Properly dispose of hazardous household items. Oils, anti-freeze, paint, solvents, cleaners, preservatives, and prescription drugs should not be poured down a household or storm drain. Check with your county waste management service to find out what hazardous materials they accept.
Reduce or eliminate use of fertilizers and chemical herbicides and pesticides. Learn to live with a dandelion or two. Lawn fertilizers and chemicals are a big source of nitrogen and phosphorus pollution and toxic runoff.