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EWG's Tap Water Database — 2021 UPDATE

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N-Nitrosodimethylamine (NDMA)

City of Riverside

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.

 

46

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
2014ND80ND
2015ND80ND
2016ND80ND
2017ND60ND
2018ND80ND
2019ND80ND

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
2014-01-079590-107-0940ND
2014-01-079590-107-0940ND
2014-04-019590-107-0915ND
2014-04-019590-107-0915ND
2014-07-189590-107-0905ND
2014-07-189590-107-0905ND
2014-10-079590-107-0840ND
2014-10-079590-107-0840ND
2015-01-069590-107-0835ND
2015-01-069590-107-0835ND
2015-04-079590-107-0937ND
2015-04-079590-107-0937ND
2015-07-079590-107-0840ND
2015-07-079590-107-0840ND
2015-10-069590-107-1032ND
2015-10-069590-107-1032ND
2016-01-059590-107-0840ND
2016-01-059590-107-0840ND
2016-04-129590-107-1230ND
2016-04-129590-107-1230ND
2016-07-129590-107-1230ND
2016-07-129590-107-1230ND
2016-10-049590-107-1233ND
2016-10-049590-107-1233ND
2017-05-029590-107-1039ND
2017-05-029590-107-1039ND
2017-07-259590-107-1055ND
2017-07-259590-107-1055ND
2017-10-039590-107-0845ND
2017-10-039590-107-0845ND
2018-01-029590-107-0900ND
2018-01-029590-107-0900ND
2018-04-039590-107-0910ND
2018-04-039590-107-0910ND
2018-07-039588-107-1015ND
2018-07-039588-107-1015ND
2018-11-069588-107-1440ND
2018-11-069588-107-1440ND
2019-01-029588-107-0900ND
2019-01-029588-107-0900ND
2019-04-029588-107-0900ND
2019-04-029588-107-0900ND
2019-07-029588-107-0910ND
2019-07-029588-107-0910ND
2019-10-019588-107-1139ND
2019-10-019588-107-1139ND