1,4-Dioxane
City of Tacoma
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 | ND | 1 | 0 | ND |
| 2015 | ND | 20 | 0 | ND |
| 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 |
| 2020 | N/A | 0 | 0 | N/A |
| 2021 | N/A | 0 | 0 | N/A |
| 2022 | N/A | 0 | 0 | N/A |
| 2023 | N/A | 0 | 0 | N/A |
ppb = parts per billion
State, National, and Health Guidelines for Drinking Water
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 |
|---|---|---|
| 2014-08-06 | 201408070493AM | ND |
| 2015-03-10 | 201503110935AM | ND |
| 2015-03-10 | 201503120179AM | ND |
| 2015-03-10 | 201502170548AM | ND |
| 2015-06-09 | 201505060001AM | ND |
| 2015-06-17 | 201505060005AM | ND |
| 2015-06-29 | 201505020034AM | ND |
| 2015-07-06 | 201505020035AM | ND |
| 2015-07-08 | 201507090318AM | ND |
| 2015-07-09 | 201506300092AM | ND |
| 2015-07-09 | 201507100395AM | ND |
| 2015-08-19 | 201508200778AM | ND |
| 2015-09-09 | 201508050009AM | ND |
| 2015-09-09 | 201508050013AM | ND |
| 2015-10-13 | 201509250020AM | ND |
| 2015-12-01 | 201511130086AM | ND |
| 2015-12-02 | 201511130082AM | ND |
| 2015-12-07 | 201511130099AM | ND |
| 2015-12-07 | 201511130096AM | ND |
| 2015-12-08 | 201511130098AM | ND |
| 2015-12-08 | 201511130097AM | ND |