EWG's Tap Water Database — 2019 UPDATE


Nitrate and nitrite

Avon Water Company

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
20122.12 ppm990.890 ppm - 4.20 ppm
20131.77 ppm880.870 ppm - 3.20 ppm
20142.06 ppm880.620 ppm - 3.80 ppm
20162.06 ppm880.780 ppm - 3.60 ppm
20171.96 ppm880.750 ppm - 3.10 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
2012-02-13E202655-1NOX4.20 ppm
2012-02-13E202655-9NOX1.20 ppm
2012-02-13E202655-8NOX1.40 ppm
2012-02-13E202655-7NOX3.10 ppm
2012-02-13E202655-6NOX0.890 ppm
2012-02-13E202655-5NOX1.40 ppm
2012-02-13E202655-4NOX3.50 ppm
2012-02-13E202655-3NOX1.10 ppm
2012-02-13E202655-2NOX2.30 ppm
2013-02-14E302938-8NOX0.870 ppm
2013-02-14E302938-7NOX3.20 ppm
2013-02-14E302938-6NOX0.950 ppm
2013-02-14E302938-5NOX1.30 ppm
2013-02-14E302938-4NOX3.20 ppm
2013-02-14E302938-3NOX1.000 ppm
2013-02-14E302938-2NOX1.20 ppm
2013-02-14E302938-1NOX2.40 ppm
2014-01-16E402153-8NOX3.80 ppm
2014-02-04E402153-7NOX0.930 ppm
2014-02-04E402153-6NOX3.00 ppm
2014-02-04E402153-5NOX0.620 ppm
2014-02-04E402153-4NOX1.20 ppm
2014-02-04E402153-3NOX1.000 ppm
2014-02-04E402153-2NOX3.00 ppm
2014-02-04E402153-1NOX2.90 ppm
2016-02-18E602H93-8NOX0.780 ppm
2016-02-18E602H93-7NOX3.00 ppm
2016-02-18E602H93-6NOX1.10 ppm
2016-02-18E602H93-5NOX1.30 ppm
2016-02-18E602H93-4NOX3.60 ppm
2016-02-18E602H93-3NOX0.870 ppm
2016-02-18E602H93-2NOX3.10 ppm
2016-02-18E602H93-1NOX2.70 ppm
2017-02-24E702M07-7NOX3.10 ppm
2017-02-24E702M07-6NOX1.000 ppm
2017-02-24E702M07-5NOX1.50 ppm
2017-02-24E702M07-4NOX3.00 ppm
2017-02-24E702M07-3NOX1.000 ppm
2017-02-24E702M07-2NOX2.70 ppm
2017-02-24E702M07-1NOX2.60 ppm
2017-02-24E702M07-8NOX0.750 ppm