MTBE
Concord Water Department
MTBE was used as gasoline oxygenation additive to boost the octane number. In 2005, MTBE was replaced by ethanol as a gasoline additive. MTBE causes cancers in rats.
41
Samples
0
Samples exceeding legal limit (MCL)
0
Samples exceeding
health guidelines
Testing results - average by year
| Year | Average result | Samples taken | Detections | Range of results |
|---|---|---|---|---|
| 2014 | 0.400 ppb | 7 | 1 | ND - 2.80 ppb |
| 2015 | 0.343 ppb | 7 | 1 | ND - 2.40 ppb |
| 2016 | 0.486 ppb | 7 | 1 | ND - 3.40 ppb |
| 2017 | 0.702 ppb | 6 | 1 | ND - 4.21 ppb |
| 2018 | 0.521 ppb | 7 | 1 | ND - 3.65 ppb |
| 2019 | 0.383 ppb | 7 | 1 | ND - 2.68 ppb |
ppb = parts per billion
State and national drinking water standards and health guidelines
EWG Health Guideline 13 ppb
The EWG Health Guideline of 13 ppb for MTBE 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.
ppb = parts per billion
All test results
| Date | Result |
|---|---|
| 2014-07-01 | ND |
| 2014-07-15 | ND |
| 2014-07-15 | ND |
| 2014-07-15 | ND |
| 2014-07-28 | 2.80 ppb |
| 2014-08-13 | ND |
| 2014-08-25 | ND |
| 2015-07-01 | ND |
| 2015-07-15 | ND |
| 2015-07-16 | ND |
| 2015-07-16 | ND |
| 2015-07-23 | 2.40 ppb |
| 2015-09-14 | ND |
| 2015-09-29 | ND |
| 2016-07-26 | ND |
| 2016-08-10 | 3.40 ppb |
| 2016-08-18 | ND |
| 2016-08-25 | ND |
| 2016-08-25 | ND |
| 2016-09-13 | ND |
| 2016-09-29 | ND |
| 2017-07-03 | ND |
| 2017-07-31 | ND |
| 2017-08-14 | 4.21 ppb |
| 2017-08-25 | ND |
| 2017-08-28 | ND |
| 2017-09-18 | ND |
| 2018-07-11 | ND |
| 2018-07-16 | 3.65 ppb |
| 2018-07-25 | ND |
| 2018-07-26 | ND |
| 2018-07-26 | ND |
| 2018-08-28 | ND |
| 2018-08-28 | ND |
| 2019-07-01 | ND |
| 2019-07-01 | 2.68 ppb |
| 2019-07-03 | ND |
| 2019-07-11 | ND |
| 2019-07-26 | ND |
| 2019-07-31 | ND |
| 2019-09-18 | ND |