1,4-Dioxane
California American Water Company - Lincoln Oaks
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 | N/A | 0 | 0 | N/A |
| 2015 | 0.0128 ppb | 39 | 5 | ND - 0.120 ppb |
| 2016 | N/A | 0 | 0 | N/A |
| 2017 | ND | 3 | 0 | ND |
| 2018 | ND | 1 | 0 | ND |
| 2019 | ND | 1 | 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 |
|---|---|---|
| 2015-02-02 | 28255701 | ND |
| 2015-02-02 | 28254801 | ND |
| 2015-02-03 | 28256701 | ND |
| 2015-02-03 | 28256801 | ND |
| 2015-02-04 | 28256301 | 0.120 ppb |
| 2015-02-04 | 28255201 | ND |
| 2015-02-10 | 28257001 | ND |
| 2015-02-10 | 28256001 | ND |
| 2015-02-12 | 28256601 | ND |
| 2015-02-12 | 28256401 | ND |
| 2015-02-17 | 28255401 | ND |
| 2015-02-17 | 28257101 | ND |
| 2015-02-19 | 28256901 | ND |
| 2015-02-19 | 28256201 | 0.0900 ppb |
| 2015-02-24 | 28256101 | 0.0800 ppb |
| 2015-02-25 | 28255101 | ND |
| 2015-02-27 | 28255901 | ND |
| 2015-05-27 | 28255801 | ND |
| 2015-06-09 | 29303701 | ND |
| 2015-06-17 | 29303901 | ND |
| 2015-08-10 | 30016301 | ND |
| 2015-08-10 | 30016001 | ND |
| 2015-08-10 | 30013601 | ND |
| 2015-08-10 | 30013201 | ND |
| 2015-08-11 | 30015201 | ND |
| 2015-08-11 | 30014201 | ND |
| 2015-08-11 | 30012901 | ND |
| 2015-08-11 | 30014801 | ND |
| 2015-08-13 | 30015701 | ND |
| 2015-08-13 | 30016801 | ND |
| 2015-08-13 | 30013901 | ND |
| 2015-08-18 | 30016701 | ND |
| 2015-08-18 | 29303801 | 0.120 ppb |
| 2015-08-18 | 30014601 | ND |
| 2015-08-19 | 30015001 | ND |
| 2015-08-19 | 30013401A | ND |
| 2015-08-24 | 30015401 | ND |
| 2015-08-25 | 30016601 | ND |
| 2015-12-07 | 30878501 | 0.0900 ppb |
| 2017-11-14 | 9590-016-0800 | ND |
| 2017-11-20 | 9590-022-0930 | ND |
| 2017-11-29 | 9590-025-1145 | ND |
| 2018-03-22 | 9590-022-1050 | ND |
| 2019-08-06 | 9590-014-1135 | ND |