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EWG's Tap Water Database — 2019 UPDATE

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Nitrate and nitrite

Marshall Waterworks

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.

 

12

Samples

0

Samples exceeding legal limit (MCL)

1

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2012ND30ND
20130.107 ppm31ND - 0.320 ppm
2014ND30ND
2015N/A00N/A
2016N/A00N/A
20170.0433 ppm31ND - 0.130 ppm

ppm = parts per million

State and national drinking water standards and health guidelines

EWG Health Guideline 0.14 ppm

The health guideline of 0.14 parts per million, or ppm, for nitrate and nitrite is based on the equivalent health guideline for nitrate, as defined in a peer-reviewed scientific study by EWG. This guideline represents a one-in-one-million annual cancer risk level.

EPA Maximum Contaminant
Level (MCL) 10 ppm

ppm = parts per million

All test results

Date Lab ID Result
2012-06-19IW021302ND
2012-06-19IW021303ND
2012-09-10IX006659ND
2013-02-12IX015197ND
2013-02-12IX015198ND
2013-02-12IX0151990.320 ppm
2014-02-05118444001ND
2014-02-11119096001ND
2014-02-19120153001ND
2017-07-181004618ND
2017-07-181004621ND
2017-07-1810046150.130 ppm