Benzo[a]pyrene
CTWC - Unionville System
NOTE: CTWC - Unionville System purchases water from Metropolitan District Commission which is required to test for benzo[a]pyrene. Sample information shown below was taken by Metropolitan District Commission.
Benzo[a]pyrene is a polycyclic aromatic hydrocarbon, or PAH, released from combustion of fossil fuels and waste incinerators. PAHs increase the risk of cancer; damage the immune, nervous and reproductive systems; and can harm developing fetuses.
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 | 7 | 0 | ND |
| 2019 | ND | 12 | 0 | ND |
| 2020 | ND | 3 | 0 | ND |
| 2021 | ND | 3 | 0 | ND |
| 2022 | ND | 6 | 0 | ND |
| 2023 | ND | 3 | 0 | ND |
ppb = parts per billion
State, National, and Health Guidelines for Drinking Water
EWG Health Guideline: 0.007 ppb
The EWG Health Guideline of 0.007 ppb for benzo[a]pyrene 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): 0.2 ppb
The legal limit for benzo[a]pyrene, established in 1992, was based on analytical detection limits at the time that the standard was set. This limit may not fully protect against the risk of cancer due to PAH exposure.
ppb = parts per billion
All test results
NOTE: CTWC - Unionville System purchases water from Metropolitan District Commission which is required to test for benzo[a]pyrene. Sample information shown below was taken by Metropolitan District Commission.
| Date | Lab ID | Result |
|---|---|---|
| 2018-06-27 | CA79476 | ND |
| 2018-06-27 | CA79477 | ND |
| 2018-06-27 | CA79475 | ND |
| 2018-09-25 | CB38504 | ND |
| 2018-09-25 | CB38505R | ND |
| 2018-09-25 | CB38869 | ND |
| 2018-09-25 | CB38505 | ND |
| 2020-12-08 | SOC 200600638 | ND |
| 2020-12-08 | SOC 200600609 | ND |
| 2020-12-09 | SOC 200600592 | ND |
| 2021-11-23 | S300107511 300107517 | ND |
| 2021-11-23 | S300107593 300107600 | ND |
| 2021-11-29 | S300109627 300109633 | ND |
| 2022-12-15 | S300287039 300287048 | ND |
| 2022-12-15 | S300287062 300287069 | ND |
| 2022-12-15 | S300287090 300287097 | ND |
| 2023-12-05 | S300456329 300456336 | ND |
| 2023-12-06 | S300456308 300456315 | ND |
| 2023-12-06 | S300456298 300456305 | ND |