Know Your Environment. Protect Your Health.

Nitrate and nitrite

Norwich Public 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.

 

22

Samples

0

Samples exceeding legal limit (MCL)

8

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20180.457 ppm54ND - 2.00 ppm
2019ND50ND
20200.426 ppm52ND - 2.00 ppm
20210.700 ppm330.150 ppm - 1.80 ppm
20220.625 ppm440.130 ppm - 1.70 ppm
2023N/A00N/A

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
2018-05-11PH-0453-6304155NOX0.0810 ppm
2018-05-11PH-0453-6304156NOX2.00 ppm
2018-05-11PH-0453-6304154NOX0.140 ppm
2018-08-20PH-0453-6304416IOCR0.0660 ppm
2018-08-20PH-0453-6304417IOCRND
2019-08-29PH-0453-6304853NOXND
2019-08-29PH-0453-6304855NOXND
2019-08-29PH-0453-6305532IOCRND
2019-09-19PH-0453-6304854NOXND
2019-11-07PH-0453-6305533IOCRND
2020-06-10PH-0453-6306432IOCR0.130 ppm
2020-06-10PH-0453-6306433IOCRND
2020-06-10PH-0453-6305938NOX2.00 ppm
2020-08-03PH-0453-6305936NOXND
2020-08-03PH-0453-6305937NOXND
2021-05-24PH-0453-6307269NOX0.150 ppm
2021-05-24PH-0453-6307278IOCR0.150 ppm
2021-06-23PH-0453-6307271NOX1.80 ppm
2022-01-13PH-0453-6308027NOX0.330 ppm
2022-01-13PH-0453-6307958IOCR0.340 ppm
2022-02-03PH-0453-6308029NOX1.70 ppm
2022-11-21PH-0453-6308028NOX0.130 ppm