1,4-Dioxane
California Domestic 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 |
|---|---|---|---|---|
| 2014 | N/A | 0 | 0 | N/A |
| 2015 | 1.30 ppb | 1 | 1 | 1.30 ppb |
| 2016 | 1.10 ppb | 4 | 3 | ND - 1.60 ppb |
| 2017 | ND | 9 | 0 | ND |
| 2018 | ND | 7 | 0 | ND |
| 2019 | ND | 8 | 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 |
|---|---|---|
| 2015-11-19 | 9588-020-1055 | 1.30 ppb |
| 2016-07-06 | 9588-020-0910 | ND |
| 2016-10-14 | 9588-020-0925 | 1.20 ppb |
| 2016-11-03 | 9588-020-0815 | 1.60 ppb |
| 2016-11-03 | 9588-020-0755 | 1.60 ppb |
| 2017-01-10 | 9588-020-0910 | ND |
| 2017-04-05 | 9588-020-0910 | ND |
| 2017-12-11 | 9588-014-1120 | ND |
| 2017-12-11 | 9588-008-1110 | ND |
| 2017-12-11 | 9588-007-1055 | ND |
| 2017-12-11 | 9588-006-1050 | ND |
| 2017-12-11 | 9588-020-1045 | ND |
| 2017-12-11 | 9588-005-1040 | ND |
| 2017-12-11 | 9588-004-1030 | ND |
| 2018-10-09 | 9588-020-0910 | ND |
| 2018-10-09 | 9588-014-0930 | ND |
| 2018-10-09 | 9588-004-0940 | ND |
| 2018-10-09 | 9588-008-0955 | ND |
| 2018-10-09 | 9588-007-1015 | ND |
| 2018-10-09 | 9588-006-1010 | ND |
| 2018-10-09 | 9588-005-0920 | ND |
| 2019-07-18 | 9588-005-0910 | ND |
| 2019-12-18 | 9588-008-1120 | ND |
| 2019-12-18 | 9588-014-1130 | ND |
| 2019-12-18 | 9588-007-1055 | ND |
| 2019-12-18 | 9588-006-1050 | ND |
| 2019-12-18 | 9588-005-1035 | ND |
| 2019-12-18 | 9588-004-1045 | ND |
| 2019-12-18 | 9588-020-1135 | ND |