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EWG's Tap Water Database — 2021 UPDATE

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N-Nitrosodimethylamine (NDMA)

Suburban Water Systems - Whittier

N-Nitrosodimethylamine 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.

Click here to read more about disinfection byproducts.

 

24

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2013N/A00N/A
20140.750 ppt41ND - 3.00 ppt
2015ND40ND
2016ND40ND
2017ND40ND
2018ND40ND
2019ND40ND

ppt = parts per trillion

State and national drinking water standards and health guidelines

EWG Health Guideline 3 ppt

The EWG Health Guideline of 3 ppt for n-nitrosodimethylamine was defined by the California Office of Environmental Health Hazard Assessment as a public health goal, the level of a drinking water contaminant that does not pose a significant health risk. This health guideline protects against cancer.

ppt = parts per trillion

All test results

Date Lab ID Result
2014-02-149588-035-1025ND
2014-02-149588-033-1005ND
2014-02-149588-031-10153.00 ppt
2014-02-149588-020-0950ND
2015-02-179588-020-1130ND
2015-02-179588-031-1140ND
2015-02-179588-035-1200ND
2015-02-179588-033-1145ND
2016-02-249588-020-0830ND
2016-02-249588-035-0910ND
2016-02-249588-033-0840ND
2016-02-249588-031-0850ND
2017-02-229588-033-0925ND
2017-02-229588-035-1010ND
2017-02-229588-020-0950ND
2017-03-109588-031-0755ND
2018-02-239588-033-0935ND
2018-02-239588-031-0950ND
2018-02-239588-035-0905ND
2018-02-239588-020-0925ND
2019-02-279588-031-0930ND
2019-02-279588-033-0905ND
2019-02-279588-035-0830ND
2019-02-279588-020-0845ND