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water quality


Clean Water Act 

The Clean Water Act was passed in 1972 and provides a framework for regulating pollutant discharges into U.S. water bodies. Since establishment of the CWA, case studies across the nation have shown significant water quality improvements.

The overarching goal of the CWA is to restore and maintain the chemical, physical and biological integrity of U.S. waters. To do this, the Act focuses on eliminating discharges of pollutants and toxic substances and achieving a level of water quality necessary for wildlife survival and human recreation. To meet these goals, the CWA requires entities to obtain permits before releasing pollutants into surface waters.

The system for granting and regulating permits is called the National Pollutant Discharge Elimination System (NPDES). The NPDES Program addresses point sources of pollution or discharges from treatment plants, discharges from industrial facilities and urban runoff. Implementation of the NPDES Program in California is handled by the State.

The CWA includes four elements in addition to the NPDES Program: 1) a system of minimum national effluent standards for each industry, 2) water quality standards, 3) provisions for special problems such as toxic chemicals and oil spills and 4) a construction loan program for publicly owned treatment works.

Water quality standards are set by the States. In California, standards are set by the California State Water Resources Control Board and nine Regional Water Quality Control Boards. Section 303(d) of the CWA requires that each State then identify a list of impaired water bodies that fail to meet the appropriate standards. The CWA also mandates that States establish Total Maximum Daily Loads (TMDLs) for the pollutants present in impaired water bodies. A TMDL specifies the amount of a particular pollutant that a body of water can receive and still meet water quality standards. The TMDL Program requires that States develop plans for reducing pollutant loading in order to acheive TMDLs.


National Pollutant Discharge Elimination System (NPDES) 

Regulatory Requirements and Applicable Standards

The Storm Water Phase II Final Rule (see also Storm Water Phase II Final Rule: An Overview) requires the operator of a regulated small municipal separate storm sewer system (MS4) to obtain NPDES permit coverage because discharges of storm water from such systems are considered point sources of potential pollution. MS4s are considered publicly owned or operated point sources because they collect storm water and direct it into discrete conveyances, including roads with drainage systems and municipal streets.

According to the 40 CFR 122.26(b)(8) in the Final Rule, "municipal separate storm sewer means a conveyance or system of conveyances (including roads with drainage systems, municipal streets, catch basins, curbs, gutters, ditches, man-made channels, or storm drains):

  • Owned or operated by a state, city, town, borough, county, parish, district, association, or other public body (created by or pursuant to State law)...including special districts under State law such as a sewer district, flood control district or an authorized Indian tribal organization, or a designated and approved management agency under section 208 of the Clean Water Act that discharges into waters of the United States;
  • Designed or used for collecting or conveying storm water;
  • Which is not a combined sewer; and
  • Which is not part of a Publicly Owned Treatment Works as defined at 40 CFR 122.2."

EPA categorizes MS4s as either small, medium or large. Regulated small MS4s are automatically designated if they are located in urbanized areas (as defined by the Bureau of the Census). The unincorporated areas of the South Coast east of Bell Canyon as well as the communities of Mission Hills, Vandenberg Village and Orcutt fall into this category. Other small MS4s located outside urbanized areas may be designated on a case-by-case basis by the NPDES permitting authority. The communities of Santa Ynez and Los Olivos have been included in this latter category. All of the areas within these two categories are covered in the County of Santa Barbara Storm Water Management Program.

Requirements for Santa Barbara County

The owner or operator of a Phase II regulated small MS4 is required to submit a Notice of Intent (NOI) to obtain coverage under an NPDES storm water permit. The submitted plan must describe how the regulated entity will identify and implement a range of Best Management Practices (BMPs) into an effective Storm Water Management Program that covers six Minimum Control Measures, evaluation/assessment and reporting efforts, and record-keeping.

The six Minimum Control Measures are:

Read Santa Barbara County's Storm Water Management Program.