Nitrate and nitrite
Connecticut Water Company - Amston Lake Division
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.
Samples
Samples exceeding legal limit (MCL)
Samples exceeding
health guidelines
Testing results - average by year
| Year | Average result | Samples taken | Detections | Range of results |
|---|---|---|---|---|
| 2018 | 0.290 ppm | 2 | 2 | 0.0200 ppm - 0.560 ppm |
| 2019 | 0.367 ppm | 2 | 1 | ND - 0.734 ppm |
| 2020 | 0.0240 ppm | 2 | 2 | 0.0230 ppm - 0.0250 ppm |
| 2021 | 0.391 ppm | 2 | 2 | 0.00700 ppm - 0.774 ppm |
| 2022 | 0.125 ppm | 2 | 2 | 0.0200 ppm - 0.230 ppm |
| 2023 | 0.543 ppm | 3 | 3 | 0.0200 ppm - 1.05 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 |
|---|---|---|
| 2018-04-09 | CA16126NOX | 0.560 ppm |
| 2018-04-09 | CA16127NOX | 0.0200 ppm |
| 2019-02-19 | NOX 200522111 | 0.734 ppm |
| 2019-02-19 | NOX 200522112 | ND |
| 2020-09-14 | NOX 200590073 | 0.0230 ppm |
| 2020-09-14 | NOX 200590072 | 0.0250 ppm |
| 2021-01-06 | NOX 200602954 | 0.00700 ppm |
| 2021-09-14 | 300059922 300059923 | 0.774 ppm |
| 2022-01-12 | CK15028 | 0.230 ppm |
| 2022-01-18 | CK18504 | 0.0200 ppm |
| 2023-01-31 | CN33437 | 1.05 ppm |
| 2023-01-31 | CN33435 | 0.0200 ppm |
| 2023-10-24 | CP33087 | 0.560 ppm |