1,4-Dioxane
Grafton 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 | N/A | 0 | 0 | N/A |
| 2015 | 0.190 ppb | 6 | 2 | ND - 0.610 ppb |
| 2016 | 0.870 ppb | 12 | 12 | 0.750 ppb - 1.10 ppb |
| 2017 | 0.544 ppb | 12 | 12 | 0.200 ppb - 0.953 ppb |
| 2018 | 0.418 ppb | 12 | 12 | 0.219 ppb - 0.620 ppb |
| 2019 | 0.0375 ppb | 12 | 3 | ND - 0.150 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 | Result |
|---|---|
| 2015-03-16 | ND |
| 2015-03-16 | ND |
| 2015-03-16 | 0.610 ppb |
| 2015-09-22 | ND |
| 2015-09-22 | ND |
| 2015-09-22 | 0.530 ppb |
| 2016-06-27 | 0.750 ppb |
| 2016-06-27 | 0.750 ppb |
| 2016-06-27 | 0.750 ppb |
| 2016-07-20 | 0.750 ppb |
| 2016-07-20 | 0.750 ppb |
| 2016-07-20 | 0.750 ppb |
| 2016-09-13 | 0.881 ppb |
| 2016-09-13 | 0.881 ppb |
| 2016-09-13 | 0.881 ppb |
| 2016-10-07 | 1.10 ppb |
| 2016-10-07 | 1.10 ppb |
| 2016-10-07 | 1.10 ppb |
| 2017-01-11 | 0.650 ppb |
| 2017-01-11 | 0.650 ppb |
| 2017-01-11 | 0.650 ppb |
| 2017-05-03 | 0.200 ppb |
| 2017-05-03 | 0.200 ppb |
| 2017-05-03 | 0.200 ppb |
| 2017-07-17 | 0.372 ppb |
| 2017-07-17 | 0.372 ppb |
| 2017-07-17 | 0.372 ppb |
| 2017-10-16 | 0.953 ppb |
| 2017-10-16 | 0.953 ppb |
| 2017-10-16 | 0.953 ppb |
| 2018-02-20 | 0.534 ppb |
| 2018-02-20 | 0.534 ppb |
| 2018-02-20 | 0.534 ppb |
| 2018-04-11 | 0.219 ppb |
| 2018-04-11 | 0.219 ppb |
| 2018-04-11 | 0.219 ppb |
| 2018-08-02 | 0.620 ppb |
| 2018-08-02 | 0.620 ppb |
| 2018-08-02 | 0.620 ppb |
| 2018-11-14 | 0.300 ppb |
| 2018-11-14 | 0.300 ppb |
| 2018-11-14 | 0.300 ppb |
| 2019-01-16 | 0.150 ppb |
| 2019-01-16 | 0.150 ppb |
| 2019-01-16 | 0.150 ppb |
| 2019-05-08 | ND |
| 2019-05-08 | ND |
| 2019-05-08 | ND |
| 2019-08-20 | ND |
| 2019-08-20 | ND |
| 2019-08-20 | ND |
| 2019-10-22 | ND |
| 2019-10-22 | ND |
| 2019-10-22 | ND |