Know Your Environment. Protect Your Health.

Nitrate and nitrite

Aquarion Water Company of Connecticut - Greenwich System

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.

 

25

Samples

0

Samples exceeding legal limit (MCL)

15

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20180.320 ppm550.291 ppm - 0.346 ppm
20190.304 ppm440.126 ppm - 0.499 ppm
20200.223 ppm440.104 ppm - 0.337 ppm
20210.318 ppm440.235 ppm - 0.402 ppm
20220.0973 ppm42ND - 0.314 ppm
20230.142 ppm42ND - 0.442 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
2018-04-02201803870-NOX0.326 ppm
2018-04-02201803870-IOCR0.326 ppm
2018-04-02201803873-NOX0.312 ppm
2018-10-01201815017-NOX0.291 ppm
2018-10-01201815016-IOCR0.346 ppm
2019-04-01201904114-NOX0.132 ppm
2019-04-01201904109-NOX0.499 ppm
2019-04-01201904111-IOCR0.126 ppm
2019-04-01201904110-IOCR0.458 ppm
2020-04-06202004726-NOX0.337 ppm
2020-04-06202004727-IOCR0.335 ppm
2020-04-07202004857-IOCR0.104 ppm
2020-04-07202004860-NOX0.114 ppm
2021-04-05202104315-NOX0.258 ppm
2021-04-05202104312-IOCR0.235 ppm
2021-05-10202106584-NOX0.402 ppm
2021-05-10202106585-IOCR0.377 ppm
2022-04-05202204953-NOX0.0750 ppm
2022-04-05202204950-IOCRND
2022-05-16202207710-NOX0.314 ppm
2022-05-16202207707-IOCRND
2023-04-03202304838-NOX0.126 ppm
2023-04-03202304835-IOCRND
2023-06-06202309335-NOX0.442 ppm
2023-06-06202309336-IOCRND