The cost to deal with the chemical contamination of two Charlotte sewage treatment plants reached $4.5 million Monday and could go millions of dollars higher.
The Charlotte City Council approved a $3.2 million contract to haul off tons of sludge contaminated by PCBs at two treatment plants. That’s in addition to the $1.3 million the council authorized in April for emergency response costs such as testing, waste handling and lab equipment.
Charlotte-Mecklenburg Utilities detected long-banned chemicals called PCBs and a second contaminant, trichlorobenzene, flowing into the Mallard Creek treatment plant on Feb. 6. They were later traced to a grocery store’s grease trap.
In April, the chemicals were found in sludge at the McAlpine Creek plant after apparently entering the plant in late 2013 or early this year.
PCBs are believed to cause cancer in people. In the environment, they accumulate in fish and wildlife tissue and don’t readily degrade into a harmless form.
The chemicals also accumulate in the sludge that is a byproduct of waste treatment.
Charlotte-Mecklenburg Utilities now has 6,000 tons of contaminated sludge that will have to be trucked to a hazardous-waste landfill in Alabama for an estimated $1.5 million. Nearly 40,000 tons with low levels of PCBs will be disposed of in local landfills for about $1.7 million.
Synagro, which already contracts with the utility to spread sludge as fertilizer on farm fields, will be awarded those contracts. The utility said it hasn’t sent sludge to be applied on fields since the PCBs were first detected.
A final step will be cleaning and decontaminating basins and tanks at the treatment plants.
“At a minimum, we think the $3.2 million is going to double,” said Barry Shearin, the utility’s deputy director for operations. The department hopes total costs don’t rise above $10 million, he said.
The costs will have no immediate impact on customer rates, Shearin said.
PCBs had also been found in four South Carolina treatment systems about a year ago. Based on their experience, the Charlotte cleanup is expected to take at least nine more months.
Spartanburg Water, a South Carolina utility, first detected PCBs in sludge at three treatment plants in June 2013. The utility, which is smaller than Charlotte’s, estimates its cleanup costs at $2.5 million.
A multi-agency investigative task force headed by the Charlotte-Mecklenburg Police Department has not announced arrests in either of the Charlotte cases. A $10,000 reward for information was posted.