Platteville presents 2025 stormwater report; initial brine use data inconclusive

City staff presented the required 2025 municipal separate storm sewer system (MS4) report at the March 10 Platteville City Council meeting and outlined a new element of the report: documenting winter brine usage on city roads.

Howard said the MS4 report — required to be submitted prior to March 31 each year — is similar to prior years but now includes brine application as part of the pollution-prevention program. Staff told the council that brine can reduce the amount of solid salt applied because it “activates” salt so it sticks to the roadway and reduces bounce-off; Howard said it may take multiple winters to measure real savings.

Dan, representing Delta 3 Engineering, described the consultant’s outfall inspections and said field crews document outfall conditions and obstructions and escalate to testing only when they observe an unusual discharge. “If we notice anything that’s unusual, then we would go through and do testing,” Dan said. Staff emphasized public-education components of the MS4 program and noted post-construction site inspections remain a primary ongoing concern to prevent construction-related sediment and pollution.

The report was presented for information only; no action was required of the council at this meeting.