Kelly Air Force Base • San Antonio Air Logistics Center = Installation Restoration Program FACT SHEET Superfund Innovative Technology Evaluation (SITE) Program Office of Public Affairs, 807 Buckner, Kelly AFB, TX 78241-5842 (210)925-7951 AV 945-7951 Air Force and EPA Join Forces to Clean Up Contaminated Soil Introduction The U.S. Environmental Protection Agency (EPA) identifies new methods for hazardous waste cleanup through its Superfund Innovative Technol- ogy Evaluation (SITE) Program. Created in 1986, this program demonstrates and evaluates innovative treatment technologies that may significantly reduce the toxicity, mobility, or volume of hazardous waste. The SITE Program also generates reliable perfor- mance and cost information on the technologies for use in evaluating cleanup alternatives for similarly contaminated sites. The Air Force, through its Installation Restora- tion Program (IRP), is seeking effective and afford- able systems for cleaning up past storage, use, and disposal sites. Cooperation between the Air Force and EPA allows government resources to be shared in technology evaluations that prevent duplication or excess cost while providing important information about environmental cleanup choices. The technology being demonstrated at Kelly Air Force Base (Kelly AFB) IRP Site S-1 is the KAI Tech- nologies, Inc. radio frequency heating (RFH) process. The purpose of the demonstration is to determine how effectively the KAI technology removes volatile, semivolatile, and nonvolatile organic compounds from contaminated soil at the test site. The technol- ogy demonstration is being carried out under a con- tract between the U.S. Air Force and Brown & Root Environmental of Oak Ridge, Tennessee. The Air Force/EPA SITE Team The Air Force is constantly alert to new scien- tific and technical concepts that offer faster, safer, more effective, or less costly methods for environ- mental cleanup. EPA's SITE Program is a major source of information and a partner in testing new technologies at Air Force bases. Each year, EPA solicits proposals from technology developers to demonstrate innovative technologies under the SITE Program. EPA selects technologies for evaluation and often obtains input from the Air Force, state agen- cies, or regional agencies. For each selected tech- nology, EPA does the following: • Identifies a site with wastes suitable for treatment by the selected technology • Prepares a technology demonstration plan • Notifies appropriate agencies for inter- governmental and community reviews • Prepares a fact sheet for the public, describing the site and technology combination • Prepares the demonstration site • Conducts and audits field sampling and laboratory analyses • Organizes a visitors' day to allow interested parties to view the technology demonstration • Evaluates the technology's performance • Prepares an Innovative Technology Evaluation Report summarizing demonstra- tion results • Prepares informational items such as technology bulletins, summaries, and a videocassette program Cooperating with the EPA, the U.S. Air Force identifies sites and provides a major share of the necessary resources for conducting innovative tech- nology evaluations on sites at various Air Force bases. Most of the actual field work for this particu- lar program will be the responsibility of the Air Force or a civilian contractor working on behalf of the Air Force. EPA will validate sampling, handle much of the data compiled during the test, and prepare the necessary reports and publications when the evalu- ation is complete. ------- Technology Description The KAI RFH system is a thermal treatment process that uses electromagnetic energy in the ra- dio frequency (RF) band to volatilize contaminants and separate them from soil and sludge matrices. The process is designed to heat the soil by molecu- lar agitation, just as a microwave oven heats food. Thus, RFH creates heat in the soil itself; whereas existing systems use thermal conduction (direct ap- plication of heat from an external source) to heat the soil. The primary components of the KAI RFH sys- tem are the RF generator and the RF heating appli- cators (antennae). The generator supplies power through flexible coaxial transmission lines to one or more antennae, which radiate the energy to the soil. This results in progressive heating of the soil in a radial direction from each antenna. Once the RF energy has heated the soil, va- porized contaminants are collected through extrac- tion wells similar to those used in soil vapor extrac- tion systems. A vacuum system transfers the va- pors to a vapor treatment system. The treatment zone is covered with a vapor barrier, which has three functions: to help maintain a vacuum for vapor col- lection, to prevent fugitive emissions from the heated surface, and to control infiltration of air into the treated zone and thus into the vapor treatment system. As an additional precaution, vapor collection lines are installed under the vapor barrier to collect any va- pors that reach the soil surface. During the demon- stration, the vapor collection and vapor treatment systems will be operated for 5 days before the power source is turned on and for 2 weeks after the power source is turned off, while the temperature of the treatment zone is decreasing. Thermocouples are placed throughout the treat- ment zone and surrounding area to allow operators to monitor the spatial temperature distribution in the heated soil. These temperature data are used to assess the operation of the RF power source and to determine when the test termination criteria have been met. The overall configuration of the KAI RFH sys- tem that will be used for the demonstration is shown in Figure 1. The treatment zone will be 15 feet long, 10 feet wide, and 20 feet deep. E1 TD1 &TD2 O T03O E2&T1 # E3 l"~l = electric field measurement well A = antenna Q = pressure transducer ^ = extraction well • = therm owell Q = thermowell & pressure transducer l» F1 ~ • B 1 m 036 I 1 1 scale in feet 20 ft. , - S\ ^1 A1 A A F3 ~ E5 • A*2 « it *1 000 TD6&T3 TD5&T2 TD4 i II F4 ~ —m— F5 ~ 1 E6 E7 E8 TD7&TD8 Q Figure 1. KAI RFH Demonstration System Configuration ------- Site History Kelly AFB is located 7 miles southwest of down- town San Antonio, Texas. A map of Kelly AFB, in- cluding Site S-1, is shown in Figure 2. From the early 1960s until 1973, IRP Site S-1 was used for tempo- rary storage of waste oils and industrial solvents prior to off-base disposal. Spills and leaks are believed to have occurred during the course of normal opera- tions. Contaminants, primarily petroleum products, carbon cleaning compounds, and industrial solvents, flowed to a nearby depression. Both soil and shal- low underground water at the site contain contami- nants. The RFH demonstration will concentrate on the southern portion of the depression. The site has a radius of approximately 150 feet. The concentration of benzene, toluene, ethylbenzene, and xylene (BTEX) is less than 10 parts per million (ppm) in the soil and shallow ground- water. The concentration of total petroleum hydro- carbons is less than 17,000 ppm in the soil. The shallow groundwater is located approximately 25 to 30 feet below the surface and is not used for drink- ing or any other domestic purpose. More than 1,000 feet of dense clay and rock form an impermeable barrier between the shallow groundwater and the local water supply in the deep Edwards Aquifer. Initial investigations of the site were carried out between 1981 and 1988. A formal Remedial Investi- gation, following the requirements of the Compre- hensive Environmental Response, Compensation and Liability Act (CERCLA), began in 1989 and is near completion. A feasibility study to determine cleanup alternatives for the site is expected to com- pare the RF heating process to more traditional cleanup technologies for sites of this type. Technology Demonstration The KAI RFH demonstration at Site S-1 is scheduled to take place during March and April. The demonstration will identify the effectiveness of the process; the potential need for pre- and post-treat- ment processing of raw and treated materials; po- tential site-specific system operating problems and their possible solutions; and approximate capital, operating, and maintenance costs including projected long-term operating and maintenance costs. Specific chemical constituents and total petro- leum hydrocarbons will be monitored to evaluate the performance of the RFH process. Soil samples will be collected before and after treatment to determine the technology's effectiveness. The effectiveness of the vapor treatment system will also be monitored. The Air Force, cooperating with EPA, has pre- pared a detailed demonstration plan outlining meth- ods and procedures for testing and evaluating the technology. When the demonstration is complete, EPA will compile and analyze the findings in an In- novative Technology Evaluation Report. This report will be used to evaluate alternatives for cleaning up similar sites across the country. ------- |