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EWG's Tap Water Database — 2021 UPDATE

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Chloromethane

Johnston Municipal Water Supply

NOTE: Johnston Municipal Water Supply purchases water from Des Moines Water Works which is required to test for chloromethane. Sample information shown below was taken by Des Moines Water Works.

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.

 

12

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2014ND60ND
2015ND40ND
2016N/A00N/A
2017N/A00N/A
2018N/A00N/A
2019N/A00N/A

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

NOTE: Johnston Municipal Water Supply purchases water from Des Moines Water Works which is required to test for chloromethane. Sample information shown below was taken by Des Moines Water Works.

Date Lab ID Result
2014-07-30180955ND
2014-07-30180953ND
2014-07-30180959ND
2014-10-08196216ND
2014-10-08196222ND
2014-10-08196219ND
2015-01-26211478ND
2015-01-26211497ND
2015-01-26211477ND
2015-04-01226435ND
2015-04-01226530ND
2015-04-01226431ND