Know Your Environment. Protect Your Health.

Nitrate and nitrite

Whitworth Water District 2

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.

 

12

Samples

0

Samples exceeding legal limit (MCL)

12

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20181.37 ppm330.605 ppm - 2.27 ppm
20190.879 ppm220.838 ppm - 0.920 ppm
2020N/A00N/A
20211.89 ppm111.89 ppm
20221.83 ppm550.779 ppm - 2.67 ppm
20230.781 ppm110.781 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
2018-05-211.22 ppm
2018-05-210.605 ppm
2018-05-212.27 ppm
2019-06-180.838 ppm
2019-06-210.920 ppm
2021-05-1741172741.89 ppm
2022-04-2142718771.24 ppm
2022-05-1842846482.67 ppm
2022-05-3142940151.91 ppm
2022-06-2743097990.779 ppm
2022-07-1443098062.54 ppm
2023-04-2744521650.781 ppm