Rainwater and snowmelt carried through the Municipal Separate Storm Sewer System (MS4) discharges directly to streams and rivers, meaning anything entering a storm sewer will not be removed at a wastewater treatment plant. This pollution can harm local water quality, fish and wildlife, drinking water intakes, and recreation.

Any unauthorized discharge from the MS4 that is not composed entirely of stormwater is considered an illicit discharge and is prohibited. Follow these tips to prevent illicit discharges:

• Never dump vehicle fluids, grass clippings, leaves, household chemicals, paint, animal waste, car washing soaps, litter, or fats, oils, and greases into storm drains.
• Do not connect sanitary, restaurant waste, or industrial wastewater lines to the storm sewer system.
• Only the following uncontaminated water sources are permitted to enter a storm sewer: water used for firefighting, fire hydrant, and water line flushing; lawn watering; groundwater; and HVAC condensate.

If you discover an illicit discharge, please report it to 412-255-2423 (Press 1).