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EWG's Tap Water Database — 2021 UPDATE

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N-Nitrosomethylethylamine

Santa Clara Valley Water District

N-Nitrosomethylethylamine is one of the DNA-damaging, cancer-causing contaminants called N-nitrosamines that can form during water treatment with the use of certain disinfectants, such as chloramine. Read More.

Pollution of water sources with effluent from municipal wastewater treatment plants and runoff from animal feeding operations contributes to nitrosamine formation. Fifteen different nitrosamines are listed as carcinogens in the U.S. Department of Health and Human Services National Toxicology Program Report on Carcinogens. The federal government has not set a legal limit for nitrosamines in drinking water and water utilities typically do not test for these contaminants. California has set a public health goal for one of the most common nitrosamines, N-nitrosodimethylamine or NDMA, at 0.003 parts per billion in drinking water, a concentration that corresponds to an estimated one-in-one-million cancer risk.

 

20

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2014ND30ND
2015N/A00N/A
2016N/A00N/A
2017ND20ND
2018ND30ND
2019ND120ND

ppb = parts per billion

All test results

Date Lab ID Result
2014-08-129590-011-0901ND
2014-08-129590-007-1010ND
2014-08-129590-005-1021ND
2017-05-169590-007-0950ND
2017-05-169590-011-0845ND
2018-11-062400-005-1025ND
2018-11-132400-007-1208ND
2018-11-132400-011-0842ND
2019-02-192400-005-0835ND
2019-02-192400-011-0728ND
2019-02-192400-007-0950ND
2019-05-212400-007-1049ND
2019-05-212400-011-0851ND
2019-05-212400-005-1030ND
2019-08-202400-007-0955ND
2019-08-202400-011-0654ND
2019-08-202400-005-0825ND
2019-11-192400-007-1207ND
2019-11-192400-011-0926ND
2019-11-192400-005-1045ND