Contaminant Level (MCL)
Tetrachloroethene—also known as tetrachloroethylene, PCE, perchloroethylene or perc—is a common chemical solvent used in dry cleaning, the cleaning of metal machinery, and in the manufacture of some consumer products and chemicals.
PCE arrives in drinking water through discharge from factories and dry cleaning facilities.
Tetrachloroethylene has toxic effects on the central nervous system. According to the WHO, when once used to treat parasitic worms, it was known to cause “inebriation, perceptual distortion, and exhilaration.” Evidence as to its carcinogenicity remains insufficient, although it is classified by the EPA as a “likely human carcinogen” that can lead to liver problems with long term exposure:
Some people who drink water containing tetrachloroethylene well in excess of the maximum contaminant level [0.005 milligrams per Liter] for many years could have problems with their liver and may have an increased risk of getting cancer.
The EPA recommends granular activated carbon (GAC) in combination with packed tower aeration (an air stripping technique) for the treatment of tetrachloroethylene. Lenntech reports that activated carbon on its own has a “high probability” of removing tetrachloroethylene.
(whole house & well units)