Green City, Clean Waters

Combined Sewer Overflow Long Term Control Plan Update

We are always working to protect and preserve our water resources. This includes working on ways to control stormwater that also helps our waterways. Our plan that accomplishes this is referred to as the CSO Long Term Control Plan. Part of our plan includes studying our combined sewer systems, rivers and streams. This means we now know how our system is working, and where we can make changes to help it work better.

Philadelphia's original CSO Long Term Control Plan was submitted in January 1997 and contained three major elements: technology-based capital improvements, comprehensive watershed planning, and ongoing implementation of the Nine Minimum Controls. These controls are low-cost actions that can reduce CSO discharges and their effect on receiving waters, and they do not require significant engineering studies or lengthy implementation.

Our original Long Term Control Plan and capital improvements program were reevaluated in 2007 in an effort to integrate additional projects that would reduce CSO frequency and volume. Building upon the experience and progress gained from the original plan, this process produced an update to the plan that involved newly-developed management alternatives to ensure capture and treatment of sanitary sewer system flows. Discharges from CSOs are also further reduced through the CSO Long Term Control Plan Update.

Additional information on the background of these reports can be located here.