Sanitary Sewer Systems General Order

Sewage is untreated or partially treated domestic, municipal, commercial and/or industrial waste (including sewage sludge), and any mixture of these wastes with inflow or infiltration of stormwater or groundwater, conveyed in a sanitary sewer system. A spill is a discharge of sewage from any portion of a sanitary sewer system due to a sanitary sewer system spill, operational failure, and/or infrastructure failure. Sewage and its associated wastewater spilled from a sanitary sewer system may threaten public health, beneficial uses of waters of the State, and the environment.

General Order Information

To provide a consistent, statewide regulatory approach to address sanitary sewer spills, the State Water Board adopted Statewide General Waste Discharge Requirements for Sanitary Sewer Systems, Water Quality Order No. 2022-0103-DWQ (Sanitary Sewer Systems General Order) on December 6, 2022. The Sanitary Sewer Systems General Order requires public agencies that own or operate sanitary sewer systems to develop and implement sewer system management plans and report all sanitary sewer spills to the State Water Board’s online California Integrated Water Quality System (CIWQS) Sanitary Sewer System Database.

Statewide Sanitary Sewer Systems General Order – Effective June 5, 2023

Quick Links

Sewage Spill Incident Maps

These interactive geographic information system (GIS) maps, which are updated nightly, plot certified spills from sanitary sewer systems (not including any spills from wastewater [sewage] treatment plants). Agencies report and certify spills in the state’s online California Integrated Water Quality System (CIWQS). Spill information includes the spill location, amount, source, and name of the responsible agency. Discrete data on category 4 spills are only required to be reported annually so are not included in this report.

View the Sanitary Sewer Systems Spills Incident Map.

The following map shows the spills from privately-owned sewer laterals and/or private sanitary sewer systems voluntarily reported into CIWQS by enrollees. Private laterals spills are caused from failures in sewer pipes that tie private businesses and homes into the public sewer system.

View the Private Sewer Laterals and/or Private Sanitary Sewer Systems Spill Incident Map

Online Sanitary Sewer System Database Access and Use

The Sanitary Sewer System 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.

SPILL CATEGORIES
CATEGORY 1	A Category 1 spill is a spill of any volume of sewage from or caused by a sanitary sewer system regulated under this General Order that results in a discharge to: A surface water, including a surface water body that contains no flow or volume of water; or A drainage conveyance system that discharges to surface waters when the sewage is not fully captured and returned to the sanitary sewer system or disposed of properly. Any spill volume not recovered from a drainage conveyance system is considered a discharge to surface water, unless the drainage conveyance system discharges to a dedicated stormwater infiltration basin or facility. A spill from an Enrollee-owned and/or operated lateral that discharges to a surface water is a Category 1 spill; the Enrollee shall report all Category 1 spills per section 3.1 of Attachment E1 (Notification, Monitoring, Reporting and Recordkeeping Requirements) of this General Order.
CATEGORY 2	A Category 2 spill is a spill of 1,000 gallons or greater, from or caused by a sanitary sewer system regulated under this General Order that does not discharge to a surface water. A spill of 1,000 gallons or greater that spills out of a lateral and is caused by a failure or blockage in the sanitary sewer system, is a Category 2 spill.
CATEGORY 3	A Category 3 spill is a spill of equal to or greater than 50 gallons and less than 1,000 gallons, from or caused by a sanitary sewer system regulated under this General Order that does not discharge to a surface water. A spill of equal to or greater than 50 gallons and less than 1,000 gallons, that spills out of a lateral and is caused by a failure or blockage in the sanitary sewer system is a Category 3 spill.
CATEGORY 4	A Category 4 spill is a spill of less than 50 gallons, from or caused by a sanitary sewer system regulated under this General Order that does not discharge to a surface water. A spill of less than 50 gallons that spills out of a lateral and is caused by a failure or blockage in the sanitary sewer system is a Category 4 spill.