Stormwater pollution is urban runoff water that has picked up pollutants as it flows through the storm drain system-a network of channels, gutters and pipes that collect runoff from city streets, neighborhoods, farms, construction sites and parking lots-and empties directly into local waterways.

Unlike sewage, which goes to treatment plants, urban runoff flows untreated through the storm drain system. Anything thrown, swept or poured into the street, gutter or a catch basin-the curbside openings that lead into the storm drain system-can flow directly into our channels, creeks, bays and ocean. This includes pollutants like trash, pet waste, cigarette butts, motor oil, anti-freeze, runoff from pesticides and fertilizers, paint from brushes and containers rinsed in the gutter and toxic household chemicals.

For more information:
The Ocean Begins at Your Front Door

How Stormwater Pollution Affects Orange County Residents

Contaminated urban runoff is an uncontrolled nonpoint source of pollution into local waters, and may contribute to beach closures. Litter, leaves and other debris clog catch basins, causing flooding when it rains.

How Stormwater Pollution Affects Orange County Businesses

Stormwater pollution may contribute to beach closures, which hurt local businesses, tourism and Orange County's image as a desirable place to live and work. It is illegal for businesses without a permit to discharge wastewater or other materials into the storm drain system.

The Answer: Preventing Stormwater Pollution

Everyone in Orange County can help prevent stormwater pollution. It is often caused by everyday behavior that you may not realize contributes to the problem. Simple behavior changes are all it takes to prevent stormwater pollution, if we all do our part. Find out how.

How residents can prevent stormwater pollution
How businesses can prevent stormwater pollution

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The Federal Water Pollution Control Act prohibits the discharge of any pollutant to navigable waters from a point source unless the discharge is authorized by a National Pollutant Discharge Elimination System (NPDES) permit.

The 1987 passage of the Water Quality Act established NPDES permit requirements for discharges of stormwater. The NPDES permit program controls water pollution by regulating point sources that discharge pollutants into waters of the United States.

Industrial facilities and construction sites are regulated by the State Water Resources Control Board, through general stormwater permits. Cities and counties are regulated through permits issued by the Regional Water Quality Control Boards. Since 1990, operators of large storm drain systems such as Orange County's have been required to:

  • Develop a stormwater management program designed to prevent harmful pollutants from being dumped or washed by stormwater runoff,into the stormwater system, then discharged into local waterbodies; and
  • Obtain a National Pollutant Discharge Elimination System (NPDES) permit.

The NPDES permit programs in California are administered by the State Water Resources Control Board and by nine regional boards that issue NPDES permits and enforce regulations within their respective region.

Orange County lies within the jurisdiction of both the Santa Ana and San Diego Regions. These two regional boards issue permits to the Orange County Permittees, which includes the County of Orange, Orange County Flood Control District and incorporated cities of Orange County. Since the program's inception, the County of Orange has served as the principal permittee.

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The following documents describe the regulations and programs for water quality in Orange County.

Basin Plans
The document for each region of the State Water Quality Board's jurisdiction, Santa Ana and San Diego, is the Water Quality Control Plan, commonly referred to as the Basin Plan. It is the foundation for the regulatory programs of each regional board. The Basin Plan documents the beneficial uses of the region's ground and surface waters, existing water quality conditions, problems, and goals, and actions by the regional board and others that are necessary to achieve and maintain water quality standards.

Water Control Plan for the Santa Ana River Basin
Water Control Plan for San Diego Region

Municipal National Pollutant Discharge Elimination System (NPDES) Permits

The permits of each region outline additional steps for a storm water management program and specify requirements to help protect the beneficial uses of the receiving waters. They require permittees to develop and implement Best Management Practices (BMPs) to control/reduce the discharge of pollutants to waters of the United States to the maximum extent practicable (MEP).

Orange County Third and Fourth Term NPDES Municipal Stormwater Permits

Drainage Area Management Plan

The Drainage Area Management Plan (DAMP) describes the Orange County Stormwater Program, implemented by the County of Orange and cities to comply with their jointly held stormwater permit. It is the principal policy and guidance document for the countywide NPDES Stormwater Program.

Orange County Stormwater Program Annual Status Report

The Annual Status Report is a requirement of the NPDES permit for submittal to the Regional Boards and United States Environmental Protection Agency. The report presents an analysis and assessment of permit compliance activities for the periods as required by the permits.

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