Arsenic
CTWC - Unionville System
NOTE: CTWC - Unionville System purchases water from Metropolitan District Commission which is required to test for arsenic. Sample information shown below was taken by Metropolitan District Commission.
Arsenic is a potent carcinogen and common contaminant in drinking water. Arsenic causes thousands of cases of cancer each year in the U.S. Click here to read more about arsenic.
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: 0.004 ppb
The EWG Health Guideline of 0.004 ppb for arsenic 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 cancer.
EPA Maximum Contaminant
Level (MCL): 10 ppb
The legal limit for arsenic, established in 2001, was based on costs for arsenic removal, as calculated at the time that the standard was set. This limit does not fully protect against the risk of cancer due to arsenic exposure.
ppb = parts per billion
All test results
NOTE: CTWC - Unionville System purchases water from Metropolitan District Commission which is required to test for arsenic. Sample information shown below was taken by Metropolitan District Commission.
| Date | Lab ID | Result |
|---|---|---|
| 2018-07-18 | AE01630GE | ND |
| 2018-07-18 | AE01632GE | ND |
| 2018-07-18 | AE01640GE | ND |
| 2018-07-18 | AE01641GE | ND |
| 2018-07-18 | AE01637GE | ND |
| 2018-07-18 | AE01636GE | ND |
| 2018-07-18 | AE01631GE | ND |
| 2019-12-03 | CE70734 | ND |
| 2019-12-03 | CE70735 | ND |
| 2019-12-03 | CE70736 | ND |
| 2019-12-03 | CE70733 | ND |
| 2019-12-03 | CE70741 | ND |
| 2019-12-03 | CE70739 | ND |
| 2019-12-03 | CE70740 | 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 300107454 | ND |
| 2021-11-23 | I300107476 300107479 | ND |
| 2021-11-23 | E300107451 300107460 | ND |
| 2021-11-29 | E300109635 300109640 | ND |
| 2021-11-29 | I300109610 300109613 | ND |
| 2021-11-30 | I300109649 300109653 | ND |
| 2021-11-30 | I300109650 300109659 | ND |
| 2022-12-08 | I300283837 300283842 | ND |
| 2022-12-08 | 300283822 300283827B | ND |
| 2022-12-15 | E300287100 300287104 | ND |
| 2022-12-15 | I300287081 300287086 | ND |
| 2022-12-15 | I300287109 300287112 | ND |
| 2022-12-15 | E300287072 300287076 | ND |
| 2022-12-15 | E300287053 300287057 | ND |
| 2023-12-05 | E300456248 300456251 | ND |
| 2023-12-05 | I300456268 300456271 | ND |
| 2023-12-05 | I300456261 300456264 | ND |
| 2023-12-05 | I300456281 300456284 | ND |
| 2023-12-06 | E300456222 300456225 | ND |
| 2023-12-06 | E300456228 300456231 | ND |
| 2023-12-06 | I300456234 300456237 | ND |