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EWG's Tap Water Database — 2019 UPDATE

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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.

Click here to read more about 1,4-dioxane.

 

31

Samples

0

Samples exceeding legal limit (MCL)

10

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20120.680 ppb53ND - 1.20 ppb
20130.160 ppb102ND - 1.20 ppb
2014ND40ND
2015ND40ND
20160.650 ppb41ND - 2.60 ppb
20174.03 ppb441.70 ppb - 7.80 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
2012-03-299588-008-1200ND
2012-03-299588-003-11401.20 ppb
2012-06-269588-003-10001.10 ppb
2012-09-189588-003-12451.10 ppb
2012-12-049588-003-1215ND
2013-03-069588-003-1130ND
2013-03-1221126901ND
2013-03-1221126401ND
2013-03-1321126501ND
2013-03-13212699010.400 ppb
2013-03-1321127201ND
2013-05-1322369901ND
2013-06-069588-003-1115ND
2013-09-109588-003-12151.20 ppb
2013-12-049588-003-1055ND
2014-03-109588-003-1115ND
2014-06-029588-003-1040ND
2014-09-039588-003-1215ND
2014-12-039588-003-1045ND
2015-03-059588-003-1010ND
2015-06-049588-003-1025ND
2015-09-089588-003-1140ND
2015-12-079588-003-1115ND
2016-03-029588-003-1030ND
2016-06-099588-003-1045ND
2016-09-079588-003-1305ND
2016-12-059588-003-11202.60 ppb
2017-03-019588-003-10357.80 ppb
2017-06-089588-003-12304.20 ppb
2017-09-289588-003-09051.70 ppb
2017-12-059588-003-10152.40 ppb