At a recent meeting at the local firehouse concerning contamination around the CTS site, a perceived health threat seemed to make people lose rational thought.
From data gathered by the Environmental Protection Agency so far, the site’s major groundwater and air contaminant is trichloroethylene (TCE), listed on the material safety data sheet (MSDS) as a “possible human carcinogen.” As a result, the cancer flag was raised, and major concerns ensued.
Numerous samples have been taken near CTS: by the EPA (within a 1-mile radius) and by Buncombe County (within a 5-mile radius). One gentleman proclaimed that his family (in the immediate area) had 10 cases of cancer that were most probably due to CTS contamination. Even the local media exclaimed that contamination levels were 4,000 times the safe drinking levels (5 parts per billion). Many residents wildly ranted that they wanted to exit the area as soon as possible, yet some couldn’t sell their houses because of the alleged contamination.
The EPA has actually reduced the maximum contaminant level (MCL) of TCE to 5 ppb; in 1985, it was 100 parts per million—or 2,000 times higher. Most of the drop was related to the EPA’s concluding that TCE posed a more significant human-health risk than previous studies had indicated.
The EPA sampled 66 wells in the immediate area. Only one exceeded the MCL. Most others were nondetectable; one was detectable but below the MCL. Additional sampling revealed an average of 1.2 ppb for residential areas very near the TCE contamination.
Several years ago, TCE was considered an excellent solvent for a variety of organic materials. It was used as a dry-cleaning solvent for years, but its major use was to extract vegetable oils from soy, coconut and palm. It was also used in coffee decaffeination and as a gas anesthetic (by breathing up to 1 percent vapor, or 10,000 ppm). Because of favorable analgesic properties, “Trilene” (TCE) inhalers were used by many to self-administer analgesia, especially those about to give birth.
Numbers [of people] exposed to high levels of TCE are certainly well into the millions, and the health risks of TCE have been studied extensively. It is interesting to note that the National Toxicology Program has shown that high exposure has sometimes produced liver cancer in mice and kidney cancer in rats—therefore, it’s listed as “reasonably anticipated to be a human carcinogen.” But so far, no human is known to have gotten cancer from TCE.
The CTS meeting included expert testimony by some eight representatives of the EPA who were directly involved with sampling and cleanup. They found some springs too dry to sample until spring, and have provided an alternate water supply to the resident whose well sampled above the MCL (5 ppb).
An EPA-approved soil-vapor extraction system has operated since installation on July 20, 2006, [and] is still successfully removing contaminants from the soils. The N.C. Department of Environment and Natural Resources has instructed CTS to expedite complete remediation, and CTS has agreed. A plan is due by April.
Local people have let their emotions run away with logical thought.
It’s amazing, the information you can get from a rogue chemical engineer who lives less than one mile from CTS.
— Kevin Roeten
Editor’s note: Kevin Roeten is a retired chemical engineer, formerly with DuPont.