1,4-Dioxane
La Habra Heights County Water District
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 | 0.925 ppb | 4 | 3 | ND - 1.40 ppb |
| 2015 | 1.12 ppb | 6 | 5 | ND - 1.50 ppb |
| 2016 | 1.28 ppb | 4 | 4 | 1.20 ppb - 1.40 ppb |
| 2017 | 1.04 ppb | 10 | 8 | ND - 1.60 ppb |
| 2018 | 1.35 ppb | 8 | 8 | 1.000 ppb - 1.80 ppb |
| 2019 | 1.11 ppb | 8 | 7 | ND - 1.50 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 |
|---|---|---|
| 2014-01-08 | 9588-009-0929 | ND |
| 2014-04-11 | 9588-009-0940 | 1.10 ppb |
| 2014-07-22 | 9588-009-0930 | 1.40 ppb |
| 2014-12-12 | 9588-009-1045 | 1.20 ppb |
| 2015-03-04 | 9588-009-0928 | 1.30 ppb |
| 2015-04-10 | 9588-009-0909 | 1.30 ppb |
| 2015-05-19 | 9588-006-1525 | 1.20 ppb |
| 2015-07-28 | 9588-009-0935 | 1.50 ppb |
| 2015-09-16 | 9588-006-1010 | ND |
| 2015-10-21 | 9588-009-0945 | 1.40 ppb |
| 2016-03-21 | 9588-009-0940 | 1.20 ppb |
| 2016-06-03 | 9588-009-0945 | 1.40 ppb |
| 2016-09-15 | 9588-009-1110 | 1.20 ppb |
| 2016-10-18 | 9588-009-0950 | 1.30 ppb |
| 2017-01-17 | 9588-009-0925 | 1.20 ppb |
| 2017-04-14 | 9588-009-0923 | 1.10 ppb |
| 2017-07-19 | 9588-009-0852 | 1.30 ppb |
| 2017-08-01 | 9588-005-0944 | ND |
| 2017-08-01 | 9588-006-0953 | ND |
| 2017-08-01 | 9588-010-0930 | 1.60 ppb |
| 2017-08-01 | 9588-009-0936 | 1.20 ppb |
| 2017-08-17 | 9588-010-0930 | 1.60 ppb |
| 2017-10-12 | 9588-009-0845 | 1.10 ppb |
| 2017-10-12 | 9588-010-0855 | 1.30 ppb |
| 2018-01-11 | 9588-009-0847 | 1.40 ppb |
| 2018-01-11 | 9588-010-0841 | 1.60 ppb |
| 2018-04-10 | 9588-009-0942 | 1.20 ppb |
| 2018-04-10 | 9588-010-0935 | 1.80 ppb |
| 2018-07-20 | 9588-010-0947 | 1.30 ppb |
| 2018-07-20 | 9588-009-0930 | 1.000 ppb |
| 2018-10-19 | 9588-009-0935 | 1.10 ppb |
| 2018-10-19 | 9588-010-0945 | 1.40 ppb |
| 2019-02-21 | 9588-009-0842 | 1.20 ppb |
| 2019-02-26 | 9588-010-0914 | 1.50 ppb |
| 2019-05-10 | 9588-010-0902 | 1.30 ppb |
| 2019-05-10 | 9588-009-0846 | ND |
| 2019-07-22 | 9588-010-0844 | 1.30 ppb |
| 2019-07-22 | 9588-009-0850 | 1.10 ppb |
| 2019-10-23 | 9588-010-0900 | 1.50 ppb |
| 2019-10-23 | 9588-009-0850 | 1.000 ppb |