Know Your Environment. Protect Your Health.

Nitrate

Nob Hill Water Association

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.

 

25

Samples

0

Samples exceeding legal limit (MCL)

15

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20180.374 ppm54ND - 0.900 ppm
20190.292 ppm54ND - 0.560 ppm
2020N/A00N/A
20210.246 ppm54ND - 0.510 ppm
20220.542 ppm53ND - 1.80 ppm
20230.250 ppm54ND - 0.486 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
2018-07-310.330 ppm
2018-07-310.120 ppm
2018-07-31ND
2018-07-310.520 ppm
2018-07-310.900 ppm
2019-07-020.440 ppm
2019-07-020.560 ppm
2019-07-020.0900 ppm
2019-07-02ND
2019-07-020.370 ppm
2021-07-074133279ND
2021-07-0741332770.340 ppm
2021-07-0741332810.300 ppm
2021-07-0741332800.0800 ppm
2021-07-0741332780.510 ppm
2022-03-2143089530.510 ppm
2022-07-0643052301.80 ppm
2022-07-064305228ND
2022-07-0643052270.400 ppm
2022-07-064305229ND
2023-07-184480366ND
2023-07-1844803640.308 ppm
2023-07-1844803680.339 ppm
2023-07-1844803670.486 ppm
2023-07-1844803650.116 ppm