1,4-Dioxane
City of Torrance Water Department
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 | ND | 7 | 0 | ND |
| 2015 | ND | 3 | 0 | ND |
| 2016 | N/A | 0 | 0 | N/A |
| 2017 | N/A | 0 | 0 | N/A |
| 2018 | ND | 8 | 0 | ND |
| 2019 | ND | 2 | 0 | ND |
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 |
|---|---|---|
| 2014-04-30 | 4D30063-01A | ND |
| 2014-04-30 | 4D30063-07A | ND |
| 2014-04-30 | 4D30063-03A | ND |
| 2014-04-30 | 4D30063-05A | ND |
| 2014-07-30 | 4G30080-01A | ND |
| 2014-10-28 | 4J28082-01A | ND |
| 2014-11-25 | 4K25091-01A | ND |
| 2015-01-28 | 5A28062-01A | ND |
| 2015-03-30 | 5C30051-03A | ND |
| 2015-03-30 | 5C30051-01A | ND |
| 2018-02-23 | 9588-024-0955 | ND |
| 2018-02-23 | 9588-023-0935 | ND |
| 2018-06-14 | 9588-024-0935 | ND |
| 2018-06-14 | 9588-023-1012 | ND |
| 2018-08-02 | 9588-024-0933 | ND |
| 2018-08-02 | 9588-023-1000 | ND |
| 2018-11-08 | 9588-024-1037 | ND |
| 2018-11-08 | 9588-023-0948 | ND |
| 2019-01-23 | 9588-024-0940 | ND |
| 2019-01-23 | 9588-023-1010 | ND |