1,4-Dioxane in Groundwater

Posted on August 31st, 2016

When addressing sites with chlorinated VOC groundwater contamination, an additional compound must now be evaluated: 1,4-dioxane. In October 2015, the New Jersey Department of Environmental Protection (NJDEP) established an interim Groundwater Quality Standard (GWQS) for 1,4-dioxane at 0.4 ug/L. The United States Environmental Protection Agency (US EPA) has determined that 1,4-dioxane as “likely carcinogenic” and can pose health threats to humans over an extended period of time. 1,4-dioxane is often used as a solvent with other chlorinated products and is also used as a laboratory reagent. 1,4-dioxane can also be found as a trace contaminant in the manufacturing of cosmetics.

A bioassay of 1,4-dioxane was conducted by the National Cancer Institute in 1978. Based on the testing of mice in the study, 1,4-dioxane was shown to produce squamous cell sarcomias and hepatocellular adenomas.

In addition to the potential toxicity of 1,4-dioxane, it is proven to be a difficult contaminant to remediate when encountered in groundwater. The available remedial options to treat 1,4-dioxane contamination are limited, still experimental and quite expensive. Some available treatments consist of biodegradation and chemical oxidation. Proven technologies used to remediate other chlorinated VOCs, such as air stripping, are not as effective on 1,4-dioxane.

1,4-dioxane has been observed on sites with 1,1,1-Tetrachloroethane (TCA) as the main contaminant of concern. Dioxane was used primarily as a stabilizer for TCA, which is why it is observed in abundance on some of these contaminated sites. The NJDEP has yet to formulate and approve effective 1,4-dioxane treatment technologies and overall strategies to remediate this compound. JM Sorge, Inc. (JMS) is addressing 1,4-dioxane contamination in groundwater on several sites, and is staying on top of NJDEP’s latest recommendations.


Nicholas Mazza

Environmental Scientist


  1. US EPA Treatment Technologies for 1,4-Dioxane: Fundamentals and Field Applications
  2. National Cancer Institute- Bioassay of 1,4-dioxane for Possible Carcinogenicity



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