Draft legislation that surfaced last week appears to prohibit the calculations on which hundreds of don’t-drink advisories were issued last year for wells near Duke Energy ash ponds.
Many of those advisories warned of hexavalent chromium, which may cause cancer. Because no specific state or federal standards exist for the toxic metal, health officials based the advisories on calculations of cancer risks.
Nearly a year later, the state Department of Health and Human Services rescinded the advisories. The agency and the Department of Environmental Quality had wrangled over what constitutes safe levels of hexavalent chromium.
Health officials, in explaining the reversal last month, said the benchmarks they used for the advisories were too stringent compared to those applied elsewhere. The levels of contamination found near Duke’s ash, they added, are commonly found in public water systems and may occur naturally.
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“I think it’s fair to say the state did inconsistent things, with one department sending out a notice and the other department saying there’s no problem here,” said Rep. Chuck McGrady, the Hendersonville Republican who cochairs the Environmental Review Commission. “I think the sense of the legislation was that we didn’t want to confuse the public further.”
The commission on Wednesday moved forward a bill that prohibits health advisories from being issued for water contaminants unless federal or interim state standards have been established. Hexavalent chromium has neither.
McGrady said he doesn’t want legislation to limit the state’s ability to issue health warnings when they are needed.
But the advocacy group Clean Water for North Carolina says the bill would gut the public notices that state health officials have issued for decades.
“This bill was carefully crafted to essentially take away any tool to provide health-based notifications,” said executive director Hope Taylor. “What they are doing is trying to give themselves statutory authority to do what they have done, and to prevent the health department from doing such a radical thing as warning people about the health of their drinking water.”
In the past year, Duke’s neighbors have received both jarring health warnings and soothing reassurance from the state about their well water.
The health and environment departments wrangled internally for months last year over what benchmark to use for hexavalent chromium.
DEQ wanted to use the state groundwater standard for total chromium, which includes its hexavalent form, of 10 parts per billion. DHHS eventually won its argument for a far lower level, 0.07 ppb, which was calculated on the risks of adding one cancer case among 1 million people over a lifetime of drinking the water.
Duke Energy says its studies show that ash is not responsible for the contamination, but the company has supplied bottled water since last year to hundreds of homes.
Environmental advocates, meanwhile, challenge the state’s assertion that similar levels of hexavalent chromium are found in municipal water systems.
Catawba Riverkeeper Sam Perkins compiled data showing that average levels of hexavalent chromium in private wells near two Duke plants, Allen and Buck, were at least 20 times higher than the averages of 11 public systems including Charlotte’s. Neighbors of Allen, on Lake Wylie, and Buck in Rowan County got the highest number of don’t-drink advisories last year.
“This is simple arithmetic with publicly available data,” Perkins said. He also cited studies saying hexavalent chromium naturally occurs less often than state officials suggest.
The environment and health departments endorsed a new protocol for issuing public health notifications about hexavalent chromium and a second contaminant, vanadium, earlier this month.
An April 1 report to the Environmental Review Commission recommended that health-risk evaluations for wells should be uniformly based on federal standards under the Safe Drinking Water Act.
The 25-year-old federal standard for chromium in public water supplies, including its hexavalent form, is 100 ppb – more than 1,400 times higher than the screening level North Carolina used to issue health warnings to Duke’s neighbors.
Including information about the higher federal standard in public health notices, the report said, “will allow for a more informed health risk conclusion by the private well owner.”
The Environmental Protection Agency is studying whether to develop a separate standard for hexavalent chromium, and the April 1 report recommended that North Carolina adopt any standard that results from that federal study. EPA has said it will reveal late this year a range of standards it may propose, DEQ spokesman Mike Rusher said.
“Based on the understanding that future action is coming, (DEQ is) recommending essentially a uniform set of standards,” Rusher said of the April 1 report.
The Department of Health and Human Services referred questions about the report to the Environmental Review Commission.