WINSTON-SALEM — Trihalomethanes: If consumed in sufficient quantities over many years, these chemicals may cause cancer as well as kidney or liver problems, and they could adversely affect the central nervous system, according to the Agency for Toxic Substances and Disease Registry, part of the U.S. Department of Health and Human Services.
Few places in North Carolina illustrate the struggle undertaken by local officials to combat trihalomethanes as clearly as the town of Madison and city of Eden, as well as Henry County, Va.
Their yearslong struggle is directly linked to the Belews Creek Steam Station, the massive coal-fired power plant owned by Duke Energy Corp. in Stokes County. According to conservationists, the presence of trihalomethanes in the public drinking water provided by Madison and Eden exposes an alarming flaw in the way the U.S. Environmental Protection Agency regulates coal-fired power plants.
“Ultimately, we have regulations to protect people and right now we’re failing,” said Amy Adams, the North Carolina program manager at the nonprofit Appalachian Voices based in Boone.
Eden has spent more than $2 million over the past few years to upgrade its water-treatment system in an effort to better deal with trihalomethanes. The new treatment system will likely be operating soon, officials said last week.
“We should be up and running within a month or so,” Mayor Wayne Tuggle said. “We should be in good shape.”
Madison has spent just under $1 million to improve its water treatment.
Efforts to contact Madison officials were unsuccessful.
In Virginia, for years Henry County purchased water from Eden for its residents in the southern portion of the county known as Sandy Level. In May, Henry County stopped buying water from Eden, in part, because of the trihalomethanes that came along with the water. Rather, officials said, the county spent about $700,000 to provide water to the Sandy Level area.
While the trihalomethane problem was a factor, it was not the driving factor, Henry County officials said. Extending water lines to residents in the Sandy Level area was something that the county had wanted to do for a while.
But the trihalomethanes issue couldn’t be ignored.
“We did have concerns about the quality of water we were purchasing,” county administrator Tim Hall said.
In all three cases, the common source of water was the Dan River.
Root of the problem
A primary cause for spikes of trihalomethanes in the drinking water provided by Madison and Eden is bromide, which comes from the Belews Creek power plant in Stokes.
Bromide has been released for years in violation of the federal Clean Water Act from the power plant’s coal ash basin. Seeps at the Belews coal ash basin allow bromide to flow into surface water and groundwater, according to the Southern Environmental Law Center.
As the crow flies, Madison and Eden lie a few miles downstream of the power plant.
Bromide from the power plant gets picked up by Madison and Eden as they pull water from the Dan.
When bromide interacts with chlorine — a necessary disinfectant commonly used by water-treatment plants to eliminate a broad spectrum of unwanted elements in raw water — an unhealthy byproduct emerges: trihalomethanes.
Duke Energy has reimbursed Madison and Eden for their water-treatment upgrades.
“We want to ensure our operations don’t hinder a downstream water system’s ability to consistently meet drinking water standards,” Duke Energy spokeswoman Erin Culbert said. “In the Dan River, we appreciated understanding the challenges some water-treatment plants were facing and provided them technical expertise and resources to protect drinking water in their communities.”
Pure drinking water?
Pure drinking water: Is there such a thing? Annual water-quality reports publicly available on the websites of municipalities and counties throughout North Carolina show that pure drinking water is hard to come by. Most water-quality reports consistently list a wide spectrum of interlopers, from heavy metals to chemicals.
Unwanted substances sometimes come in the form of a chemical compound with a five-syllable name derived from Latin, such as trihalomethanes.
Local, state and federal water-quality officials try to regulate public water supplies to keep such chemicals as trihalomethanes at bay, down to a level that presents merely a slight chance of making people sick. For trihalomethanes, the level is 80 parts per billion, set by the EPA.
But in the universe of water-quality regulation, there are usually two levels. One level is based on a goal that is more protective of public health, known as a maximum contaminant level goal, or MCLG. The other level is based on a goal that weighs what it may cost to control the pollutant as well as other factors. It’s known as a maximum contaminant level, or MCL.
“MCLs are set as close to MCLGs as feasible using the best available treatment technology and taking cost into consideration,” the EPA said.
For certain chemicals, the MCLG is frequently based on this formula: If a person weighing 70 kilograms (about 155 pounds) drinks 2 liters of water (about 81/2 8-ounce cups) over a lifetime, the person would run a one-in-a-million chance of getting cancer.
The level of 80 parts per billion related to trihalomethanes is not the public health goal.
It’s the enforceable goal, or MCL.
Companies monitor the MCL number because it’s the one on which they may be cited with a notice of violation or financial penalties.
When water-quality officials inspect for the presence of trihalomethanes in public water supplies, they check for something known as total trihalomethanes, a group od four chemicals: bromodichloromethane, bromoform, dibromochloromethane and chloroform.
There is no collective MCLG for the group, according to the EPA. But there are individual MCLGs for some of the individual contaminants. For bromodichloromethane, the MCLG is zero. For bromoform, it’s also zero. For dibromochloromethane, it’s 60 ppb. And for chloroform, it’s 70 ppb.
All are more protective of health than the enforcement MCL of 80 ppb.
The town of Madison and city of Eden provide water that, on an annual average, contains TTHM levels in compliance with the MCL of 80 ppb.
Eden’s 2016 annual average, for example, runs about 55 ppb. But there are spikes. On the high range, some quarterly results show, TTHM levels reach between 95 and 100 ppb.
Over the years, those spikes forced a decision.
To combat the presence of trihalomethanes, Eden officials chose to move away from chlorine in favor of chloramine — the new treatment system that according to Tuggle, Eden’s mayor, should be running soon.
As Eden moved to convert its water-treatment process from chlorine to chloramine, Henry County decided to spend money to connect its residents in Sandy Level to the public water that Henry County itself treats and provides to the rest of its residents. The option of switching to a water supply treated by chloramine was not an attractive one.
“We weren’t really in favor of the chloramine thing. Some use it, and it helps with the THM problem, but there are still some unknowns,” said Mike Ward, the director of regulatory compliance and technical applications at the Henry County Public Service Authority.
Many public water systems have switched to chloramine as a disinfectant to combat trihalomethanes, according to the EPA. As with any chemical, it’s the dose, frequency and duration of exposure that can have an effect. Still, Eden provides its own advisory about chloramine.
Eden’s 2015 water-quality report highlights the city’s planned switch from chlorine to chloramines, noting that three groups need to take precautions when using chloraminated water: kidney dialysis patients, fish pond and aquarium owners, and businesses that must use high quality water.
Bernie Moore, a member of the Eden City Council, said he was confident that the switch to chloramines would produce safe drinking water, but he said he was not aware of any group who may need to take precautions.
“I’m drinking the water, too. I want it to be safe,” Moore said.
No easy solution
The increased presence of bromide in the Dan River is an indirect result of a clean-air law enacted by North Carolina in 2002. The state’s Clean Smokestacks Act set limits on the amount of nitrogen oxides and sulfur dioxide puffed into the air by coal-fired power plants. As a result, Duke Energy installed “scrubbers” required by the state law to reduce those emissions.
And that led to cleaner air.
In 2006, before the scrubbers were installed, air-quality data reported 95,365 and 21,013 tons of emission, respectively, of sulfur dioxide and nitrogen oxides from the Belews Creek power plant, according to state environmental officials.
In 2010, two years after the scrubbers were installed, the emission of sulfur dioxide and nitrogen oxides fell to 3,643 and 3,277 tons, respectively.
But there’s a drawback. Scrubbers may take more sulfur dioxide and nitrogen oxides out of the air but the process results in wastewater that contains bromide. After scrubbers were installed at the Belews Creek power plant in 2008, trihalomethanes started showing up in Madison and Eden.
“It’s been almost a decade since downstream drinking-water providers noticed spikes in carcinogens caused by discharges from Duke Energy’s Belews Creek facility, yet Duke Energy’s response confirms that the problem has not been fixed to date,” said Frank Holleman, a senior attorney at the Southern Environmental Law Center.
“Duke Energy needs to implement the only known solution that will eliminate bromide discharges from the coal ash basin: excavation of the coal ash,” Holleman said.
There’s no easy fix.
Culbert, the Duke Energy spokeswoman, said that utilities nationwide are dealing with the same “emerging” issue.
“There is no commercial technology to remove bromides from plant wastewater. As we participate in groundbreaking research, we’ve been addressing this by avoiding high-bromide coals as much as practical and by partnering with downstream water utilities as needed,” she said.
Duke Energy has spent about $3.7 million in bromide research.
The EPA does not regulate bromide.
Although the power plant’s coal ash basin has allowed bromide to seep into groundwater and surface water, there is no MCL to regulate the bromide once it gets into the Dan.
“The bromide at Belews is coming from the scrubber and not the coal ash, and the method of basin closure will have no effect on addressing bromide,” Culbert said. “We’ll safely remove ash basin water no matter how we close the basin, and bromide will continue to be released from the scrubber process just as it is from other coal plants with scrubbers across the nation.”
The bromide problem merits a broad review, according to Adams, the Appalachian Voices program manager.
“Is this a Dan River basin issue or is this more systemic? Are we going to find more of this with other scrubber systems?” Adams said. “This is the problem when you permit Duke Energy and other large polluters to put waste in streams that provide drinking water to thousands of people.”