Nitrate
Aquarion Water Company of Connecticut - Main System
Nitrate, a fertilizer chemical, frequently contaminates drinking water due to agricultural and urban runoff, and discharges from municipal wastewater treatment plants and septic tanks. Excessive nitrate in water can cause oxygen deprivation in infants and increase the risk of cancer. 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 | 0.685 ppm | 5 | 5 | 0.0930 ppm - 1.29 ppm |
| 2019 | 0.733 ppm | 5 | 5 | 0.167 ppm - 1.34 ppm |
| 2020 | 0.688 ppm | 5 | 5 | 0.123 ppm - 1.28 ppm |
| 2021 | 0.719 ppm | 5 | 5 | 0.111 ppm - 1.33 ppm |
| 2022 | 0.772 ppm | 5 | 5 | 0.127 ppm - 1.60 ppm |
| 2023 | 0.805 ppm | 5 | 5 | 0.0690 ppm - 1.56 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
The legal limit for nitrate, established in 1962, was developed to protect infants from acute methemoglobinemia, a life-threatening disorder of oxygen transport in the body. This limit does not fully protect against the risk of cancer and harm to the developing fetus.
ppm = parts per million
All test results
| Date | Lab ID | Result |
|---|---|---|
| 2018-02-05 | 201801570-NOX | 0.337 ppm |
| 2018-02-05 | 201801586-NOX | 0.0930 ppm |
| 2018-02-05 | 201801604-NOX | 0.599 ppm |
| 2018-07-05 | 201809662-NOX | 1.11 ppm |
| 2018-07-05 | 201809658-NOX | 1.29 ppm |
| 2019-02-04 | 201901554-NOX | 0.523 ppm |
| 2019-02-04 | 201901581-NOX | 0.378 ppm |
| 2019-02-04 | 201901613-NOX | 0.167 ppm |
| 2019-07-01 | 201909695-NOX | 1.26 ppm |
| 2019-07-01 | 201909693-NOX | 1.34 ppm |
| 2020-02-03 | 202001681-NOX | 0.600 ppm |
| 2020-02-03 | 202001624-NOX | 0.326 ppm |
| 2020-02-03 | 202001640-NOX | 0.123 ppm |
| 2020-07-07 | 202010259-NOX | 1.11 ppm |
| 2020-07-07 | 202010253-NOX | 1.28 ppm |
| 2021-02-02 | 202101448-NOX | 0.684 ppm |
| 2021-02-02 | 202101406-NOX | 0.111 ppm |
| 2021-02-02 | 202101394-NOX | 0.355 ppm |
| 2021-07-06 | 202110289-NOX | 1.12 ppm |
| 2021-07-06 | 202110283-NOX | 1.33 ppm |
| 2022-02-07 | 202202090-NOX | 0.477 ppm |
| 2022-02-07 | 202202022-NOX | 0.287 ppm |
| 2022-02-07 | 202202033-NOX | 0.127 ppm |
| 2022-07-05 | 202210995-NOX | 1.37 ppm |
| 2022-07-05 | 202210989-NOX | 1.60 ppm |
| 2023-02-06 | 202301854-NOX | 0.565 ppm |
| 2023-02-06 | 202301775-NOX | 0.0690 ppm |
| 2023-02-09 | 202302139-NOX | 0.418 ppm |
| 2023-06-07 | 202309441-NOX | 1.42 ppm |
| 2023-06-07 | 202309440-NOX | 1.56 ppm |