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EWG's Tap Water Database — 2021 UPDATE

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N-Nitrosodi-N-propylamine

San Diego County Water Authority

N-Nitrosodi-N-propylamine 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.

 

6

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2014ND10ND
2015ND10ND
2016ND10ND
2017ND10ND
2018ND10ND
2019ND10ND

ppb = parts per billion

All test results

Date Lab ID Result
2014-12-299590-001-0943ND
2015-08-259590-003-1303ND
2016-11-299590-003-1240ND
2017-07-059590-003-1105ND
2018-09-179590-003-1135ND
2019-09-179590-003-1140ND