2016 Sewer Spill Report

For the last four years we have compiled and analyzed data from DHEC's sanitary sewer overflow (SSO) database to produce a report on the previous year's sewer spills. In 2016 there were 184 reported sewer spills resulting in more than 2.4 million gallons of sewage spilled in the Congaree Riverkeeper jurisdictional area.

2016 Sewer Spill Summary

Some important things to note:

• The table above only represents the reported spills within Congaree Riverkeeper’s jurisdictional area.  Several sewer providers had additional spills impacting other waters in the Midlands, including Lake Murray (Town of Chapin) and the Wateree River watershed (Palmetto Utilities Inc).

• Some sewer providers including the City of West Columbia and Serenity Apartments experienced spills that were not reported to DHEC.  You can see evidence of a 2016 City of West Columbia spill that was not reported to DHEC here.

• Unlike other permittees that only have to report spills that are over 500 gallons or that impact a waterbody, the City of Columbia is required to report all of their spills.  The City of Columbia also operates the largest sewer system in the region and one of the largest in the state.

Top Ten Reported Sewer Spills

(Click chart to enlarge)

• The top 10 spills accounted for approximately 84% of the total volume of all sewer spills for the year.

• 7 of the top 10 spills were related to two storm events; Hurricane Hermine and Hurricane Matthew.

• While the February 17th Stoops Creek spill was the largest reported spill of the year at over half a million gallons, we estimated that the volume of that spill was actually between 5 and 15 million gallons. You can read more about that spill in this article from the Free Times.


(Video of Stoops Creek SSO)


The DHEC database lists several different causes for sewer spills.  The most significant cause, in terms of both number of reported spills and volume of sewage spilled was "collapsed line / force main" (approx. 22% of spills, 50% of total volume spilled).  Other significant causes included "roots" (19% of spills, 2% of volume), "wet weather" (11% of spills, 26% of volume), "equipment / pump station failure" (11% of spills, 15% of volume) and "grease" (11% of spills, 1% of volume).

Past Reports

Click on the year to view sewer spill reports from previous years: 2015, 2014, 2013.


(Video of May 3rd Broad River SSO)