MTBE
Ephesus
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.
22
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 | ND | 6 | 0 | ND |
| 2015 | ND | 3 | 0 | ND |
| 2016 | 0.905 ppb | 4 | 4 | 0.590 ppb - 1.10 ppb |
| 2017 | 0.825 ppb | 4 | 2 | ND - 1.80 ppb |
| 2018 | 0.128 ppb | 4 | 1 | ND - 0.510 ppb |
| 2019 | ND | 1 | 0 | ND |
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 | Lab ID | Result |
|---|---|---|
| 2014-01-15 | AI26793 | ND |
| 2014-01-15 | AI26792 | ND |
| 2014-01-15 | AI26791 | ND |
| 2014-04-22 | AI38581 | ND |
| 2014-07-09 | AI45367 | ND |
| 2014-11-12 | AI59496 | ND |
| 2015-03-19 | AI69473 | ND |
| 2015-03-19 | AI69472 | ND |
| 2015-03-19 | AI69471 | ND |
| 2016-03-23 | AJ08658 | 0.830 ppb |
| 2016-05-24 | AJ12853 | 1.10 ppb |
| 2016-08-09 | AJ21897 | 1.10 ppb |
| 2016-10-26 | AJ32285 | 0.590 ppb |
| 2017-02-01 | AJ43873 | 1.50 ppb |
| 2017-04-26 | AJ54083 | 1.80 ppb |
| 2017-07-31 | AJ62157 | ND |
| 2017-10-24 | AJ72297 | ND |
| 2018-01-30 | AJ78082 | ND |
| 2018-01-30 | AJ78081 | 0.510 ppb |
| 2018-01-30 | AJ78080 | ND |
| 2018-04-11 | AJ87337 | ND |
| 2019-05-14 | AK17469 | ND |