Posted on: July 21, 2017

No Pesticides or Herbicides Found in Charleston Water System Water

Recent Charleston Water System (CWS) tests match at least 20 years of South Carolina Department of Health and Environmental Control (DHEC) sampling data indicating no pesticides or herbicides in its drinking water. Five water samples, including both raw and treated water, were analyzed for more than 200 analytes, which includes pesticides, herbicides and other organic compounds.

“Every decision we make begins with public health in mind and we are committed to providing clean, safe, and reliable drinking water to our customers,” said Kin Hill, CEO at CWS. “We responded immediately to this situation out of an abundance of caution and because we wanted to assure the community that there are no pesticides or herbicides in our drinking water.”

CWS will participate in a community meeting to discuss test results at 6:30 p.m. July 24 at the Mount Pleasant Waterworks’ Operations Center located at 1619 Rifle Range Road, Mount Pleasant, SC 29464. Complete CWS test results are available at This complete absence of pesticides and herbicides mirrors Mount Pleasant Waterworks and DHEC test results available at and

CWS voluntarily expanded tests to its water system in response to community concern. These concerns originated from non-certified water screening test kits utilized by homeowners that appeared to indicate the presence of pesticides in Mount Pleasant drinking water, a portion of which is supplied by CWS.

CWS water samples were collected at five sites July 12 and July 14. They included:
•    Raw water from the Bushy Park Reservoir and the Edisto River as they enter the Hanahan Water Treatment Plant.
•    Treated water as it exited the Hanahan Water Treatment Plant, which supplies the entire 460 square mile CWS service area.
•    Treated water at the CWS feed point into Mount Pleasant at I-526.
•    Treated water at the CWS feed point into Mount Pleasant at Highway 41, which serves the general area of the Rivertowne, Park West and Dunes West communities where recent concerns were concentrated.

Eurofins Eaton Analytical, the only lab certified by SCDHEC to test for this extensive battery of pesticides and herbicides, analyzed CWS samples at its South Bend, Indiana facility. Because the samples were collected over two days, official Eurofins results were delivered to CWS in two separate reports July 19 and July 20, which were then evaluated by the utility. All samples tested negative for pesticides and herbicides.

Eurofins results included the presence of three Trihalomethane (THM) analytes, which are not pesticides or herbicides. Rather, they are very common chloramine/chlorine disinfection by-products consistently found in water systems that source their product from surface water. The CWS total THM (TTHM) level was 12.3 ppb (parts per billion), far below the DHEC and United States Environmental Protection Agency (EPA) regulatory limit of 80 ppb locational running annual average.

“We’re a highly regulated public utility that complies with, meets, and exceeds all water industry standards set by DHEC and the EPA to assure our water is safe for public consumption,” said Hill. “We take that responsibility very seriously every day.”

Founded in 1917 and celebrating its 100th anniversary in 2017, CWS is a public water and wastewater utility that provides water service to more than 400,000 people in the greater Charleston area and sewer service to more than 180,000.

Sampling  Results 1 

Sampling Results 2 

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