The Dubuque City Council on Monday approved by unanimous vote an administrative consent order from the Iowa Department of Natural Resources that follows self‑reported wastewater permit violations at the Water and Resource Recovery Center between 2020 and 2024.

Water and Resource Recovery Center Director Darren Mearing told the council the city self‑reported a total of 72 permit violations over that five‑year span. Many of the exceedances stemmed from two principal causes: biological instability linked to filamentous bacteria beginning in 2022 and a contractor error in 2023 that left the facility boiler inoperable for several weeks, reducing digester performance. A December 2024 explosion of third‑party equipment also damaged systems and contributed to additional violations.

Mearing said the city and plant staff have addressed the root causes. He described steps taken and planned: enhanced monitoring; targeted biological controls to stabilize filamentous bacteria populations; the addition of a plant manager and an industrial pretreatment coordinator to improve oversight; forthcoming digester cleaning planned for 2026; a $7.3 million hauled‑waste receiving and storage project in design; and a $3 million electrical controls replacement to reduce equipment‑failure risk.

The proposed consent order acknowledged the incidents and assessed a total administrative penalty of $7,000, a figure Mearing said the DNR could have set higher. The order, citing Iowa administrative penalty authority and Iowa Code provisions, brings closure to the self‑reported incidents and sets a baseline for continued compliance and follow‑up.

Council members pressed staff on odor control and near‑term impacts. Mearing said staff had used temporary storage and chemical dosing to avoid discharging higher solids during disruptions, actions that sometimes increased local odor; he noted the city is dosing primary clarifiers and experimenting with ferric dosing to reduce odors and struvite formation. Council members asked for ongoing communication to neighbors when planned maintenance or digester work could affect odors.

Mayor Cavanagh and council members praised plant staff and reiterated that city investment in infrastructure and staffing in recent years is intended to reduce future violations. City staff noted the council has committed roughly $134 million in sewer collection and treatment improvements through 2030, including Old Mill Road lift‑station work and other upgrades.

The council approved the consent order by roll call. Staff said they would continue facility planning and capital investments and report progress to the council and the DNR.