850 Billion Gallons of Raw Sewage Dumped Into US Waterways Annually via CSOs

Approximately 700 US communities still operate combined sewer systems (CSS) that carry both stormwater runoff and raw sewage in the same pipe. When it rains, these systems are overwhelmed and discharge a mixture of untreated human waste, industrial chemicals, and stormwater directly into rivers, lakes, and coastal waters. The EPA estimates over 40,000 combined sewer overflow (CSO) events dump 850 billion gallons of untreated wastewater into surface waters every year, affecting 40 million people served by these systems. This matters because the discharged water contains pathogens like E. coli, Cryptosporidium, hepatitis A virus, and even antibiotic-resistant bacteria like MRSA. University of Maryland researchers found E. coli levels at overflow discharge points exceeding EPA recreational water quality standards by over 10,000 times. People who swim, fish, or boat in these waters face elevated risk of gastrointestinal illness, skin infections, and in severe cases, hemolytic uremic syndrome that can cause kidney failure, particularly in children under five. The economic damage compounds: contaminated waterways reduce property values along riverfronts, cities face EPA consent decrees requiring billions in remediation, and tourism and recreation industries lose revenue when beaches and waterways are closed due to sewage advisories. New York City alone reports hundreds of CSO events per year into the Hudson and East Rivers. This problem persists because combined sewer systems were the standard engineering approach from the mid-1800s through the early 1900s. Separating these systems requires digging up streets and laying entirely new pipe networks, costing tens of billions per city. Most municipalities cannot afford this, and federal funding has been insufficient. The Clean Water Act's CSO Policy from 1994 requires long-term control plans, but the GAO found in 2023 that EPA does not systematically track whether these controls actually improve water quality, meaning cities can spend decades and billions without verified results.