When is water clean enough? Duke Energy’s neighbors and the state debate.

As hundreds of people who live near Duke Energy’s power plants wait for alternative water sources, state officials are again grappling with water standards meant to protect public health.

Hundreds of homeowner wells near Duke’s plants, including two in Gaston and Rowan counties, were found with elevated levels of potentially toxic metals. The biggest concern was hexavalent chromium, which might cause cancer when found in drinking water.

Duke says the hexavalent chromium in the wells didn’t come from its stocks of coal ash stored at the plants. But state legislators last year ordered Duke to offer alternate water to its neighbors.

Most of the 900 households will connect to municipal water lines. But Duke plans to offer systems to filter contaminants out of well water to about 20 percent of the residents.

The debate now is how effective those filters should be.

On July 7, the state Department of Environmental Quality announced that the filters could leave no more than 10 parts per billion of chromium – including its hexavalent form – in household water.

But, confusingly to Duke’s neighbors, the state has a separate “health goal” for hexavalent chromium. It’s based on the risk of hexavalent chromium causing more than one cancer case in 1 million people over a lifetime of drinking the water.

The health goal is .07 ppb, 140 times more restrictive than the filter standard.

A Salisbury law firm representing people who live near Duke’s Allen power plant in Belmont and the Buck plant near Salisbury said the filter standard wouldn’t protect residents. Most of those residents, however, are expected to connect to water lines.

“While we appreciate other efforts the DEQ has taken to address the coal ash problems, we believe the newly-announced standards are far too lenient to Duke,” law firm founder Mona Lisa Wallace said in a statement Wednesday. “They would allow Duke to install water filtration systems that could contaminate at levels far above what hook-ups to municipal water would provide. We believe all Duke coal ash neighbors and their families are entitled to municipal water hook-ups and clean water.”

WBTV this week reported on an internal memo in which two state health scientists also said the new filter standard wouldn’t adequately protect well owners.

Duke Energy said Thursday it selected filter systems that would get as close to the more restrictive health goal as possible.

“The performance targets we provided to the treatment system vendors from the outset was the health screening levels, and we have no plans to change those expectations,” spokeswoman Erin Culbert said. The systems to be used typically reduce hexavalent chromium to below 1 ppb, she said, well within the 10 ppb filter standard.

But on Wednesday night, DEQ backtracked. The department said it would ask a state science panel whether the filter standard should be revised.

“We recognize the widespread community interest and concerns about these performance standards,” DEQ Secretary Michael Regan said in a statement.

The science panel will “evaluate more recent health data on hexavalent chromium and provide a public forum to address these important issues,” he said. DEQ will make a final decision on the filter standard after hearing the panel’s recommendations.

DEQ spokesman Jamie Kritzer said that while the filter standard is enforceable, meaning failures to comply could result in penalties, the health goal is not.

“There are sometimes differences among scientists about things when it comes to what is allowable by law versus what is a goal set from a health perspective,” he said. “We would all hope that the lowest level, or no, hexavalent chrome would be achievable” by the filters.

A similar debate over hexavalent chromium roiled former Gov. Pat McCrory’s administration last year, leading to the resignation of the state epidemiologist.

Affected homeowners have said they don’t know what to believe about the safety of their wells, so many have continued to drink only bottled water.

This story was originally published July 13, 2017 at 11:24 AM with the headline "When is water clean enough? Duke Energy’s neighbors and the state debate.."