Know Your Environment. Protect Your Health.

Nitrate

Town of Sunnyvale

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.

 

6

Samples

0

Samples exceeding legal limit (MCL)

4

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20180.739 ppm110.739 ppm
20190.734 ppm110.734 ppm
20200.618 ppm110.618 ppm
20210.551 ppm110.551 ppm
20220.0982 ppm110.0982 ppm
20230.0845 ppm110.0845 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
2018-05-08Q18184650020.739 ppm
2019-01-08Q19008020030.734 ppm
2020-01-08Q20008410030.618 ppm
2021-01-06Q21004210010.551 ppm
2022-09-13Q22271400010.0982 ppm
2023-08-02Q23314500010.0845 ppm