1,4-Dioxane
North Shelby 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 | 0.141 ppb | 16 | 10 | ND - 0.330 ppb |
| 2016 | N/A | 0 | 0 | N/A |
| 2017 | N/A | 0 | 0 | N/A |
| 2018 | N/A | 0 | 0 | N/A |
| 2019 | N/A | 0 | 0 | N/A |
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 |
|---|---|---|
| 2015-01-27 | 3178414 | 0.240 ppb |
| 2015-01-27 | 3178333 | ND |
| 2015-01-27 | 3178441 | ND |
| 2015-01-27 | 3178303 | 0.270 ppb |
| 2015-04-21 | 3229907 | ND |
| 2015-04-21 | 3229925 | 0.150 ppb |
| 2015-04-21 | 3229859 | ND |
| 2015-04-21 | 3229885 | 0.150 ppb |
| 2015-07-16 | 3281771 | 0.150 ppb |
| 2015-07-16 | 3281573 | ND |
| 2015-07-16 | 3281755 | 0.160 ppb |
| 2015-07-16 | 3281668 | 0.150 ppb |
| 2015-10-12 | 3340782 | 0.320 ppb |
| 2015-10-12 | 3340842 | 0.330 ppb |
| 2015-10-12 | 3340791 | ND |
| 2015-10-12 | 3340805 | 0.330 ppb |