1,4-Dioxane
California Water Service (CWS) - Salinas
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 | 0.264 ppb | 41 | 11 | ND - 1.80 ppb |
| 2015 | 0.775 ppb | 4 | 2 | ND - 1.60 ppb |
| 2016 | 1.48 ppb | 4 | 4 | 1.10 ppb - 1.80 ppb |
| 2017 | 1.02 ppb | 5 | 4 | ND - 1.50 ppb |
| 2018 | 1.08 ppb | 4 | 4 | 1.000 ppb - 1.20 ppb |
| 2019 | ND | 4 | 0 | ND |
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 |
|---|---|---|
| 2014-01-15 | 9590-019-1328 | 1.50 ppb |
| 2014-04-02 | 201404030382AM | ND |
| 2014-04-02 | 201404030347AM | 0.890 ppb |
| 2014-04-03 | 201404040296AM | 0.140 ppb |
| 2014-04-08 | 201404090687AM | 0.590 ppb |
| 2014-04-09 | 201404100794AM | ND |
| 2014-04-09 | 201404120177AM | ND |
| 2014-04-09 | 201404100825AM | ND |
| 2014-04-10 | 201404120137AM | ND |
| 2014-04-10 | 201404120155AM | ND |
| 2014-04-10 | 201404120075AM | ND |
| 2014-04-10 | 201404120139AM | ND |
| 2014-04-10 | 201404150246AM | ND |
| 2014-04-16 | 9590-019-1437 | 1.10 ppb |
| 2014-04-17 | 201404190054AM | ND |
| 2014-04-17 | 201404190063AM | ND |
| 2014-04-22 | 201404230389AM | ND |
| 2014-04-24 | 201404250180AM | ND |
| 2014-04-29 | 201404300780AM | ND |
| 2014-05-29 | 201405300257AM | ND |
| 2014-07-16 | 9590-019-1150 | 1.80 ppb |
| 2014-09-09 | 201409100992AM | ND |
| 2014-09-09 | 201409100972AM | ND |
| 2014-09-10 | 201409110897AM | 0.790 ppb |
| 2014-09-10 | 201409110695AM | ND |
| 2014-09-11 | 201409120732AM | 0.230 ppb |
| 2014-09-11 | 201409120748AM | 0.380 ppb |
| 2014-09-15 | 201409160391AM | ND |
| 2014-09-16 | 201409170786AM | ND |
| 2014-09-16 | 201409170676AM | ND |
| 2014-09-16 | 201409170650AM | ND |
| 2014-09-16 | 201409180651AM | 1.70 ppb |
| 2014-09-17 | 201409180668AM | ND |
| 2014-09-18 | 201409190382AM | ND |
| 2014-09-18 | 201409190386AM | ND |
| 2014-09-19 | 201409230182AM | ND |
| 2014-09-25 | 201409260434AM | ND |
| 2014-09-25 | 201409260416AM | ND |
| 2014-09-25 | 201409260405AM | ND |
| 2014-09-25 | 201409260425AM | ND |
| 2014-10-14 | 9590-019-1028 | 1.70 ppb |
| 2015-01-12 | 9590-019-1245 | ND |
| 2015-04-14 | 9590-019-0930 | ND |
| 2015-07-22 | 9590-019-1137 | 1.50 ppb |
| 2015-10-20 | 9590-019-1200 | 1.60 ppb |
| 2016-01-05 | 9590-019-0952 | 1.30 ppb |
| 2016-04-05 | 9590-019-1116 | 1.10 ppb |
| 2016-08-30 | 9590-019-1024 | 1.80 ppb |
| 2016-10-04 | 9590-019-1108 | 1.70 ppb |
| 2017-01-10 | 9590-019-1356 | 1.20 ppb |
| 2017-03-02 | 9590-132-1110 | ND |
| 2017-04-11 | 9590-019-0919 | 1.000 ppb |
| 2017-07-12 | 9590-019-1328 | 1.50 ppb |
| 2017-10-18 | 9590-019-0925 | 1.40 ppb |
| 2018-01-09 | 9590-019-0926 | 1.000 ppb |
| 2018-05-01 | 9590-019-0945 | 1.000 ppb |
| 2018-07-10 | 9590-019-0925 | 1.20 ppb |
| 2018-10-02 | 9590-019-0958 | 1.10 ppb |
| 2019-01-23 | 9590-019-0932 | ND |
| 2019-04-09 | 9590-019-0931 | ND |
| 2019-07-09 | 9590-019-0940 | ND |
| 2019-10-02 | 9590-019-1128 | ND |