U.S. EPA Contaminated Site Cleanup Information (CLU-IN)

U.S. Environmental Protection Agency
U.S. EPA Technology Innovation and Field Services Division

For more information on 1,4-Dioxane, please contact:

Linda Fiedler
Technology Assessment Branch

PH: (703) 603-7194 | Email: fiedler.linda@epa.gov


Treatment Technologies

1,4-Dioxane does not yield to air stripping and liquid-phase granular activated carbon, but advanced oxidation techniques involving hydrogen peroxide and ultraviolet light (UV) or ozone have been applied successfully to destroy it. Distillation is physically viable, but the relatively high boiling point (101ºC) makes this approach uneconomical for most applications.

Chlorination of dioxane has been found to break it down optimally at 75ºC and pH 5.2; however, chlorination byproducts are from 12 to 1,000 times more toxic than 1,4-dioxane. Conventional activated sludge and other common municipal wastewater treatment technologies have proven ineffective.

The monitored natural attenuation approach to solvent contamination is unlikely to achieve degradation of 1,4-dioxane. Though typically not degraded by indigenous soil microorganisms under ambient conditions, microbial degradation in engineered bioreactors has been documented under enhanced conditions or where selected strains of bacteria capable of degrading 1,4-dioxane are cultured. Phytoremediation is being explored as a means to remove the compound from shallow ground water. Research on hybrid poplars has demonstrated their ability to take up and effectively degrade or deactivate a variety of contaminants, including atrazine, TNT, trichloroethene, and 1,4-dioxane.

Adapted from:

Adobe PDF Logo Bioenergy Crops and Bioremediation: a Review
C. Britt, et al., 2002

Adobe PDF Logo Solvent Stabilizers: White Paper
T.K.G. Mohr, Santa Clara Valley Water District, 2001.
Contact: Tom Mohr, tommohr@scvwd.dst.ca.us

Adobe PDF LogoAdvanced Oxidation Processes (AOP)
USACE/NAVFAC/AFCESA. Unified Facilities Guide Specification UFGS-46 30 13, 41 pp, February 2011

This guide specification covers the product and execution requirements for liquid-phase ex situ advanced oxidation processes using titanium dioxide or hydrogen peroxide and/or ozone with or without ultraviolet light. The guide specifies AOP equipment needs to provide a complete and functional system within identified limits. AOP systems have been shown to provide successful treatment for 1,4-dioxane, among other hazardous compounds.

Adobe PDF LogoAMEC Geomatrix/ARA Groundwater Remediation Trip Report
S.A. Simmons, K.M. Hodgson, and M.E. Byrnes.
SGW-38552, 15 pp, 2008

To examine alternatives for capturing carbon tetrachloride, nitrates, and other contaminants from Hanford groundwater, visits were made in July 2008 to 2 California sites to investigate the treatment systems. The City of Rialto's Well #3 currently has a 2,000 gpm single-use resin ion exchange system to treat perchlorate. An under-construction ESTCP demonstration system will use the WBA IX resin selective for nitrate and perchlorate. The Baldwin Park Operable Unit (a Superfund site) system removes carbon tetrachloride, chloroform, TCE, PCE, 1,4,-dioxane, 1,2,3-trichloropropane, NDMA, perchlorate, and nitrate from the groundwater. Treatment unit processes include air stripping, with vapor-phase GAC treatment of VOCs, liquid-phase of GAC of l,2,3-TCP, Calgon ISEP ion exchange for nitrate and perchlorate, weak-base one-pass ion exchange (a new perchlorate technology), and UV oxidation for NDMA and 1,4-dioxane.

Adobe PDF LogoBiodegradation of 1,4-Dioxane
R.J. Steffan, K.R. McClay, H. Masuda, and G.J. Zylstra.
Strategic Environmental Research and Development Program, SERDP project CU-1422, 118 pp, 2007

Results of this study demonstrated the recalcitrance of 1,4-dioxane. Although several organisms were shown to degrade 1,4-dioxane via cometabolism during growth on propane or tetrahydrofuran, 1,4-dioxane was not degraded in microcosms created with samples from two different aquifers regardless of the redox conditions employed. Likewise, 1,4-dioxane was not degraded in samples from 2 different treatment systems that had been exposed to 1,4-dioxane for extended periods. No bacteria that could grow on 1,4-dioxane were enriched or isolated from the four systems tested; therefore, the results indicate that biological treatment and natural biological attenuation are unlikely to be successful remedial alternatives for 1,4-dioxane-contaminated sites.

Adobe PDF LogoCase Study Comparison of Multiple Activation Methods for Sodium Persulfate ISCO Treatment
G. Cronk.
Sixth International Conference on Remediation of Chlorinated and Recalcitrant Compounds, May 19-22, 2008, Monterey, California. Battelle Press, Columbus, OH. 8 pp, 200

Six brief in situ chemical oxidation (ISCO) case studies (full and pilot scale) from sites in California illustrate the use of different methods--hydrogen peroxide, ferrous or chelated iron, alkaline conditions (high pH)--for persulfate activation. Good to excellent contaminant reductions (generally >85%) were achieved in all 6 cases for contaminants such as 1,4-dioxane and chlorinated solvents (2), a mixed chlorinated solvent plume (1), methylene chloride DNAPL (1), gasoline-range hydrocarbons (1), and benzene (1).

Adobe PDF LogoEngineering Issue Paper: In Situ Chemical Oxidation
EPA 600-R-06-072, 2006

This issue paper was produced by the EPA Risk Management Research Laboratory and the Engineering Forum. It provides an up-to-date overview of ISCO remediation technology and fundamentals, and is developed based on peer-reviewed literature, EPA reports, web sources, current research, conference proceedings, and other pertinent information.

Ex-Situ Wellhead Treatment of 1,4-Dioxane Using Fenton's Reagent
Kiker, J.H., J.B. Connolly, W.A. Murray, S.C. Pearson, S.E. Reed, and R.J. Tess.
Proceedings of the Annual International Conference on Soils, Sediments, Water and Energy 15(18):210-226(2010)

At the U.S. Army Natick Soldier System Center in Natick, MA, the presence of 1,4-dioxane was discovered in groundwater being pumped and treated to provide containment of an historical TCE plume. Air stripping and GAC--the existing treatment--have low efficiency for treating 1,4-dioxane. Because 1,4-dioxane was identified in only an isolated portion of the TCE plume, ex situ application of Fenton's reagent at the wellhead was selected as a practical and cost-effective solution. After 1.5 years of successful operation, the well-head treatment plant has the demonstrated capacity to treat influent 1,4-dioxane levels of 35 ug/L, and with minimal changing of hydrogen peroxide dosing rates this unit could treat influent with higher 1,4-dioxane levels and higher flow rates.

Fast-Track Remedial Design of Full-Scale ISCO Application Using Pilot Scale Testing and Field Screening Parameters
Dombrowski, P.M., B.A. Weir, K.M. Kelly, and J. Brown.
Proceedings of the Annual International Conference on Soils, Sediments, Water and Energy 15(16):169-194(2010)

At the Ottati and Goss Superfund Site in Kingston, NH, soil and groundwater contaminated with chlorinated VOCs, BTEX, and 1,4-dioxane were addressed with base-activated persulfate. This paper describes pilot test planning, performance monitoring, and full-scale design using data collected from the 2007-2008 pilot test for this fast-track remediation. The full-scale application was completed between July and September 2008. Additional information: Ottati & Goss/Kingston Steel Drum, Kingston, NH.

Final New Pretreatment Plant Pilot-Scale Testing Summary Report, Stringfellow Site, Glen Avon, California
California Department of Toxic Substances Control, 159 pp, July 2008

The soil and ground water of this former Class I industrial waste disposal facility are affected by 1,4-dioxane, perchlorate, NDMA, p-CBSA, organochlorine pesticides, chlorinated ethenes, chlorinated benzenes, and heavy metals. The new pretreatment plant pilot-scale testing program successfully field tested a sequential anoxic/aerobic biotreatment (SAAB) process coupled first with a Fenton's reagent oxidation process and then with an ozone/hydrogen peroxide-based advanced oxidation process (HiPOx), demonstrating that the unit treatment processes that comprise the treatment train can be scaled up successfully. The SAAB process successfully removed p-CBSA, perchlorate, and VOCs, and the HiPOx process successfully oxidized both 1,4-dioxane and NDMA.

Adobe PDF LogoFocused In-Situ Chemical Oxidation of Chlorinated VOCs and 1,4-Dioxane Using Sodium Persulfate in Fine-Grained Soils
K.S. Houston, J. Horst, and G. Wroblewski.
Pollution Engineering, 8 pp, Mar 2009

At a former machining and metal working site where the groundwater is affected by PCE, TCE, 1,1-DCE, and 1,4-dioxane, focused ISCO using sodium persulfate was considered for discrete source mass treatment to expedite mass removal and decrease the operational timeframe, but lab treatability tests indicated that strategic oxidant dosing would achieve the remediation goal. In a field pilot test, effective 1,4-dioxane and VOC treatment was achieved, likely the result of naturally occurring reduced metals (e.g., ferrous iron) that facilitated sulfate radical formation, which also showed that oxidant field loading based solely on lab-determined total oxidant demand of site soil and groundwater slurries can overstate the mass of oxidant required to achieve effective treatment.

Adobe PDF LogoIn Situ Chemical Oxidation of 1,4-Dioxane and VOCs with Ozone and Hydrogen Peroxide
E. Yunker.
National Association of Remedial Project Managers 17th Annual Training Conference, 21-25 May 2007, 34 slides, 2007

A pilot-scale field evaluation was carried out to assess the effectiveness of an innovative in situ oxidation process (using ozone with and without hydrogen peroxide) for remediation of 1,4-dioxane and chlorinated volatile organic compounds at the Cooper Drum Company Superfund site in South Gate, Los Angeles County, California. The ozone/hydrogen peroxide generation and delivery systems were installed in mid-July 2005 and the system operated continuously until early May 2006, a period of 10.5 months. Ozone alone was injected into the subsurface in the initial operation phase, followed five months later by injection of hydrogen peroxide to evaluate the effectiveness of combined injection of ozone/hydrogen peroxide in remediating the recalcitrant compounds present in the ground water. The field pilot test results indicated that ozone injection alone can reduce the concentrations of the site chemicals of concern (COC)--trichloroethene (TCE), cis-1,2-dichloroethylene, 1,1-dichloroethane, and 1,4-dioxane--significantly. The effect of hydrogen peroxide on destruction of COCs is not clear; however, ex situ testing of the site ground water indicates that it is likely that injection of stoichiometric (0.7:1 mole:mole) or less of hydrogen peroxide to ozone is required to achieve optimal results and increase oxidation kinetics. The presence of high levels of secondary constituents in the ground water (e.g., iron, bicarbonates, and organic matter) may have enhanced the effectiveness of oxidation by ozone.

Adobe PDF LogoInterim Feasibility Study for the Unit E Plume
Pall Corporation.
Hazardous Substance Research Center, Michigan State University. 68 pp, 2004

Considers ground-water treatment ex situ with UV/hydrogen peroxide oxidation or ozone and hydrogen peroxide oxidation, and in situ with recirculating ozone wells, Fenton's reagent, ozone-rich water injection, ozone sparging, ozone sparging and hydrogen peroxide injection, or hydrogen peroxide injection only for remediation of 1,4-dioxane contamination at the Gelman Road site, Ann Arbor, MI.

Adobe PDF LogoNAS Brunswick Groundwater Extraction & Treatment System: A Practical Approach to Sustainable Remediation
C. Varner and T.A. Bober.
E2S2 2010: Environment, Energy Security, and Sustainability Symposium and Exhibition, 14-17 June 2010, Denver, Colorado. National Defense Industrial Association (NDIA), Abstract 9985, 25 slides, 2010

In 1995, a groundwater extraction and treatment system (GWETS) was installed for remediation of a chlorinated solvent plume at NAS Brunswick to address a large groundwater plume of VOCs, mainly TCA, DCA, TCE, and DCE. When 1,4-dioxane was discovered in the groundwater, a HiPOx advanced oxidation system was added to the GWETS to remove 1,4-dioxane prior to the existing air-stripper and GAC treatment units. The Navy completed construction of an on-site infiltration gallery in December 2009 to accept the treated GWETS effluent, reducing the hydraulic loading on the local sewer authority by ~26 million gallons per year. A pilot test to evaluate the efficacy of operating the GWETS without the air-stripper and vapor-phase GAC, relying instead on the HiPOx unit, saved the Navy 16,000 KWh/month and reduced the GWETS carbon footprint and other emissions. As a follow-on to GWETS, the Navy plans a transition to enhanced natural attenuation (including phytoremediation and bioremediation) for mitigation of the residual chlorinated VOCs and 1,4-dioxane. See longer abstract

San Fernando Valley Superfund Sites, Area 1: North Hollywood and Burbank, California
U.S. EPA Region 9 Web site.

The groundwater beneath the San Fernando Valley Area 1 is contaminated with TCE and PCE. In addition, EPA has detected Cr(VI) and 1,4-dioxane, which the existing groundwater VOCs treatment system is not designed to address. The 2009 Second Interim Remedy adds wellhead treatment systems to remove hexavalent chromium and 1,4-dioxane. The treatment technology for 1,4-dioxane is a UV light and hydrogen peroxide advanced oxidation process. The 2009 Focused Feasibility Study identifies the preferred technology for Cr(VI) as ferrous iron reduction with microfiltration. Alternatively, an anion-exchange-based treatment process could be installed if pilot test results expected from the groundwater operable unit in 2010 demonstrate that the process is effective and does not produce other problematic organic compounds. The Area 1 page provides access to the technical reports, and the San Fernando Valley (All Areas) page contains additional monitoring data and the presentations from the March 10, 2008, San Fernando Valley Chromium Workshop.

Adobe PDF LogoTechnical Report: Subsurface Injection of In Situ Remedial Reagents (ISRRs) within the Los Angeles Regional Water Quality Control Board Jurisdiction
Wilson, S., D. Clexton, C. Sandefur, et al.
In Situ Remediation Reagents Injection Working Group, 46 pp, 2009

This compilation of general tools and best practices provides a reference manual for the planning, design, and field implementation phases of ISCO projects, with a strong emphasis on safety considerations. Specific attention is given to avoiding the visible surfacing of injected ISRR materials, minimizing impact to landscaping, and ensuring no surface pathway for potential ISRR runoff.

Adobe PDF LogoTreatment Options for Remediation of 1,4-Dioxane in Groundwater
W. DiGuiseppi and C. Whitesides.
Environmental Engineer: Applied Research and Practice, Volume 2, 7 pp, Spring 2007.

The solvent stabilizer 1,4-dioxane has emerged in the environmental engineering arena as an unexpected and recalcitrant groundwater contaminant at many sites across the US. Decreases in the analytical detection limit in water have revealed the presence of this contaminant in sites where no 1,4-dioxane was identified during earlier, higher MDL sampling events. Toxicological studies suggest that 1,4-dioxane may be harmful, and it has been designated as a probable human carcinogen. However, the toxicity of 1,4-dioxane is in dispute and the United States Environmental Protection Agency is in the process of reviewing the toxicological information on 1,4-dioxane towards potentially revising the oral cancer slope factor and associated risk screening levels. Chemical characteristics of 1,4-Dioxane, such as high mobility, enable it to migrate much further than the solvent from which it likely originated. This has challenged remedial project managers to redesign treatment systems and monitoring networks to accommodate widespread contamination. This paper summarizes the fate and transport characteristics of 1,4-dioxane and presents current thinking in the environmental engineering community related to remedial technologies that may be applicable to groundwater treatment. At this point in time, ex-situ remediation has been performed at numerous sites for 1,4-dioxane, but no full scale in-situ remediation projects have been completed.

Adobe PDF LogoTreatment Technologies for 1,4-Dioxane: Fundamentals and Field Applications
EPA-542-R-06-009, 2006

Tucson International Airport Area Superfund Site
U.S. EPA Region 9 Fact Sheet, 2008

The site contains 7 major project areas: Air Force Plant 44 (AFP 44, operated by Raytheon Missile Systems Company), Tucson Airport Remediation Project (TARP), the Airport Property, the Arizona Air National Guard (AANG) 162nd facility, Texas Instruments, Inc. (formerly Burr-Brown Corporation), the former West-Cap property, and West Plume B. The groundwater COCs include TCE, DCE, chloroform, and chromium, and PCBs and metals have been found in some of the site soils. In 2002, 1,4-dioxane was discovered in several project areas. In July 2008, the Air Force installed an advanced oxidation process (AOP) treatment system for 1,4-dioxane. The AOP system injects hydrogen peroxide and ozone at multiple points into the mixing chamber with the contaminated water. The reaction of the water and chemicals together rids the contaminated water of both 1,4-dioxane and TCE. The addition of the new system will ensure TARP continues to meet its goal of no more than 3 ppb of 1,4-dioxane in drinking water. The TARP treatment plant has been in operation since 1994, using air stripping technology and carbon filtration to remove TCE from the groundwater. As of March 2008, 29.5 billion gallons of water have been cleaned and 3,557 pounds of TCE have been removed. This system provides clean drinking water to 50,000 residents of Tucson.

Work Plan for the Testing of In-Situ Oxidation Using Hydrogen Peroxide for the Treatment of 1,4-Dioxane at the Pall Life Sciences Facility
Pall Corporation.
City of Ann Arbor, MI. 6 pp, Dec 22, 2003

CLU-IN Technology Focus: The Remediation Technology Information Center

Visit the Technology Focus area for more information on in situ oxidation and phytoremediation.

Literature References

Technology Innovation News Survey Archives
The Technology Innovation News Survey archive contains resources gathered from published material and gray literature relevant to the research, development, testing, and application of innovative technologies for the remediation of hazardous waste sites. The collected abstracts date from 1998 to the present, and the archive is updated twice each month.