California Water Boards' Annual Performance Report - Fiscal Year  2017-18 

REGULATE: NPDES STORMWATER

MEASUREMENTS

WHAT THE MEASURE IS SHOWING

WHY THIS MEASURE IS IMPORTANT

TECHNICAL CONSIDERATIONS

• Data Source: CIWQS. Period July 1, 2017 to June 30, 2018.
• Unit of Measure: Number of active MS4 facilities inspected or audited at least once during FY 17-18.
• Data Definitions: Inspections: Include inspections and audits conducted by Regional or State Water Board staff, or US EPA. It includes any inspection type.
• References: Information on the Water Boards’ NPDES Storm Water Program
  Public Reports and Data
  Enforcement and Compliance Assurance Information

GLOSSARY

Municipal Storm Water Phase I Facilities

The Municipal Storm Water Permits regulate storm water discharges from municipal separate storm sewer systems (MS4s). Under Phase I, which began in 1990, the Regional Water Boards have issued NPDES MS4 permits to permittees serving populations greater than 100,000 people. Many of these permits are issued to a group of co-permittees encompassing an entire metropolitan area. These permits are reissued as the permits expire.

Municipal Storm Water Phase II Facilities

Under Phase II, the State Water Board adopted a General Permit for the Discharge of Storm Water from Small MS4s (WQ Order No. 2013-0001-DWQ) to provide permit coverage for smaller municipalities (10,000 to 100,000 people), including non-traditional small MS4s which are governmental facilities such as military bases, public campuses, prisons and hospital complexes.

National Pollutant Discharge Elimination System (NPDES)

The NPDES permit program (Section 402 of the Clean Water Act) 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.

Inspection (Compliance and Non Compliance)

The Regional Board or State Board may inspect the facilities of any discharger at any time pursuant to Water Code, Section 13267. Compliance activities include all activities necessary to determine if discharges are in compliance with waste discharge requirements, NPDES permits, and related enforcement orders. Compliance inspections are classified as either Level A or Level B, with Level A being more thorough.

Audit (MS4 Program)

An MS4 audit is used to evaluate overall MS4 storm water program implementation, and identify problems the local government may have in implementing the program. MS4 audits involve a comprehensive review of the local government's MS4 storm water program including: a review of the program elements including structural and source control measures, detection and removal of illicit discharges and improper disposal into storm sewers, monitoring and controlling pollutants in storm water discharges, implementing and maintaining structural and nonstructural Best Management Practices (BMPs), verification of implementation schedules, assignment of appropriate individuals, review of the inspection and enforcement program for industrial facilities and construction sites, evaluation of the dry weather screening program, determination of whether controls are in place and are in good working order, and whether facilities have schedules for construction of structural control measures.