EWG's Tap Water Database — 2019 UPDATE



Prescott Valley WD Upper

Nitrate, a fertilizer chemical, frequently contaminates drinking water due to agricultural and urban runoff, and discharges from municipal wastewater treatment plants and septic tanks. Excessive nitrate in water can cause oxygen deprivation in infants and increase the risk of cancer. 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
20120.742 ppm11110.210 ppm - 1.50 ppm
20130.679 ppm11110.200 ppm - 1.20 ppm
20140.567 ppm11110.210 ppm - 1.20 ppm
20150.594 ppm11110.140 ppm - 1.60 ppm
20160.754 ppm12120.220 ppm - 2.10 ppm
20170.718 ppm11110.250 ppm - 1.80 ppm

ppm = parts per million

State and national drinking water standards and health guidelines

EWG Health Guideline 0.14 ppm

The EWG Health Guideline of 0.14 ppm for nitrate was defined by EWG . This health guideline protects against cancer and harm to fetal growth and development.

EPA Maximum Contaminant
Level (MCL) 10 ppm

The legal limit for nitrate, established in 1962, was developed to protect infants from acute methemoglobinemia, a life-threatening disorder of oxygen transport in the body. This limit does not fully protect against the risk of cancer and harm to the developing fetus.

ppm = parts per million

All test results

Date Lab ID Result
2012-01-31201202010049I0.210 ppm
2012-01-31201202010048I0.360 ppm
2012-01-31201202010047I0.270 ppm
2012-01-31201202010046I0.240 ppm
2012-01-31201202010045I1.20 ppm
2012-01-31201202010044I0.280 ppm
2012-01-31201202010043I0.980 ppm
2012-01-31201202010042I1.50 ppm
2012-01-31201202010041I0.920 ppm
2012-01-31201202010040I1.10 ppm
2012-03-15201203160214I1.10 ppm
2013-02-14201302150327I0.640 ppm
2013-02-14201302150323I1.10 ppm
2013-02-14201302150324I1.000 ppm
2013-02-14201302150325I0.860 ppm
2013-02-14201302150326I0.800 ppm
2013-02-14201302150329I0.230 ppm
2013-02-14201302150330I0.330 ppm
2013-02-14201302150331I0.330 ppm
2013-02-14201302150332I0.200 ppm
2013-02-14201302150328I0.780 ppm
2013-10-16201310170112I1.20 ppm
2014-01-15201401150462I0.260 ppm
2014-01-15201401150454I0.870 ppm
2014-01-15201401150455I0.940 ppm
2014-01-15201401150456I0.880 ppm
2014-01-15201401150457I1.20 ppm
2014-01-15201401150458I0.740 ppm
2014-01-15201401150459I0.300 ppm
2014-01-15201401150460I0.240 ppm
2014-01-15201401150461I0.250 ppm
2014-01-15201401150463I0.350 ppm
2014-01-15201401150464I0.210 ppm
2015-02-26201502260183I0.140 ppm
2015-02-26201502260182I0.330 ppm
2015-02-26201502260173I0.830 ppm
2015-02-26201502260174I1.000 ppm
2015-02-26201502260175I0.300 ppm
2015-02-26201502260176I1.60 ppm
2015-02-26201502260177I0.930 ppm
2015-02-26201502260178I0.290 ppm
2015-02-26201502260179I0.240 ppm
2015-02-26201502260180I0.520 ppm
2015-02-26201502260181I0.350 ppm
2016-02-09201602100066I1.000 ppm
2016-02-09201602100057I0.260 ppm
2016-02-09201602100056I1.000 ppm
2016-02-09201602100055I1.000 ppm
2016-02-10201602110034I0.360 ppm
2016-02-10201602110028I1.000 ppm
2016-02-10201602110029I1.10 ppm
2016-02-10201602110030I2.10 ppm
2016-02-10201602110031I0.380 ppm
2016-02-10201602110032I0.250 ppm
2016-02-10201602110033I0.380 ppm
2016-02-10201602110035I0.220 ppm
2017-02-14201702150180I1.000 ppm
2017-02-14201702150190I0.380 ppm
2017-02-14201702150189I0.390 ppm
2017-02-14201702150188I0.320 ppm
2017-02-14201702150187I0.280 ppm
2017-02-14201702150186I0.250 ppm
2017-02-14201702150185I0.380 ppm
2017-02-14201702150184I1.000 ppm
2017-02-14201702150183I1.80 ppm
2017-02-14201702150182I1.10 ppm
2017-02-14201702150181I1.000 ppm