In many cities, SSOs and basement backups occur because of blockages, broken pipes and excessive water flowing into the pipes. SSOs present environmental and health problems because they discharge untreated wastewater that contains bacteria, viruses, suspended solids, toxics, trash and other pollutants into waterways.
These overflows may also contribute to beach closures, shellfish bed closures, contamination of drinking water supplies and other environmental and health concerns, EPA said.
Infrastructure issues were discussed at the Coming Together for Clean Water Conference held by EPA Administrator Lisa Jackson on April 15, 2010. The agency plans to address these issues as part of its efforts to protect public health and revitalize local waterways.
EPA is considering two possible modifications to existing regulations. One is establishing standard National Pollutant Discharge Elimination System (NPDES) permit conditions for publicly owned treatment works (POTWs) permits that specifically address sanitary sewer collection systems and SSOs.
The other is clarifying the regulatory framework for applying NPDES permit conditions to municipal satellite collection systems. Municipal satellite collection systems are sanitary sewers owned or operated by a municipality that conveys wastewater to a POTW operated by a different municipality.
As a part of this effort, the agency is also considering to address long-standing questions about peak wet weather flows at municipal wastewater treatment plants to allow for a holistic, integrated approach to reducing SSOs while at the same time addressing peak flows at POTWs.
