History

The City of Atlanta’s wastewater collection, conveyance and treatment system consists of approximately 2,000 miles of sanitary and combined sewers, seven combined sewer overflow (CSO) treatment plants, two CSO regulators, four water reclamation centers (WRCs) and sixteen pump stations. Atlanta’s sewer system dates back to the 19th Century, and much of the original infrastructure remains.

In the City’s center, in an area roughly 19 square miles, a combined sewer system conveys sewage and stormwater flows in a single pipe. The combined system represents about 15% of the total wastewater system area. Beyond the 19-square-mile combined sewer area, Atlanta’s sewers are separated. Sanitary wastewater flows in its own pipe to the treatment facility, and stormwater flows in a separate pipe directly into a receiving stream.

Atlanta’s sewer systems are aged and in disrepair. Excessive overflows from the combined sewer system, coupled with sanitary sewer overflows and leaks in the separated area, have negatively impacted area water quality. Combined Sewer Area is shown above in orange Atlanta’s Combined Sewer System was completed around 1920.