Nitrate
CTWC - Naugatuck Region-Central 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 | 0.904 ppm | 5 | 5 | 0.330 ppm - 2.13 ppm |
| 2019 | 0.394 ppm | 2 | 2 | 0.390 ppm - 0.398 ppm |
| 2020 | 0.299 ppm | 2 | 2 | 0.298 ppm - 0.300 ppm |
| 2021 | 0.532 ppm | 3 | 3 | 0.468 ppm - 0.635 ppm |
| 2022 | 0.340 ppm | 1 | 1 | 0.340 ppm |
| 2023 | 0.270 ppm | 1 | 1 | 0.270 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 |
|---|---|---|
| 2018-01-15 | BZ72858NOX | 0.330 ppm |
| 2018-04-10 | CA17352NOX | 0.440 ppm |
| 2018-05-21 | CA50443NOX | 2.13 ppm |
| 2018-06-11 | CA67843NOX | 0.800 ppm |
| 2018-06-11 | CA67844NOX | 0.820 ppm |
| 2019-01-16 | NOX 200518936 | 0.390 ppm |
| 2019-01-29 | NOX 200519832 | 0.398 ppm |
| 2020-01-13 | NOX 200562694 | 0.300 ppm |
| 2020-01-13 | NOX 200562697 | 0.298 ppm |
| 2021-04-06 | NOX 200611960 | 0.492 ppm |
| 2021-04-06 | NOX 200611962 | 0.468 ppm |
| 2021-04-06 | NOX 200611959 | 0.635 ppm |
| 2022-02-14 | CK66672 | 0.340 ppm |
| 2023-01-16 | CN24828 | 0.270 ppm |