Document jmM6BngjdJNLrzB0JMYVL6r9Z

U.S. EPA Region 8 NPDES Inspection Report National Database Information Inspection Date: September 20, 2022 Entry / Exit Time: 08:00 AM / 14:00 PM Major / Non-Major Facility: Non-Major Inspection Type: Compliance Evaluation Inspection NPDES ID: SDG589616 (EPA Region 8 Lagoon General Permit SDG589###) Program Sector(s): Publicly-Owned Treatment Works (POTW) NAICS Code: 221320 (Sewage Treatment Facilities) Inspection ID: 202209_SDG589616 Lead inspector and affiliation: Akash Johnson / U.S. EPA Region 8 Inspector and affiliation: Stephanie Meyers / U.S. EPA Region 8 Facility Location Information Site/Facility Name & Location: St. Francis Wastewater Treatment Facility St. Francis (Todd County), South Dakota 57572 West Lagoon: 43.148656, -100.909131 East Lagoon: 43.154742, -100.894499 Email Report to: Young Colombe Sewer Revenue Department Director Rosebud Sioux Tribe ycolombe@sicangu.com Contact Information Name(s)/Title Facility Contacts Young Colombe / Director / Sewer Revenue Department, Rosebud Sioux Tribe (present for opening conference only) James Begeman / Tribal Utility Consultant / Indian Health Service (present) Indian Health Service Erik Anderson / Senior Environmental Engineer / Indian Health Service Contacts (present for opening conference only) Chuck Mack / Environmental Health Officer / Indian Health Service (present) Tribal Government Contacts Ivan Crow Eagle / Environmental Director / Rosebud Sioux Tribe (not present) Person/Company meeting definition of "Owner" Rosebud Sioux Tribe Person/Company meeting definition of "Operator" Sewer Revenue Department, Rosebud Sioux Tribe Responsible Official(s) Young Colombe / Director / (present for opening conference only) Page 1 of 15 Permit / Facility Information Permit on site and available: Yes Permit Application Date: Received March 22, 2016 Effective Date: April 5, 2016 Expiration Date: December 31, 2020 (administratively continued at time of inspection) Latitude and Longitude: West Lagoon: 43.148656, -100.909131; East Lagoon: 43.154742, -100.894499 Receiving Water(s): Unnamed tributary to West Branch of Rosebud Creek via East Lagoon (according to 2016 Notice of Intent) Weather Conditions: Clear Inspector's source of information: Facility representatives and records, Indian Health Service representatives and records, EPA records and databases, and inspection observations 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 Page 2 of 15 Report Review and Signature Lead Inspector Name/Signature/Final Date Draft Date AKASH Digitally signed by AKASH JOHNSON JOHNSON 10:25:17 -07'00' Date: 2023.01.06 January 3, 2023 Akash Johnson, NPDES and Wetlands Enforcement Section Co-Inspector Name Review Date Contact Information U.S. EPA Region 8 Denver, Colorado johnson.akash@epa.gov (303) 312-6067 Contact Information Stephanie Meyers January 4, 2023 U.S. EPA Region 8 Denver, Colorado meyers.stephanie@epa.gov (303) 312-6938 Management Reviewer Name/Signature/Approval Date Contact Information MICHAEL BOEGLIN Digitally signed by MICHAEL BOEGLIN Date: 2023.01.06 10:10:13 -07'00' U.S. EPA Region 8 Denver, Colorado boeglin.michael@epa.gov (303) 312-6250 Michael Boeglin, NPDES and Wetlands Enforcement Section Supervisor Page 3 of 15 Inspection Narrative and Facility Description 1.0 Introduction On Tuesday, September 20, 2022, I, U.S. Environmental Protection Agency (EPA) inspector Akash Johnson, accompanied by EPA inspector Stephanie Meyers (collectively, "we"), conducted a compliance evaluation inspection of the St. Francis wastewater treatment facility (WWTF; facility), located in Todd County, South Dakota, on the Rosebud Reservation (Reservation). We were accompanied by Indian Health Service (IHS) representatives James Begeman and Chuck Mack for the entirety of the inspection, and IHS representative Erik Anderson and Rosebud Sioux Tribe Sewer Revenue Department representative Young Colombe for the opening conference portion of the inspection. The inspection was coordinated with the Sewer Revenue Department and Rosebud Sioux Tribe Environmental Protection Office several weeks in advance, and an inspection notification letter was sent to the Rosebud Sioux Tribe on August 30, 2022. The purpose of the inspection was to evaluate compliance with applicable National Pollutant Discharge Elimination System (NPDES) and Clean Water Act requirements. Throughout the inspection, we took notes on our discussions and observations in bound checklists. Photographs taken during the inspection are included in the attached photo log. 2.0 Background At the time of the inspection, the facility was authorized to discharge in accordance with the conditions of the 2016-2020 EPA Region 8 Lagoon General Permit SDG589### (Permit; 2016 LGP). The Permit expired on December 31, 2020, but Permit coverage for the facility was administratively continued by the EPA and remains in effect as of drafting this report. The facility was assigned facility-specific NPDES ID SDG589616 with semi-annual reporting requirements identified in Subcategory C in Part 3.2.1.2 of the 2016 LGP. As of drafting this report, the EPA has not received a Notice of Intent (NOI) from the Sewer Revenue Department requesting coverage for the facility under the 2022-2027 LGP (2022 LGP). Based on my review of EPA records, prior to the subject inspection, the most recent EPA NPDES inspection of the facility occurred on September 17, 2015 (Inspection ID: 201509_SDG58961). The Town of St. Francis historically claimed at least some ownership and operatorship responsibility over the facility, but, according to Young, following a legal action involving the facility, the Rosebud Sioux Tribe and Sewer Revenue Department took over full ownership and operatorship of the facility. We did not clarify the timing of this legal action during the inspection, but based on information in EPA records and databases, it appears to have concluded within approximately 10 years prior to the inspection. Records pertaining to the aforementioned activities are maintained in EPA files. Engineering records pertaining to the facility are primarily maintained by the IHS and the Sewer Revenue Department. 3.0 Inspection Narrative and Facility Description The inspection began when we arrived at the Rosebud Sioux Tribe Water Resources building at approximately 08:00 AM. We convened with Young, James, Erik, and Chuck in a conference room, presented our inspector credentials, and conducted an opening conference. During the opening conference, we asked questions pertaining to the design, operation, and CWA and NPDES compliance of multiple wastewater treatment facilities operated by the Sewer Revenue Department, including the subject facility. Page 4 of 15 Inspection Narrative and Facility Description At the time of the inspection, the Sewer Revenue Department maintained two full-time operators on staff, dedicated solely to wastewater operations across approximately fourteen communities served. Routine operator tasks and schedules, such as daily rounds, were not regularly documented, but nonroutine tasks, such as responding to backups, were assigned and tracked through an electronic work order management system. Young and IHS representatives indicated the tracking of non-routine tasks through the work order management system had helped identify recurring problems and areas where infrastructure improvements could be beneficial, which had resulted in some wastewater infrastructure improvement projects being completed through the IHS's Sanitary Deficiencies System (SDS). Sewer Revenue Department finances were briefly discussed during the opening conference, but no financial records were reviewed. Young stated the following: approximately 1,100 Tribal Housing Authority residences were served across the Reservation; the Housing Authority had historically paid the Sewer Revenue Department $15 per month per Housing Authority residence served; the arrangement had ceased several years prior to the inspection; a resolution had more recently been passed enabling the Sewer Revenue Department to resume charging the Housing Authority for services; no revenue had been collected since passing of the resolution. Commercial billing and other potential sources of revenue were not discussed at-length during the inspection. Young stated funding received through the Coronavirus Aid, Relief, and Economic Security (aka CARES) Act and American Rescue Plan Act (aka ARPA) was supporting some Sewer Revenue Department operations at the time of the inspection. Young managed both Rosebud Sioux Tribe Rural Water System, also known as Sicangu Mni Wiconi, and Sewer Revenue Department operations, and indicated Sewer Revenue Department finances and other resources, such as vehicles, personnel, etc., were managed separately from Rural Water System resources. Young estimated approximately 90% of his time was spent on water operations, with approximately 10% of his time spent on wastewater operations. According to information provided in the 2016 NOI, the facility served an estimated population of 709 and did not receive any non-domestic wastewater. Non-residential users were not discussed during the inspection, but after the inspection, I performed a cursory review of aerial imagery and business information accessible via Google Earth and identified potential commercial users including schools, churches, grocery and convenience stores, gas stations, and community centers in the general service area. According to information in the 2016 NOI, the facility also received septage from three septic haulers. The 2016 NOI did not provide figures for actual, estimated, or design flows for the facility. Young and IHS representatives indicated water usage, and subsequently, wastewater flows, in the service area may have been greater than typically seen in similar communities because water was provided free to many users through the Rural Water System. Additionally, the Tribal Housing Authority encouraged residents to keep water running during the winter to prevent pipes from freezing. The facility comprised two collection systems, one lift station (lat, long: 43.147014, -100.907624), and two two-cell lagoon systems. According to various records reviewed, the service area was divided into two collection systems approximately along the north-south running Main Street (Bureau of Indian Affairs Highway 1), with the western portion of St. Francis served by the West Collection System and the eastern portion of St. Francis served by the East Collection System. All wastewater from the West Collection System was conveyed via gravity flow to the lift station then pumped into the West Lagoon. During the opening conference, Young stated operators visited the lift station and cleaned the trash basket on a daily basis, and the wet well was not pumped dry and cleaned on any planned or routine basis. For the purposes of this report, the West Lagoon western cell is referred to as Cell 1 and the West Lagoon eastern cell is referred to as Cell 2. Cells 1 and 2 were to designed to allow configuration in series or parallel, although it was not clear how they were configured Page 5 of 15 Inspection Narrative and Facility Description during the inspection, discussed further in this section and in Finding 2. According to the 2016 NOI and several IHS records, effluent flowed out of the West Lagoon from the northeast corner of Cell 2 via subsurface piping, gravity-flowed northeast, under Main Street, joined a gravity sewer main conveying wastewater from the East Collection System, and, from this juncture, all wastewater from the West Collection System, via the West Lagoon, and East Collection System, was conveyed into the East Lagoon (see Figure 1, below). While the aforementioned connection between the West Lagoon and East Lagoon is reflected in facility design documents and the 2016 NOI, during the inspection, we were not able to locate any manholes, valves, or piping confirming the existence of such a connection, and, during my post-inspection records review, I was not able to locate any as-built drawings or other engineering records indicating this proposed connection was completed. For the purposes of this report, it is presumed this connection was constructed, and confirmation of its existence is requested via the corrective action pursuant to Finding 3. All wastewater from the East Collection System was conveyed by gravity into the East Lagoon. For the purposes of this report, the East Lagoon southern cell is referred to as Cell 3 and the East Lagoon northern cell is referred to as Cell 4. Cells 3 and 4 were operated in series, with wastewater entering Cell 3 and flowing into Cell 4. The outfall from Cell 4 was located on the northwest side of Cell 4. The facility was discharged from Cell 4 on an intermittent basis. A copy of a facility schematic provided with the 2016 NOI showing the presumed facility configuration is included as Figure 1, below. Page 6 of 15 Inspection Narrative and Facility Description Figure 1. Presumed facility configuration as shown in schematic provided with the 2016 NOI According to the 2016 NOI, Cells 1 and 2 had a hydraulic capacity of approximately 2.48 million gallons (MG) each, Cell 3 had a hydraulic capacity of 3.16 MG, and Cell 4 had a hydraulic capacity of 2.48 MG. According to facility design drawings reviewed after the inspection (IHS Project No. AB-94503, Sheets 2, 7, and 8 of 10, approved August 14, 1995 by the IHS), a two-valve level control structure was planned between Cell 3 and Cell 4 and a three-valve level control structure was planned at the outfall from Cell 4. During the opening conference, we discussed that, while no effluent flow measurement device was installed at the facility, average flow rates and total flow could be estimated for discharge events by performing calculations based on the dimensions of the lagoon, change in water level, and duration of discharge. Following the opening conference, remaining in the Water Resources Building, we observed copies of wastewater-related records, including the Permit, lift station operation and maintenance (O&M) manuals, and laboratory and field parameter measurement equipment. Young stated that, during Page 7 of 15 Inspection Narrative and Facility Description effluent monitoring activities, pH measurements were taken in the field and recorded on sample chainof-custody forms (COCs), and the analytical laboratory included the field pH measurements from the COCs on the corresponding final laboratory analytical reports. Young indicated no records of pH meter calibration were maintained. We observed several bottles of expired buffer solutions and informed Young that non-expired buffer solutions should be used to calibrate the pH meter during the next discharge monitoring event. We did not have time to review monitoring and reporting records during the inspection, so I informed Young that, after the inspection, I would review monitoring information accessible via EPA databases and request additional records via email, if needed. We then proceeded with the site review portion of the inspection. Young indicated neither he nor Sewer Revenue Department operators would be able to join for the field portion of the inspections, as they had other business to attend to, but that we could contact them if we had any questions throughout the day and request they meet us in the field, if needed. IHS representatives indicated they would be able to accompany us on the field portion of the inspection and could provide access to the requested facilities. We then left the Water Resources Building and visited another WWTF operated by the Sewer Revenue Department before arriving at the subject facility. We arrived at the subject facility at approximately 12:55 PM, beginning our facility observations at the lift station (Photographs 23-24). We then walked to the West Lagoon (Photographs 25, 26 and 28-33). Evidence of septage dumping was present in the southeast corner of Cell 2 (Photograph 25), the same cell from which wastewater presumably left the West Lagoon and flowed to the East Lagoon. We then identified what appeared to be an outfall pipe in the southern berm of Cell 2 (Photographs 26 and 28). Information on this potential outfall was not included in the 2016 NOI. No water was flowing through this pipe during the inspection, but were not able to visually ascertain any valves, plugs, or other mechanisms installed that could control flow from this potential outfall. The water level in the lagoon appeared to be below the elevation of the pipe outlet, but we did not measure these respective elevations or otherwise empirically confirm this. We were not able to visually ascertain the location of the inlet of this pipe on the interior of the berm. We then observed the splitter box between Cells 1 and 2 (Photographs 29 and 30). Inside the splitter box, the inlet to Cell 1 appeared to have been plugged (Photograph 30), so we were not able to determine whether wastewater was entering Cell 1 through the splitter box, through valves between Cells 1 and 2, or through another conveyance. We then observed Cells 1 and 2 from the berm dividing them (Photographs 31 and 32), then drove to the northeast corner of Cell 2 to try and identify any indication of the presence of the presumed connection between the West Lagoon and the East Lagoon. In the eastern berm of Cell 2, we observed some buried PVC pipe running parallel to the berm (Photograph 33), but were not able to identify any manholes, valves, or piping that confirmed the existence of the presumed connection between Cells 2 and 3. We then drove the East Lagoon, where we walked and drove a portion of the perimeters of Cells 3 and 4 and observed the outfall from Cell 4 (Photographs 34 and 35). The onsite portion of the inspection concluded when we left the East Lagoon at approximately 14:00 PM. 4.0 Post-Inspection Activities and Conclusion After the inspection, I reviewed facility engineering records accessed via the IHS Sanitation Tracking and Reporting System (STARS) database and various records and data in EPA files and databases. Monitoring records reviewed included Discharge Monitoring Reports (DMRs) submitted via the EPA's web-based NetDMR platform and accessed via the EPA's Compliance Information System and Central Data Exchange database on December 30, 2022. DMRs were reviewed for the four semi-annual Page 8 of 15 Inspection Narrative and Facility Description reporting periods prior to the inspection, spanning July 1, 2020 through June 30, 2022. No discharge was reported for these four consecutive monitoring periods, but several DMRs were submitted late, discussed further in Finding 5. Findings, requested corrective actions, and recommendations identified pursuant to this inspection are included in the section below. Page 9 of 15 Findings, Corrective Actions, and Recommendations Finding 1: We identified what appeared to be an outfall pipe in the southern berm of Cell 2 (Photographs 26 and 28). Information on this potential outfall was not included in the 2016 NOI. No water was flowing through this pipe during the inspection, but were not able to visually ascertain any valves, plugs, or other mechanisms installed that could control flow from this potential outfall. The water level in the lagoon appeared to be below the elevation of the pipe outlet, but we did not measure these respective elevations or otherwise empirically confirm this. We were not able to visually ascertain the location of the inlet of this pipe on the interior of the berm. Permit Requirements: The facility is only authorized to discharge in accordance with Permit conditions from Outfall 01 from Cell 4. Part 2.3 of the Permit (Contents of Notice of Intent) states: The Notice of Intent to be authorized to discharge under the provisions of this permit shall be submitted to the EPA and must include the following information... 2.3.10. For each discharge point from which the facility has either an existing or potential release of treated or untreated wastewater, assign an outfall number (e.g., 001, 002, 003, etc.,) and provide a brief description of the discharge point (e.g., 001, outlet from cell number 3; 002, overflow structure on cell no. 2; 003, bypass structure at headworks of lagoon system, etc.,). Include discharge points for intermittent or non-continuous overflows, bypasses or seasonal discharges. Include latitude and longitude to the nearest 15 seconds for each outfall. If outfall numbers have been assigned on a previous permit application for this facility, the same designation shall be used. 2.3.11. A map and/or diagram showing the location of the lagoon system, existing or potential discharge points, and the receiving waterway. Label discharge points by outfall number. All maps and diagrams are to be on 8 " by 11" paper. It is acceptable to use a photocopy of the appropriate part of a 7 minute USGS quadrangle map with the necessary information added as appropriate, or satellite or aerial internet images. 2.3.12. Provide the following plant design and treatment data... 2.3.12.2. A line drawing (flow diagram) of the current treatment system. Show all treatment units and existing or potential discharge points. Label the discharge points with outfall numbers... Part 6.7.3 of the Permit (Prohibition of Bypass) states: 6.7.3.1. Bypass is prohibited and the Director may take enforcement action against a permittee for a bypass, unless: 6.7.3.1.1. The bypass was unavoidable to prevent loss of life, personal injury, or severe property damage; 6.7.3.1.2. There were no feasible alternatives to the bypass, such as the use of auxiliary treatment facilities, retention of untreated wastes, or maintenance during normal periods of equipment downtime. Page 10 of 15 Findings, Corrective Actions, and Recommendations This condition is not satisfied if adequate back-up equipment should have been installed in the exercise of reasonable engineering judgment to prevent a bypass which occurred during normal periods of equipment downtime or preventive maintenance; and, 6.7.3.1.3. The permittee submitted notices as required under Part 6.7.2. 6.7.3.2. The Director may approve an anticipated bypass, after considering its adverse effects, if the Director determines that it will meet the three conditions listed above in Part 6.7.3.1. Corrective Action 1: Evaluate the potential for the subject pipe in the southern berm of Cell 2 to discharge wastewater from Cell 2 and take any actions necessary to prevent an unauthorized release of wastewater from this potential outfall. In a response, provide a description of the evaluation, findings, and any actions taken, and the date(s) of the evaluation and any responsive actions. Additionally, ensure all required information on facility outfalls is included in future NOIs for the facility. Finding 2: Inside the splitter box between Cells 1 and 2, the inlet to Cell 1 appeared to have been plugged (Photograph 30), so we were not able to determine whether wastewater was entering Cell 1 through the splitter box, through valves between Cells 1 and 2, or through another conveyance. Facility design records indicate Cells 1 and 2 were designed to allow configuration in series or parallel; however, if the inlet to Cell 1 is plugged and wastewater leaves the West Lagoon from Cell 2 via the presumed connection to Cell 3, neither series nor parallel operation of Cells 1 and 2 would be feasible, and potential short-circuiting of wastewater in Cell 2 could occur. Understanding where influent enters the West Lagoon could also inform planning of future sludge depth studies and removal. Permit Requirements: Part 6.5 of the Permit (Proper Operation and Maintenance) states: The permittee shall at all times properly operate and maintain all facilities and systems of treatment and control (and related appurtenances) which are installed or used by the permittee to achieve compliance with the conditions of this permit. Proper operation and maintenance also includes adequate laboratory controls and appropriate quality assurance procedures. This provision requires the operation of back-up or auxiliary facilities or similar systems which are installed by a permittee only when the operation is necessary to achieve compliance with the conditions of the permit. However, the permittee shall operate, at a minimum, one complete set of each main line unit treatment process whether or not this process is needed to achieve permit effluent compliance. Corrective Action 2: Properly operate and maintain the facility with respect to the splitter box between Cells 1 and 2. Evaluate whether the inlet to Cell 1 in the splitter box is plugged, determine the optimal configuration for operation of Cells 1 and 2 based on appropriate engineering and operational guidance, and Page 11 of 15 Findings, Corrective Actions, and Recommendations implement the desired configuration of Cells 1 and 2. In a response, provide a description of how this corrective action was implemented and provide the dates of any requisite actions taken. Finding 3: A connection between the West Lagoon and East Lagoon is reflected in facility design documents and the 2016 NOI; however, during the inspection, we were not able to locate any manholes, valves, or piping confirming the existence of such a connection, and, during my post-inspection records review, I was not able to locate any as-built drawings or other engineering records indicating this proposed connection was completed. Permit Requirements: Part 2.3 of the Permit (Contents of Notice of Intent) states: The Notice of Intent to be authorized to discharge under the provisions of this permit shall be submitted to the EPA and must include the following information... 2.3.12. Provide the following plant design and treatment data... 2.3.12.2. A line drawing (flow diagram) of the current treatment system. Show all treatment units and existing or potential discharge points. Label the discharge points with outfall numbers... Part 6.5 of the Permit (Proper Operation and Maintenance) states: The permittee shall at all times properly operate and maintain all facilities and systems of treatment and control (and related appurtenances) which are installed or used by the permittee to achieve compliance with the conditions of this permit. Proper operation and maintenance also includes adequate laboratory controls and appropriate quality assurance procedures. This provision requires the operation of back-up or auxiliary facilities or similar systems which are installed by a permittee only when the operation is necessary to achieve compliance with the conditions of the permit. However, the permittee shall operate, at a minimum, one complete set of each main line unit treatment process whether or not this process is needed to achieve permit effluent compliance. Corrective Action 3: In a response, provide confirmation of the presumed connection between the West Lagoon and East Lagoon as indicated in facility design drawings and the 2016 NOI. This confirmation can be provided through photographs, as-built drawings, or other engineering and construction records. Finding 4: Weekly inspections were not conducted and recorded in accordance with the Permit. Permit Requirements: Part 3.3 of the Permit (Authorization to Discharge; Inspection Requirements) states: Page 12 of 15 Findings, Corrective Actions, and Recommendations 3.3.1. On at least a weekly basis, unless otherwise modified by written approval from the EPA, the permittee shall inspect its wastewater treatment facility. The permittee shall maintain a notebook recording all information obtained during the inspection. At a minimum, the notebook shall include the following: 3.3.1.1. Name of facility and permit number; 3.3.1.2. Date and time of the inspection; 3.3.1.3. Name of the inspector(s); 3.3.1.4. The facility's discharge status; 3.3.1.5. The flow rate of the discharge if occurring; 3.3.1.6. If a discharge is occurring, has occurred since the previous inspection, and/or if a discharge is likely to occur before the next inspection. (Note: If a discharge has occurred or is likely to occur before the next inspection, perform the appropriate monitoring and reporting requirements in Parts 3.2 and 5.4 of this permit if not already done.); 3.3.1.7. Is there is any leakage through the dikes; 3.3.1.8. Are there are any animal burrows in the dike; 3.3.1.9. Is there any erosion of the dikes (e.g., rills, cracks or other structural indications of erosion); 3.3.1.10. Are there are any rooted plants, including weeds growing in the water; 3.3.1.11. Does the vegetation growth on the dikes needs mowing (e.g. greater than 6" tall); 3.3.1.12. List the date scheduled for operation and maintenance procedures to be undertaken at the wastewater treatment facility. 3.3.1.13. Identification of operational problems and/or maintenance problems; 3.3.1.14. Recommendations, as appropriate, to remedy identified problems; 3.3.1.15. A brief description of any actions taken with regard to problems identified; and, 3.3.1.16. Other information, as appropriate. The permittee shall maintain the notebook in accordance with required record-keeping items listed above and shall make the log available for inspection, upon request, by authorized representatives of the U.S. Environmental Protection Agency or the applicable Tribe (see Part 5.10 of this permit). 3.3.3. Problems identified during the inspection shall be listed with corrective action and a time frame to correct the issue. Example: repair cracks in North berm, remove animal and repair burrow, within 7 days. (See Part 6.5 of this permit.) Corrective Action 4: Conduct and record weekly inspections in accordance with Part 3.3 of the Permit (or similar requirements of the 2022 LGP, if 2022 LGP coverage is issued to the facility prior to completion of this corrective action). In a response, provide a copy of at least two consecutive weekly inspection records containing all the information required by the requisite NPDES permit. Finding 5: DMRs for the four semi-annual monitoring periods evaluated (spanning July 1, 2020 through June 30, 2022) were submitted late. DMRs are due 28 days after the conclusion of the subject reporting period. For the reporting period ending December 31, 2020, the DMR was submitted on February 4, 2021, 7 days late; for the reporting period ending June 30, 2021, the DMR was submitted on August 9, 2021, 12 days late; for the reporting Page 13 of 15 Findings, Corrective Actions, and Recommendations period ending December 31, 2021, the DMR was submitted on February 8, 2022, 11 days late; and for the reporting period ending June 30, 2022, the DMR was submitted on August 8, 2022, 11 days late. Permit Requirements: Part 5.4.2 of the Permit (Reporting of Effluent Monitoring Results for Calendar Quarter or SemiAnnual Period Discharge Facilities) states: Effluent monitoring results obtained during the previous calendar quarter or semi-annual period shall be summarized and reported on a Discharge Monitoring Report (DMR) Form (EPA No. 3320-1), postmarked no later than the 28th day of the month following the completed reporting period. If no discharge occurs during the reporting period, "no discharge" shall be reported, see example below. Legible copies of these, and all other reports required herein, shall be signed and certified in accordance with the Signatory Requirements (see Part 7.7), and submitted to the Planning and Targeting Program and the applicable Tribe at the addresses given in Part 5.4.4 below. Corrective Action 5: Ensure all DMRs are submitted within 28 days following the end of the corresponding reporting period. In a response, provide an explanation of how the Sewer Revenue Department will ensure future DMRs are submitted within required timeframes. Finding 6: No records of pH meter calibration were maintained. Permit Requirements: Part 5.7 of the Permit (Retention of Records) states: The permittee shall retain records of all monitoring information, including all calibration and maintenance records and all original strip chart recordings for continuous monitoring instrumentation, copies of all reports required by this permit, and records of all data used to complete the application for this permit, inspection records, notifications to the EPA per this permit, and DMRs, for a period of at least five years from the date of the sample, measurement, report, application or submittal. Records of monitoring required by this permit related to sludge use and disposal activities must be kept at least five years (or longer as required by 40 C.F.R. Part 503). This period may be extended by request of the Director at any time. Data collected on site, data used to prepare the DMR, copies of DMRs, a copy of this NPDES permit, and the notice of intent for permit coverage, must be maintained on site. Corrective Action 6: Ensure the pH meter used to conduct field measurements is calibrated in accordance with manufacturer recommendations and records of calibration and field measurements are generated and maintained in Page 14 of 15 Findings, Corrective Actions, and Recommendations accordance with Part 5.7 of the Permit (or similar requirements of the 2022 LGP, if 2022 LGP coverage is issued to the facility prior to completion of this corrective action). In a response, provide a description of how this corrective action has been completed or will be completed prior to the next field measurement event. Finding 6: Evidence of septage dumping was present in the southeast corner of Cell 2 (Photograph 25), the same cell from which wastewater presumably left the West Lagoon and flowed to the East Lagoon. Septage generally contains higher concentrations of pollutants than domestic wastewater. The proximity of the septage dumping location in Cell 2 to the presumed outlet to Cell 3 (as opposed to dumping septage in Cell 1, further from the presumed outlet to Cell 3) increases the potential for reduced hydraulic retention and treatment of septage in the West Lagoon, potentially reducing the overall treatment efficacy of the facility. EPA Guidance: The EPA's March 2022 Compliance Advisory: Compliance Tips for Small Wastewater Treatment Lagoons with Clean Water Act Discharge Permits (https://www.epa.gov/system/files/documents/202203/lagoon-complianceadvisory.pdf), states: Retention or detention time is a key design parameter for both facultative and aerated lagoons. If the designed retention time is reduced, treatment effectiveness is reduced. One cause of lost retention time is short circuiting. Short circuiting occurs when wastewater passes through a lagoon system too quickly without adequate treatment. Dead spots in the flow pattern of material through a lagoon system, improper placement of influent and effluent points, and lack of mixing can cause short circuiting. Water layer stratification due to differences in temperature, particularly in cold weather, can cause influent short circuiting. Reduced retention time of wastewater in the system can result in high BOD and effluent violations. Recommendation: Evaluate the location of septic dumping in the West Lagoon as it relates to treatment efficacy of the facility. No response is requested pursuant to this recommendation. Page 15 of 15