Water treatment process tested

Gwinnett County’s water treatment system has passed a test showing it is capable of removing certain compounds that may become regulated by the government.

The study, conducted by the University of North Carolina, tested water for 19 compounds primarily found in pharmaceuticals, cleaners, lotions and sunscreens. The study used an unusually low reporting limit of 10 ng/L (nanograms per liter or parts per trillion), which requires special lab equipment to detect.

Tests were conducted at four points: the raw water intake for the Shoal Creek Filter Plant at Lake Lanier; processed drinking water after treatment; wastewater entering the Hill Water Resources Center; and treated effluent returned to the Chattahoochee River.

The U.S. Environmental Protection Agency sets national standards for water quality under the Safe Drinking Water Act, but it has not issued regulations for these particular compounds, collectively known as PPCPs.

Results showed most of the 19 targeted compounds were removed to below detection limits by the Hill plant. Four compounds —- sulfamethoxazole, primidone, caffeine and DEET —- were detected at concentrations above 10 ng/L.

Intermediary treatment steps reduced the levels further.

None of the compounds was found at concentrations above the level of 10 ng/L in the finished drinking water.

These compounds can enter the environment when people flush medications or rinse other products down the drain, through excretion by humans or animals, and other disposal methods both proper and improper.

“Although it’s not been required, we believe it’s important to know what’s in our water and how effective our treatment processes are at removing these compounds,” said Lynn Smarr, Gwinnett’s acting director of Water Resources.

The EPA has published a strategy to address the issue of PPCPs that includes expanding the science as well as providing education, partnerships and regulations as necessary.