plastics molding and forming, and paint formulating. The EPA expects to complete these data reviews by Winter 2024 to inform whether there are sufficient data to initiate a potential rulemaking. x Monitor industrial categories where the phaseout of PFAS is projected by 2024, including pulp, paper, paperboard, and airports. x The EPA is conducting a POTW Influent PFAS Study to collect and analyze nationwide data on industrial discharges of PFAS to POTWs, as well as PFAS in POTW influent, effluent, and sewage sludge. The EPA will require, through an Information Collection Request (ICR), a subset of large POTWs across the United States to complete a questionnaire and collect and analyze wastewater and sewage sludge samples. 14.1.1.6 Leverage NPDES permitting to reduce PFAS discharges to waterways 52 City of Rock Springs Pretreatment Audit Report WY-0022357 August 21, 2024 to August 22, 2024 The National Pollutant Discharge Elimination System (NPDES) program interfaces with many pathways by which PFAS travel and are released into the environment and ultimately impact people and water quality. On December 5, 2022, the EPA issued the Addressing PFAS Discharges in NPDES Permits and Through the Pretreatment Program and Monitoring Programs Memo to the U.S. States to proactively use existing NPDES authorities to reduce discharges of PFAS at the source and obtain more comprehensive information through monitoring on the sources of PFAS and quantity of PFAS discharged by these sources. This memorandum provides EPA's guidance to states and updates the April 28, 2022 guidance to EPA Regions for addressing PFAS discharges when they are authorized to administer the NPDES permitting program or Pretreatment program. The memo provides the following recommendations for POTW NPDES permits and Pretreatment programs: x POTW NPDES Permits: o Quarterly Effluent, Influent and biosolids monitoring using EPA Method 1633 o Recommended biosolids assessment, based on biosolids monitoring and a PFAS source reduction for IUs in the POTW's service area, if necessary o Public notice of downstream drinking systems that are potentially affected by the POTW effluent when the POTW's NPDES permit is renewed or issued. x Pretreatment Programs: o Source Identification: Update IU inventory to include PFAS sources o Source Control: Utilize BMPS and pollution prevention to address PFAS discharges to the POTW Update IU permits to required quarterly PFAS monitoring Develop IU BMPS or local limits for PFAS, where authority exists through the NPDES permit limits or PFAS ELG promulgation. 14.1.1.7 Publish multi-laboratory validated analytical method for 40 PFAS In September 2021, EPA (in collaboration with the Department of Defense) published a single-laboratory validated method to detect PFAS. The method can measure up to 40 specific PFAS compounds in eight environmental matrices (including wastewater, surface water and biosolids) and has numerous applications, including NPDES compliance monitoring. EPA and DOD are continuing this collaboration to complete a multi-laboratory validation of the method. In response to stakeholder requests to update the method with multi-laboratory validation data as soon as practical, the EPA is releasing multiple revisions of the draft method. These revisions (past, present, and future) are outlined below. It should be noted that none of these revisions significantly changed (or are anticipated to change) the procedure. x August 2021: EPA posted the initial draft of Method 1633 at this website using the data from the single laboratory validation. 53 City of Rock Springs Pretreatment Audit Report WY-0022357 August 21, 2024 to August 22, 2024 x June 2022: Second draft of Method 1633 included clarification on several issues that the laboratories participating in the multi-laboratory validation thought were vague or confusing. x December 2022: Third draft of Method 1633 included some multi-laboratory validation data for the wastewater matrix, which added required QC criteria for the wastewater matrix. This revision had some additional clarifications and flexibilities that were responsive to formal comments received from multiple parties. x July 2023: Fourth draft of Method 1633 incorporates the QC acceptance criteria for all aqueous matrices (surface water, ground water, and wastewater), derived from the multi-lab validation study. A multi-laboratory validation study report (published by DoD) is available below that summarizes the results of the multilaboratory study for these aqueous matrices. x The Final version of EPA Method 1633 was published on January 31, 2024, and is a validated analytical method to test for 40 PFAS in wastewater, surface water, groundwater, soil, biosolids, sediment, leachate and fish tissue. The method, while final, will not be required until the EPA formally adopts it through rulemaking. In addition, on April 8, 2022, the EPA published a new Adsorbable Organic Fluorine (AOF) method 1621 that can broadly screen for the presence of PFAS in water at the part per billion level. The new AOF Method 1621 provides an aggregate measurement of chemical substances that contain carbon-fluorine bonds. PFAS are a common source of organofluorines in wastewater. This new method is especially useful for understanding the presence and forms of PFAS in wastewater when used in conjunction with methods that target individual PFAS. EPA's Draft Method 1621 has successfully completed single laboratory validation. 14.1.1.8 Publish updates to PFAS analytical methods to monitor drinking water Expected Fall 2024 SDWA requires the EPA to use scientifically robust and validated analytical methods to assess the occurrence of contaminants of emerging concern, such as an unidentified or newly detected PFAS chemical. The EPA will update and validate analytical methods to monitor additional PFAS. First, the EPA will review reports of PFAS of concern and seek to procure certified reference standards that are essential for accurate and selective quantitation of emerging PFAS of concern in drinking water samples. The EPA will evaluate analytical methods previously published for monitoring PFAS in drinking water (EPA Methods 533 and 537.1) to determine the efficacy of expanding the established target PFAS analyte list to include any emerging PFAS. Upon conclusion of this evaluation, the EPA will complete multi-laboratory validation studies and peer review and publish updated EPA PFAS analytical methods for drinking water, making them available to support future drinking water monitoring programs. 14.1.1.9 Publish final recommended ambient water quality criteria for PFAS Tribes and states use EPA recommended water quality criteria to develop water quality standards to protect and restore waters, issue permits to control PFAS discharges, and 54 City of Rock Springs Pretreatment Audit Report WY-0022357 August 21, 2024 to August 22, 2024 assess the cumulative impact of PFAS pollution on local communities. On April 28, 2022, the EPA published proposed national recommended ambient water quality criteria for PFAS to protect aquatic life. The EPA is proposing the first Clean Water Act aquatic life criteria for perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS)--two of the most well-studied chemicals in this group. The criteria are intended to protect aquatic life in the United States from short-term and long-term toxic effects of PFOA and PFOS. Following the comment period, EPA intends to issue final PFOA and PFOS recommended criteria, considering public comments and any new toxicity data. States and Tribes may consider adopting the final criteria into their water quality standards or can adopt other scientifically defensible criteria that are based on local or site-specific conditions. 14.1.1.10 Monitor fish tissue for PFAS from the nation's lakes and evaluate human biomarkers for PFAS States and Tribes have highlighted fish tissue data in lakes as a critical information need. Food and water consumption are important pathways of PFAS exposure, and PFAS can accumulate in fish tissue. In fact, EPA monitoring to date shows the presence of PFAS, at varying levels, in approximately 100 percent of fish tested in the Great Lakes and large rivers. In Summer 2022, EPA will collect fish tissue in the National Lakes Assessment for the first national study of PFAS in fish tissue in U.S. lakes. This will provide a better understanding of where PFAS fish tissue contamination is occurring, which PFAS are involved, and the severity of the problem. The new data will complement the EPA's analyses of PFAS in fish tissue and allow then EPA to better understand unique impacts on subsistence fishers, who may eat fish from contaminated waterbodies in higher quantities. EPA's preliminary analysis on whether concentrations of certain PFAS compounds in human blood could be associated with eating fish using the Centers for Disease Control and Prevention's National Health and Nutrition Examination Survey (NHANES) data found a positive correlation. Completing this analysis will help make clear the importance of the fish consumption pathway for protecting communities. EPA will continue to pursue collaboration with Tribal and federal partners to investigate this issue of mutual interest. 14.1.1.11 Finalize list of PFAS for use in fish advisory programs The EPA will publish a list of PFAS for state and Tribal fish advisory programs that are either known or thought to be in samples of edible freshwater fish in high occurrence nationwide. This list will serve as guidance to state and Tribal fish tissue monitoring and advisory programs so that they know which PFAS to monitor and how to set fish advisories for PFAS that have human health impacts via fish consumption. This information will encourage more robust data collection from fish advisory programs and promote consistency of fish tissue PFAS monitoring results in EPA's publicly accessible Water Quality Portal. By issuing advisories for PFAS, state and Tribal programs can provide high-risk populations, including communities and individuals who depend on subsistence fishing, with more information about how to protect their health. 14.1.1.12 Finalize risk assessment for PFOA and PFOS in biosolids 55 City of Rock Springs Pretreatment Audit Report WY-0022357 August 21, 2024 to August 22, 2024 Biosolids, or sewage sludge, from wastewater treatment facilities can sometimes contain PFAS. When spread on agricultural fields, the PFAS can contaminate crops and livestock. The CWA authorizes the EPA to set pollutant limits and monitoring and reporting requirements for contaminants in biosolids if sufficient scientific evidence shows that there is potential harm to human health or the environment. A risk assessment is key to determining the potential harm associated with human exposure to chemicals. The EPA will complete the risk assessment for PFOA and PFOS in biosolids by the end of 2024. The risk assessment will serve as the basis for determining whether regulation of PFOA and PFOS in biosolids is appropriate. If the EPA determines that a regulation is appropriate, biosolids standards would improve the protection of public health and wildlife health from health effects resulting from exposure to biosolids containing PFOA and PFOS. 14.2 Impact of the NPDES Initiatives on the City's Pretreatment Program The analytical tools, rules, procedures, and methods developed by the EPA in the PFAS Strategic Roadmap and identified in 14.1.1.1 through 14.1.1.12 are currently recommendations to identify and control non-domestic or IU sources in a POTW's service area. The requirement to control IUs will occur either when the EPA promulgates categorical Pretreatment Standards for specific IU sectors such as OCPSF, Metal Finishers or other future rulemakings, as identified in 14.1.1.5 or when the NPDES State adopts the EPA National Water Quality Criteria for PFAS and PFOS, identified in 14.1.1.9 as State water quality standards and begin implementing these as NPDES permit limits. However, the EPA recommends the City evaluate these recommendations and determine proactive measures to identify PFAS non-domestic sources in its service area and determine appropriate level of control or compliance assistance. 56 City of Rock Springs Pretreatment Audit Report WY-0022357 August 21, 2024 to August 22, 2024