1,4-Dioxane
California Water Service (CWS) - Los Altos Suburban
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 |
|---|---|---|---|---|
| 2013 | ND | 25 | 0 | ND |
| 2014 | ND | 2 | 0 | ND |
| 2015 | N/A | 0 | 0 | N/A |
| 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 |
|---|---|---|
| 2013-06-05 | 201306060175AM | ND |
| 2013-06-05 | 201306060220AM | ND |
| 2013-06-05 | 201306060247AM | ND |
| 2013-06-10 | 201306110396AM | ND |
| 2013-06-10 | 201306110406AM | ND |
| 2013-06-10 | 201306110145AM | ND |
| 2013-06-10 | 201306110152AM | ND |
| 2013-06-12 | 201306130098AM | ND |
| 2013-06-18 | 201306190309AM | ND |
| 2013-06-18 | 201306190266AM | ND |
| 2013-06-18 | 201306190288AM | ND |
| 2013-09-11 | 201309120297AM | ND |
| 2013-12-03 | 201312040565AM | ND |
| 2013-12-04 | 201312050168AM | ND |
| 2013-12-05 | 201312060282AM | ND |
| 2013-12-09 | 201312100209AM | ND |
| 2013-12-09 | 201312100196AM | ND |
| 2013-12-10 | 201312110683AM | ND |
| 2013-12-10 | 201312110718AM | ND |
| 2013-12-11 | 201312120625AM | ND |
| 2013-12-16 | 201312170386AM | ND |
| 2013-12-16 | 201312170376AM | ND |
| 2013-12-17 | 201312180648AM | ND |
| 2013-12-17 | 201312180732AM | ND |
| 2013-12-18 | 201312200055AM | ND |
| 2014-03-05 | 201403060202AM | ND |
| 2014-06-04 | 201406050002AM | ND |