Dozens of contaminants were found within the protected areas of Congaree National Park, according to a recent study by the U.S. Geological Survey in cooperation with the National Park Service.
Researchers collected 72 water and sediment samples from 16 river and lake sites around the park and found 49 pharmaceuticals and 47 other contaminants, including pesticides and chemicals associated with wastewater.
The study examined whether contaminants are commonly found within protected areas, and if so, their sources.
Congaree National Park is a 27,000-acre nature preserve southeast of Columbia.
“Congaree National Park, like other parks around the country, is positioned in a landscape where surrounding land uses, municipal wastewater discharges and on-site visitation can potentially introduce contaminants into the protected areas,” Paul Bradley, USGS Research Ecologist/Hydrologist and lead author of the study, said in a statement. “Our main goal with this study, which was requested by the National Park Service, was to provide key information to help park managers understand the potential sources of a variety of water contaminants detected in protected areas.”
More from the statement from the USGS:
▪ “The contaminants found were detected at levels below any considered to pose a risk to the health of park visitors who might drink or come in contact with waters in the backcountry. Additional research would need to take place to determine if the present levels or mixture of contaminants could cause adverse health impacts to aquatic organisms.”
▪ “Pharmaceuticals were found in water samples from across the park, with higher occurrences and concentrations near the Congaree and Wateree Rivers and in Horseshoe Lake, which are all locations downstream of municipal wastewater discharges from Columbia, South Carolina and Charlotte, North Carolina.”
▪ “Metformin, a drug used to treat diabetes and one often found when wastewater discharges into rivers or streams, was the most frequently detected pharmaceutical. It was found in 61 percent of the samples, and was the only pharmaceutical observed in either water or sediments at all 16 sites.”
▪ “Some of the contaminants found, like antibiotics and antibacterials, have been shown in studies elsewhere to negatively affect microbes, which form the base of aquatic food webs. Other pharmaceuticals detected in the park have been shown elsewhere to alter fish behavior and health.”
▪ “The insect repellant DEET, or N, N-diethyl-m-toluamide, was one of the most commonly found contaminants in the park, being detected in 71 percent of all water samples. It was found at least once in every surface water body within the park, including those deep in the park unaffected by wastewater discharges.”
According to Bradley: “The National Parks are protected areas, but contaminants that may be of health concern to aquatic life have the potential of entering the park from both inside and outside sources. Understanding if contaminants are present and, if so, what their likely sources are is key to helping park leadership manage the risk of exposure to people and wildlife.”