Cooperative Extension Fresno County
University of California
Cooperative Extension Fresno County

Storm Drain vs. Sewer System

Storm drains are frequently located in streets, usually along curbs, but may also be in alleys, driveways, etc.  You may have seen logos of fish painted near them with a warning against dumping of toxic materials into them.  Stormwater and irrigation runoff from gardens and lawns, car washing, etc., runs down the streets via gutters into the storm drains. The runoff flows through pipes into regional ponding basins and either infiltrates into groundwater or discharges into creeks, canals or the San Joaquin River.  Sanitary sewers collect wastewater and greywater discharged from toilets, sinks, and showers in homes and carries it to municipal waste water treatment plants where the organic wastes are treated.

United States Environmental Protection Agency (USEPA):  Under the Clean Water Act (CWA) the USEPA develops water quality criteria to reduce the impact from pollutants in stormwater discharges. The criteria focuses on preventing storm water pollutants through source reduction strategies and Best Management Practices aimed at specific sources of stormwater pollutants (erosion control, sediment removal, Integrated Pest Management).

The State Regional Water Quality Control Boards are responsible for enforcing the CWA stormwater regulations.

The Fresno Metropolitan Flood Control District, the Cities of Fresno and Clovis, the County of Fresno, and the California State University of Fresno share a National Pollutant Discharge Elimination System (NPDES) stormwater permit from the federal government that allows them to discharge stormwater into local creeks, canals and the San Joaquin River.

The Federal permit states that stormwater discharges should be non-toxic. If the San Joaquin River or any local creeks or canals are found to have toxic stormwater, they are required to implement additional mitigation/control measures. The Fresno Metropolitan Flood Control District is helping implement this educational outreach program to educate consumers, homeowners and the general public of the potential problem associated with stormwater runoff and pesticides. The result is that residents may see higher utility or assessment taxes.  Many other communities in California including Santa Clara, Contra Costa, Stockton, Sacramento and Modesto have stormwater permits and are facing contamination problems.

Pest Note:  How Do Pesticides Get Into Our Creeks and Rivers?

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