1,4-Dioxane
City of La Palma
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 | 4 | 0 | ND |
| 2014 | ND | 2 | 0 | ND |
| 2015 | ND | 2 | 0 | ND |
| 2016 | ND | 1 | 0 | ND |
| 2017 | ND | 2 | 0 | ND |
| 2018 | ND | 2 | 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 |
|---|---|---|
| 2013-02-04 | 3010100803 | ND |
| 2013-02-04 | 3010100802 | ND |
| 2013-08-05 | 3010100802-2 | ND |
| 2013-09-03 | 3010100804-3 | ND |
| 2014-02-03 | 4417-001-0900 | ND |
| 2014-02-03 | 4417-006-0925 | ND |
| 2015-03-02 | 4417-006-0945 | ND |
| 2015-05-04 | 4417-001-0835 | ND |
| 2016-02-08 | 4417-006-0850 | ND |
| 2017-01-30 | 4417-006-1040 | ND |
| 2017-05-01 | 4417-001-0915 | ND |
| 2018-02-05 | 4417-006-0835 | ND |
| 2018-04-02 | 4417-001-0825 | ND |
| 2019-02-04 | 4417-001-0820 | ND |
| 2019-02-04 | 4417-006-0840 | ND |