Dave Mistich Published

Experts Say Lingering Odor Means Crude MCHM Remains in Water System


Researchers involved in a taxpayer-funded, independent water testing project in response to the January 9 spill by Freedom Industries began releasing findings earlier this week. The project, known as WV TAP, is currently attempting to determine the odor threshold for the chemical in question—crude MCHM. They are also investigating the safety factors applied by the CDC in determining how much chemical can be in water and still be called safe to drink.

Dr. Michael McGuire is conducting odor analysis panels to determine at what levels Crude MCHM can be smelled in the water. Results released Monday from an expert panel conducted by McGuire put that number at 0.15 parts per billion (ppb).

Researchers took time Tuesday to answer questions about the first round of studies that have been released.

To put that number in a bit of perspective, consider that testing conducted by the National Guard could detect levels down to 2 ppb, which indicates that the human nose has the ability to smell the chemical far better than analytical testing methods currently allow. 

“It’s pretty clear, from some of the sampling and some of the anecdotal information, that all of the water that got into the distribution system doesn’t appear to have been flushed out of the system or out of peoples’ houses,” McGuire said.

“People are still smelling water that was associated with the original chemical spill and the aftermath.”

Dr. McGuire noted that while Crude MCHM isn’t any longer being introduced into West Virginia American Water’s intake, there’s little doubt the chemical lingers throughout the distribution system.

“People, as I’ve noted, can smell this compound at very, very low levels. So, if they have not flushed out their houses or their housing premise—plumbing systems—if there are any dead zones in the distribution containing this old water, people will still be able to smell it,” McGuire said.

“So that’s why, obviously, it’s essential that a flushing program be conducted and be conducted thoroughly,” he added.

While McGuire is handling odor analysis for Crude MCHM, WV TAP project manager Jeff Rosen of Corona Environmental Consulting has tapped Dr. Craig Adams of Utah State University’s Water Research Laboratory to conduct a literature review of toxicological studies on the chemical.

Asked whether current data would—or, should—allow for EPA regulation in regards to drinking water quality, Adams said the data available on the chemical is “much, much less” than what would be available for a compound for which the federal agency would make a regulatory determination.

“The reason for that, I believe, is because these compounds would not be expected to be commonly found in drinking water,”Adams said.

Based on Adams’ literature review, another expert panel will investigate whether the data available on the chemical was sufficient in the CDC’s determination that the water was “safe for use” at levels of Crude MCHM below 1 part per million (ppm).

He said exposure to the chemical in other ways, either by contact with skin or breathing, also needs to be considered. 

“Dermal exposure and inhalation exposure are two potentially important routes for any contaminate—as well as ingestion through drinking water and, frankly, food and so on. So they are important routes to consider.”

As for the relationship between the black licorice odor of Crude MCHM and potential health effects for those exposed to the chemical, Dr. McGuire is careful not to link the two quite yet.

“There’s not a direct relationship between, of course, odor and toxicity. For some compounds you can smell it before it’s bad for you and for others it’s reversed,” McGuire said.

“In this case, we have an early warning system of the human nose to be able to detect when MCHM—the Crude MCHM—is present in the water.”

Researchers involved in the WV TAP project plan to convene in Charleston to release in-home testing results from 10 homes sampled across the region by Dr. Andrew Whelton of the University of South Alabama, a lead researcher on the project.