The toxic chemicals found in the sewer system in February will cost Charlotte more than $1.3 million to clean up as the city increases testing for the substances.
PCBs traced to a grocery store grease trap were detected as they flowed into the Mallard Creek treatment plant in early February. This month the Charlotte-Mecklenburg Utility Department said the carcinogenic chemicals also showed up in sludge at the McAlpine Creek plant.
CMUD suspects the dumping was by someone who wanted to avoid the expense of legally disposing of the chemicals. Authorities offered a $10,000 reward for information.
The Charlotte City Council approved vendor contracts Monday night totaling $970,000 for testing, waste handling and decontamination from the PCB episodes. Council approved an additional $317,000 to buy new new lab equipment and supplies as testing for PCBs increased.
Those dont represent the full cost of the PCB response, CMUD spokesman Cam Coley said. Cost details will be updated later, he said.
Once widely used as a coolant and lubricant, PCBs were banned in the United States in 1979. The chemicals are likely to cause cancer and dont readily break down in the environment, accumulating in fish and wildlife.
Charlotte joined several treatment systems in South Carolina that were victims of illegal dumping last year. The discoveries heightened health concerns about the potential spread of contaminated sewage sludge.
PCBs were detected in four South Carolina treatment systems, beginning in July. None has been found in North Carolina cities other than Charlotte, state officials say.
The chemicals accumulate in the sludge byproduct of sewage treatment. Nutrient-rich sludge is commonly applied to farm fields as fertilizer, and that has raised concerns about whether PCBs were inadvertently spread on crops.
The S.C. Department of Health and Environmental Control issued an emergency ban last September on spreading PCB-contaminated sludge. A bill to permanently tighten controls on PCBs in sludge is before the legislature.
Its not clear whether Charlottes and the four S.C. systems were targeted by the same person.
Two forms of PCBs detected at the Charlotte treatment plants were also found in South Carolina, said CMUD environmental management Director Jackie Jarrell. That tends to make you think it could be connected, she said.
The department believes PCBs flowed into the McAlpine plant sometime between November and early March. An initial report of PCBs at McAlpine last October is believed to have resulted from a lab error.
CMUD has increased the frequency of testing of wastewater and sludge for PCBs from once a year to three times a week.
Sludge with PCB concentrations of less than 50 parts per million can be sent to local landfills. CMUD has about 1,000 cubic yards of sludge with concentrations of 60 to 70 ppm that will be sent to a hazardous waste landfill in Alabama.
Sludge sent to farms
CMUD ships thousands of tons of sludge a year to farms in the region.
The PCB contamination heightened concerns in South Carolina, where about half of CMUDs sludge goes. Residents there have been highly critical of sludge spreading, with 300 turning out last year to protest renewal of the departments South Carolina sludge permit.
Chester County, S.C., resident Dave Cole, a leading critic of CMUD, says new analytic tests could have found PCBs that were in sludge sent to the state.
We believe that because Charlotte is now all of a sudden testing and finding it, that leads us to believe Charlotte has probably distributed PCBs in South Carolina, Cole said.
CMUD says no contaminated sludge crossed the border after the first hint of PCBs emerged in September.
We chose not to do land application even when we saw it was a small amount, Jarrell said. Because we didnt know for sure, we chose not to land apply that batch of solids.
DHEC said no Charlotte sludge has been spread in South Carolina since the state ban took effect in late September. CMUD says no S.C. land applications will be done in April or May.
Were going to be as responsible as we can be with land application, Jarrell said. Weve been diligent about monitoring and if we see anything at all, our decision was to send it to the landfill. I think the people in South Carolina can feel good about that.