Requirements & Resources

Construction sites over one (1) acre are required to develop a Stormwater Pollution Prevention Plan (SWPPP) to address stormwater runoff from the project.  Stormwater runoff from construction sites can cause significant harm to our rivers, lakes, and coastal waters.  In California, the State Water Resources Control Board (SWRCB) is the governing agency responsible for implementing the SWPPP requirements.

The Stormwater Pollution Prevention Plan (SWPPP) describes the contractor's activities to prevent stormwater contamination, control sediment and erosion, and comply with the requirements of the SWRCB.  A SWPPP may also be called a "construction best practices plan," "sediment and stormwater plan," erosion, sedimentation, and pollution prevention plan," or similar term.  The SWPPP is a site-specific written document that: 
  • Identifies potential sources of stormwater pollution at the construction site
  • Describes practices to reduce pollutants in stormwater discharges from the construction site.  Reduction of pollutants is often achieved by controlling the volume of stormwater runoff (e.g., taking steps to allow stormwater to infiltrate into the soil).
  • Identifies procedures the contractor will implement to comply with the terms and conditions of a construction general permit.
Failure to develop and implement a SWPPP could result in significant fines from the EPA or SWRCB.  It is important for the SWPPP to address specific conditions at the site.  The SWPPP should be fully implemented throughout construction and kept up-to-date to reflect changes at the site. 

The Clean Water Act requires construction sites that disturb one acre or more, including smaller sites in a larger common plan of development or sale, to obtain coverage under a National Pollutant Discharge Elimination System (NPDES) permit for their stormwater discharge.  Most states, including California, are authorized to implement the NPDES program and issue their own permits for stormwater discharges associated with construction activities.  These permits, generally, can be thought of as umbrella permits that cover all stormwater discharges associated with construction activity for a designated time period.  Operators of individual construction sites then apply for coverage under the state's General Permit.  In California, the General Permit (Order No. 2009-0009-DWQ) went into effect on July 1, 2010.