Mercury (inorganic)
CTWC - Unionville System
NOTE: CTWC - Unionville System purchases water from Metropolitan District Commission which is required to test for mercury (inorganic). Sample information shown below was taken by Metropolitan District Commission.
Mercury is a potent neurotoxin that also damages the kidneys and other internal organs. Mercury enters drinking water from industrial pollution, mining wastes and coal-fired power plants.
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 | 1 | 0 | ND |
| 2019 | ND | 2 | 0 | ND |
| 2020 | ND | 2 | 0 | ND |
| 2021 | ND | 1 | 0 | ND |
| 2022 | ND | 1 | 0 | ND |
| 2023 | ND | 1 | 0 | ND |
ppb = parts per billion
State, National, and Health Guidelines for Drinking Water
EWG Health Guideline: 1.2 ppb
The EWG Health Guideline of 1.2 ppb for mercury (inorganic) was defined by the California Office of Environmental Health Hazard Assessment as a public health goal, the level of a drinking water contaminant that does not pose a significant health risk. This health guideline protects against harm to internal organs.
EPA Maximum Contaminant
Level (MCL): 2 ppb
The legal limit for inorganic mercury, established in 1991, was based on toxicity studies conducted in laboratory animals in the 1970s and 1980s. This limit does not include any additional consideration of children’s health.
ppb = parts per billion
All test results
NOTE: CTWC - Unionville System purchases water from Metropolitan District Commission which is required to test for mercury (inorganic). Sample information shown below was taken by Metropolitan District Commission.
| Date | Lab ID | Result |
|---|---|---|
| 2018-07-18 | CA93877 | ND |
| 2018-07-18 | CA93878 | ND |
| 2018-07-18 | CA93875 | ND |
| 2018-07-18 | CA93874 | ND |
| 2018-07-18 | CA93870 | ND |
| 2018-07-18 | CA93876 | ND |
| 2019-10-09 | CE39274 | ND |
| 2019-10-09 | CE39273 | ND |
| 2019-10-09 | CE39276 | ND |
| 2019-10-09 | CE39275 | ND |
| 2019-10-09 | CE39269 | ND |
| 2019-10-09 | CE39270 | ND |
| 2019-10-09 | CE39268 | ND |
| 2020-12-08 | IOC1 200600637 | ND |
| 2020-12-08 | IOC1 200600611 | ND |
| 2020-12-08 | IOCR 200600614 | ND |
| 2020-12-08 | IOCR 200600615 | ND |
| 2020-12-08 | IOCR 200600616 | ND |
| 2020-12-08 | IOCR 200600617 | ND |
| 2020-12-09 | IOC1 200600603 | ND |
| 2021-11-23 | E300107450 300107456 | ND |
| 2021-11-23 | I300107476 300107482 | ND |
| 2021-11-23 | E300107451 300107462 | ND |
| 2021-11-29 | E300109635 300109642 | ND |
| 2021-11-29 | I300109610 300109616 | ND |
| 2021-11-30 | I300109649 300109656 | ND |
| 2021-11-30 | I300109650 300109662 | ND |
| 2022-12-08 | I300283837 300283845 | ND |
| 2022-12-08 | 300283822 300283830B | ND |
| 2022-12-15 | E300287100 300287106 | ND |
| 2022-12-15 | I300287081 300287089 | ND |
| 2022-12-15 | I300287109 300287115 | ND |
| 2022-12-15 | E300287072 300287078 | ND |
| 2022-12-15 | E300287053 300287059 | ND |
| 2023-12-05 | E300456248 300456253 | ND |
| 2023-12-05 | I300456268 300456274 | ND |
| 2023-12-05 | I300456261 300456267 | ND |
| 2023-12-05 | I300456281 300456287 | ND |
| 2023-12-06 | E300456222 300456227 | ND |
| 2023-12-06 | E300456228 300456233 | ND |
| 2023-12-06 | I300456234 300456240 | ND |