Porter County, IN Environmental Rules: Stormwater Management (2026)

" Agricultural, timber harvesting and mining runoff is exempt unless it carries pollutants beyond standard practice, though farm residences and structures are carved back out of that exemption. Discharges already permitted under a federal NPDES permit, waiver or order are also exempt if the discharger stays in full compliance. Subsection (b) puts enforcement in the hands of the county executive director/county planner or the MS4 coordinator, who can require dischargers to install best-management-practice pollution prevention measures. Subsection (g) gives the executive director, MS4 coordinator or a designee authority to periodically inspect the county-controlled storm drainage system, screen outfalls for prohibited flows, and, once an illicit discharge is suspected, enter the discharger's property at any hour necessary to inspect and sample, placing testing equipment on site if needed; identified illicit connections bypass the standard 72-hour warning and go straight to enforcement under state law limits.

Section 20-42(b) sets the general enforcement standard for the chapter: a first violation at a location gets a written warning, and if it isn't abated within 72 hours the violator is fined $250 per day, with each day of continuing violation treated as a separate offense, plus outstanding fines can block future permits and approvals.