1,4-Dioxane
Golden State Water Company (GSWC) - San Dimas
1,4-Dioxane is a solvent classified by the EPA as a likely human carcinogen. It contaminates groundwater in many states due to industrial wastewater discharges, plastic manufacturing runoff and landfill runoff. Read More.
Animal studies show that 1,4-dioxane can target the liver, kidneys and respiratory system, and that prenatal exposure can harm the developing fetus. The State of California has set a Public Heatlh Goal of no more than 1 part per billion of 1,4-dioxane in drinking water. The state of Massachusetts sets a legal limit of 0.3 ppb, and New Hampshire's limit is 3 parts per billion. There is no national drinking water standard for this contaminant.
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 | N/A | 0 | 0 | N/A |
| 2015 | ND | 16 | 0 | ND |
| 2016 | N/A | 0 | 0 | N/A |
| 2017 | N/A | 0 | 0 | N/A |
| 2018 | N/A | 0 | 0 | N/A |
| 2019 | N/A | 0 | 0 | N/A |
ppb = parts per billion
State and national drinking water standards and health guidelines
EWG Health Guideline 0.35 ppb
The EWG Health Guideline of 0.35 ppb for 1,4-dioxane was defined by the Environmental Protection Agency as a one-in-a-million lifetime risk of cancer. Values greater than one-in-a-million cancer risk level can result in increased cancer cases above one in a million people.
ppb = parts per billion
All test results
| Date | Lab ID | Result |
|---|---|---|
| 2015-01-21 | 5A21031-11A | ND |
| 2015-01-21 | 5A21031-09A | ND |
| 2015-01-21 | 5A21031-03A | ND |
| 2015-01-21 | 5A21031-05A | ND |
| 2015-01-21 | 5A21031-01A | ND |
| 2015-01-21 | 5A21031-07A | ND |
| 2015-04-17 | 5D17033-03A | ND |
| 2015-04-17 | 5D17033-01A | ND |
| 2015-07-21 | 5G21057-11A | ND |
| 2015-07-21 | 5G21057-09A | ND |
| 2015-07-21 | 5G21057-05A | ND |
| 2015-07-21 | 5G21057-01A | ND |
| 2015-07-21 | 5G21057-03A | ND |
| 2015-07-21 | 5G21057-07A | ND |
| 2015-10-20 | 5J21034-01A | ND |
| 2015-10-20 | 5J21034-03A | ND |