Monochlorobenzene (chlorobenzene)
Twin Buttes Water System
NOTE: Twin Buttes Water System purchases water from City of San Angelo which is required to test for monochlorobenzene (chlorobenzene). Sample information shown below was taken by City of San Angelo.
Monochlorobenzene is used as a solvent for pesticides, a degreasing agent and an intermediate for manufacturing other chemicals. It causes liver and kidney damage in studies of laboratory animals.
Samples
Samples exceeding legal limit (MCL)
Samples exceeding
health guidelines
Testing results - average by year
| Year | Average result | Samples taken | Detections | Range of results |
|---|---|---|---|---|
| 2014 | ND | 9 | 0 | ND |
| 2015 | ND | 1 | 0 | ND |
| 2016 | ND | 2 | 0 | ND |
| 2017 | ND | 1 | 0 | ND |
| 2018 | ND | 1 | 0 | ND |
| 2019 | ND | 1 | 0 | ND |
ppb = parts per billion
State and national drinking water standards and health guidelines
EWG Health Guideline 70 ppb
The EWG Health Guideline of 70 ppb for monochlorobenzene 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) 100 ppb
The legal limit for monochlorobenzene, established in 1991, was based on a toxicity study in laboratory animals conducted in the 1960s.
ppb = parts per billion
All test results
NOTE: Twin Buttes Water System purchases water from City of San Angelo which is required to test for monochlorobenzene (chlorobenzene). Sample information shown below was taken by City of San Angelo.
| Date | Lab ID | Result |
|---|---|---|
| 2014-04-29 | AC52069 | ND |
| 2014-04-29 | AC52067 | ND |
| 2014-04-29 | AC52065 | ND |
| 2014-04-29 | AC52063 | ND |
| 2014-04-29 | AC52037 | ND |
| 2014-04-29 | AC52059 | ND |
| 2014-04-29 | AC52039 | ND |
| 2014-04-29 | AC52071 | ND |
| 2014-08-11 | AC63095 | ND |
| 2015-08-12 | AD03968 | ND |
| 2016-02-17 | AD24323 | ND |
| 2016-05-17 | AD37069 | ND |
| 2016-07-20 | AD45007 | ND |
| 2016-11-09 | AD57412 | ND |
| 2017-05-09 | Q1719085002 | ND |
| 2018-02-28 | Q1808687007 | ND |
| 2019-05-07 | Q1920785002 | ND |