For six consecutive years, Congaree Riverkeeper has compiled and analyzed data from
DHEC's sanitary sewer overflow (SSO) database
to produce an annual sewer spill report. In 2018, there were 229 reported sanitary sewer overflows resulting in just over 400,000 gallons of sewage spilled in Congaree Riverkeeper’s jurisdictional area. While this marks another significant reduction in the total SSO volume from previous years, there are some important caveats.
2018 Sewer Spill Summary
*While the above numbers depict an overall improvement in the reduction of sewer spills, especially as it relates to the City of Columbia, the data, alone, does not provide a full snapshot of the impact of sewer spills in the Midlands area. For example, in November, an incident occurred at the City of Columbia's wastewater treatment plant that resulted in the “unanticipated bypass” of an approximately
2.25 million gallons of partially treated sewage.
The bypass, caused by a combination of factors including high water and equipment failure, was not reported as a Sanitary Sewer Overflow (SSO), because the sewage had already entered the treatment plant and gone through the first stage of treatment. Despite the event not being labelled an "SSO," the bypass nonetheless resulted in significant discharge of sewage into the Congaree River. Congaree Riverkeeper met with City of Columbia wastewater staff at the treatment plant in early December to discuss the incident and what actions the City is taking to prevent spills of this nature in the future.
Additional, Important Notes
- The table above only
represents the reported sanitary sewer overflows within the Congaree Riverkeeper jurisdictional area. Several sewer providers in the Midlands, including the Town of Chapin, Richland County Utilities, and Blue Granite Water Company/Carolina Water Service also had spills that impacted other waterbodies, like Lake Murray. This includes a 28,800-gallon spill from Blue Granite Water Company/Carolina Water Service’s Watergate Plant into the lake in December.
- Most sewer providers are only required to report spills that are over 500 gallons or that impact a waterbody. The City of Columbia is required by its consent decree to report all of its spills, no matter the volume or impacted area.
- This report only shows sewer overflows that were reported to DHEC. Some sewer providers and satellite sewer systems fail to officially report their spills, like the December spill at the Riverbend Apartments that Congaree Riverkeeper documented and reported (see video below).
Top Ten Reported Sewer Spills
SSO Hotspots
Lake Catherine / Gills Creek
Lake Katherine, in the Gills Creek watershed, is the number one SSO hotspot with spills regularly occurring whenever the Midlands receives any significant amount of rainfall. The City of Columbia is working on a sewer project that it hopes will resolve the SSO issues. The project should be completed in the next year.
Rawls Creek
Blue Granite Water Company/Carolina Water Service had several SSOs from its Friarsgate system that impacted Rawls Creek, a tributary to the Lower Saluda River that runs through Saluda Shoals Park. While the discharge from the Friarsgate wastewater plant into the Saluda River is scheduled to be eliminated this spring, it is clear that the company still has significant work to do on its collection system.
Top SSO Volumes From Around the State