Know Your Environment. Protect Your Health.

Nitrate and nitrite

Hidden Lake Yellowstone County W and S D

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.

 

7

Samples

0

Samples exceeding legal limit (MCL)

3

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20180.440 ppm110.440 ppm
20190.335 ppm220.230 ppm - 0.440 ppm
20200.0900 ppm110.0900 ppm
20210.0800 ppm110.0800 ppm
20220.0800 ppm110.0800 ppm
20230.0600 ppm110.0600 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

ppm = parts per million

All test results

Date Lab ID Result
2018-08-14B18081602-001A0.440 ppm
2019-08-26B19082503-002A0.230 ppm
2019-09-27B19092743-001C0.440 ppm
2020-10-02B20100267-001B0.0900 ppm
2021-09-03B21090383-001C0.0800 ppm
2022-10-04B22100350-001A0.0800 ppm
2023-10-02B23100094-001A0.0600 ppm