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EWG's Tap Water Database — 2019 UPDATE

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Chloromethane

Golden State Water Company (GSWC) - San Dimas

Chloromethane is an industrial solvent, aerosol propellant and a refrigerant. It also forms as a byproduct of water disinfection. The EPA classifies chloromethane as possibly carcinogenic to humans.

 

28

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2012ND20ND
2013ND20ND
2014ND20ND
2015ND180ND
2016ND20ND
2017ND20ND

ppb = parts per billion

State and national drinking water standards and health guidelines

EWG Health Guideline 2.69 ppb

The EWG Health Guideline of 2.69 ppb for chloromethane was defined by the Environmental Protection Agency as a benchmark for testing under the Unregulated Contaminant Monitoring Rule program. This health guideline protects against cancer.

ppb = parts per billion

All test results

Date Lab ID Result
2012-02-089588-051-0940ND
2012-05-149588-014-1000ND
2013-02-209588-051-0925ND
2013-06-279588-014-1015ND
2014-02-199588-051-0930ND
2014-05-149588-014-1010ND
2015-01-215A21031-01AND
2015-01-215A21031-05AND
2015-01-215A21031-03AND
2015-01-215A21031-09AND
2015-01-215A21031-07AND
2015-01-215A21031-11AND
2015-02-189588-051-0920ND
2015-04-175D17033-03AND
2015-04-175D17033-01AND
2015-05-189588-014-0915ND
2015-07-215G21057-07AND
2015-07-215G21057-11AND
2015-07-215G21057-09AND
2015-07-215G21057-05AND
2015-07-215G21057-01AND
2015-07-215G21057-03AND
2015-10-205J21034-01AND
2015-10-205J21034-03AND
2016-02-169588-051-0825ND
2016-05-129588-014-0925ND
2017-01-059588-051-0800ND
2017-05-159588-014-0905ND