Sanitary Sewer Overflow (SSO) Reduction Program

A sanitary sewer overflow (SSO) is any overflow, spill, release, discharge or diversion of untreated or partially treated wastewater from a sanitary sewer system. SSOs often contain high levels of suspended solids, pathogenic organisms, toxic pollutants, nutrients, oil, and grease. SSOs pollute surface and ground waters, threaten public health, adversely affect aquatic life, and impair the recreational use and aesthetic enjoyment of surface waters. Typical consequences of SSOs include the closure of beaches and other recreational areas, inundated properties, and polluted rivers and streams.

Quick Links

• New! 2011 SSO Reduction Program Annual Report (rev 9/9/11)
• SSO Reduction Program Review and Update
• General Order Information
• Interactive SSO Report
• Sewage Spill Incident Maps
• Online SSO Database Access and Use
• SSO Data
• Sewer System Management Plan Development/Implementation
• Sanitary Sewer Systems WDR Training
• Historical Information
• SSO Program Contacts

General Order Information

To provide a consistent, statewide regulatory approach to address SSOs, the State Water Resources Control Board (State Water Board) adopted Statewide General Waste Discharge Requirements (WDRs) for Sanitary Sewer Systems, Water Quality Order No. 2006-0003 (Sanitary Sewer Systems WDR) on May 2, 2006. The Sanitary Sewer Systems WDR requires public agencies that own or operate sanitary sewer systems to develop and implement sewer system management plans and report all SSOs to the State Water Board’s online SSO database. The Sanitary Sewer Systems WDR and its supporting documents can be viewed through the links below:

• Glossary of Terms (posted 9/30/08)
• Statewide General WDRs for Sanitary Sewer Systems, WQO No. 2006-0003
• Revised Monitoring and Reporting Program (WQ 2008-0002-EXEC)
  • Revised MRP WQ 2008-0002-Exec
  • Revision Transmitted Letter
• SSO Fact Sheets
  • Trifold Brochure - 2009
  • WQO 2006-0003
• SSO Compliance & Enforcement Information
  • New! 2011 SSO Reduction Program Annual Report (rev 9/9/11)
  • SSO Reduction Program Compliance and Enforcement Plan
  • 2010 SSO Reduction Program Annual Report
  • 2009 SSO Reduction Program Annual Report
  • 2008 SSO Reduction Program Annual Report

All public agencies that own or operate a sanitary sewer system that is comprised of more than one mile of pipes or sewer lines which conveys wastewater to a publicly owned treatment facility must apply for coverage under the Sanitary Sewer Systems WDR. The application or Notice of Intent (NOI) for coverage under the Sanitary Sewer Systems WDR should have been submitted to the State Water Board by November 2, 2006 and is available at the link below:

• NOI Form - Notice of Intent to Comply with the Terms of the Statewide General Waste Discharge Requirements for Sanitary Sewer Systems
• Instructions for Completing the NOI Form
• LRO Form
• Data Submitter Form
• Dischargers User Guide

Sewage Spill Incident Maps

These interactive geographic information system (GIS) maps, updated nightly, plot all certified sanitary sewer overflows (SSOs) and Private Lateral Sewage Discharges from sanitary sewer collection systems (not including any spills from wastewater (sewage) treatment plants), reported by agencies into the state’s online California Integrated Water Quality System. This includes the spill location, amount, source, and name of the responsible or reporting agency.

• View the SSO Incident Map

A second map allows users to see Private Lateral Sewage Discharges, voluntarily reported from enrollees in the program from pipes which empty into public sewer collection systems. Private lateral spills are caused from failures in pipes that tie private businesses and homes into the public sewer collection system, and are maintained by individual property owners. They often suffer from overflows which can affect public sewer collection systems.

• View the Private Lateral Sewage Discharge Incident Map

Online SSO Database Access and Use

The SSO database is used to collect and store an enrollee’s (defined as an agency which is covered under the Sanitary Sewer Systems WDR) facility and organizational information (collection system questionnaire) and details of all SSOs which occur from an enrollee’s sanitary sewer system (SSO reports). All of the information collected in the SSO database is entered by enrollees. State and Regional Water board staff cannot enter or modify any information in the SSO database. The SSO database is accessed through the California Integrated Water Quality System (CIWQS), which is the State Water Board’s regulatory and water quality information management system. Enrollees will automatically be assigned a CIWQS account to access the SSO database. The implementation of the SSO database is being phased in throughout the state on a regional basis as discussed below.

Access to the SSO database allows enrollees to complete the collection system questionnaire and submit SSO reports as required by the Sanitary Sewer Systems WDR. The Sanitary Sewer Systems WDR requires enrollees to complete the collection system questionnaire within 30 calendar days of receiving their CIWQS user ID and password. The Legally Responsible Official for each enrollee will receive their CIWQS user ID and password, via email message, to access the SSO database according to the schedule below:

Once the Legally Responsible Official has received their CIWQS user ID and password, the enrollee can register additional staff for individual access to CIWQS for submitting agency information to the SSO database. Instructions regarding this registration process are available on the CIWQS Help Center webpage.

The Sanitary Sewer Systems WDR requires enrollees to begin reporting all SSOs to the SSO database according to the following schedule:

The collection system questionnaire gathers information related to an enrollee’s agency and facilities. This information will allow the performance of an enrollee’s sanitary sewer system to be put into the context of site specific characteristics. The information collected includes population served, miles of pipe, and age of the sanitary sewer system. To view a copy of the collection system questionnaire, select the link below:

• Collection System Questionnaire

The SSO report collects detailed information on a specific overflow event. Enrollees are required to report all SSOs that result from a failure in any portion of a sanitary sewer system under their management. For the purposes of reporting, SSOs fall into one of two categories: Category 1 (greater threat to public health of water quality) and Category 2 (lesser threat to public health of water quality). A Category 1 SSO is defined as a failure in an enrollee’s sanitary sewer system that results in a (1) discharge of sewage which equals or exceeds 1,000 gal, or (2) discharge of sewage to a surface water and/or drainage channel, or (3) discharge of sewage to a storm drainpipe which was not fully captured and returned to the sanitary sewer system. A Category 2 SSO is defined as any discharge of sewage resulting from a failure in an enrollee’s sanitary sewer system which does not meet the criteria for a Category 1 SSO.

SSO information reported by enrollees includes location of overflow, volume of sewage spilled, and cause of the overflow. A copy of the Category 1 and Category 2 SSO report form can be viewed at the links below:

• Category 1 SSO Report
• Category 2 SSO Report

If an enrollee does not have any SSOs in a calendar month, they are required to complete a no spill certification. The no spill certification form can be viewed at the link below:

• No Spill Certification

Sewer System Management Plan Development/Implementation

Every enrollee is required to develop and implement a sewer system management plan (SSMP). The SSMP documents an enrollee’s program to properly operate and maintain its sanitary sewer system.; Each SSMP should address the following elements:

1. Goal
2. Organization
3. Legal Authority
4. Operation and Maintenance Program
5. Design and Performance Provisions
6. Overflow Emergency Response Plan
7. Fats, Oils, and Grease (FOG) Control Program
8. System Evaluation and Capacity Assurance Plan
9. Monitoring, Measurement, and Program Modifications
10. SSMP Program Audits
11. Communication Program

For a detailed explanation of the SSMP elements, please refer to the Sanitary Sewer Systems WDR above.

The Sanitary Sewer Systems WDR gives enrollees a reasonable amount of time to develop and implement their SSMP with smaller communities having more time than larger ones. The time schedule for each enrollee to develop and implement their SSMP is presented below:

Enrollees are required to certify that the final SSMP and its constituent subparts are in compliance with the Sanitary Sewer Systems WDR within the time frames above. This certification is done electronically in the SSO database and will be available for use beginning July 9, 2007. Enrollees are also required to obtain their governing board’s approval of the SSMP Development Plan and Schedule and final SSMP at a public hearing prior to certification as complete and in compliance. Enrollees do not send their SSMP to the State or Regional Water Boards for review or approval; but, need to make them available upon request.

Sanitary Sewer Systems WDR Enrollee Training

The State Water Board signed a memorandum of agreement (MOA) with California Water Environment Association (CWEA) to develop a training course for the Sanitary Sewer Systems WDR. CWEA will offer the courses statewide to educate enrollees about the terms of the Sanitary Sewer Systems WDR, use of the online SSO database, and development of a sewer system management plan (SSMP). For details about the course content and schedule, please visit the CWEA Website.

Related Links:

• U.S. Environmental Protection Agency - information on SSOs
• California Water Environment Association – register for training on SSO reporting and SSMP development
• Southern California Alliance of Publicly Owned Treatment Works – site contains resources for SSMP development and implementation
• CIWQS Help Center – technical support on access (e.g., user ID and password information and login questions) to and use of the SSO database

Historical Information

• Written comments received on revised proposed Order; Prior to adoption and part of the public hearing process; Deadline for comments was April 24, 2006; Hearing was held on May 2, 2006.
• Written comments received on proposed Order; Prior to adoption and part of the public hearing process; Deadline for comments was January 25, 2006; Hearing was held on February 8, 2006.

SSO Program Contacts

(Updated 5/15/12)