Chromium (total)
CTWC - Naugatuck Region-Central System
Chromium is a naturally occurring metal, but industrial uses can elevate its levels in water. One form, hexavalent chromium, causes cancer. Total chromium is not a good indicator of the amount of hexavalent chromium in drinking water.
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 | ND | 3 | 0 | ND |
| 2019 | ND | 2 | 0 | ND |
| 2020 | ND | 2 | 0 | ND |
| 2021 | ND | 2 | 0 | ND |
| 2022 | ND | 2 | 0 | ND |
| 2023 | 1.000 ppb | 2 | 1 | ND - 2.00 ppb |
ppb = parts per billion
State, National, and Health Guidelines for Drinking Water
EPA Maximum Contaminant
Level (MCL): 100 ppb
The legal limit for total chromium, established in 1991, was based on a 1958 toxicity study in laboratory animals, and applies to both the less-toxic trivalent chromium and the more-toxic hexavalent chromium forms of this compound. This limit does not protect against the risk of cancer from ingestion of hexavalent chromium.
ppb = parts per billion
All test results
| Date | Lab ID | Result |
|---|---|---|
| 2018-04-10 | CA17352IOC1 | ND |
| 2018-06-11 | CA67844IOC1 | ND |
| 2018-11-14 | IOCR 200512736 | ND |
| 2019-01-16 | IOC1 200518936 | ND |
| 2019-01-18 | IOCR 200519147 | ND |
| 2020-01-13 | IOC1 200562694 | ND |
| 2020-01-13 | IOCR 200562691 | ND |
| 2021-04-06 | IOC1 200611960 | ND |
| 2021-04-06 | IOCR 200611959 | ND |
| 2022-02-14 | CK66672 | ND |
| 2022-02-14 | CK66670 | ND |
| 2023-01-16 | CN24828 | ND |
| 2023-01-16 | CN24826 | 2.00 ppb |