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EWG's Tap Water Database

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1,4-Dioxane

Clearwater Water System

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.

 

10

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2010N/A00N/A
2011N/A00N/A
2012N/A00N/A
2013ND40ND
2014ND50ND
2015ND10ND

ppb = parts per billion.

State and national drinking water standards and health guidelines

Health Guideline 0.35 ppb

The 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 Result
2013-12-11ND
2013-12-16ND
2013-12-16ND
2013-12-17ND
2014-03-18ND
2014-06-24ND
2014-06-24ND
2014-06-24ND
2014-09-24ND
2015-08-05ND