Rainwater picks up chemicals, metals, and other toxic substances when it runs off our roofs, streets, and lawns. In a process called atmospheric deposition, mercury and nitrogen from auto and power plant emissions eventually settle on land and get washed into creeks and streams. There, it’s joined by corrosive dust from vehicle brakes, oil from leaking automobiles, and whatever pesticides, fertilizers, and household chemicals people poured onto the ground or into a storm drain.
Store chemicals away from rainwater and dispose of them properly. Maintain vehicles so they don’t leak. Wash your car at a car wash or on grass or gravel so water can sink in, instead of running off into storm drains, which do not treat water before releasing it to streams. Apply lawn chemicals in the correct dosages. These simple steps prevent many chemicals from entering our waterways.