Know Your Environment. Protect Your Health.

Nitrate and nitrite

North Castle Water District #1

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.

 

9

Samples

0

Samples exceeding legal limit (MCL)

8

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20180.146 ppm110.146 ppm
20190.214 ppm110.214 ppm
2020ND10ND
20210.169 ppm110.169 ppm
20220.172 ppm110.172 ppm
20230.165 ppm440.143 ppm - 0.202 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
2018-07-24AU15717-NIT0.146 ppm
2019-08-05AV16472-NIT0.214 ppm
2020-07-29AW14502-NITND
2021-08-04AX15703-NIT0.169 ppm
2022-07-12AY12751-NIT0.172 ppm
2023-03-22AZ05098-NIT0.154 ppm
2023-03-22AZ05100-NIT0.143 ppm
2023-07-10AZ12338-NIT0.161 ppm
2023-07-25AZ13471-NIT0.202 ppm