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EWG's Tap Water Database — 2019 UPDATE

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N-Nitrosodimethylamine (NDMA)

California Water Service (CWS) - Salinas

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.

 

13

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2012N/A00N/A
2013N/A00N/A
2014N/A00N/A
2015ND50ND
2016N/A00N/A
2017ND80ND

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
2015-09-169590-119-1250ND
2015-09-169590-120-1143ND
2015-09-169590-126-0951ND
2015-09-289590-101-1202ND
2015-09-289590-129-1315ND
2017-03-029590-132-1110ND
2017-03-029590-132-1110ND
2017-09-199590-101-1146ND
2017-09-199590-129-1048ND
2017-09-209590-119-1005ND
2017-09-209590-120-1117ND
2017-09-209590-126-0905ND
2017-12-269590-101-1135ND