1,4-Dioxane
Golden State Water Company (GSWC) - South San Gabriel
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.
Testing results - average by year
Year | Average result | Samples taken | Detections | Range of results |
---|---|---|---|---|
2013 | 0.0550 ppb | 4 | 1 | ND - 0.220 ppb |
2014 | 0.0333 ppb | 6 | 1 | ND - 0.200 ppb |
2015 | N/A | 0 | 0 | N/A |
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 |
---|---|---|
2013-12-18 | 3L19004-07A | ND |
2013-12-18 | 3L19004-03A | ND |
2013-12-18 | 3L19004-01A | ND |
2013-12-18 | 3L19004-05A | 0.220 ppb |
2014-03-18 | 4C18022-01A | ND |
2014-06-24 | 4F24036-01A | ND |
2014-06-24 | 4F24036-03A | ND |
2014-06-30 | 4F30035-01A | 0.200 ppb |
2014-09-24 | 4I24014-01A | ND |
2014-09-30 | 4I30020-01A | ND |