In 1972, the federal Water Pollution Control Act (also referred to as the Clean Water Act (CWA)) was amended to provide that the discharge of pollutants to waters of the United States from any point source is unlawful unless the discharge is in compliance with a National Pollutant Discharge Elimination System (NPDES) permit. The 1987 amendments to CWA added section 402(p), which established a framework for regulating storm water discharges under the NPDES Program.

Subsequently, in 1990, the U.S. Environmental Protection Agency (U.S. EPA) promulgated regulations for permitting storm water discharges from industrial sites (including construction sites that disturb five acres or more) and from municipal separate storm sewer systems (MS4) serving a population of 100,000 people or more. These regulations, known as the Phase I regulations, require operators of medium and large MS4 to obtain storm water permits.

On December 8, 1999, U.S. EPA promulgated regulations, known as Phase II, requiring permits for storm water discharges from Small MS4s and from construction sites disturbing between one and five acres of land. Lake County has been designated as a Phase II Municipality.


In October 2003, The County of Lake, City of Clearlake and City of Lakeport submitted a Stormwater Management Plan (SWMP) and Notice of Intent (NOI), as co-permittees, for compliance with State Waste Discharge Requirements for Storm Water Discharges from Municipal Separate Storm Sewer Systems (General Permit) under the NPDES Phase II Program. On July 7, 2004 the County of Lake, City of Clearlake and City of Lakeport were authorized to discharge from those municipalities MS4 under the General Permit, provided that municipalities implement and monitor the SWMP and are in full compliance with the requirements and prohibitions of the General Permit.

Compliance with the General Permit requires the co-permittees to implement 6 Best Management Practices (BMP). The 6 BMP are:

Public Education, Outreach & Participation Workgroup (PEOP)

PEOP is responsible for development of materials and products, technical workshops, marketing, public outreach and public involvement with input from the other workgroups as appropriate.

Illicit Discharge Detection & Elimination Workgroup (IDDE)

IDDE is responsible for the development and implementation of a program to detect, address and/or eliminate illicit discharges including illegal dumping.

Construction Site Stormwater Runoff Control Workgroup (CON)

CON is responsible for development and implementation of a program to control the discharge of pollutants from construction sites.

Post Construction Stormwater Management Workgroup (PCON)

PCON is responsible for the development and implementation of long-term development measures for post construction stormwater management in new development and redevelopment projects. The Construction Stormwater Management Workgroup and the Post Construction Stormwater Management Workgroup meet concurrently.

Municipal Operations Workgroup (MUNI)

MUNI is responsible for evaluating municipal maintenance activities and developing a program to prevent the discharge of pollutants from these activities.