Moscow council adopts updated stormwater code, enforcement policies and BMP manual

Mayor Art Butky and the Moscow City Council on May 19 approved an ordinance replacing the city's stormwater regulations and adopting new enforcement and technical standards designed to meet the requirements of the city's MS4 (municipal separate storm sewer system) permit issued by the U.S. Environmental Protection Agency.

Ty Thompson, a city stormwater staff member, told the council the packet was “dense, it’s deep,” and walked council through key changes: consolidation of scattered code into one chapter (Title 5, Chapter 15), adoption of a new BMP handbook to replace a 27‑year‑old manual, explicit illicit discharge detection and elimination (IDDE) rules, and written enforcement response policies (ERPs) required by the MS4 permit. Thompson said the updates formalize existing operations created after the city launched a stormwater utility in 2021 and added an environmental compliance inspector in 2022.

The ordinance sets technical standards for post‑construction controls and for construction site runoff. Thompson said retention is required where feasible; where infiltration is not possible the city will require detention sized to meet a 0.82‑inch, 24‑hour standard and an equivalent pollutant‑removal treatment. For large construction projects (those disturbing one or more acres or part of a common plan of development) developers must obtain Idaho Construction General Permit (CGP) coverage and prepare a stormwater pollution prevention plan (SWPPP). Thompson also described erosion and sediment control plan thresholds and said the BMP handbook will provide a prescriptive, step‑by‑step guide for designers and contractors, citing the Idaho BMP catalog and the Stormwater Manual for Eastern Washington as references.

The ERPs establish an escalating compliance approach: verbal education and documented instructions, written warnings with compliance schedules, notices of violation, and, where appropriate, stop‑work orders, infractions and misdemeanor citations. Thompson said continued violations can be assessed per day and that responses may consider documented corrective actions the responsible party has taken. He described the city’s inspection program, including closed‑circuit TV inspections and routine construction site inspections, and said routine operations have removed volumes of material that “would fill up council chambers nearly four times.”

Council members asked for clarifications about accidental spills and operator negligence. Diane (last name not specified), a councilmember, asked whether unintentional spills would trigger penalties; Thompson said the ERP framework allows calibration of response to intent, severity and environmental harm. Fire Chief Brian Nickerson described emergency response procedures for hazardous spills and said the city is able to recover cleanup costs from responsible parties.

The council voted to approve Ordinance No. 2025‑O6 under suspension. The roll call recorded four recorded ayes: Bryce (last name not specified), Gina (last name not specified), Sandra (last name not specified) and Julia (last name not specified). A subsequent resolution adopting the ordinance attachments and related documents was also approved by the same vote.

Why it matters: The ordinance consolidates scattered stormwater provisions, clarifies developer requirements, and sets enforceable inspection and penalty paths the city must maintain to comply with the federal MS4 permit. That compliance underpins permit conditions that affect development approvals, construction costs and local waterway protections.

Council documents and the new BMP handbook provide prescriptive standards designers and contractors must follow; the city emphasized compliance assistance and education as the first step in enforcement.

The council approved the ordinance and resolution without amendment; staff said the new code will guide permit compliance and field work going forward, and city inspectors will continue outreach and education with developers and contractors.