The purpose of the storm drain system is to protect against flooding and water damage by quickly removing rainwater from our streets. The storm sewer system is completely separate from the sanitary sewer system, which is designed to capture and treat wastewater from sinks, toilets and other sources.  Unlike the sanitary sewer system, discharges from the storm sewer system gets no treatment and may ultimately drain into washes, lakes, retention basins, community parks, and can even make its way into the Salt and Gila rivers.

Stormwater contamination occurs when chemicals, debris, and waste enter the storm sewer system. These materials can enter into the system through:

• the illegal dumping of products or waste into the storm sewer system and/or curb and gutter system
• the over application of pesticides, herbicides and fertilizers
• leaking fluids from motor vehicles

Once these hazardous materials enter the storm sewer system they drain to our rivers where they can:

• harm fish and wildlife
• promote weed growth
• create stagnant pools that breed disease carrying pests
• inhibit the natural beauty and safety of our outdoor recreation areas