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2023 Sewer Spill Report

January 30, 2024

For the last eleven years we have compiled 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. In 2023 there were 114 reported sanitary sewer overflows (SSO's) totaling 4,190,509 gallons of sewage spilled in our watershed. This is a very significant increase from previous years.

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.

2023 Sewer Spill Summary

PERMITTEE	# of Spills	Volume of Spills (Gallons)	% of Total
CITY OF COLUMBIA	87	4,084,723	97.48%
RICHLAND COUNTY - BROAD RIVER WWTP	7	43,946	1.05%
RICHLAND COUNTY - EASTOVER WWTP	2	40,500	0.97%
FAIRFIELD COUNTY - WINNSBORO JACKSON CREEK WWTP	1	9,000	0.21%
SOUTHWEST WATER COMPANY - ALPINE, BUSH RIVER, AND WOODLAND WWTPs	10	3,600	0.09%
LOWER RICHLAND BUS TRANSIT STATION	1	3,000	0.07%
FORT JACKSON SEWER COLLECTION SYSTEM	2	1,660	0.04%
BLUE GRANITE WATER COMPANY	2	1,580	0.04%
EAST RICHLAND CO PSD - GILLS CREEK WWTP	1	1,500	0.04%
CITY OF CAYCE	1	1,000	0.02%
CITY OF WEST COLUMBIA	?	?	-
TOWN OF LEXINGTON	?	?	-
TOTAL	114	4,190,509	100.00%

The more than 4 million gallons of sewage spilled in 2023 marks the second largest total volume of sewage spilled in all the years we've compiled these annual reports. Approximately 94% of that total volume is related to two specific events experienced by the City of Columbia: a nearly 3.5 million gallon spill on April 9th (discussed more below), and a half a million gallon spill in August caused by a mechanical issue. All of these spills highlight the need to invest in sewer systems, conduct regular preventative maintenance, and perhaps most importantly, to learn from past mistakes so they won't happen again.

Wastewater Plant Upsets and Bypasses

While this report focuses on sewer overflows (when untreated wastewater spills from the collection system before it reaches a treatment plant), sewer providers in our area also experienced several "unanticipated bypass" or "plant upset" events at their wastewater treatment plants. These events occur when wastewater leaves the treatment plant before being fully treated, and generally have similar impacts to sewer overflows.

The City of Columbia experienced three bypass events at their wastewater treatment plant in 2023, the most significant of which was the April 9th (Easter Sunday) event. The bypass event was caused by a complete loss of utility power at the wastewater treatment plant. The loss of power caused wastewater flowing to the treatment plant to backup and spill out of the collection system, impacting several waterbodies, including the Congaree River and Gills Creek. The other bypass events occurred on February 8th and September 13th. You can read more about the April bypass event as well as the City's efforts to address sewer spills in this article from The Post and Courier.

The Town of Lexington also experienced a significant bypass event from the Watergate wastewater treatment plant in March of 2023 impacting 14 Mile Creek, a tributary to the Lower Saluda River. The aging wastewater treatment plant, which the Town took over from Blue Granite Water several years ago, discharged partially treated wastewater into the creek for nearly 2 weeks. The plant has since been connected to the regional sewer system and the discharge to 14 Mile Creek has been eliminated.

Top 10 Reported Sewer Spills

Date	Permitte	Spill Volume (Gallons)	Location / Receiving Water	Notes / Cause
Apr 9, 2023	CITY OF COLUMBIA	3,435,100	Various waterbodies, including Congaree River and Gills Creek	Equipment failure resulting from a loss of Utility Power
Aug 7, 2023	CITY OF COLUMBIA	495,040	Tributary to Gills Creek	Failure of an air release valve on a pressurized sewer line, while maintenance was being performed
Dec 11, 2023	RICHLAND COUNTY - BROAD RIVER WWTP	41,000	Broad River	Excessive flow from rainfall entering plant. 2.25 inches of rainfall at plant’s rain gauge.
Jul 15, 2023	RICHLAND COUNTY - EASTOVER WWTP	40,000	Hampton Williams Rd & Congaree Church Rd, near Tom’s Creek	Bore machine struck side of force main puncturing a large hole in the side
Feb 21, 2023	CITY OF COLUMBIA	31,279	Tributary to Broad River	Blockage - Debris
Feb 8, 2023	CITY OF COLUMBIA	14,200	Storm drain at WWTP	Blockage in a solids transfer pipe appears to have caused the unanticipated bypass of partially treated wastewater at the WWTP
Aug 8, 2023	CITY OF COLUMBIA	14,000	Reeder Point Branch	Temporary shutdown of the city pumpstation to address the downstream air release valve failure (related to Aug. 7th overflow above)
Jun 1, 2023	FAIRFIELD COUNTY - WINNSBORO JACKSON CREEK WWTP	9,000	Behind 1 Pro Pallet Way - Stream Behind right-of-way	Blockage
Apr 18, 2023	CITY OF COLUMBIA	7,603	Stormwater ditch near Columbia Canal	Blockage - Roots
Sep 12, 2023	CITY OF COLUMBIA	7,015	Unnamed tributary to Smith Branch	Blockage - Roots

Important Notes

This report only represent 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 had numerous 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 public information about. Some sewer providers and satellite sewer systems experienced spills but failed to officially report the data to DHEC, including the City of West Columbia and the Westwood Estates Apartments (formerly Riverbend Apartments).