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EWG's Tap Water Database — 2021 UPDATE

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Nitrate and nitrite

Dublin

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)

6

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20140.160 ppm21ND - 0.320 ppm
20150.130 ppm21ND - 0.260 ppm
20160.145 ppm21ND - 0.290 ppm
20170.110 ppm21ND - 0.220 ppm
20180.160 ppm21ND - 0.320 ppm
20190.135 ppm21ND - 0.270 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
2014-06-10AI428920.320 ppm
2014-06-10AI42893ND
2015-06-22AI805170.260 ppm
2015-06-22AI80518ND
2016-05-26AJ129960.290 ppm
2016-05-26AJ12997ND
2017-06-05AJ566910.220 ppm
2017-06-05AJ56692ND
2018-06-13AJ91567ND
2018-06-13AJ915680.320 ppm
2019-06-06AK19093ND
2019-06-06AK190940.270 ppm