Know Your Environment. Protect Your Health.

Nitrate

Humboldt, City of

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.

 

12

Samples

0

Samples exceeding legal limit (MCL)

10

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20180.435 ppm220.290 ppm - 0.580 ppm
20190.690 ppm220.680 ppm - 0.700 ppm
20200.545 ppm220.540 ppm - 0.550 ppm
20210.640 ppm220.630 ppm - 0.650 ppm
20220.645 ppm220.630 ppm - 0.660 ppm
2023ND20ND

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
2018-04-039385370.580 ppm
2018-04-169385410.290 ppm
2019-04-0811398390.680 ppm
2019-04-0811398410.700 ppm
2020-04-1313565700.540 ppm
2020-04-1313567110.550 ppm
2021-04-0518108050.650 ppm
2021-04-0518109590.630 ppm
2022-04-0422300760.660 ppm
2022-04-0422299700.630 ppm
2023-04-032474485ND
2023-04-032474486ND