True. Storm water is created by precipitation and runoff from land, pavements, building rooftops and other surfaces. Some of the water does seep into the ground and some of it enters the storm sewer system. The storm sewer system is a way for the water to get to ponds, other storm sewer pipes, and also into our local bodies of water, including the Mississippi River.

However, on the way to the water bodies, storm water runoff accumulates pollutants such as oil and grease, pesticides, sediment, litter, chemicals, nutrients, metals, and bacteria as it travels across land. Heavy precipitation or snowmelt also can cause sewer overflows which may lead to contamination of other water sources. Pollution prevention is a major reason why we want to manage our storm water.

The U.S. Environmental Protection Agency controls storm water and sewer overflow discharges through its National Pollutant Discharge Elimination System (NPDES). NPDES created guidelines for municipalities and other agencies for minimizing or reducing storm water pollution; the permit is administered by individual states. The Minnesota Pollution Control Agency (MPCA) issued permits to the City of Cottage Grove and other units of government which allows them to discharge storm water to waters of the state, after meeting certain requirements.