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The 1,4-Dioxane Book

The Complete Reference
Introduction – What about 1,4-Dioxane?
Continues from previous

While the White Paper was a catalyst that led to several discoveries of 1,4-dioxane at sites across the United States, some of the information in the White Paper was acquired by networking with California regulatory agency professionals at the SFBWB, DTSC, Department of Health Services, and Office of Environmental Health Hazard Assessment, all of whom preceded me in researching the nature and occurrence of 1,4-dioxane. Some dismissed 1,4-dioxane because it is not regulated, while others were intrigued and required testing and remediation at sites they oversaw, yet all were overwhelmed with their daily case loads and a few had the opportunity to research this contaminant in depth. The White Paper clearly filled an information void, and after it was downloaded more than a 1000 times, I decided that this book must be written.

The book is organized around the uses of chlorinated solvents to which solvent stabilizers, including 1,4-dioxane, were added and focuses on how different uses changed the composition of solvent wastes that were released to groundwater through spills, leaks, dumping, unlined lagoons, unlined landfills, leaking sewer lines, and other avenues. This focus on what I have termed “contaminant archeology,” that is, studying the industrial fate of the contaminant before it was discharged, affords some unique material that may provide insights for forensic investigations into the origins of solvents in contaminated groundwater. In the course of researching the contaminant archeology aspects of solvent stabilizers, I encountered more than 300 chemicals patented for use as solvent stabilizers for the four major chlorinated solvents in nearly 100 patents. The documented use of several dozen stabilizers for the major chlorinated solvents is detailed in Chapter 1.

The environmental fate and transport properties of confirmed solvent stabilizers are profiled in Chapter 3; however, the focus of the book is 1,4-dioxane. Accordingly, Chapter 2 focuses on the chemistry and the many industrial uses and manifestations of 1,4-dioxane. For example, I was surprised to learn that nearly every landfill serving universities and other institutions with life science research laboratories in the 1960s–1980s was found to harbor 1,4-dioxane contamination from discarded liquid scintillation cocktail waste. Chapter 4 examines the challenges of laboratory analysis of 1,4-dioxane—coaxing this hydrophilic ether compound out of the water and reliably separating and quantifying it at low concentrations and new methods for 1,4-dioxane analysis, such as USEPA

Method 522, which uses solid phase extraction coupled with tandem mass spectrometry.

The toxicology of 1,4-dioxane is featured in Chapter 5, written by Julie Stickney of the Syracuse Research Corporation, a leading researcher of 1,4-dioxane toxicity. Chapter 6 profiles the regulation and risk assessment of 1,4-dioxane and the wide range of state guidance on 1,4-dioxane cleanup levels and drinking water levels. William DiGuiseppi of the AECOM (formerly Earth Tech) consulting team has acquired a wealth of hands-on experience managing 1,4-dioxane treatment projects, including the large and complex but successful cleanup of Air Force Plant 44 in Tucson, Arizona. Consequently, he is ideally suited to write about treatment technologies for 1,4-dioxane in groundwater (Chapter 7) and has provided several examples of solutions employed at cleanup sites across the United States.

The seven case studies in Chapter 8 describe the nature and extent of 1,4-dioxane releases, their regulation, and their remediation in geologic settings, including limestone, sandstone, glacial outwash plains, and a variety of alluvial environments. In these case studies, the amounts released range from small to massive, resulting in plumes spanning a few hundred feet to several miles. The consequences of the 1,4-dioxane spills summarized in the case studies range from inconsequential impacts to groundwater locked up in bedrock and used by no one to widespread contamination of private and municipal wells and long-term consumption of 1,4-dioxane in drinking water. The corresponding regulatory responses range from treatment train modification to purchasing and condemning private wells, and even an outright ban on using groundwater for any purpose—the establishment of a “groundwater exclusion zone”—to clear the way for the inexorable march of a massive and unstoppable 1,4-dioxane plume beneath Ann Arbor, Michigan, on its way to the Huron River where it will be discharged, diluted, and dismissed.