Know Your Environment. Protect Your Health.

Nitrate and nitrite

East Hampton WPCA - Royal Oaks System

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.

 

15

Samples

0

Samples exceeding legal limit (MCL)

12

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20180.485 ppm220.440 ppm - 0.530 ppm
20191.06 ppm330.180 ppm - 2.49 ppm
20200.880 ppm220.180 ppm - 1.58 ppm
20210.155 ppm220.150 ppm - 0.160 ppm
20221.20 ppm42ND - 2.40 ppm
20231.74 ppm21ND - 3.48 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
2018-03-13116552GE0.440 ppm
2018-03-13116553GE0.530 ppm
2019-07-021257710.180 ppm
2019-07-021257722.49 ppm
2019-12-091293360.510 ppm
2020-02-251306460.180 ppm
2020-02-251306471.58 ppm
2021-03-231386540.150 ppm
2021-03-231386550.160 ppm
2022-10-12152052ND
2022-10-12152054ND
2022-10-121520552.40 ppm
2022-10-121520532.40 ppm
2023-12-28166824ND
2023-12-281668253.48 ppm