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EWG's Tap Water Database

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Nitrate and nitrite

Washington

Nitrate and nitrite enter water from fertilizer runoff, septic tanks and urban runoff. These contaminants can cause oxygen deprivation for infants and increase the risk of cancer. Nitrite is significantly more toxic than nitrate. Click here to read more about nitrate.

 

4

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2010N/A00N/A
2011N/A00N/A
20120.0350 ppm21ND - 0.0700 ppm
2013N/A00N/A
2014N/A00N/A
20150.0550 ppm21ND - 0.110 ppm

ppm = parts per million.

State and national drinking water standards and health guidelines

Health Guideline 5 ppm

The health guideline of 5 ppm for nitrate and nitrite was defined by EWG based on studies by scientists at the National Cancer Institute and other independent researchers. This health guideline protects against cancer and harm to fetal growth and development.

ppm = parts per million.

EPA Maximum Contaminant
Level (MCL) 10 ppm

The enforceable federal standard that defines the highest level of a contaminant allowed in drinking water.

ppm = parts per million.

EPA Maximum Contaminant
Level Goal (MCLG)10 ppm

A non-enforceable federal health guideline. For cancer-causing chemicals, these health goals are typically set to zero.

ppm = parts per million.

All test results

Date Lab ID Result
2012-04-102041209-01ND
2012-04-102041209-020.0700 ppm
2015-05-055050438-010.110 ppm
2015-05-055050438-02ND