Runoff from rainstorms and snowmelt is the most significant source of water pollution today. Reducing water pollution from runoff can best be addressed by observing a number of "best practices" at home, in the yard, and in the garage.
Vehicle & Garage
Take your car to a car wash; don't wash it in the driveway
Check your car, motorcycle, and equipment for leaks
Recycle your motor oil
Lawn & Garden
Use fertilizers and pesticides properly and sparingly