Chromium (total)
Connecticut Water Company - Northern Region-Western 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 | 5 | 0 | ND |
| 2019 | ND | 2 | 0 | ND |
| 2020 | 0.333 ppb | 3 | 1 | ND - 1.000 ppb |
| 2021 | ND | 2 | 0 | ND |
| 2022 | 0.167 ppb | 6 | 1 | ND - 1.000 ppb |
| 2023 | 0.200 ppb | 5 | 1 | ND - 1.000 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 |
|---|---|---|
| 2018-01-23 | BZ78887IOC1 | ND |
| 2018-01-31 | BZ82691IOCR | ND |
| 2018-03-02 | BZ97488IOC1 | ND |
| 2018-07-12 | CA89150 | ND |
| 2018-07-13 | CA89903 | ND |
| 2019-01-10 | IOCR 200518412 | ND |
| 2019-01-15 | IOC1 200518779 | ND |
| 2020-01-09 | IOC1 200562368 | ND |
| 2020-01-15 | IOCR 200563111 | ND |
| 2020-09-21 | IOC1 200591023 | 1.000 ppb |
| 2021-02-17 | IOC1 200607102 | ND |
| 2021-03-05 | IOCR 200608709 | ND |
| 2022-01-24 | CK22294 | ND |
| 2022-01-25 | CK23176 | 1.000 ppb |
| 2022-02-01 | CK27430 | ND |
| 2022-02-01 | CK27434 | ND |
| 2022-02-16 | CK69357 | ND |
| 2022-09-08 | CM25672 | ND |
| 2023-01-11 | CN20957 | ND |
| 2023-01-18 | CN25096 | ND |
| 2023-08-23 | CO81672 | 1.000 ppb |
| 2023-10-31 | CP38331 | ND |
| 2023-12-13 | CP67269 | ND |