Nitrate and nitrite
CTWC - Naugatuck Region-Central 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.
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 | 0.780 ppm | 6 | 6 | 0.158 ppm - 2.13 ppm |
| 2019 | 0.398 ppm | 3 | 3 | 0.390 ppm - 0.406 ppm |
| 2020 | 0.294 ppm | 3 | 3 | 0.283 ppm - 0.300 ppm |
| 2021 | 0.558 ppm | 4 | 4 | 0.468 ppm - 0.635 ppm |
| 2022 | 0.320 ppm | 2 | 2 | 0.300 ppm - 0.340 ppm |
| 2023 | 0.265 ppm | 2 | 2 | 0.260 ppm - 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
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 |
| 2018-11-14 | IOCR 200512736 | 0.158 ppm |
| 2019-01-16 | NOX 200518936 | 0.390 ppm |
| 2019-01-18 | IOCR 200519147 | 0.406 ppm |
| 2019-01-29 | NOX 200519832 | 0.398 ppm |
| 2020-01-13 | NOX 200562697 | 0.298 ppm |
| 2020-01-13 | IOCR 200562691 | 0.283 ppm |
| 2020-01-13 | NOX 200562694 | 0.300 ppm |
| 2021-04-06 | NOX 200611960 | 0.492 ppm |
| 2021-04-06 | NOX 200611962 | 0.468 ppm |
| 2021-04-06 | IOCR 200611959 | 0.635 ppm |
| 2021-04-06 | NOX 200611959 | 0.635 ppm |
| 2022-02-14 | CK66672 | 0.340 ppm |
| 2022-02-14 | CK66670 | 0.300 ppm |
| 2023-01-16 | CN24828 | 0.270 ppm |
| 2023-01-16 | CN24826 | 0.260 ppm |