City Council to Consider Iowa DNR Administrative Consent Order

Aug. 15, 2025

The Dubuque City Council will consider approval of an agreement between the City and the Iowa Department of Natural Resources (IDNR) related to self-reported violations from 2020-2024 at the City of Dubuque Water and Resource Recovery Center (WRRC). A proposed administrative consent order is on the city council’s Aug. 18 meeting agenda.

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. The City is seeking compensation for damages related to this contractor error.

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 dedicated to its sanitary sewer collection system. Through the first seven months of 2025, the WRRC has had only seven effluent 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.

“We have been actively working to reduce and minimize violations through operational improvements, added staffing, and long-term planning,” said WRRC Director Deron Muehring. “We have 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. Muehring said 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.

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