EWG's Tap Water Database — 2021 UPDATE


Nitrate and nitrite

City of Scottsdale

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.





Samples exceeding legal limit (MCL)


Samples exceeding
health guidelines

Testing results - average by year

YearAverage resultSamples takenDetectionsRange of results
20141.11 ppm1311ND - 4.00 ppm
20154.90 ppm114.90 ppm
20170.978 ppm98ND - 5.00 ppm
20181.19 ppm990.200 ppm - 6.40 ppm
20191.09 ppm98ND - 5.70 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
2014-02-05AB45662I0.300 ppm
2014-02-05AB45661I1.10 ppm
2014-02-05AB45660I4.00 ppm
2014-02-05AB45659I0.200 ppm
2014-02-11AB45852I0.500 ppm
2014-02-12AB45865I0.800 ppm
2014-02-13AB45913I0.500 ppm
2014-02-13AB45912I0.600 ppm
2014-03-13AB46644I0.900 ppm
2014-06-124061175-013.71 ppm
2014-08-27AB50551I1.80 ppm
2015-01-26AB541804.90 ppm
2017-01-23AB72209T1.10 ppm
2017-01-31AB72398T5.00 ppm
2017-04-11AB742810.500 ppm
2017-04-18AZ744560.500 ppm
2017-05-03AB749520.500 ppm
2017-05-03AB749540.600 ppm
2017-05-11AB752520.300 ppm
2017-05-25AB755600.300 ppm
2018-01-04AB818570.200 ppm
2018-01-08AB819310.300 ppm
2018-01-31AB824256.40 ppm
2018-03-15AB835421.000 ppm
2018-07-24AB868780.500 ppm
2018-07-26AB869750.600 ppm
2018-07-31AB870630.500 ppm
2018-08-22AB876511.000 ppm
2018-09-13AB88206 IOC0.200 ppm
2019-01-08AB90901 IOC0.600 ppm
2019-01-28AB91381 IOCND
2019-02-20AB91936 IOC5.70 ppm
2019-02-21AB91994 IOC0.300 ppm
2019-03-08AB92407 IOC0.600 ppm
2019-03-14AB925370.700 ppm
2019-05-15AB939680.600 ppm
2019-06-20AB946610.300 ppm
2019-08-22AB961461.000 ppm