Threats to the environment from a toxic industrial chemical sparked action Thursday from state regulators, who are concerned the material could show up in sewage sludge that farmers use to fertilize their fields.
The S.C. Department of Health and Environmental Control board voted unanimously to require that wastewater treatment plants and others monitor more often for PCBs in sewage sludge that will be applied to farm fields.
The board’s action also reserves the agency’s right to require cleanup when the toxins reach elevated levels.
Thursday’s decision to establish the sludge regulations needs approval from the Legislature, a potentially difficult task if utilities, farmers and sludge haulers oppose tighter oversight. Some complained at a public hearing that the rules were too restrictive.
But DHEC officials said they hope the regulations will give them a better handle on the scope of PCBs in sludge across South Carolina. PCBs, short for polychlorinated biphenyls, are probable human carcinogens that persist in the environment for generations.
DHEC water bureau chief David Wilson said the rules “provide public health protection and protection for the environment.’’ About 70 utilities and organizations have approval to land apply sludge across South Carolina.
The new rules apply to PCB levels that are lower than the federal limit of 50 parts per million in sludge. Wastewater plants and others would have to monitor farm-bound sludge four times a year, as opposed to once.
The federal government banned production of PCBs in 1979 because of the health impacts the material can have on people and wildlife. A handful of waterways in South Carolina, including lakes Hartwell and Wateree, contain state warnings to limit consumption of some fish because of water pollution believed to have occurred decades ago.
Despite the long-standing ban, elevated levels of PCBs began showing up in the sludge at Upstate sewage plants last year and later were found in Richland County, causing concerns that the toxins could be applied to farms in sludge used to grow some crops.
That prompted DHEC to approve emergency regulations limiting the use of sludge containing PCBs on crops. But those regulations are temporary and expire later this month. The agency now is looking for a permanent solution to protect against PCBs in sludge.
So far, no one is sure where the PCBs came from, but many of the materials are believed to still be in use by industries — and as equipment breaks down, PCB waste is created. The PCBs found last year sparked a criminal investigation of illicit sewage dumping in the Upstate.
Sewage sludge, a byproduct of the waste treatment process, is used by some farmers as an affordable way to fertilize their fields. Utilities often have been willing to provide sludge, rather than send it to a landfill, which can be expensive.