2024 Sewer Spill Report

For the last twelve years we have published an annual sewer spill report for Congaree Riverkeeper's jurisdictional area, which includes the Lower Saluda, Lower Broad, and Congaree Rivers, and their tributaries, using data from DHEC's Sewer Overflow Database as well as other spills we investigated.  In 2024 there were more than 100 reported sanitary sewer overflows (SSO's) totaling well over a million gallons of sewage spilled in our watershed.

Sewer overflows can contaminate waterways and impact water quality, creating both ecological and public health issues. River users who are exposed to sewer overflows may experience health problems including infections, rashes, and gastrointestinal issues.

2024 Sewer Spill Summary

Hurricanes and Data Constraints

The Midlands were impacted by two hurricanes in 2024: Debbie in August and Helene in September. Both storms brought significant rainfall and flooding, and resulted in numerous sewer spills across the region.

Identifying and addressing sewer spills during flood events can be very difficult. The spill location can be underwater or in areas that are unsafe to access for days, and estimating volumes can be nearly impossible. For example, the City of Columbia was unable to provide volume estimates for the spills during Helene and the flooding that followed and were only able to provide a list of locations where spills were confirmed (see below).

Additionally, during the flooding after Helene the City of Columbia's wastewater plant on the Congaree River experienced flooding and was only able to provide partial treatment to the wastewater being discharged into the river.

Another example of the difficulty of storm-related spills and the limits of some of this data is the spill that the City of Cayce reported in late October (several weeks after Helene) that impacted 6 Mile Creek. The City estimated the spill volume at "over 5,000 gallons" based on when they first observed the spill, but it was likely flowing for several weeks and much larger.

All this is to say that the 1.1 million gallon total on the chart above is significantly lower than the actual volume of sewage spilled into the watershed in 2024.

SSO Hotspots

Broad River / Columbia Canal

The Broad River and its tributaries (including the Columbia Canal, a drinking water source for the City of Columbia) experienced numerous SSOs throughout the year, including during the two hurricanes. The video below shows a large spill impacting the Columbia Canal in March of 2024.

Lower Saluda River

The Lower Saluda River and its tributaries experienced several large SSOs from various sewer providers.

Gills Creek / Lake Katherine

The Gills Creek watershed experienced multiple large SSOs during both hurricanes.

Reeder Point Branch

The City of Columbia had two of the larger spills of the year near their sewer pump station off Bluff Road that impacted Reeder Point Branch, a tributary to Mill Creek and eventually the Congaree River.

 Additional Important Notes

• This report only represents the reported sanitary sewer overflows within the Congaree Riverkeeper jurisdictional area. Some sewer providers in the Midlands had spills that impacted other waterbodies outside of our jurisdiction. For example, the Town of Chapin and Richland County had several spills impacting Lake Murray, Palmetto Utilities impacting the Spears Creek / Wateree River watershed, and the Town of St Matthews impacting the headwaters of Lake Marion.

• Most sewer providers are only required to report spills that are more than 500 gallons or that impact a waterbody.
  
  
• This report also only accounts for sewer overflows that were reported to DHEC or that we had information about. Some sewer providers and satellite sewer systems experienced spills but did not officially report the data to DHEC (like the Westwood Estates Apartments that regularly has spills but fails to report them).

Past Reports

Click the links to view the past reports from 2022 and 2023.