Know Your Environment. Protect Your Health.

Nitrate and nitrite

Dorchester, Village of

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.

 

12

Samples

0

Samples exceeding legal limit (MCL)

3

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20180.800 ppm21ND - 1.60 ppm
20190.0535 ppm21ND - 0.107 ppm
20200.286 ppm21ND - 0.571 ppm
2021ND20ND
2022ND20ND
20232.33 ppm21ND - 4.66 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
2018-02-26531102ND
2018-11-265786211.60 ppm
2019-02-26591155ND
2019-11-196391850.107 ppm
2020-02-26648819ND
2020-11-177020850.571 ppm
2021-02-17715741ND
2021-11-22765455ND
2022-03-08780123ND
2022-11-28828661ND
2023-03-07843013ND
2023-11-138901144.66 ppm