Township hears MS4 stormwater update; presentation cites 319 monitored outfalls and possible infiltration testing

At a regular Summit Township board meeting, the township’s MS4 public input session outlined current stormwater monitoring and possible retrofit steps for Walnut Creek.

Presenter Junior Jonas described the township’s current permit status and monitoring work. "We have 319 MS4 outfalls that we monitor," Jonas said, adding that 67 outfalls were monitored in the 2023–24 cycle and 34 of those resulted in dry‑weather closures. He said the township currently operates under prior permit conditions while a new MS4 permit was under review as of January 2025.

Jonas said the municipality tracks roughly 130 private best‑management practices (BMPs), 112 of which are in the MS core area, and that about 22 BMP inspections are due or overdue this year. "We've actually kinda seen a downtick on dry weather close because it's been so dry the past couple years," he said.

On retrofit options for Walnut Creek, Jonas said the township has discussed infiltration wells (test drilling) and, if subsurface conditions are unsuitable, an extended dry detention basin to slow runoff. "We’re gonna once we get approval, we'll do some test drilling to see what's there," he said, adding that work cannot proceed until the township gets the okay from DEP.

Jonas also reminded residents to report illicit discharges: "If anyone does see illicit discharges, you can call the township, email the township, or use the township's website." He listed typical problems to report — paint, chemicals, grease, excessive sediment and garbage in storm drains — and described naturally occurring iron oxide and bacterial sheens that can resemble oil but are not illicit discharges.

The presentation closed with a brief discussion of public‑private facilities the township monitors and next steps that depend on regulatory approval. The board did not take a formal vote on MS4 actions during the meeting.