bluuebunny/crossref_metadata_2025 huggingface dataset:
Studies of the causes of soil erosion on marl soils in northern Algeria: The role of traditional soil tillage
Authors: Prinz D. , Gomer D. , Belz S.
Published: February 2007

In semiarid regions such as the Maghreb, the pressure on natural resources such as water and soil are increasing. Reservoir sedimentation and soil degradation are basic problems in these areas. The Oued Mina watershed (5000km2) has been chosen by the Algerian Ministry of Agriculture and the Deutsche Gesellschaft für Technische Zusammenarbeit (GTZ) GmbH for a Technical Cooperation Project to quantify soil erosion and to assess various methods of soil and water conservation at the watershed level. The study area (about 1000km2) is essentially a landscape of ancient dissected plateaux, with badlands as a major feature in some places. Both the agricultural areas and the reservoir, located at the basin outlet, are strongly affected by soil degradation. The climate is semiarid Mediterranean (wet winters), with an average annual rainfall of 300–350mm. Investigations using a large rainfall simulator revealed that soil tillage on marls under semiarid conditions could be an excellent tool to diminish runoff and soil erosion.
Agricultural terrace abandonment in the alpujarra, andalucia, spain
Authors: Douglas T. D. , Kirkby S. J. , Critchley R. W. , Park G. J.
Published: February 2007

The environmental impact of recent changes in land use is assessed in a part of Andalucia, southern Spain, where the deintensification and abandonment of low productivity upland areas is taking place. In the uplands of the Alpujarra, the traditional landscape most at risk is that of the irrigated cultivation terraces. These have often been established centuries ago and rely on water abstracted from streams draining the southern slopes of the Sierra Nevada. The causes of this deintensification include labour shortages, with many Alpujarra municipios reporting population decreases of up to 50 per cent since 1950. Landsat Thematic Mapper digital data from May and August 1992 have been used to identify the various land cover components of the Alpujarra. Ground verification undertaken in September 1992 and April 1993 has confirmed that deintensification of terraced areas around the villages of Trevélez (at 1500m, the highest village in Spain) and Pórtugos (1300 m) can be identified as either grassland or matorral. It is recognized that many classes of land cover are mosaics with several elements at a subpixel scale (e.g. terrace risers with fruit trees). However, the output from image processing has allowed areal estimates of the main land covers representing deintensification within the terraced zone. The pattern of deintensification of terraced land is fairly complex. It can be assumed that all terraces were irrigated and cropped at some stage. Land which is no longer cropped is usually grazed and the invasion of matorral species is common, particularly when irrigation ceases. Unirrigated tree crops and vines are sometimes planted on terraces no longer used for cropping. A model of deintensification of farming on terraced land in the Alpujarra is presented.
Mapping environmental carrying capacity using an artificial neural network: A first experiment
Authors: Lein J. K.
Published: February 2007

The economic development activities of an increasing world population threaten the assimilative capacity of our environment and have stimulated interest in the concept of environmental carrying capacity. While the pace of land transformations has encouraged the refinement of information technologies such as satellite remote sensing to provide a synoptic view of earth‐system processes, the volume of information these systems generate and the high level of expertise required to translate these data retard effective and timely land‐management decision making. This paper introduces a methodology that employs an artificial neural network trained to recognize categories of population support capacity from satellite data acquired from the NOAA‐AVHRR. The network, functioning as an ‘intelligent’ mapping tool, achieved a classification accuracy of 77.5 per cent for the study site and points to the potential role a model of this type may play in land degradation monitoring.
The early performance of deciduous trees grown in acidic minespoil ameliorated with pulverized fuel ash
Authors: Perkins P. V. , Vann A. R.
Published: February 2007

A field trial investigated the early performance of six tree species planted into an acidic minespoil ameliorated by ploughing or incorporation of 10 per cent by weight of pulverized fuel ash (PFA). Common alder, Italian alder and silver birch produced the greatest total shoot extensions for PFA‐ameliorated minespoil. Rowan, sycamore and aspen were unsatisfactory for both ameliorative treatments. PFA increased the pH of the minespoil for a period of time potentially beneficial for the establishment of the tree species. For the rate of PFA application studied, general salinity effects and cold‐water‐soluble boron both presented problems for successful tree growth.
Effects of livestock farming and recommendations for management and conservation of páramo grasslands (Colombia)
Authors: Hofstede R. G. M.
Published: February 2007

Although páramos cover extensive areas in the northern Andean countries, this tropical alpine ecosystem, which evolved without large mammals, is almost unique in the world. The ecological processes of the páramos ecosystem on volcanic soils are to a large extent controlled by low temperatures and phosphorous limitation.Páramos are considered an important ecosystem because of the high degree of endemism and because of their regulative function in the hydrology of the northern Andes. Their economic value reflects their function as a drinking water reserve and their role in agriculture. Grazing and burning have a large impact on the structure of the vegetation and soil, but nutrient concentrations remain almost unchanged owing to the large nutrient immobilization capacity. The high aboveground biomass and complete coverage of the soil is of the utmost importance for the ecosystem. The management and conservation of the ecosystem is difficult if the various functions of the páramos are to be respected. If plant diversity and water storage are to be protected, but if the same production of beef and milk is to be achieved, grazing should be concentrated in a few areas only. In these areas, which must be flat and have good ground coverage, production can be sustained by an input of organic and inorganic fertilizers (phosphorus). Many other areas can remain ungrazed and left for recovery of the natural, tall vegetation with its high endemism. In the future, tourism might play an important role in the conservation of some páramos areas.
Soil factors affecting tree growth on former opencast coal land
Authors: Scullion J. , Malinovszky K. M.
Published: February 2007

The growth of three tree species (Alnus glutinosa, Betula spp. and Quercus spp.) was related to soil factors on two restored opencast coal sites in South Wales, UK. The main factors favouring tree growth were greater soil depth and organic content. Factors limiting growth included poor site drainage and high magnesium levels. Whilst all species were related to most of the above factors, soil depth was of particular importance for Alnus glutinosa and Betula spp., whilst site drainage had the greatest influence for Betula spp. Soil‐tree associations tended to be closer on the older of the two sites. Combinations of soil depth, percentage clay and percentage organic content in a multiple regression predicted around 40 per cent of the growth variation in Alnus glutinosa, between 6.9 and 32 per cent of that for Betula spp. and between 14.5 and 32.6 per cent of that for Quercus spp. Growth prediction for Betula spp. improved to 40.9 and 34.8 per cent when a site drainage factor was included in the regression. The development of such predictive relationships might contribute to the planning of site reinstatement for tree planting after opencast mining, and to a better ‘matching’ of tree species to site characteristics.
Laconex: A rule‐based implementation to advise on plot‐level land conservation in Vilathikulam, Southeastern India
Authors: Balachandran C. S.
Published: February 2007

Knowledge about land conservation exists along a spatial continuum, represented at the broadest level (with least depth) by international‐level experts who have international‐level expertise, and at the narrowest level (with most depth) by the individual farmer with the most site‐specific knowledge at the plot level. This continuum covers many different aspects of knowledge about land degradation and its amelioration, including technical and cultural knowledge. This paper reports an effort (one in a series of steps) to gather, formalize, codify, and operationalize knowledge about land conservation from two different levels of the continuum. Land conservation knowledge was elicited from farmers and extension agents in Vilathikulam taluk (an area of contiguous villages) in Tamil Nadu, southeastern India, using semi‐structured interviews. The knowledge thus gained was combined with knowledge from the literature on soils and land conservation for the area. This information was organized into factual knowledge and process knowledge, and implemented in the form of general recommendations, constraints, and specific recommendations. The process of arriving at these categories was organized into several steps using a spatial anchor and soil type as keys. These were operationalized in a rule‐based computer program (LAnd CONservation EXpert ‐LACONEX), which offers land conservation advice at the plot level for Vilathikulam taluk, using an expert system development environment.
Collaboration in contingent capacities with information asymmetry
Authors: Chakravarty Amiya K. , Zhang Jun
Published: February 2007

We study the optimal contracting problem between two firms collaborating on capacity investment with information asymmetry. Without a contract, system efficiency is lost due to the profit‐margin differentials among the firms, demand uncertainty, and information asymmetry. With information asymmetry, we demonstrate that the optimal capacity level is characterized by a newsvendor formula with an upward‐adjusted capacity investment cost, and no first‐best solution can be achieved. Our analysis shows that system efficiency can always be improved by the optimal contract and the improvement in system efficience is due to two factors. While the optimal contract may bring the system's capacity level closer to the first‐best capacity level, it prevents the higher‐margin firm from overinvesting and aligns the capacity‐investment decisions of the two firms. Our analysis of a special case demonstrates that, under some circumstances, both firms can benefit from the principal having better information about the agent's costs. © 2007 Wiley Periodicals, Inc. Naval Research Logistics 54:, 2007
Heteroarm H‐shaped terpolymers through click reaction
Authors: Gungor Eda , Cote Gulay , Erdogan Tuba , Durmaz Hakan , Demirel A. Levent , Hizal Gurkan , Tunca Umit
Published: February 2007

Heteroarm H‐shaped terpolymers, (polystyrene)(poly(methyl methacrylate))‐ poly(tert‐butyl acrylate)‐(polystyrene)(poly(methyl methacrylate)), (PS)(PMMA)‐PtBA‐(PMMA)(PS), and, (PS)(PMMA)‐poly(ethylene glycol)(PEG)‐(PMMA)(PS), through click reaction strategy between PS‐PMMA copolymer (as side chains) with an alkyne functional group at the junction point and diazide end‐functionalized PtBA or PEG (as a main chain). PS‐PMMA with alkyne functional group was prepared by sequential living radical polymerizations such as the nitroxide mediated (NMP) and the metal mediated‐living radical polymerization (ATRP) routes. The obtained H‐shaped polymers were characterized by using 1H‐NMR, GPC, DSC, and AFM measurements. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 1055–1065, 2007
A risk‐based approach to how clean is clean
Authors: Marshall Thomas C. , Sieg Philip M.
Published: February 2007

Clearly defined remedial action objectives are a key factor in successful remediation programs. Chemical‐specific cleanup criteria are critical components of remedial action objectives. A common risk‐based approach can be applied for developing cleanup criteria for remediations under CERCLA, RCRA, and TSCA. This approach involves four steps: identify regulatory requirements; identify chemical‐specific cleanup guidelines from previous cleanups; evaluate site‐specific risk considering mitigating factors for a given site; select the final cleanup criteria based on information from the first three steps.

To describe this approach, this paper presents a case study on a PCB cleanup conducted under TSCA. An objective risk‐based approach was used to capitalize on the flexibility built into EPA's PCB cleanup guidelines. EPA granted an exemption to the stated policy on the basis of competing risk factors using a comparative risk‐assessment approach. Similarly, risk assessment can be used to take advantage of regulatory flexibility in the selection of applicable or appropriate and relevant requirements (ARARs) under CERCLA, or in the selection of media protection standards under RCRA.
Bioremediation of pesticide‐contaminated groundwater
Authors: Portier Ralph J. , Zoeller Anne L. , Fujisaki Kuniko
Published: February 2007

A biological treatment process employing immobilized microbial populations was field‐tested on contaminated groundwater containing elevated concentrations of volatile organics and organic pesticides. The process consisted of parallel biological reactors, one a continuously stirred biological reactor packed with pall rings (Conventional Biotower) and the other a packed bed reactor operated in a plug flow configuration (Manville Packed Bed Reactor). Gas chromato graphy/mass spectroscopy analyses for forty two groundwater contaminants in feed and treated streams indicate that both reactors were very effective in the reduction of organophosphates and organochlorines.
Developing site‐specific cleanup levels: Practical considerations
Authors: LaGoy Peter K. , Hopkins Loren
Published: February 2007

The development of site‐specific cleanup levels has become an important part of remedial actions at contaminated facilities. These levels must not only protect human and environmental health but must also be acceptable to regulators, local authorities, and nearby communities who may be responsible for overseeing the cleanup. Determining health‐based cleanup values based on a site‐specific risk assessment is a critical step in the process of developing cleanup criteria. In many cases, however, these health‐based values may be perceived as unacceptable by the regulators or by the local community. In some cases, factors such as past regulatory decisions, analysis of background levels, volumetric considerations, or a description of a chemical's environmental behavior can be used to influence the public perception of the cleanup criteria.
Remote monitoring and control of hazardous waste remediation activities
Authors: Shirk Barry L.
Published: February 2007

With increasingly stringent federal, state, and local regulations, reliable operation of environmental remediation systems is critical. Most environmental systems are required to operate continuously—night and day—and to be closely monitored for performance and reporting. For the owners of these systems, the cost associated with their long‐term operation and monitoring is a growing concern. This article describes a cost‐effective solution to control and monitor these systems, both locally and from remote locations. Two case studies are provided.
Successful solid‐phase bioremediation of petroleum‐contaminated soil
Authors: Cioffi John C. , Mahaffey William R. , Whitlock Tanni M.
Published: February 2007

Biological processes have been used to remediate petroleum hydrocarbons, pesticides, chlorinated solvents, and halogenated aromatic hydrocarbons. Biological treatment of contaminated soils may involve solid‐phase, slurry‐phase, or in situ treatment techniques. This article will review the general principle of solid‐phase bioremediation and discuss the application of this technique for the cleanup of total petroleum hydrocarbons on two sites.

These remedial programs will reduce total petroleum hydrocarbon contamination from the mean concentration of 2,660 ppm to under the 200‐ppm cleanup criteria for soil and under the 15‐ppm cleanup criteria for groundwater. Over 32,000 yards of soil have been treated by solid‐phase treatment to date. The in situ system operation is effectively producing biodegradation in the subsurface. The project is approximately one‐third complete.
Equipment choices for dredging contaminated sediments
Authors: Palermo Michael R.
Published: February 2007

This article describes the selection and field evaluation of dredging equipment and techniques for removal of highly contaminated sediments from the upper estuary of the Acusbnet River, a portion of the New Bedford Harbor Supetfund Project. Site conditions as related to dredge selection and operation, factors considered in selection of equipment, and various dredge types considered for use are described. Each of the dredge types is ranked according to the following criteria: availability, safety, potential for sediment resuspension, maneuverability, cleanup precision, cost and production, flexibility, required water depth for operation, ability to access the site, and compatibility with disposal options. A field pilot study comparing three dredge types indicated that dredging could be conducted at the site without a significant increase in the contaminant release from the upper estuary to the lower harbor.
Pneumatic fracturing to remove VOCS
Authors: Schuring John R. , Jurka Valdis , Chan Paul C.
Published: February 2007

A new process for enhancing in‐situ remediation of low‐permeability soil and rock formations is presently under development at the Hazardous Substance Management Research Center (HSMRC). The patented process, known as „pneumatic fracturing,”︁ consists of injecting high‐pressure air or other gas into contaminated geologic formations at controlled flow rates and pressures. In fine‐grained soils such as clay, pneumatic fracturing creates conductive channels in the formation, thereby increasing the permeability and exposed surface area of the contaminated soil. The potential benefits of pneumatic fracturing are significant, since in‐situ remedial technologies are essentially limited by the pore gas exchange rate of the soil being treated.

This article describes the results of a recent demonstration of pneumatic fracturing at an industrial site to enhance a volatile organic compound (VOC) extraction system. After establishing the baseline removal rate of soil gas effluent from the clay, soil surrounding the extraction system was fractured to enhance VOC with drawal. A substantial improvement in the VOC removal rate was observed, including: (1) flush effluent concentrations that increased up to 200 times; and (2) air flows in the formation that increased up to 1,000 times.
The active role of state laws in superfund cleanups
Authors: Kohn Elizabeth J.
Published: February 2007

The Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA or Superfund) did not ignore the fifty individual states when establishing responsibility, authority, and liability for cleaning up hazardous waste sites. Although CERCLA gives EPA the ultimate authority to select a remedy for a contaminated site, the law was drafted not only to allow for state activity without EPA, but also for significant state input when EPA is involved. The relationship between a state (and its environmental laws) and EPA can help decide the remedial and financial interests of any potentially responsible party (PRP). This article discusses the relevant CERCLA provisions, recent court decisions, and resolved and unresolved issues in federal‐state Superfund involvement, and recommends several common‐sense strategies for PRPs when working with a state in a Superfund cleanup.
Forum
Authors: Soundararajan Rengarajan
Published: February 2007

Most waste management techniques—including stabilization/solidification, soil washing, and precipitation/filter press—take more of a trial‐and‐error approach to environmental cleanups, failing to exploit the waste's fundamental chemical behavior. The result is scientifically inferior processes, wasted time and resources, and recurrence of the same old problems at treated sites. This column defines some of the principal problems of waste management technologies and recommends a prudent approach to their resolution. Several of the author's personal experiences are used to support his arguments. The technologies cited here were selected based on their widespread use, their cost‐effectiveness, their ease of application, and their intrinsic limitations.
Ten ways to control cleanup costs
Authors: Duvel William A.
Published: February 2007

The ten management guidelines discussed in this article can help site owners (and their remediation consultants) achieve environmental results that are acceptable to government regulators—at the lowest possible cost to all concerned. They remind site owners to learn everything possible about the nature and extent of their contamination problems, then maintain control of the cleanup process by defining obligations in consulting contracts and establishing positive working relationships with regulatory agencies.
Defining contamination limits with pneumatic hammer soil probes
Authors: Kerfoot William B.
Published: February 2007

There have been more than 100,000 confirmed releases of petroleum from underground storage tanks (USTs) in the United States and its territories. The 10,000‐gallon spill and cleanup of unleaded gasoline, detailed in this article, that occurred from 1988 to 1990 on Cape Cod, Massachusetts, illustrates the author's argument that electric pneumatic‐hammer soil probes are the fastest, most convenient, and least costly way of performing the soil‐gas surveys needed to locate spilled petroleum product, evaluate vapor intrusion into basements, and determine the extent of groundwater contamination for remediation purposes. Current state soil‐gas requirements are also included.
Contaminant dynamics: Key to remedial performance and regulatory relief
Authors: Gerath Mark , Galya Donald P.
Published: February 2007

Remediation results depend on thorough consideration of all the forces that influence contaminant behavior, including how the contaminant is distributed and the site's hydrogeology, as well as the physical, chemical, and biological factors involved in contaminant mobility and persistence. This information supports a cleanup project's initial investigation, helping decide the goals of the later remediation method, the usefulness of specific technologies, and the method's ultimate performance. This article discusses how the principal environmental and chemical processes influence contaminant fate and transport and explores four case histories that illustrate how that influence can help predict whether a project's goals are achievable, whether the project is needed at all, and whether those goals were actually achieved.
Evaluating regulatory issues and emission control equipment for air toxics applications
Authors: McCullough Matthew L. , Dagdigian Jeffrey V.
Published: February 2007

This article describes regulatory issues and emission control equipment for air toxics applications. A brief history of air quality legislation is provided, illustrating the difficulty government has had in implementing air quality statutes; this has contributed to the complexity of air quality regulations. Evaluation methodologies are described for three different emission control technologies: thermal oxidation, catalytic oxidation, and adsorption. Brief case histories are provided that describe the pitfalls and benefits associated with each technology. The benefits of integrating health risk assessment into an air quality program are also discussed.
Soil washing: Practical considerations and pitfalls
Authors: Dove Dennis , Bhandari Alok , Novak John
Published: February 2007

The use of soil washing to remove petroleum hydrocarbon contamination from the soil matrix is becoming more widely used. When viewed as a volume reduction tool, this technology shows some promise. However, ongoing research and treatability studies indicate that without further treatment, even larger‐sized soil fractions (sands and cobbles) may retain hydrocarbon contamination at levels that require further cleaning prior to permanent disposal or reuse. The perception has been that by removing the sand from the soil matrix, thus achieving a 30 percent to 60 percent volume reduction, expensive post‐washing treatment or approved disposal of the finer materials (silts and clays) would be cost‐effective. There exists evidence to the contrary, however. Hydrocarbon retention after soil washing may be influenced by a number of factors unrelated to particle size. Soil characteristics that may play a role include soil humic acids, metal oxide coatings, geologic origin of the soil particles, and clay type. In this article the authors describe a laboratory study designed to evaluate the “cleanability” of two soils.
Applied geologic, microbiological, and engineering constraints of in‐situ BTEX bioremediation
Authors: Kennedy Lonnie G. , Hutchins Stephen R.
Published: February 2007

An in‐situ bioremediation project has been designed and constructed for a site in south‐central Kansas just north of Wichita. A pipeline leaked an unknown quantity of refinedfuels in the 1970s. The spill was undetected until hydrocarbons were found in a nearby municipal water supply well. Of concern, from a regulatory perspective, are the alkylbenzene components found in the groundwater, including benzene, toluene, ethylbenzene, and xylene (BTEX). Initial abatement procedures, including free product removal and pumping, had become ineffective. In‐situ bioremediation was selected to complete the restoration process.

The project emphasizes the need for a strong understanding of the geologic and hydrogeologic conditions prevalent under the site. Site studies were conducted to determine the distribution and mass of the contaminant and the hydraulic regime. Laboratory microbial studies were used to determine the efficacy of nitrate as a primary electron acceptor. Information from site studies was used to design a treatment system tailored to the requirements of the site. The treatment system is designed to deliver the maximum amount of nutrient‐enriched water to the contaminated zone while maintaining hydraulic control of the site.
Superfund: Past experiences and new directions
Authors: English Mary R.
Published: February 2007

Ten case studies of Superfund sites were done by the University of Tennessee's Waste Management Research and Education Institute. The case studies, which focused on stakeholder perspectives of site processes, revealed a number of problems with the Superfund process. They also revealed that some improvements had begun to take place. Recently, several modifications have been instituted in the Superfund program. Although it is too early to determine their efficacy, it appears that the Superfund program is beaded in the right direction.
Environmental assessment and remediation: Estimating the costs of uncertainty
Authors: Morse Michael A.
Published: February 2007

Current cost estimates for the assessment and remediation of environmental contamination at facilities operated by the U.S. Department of Energy (DOE) are based largely on assumptions, with a resulting high level of uncertainty. Therefore, consistent and reliable methods for estimating the uncertainty inherent in the estimates are of vital importance. This article presents an approach and format for estimating contingency in DOE's Environmental Restoration Program. The method involves an analysis of risk factors having a potential to affect the cost of the major elements in the estimate. Application of the contingency analysis to a project site is included in the discussion.
RCRA corrective action costs: An estimating model for nonfederal facilities
Authors: Tonn Bruce , Russell Milton , Warren John
Published: February 2007

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.
Critical considerations for project sites containing unexploded ordnance
Authors: Pastorick James P.
Published: February 2007

To date, most of the development of unexploded ordnance (UXO)‐related requirements and procedures have been accomplished by the U.S. Army Corps of Engineers and the U.S. Army Toxic and Hazardous Materials Agency. The U.S. Navy and U.S. Air Force also have a significant requirement for environmentally related UXO expertise. This article traces the evolution of the UXO field, as developed by small businesses and the various branches of the U.S. Army, and describes the implications of conducting an environmental investigation or remediation in an area contaminated, or suspected to be contaminated, with UXO. Lastly, the basic procedures and the tools and equipment used to accomplish UXO decontamination are described to inform field managers of the impact that UXO hazards can have on their overall project.
Evaluation of remedial options for treatment of heavy metal and petroleum hydrocarbon contaminated soil
Authors: McCullough Matthew L. , Dagdigian Jeffrey V.
Published: February 2007

This article describes remedial options for the treatment of heavy metal and petroleum hydrocarbon contaminated soil. Treatment of these soils with traditional methods often requires a combination of techniques, resulting in treatment costs that are unacceptable in today's financial climate. A detailed review of relevant remedial technologies is presented, as well as treatability studies for hybrid immobilization, petroleum hydrocarbon reduction, extraction, and soil washing technologies. Our studies and review demonstrate that hybrid immobilization may be suitable for sites where only soluble chemical levels exceed federal or state guidelines; soil washing may provide a viable alternative for sites with appropriate soil characteristics; petroleum hydrocarbon bioremediation can potentially reduce soluble lead levels; and extraction processes, though promising, still require some development. Descriptions of the chemical and physical properties of heavy metals and petroleum hydrocarbons in soil and residual levels of these chemicals in soil following treatment are also given.
Soil washing for volume reduction of radioactively contaminated soils
Authors: Eagle Michael C. , Richardson William S. , Hay Scott S. , Cox Clinton
Published: February 2007

The Office of Radiation and Indoor Air of the U.S. Environmental Protection Agency has demonstrated a soil washing plant for the treatment of radioactively contaminated soils from two Superfund sites in New Jersey. The plant employs unit operations that are widely used in the processing of minerals and coal. These operations were examined and tested to determine how they would apply to volume reduction of these contaminated soils. In this context, they are considered to be innovative candidates for remediation of other sites with large volumes of soil contaminated with low‐level radioactivity. Laboratory testing of soil characteristics and behavior in unit processes is used to assess the applicability of volume reduction/chemical extraction (VORCE) technology to specific sites.
Keys to success as an environmental consultant: Liability control, client satisfaction, and growth
Authors: Smith Diane R.
Published: February 2007

Environmental consulting is a relatively new and rapidly growing field. It involves traditional engineering and construction risks as well as the specter of potential—and likely uninsured or uninsurable—liability for environmental conditions and professional errors. To succeed in today's litigious society, environmental consultants and contractors need to understand the risks inherent in their work. They must conduct their operations in a manner conducive to quality assurance, risk control, and effective project management. Constant and clear communication with the client is essential to a good working relationship and repeat business. Effective project control, risk management, file documentation, and contract negotiation are critical tools for profitable growth and our professional liability defense.
Groundwater treatment and aquatic toxicity reduction at a chemical production site
Authors: Usinowicz Paul J. , Rozich Alan F. , Clay Stephanie G. , Colvin Richard J.
Published: February 2007

Contaminated groundwater at a chemical antioxidant and phenolic resin chemical production site was subjected to treatability studies to develop design criteria for surface water discharge. Raw groundwater required pretreatment for total suspended solids (TSS) and color removal prior to treatment by ultraviolet light/hydrogen peroxide (UV/H2O2). Because of high capital and operating costs for UV/H2O2, biological treatment was evaluated as an alternate. Respirometric analyses showed that completely mixed activated sludge could be applied as a treatment technology to the groundwater. Biotreatment resulted in an approximately 70 percent reduction in soluble chemical oxygen demand (SCOD). Residual SCOD was recalcitrant to further biodegradation. The treated effluent was tested for aquatic toxicity using fathead minnows (Pimephales promelas) and Ceriodaphnia dubia and was found to be toxic. Toxicity reduction of biotreatment effluent was evaluated in bench‐scale experiments using activated carbon adsorption, filtration, and UV/H2O2. Subsequent toxicity testing showed that filtration alone could reduce the bioeffluent toxicity and that residual SCOD was not the primary source of toxicity.
Risk communication as a key component of a successful remediation project
Authors: Lichten Steven M.
Published: February 2007

Decisions made during the course of investigating and remediating a contaminated site, as well as the technology used, are most often driven exclusively by physical, technical, and health‐based concerns. Additionally, in both determining and managing the potential risks posed by a remediation project, the focus tends to be placed primarily on health risks. However, a contaminated site and its remediation are neither static over time nor do they exist in a vacuum. Other elements of risk associated with the site and remedial activities include continuing regulatory oversight and compliance, public and agency relations, remedial technology costs, current and future land‐use issues, and future technological/regulatory risks. Agencies, consultants, contractors, and facility management must consider these other non‐health‐related elements of risk. Additionally, efforts made to communicate a project's decisions, technologies, and risks are often made in a defensive or reactive posture, resulting in ineffective communication and an alienated, angry, or distrustful public. Proactive risk communication, as well as public involvement in the remedial process, are critical to the success of any remedial activity.
Alternative method of groundwater sparging for petroleum hydrocarbon remediation
Authors: Schrauf Todd W. , Sheehan Patrick J. , Pennington Leslie H.
Published: February 2007

An alternative method of in‐situ groundwater sparging, termed density‐driven convection (patent pending), is presented. This method has been successfully used to remediate eight underground storage tank releases involving a wide distillation range of petroleum hydrocarbons (gasoline to waste oil) and in a variety of site soils (clay to sandy gravel).

Application of the density‐driven convection method is detailed in a case study. The system, installed to remediate a gasoline and diesel release from an underground storage tank, was operated and monitored for a period of one year. Monitoring data indicate reductions in total petroleum hydrocarbon concentrations in groundwater and in soil. Concentrations of aromatic hydrocarbons (benzene, toluene, ethylbenzene, xylenes, and naphthalene) also decreased in both media. Stimulation of natural biodegradation, the primary mechanism of removal, occurred rapidly. Natural biological activity gradually declined over the subsequent 150 days. After one year of operation, the sparging system has achieved or is rapidly approaching the regulatory cleanup goals for both soil and groundwater, including reduction of dissolved concentrations below maximum contaminant levels established under the Safe Drinking Water Act.
Technical and economic analyses in the development of bioremediation processes
Authors: Ammann Paul R. , Koch Gayle S.
Published: February 2007

The very large extent of subsurface and groundwater contamination with toxic organic compounds has prompted research on a number of bioremedial processes. The justification of this research has been to achieve lower overall remedial costs than are incurred by currently existing technologies. Laboratory studies are often undertaken with the notion that a new set of process conditions can reduce reagent consumption or the time for treatment by a significant factor with an attendant reduction in overall remediation costs. Research programs are initiated on the basis of these simple premises. Our work has shown that many research projects have been undertaken for the wrong reasons and that experimental effort has often not been directed toward large‐scale implementation.

A preliminary process analysis has been shown to be a very valuable component of any research and development program on bioremedial and other innovative technologies. As described in this article, the analysis (1) identifies the critical engineering and cost parameters and (2) provides guidance to the research program in the design of experiments and the collection of data. The methodology is also useful in the review of proposed new technologies and treatment equipment. The article includes an example of a process analysis for an actual development project directed toward the remediation of solids contaminated with chlorinated hydrocarbons to illustrate the benefits and the power of the technique.
Impact: A Model for calculation of soil cleanup levels
Authors: Korfiatis George P. , Talimcioglu Nazmi M.
Published: February 2007

The establishment of soil cleanup levels is a primary concern in site remediation projects. Soil cleanup levels provide targets that drive the remediation process from technology selection through closure. Several state regulatory agencies are currently in the process of developing scientifically based soil cleanup standards. The underlying premise in the derivation of such standards is to ensure that the site will not pose a threat to human health and the environment after remediation has been completed. To accomplish this, remediation project managers must consider several contaminant transport pathways. This article presents the salient features of a model named IMPACT, which was developed to assist in the derivation of soil cleanup levels. IMPACT considers the soil‐to‐groundwater pathway and predicts the cleanup levels in a contaminated soil layer in the vadose zone such that groundwater quality standards are met at any point in the aquifer.
Thermal desorption of PCB‐contaminated waste at the waukegan harbor superfund site
Authors: Hutton Joseph H. , Shanks Robert
Published: February 2007

In June 1992, SoilTech ATP Systems, Inc., completed the soil treatment phase of the Waukegan Harbor Superfund Project in Waukegan, Illinois, after approximately five months of operation. SoilTech successfully treated 12,700 tons of sediment contaminated with polychlorinated hiphenyls (PCBs) using a transportable SoilTech anaerobic thermal processor (ATP) system nominally rated at ten tons per hour throughput capacity. The SoilTech ATP technology anaerobically desorbs contaminants such as PCBs from solids and sludges at temperatures over 1,000° F. Principal products of the process are clean, treated solids and an oil condensate containing the hydrocarbon contaminants.

At the Waukegan Harbor Superfund site, PCB concentrations in the sediments excavated and dredged from a ditch, lagoon, and harbor slip averaged 10,400 parts per million (ppm) (1.04 percent) and were as high as 23,000 ppm (2.3 percent). Treated soil was backfilled in an on‐site containment cell. The removal efficiency of PCBs from the soil averaged 99.98 percent, relative to the project performance specification of 97 percent, and treated soil PCB concentrations were measured below 2 ppm. Approximately 30,000 gallons of PCB oil, desorbed from the feed material, were returned to the owner for subsequent off‐site disposal. After modifications to the emissions control equipment, compliance with the 99.9999 percent destruction and removal efficiency (DRE) for PCBs in stack emissions required by the U.S. Environmental Protection Agency was achieved.
On‐site remediation of PCB contamination using transportable incineration systems
Authors: Johnson Nancy
Published: February 2007

Many Superfund or hazardous waste sites prove to be excellent candidates for remediation using transportable incineration. Transportable incineration has been selected as the alternative of choice to remediate numerous sites throughout the United States. There are a number of firms that provide mobile and transportable incineration equipment and services. A variety of treatment systems are available, including rotary kilns, fluidized beds, and infrared incinerators.

Roy F. Weston, Inc., has been instrumental in the development, design, permitting, construction, performance testing, and operation of hazardous and toxic waste thermal treatment systems. Weston owns and operates two high‐temperature transportable incineration systems (TISs). The first system is Weston's seven‐ton‐per‐hour (tph) TIS‐5. The second is the TIS‐20, with a design capacity of up to 30 tph. These units are typical rotary kiln incinerators, the most flexible, adaptable type of incineration unit. This article discusses Weston's use of these incinerators to remediate soils at sites contaminated with polychlorinated biphenyls (PCBs).
Improved methodology for designing and operating biological treatment systems
Authors: Rozich Alan F.
Published: February 2007

Biological systems are frequently used for wastewater treatment and hazardous materials remediation. The primary problem cited with these systems is the lack of a structured methodology that can be used to predict the performance for design and operational applications. The purpose of this article is to present the background and examples of a novel methodology for analyzing biological treatment processes. This technique is much more cost‐effective and accurate than conventional approaches. The article will address applications for both biological wastewater treatment systems and bioremediation processes.
The challenge of remediation technology development
Authors: Maxwell R. Steven
Published: February 2007

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.
Bioremediation using a commercial slurry‐phase biological treatment system: Site‐specific applications and costs
Authors: Woodhull Patrick M. , Jerger Douglas E.
Published: February 2007

Slurry‐phase bioremediation is an engineered process for treating contaminated soils or sludges. Slurry‐phase biological treatment can be applied to a variety of contaminated wastes amenable to microbial degradation, including manufactured gas plant wastes, wood‐treating wastes, refinery wastes, petroleum hydrocarbons, and select chlorinated compounds, including PCBs. This article describes the process by which a commercial slurry‐phase treatment system was used to bioremediate contaminants at two sites–a wood treatment facility and a manufactured gas plant. A process description of the system and an analysis of project costs are provided.

Bioremediation offers two advantages over other remediation alternatives: on‐site destruction of the contaminant(s) and lower total remedial costs. Slurry‐phase biological treatment offers several advantages over conventional bioremediation technologies (i.e., land treatment). Slurry‐phase biological treatment can achieve increased degradation rates, higher treatment efficiencies, greater control of environmental and operating conditions, and smaller treatment area requirements. Slurry‐phase biological treatment costs range from approximately $200 to $230 per cubic yard, which is comparable to other on‐site remediation technologies.
Risk assessment and accepted regulatory cleanup levels
Authors: Chrostowski Paul
Published: February 2007

The determination of cleanup levels at a CERCLA or RCRA site is often the single most important decision made by risk managers. This decision can have a major impact on the costs and time required for remediation, as well as on the selection of remedial technologies. The object of this article is to provide a critical review of the methods used by regulatory agencies and the regulated community to calculate chemical‐specific cleanup goals for inactive hazardous waste sites, focusing on those cleanup goals that are designed to protect human health from the effects of chemicals. In addition to this analysis of historical methods that have been used, this article discusses some innovative solutions to the problem of calculating cleanup levels and presents an analysis of controversial topics related to cleanup levels currently under debate by regulatory agencies, industry, environmentalists, and legislative bodies.
On‐site analytical support: A cost‐effective alternative to fixed laboratory services
Authors: Goldschmidt William , Gallis David , Catherman David
Published: February 2007

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.