Lancaster, like hundreds of other cities across the county, has both a combined sewer system (CSS) and a municipal separate storm sewer system (MS4). While the CSS collects both sewage and stormwater and conveys flows to a wastewater treatment plant (WWTP), the MS4 collects only stormwater runoff and discharges flows directly to receiving streams. The benefits analysis summarized in this report evaluates how installing green infrastructure in the CSS area could reduce gray infrastructure capital investments and associated wastewater pumping and treatment costs; as well as how installing green infrastructure in both the CSS and MS4 areas could produce a range of environmental benefits across the city. This screening-level analysis suggests that green infrastructure can be a cost-effective solution to stormwater management that provides multiple environmental benefits.You may need a PDF reader to view some of the files on this page. See EPA’s About PDF page to learn more.