Sanitary Sewer Overflows

OVERVIEW

Properly designed, operated, and maintained sanitary sewer systems are meant to collect and transport all of the sewage that flows into them to a publicly owned treatment works (POTW). However, occasional unintentional discharges of raw sewage from municipal sanitary sewers occur in almost every system. These types of discharges are called sanitary sewer overflows (SSOs). SSOs have a variety of causes, including but not limited to severe weather, improper system operation and maintenance, and vandalism. EPA estimates that there are at least 40,000 SSOs each year. The untreated sewage from these overflows can contaminate our waters, causing serious water quality problems. It can also back-up into basements, causing property damage and threatening public health.

WHAT CAN I FIND ON THIS WEB SITE?

NPDES Permit Requirements for Municipal Sanitary Sewer Collection Systems and SSOs - The draft fact sheet [PDF - 41 KB - 3 pp] and model permit conditions [PDF - 74 KB - 7 pp] explain that NPDES permit authorities should be improving implementation of NPDES permit requirements for SSOs and sanitary sewer collection systems by clarifying how conditions in NPDES permits for discharges from POTWs apply to the collection system serving the treatment works.

Proposed Peak Wet Weather Discharge Policy - EPA is seeking comments on a proposed policy for addressing peak wet weather events at wastewater treatment plants. The public comment period is open for 30 days after publication in the Federal Register.

Report to Congress: Impacts and Control of CSOs and SSOs

Featured Case Studies, Fact Sheets, and Other Information - Contains a series of case studies that document innovative techniques for addressing overflows of sanitary sewers.

SSO Toolbox - Provides educational materials and other useful links for municipalities looking to EPA for assistance in understanding and adopting parts of the Draft SSO Proposed Rule.

SSO Federal Advisory Subcommittee - Contains information on the activities of the SSO Subcommittee, which was formed in 1995 to provide a forum for stakeholders to identify and evaluate issues associated with the development of a formal SSO Rule.

FAQs - Contains Frequently Asked Questions related to SSOs. This is the best place to start when looking for general information on EPA's efforts to control SSOs.

SSO Proposed Rule - Was withdrawn from publication in the Federal Register.

Wet Weather Discharges - Contains information on EPA's program activities for "wet weather" pollution sources, which include stormwater runoff, combined sewer overflows (CSOs), and wet weather sanitary sewer overflows (SSOs)

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Last updated on April 01, 2009 4:22 PM
URL:http://cfpub.epa.gov/npdes/home.cfm