Document 6BaQLzErZGvoo673Rmd4LRke6

Pretreatment Program Evaluation Report St. Vrain Sanitation District CO-0041700 Longmont, Colorado September 16, 2022 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 St. Vrain Sanitation District - Pretreatment Program Evaluation Report CO-0041700 September 16, 2022 Report Review and Signature Drafter Name Al Garcia Reviewer Name Stephanie DeJong Supervisor Signature/Name STEPHANIE DEJONG Stephanie DeJong Digitally signed by STEPHANIE DEJONG Date: 2023.01.30 16:44:20 -07'00' 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 8WD-CW Denver, Colorado 80202 303-312-6362 Address/Phone Number U.S. EPA Region 8 1595 Wynkoop Street 8WD-CW Denver, Colorado 80202 303-312-6362 Date 01/17/2023 Date 01/27/2023 Date 01/30/2023 2 St. Vrain Sanitation District - Pretreatment Program Evaluation Report CO-0041700 September 16, 2022 Pretreatment Audit Summary Table St. Vrain Sanitation District - Pretreatment Program Evaluation Report CO-0041700 September 16, 2022 Pretreatment Audit Findings Pretreatment Requirement and Corrective Action Section 3.0 - Evaluation of the St. Vrain Sanitation District POTW 1. EPA evaluated the St. Vrain Sanitation District to determine if it needs to develop an EPA-approved Pretreatment program, as required by 40 C.F.R. 403.8(a). The determination under section 403.8(a) is based on two distinct inquiries: 1) whether one or more circumstances present a real possibility of interference or pass through; and 2) whether there is a nexus between the Pretreatment program and the possibility of interference or pass through. The District has experienced significant residential and non-residential growth within its service area from CY 2000. This growth has been from the residential or domestic and non-domestic sectors. The number of industrial (IU) sewer taps has increased from 374 in 2012 to 502 in 2022. As a result of non-domestic or IU growth in the service area, the District has increased the number of Pretreatment permits issued to IUs to protect the publicly owned treatment works (POTW). The District currently issues 10 Pretreatment permits to establish control of the pollutants in the IU's nondomestic wastewater and protect the POTW from the interference or pass through. A nexus exists between a potential for pass through or interference at the POTW and the Pretreatment program because the industrial wastewater discharges from these IUs are subject to either the Categorical Pretreatment Standards developed by EPA or are subject to the Pretreatment Standards incorporated in the District's Rules and Regulations (i.e., local limits and general and specific discharge prohibitions found in 40 CFR 403.5). The Pretreatment Standards applied by the District in its IU permits are designed to protect the District's POTW from the impacts of such wastewater. Pretreatment Requirements 40 C.F.R. 403.8(a) 40 C.F.R. 403.8(b) 40 C.F.R. 403.8(f) Corrective Action Item EPA plans to provide a notification, in accordance with 40 C.F.R. 403.8(b) that provides the District a one -year timeframe to develop and submit a Pretreatment Program for approval. 3 St. Vrain Sanitation District - Pretreatment Program Evaluation Report CO-0041700 September 16, 2022 Based on information gathered during the program evaluation, the District meets the 40 C.F.R. 403.8(a) criteria of a POTW with a design flow of 5 MGD and receiving pollutants from IUs that have the potential to cause pass through or interference or are subject to Pretreatment Standards. 2. As a follow-up to the District's program evaluation, EPA plans to provide a notification that provides the District a one-year timeframe to develop and submit a Pretreatment Program for approval. The elements of a Pretreatment program submittal that meets the requirements under 40 C.F.R. 403.8(f) include the following: x 40 C.F.R. 403.8(f)(1), Legal Authority: 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. x 40 C.F.R. 403.8(f)(2), Procedures: The POTW shall develop and implement procedures to ensure compliance with the requirements of a Pretreatment Program. x 40 C.F.R. 403.8(f)(3), Funding: The POTW shall have sufficient resources and qualified personnel to carry out the authorities and procedures described in its program approval submittal. x 40 C.F.R. 403.8(f)(4), Local Limits: The POTW shall develop local limits as required in 403.5(c)(1) or demonstrate that they are not necessary. 3. 40 C.F.R. 403.8(f)(5), Enforcement Response Plan: he 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 Pretreatment Requirements 40 C.F.R. 403.8(b) 40 C.F.R. 403.8(f) Corrective Action Item EPA plans to provide a notification, in accordance with 40 C.F.R. 403.8(b) that provides the District a one -year timeframe to develop and submit a Pretreatment Program for approval. Additional corrective actions, identified below in Sections 4.0 through 9.0 will help the District determine necessary updates to elements of its current unapproved Pretreatment Program to ensure the submittal is approvable. 4 St. Vrain Sanitation District - Pretreatment Program Evaluation Report CO-0041700 September 16, 2022 of industrial user noncompliance. 4. 40 C.F.R. 403.8(f)(6), Industrial User Inventory/SIU List: The POTW shall prepare and maintain a list of its 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. Section 4.0 - Rules and Regulations and Intergovernmental Agreements 5. 40 C.F.R. 403.8(f)(1) 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." EPA evaluated the District's Pretreatment legal authority found in Chapter 10 of its Rules and Pretreatment Requirements 40 C.F.R. 403.8(f)(1) Corrective Action Item Regulations. Based on EPA's review, Chapter 10 x Update the Pretreatment Standard and provides the District the framework to implement the POTW definitions in the Rules and Pretreatment Program in the POTW's service area, Regulations. with the following exceptions: x Incorporate the provisions and waiver x EPA recommends the District ensure it certification required for the Pollutants consistently uses the definition of Industrial user Not Present optional Pretreatment in its Rules and Regulations. The District Streamlining provision adopted in currently uses the definition of User in language 10.5.2(A)(5) of the District's Rules and where it appears that Industrial User is required. Regulations. x Pretreatment Standard Definition - 10.1.4(FF): Recommended Action Item the District needs to add Best Management Practices (BMP) to the definition of Pretreatment x Ensure the use of the Industrial User Standards using a definition consistent with 40 definition is consistent in the District's C.F.R. 403.3(e). Rules and Regulations. x EPA recommends the District require x POTW - 10.1.4(HH): The definition needs to be waste tracking forms or manifests for modified to add the following language to be trucked/hauled domestic waste loads. consistent with 40 C.F.R. 403.3(q): "It also includes sewers, pipes and other conveyances only if they convey wastewater to a POTW Treatment Plant. The term also means the municipality as defined in section 502(4) of the Act, which has jurisdiction over the Indirect 5 St. Vrain Sanitation District - Pretreatment Program Evaluation Report CO-0041700 September 16, 2022 Discharges to and the discharges from such a treatment works." x 10.1.4(KK) citation refers to both SIU and Slug Discharge definitions. EPA recommends correcting the typo. x Pollutants Not Present: the District has established permit conditions for Pollutants not Present in 10.5.2(A)(1) but has not established the required provisions or waiver certification in 40 C.F.R. 403.12(e)(2). In order to implement this provision, add these items to the District's legal authority. If the District does not want to implement this provision, remove the permit conditions from the legal authority. x Trucked and Hauled Waste - 10.3.5: EPA recommends the District require waste tracking forms or manifests for domestic loads. The District's Rules and Regulations at 10.2.1(B)(13) prohibit "Sludges, screenings or other residues from the pretreatment of industrial wastes" to be introduced or cause to be introduced into the POTW. It is unclear if this prohibition language precludes the acceptance of these types of nondomestic waste loads. 6. 40 C.F.R. 403.8(f)(1) of the Federal Pretreatment Regulations require the following: "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 Pretreatment Requirements 40 C.F.R. 403.8(f)(1) requirements of sections 307 (b) and (c), and Corrective Action Item 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." Provide information to EPA if IUs exist outside of District boundaries and if IGAs or other mechanisms are established that allow the District to adequately implement the Pretreatment program, including right of entry to inspect and copy records, inspect to identify According to information gathered during the flows and characterize the pollutants in the program evaluation, the District has the following IU's wastewater, sample, issue permits or outside jurisdictions that contribute wastewater to other forms of control mechanisms, evaluate the District's POTW: Town of Mead, the Longview compliance and enforce. If no such Community LLC, and the Colorado Real Estate and mechanisms exist, work with these outside Investment Company (River Valley Village Mobile jurisdictions to develop and implement them. Home Community). EPA did not evaluate these outside contributing 6 St. Vrain Sanitation District - Pretreatment Program Evaluation Report CO-0041700 September 16, 2022 jurisdictions during the program evaluation to determine if these jurisdiction contain IUs or if the District has established intergovernmental agreements (IGAs) with these jurisdictions that allow the District to implement the Pretreatment program to IUs within these jurisdictions. Section 5.0 - Pretreatment Operating Procedures 7. 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." The District has developed the following Pretreatment program implementation procedures: x Section 1 - Pretreatment Program Overview and Organization x Sections 2 and 3 - Industrial User Inventory and Characterization - This procedure needs to be updated to include methods on how the current IU inventory is maintained to capture current information at the IU. x Section 4 - Wastewater Permitting x Sections 5, 9 and 10 - Sampling Plan, including chain-of-custody and QA/QC. The sampling plan needs to be updated to include sampling protocols at each permitted IU. x Section 6 and 7 - Enforcement action proceedings x Section 8 - Information Requirements In addition, EPA evaluated the District's permit template to ensure it aligns with 40 CFR 403.8(f)(1)(iii)(B)(1-6) of the Pretreatment Regulations: Pretreatment Requirements 40 C.F.R. 403.8(f) 40 CFR 403.8(f)(1)(iii)(B)(1-6) 40 C.F.R. 403.8(f)(2) 40 C.F.R. 403.8(f)(2)(i-viii) 40 C.F.R. 403.12(g)(3) and (6) Corrective Action Item Update the permit template to align with 40 CFR 403.8(f)(1)(iii)(B)(1-6) and related provisions in 40 C.F.R. 403.12 of the Pretreatment Regulations. x The District needs to update its permit template to include the following: o Statement of Non-Transferability - include the following language to Section I.7.b "and provisions for furnishing the new owner or operator with a copy of the existing wastewater discharge permit." o Requirement to conduct representative sampling - The requirement to conduct representative sampling in 40 C.F.R. 7 St. Vrain Sanitation District - Pretreatment Program Evaluation Report CO-0041700 September 16, 2022 403.12(g)(3) is absent and needs to be added. o Submission of all monitoring data in Section F.1.a needs to be modified to align with 40 C.F.R. 403.12(g)(6). o Pollutants Not Present is adopted in the District's Rules and Regulations but not included in the permit template. Ensure the missing provisions noted above in the legal authority finding are also addressed. o Equivalent mass or concentration limits are adopted in the District's Rules and Regulations but not included in the permit template. Section 6.0 - Resources 8. The Pretreatment Regulations at 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 procedures" of the Pretreatment program. Pretreatment Requirements Based on EPA's evaluation of the District's current 40 C.F.R. 403.8(f)(3) non-approved Pretreatment program, it appears that the District's funding commitment is adequate. However, it appears that the District's current staffing commitment of less than 1.0 FTE to implement the Pretreatment program is not adequate to conduct all field and programmatic activities of the District's current Pretreatment program including development of local limits, CIU/SIU permit management (including renewals, IU inspections, receipt of self-monitoring compliance reports and notices, compliance evaluation, and enforcement), FOG interceptor inspections, dental Corrective Action Item Submit a staffing plan in the approved Pretreatment program submittal to address the District's commitment to the Pretreatment program, providing details regarding training opportunities for the current staff and an evaluation of the current and projected scope of the Pretreatment program, in case of future non-domestic growth in the service area and to maintain institutional knowledge of the current program. office inspection, and spending time in the service identifying potential SIU/CIUS for the industrial user inventory. Section 7.0 - Local Limits 9. 40 C.F.R. 403.8(f)(4) of the Pretreatment pretreatment programs to develop and enforce Regulations require POTWs that are developing Pretreatment Requirements specific limits on prohibited discharges or 40 C.F.R. 403.8(f)(4) demonstrate that the limits are not necessary. 40 C.F.R. 403.5(c)(1) states, "Each POTW 40 C.F.R. 403.5(c)(1) 8 St. Vrain Sanitation District - Pretreatment Program Evaluation Report CO-0041700 September 16, 2022 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." The District has established local limits in 10.2.4(B) of its Rules and Regulations. EPA has not approved these local limits since the District does not currently have an EPA-approved Pretreatment program. Corrective Action Item Submit the local limit development records, including but not limited to POTW and service area data, standards used to develop the local limits, the technical calculations, assumptions / justifications used during the calculations, development of non-technical numeric limits and public participation records for its existing local limits established in 10.2.4(B) of its Rules and Regulations to EPA to determine if these are approvable. Section 8.0 - Industrial User Inventory and Characterization 10. 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]. x "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. x "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. x "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 Pretreatment Requirements 40 C.F.R. 403.8(f)(2)(i-iii) 40 C.F.R. 403.8(f)(6) 40 C.F.R. 403.9 Corrective Action Item Submit a current IU inventory of the IUs in its service area for EPA to review. The IU inventory needs to be representative of current conditions in the service area to provide current characterization of the IUs (all nondomestic users, including restaurants/food service establishments, dental facilities, other potential users) on the inventory to identify flows and non-domestic pollutants that may impact the POTW and the collection system. 9 St. Vrain Sanitation District - Pretreatment Program Evaluation Report CO-0041700 September 16, 2022 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)." During the program evaluation, EPA was not provided a IU inventory of the District's service area. Section 9.0 - Enforcement Response Plan 11. 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 Pretreatment Requirements 40 C.F.R. 403.8(f)(5)(i-iv) Corrective Action Item Update the District's ERP to align with 40 C.F.R. 403.8(f)(5)(i-iv) of the Pretreatment Regulations. 10 St. Vrain Sanitation District - Pretreatment Program Evaluation Report CO-0041700 September 16, 2022 responsibility to enforce all applicable pretreatment requirements and standards." EPA evaluated the District's ERP to ensure the District is adequately implementing the authority established in its Rules and Regulations. Based on EPA's review, the District needs to update its ERP to align with 40 C.F.R. 403.8(f)(5)(i-iv) . x The ERP needs to include procedures for permitting and SNC evaluation/determination. x DESCRIPTION OF ENFORCEMENT ACTIONS header on Page 6: EPA recommends the District provide a citation to its Rules and Regulations to identify where the enforcement actions are established. x The following anticipated types of violations either need to be incorporated or modified: o Unpermitted Dischargers submitting the permit application past 45 days late - Does this violation meet the District's SNC criteria for late reporting? o Not Included in the ERP: Any other violation of a Pretreatment Standard or Requirement as defined by 40 CFR 403.3(l) that the POTW determines has caused Interference or Pass Through (including endangering the health of POTW personnel or the general public). (SNC Criteria # C) is not included in the ERP Failure to notify (24-hour, slug/potential problems, changed discharges, hazardous waste, upset, bypass) Tampering with equipment/methods monitoring Trucked and Hauled waste, if applicable Any discharge of a pollutant that has caused imminent endangerment to human health, welfare or to the environment or has resulted in the POTW's exercise of its emergency authority (SNC Criteria # D) Failure to accurately report noncompliance. (SNC Criteria # G) 11 St. Vrain Sanitation District - Pretreatment Program Evaluation Report CO-0041700 September 16, 2022  Any other violation or group of violations, which may include a violation of Best Management Practices, which the POTW determines will adversely affect the operation or implementation of the local Pretreatment program. (SNC Criteria # H) 12 St. Vrain Sanitation District - Pretreatment Program Evaluation Report CO-0041700 September 16, 2022 Table of Contents 1.0 Introduction............................................................................................................ 15 2.0 Publicly Owned Treatment Works (POTW) Information ..................................... 15 2.1 NPDES Permit - Pretreatment Language .......................................................... 16 2.1.1 NPDES Permit, Part 1.B.8 - Industrial Waste Management ...................... 17 3.0 Evaluation of the St. Vrain Sanitation District POTW .......................................... 23 3.1 Regulatory Background...................................................................................... 23 3.2 EPA Evaluation of St. Vrain Sanitation District ................................................ 23 3.3 Contents of a Pretreatment Program Submittal.................................................. 27 4.0 Rules and Regulations and Intergovernmental Agreements.................................. 28 5.0 Pretreatment Operating Procedures ....................................................................... 31 6.0 Resources ............................................................................................................... 33 6.1 Resources Regulatory Background .................................................................... 33 6.2 Evaluation of the District's Resources and Funding.......................................... 33 6.3 Examples of Available Pretreatment Training/Resources ................................. 34 7.0 Local Limits ........................................................................................................... 35 7.1 Local Limits Regulatory Background ................................................................ 35 7.2 Local Limits Requirements Established in the District's NPDES Permits........ 36 7.3 The EPA Evaluation of the District's Local Limits ........................................... 37 7.3.1 Technically-based Local Limits.................................................................. 37 7.3.2 Numeric Ordinance Limits ......................................................................... 38 7.3.3 Dilution Prohibition .................................................................................... 38 7.4 Local Limits Technical Evaluation-Regulatory Background............................. 39 7.5 Technical Evaluation of the District's Local Limits .......................................... 39 7.6 Permit or Site-Specific Limits............................................................................ 40 8.0 Industrial User Inventory and Characterization..................................................... 40 8.1 Regulatory Background...................................................................................... 40 8.2 Industrial User Identification and Characterization Procedure .......................... 42 8.3 Industrial User Database of the District's Service Area .................................... 42 9.0 Enforcement Response Plan .................................................................................. 42 9.1 Regulatory Background...................................................................................... 42 13 St. Vrain Sanitation District - Pretreatment Program Evaluation Report CO-0041700 September 16, 2022 9.2 Enforcement Legal Authority............................................................................. 43 9.3 Enforcement Response Plan............................................................................... 43 Figures Figure 1 -St. Vrain Sanitation District Service Area........................................................ 20 Figure 2 - St. Vrain Sanitation District Service Area-Sewer Collection Lines ................ 21 Figure 3 - St. Vrain Sanitation District POTW, Google Maps View ............................... 22 Figure 4 - St. Vrain Sanitation District Sewer Tap Growth, 1999-2021 .......................... 24 Tables Table 1 - St. Vrain Sanitation District - Number of IU taps, 2012-2022 ........................ 25 Table 2 - St. Vrain Sanitation District - CIU/SIU Permits Growth, 1995-2020 .............. 25 Table 3 - St. Vrain Sanitation District Local Limits ........................................................ 37 14 St. Vrain Sanitation District - Pretreatment Program Evaluation Report CO-0041700 September 16, 2022 1.0 Introduction The U.S. Environmental Protection Agency, Region 8 (EPA) conducted an evaluation of the Pretreatment program, administered by the St. Vrain Sanitation District (District) on September 16, 2022. The Pretreatment evaluation consisted of an overview of the District's current non-approved Pretreatment program. Pretreatment records were requested and reviewed to determine if the District's current Pretreatment program needs to be approved by EPA. Participants in the audit included: St. Vrain Sanitation District, CO Christian Somoza David Cross Pretreatment Coordinator District Engineer/Project Manager EPA Al Garcia Region 8 Pretreatment Coordinator The EPA evaluated the following areas of the District's non-approved Pretreatment program: x The District's legal authority codified in Section 10 - Pretreatment Regulations within the District's Rules and Regulations. The Pretreatment Regulations were last modified on April 17, 2019, x Development and implementation of the District's local limits. x The District's resources to implement the Pretreatment program in its service area. x Implementation policies and templates developed by the District. 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 Evaluation Summary Table, beginning on page 2 of this report. Specific actions to clarify and strengthen program implementation are provided as recommendations within the body of the report. 2.0 Publicly Owned Treatment Works (POTW) Information The District owns and operates a Publicly Owned Treatment Works (POTW) located at 6501 WCR 26, Longmont CO 80504. The POTW serves the boundary of the St. Vrain Sanitation District. The service area for the St. Vrain Sanitation District includes the St. Vrain 208 boundary. In addition, based on the 2017 NPDES permit application submitted ot the CDPHE, the District's service area also includes the following outside contributing jurisdictions: Town of Mead, the Longview Community LLC, and the Colorado Real Estate and Investment Company (River Valley Village Mobile Home Community). The 15 St. Vrain Sanitation District - Pretreatment Program Evaluation Report CO-0041700 September 16, 2022 service area for the POTW is shown in Figure 1, the sewer collection system is shown in Figure 2 and the Google Earth view of the District's POTW is shown in Figure 3. A POTW tour was not completed during the Pretreatment program evaluation. A narrative description of the POTW was provided by Mr. Christian Samozsa and Mr. Dave Cross from the District. The District's POTW is designed to accept 6 MGD wastewater flow and receives approximately 3.25 to 3.5 MGD from the District's service area. According to information gathered during the program evaluation, the District plans to expand or upgrade to 8 MGD. The wastewater from the service area is pumped from the influent pump station to the headworks. The headworks consists of two -inch automatic step screens to remove solids and large organic material. The screened wastewater enters two vortex chambers for grit removal. The headworks effluent then enters the two anaerobic selectors to encourage biological treatment for removal and recovery of phosphorus. The wastewater from the anaerobic selectors then enters the two oxidation ditches. The oxidation ditches have aerobic and anoxic zones to further facilitate nutrient removal. The wastewater from the oxidation ditches enters the two aeration basins. The mixed liquor from the aeration basins is returned to the anoxic zones of the oxidation ditches. The aeration basin effluent flows to the two secondary clarifiers and activated sludge is either wasted (WAS) to biosolids treatment or returned (RAS) to the anaerobic selectors. The secondary effluent is sent to UV treatment and then through a parshall flume for flow measurement and then discharged to St. Vrain Creek The WAS is collected in a waste tank and then to an aerobic digester (ATAD) to thicken to about 6%. The thickened sludge is sent to a simultaneous nitrite/denite reactor (SNDR) for further digestion to meet Class A biosolids. The solids retention time for the ATAD is approximately 10-15 days and the SRT for the SNDR is approximately 7-11 days. The digested sludge is screw pressed to achieve 20% solids and dried in a drying pad. The biosolids are beneficially reused in farms, city golf courses, public works and by the public. The biosolids production for the POTW is the following: x 2019 639.42 Dry Metric Tons x 2020 623.85 Dry Metric Tons x 2021 640.20 Dry Metric Tons x 2022 433.26 Dry Metric Tons January until August 2022 2.1 NPDES Permit - Pretreatment Language Part I.B.8 of the District's NPDES permit #CO-0041700, issued by the Colorado Department of Public Health and Environment (CDPHE) contains provisions for Industrial Waste Management for municipalities without EPA-approved Pretreatment programs. The permit was effective on December 1, 2012 and expired on November 30, 2017. The St. Vrain Sanitation District is in the South Platte watershed basin. Based on the CDPHE's current schedule for watershed basin assessment and reviews, the CDPHE will assess the South Platte basin and update the 303d list for the basin in May 2025. The NPDES permits 16 St. Vrain Sanitation District - Pretreatment Program Evaluation Report CO-0041700 September 16, 2022 will be issued after the watershed basin is assessed and applicable water quality standards are developed. 2.1.1 NPDES Permit, Part 1.B.8 - Industrial Waste Management Part 1.B.8 of the District's NPDES permit include the following Pretreatment language, in accordance with 40 C.F.R. 122: "a. The Permittee has the responsibility to protect the Domestic Wastewater Treatment Works (DWTW), as defined at section 25.8.103(5) of the Colorado Water Quality Control Act, or the Publicly-Owned Treatment Works (POTW), as defined at 40 CFR section 403.3(q) of the federal pretreatment regulations, from pollutants which would cause pass through or interference, as defined at 40 CFR 403.3(p) and (k), or otherwise be incompatible with operation of the treatment works including interference with the use or disposal of municipal sludge. b. Pretreatment Standards (40 CFR Section 403.5) developed pursuant to Section 307 of the Federal Clean Water Act (the Act) require that the Permittee shall not allow, under any circumstances, the introduction of the following pollutants to the DWTW from any source of non-domestic discharge: i. Pollutants which create a fire or explosion hazard in the DWTW, including, but not limited to, wastestreams with a closed cup flashpoint of less than sixty (60) degrees Centigrade (140 degrees Fahrenheit) using the test methods specified in 40 CFR Section 261.21. ii. Pollutants which will cause corrosive structural damage to the DWTW, but in no case discharges with a pH of lower than 5.0 s.u., unless the treatment facilities are specifically designed to accommodate such discharges. iii. Solid or viscous pollutants in amounts which will cause obstruction to the flow in the DWTW, or otherwise interfere with the operation of the DWTW. iv. Any pollutant, including oxygen demanding pollutants (e.g., BOD), released in a discharge at a flow rate and/or pollutant concentration which will cause Interference with any treatment process at the DWTW. v. Heat in amounts which will inhibit biological activity in the DWTW resulting in Interference, but in no case heat in such quantities that the temperature at the DWTW treatment plant exceeds forty (40) degrees Centigrade (104 degrees Fahrenheit) unless the Approval Authority, upon request of the DWTW, approves alternate temperature limits. vi. Petroleum oil, non-biodegradable cutting oil, or products of mineral oil origin in amounts that will cause Interference or Pass Through. vii. Pollutants which result in the presence of toxic gases, vapors, or fumes within the DWTW in a quantity that may cause acute worker health and safety problems. viii. Any trucked or hauled pollutants, except at discharge points designated by the DWTW; and ix. Any specific pollutant that exceeds a local limitation established by the Permittee in accordance with the requirements of 40 CFR Section 403.5(c) and (d). 17 St. Vrain Sanitation District - Pretreatment Program Evaluation Report CO-0041700 September 16, 2022 x. Any other pollutant which may cause Pass Through or Interference. c. EPA shall be the Approval Authority and the mailing address for all reporting and notifications to the Approval Authority shall be: USEPA 1595 Wynkoop St. 8ENF-W-NP, Denver, CO 80202-1129. Should the State be delegated authority to implement and enforce the Pretreatment Program in the future, the Permittee shall be notified of the delegation and the state permitting authority shall become the Approval Authority. d. In addition to the general limitations expressed above, more specific Pretreatment Standards have been and will be promulgated for specific industrial categories under Section 307 of the Act (40 CFR Part 405 et. seq.). e. The Permittee must notify the state permitting authority and the Approval Authority, of any new introductions by new or existing industrial users or any substantial change in pollutants from any industrial user within sixty (60) calendar days following the introduction or change. Such notice must identify: i. Any new introduction of pollutants into the DWTW from an industrial user which would be subject to Sections 301, 306, or 307 of the Act if it were directly discharging those pollutants; or ii. Any substantial change in the volume or character of pollutants being introduced into the DWTW by any industrial user. iii. For the purposes of this section, adequate notice shall include information on: (A) The identity of the industrial user. (B) The nature and concentration of pollutants in the discharge and the average and maximum flow of the discharge to be introduced into the DWTW; and (C) Any anticipated impact of the change on the quantity or quality of effluent to be discharged from or biosolids or sludge produced at such DWTW. iv. For the purposes of this section, an industrial user shall include: (A) Any discharger subject to Categorical Pretreatment Standards under Section 307 of the Act and 40 CFR chapter I and subchapter N. (B) Any discharger which has a process wastewater flow of25,000 gallons or more per day. (C) Any discharger contributing five percent or more of the average dry weather hydraulic or organic capacity of the DWTW treatment plant. (D) Any discharger who is designated by the Approval Authority as having a reasonable potential for adversely affecting the DWTWs operation or for violating any Pretreatment Standard or requirements. f. At such time as a specific Pretreatment Standard or requirement becomes applicable to an industrial user of the Permittee, the state permitting authority and/or Approval Authority may, as appropriate: i. Amend the Permittee's CDPS discharge permit to specify the additional pollutant(s) and corresponding effluent limitation(s) consistent with the applicable national 18 St. Vrain Sanitation District - Pretreatment Program Evaluation Report CO-0041700 September 16, 2022 Pretreatment Standards. ii. Require the Permittee to specify, by ordinance, order, or other enforceable means, the type of pollutant(s) and the maximum amount which may be discharged to the Permittee's DWTW for treatment. Such requirement shall be imposed in a manner consistent with the program development requirements of the General Pretreatment Regulations at 40 CFR Part 403; and/or, iii. Require the Permittee to monitor its discharge for any pollutant which may likely be discharged from the Permittee's DWTW, should the industrial user fail to properly pretreat its waste. The state permitting authority and the Approval Authority retains, at all times, the right to take legal action against any source of nondomestic discharge, whether directly or indirectly controlled by the Permittee, for violations of a permit, order or similar enforceable mechanism issued by the Permittee, violations of any Pretreatment Standard or requirement, or for failure to discharge at an acceptable level under national standards issued by EP A under 40 CFR, chapter I, subchapter N. In those cases where a CDPS permit violation has occurred because of the failure of the Permittee to properly develop and enforce Pretreatment Standards and requirements as necessary to protect the DWTW, the state permitting authority and/or Approval Authority shall hold the Permittee and/or industrial user responsible and may take legal action against the Permittee as well as the Industrial user(s) contributing to the permit violation." 19 St. Vrain Sanitation District - Pretreatment Program Evaluation Report CO-0041700 September 16, 2022 Figure 1 -St. Vrain Sanitation District Service Area 20 St. Vrain Sanitation District - Pretreatment Program Evaluation Report CO-0041700 September 16, 2022 Figure 2 - St. Vrain Sanitation District Service Area-Sewer Collection Lines 21 St. Vrain Sanitation District - Pretreatment Program Evaluation Report CO-0041700 September 16, 2022 St. Vrain Creek St. Vrain Sanitation District POTW Figure 3 - St. Vrain Sanitation District POTW, Google Maps View 22 St. Vrain Sanitation District - Pretreatment Program Evaluation Report CO-0041700 September 16, 2022 3.0 Evaluation of the St. Vrain Sanitation District POTW 3.1 Regulatory Background In 1972 Congress passed the Clean Water Act (CWA) to restore and maintain the integrity of the nation's waters. The goals of the CWA are to eliminate the introduction of pollutants into the nation's navigable waters and to achieve fishable and swimmable water quality levels. The CWA's National Pollutant Discharge Elimination System (NPDES) Permit Program represents one of the key components established to accomplish the goals of the CWA. The NPDES Permit Program generally requires that point source discharges of pollutants to waters of the United States, i.e., direct dischargers, obtain an NPDES permit. In addition to addressing these direct discharges, the CWA also established a regulatory program to address indirect discharges from industries to publicly owned treatment works (POTWs) through the National Pretreatment Program, a component of the NPDES Permit Program. The National Pretreatment Program requires industrial and commercial dischargers, called industrial users (IUs), to obtain permits or other control mechanisms to discharge wastewater to the POTW. A Pretreatment permit designed to protect the POTW may require the IU to treat, manage or otherwise control pollutants in its wastewater before discharging it to a POTW. Certain industrial discharge practices can interfere with the operation of POTWs, leading to the discharge of untreated or inadequately treated wastewater into rivers, lakes, and other waters of the United States. A discharge that causes interference inhibits or disrupts the POTW, its treatment processes or operations, or its sludge processes, use, or disposal and therefore causes a violation of any requirement of the POTW's NPDES permit. Some pollutants are not amenable to biological wastewater treatment at POTWs and can pass through the treatment plant untreated or partition into the sewage sludge or biosolids. This pass through of pollutants to the receiving water has the potential to cause fish kills or other deleterious effects or to the sewage sludge can inhibit the ability of the POTW to beneficially reuse its biosolids. The General Pretreatment Regulations at 40 C.F.R. 403.8(a) state that "Any POTW (or combination of POTWs operated by the same authority) with a total design flow greater than 5 million gallons per day (mgd) and receiving from Industrial Users pollutants which Pass Through or Interfere with the operation of the POTW or are otherwise subject to Pretreatment Standards will be required to establish a POTW Pretreatment Program. The Regional Administrator or Director may require that a POTW with a design flow of 5 mgd or less develop a POTW Pretreatment Program if he or she finds that the nature or volume of the industrial influent, treatment process upsets, violations of POTW effluent limitations, contamination of municipal sludge, or other circumstances warrant in order to prevent Interference with the POTW or Pass Through." 3.2 EPA Evaluation of St. Vrain Sanitation District EPA Region 8 continually evaluates municipalities without approved Pretreatment programs by reviewing the ICIs and ECHO databases to determine if these POTWs have experienced NPDES permit violations that may be attributable to pollutants from non- 23 St. Vrain Sanitation District - Pretreatment Program Evaluation Report CO-0041700 September 16, 2022 domestic IUs. In addition, EPA evaluates information gathered from NPDES permit applications, fact sheets, annual reports, correspondence with State NPDES permitting agencies and other sources to track service area growth in these municipalities that may result in new or increased contributions from non-domestic IUs that have the potential to cause interference or pass through at the POTW or otherwise be subject to Pretreatment Standards and Requirements. EPA evaluated the St. Vrain Sanitation District to determine if it needs to develop an EPAapproved Pretreatment program, as required by 40 C.F.R. 403.8(a). The determination under section 403.8(a) is based on two distinct inquiries: 1) whether one or more circumstances present a real possibility of interference or pass through; and 2) whether there is a nexus between the Pretreatment program and the possibility of interference or pass through. The District has experience significant residential and non-residential growth within its service area from CY 2000, based on the data shown in Figure 3. (Note: SFE = Single Family Equivalent) Figure 4 - St. Vrain Sanitation District Sewer Tap Growth, 1999-2021 This growth has been from the domestic (residential) and non-domestic sectors. The number of IU sewer taps has increased from 374 in 2012 to 502 in 2022, as shown in Table 1. As a result of non-domestic or IU growth in the service area, the District has increased the number of Pretreatment permits issued to IUs to protect the POTW, as shown in Table 2. The District currently issues 10 Pretreatment permits to establish control of the pollutants in the IU's non-domestic wastewater and protect the POTW from interference or pass through. 24 St. Vrain Sanitation District - Pretreatment Program Evaluation Report CO-0041700 September 16, 2022 Table 1 - St. Vrain Sanitation District - Number of IU taps, 2012-2022 Year 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 Number of IU taps 374 378 378 399 409 411 420 435 465 497 502 Table 2 - St. Vrain Sanitation District - CIU/SIU Permits Growth, 19952020 Name of IU Stericycle Permit Issuance date 1995 Applicable Pretreatment Standard Local Limits Star Precision 2007 Del Camino 2007 Truck Wash Aurora Organic 2008 Dairy Mile High Metal 2010 Works ARC Colorado 2012 Metal Finisher 40 C.F.R. 433 Local Limits Local Limits Metal Finisher 40 C.F.R. 433 Metal Finisher 40 C.F.R. 433 Type of permit Discharge Zero Discharge Discharge Discharge Zero Discharge Zero Discharge Operations/Process Medical Sterilization Sharps Metal forming/Phosphate Washing/Powder Coating Semi-Truck Wash Organic Milk Metal forming/Phosphate Washing/Powder Coating Metal forming/Phosphate Washing 25 St. Vrain Sanitation District - Pretreatment Program Evaluation Report CO-0041700 September 16, 2022 Agilent Smucker's Applied Coatings Technology Boulder Scientific 2018 2019 2020 2020 Pharmaceutical 40 C.F.R. 439 Local Limits Metal Finisher 40 C.F.R. 433 Discharge Discharge Zero Discharge Oligonucleuotides-APIs Frozen PB&J Sandwiches Powder Coating Pharmaceutical 40 C.F.R. 439 Zero Discharge Organo Metallic Catalyst The District currently has 6 IUs in its service area that generates wastewater subject to the Categorical Pretreatment Standards if the IUs discharge this wastewater to the POTW. In addition, the District has categorized an additional 4 more IUs in its service area as significant industrial users (SIU) and issues Pretreatment permits with local Pretreatment Standards. A nexus exists between the potential for pass through or interference at the POTW and the Pretreatment program because the industrial wastewater discharges from these IUs are subject to either the Categorical Pretreatment Standards developed by EPA or are subject to the Pretreatment Standards incorporated in the District's Rules and Regulations (i.e., local limits and general and specific discharge prohibitions found in 40 CFR 403.5). The Pretreatment Standards applied by the District in its IU permits are designed to protect the District's POTW from the impacts of such wastewater. Based on information gathered during the program evaluation, the District meets the 40 C.F.R. 403.8(a) criteria of a POTW with a design flow of 5 MGD and receiving pollutants from IUs that have the potential to cause pass through or interference or are subject to Pretreatment Standards. As a follow-up to the District's program evaluation, EPA plans to provide a notification that provides the District a one-year timeframe to develop and submit a Pretreatment Program for approval. A compliance schedule to develop and submit an approved Pretreatment program to EPA will also be provided in the one-year notification. The compliance schedule will contain the elements of a Pretreatment program submittal that meets the requirements under 40 C.F.R. 403.8(f), including the following: 1. 40 C.F.R. 403.8(f)(1), Legal Authority: 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. 2. 40 C.F.R. 403.8(f)(2), Procedures: The POTW shall develop and implement procedures to ensure compliance with the requirements of a Pretreatment Program. 3. 40 C.F.R. 403.8(f)(3), Funding: The POTW shall have sufficient resources and qualified personnel to carry out the authorities and procedures described in its program 26 St. Vrain Sanitation District - Pretreatment Program Evaluation Report CO-0041700 September 16, 2022 approval submittal. 4. 40 C.F.R. 403.8(f)(4), Local Limits: The POTW shall develop local limits as required in 403.5(c)(1) or demonstrate that they are not necessary. 5. 40 C.F.R. 403.8(f)(5), Enforcement Response Plan: he 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. 6. 40 C.F.R. 403.8(f)(6), Industrial User Inventory/SIU List: The POTW shall prepare and maintain a list of its 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. EPA evaluated the District's current program to determine updates are necessary for submittal of a Pretreatment program to EPA under 40 C.F.R. 403.8(b), as identified in the following sections of this report. 3.3 Contents of a Pretreatment Program Submittal The elements of a Pretreatment program that meets the requirements under 40 C.F.R. 403.8(f) must be submitted in accordance with 40 C.F.R. 403.9(b) that outlines the contents of a Pretreatment program submittal: (1) A statement from the City Solicitor or a city official acting in a comparable capacity (or the attorney for those POTWs which have independent legal counsel) that the POTW has authority adequate to carry out the programs described in 403.8. This statement shall: (i) Identify the provision of the legal authority under 403.8(f)(1) which provides the basis for each procedure under 403.8(f)(2); (ii) Identify the manner in which the POTW will implement the program requirements set forth in 403.8, including the means by which Pretreatment Standards will be applied to individual Industrial Users (e.g., by order, permit, ordinance, etc.); and, (iii) Identify how the POTW intends to ensure compliance with Pretreatment Standards and Requirements, and to enforce them in the event of noncompliance by Industrial Users. (2) A copy of any statutes, ordinances, regulations, agreements, or other authorities relied upon by the POTW for its administration of the Program. This Submission shall include a statement reflecting the endorsement or approval of the local boards or bodies responsible for supervising and/or funding the POTW Pretreatment Program if approved. (3) A brief description (including organization charts) of the POTW organization which will administer the Pretreatment Program. If more than one agency is responsible for administration of the Program the responsible agencies should be identified, their respective responsibilities delineated, and their procedures for coordination set forth. (4) A description of the funding levels and full- and part-time manpower available to implement the Program. 27 St. Vrain Sanitation District - Pretreatment Program Evaluation Report CO-0041700 September 16, 2022 4.0 Rules and Regulations 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... 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. 28 St. Vrain Sanitation District - Pretreatment Program Evaluation Report CO-0041700 September 16, 2022 (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 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 St. Vrain Sanitation District Rules and Regulations The District has established its Pretreatment legal authority in Section 10 of the St. Vrain Sanitation District Rules and Regulations. EPA evaluated the District's Rules and Regulations to determine if they need to be updated to comply with the Federal Regulations and if they are approvable by EPA. Based on EPA's review, The Pretreatment Regulations established in Chapter 10 of the District 's Rules and Regulations provide the District the framework to implement the Pretreatment Regulations in the POTW's service area, with the following exceptions (The items needed to be updated are identified in the attached St. Vrain Sanitation District legal authority review.docx and EPA comments are embedded in the Rules_and_Regs_updated_June_2021-EPA.pdf ): 1. EPA recommends the District ensure it uses Industrial user in its Rules and Regulations. The District currently uses the definition of User in language where it 29 St. Vrain Sanitation District - Pretreatment Program Evaluation Report CO-0041700 September 16, 2022 appears that Industrial User is required. 2. Pretreatment Standard Definition - 10.1.4(FF): the District needs to add Best Management Practices (BMP) to the definition of Pretreatment Standards using a definition consistent with 40 C.F.R. 403.3(e). 3. POTW - 10.1.4(HH): The definition needs to be modified to add the following language to be consistent with 40 C.F.R. 403.3(q): "It also includes sewers, pipes and other conveyances only if they convey wastewater to a POTW Treatment Plant. The term also means the municipality as defined in section 502(4) of the Act, which has jurisdiction over the Indirect Discharges to and the discharges from such a treatment works." 4. 10.1.4(KK) citation refers to both SIU and Slug Discharge definitions. EPA recommends correcting the typo. 5. Pollutants Not Present: the District has established permit conditions for Pollutants not Present in 10.5.2(A)(1) but has not established the required provisions or waiver certification in 40 C.F.R. 403.12(e)(2). In order to implement this provision, add these items to the District's legal authority. If the District does not want to implement this provision, remove the permit conditions from the legal authority. 6. Trucked and Hauled Waste - 10.3.5: EPA recommends the District require waste tracking forms or manifests for domestic loads. The District's Rules and Regulations at 10.2.1(B)(13) prohibit "Sludges, screenings or other residues from the pretreatment of industrial wastes" to be introduced or cause to be introduced into the POTW. It is unclear if this prohibition language precludes the acceptance of these types of nondomestic waste loads. 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 30 St. Vrain Sanitation District - Pretreatment Program Evaluation Report CO-0041700 September 16, 2022 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 District's IGAs with Outside Contributing Jurisdictions According to information gathered during the program evaluation, the District has the following outside jurisdictions that contribute wastewater to the District's POTW: Town of Mead, the Longview Community LLC, and the Colorado Real Estate and Investment Company (River Valley Village Mobile Home Community). 40 C.F.R. 403.8(f)(1) of the Federal Pretreatment Regulations require the following: "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." EPA did not evaluate these outside contributing jurisdictions during the program evaluation to determine if these jurisdiction contain IUs or if the District has established IGAs with these jurisdictions that allow the District to implement the Pretreatment program to IUs within these jurisdictions. Provide information to EPA if IUs exist outside of District boundaries and if IGAs or other mechanisms are established that allow the District to adequately implement the Pretreatment program, including right of entry to inspect and copy records, inspect to identify flows and characterize the pollutants in the IU's wastewater, sample, issue permits or other forms of control mechanisms, evaluate compliance and enforce. If no such mechanisms exist, work with these outside jurisdictions to develop and implement them. 5.0 Pretreatment Operating Procedures 5.1 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, x Investigate instances of noncompliance with Pretreatment standards and requirements, 31 St. Vrain Sanitation District - Pretreatment Program Evaluation Report CO-0041700 September 16, 2022 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." 5.2 Standard Operating Procedures (SOPs) and Templates The District has developed the following Pretreatment program implementation procedures and templates: x Pretreatment Program Procedures: o Section 1 - Pretreatment Program Overview and Organization o Sections 2 and 3 - Industrial User Inventory and Characterization - This procedure needs to be updated to include methods on how the current IU inventory is maintained to capture current information at the IU. o Section 4 - Wastewater Permitting o Sections 5, 9 and 10 - Sampling Plan, including chain-of-custody and QA/QC. The sampling plan needs to be updated to include sampling protocols at each permitted IU. o Section 6 and 7 - Enforcement action proceedings o Section 8 - Information Requirements x Permit Template - The District needs to update the permit template to align with 40 CFR 403.8(f)(1)(iii)(B)(1-6) and related provisions in 40 C.F.R. 403.12 of the Pretreatment Regulations: o Statement of Non-Transferability - include the following language to Section I.7.b "and provisions for furnishing the new owner or operator with a copy of the existing wastewater discharge permit." 32 St. Vrain Sanitation District - Pretreatment Program Evaluation Report CO-0041700 September 16, 2022 o Requirement to conduct representative sampling - The requirement to conduct representative sampling in 40 C.F.R. 403.12(g)(3) is absent and needs to be added. o Submission of all monitoring data in Section F.1.a needs to be modified to align with 40 C.F.R. 403403.12(g)(6) o Pollutants Not Present is adopted in the District's Rules and Regulations but not included in the permit template. Ensure the missing provisions noted above in the legal authority finding are also addressed. o Equivalent mass or concentration limits Present is adopted in the District's Rules and Regulations but not included in the permit template. EPA recommends the District develop program implementation procedures for programmatic activities such as data management, recordkeeping, management of confidential information, facility inspections, and other programmatic activities, as necessary. 6.0 Resources 6.1 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. 6.2 Evaluation of the District's Resources and Funding According to the information gathered during the evaluation, the District's resource commitment to the Pretreatment program is less than 1.0 FTE. The District commits approximately $125,000 annually to the Pretreatment program, which appears to be adequate to fund its current program. Currently, the Pretreatment Coordinator is responsible for all field and activities for the District's non-approved Pretreatment program. In Pretreatment Coordinator is responsible for the following duties: 33 St. Vrain Sanitation District - Pretreatment Program Evaluation Report CO-0041700 September 16, 2022 programmatic addition, the x 40% Permit Management (Reviewing reports, sampling, inspections, permit writing, violation management, reviewing renewal applications) x 10-15% Interceptor inspections x 5% plan and waste survey review x 5% CIPCA/R8PA x 25% Outside Pretreatment Duties (Collection Department duties, Maintenance of Generator and Flow Meters, Water Usage Data collection annual, customer service, in-house committees, nuisance rabbit relocation) x 5-10% Field Sampling (Collections, Plant) The Pretreatment Regulations at 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 procedures" of the Pretreatment program. Based on EPA's evaluation of the District's current Pretreatment program, it appears that the District's funding commitment is adequate. However, it appears that the District's current staffing commitment of less than 1.0 FTE to implement the Pretreatment program is not adequate to conduct all field and programmatic activities of the District's current Pretreatment program including development of local limits, CIU/SIU permit management (including renewals, IU inspections, receipt of selfmonitoring compliance reports and notices, compliance evaluation, and enforcement), FOG interceptor inspections, dental office inspection, and spending time in the service identifying potential SIU/CIUS for the industrial user inventory. To ensure the District's ability to consistently implement the Pretreatment program in its service area, the District needs to submit a staffing plan in the approved Pretreatment program submittal to address the District's commitment to the Pretreatment program, providing details regarding training opportunities for the current staff and an evaluation of the current and projected scope of the Pretreatment program, in case of future non-domestic growth in the service area and in addition, to maintain institutional knowledge of the current program. 6.3 Examples of Available Pretreatment Training/Resources The EPA is available to help with training and outreach assistance to the Pretreatment personnel. In addition, there are opportunities for training and peer communication with the CIPCA and R8PA organization within Region 8.This is not a comprehensive list of all Pretreatment related training/resources available. The District is encouraged to seek out training and resources that will support its Pretreatment program implementation. EPA is also available to the District 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. 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-webinar. Archived presentations may be downloaded, and a schedule of future training opportunities is located at the website. 34 St. Vrain Sanitation District - Pretreatment Program Evaluation Report CO-0041700 September 16, 2022 An additional resource available is the Pretreatment Coordinators Group discussion forum, found at the following website: https://groups.io/g/Pretreatment/topics 7.0 Local Limits 7.1 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 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 mass- 35 St. Vrain Sanitation District - Pretreatment Program Evaluation Report CO-0041700 September 16, 2022 balance 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. 7.2 Local Limits Requirements Established in the District's NPDES Permits The District's NPDES permit that was issued by the CDPHE and expired on November 30, 2017 does not establish local limit requirements, however, the renewed permit will establish local limits and technical evaluation of local limits requirements. 36 St. Vrain Sanitation District - Pretreatment Program Evaluation Report CO-0041700 September 16, 2022 7.3 The EPA Evaluation of the District's Local Limits 7.3.1 Technically-based Local Limits The District has established local limits in 10.2.4(B) of its Rules and Regulations. EPA has not approved these local limits since the District does not currently have an EPAapproved Pretreatment program. The District needs to submit the local limit development records, including but not limited to POTW and service area data, standards used to develop the local limits, the technical calculations, assumptions / justifications used during the calculations, development of non-technical numeric limits and public participation records for its existing local limits established in 10.2.4(B) of its Rules and Regulations to EPA to determine if these are approvable.. The local limits applicability language 10.2.4(A) states the following: "The following pollutant limits are established to protect against Pass-Through and Interference. No Significant Industrial User shall discharge wastewater containing in excess of the following daily maximum limits." Table 3 - St. Vrain Sanitation District Local Limits Pollutant Symbol Arsenic, Total Biochemical Oxygen Demand Cadmium, Total Chromium, Total Chromium VI Copper, Total Lead, Total Mercury, Total Molybdenum, Total Nickel, Total Selenium, Total As BOD Cd Cr Cr VI Cu Pb Hg Mo Ni Se Daily Maximum (lbs/day) 0.065 1,350 0.049 24.06 2.925 0.846 0.365 0.0045 0.202 0.864 0.192 37 St. Vrain Sanitation District - Pretreatment Program Evaluation Report CO-0041700 September 16, 2022 Pollutant Silver, Total Total Suspended Solids Zinc, Total Symbol Ag TSS Zn Daily Maximum (lbs/day) 1.032 1,300 2.305 7.3.2 Numeric Ordinance Limits In addition to the established technically-based local limits, the District has incorporated the following numeric ordinance limits in 10.2.1(B) of the Rules and Regulations. These numeric ordinance limits are not site-specific and have not undergone the rigor of approval/public participation for the technically-based local limits: x Upper pH limit [10.2.1 (B)(2)]: Wastewater having a pH less than five (5.0) or greater than twelve and one half (12.5) standard units, or otherwise causing corrosive structural damage to the POTW or equipment. x Solids [10.2.1 (B)(3)]: Solid or viscous substances in amounts which will cause obstruction of the flow in the POTW resulting in Interference, but in no case solids greater than one half inch (1/2") in any dimension. x Lower Explosive Limit (LEL) [10.2.1 (B)(16)]: - Wastewater causing two readings on an explosion hazard meter at the point of discharge into the POTW, or at any point in the POTW, of more than five percent (5%) or any single reading over ten percent (10%) of the Lower Explosive Limit of the meter. 7.3.3 Dilution Prohibition The District has incorporated a prohibition on dilution in 10.2.6 of the Rules and Regulations to ensure the IUs are appropriately managing their regulated wastestreams to meet compliance with an applicable Pretreatment Standard or Requirement: "No IU 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 Manager may impose mass limitations on IUs 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 10.2.6 meets the requirement in 40 C.F.R. Part 403.6(d) of the Pretreatment Regulations. 38 St. Vrain Sanitation District - Pretreatment Program Evaluation Report CO-0041700 September 16, 2022 7.4 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, 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. POTW should compare its current conditions and requirements with those that existed when the local limits were developed to conduct an adequate technical evaluation of its local limits, in accordance with 40 C.F.R. 122.44(j)(2)(ii). 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 7.5 Technical Evaluation of the District's Local Limits Because the District will be required to develop an EPA-approved Pretreatment program, the District's renewed NPDES permit will require a technical evaluation of the District's local limits to ensure it incorporates new limits and standards incorporated by the NDPES permit or considered during the permit renewal process, in accordance with 40 C.F.R. 122.44(j)(2)(ii) of the NPDES regulations. The local limits technical evaluation will be required within 12 months of the effective date of renewed permit. 39 St. Vrain Sanitation District - Pretreatment Program Evaluation Report CO-0041700 September 16, 2022 7.6 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. 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 District has established the ability to develop site or permit-specific limits in 10.2.5 of its Rules and Regulations: "The District reserves the right to establish, by regulation or in wastewater discharge permits, more stringent standards or requirements on discharges to the POTW consistent with the purpose of this regulation." It does not appear that the District has established site-specific limits in its IU permits. 8.0 Industrial User Inventory and Characterization 8.1 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. 40 St. Vrain Sanitation District - Pretreatment Program Evaluation Report CO-0041700 September 16, 2022 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 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. 41 St. Vrain Sanitation District - Pretreatment Program Evaluation Report CO-0041700 September 16, 2022 8.2 Industrial User Identification and Characterization Procedure 40 C.F.R. 403.8(f)(2) of the Pretreatment Regulations require the District to "develop and implement procedures" that "enable the POTW" to comply with these Pretreatment Program requirements. As discussed in 5.2 of this report, the District needs to develop an IU Identification and Characterization procedure that describe current methods and procedures the District uses to identify and characterize IUs in the service area of its POTW and to notify these IUs of applicable Pretreatment Standards. The procedure needs to include maintenance of the IU inventory to ensure the information and records capture current conditions of the IUs. based on available tools to the District such as the industrial waste survey, drive by inspections, facility inspections, sampling, etc. 8.3 Industrial User Database of the District's Service Area 40 C.F.R. 403.8(f)(2)(i-iii) of the Pretreatment regulations require the District 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 Pretreatment Standards and Requirements. The District needs to submit a current IU inventory of the IUs in its service area for EPA to review. The IU inventory needs to be representative of current conditions in the service area to provide current characterization of the IUs (all non-domestic users, including restaurants/food service establishments, dental facilities, other potential users) on the inventory to identify flows and non-domestic pollutants that may impact the POTW and the collection system. EPA recommends the District collaborate with the Fire Departments 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. 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 9.0 Enforcement Response Plan 9.1 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. 42 St. Vrain Sanitation District - Pretreatment Program Evaluation Report CO-0041700 September 16, 2022 (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. 9.2 Enforcement Legal Authority The EPA evaluated the District's enforcement authority and remedies found in its Rules and Regulations. 1. Enforcement Response Plan incorporated in 10.10.1 2. Civil/Criminal penalties established in 10.11.2 and 10.11.3 3. Injunctive relief provisions established in 10.11.1 4. Authority to enforce against falsification/tampering established in 10.11.3(A) 5. Notice of violations authority established in 10.10.2 6. Administrative orders authority established in 10.10.5 7. Show cause hearing provisions in 10.10.4 8. Cease and Desist Order established in 10.10.6 9. Administrative Penalty Authority established in 10.10.7 10. Suspensions of service provisions in 10.10.8 11. Permit termination provisions established in 10.10.9 12. Publication of IUs in significant noncompliance in 10.9 Based on EPA's review, the District has adequately established the authority to enforce non-compliance with its Pretreatment program in its Rules and Regulations. 9.3 Enforcement Response Plan EPA evaluated the District's ERP to ensure the District is adequately implementing the authority established in its Rules and Regulations. Based on EPA's review, the District needs to update its ERP to align with 40 C.F.R. 403.8(f)(5)(i-iv) . (Note: EPA's 43 St. Vrain Sanitation District - Pretreatment Program Evaluation Report CO-0041700 September 16, 2022 comments are included in the attached St. Vrain Sanitation District - ERP Review.dox.} x The ERP needs to include procedures for permitting and SNC evaluation/determination. x DESCRIPTION OF ENFORCEMENT ACTIONS header on Page 6: EPA recommends the District provide a citation to its Rules and Regulations to identify where the enforcement actions are established. x The following anticipated types of violations either need to be incorporated or modified: o Unpermitted Dischargers submitting the permit application past 45 days late - Does this violation meet the District's SNC criteria for late reporting? o Not Included in the ERP: Any other violation of a Pretreatment Standard or Requirement as defined by 40 CFR 403.3(l) that the POTW determines has caused Interference or Pass Through (including endangering the health of POTW personnel or the general public). (SNC Criteria # C) is not included in the ERP Failure to notify (24-hour, slug/potential problems, changed discharges, hazardous waste, upset, bypass) Tampering with monitoring equipment/methods Trucked and Hauled waste, if applicable Any discharge of a pollutant that has caused imminent endangerment to human health, welfare or to the environment or has resulted in the POTW's exercise of its emergency authority (SNC Criteria # D) Failure to accurately report noncompliance. (SNC Criteria # G) Any other violation or group of violations, which may include a violation of Best Management Practices, which the POTW determines will adversely affect the operation or implementation of the local Pretreatment program. (SNC Criteria # H) 44 St. Vrain Sanitation District - Pretreatment Program Evaluation Report CO-0041700 September 16, 2022