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EWG's Tap Water Database — 2021 UPDATE

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Nitrate and nitrite

Desert Water Agency

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.

 

32

Samples

0

Samples exceeding legal limit (MCL)

31

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20140.870 ppm110.870 ppm
20150.840 ppm110.840 ppm
20161.28 ppm2827ND - 4.50 ppm
2017N/A00N/A
20182.20 ppm221.20 ppm - 3.20 ppm
2019N/A00N/A

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
2014-06-253761-060-10450.870 ppm
2015-09-233761-047-10000.840 ppm
2016-05-043761-043-10301.10 ppm
2016-05-043761-060-09351.20 ppm
2016-05-113761-015-10150.460 ppm
2016-05-113761-022-10451.90 ppm
2016-05-113761-026-11250.780 ppm
2016-05-183761-030-11000.720 ppm
2016-05-183761-029-10301.10 ppm
2016-06-083761-024-10150.500 ppm
2016-06-083761-044-09451.10 ppm
2016-06-153761-033-00000.730 ppm
2016-06-223761-046-10302.60 ppm
2016-06-223761-018-11153.10 ppm
2016-06-223761-017-11454.50 ppm
2016-06-223761-008-09452.00 ppm
2016-06-293761-040-11300.640 ppm
2016-07-133761-010-11150.890 ppm
2016-07-133761-025-09300.550 ppm
2016-07-133761-020-1200ND
2016-07-203761-039-11100.400 ppm
2016-07-213761-031-10250.560 ppm
2016-07-273761-027-10150.730 ppm
2016-08-173761-034-09503.40 ppm
2016-08-173761-038-11000.840 ppm
2016-09-073761-032-09300.630 ppm
2016-09-073761-028-11000.960 ppm
2016-09-073761-047-10100.810 ppm
2016-09-293761-045-09251.000 ppm
2016-09-293761-019-09352.60 ppm
2018-07-113761-034-10003.20 ppm
2018-07-113761-037-07451.20 ppm