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EWG's Tap Water Database — 2021 UPDATE

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Nitrate and nitrite

Ojo Caliente Mutual Domestic Water Consumers Association

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.

 

13

Samples

0

Samples exceeding legal limit (MCL)

12

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20140.260 ppm220.200 ppm - 0.320 ppm
20150.305 ppm220.200 ppm - 0.410 ppm
20160.240 ppm220.210 ppm - 0.270 ppm
20170.210 ppm220.150 ppm - 0.270 ppm
20180.190 ppm220.1000 ppm - 0.280 ppm
20190.207 ppm330.200 ppm - 0.210 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
2014-08-1920140268710.200 ppm
2014-08-1920140268700.320 ppm
2015-07-0820150198160.200 ppm
2015-07-0820150198150.410 ppm
2016-01-2020160018530.270 ppm
2016-01-2020160018540.210 ppm
2017-02-1420170045300.270 ppm
2017-02-1420170045310.150 ppm
2018-02-1320180055520.280 ppm
2018-02-1320180055530.1000 ppm
2019-04-3020190115790.210 ppm
2019-04-3020190115800.210 ppm
2019-07-3020190209640.200 ppm