Know Your Environment. Protect Your Health.

Nitrate and nitrite

Groton Utilities

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.

 

13

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20180.0980 ppm220.0880 ppm - 0.108 ppm
20190.0420 ppm220.0420 ppm
20200.00450 ppm220.00200 ppm - 0.00700 ppm
20210.0290 ppm220.0290 ppm
20220.0373 ppm330.0260 ppm - 0.0430 ppm
20230.0600 ppm220.0560 ppm - 0.0640 ppm

ppm = parts per million

State, National, and Health Guidelines for Drinking Water

EWG Health Guideline: 0.14 ppm

The EWG 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
2018-11-2928467IOCR0.108 ppm
2018-11-2928468NOX0.0880 ppm
2019-11-2030564IOCR0.0420 ppm
2019-11-2030568NOX0.0420 ppm
2020-12-0132781IOCR0.00700 ppm
2020-12-0132785NOX0.00200 ppm
2021-10-2734806IOCR0.0290 ppm
2021-10-2734810NOX0.0290 ppm
2022-09-1536588IOCR0.0260 ppm
2022-09-1536618NOX0.0430 ppm
2022-09-1536587IOCR0.0430 ppm
2023-09-1438748IOCR0.0640 ppm
2023-09-1438743NOX0.0560 ppm