By Peter Chawaga, Associate Editor, Water Online
An environmental research group with a penchant for uncovering widespread drinking water contamination has released a report pointing to a surprising
The Environmental Working Group (EWG) recently reported that chloroform, the compound most recognizable for knocking people out in the movies, is a common contaminant in
the drinking water of 220 million
Americans around the country. It gets there as a byproduct of chlorination.
“The chloroform found in tap water is one of the trihalomethanes, a class of contaminants that form as byproducts when chlorine or other disinfectants are added to drinking
water,” EWG reported. “Water utilities add chlorine because bacteria get into tap water from rivers and lakes contaminated with wastewater and animal farm runoff. Bacteria can also get into the water
distribution system from groundwater through cracks and micro-leaks common in our aging infrastructure.”
EWG reported that more than 660 water utilities in California, serving nearly 30 million people, have chloroform in their water. And that over 22 million people in Texas, 18
million in New York, 12 million in Illinois, 9.5 million in Pennsylvania, and 9 million in Ohio are similarly affected.
Total trihalomethanes have a maximum contaminant level of .08 mg/L, per the U.S. EPA’s National Primary Drinking Water
Regulations, though EWG reported that chloroform itself doesn’t have a maximum federal legal limit that utilities must adhere to.
“Some utilities have detected chloroform, as part of the federally regulated trihalomethanes class, at levels that exceed the federal maximum legal limit of 80 parts per
billion for the entire group of chemicals,” per EWG. “The limit allows levels of trihalomethanes 100 times greater than what scientists say cause a negligible risk.”
EWG recommends the use of home filters to rid drinking water of chloroform.
For similar stories visit Water Online’s Drinking Water Disinfection Solutions
Image credit: "Chloroform & morphin," dynamosquito © 2011, used under an Attribution 2.0 Generic