The chemical that contaminated West Virginia’s drinking water supply last year traveled father and lingered longer than had been previously recorded, according to a new study by U.S. Geological Survey researchers.
Published online in the journal Chemosphere, the peer-reviewed research shows that the chemical — 4-Methylcyclohexanemethanol, also known as crude MCHM — was present at very low concentrations in Charleston, West Virginia’s tap water more than six weeks after the spill began on Jan. 9, 2014. The official tap water ban in Charleston was lifted five days later, with the Center for Disease Control saying concentrations of MCHM had reached an “appropriate” level of below 50 parts per billion. By Feb. 25, the researchers said Charleston’s tap water still measured crude MCHM concentration of 1 part per billion.
The researchers also say they detected crude MCHM in the Ohio River at Louisville, Kentucky, meaning the chemical traveled at least 390 miles downriver from the spill. Though prominent spill researchers have long speculated that the chemical traveled across state lines, the study’s leader author Bill Foreman told ThinkProgress that his represented, “as far as I know of, the first, reported, published-in-a-journal documentation of [crude MCHM] found there in the Louisville area.”
The spill saw approximately 10,000 gallons of MCHM leak from a neglected storage tank into West Virginia’s Elk River, just upstream from a major water intake facility. Along with taking away normal drinking water from 300,000 civilians, nearly 600 people checked themselves into local hospitals with what federal epidemiologists called “mild” illnesses, such as rash, nausea, vomiting, abdominal pain, and diarrhea. Despite its proximity to the drinking water supply, very little was and currently is known about crude MCHM and its potential long-term impact on humans and the environment.
Andrew Whelton, an environmental engineer who received a rapid response grant from the National Science Foundation to study the West Virginia chemical spill, said he and his colleagues have already shown that the incident saw a chemical plume that eventually reached Kentucky, Ohio, and Indiana. What was new to him, however, was the method Foreman and his colleagues used to measure the chemical — a technique called “Purge and Trap.”
“We knew that chemicals traveled hundreds of miles downstream,” Whelton said. “What’s new about this is the method and provisional data showing the chemicals traveled downstream.”
Because they used the “Purge and Trap” method, Whelton said the USGS researchers could for the first time detect crude MCHM at lower concentrations than researchers who used different detection methods. The way Whelton describes it, the researchers put contaminated water into a vial, heated it, and captured the gases that escape into air. They then analyze that gas to determine the concentration of MCHM.
“That method has been used for years to look at volatile chemicals in water,” he said. “When we know that they’re odoriferous, this type of method is considered.”
Using this method, Foreman said he and his team actually found another chemical present at low levels in the water, one that had not been previously detected. That chemical is called methyl 4-methylcyclohexanecarboxylate, or MMCHC, and makes up 5 percent of crude MCHM, he said. According to the chemical’s Material Safety Data Sheet, MMCHC is flammable and can cause serious eye irritation.
Foreman acknowledges that both the MMCHC found in West Virginia’s water and the crude MCHM in Kentucky’s water were both very diluted. Indeed, the average concentration of crude MCHM in Kentucky’s water was roughly 5 parts per billion, well below the CDC’s recommended limit for the chemical. When it was shown that the chemical had reached the Ohio River in the days following the spill, The Louisville Water Company said it did not pose a danger to the region’s drinking water.
However, Whelton said the findings are still important when it comes to spill response — specifically, that it shows the USGS could play a larger role.
“There’s a role to play when contaminated water crosses state boundaries for organizations like the USGS. The agency could deploy teams out to collect water samples, then relay that information to a central command center that informs other states downstream,” he said. “The study shows that USGS has a capability that could be tapped in a more formal capacity.”