The Use of Electrokinetics for Hazardous Waste Site Remediation

The Superfund Innovative Technology Evaluation (SITE) program was authorized as part of the 1986 amendments to the Superfund legislation. It represents a joint effort between U.S. EPA’s Office of Research and Development and Office of Solid Waste and Emergency Response. The program is designed to assist and encourage the development of waste treatment technologies that would contribute to more solutions to our hazardous waste problems.

Recently, EPA, through the SITE program, issued a work assignment to assess the “stateof- the-art” of electroklnetically enhanced contaminant removal from soils. Prior research efforts, both laboratory and field, have demonstrated that electroosmosis has the potential to be effective In facilitating the removal of certain types of hazardous wastes from soils. Particularly encouraging results have been achieved with inorganics in fine-grained soils where more traditional removal alternatives are less effective.

Although the results of various studies suggest that electrokinetics is a promising technology, further testing Is needed at both the laboratory and field levels to fully develop this technology for site remediation. A conceptual test program Is presented based on best available data which incorporates system design and operating parameters used in previous applications of this technology In the use of electrokinetics treatment as a remediation technique at hazardous waste sites.     

Distribution of Pb, Cd and Ba in soils and plants of two contaminated sites

Evaluation of metal accumulation in soils and plants is of environmental importance due to their health effects on humans and other biota. Soil material and plant tissue were collected along transects in two heavily contaminated facilities, a Superfund site and a lead-acid battery dump, and analyzed for metal content. Soil lead (Pb), cadmium (Cd) and barium (Ba) concentrations for the Superfund site averaged 55,480, 8.5 and 132.3 mg/kg, respectively. Soil Pb occurred primarily in the carbonate, sulfide/residual and organic chemical fractions (41.6, 28.6 and 16.7%, respectively). Soil Pb, Cd and Ba concentrations for the dump site averaged 29,400, 3.9 and 1130 mg/kg, respectively. Soil Pb occurred mostly in the organic and carbonate fractions as 48.5 and 42.5%, respectively. Pb uptake in the two sites ranged from non-detectable (Agrostemma githago, Plantago rugelii, Alliaria officinalis shoots), to 1800 mg/kg (Agrostemma githago root). Cd uptake was maximal in Taraxacum officinale at 15.4 mg/kg (Superfund site). In the majority > or =65%) of the plants studied, root Pb and Cd content was higher than that for the shoots. Tissue Pb correlated slightly with exchangeable and soluble soil Pb; however, tissue Cd was poorly correlated with soil Cd species. None of the sampled plants accumulated measurable amounts of Ba. Those plants that removed most Pb and Cd were predominantly herbaceous species, some of which produce sufficient biomass to be practical for phytoremediation technologies. Growth chamber studies demonstrated the ability of T. officinale and Ambrosia artemisiifolia to successfully remove soil Pb and Cd during repeated croppings. Tissue Pb was correlated with exchangeable soil Pb at r(2)=0.68 in Ambrosia artemisiifolia.     

Making Cleanup Decisions at Hazardous Waste Sites: The Clean Sites Approach

This paper provides a summary of the results of an 18-month study conducted by Clean Sites, Inc. of Alexandria, Virginia. The study was designed to take a critical look at the way remedies are selected for abandoned hazardous waste sites that are cleaned up under the authority of the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA or Superfund) and to develop recommendations for improving that process. The recommendations were released in an October 1990 report entitled “Improving Remedy Selection: An Explicit and Interactive Process for the Superfund Program.” Through a cooperative agreement with the U.S. Environmental Protection Agency, Clean Sites is working to test these recommendations. At two actual Superfund sites, Clean Sites will assist EPA in performing the remedy selection in accordance with the process Clean Sites has developed.     

Making cleanup decisions at hazardous waste sites: the clean sites approach.

This paper provides a summary of the results of an 18-month study conducted by Clean Sites, Inc. of Alexandria, Virginia. The study was designed to take a critical look at the way remedies are selected for abandoned hazardous waste sites that are cleaned up under the authority of the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA or Superfund) and to develop recommendations for improving that process. The recommendations were released in an October 1990 report entitled "Improving Remedy Selection: An Explicit and Interactive Process for the Superfund Program." Through a cooperative agreement with the U.S. Environmental Protection Agency, Clean Sites is working to test these recommendations. At two actual Superfund sites, Clean Sites will assist EPA in performing the remedy selection in accordance with the process Clean Sites has developed.     

Overview and update of the Superfund Innovative Technology Evaluation (SITE) Demonstration Program

The Superfund Innovative Technology Evaluation (SITE) Program is now in its sixth year of demonstrating technologies applicable to Superfund sites. The SITE Program, conducted by the U.S. Environmental Protection Agency's Risk Reduction Engineering Laboratory, is intended to accelerate the use of new and innovative treatment processes as well as evaluate innovative measurement and monitoring techniques. Within the SITE Program, the Demonstration Program and the Emerging Technologies Program are responsible for innovative/alternative waste treatment technology development. Separate and parallel activities are progressing for development and evaluation of measuring and monitoring technologies as well as technology transfer operations.     

A review of the Texas,USA San Jacinto Superfund site and the deposition of polychlorinated dibenzo-p-dioxins and dibenzofurans in the San Jacinto River and Houston Ship Channel

The San Jacinto River (SJR) waste pits that lie just under the 1–10 overpass in eastern Harris County east of Houston, Texas, USA, were created in the 1960s as dumping grounds for paper mill waste. The deposition of this waste led to accumulation of highly toxic polychlorinated dibenzo-p-dioxins and dibenzofurans (PCCDDs/PCDFs) over the course of several decades. After abandonment, the waste material eventually became submerged under the waters of the SJR, resulting in widespread environmental contamination that currently constitutes a significant health concern for eastern Harris County communities. The original waste pits were rediscovered in 2005, and the San Jacinto waste site is now a designated EPA superfund site. The objective of this review then is to discuss the history and current state of containment around the San Jacinto waste pits and analyze spatial and temporal trends in the PCDD/PCDF deposition through the SJR system from the data available. We will discuss the current exposure and health risks represented by the Superfund site and the SJR system itself, as well as the discovery of liver, kidney, brain (glioma), and retinoblastoma cancer clusters in eastern Harris County across multiple census tracts that border the Superfund site. We will also cover the two primary management options, containment versus removal of the waste from the Superfund and provide recommendations for increased monitoring of existing concentrations of polychlorinated waste in the SJR and its nearby associated communities.     

Factors affecting EDTA extraction of lead from lead-contaminated soils

The effects of solution:soil ratio, major cations present in soils, and the ethylenediaminetetraacetic acid (EDTA):lead stoichiometric ratio on the extraction of lead using EDTA were studied for three different Superfund site soils, one rifle range soil, and one artificially lead-contaminated soil. Extraction of lead from the lead-contaminated soils was not affected by a solution:soil ratio as low as 3:1 but instead was dependent on the quantity of EDTA present. Results of the experiments showed that the extraction efficiencies were different for each soil. If sufficiently large amount of EDTA was applied (EDTA-Pb stoichiometric ratio greater than 10), most of the lead were extracted for all soils tested except for a Superfund site soil from a lead mining area. The differences in extraction efficiencies may be due to the major cations present in soils which may compete with lead for active sites on EDTA. For example, iron ions most probably competed strongly with lead for EDTA ligand sites for pH less than 6. In addition, copper and zinc may potentially compete with lead for EDTA ligand sites. Experimental results showed that addition of EDTA to the soil resulted in a very large increase in metals solubility. The total molar concentrations of major cations extracted were as much as 20 times the added molar concentration of EDTA. For some of the soils tested, lead may have been occluded in the iron oxides present in the soil which may affect lead extraction. While major cations present in the soil may be one of the factors affecting lead extraction efficiency, the type of lead species present also play a role.     

Solvent Extraction Processes: A Survey of Systems in the SITE Program

Solvent extraction of contaminated soils, sludges and sediments has been successfully completed at a number of Superfund sites. Each commercialized process uses a unique operating system to extract organic contaminants from solids. These operating systems may be classified by the properties of the solvents each utilizes: (1) standard solvents, (2) near-critical fluids/liquified gases, and (3) critical solution temperature solvents. Pretreatment and post-treatment requirements vary depending upon the operating systems of the solvent extraction system. Future demonstrations of these technologies by the U.S. EPA’s Superfund Innovative Technology Evaluation Program will provide additional information regarding the efficacy of these processes.     

Overview and Update of the Superfund Innovative Technology Evaluation (site) Demonstration Program

The Superfund Innovative Technology Evaluation (SITE) Program is now in its sixth year of demonstrating technologies applicable to Superfund sites. The SITE Program, conducted by the U.S. Environmental Protection Agency’s Risk Reduction Engineering Laboratory, is intended to accelerate the use of new and innovative treatment processes as well as evaluate innovative measurement and monitoring techniques. Within the SITE Program, the Demonstration Program and the Emerging Technologies Program are responsible for innovative/ alternative waste treatment technology development. Separate and parallel activities are progressing for development and evaluation of measuring and monitoring technologies as well as technology transfer operations.     

Control of incidental asbestos exposure at hazardous waste sites

This paper discusses asbestos regulations that are not part of Superfund and examines how these regulations can help to identify, evaluate and manage the risk associated with Asbestos Containing Material (ACM) at hazardous waste cleanup sites. Unless one knows where to look for ACM at hazardous waste sites, it may go undetected even after all the traditional sampling is done. Although EPA is currently developing a policy for evaluating risk from asbestos exposure at certain Superfund sites, information from existing regulations can be used to manage hazards associated with asbestos exposure at hazardous waste sites. This paper also identifies where to find governmental agency personnel and consultants who may be retained for site-specific help.     

Incineration at Bayou Bonfouca Remediation Project

The Bayou Bonfouca hazardous waste site is located in Slidell, Louisiana, approximately 96 kilometers (60 miles) northeast of New Orleans. This site is ranked number 1,006 on the National Priorities List of Superfund sites. The U.S. Environmental Protection Agency (EPA) conducted a remedial investigation in 1986 and determined the primary potential exposure sources to be groundwater, surface waste piles, and contaminated sediment in Bayou Bonfouca. Based on the results of investigations, EPA and the Louisiana Department of Environmental Quality chose a remedy that involves dredging contaminated sediment from the bayou, excavating contaminated waste piles and soil, and incinerating the solid wastes in a transportable incinerator. The site remedy, which included incineration, was specified in the Record of Decision signed in March 1987.

Of the total 142,000 megagrams (Mg) (157,000 tons) of waste to be incinerated, approximately 119,000 Mg (132,000 tons) consist of hazardous sediment from the bayou; 22,600 Mg (25,000 tons) consist of lightly contaminated soils and waste piles, cellulosic materials, and other miscellaneous wastes on the ground. The solid wastes are primarily low heat content sediment and soils and cellulosic materials with polyaromatic hydrocarbon (PAH) concentrations from milligrams per kilogram (parts per million) levels up to two percent. The dredged bayou sediment will be dewatered in six, 115-cubiometer (150-cubic-yard) plate and frame filter presses before processing in the incinerator. A rotary-kiln-based single train incinerator is deployed at Bayou Bonfouca to process the solid waste feed.

On-site pilot studies indicated that the PAHs in groundwater could be removed by on-site pumping, treatment, and discharge of treated effluent to the bayou. The groundwater treatment plant went on-stream in June 1991. Treatment involves oil/water separation, filtration, carbon bed adsorption, and aeration.

IT Corporation-OH Materials, a joint venture, was awarded a contract in May 1991 and a notice to proceed in February 1992 to remediate and restore the Bayou Bonfouca site. The remediation project includes air quality monitoring and controls, site preparation, dredging and excavation, bayou bank stabilization and monitoring, equipment mobilization and erection, the trial burn, incineration, demobilization, and site closure. The project completed a successful trial burn in November 1993, and the commercial operation began in December 1993. The expected duration of the project is 40 months from mobilization to site closure.     

1990 Thermal Remediation Industry Contractor Survey

The treatment of soil contaminated with organics and inorganics is becoming a major industry in the United States and Europe. The soil cleanup bill for the United States could run as high as $200 to $300 billion over the next 30 to 40 years. European soil cleanup costs could run as high as $130 billion.¹

The types of sites in the United States that will require soil treatment can be broken down into the following categories: ? CERCLA (Superfund) Actions

? RCRA Corrective Actions

? RCRA Closures

? Underground Storage Tanks

? Real Estate Transfers

? Spill Clean-ups.

The cleanup of sites in each of these categories, with the exception of the Real Estate Transfer category, is being driven by different sets of Federal regulations. Real Estate Transfer type regulations were first instituted in New Jersey and have now been promulgated in a number of other states.

The eventual cleanup cost for the Superfund sites will be close to $200 billion. Estimated costs for the industrial sector Superfund are $25 to $50 billion and the estimated cost for the Department of Energy sites is over $150 billion.2 An early RCRA Corrective Action cleanup estimate is $25 billion.3 This estimate may well be low, however, since the permitting, cleanup and delisting criteria are still not clearly defined. The EPA’s RCRA Corrective Action cost estimate is $7.4 billion. However, the Office of Management and Budget feels that this estimate is low.⁴

The potential magnitude of the cleanup costs has resulted in the development and implementation of many technologies for the decontamination of soils. Of the available remedial technologies, thermal treatment has perhaps had the most field testing. The purpose of this paper is to focus on the full scale site remediations which have been or are being conducted using thermal processing equipment. Projects which have been completed, are on-going, or have been contracted for, through January of 1990 are described.     

Results of Treatment Evaluations of a Contaminated Synthetic Soil

Under Phase I of EPA’s Superfund soil treatability research program, which was conducted from April to November 1987, a surrogate soil containing a wide range of chemical contaminants typically occurring at Superfund sites was prepared and subjected to bench- or pilot-scale performance evaluations using the following treatment technologies: 1) physical separation/volume reduction (soil washing); 2) chemical treatment (KPEG); 3) thermal desorption; 4 ) incineration; and 5) stabilization/fixation. This report covers the formulation and development of the surrogate soil; it also highlights the results of the five treatment evaluations. Virtually all of the analytical data underlying this research were developed using EPA-SW846 methods. Detailed project reports covering the findings of each study are available through EPA’s Risk Reduction Engineering Laboratory in Cincinnati, Ohio.     

Treatment of Nonhazardous Petroleum-Contaminated Soils by Thermal Desorption Technologies

Spills, leaks, and accidental discharges of petroleum products have contaminated soil at thousands of sites in the United States. One remedial action technique for treating petroleum contaminated soil is the use of thermal desorption technologies.

This paper describes key elements of the U.S. Environmental Protection Agency report titled “Thermal Desorption Applications Manual for Treating Nonhazardous Petroleum Contaminated Soils.”¹ The applications manual describes the types, mechanical and operating characteristics of thermal desorption technologies that are commercially available to treat petroleum-contaminated soils. It also provides step-by-step procedures to rate the critical success factors influencing the general applicability of thermal desorption at a particular site. These factors include site, waste and soil characteristics, regulatory requirements, and process equipment design and operating characteristics. Procedures are provided to determine the types of thermal desorption systems that are most technically suitable for a given application and to determine whether on-site or off-site treatment is likely to be the most cost-effective alternative. Key factors that determine process economics are identified, and estimated cost ranges for treating petroleum-contaminated soils are presented. Spreadsheets are provided that can be used for performing cost analyses for specific applications.

The aforementioned report is applicable only to the treatment of petroleum-contaminated soils that are exempt from being classified as hazardous wastes under the Resource Conservation and Recovery Act (RCRA) or as toxic materials under the Toxic Substances Control Act (TSCA). Although much of the technical discussion in this paper is applicable to the treatment of both nonhazardous and hazardous ortoxic materials, permitting requirements and treatment costs are significantly different forthe individual categories of waste materials.     

1992 Update of U.S. EPA’s Superfund Innovative Technology Evaluation (SITE) Emerging Technology Program

The Superfund Innovative Technology Evaluation (SITE) Emerging Technology Program (ETP) has encouraged and financially supported further development of bench- and pilot-scale testing and evaluation of innovative technologies suitable for use at hazardous waste sites for five years. The ETP was established under the Superfund Amendments and Reauthorization Act (SARA) of 1986. The ETP complies with the goal of the SITE Program to promote, accelerate and make commercially available the development ofalternative /innovative treatment technologies for use at Superfund sites.

Technologies are submitted to the ETP through yearly solicitations for Preproposals. Following a technical review, chosen applicants are asked to submit a detailed project proposal and a cooperative agreement application that requires Developer I EPA cost sharing. EPA co-funds selected Developers for one to two years. Second-year funding requires documentation of significant progress during the first year. Facilities, equipment, data collection, performance and development are monitored throughout the project. The U. S. Department of Energy (DOE) and the U. S. Air Force (USAF) are participants in the ETP. DOE has co-funded ETP projects since 1990 and the USAF since 1991.

A primary goal of the ETP is to move developed technologies to the field-demonstration stage. Therefore, a developer may be considered for participation in the SITE Demonstration Program provided performance in the ETP indicates the technology is field-ready for demonstration and evaluation.

Six technology categories: biological, chemical, materials handling, physical, solidification/ stabilization and thermal, are presently in the ETP.

Technologies of primary interest to EPA are those that can treat complex mixtures of hazardous organic and inorganic contaminants and provide improved solids handling and/orpretreatment.

An account of the background and progress of the ETP’s first five years is presented in this paper. Technologies currently in the ETP, including those selected from the fifth (EOS) solicitation, are noted, and developers, along with EPA Project Managers, are listed.     

Thermal Encapsulation of Metals in Superfund Soils

Abstract

Superfund sites frequently contain both heavy metals and organic hazardous waste. If not properly controlled, the metals may be changed to a more leachable form and may also be emitted to the atmosphere via the exhaust stack. This paper documents a batch kiln R&D test program to solve these metal-related problems. It was performed under the U.S. EPA’s SITE (Superfund Innovative Technology Evaluation) Emerging Technology Program. Allis Mineral Systems has developed the Thermal Encapsulation Process. Metals with limits set by EPA’s TCLP (Toxicity Characteristic Leaching Procedure) test and BIF (boiler and industrial furnace) stack emission regulations, such as cadmium, chromium, and lead, are the initial target of this process. This process, while unproven in these areas, may also apply to mixed waste (EPA hazardous waste/low-level radioactive wastes) and may also benefit commercial hazardous waste or Superfund thermal treatment systems. The results of the SITE tests were positive: strong, durable nodules were produced with excellent crush strength and improved resistance to leaching. Feed preparation, particularly control of moisture content, was found to be a key element in initiation of agglomeration. A good correlation was found between decreasing TCLP metals leachate levels and increasing crush strength.     

The Superfund Remedial Action Decision Process: A Review of Fifty Records of Decision

Abstract

Although the Superfund remedial action decision process is a complex process involving a variety of technical, political, and public health issues, the primary goal of remedial action is the protection of public health. We performed an in-depth analysis of 50 post-SARA Records of Decision in order to characterize the role of risk assessment in the decision-making process and determine whether decisions are being made in an effective and environmentally protective manner. Our findings indicate that the majority of decisions to remediate Superfund sites are based on the existence of contamination per se and not on actual public health risk. Although hypothetical risk is an essential consideration, this gray area is not well-defined in the current decision-making process.

The lack of assessment of the degree of risk reduction associated with the remedial alternatives evaluated and the lack of support indicating the effectiveness of the remedial alternatives selected also constitute major weaknesses in the majority of decisions. These inadequacies undermine rationales regarding the protectiveness and cost-effectiveness of the remedial alternatives selected. The fact that objectives beyond addressing public health risk are often unclear in the decision-making process also weakens rationales for costeffectiveness.     

Measurement of Ozone Levels by Ship Along the Eastern Shore of Lake Michigan

The U.S. Environmental Protection Agency (EPA), in cooperation with the Toronto Harbour Commissioners (THC), conducted a Superfund Innovative Technology Evaluation (SITE) demonstration of the THC Soil Recycle Treatment Train. The treatment train consists of three technologies operated in sequence: a soil wash process, a metals removal process, and a biological treatment process. The THC conducted an extensive demonstration of the treatment train at a 55 tons per day pilot plant in order to evaluate an approach for remediation of industrial/commercial sites that are situated in the Toronto Port Industrial District (PID). Three soils were processed during the THC demonstration. The EPA SITE demonstration project examined, in detail, soil processing from one of the sites being evaluated as part of the overall THC project. Contaminants included organic compounds and heavy metals. It has been estimated by THC that as much as 2,200,000 tons of soil from locations within the PID may require some form of treatment due to heavy metal and/or organic contamination that resulted from various industrial processing operations. The objective of the SITE demonstration was to evaluate the technical effectiveness of the process in relation to THC’s target criteria.

Gravel and sand that met the THC target criteria for medium to fine soil suitable for industrial/commercial sites was produced. The fine soil from the biological treatment process did not meet the target level of 2.4 ppm for benzo(a)pyrene. However, there was a significant reduction in polynuclear aromatic hydrocarbon (PAH) compounds. The metals removal process achieved reductions of greater than seventy percent for copper, lead, nickel, and zinc.     

A Modular Approach to A Microcomputer Monitoring System

Abstract

Under a cooperative agreement with the U.S. Environmental Protection Agency's (USEPA) Superfund Innovative Technology Evaluation (SITE) Emerging Technology Program, COGNIS, Inc. conducted bench-scale studies on the COGNIS TERRAMET® Lead Extraction Process. The process leaches, or extracts, lead from contaminated soil and consists of a lead leaching stage followed by recovery of the dissolved lead from the leachant. Prior to treatment, the soil is characterized, the type and extent of lead contamination is identified, and the soil is pretreated by physical separation methods to facilitate the extraction process. The physical pretreatment, for example, may include particle size separation to allow separate leaching of the sand and fines fractions and removal of larger lead particles by density separation techniques. As part of the SITE Program, COGNIS investigated seven different lead-contaminated soil samples in small bench-scale batch studies and three soils in larger bench-scale continuous-treatment studies. This bench-scale work led to the design, construction, and operation of a full-scale treatment plant by COGNIS at the Twin Cities Army Ammunition Plant (TCAAP), New Brighton, MN where lead and seven other heavy metals were extracted and recovered from over 20,000 tons of treated soil to meet cleanup criteria.