Know Your Environment. Protect Your Health.

Nitrate

Wallingford Water Department

Nitrate, a fertilizer chemical, frequently contaminates drinking water due to agricultural and urban runoff, and discharges from municipal wastewater treatment plants and septic tanks. Excessive nitrate in water can cause oxygen deprivation in infants and increase the risk of cancer. Click here to read more about nitrate.

 

16

Samples

0

Samples exceeding legal limit (MCL)

11

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20181.46 ppm330.0400 ppm - 2.72 ppm
20191.51 ppm330.0600 ppm - 2.98 ppm
20202.00 ppm330.0200 ppm - 3.13 ppm
20211.44 ppm330.130 ppm - 2.85 ppm
20221.56 ppm220.110 ppm - 3.00 ppm
20230.745 ppm220.150 ppm - 1.34 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

The legal limit for nitrate, established in 1962, was developed to protect infants from acute methemoglobinemia, a life-threatening disorder of oxygen transport in the body. This limit does not fully protect against the risk of cancer and harm to the developing fetus.

ppm = parts per million

All test results

Date Lab ID Result
2018-03-12CA01121A0.0400 ppm
2018-03-19CA048581.63 ppm
2018-07-17CA91980-012.72 ppm
2019-02-21CC55842-032.98 ppm
2019-03-06CC62592-030.0600 ppm
2019-03-06CC62591-031.50 ppm
2020-02-05CF27861-NOX2.85 ppm
2020-03-02CF41927-NOX0.0200 ppm
2020-03-11CT48935-NOX3.13 ppm
2021-01-06CH41480-NOX0.130 ppm
2021-02-03CH55990-NOX2.85 ppm
2021-03-10CH75493-NOX1.35 ppm
2022-01-20CK200673.00 ppm
2022-02-02CK28223-NOX0.110 ppm
2023-02-08CN38363-NOX0.150 ppm
2023-02-08CN38361-NOX1.34 ppm