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Iowa Department of Natural Resources Proposed Administrative Consent OrderCity of Dubuque City Council ACTION ITEMS # 11. Copyrighted August 18, 2025 ITEM TITLE: Iowa Department of Natural Resources Proposed Administrative Consent Order SUMMARY: City Manager recommending City Council approve the proposed Administrative Consent Order received from the Iowa Department of Natural Resources (IDNR) that pertains to effluent permit violations between January 1, 2020, and December 31, 2024 at the Water & Resource Recovery Center (WRRC). SUGGUESTED Receive and File; Approve DISPOSITION: ATTACHMENTS: 1. MVM Memo 2. Staff Memo 3. Dubuque ACO Proposed Final 4. Presentation_Uploaded 8.18.25 Page 540 of 579 Dubuque THE C D!Uj-!B AII-America City 11111, II Masterpiece PP iece on the Mississippi 2°°17*2.2°13 zozoi9 TO: The Honorable Mayor and City Council Members FROM: Michael C. Van Milligen, City Manager SUBJECT: Iowa Department of Natural Resources Proposed Administrative Consent Order DATE: August 13, 2025 Water & Resource Recovery Center Director Deron Muehring is providing information related to the recommended Administrative Consent Order received from the Iowa Department of Natural Resources (IDNR) that pertains to self -reported effluent permit violations between January 1, 2020, and December 31, 2024, at the Water & Resource Recovery Center (WRRC). The WRRC is the City's wastewater treatment facility which holds a National Pollutant Discharge Elimination System (NPDES) permit from the IDNR which authorizes the discharge of treated wastewater into the Mississippi River. The permit requires the City to meet more than 2,000 individual permit conditions at the WRRC each year, including sampling, monitoring, and discharge limits to ensure the water returned to the environment is safe and meets requirements. A total of 72 permit violations were self -reported over the five-year period, with the majority occurring in 2023 and 2024 during periods of facility disruption. The violations stem from two main causes, both of which have been addressed: • Biological instability in the treatment process beginning in 2022. This condition has been stabilized for more than a year through enhanced monitoring, targeted treatment, and modified process controls. • A contractor error in Fall 2023 rendered the facility's boiler inoperable for several weeks. This led to loss of digester performance and resulted in 33 violations. An explosion at the facility in December 2024 related to third -party equipment, not City infrastructure, damaged systems and contributed to additional permit violations. The contractor error in 2023 and third -party equipment malfunction in 2024 caused or contributed to 40 permit violations. The IDNR's proposed administrative consent order and limited levy of $7,000 in total administrative penalties acknowledges the challenges and opportunities the WRRC's system has faced since 2023, as well as the ongoing work and funding the City has Page 541 of 579 dedicated to its sanitary sewer collection system. Through the first half of 2025, the WRRC has had only seven permit violations, all tied to a single day when sampling levels were elevated, which was directly related to the December 2024 explosion —not ongoing process issues. The city has been actively working to reduce and minimize violations through operational improvements, added staffing, and long-term planning. The city also started early work on a developing a facility plan update for the WRRC to guide the next 20-30 years of treatment capacity, reliability, and odor control. Within the last two years, the City has added a plant manager and industrial pretreatment coordinator to the WRRC's staff to improve systems oversight and control over what enters the facility. Both roles have helped identify and manage issues that caused permit issues. Additional investments to improve operations at the WRRC are planned. A $7.3 million project to improve hauled high -strength waste is budgeted and under design and will be ready for bidding in 2025. These improvements will be funded through fees charged to the hauled waste generators/customers. Federal funding sources are being pursued to help reduce costs to these local businesses. Also, later this summer, the City will go out for bid on the first phase of a $3 million project to replace electrical controls at the WRRC to replace existing infrastructure and prevent system failures. The City has committed over $134 million in sanitary sewer collection and treatment system improvements through FY2030. This includes the $43.4 million phases one and two of the Old Mill Road Lift Station and Force Main Project that is already under construction. These targeted investments in the sanitary sewer collection system will reduce backups, eliminate bypasses, and support future growth. Improvements include upgrades to lift stations, force mains, and key segments of the citywide gravity sewer network. Overall, the WRRC has generally operated in conformity with its NPDES permit, and the permit violations that have occurred were primarily the result of specific, identifiable events rather than systemic deficiencies. The City has responded to these incidents by addressing root causes and has also taken proactive steps to prevent future violations — both by mitigating the risk of unusual disruptions and by strengthening systems to guard against broader, systemic issues. The consent Decree says, "Iowa Code section 45513.109 authorizes the Commission to establish by rule a schedule of administrative penalties up to $10,000 that may be assessed administratively." The Consent Decree further says, "Iowa Code section 455B.191 provides for penalties of up to $5,000 per day for wastewater violations." 2 Page 542 of 579 While the Iowa Department of Natural Resources had the authority to assess higher penalties the Consent Decree reads, "City shall pay an administrative penalty of $7,000 within 30 days of the effective date of this Order." I respectfully recommend Mayor and City Council approval of the Administrative Consent Decree. Mic ael C. Van Milligen MCVM:sv Attachment cc: Crenna Brumwell, City Attorney Cori Burbach, Assistant City Manager Deron Muehring, Water & Resource Recovery Center Director Jason Lehman, Assistant City Attorney Willie O'Brien, WRRC Plant Manager 3 Page 543 of 579 THE CITY OF Dubuque DUB E AII.America City ' Masterpiece on the Mississippi rP pp zoo�•o 13 zoi7*20*zol9 TO: Michael Van Milligen, City Manager FROM: Deron Muehring, Water & Resource Recovery Center Director SUBJECT: Iowa Department of Natural Resources Proposed Administrative Consent Order DATE: July 17, 2025 INTRODUCTION The purpose of this memo is to provide information related to the proposed Administrative Consent Order received from the Iowa Department of Natural Resources (IDNR) that pertains to effluent permit violations between January 1, 2020, and December 31, 2024 at the Water & Resource Recovery Center (WRRC). The memo provides context for the violations and a summary of the City's actions to improve operations and ensure ongoing compliance. BACKGROUND The WRRC is the City's regional wastewater treatment facility, operating under National Pollutant Discharge Elimination System (NPDES) Permit #3126001 issued by the IDNR. The WRRC receives a mix of domestic and industrial wastewater conveyed through the City's sanitary sewer collection system, as well as high -strength waste delivered by truck from local businesses. The facility treats this material using a combination of physical, biological, and chemical processes that must perform reliably to consistently meet the effluent limits established in the permit. Effluent is the treated water that flows out of the wastewater treatment facility and is discharged to the environment. The WRRC discharges to the Mississippi. Since 2020, the City has self -reported 72 effluent permit violations through routine Discharge Monitoring Reports (DMRs) submitted to the IDNR, in accordance with the reporting requirements of the NPDES permit. In Fiscal Year 2023, the City Council approved the addition of two new full-time positions. The first was originally approved as an Assistant Water & Resource Recovery Center Manager; however, the department was subsequently reorganized to establish the WRRC Director (Department Manager) position and a new Plant Manager role. The Plant Manager, responsible for overseeing day-to-day treatment system performance, was filled in November 2023. The second position, Industrial Pretreatment Coordinator, was filled in December 2023. This role is responsible for monitoring and managing waste contributions from industrial users to ensure, as required by the U.S Environmental Page 544 of 579 Protection Agency (EPA) and the IDNR, that they do not interfere with the City's ability to collect and treat wastewater in compliance with its NPDES permit. In 2023, the City retained a contractor to assist with a scheduled inspection of the boiler responsible for maintaining temperatures in the anaerobic digesters. Inspection activities began in October 2023. Following the inspection, the contractor failed to properly reconnect the wiring. As a result, the boiler remained inoperable until mid -November, until WRRC staff were able to diagnose the issue and ultimately identified the miswiring as the cause of the failure. And even though the boiler was eventually restored to service in November of 2023, the prolonged outage caused the digesters to lose temperature and sour, significantly reducing their ability to process solids until the spring of 2024. The City was forced to limit waste feed to the digesters, resulting in solids accumulation throughout the system and elevated sludge blankets in the final clarifiers. On December 4, 2024, an explosion occurred at the WRRC, causing an estimated $3.5 million in damage. The incident was not caused by City -owned infrastructure or result from the actions of City personnel. It was caused by equipment owned, operated, and maintained by a private company to further clean the methane gas produced at the WRRC for use as Renewable Natural Gas (RNG). The explosion disrupted electrical service to key solids handling systems, including sludge thickening, digestion, and dewatering, requiring a ten-day suspension of normal operations while power was safely restored. Over a million gallons of solids accumulated in the system during this period, contributing to operational challenges and subsequent effluent violations in April of 2025. With the adoption of the Fiscal Year 2025 Capital Improvement Program (CIP) budget, the City Council allocated funding to support an update to the WRRC Facility Management Plan. This comprehensive planning effort will evaluate treatment processes, solids handling, energy use, and system capacity to help prioritize future capital investments and operational improvements. Following adoption of FY25 Budget Amendment No. 1, a total of $465,000 has been allocated for the effort. As part of the Fiscal Year 2025 (FY25) budget process, the City Council approved an improvement package to support the long-term functionality and reliability of the Water & Resource Recovery Center's solids handling system. Beginning in FY25 and continuing into FY26 and beyond, the City has committed $75,000 annually to implement a rotating cleaning schedule for the facility's four anaerobic digesters. This proactive measure allows the WRRC to clean one digester each year, reducing the risk of buildup and system inefficiencies while maintaining stable biological performance and preserving overall treatment capacity. On May 14, 2025, the City received a proposed Administrative Consent Order from the Iowa Department of Natural Resources (IDNR). The proposed order reflected self - reported NPDES effluent permit violations and IDNR-issued Notices of Violation (NOVs) for the 5-year period starting on January 1, 2020 and running through December 31, 2024. IDNR ACo 2 Page 545 of 579 DISCUSSION The Water & Resource Recovery Center (WRRC) plays a critical role in protecting public health, supporting economic activity, and safeguarding the environment in Dubuque and the surrounding tri-state area. In addition to treating sanitary wastewater from homes and businesses, the WRRC provides a regional service by accepting trucked high -strength waste (HSW), such as grease from restaurants and septage from private systems. These are materials that would otherwise burden the sewer system or require specialized disposal at private facilities. As outlined in the WRRC mission statement, we are committed to protecting the environment and public health through reliable, cost-effective treatment of wastewater and resource recovery. We take seriously our role as the final line of defense before pollutants reach the Mississippi River and work every day to maintain the high level of treatment required by our National Pollutant Discharge Elimination System (NPDES) permit. While permit violations are tracked and reported to the IDNR, it is important to understand that not every violation necessarily results in environmental harm. For example, when setting effluent limits for ammonia in the WRRC's NPDES permit, the IDNR's water quality modeling showed that the Mississippi River could assimilate ammonia concentrations up to 105 mg/L in July without adverse impact. However, the WRRC's permit limit is set at 52 mg/L—well below the modeled environmental threshold. This approach adds a safety factor to ensure water quality is protected but also means that not every exceedance of a permit limit represents a direct risk to the river or the ecosystem. And one root cause of a permit violation, such as the buildup of solids in the treatment system, can lead to multiple violations across different parameters. For example, elevated solids can increase Total Suspended Solids (TSS) effluent, which in turn contributes to higher Carbonaceous Biochemical Oxygen Demand (CBODS), and diminished ultraviolet (UV) light penetration needed for E. coli disinfection. These interrelated effects are typical in wastewater operations, where a single disruption may result in a cluster of related permit violations. Between January 1, 2020 and December 31, 2024, the WRRC self -reported 72 NPDES permit violations through routine Discharge Monitoring Reports. To fully understand the significance of this number, it is important to consider the operational complexity of the WRRC and the nature of its permit. The WRRC collects hundreds of samples per year across multiple permit parameters. Each parameter includes multiple reporting metrics (e.g., daily maximum, weekly average, 30-day average), and each exceedance of any one metric counts as a separate violation. In addition, many parameters are reported in both concentration (mg/L) and total mass (pounds), meaning a single underlying issue — such as elevated solids in the system —can result in multiple separate violations for the same pollutant. These violations were not evenly distributed over the five-year period but were concentrated primarily in the years 2022 through 2024, reflecting specific operational challenges during that timeframe. The distribution is shown in Table 1 below. IDNR ACo 3 Page 546 of 579 Table 1. Breakdown of Effluent Permit violations at the WRRC by year Calendar Year Number of Effluent Violations 2020 2 2021 7 2022 15 2023 28 2024 20 TOTAL 72 As shown in the table above, the bulk of the WRRC's effluent permit violations occurred between 2022 and 2024. These were not the result of ongoing systemic issues but stemmed from isolated disruptions such as the emergence of filamentous bacteria and a temporary boiler failure that are discussed in more detail below. Each of these incidents presented unique operational challenges that resulted in clusters of permit violations during those specific years. One significant contributor to permit violations during 2022 and 2023 was the emergence of filamentous bacteria in the secondary treatment process. While filamentous organisms are always present in activated sludge systems, changes in pollutant loading and environmental conditions can cause them to proliferate and outcompete beneficial bacteria. This impairs settling in the final clarifiers and increases turbidity, leading to higher TSS and CBODS, as well as reduced UV disinfection effectiveness. The WRRC had not previously experienced a filamentous overgrowth of this magnitude, and staff had to quickly identify the bacterial species and determine an effective response. The team conducted side -by -side testing of treatment basins, settled sludge samples, and UV transmittance readings. Working with a wastewater microbiology lab, the WRRC confirmed the species and began applying sodium hypochlorite (bleach) to the Return Activated Sludge (RAS) line to suppress filamentous growth. Chlorination dosing was carefully adjusted to avoid harming beneficial microbes. A third aeration basin was also brought online to increase retention time, allowing healthier biological populations to rebound. These efforts were ultimately successful and continue today as part of ongoing process control. A second major disruption occurred starting in late October 2023, when the WRRC retained a contractor to assist with a proactive boiler inspection. The boiler is responsible for maintaining temperature in the anaerobic digesters, which is critical for solids stabilization. The contractor was tasked with disassembling the unit for inspection by a state -certified boiler inspector and restoring it to service afterward. However, the contractor failed to properly reconnect critical wiring during reassembly, rendering the boiler inoperable until mid -November. Without heat, the digesters lost temperature and "soured," severely impairing their biological treatment capacity. The City had to stop feeding waste into the digesters, leading to solids accumulation throughout the treatment system and elevated sludge blankets in the final clarifiers. The digesters did not fully recover until spring 2024. This event directly contributed to several permit violations related to solids and CBODS. IDNR ACo 4 Page 547 of 579 Overall, the WRRC has generally operated in conformity with its NPDES permit, and the permit violations that have occurred were primarily the result of specific, identifiable events rather than systemic deficiencies. The City has responded to these incidents by addressing root causes and has also taken proactive steps to prevent future violations — both by mitigating the risk of unusual disruptions and by strengthening systems to guard against broader, systemic issues. Recognizing the need for tighter control of treatment operations and upstream waste inputs, the City Council approved the addition of two new full-time positions in Fiscal Year 2023. First, the department was reorganized to create the WRRC Director position and a dedicated Plant Manager role. The Plant Manager, hired in November 2023, is responsible for daily oversight of treatment system performance and serves as the facility's lead process expert. The Plant Manager plays a proactive role —more akin to a physician monitoring a patient —by tracking biological health metrics across the system. By evaluating data like sludge volume index, mixed liquor suspended solids, UV transmittance, and ammonia removal rates, the Plant Manager can detect subtle deviations in system performance and respond quickly before they escalate into violations. Second, an Industrial Pretreatment Coordinator was hired in December 2023 to strengthen regulatory oversight of waste contributions from industrial users. This includes both discharges to the collection system and high -strength hauled waste. They are responsible for evaluating sampling data, tracking pollutant loadings, and enforcing pretreatment requirements to prevent interference with WRRC processes. These two roles are already producing measurable benefits in terms of permit violations, and their impact is expected to grow as the programs mature. The City is preparing to implement a Computerized Maintenance Management System (CMMS). The WRRC relies on hundreds of interdependent assets —pumps, valves, blowers, chemical feed systems, and treatment process controls —that must work in concert to treat wastewater effectively. A CMMS will allow staff to schedule and track preventive maintenance, monitor equipment condition over time, and generate work orders for inspections, lubrication, calibration, and parts replacement. By proactively addressing mechanical and operational issues before they escalate, the CMMS will improve reliability and reduce the likelihood of equipment -related permit violations. It will also support data -driven asset management, optimize maintenance staff time, and enable more strategic capital planning. To enhance the reliability and effectiveness of the WRRC's solids handling processes, the City is implementing a strategy to clean each of the facility's four anaerobic digesters on a rotating basis. This program, funded through an annual $75,000 improvement package beginning in FY25, allows for one digester to be cleaned each year. Routine cleaning is critical to removing accumulated inorganic materials —such as grit, debris, and other non -biodegradable substances —that impair digestion efficiency and reduce available treatment capacity. By maintaining optimal digester functionality, the WRRC can better manage incoming solids and prevent system overloads that could otherwise lead to elevated sludge blankets in the final clarifiers. Such conditions are known to cause IDNR ACO 5 Page 548 of 579 violations of effluent permit limits for total suspended solids (TSS), carbonaceous biochemical oxygen demand (CBOD), and, indirectly, reduced UV disinfection performance. Although funding was allocated for this work in FY25, it was postponed due to the December 2024 explosion and the extended recovery efforts that followed. This targeted investment remains a priority and supports the City's broader effort to minimize permit violations by ensuring stable and effective operation of the WRRC's biological treatment system. The City is also in the process of updating its Facility Plan for the WRRC. This plan, developed in close coordination with regulatory agencies and engineering consultants, serves as a comprehensive roadmap for future improvements to the treatment facility. It evaluates current performance, regulatory trends, equipment condition, future loading projections, and operational risks to prioritize investments over the next 20 years. The updated Facility Plan will allow the City to strategically phase improvements to maximize cost-effectiveness, support permit compliance, reduce the possibility of odors, and extend the useful life of existing infrastructure. It also ensures that the WRRC remains well - positioned to adapt to new regulatory requirements, emerging contaminants, and the changing needs of the community. The City is undertaking a series of significant infrastructure improvements at the WRRC to address operational challenges, reduce the risk of permit violations, and improve the long-term reliability of the treatment system. Several of these improvements are either in the design phase or already funded, representing a substantial investment in the future of the facility and the broader utility system. First among these efforts is the $7.3 million High -Strength Waste (HSW) Receiving and Storage Improvements Project. The WRRC receives and treats high -strength hauled waste from industrial, commercial, and residential sources, including food processors, restaurants, and septic haulers. These materials often have high organic loads and, if not carefully managed, can upset treatment performance and contribute to violations. The planned improvements include a new receiving station, enclosed storage tanks, enhanced metering, and odor control systems. These upgrades will provide greater control over the volume and characteristics of HSW introduced to the plant, allowing for more consistent and predictable digestion performance. Another is a $3 million investment in modernizing the WRRC's electrical control systems. Many of the facility's electrical components —especially motor control centers, programmable logic controllers (PLCs), and supervisory control and data acquisition (SCADA) systems —are at the end of their useful life or no longer supported by manufacturers. The new control system will improve real-time monitoring, increase automation, and allow for faster operator response to emerging issues, all of which are critical for maintaining compliance with effluent discharge standards. These in -plant improvements are paralleled by investments in the City's sanitary sewer collection system. Over the next five years, the City will invest approximately $130 million in collection system improvements designed to reduce inflow and infiltration, eliminate capacity constraints, and prevent bypasses and basement backups. The initial investment is the $43.4 million Old Mill Road Lift Station and Force Main Project, which is currently IDNR ACo 6 Page 549 of 579 under construction. This project will relieve pressure on the downstream Catfish Creek Lift Station and interceptor, which currently serves a large portion of the City's south and westerly growth areas. The planned improvements to the conveyance infrastructure will improve capacity and address wet -weather vulnerabilities that can lead to bypasses and overflows. By proactively investing in the reliability and resiliency of the collection system, the City aims to reduce the frequency of peak flow events that strain the treatment plant and can contribute to effluent permit violations. Together, these efforts reflect the City's forward -looking strategy to improve treatment reliability, enhance system resiliency, and protect water quality for years to come. Whether focused on managing high -strength waste, modernizing electrical controls, implementing preventive maintenance, or expanding collection system capacity, these efforts directly support the overarching goal of minimizing effluent permit violations. While the Administrative Consent Order (ACO) acknowledges past challenges, the actions described above demonstrate that the City is already taking meaningful steps to address the root causes of permit violations. These investments position the WRRC and the City to meet both current and future regulatory obligations while continuing to protect public health and the Mississippi River. The proposed ACO reflects five years of self -reported permit violations and includes a one-time administrative penalty. However, aside from the financial penalty, the ACO does not require the City to take any actions beyond what is already mandated in its existing NPDES permit and the City's ongoing Consent Decree obligations with the U.S. Department of Justice. Under Iowa law, the DNR may assess penalties of up to $5,000 per day, per violation. The ACO acknowledges that many of Dubuque's violations resulted from exceptional incidents beyond the City's control —such as the contractor -caused boiler outage or the December 2024 explosion. The ACO represents an opportunity to bring closure to the past five years and recognizes the City's efforts to minimize effluent permit violations going forward. So far in 2025, the WRRC has recorded seven effluent permit violations, all from a single day in April when staff attempted to process the excess solids that had accumulated following the explosion. Excluding this one -day occurrence, the WRRC has not had any effluent limit violations in 2025. ACTION REQUESTED This memo is intended to provide information relating to the proposed Administrative Consent Order with the Iowa Department of Natural Resources. CC: Crenna Brumwell, City Attorney Jason Lehman, Assistant City Attorney Willie O'Brien, WRRC Plant Manager IDNR ACO 7 Page 550 of 579 IOWA DEPARTMENT OF NATURAL RESOURCES ADMINISTRATIVE CONSENT ORDER IN THE MATTER OF: The City of Dubuque, Iowa NPDES permit no. 3126001 To: City of Dubuque c/o Crenna Brumwell 50 W 13th St. Dubuque, IA 52001 ADMINISTRATIVE CONSENT ORDER No. 2025-WW- Re: Failure to comply with terms of NPDES permit and Stormwater permit. 1. SUMMARY This Administrative Consent Order is entered into between the Iowa Department of Natural Resources (DNR) and the City of Dubuque, Iowa to resolve violations of Iowa wastewater law. The City of Dubuque shall take the corrective actions listed below and pay an administrative penalty of $7,000. Relating to technical requirements: Michele Smith, Env. Specialist Sr. DNR Field Office no. 1 11o1 Commercial Court, Ste 1o, Manchester, IA 52057 Phone: (563) 927-264o ext. 3o8 Payment of penalty to: Director of the Iowa DNR 6200 Park Ave., Ste. 200 Des Moines, Iowa 50321 Relating to legal requirements: Bradley Adams Attorney for the DNR 6200 Park Ave., Ste. 200 Des Moines, IA 50321 Phone: (515) 664-8894 Page 551 of 579 IOWA DEPARTMENT OF NATURAL RESOURCES ADMINISTRATIVE CONSENT ORDER ISSUED TO: THE CITY OF DUBUQUE, IOWA 2. JURISDICTION This Order is issued pursuant to Iowa Code section 455B. 175(1), which authorizes the Director to issue any order necessary to secure compliance with or prevent a violation of Iowa Code chapter 455B, Division III, Part 1 and the rules adopted or permits issued pursuant thereto; and Iowa Code section 455B• log and 567 Iowa Administrative Code (IAC) chapter 1o, which authorize the Director to assess administrative penalties. 3. STATEMENT OF FACTS The City of Dubuque (the City) is the oldest city in the state of Iowa, chartered in 1837 situated overlooking the Mississippi River. Its topography is that of bluffs stretching down to flats at the river. 2. The City owns and operates an activated sludge plant with UV disinfection (the facility), which treats wastewater from local industries, residents, commercial businesses, and similar waste products from surrounding areas in Dubuque County. The facility accepts and treats hauled high -strength waste (HSW) from local industries, providing a vital service to the region by treating the waste though a publicly regulated system. 3. Each month the City submits a Discharge Monitoring Report (DMR) to the Iowa Department of Natural Resources (DNR) Field Office 1 (F01), which documents all monitoring results, including any violations of effluent limits. 4. The City's NPDES permit identifies multiple bypass outfalls at six specific lift stations. These are engineered to prevent damage to the lift stations when the wet well floods resulting from excessive flows to the lift stations or a mechanical failure. The inclusion of the bypass outfalls in the permit reflects regulatory acknowledgment of their existence and function. 5. On November 1, 2019, the DNR issued the City National Pollutant Discharge Elimination System (NPDES) permit no. 3126001, which included effluent limitations for E. Coli, Ammonia, TSS, and CBOD5.1 6. On October 14, 2022, DNR Field Office 1(FO 1) Environmental Specialist Sr. Amber Sauser performed a routine compliance inspection at the facility. 7. That same day, FO 1 issued a Notice of Violation (NOV) to the City for treatment system bypasses, deficiencies related to the sludge management plan, deficiencies in biosolids annual reporting, and deficiencies in toxicity sampling. The NOV listed a number of corrective actions and set a response deadline for each action listed by November 15, 2022. Page 552 of 579 IOWA DEPARTMENT OF NATURAL RESOURCES ADMINISTRATIVE CONSENT ORDER ISSUED TO: THE CITY OF DUBUQUE, IOWA 8. On November 1, 2022, DNR issued the City amended NPDES permit no. 3126001. The permit was amended to remove the Nutrient Reduction Requirements page and to replace it with an updated Nutrient Reduction Requirements page that would require a new feasibility study in five years. 9. On January 18, 2023, the City approved the creation of an Industrial Pretreatment Coordinator. The position was filled in December, 2023. 10. On February 2, 2023, FO 1 issued an NOV to the City for a failure to meet its TSS and CBOD5 effluent limitations for the violations reported in August, September, October, November, and December of 2022. 11. On March 24, 2023, the City approved funding to create an Assistant Water & Resource Recovery Center Manager. The position, retitled as Water & Resource Recovery Center Plant Manager, was filled in November of 2023. 12. On April 21, 2023, FO 1 issued the City an NOV for a failure to meet its TSS limitations for the violation reported in February of 2023. 13. In the fall of 2023, the City retained a contractor to perform a scheduled inspection of the boiler system, which maintains the temperature in the facility's anaerobic digesters. Inspection activities began on October 23, 2023. 14. Following October 23, 2023 inspection, the contractor failed to properly reconnect critical wiring, rendering the boiler inoperable until November lo, 2023, causing unintentional and temporary noncompliance with technology - based effluent limits. The City posits that this incident was beyond its reasonable control, and was not the result of operational mistakes, poor facility design, inadequate maintenance, or careless operation. 15. As a result of the inoperable boiler, the digesters lost temperature and soured, significantly reducing their treatment capacity. The City was required to limit the feeding of waste to the digesters, leading to solids accumulating in the system and elevated sludge blankets in the final clarifiers. These conditions contributed, either wholly or in part, to 33 effluent permit violations beginning in late October 2023. Recovery of digester performance took several months, with normal operation restored in June of 2024. 16. On February 1, 2024, FO 1 issued an NOV to the City for a failure to meet its TSS and CBOD5 effluent limitations. 17. On February 27, 2024, DNR approved the renewal of the City's coverage under NPDES General Permit no. 1 (GP 1). Among other items, GP 1 requires the implementation of a stormwater pollution prevention plan (SWPPP). Page 553 of 579 IOWA DEPARTMENT OF NATURAL RESOURCES ADMINISTRATIVE CONSENT ORDER ISSUED TO: THE CITY OF DUBUQUE, IOWA 18. On April 30, 2024, FO 1 issued an NOV to the City for failure to meet its TSS and CBOD5 effluent limitations for the violations reported in January, February, and March of 2024. 19. On November 5, 2024, FO 1 issued an NOV to the City for failure to meet its TSS, E. Coli, Ammonia, and CBOD5 effluent limitations for the violations reported in April, May, July, and September of 2024. 20. On November 19, 2024, DNR FO 1 Environmental Specialist Sr. Michele Smith performed a stormwater and wastewater inspection at the facility. 21. On December 4, 2024, an explosion occurred at the WRRC causing an estimated $3.5 million in damage. The incident was not caused by city -owned infrastructure or the actions of city personnel. 22. The result of the explosion was an exceptional incident that caused unintentional and temporary noncompliance with technology -based effluent limits due to factors beyond the reasonable control of the City. Post explosion, the electrical service to the solids handling system was disrupted, including systems supporting sludge thickening, digestions, and dewatering. This forced the City to suspend normal solids processing operations for ten days while power was safely restored. During this time, solids accumulated in the treatment process, contributing to operational challenges and subsequent effluent violations. The noncompliance with permit effluent limitations was not the result of operational mistakes, poor facility design, inadequate maintenance, or careless operation by the City. As of the effective date of this order, the City is in the process of restoring the facility to pre -explosion conditions in cooperation with investigators and inspectors, both public and private. 23. On December 4, 2024, FO 1 issued an NOV to the City for not having a valid SWPPP and not retaining records in accordance with the terms of GP 1. 24. On December 13, 2024, FO 1 issued an NOV to the City for failure to meet its E. Coli, TSS, and Ammonia effluent limitations for the violations reported in October of 2022, and; February, July, August, and November of 2023. 25. On January 5, 2025, the City hired a qualified consultant to assist in updating the SWPPP. The updated SWPPP was scheduled for completion by March 31, 2025, in accordance with the terms of the agreement. 26. On January 16, 2025, FO 1 issued an NOV to the City for failure to meet its E. Coli effluent limitations for the violations reported in November of 2024. 27. On March 26, 2025, the City submitted the completed and signed SWPPP to F01 wherein the City committed to implementation of the SWPPP provisions and compliance with applicable requirements of GP1, including staff training and performing routine inspections. Page 554 of 579 IOWA DEPARTMENT OF NATURAL RESOURCES ADMINISTRATIVE CONSENT ORDER ISSUED TO: THE CITY OF DUBUQUE, IOWA 28. The City has performed the following acts to provide its wastewater treatment system and staff the resources needed to achieve compliance following the events outlined above: a. From FY 2023 to 2025, the City has increased rates by nine percent, six percent, and nine percent respectively. The rate increases account for the costs associated with new positions, programs, operating, and capital improvement expenditures. b. During FY 2026 to 2030, the City has budgeted $92,378,623 in funding dedicated to sanitary sewer extensions and system improvements. Including carryovers from prior years, the City has committed $134,2o6,288 toward sanitary sewer system improvements. c. Since 2022, the City has committed $40,530,5o8.82 to the repair and/or replacement of collection system components. 4. CONCLUSIONS OF LAW 29. Iowa Code section 455B.186 prohibits the discharge of pollutants into waters of the state, except for adequately treated pollutants discharged pursuant to a permit. 30. Iowa Code section 455B.173(3) authorizes and requires the Environmental Protection Commission (Commission) to promulgate rules relating to the operation of waste disposal systems, the discharge of pollutants into waters of the state, and the issuance of permits to waste disposal systems. The Commission has done so at 567 IAC 6o through 69. 31. 567 IAC 64.3(1) states that "no person shall operate any wastewater disposal system... contrary to any condition of an operation permit issued by the director." 32. 567 IAC 64.6 specifies the conditions that are to be included in a permit, including applicable effluent limitations as established in Chapters 61 and 62 of the rules. 33• 567 IAC 64.7(4)(e) states that "if a permittee fails ... to comply with an interim or final requirement in an NPDES permit such noncompliance shall constitute a violation of the permit for which the director may ... suspend or revoke the permit or take direct enforcement action." 34• 567 IAC 63.6(1) states that "bypasses from any portion of a treatment facility or from a sanitary sewer collection system designed to carry only sewage are prohibited." 35• Part III(C) of NPDES GP 1 requires facilities under its coverage to prepare and implement a stormwater pollution prevention plan. Page 555 of 579 IOWA DEPARTMENT OF NATURAL RESOURCES ADMINISTRATIVE CONSENT ORDER ISSUED TO: THE CITY OF DUBUQUE, IOWA The above -stated facts establish violations of these provisions. 5. ORDER Therefore, the DNR orders, and the City agrees to the following: The City shall comply with all NPDES permit effluent limits. 2. The City shall continue to comply with the terms of its existing Consent Decree between the City and the U.S. Environmental Protection Agency (EPA) related to the elimination of sanitary sewer overflows (SSOs) and bypasses, including all requirements for system evaluation, rehabilitation, and reporting intended to address deficiencies in the collection system. The City provides semi-annual reports to the EPA on the progress related to the Consent Decree. The Iowa DNR shall be added as recipients on the semi-annual reporting. The semi-annual reports shall be provided to the following individuals, on behalf of the Iowa DNR: Michelle Smith, Environmental Specialist Senior michelle.smith@dnr.iowa.gov Bradley Adams, Attorney 2 bradley.adams@dnr.iowa.gov If the City becomes aware that these individuals are unable to receive the aforementioned semi-annual report on behalf of the DNR, then the City shall submit the semi-annual report to an appropriate DNR representative. 3. The City shall pay an administrative penalty of $7,000 within 3o days of the effective date of this Order. 6. ADMINISTRATIVE PENALTY 1. Iowa Code section 455B.log authorizes the Commission to establish by rule a schedule of administrative penalties up to $1o,000 that may be assessed administratively. The Commission has adopted this schedule with procedures authorizing the Director to assess administrative penalties at 567 IAC 1o. 2. Iowa Code section 455B.191 provides for penalties of up to $5,000 per day for wastewater violations. 3• 567 IAC 10 establishes the criteria that the DNR must consider in determining whether an administrative penalty is warranted, and if so, how much the penalty should be. The general categories for consideration are the economic benefit of the alleged non-compliance by the violator, the gravity of the alleged violation, and the culpability of the violator. Pursuant to this chapter, the DNR has determined that the most effective and efficient means of addressing the above cited violations is the issuance of an administrative consent order with an Page 556 of 579 IOWA DEPARTMENT OF NATURAL RESOURCES ADMINISTRATIVE CONSENT ORDER ISSUED TO: THE CITY OF DUBUQUE, IOWA administrative penalty of $7,000.00. The administrative penalty assessed by this Order is determined as follows: a. Economic Benefit: 567 IAC chapter 10 requires that the DNR consider the costs saved or that were likely to be saved by noncompliance. 567 IAC 10.30(1) states that "where a violator realizes an economic benefit through the violation or by not taking timely compliance or corrective measures, the department shall take enforcement action which includes penalties to offset the economic benefit." 567 IAC 10.30(1) further states, "reasonable estimates of economic benefit should be made where clear data are not available." Dubuque has struggled with managing high strength hauled waste for many years, which has resulted in the periodic overloading of the facility's anerobic digester system. Overloading the digesters with high strength organic waste has been linked to the propagation of filamentous bacteria that negatively impacts the overall activated sludge treatment process, causing effluent violations. The City has identified high strength waste receiving and storage as an operational priority. Upgrades to this portion of the facility are currently in the design phase. However, this project should have been completed several years ago, thereby delaying the costs associated with this capital investment. As such, $2,000 is assessed for this factor. b. Gravity of the Violations: Elements to consider when determining the gravity of a violation include the actual or threatened harm to the environment or public health and safety, and whether the violation threatens the integrity of the regulatory program. The City exceeded its permit's effluent limits approximately 72 times dating back to January of 2020, including two consecutive quarters of significant non- compliance for TSS in 2022/2023 and two consecutive quarters of significant non-compliance for TSS and CBOD5 in 2023/2024. Failure to comply with NPDES effluent limits degrades water quality in Iowa's surface waters. This harms aquatic life, prevents the attainment of water quality goals, and limits the Department's ability to deliver its mission for the citizens of Iowa. Furthermore, noncompliance with an NPDES permit thwarts the integrity of the state's water quality program. The facility's collection system also experienced repeated bypasses and basement backups, resulting in the release of untreated wastewater to the environment and within residential homes. As such, $4,000 is assessed for this factor. c. Culpability: The factors to be considered in determining the culpability of the violator include the degree of intent or negligence of the violator, whether the case involves false reporting of required information and whether the violator has taken remedial measures to address the harm caused by the violations. Page 557 of 579 IOWA DEPARTMENT OF NATURAL RESOURCES ADMINISTRATIVE CONSENT ORDER ISSUED TO: THE CITY OF DUBUQUE, IOWA Dubuque owns and operates a major wastewater treatment plant. This highly regulated activity obligates the City to be aware of the applicable regulations and to comply with those regulations. The Department has repeatedly communicated the need for the City to comply with its NPDES permit. Even so, over 70 unauthorized discharges have occurred. As such, $1,000 is assessed for this factor. 7. APPEAL RIGHTS As this Order is entered by consent of the parties, there is no right of appeal. 8. NONCOMPLIANCE WITH THIS ORDER Failure to comply with any requirement of this Order may result in the imposition of further administrative penalties or referral to the Iowa Attorney General to obtain injunctive relief and/or civil penalties. Kayla Lyon, Director Iowa Department of Natural Resources 2025. Bra(!-Cava,4ast0veayor Month Day Iowa DNR Administrative Consent Order — Context & Path Forward — City of Dubuque — Water & Resource Recovery Center August 18, 2025 -: go be I., " a6ki;ii- 'AMe A ,.;sit ii��li II II`�y�� � What is the WRRC? �p 4 • Regional wastewater treatment for Dubuque & surrounding communities • Handles domestic, industrial, and hauled high -strength waste • Discharges to Mississippi River under strict NPDES permit • Over 2,000 individual permit conditions checked each year Why Are We Here Today? • May 2025: IDNR issued proposed Administrative Consent Order • Covers 72 self -reported effluent permit violations (Jan 2020 — Dec 2024) • Goal: Provide context, explain causes, and share solutions How Effluent Permit Violations Are Counted... Effluent is the water discharged from the facility following treatment • Each effluent parameter has multiple metrics (e.g., mg/L, lbs/day, 24-hour max, 7-day avg, monthly avg, etc.) • One incident can trigger multiple effluent permit violations for the same pollutant The Numbers in Context • 72 effluent permit violations - 1% of ^'7,000 compliance checks over 5 year period • Most in 2022-2024 during specific operational disruptions • Not related to systemic operational failure How They're All Connected • Elevated solids � higher TSS • Higher TSS -> higher CBOD5 • Higher TSS 4 reduced UV penetration 4 E. coli exceedance • One root cause = multiple effluent permit violations Timeline of Events • 2020-2021: 9 effluent permit violations — isolated issues • 2022: Filamentous bacteria emergence • Nov 2023: Boiler outage — contractor wiring error • Dec 2024: Explosion from third -party RNG equipment Filamentous Bacteria (2022-2023) • Present in all wastewater systems; normally thrive in low - strength waste • In Dubuque's case, waste strength was high, causing rapid filamentous growth • All microbes break down waste, but filamentous types: • - Do not settle out well in clarifiers •-Morelikelytopassintofinaleffluent • Result: Elevated solids -> TSS, CBOD5i and E. coli effluent permit violations • Controlled through species identification, targeted chlorination, and process adjustments 2023 Boiler Outage • Proactively scheduled state- and insurance -required boiler inspection • Contractor failed to reconnect wiring after inspection • Boiler offline N3 weeks -> digesters lost temperature and "soured" • Reduced solids processing -> solids accumulated in system • Led to TSS, CBOD5, and E. coli effluent permit violations • Cause: Third -party contractor error — City pursuing damages December 2024 Explosion • Caused by third -party Renewable Natural Gas (RNG) equipment • Not related to City -owned systems or staff actions • Explosion damaged solids handling systems and disrupted power • 10-day outage -> >1M gallons solids accumulated • Recovery extended into April 2025, causing seven (7) effluent permit violations 2025 Example — One Day, Multiple Effluent Violations • First 8 months of 2025: 7 effluent permit violations, all from one day in April • Cause: Processing stored solids from Dec 2024 explosion recovery • One day caused daily, weekly, and monthly exceedances — (1) Total Suspended Solids 7-day concentration exceedance — (2) Total Suspended Solids 7-day total pounds exceedance — (3) Total Suspended Solids monthly concentration exceedance — (4) CBOD 7-day concentration exceedance — (5) CBOD 7-day total pounds exceedance — (6) CBOD monthly concentration exceedance — (7) CBOD monthly total pounds exceedance Effluent Violations do not Mean Environmental Harm • Some effluent limits are set far below environmental thresholds for safety • Not every exceedance means actual harm to river • Many effluent permit violations tied to the same operational issue During the 2020-2024 Period the City has: • Added Plant Manager for daily process oversight • Added Industrial Pretreatment Coordinator for upstream control • Implemented filamentous control program • Funded proactive digester cleaning plan Major Capital Investments Underway • $7.3M High -Strength Waste Receiving &Storage (design) • $3M Electrical Controls Modernization (bidding soon) • $43M Old Mill Road Lift Station &Force Main (under construction) • $134M committed through FY2030 2025 Performance to Date • Only seven (7) effluent permit violations so far in 2025 — all from one day in April • No other effluent limit exceedances What the ACO Means • One-time penalty, no new requirements beyond current permit • Acknowledges most effluent permit violations caused by exceptional incidents • Brings closure to the past 5 years Looking Ahead • Facility Plan Update for 20-30 year outlook • Continued investment in people, systems, and infrastructure • Goal: Reliable compliance, resiliency, environmental protection Closing Message • Effluent permit violations were isolated and addressed • Changes and improvements over the past five years are already making a difference. • We are always looking for ways to improve what we do at the WRRC. 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