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EWG's Tap Water Database — 2021 UPDATE

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Nitrate and nitrite

Chatsworth

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.

 

18

Samples

0

Samples exceeding legal limit (MCL)

12

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20140.727 ppm32ND - 1.70 ppm
20150.717 ppm32ND - 1.70 ppm
20160.733 ppm32ND - 1.70 ppm
20170.713 ppm32ND - 1.80 ppm
20180.750 ppm32ND - 1.90 ppm
20190.717 ppm32ND - 1.70 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
2014-08-04AI478771.70 ppm
2014-08-04AI478760.480 ppm
2014-08-04AI47873ND
2015-07-21AI83780ND
2015-07-21AI837790.450 ppm
2015-07-21AI837781.70 ppm
2016-08-01AJ203270.500 ppm
2016-08-01AJ203291.70 ppm
2016-08-01AJ20328ND
2017-07-12AJ601311.80 ppm
2017-07-12AJ601300.340 ppm
2017-07-12AJ60127ND
2018-08-01AJ962011.90 ppm
2018-08-01AJ961980.350 ppm
2018-08-01AJ96197ND
2019-07-22AK230581.70 ppm
2019-07-22AK230600.450 ppm
2019-07-22AK23059ND