Document RGEOnmDb82BL8dkwM3zm3MGz

NPDES Pretreatment Categorical Industrial User Inspection Coil Coating-Can Making Point Source Category; 40 CFR Part 465, etc. National Database Information Inspection Type NPDES ID Number Inspection ID Inspection Date Entry Time Exit Time Pretreatment Categorical Industrial User (CIU) Compliance Evaluation Inspection (CEI) CO-PF00102 202504_COPF00102 April 7, 2025 9:30 AM 1:45 PM General Inspector Name Akash Johnson Telephone 303.312.6067 Inspector Type Inspector Name Telephone Inspector Type EPA Region 8 Althea Wilson 303.312.6026 EPA Region 8 Business Name Facility Location Mailing Address Type of Business/Operations Average Production Rate Number of Employees Days of Operation Type/Number of Shifts Facility Location Information Metal Container Corporation 1201 Metal Container Court, Windsor, CO 80550 1201 Metal Container Court, Windsor, CO 80550 Can making facility 6 million cans per day 89 hourly employees and 5 salaried employees 365 days per year, 24 hours per day; about 3-10 days of no production due to annual maintenance/cleaning Two 12-hour shifts, 4 crews Tasha Greene Name Devin Bjorneboe Dennis Markham Carlos Chaparro Title Environmental Health and Safety Manager, Metal Container Corporation (Present for the entire inspection) Quality and Environmental Coordinator, Metal Container Corporation (Present during the opening conference only) Wastewater Treatment Facility Superintendent, Town of Windsor (Present for the entire inspection) Plant Manager, Metal Container Corporation (Present during the first part of the opening conference only) Page 1 of 17 Publicly Owned Treatment Works (POTW) and Permit Number Ultimate Receiving Water(s) POTW/Receiving Water Town of Windsor POTW; NPDES ID CO-0020320 Cache La Poudre River Areas Evaluated During Inspection Permit Self-Monitoring Program Records Compliance Schedule Facility/Site Review Laboratory Effluent/Receiving Waters Operations and Maintenance Flow Measurement Sludge Handling/Disposal Pretreatment Pollution Prevention Stormwater Combined Sewer Overflow Sanitary Sewer Overflow Report Review and Signature Lead Inspector and Report Writer Name/Signature/Final Date ALTHEA WILSON Digitally signed by ALTHEA WILSON Date: 2025.05.22 08:50:25 -06'00' Contact Information U.S. EPA Region 8 Denver, Colorado wilson.althea@epa.gov (303) 312-6026 Reviewer Name Review Date Contact Information Akash Johnson 05/14/2025 U.S. EPA Region 8 Denver, Colorado johnson.akash@epa.gov (303) 312-6067 Al Garcia 05/16/2025 U.S. EPA Region 8 Denver, Colorado garcia.al@epa.gov (303) 312-6382 Management Reviewer Name/Signature/Date Contact Information EMILIO LLAMOZAS Digitally signed by EMILIO LLAMOZAS Date: 2025.05.21 13:54:28 -06'00' U.S. EPA Region 8 Denver, Colorado llamozas.emilio@epa.gov (303) 312-6407 Emilio Llamozas, NPDES and Wetlands Enforcement Section Supervisor Page 2 of 17 1.0 Introduction General Inspection and Facility Information On Monday April 7, 2025, U.S. Environmental Protection Agency (EPA) inspectors Althea Wilson and Akash Johnson (collectively, "inspectors"), conducted a compliance evaluation inspection of Metal Container Corporation (Metal Container; Facility), a pretreatment categorical industrial user located in Windsor, Colorado. The purpose of the inspection was to evaluate Metal Container's compliance with applicable Clean Water Act and National Pollutant Discharge Elimination System (NPDES) requirements, under 40 C.F.R. Part 465, the Coil Coating Point Source Category, Subpart D-Canmaking Subcategory and the applicable pretreatment standards that fall under this code, summarized in a Notification of Discharge Requirements (NDR) issued to the Facility by the EPA on March 30, 2022. Throughout the inspection, the inspectors recorded notes and observations in bound checklists. Photographs taken during the inspection are included in an attached photo log. 2.0 Inspection Narrative At approximately 9:30 AM, the EPA inspectors met with Metal Container representatives, Ms. Tasha Greene, Mr. Devin Bjorneboe, and Mr. Carlos Chaparro, along with the Town of Windsor representative, Mr. Dennis Markham, at the Metal Container office to have an opening conference to discuss the inspection of the Facility. The inspectors presented their credentials and explained the purpose of the inspection. Carlos Chaparro departed after the introductory part of the opening conference. The remaining group then proceeded to discuss the Facility manufacturing operations/processes, starting with the raw materials and chemicals through the finished products, and the management and treatment of discharged and non-discharged wastestreams. Before the inspection, inspectors requested and received various records associated with Facility operations and compliance. Prior to, during, and after the inspection, inspectors reviewed select records, identified in the "Records Reviewed" section of this report. After finishing the opening conference and document review, the inspectors along with Ms. Greene and Mr. Markham, conducted a walk-through of the Facility. During the walk-through, the inspectors viewed the entire can-making process, the discharged and non-discharged wastestreams, the flow monitoring and sampling points, as well as the wastewater treatment system. Throughout the walk-through, the inspectors took photographs of the Facility, included in the attached photo log and referenced throughout Sections 37 of this report. After the Facility walk-through, the inspectors returned to the office meeting room and held a closing conference with Ms. Greene and Mr. Markham. The inspectors notified Facility representatives that an email containing preliminary findings would be sent out within two weeks of the inspection date. The inspection concluded when the inspectors left the site at approximately 1:45 PM. After the inspection, on April 15, 2025, the EPA sent an email to Ms. Greene with the preliminary findings from the inspection. Over the weeks between the inspection and issuance of this report, the inspectors corresponded with Ms. Greene on various occasions via email, phone calls, and virtual meetings to request and receive additional records and clarify follow-up questions from the inspection. 3.0 Facility Manufacturing Information Page 3 of 17 All volumes of the tanks and sumps provided throughout this report were sourced from the NDR Fact Sheet and were not verified during this inspection. Metal Container is a can-making facility that produces approximately 6 million aluminum beverage cans per day, operating 24 hours per day 365 days per year, with typically 3-10 down days per year for maintenance, repairs, and other downtime. Facility representatives stated that, due to market conditions, they have seen an increased number of down days (upwards of 50-60 non-consecutive per year) in the last few years, but they expect down days to go back to typical levels in 2025. At the beginning of the manufacturing process, the Facility receives 25,000-pound aluminum coils that are stored on pallets until use (photo 1). The Facility has the capacity to store up to 27 coils at a once, but typically only stores around 10 coils at any given time and uses about four coils in process during an average production day. The Facility operates two process lines in parallel, each can hold two coils at a time. One process line is shut down every 8 weeks for cleaning and maintenance, therefore each line gets cleaned every 16 weeks. The Facility representatives stated the lines are differentiated as process line 1, "The Fast Line," and process line 2, "The Slow Line." Process line 1 runs faster than process line 2 due to the presence of some tandem equipment on line 1. The coils are laid on their side and loaded into the uncoiler machine which uncoils the aluminum, then an applicator roll lubricates the straightened aluminum prior to stamping (photos 2 and 3). The Cupper lubricant is supplied from a 400-gallon day tank that is gravity fed to the uncoiler machine (photo 52). Once the straightened aluminum is lubricated, it goes through a hydraulic press where blanks are stamped out, then a die is used to form cups out of the blanks (photo 4). The scrap metal from the cupping process is collected through a vacuum for recycling. The cups are then conveyed overhead to the Bodymaker machines where drawing and ironing is performed (photo 5). Each process line consists of seven individual Bodymaker machines which form straight walls on the cups to form a can (photo 7). The coolant is supplied to the Bodymaker machines from an 8,000-gallon sump. Dirty coolant is sent to an oil filtration system where it passes through a series of paper filters for reclamation and is returned to the 8,000-gallon sump for further use (photo 9). According to the NDR Fact Sheet, Bodymaker coolant is stored in a 10,000-gallon tank and pumped to a 60-gallon day tank to supplement the Bodymaker coolant sump as needed (photo 53). The Facility representatives stated that once per year, all coolant is removed from the system, profiled, and disposed of. Waste coolant characterization and disposal procedures were not evaluated during the inspection. Once the cans have gone through drawing and ironing, they are moved to a trimmer where they are trimmed to a finished height (photo 5). The scrap metal form the trimming process is collected for recycling. The trimmed cans then enter a large conveyance trench which runs underneath both drawing and ironing lines (photo 6). The trench conveys the cans to the washing process. The conveyance trench for the cans running underneath the Bodymaker machines also acts as a container for any leaked or excess fluids from the machines and cans. The trench eventually connects to the wastewater treatment system. The cans in the conveyance trench are loaded into two parallel can spray washing process lines with identical configurations and tanks. To aid in the draining of the solutions and spray rinses in the process line, the cans are inverted using the wet can converter to turn them dome side up before entering the six wash stages (photo 8). During the inspection, the inspectors identified several differences between rinse Page 4 of 17 processes as described in the NDR Fact Sheet and those implemented at the Facility, including the configuration of makeup water flow between stages and the "dirtiness" of various rinse stages. A full evaluation of these differences, possible configurations of makeup water flow, and whether rinse stages were open-loop or closed-loop, was not conducted during the inspection and is not described in this report. Broadly speaking, Facility representatives confirmed used water from some rinse stages was routed to at least some other stages for use as makeup water and all wastewaters from the rinse line were eventually directed to the wastewater treatment system. Each stage contains 50 psi spray nozzles to clean the interior of the cans. The can spray washing process line consists of the following six stages (photos 10-16): x Stage 1: Sulfuric acid cleaning/etch - A sulfuric acid solution with a pH of 1.8 is heated and sprayed into the cans (photo 10). During the inspection, Facility representatives stated that this is the "dirtiest" of the six wash stages due to the presence of oils and coolants on cans entering the process. x Stage 2: Hydrofluoric acid (HF) - The HF in solution with sulfuric acid surfactant cleaner is heated and sprayed into the cans (photo 11). x Stage 3: Brominated water rinse - The bromine is added to city water and sprayed into the cans to rinse them (photo 12). x Stage 4: Sulfuric acid rinse - The sulfuric acid in solution with city water, at a pH of 4.5, is sprayed into cans (photo 14). x Stage 5: Deionized (DI) water rinse - The DI water generated in-house is sprayed into the cans to rinse them (photo 14). x Stage 6: DI water with a mobility enhancer (ME50) - The DI water with ME50 (a food grade lubricant) is sprayed into the cans to help the cans move more effectively through subsequent steps in the manufacturing process (photo 15). After the cans have gone through all six stages of the wash line, they are dried in a natural gas oven (photo 15). All waste rinsewaters from the can-washing line, as well as skimmed oils and coolants, are collected in the conveyance trench which drains into a large below-grade sump (photo 16). The sump overflows into a pipe that leads to the wastewater treatment system. The Facility representatives stated approximately 90% of wastewater entering the wastewater treatment system at the Facility, is generated during the canwashing line. The washed cans are then conveyed to three printer lines (photo 45). The printers apply color on the can from light to dark and have the capability of applying multiple runs of ink colors at one time. The ink is supplied with pots located next to the printers and is applied to the cans through ink plates loaded onto the printer (photo 46). Bulk ink is stored in the Facility's warehouse along with machine parts and palletized finished cans (photo 43). The waste ink generated is captured in a satellite waste accumulation drum and stored in a designated hazardous waste location until third party disposal (photo 51). Waste ink characterization and disposal procedures were not evaluated during the inspection. After the printer ink application, an overvarnish is applied to the cans before the coatings are cured in an oven (photo 48). Overvarnish is stored in a 10,000-gallon tank and pumped to the printer resevoir (photos 40 and 41). Page 5 of 17 The cured cans are then conveyed to the inside spray process to apply an epoxy spray to the inside of the cans, providing separation between the beverage and the aluminum can (photo 47). The Facility has 13 epoxy spray machines on each line, each machine containing spray guns at different depths to apply even coverage to the interior of the can. The inside spray is contained in a 10,000-gallon tank and pumped to the epoxy spray machines (photos 40 and 41). After the inside spray process, the cans are sent to an oven to cure the epoxy spray. The waste epoxy spray is captured as non-hazardous regulated waste and hauled offsite by a third-party company to be incinerated (photo 49). Waste epoxy characterization and disposal procedures were not evaluated during the inspection. The cans then move on to the necker process. The Facility has two parallel necker process lines. First, necker wax is applied on the top cut edge of the cans. After the necker wax application, the cans go through the necker process to draw out the neck of the can. The Facility representatives stated that approximately 20,000 cans per minute are run through each of the necker process lines. The cans are then flanged, and the base is reformed in the inside base profile reformer to add strength to the can during palletizing and filling. A date and time code are then applied to the cans. The last step in the can-making process before they are palletized and shipped out is the quality control/quality assurance (QC/QA). The QC/QA consists of inspection through a light tester to identify defects in the can, and a Mixed Label Detector where cans are checked for label inconsistencies or errors. The cans that fail these tests are kicked out of the process line and collected as scrap metal. The finished cans are then sent through a conveyor line to the warehouse for palletizing and storage. It is noted, Facility representatives stated there were over one-thousand other QC checks throughout the entire manufacturing process. 4.0 Wastewater Treatment The Facility's wastewater treatment system consists of six collection tanks (three process wastewater tanks referred to as "CE1 tank," "CE2 tank," and "CE3 tank," two oil collection tanks referred to as "Oil Split A tank" and "Oil Split B tank," and a Waste Solids Tank (photo 34)), a four-stage reactor batch treatment system, and a clarifier. The CE tanks act as wastewater collection and equalization. The CE2 tank is the primary wastewater collection tank; wastewater from the below-grade sump at the end of the can-washing lines is pumped to the CE2 tank (photo 27). The CE1 tank is used for overflow when needed from the CE2 tank, and the CE3 tank is for extra storage or for an emergency shut down. The location and capacities of the wastewater treatment tanks are the following (note, the capacities of the tanks and sumps were sourced from the NDR Fact Sheet and were not verified during this inspection): x Split A x Split B x Waste Solids Tank x Used Oil Tank x CE1 x CE2 x CE3 x Reactor Stage 1 x Reactor Stage 2 Wastewater Treatment - 1st floor Wastewater Treatment - 1st floor Wastewater Treatment - 1st floor Bulk Tank Area Wastewater Treatment - 1st floor Wastewater Treatment - 1st floor Wastewater Treatment - 1st floor Wastewater Treatment - 2nd floor Wastewater Treatment- 2nd floor Page 6 of 17 10,000 gallons 10,000 gallons 13,000 gallons 10,000 gallons 13,000 gallons 13,000 gallons 13,000 gallons 2,500 gallons 2,500 gallons x Reactor Stage 3 x Reactor Stage 4 Wastewater Treatment- 2nd floor Wastewater Treatment- 2nd floor 2,500 gallons 2,500 gallons After the wastewater enters the CE2 tank, it is sent to the four-stage reactor batch treatment tank. The stages for the reactor batch treatment are as follows: 1. Acid Break Stage: Sulfuric acid is added to crack/break the oil and the contents of this stage are mixed (photo 20). The sulfuric acid is stored in 55-gallon drums on secondary containment and transferred to a day tank for use (photos 32 and 42). 2. Oil Skimming Stage: A rope mop is used to skim oil off the top. The skimmed oil is collected in a pan and sent to the Oil Split A tank (photo 21). 3. Lime Addition Stage: Lime slurry that is created on-site (photo 24) is added to this stage to aid in solids precipitation (photo 22). 4. Retention Stage: This is the mixing and contact time stage. If needed, additional lime slurry can be added here (photo 22). The wastewater from the final reactor batch tank (Stage 4) is then sent to the clarifier (photo 29). Polymer is stored in a day tank and is metered into the clarifier to aid in solids formation and precipitation (photo 28). The solids accumulate on the bottom of the clarifier and are collected in a sump that is pumped to the Waste Solids Tank (photo 34). The scum that accumulates on the top of the clarifier is raked, collected in the sump, and then sent back to the first stage (Stage 1) of the reactor batch process. A continuous pH monitoring meter is installed in the weir overflow to the effluent trough that leads to the discharge pipe (photo 37). Additional discussion of effluent pH monitoring at the Facility is included in the "Findings, Corrective Actions, and Recommendations" section of this report. The Facility also has a flow meter that continuously measures flow at the clarifier outfall (photo 38 and 39). The discharge pipe from the clarifier to the POTW is identified as Outfall 001 (photo 36). A gate valve was present at Outfall 001 which could be closed to stop all flow to the outfall, if needed. The solids from the Waste Solids Tank are pumped to a filter press where the filtrate from the filter press is then sent back to the clarifier (photo 23). The solids are pressed, collected in a filter press collection bin and then hauled off-site (photo 26). The Facility representatives stated that A1 Organics, a third-party company, transports the pressed solids waste for use in composting. There is a floor drain between the filter press and lime slurry maker that collects any spills and transfers them to the wastewater sump which eventually enters the wastewater treatment system (photo 25). 5.0 Waste Oil Treatment/Management Waste oil treatment/management/disposal was not evaluated in-depth during the inspection. Some of the information included in this section was sources from the NDR Fact Sheet and was not verified during the inspection. The skimmed oil from the reactor batch tank Stage 2, and the tramp/skimmed oil from the oil filtration system are collected in Oil Split A tank. Sulfuric acid is added to the contents of the tank with an air sparge to crack the oil. The contents of the Oil Split A tank are left to quiesce for three to four hours to allow for oil separation. The tank is then dewatered, and the water fraction is pumped to CE2 while the oily fraction is sent to the Oil Split B tank (photo 18). Page 7 of 17 The Oil Split B tank is heated to 140 degrees F to provide further separation of the oil/water fraction. The Oil Split B tank is dewatered, and the water fraction is pumped to CE2, while the waste oil is sent to the Used Oil Tank. A final dewatering occurs in the Used Oil Tank, the water fraction is sent this time to the Oil Split A tank and the waste oil is hauled off-site by a third-party company. There is a drain between the Split A and B tanks and the CE tanks that leads to an underground trench (photo 35). The trench collects any spills and conveys them back to the wastewater treatment system. 6.0 Non-regulated Wastestreams In addition to wastewater generated from the manufacturing process, the facility generates non-regulated wastewater. According to Facility representatives, non-regulated wastewater comes from mopping, process floor hand sinks, cooling tower blowdown, DI backwash, and DI regeneration. There are hand sinks installed on the process floor in different areas that discharge to the process wastewater treatment system and contribute less than 50 gpd. The custodial staff cleans and mops the floors throughout the week and the used mop water is discharged to the process wastewater treatment system. The flow contributed by mop water is less than 50 gpd. Facility representatives indicated sanitary wastewater from showers, break rooms, and bathrooms was all piped directly to the sanitary sewer, bypassing the wastewater pretreatment system. The cooling tower blowdown is discharged to the Facility's wastewater treatment system (photo 19). The Facility representatives stated that cooling tower blowdown contains corrosion inhibitors. The quantity of cooling tower blowdown that is discharged varies greatly, with the average amount in 2024 being 1,853 gpd and the maximum amount being 5,284 gpd (values calculated by the EPA using data provided by the Facility). In 2024, the Facility discharged DI backwash wastewater one to three times per month with an average volume of 1,500 gallons per event (as noted in the flow spreadsheets provided by the Facility). The Facility discharged DI regeneration wastewater about six times per month with an average of 4,460 gallons per event and a maximum of 31,024 gallons per event (values calculated by the EPA using data provided by the Facility). The DI backwash and regeneration wastewaters are both discharged to the process wastewater treatment system (photo 17). The NDR Fact Sheet explains that when pretreatment standards for canmaking production were developed, a model flow rate per unit of production was based on expected water consumption and flow reduction methods. At the Facility, nonregulated and regulated wastestreams are mixed and discharged together, which can dilute pollutant concentrations in the effluent, making them unrepresentative of regulated wastestreams. The EPA found that daily average flows of these wastestreams were too unstable to set long-term mass or concentration limits to account for dilution. Therefore, to comply with federal pretreatment regulations, the EPA established effluent limits based on production data, considering dilution during each sampling event. The Facility must calculate a dilution factor for each sampling event to adjust pollutant concentrations in compliance samples for reporting. However, during the inspection, Facility representatives admitted they were not calculating or applying these dilution factors, as detailed in the "Findings, Corrective Actions and Recommendations" section of this report. It is important to note that the NDR does not require a dilution factor for pH measurements. Page 8 of 17 7.0 Chemical Storage The bulk chemicals used at the Facility are stored in either 10,000-gallon bulk tanks located in secondary containment (photos 40 and 41), intermediate bulk container (IBC) totes (photo 44), or 55-gallon drums (photo 42), and are generally transferred to day tanks of various sizes for daily production use. The coolants and lubricants are pumped by demand into reservoirs for machinery throughout the Facility. Spills and other non-routine episodic slug discharges such as inadequately treated wastewater, have the potential to pass through the system and reach the Town of Windsor's sanitary sewer. The Facility has developed a Slug Discharge Control Plan (SDCP) that addresses the management of potential spills and slug discharges. The EPA performed a cursory review of Metal Containers SDCP as part of the inspection. The below table of chemicals and raw materials is pulled from the NDR Fact Sheet; the accuracy of its contents was not verified during the inspection. Chemical/Raw Material Bonderite L-FM 1525-B Bodymaker Coolant Mobilgear 600 XP 220 Bodymaker Lube DTI SNL 4 Cupper Lubricant Lubrication and Hydraulic Oil Inside Spray Metal deco ink Sulfuric Acid (surfactant) Chemicals/ Raw Materials Overview Volume/Mass Storage Location 10,000-gallon tank pumped into a 60-gallon day tank (about 18 gallons used /shift) 10,000-gallon tank Tank farm Day tank on process floor Tank Farm Six 330-gallon totes transferred to a 650-gallon bulk tank. The bulk tank is pumped to a 400-gallon day tank for process use. 55-gallon and 75-gallon drums contained in a dispensing rack system 10,000-gallon tank Tank Farm Day tank on process floor Oil drum storage room Tank Farm Ink containers Ink storage rack room 10,000-gallon tank pumped to a 500-gallon day tank Tank farm Day tank in wastewater treatment system area Page 9 of 17 Process Use Bodymaker process line Bodymaker process line Cupper process line Process machinery Inside Spray Process lines printers Washer Sulfuric acid (H2SO4) Hydrochloric Acid (HCl) Hydrofluoric acid (HF) Overvarnish Mobility Enhancer-ME50 Sulfuric Acid (surfactant) 55-gallon drums transferred into a day tank; 6 drums delivered weekly 55-gallon drums (about 1 drum used/6 days) 330-gallon totes pumped to a day tank (about 20- gallons used per shift) 10,000-gallon tank pumped to printer reservoirs Drums pumped into 15gallon day tank 10,000-gallon tank pumped to a 500-gallon day tank Wastewater treatment area Chemical Storage Chemical storage Day tank on process floor Tank farm Chemical storage Day tank on process floor Tank farm Day tank in wastewater treatment system area Wastewater treatment Regen acid for DI column maintenance Washer Printers Washer Washer Records Reviewed x SDCP and Appendices, January 2025 x Select 2023 and 2024 DMRs x Select 2023 and 2024 production data and calculations x Select 2023 and 2024 flow data and calculations x Select 2023 and 2024 Laboratory Analytical Reports x Select 2023 and 2024 Chains of Custody Finding #1: Findings, Corrective Actions and Recommendations Since the March 30, 2022, issuance of the NDR to the Facility, dilution factors had not been calculated or applied to determine applicable pollutant concentrations reported on DMRs. Instead, Facility representatives indicated they subtracted non-regulated wastestream flows from regulated wastestream flows to account for dilution, which does not meet NDR requirements. It is noted, the Facility reported a numeric effluent limit excursion for manganese in March 2023. The EPA has not evaluated whether the reported value resulting in this excursion will change with proper application of a dilution factor. NDR and NDR Fact Sheet Citations: Parts II.B (Specific Effluent Limitations and Monitoring Requirements), III.B.2 (Discharge Monitoring Report), III.B.7 (Supporting Calculations) of the NDR and Parts 3.1.4 (Compliance with the Production-Based Standards) and subparts of the NDR Fact Sheet contain requirements and instructions for conducting, applying, and submitting dilution factor calculations. Page 10 of 17 Part 3.1.4.2.3 (Alternative to Calculating a Dilution Factor for the Daily and Monthly Compliance Data) of the NDR Fact Sheet identifies an option for avoiding dilution of regulated wastestreams and therefore eliminating the need for use of the dilution factor. Another alternative not directly discussed in the NDR Fact Sheet may be to stabilize non-regulated wastestream flows such that long-term equivalent mass or concentration limits could be established to account for dilution of regulated wastestreams. Corrective Action 1: For all monitoring and reporting periods since the March 30, 2022, issuance of the NDR, calculate and apply the dilution factor to all applicable pollutant concentrations and resubmit corrected DMRs and required supporting calculations in NetDMR. In a response to the EPA, provide the date this corrective action was completed and a summary of any effluent excursions identified during re-calculation and re-reporting of monitoring data over this time period. Corrective Action 2: Moving forward, ensure that all applicable pollutant concentrations reported on future DMRs are calculated with the dilution factor formula and dilution factor calculations are submitted as required by the NDR. Alternatively, if the Facility wishes to avoid use of the dilution factor in the future, the Facility may choose to discharge some or all non-regulated wastestreams through a separate outfall, potentially allowing for the EPA to either: 1) establish long-term equivalent mass or concentration limits accounting for relatively stable dilution of regulated wastestreams; or 2) directly apply applicable categorical pretreatment standards if dilution was eliminated or reduced to negligible levels ("negligible levels" would have to be determined by the Region 8 Pretreatment Coordinator). In a response, provide a narrative explaining how this corrective action has been implemented, including which of these options the Facility has elected to pursue. Recommendation: Submit an example dilution factor calculation spreadsheet to the Region 8 Pretreatment Coordinator for review. Finding #2: In the spreadsheets used by the Facility to calculate reportable data, the following discrepancies were noted for flow values: 1. CY23Q2 a. In the "2023 WWT Production-Based Worksheet" file, the value for 5/3/2023 (cell E15) is "65,986." However, in the "2023 Flow" file, the value for 5/3/2023 Prod Effluent (cell H7) is "63,282." Page 11 of 17 b. In the "2023 WWT Production-Based Worksheet" file, the value for 5/4/2023 (cell E16) is "36,766." However, in the "2023 Flow" file, the value for 5/4/2023 Prod Effluent (cell H8) is "39,067." 2. CY23Q3 a. In the "2023 WWT Production-Based Worksheet" file, the value for 8/3/2023 (cell E15) is "56,537." However, in the "2023 Flow" file, the value for 8/3/2023 Prod Effluent (cell H7) is "-2,146." b. In the "2023 WWT Production-Based Worksheet" file, the value for 8/31/2023 (cell E19) is "51,302." However, in the "2023 Flow" file, the value for 8/31/2023 Prod Effluent (cell H35) is "43,482." 3. CY23Q4 a. In the "2023 WWT Production-Based Worksheet" file, the value for 11/2/2023 (cell E15) is "56,537." However, in the "2023 Flow" file, the value for 11/2/2023 Prod Effluent (cell H6) is "50,574." 4. CY24Q1 a. In the "2024 WWT Production-Based Worksheet" file, the value for 2/2/2024 flow (cell E15) is "43,792." However, in the "2024 Flow" file, the value for 2/2/2024 flow (cell H6) is "41,094." 5. CY24Q3 a. In the "2024 WWT Production-Based Worksheet" file, the value for 9/11/2024 flow (cell E15) is "44,544." However, in the "2024 Flow" file, the value for 9/11/2024 flow (cell H15) is "44,554." 6. CY24Q4 a. In the "2024 WWT Production-Based Worksheet" file, the value for 10/2/2024 flow (cell E15) is "42,369." However, in the "2024 Flow" file, the value for 10/2/2024 Prod Effluent flow is (cell H6) "38,311". NDR Citations: Part III (Reporting and Notification Requirements) of the NDR contains reporting and calculation requirements. Corrective Action 1: For all monitoring and reporting periods since the March 30, 2022, issuance of the NDR, review flow data used for calculations and reporting and ensure accurate flow data is used for reportable values and calculations. Resubmit corrected DMRs and required supporting calculations in NetDMR as necessary. In a response, provide the date this corrective action was completed, a summary of any additional discrepancies identified and rectified, a narrative explaining the cause(s) of these discrepancies, and a summary of any effluent excursions identified during re-calculation and re-reporting of monitoring data over this time period. Corrective Action 2: Page 12 of 17 Moving forward, ensure accurate flow data is used for reportable calculations and values reported on DMRs. In a response, provide a narrative explaining how this corrective action will be implemented, including any actions taken by the Facility to mitigate the causes of the discrepancies identified in the narrative responsive to Corrective Action 1, above. Recommendation: Automate calculations and spreadsheets involving flow data and calculations to minimize potential human error. Finding #3: The start and end times of the 24-hour period over which composite samples were collected did not correspond with the 24-hour period over which flow and production data was used for calculations and reporting. Facility representatives indicated composite samples were typically collected beginning around 4:00 AM or 5:00 AM and ending around 4:00 AM or 5:00 AM the following day, but flow and production data used in corresponding calculations and reporting spanned midnight to midnight. NDR Citations: Part IV.B (Retention of Records) of the NDR states, "The facility is required to retain for a minimum of three (3) years any records of monitoring activities and results (whether or not such monitoring activities are required). This includes but is not limited to any calibration and maintenance records and all original strip chart recordings for continuous monitoring instrumentation, copies of all reports required by the Pretreatment Regulations, records of all data and laboratory reports, and records of Best Management Practices (BMPs). The facility shall make such records available for inspection and copying by the EPA. This period of retention shall be extended during the course of any unresolved litigation regarding the facility or when requested by the EPA." Part III.B.4 (Flow Data) of the NDR states, "Submit the measured total monthly flows, calculated daily average flows, and the flow on the day of composite sampling events from Outfall 001 for each month in the reporting period on the DMR. In addition, submit total monthly flows and calculated daily average flows for the unregulated wastewater flow..." Part III.B.5 (Production Data) of the NDR states, "Submit the total number of cans produced, calculated daily average of cans produced, and the actual number of can produced on the day of composite sampling events for each month in the reporting period on the DMR." Corrective Action: Ensure the same 24-hour period is used for composite sampling, flow measurement, and production data. In a response, provide a narrative explaining how this corrective action has been implemented. Finding #4: The exact start and end date and times of composite sample collection were not documented until sometime in 2024. Facility representatives indicated, beginning sometime in 2024, exact start and end dates and times Page 13 of 17 of composite sample collection have been documented on COCs. NDR Citations: Part II.D (Record-Keeping Requirements) of the NDR states, "The facility shall maintain records of all information resulting from any monitoring activities required by the Pretreatment Regulations, including documentation associated with Best Management Practices (BMPs) (e.g., inspections of spill control BMPs) for a minimum of three years. Refer to Part IV.B of this enclosure for additional information about Retention of Records. Such records shall include for all samples: 1. The date, exact place, method, and time of sampling and the names of the person or persons taking the samples. 2. The dates analyses were performed. 3. Who performed the analyses. 4. The analytical techniques/methods used. 5. The results of such analyses." Part IV.B (Retention of Records) of the NDR states, "The facility is required to retain for a minimum of three (3) years any records of monitoring activities and results (whether or not such monitoring activities are required). This includes but is not limited to any calibration and maintenance records and all original strip chart recordings for continuous monitoring instrumentation, copies of all reports required by the Pretreatment Regulations, records of all data and laboratory reports, and records of Best Management Practices (BMPs). The facility shall make such records available for inspection and copying by the EPA. This period of retention shall be extended during the course of any unresolved litigation regarding the facility or when requested by the EPA." Corrective Action - Complete: Ensure exact start and end times and dates of composite sample collection are documented on the COCs and elsewhere as appropriate. Facility representatives indicated, beginning sometime in 2024, exact start and end dates and times of composite sample collection have been documented on COCs. No response is requested pursuant to this completed corrective action. Finding #5: Effluent pH was not being monitored and recorded as described in the NDR Fact Sheet. Facility representatives indicated effluent pH was monitored by an in-line meter which measured pH at least every few seconds and recorded pH measurements at variable frequencies, ranging from multiple times per minute to sometimes greater than 1-minute intervals. NDR and NDR Fact Sheet Citation: Table 1 (Outfall 001 - Limits and Sampling Requirements) of the NDR requires "continuous measurement" and "continuous recording" of pH. The EPA acknowledges "continuous" is not defined in the NDR, as discussed during a virtual inspection follow-up meeting between the inspectors, Facility Page 14 of 17 representatives, and the Region 8 Pretreatment Coordinator. Part 3.2.2 (Monitoring Requirements) and footnote 1 to Table 6 (Metal Container Monitoring Frequency, Outfall 001) of the NDR Fact Sheet both state, "...At a minimum, the pH and flow measurements shall be recorded at one-minute intervals on a continuous recording device." Corrective Action: Ensure pH is being recorded as described in the NDR Fact Sheet or as otherwise approved by the EPA Region 8 Pretreatment Coordinator. In a response, provide a narrative explaining how this corrective action has been implemented, including any relevant changes to pH recording procedures and/or approvals from the Region 8 Pretreatment Coordinator. Finding #6: During the inspection, pH monitoring data was not readily accessible to on-site Facility staff or the inspectors. Additionally, it was not clear how the reportable highest and lowest pH values were identified for each monitoring period. Facility representatives indicated pH monitoring data was stored on corporate servers and was not immediately accessible to on-site Facility staff. Rather, it had to be requested from the corporate office and the request took several days to process. Facility representatives indicated they could request pH data from their corporate office and provide it to the inspectors after the on-site inspection, but the inspectors did not request or review this data. Facility representatives also indicated pH data could not be easily queried to quickly identify the highest and lowest pH value for each monitoring period. Instead, Facility staff indicated they identified high and low pH "trends" across tens of thousands of data points per monitoring period, then investigated the trends to identify the highest and lowest pH value for each monitoring period. NDR Citations: Part IV.B (Retention of Records) of the NDR states, "The facility is required to retain for a minimum of three (3) years any records of monitoring activities and results (whether such monitoring activities are required). This includes but is not limited to any calibration and maintenance records and all original strip chart recordings for continuous monitoring instrumentation, copies of all reports required by the Pretreatment Regulations, records of all data and laboratory reports, and records of Best Management Practices (BMPs). The facility shall make such records available for inspection and copying by the EPA. This period of retention shall be extended during the course of any unresolved litigation regarding the facility or when requested by the EPA." Table 1 (Outfall 001 - Limits and Sampling Requirements) of the NDR, along with other sections of the NDR and applicable pretreatment regulations (e.g. 40 C.F.R. 403.5(b)), require effluent pH remain 5.0 or higher. Part III.B.6 (pH Data) of the NDR states, "Submit the measured minimum and maximum pH from Page 15 of 17 Outfall 001 for each month in the reporting period on the DMR." Part IV.F (Right of Entry) of the NDR states, "Pursuant to section 308 of the Clean Water Act, the EPA or an EPA authorized representative (including an authorized contractor acting as a representative of the EPA), upon presentation of his or her credentials, shall have a right to: 1. Enter upon the premises where a regulated facility or activity is located or conducted, or where records must be kept. 2. Have access to and copy, at reasonable times, any records that must be kept. 3. Inspect at reasonable times any facilities, equipment (including monitoring and control equipment), practices, or regulated operations. 4. Sample or monitor, for the purposes of assuring compliance, any substances or parameters at any location. 5. Inspect any production, manufacturing, fabricating, or storage area where regulated pollutants could originate, be stored, or be discharged to the POTW." Recommendation 1: Ensure all pH monitoring data is readily accessible on-site to Facility staff and EPA inspectors. Recommendation 2: Ensure all pH monitoring data can be easily queried to identify the reportable highest and lowest pH values for each monitoring period. Finding #7 The facility reported a numeric effluent limit excursion for the monthly average manganese value in March 2023, shown in the table below. DischDesig Monitoring Period End Date 001-P 03/31/2023 Parameter Desc Manganese, total [as Mn] [Can Production] Monitoring Location Desc Pretreatment, Process Complete Limit Unit Short Desc Limit Value DMR Value lb/Mcans 0.041 0.0545 Stat Base Desc MO AVG Over Limit 33% NDR Citations: Table 1 (Outfall 001 - Limits and Sampling Requirements) of the NDR contains numeric effluent limits applicable to the Facility. Page 16 of 17 Corrective Action - Complete: Ensure the Facility meets its discharge limitations, including monthly average values for manganese. During the inspection, Facility representatives indicated they investigated the cause of this exceedance and determined it was likely due to an operator process control error. Facility representatives indicated wastewater treatment operators had subsequently been provided training on how to prevent similar types of errors from recurring. No response is requested pursuant to this completed corrective action. Page 17 of 17