Document qdkeDzM2JM650bG2EE5Qn6MKq

Pretreatment Audit Report South Adams County Water and Sanitation District Pretreatment Audit Report CO-0026662 Henderson, Colorado January 27, 2025 to January 30, 2025 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 South Adams County Water and Sanitation District Pretreatment Audit Report CO-0026662 January 27, 2025 to January 30, 2025 Report Review and Signature Drafter Name Al Garcia Reviewer Name Monica Crosby Supervisor Signature/Name MICHAEL BOEGLIN Digitally signed by MICHAEL BOEGLIN Date: 2025.03.11 09:11:30 -06'00' Michael Boeglin Address/Phone Number U.S. EPA Region 8 1595 Wynkoop Street 8WD-CWW Denver, Colorado 80202 303-312-6382 Address/Phone Number U.S. EPA Region 8 1595 Wynkoop Street 8ENF-W-NP Denver, Colorado 80202 410-305-3029 Address/Phone Number U.S. EPA Region 8 1595 Wynkoop Street 8WD-CWW Denver, Colorado 80202 303-312-6250 Date 03/03/2025 Date 03/04/2025 Date 03/11/2025 2 South Adams County Water and Sanitation District Pretreatment Audit Report CO-0026662 January 27, 2025 to January 30, 2025 Pretreatment Audit Summary Table South Adams County Water and Sanitation District Pretreatment Audit Report CO-0026662 January 27, 2025 to January 30, 2025 Pretreatment Audit Findings Pretreatment Requirement and Corrective Action Section 4.0 - Municipal Ordinance and Intergovernmental Agreements (IGA) 1. 40 C.F.R. 403.8(f)(1) states, "The POTW [publicly owned treatment works] 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 Pretreatment Requirements powers agreements which the POTW is authorized to enact, enter into or implement, and which are authorized by State law." 40 C.F.R. 403.8(f)(1) Corrective Action Item The District provided its Pretreatment legal authority found in Articles III and IV of its Rules and Regulations for the EPA to review. Based on the Update Article IV of the District's Rules and Regulations to align with the Federal Pretreatment Regulations. EPA's review, the Pretreatment Regulations incorporated in its Rules and Regulations, Articles III and IV provide the District the framework to implement the Pretreatment Regulations in the POTW's service area, with the following exceptions in Article IV summarized below: Categorical Standards, section 2.7 [40 C.F.R. 403.6] -- Remove the following sentence from the definition: "This term includes the general and specific prohibitions and Local Limits established pursuant to Article III." [Note: Categorical Pretreatment standards are The EPA's comments to the District's Rules and Regulations, Article IV are included in the enclosed SACWSD Legal Authority Review.docx and embedded in Article IV (2014)-EPA.pdf. Recommendation The EPA recommends the District remove the incorrect SNC criteria in section 2.39. The EPA recommends the District incorporate the use of digital photos in its Right of Entry section 18.2. technology-based standards developed by the EPA and do not include general/specific prohibitions or local limits.] National Prohibitive Discharge Standard, section 2.23 -- Prohibitive Discharge Standards only include general and specific prohibitions found in 40 C.F.R. 403.5(a) and (b) and do not include local limits. 3 South Adams County Water and Sanitation District Pretreatment Audit Report CO-0026662 January 27, 2025 to January 30, 2025  Pretreatment Standards, section 2.32 [40 C.F.R. 403.6] - Pretreatment Standards include (1) categorical Pretreatment Standards, (2) general and specific prohibitions, (3) local limits and (4) BMPs. Recommend the following changes to the definition to align with Federal Regulations. o Means any regulation containing pollutant discharge limits promulgated by the EPA or the District in accordance with sections 307(b) and (c) of the Act, which applies to Industrial Users. This term includes prohibitive discharge limits standards established pursuant to 40 C.F.R. 403.5, categorical Pretreatment Standards, and local limits / BMPs developed by the Control Authority. In cases of differing standards or regulations, the more stringent shall apply. Significant Noncompliance (SNC), Sections 2.39 and 19.8.1 - 19.8.7 [40 C.F.R. 403.8(f)(2)(viii)] - the District has two sections within its Rules and Regulations that define the SNC criteria, and they are not consistent with each other. The SNC criteria in section 19.8.1 - 19.8.7 is aligned with the Federal Regulations. Specific Discharge Prohibition Standard - "Pollutants which result in the presence of toxic gases, vapors, or fumes within the POTW in a quantity that may cause acute worker health and safety problems," required by 40 C.F.R. 403.5(b)(7), is absent, and there does not appear to be an equivalent definition in the Rules and Regulations. Additional Permit Conditions for significant industrial users (SIUs) in section 3.9 states that the SIU permit may include the following permit conditions required by 40 C.F.R. 403.8(f)(1)(B)(1-6). This establishes these permit conditions as optional. The District is required to include all permit conditions required by the Pretreatment Regulations in issued SIU permits. The District has adopted all reporting and notification requirements in section 11.1. The EPA recommends the District incorporate the 4 South Adams County Water and Sanitation District Pretreatment Audit Report CO-0026662 January 27, 2025 to January 30, 2025 required notices and reports in 40 C.F.R. 403.12 instead of referencing for the following reasons: o 40 C.F.R. 403.12 includes reporting requirements for the POTW that are not applicable to Industrial Users (IUs) in the District's service area. o The incorporation of notices and reports in the District's Rules and Regulations provide the public more user-friendly access to the required SIU reports and notifications. o The appropriate sampling and analytical procedures may be difficult to find for SIUs needing this information for their monitoring programs. o Some reporting requirements found in 40 C.F.R. 403.12 are already incorporated: SIU Compliance reports - (section 11.4) 24-hour notification / 30-day resampling (section 3.9.6) Hazardous Waste notification (section 22.1 Reporting certification and signatory (section 3.11) Submission of all monitoring data (section 3.9.7) Pollutants Not Present [40 C.F.R. 403.8(f)(1)(B)(4) and 40 C.F.R. 403.12(e)(2)] - As a result of referencing 40 C.F.R. 403.12 in section 11.1, the District adopted this provision by reference and is required to ensure the process for seeking a waiver for Pollutants Not Present is also incorporated in the following sections of Article IV: o Permit Application (section 3.2) - the application contents need to be updated to include the process and information necessary for a waiver due to Pollutants not present. o Process for seeking a waiver - absent from the Rules and Regulations. The EPA will provide a fact sheet on the process requirements for seeking a waiver. 5 South Adams County Water and Sanitation District Pretreatment Audit Report CO-0026662 January 27, 2025 to January 30, 2025 Section 7.0 - Industrial User Inventory and Characterization 2. The Pretreatment Regulations at 40 C.F.R. 403.8(f)(2)(i-iii) states, "The POTW shall develop and implement procedures to ensure compliance with the requirements of a Pretreatment Program. At a minimum, these procedures shall enable the POTW to: 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. "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 Pretreatment Requirements 40 C.F.R. 403.8(f)(2)(i-iii) Administrator or Director upon request." This Corrective Action Item requires a POTW to characterize the IUs in Update the Industrial User Inventory and the inventory of the service area. Characterization procedure to incorporate IU "Notify Industrial Users identified under notification procedures for applicable paragraph (f)(2)(i) of this section, of Pretreatment Standards. 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 District has developed an Industrial User Inventory and Characterization Procedure that details how the District initially developed its IU inventory and characterized these IUs and the procedures the District uses to update existing IUs on 6 South Adams County Water and Sanitation District Pretreatment Audit Report CO-0026662 January 27, 2025 to January 30, 2025 the inventory and gather information on new IUs to its service area. The District's Industrial User Inventory and Characterization Procedure implements the Pretreatment requirement found in 40 C.F.R. 403.8(f)(2)(i-ii) that require the District to identify and locate all possible IUs which might be subject to the POTW Pretreatment Program and to identify the character and volume of pollutants contributed to the POTW by the IUs. However, the IU Inventory and Characterization SOP needs to also incorporate IU notification procedures of applicable Pretreatment Standards, as required in 40 C.F.R. 403.8(f)(2)(iii). Section 8.0 -Evaluation of Pretreatment Records and Permit Specific Issues Pretreatment Records Pretreatment Requirements 3. The Pretreatment Regulations at 40 C.F.R. 40 C.F.R. 403.8(f)(2)(ii) 403.8(f)(2)(ii) require the District to "Identify the character and volume of pollutants contributed to the Corrective Action Item POTW." The 2023 and 2024 inspection reports include brief descriptions of the manufacturing processes and should include more detail regarding the facility's chemical storage/handling/transfer, process/unit operations, wastestream generation from these unit operations, wastestream Provide more detail in the SIU inspection reports to capture current conditions at the facility and to identify the character and volume of contributed pollutants. Recommendation management or wastewater treatment, sampling procedures to provide a current characterization, including an evaluation of slug discharge potential and process or treatment plant changes. This information is important to capture current conditions and determine if control such as an SIU permit or BMPs or if modifications to existing control mechanisms or control plans such as slug discharge control plans or spill plans are necessary. During the audit, the EPA provided compliance assistance and training on conducting facility inspections, gathering data/information, and generating inspection reports that provide current facility conditions that may impact categorical determinations, permit conditions, or control documents such as the slug discharge control plan or toxic organic management plans. The EPA recommends the District remove the "briefly describe the manufacturing process or service provided" in the inspection report form; this appears to limit the characterization to a brief paragraph or two in the reports the EPA reviewed. It appears that the District takes digital photos during the annual facility inspections, but the photos are not included in the inspection reports, nor is there a reference to where these photos are stored. The EPA recommends the District ensure these photos capture areas relevant to the Pretreatment permit, including but not limited to floor drains, unit operations, raw material/chemical storage, applicable chemical handling equipment, wastestreams, wastewater treatment, and discharge 7 South Adams County Water and Sanitation District Pretreatment Audit Report CO-0026662 January 27, 2025 to January 30, 2025 locations/monitoring points. In addition, the EPA recommends the District include these photos in the facility inspection reports or provide a reference in the inspection reports to where these photos are stored. 4. The Pretreatment Regulations at 40 C.F.R. 403.8(f)(2)(iii) require the District to "Notify Industrial Users identified under paragraph (f)(2)(i) Pretreatment Requirements of this section, of applicable Pretreatment 40 C.F.R. 403.8(f)(2)(iii) Standards..." Based on the EPA's review of the Pretreatment records, the District provides a followup letter after each SIU inspection. However, the inspection follow-up letter does not consistently provide a notification to the IU of applicable Corrective Action Item Provide adequate follow up after an IU inspection to provide notice to the SIU or IU of applicable Pretreatment Standards. Pretreatment Standards or its status under the Pretreatment program. The District needs to ensure it provides adequate follow up after an inspection to provide notice to the IU of applicable Pretreatment Standards or to provide determination of any Recommendation The EPA recommends the District state, "No corrective action items" be included in the follow-up letter, if applicable. corrective action items. 5. The Pretreatment Regulations at 40 C.F.R. Pretreatment Requirements 403.8(f)(1)(iii) require the District to "Control 40 C.F.R. 403.8(f)(1)(iii) through Permit, order, or similar means, the contribution to the POTW by each Industrial User to 40 C.F.R. 403.8(f)(1)(iii)(B)(1-6) ensure compliance with applicable Pretreatment Standards and Requirements." The regulations further establish the minimum permit conditions at 40 CFR 403.12(e) 40 CFR 403.12 (g)(6) 40 C.F.R. 403.8(f)(1)(iii)(B)(1-6). South Adams County Water and Sanitation The EPA reviewed the permit templates for the District Rules and Regulations, Part II, Section discharging and non-discharging IUs. Based on the 1(E) EPA's review, the permit template and the standard conditions are equivalent to the Federal Pretreatment Regulations, with the following corrective action items summarized below: Part II, Section I(E) of the permit template provides the following statement for submission of all monitoring data: "Results of self-monitoring performed in excess of the required minimum frequencies, for the parameters regulated herein, must be included with the Discharge Monitoring Corrective Action Item Evaluate and modify the permit templates language to be equivalent with the Pretreatment Regulations and the District's Rules and Regulations. Establish the authority in the District's Rules and Regulations to administratively extend zero discharge permits or remove this provision from the zero discharge permits. Report (DMR) forms submitted to the District (40 The EPA's comments to the District's Permit CFR 403.12(g)(6))." The District's Rules and templates are included in the enclosed Regulations at section 3.9.7 states the same language SACWSD Permit Template Review.docx and but includes "using the procedures prescribed in comments embedded in 2023 Permit 8 South Adams County Water and Sanitation District Pretreatment Audit Report CO-0026662 January 27, 2025 to January 30, 2025 paragraph 40 CFR 403.12 (g)(6)." The District incorporated 40 CFR 403.12 by reference and as a result, incorporate all reporting and notification provisions such as Pollutants Not Present in 40 CFR 403.12(e). The District's permit template does not contain applicability and implementation language for the Pollutants Not Present including: Identification of the pollutants to be monitored (including the process for seeking a waiver for a pollutant neither present nor expected to be present in the Discharge in accordance with 403.12(e)(2), or a specific waived pollutant in the case of an individual control mechanism), sampling location, sampling frequency, and sample type, based on the applicable general Pretreatment Standards in part 403 of this chapter, categorical Pretreatment Standards, local limits, and State and local law; Template-EPA, 2023 Zero Discharge Permit Template-EPA, and 2021 Zero Discharge_Metal Finisher Permit TemplateEPA pdf. Recommendation The EPA recommends the District remove the PWS language and replace with local limits. The EPA recommends the District remove BOD and TSS from the local limits table and put into a separate surcharge levels table. The District establishes Prohibitive Discharge Standards (PWS) in the permit template at Part 1, section 1(A) and at outfall 002. PWS is not defined in the Rules and Regulations. The District includes numeric levels for BOD and TSS to surcharge for treatment beyond normal domestic-strength waste. The permit states in the limits table that "All Non-residential users which discharge a waste with five-day biochemical oxygen demand (BOD5) of greater than 272 mg/L and total suspended solids (TSS) of greater than 264 mg/L shall pay a surcharge as described in the NonResidential User Fee Schedule. (Statement of Basis, Attachment A)." These numeric levels are used for billing purposes and are not considered to be enforceable local limits. The District issues zero discharge permits for three years. The 2021 Zero Discharge Permit Template and the 2021 Zero Discharge Metal Finisher Permit Template both allow the permit to be administratively extended and includes the following statement on the cover page: "An expired Permit will continue to be effective and enforceable after expiration of the Permit if: (1) The Permittee has reapplied for a new permit within the 9 South Adams County Water and Sanitation District Pretreatment Audit Report CO-0026662 January 27, 2025 to January 30, 2025 timeframe required, (2) Failure to reissue a new permit is not due to any act, or failure to act, on the part of the Permittee or (3) The Permittee receives written communication extending the Permit from the District." However, the District has not established the authority to administratively extend permits in its Rules and Regulations. 6. The Pretreatment Regulations at 40 C.F.R. 403.8(f)(1)(iii) require the District to "Control through Permit, order, or similar means, the contribution to the POTW by each Industrial User to Pretreatment Requirements ensure compliance with applicable Pretreatment Standards and Requirements." 40 C.F.R. 403.8(f)(1)(iii) For SIUs subject to both local limits and categorical Corrective Action Item Pretreatment Standards, the District needs to Determine and implement the most stringent determine and implement the most stringent limit limit between the local limits and applicable between the local limits and applicable categorical categorical Pretreatment Standard, when both Pretreatment Standard, when both are expressed as are expressed as daily maximum limits. The daily maximum limits. The EPA recommends the EPA recommends the determination of the determination of the most stringent permit limit be most stringent permit limit be justified in the justified in the statement of basis and implemented statement of basis and implemented in the SIU in the SIU permits. permits. Based on the EPA's review, the Pretreatment Specialists or Technicians are signing the issued or renewed Pretreatment permits. The EPA does not have a current delegation of authority from the District that allows the Pretreatment Specialists or Technicians to sign and issue the permits. Provide a delegation of authority to allow the permit writers to sign the issued SIU permits or ensure the proper official signs the permits. Birko Corporation Pretreatment Requirements 7. The Pretreatment Regulations at 40 C.F.R. 40 C.F.R. 403.8(f)(2)(ii) 403.8(f)(2)(ii) require the District to "Identify the Corrective Action Item character and volume of pollutants contributed to the POTW." The 2023 and 2024 facility inspection reports at the Birko Corporation provide adequate information regarding floor drains in various process rooms within the facility. However, the inspection reports only provide a brief description of the soap and detergent manufacturing process. Provide adequate information and detail in the SIU inspection reports to capture current conditions at Birko such as chemical handling and transfer from the chemical storage locations to the blending tanks from the raw material storage. In addition, the reports should include tank capacities for the blending and wastewater treatment tanks to help the District determine the impact of a spill or slug 10 South Adams County Water and Sanitation District Pretreatment Audit Report CO-0026662 January 27, 2025 to January 30, 2025 discharge. 8. The Pretreatment Standards for New Source (PSNS) in the Soap and Detergent Point Source Category, Subparts P and Q [40 C.F.R. 417] establish numeric prohibitions for manufacturing of liquid detergents at 40 C.F.R. 417.166(a) and for manufacturing of dry detergents at 40 C.F.R. 417.176(a). Based on a review of the Pretreatment records, Birko blends ingredients to produce liquid and dry detergents. The District categorized the manufacturing processes as subject to Pretreatment Standards for New Sources (PSNS) from the Soap and Detergent Point Source Category, Subparts P and Q. The PSNS applicable to discharges resulting from all operations associated with the manufacture of liquid detergents at 40 C.F.R. 417.166(a) state that "There shall be no discharge of wastewater streams in which both the COD/BOD7 ratio exceeds 10.0 and the COD exceeds 1.10 kg/kkg of anhydrous product." The PSNS applicable to discharges resulting from all operations associated with the manufacture of dry detergents at 40 C.F.R. 417.176(a) state that "There shall be no discharge of wastewater streams in which both the COD/BOD7 ratio exceeds 10.0 and the COD exceeds 0.26 kg/kkg of anhydrous product." Pretreatment Requirements 40 C.F.R. 417.166(a) 40 C.F.R. 417.176(a) Corrective Action Item The District is required to implement the appropriate numeric prohibitions established in 40 C.F.R. 417.166(a) and 40 C.F.R. 417.176(a). The District converted the COD numeric prohibitions 40 C.F.R. 417.166(a) and 40 C.F.R. 417.176(a) of each subpart and calculated an alternative COD mass limit of 1.36. Alternative mass limits are allowed for production-based standards, however, the Soap and Detergent PSNS are not production-based standards. 9. The Pretreatment Regulations at 40 C.F.R. Pretreatment Requirements 403.8(f)(2)(ii) require the District to "Identify the character and volume of pollutants contributed to the POTW." 40 C.F.R. 403.8(f)(2)(vi) Corrective Action Item In addition, the Pretreatment Regulations at 40 C.F.R. 403.8(f)(2)(vi) require a POTW to evaluate whether each such Significant Industrial User needs Ensure Birko's SPCC plan complies with the elements of a slug discharge control plan, as required in 40 C.F.R. 403.8(f)(2)(vi). 11 South Adams County Water and Sanitation District Pretreatment Audit Report CO-0026662 January 27, 2025 to January 30, 2025 a plan or other action to control Slug Discharges. A Slug Discharge is any discharge of a non-routine, episodic nature, including but not limited to an accidental spill or a non-customary batch Discharge, which has a reasonable potential to cause Interference or Pass Through, or in any other way violate the POTW's regulations, local limits or Permit conditions. The District required Birko to develop a slug discharge control plan. However, Birko developed a spill plan in accordance with the Spill Prevention, Containment and Countermeasures (SPCC) in 40 C.F.R. 112. 10. The Birko permit at Part II, section I(c) specifies a manual composite sample type for oil and grease. The footnote to the monitoring requirements defines manual composite as "obtaining a series of discrete grab samples and compositing the individual aliquots into a single sample container for analysis with results reported as a single value." The Pretreatment Regulations at 40 CFR 403.12(g)(3) require grab sampling for oil and grease. The oil and grease may be lab composited but shall not be composited in the field. Pretreatment Requirements 40 C.F.R. 403.12(g)(3) Corrective Action Item Modify the Birko permit to establish appropriate sample types for oil and grease, in accordance with 40 CFR 403.12(g)(3). 11. The Pretreatment Regulations at 40 C.F.R. 403.8(f)(2)(vii) require the City to "Investigate instances of noncompliance with Pretreatment Standards and Requirements, as indicated in the reports and notices." In addition, the Pretreatment Regulations at 40 C.F.R. 403.8(f)(5)(iv) require the City to develop an enforcement response plan (ERP) to "Adequately reflect the POTW's primary responsibility to enforce all applicable pretreatment requirements and standards. Birko submitted a 3rd quarter discharge monitoring report (DMR) on October 28, 2024. The SIU submitted the following oil and grease data from sampling events taken throughout the production day on September 25, 2024: 12:15 pm - 396 mg/L 1:20 p.m. - 1,237 mg/L 2:15 pm - 87 mg/L 2:10 pm - 88mg/L Pretreatment Requirements 40 C.F.R. 403.8(f)(2)(vii) 40 C.F.R. 403.8(f)(5)(iv) Corrective Action Item Provide an enforcement response to the oil and grease violations on September 25, 2024, according to the ERP. 12 South Adams County Water and Sanitation District Pretreatment Audit Report CO-0026662 January 27, 2025 to January 30, 2025 The 396 mg/L and 1,237 mg/L data results are violations of the oil and grease limit of 387 mg/L established in the permit. Based on the EPA's review of the Pretreatment records, it does not appear that the District identified these violations and provided an enforcement response. 12. The Pretreatment Regulations at 40 C.F.R. 403.8(f)(1)(iii) require a POTW to "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." The EPA conducted an oversight facility inspection at Birko on January 29, 2025 as part of the Pretreatment audit of the District. The inspection report was submitted to the facility on February 13, 2025. The inspection report and cover letter are enclosed with this audit report. Based on observations during the inspection, the EPA recommends the facility remove the flexible hosing from the wastewater discharge tank that connects to the discharge location and replace with hard piping to eliminate the potential for operator error during discharge events. The facility may install a sampling port on the hard piping for monitoring purposes. Pretreatment Requirements 40 C.F.R. 403.8(f)(1)(iii) Corrective Action Item Follow up with Birko and determine if the facility replaced the flexible hosing from the wastewater discharge tank that connects to the discharge location with hard piping to eliminate the potential for operator error during discharge events. Merritt Trailers 13. The Pretreatment Regulations at 40 C.F.R. 403.8(f)(2)(ii) require the District to "Identify the character and volume of pollutants contributed to the POTW." The 2023 and 2024 inspection reports provide a brief description of the manufacturing processes at the Merritt Trailers facility and should include more detail regarding the facility's fabrication and assembly unit operations, descriptions of the wash bay area including raw materials and sprayer and the painting process. In addition, the inspection reports should include detail regarding processing of offspec paint parts. Pretreatment Requirements 40 C.F.R. 403.8(f)(2)(ii) Corrective Action Item Provide more detail in the Merritt Trailers inspection reports to capture current conditions at the facility and to identify the character and volume of contributed pollutants. This information is important to capture current conditions and determine if control such as an SIU permit or BMPs or if modifications to existing 13 South Adams County Water and Sanitation District Pretreatment Audit Report CO-0026662 January 27, 2025 to January 30, 2025 control mechanism or control plans such as slug discharge control plans and spill plans are necessary. 14. The Pretreatment Regulations at 40 C.F.R. 403.8(f)(1)(iii) require the District to "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." The permit issued to Merritt Trailers includes the District's local limits and categorical Pretreatment Standards found in the Metal Finishing Point Source Category at 40 C.F.R. 433.17. Pretreatment Requirements 40 C.F.R. 403.8(f)(1)(iii) Corrective Action Item Modify the Merritt Trailers permit to implement the most stringent limit between the District's local limits and the categorical Pretreatment Standards. 15. The Merritt Trailers permit at Part II, specify a manual composite sample type for cyanide and total toxic organics (TTO) in section I(c) and for oil and grease in section I(d). The Pretreatment Regulations at 40 C.F.R. 403.12(g)(3) requires grab sampling for oil and grease, pH, cyanide, total phenols, sulfide, and volatile organic compounds. The footnote to the monitoring requirements in Part II, section I(c) for cyanide and total toxic organics defines manual composite as "obtaining a series of discrete grab samples and compositing the individual aliquots into a single sample container for analysis with results reported as a Pretreatment Requirements single value. TTO grab samples must be manually composited in the laboratory in accordance with 40 CFR 403.12(g)(3)." The 40 C.F.R. 403.12(g)(3) Corrective Action Item Pretreatment regulations do not require TTO samples to be laboratory composited but allow this as an option by stating multiple grab samples "may be composited in the laboratory." The facility may choose to analyze each grab sample Modify the Merritt Trailers permit to establish appropriate sample types for oil and grease and TTOs, in accordance with 40 C.F.R. 403.12(g)(3). separately. The footnote to the monitoring requirements in Part II, section I(d) for oil and grease defines manual composite as "obtaining a series of discrete grab samples and compositing the individual aliquots into a single sample container for analysis with results reported as a single value. Oil and grease grab samples must be manually composited in the laboratory in accordance with 40 CFR 403.12(g)(3)." The Pretreatment regulations do not require oil and grease samples to be laboratory composited but 14 South Adams County Water and Sanitation District Pretreatment Audit Report CO-0026662 January 27, 2025 to January 30, 2025 allow this as an option by stating multiple grab samples "may be composited in the laboratory." The facility may choose to analyze each grab sample separately. 16. The Pretreatment Regulations at 40 C.F.R. 403.12(g)(3) require Merritt Trailers to submit compliance reports that are based upon data obtained through appropriate sampling and analysis performed during the period covered by the report, which data are representative of conditions occurring during the reporting period. The 4th quarter 2023 DMR received by the District on January 25, 2024 includes a TTO certification statement that is signed by the authorized representative on December 3, 2023, prior to the end of the reporting period (December 31, 2023). Pretreatment Requirements 40 C.F.R. 403.12(g)(3) Corrective Action Item Require Merritt Trailers to correct the 4th quarter DMR and sign and date the TTO certification statement after the reporting period is completed. Bimbo Bakeries 17. The Pretreatment Regulations at 40 C.F.R. 403.8(f)(2)(ii) require the District to "Identify the character and volume of pollutants contributed to the POTW." The 2023 and 2024 Bimbo Bakeries inspection reports include brief descriptions of the manufacturing processes and should include more detail regarding the facility's chemical volumes and storage of pan oil, sugar, glycol and soybean oil tanks, including handling and transfer to the bakery operations. The inspection reports from 2023 and 2024 state the following: "As detailed in the Process Wastewater Flow Section below, some wastewater conveyances such as floor drains, trenches, and sumps commingle with domestic wastewater and bypass the grease interceptor. Diagrams detailing the destination of each drain are available, however, Bimbo does not have this information readily available. The District recommends that Bimbo familiarize themselves with this information for use in the event of a slug discharge or spill to the sewer system." This observation for two years in a row is a concern to EPA regarding the appropriate procedures, equipment and maintenance to prevent slug discharge from occuring. Pretreatment Requirements 40 C.F.R. 403.8(f)(2)(ii) Corrective Action Item Provide more detail in the Bimbo Bakeries inspection reports to capture current conditions at the facility and to identify the character and volume of contributed pollutants. Based on the slug discharge of vinegar on October 19, 2023, confirm the facility is aware of the destinations of floor drains, trenches and sumps in its processing areas, including signage and that these procedures be included in the facility's slug discharge control plan. Recommendation In addition, the reports should capture information regarding wastewater generation and management to ensure the sampling is representative of the production day. 15 South Adams County Water and Sanitation District Pretreatment Audit Report CO-0026662 January 27, 2025 to January 30, 2025 18. The Bimbo Bakeries permit at Part II, section I(c) specifies a manual composite sample type for oil and grease. The footnote to the monitoring requirements defines manual composite as "obtaining a series of discrete grab samples and compositing the individual aliquots into a single sample container for analysis with results reported as a single value." 40 C.F.R. 403.12(g)(3) requires sampling for oil and grease as instantaneous grab samples. The oil and grease may be lab composited but shall not be composited in the field. Pretreatment Requirements 40 C.F.R. 403.12(g)(3) Corrective Action Item Modify the Bimbo Bakeries permit to establish appropriate sample types for oil and grease, in accordance with 40 C.F.R. 403.12(g)(3). 19. The Pretreatment Regulations at 40 C.F.R. 403.8(f)(2)(vii) require the District to "Investigate instances of noncompliance with Pretreatment Standards and Requirements, as indicated in the reports and notices required under 403.12." In addition, the Pretreatment Regulations at 40 C.F.R. 403.8(f)(5)(iv) require the City to develop an ERP to "Adequately reflect the POTW's primary responsibility to enforce all applicable pretreatment requirements and standards." The Bimbo Bakeries permit establishes a pH limit with a range between a lower pH limit of 5.0 to an upper pH limit of 10.0. The facility violated the pH limits of the permit due to a slug discharge of vinegar on October 19, 2023. The facility reported the violations in a letter of response dated October 24, 2023. The following table lists the violations (listed as pH 1 through pH 6): Pretreatment Requirements 40 C.F.R. 403.8(f)(2)(vii) 40 C.F.R. 403.8(f)(5)(iv) Corrective Action Item Provide an enforcement response to the pH violations on October 19, 2023, according to its ERP. Based on the EPA's review, there appears to be no record of an enforcement response from the District for these pH violations. 20. The Pretreatment Regulations at 40 C.F.R. 403.8(f)(2)(vi) require the District to evaluate Bimbo Bakeries to determine if it needs a slug discharge control plan. The District determined that Bimbo Bakeries is required to develop slug control plan; the plan shall contain, at a minimum, the Pretreatment Requirements 40 C.F.R. 403.8(f)(2)(vi) Corrective Action Item The District needs to evaluate the Bimbo 16 South Adams County Water and Sanitation District Pretreatment Audit Report CO-0026662 January 27, 2025 to January 30, 2025 following elements: o (A) Description of discharge practices, including non-routine batch Discharges. o (B) Description of stored chemicals. o (C) Procedures for immediately notifying the POTW of Slug Discharges, including any Discharge that would violate a prohibition under 403.5(b) with procedures for follow-up written notification within five days. o (D) If necessary, procedures to prevent adverse impact from accidental spills, including inspection and maintenance of storage areas, handling and transfer of materials, loading and unloading operations, control of plant site runoff, worker training, building of containment structures or equipment, measures for containing toxic organic pollutants (including solvents), and/or measures and equipment for emergency response. Bimbo Bakeries developed a spill prevention, control and countermeasure (SPCC) plan in accordance with 40 CFR 112 instead of a slug discharge control plan. Bakeries spill prevention, countermeasures and control plan to ensure it complies with the slug discharge control plan requirements in 40 C.F.R. 403.8(f)(2)(vi). The facility had a vinegar slug discharge to the sanitary sewer that resulted in pH violations on October 19, 2023. The slug discharge control plan needs to provide procedures, equipment and measures in place to prevent or minimize slug discharges such as the vinegar incident on October 19, 2023 from occurring in the future. In addition, the slug discharge control plan needs to include procedures, training, equipment and possibly signage to ensure the personnel understand which floor drains go to the interceptor. Other SIUs 21. The Pretreatment Regulations at 40 C.F.R. 403.8(f)(1)(iii) require a POTW to "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." The EPA conducted an oversight facility inspection at S &S Anodizing on January 28, 2025 as part of the Pretreatment audit of the District. Based on observations from the facility inspection, the EPA recommends the SIU promptly address the standing water in the containment located around the evaporator storage tank and the evaporators. Based on the volume of the water in the containment area, it appears that the wastewater management in this area is not in control. Pretreatment Requirements 40 C.F.R. 403.8(f)(1)(iii) Corrective Action Item Follow up with S & S Anodizing and determine if the facility addressed the standing water in the containment located around the evaporator storage tank and the evaporators. 22. The Pretreatment Regulations at 40 C.F.R. Pretreatment Requirements 403.8(f)(2)(vi) require the District to evaluate Good 17 South Adams County Water and Sanitation District Pretreatment Audit Report CO-0026662 January 27, 2025 to January 30, 2025 Paints to determine if it needs a slug discharge control plan. If necessary, the slug discharge control plan shall contain, at a minimum, the following elements: (A) Description of discharge practices, including non-routine batch Discharges. (B) Description of stored chemicals. (C) Procedures for immediately notifying the POTW of Slug Discharges, including any Discharge that would violate a prohibition under 403.5(b) with procedures for follow-up written notification within five days. (D) If necessary, procedures to prevent adverse impact from accidental spills, including inspection and maintenance of storage areas, handling and transfer of materials, loading and unloading operations, control of plant site runoff, worker training, building of containment structures or equipment, measures for containing toxic organic pollutants (including solvents), and/or measures and equipment for emergency response. The District determined that Good Paints is required to develop and implement a slug discharge control plan, but only a spill plan was provided. The spill plan doesn't include inspections and maintenance of chemical storage, handling, and transfer of materials, or procedures to prevent adverse impact from accidental spills that are applicable to the facility. 40 C.F.R. 403.8(f)(2)(vi) Corrective Action Item Require Good Paints to modify its existing spill plan to comply with the slug discharge control requirements found in 40 C.F.R. 403.8(f)(2)(vi)(D). 23. The Pretreatment Regulations at 40 C.F.R. 403.8(f)(2)(vi) require the District to evaluate Concrete Washout Systems (CWS) to determine if it needs a slug discharge control plan. If necessary, the slug discharge control plan shall contain, at a minimum, the following elements: (A) Description of discharge practices, including non-routine batch Discharges. (B) Description of stored chemicals. (C) Procedures for immediately notifying the POTW of Slug Discharges, including any Discharge that would violate a prohibition under 403.5(b) with procedures for follow-up written Pretreatment Requirements 40 C.F.R. 403.8(f)(2)(vi) Corrective Action Item Require CWS to modify its existing spill plan to comply with the slug discharge control requirements found in 40 C.F.R. 403.8(f)(2)(vi)(D). 18 South Adams County Water and Sanitation District Pretreatment Audit Report CO-0026662 January 27, 2025 to January 30, 2025 notification within five days. (D) If necessary, procedures to prevent adverse impact from accidental spills, including inspection and maintenance of storage areas, handling and transfer of materials, loading and unloading operations, control of plant site runoff, worker training, building of containment structures or equipment, measures for containing toxic organic pollutants (including solvents), and/or measures and equipment for emergency response. The District determined that CWS is required to develop and implement a slug discharge control plan, but only a spill plan was provided. This spill plan does not include information relating to inspections or maintenance. The plan also does not provide any information on how the facility plans to prevent a slug discharge. 24. The Pretreatment Regulations at 40 C.F.R. 403.8(f)(1)(iii) require a POTW to "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." The EPA conducted an oversight facility inspection at CWS on January 29, 2025 as part of the Pretreatment audit of the District. The inspection report was submitted to the facility on February 27, 2025. The inspection report and cover letter are enclosed with this audit report. Based on observations during the inspection, the EPA observed a water meter to the east of the treatment shed to be leaking city water. Pretreatment Requirements 40 C.F.R. 403.8(f)(1)(iii) Corrective Action Item Follow up with CWS to repair this water meter and ensure that water doesn't continue to leak. Section 10.0 - Control Authority Compliance Monitoring 25. As required in 40 C.F.R. 403.8(f)(2), the POTW shall "develop and implement procedures to ensure compliance with the requirements of a Pretreatment Program." The development and implementation of a sampling plan or procedures ensures the POTW is appropriately and consistently performing sampling or monitoring events, as well as providing enforceable data that is representative of the discharge conditions at the facility. The sampling Pretreatment Requirements 40 C.F.R. 403.8(f)(2) 40 C.F.R. 403.8(f)(2)(vii) Corrective Action Item Update the sampling plans and SIU-specific protocols to include appropriate QA/QC such as equipment blanks, trip blanks, sample 19 South Adams County Water and Sanitation District Pretreatment Audit Report CO-0026662 January 27, 2025 to January 30, 2025 plan should include the following: purpose and objective of the sampling program, specific sampling protocols at each facility sampling location to ensure representative sampling, and appropriate QA/QC procedures to ensure legally defensible data. In addition, the Pretreatment Regulations at 40 C.F.R. 403.8(f)(2)(vii) require the District to ensure "Sample taking and analysis and the collection of other information shall be performed with sufficient care to produce evidence admissible in enforcement proceedings or in judicial actions." The District has developed an Interceptor Sampling standard operating procedure (SOP) for sampling interceptors and manholes in the service area. In addition, the District also establishes site-specific sampling protocols for each permitted SIU to ensure consistent sampling that is representative for the production day. The SIU-specific sampling protocols need to incorporate QA/QC such as equipment blanks, trip blanks, sample duplicates, matrix spikes, control standards to ensure the sampling and analytical techniques are in control and compliance with 40 CFR 136. duplicates, matrix spikes, control standards to ensure the sampling and analytical techniques are in control and comply with 40 C.F.R. 136. Recommended The EPA recommends the District incorporate digital photos in the SIU-specific sampling protocols. Section 11.0 - Enforcement 26. The Pretreatment Regulations at 40 C.F.R. 403.8(f)(5)(iv) require the City to develop an ERP to "Adequately reflect the POTW's primary responsibility to enforce all applicable pretreatment requirements and standards. The District submitted its ERP to the EPA for review, prior to the audit. The EPA reviewed the District's ERP and is providing the following comments to align with the Federal Regulations: The term Letter of Violation (LOV) is not consistent with Notice of Violation (NOV) established in the Rules/Regs. Defined Terms (page 2) - The EPA recommends the District remove the glossary and refer to definitions in its Rules and Regulations. The following definitions in the Glossary of the ERP are not equivalent with the Rules/Regs: Pretreatment Requirements 40 C.F.R. 403.8(f)(5)(iv) Corrective Action Item Modify the ERP to align with the Federal Regulations. The EPA's comments to the District's Enforcement Response Plan are included in the enclosed SACWSD ERP Review.docx and comments embedded in 2012 Enforcement Response Plan-EPA.pdf Recommended The EPA recommends the District remove the glossary and refer to definitions in its Rules and Regulations. 20 South Adams County Water and Sanitation District Pretreatment Audit Report CO-0026662 January 27, 2025 to January 30, 2025 i. Approval Authority ii. Categorical Industrial User iii. Local Limits iv. National Categorical Pretreatment Standard v. National Prohibitive Discharge Standard vi. Pollutant vii. POTW viii. Prohibitive Waste Standard ix. SNC x. Zero Discharge Permit Due Date for late Reports (Section IV.E.6) and SNC (Section IV.E.7) state 45 days late that is not equivalent with the 30 days late established in the Rules/Regs. Enforcement actions for Failure to Notify for slug/potential problems, hazardous waste, upset and bypass required by 40 CFR 403.12 are not included in the ERP. Enforcement actions for the following anticipated types of noncompliance are not established: i. Tampering with equipment/methods monitoring ii. Recordkeeping iii. Dilution iv. Refusal of entry v. Sector control programs (FOG, dental) The District establishes enforcement actions for SNC criteria in Section IV.G by referring to the SNC criteria in the glossary. However, some criteria are incorrect, as identified above. The EPA recommends the District establish the SNC criteria directly in Section IV.G of the ERP instead of referencing the glossary. The EPA recommends the District remove these Appendices C (examples of enforcement documents) and D (Pretreatment Compliance Forms) as these are not relevant to the ERP. Section 13.3 - Best Management Practices - Dental Amalgam Rule 27. The Dental Amalgam Rule, found in 40 C.F.R. Part 441, was promulgated as a final rule with new source dental facilities required to be in compliance with the Pretreatment Standards as of July 14, 2017, and existing source dental facilities required to be in compliance as of June 14, 2020. Compliance with the rule requires the installation of an ISO1143 amalgam separator or equivalent device, and compliance with the following two BMPs: Prohibition on the use of oxidizing or chlorine- Pretreatment Requirements 40 C.F.R. 441.50 Corrective Action Item Ensure Adventure Dental and Kids in Need of Dentistry offices submit complete One-Time Compliance Reports, as required by the Dental Amalgam Rule. Recommendation 21 South Adams County Water and Sanitation District Pretreatment Audit Report CO-0026662 January 27, 2025 to January 30, 2025 containing line cleaners; and Ensuring all amalgam process wastewater including chair-side traps, screens, vacuum pump filters, dental tools, cuspidors or collection devices are treated through the amalgam separator. In addition, the new and existing dental facilities are required in 40 C.F.R. 441.50 of the Dental Amalgam Rule to provide a report that characterizes the dental facility and certifies compliance. The new source dental facilities are required to be in compliance upon discharge and submit a one-time compliance report within 90 days of startup. The District has identified 19 dental facilities in its service area and has received one-time compliance reports within the deadline required by the Rule. The EPA reviewed the one-time compliance reports to ensure compliance with the reporting requirements of the Dental Amalgam Rule in 40 C.F.R. 441.50. The majority of the reports are complete and comply with the reporting requirements with the following exceptions identified below: Adventure Dental - Section D of the compliance report is not completed. Kids in Need of Dentistry - the contact information of the compliance report is not completed. Commerce City Dental Center - the facility states that "it is looking for a 3rd party contractor for its amalgam separator" on July 29, 2020. The EPA recommends the District ensure the Commerce City Dental Center has either found a contractor to maintain its separator or has provided internal maintenance to comply with the Dental Amalgam Rule.` 22 South Adams County Water and Sanitation District Pretreatment Audit Report CO-0026662 January 27, 2025 to January 30, 2025 Table of Contents 1.0 Introduction............................................................................................................ 26 2.0 Publicly Owned Treatment Works (POTW) Information ..................................... 27 2.1 NPDES Permit.................................................................................................... 28 3.0 Resources ............................................................................................................... 32 3.1 Resources Regulatory Background .................................................................... 32 3.2 Evaluation of the District's Resources and Funding.......................................... 32 3.3 Examples of Available Pretreatment Training/Resources ................................. 33 4.0 Municipal Ordinance and Intergovernmental Agreements.................................... 33 4.1 Legal Authority Background.............................................................................. 33 4.2 SACWSD Municipal Ordinance ........................................................................ 35 4.3 Inter-Jurisdictional or Governmental Agreements (IGA) .................................. 37 4.3.1 IGA Regulatory Background ...................................................................... 37 4.3.2 Evaluation of the District's IGAs with Outside Contributing Jurisdictions 37 5.0 Local Limits ........................................................................................................... 38 5.1 Local Limits Regulatory Background ................................................................ 38 5.2 Local Limits Requirements Established in the District's NPDES Permits........ 39 5.3 The EPA Evaluation of the District's Local Limits ........................................... 40 5.3.1 Technically based Local Limits .................................................................. 40 5.3.2 Other Numeric Limits ................................................................................. 41 5.3.3 Dilution Prohibition .................................................................................... 42 5.4 Local Limits Technical Evaluation-Regulatory Background............................. 42 5.5 Technical Evaluation of the District's Local Limits .......................................... 43 5.6 Permit or Site-Specific Limits............................................................................ 44 6.0 Pretreatment Operating Procedures ....................................................................... 44 6.1 Regulatory Background...................................................................................... 44 6.2 Standard Operating Procedures (SOPs) ............................................................. 45 6.3 Templates ........................................................................................................... 46 6.4 Records and Data Management.......................................................................... 46 6.4.1 Regulatory Background .............................................................................. 46 6.4.2 Recordkeeping and Data Management ....................................................... 47 23 South Adams County Water and Sanitation District Pretreatment Audit Report CO-0026662 January 27, 2025 to January 30, 2025 6.5 Receipt of Discharge Monitoring Reports and Notifications............................. 47 6.6 Management of Confidential Records................................................................ 48 7.0 Industrial User Inventory and Characterization..................................................... 48 7.1 Regulatory Background...................................................................................... 48 7.2 Industrial User Identification and Characterization Procedure .......................... 50 7.3 Industrial User Database of the District's Service Area .................................... 50 8.0 Evaluation of Pretreatment Records and Permit Specific Issues ........................... 51 8.1 Regulatory Background...................................................................................... 51 8.2 The EPA's Evaluation of the District's Permitting Legal Authority ................. 53 8.3 Permit Template Overview ................................................................................ 54 8.4 Specific Permit Record Findings ....................................................................... 54 8.4.1 Permit records Overview ............................................................................ 54 8.4.2 Birko Corporation ....................................................................................... 57 8.4.3 Merritt Trailers............................................................................................ 59 8.4.4 Bimbo Bakeries........................................................................................... 60 9.0 Significant Industrial User Facility Inspections..................................................... 64 9.1 Regulatory Background...................................................................................... 64 9.2 Right of Entry..................................................................................................... 65 9.3 Facility Inspection Records - Background ........................................................ 65 9.4 Evaluation of the District's Inspection Reports/Records ................................... 67 9.5 Notification of Applicable Pretreatment Standards ........................................... 67 9.6 Facility Inspections ............................................................................................ 67 10.0 Control Authority Compliance Monitoring ........................................................... 67 10.1 Regulatory Background .................................................................................. 67 10.2 Sampling Plan and Protocols .......................................................................... 68 10.2.1 Site-Specific Sampling Protocols ............................................................... 68 10.2.2 Quality Assurance/Quality Control (QA/QC) ............................................ 69 10.3 The EPA Evaluation of the District's Control Authority Monitoring ............ 69 10.3.1 SOPs............................................................................................................ 69 10.3.2 District's Control Authority Monitoring..................................................... 70 11.0 Enforcement........................................................................................................... 70 24 South Adams County Water and Sanitation District Pretreatment Audit Report CO-0026662 January 27, 2025 to January 30, 2025 11.1 Regulatory Background .................................................................................. 70 11.2 Enforcement Legal Authority ......................................................................... 70 11.3 Enforcement Response Plan (ERP) ................................................................ 71 11.4 Compliance Evaluation................................................................................... 72 11.5 SNC Calculations and Public Participation .................................................... 72 12.0 Trucked and Hauled Waste.................................................................................... 72 12.1 Regulatory Background .................................................................................. 72 12.2 Legal Authority............................................................................................... 73 12.3 Trucked and Hauled Waste Disposal Location and Control Mechanisms ..... 73 13.0 Best Management Practices - Sector Control Programs ....................................... 74 13.1 Regulatory Background .................................................................................. 74 13.2 Authority in Rules and Regulations................................................................ 74 13.3 Dental Amalgam BMP Sector Control Program ............................................ 74 13.4 FOG Sector Control Program ......................................................................... 75 14.0 PFAS Roadmap and Implementation .................................................................... 76 14.1 2021 EPA PFAS Strategic Roadmap.............................................................. 76 14.2 Impact of the NPDES Initiatives on the District's Pretreatment Program ..... 78 14.3 CDPHE's PFAS Policy 20-1 .......................................................................... 78 Figures Figure 1 -SACWSD Service Area.................................................................................... 29 Figure 2 - SACWSD POTW Process Diagram ................................................................ 30 Figure 3 - SACWSD POTW - Google Maps View .......................................................... 31 Tables Table 1 - Local Limits (SACWSD Rules and Regulations, Article III, Section 2.3.21) . 40 25 South Adams County Water and Sanitation District Pretreatment Audit Report CO-0026662 January 27, 2025 to January 30, 2025 1.0 Introduction The U.S. Environmental Protection Agency, Region 8 (EPA) conducted an audit of the Pretreatment program, administered by the South Adams County Water and Sanitation District, CO (SACWSD or District) from January 27, 2025 to January 30, 2025. The Pretreatment audit started on January 27, 2025 at 9:00 a.m. with an opening interview. The closing conference was held on January 30, 2025 at 10:00 a.m. during which the EPA presented the preliminary observations, conclusions, and findings from the audit. Participants in the audit included: South Adams County Water and Sanitation District Gary Bassett Molly Barber Carissa Cumine Zach Shellum Heather Miller Jordan Tate Gary Smith Pretreatment Coordinator, gbassett@sacwsd.org Pretreatment Specialist, mbarber@sacwsd.org Pretreatment Specialist, ccumine@sacwsd.org Pretreatment Technician, zshellum@sacwsd.org Pretreatment Technician, hmiller@sacwsd.org Operator Responsible in Charge (ORC) (POTW Tour only) Wastewater Systems Manager (closing conference only), gsmith@sacwsd.org EPA Al Garcia Monica Crosby Region 8 Pretreatment Coordinator ECAD NPDES Unit The primary purpose of the EPA audit was to evaluate the Pretreatment program administered and implemented by the District. In addition, the audit served as a forum for the EPA and the District to discuss issues related to the implementation of the Pretreatment program, including PFAS requirements in the District's NPDES permit, and for the EPA to provide outreach and training to the District. The EPA Pretreatment audit consisted of an evaluation of the following: The District's legal authority codified in its Articles III and IV of the Rules and Regulations. Development and implementation of the District's local limits. The District's resources to implement the Pretreatment program in its service area. Implementation policies and templates developed by the District. Review and evaluation of the Pretreatment programmatic activities and records maintained for the permitted Significant Industrial Users (SIUs). Site inspection of selected SIUs and Industrial Users (IUs) in the service area to ensure the Pretreatment records reflect current conditions at the facilities. Discussion of the Pretreatment Regulations and implementation. The following sections of the report highlight the findings, corrective actions, and 26 South Adams County Water and Sanitation District Pretreatment Audit Report CO-0026662 January 27, 2025 to January 30, 2025 recommended actions of the audit. The action items to correct program deficiencies and meet regulatory requirements are identified in the Pretreatment Audit Summary Table, beginning on page 2 of this report. Specific actions to clarify and strengthen program implementation are provided as recommendations within the body of the audit report. 2.0 Publicly Owned Treatment Works (POTW) Information The District owns and operates a POTW located at 9702 Monaco St, Henderson, CO 80640. The POTW serves the boundary of the District and two outside contributing jurisdictions, Hazeltine Heights and a small portion of the District of Brighton that contribute wastewater to the District's POTW. The service area for the POTW is shown in Figure 1, a POTW process diagram is shown in Figure 2, and the Google Earth view of the District's POTW is shown in Figure 3. A site visit of the POTW was performed during the audit to develop an overview of the District's POTW processes and operation. The POTW information and site visit was provided by Mr. Jordan Tate, Operator Responsible in Charge (ORC) for the District's POTW. Service Area - The service area for the SACWSD POTW is projected to have significant changes in 2025. A portion of the service area will be transitioned over to the Metro Water Recovery POTW that is generally represented by the Northern Range and E-470 Influence Area shown in the POTW service area in Figure 1. This will result in a loss of 1.5 MGD and an estimated 50% of its current residential flow. POTW - The flow from the POTW's current service is collected in ten main trunk lines that combine into two primary 24-inch trunk lines north of 96th Avenue. The trunk lines then combine into a main 36-inch interceptor that flows into the Headworks building. The flow enters two separate channels leading to parallel bar screens to remove the organic material and solids. The POTW also has a 3rd channel with a bar screen to bypass in case of emergencies or maintenance. The bar screens have raking mechanisms that automatically remove and clean the material off the screens; these materials are collected, dewatered in a Vulcan press, and disposed of in a dumpster. The dumpster is sent to a landfill on Monday, Wednesday, and Friday each week. The screened wastewater is sent to a wet well and head cell outfitted with 20-inch cones for grit removal. The grit is collected from the bottom of the cones and into a grit dumpster that is transported to the landfill with the headwork screenings. The screened headworks effluent is sent to two primary clarifiers where the fats and oils float to the top of the clarifiers and are skimmed and pumped to the gravity thickener. The primary solids are pumped from the bottom of the primary clarifiers and are sent to the gravity thickener. The primary effluent overflows the primary clarifier and is sent to a splitter box. 27 South Adams County Water and Sanitation District Pretreatment Audit Report CO-0026662 January 27, 2025 to January 30, 2025 The splitter box allows the POTW to send the wastewater to the four trains of the integrated fixed film activated sludge (IFAS) system. Each IFAS train is rated at 2 MGD, and the POTW currently operates three trains at a time. The IFAS train provides anaerobic, anoxic, and two successive aerobic zones to promote nutrient removal. Growth media is added to the anoxic zone of the IFAS train to facilitate biomass growth and strengthen the treatment process. An internal recycle and return activated sludge (RAS) from the secondary clarifiers is also introduced in the IFAS zones to facilitate growth. The IFA effluent is sent to the three secondary clarifiers; RAS is sent back to the IFAS system, and waste activated sludge (WAS) and skimmed foam are sent to the gravity thickener. The secondary effluent is sent to the UV disinfection system consisting of two parallel channels with two UV banks per channel. The disinfected effluent is sent to the junction box, where it cascades to the South Platte River through outfall 001. Solids - The primary and secondary sludge are thickened to about 1.5% in the gravity thickener and are either pressed for dewatering or sent to digesters for storage. The biosolids are dewatered to about 18 to 20% solids and are sent to a compost facility. The POTW does not currently have digester operations and projects that it may take up to ten years to update the digesters and get them functional. 2.1 NPDES Permit The District's NPDES permit #CO-0026662, issued by the Colorado Department of Public Health and Environment (CDPHE), contains provisions for an EPA-approved Pretreatment program in Part I.B.7. The permit was issued and effective on August 1, 2010, expired on July 31, 2015. The District's NPDES permit is currently administratively extended by the CDPHE. 28 South Adams County Water and Sanitation District Pretreatment Audit Report CO-0026662 January 27, 2025 to January 30, 2025 Figure 1 -SACWSD Service Area 29 South Adams County Water and Sanitation District Pretreatment Audit Report CO-0026662 January 27, 2025 to January 30, 2025 Figure 2 - SACWSD POTW Process Diagram 30 South Adams County Water and Sanitation District Pretreatment Audit Report CO-0026662 January 27, 2025 to January 30, 2025 SACWSD Ouftall to the South Platte River Figure 3 - SACWSD POTW - Google Maps View 31 South Adams County Water and Sanitation District Pretreatment Audit Report CO-0026662 January 27, 2025 to January 30, 2025 3.0 Resources 3.1 Resources Regulatory Background The Pretreatment Regulations found in 40 C.F.R. 403.8(f)(1-6) include POTW Pretreatment requirements and procedures to implement an approved Pretreatment program. These requirements and procedures include the legal authority and the implementation procedures of the Pretreatment program (permitting, inspections, sampling, industrial waste survey, receipt of IU reporting and notification, record-keeping, slug discharge control, data evaluation, and enforcement for non-compliance). In addition, the Pretreatment Regulations found in 40 C.F.R. 403.8(f)(3) state that the POTW shall have sufficient resources and qualified personnel to carry out the authorities and implementation procedures of the Pretreatment program. A Pretreatment program, in compliance with the criteria listed in the Pretreatment Regulations, requires adequate and qualified staffing to implement the Pretreatment program in its service area. The resources required for each implementation activity depend largely on the size of the service area, the number of IUs/SIUs/sector control programs, and Pretreatment program policies. A compliant program also requires a consistent funding mechanism to ensure the program is adequately funded and equipped to fully implement the program. 3.2 Evaluation of the District's Resources and Funding According to the CY23 Pretreatment Annual Report, the District's resource commitment to the Pretreatment program is 5.0 FTE that includes the Pretreatment Coordinator, two Pretreatment Specialists, and two Pretreatment Technicians. The Pretreatment Specialists and Pretreatment Technicians implement the programmatic activities of the District's Pretreatment program, such as the industrial user inventory/characterization, permitting, field activities such as inspections/sampling, compliance evaluation, and enforcement. The Pretreatment Coordinator provides oversight of the program and is available for training and as an additional resource. The Pretreatment Coordinator reports to the Wastewater Systems Manager, who reports to the District Manager and District Board. The Pretreatment program is supported by the District Attorney. The District reported in its CY23 Pretreatment Annual Report that its Pretreatment program is budgeted at $653,358 and is funded by the District's Enterprise Fund, generated from residential and non-residential users in the service area. The District appears to be well equipped to implement the field activities of the Pretreatment program and has portable automatic samplers, sampling equipment, peristaltic pumps for grab sampling, dedicated vehicles, confined space entry equipment, and personal protective equipment. In addition, the District has adequate storage space for its field equipment and access to the laboratory for cleaning, decontamination, and calibration of its equipment. Based on the EPA's review of the District's implementation of its Pretreatment program, it appears that the District's current resources and budget is adequate to implement all programmatic activities of the Pretreatment program, in compliance with 40 C.F.R. 403.8(f)(3). 32 South Adams County Water and Sanitation District Pretreatment Audit Report CO-0026662 January 27, 2025 to January 30, 2025 3.3 Examples of Available Pretreatment Training/Resources The District's current personnel in the Pretreatment program is relatively new to the program and appears to be very open and enthusiastic to acquiring training and experience in the various programmatic activities of the program. The Pretreatment Coordinator has a significant amount of experience and is very qualified to provide institutional knowledge and training to the current personnel, which was apparent during the EPA's audit. However, the EPA recommends the District continue to engage in available Pretreatment training opportunities to acquire the necessary training to ensure its personnel is qualified to implement the Pretreatment program. This is not a comprehensive list of all Pretreatment related training/resources available. The District is encouraged to seek out training and resources that will support its Pretreatment program implementation. The EPA is also available to the District for Pretreatment training opportunities, and during the Pretreatment audit, provided training on gathering information and characterizing IUs during facility inspections. The Region 8 Pretreatment workshop, provided by the 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-webinars. Archived presentations may be downloaded, and a schedule of future training opportunities is located at the website. An additional resource available is the Pretreatment Coordinators Group discussion forum, found at the following website: https://groups.io/g/Pretreatment/topics 4.0 Municipal Ordinance and Intergovernmental Agreements 4.1 Legal Authority Background The Pretreatment Regulations at 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. 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: 33 South Adams County Water and Sanitation District Pretreatment Audit Report CO-0026662 January 27, 2025 to January 30, 2025 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. (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 34 South Adams County Water and Sanitation District Pretreatment Audit Report CO-0026662 January 27, 2025 to January 30, 2025 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 SACWSD Municipal Ordinance The EPA approved the District's Pretreatment program on January 8, 1986. According to records maintained by the EPA, the District has modified its Pretreatment program, including the following in the past ten years: Local Limits Update - Approved by the EPA on January 12, 2012. Updates to Trucked/Hauled Waste provision in the Rules and Regulations, Article III - Approved by the EPA on August 8, 2013. Updates to the Rules and Regulations, Article IV - Approved by the EPA on June 8, 2014. The District provided its Pretreatment legal authority found in Articles III and IV of its Rules and Regulations for the EPA to review. Based on the EPA's review, the Pretreatment Regulations incorporated in its Rules and Regulations, Articles III and IV, provide the District with the framework to implement the Pretreatment Regulations in the POTW's service area, with the following exceptions in Article IV summarized below: (In addition, the EPA's comments are included in the SACWSD Legal Authority Review.docx and embedded in Article IV (2014)-EPA.pdf, both enclosed with this audit report.) Categorical Standards, section 2.7 [40 C.F.R. 403.6] -- Remove the following sentence from the definition. "This term includes the general and specific prohibitions and Local Limits established pursuant to Article III." [Note: Categorical Pretreatment standards are technology-based standards developed by the EPA and do not include general/specific prohibitions or local limits.] National Prohibitive Discharge Standard, section 2.23 -- Prohibitive Discharge Standards only include general and specific prohibitions found in 40 C.F.R. 403.5(a) and (b) and do not include local limits. 35 South Adams County Water and Sanitation District Pretreatment Audit Report CO-0026662 January 27, 2025 to January 30, 2025  Pretreatment Standards, section 2.32 [40 C.F.R. 403.6] - Pretreatment Standards include (1) categorical Pretreatment Standards, (2) general and specific prohibitions, (3) local limits, and (4) BMPs. The EPA recommends the following changes to the definition to align with Federal Regulations: o Means any regulation containing pollutant discharge limits promulgated by the EPA or the District in accordance with sections 307(b) and (c) of the Act, which applies to Industrial Users. This term includes prohibitive discharge limits standards established pursuant to 40 C.F.R. 403.5, categorical Pretreatment Standards, and local limits / BMPs developed by the Control Authority. In cases of differing standards or regulations, the more stringent shall apply. Significant Noncompliance, Sections 2.39 and 19.8.1 - 19.8.7 [40 C.F.R. 403.8(f)(2)(viii)] - the District has two sections within its Rules and Regulations that define the SNC criteria, and they are not consistent with each other. The SNC criteria in section 19.8.1 - 19.8.7 is aligned with the Federal Regulations. The EPA recommends the District remove the incorrect SNC criteria in section 2.39. Specific Discharge Prohibition Standard - "Pollutants which result in the presence of toxic gases, vapors, or fumes within the POTW in a quantity that may cause acute worker health and safety problems," required by 40 C.F.R. 403.5(b)(7), is absent, and there does not appear to be an equivalent definition in the Rules and Regulations. Additional Permit Conditions for SIUs in section 3.9 states that SIU permit may include the following permit conditions required by 40 C.F.R. 403.8(f)(1)(B)(16). This establishes these permit conditions as optional. The District is required to include all permit conditions required by the Pretreatment Regulations in issued SIU permits. The District has adopted all reporting and notification requirements in section 11.1. The EPA recommends the District incorporate the required notices and reports in 40 C.F.R. 403.12 instead of referencing for the following reasons: o 40 C.F.R. 403.12 includes reporting requirements for the POTW that are not applicable to IUs in the District's service area. o The incorporation of notices and reports in the District's Rules and Regulations provide the public more user-friendly access to the required SIU reports and notifications. o The appropriate sampling and analytical procedures may be difficult to find for SIUs needing this information for their monitoring programs. o Some reporting requirements found in 40 C.F.R. 403.12 are already incorporated: SIU Compliance reports - (section 11.4) 24-hour notification/30-day resampling (section 3.9.6) Hazardous Waste notification (section 22.1) Reporting certification and signatory (section 3.11) Submission of all monitoring data (section 3.9.7) Pollutants Not Present [40 C.F.R. 403.8(f)(1)(B)(4) and 40 C.F.R. 403.12(e)(2)] - As a result of referencing 40 C.F.R. 403.12 in section 11.1, the District adopted this provision by reference and is required to ensure the process for seeking a 36 South Adams County Water and Sanitation District Pretreatment Audit Report CO-0026662 January 27, 2025 to January 30, 2025 waiver for Pollutants Not Present is also incorporated in the following sections of Article IV: o Permit Application (section 3.2) - the application contents need to be updated to include the process and information necessary for a waiver due to pollutants not present. o Process for seeking a waiver - absent from the Rules and Regulations. The EPA will provide a fact sheet on the process requirements for seeking a waiver. The EPA recommends the District incorporate the use of digital photos in its Right of Entry section 18.2. 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 its ordinance or Rules and Regulations, which are in effect for its service area. Local entities with connectors, or outside jurisdictions to the service area that contribute wastewater, must establish legally binding mechanisms to ensure that all IUs in these outside contributing jurisdictions are subject to enforceable Pretreatment standards and requirements, as required in 403.8(f)(1). 40 C.F.R. 403.8(f)(1)(i) states, "The POTW shall operate pursuant to legal authority enforceable in Federal, State or local courts, which authorizes or enables the POTW to apply and to enforce the requirements of sections 307 (b) and (c), and 402(b)(8) of the Act and any regulations implementing those sections. Such authority may be contained in a statute, ordinance, or series of contracts or joint powers agreements which the POTW is authorized to enact, enter into or implement, and which are authorized by State law." [Emphasis added] The local entity that implements the Pretreatment program must either obtain this authority for itself through an IGA or ensure that the outside contributing jurisdiction has both the authority and the obligation to implement and enforce the Pretreatment Standards and Requirements against every IU that discharges to the POTW. 4.3.2 Evaluation of the District's IGAs with Outside Contributing Jurisdictions The District has two outside contributing jurisdictions, Hazeltine Heights and portions of the District of Brighton that discharge non-domestic wastewater to the District's POTW. The Hazeltine Heights IGA modified on January 3, 2009 and the District of Brighton IGA, established on January 25, 2001 adequately delegate the District authority to implement the Pretreatment program and enforce its Rules and Regulations. 37 South Adams County Water and Sanitation District Pretreatment Audit Report CO-0026662 January 27, 2025 to January 30, 2025 5.0 Local Limits 5.1 Local Limits Regulatory Background The Pretreatment Regulations at 40 C.F.R. 403.8(f)(4) 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 the Pretreatment Regulations at 40 C.F.R. 403.5(a) and (b), 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 protections 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 technically based 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 technically based 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-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 38 South Adams County Water and Sanitation District Pretreatment Audit Report CO-0026662 January 27, 2025 to January 30, 2025 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: 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), Evaluation of the current POTW standards/criteria (including, but not limited to: NPDES permit limits/conditions, water quality standards, biosolids standards), Identification of the POTW removal efficiency and pollutant partitioning, Evaluation of data to ensure it is current and representative of current conditions, Identification of pollutants of concern, Calculations of loadings and determination of MAHL, and Development of local limits and allocation methods. 5.2 Local Limits Requirements Established in the District's NPDES Permits The District's NPDES permit expired on July 31, 2015 and is currently administratively extended by the CDPHE. The District's administratively extended permit include local limit requirements in Part I.B.8.b. Based on the EPA's oversight of the CDPHE, the permit, when renewed by CDPHE, will include equivalent Pretreatment requirements, including the requirement to establish, enforce and provide a technical evaluation of the District's local limits within 12 months after permit renewal. 39 South Adams County Water and Sanitation District Pretreatment Audit Report CO-0026662 January 27, 2025 to January 30, 2025 5.3 The EPA Evaluation of the District's Local Limits 5.3.1 Technically based Local Limits The District's current local limits were public noticed on December 4, 2011 by the EPA for a 30-day public comment period and approved by the EPA on January 12, 2012. The local limits were developed by the District using SIU regulated flows located at the permitted monitoring points and are applicable to SIUs. The District's local limits are incorporated in Article III, section 2.3.21of its Rules and Regulations. The local limits applicability language in Article III, section 2.3.21 states the following: "No Significant Industrial User shall discharge wastewater that exceeds the following limits at any time for any length of time." Table 1 - Local Limits (SACWSD Rules and Regulations, Article III, Section 2.3.21) Pollutant Symbol Daily Maximum (mg/L) Arsenic, Total As 0.23 Cadmium, Total Cd 0.47 Chromium Cr 3.04 Chromium VI Cr 6+ 3.04 Copper, Total Cu 1.75 Lead, Total Pb 1.11 Mercury, Total Hg 0.04 Molybdenum, Total Mo 0.89 Nickel, Total Ni 3.49 Selenium, Total Se 0.82 Silver, Total Ag 1.18 Zinc, Total Zn 4.96 Total Oil and Grease O+G 387 40 South Adams County Water and Sanitation District Pretreatment Audit Report CO-0026662 January 27, 2025 to January 30, 2025 Pollutant Symbol Daily Maximum (mg/L) Biochemical Oxygen Demand BOD 272(1) Total Suspended Solids TSS 264(1) (1) Surcharge levels for BOD and TSS incorporated in Article IV, section 17.1.5 of the District's Rules and Regulations. 5.3.2 Other Numeric Limits In addition to the established technically based limits in the municipal ordinance, the District has established the following numeric limits in its Rules and Regulations by adoption in Article III: [2.3.1] - Must have an instantaneous pH value in the range of five (5.0) to ten (10.0) standard units. Must not contain pollutants that will cause corrosive structural damage to the District's facilities. [2.3.6] - Must not contain heat in amounts that will inhibit biological activity in the POTW resulting in interference, but in no case heat in such quantities that the temperature at the POTW treatment plant exceeds 40C (104F). Must have a temperature between 32 to 150F. [2.3.8] - Must not contain insoluble substances in excess of 10,000 ppm. [2.3.9] - Must not contain total solids in excess of 20,000 ppm. [2.3.10] - Must not contain insoluble substances having a specific gravity greater than 2.65. [2.3.11] - Must not contain garbage that has not been ground or comminuted to such a degree that all particles will be carried freely in suspension under flow conditions normally prevailing in the District's wastewater facilities to which the user is connected. At all times, no garbage particle discharged into the District's facilities shall be greater than one-half inch (") in any direction. [2.3.13] - Must not have a chlorine demand greater than 15 ppm. [2.3.16] - Must not contain in excess of 387 ppm, any grease or oil or any oily substance of petroleum, mineral, animal or vegetable origin including, but not limited to: cooking greases, fats and oils; cooling or quenching oils; lubrication oils; cutting oils; and non-saponifiable oils. [2.3.20] - Must not The following limits shall apply to wastewaters that are discharged from the ground water cleanup of petroleum or gasoline underground storage tanks or other remediation wastewaters containing these pollutants or where these pollutants are appropriate surrogates. o Total Benzene, 0.050 mg/L o Total BTEX, 0.750 mg/L 41 South Adams County Water and Sanitation District Pretreatment Audit Report CO-0026662 January 27, 2025 to January 30, 2025 5.3.3 Dilution Prohibition The District has incorporated a prohibition on dilution in Article IV, 12.1 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: "Dilution Prohibition: No User shall increase the use of process water or, in any other way, attempt to dilute a Discharge as a partial or complete substitute for adequate treatment to achieve compliance with the limitations contained in the National Categorical Pretreatment Standards, or in any other specific pretreatment standard developed by the District, State or EPA." The dilution prohibition language in Article IV, 12.1 meets the Pretreatment requirement in 40 C.F.R. Part 403.6(d). 5.4 Local Limits Technical Evaluation-Regulatory Background 40 C.F.R. 122.44(j)(2)(ii) of the NPDES regulations require POTWs to provide a written technical evaluation of the need to revise local limits following permit issuance or reissuance. The technical evaluation is a detailed re-evaluation of data, criteria, conditions, and assumptions on which local limits are based to determine whether any significant changes affecting the local limits have occurred. Chapter 7 of the Local Limits Development Guidance Manual, EPA-833-R-04-002A, July 2004 provides guidance on completing the technical evaluation of local limits. The Annual Pretreatment Reports submitted to the EPA provide the POTW with an opportunity to perform reviews for exceedances of the established MAHL for the POCs on an annual basis. The POTW compares both the maximum and average influent data for the reporting year against the MAHL to determine if there were any exceedances. In addition, the POTW is required to report biosolids data to determine if there were any changes or concerns with the biosolids loadings. An exceedance of the established MAHL may be indicative of a change in the service area, changes to the POTW operations, or changes to domestic or non-domestic loadings and may indicate a need to recalculate the local limits. However, the annual review may not have addressed conditions that can change over time, such as operating conditions, environmental criteria/standards, data, or assumptions that may make local limits no longer appropriate, protective, or legally defensible. As a follow-up to MAHL exceedances listed on the annual report and as required during a permit reissuance, a POTW should compare its current conditions and requirements with those that existed when the local limits were developed. The EPA recommends that POTWs determine if re-calculating existing local limits or developing MAHLs for new pollutants of concern is necessary in response to the following criteria: 1. Removal Efficiencies a. Modification to the POTW or new POTW brought online. b. Changes in POTW processes or operations that have affected the POTW removal efficiencies. 2. Total POTW or IU Loading 42 South Adams County Water and Sanitation District Pretreatment Audit Report CO-0026662 January 27, 2025 to January 30, 2025 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 5.5 Technical Evaluation of the District's Local Limits The District's renewed NPDES permit issued by the CDPHE will include the following requirements for a technical evaluation of the local limits: "The Permittee shall establish and enforce specific local limits to implement the general and specific prohibitions found in 40 CFR 403.5(a) and (b). The Permittee shall continue to develop these limits as necessary and effectively enforce such limits. Where the Permittee determines that revised or new local limits are necessary, the Permittee shall submit the proposed local limits to the Approval Authority in an approvable form in accordance with 40 CFR 403.18. In accordance with 40 CFR 122.44(j)(2)(ii), the permittee shall submit to the Division and Approval Authority a technical evaluation of the need to revise or develop local limits in accordance with 40 CFR 403.5(c) and a local limits package if a technical evaluation reveals that development or revision of local limits is necessary. The evaluation shall include, but not be limited to, a consideration of any new or revised numeric and practicebased effluent limits in this permit." The District will be required to provide a technical evaluation of its current local limits within 12 months after renewal of the administratively extended permit. In addition, the District should evaluate the incorporation of adopted numeric limits in its Rules and Regulations for pollutants identified in 5.3.2 of this audit report, during the local limits update and determine the justification for these adopted limits. The EPA will provide the District EPA guidance titled 1989-June - Model NPDES Permit for Discharges-UST.pdf for adoption of the BTEX/benzene numeric limits. According to information gathered during the audit and as addressed in section 2.0 of this audit report, the service area for the SACWSD POTW is projected to have significant changes in 2025. A portion of the service area will be transitioned over to the Metro Water Recovery POTW that is generally represented by the Northern Range and E-470 Influence Area shown in the POTW service area in Figure 1. This will result in a loss of 1.5 MGD and an estimated 50% of its current residential flow. 43 South Adams County Water and Sanitation District Pretreatment Audit Report CO-0026662 January 27, 2025 to January 30, 2025 The EPA recommends the District evaluate its current local limits service area and determine which dataset(s) need to be updated or developed based on these changes. For example, the domestic dataset may need to be updated due to the loss of relevant residential areas in the service area, and the POTW influent dataset may need to be developed after the changes occur and the POTW influent is in steady state regarding hydraulic and organic loadings. The EPA recommends the District develop a service area sampling plan to develop a dataset for loadings in the service to capture current conditions and that is representative of potential seasonal variations and requires a minimum of 10 data points in the datasets to ensure adequate data to calculate local limits. 5.6 Permit or Site-Specific Limits Local municipalities implementing the Pretreatment program should have the ability to establish site- or permit-specific limits as deemed necessary to be protective of the POTW. This is a beneficial authority because situations or projects may occur in the service area that the municipality may want to provide control to protect the POTW. However, the current limits in the ordinance may not address the pollutant of concern. 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. The Pretreatment Regulations at 40 C.F.R 403.5(c)(3) 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 not established the ability to develop site- or permit-specific limits in its Rules and Regulations and based on the EPA's review of the Pretreatment records, have not established site-specific limits in the SIU permits. 6.0 Pretreatment Operating Procedures 6.1 Regulatory Background The Pretreatment Regulations at 40 C.F.R. 403.8(f)(2) 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: 44 South Adams County Water and Sanitation District Pretreatment Audit Report CO-0026662 January 27, 2025 to January 30, 2025  Identify and locate all possible IUs that might be subject to the Pretreatment program, Obtain information describing the character and volume of wastes discharged by IUs, Notify IUs of all applicable Pretreatment standards and other applicable State or Federal standards or requirements, Review self-monitoring reports and other notices submitted by IUs, Randomly sample and analyze effluents from IUs, Evaluate whether each SIU needs a slug discharge control plan, Investigate instances of noncompliance with Pretreatment standards and requirements, 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: Develop the baseline knowledge of the Pretreatment Regulations and establish the framework for program implementation, Adequately implement the authorities established in the municipal ordinance and ensure consistency in program implementation, Retain institutional and historical knowledge developed within the POTW's program, and Provide a valuable training resource for new or inexperienced staff members. Ultimately, the benefits of valid SOPs to the Pretreatment program are increased efficiency, along with improved data comparability, credibility, and legal defensibility. In addition, the development of written SOPs and templates allow the EPA to determine if the procedures adequately implement the legal authority developed in the municipal ordinance/rules and regulations as required in 40 C.F.R. 403.8(f): "A POTW Pretreatment program must be based on the following legal authority and include the following procedures. These authorities and procedures shall at all times be fully and effectively exercised and implemented." 6.2 Standard Operating Procedures (SOPs) The EPA evaluated the District's procedures and templates during the audit to ensure these meet the requirements listed in 40 C.F.R. 403.8(f)(2). As previously discussed, developing SOPs is beneficial for the District's Pretreatment program, but most importantly, it ensures adequate implementation of the authorities established in the municipal ordinance and ensures consistency in program implementation. The EPA considers the Industrial User Inventory and Characterization, Sampling Plan/QA-QC, and the Enforcement Response Plan to be priority and required SOPs to ensure consistent implementation of the District's legal authority. The EPA evaluated these priority SOPs and provided comments in the following sections within this audit report: 45 South Adams County Water and Sanitation District Pretreatment Audit Report CO-0026662 January 27, 2025 to January 30, 2025  Industrial User Inventory and Characterization Procedures (discussed in 7.0), Sampling Plan, Site-Specific Sampling Protocol, Quality Assurance and Quality Control (discussed in 10.0), and Enforcement Response Plan and Data Compliance Evaluation (discussed in 11.0). In addition, the EPA evaluated the following SOPs submitted by the District and these appear to be a valuable resource to ensure the District is consistently implementing the programmatic activities of the District's Pretreatment program: 02-10 Linko Software SOP Interceptor Sampling SOP SNC Narrative Criteria Evaluation SOP - LINKO SNC Report As discussed in Section 3.3 of this audit report, the District's current personnel are relatively new to the program, with the exception of the Pretreatment Coordinator, and this appears to be a beneficial opportunity to incorporate the new perspectives of the current Pretreatment staff into the existing and new SOPs necessary to implement the program. 6.3 Templates Templates and checklists are also critical to a Pretreatment program to ensure consistent and appropriate implementation of the Pretreatment regulations. The District has developed an IU permit application and permit templates for discharging and zerodischarge IUs. The permit application appears to provide adequate information and data for the District to develop an appropriate control mechanism. The evaluation of the permit template is included in 8.4 of this audit report. 6.4 Records and Data Management 6.4.1 Regulatory Background The recordkeeping requirements of the Pretreatment program are established in 40 C.F.R. 403.12(o)(1-3): "(1) Any Industrial User and POTW subject to the reporting requirements established in this section shall maintain records of all information resulting from any monitoring activities required by this section, including documentation associated with Best Management Practices. Such records shall include for all samples: (i) The date, exact place, method, and time of sampling and the names of the person or persons taking the samples. (ii) The dates analyses were performed. (iii) Who performed the analyses. (iv) The analytical techniques/methods use; and (v) The results of such analyses. 46 South Adams County Water and Sanitation District Pretreatment Audit Report CO-0026662 January 27, 2025 to January 30, 2025 (2) Any Industrial User or POTW subject to the reporting requirements established in this section (including documentation associated with Best Management Practices) shall be required to retain for a minimum of 3 years, any records of monitoring activities and results (whether or not such monitoring activities are required by this section) and shall make such records available for inspection and copying by the Director and the Regional Administrator (and POTW in the case of an Industrial User). This period of retention shall be extended during the course of any unresolved litigation regarding the Industrial User or POTW or when requested by the Director or the Regional Administrator. (3) Any POTW to which reports are submitted by an Industrial User pursuant to paragraphs (b), [baseline monitoring reports] (d), [90-day compliance reports] (e), [categorical industrial user monitoring reports] and (h) [significant industrial user monitoring reports] of this section shall retain such reports for a minimum of 3 years and shall make such reports available for inspection and copying by the Director and the Regional Administrator. This period of retention shall be extended during the course of any unresolved litigation regarding the discharge of pollutants by the Industrial User or the operation of the POTW Pretreatment Program or when requested by the Director or the Regional Administrator." 6.4.2 Recordkeeping and Data Management Based on information gathered during the audit, the Pretreatment records for IUs and permitted SIUs are maintained by the Pretreatment program. The working copies are maintained in the workspace of the Pretreatment Specialists and Pretreatment Technicians. The stored or archived Pretreatment records are kept electronically on a Pretreatment IPP drive, and paper documents are kept in a locked records room located next to the Pretreatment staff offices. The IU records for the service area are organized by the eleven subdistricts within the service area. All IU information such as IU questionnaire/sampling results/inspection reports are maintained in the IU folders. The SIU folders are organized sequentially in the following binders and subfolders: Permit/statement of basis/permit application Progress notes/letters or notice of violation/billing/inspection reports/wastewater questionnaire/photos/SNC calculations-determinations Based on the EPA's evaluation, the Pretreatment records are very well organized and well maintained. The EPA acknowledges the Districts effort in maintaining the Pretreatment records as this is beneficial to the overall implementation of the District's Pretreatment program. 6.5 Receipt of Discharge Monitoring Reports and Notifications The Pretreatment regulations in 40 C.F.R. 403.8(f)(2)(vii) require a POTW to "Investigate instances of noncompliance with Pretreatment Standards and Requirements, as indicated in the reports and notices required under 403.12 [IU compliance reports], or indicated by analysis, inspection, and surveillance activities [control authority monitoring]." This 47 South Adams County Water and Sanitation District Pretreatment Audit Report CO-0026662 January 27, 2025 to January 30, 2025 requires the POTW to ensure adequate receipt and tracking of self-monitoring reports and notifications, have procedures to evaluate the data and information contained within these reports and notices, and determine compliance with the Pretreatment standards (e.g., permit limits and conditions). The SIU self-monitoring reports, notifications, and other reports submitted are datestamped by hand as received. The District ensures the reports/notifications are complete, received by the due date, and evaluates compliance based on its review of the information in the reports and notifications. 6.6 Management of Confidential Records The Pretreatment Regulations at 40 C.F.R. 403.14 establish the public availability of the Pretreatment records and the provisions to establish confidential business information (CBI). The District has incorporated the public availability and confidentiality requirements in Section 21 of the Rules and Regulations: "21.1 Public Information: Information and data on an Industrial User obtained from reports, questionnaires, and monitoring programs and inspections shall be available to the public or other governmental agency without restriction unless the Industrial User specifically requests and is able to demonstrate to the satisfaction of the Industrial Pretreatment Coordinator that the release of such information would divulge information, process or methods of production entitled to protection as trade secrets of the Industrial User or otherwise confidential where release would be injurious to the Industrial User or the Industrial User's business. 21.2 Confidential Information: When requested by the person furnishing a report, the portions of a report which might disclose trade secrets or secret processes and accepted by the Industrial Pretreatment Coordinator as confidential shall not be made available for inspection by the public but shall be made available to governmental agencies, upon receipt of a written request by the Industrial Pretreatment Coordinator from the agency, for uses related to this Article, the National Pollutant Discharge Elimination System (NPDES) Permit, State Disposal System Permit and/or the Pretreatment Programs. In addition, such portions of a report shall be available for use by the State and any state or local agency in judicial review or enforcement proceedings. Wastewater constituents and characteristics, including effluent data, standards or limitations, will not be recognized as confidential information. Notwithstanding anything to the contrary, the District may disclose documents if required pursuant to the valid court order." According to information gathered during the audit, the District has not received confidential business information. 7.0 Industrial User Inventory and Characterization 7.1 Regulatory Background The Pretreatment Regulations state in 40 C.F.R. 403.8(f)(2)(i-iii) that a POTW shall develop and implement procedures to ensure compliance with requirements of a Pretreatment Program. [These requirements are summarized after the regulation language 48 South Adams County Water and Sanitation District Pretreatment Audit Report CO-0026662 January 27, 2025 to January 30, 2025 in bold and italics font]. i. "Identify and locate all possible Industrial Users which might be subject to the POTW Pretreatment Program. Any compilation, index or inventory of Industrial Users made under this paragraph shall be made available to the Regional Administrator or Director upon request." This requires a POTW to develop and maintain an inventory of IUs in the service area. ii. "Identify the character and volume of pollutants contributed to the POTW by the Industrial Users identified under paragraph (f)(2)(i) of this section. This information shall be made available to the Regional Administrator or Director upon request." This requires a POTW to characterize the IUs in the inventory of the service area. iii. "Notify Industrial Users identified under paragraph (f)(2)(i) of this section, of applicable Pretreatment Standards and any applicable requirements under sections 204(b) and 405 of the Act and subtitles C and D of the Resource Conservation and Recovery Act. Within 30 days of approval pursuant to 40 C.F.R. 403.8(f)(6), of a list of significant industrial users, notify each significant industrial user of its status as such and of all requirements applicable to it as a result of such status." These procedures must include the notification of IUs of applicable Pretreatment Standards and other applicable requirements. The Pretreatment Regulations at 40 C.F.R. 403.8(f)(6) state, "The POTW shall prepare and maintain a list of its non-domestic or Industrial Users meeting the criteria in 403.3(v)(1). The list shall identify the criteria in 403.3(v)(1) applicable to each Industrial User and, where applicable, shall also indicate whether the POTW has made a determination pursuant to 403.3(v)(2) that such Industrial User should not be considered a Significant Industrial User. The initial list shall be submitted to the Approval Authority pursuant to 403.9 or as a non-substantial modification pursuant to 403.18(d)." Approved Pretreatment programs are required by the Pretreatment Regulations to understand their service area and outside contributing jurisdictions, by developing and maintaining an inventory of IUs. In addition, the Pretreatment Regulations require a Pretreatment program to characterize the IUs listed on the inventory and notify the IU of their status under the Pretreatment program. For example, the following characterizations may apply to an IU, based on information received from questionnaires, drive-by or facility inspections: The IU is not characterized as significant, based on volume and characteristic of the discharged wastewater. The IU is characterized as significant and is issued a permit. The IU is not characterized as significant, but loadings need to be controlled using best management practices in a source control program such as a FOG program. The IU is generating wastewaters that are significant but does not discharge to the POTW and 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 of an effective Pretreatment 49 South Adams County Water and Sanitation District Pretreatment Audit Report CO-0026662 January 27, 2025 to January 30, 2025 program because this is a POTW's first exposure to the IUs, allows the POTW to determine if an IU is significant, notifies the IU of its status under the Pretreatment regulations, and determines the appropriate type of control mechanisms for these facilities to protect the POTW and collection system. 7.2 Industrial User Identification and Characterization Procedure The Pretreatment Regulations at 40 C.F.R. 403.8(f)(2) require the District to "develop and implement procedures" that "enable the POTW" to comply with these Pretreatment Program requirements. The District has developed an Industrial User Inventory and Characterization Procedure SOP that details how the District initially developed its IU inventory and characterized these IUs and the procedures the District uses to update or maintain existing IUs on the inventory and gather information on new IUs to its service area. According to the SOP, the industrial waste inventory is updated by the District through wastewater questionnaires, inspections and sampling, with new information provided to the District by the IUs, and by requiring IUs to complete a wastewater questionnaire prior to receiving written approval by the District for tapping. The District's procedure for authorizing new sewer taps for nonresidential users requires that a wastewater questionnaire be submitted to and reviewed by the Pretreatment department prior to sewer tapping. A wastewater questionnaire is also required when a tenant moves to a new building or meter service is changed. The District participates in the District's Business Development Review meetings to gather information for new IUs during the pre-construction phase. In addition, the District receives information in emails regarding sewer tap approvals. The District's Industrial User Inventory and Characterization Procedure SOP implements the Pretreatment requirement found in 40 C.F.R. 403.8(f)(2)(i-ii) that require the District to identify and locate all possible IUs which might be subject to the POTW Pretreatment Program, and to identify the character and volume of pollutants contributed to the POTW by the IUs. However, the IU Inventory and Characterization SOP needs to incorporate IU notification procedures of applicable Pretreatment Standards, as required in 40 C.F.R. 403.8(f)(2)(iii). 7.3 Industrial User Database of the District's Service Area The Pretreatment Regulations at 40 C.F.R. 403.8(f)(2)(i-iii) 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 provided a current IU inventory of the IUs in its service area for the EPA to review. Based on the EPA's review, the District's IU inventory appears to be current and representative of the POTW's service area. It also appears that the District is devoting resources to continually maintain the inventory and capture current conditions of IUs in its service area. As described in section 6.4.2 of this audit report, the Pretreatment records for the IUs in the POTW's service area are organized by the eleven subdistricts and are filed by location/inspection prioritization and contain relevant information to identify and 50 South Adams County Water and Sanitation District Pretreatment Audit Report CO-0026662 January 27, 2025 to January 30, 2025 characterize these Ius, such as IU survey and inspection/sample results. The District will update the IUs within its files sequentially in the folders with a goal of visiting every IU in its service area at least once every three years. The District's IU data is maintained in a database and currently has about 950 IUs. The database provides the site address and a general IU classification. The EPA currently provides "Pretreatment 101" webinar training, and a training for "Industrial User Inventory and Characterization Procedures," provided in September 2010, is archived at the following website: https://www.epa.gov/npdes/national-pretreatment-program-events-training-andpublications#pretreat101 8.0 Evaluation of Pretreatment Records and Permit Specific Issues 8.1 Regulatory Background POTWs are required to issue control mechanisms to IUs identified as SIUs through IU Inventory and Characterization procedures. Individual permits or general control mechanisms authorize the discharge of wastewater to a POTW upon condition that the discharger complies with the permit limitations and conditions. An SIU permit is effective for only a limited period and should be revocable by the issuing authority at any time for just cause. In addition, the POTW's legal authority will typically include a provision that forbids the discharge of industrial wastewater from a SIU without a current permit. The Pretreatment Regulations establish the required permit conditions in 40 C.F.R. 403.8(f)(1)(iii)(B)(1-6) that include the following minimum elements: 1. Statement of duration (in no case more than five years). 2. Statement of non-transferability without, at a minimum, prior notification to the POTW and provision of a copy of the existing control mechanism to the new owner or operator. 3. Effluent limits, including Best Management Practices, based on applicable general Pretreatment Standards, categorical Pretreatment Standards, local limits, and state and local law. 4. Self-monitoring, sampling, reporting, notification and recordkeeping requirements, including an identification of the pollutants to be monitored, sampling location, sampling frequency, and sample type, based on the applicable general Pretreatment Standards, categorical Pretreatment Standards, local limits, and state and local law. 5. Statement of applicable civil and criminal penalties for violation of Pretreatment Standards and requirements, and any applicable compliance schedule. Such schedules may not extend the compliance date beyond applicable federal deadlines. 6. Requirements to control Slug Discharges, if determined by the POTW to be necessary. The reporting and notification requirements in permit condition #4 above are found in 40 C.F.R. 403.12 of the Pretreatment Regulations and include the following: 51 South Adams County Water and Sanitation District Pretreatment Audit Report CO-0026662 January 27, 2025 to January 30, 2025  Baseline Monitoring Reports - 403.12(b) Compliance Schedule Progress Reports - 403.12(c) 90-Day Compliance Reports - 403.12(d) CIU Periodic Compliance Reports - 403.12(e) Notice of Potential Problems, including Slug Loading - 403.12(f) Notification of Changes Affecting Slug Discharge Potential - 403.8(f)(2)(vi) 24-Hour Non-Compliance Notification - 403.12(g) SIU Periodic Compliance Reports - 403.12(h) Notification of Changed Discharge - 403.12(j) Notification of Hazardous Waste Discharge - 403.12(p) Notification of Bypass - 403.17 Under general principles of administrative law, permit applicants and other interested parties may challenge the POTW's permit decisions, including the permit limitations and conditions and the POTW's authority to issue the permit. The POTW must ensure that it has the requisite legal authority to impose Pretreatment Standards and Requirements in SIU permits and that it exercises its authority in a consistent and non-arbitrary manner. The local ordinance must clearly provide the POTW with the following authorities to support the permit requirements found in 40 C.F.R. 403.8(f)(1)(iii): Authority to regulate all Industrial Users contributing wastewater to the POTW. Authority to require and issue permits, orders, or other control mechanisms, including: o Authority to require Industrial Users to submit all data that the POTW deems relevant to permit decisions and provisions for public access to data. o Authority to enter, inspect, and sample to verify information supplied by the Industrial User as well as to assess the Industrial User's compliance status. o Authority to incorporate local limits, including BMPs (if applicable). o Authority to incorporate federal and state Pretreatment Standards and Requirements. o Authority to require self-monitoring, record keeping, reporting, and notifications by the permittee. o Authority to develop other appropriate permit conditions. Authority to enforce sewer use ordinance and discharge permit violations. Authority to require the development of a slug discharge control plan. The POTW is required to establish the legal authority to require an IU to complete and file a permit application, with current information, to receive an initial or reissued permit. A permit application enables the POTW to obtain the information necessary to characterize the facility, to evaluate the quality and quantity of wastewater discharged or projected to be discharged for a new facility, and to determine the applicable Pretreatment Standards and controls. The permit application serves as the formal request from the IU to discharge to the POTW and is required to be signed by a responsible corporate officer of the IU, as defined in 40 C.F.R. 403.12(l) of the Pretreatment Regulations. In addition to the permit application, the POTW should evaluate, if available, historic IU effluent data, compliance reports, previous inspection reports, Safety Data Sheets, etc. 52 South Adams County Water and Sanitation District Pretreatment Audit Report CO-0026662 January 27, 2025 to January 30, 2025 Throughout the permit drafting process, the POTW should carefully and thoroughly document each step in a permit rationale or statement of basis. A statement of basis is a document that provides a justification of the permit conditions and limits based on a characterization of the IU, its wastewater discharge, and the applicable Pretreatment Standards and Requirements. The statement of basis should include a description of the facility's production, process(es), wastewater generation/management, and discharge locations to adequately characterize the facility. The statement of basis should also identify the appropriate federal, state, and local Pretreatment Standards, based on the IU's characterization and should provide justification for permit conditions and requirements, such as pollutants of concern, monitoring/reporting frequencies, representative sampling types, notification requirements, slug discharge control, operation and maintenance requirements, etc. The statement of basis facilitates defending any challenges that the permit terms and conditions were developed arbitrarily or capriciously and provides the required documentation in the permit record of any relief from otherwise applicable requirements (i.e., pollutants not expected to be present, equivalent limits, decisions on general control mechanisms, decisions on Non-Significant Categorical Industrial User (NSCIU) classification, and decisions on reduced monitoring requirements). In addition, the statement of basis can serve as a resident document to preserve institutional knowledge and continuity for new or different staff members. The EPA updated the IU Permitting Guidance Manual, 833-R-12-0001A, in September 2012. This guidance manual supports the implementation of the permit conditions found in 40 C.F. R. 403.8(f)(1)(iii)(B)(1-6) of the Pretreatment Regulations. The guidance manual is intended to provide both new and experienced permit writers with conceptual support and specific examples to strengthen their permit development expertise. The guidance manual references technical guidance developed by the EPA regarding local limits, enforcing Pretreatment Standards and Requirements, controlling hauled waste, information regarding compliance inspections and sampling, and BMPs. The IU Permitting Guidance Manual can be found at the following website: https://www.epa.gov/sites/production/files/201510/documents/industrial_user_permitting_manual_full.pdf 8.2 The EPA's Evaluation of the District's Permitting Legal Authority The EPA evaluated the District's Rules and Regulations to ensure it provides an adequate framework to require permit coverage, to deny or condition non-domestic wastewater contributions and to establish adequate permit conditions. Section 3.4 -establishes the requirement for SIUs and CIUs to obtain a wastewater discharge permit. Section 3.5 -establishes the requirement for other IUs to obtain a wastewater discharge permit, if applicable. Section 3.2 - contains the permit application contents. Sections 3.12 -- establishes the authority for the District to deny or conditions 53 South Adams County Water and Sanitation District Pretreatment Audit Report CO-0026662 January 27, 2025 to January 30, 2025 wastewaters discharged to the public sewers. Sections 3.8 and 3.9 - establishes the permit conditions to prevent Passthrough or Interference and to protect the POTW, worker health and safety, biosolids and the receiving stream water quality. 8.3 Permit Template Overview The EPA evaluated the District's permit template to ensure the District is incorporating the required permit conditions found in 40 C.F.R. 403.8(f)(1)(iii)(B)(1-6) of the Pretreatment required Regulations and Sections 3.8 and 3.9 of the District's Rules and Regulations. The results of the EPA's review of the District's permit template is found in Section 8.4.4. 8.4 Specific Permit Record Findings The District has identified eleven IUs in the service area that is determined to be SIUs and that have been issued a permit under the Pretreatment program. Six of these SIUs has been identified as a categorical industrial user (CIU) subject to Categorical Pretreatment Standards developed by the EPA. Five of these SIUs are subject to the District's local limits. In addition, the District has issued twelve zero discharge permits to IUs in the POTW's service area. The EPA reviewed the Pretreatment records from a representative number of SIUs, CIUs and zero discharge permittees. Findings and observations from the EPA's review of the Pretreatment records, including the facility inspection report, statement of basis, permit, compliance evaluation, and enforcement records are listed below: 8.4.1 Permit records Overview 1. SIU Facility Inspection Reports: The Pretreatment Regulations at 40 C.F.R. 403.8(f)(2)(ii) require the District to "Identify the character and volume of pollutants contributed to the POTW." Based on the EPA's review of the District's Pretreatment records, the District is inspecting the SIUs at least annually. a. The SIU inspection reports include brief descriptions of the manufacturing processes and should include more detail regarding the SIU's chemical storage/handling/transfer, process/unit operations, wastestream generation from these unit operations, wastestream management or wastewater treatment, and sampling procedures to provide a current characterization, including an evaluation of slug discharge potential and process or treatment plant changes. This information is important to capture current conditions and determine if control such as an SIU permit or BMPs are necessary or if modifications to existing control mechanism or control plans such as slug discharge control plans or spill plans are necessary. b. The EPA recommends the District remove the statement "briefly describe the manufacturing process or service provided" in the inspection report form. This appears to limit the characterization to a brief paragraph or two in the reports the EPA reviewed. 54 South Adams County Water and Sanitation District Pretreatment Audit Report CO-0026662 January 27, 2025 to January 30, 2025 c. It appears that the District takes digital photos during the annual facility inspections, but these photos are not included, nor is a reference to where these photos are stored included in the inspection reports. As a result, the EPA was not aware of these photos until the closing conference and as a result, did not review these photos. The EPA recommends the District ensure these photos capture areas relevant to the Pretreatment permit, including but not limited to floor drains, unit operations, raw material/chemical storage, applicable chemical handling equipment, wastestreams, wastewater treatment, and discharge locations/monitoring points. In addition, the EPA recommends the District provide a reference to where these photos are stored or include them in the facility inspection reports. d. During the audit, the EPA provided compliance assistance and training on conducting facility inspections, gathering data/information, and generating inspection reports that provide current facility conditions that may impact categorical determinations, permit conditions, or control documents such as the slug discharge control plan or toxic organic management plans. 2. The Pretreatment Regulations at 40 C.F.R. 403.8(f)(2)(iii) require the District to "Notify Industrial Users identified under paragraph (f)(2)(i) of this section, of applicable Pretreatment Standards..." Based on the EPA's review of the Pretreatment records, the District provides a follow-up letter after each SIU inspection. However, the inspection follow-up letter does not consistently provide a notification to the IU of applicable Pretreatment Standards or its status under the Pretreatment program. The District needs to ensure it provides adequate follow-up after an inspection to provide notice to the IU of applicable Pretreatment Standards or to provide a determination of any corrective action items. The EPA recommends the District state "no corrective action items" identified in the follow-up letter, if applicable. 3. Statement of Basis: The District develops a statement of basis for every issued SIU and zero discharge permit. The statement of basis adequately captures current conditions at the SIUs, identifies applicable Pretreatment Standards and justifies permit conditions, representative monitoring type/frequencies based on the SIU's wastewater discharge and recent compliance history, slug discharge/spill potential, reporting frequency and reportable data, TOMP requirements, and requirements for slug discharge control plan based on current conditions. 4. Permit Template: The EPA reviewed the permit templates for the discharging and non-discharging IUs. Based on the EPA's review, the permit template and the standard conditions are equivalent to the Federal Pretreatment Regulations, with the following corrective action items summarized below: (The EPA's review of the District's permit template is included in the SACWSD Permit Template Review.docx and comments embedded in 2023 Permit TemplateEPA, 2023 Zero Discharge Permit Template-EPA, and 2021 Zero Discharge_Metal Finisher Permit Template-EPA pdf) a. Part II, Section I(E) of the permit template provides the following statement 55 South Adams County Water and Sanitation District Pretreatment Audit Report CO-0026662 January 27, 2025 to January 30, 2025 for submission of all monitoring data: "Results of self-monitoring performed in excess of the required minimum frequencies, for the parameters regulated herein, must be included with the Discharge Monitoring Report (DMR) forms submitted to the District (40 CFR 403.12 (g) (6))." The District's Rules and Regulations at section 3.9.7 state the same language but includes "using the procedures prescribed in paragraph 40 CFR 403.12 (g)(5);" The District needs to modify the permit template language to be equivalent with the District's Rules/Regs. b. As described in section 4.2 of this audit report, the District incorporated 40 CFR 403.12 by reference and all optional provisions such as Pollutants Not Present in 40 CFR 403.12(e). The District's permit template does not contain applicability and implementation language for the Pollutants Not Present including: i. Identification of the pollutants to be monitored (including the process for seeking a waiver for a pollutant neither present nor expected to be present in the Discharge in accordance with 403.12(e)(2), or a specific waived pollutant in the case of an individual control mechanism), sampling location, sampling frequency, and sample type, based on the applicable general Pretreatment Standards in part 403 of this chapter, categorical Pretreatment Standards, local limits, and State and local law; c. The District establishes Prohibitive Discharge Standards (PWS) in the permit template at Part 1, section 1(A), and at outfall 002. PWS is not defined in the Rules and Regulations. The EPA recommends the District remove the PWS language and replace it with local limits. d. The District includes numeric levels for BOD and TSS to surcharge for treatment beyond normal domestic-strength waste. The permit states in the limits table that "All Non-residential users which discharge a waste with five-day biochemical oxygen demand (BOD5) of greater than 272 mg/L and total suspended solids (TSS) of greater than 264 mg/L shall pay a surcharge as described in the Non-Residential User Fee Schedule. (Statement of Basis, Attachment A)." i. These numeric levels are used for billing purposes and are not considered to be enforceable local limits. The EPA recommends the District remove BOD and TSS from the local limits table and put them into a separate surcharge levels table. e. The District issues zero discharge permits for three years. The 2021 Zero Discharge Permit Template and the 2021 Zero Discharge Metal Finisher Permit Template both allow the permit to be administratively extended and include the following statement on the cover page: "An expired Permit will continue to be effective and enforceable after expiration of the Permit if: (1) The Permittee has reapplied for a new permit within the timeframe required, (2) Failure to reissue a new permit is not due to any act, or failure to act, on the part of the Permittee or (3) The Permittee 56 South Adams County Water and Sanitation District Pretreatment Audit Report CO-0026662 January 27, 2025 to January 30, 2025 receives written communication extending the Permit from the District." However, the District has not established the authority to administratively extend permits in its Rules and Regulations. The District needs to establish the authority in its Rules and Regulations to administratively extend zero discharge permits or remove this provision from the zero discharge permits. 5. SIU Discharge Permits: The District developed local limits with applicability language to provide flexibility to implement local limits for short-term (instantaneous/daily maximum) and long-term (monthly average) determinations during sampling events. The EPA, during a 2014 PCI, misinterpreted the applicability as instantaneous only and not equivalent to daily maximum, as expressed in categorical Pretreatment Standards. As a result, the EPA stated in a 2014 PCI that the local limits and categorical Pretreatment Standards need to be implemented as separate limits. However, the District is implementing its local limits as a daily maximum, with the flexibility to take instantaneous grab samples, if needed. a. For SIUs subject to both local limits and categorical Pretreatment Standards, the District needs to determine and implement the most stringent limit between the local limits and applicable categorical Pretreatment Standard when both are expressed as daily maximum limits. The EPA recommends the determination of the most stringent permit limit be justified in the statement of basis and implemented in the SIU permits. b. Based on the EPA's review, the Pretreatment Specialists or Technicians are signing the issued or renewed Pretreatment permits. The EPA does not have a current delegation of authority from the District that allows the Pretreatment Specialists or Technicians to sign and issue the permits. The District needs to provide a delegation of authority to allow the permit writers to sign the issued SIU permits or ensure the proper official signs the permits. 6. Recordkeeping: Based on the EPA's evaluation, the Pretreatment records are very well organized and well maintained. The EPA acknowledges the Districts effort in maintaining the Pretreatment records as this is beneficial to the overall implementation of the District's Pretreatment program. 8.4.2 Birko Corporation 1. The Pretreatment Regulations at 40 C.F.R. 403.8(f)(2)(ii) require the District to "Identify the character and volume of pollutants contributed to the POTW." The 2023 and 2024 facility inspection reports provide adequate information regarding floor drains in various process rooms within the facility. However, the inspection reports only provide a brief description of the soap and detergent manufacturing process. The inspection reports should include more detail regarding the SIU's chemical handling and transfer from the chemical storage locations to the blending tanks from the raw material storage. In addition, the reports should include tank capacities for the blending and wastewater treatment tanks to help the District determine the impact of a spill or slug 57 South Adams County Water and Sanitation District Pretreatment Audit Report CO-0026662 January 27, 2025 to January 30, 2025 discharge. 2. Based on a review of the Pretreatment records, Birko blends ingredients to produce liquid and dry detergents. The District appropriately categorized the manufacturing processes as subject to Pretreatment Standards for New Sources (PSNS) from the Soap and Detergent Point Source Category, Subparts P and Q [40 C.F.R. 417]. a. The PSNS found in Subpart P are applicable to discharges resulting from all operations associated with the manufacture of liquid detergents, commencing with the blending of ingredients to include bottling or packaging finished products and apply a numeric prohibition at 40 C.F.R. 417.166(a) stating that "There shall be no discharge of wastewater streams in which both the COD/BOD7 ratio exceeds 10.0 and the COD exceeds 1.10 kg/kkg of anhydrous product." b. The PSNS found in Subpart P are applicable to discharges resulting from all operations associated with the manufacture of liquid detergents, commencing with the blending of ingredients to include bottling or packaging finished products and apply a numeric prohibition at 40 C.F.R. 417.176(a) stating that "There shall be no discharge of wastewater streams in which both the COD/BOD7 ratio exceeds 10.0 and the COD exceeds 0.26 kg/kkg of anhydrous product." c. The District converted the COD numeric prohibitions 40 C.F.R. 417.166(a) and 40 C.F.R. 417.176(a) of each subpart and calculated an alternative COD mass limit of 1.36. Alternative mass limits are allowed for production-based standards; however, the Soap and Detergent PSNS are not production-based standards. The District is required to implement the appropriate numeric prohibitions established in 40 C.F.R. 417.166(a) and 40 C.F.R. 417.176(a). 3. The District requires control plans to ensure the SIU appropriately manages spills, maintains its treatment system and discharge filters, and develops procedures for anhydrous product determination, and wastewater pit monitoring. a. The District required the SIU to develop a slug discharge control plan. However, the SIU developed the spill plan in accordance with the SPCC measures in 40 CFR 112. The District is required to ensure the SPCC plan complies with the elements of a slug discharge control plan, as required in 40 C.F.R. 403.8(f)(2)(vi). 4. The monitoring requirements in the permit at Part II, section I(c) specify a manual composite sample type for oil and grease. The footnote to the monitoring requirements defines manual composite as "obtaining a series of discrete grab samples and compositing the individual aliquots into a single sample container for analysis with results reported as a single value." 40 CFR 403.12(g)(3) requires sampling for oil and grease as instantaneous grab samples. The oil and grease may be lab-composited but shall not be composited in the field. 58 South Adams County Water and Sanitation District Pretreatment Audit Report CO-0026662 January 27, 2025 to January 30, 2025 5. Birko submitted a 3rd quarter discharge monitoring report (DMR) on October 28, 2024. The SIU submitted the following oil and grease data from sampling events taken throughout the production day on September 25, 2024: a. 12:15 pm - 396 mg/L b. 1:20 PM - 1,237 mg/L c. 2:15 pm - 87 mg/L d. 2:10 pm - 88mg/L e. The 396 mg/L and 1,237 mg/L data results are violations of the oil and grease limit of 387 mg/L established in the permit. Based on the EPA's review of the Pretreatment records, it does not appear that the District identified these violations and provided an enforcement response. The District is required to provide an enforcement response to the oil and grease violations, according to its ERP. 6. The EPA conducted an oversight facility inspection at Birko on January 29, 2025, as part of the Pretreatment audit of the District. The inspection report was submitted to the facility on February 13, 2025. The inspection report and cover letter are enclosed with this audit report. a. Based on observations during the inspection, the EPA recommends the facility remove the flexible hosing from the wastewater discharge tank that connects to the discharge location and replace it with hard piping to eliminate the potential for operator error during discharge events. The facility may install a sampling port on the hard piping for monitoring purposes. 8.4.3 Merritt Trailers 1. The Pretreatment Regulations at 40 C.F.R. 403.8(f)(2)(ii) require the District to "Identify the character and volume of pollutants contributed to the POTW." The 2023 and 2024 inspection reports provide a brief description of the manufacturing processes at the Merritt Trailers facility. The facility inspection reports should include more detail regarding the facility's fabrication and assembly unit operations, descriptions of the wash bay area including raw materials and sprayer, and the painting process. In addition, the inspection reports should include details regarding the processing of off-spec paint parts. 2. The permit issued to Merritt Trailers includes separate limits for local limits and the Metal Finishing PSNS found at 40 C.F.R. 433.17. The Pretreatment Regulations at 40 C.F.R. 403.8(f)(1)(iii) require the District to "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." This requires the District to implement the most stringent limit between its local limits and the categorical Pretreatment Standards. 3. Based on the District's implementation of the Pretreatment program and its evaluation/characterization, it has required the facility to develop and implement a slug discharge control plan, toxic organic management plan, current chemical inventory, treatment system maintenance manual, and site- 59 South Adams County Water and Sanitation District Pretreatment Audit Report CO-0026662 January 27, 2025 to January 30, 2025 specific sampling protocols. The EPA acknowledges the District's efforts in providing appropriate control of the SIU through the control plans/procedures. 4. The monitoring requirements in the permit at Part II, section I(c) for cyanide and total toxic organics and at Part II, section I(d) for oil and grease specify a manual composite sample type. 40 CFR 403.12(g)(3) states that grab samples must be used for pH, cyanide, total phenols, oil and grease, sulfide, and volatile organic compounds. a. The footnote to the monitoring requirements in Part II, section I(c) for cyanide and total toxic organics defines manual composite as "obtaining a series of discrete grab samples and compositing the individual aliquots into a single sample container for analysis with results reported as a single value. TTO grab samples must be manually composited in the laboratory in accordance with 40 CFR 403.12(g)(3)." The Pretreatment regulations do not require TTO samples to be laboratory composited but allow this as an option by stating multiple grab samples "may be composited in the laboratory." The facility may choose to analyze each grab sample separately. b. The footnote to the monitoring requirements in Part II, section I(d) for oil and grease defines manual composite as "obtaining a series of discrete grab samples and compositing the individual aliquots into a single sample container for analysis with results reported as a single value. Oil and grease grab samples must be manually composited in the laboratory in accordance with 40 CFR 403.12(g)(3)" The Pretreatment regulations do not require oil and grease samples to be laboratory composited but allow this as an option by stating multiple grab samples "may be composited in the laboratory". The facility may choose to analyze each grab sample separately. 5. The 4th quarter 2023 DMR received by the District on January 25, 2024, includes a TTO certification statement that is signed by the authorized representative on December 3, 2023, prior to the end of the reporting period (December 31, 2023). The report needs to be corrected to ensure the TTO certification statement is signed after the reporting period is completed. 8.4.4 Bimbo Bakeries 1. The Pretreatment Regulations at 40 C.F.R. 403.8(f)(2)(ii) require the District to "Identify the character and volume of pollutants contributed to the POTW." The 2023 and 2024 inspection reports provide a brief description of the manufacturing processes at the Bimbo Bakeries facility. The facility inspection reports should include more detail regarding the SIU's chemical volumes and storage of pan oil, sugar, glycol, and soybean oil tanks, including handling and transfer to the bakery operations. In addition, the reports should capture information regarding wastewater generation and management to ensure the sampling is representative of the production day. a. The inspection reports from 2023 and 2024 state the following: "As detailed in the Process Wastewater Flow Section below, some wastewater conveyances such as floor drains, trenches, and sumps commingle with domestic wastewater and bypass the grease interceptor. Diagrams detailing 60 South Adams County Water and Sanitation District Pretreatment Audit Report CO-0026662 January 27, 2025 to January 30, 2025 the destination of each drain are available; however, Bimbo does not have this information readily available. The District recommends that Bimo familiarize themselves with this information for use in the event of a slug discharge or spill to the sewer system." b. This observation for two years in a row is a concern to EPA regarding the appropriate procedures, equipment, and maintenance to prevent slug discharge occurring. Based on the slug discharge of vinegar on October 19, 2023, the District needs to ensure the facility is aware of the drain's destinations, including signage, and that these procedures be included in the facility's slug discharge control plan. 2. The monitoring requirements in the permit at Part II, section I(c) specify a manual composite sample type for oil and grease. The footnote to the monitoring requirements defines manual composite as "obtaining a series of discrete grab samples and compositing the individual aliquots into a single sample container for analysis with results reported as a single value." 40 C.F.R. 136 requires sampling for oil and grease as instantaneous grab samples. The oil and grease may be lab-composited but shall not be composited in the field. 3. The Pretreatment Regulations at 40 C.F.R. 403.8(f)(2)(vii) require the District to "Investigate instances of noncompliance with Pretreatment Standards and Requirements, as indicated in the reports and notices required under 403.12." The regulations at 40 C.F.R. 403.8(f)(5) further require the District to "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." a. The Bimbo Bakeries permit establishes a pH limit with a range between a lower pH limit of 5.0 and an upper pH limit of 10.0. The facility violated the pH limits of the permit due to a slug discharge of vinegar on October 19, 2023. The facility reported the violations in a letter of response dated October 24, 2023. The following table lists the violations (listed as pH 1 through pH 6): b. Based on the EPA's review, there appears to be no record of an enforcement response from the District for these pH violations. The District is required to provide an enforcement response to the pH violations on October 19, 2023, according to its ERP. 4. The Pretreatment Regulations at 40 C.F.R. 403.8(f)(2)(vi) require the 61 South Adams County Water and Sanitation District Pretreatment Audit Report CO-0026662 January 27, 2025 to January 30, 2025 District to evaluate Bimbo Bakeries to determine if it needs a slug discharge control plan. The District determined that Bimbo Bakeries is required to develop a slug control plan; the plan shall contain, at a minimum, the following elements: a. Description of discharge practices, including non-routine batch Discharges. b. Description of stored chemicals. c. Procedures for immediately notifying the POTW of Slug Discharges, including any Discharge that would violate a prohibition under 403.5(b) with procedures for follow-up written notification within five days. d. If necessary, procedures to prevent adverse impact from accidental spills, including inspection and maintenance of storage areas, handling and transfer of materials, loading and unloading operations, control of plant site run-off, worker training, building of containment structures or equipment, measures for containing toxic organic pollutants (including solvents), and/or measures and equipment for emergency response. e. The facility developed a spill prevention, control, and countermeasure (SPCC) plan in accordance with 40 CFR 112. The District needs to evaluate the SIU's slug discharge control plan to ensure it complies with the slug discharge control plan requirements in CFR 403.8(f)(2)(vi). f. As discussed previously, the facility had a vinegar slug discharge to the sanitary sewer that resulted in pH violations on October 19, 2023. The slug discharge control plan needs to provide procedures, equipment, and measures in place to prevent or minimize slug discharges, such as the vinegar incident on October 19, 2023 from occurring in the future. g. The slug discharge control plan needs to include procedures, training, equipment, and possibly signage to ensure the personnel understand which floor drains go to the interceptor. 8.4.5 S & S Anodizing 1.The EPA conducted an oversight facility inspection at S &S Anodizing on January 28, 2025, as part of the Pretreatment audit of the District. The inspection report was submitted to the facility on February 13, 2025. The inspection report and cover letter are enclosed with this audit report. a. Based on observations from the facility inspection, the EPA recommends the SIU promptly address the standing water in the containment located around the evaporator storage tank and the evaporators. Based on the volume of the water in the containment area, it appears that the wastewater management in this area is not in control. 8.4.6 Veolia 1. The Pretreatment Regulations at 40 C.F.R. 403.8(f)(2)(ii) require the District to "Identify the character and volume of pollutants contributed to the POTW." The 2023 and 2024 inspection reports provide an adequate description of the waste receipt, handling, and treatment processes at the Veolia facility. The 2024 62 South Adams County Water and Sanitation District Pretreatment Audit Report CO-0026662 January 27, 2025 to January 30, 2025 inspection Report includes a question asking if there has been a significant increase or decrease in flow, and the report answers "yes." However, it is not clear whether production has increased or decreased. The EPA recommends the initial question regarding an increase or decrease in flow be followed up with a second question that asks the inspector to describe the change in production. 8.4.7 Good Paint 1. The District has a response of "TBD" in the 2024 inspection reports for the question of if sampling procedures were assessed. According to the inspection report, the facility requested that the POTW watch their sampling because there were changes in personnel. No follow-up information or documentation was provided in the inspection report to close out this question. As a result, the inspection report was incomplete because it is not possible to determine compliance. The EPA recommends the District maintain documentation on any uncertainties or deficiencies found during an inspection. 2. The Pretreatment Regulations at 40 C.F.R. 403.8(f)(2)(vi)(D) state, "If necessary, procedures to prevent adverse impact from accidental spills, including inspection and maintenance of storage areas, handling and transfer of materials, loading and unloading operations, control of plant site run-off, worker training, building of containment structures or equipment, measures for containing toxic organic pollutants (including solvents), and/or measures and equipment for emergency response." a. The District determined that Good Paints is required to develop and implement a slug discharge control plan, but only a spill plan was provided. The spill plan doesn't include inspections and maintenance of chemical storage, handling, and transfer of materials, or procedures to prevent adverse impact from accidental spills that are applicable to the facility. The spill plan developed by Good Paints needs to be modified to comply with the slug discharge control requirements found in 40 C.F.R. 403.8(f)(2)(vi)(D). 8.4.8 Concrete Washout (CWS) 1. The Pretreatment Regulations at 40 C.F.R. 403.8(f)(2)(vi)(D) state, "If necessary, procedures to prevent adverse impact from accidental spills, including inspection and maintenance of storage areas, handling and transfer of materials, loading and unloading operations, control of plant site run-off, worker training, building of containment structures or equipment, measures for containing toxic organic pollutants (including solvents), and/or measures and equipment for emergency response." a. The District determined that CWS is required to develop and implement a slug discharge control plan, but only a spill plan was provided. This spill plan does not include information relating to inspections or maintenance. The plan also does not provide any information on how the facility plans to 63 South Adams County Water and Sanitation District Pretreatment Audit Report CO-0026662 January 27, 2025 to January 30, 2025 prevent a slug discharge. The spill plan developed by CWS needs to be modified to comply with the slug discharge control requirements found in 40 C.F.R. 403.8(f)(2)(vi)(D). 2. The lab analytical for the 2024 Q1 sample of total metals was marked as having insufficient preservative. It was further stated that additional preservative was added by the lab, but the sample remained too basic and did not meet quality control parameters. Without sufficient preservative, the quality of the sample is jeopardized and cannot be considered a representative sample. 8.4.9 Land O Lakes 1. The District issued a zero-discharge permit to Purina (208). The District responded yes to the question, "Has there been any discharge of process/wastewater from the facility?" in the 2014 inspection report. However, the inspection report does not provide an answer to the follow-up question, "If yes, describe the source of discharge." The District provided clarification during EPA's Audit that the facility has a boiler and the blowdown from that boiler is a permitted discharge. The EPA recommends the District document sources of discharge in the inspection reports. 9.0 Significant Industrial User Facility Inspections 9.1 Regulatory Background The General Pretreatment Regulations at 40 C.F.R. 403.8(f)(1)(v) state that the POTW shall have the legal authority to: "Carry out all inspection, surveillance, and monitoring procedures necessary to determine, independent of information supplied by Industrial Users, compliance or noncompliance 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;" The Pretreatment Regulations at 40 C.F.R. 403.8(f)(2)(v) require the POTW to inspect its SIUs at least once per year. 40 C.F.R. 403.8(f)(2)(ii) requires the District to "Identify the character and volume of pollutants contributed to the POTW." 40 C.F.R. 403.8(f)(2)(vii) establishes the standard of evidence collection during sampling or inspection activities: "Investigate instances of noncompliance with Pretreatment Standards and Requirements, as indicated in the reports and notices required under 403.12, or indicated by analysis, inspection, and surveillance activities described in paragraph (f)(2)(v) of this section. Sample taking and analysis and the collection of other information shall be performed with sufficient care to produce evidence admissible in enforcement proceedings or in judicial actions." 64 South Adams County Water and Sanitation District Pretreatment Audit Report CO-0026662 January 27, 2025 to January 30, 2025 Typically, an inspector is the only representative from the POTW that regularly appears at the IU's facility and significantly represents the POTW's role as a responsible public agency, observing the actions and evaluating the performance of the regulated industry. 9.2 Right of Entry The District has established the authority for right of entry in 18.2 of the Rules and Regulations: "18.2 Right of Entry: 18.2.1 The Industrial Pretreatment Coordinator and/or his authorized representative(s) shall have the right to enter upon: (a) the property and premises of any Industrial User in which a Discharge source or treatment system is located or in which records are required to be kept at all times for the purposes of inspection, sampling, monitoring, records examination and copying or in the performance of any of the duties required to implement and enforce the provisions of this Article and to determine, independent of information supplied by Industrial Users, compliance or noncompliance by Industrial Users with applicable Pretreatment Standards and other Rules and Regulations of the District. 18.2.2 The Industrial Pretreatment Coordinator and/or his authorized representative(s) shall have the right to enter upon the property and premises of any industrial user located within the District, regardless of whether they Discharge to the POTW, to determine whether a Discharge source or treatment system is located on the property or should be required. 18.2.3 Upon arrival at the facility, the Industrial Pretreatment Coordinator and/or his authorized representative(s) shall identify themselves to the manager or supervising staff person on duty at the facility, prior to conducting inspections, sampling, or records examination." The Rules and Regulations adequately establishes the right of entry authority for the District, as required in the Pretreatment Regulations at 40 C.F.R. 403.8(f)(1)(v). 9.3 Facility Inspection Records - Background The Pretreatment Regulations at 40 C.F.R. 403.8(f)(2)(vii) require the POTW to meet the criterion for evidence collection "with sufficient care to produce evidence admissible in enforcement proceedings or in judicial actions." This is performed during facility inspections by adequate documentation in the inspection report of the observations, surveillance, inspections, sampling performed, and analysis gathered during facility inspections. A complete and well-developed inspection report that provides a current characterization of the facility will benefit the POTW's Pretreatment program for programmatic decisions such as categorical determinations, slug discharge/spill potential, changes at the facility that may affect the current permit conditions, sampling frequencies, etc. As discussed in 2.11.2 of the Industrial User Inspection and Sampling Manual for POTWs, EPA-831B17001, January 2017, the inspection report generated from the facility inspections should accomplish the following three objectives: 1) organize and coordinate 65 South Adams County Water and Sanitation District Pretreatment Audit Report CO-0026662 January 27, 2025 to January 30, 2025 all information in a comprehensive, usable manner for use by the POTW's compliance personnel; 2) identify areas that may require follow-up activity; and 3) provide significant background information on the facility that can be reviewed prior to conducting subsequent inspections at the facility. The quality of this documentation will, to a large degree, determine how effective these follow-up activities will be at the facility. The information in the inspection report must be presented in a clear, concise, and well-organized manner. The Industrial User Inspection and Sampling Manual for POTWs describes the information necessary to characterize a facility in 2.10.3 and 2.12. The manual also discusses the records to review at a facility to help determine the facility's compliance in 2.10.8. It is important for Pretreatment programs to capture the following information during facility inspections to characterize the facility, and document facility changes to ensure the SIU's permit addresses current conditions: Chemical storage areas, including potential spill concerns during chemical receiving and transfer/handling. Process tanks or processing areas - detailed descriptions of the process, including tank contents, capacities. Wastestream generation from the process areas and disposal/discharge practices - frequency of discharge rinse water tanks, whether spent chemical solutions tanks discharged to the POTW or hauled off site, proximity to floor/trench drains, slug discharge control, and spill containment measures, etc. Wastestream management (treatment, recycling, hauling off site, evaporation, etc.). Waste treatment system. Wastestream or hazardous waste storage areas, including potential spill concerns. Discharge monitoring points. o Evaluation of the sampling/monitoring protocols to determine if these are appropriate to provide representative data of the wastewaters regulated by the permit. A facility inspection of a permitted SIU should include a review of relevant records used to support compliance with the permit conditions and that may not be reported in the selfmonitoring compliance reports, such as pH and continuous flow monitoring records, tank change-out logs, analytical reports, waste manifests, operation and maintenance logs, etc. A detailed facility inspection report with descriptions of tank contents, capacities, generated wastestreams, plumbing, and management of the wastestreams will benefit the POTW to establish the baseline for the year and to determine if any changes will impact the permit conditions/limits or associated documents such as the slug discharge control plan, spill plan, treatment system operation manual, or sampling protocol. During the Pretreatment audit, the EPA discussed inspection procedures with the City, including the EPA's procedures. The EPA performs facility inspections by gathering verbal information in an opening conference, then performing a walkthrough to visually confirm the information gathered during the opening interview. The EPA structures its information gathering by following the raw materials/chemical supply through the unit operations and ultimately to the finished product or service. A closing conference is performed to gather follow-up information, review records, and to provide preliminary conclusions to the 66 South Adams County Water and Sanitation District Pretreatment Audit Report CO-0026662 January 27, 2025 to January 30, 2025 facility. 9.4 Evaluation of the District's Inspection Reports/Records The EPA evaluated the inspection reports and other records related to the facility inspection for the SIU annual facility inspection. As discussed in section 8.4.1.1 of this audit report, the SIU inspection reports provide minimal characterization of the facility and need to be improved to include information regarding the facility's chemical storage/handling, process (sources, flow volume, and types of discharges), wastewater generation, slug discharge potential, waste treatment methods, sampling procedures, and review of records in the annual inspection report. The inspection reports should also include digital photos to further support information gathered during the inspection. 9.5 Notification of Applicable Pretreatment Standards The Pretreatment Regulations at 40 C.F.R. 403.8(f)(2)(iii) require the District to notify IUs of applicable Pretreatment Standards and Requirements. Based on the EPA's review of the inspection records, it appears that the District is inconsistently providing notification to the SIUs regarding the applicable Pretreatment Standards and applicable corrective action items as a follow-up to the facility inspections. 9.6 Facility Inspections During the audit, the EPA and the District inspected S & S Anodizing and Veolia on January 28, 2024, and Birko Corporation and Concrete Washout Systems on January 29, 2024. The inspection reports were submitted to the facilities and are included in this audit report as an enclosure. Areas of concern during the facility inspection are provided in the facility inspection reports for the District to provide direct follow-up with the inspected SIUs. 10.0 Control Authority Compliance Monitoring 10.1 Regulatory Background The Pretreatment Regulations at 40 C.F.R. 403.8(f)(1)(v) require the POTW to have the legal authority to "Carry out all inspection, surveillance, and monitoring procedures necessary to determine, independent of information supplied by Industrial Users, compliance or noncompliance with applicable Pretreatment Standards and requirements." Further, 40 C.F.R. 403.8(f)(2)(v) requires a POTW to "Randomly sample and analyze the effluent from Industrial Users and conduct surveillance activities in order to identify, independent of information supplied by Industrial Users, occasional and continuing noncompliance with Pretreatment Standards. Inspect and sample the effluent from each Significant Industrial User at least once a year." The standard to which POTWs are held for purposes of evidence collection during a Control Authority monitoring event is outlined in 40 C.F.R. 403.8(f)(2)(vii): "Sample taking and analysis and the collection of other information shall be performed with 67 South Adams County Water and Sanitation District Pretreatment Audit Report CO-0026662 January 27, 2025 to January 30, 2025 sufficient care to produce evidence which is admissible in enforcement proceedings or judicial actions." In addition, a POTW is required to ensure the Control Authority monitoring events are based on representative conditions at the monitoring point to ensure that these sampling events are legally defensible and of the same quality as required for self-monitoring events. The Pretreatment Regulations at 40 C.F.R. 403.12(g)(3) require, "The reports ... must be based upon data obtained through appropriate sampling and analysis performed during the period covered by the report, which data are representative of conditions occurring during the reporting period." An enforceable sample must be representative of the nature and character of the discharges during the reporting period and is required to be representative in composition to that in the larger volume of wastewater being discharged. A POTW is required to implement a Control Authority monitoring program that meets the compliance monitoring requirements of the Pretreatment Regulations, provides representative data for compliance determinations, and would be legally defensible in court if such an enforcement action is taken by the POTW. In addition, representative and legally defensible data helps the POTW support other program objectives such as local limits evaluation and permit development or reissuance. 10.2 Sampling Plan and Protocols As required in 40 C.F.R. 403.8(f)(2), the POTW shall "develop and implement procedures to ensure compliance with the requirements of a Pretreatment Program." The development and implementation of a sampling plan or procedures ensures the POTW is appropriately and consistently performing sampling or monitoring events, as well as providing enforceable data that is representative of the discharge conditions at the facility. The sampling plan should include the following: purpose and objective of the sampling program, specific sampling protocols at each facility sampling location to ensure representative sampling, and appropriate QA/QC procedures to ensure legally defensible data. 10.2.1 Site-Specific Sampling Protocols The sampling protocols must include specific procedures used at each facility to ensure adequate and representative sampling protocols. The development of the sampling protocols will ensure the sampling events are performed in accordance with appropriate standards and procedures and produce quality data that is legally defensible. At a minimum, the specific sampling protocols at each sampling location should include the following: Sampling locations - should include all monitoring points included in the SIU's permit, including the use of digital photos for each monitoring point. Type of sample - the POTW is required to ensure the sampling event is 68 South Adams County Water and Sanitation District Pretreatment Audit Report CO-0026662 January 27, 2025 to January 30, 2025 representative of the SIU's discharge, as required by 40 C.F.R. 403.12(g)(3). The type of sample will be dependent on the parameter to be sampled and discharge characteristics. The type of sample could include specifications for the use of automatic samplers (including programming to provide representative sampling) or manual sampling techniques. Type of Flow Measurement - if applicable Parameters for Analysis - based on the SIU's permit Sample Volume Type of Sample Containers Sample Preservation Techniques Sample Identification and Chain of Custody Procedures QA/QC Procedures 10.2.2 Quality Assurance/Quality Control (QA/QC) QA and QC are tools that are necessary in a sampling program to maintain a level of quality, such as legally defensible data, in the measurement, documentation, and interpretation of sampling data. The QA/QC procedures are used to obtain data that are both precise (degree of closeness between two or more samples) and accurate (degree of closeness between the results obtained from the sample analysis and the true value that should have been obtained). Proper implementation of QA/QC procedures will result in an increase in the POTW's confidence in the validity of the reported analytical data. The QA/QC procedures used to ensure data collected is valid and legally defensible include, but are not limited to, the following: equipment maintenance/calibration, proper sampling bottles, proper sampling techniques that are adequate and representative of the discharge from the facility, field blanks, equipment blanks, method blanks, standards, blind duplicates, and ensuring sampling personnel are adequately trained. 10.3 The EPA Evaluation of the District's Control Authority Monitoring 10.3.1 SOPs The District has developed an Interceptor Sampling SOP for sampling interceptors and manholes in the service area. In addition, the District also establishes site-specific sampling protocols for each permitted SIU to ensure consistent sampling that is representative for the production day. The SIU-specific sampling protocols need to incorporate QA/QC such as equipment blanks, trip blanks, sample duplicates, matrix spikes, control standards to ensure the sampling and analytical techniques are in control and compliance with 40 CFR 136. In addition, the EPA recommends the District incorporate digital photos into the SIUspecific sampling protocols. 69 South Adams County Water and Sanitation District Pretreatment Audit Report CO-0026662 January 27, 2025 to January 30, 2025 10.3.2 District's Control Authority Monitoring Based on the EPA's review of the Pretreatment records, the District samples the permitted SIUs at least once per year and meets the Control Authority monitoring frequency required in 40 C.F.R. 403.8(f)(2)(v). 11.0 Enforcement 11.1 Regulatory Background The EPA establishes the regulatory requirement to develop and implement an Enforcement Response Plan (ERP) in the Pretreatment Regulations at 40 C.F.R. 403.8(f)(5)(i-iv). The regulations state: "The POTW shall develop and implement an enforcement response plan. This plan shall contain detailed procedures indicating how a POTW will investigate and respond to instances of industrial user noncompliance. The plan shall, at a minimum: (i) Describe how the POTW will investigate instances of noncompliance. (ii) Describe the types of escalating enforcement responses the POTW will take in response to all anticipated types of industrial user violations and the time periods within which responses will take place. (iii) Identify (by title) the official(s) responsible for each type of response. (iv) Adequately reflect the POTW's primary responsibility to enforce all applicable pretreatment requirements and standards." The development and implementation of an ERP is an important component of an effective Pretreatment Program. Although a successful Pretreatment program should provide outreach to facilities in the service area regarding the applicability of the Pretreatment Standards and compliance with these standards, in many situations, enforcement is the necessary driving force that makes the Pretreatment program functional. The ERP establishes a framework for POTWs to formalize procedures for investigating and responding to instances of IU noncompliance and to ensure that POTWs enforce against IUs objectively, consistently, and equitably. A well-developed ERP should help the POTW decide what resources are needed to enforce the Pretreatment Standards/Requirements and assist in dealing with IU violations. In addition, the ERP will provide notice to the IUs regarding the POTW's responsibility to respond to violations of Pretreatment Standards/Requirements. 11.2 Enforcement Legal Authority The EPA evaluated the District's enforcement authority and remedies found in its municipal ordinance. 1. ERP incorporated into the Rules and Regulations at 1.4 and 19.1. 2. Civil/Criminal penalties established in 20.1 and 20.2. 70 South Adams County Water and Sanitation District Pretreatment Audit Report CO-0026662 January 27, 2025 to January 30, 2025 3. Injunctive relief provisions established in 19.7. 4. Authority to enforce against falsification/tampering established in 11.3. 5. Notice of violations authority established in 19.6. 6. Compliance orders authority established in 19. 7. Administrative penalty authority established in 20.1. 8. Show cause hearing provisions in 19.9. 9. Suspensions of service provisions in 19.3. 10. Permit termination provisions established in 3.10 and 19.2. 11. Publication of IUs in significant noncompliance in 19.8. 11.3 Enforcement Response Plan (ERP) The District submitted its ERP to the EPA for review, prior to the audit. The EPA reviewed the District's ERP and is providing the following comments to align with the Federal Regulations: (the EPA's review is included in the SACWSD ERP Review.docx and comments embedded in 2012 Enforcement Response Plan-EPA.pdf). The term Letter of Violation (LOV) is not consistent with Notice of Violation (NOV) established in the Rules/Regs. Defined Terms (page 2) - The EPA recommends the District remove the glossary and refer to definitions in the Rules and Regulations. The following definitions in the Glossary of the ERP are not equivalent with the Rules/Regs: o Approval Authority o Categorical Industrial User o Local Limits o National Categorical Pretreatment Standard o National Prohibitive Discharge Standard o Pollutant o POTW o Prohibitive Waste Standard o SNC o Zero Discharge Permit Due Date for late Reports (Section IV.E.6) and SNC (Section IV.E.7) state 45 days late, which is not equivalent with the 30 days late established in the Rules/Regs. Enforcement actions for the failure to notify for slug/potential problems, hazardous waste, upset, and bypass required by 40 CFR 403.12 are not included in the ERP. Enforcement actions for the following anticipated types of noncompliance are not established: o Tampering with monitoring equipment/methods o Recordkeeping o Dilution o Refusal of entry o Sector control programs (FOG, dental) The District establishes enforcement actions for SNC criteria in Section IV.G by referring to the SNC criteria in the glossary. However, some criteria are incorrect, as identified above and the EPA recommends the District establish the SNC criteria directly in Section IV.G instead of referencing the glossary. 71 South Adams County Water and Sanitation District Pretreatment Audit Report CO-0026662 January 27, 2025 to January 30, 2025  The ERP includes attachments that are not relevant, such as Appendix C (examples of enforcement documents) and D (Pretreatment Compliance Forms). EPA recommends the District remove these appendices. 11.4 Compliance Evaluation Based on the EPA's review of the Pretreatment records, it appears that the District is consistently evaluating compliance in the self-monitoring reports or notices submitted by the SIUs and IUs in the POTW's service area. 11.5 SNC Calculations and Public Participation The Pretreatment Regulations at 40 C.F.R. 403.8(f)(2)(viii) require a POTW to comply with the public participation requirements in the enforcement of National Pretreatment Standards. These procedures shall include a provision for at least annual public notification in a newspaper of general circulation that provides meaningful public notice within the jurisdictions served by the POTW, of IUs, that, at any time during the previous 12 months, were in SNC with applicable Pretreatment requirements. The SNC determinations are both a calculation of numeric Pretreatment Standards, as listed in 40 C.F.R. 403.8(f)(2)(viii)(A-D), and a determination of violations of the narrative Pretreatment Standards, as listed in 40 C.F.R. 403.8(f)(2)(viii)(E-H). Based on EPA's review of the Pretreatment records, the District is calculating numeric SNC and determining narrative SNC as necessary. 12.0 Trucked and Hauled Waste 12.1 Regulatory Background In addition to receiving waste through the collection system, many POTWs accept trucked and hauled waste. As stated in 40 C.F.R. 403.1(b)(1), pollutants from nondomestic sources that are transported to the POTW by truck or rail are also subject to the Pretreatment Regulations. They may also be subject to categorical Pretreatment Standards. Therefore, hauled wastes from CIUs or hauled waste that otherwise qualifies the discharger as an IU must be regulated in accordance with the requirements of the Pretreatment Regulations, including any applicable requirements for permitting and inspecting the generating facility. Hauled wastes, like wastes received through the collection system, have the potential to negatively affect the POTW, making regulatory control of the wastes necessary. Most wastewaters hauled or trucked to a POTW are domestic septage, typically from homes outside the POTW's service area, but compatible in nature. Because such discharges are predominantly compatible wastes, treatment at a POTW is the most appropriate disposal method. The biosolids regulations at 40 C.F.R. 503.9(f) define domestic septage as the liquid or solid material removed from a septic tank, cesspool, portable toilet, Type III marine sanitation device, or similar system that holds only domestic sewage. Domestic septage does not include liquid or solid material removed from any system that receives either commercial wastewater or industrial wastewater, and it does not include grease 72 South Adams County Water and Sanitation District Pretreatment Audit Report CO-0026662 January 27, 2025 to January 30, 2025 removed from a restaurant grease trap. The POTW cannot know for certain the nature and concentration of the trucked wastes and the impact on the POTW without implementing some type of control or surveillance program. Unlike discharges from IUs directly connected to the POTW, the makeup of a load of hauled waste is virtually unknown without some type of monitoring, be it visual or analytical. Even compatible loads of domestic septage can cause problems for a POTW due to high strength or discharge rate. Domestic septage can be partially digested, higher in metals concentrations than normal domestic wastes, or contain small amounts of household contaminants (e.g., cleaners). Similarly, disinfectants used in portable toilets have the potential to affect POTW operations. Receipt of hauled hazardous waste (as defined in the Resource Conservation and Recovery Act (RCRA)) might not only affect POTW operations but also could subject the POTW to additional reporting requirements. The Domestic Sewage Exclusion, specified in 40 C.F.R. 261.4(a)(1)(ii), provides that hazardous wastes mixed with domestic sewage and under control of the Pretreatment program are exempt from the RCRA waste regulations. However, hazardous wastes received by truck or rail (or dedicated pipe) at the treatment plant are not exempt from the regulations. POTWs that accept hazardous wastes from those sources are subject to permit by rule status under RCRA [40 C.F.R. 270.60(c)] provided that certain requirements are met. The POTW must be in compliance with all its NPDES permit requirements and the waste must comply with all federal, state, and local pretreatment requirements. 12.2 Legal Authority The District has adopted the Federal specific discharge prohibitions for trucked and hauled wastes found in the Pretreatment Regulations at 40 C.F.R. 403.5(b)(8). This is incorporated by the District in Article III, section 2.5 of its Rules and Regulations: "Trucked or Hauled Pollutants: All trucked or hauled wastewater shall be preapproved by the Industrial Pretreatment Coordinator and the District's Board of Directors prior to discharge to the District's facilities, with the exception of domestic waste from RVs owned by District residents, and only at discharge points designated by the Industrial Pretreatment Coordinator. Approved trucked or hauled wastewater discharges shall meet all of the District's Prohibitive Waste Standards, be treated in a facility located within the District's service area, and only be discharged once an Industrial User has been issued a wastewater discharge permit." 12.3 Trucked and Hauled Waste Disposal Location and Control Mechanisms According to information gathered during the audit, the District does not accept trucked or hauled waste and has four RV disposal sites in the POTW's service area. These RV disposal sites located at an RV storage does not allow public access to the disposal site unless the RV is stored. In addition, two bus companies, and one port-o-let company had a constructed RV disposal site. It appears that the District has adequate control of the four RV satellite disposal sites in the service area. 73 South Adams County Water and Sanitation District Pretreatment Audit Report CO-0026662 January 27, 2025 to January 30, 2025 13.0 Best Management Practices - Sector Control Programs 13.1 Regulatory Background BMPs are defined in 40 C.F.R. 403.3(e) as "schedules of activities, prohibitions of practices, maintenance procedures, and other management practices to implement the prohibitions listed in 40 C.F.R. 403.5(a)(1) [General Prohibitions] and (b) [Specific Prohibitions]. BMPs also include treatment requirements, operating procedures, and practices to control plant site runoff, spillage or leaks, sludge or waste disposal, or drainage from raw materials storage." 40 C.F.R. 403.5(c)(4) states, "POTWs may develop Best Management Practices (BMPs) to implement paragraphs (c)(1) [develop limits to implement the general/specific prohibitions] and (c)(2) [develop and enforce specific effluent limits for industrial users that contribute pollutants that may result in Interference and Pass-Through] of this section. Such BMPs shall be considered local limits and Pretreatment Standards for the purposes of this part and section 307(d) of the Act." The regulations establish that BMPs are enforceable Pretreatment Standards. 13.2 Authority in Rules and Regulations The District established the authority to implement BMPs in its Rules and Regulations as follows: BMP definition in 2.4. BMPs are established as Pretreatment Standards in 5.1. BMPs established as a permit condition in 3.9.4. BMP recordkeeping requirements referenced in 11.1. BMPs established as an SNC criterion in 19.8.7. 13.3 Dental Amalgam BMP Sector Control Program The Dental Amalgam Rule, found in 40 C.F.R. Part 441, was promulgated as a final rule with new source dental facilities required to be in compliance with the Pretreatment Standards as of July 14, 2017, and existing source dental facilities required to be in compliance as of June 14, 2020. Compliance with the rule requires the installation of an ISO1143 amalgam separator or equivalent device, and compliance with the following two BMPs: Prohibition on the use of oxidizing or chlorine-containing line cleaners; and Ensuring all amalgam process wastewater including chair-side traps, screens, vacuum pump filters, dental tools, cuspidors or collection devices are treated through the amalgam separator. In addition, the new and existing dental facilities are required in 40 C.F.R. 441.50 of the Dental Amalgam Rule to provide a report that characterizes the dental facility and certifies compliance. The new source dental facilities are required to be in compliance upon discharge and submit a one-time compliance report within 90 days of startup. 74 South Adams County Water and Sanitation District Pretreatment Audit Report CO-0026662 January 27, 2025 to January 30, 2025 The District has identified 19 dental facilities in its service area and has received one-time compliance reports within the deadline required by the Rule. The EPA reviewed the onetime compliance reports to ensure compliance with the reporting requirements of the Dental Amalgam Rule in 40 C.F.R. 441.50. The majority of the reports are complete and comply with the reporting requirements with the following exceptions identified below: Adventure Dental - Section D of the compliance report is not completed. Kids in Need of Dentistry - the contact information of the compliance report is not completed. Commerce City Dental Center - the facility states that "it is looking for a 3rd party contractor for its amalgam separator on 07/29/2020. The EPA recommends the District ensure the dental office has either found a contractor to maintain its separator or has provided internal maintenance to be in compliance with the Dental Amalgam Rule. 13.4 FOG Sector Control Program The District has established sector control requirements for the food service establishments (FSE) with grease interceptors and IUs with sand interceptors in the service area to control fats, oils, and greases (FOG). The requirements are established in Article III, section 3 of the Rules and Regulations. Section 3.1.2 requires FSEs to install a grease interceptor, and section 3.2.2 requires IUs such as "all parking and repair garages, filling stations, car washes, truck terminals with washout facilities, engine steam cleaning facilities, commercial laundries, and any other commercial or industrial establishments that have wash racks or oil-producing waste products" to install a sand interceptor. The requirements establish sizing and design criteria, and all grease interceptors/traps and sand/oil interceptors/traps shall meet specific requirements established by the District, and the installation of all grease and sand/oil interceptors/traps shall be subject to inspection and approval by the District. Section 3.1.6 requires proper maintenance and operation of all grease and sand interceptors by a licensed contractor. The District has about 400 IUs with grease or sand interceptors in the POTW's service area. The District samples and inspects these interceptors as part of its industrial waste survey schedule described in section 7.3 of this audit report. The IUs are required to maintain their interceptors at a minimum every six months and ensure they are in proper working condition. The manifests from the pump-out event are emailed to the District as part of the IU's Pretreatment records. The District maintains documentation of these records in a spreadsheet. The District has developed a pamphlet that describes the interceptor program requirements to promote compliance assistance for these IUs. The District sends out 10-day pumping letters and will escalate enforcement for violations of the interceptor operations and maintenance requirements. 75 South Adams County Water and Sanitation District Pretreatment Audit Report CO-0026662 January 27, 2025 to January 30, 2025 14.0 PFAS Roadmap and Implementation Harmful per- and poly-fluoroalkyl substances (PFAS) are an urgent public health and environmental issue facing communities across the United States. PFAS have been manufactured and used in a variety of industries in the United States and around the globe since the 1940s, and they are still being used today. Because of the duration and breadth of use, PFAS can be found in surface water, groundwater, soil, and air--from remote rural areas to densely populated urban centers. A growing body of scientific evidence shows that exposure at certain levels to specific PFAS can adversely impact human health and other living things. Despite these concerns, PFAS are still used in a wide range of consumer products and industrial applications. Every level of government--federal, tribal, state, and local--needs to exercise increased and sustained leadership to accelerate progress to clean up PFAS contamination, prevent new contamination, and make game-changing breakthroughs in the scientific understanding of PFAS. 14.1 2021 EPA PFAS Strategic Roadmap On October 18, 2021, the EPA developed the Agency's PFAS Strategic Roadmap -- laying out a whole-of-agency approach to addressing PFAS. The roadmap sets timelines by which EPA plans to take specific actions and commits to policies designed to safeguard public health, protect the environment, and hold polluters accountable. The PFAS Strategic Roadmap may be found at the following link: https://www.epa.gov/pfas/pfas-strategicroadmap-epas-commitments-action-2021-2024 The EPA's integrated approach to PFAS is focused on three central directives: 1. Research. Invest in research, development, and innovation to increase understanding of PFAS exposures and toxicities, human health and ecological effects, and effective interventions that incorporate the best available science. 2. Restrict. Pursue a comprehensive approach to proactively prevent PFAS from entering air, land, and water at levels that can adversely impact human health and the environment. 3. Remediate. Broaden and accelerate the cleanup of PFAS contamination to protect human health and ecological systems. The EPA's approach is shaped by the unique challenges to addressing PFAS contamination. The EPA cannot solve the problem of "forever chemicals" by tackling one route of exposure or one use at a time. Rather, the EPA understood that it needed to take a lifecycle approach to PFAS to make meaningful progress. PFAS pollution is not a legacy issue--these chemicals remain in use in U.S. commerce. The risks posed by PFAS demand that the Agency attack the problem on multiple fronts at the same time. In the 2021 PFAS Roadmap, the EPA is leveraging the full range of statutory authorities to confront the human health and ecological risks of PFAS: Water - Clean Act (CWA) 76 South Adams County Water and Sanitation District Pretreatment Audit Report CO-0026662 January 27, 2025 to January 30, 2025  Solid Waste - Resource Conservation and Recovery Act (RCRA) Land - Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) Air - Clean Air Act (CAA) Chemical Safety and Pollution Prevention - Toxic Substances Control Act (TSCA) For purposes of this audit, the EPA is addressing the initiatives used in the Office of Water under the Clean Water Act and the NPDES Permitting program and associated programs under the NPDES regulatory umbrella, including the pretreatment program. The specific PFAS Roadmap commitments and updates may be found at the following link: https://www.epa.gov/pfas/pfas-strategic-roadmap-epas-commitments-action-20212024#ow . 14.1.1 Leverage NPDES permitting to reduce PFAS discharges to waterways The National Pollutant Discharge Elimination System (NPDES) program interfaces with many pathways by which PFAS travel and are released into the environment and ultimately impact people and water quality. On December 5, 2022, the EPA issued the Addressing PFAS Discharges in NPDES Permits and Through the Pretreatment Program and Monitoring Programs Memo to the U.S. States to proactively use existing NPDES authorities to reduce discharges of PFAS at the source and obtain more comprehensive information through monitoring on the sources of PFAS and the quantity of PFAS discharged by these sources. This memorandum provides the EPA's guidance to states and updates the April 28, 2022 guidance to the EPA Regions for addressing PFAS discharges when they are authorized to administer the NPDES permitting program or Pretreatment program. The memo provides the following recommendations for POTW NPDES permits and Pretreatment programs: POTW NPDES Permits: o Quarterly Effluent, Influent and biosolids monitoring using EPA Method 1633 o Recommended biosolids assessment, based on biosolids monitoring and a PFAS source reduction for IUs in the POTW's service area, if necessary. o Public notice of downstream drinking systems that are potentially affected by the POTW effluent when the POTW's NPDES permit is renewed or issued. Pretreatment Programs: o Source Identification: Update IU inventory to include PFAS sources o Source Control: Utilize BMPS and pollution prevention to address PFAS discharges to the POTW Update IU permits to required quarterly PFAS monitoring. Develop IU BMPS or local limits for PFAS, where authority exists through the NPDES permit limits or PFAS ELG promulgation. 77 South Adams County Water and Sanitation District Pretreatment Audit Report CO-0026662 January 27, 2025 to January 30, 2025 14.2 Impact of the NPDES Initiatives on the District's Pretreatment Program The analytical tools, rules, procedures, and methods developed by the EPA in the PFAS Strategic Roadmap and identified in 14.1 are currently recommendations to identify and control non-domestic or IU sources in a POTW's service area. The requirement to control IUs will occur either when the EPA promulgates categorical Pretreatment Standards for specific IU sectors such as OCPSF, Metal Finishers or other future rulemakings or when the NPDES State adopts the EPA National Water Quality Criteria for PFAS and PFOS as State water quality standards and begins implementing these as NPDES permit limits. However, EPA recommends the District evaluate these recommendations and determine proactive measures to identify PFAS non-domestic sources in its service area and determine appropriate levels of control or compliance assistance. 14.3 CDPHE's PFAS Policy 20-1 The Colorado Water Quality Control Commission approved PFAS Policy 20-1 on July 14, 2020 to implement and interpret the narrative standard provisions in the commission's Regulations No. 31.11(1)(a)(iv) and No. 41.5(A)(1) for PFAS. Section 31.11(1)(a)(iv) of the commission's regulations states, in relevant part, that "state surface waters shall be free from substances attributable to human-caused point source or nonpoint source discharge in amounts, concentrations or combinations which are harmful to the beneficial uses or toxic to humans, animals, plants, or aquatic life." Section 41.5(A)(1) states that "Groundwater shall be free from pollutants not listed in the tables referred to in section 41.5(B), which alone or in combination with other substances, are in concentrations shown to be...Carcinogenic, mutagenic, teratogenic, or toxic to human beings, and/or...A danger to the public health, safety, or welfare." The PFAS Policy 20-1 directs the CDPHE to consider applying policy requirements for all existing and future, domestic and non-domestic, surface water and groundwater discharge permits issued by the division. The policy's approach for interpreting the PFAS narrative standards includes laboratory method and sampling considerations, translating the narrative standards for PFAS, cleanup of contaminated groundwater considerations, implementation in Colorado Discharge System Permits, and Colorado's impaired water list considerations. The CDPHE began implementation of PFAS Policy 20-1 in 2021 with permit modifications to require monitoring for PFAS and to require preliminary PFAS source identification and is including these policy requirements in renewed/reissued permits. 78 South Adams County Water and Sanitation District Pretreatment Audit Report CO-0026662 January 27, 2025 to January 30, 2025