Back to Water Quality
Stormwater, either discharging from the end of a pipe or entering a body of water after flowing over the land, is a key threat to water quality. Stormwater may carry a variety of substances as it makes its way to the water: grit, oils and litter from city streets and parking lots; waste from domestic and wild animals; nutrients such as phosphorous from lawns, gardens and farms; yard waste; and sediment and bacteria. All of these substances can harm water quality.
For example, nutrients in stormwater runoff contributes to the growth of algae in the Great Lakes that often turns into a smelly muck on beaches and harm recreation.
Development around the Great Lakes results in additional pollution that runs off into the Great Lakes. The polluted runoff generally contains high levels of oil and grease, sediment, salt, heavy metals and bacteria. Local officials can help to significantly reduce stormwater runoff by working with communities to ensure that new development is managed properly.