EWG's Tap Water Database — 2019 UPDATE



Northampton Bucks County Municipal Authority

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
20150.0101 ppb343ND - 0.170 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
2015-02-1200115 022015ND
2015-02-1200108 0220150.170 ppb
2015-02-1200111 022015ND
2015-02-1200109 022015ND
2015-02-1200106 022015ND
2015-02-1200114 0220150.0730 ppb
2015-02-1200113 022015ND
2015-02-1200107 022015ND
2015-02-1200110 022015ND
2015-02-1200112 022015ND
2015-02-1800101 022015ND
2015-02-1800104 022015ND
2015-02-1800105 022015ND
2015-02-1800102 022015ND
2015-02-1800103 022015ND
2015-02-1800010 022015ND
2015-05-1200010 072015ND
2015-08-180010 0815ND
2015-08-1800102 0815ND
2015-08-1800010 0815ND
2015-08-1800103 0815ND
2015-08-1800104 0815ND
2015-08-1800114 0815ND
2015-08-1800115 0815ND
2015-08-1800112 0815ND
2015-08-1800113 0815ND
2015-08-2500108 08150.1000 ppb
2015-08-2500109 0815ND
2015-08-2500105 0815ND
2015-08-2500106 0815ND
2015-08-2500107 0815ND
2015-08-2500110 0815ND
2015-08-2500111 0815ND
2015-11-1700010 1115ND