1,4-Dioxane
Cal-am Water Company - Duarte
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 |
|---|---|---|---|---|
| 2013 | 0.0835 ppb | 17 | 2 | ND - 1.02 ppb |
| 2014 | ND | 4 | 0 | ND |
| 2015 | ND | 4 | 0 | ND |
| 2016 | 0.650 ppb | 4 | 1 | ND - 2.60 ppb |
| 2017 | 4.03 ppb | 4 | 4 | 1.70 ppb - 7.80 ppb |
| 2018 | 0.800 ppb | 2 | 1 | ND - 1.60 ppb |
| 2019 | 3.26 ppb | 5 | 4 | ND - 6.20 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 |
|---|---|---|
| 2013-03-06 | 21126801 | ND |
| 2013-03-06 | 21127101 | ND |
| 2013-03-06 | 21127001 | ND |
| 2013-03-12 | 21126901 | ND |
| 2013-03-12 | 21126401 | ND |
| 2013-03-13 | 21126501 | ND |
| 2013-03-13 | 21127201 | ND |
| 2013-03-13 | 21269901 | 0.400 ppb |
| 2013-05-13 | 22369901 | ND |
| 2013-09-10 | 23394201 | ND |
| 2013-09-10 | 23394601 | ND |
| 2013-09-10 | 23394701 | ND |
| 2013-09-10 | 23394401 | 1.02 ppb |
| 2013-09-10 | 23394301 | ND |
| 2013-09-10 | 23394501 | ND |
| 2013-09-10 | 23394801 | ND |
| 2013-09-10 | 23394901 | ND |
| 2014-03-10 | 9588-003-1115 | ND |
| 2014-06-02 | 9588-003-1040 | ND |
| 2014-09-03 | 9588-003-1215 | ND |
| 2014-12-03 | 9588-003-1045 | ND |
| 2015-03-05 | 9588-003-1010 | ND |
| 2015-06-04 | 9588-003-1025 | ND |
| 2015-09-08 | 9588-003-1140 | ND |
| 2015-12-07 | 9588-003-1115 | ND |
| 2016-03-02 | 9588-003-1030 | ND |
| 2016-06-09 | 9588-003-1045 | ND |
| 2016-09-07 | 9588-003-1305 | ND |
| 2016-12-05 | 9588-003-1120 | 2.60 ppb |
| 2017-03-01 | 9588-003-1035 | 7.80 ppb |
| 2017-06-08 | 9588-003-1230 | 4.20 ppb |
| 2017-09-28 | 9588-003-0905 | 1.70 ppb |
| 2017-12-05 | 9588-003-1015 | 2.40 ppb |
| 2018-03-06 | 9588-003-1120 | 1.60 ppb |
| 2018-06-14 | 9588-003-1225 | ND |
| 2019-02-06 | 9590-022-1230 | ND |
| 2019-03-19 | 9588-003-1135 | 1.50 ppb |
| 2019-05-13 | 9588-003-1155 | 6.20 ppb |
| 2019-08-07 | 9588-003-1200 | 5.30 ppb |
| 2019-11-19 | 9588-003-1050 | 3.30 ppb |