EWG's Tap Water Database


Monochloroacetic acid

South Hero Fire District 4

Monochloroacetic acid, one of the group of five haloacetic acids regulated by federal standards, is formed when chlorine or other disinfectants are used to treat drinking water. Haloacetic acids and other disinfection byproducts increase the risk of cancer and may cause problems during pregnancy. Click here to read more about disinfection byproducts.





Samples exceeding legal limit (MCL)


Samples exceeding
health guidelines

Testing results - average by year

YearAverage resultSamples takenDetectionsRange of results
20105.67 ppb65ND - 13.0 ppb
20112.25 ppb440.00600 ppb - 4.00 ppb
20125.75 ppb444.00 ppb - 7.00 ppb
20133.75 ppb442.00 ppb - 6.00 ppb
20144.25 ppb443.00 ppb - 5.00 ppb
20153.25 ppb43ND - 5.00 ppb

ppb = parts per billion.

All test results

Date Lab ID Result
2010-02-0410S2804.00 ppb
2010-02-0410S2793.00 ppb
2010-06-1810S39513.0 ppb
2010-09-1411S0609.00 ppb
2010-12-1411S0965.00 ppb
2011-03-2811S1193.00 ppb
2011-06-2611S1464.00 ppb
2011-09-2312S0960.00600 ppb
2011-12-0512S1112.00 ppb
2012-03-0712S1657.00 ppb
2012-05-1412S1865.00 ppb
2012-09-1713S001024.00 ppb
2012-12-1113S001417.00 ppb
2013-03-0613S001854.00 ppb
2013-05-1413S002132.00 ppb
2013-08-1814S000513.00 ppb
2013-11-0614S000976.00 ppb
2014-02-0414S001243.00 ppb
2014-05-2214S001654.00 ppb
2014-08-2015S000905.00 ppb
2014-11-0515S001405.00 ppb
2015-05-2615S002065.00 ppb
2015-08-0716S000225.00 ppb
2015-11-1116S000863.00 ppb