Charlotte officials on Friday announced an interagency task force would investigate the PCBs and other toxic chemicals that were apparently dumped into the citys sewer system.
The chemicals, which were discovered around midday Thursday at the Mallard Creek sewage-treatment plant, are not believed to have reached the creek itself. The citys water supply was not affected.
Anything thats coming out of your faucet is OK, Mayor Patrick Cannon said at a late-afternoon news conference.
The full-time task force of local, state and federal agencies will operate under the Charlotte-Mecklenburg Police Departments arson investigations unit.
It will pursue felony charges for contaminant dumping under state and federal law. Surveillance video is already being reviewed, police Chief Rodney Monroe said.
The treatment plant shut down Thursday once workers detected a suspicious sheen on the wastewater coming into the plant. The plant started back up Friday morning.
They had to be paying attention to see it, Charlotte-Mecklenburg Utilities Director Barry Gullet said of his staff.
PCBs, a family of chemical compounds that is a long-lived environmental contaminant, were measured coming into the treatment plant at 26 parts per million, Gullet said. They were banned in 1979.
Treated sewage leaving the plant, soon after its restart, varied from 1.4 to 4.8 parts per billion thousands of times cleaner than what came in. The Environmental Protection Agency standard for PCBs in treated wastewater is 3 ppb.
Treated levels of trichlorobenzene, a solvent that also was detected, ranged from 12 ppb to 64 ppb, just above the safety threshold in streams of 61 ppb.
If there is any impact on the environment, I believe it will be very minimal, probably undetectable, Gullet said. He said the first water intake, 50 miles downstream on Blewett Falls Lake, should not be affected.
Still, authorities advised residents in a four-county area downstream from the plant, which is in northeast Mecklenburg County near the Cabarrus County line, to avoid contact with water in Mallard Creek and the Rocky River.
The Rocky River flows through Cabarrus, along the Stanly-Union county line, and then joins the Pee Dee River near the Anson County line. State officials said Friday afternoon that residents in Cabarrus, Union, Stanly and Anson counties have been warned.
Tom Reeder, director of the N.C. Division of Water Resources, said the chemicals would have been very damaging to both the Mallard Creek Wastewater Treatment plant and the environment, had they been released.
Amy Ringwood, an associate professor at UNC Charlotte who specializes in environmental toxicology, said PCBs, or polychlorinated biphenyls, are among the longest-lasting environmental contaminants and toxic in very low doses.
I consider PCBs to be one of our worst, Ringwood said. To be honest, I put them with mercury.
PCBs were used for decades to insulate and lubricate a vast range of products, from electrical transformers and capacitors to caulk and paint. Ingested in large doses, they can hurt the neurological development of children, the reproductive and immune systems, and may cause cancer.
North Carolina last year issued fish-consumption advisories for PCBs in striped bass caught in Lake Norman. Advisories were issued for Mountain Island Lake, Charlottes main water source, and the North Carolina portion of Lake Wylie in 2011.
Ingested by fish and other aquatic life, or birds that feed near creeks, PCBs accumulate in the animals tissue. The compounds dont break down completely, leaving affected wildlife with reproductive or immunity problems that can make them susceptible to disease.
Dump site identified
City officials said they believe the chemicals were dumped into the sewer system 10 miles from the Mallard Creek sewage-treatment plant.
We think we have traced it back to a sanitary sewer near West Sugar Creek Road and W.T. Harris Boulevard, said Charlotte-Mecklenburg police Detective Rob Klass.
Officials said there is a Food Lion store near that sewer but said the store is not suspected in the case. An Emergency Response truck from the federal Environmental Protection Agency and a number of firetrucks were parked near the store for several hours Friday, apparently conducting tests on the sewer.
City Manager Ron Carlee said authorities surmise a septic truck probably dumped the materials into the sewer. The materials then flowed through the sewer system about 10 miles to the Mallard Creek plant.
We are looking at a time frame from late Wednesday night to early Thursday, Klass said, adding that trucks typically can carry between 3,000 and 5,000 gallons of sewage.
Klass said he does not believe there was an attempt to harm anyone. What we have learned from similar incidents elsewhere is that it is usually the result of someone trying to save money.
While PCBs are banned, they are still found in the environment in transformers and other devices built before the late 1970s. Gullet said it is very expensive to dispose of PCBs, and he suspects someone dumped the chemicals illegally in an attempt to save money.
Authorities in South Carolinas Upstate have been investigating several illegal dumpings of PCB-tainted sewage last year in Spartanburg, Greenville and Lyman. The Spartanburg Herald-Journal reported in December that an official with a sewage company was arrested and charged with perjury and obstruction of justice. The newspaper reported the charges stemmed from comments made by the official in an Aug. 9 hearing about PCB being found in the Lyman sewage system.
Klass said police are asking anyone who might have seen suspicious activity near the Food Lion store late Wednesday or early Thursday to call 911 or leave information with Crime Stoppers, 704-334-1600.
Davie Hinshaw contributed.
Henderson: 704-358-5051; Twitter: @bhender