1,4-Dioxane
California Water Service - Stockton
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 | 0.0189 ppb | 24 | 3 | ND - 0.250 ppb |
| 2015 | ND | 3 | 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 |
|---|---|---|
| 2014-01-09 | 201401100159AM | ND |
| 2014-01-09 | 201401100141AM | ND |
| 2014-01-09 | 201401100118AM | ND |
| 2014-01-14 | 201401150488AM | ND |
| 2014-01-14 | 201401150651AM | ND |
| 2014-01-14 | 201401150324AM | ND |
| 2014-01-16 | 201401170454AM | ND |
| 2014-01-16 | 201401170409AM | ND |
| 2014-01-16 | 201401170467AM | 0.130 ppb |
| 2014-01-22 | 201401230169AM | ND |
| 2014-04-21 | 201404220354AM | ND |
| 2014-04-21 | 201404220292AM | ND |
| 2014-07-07 | 201407090858AM | ND |
| 2014-07-08 | 201407090792AM | ND |
| 2014-07-08 | 201407090772AM | ND |
| 2014-07-08 | 201407090711AM | ND |
| 2014-07-08 | 201407090765AM | ND |
| 2014-07-14 | 201407150432AM | 0.250 ppb |
| 2014-07-15 | 201407160585AM | ND |
| 2014-07-15 | 201407160568AM | ND |
| 2014-07-15 | 201407160596AM | ND |
| 2014-07-23 | 201407240451AM | 0.0730 ppb |
| 2014-10-08 | 201410090340AM | ND |
| 2014-10-08 | 201410090368AM | ND |
| 2015-01-07 | 201501080585AM | ND |
| 2015-06-03 | 201506040499AM | ND |
| 2015-09-16 | 201509170576AM | ND |