1,4-Dioxane
San Jose Water Company
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 | 0.0105 ppb | 21 | 1 | ND - 0.220 ppb |
| 2014 | N/A | 0 | 0 | N/A |
| 2015 | ND | 1 | 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 |
|---|---|---|
| 2013-08-05 | 2872072 | ND |
| 2013-08-05 | 2872046 | ND |
| 2013-08-05 | 2871995 | ND |
| 2013-08-05 | 2872012 | ND |
| 2013-08-05 | 2871979 | ND |
| 2013-08-12 | 2877907 | ND |
| 2013-08-19 | 2883554 | ND |
| 2013-08-19 | 2882254 | ND |
| 2013-08-19 | 2882207 | ND |
| 2013-08-19 | 2882278 | ND |
| 2013-08-19 | 2883565 | ND |
| 2013-08-26 | 2886322 | ND |
| 2013-08-26 | 2886354 | ND |
| 2013-08-26 | 2886343 | ND |
| 2013-08-26 | 2887315 | ND |
| 2013-08-26 | 2887281 | ND |
| 2013-08-27 | 2886933 | 0.220 ppb |
| 2013-11-06 | 2927648 | ND |
| 2013-11-06 | 2927624 | ND |
| 2013-11-06 | 2927613 | ND |
| 2013-11-06 | 2927602 | ND |
| 2015-02-11 | 3189324 | ND |