Chromium (total)
Norwich Public Utilities
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 | 4 | 0 | ND |
| 2019 | ND | 5 | 0 | ND |
| 2020 | ND | 5 | 0 | ND |
| 2021 | ND | 2 | 0 | ND |
| 2022 | ND | 3 | 0 | ND |
| 2023 | ND | 2 | 0 | ND |
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 |
|---|---|---|
| 2018-08-20 | PH-0453-6304414IOC1 | ND |
| 2018-08-20 | PH-0453-6304416IOCR | ND |
| 2018-08-20 | PH-0453-6304417IOCR | ND |
| 2018-08-20 | PH-0453-6304413IOC1 | ND |
| 2019-08-29 | PH-0453-6305529IOC1 | ND |
| 2019-08-29 | PH-0453-6305531IOC1 | ND |
| 2019-08-29 | PH-0453-6305532IOCR | ND |
| 2019-09-19 | PH-0453-6305530IOC1 | ND |
| 2019-11-07 | PH-0453-6305533IOCR | ND |
| 2020-06-10 | PH-0453-6306357IOC1 | ND |
| 2020-06-10 | PH-0453-6306433IOCR | ND |
| 2020-06-10 | PH-0453-6306432IOCR | ND |
| 2020-06-10 | PH-0453-6306358IOC1 | ND |
| 2020-06-10 | PH-0453-6306356IOC1 | ND |
| 2021-05-24 | PH-0453-6307275IOC1 | ND |
| 2021-05-24 | PH-0453-6307278IOCR | ND |
| 2022-01-13 | PH-0453-6307955IOC1 | ND |
| 2022-01-13 | PH-0453-6307958IOCR | ND |
| 2022-11-21 | PH-0453-6307956IOC1 | ND |
| 2023-11-14 | D3K1545-01IOC | ND |
| 2023-11-14 | D3K1545-02IOC | ND |