Catawba Riverkeeper Sam Perkins is co-author of a report on municipal sewage sludge and water contamination.
Sludge is the nutrient-rich byproduct of water and sewage treatment that is spread on farm fields as fertilizer. It’s approved for that use, but with caveats.
Experts say sludge contains heavy metals that can be toxic and traces of everything you might flush down a toilet, from pharmaceuticals to pathogens. State laws dictate that sludge must not be spread near water or during rain.
Charlotte Water has faced protests over its sludge from farm communities in Rowan and Cabarrus counties and in South Carolina.
The report from Waterkeepers Carolina cites two examples, both in the Haw River basin west of Raleigh, where sludge may have contaminated water.
Cancer-causing perfluorinated chemicals, found in Chatham County in 2007, probably came from sludge runoff and wastewater effluent, the report says. It’s “logical to conclude,” the report adds, that related chemicals found in Orange County also came from sludge.
PCBs, short for a family of toxic chemicals called polychlorinated biphenyls, were dumped into Charlotte’s wastewater stream last year. Charlotte Water says no PCBs reached its sludge, but halted its distribution for several months.
The ability of sludge to contaminate water, the Waterkeeper report concludes, is compounded by weak regulations and poor oversight.