Know Your Environment. Protect Your Health.

Nitrate and nitrite

North Castle Water District #5

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.

 

5

Samples

0

Samples exceeding legal limit (MCL)

4

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20180.275 ppm110.275 ppm
20190.358 ppm110.358 ppm
20200.500 ppm21ND - 1.000 ppm
20210.835 ppm220.129 ppm - 1.54 ppm
20220.828 ppm220.106 ppm - 1.55 ppm
20230.203 ppm330.114 ppm - 0.301 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
2018-07-24AU15719-NIT0.275 ppm
2019-08-05AV16475-NIT0.358 ppm
2023-03-21AZ05019-NIT0.114 ppm
2023-07-10AZ12339-NIT0.301 ppm
2023-09-12AZ16819-NIT0.193 ppm