Test results indicate that PFAS levels in Columbia’s drinking water are well below EPA’s health advisory levels.
Summary: The City of Columbia collected finished drinking water samples from each of its two water plants on October 28, 2020, just as DHEC did on June 8, 2020, and had those samples analyzed for the same 29 PFAS compounds using the same two testing methods. The City also collected samples from each of its two source waters, the Columbia Canal and Lake Murray, and had those samples analyzed for the same 29 compounds using a third testing method.
Finished Drinking Water Sample Results: The same eight PFAS compounds that were detected in DHEC’s June drinking water samples were also detected in the City’s October samples. Two additional compounds were also detected in the Canal Plant’s October samples, resulting in a total of ten PFAS compounds detected in the drinking water samples from one or both of the City’s water treatment plants. All compounds detected in the October samples were found at low levels similar to those found in the June samples. Combined levels of PFOA and PFOS were 12.58 and 12.70 parts per trillion (ppt) for the two testing methods in the Canal Plant samples, and 3.94 ppt for both methods in the Lake Plant samples, all well below the 70 ppt health advisory level. There are no health advisories for any of the ten detected compounds other than PFOA and PFOS.
Source Water Sample Results: Eleven of the 29 PFAS compounds tested for were detected in one or both of the Columbia Canal and Lake Murray source water samples, including seven of the ten compounds found in the drinking water samples plus four additional compounds, all at low levels. The highest level of any compound found in the source waters was 7.25 ppt, and five of the eleven compounds were found at levels less than one ppt. There are no health advisories for source water samples.
For More Information: In order to continue to develop information about PFAS levels going forward, Columbia Water will conduct its own PFAS testing every six months.
Please visit the EPA’s PFAS web page at www.ep.gov/pfas for tools, resources, and EPA actions to address PFAS. SCDHEC also has a resource page at www.scdhec.gov/BOW/perfluoroalkyl-substances-pfas which includes results from all the drinking water systems they sampled.