Storm drain stenciling is a community-based, environmental stewardship activity that helps people understand where storm water travels after a rain and what it carries with it. Volunteers working with extension staff and local departments of public works paint messages alongside storm drains that tell passers-by where the water in that storm drain is going. Runoff carries everything it can pick up from our roofs, lawns, driveways, streets, parking lots, farms, construction sites and commercial areas. It brings it to the nearest body of water, more often by way of the storm drain system.
Many people mistakenly believe storm drain systems deliver runoff to treatment plants.
Most storm drains merely serve as collectors and conduits of storm water from streets into the nearest water body. Water contaminants that result from our daily activities and come from many different sources are collectively called nonpoint source pollution. Nonpoint source pollution is now considered by the Environmental Protection Agency to be the largest source of pollution in the United States. As rainwater falls in our neighborhoods and flows downhill, it picks up nonpoint source pollutants like automotive fluids, pet waste and excess fertilizer, and carries them into local streams, rivers, ponds, lakes, estuaries and oceans. UNH Cooperative Extension Water Resource Specialists in New Hampshire and in many other states around the country coordinate storm drain stenciling projects.