An Updated Cost Study for Enhanced Sludge Washing of Radioactive Waste

This article updates previous cost savings studies conducted to evaluate the use of enhanced sludge washing (ESW) of high‐level radioactive waste at the United States Department of Energy Hanford Site. The cost savings estimate was updated using stochastic analysis based on new information from the Independent Review of Hanford High Level Waste Volume and the more recent Tank Waste Remediation System Operation and Utilization Plan. It is estimated that implementation of ESW in the tank waste remediation system (TWRS) at the Hanford Site can save approximately $4.8 billion compared to the use of an alternative, simpler water wash. The simpler water wash dissolution was found to be 85 percent as effective as the ESW dissolution. Further, the updated remediation cost estimate of $4.8 billion savings is uncertain only within ±$1.6 billion at the 95 percent confidence interval. © 2002 Wiley Periodicals, Inc.     

A Cost Comparison of Organic versus Inorganic Ion Exchange Resin for Remediation of High-Level Waste

Ion exchange (IX) can be used to aid in the remediation of underground storage tank (UST) radioactive waste at the U.S. Department of Energy's Hanford site in the state of Washington. In particular, IX can be used to concentrate the radionuclides in liquid-based waste prior to immobilization for final disposal. Concentration of the radionuclides can significantly reduce the final immobilized high-level waste volume and consequent overall remediation cost. Organic and inorganic IX resins each have unique advantages and disadvantages regarding the remediation process. This study presents a comparison of the remediation cost for UST waste at Hanford for a phenol-formaldehyde type organic resin versus crystalline silico-titanate inorganic resin. It was determined that with optimum processing conditions such as waste blending and sludge washing, remediation with the inorganic resin would be less expensive than the organic resin. Assuming baseline remediation conditions, the use of inorganic rather than organic IX resin for UST remediation at Hanford can save approximately $383 million. A limited sensitivity analysis was performed as pan of this study and is reported in the following. © 1999 John Wiley & Sons, Inc.     

In-situ bioremediation of hanford groundwater

The U.S. Department of Energy has generated liquid wastes containing radioactive and hazardous chemicals throughout the more than forty years of operation at its Hanford site in Washington State. Many of the waste components, including nitrate and carbon tetrachloride (CCl₄), have been detected in the Hanford groundwater. In-situ bioremediation of CCl₄ and nitrate is being considered to clean the aquifer. Preliminary estimates indicate that this technology should cost significantly less than ex-situ bioremediation and about the same as air stripping/granular activated carbon. In-situ bioremediation has the advantage of providing ultimate destruction of the contaminant and requires significantly less remediation time. Currently, a test site is under development. A computer-aided design tool is being used to design optimal remediation conditions by linking subsurface transport predictions, site characterization data, and microbial growth and contaminant destruction kinetics.     

In-situ biological treatment of vinyl acetate-contaminated soil: An emergency response action

In-situ biological solid-phase (or land) treatment was cost-effectively used to remediate 1,500 cubic yards (1,100 m³) of contaminated soil within three months of field operation following spillage of an estimated 12,000 gallons (45,000 L) of vinyl acetate from a railroad tank car onto surface soil. The vinyl acetate rapidly hydrolyzed to acetate and acetaldehyde with concentrations ranging up to 22,000 and 3,000 mg/kg, respectively. Ethanol, a metabolic intermediate, was found to accumulate in soil to concentrations as high as 280 mg/kg. The estimate for excavation, transportation, and disposal of the contaminated soil as a special waste, and for backfilling of the excavated area, was $850,000. The cost for biological remediation of the contaminated soil was $400,000, which was less than half the cost of excavation. In-situ biological treatments have been used to readily remove contaminants, such as acrylonitrile, styrene, butylcellosolve, ethylacrylate, and n-butylacrylate, at other sites involving railroad incidents.     

Cost effectively decommissioning an automotive parts facility

Using a comprehensive approach to decommission a 180,000-square-foot automotive parts manufacturing facility saves time and money while reducing environmental liability. Prior to starting the facility decommissioning, a detailed facility characterization was conducted to identify contaminated areas. Remediation activities were scheduled to coincide with facility demolition. Specialized subcontractors were used to perform tasks such as asbestos and lead-paint abatement, soil bioremediation, underground storage tank and clarifier removal, and facility destruction and recycling. The project timetable was reduced by using several crews simultaneously to conduct recycling, demolition, and remediation. Costs were offset by selling remaining equipment, scrap metals, overhead lights and fixtures, and a premanufactured steel building. A total of 415 tons of scrap metal was recycled, not including the aforementioned steel building. On-site recycling and remediation were used wherever possible to reduce cost and associated hauling liabilities. For example, concrete and asphalt debris were crushed and used as base for final site paving, saving disposal costs and base material purchase costs. On-site bioremediation of soil impacted by perchloroethene (PCE) saved over $1.5 million, with total project savings of $2.4 million. On-site remediation and recycling also reduced both long-term and short-term environmental liability.     

On-site analytical support: A cost-effective alternative to fixed laboratory services

Two recent projects involving soils remediation at Superfund sites in southern New Jersey and northeastern Pennsylvania exemplify the power of “real time” field analytical support in reducing time and expense during a project's remedial phase. The remediation efforts at both of these CERCLA sites were supported by ERM-FAST on-site analytical facilities which, in a “real-time” scenario, achieved all data quality objectives (DQOs), met all regulatory agency requirements, and satisfied the client's needs. Both of these sites offer illustrations of the effectiveness of field analysis for vastly differing site contaminants. The client benefited from substantial savings on analytical cost as well as the savings realized through efficient and effective process and schedule management.     

Remediation and review: Developing groundwater strategy at the hanford site

The U.S. Department of Energy's (US DOE's) environmental challenges include remediation of the Hanford Site in Washington State. The site's legacy from nuclear weapons “production” activities includes approximately 80 square miles of contaminated groundwater, containing radioactive and other hazardous substances at levels above drinking water standards. In 1998, the U.S. General Accounting Office (US GAO), the auditing arm of Congress, concluded that groundwater remediation at Hanford should be integrated with a comprehensive understanding of the “vadose zone,” the soil region between the ground surface and groundwater. The US DOE's Richland Operations Office adjusted its program in response, and groundwater/vadose‐zone efforts at Hanford have continued to develop since that time. Hanford provides an example of how a federal remediation program can be influenced by reviews from the US GAO and other organizations, including the US DOE itself. © 2008 Wiley Periodicals, Inc.     

SITE Program Success: Cost Savings to Government and Increased Revenue for Technology Vendors

The Superfund Innovative Technology Evaluation (SITE) program is a program mandated by Congress through the 1986 Superfund Amendments and Reauthorization Act (SARA). The original Superfund allowed no provisions for research and development of needed remediation technologies. Problems arose when the demand for involved, complex treatment could not be met by the traditional contain, haul, and dispose process that hazardous waste handlers had become familiar with. In response to the increasing complexity of hazardous waste site remediation, SARA called for an “Alternative or Innovative Treatment Technology Research and Demonstration Program.” As a result, EPA's Office of Solid Waste and Emergency Response and the Office of Research and Development established the SITE program. This article is a historical analysis of the unique cost savings of the SITE program.     

RCRA corrective action costs: An estimating model for nonfederal facilities

This article presents an analysis of the prospective costs of RCRA corrective action for private, nonfederal facilities. Two data bases developed by Research Triangle Institute and a remedial action cost model developed by CH2M Hill provide the foundation for this work. The methodology has two components, a remedial action knowledge base and a discrete-state Monte Carlo analysis. Under base case assumptions, it is estimated that the total costs of RCRA corrective action will be $240 billion, with a 5 percent chance the costs will be less than $170 billion and a 5 percent chance the costs will be more than $377 billion.     

Evaluating the cost-effectiveness of new environmental technologies

The purpose of this article is to present a framework for evaluating the cost-effectiveness of innovative technologies for environmental characterization, remediation, monitoring, and waste management. The authors describe the steps involved in actually using the methodology to perform a cost-effectiveness analysis. They provide basic techniques for designing a fair comparison, developing scenarios, choosing a baseline technology, assessing relative performance, evaluating life-cycle costs, and calculating cost savings. Examples are used to illustrate these concepts and a case study is presented involving a new remediation technology called in-situ air stripping.     

Physicochemical mechanisms controlling the periodic release of flammable gases from hanford tanks

Hanford tanks contain more than 60 million gallons of high-level wastes produced by decades of extracting plutonium from irradiated uranium fuel. The wastes were concentrated to a thick slurry consistency by evaporation prior to storage to minimize space. The resulting concentrated waste properties introduced unanticipated, detrimental conditions affecting workers' and the public's health and safety and involving the release of potentially flammable gases. The released gases consist primarily of hydrogen, nitrous oxide, and ammonia. Dilution and sluicing were initially proposed to mitigate the flammable gas safety conditions. As a result of evaluations, the mechanisms and conditions that are thought to control the accumulation and spontaneous release of flammable gases were identified and confirmed. The technical rationale was established for developing operational approaches to mitigate the periodic generation of flammable gases in existing tanks and to avoid any reoccurrence of this serious safety problem during future waste management activities. The chemistry of the two highest risk tanks was examined to test the potential for reversing the conditions causing gas buildup and the consequences of sluicing without appropriate chemical conditioning. The identified mechanisms apply equally to the remaining flammable gas tanks at Hanford as well as to other waste tanks in the DOE complex, particularly those at Savannah River. Passive means of mitigating the flammable gas condition require less than 1:1 dilution, and sluicing wastes from tank 106-C can be accomplished without creating a flammable gas condition. Carbonate equilibria reactions and their effect on aluminum speciation are largely overlooked and provided the key for explaining the episodic release of flammable gases from tank wastes. The reaction of atmospheric carbon dioxide with a sodium hydroxide-rich waste solution produces carbonate precipitates. More importantly, this reaction lowers the pH of the waste and precipitates aluminum hydroxide as a gel. The wastes contain substantial amounts of complexing agents such as ethylene diamine tetraacidicacid (EDTA), hydroxy ethylene diamine triacidic acid (HEDTA), and their degradation products. These complexing agents stabilize the aluminum hydroxide gel together with chromium, manganese and iron hydroxides, and oxybydroxides under the resulting pH conditions. These complex species may coprecipitate and accumulate as a metastable layer in the middle and lower levels of th tank. The complexed aluminum hydroxide acts as a binding agent trapping other particulates in a microcrystalline mat. Microcrystalline particles such as sodium nitrite provide the structural strength for the mat. Once the gas accumulation below the gel layer achieves a critical buoyancy sufficient to rupture the microcrystalline mat, a gas release event occurs. The cycle of gas buildup and release continues each time the buoyancy of the trapped gas exceeds the hydrostatic pressure and the gels' plasticity modulus. Stokes Law predicts a particle settling rate in the tank of less than 50 days, well within the bistorical periodicity of GREs. Laboratory tests, forming the basis of a recent patent application, verify that large quantities of complexed aluminum hydroxide gel are produced by passing carbon dioxide through simulated waste solutions (Hobl, 1993) equivalent to those found in tank 101-SY. It was confirmed that a simple adjustment of pH witll redissolve the gel, thereby reducing viscosity and safely facilitating continuous flammable gas release. Additional experiments were undertaken to provide a basis for understanding the role of complexed aluminum hydroxides in the CO₂/NaOH/Al(OH)₃ (complexing agents)/NaAlO₂ system. This article examines a plausible mechanism for the periodic release of flammable gas and considerations for: (1) remediating existing flammable gas tanks through a combination of chemical treatment and mixer pumps; (2) diluting, combining, retrieving, and storing wastes; (3) preventing clogging of transfer lines; (4) sludge and soil washing; and (5) cribs, ponds, basins, and ground-water cleanup. This study provides a singificant breakthrough for tank waste management by explaining key mechanisms controlling episodic release of flammable gases. The breakthrough provides the bases for removing the tanks classified as flammable gas from the wathclist and has broad operational applications with a potential for billions of dollars in cost savings.     

The challenge of remediation technology development

A huge commercial environmental industry, currently estimated at some $130 billion in size in the United States alone, has sprung up to manage and remediate environmental problems. Hundreds of innovative remediation technologies are being developed under EPA's SITE program, which has provided R&D funding for more than 100 new treatment technologies. Despite the obvious demand, numerous regulatory, marketing, technical, and financial barriers have impeded progress in the field of remediation technology development. Developers of remediation technologies are faced with a significant challenge to overcome these barriers and successfully bring a technology to market. This article examines the barriers to technology development and offers strategic planning alternatives for long-term economic success and commercial viability of remediation technologies.     

Citizen board issues and local newspaper coverage of risk,remediation, and environmental management: Six U.S. nuclear weapons facilities

We examined site‐specific advisory board (SSAB) minutes and local newspaper coverage of the Fernald, Hanford, Idaho, Oak Ridge, Rocky Flats, and Savannah River sites of the U.S. Department of Energy (US DOE) in order to determine the importance of risk‐related issues related to remediation and other forms of environmental management. About one‐third of SSAB issues were risk‐related, and these were disproportionately major issues at meetings. The media focused on risks associated with remediation and other forms of waste management. The analysis implies that contractors and government officials need to establish and maintain communications with advisory panels and accentuate these contacts well in advance of contemplated new actions. © 2008 Wiley Periodicals, Inc.     

Remediation,land use,and risk at Hanford

U.S. Department of Energy (US DOE) remediation responsibilities include the Hanford site in Washington State. Cleanup is governed by the Tri‐Party Agreement (TPA) between the US DOE as the responsible party and the U.S. Environmental Protection Agency and Washington State Department of Ecology as joint regulators. In 2003, the US DOE desired to implement a “Risk‐Based End State” (RBES) policy at Hanford, with remediation measures driven by acceptable risk standards using exposure scenarios based on the 1999 Hanford Comprehensive Land‐Use Plan. Facing resistance from regulators and stakeholders, the US DOE solicited public input on its policy. This led to a Hanford Site End State Vision in 2005 and a commitment that the TPA would continue to control remediation. This article describes how regulator and public participation modified RBES to an end‐state vision. © 2010 Wiley Periodicals, Inc.     

How shell cleaned up a 400,000-gallon oil spill

On April 23, 1988, approximately 9,500 barrels (400,000 gallons) of San Joaquin Valley crude oil leaked from an aboveground storage tank at Shell Oil Company's Martinez Manufacturing Complex in Martinez, California and entered Suisun Bay, an important recreation area. This article describes the remediation techniques Shell used to protect and clean up the Bay's oiled marshes, sloughs, rocky shores, marinas, and sandy beaches, and discusses the main methods of oil spill response, site-specific factors that must be considered in choosing remediation techniques, the interaction between Shell and government agencies, and the costs associated with the spill. The cleanup's total cost was approximately $8.3 million, which did not include private claims and claims handling costs; Shell also signed a separate consent decree for $19.75 million with the state of California and the federal government. This spill and its aftermath emphasize the need for preparation that facilitates response actions, improves the chances for cooperation between responsible parties and government agencies, minimizes the time needed for remediation, lowers cleanup costs, and limits natural resource damage claims and penalties.     

Combined thermal and zero‐valent iron In Situ soil mixing remediation technology

Thermal remediation of contaminated soils and groundwater by injection of hot air and steam using large‐diameter auger in situ soil mixing effectively remediates volatile and semivolatile organic compounds. This technology removes large amounts of contamination during the early treatment stages, but extended treatment times are needed to achieve high removal percentages. Combining thermal treatment with another technology that can be injected and mixed into the soil, and that continues to operate after removal of the drilling equipment, improves removal efficiency, and reduces cost. Using field‐determined pseudo first‐order removal rates, the cost of the combined remediation of chlorinated volatile organic compounds (CVOCs) by thermal treatment followed by reductive dechlorination by iron powder has been estimated as 57 percent of the cost of thermal treatment alone. This analysis was applied to a case‐study remediation of 48,455 cubic yards, which confirmed the cost estimate of the combined approach and showed over 99.8 percent removal of trichloroethene and other chlorinated VOCs. © 2010 Wiley Periodicals, Inc.     

Using an integrated approach for quantifying VOC source areas for site remediation

Locating and quantifying free-phase volatile organic compounds (VOCs) in the subsurface represent one of the more difficult challenges facing hazardous waste site remediation programs. Successful remediation programs require reliable data on the size and extent of potential VOC contamination sources. Improving subsurface quantification of VOCs requires a large number of reliable low-cost samples. Satisfying this objective relies on improved sampling techniques, field analysis of samples, and a modified quality assurance program. This paper describes an integrated approach using conventional split-spoon samplers, microcore sampling, hexane extractions, and a field gas chromatograph with an autosampler as part of a technical demonstration for innovative remediation technologies. Using this approach, it was possible to delineate a subsurface source of free-phase VOCs at a cost of $15 per sample. The distribution of dense nonaqueous phase liquid determined by this sampling approach agreed with the conceptual model for the site.     

Sustainable remediation at the Massachusetts Military Reservation

When does remediation do more harm than good? After conducting a sustainability analysis on a large pump‐and‐treat site at the Massachusetts Military Reservation (MMR), the Air Force Center for Engineering and the Environment (AFCEE) found evidence suggesting that the remediation systems were creating more pollution than they were remediating. For several years, the AFCEE/MMR has had an aggressive “better, cheaper, faster” optimization program intended to expedite aquifer restoration, reduce costs to the taxpayers, and reduce cleanup time frames. An initial sustainability analysis was conducted in 2005 as part of this program. The analysis identified several concerns, one of which was the indirect generation of air emissions from conventional fossil fuel–based power plants used to power the remediation systems. In addition to the environmental impact of these air emissions, the cost of electricity continues to increase. The AFCEE/MMR evaluated options for addressing both of these concerns and opted to employ renewable energy technology in the form of a utility‐scale wind turbine. This case study presents a more sustainable approach to remediation at the MMR through the use of renewable energy, in the form of a 1,500‐kW wind turbine. Power costs for operating the treatment systems, which processed up to 16 million gallons per day, amounted to over $2.2 million in 2008. The wind turbine is anticipated to reduce the program's electricity costs and offset air emissions, generated indirectly through the use of electricity from fossil fuel–based power plants, by approximately 25 to 30 percent. Based on a range of utility cost projections and an estimate of the turbine's energy production, the $4.6 million project is anticipated to have a payback period between six and eight years. © 2010 Wiley Periodicals, Inc. *

1 This article is a U.S. Government work and, as such, is in the public domain of the United States of America.

     

New paradigms for hazardous waste engineering

Today's hazardous waste engineering practice is based on the premise that the current technologies for conducting hazardous waste remediation are sufficient to solve most problems. The premise is false: Except for simple sites, the current practice cannot deliver answers with the required accuracy and precision. This article describes the huge uncertainties present in complex hazardous waste remediation efforts. It also discusses the “observational” method, which originated in the geotechnical engineering field, as a means of coping with these uncertainties during site characterization and remediation. The article includes case-study examples illustrating the use of the observational method at hazardous waste sites.     

Influences on RCRA corrective action costs for nonfederal facilities

Thousands of known hazardous waste sites across the country require remediation, with thousands more yet to be discovered, at estimated cleanup costs of billions of dollars over the next few decades. With this enormous financial burden placed on all members of society through increased prices, taxes, and lost investment opportunities, policy makers face the difficult prospect of defining cleanup standards that meet the goals of protecting human health and the environment and achieving remediation in the most cost-effective manner. Using a statistical methodology to investigate factors influencing the cost of RCRA corrective action, this article examines site characteristics that significantly affect cleanup costs and explains differences in costs among EPA's four proposed Subpart S corrective action options.