Washing cars in your driveway can add pollutants to streams and rivers. Wash water flows from hard surfaces into storm drains, carrying detergents, oil, grease, heavy metals and dirt. Storm drains carry polluted wash water to local waterways. Sloppy car maintenance is also a problem for Washtenaw County’s water resources. For example, four quarts of motor oil can cause an eight acre oil slick on lakes and rivers. In addition, antifreeze is poisonous to people, pets, and wildlife.