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EWG's Tap Water Database — 2021 UPDATE

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Nitrate and nitrite

Waterworks District 7

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.

MORE ABOUT THIS CONTAMINANT

 

64

Samples

0

Samples exceeding legal limit (MCL)

6

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2014ND40ND
20150.425 ppm440.420 ppm - 0.430 ppm
20160.0143 ppm246ND - 0.0750 ppm
20170.0550 ppm42ND - 0.110 ppm
20180.0460 ppm42ND - 0.0920 ppm
20190.0288 ppm248ND - 0.180 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
2014-11-18AD99869ND
2014-11-18AD99868ND
2014-11-18AD99869ND
2014-11-18AD99868ND
2015-05-12351886370060.420 ppm
2015-05-12351886370050.430 ppm
2015-05-12351886370050.430 ppm
2015-05-12351886370060.420 ppm
2016-08-03352585130090.0750 ppm
2016-08-03352585130080.0710 ppm
2016-08-03352585130080.0710 ppm
2016-08-03352585130090.0750 ppm
2016-12-0535281860008ND
2016-12-0535281860007ND
2016-12-0535281860009ND
2016-12-0535281860010ND
2016-12-0535281860007ND
2016-12-0535281860006ND
2016-12-0535281860005ND
2016-12-05352818600040.0250 ppm
2016-12-0535281860003ND
2016-12-0535281860002ND
2016-12-0535281860001ND
2016-12-0535281860006ND
2016-12-0535281860005ND
2016-12-05352818600040.0250 ppm
2016-12-0535281860003ND
2016-12-0535281860002ND
2016-12-0535281860001ND
2016-12-0535281860010ND
2016-12-0535281860008ND
2016-12-0535281860009ND
2017-10-2035344160002ND
2017-10-20353441600010.110 ppm
2017-10-20353441600010.110 ppm
2017-10-2035344160002ND
2018-11-02354318520010.0920 ppm
2018-11-0235431852002ND
2018-11-02354318520010.0920 ppm
2018-11-0235431852002ND
2019-07-2235487972001ND
2019-07-22354879720020.0350 ppm
2019-07-2235487972001ND
2019-07-22354879720020.0350 ppm
2019-11-1935514133001ND
2019-11-1935514133001ND
2019-11-1935514133002ND
2019-11-19355141330030.0840 ppm
2019-11-19355141330040.180 ppm
2019-11-1935514133005ND
2019-11-1935514133006ND
2019-11-1935514133007ND
2019-11-1935514133008ND
2019-11-1935514133009ND
2019-11-19355141330100.0470 ppm
2019-11-19355141330100.0470 ppm
2019-11-1935514133002ND
2019-11-19355141330030.0840 ppm
2019-11-19355141330040.180 ppm
2019-11-1935514133005ND
2019-11-1935514133006ND
2019-11-1935514133007ND
2019-11-1935514133008ND
2019-11-1935514133009ND