Know Your Environment. Protect Your Health.

Nitrate and nitrite

South Norwalk Electric and Water

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)

5

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20180.255 ppm220.240 ppm - 0.270 ppm
20190.170 ppm220.150 ppm - 0.190 ppm
20200.00500 ppm21ND - 0.01000 ppm
20210.133 ppm220.124 ppm - 0.142 ppm
2022ND20ND
20230.0250 ppm220.0200 ppm - 0.0300 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
2018-05-1018051007-NOX0.270 ppm
2018-05-1018051001-IOCR0.240 ppm
2019-05-0919050907-NOX0.190 ppm
2019-05-0919050901-IOCR0.150 ppm
2020-05-1420051407-NOX0.01000 ppm
2020-05-1420051401-IOCRND
2021-05-1321051307-NOX0.124 ppm
2021-05-1321051301-IOCR0.142 ppm
2022-05-1222051207-NOXND
2022-05-1222051201-IOCRND
2023-05-1723051707-NOX0.0300 ppm
2023-05-1723051701-IOCR0.0200 ppm