1,4-Dioxane
Park WC - Lynwood
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 | 2.10 ppb | 2 | 2 | 2.00 ppb - 2.20 ppb |
| 2015 | 0.844 ppb | 9 | 4 | ND - 2.20 ppb |
| 2016 | 2.05 ppb | 2 | 2 | 1.70 ppb - 2.40 ppb |
| 2017 | 1.80 ppb | 2 | 2 | 1.80 ppb |
| 2018 | 1.90 ppb | 1 | 1 | 1.90 ppb |
| 2019 | 2.60 ppb | 1 | 1 | 2.60 ppb |
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 |
|---|---|---|
| 2014-04-17 | 9588-005-1130 | 2.00 ppb |
| 2014-10-16 | 9588-005-1400 | 2.20 ppb |
| 2015-01-23 | 201501230226AM | ND |
| 2015-01-23 | 201501230292AM | ND |
| 2015-01-23 | 201501230287AM | 1.70 ppb |
| 2015-02-26 | 9588-005-1230 | 1.90 ppb |
| 2015-04-24 | 201504240365AM | ND |
| 2015-07-20 | 201507200366AM | 1.80 ppb |
| 2015-07-20 | 201507200370AM | ND |
| 2015-08-05 | 9588-005-0915 | 2.20 ppb |
| 2015-10-19 | 201510190350AM | ND |
| 2016-04-14 | 9588-005-0945 | 1.70 ppb |
| 2016-08-04 | 9588-005-1210 | 2.40 ppb |
| 2017-02-23 | 9588-005-1315 | 1.80 ppb |
| 2017-11-30 | 9588-005-0945 | 1.80 ppb |
| 2018-02-27 | 9588-005-1230 | 1.90 ppb |
| 2019-02-13 | 9588-005-0930 | 2.60 ppb |