Rapides Parish, LA Environmental Rules: Stormwater Management (2026)

Unincorporated Rapides Parish runs its own municipal separate storm sewer system (MS4), and Sec. 24-6 flatly bars discharging anything into it that isn't storm water. The parish carves out sixteen narrow categories as an affirmative defense under Sec. 24-6(b): NPDES-permitted discharges, firefighting water, agricultural runoff, water-line flushing (short of chlorinated disinfection water), lawn and landscape irrigation, diverted springs, uncontaminated groundwater, foundation-drain water, clean air-conditioning condensate, potable water not contaminated by tank cleaning, individual residential car washing, riparian or wetland flows, clean street-washing water, and uncontaminated roof runoff.

None of those defenses survive if the parish's storm water committee determines the discharge is a pollutant source, gives written notice, and the discharger keeps discharging more than ten days later, per Sec. 24-6(c). Sec. 24-7 then bans specific dumping outright regardless of any defense: used motor oil and other vehicle fluids, industrial and hazardous waste, domestic sewage and septic or grease-trap waste, commercial vehicle and carwash wastewater, aircraft washdown water, commercial carpet-cleaning wastewater, animal-pen runoff, contaminated fire-protection water, and any connection of a sanitary sewer line to the MS4.

Sec. 24-8 separately forbids discharging used oil into the MS4, mixing it with landfill-bound solid waste, or spreading it on roads for dust or weed control. Sec. 24-9 lets pool and spa owners discharge low-chlorine backwash and drain water to the MS4 only if it meets numeric limits (chlorine under 1 mg/l, total suspended solids under 45 mg/l, pH 7 to 8) and doesn't cross a neighbor's property or pond in a gutter. The director of public works enforces the chapter with notices of noncompliance, cease-and-desist orders, and the escalating fine schedule in Sec. 24-25.