The California Water Boards' Annual Performance Report - Fiscal Year  2015-16 

REGULATE: NPDES WASTEWATER FACILITIES

MEASUREMENTS  - Data Last Updated on: March 20, 2017

WHAT THE MEASURE IS SHOWING

494 facilities are regulated under individual NPDES permit, of those facilities 266 are classified as major facilities and 228 are classified as minor facilities. Major NPDES facilities are concentrated in the most populous areas, with 75 percent of the state's major facilities in the San Francisco Bay Region (Region 2), the Los Angeles Region (Region 4), the Central Valley Region (Region 5), and San Diego Region (Region 9). In addition to individually permitted facilities, the NPDES Program also regulates 859 facilities under a General NPDES Permit.

WHY THIS MEASURE IS IMPORTANT

In order to ensure that discharges to surface waters do not adversely affect the quality and beneficial uses of such waters, NPDES permits must be reviewed and revised to reflect new standards and requirements (such as new TMDLs and other water quality plans and policies adopted) and updates to monitoring and reporting requirements (reflecting previous facility performance and compliance history). NPDES permits expire five years after issuance and are required to be reissued (i.e., renewed) every five years or less (40 CFR Part 122.46 and California Water Code section 13380). Typically, permit requirements remain in effect until the permit is reissued, however NPDES permits may also be revoked or terminated. Revising and reissuing permits for major facilities requires a significant amount of time and resources, and is considered a good indicator of overall program performance.

TECHNICAL CONSIDERATIONS

• Data Source: CIWQS.
• Unit of Measure: Number of facilities discharging under an active NPDES permit.
• Data Definitions: Permits Active.
• References: Information on the Water Boards' NPDES Program
  Public Reports and Data
  US Environmental Protection Agency California Water Performance Dashboard

GLOSSARY

Major Facility

Major municipal dischargers include all facilities with design flows of greater than one million gallons per day and facilities with approved industrial pretreatment programs. Major industrial facilities are determined based on specific ratings criteria developed by US EPA/State.

Minor Facility

A minor facility is a discharge with a design flow of less than one million gallons per day (MGD) that has not been determined to have an actual or potential adverse environmental impact classifying the discharge as major.

General Facility

A general facility is a discharge with a design flow of less than one million gallons per day (MGD) that has not been determined to have an actual or potential adverse environmental impact classifying the discharge as major.

National Pollutant Discharge Elimination System (NPDES)

The NPDES permit program (CWA Section 402) controls water pollution by regulating point sources that discharge pollutants into waters of the United States. Point sources are discrete conveyances such as pipes or man-made ditches. Individual homes that are connected to a municipal system, use a septic system, or do not have a surface discharge do not need an NPDES permit; however, industrial, municipal, and other facilities must obtain permits if their discharges go directly to surface waters. US EPA has approved the Water Board's program to issue NPDES permits.

NPDES Permit

The Clean Water Act prohibits anybody from discharging "pollutants" through a "point source" into a "water of the United States" unless they have an NPDES permit. The permit contains limits on what can be discharged, monitoring and reporting requirements, and other provisions to protect water quality and public health. In essence, the permit translates general requirements of the Clean Water Act into specific provisions tailored to the operations of each person discharging pollutants.

( Page last updated:  10/10/17 )