In June, the Alabama Department of Environmental Management tested for PFOA and PFOS contaminants in drinking water from three Coosa River Basin water systems and found mixed results: None tested above the safe level for contaminants, one system tested well below the top amount considered safe, and two others were near or at the safe line.

In response to those results, ADEM conducted another four weeks of testing in July for water systems in Gadsden and Centre, where higher levels of the contaminants were detected. No further testing was deemed necessary for the Coosa Valley Water Supply District.

The last of the results from July’s testing is expected next week, according to ADEM.

The tests were conducted after the US Environmental Protection Agency established new, lower drinking water limits for PFOA and PFOS. Several Alabama water systems on the Tennessee and Coosa rivers found themselves over the new limit and faced with making technical or hardware changes to lower the levels of the chemicals.

The initial four weeks of tests for the three systems showed average individual and combined PFOA and PFOS levels at or below the new EPA Health Advisory Level of 70 parts per trillion. ADEM spokesperson Lynn Battle said that, although average readings from the first round of sampling were not above the minimum safe drinking water levels, “based on the sample results and out of an abundance of caution, a second four weeks of tests were conducted for Gadsden and Centre.”

July test results that are available show PFOS and PFOA levels trending down for Gadsden’s water, according to Mike Lankford, superintendent of environmental services. Lankford said recent technical adjustments to the water system included an enhanced coagulation process and the addition of a positive-charged polymer to try to capture the slightly negative-charged PFOS in the water. The changes “appear to have had a beneficial effect on the levels of these chemicals,” he said.

The source of the contaminants has not been determined, but Lankford pointed out that northwestern Georgia is in the Coosa River basin and is the location of many facilities that used to use PFOA and PFOS to make carpet. The compounds were also used to make nonstick cookware, waterproof clothing and other products that are resistant to grease, water, or stains. “These compounds were used for almost 70 years, and industry continues to recycle carpet, which could be a potential source of PFOA and PFOS,” he said. “Another source could be the biosolids and effluent produced by wastewater treatment plants in that area of Georgia, he said.

Efforts to reach the Centre and Coosa Valley water systems failed.

In the Tennessee River area, the West Morgan East Limestone Water and Sewer Authority recently ordered the installation of a $4 million filtration system to deal with PFOA and PFOS contaminants.