EWG's Tap Water Database



Plainview WD

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.





Samples exceeding legal limit (MCL)


Samples exceeding
health guidelines

Testing results - average by year

YearAverage resultSamples takenDetectionsRange of results
20141.98 ppb13130.180 ppb - 5.80 ppb

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 Lab ID Result
2014-05-13UCMR3 SRN109294.40 ppb
2014-05-13UCMR3 SRN109270.670 ppb
2014-05-13UCMR3 SRN109303.70 ppb
2014-05-13UCMR3 SRN065800.180 ppb
2014-05-14UCMR3 SRN108400.730 ppb
2014-05-14UCMR3 SRN4095A0.710 ppb
2014-05-3034294 0520142.20 ppb
2014-11-0596580 1120141.20 ppb
2014-11-0504095 1120140.860 ppb
2014-11-1210927 1120140.740 ppb
2014-11-1210930 1120145.80 ppb
2014-11-1210840 1120140.690 ppb
2014-11-1310929 1120143.80 ppb