What is a storm drain?
Storm drains are the openings you see along curbs and in streets and parking lots. They carry rainwater and snowmelt and transport it through the system to nearby lakes and streams. Water and other debris that enter storm drains do not go to a treatment facility.

What is a sanitary sewer?
A sanitary sewer takes household water and waste from toilets, sinks and showers, and transports it to a wastewater treatment facility. There, the water is treated and then discharged back to a lake or stream.

Household -wastewater

Household Street surface
Wastewater enters runoff enters the underground
the Sanitary System storm drain system

What is stormwater?
Stormwater is the rainfall or snowmelt that flows over our yards, streets, parking lots, and buildings and either enters the storm drain system or runs directly into a river or stream.

How does stormwater get polluted?
As stormwater flows over our lawns and driveways, it picks up fertilizers, oil, chemicals, grass clippings, litter, pet waste, and anything else in its path. The storm drain system then transports these pollutants, now in the water, to local lakes and streams. Anything that goes into a storm drain eventually ends up in a river or stream.