U.S. EPA, Office of Enforcement and Compliance Assurance, Office of Solid Waste and Emergency Response, Office of Site Remediation Enforcement, and Office of Superfund Remediation and Technology Innovation.
Fact Sheet No: EPA 330-F-08-001, 12 pp, May 2008

The purpose of this document is to provide answers to some of the questions that a prospective purchaser might have when considering whether to purchase property at a privately owned Superfund site. U.S. EPA supports the reuse of Superfund sites and has developed this document to clarify some of the opportunities and issues associated with their reuse. For purposes of this document, a Superfund site is defined as any property on EPA's National Priorities List where a hazardous substance has been released into the environment or has come to be located on or beneath it. Thus, even if a property is not the source of the release of the contamination, it can be part of a Superfund site. The 2002 Superfund liability protections are designed to be self-implementing, meaning that a prospective purchaser does not need to obtain approval from EPA prior to purchasing a Superfund site where an EPA cleanup or enforcement action is ongoing or has been completed; however, EPA strongly recommends that prospective purchasers contact the appropriate EPA Regional office prior to purchasing a Superfund site or a property within a site to discuss the cleanup status of the site and other site-related issues. This document does not address the unique considerations associated with the purchase and transfer of real property on federally owned Superfund sites (also known as federal facilities). This document is provided solely as general information to highlight certain aspects of a more comprehensive program; it does not provide legal advice. Fact sheet at http://www.epa.gov/compliance/resources/publications/cleanup/superfund/t
op-10-ques.pdf

U.S. Department of Housing and Urban Development (HUD), Funding Opportunity FR-5200-N-06, 6 May 2008

The purpose of the Lead-Based Paint Hazard Control Grant Program is to assist states, Native American Tribes, cities, counties/parishes, or other units of local government in undertaking comprehensive programs to identify and control lead-based paint hazards in eligible privately owned rental or owner-occupied housing. The purpose of the Lead Hazard Reduction Demonstration Grant Program is the same as the Lead-Based Paint Hazard Control; however, the Lead Hazard Reduction Demonstration Grant Program is targeted for urban jurisdictions with the greatest lead-based paint hazard control needs. The purpose of the Operation Lead Elimination Action Program (LEAP) is to leverage private sector resources to eliminate lead poisoning as a major public health threat to children under age six living in eligible privately owned housing units. Approximately $132 million (Lead-Based Paint Hazard Control Grant Program, Lead Hazard Reduction Demonstration Grant Program, and Operation LEAP) is available from current and previous years' funding. Matching funds are required for the Lead-Based Paint Hazard Control Grant Program and Lead Hazard Reduction Demonstration Grant Program. For the Lead Hazard Reduction Demonstration Grant Program, HUD may grant a waiver of the 25% match requirement if the applicant submits a request that meets HUD's criteria. The application deadline date for the Lead-Based Paint Hazard Control Grant Program and Operation LEAP is July 10, 2008. The application deadline date for the Lead Hazard Reduction Demonstration Grant Program is July 17, 2008. Additional information on contacts and eligibility available at http://www07.grants.gov/search/search.do?oppId=41597&flag2006=false&mode
=VIEW
The complete grant information package can be requested at https://apply07.grants.gov/apply/forms_apps_idx.html

National Science Foundation, NSF Program PD 05-1636, 17 Mar 2008

The research portfolio for NSF's Geoenvironmental Engineering and GeoHazards Mitigation program element contains projects on geoenvironmental engineering, including physical, chemical, thermal, and biological processes that affect the properties of geologic materials; contaminant transport and hydraulic properties of geologic materials involved in surface and subsurface flow; and construction for remediation and containment of geoenvironmental contamination. Examples of the types of proposals accepted under this program that are applicable to the remediation of hazardous waste sites include "Remediation of Contaminated Subsurface Using Nanoscale Iron Particles" and "A Study of Predominant Flow Mechanisms and Parameters Controlling Contaminant Migration in Fractured Heterogeneous Rocks." The windows of opportunity for submitting full proposals for this program are 1 September 2008 - 1 October 2008 and 15 January 2009 - 15 February 2009. More information at http://www.nsf.gov/funding/pgm_summ.jsp?pims_id=13351

National Advisory Council for Environmental Policy and Technology (NACEPT), Environmental Technology Subcommittee.
Report No: EPA 130-R-07-004, 72 pp, May 2007

The NACEPT Subcommittee has reviewed EPA's technology programs in the context of the unique role that EPA plays in the broad spectrum of public and private activities that must occur to bring increasingly cost-effective technologies into use. In this report, the Subcommittee focuses analyses and recommendations on four major areas: (1) management issues that affect the Agency's ability to coordinate its programs and interface with the diverse governmental and private-sector organizations that constitute the environmental marketplace; (2) the critical area of the Agency's ability to build, join, coordinate, sustain, and leverage partnerships with key government and private-sector organizations; (3) the complex issues of EPA's role in impacting market demand forces to empower technology deployment both within the United States and abroad; and (4) the looming technological challenges associated with mitigation of and adaptation to climate change. Report at http://www.epa.gov/etop/nacept/NACEPTEnvironmentalTechnologySubcommittee
SecondReport-5-6-07.pdf

Hanley, Rachael.
Watertown Daily Times, 12 May 2008

Decades of spills and leaks along Fort Drum's Gasoline Alley eventually accumulated in a 162,000-gallon plume of petroleum hydrocarbons in the ground water, which was discovered in 1988. The fuel tanks were removed in 1994. The plume spread away from its initial source, and by the time it was discovered, petroleum-laced water was flowing through a 50-acre old sanitary landfill and had begun leaching into a small creek that ran along the landfill edges. Today, the leading edge of the plume can be found where the creek runs along a wooded ravine. In 2001, willow trees were planted along the creek in a phytoremediation project to address the contaminated ground water as a joint project among participants from Fort Drum, SUNY College of Environmental Science and Forestry, Army Corps of Engineers, Army Environmental Command, New York Department of Environmental Conservation, and Malcolm Pirnie, Inc. The trees naturally filter and disperse the contamination in a relatively cost-effective and environmentally friendly way. The phytoremediation effort initially consisted of a quarter-acre pilot project. Over the next six years, Christopher A. Nowak, a SUNY associate professor and undergraduate education coordinator, and 30 of his students conducted tests at a pilot site at Fort Drum. They planted 30 different varieties of willows, mixing hybrids and true species; eventually, 11 varieties were chosen for planting at a larger scale. They also tested planting methods, such as hills of soil, cardboard cylinders, and direct planting. Wooden boxes, inside which the young trees could be planted, were found to work best. In 2007, the project was expanded to include 22,000 willows planted across another two-acre site. After one year of growth, the willows planted at the full-scale project appear to be thriving. A 90% survival rate is anticipated. Willows consume up to three or four gallons per plant per day. With 22,000 willows planted at Fort Drum, more than 50,000 gallons of water can filter through the system daily. Once the system is established, the only intervention the trees need is occasional weeding and fertilizing. Every time a tree is chopped down, several more grow from the roots. In 2003, after years of studying the source, location, and size of the plume, Fort Drum spent about $6 million on more than 170 wells and treatment systems to stop additional contamination from entering the landfill. Cleanup completion is anticipated by 2024. Full story at http://www.watertowndailytimes.com/article/20080512/NEWS03/314970450

Landmeyer, J.E. (USGS); A.R. Contrael (MTR); T.N. Effinger (SCE&G). Fourth International Phytotechnologies Conference, 24-26 September 2007, Denver, Colorado: Abstracts, p 39, 2007

Changes in ground-water levels and contaminant geochemistry were observed in a shallow aquifer contaminated with coal-tar near Charleston, South Carolina, before and after the installation of a hybrid poplar tree grove. The grove was planted in the fall of 1998 as part of site remediation activities and consisted of about 600 6-ft rooted hybrid poplar cuttings. Monitoring of ground water, tree tissue samples, and sap flow was performed to evaluate performance. Ground-water levels decreased about 3.5 ft across the planted and unplanted areas of the site between 1998 and late 2000 due to regional drought conditions in the Southeast. After 2001, decreases in ground-water levels in the planted area were about 1 ft deeper than measured in unplanted areas. Estimates of water flow through the 7-year old trees using sap-flow instruments indicate that the poplar trees are transpiring nearly 5 gallons of water per day per tree. Long-term monitoring activities show that the hybrid poplars also have decreased ground-water contaminant concentrations in planted areas to a larger extent than observed in unplanted areas. The magnitude of the observed decrease in ground-water contaminant concentrations in the planted area is dependent upon the presence or absence of pockets of coal-tar as a dense nonaqueous-phase liquid (DNAPL) beneath the trees. In the planted areas not characterized by DNAPL, milligram per liter concentrations of benzene, toluene, and naphthalene in monitoring wells have decreased since 2000 by an average of 85, 83, and 82%, respectively. These areas exhibited a seasonal variation in dissolved-phase contaminant concentrations, with the lowest concentrations observed during spring and summer, when transpiration rates and ground-water uptake by the hybrid poplar trees were measured to be at maximum. Benzene, toluene, and naphthalene, as well as other coal-tar related polycyclic aromatic hydrocarbons, such as styrene, were detected in various tree tissues sampled during the summers, when the concentrations in ground water were lowest. In areas where DNAPL existed beneath the trees, concentrations of benzene, toluene, and naphthalene have decreased only an average of 32, 55, and 49%, respectively. A long-term trend is noted in decreasing dissolved-phase contaminant concentrations in ground water beneath the trees in areas with no DNAPL present.

Green, R. (Pilbara Iron, Perth, WA, Australia); T.D. Waite and M.D. Melville (Univ. of New South Wales, Sydney, NSW, Australia).
Water, Air, and Soil Pollution, Vol 178 Nos 1-4, p 59-68, 2007

For active treatment of a creek's acid sulfate soil catchment, alkaline reagents ranging from 438 to 1,837 mg/L calcium carbonate were added to oxidized shallow drains to remove acidities. A fine limestone slurry was produced by processing limestone rock fragments within a rotating drum. Upon addition to drain waters, the limestone slurry removed acidity with an effectiveness ranging from 12 to 100%. The efficiency decreased as the pH of the water approached neutrality due to calcite saturation and the slow reaction rate of limestone at high pH. Hydrated lime powder also was mixed with drain water in the rotating drum. Most of the mixing occurred once the slurry entered the drain, where efficiencies ranging from 67 to 89%. A powdered mixture of magnesium carbonate and calcium carbonate was only 11% effective in treatment of the drainage water due to magnesium carbonate's slow rate of reaction. The active treatment system was capable of treating a large acidity flux, particularly when using hydrated lime, but regular addition of reagent was required, and the dosing of hydrated lime was particularly difficult to control. Automated dispensing of the alkaline reagents is planned for this active treatment system to prevent adverse aquatic impacts due to overdosing.

Stathyelich, J.L., W.B. Lozier, and J.H. Jacobs.
Fourth International Phytotechnologies Conference, 24-26 September 2007, Denver, Colorado: Abstracts, p 66, 2007

The Greiner's Lagoon site in Sandusky County, Ohio was originally developed with lagoons for storing waste oil from local industry. From 1981 to 1988, U.S. EPA and Ohio EPA conducted a variety of removal actions at the site, including lagoon dike reinforcement, surface oil removal, liquid treatment and discharge, sludge solidification, lagoon backfilling, and placement of soil cover over the filled lagoons. In 1991, U.S. EPA issued an Administrative Order on Consent to perform a non time-critical removal action at the site. U.S. EPA initially selected soil chemical stabilization and a clay cap with geomembrane layer as the site remedy; however, based on the results of a health risk study performed by the Agency for Toxic Substances and Disease Registry, as well as a phytoremediation feasibility study performed by Environmental Resources Management, EPA later concluded that installation of a vegetative cap would mitigate hazards to human receptors sufficiently and provide hydraulic control and treatment. Construction activities for installation of the phytoremediation system were conducted in 2005 and included regrading of sandy backfill, mixing with clean fill from off site, and placement of topsoil. The site was seeded with tall fescue to establish the vegetative cap and minimize stormwater migration through the stabilized lagoons. The fescue exhibited vigorous growth in most locations during 2006. Poplars and willows were planted along the site perimeter to minimize migration of contaminated shallow ground water. Trees in some areas have required interplanting or replacement due to apparent phytotoxicity. Willow replants have performed particularly well. Survival and growth patterns have been improved through the application of sulfur to alkaline soil in an area formerly occupied by a limestone road, as well as regrading to reduce ponding around trees near a swale. Ground-water samples collected in November 2006 showed a reduction in volatile organic compounds compared to previous sampling in 1996 and 1998, except for acetone and 4-methyl-2-pentanone at one of 11 monitoring wells. The ground-water flow direction at the site is in the direction of the most vigorous tree growth. Results to date indicate that a vegetative cap is a viable alternative to the chemical stabilization and clay cap originally selected as the site remedy, at an estimated savings of $1.2 million. Annual ground-water sampling is expected to demonstrate continued reduction in detected levels in ground water, and water-level measurements are expected to demonstrate improved hydraulic control across the site as the plantings reach maximum rooting depth.

Indiana Department of Environmental Management (IDEM), Indianapolis, IN.
U.S. EPA Region 5, 41 pp, Sep 2007

The Continental Steel Superfund site was operated from 1914 to 1986 for the production of nails, wire, and wire fence from scrap metal. The site is located in a mixed residential, commercial, and industrial area and is zoned mainly for general use. The 183-acre site is divided into six operable units: the abandoned steel manufacturing facility (Main Plant), pickling liquor treatment lagoons, a former waste disposal area (Markland Avenue Quarry), a former waste disposal and slag processing area, on-site creeks, and ground water. The site was placed on the National Priorities List in 1989. A record of decision, which outlined the final remedy for the entire site, was signed in 1998 and subsequently amended in 2003 to address new information gathered from predesign investigations. This second five year review for the site was completed on September 4, 2007. Volatile organic compounds (VOCs), polychlorinated biphenyls, polycyclic aromatic hydrocarbons, and metals were found in the site ground water, soil, sludges, and sediments. Several demolitions and response and removal actions were completed between 1989 and 2000, and design plans were finalized in 2002, 2004, and 2006. Construction of the Main Plant remedy was initiated by IDEM in 2000 and is currently ongoing. When the remedy is completed, solid media will be treated in situ using heated soil vapor extraction (HSVE). HSVE in the VOC-contaminated area of the Main Plant is expected to be more effective and simpler to implement than excavation. Site studies have included assessment of the potential for VOC vapors in the Markland Quarry Area to migrate from the ground water to indoor air in nearby residences. U.S. EPA collected sediment samples in the Markland Quarry Area to determine the feasibility of using zero-valent iron to treat the sediment in situ instead of excavating it. Although the sediment did exhibit the desired reactions in the laboratory, no practical way of applying the technology could be developed for this situation that would reliably capture and treat VOCs (e.g., trichloroethene) in the quarry sediment and prevent migration to surrounding ground water. EPA and IDEM have determined that excavation of the VOC-contaminated sediment remains the most effective approach. Report at http://www.epa.gov/superfund/sites/fiveyear/f2007050001940.pdf

Federal Remediation Technologies Roundtable Cost and Performance Database, 2007

Dry Clean USA No. 11502 is a former dry cleaning facility that operated from 1988 to 1998. The site is located in a shopping center in a mixed retail commercial/ residential setting. Early site investigations conducted in 1993 and 1994 indicated chlorinated solvents, particularly tetrachloroethene (PCE), to be the main contaminants at the site. PCE was detected at a maximum concentration of 27,300 µg/L in ground water, indicating the possible presence of dense nonaqueous-phase liquid. The area of the plume was estimated to be 70,000 ft². Site investigations conducted in 1997 accurately defined the source area at the facility and assessed the horizontal and vertical extent of chlorinated solvents in the subsurface. These investigations indicated that an area of elevated concentrations of chlorinated solvents existed in the soil and ground water, extending approximately 300 ft east-southeast of the Dry Clean USA facility. After a successful pilot test in April 1998, soil vapor extraction (SVE) was chosen to remediate the contaminated site soil. Pump and treat (P&T) using an aboveground air stripper was selected to contain the contaminant plume and remediate the ground water. The SVE system operated from April 1999 to December 2000, and the P&T system operated until November 2002. Monitored natural attenuation was the remedy at the site after deactivation of the P&T system. In July 2004, increased concentrations of PCE were detected in samples from one source area well. In situ chemical oxidation with hydrogen peroxide was used to address PCE in the vicinity of the well to expedite remediation of this hot spot. Case study at http://costperformance.org/profile.cfm?ID=405&CaseID=405

Chadwick, B. and A. Hawkins.
SPAWAR Systems Center, San Diego. Technical Report 1966, 75 pp, 2008

The overall objective of this project was to demonstrate and evaluate the field effectiveness of two technologies for characterizing coastal contaminant migration. The specific objectives of the demonstration were to achieve the following: (1) demonstrate that the Trident probe can be used to help delineate areas where ground-water seepage is occurring and contaminants of concern concentrations in those areas; (2) demonstrate that the UltraSeep system can be used to quantify the flow of ground water and concentration of contaminants that may impinge on the surface water system; (3) demonstrate the technology to end users to determine the utility of these tools for making decisions at DoD coastal landfills and hazardous waste sites; and (4) quantify costs associated with the operation of each technology. At the NSA Panama City site, the Trident probe was used successfully to identify areas of ground-water discharge from the site to the surface waters of St. Andrews Bay. Thirty offshore stations were sampled with the probe sensors and water sampler, and the results were validated with shallow piezometers. The UltraSeep was used successfully at the NSA Panama City site to quantify ground-water discharge rates and VOC discharge concentrations in two discharge zones identified with the Trident probe. Although ground-water discharge was detected, all target VOC analytes (including DCE) in all UltraSeep samples were below the practical quantitation limit. Results from three shallow piezometers installed adjacent to each UltraSeep station validated the results obtained from the UltraSeep. The utility of the Trident probe and UltraSeep in assessing coastal contaminant migration was demonstrated successfully at the NSA Panama City. No DCE discharge into St. Andrews Bay at levels above the surface water cleanup target level (3.2 µg/L) was detected. The results from the study support the selection of monitored natural attenuation as a corrective action alternative for the site. A second demonstration was performed at the former NTC Orlando in Florida. Report at http://www.spawar.navy.mil/sti/publications/pubs/tr/1966/tr1966cond.pdf

Wang, L., A.S.C. Chen, and G.M. Lewis, Battelle, Columbus, OH.
Report No: EPA 600-R-08-026, 62 pp, Apr 2008

A hybrid ion exchange (HIX) system designed by VEETech for the Upper Bodfish site consisted of two trailer-mounted, single-stage, fiberglass-reinforced plastic vessels, each capable of treating up to 50 gal/min (gpm) of flow. The vessels were 42 inches in diameter and 60 inches in height, each containing 27 cubic ft of ArsenXnp, a hybrid anion exchange resin impregnated with hydrous iron oxide nanoparticles manufactured by Purolite. During normal operation, one vessel was put into service while the other was on standby. During the study period from October 13, 2005, through August 3, 2006, the HIX system operated for a total of 4,631 hrs, treating approximately 6,693,700 gal of water from the Upper Bodfish Well CH2-A. During the first 10 months of system operation, total arsenic concentrations in the treated water were reduced to <0.1 µg/L initially and gradually increased to 10.5 µg/L after 33,100 bed volumes (BV) of throughput. This run length was 65% higher than the vendor-provided estimate of 20,000 BV. Uranium was completely removed to below the detection limit of 0.1 µg/L throughout the 10-month study period. The better-than-expected performance of the full-scale system might have resulted from the lower flowrates and longer empty bed contact times experienced by the system.
      If a water system generates uranium-containing residuals in which the uranium exceeds 0.05% (by weight), the uranium can be considered "source material" and may be subject to the Nuclear Regulatory Commission's licensing requirements. If so, the spent media cannot be regenerated at the Mobile Processing Technology (MPT) facility in Memphis, Tennessee, as planned because MPT is not licensed to process non-exempt material. Three options were proposed by the vendor for spent media disposition: (1) partial on-site regeneration to reduce the uranium loading to below 0.05%, followed by offsite regeneration to remove additional arsenic and uranium; (2) complete on-site regeneration to remove both arsenic and uranium from the media; and (3) replacement and disposal of the spent media at a permitted facility. The approach for actual spent media disposition will be described in the Final Performance Evaluation Report. The capital investment cost of $114,070 covered $82,470 for equipment, $12,800 for engineering, and $18,800 for installation. Using the system's rated capacity of 50 gpm, the capital cost was $2,281/gpm (or $1.58/gallon/day). The HIX system did not require electricity to operate. Routine activities to operate and maintain the system consumed only 50 min per week and the estimated labor cost was $0.13/1,000 gal of water treated. Available at http://www.epa.gov/nrmrl/pubs/600r08026/600r08026.htm

Shiao, H.T., L. Wang, and A.S.C. Chen, Battelle, Columbus, OH.
Report No: EPA 600-R-08-018, 71 pp, Apr 2008

The APU-30S system was installed and started up on April 25, 2006. The system consists of two 63-inch diameter and 86-inch tall adsorption vessels configured in series, with 53.6 cubic ft of SORB 33™ in the lead vessel and 70.3 cubic ft in the lag vessel, gas prechlorination equipment, sample taps, and associated instrumentation. At the design flow rate of 150 gallons per minute (gpm), the system has a hydraulic loading rate of 6.9 gpm/ft² and an empty bed contact time (EBCT) of 6.2 minutes. Based on the actual flow rate of only 134 gpm, the system operates at a hydraulic loading of 6.2 gpm/ft² and an EBCT of 6.9 minutes. Source water has a combined average concentration of 43.8 µg/L for total arsenic, with arsenic (III) as the predominating soluble species at 35.2 µg/L. Iron exists mostly in the particulate form, with concentrations ranging from 34.2 to 100 µg/L and averaging 60.5 µg/L. Total manganese concentrations average 54.4 µg/L, existing almost entirely in the soluble form. After prechlorination, arsenic(III) was effectively oxidized to arsenic(V), with concentrations averaging 0.6 and 27.1 µg/L, respectively. Somewhat unexpectedly, manganese(II) also was oxidized, presumably to manganese dioxide, leaving only 2.8 µg/L (or 6.5%) in the chlorinated water. A large amount of solids discharged from Vessel B, and this solids production is being investigated for explanation in the final performance evaluation report. The capital investment for the system was $179,750, consisting of $124,103 for equipment, $14,000 for site engineering, and $41,647 for installation, shakedown, and startup. Using the system's rated capacity of 150 gpm (or 216,000 gallons per day [gpd]), the capital cost was $1,198/gpm (or $0.83/gpd). This calculation does not include the cost of the building to house the treatment system. Operation and maintenance cost, estimated at $0.21 per 1,000 gallons, included only the incremental cost for labor. There was no incremental cost for electricity or chemical consumption since gas chlorination was being performed prior to the demonstration study. Available at http://www.epa.gov/nrmrl/pubs/600r08018/600r08018.htm

Ludlow, A. and W. Eifert (Roux Associates, Inc.); K. Kitzman, L. Schmelter, S. Courtney, and J. Fu (Alcoa, Inc.). Fourth International Phytotechnologies Conference, 24-26 September 2007, Denver, Colorado: Abstracts, p 45, 2007

As part of Alcoa's corporate-wide sustainable development strategy, Alcoa worked with Roux Associates to implement pilot-scale studies at the Mount Holly facility located in Goose Creek, North Carolina. The objectives of the pilot studies were to identify and evaluate passive Engineered Natural System^SM (ENS^SM) technologies to minimize the quantity and enhance the quality of water discharged from the site. Constituents of interest include part per million levels of fluoride, aluminum, and other metals. Phytotechnologies were evaluated at the site for the consumptive use of water to reduce site discharge and sequester site contaminants. This presentation summarizes the performance data and presents the findings of the pilot sprayfield study over a three-year period, December 2003 to October 2006. From 1980 to 1997, approximately 75 gallons per day (gpd) of process water from the facility were applied to a 28-acre sprayfield; during the next six years, the process water was diverted to a publicly owned treatment works (POTW). In 2003, two 1.3-acre pilot phytoremediation plots were installed in the former sprayfield to evaluate consumptive use and stabilization of the process water. In the first plot, a total of 1,131 hybrid poplar whips was planted over the 1.3-acre tree plot. The second plot contained native grasses and served as the study control. A weather station was installed on site to monitor real-time climatologic parameters to generate potential evapotranspiration estimates and evaluate water balances for the plots. Over the course of the pilot study period, the hybrid poplar trees exhibited significant growth and maturation, averaging approximately 25 ft in height by the end of 2006. As the hybrid poplar trees matured, the total volume of process water application increased. By 2005, over one million gallons of process water had been applied to both the grass and tree plots. Over the 2006 growing season, the pilot plots effectively consumed approximately 20% of the POTW discharge. Peak monthly application reached 360,000 gallons in July 2006. The results of the three-year pilot study period effectively demonstrated the hydraulic control and phytostabilization mechanisms provided by hybrid poplar trees.

Muherei, Mazen Ahmed and Radzuan Junin, FKKKSA, Johor, Malaysia.
Modern Applied Science, Vol 2 No 3, p 3-12, May 2008

Nonionic surfactants are good candidates for surfactant-enhanced aquifer remediation, enhanced oil recovery, and in situ/ex situ soil washing. Their wide application is based on high solubilization capacities and low bio-toxicity. Surfactant loss due to adsorption and/or partitioning on adsorbents can impair their effectiveness to solubilize or mobilize and reduce the oil/water interfacial tension, thus rendering contaminant remediation economically unfeasible. In an evaluation of the ability of anionic (SDS) and nonionic (TX100) surfactants and their mixtures (1:2, 1:1, 2:1; TX100:SDS mass ratios) to reduce surfactant partitioning losses to an organic phase and/or adsorption to shale, results showed that all mixtures behave similarly and have properties superior to either surfactant alone. Partitioning and adsorption of TX100 into an organic phase (Sarapar147) and shale were decreased by mixing with SDS. The data showed a 40% reduction in surfactant losses due to adsorption to shale and around 60% reduction due to both partitioning and adsorption. Available at http://www.ccsenet.org/mas/MAS200803.pdf

Shi, Lei, Doctoral dissertation, Leipzig University, Leipzig, Germany, 119 pp, Feb 2008

During successful bioremediation, microorganisms convert pollutants to less harmful compounds; however, bioremediation of soil contaminated with hydrophobic organic compounds (HOCs) is restricted by low compound bioavailability. Low water solubility and strong interaction with the soil matrix results in limited HOC mobility in the soil and a low rate of availability for microbial transformation. Electro-bioremediation, a hybrid technology combining bioremediation and electrokinetics, has the potential to mobilize both bacteria and their substrates by electrokinetic transport processes, such as electrophoresis and/or electroosmosis. Present electro-bioremediation approaches aim mainly at transport of hydrophilic chemicals in the centimeter to meter range and often overlook the role of direct current (DC)-electric fields for bacterial dispersion and HOC release at the micrometer scale. A study was conducted to (1) develop a conceptual framework to describe the potential effects of DC electric fields on the microscale interactions governing HOC bioavailability in soil, (2) assess the effect of weak DC electric fields typical of electro-bioremediation measures on microbial physiology, (3) determine the mechanisms governing the electrokinetic subsurface dispersion of bacteria, and (4) quantify the effect of electroosmosis on the release of (model) soil-bound HOCs. To achieve these goals, well-defined experimental systems were used to obtain reproducible results. Polycyclic aromatic hydrocarbons (PAHs) were used as model compounds and the bacterium Sphingomonas sp. LB126 as a representative PAH-degrading microorganism. This thesis showed that electro-bioremediation is able to mobilize both soil-bound HOCs and HOC-degrading microbes at the micro to centimeter scale and hence to increase local HOC bioavailability in the soil matrix and HOC bioremediation efficiency. Chapters 2 through 5 of this dissertation have been or are being published as individual papers in scientific journals. Chapter 2: Electro-bioremediation of hydrophobic organic soil-contaminants: A review of fundamental interactions (Electrochimica Acta 52(10):3441-3448(2007)); Chapter 3: Limits of propidium iodide as a cell viability indicator for environmental bacteria (Cytometry Part A 71(8):592-598(2007)); Chapter 4: Effect of electrokinetic transport on the vulnerability of PAH-degrading bacteria in a model aquifer (Environmental Geochemistry and Health 30(2):177-182(2008)); Factors influencing the electrokinetic dispersion of PAH-degrading bacteria in a laboratory model aquifer (submitted to Applied Microbiology and Biotechnology); Chapter 5: Electroosmotic flow stimulates the release of alginate-bound phenanthrene (Environmental Science & Technology 42(6):2105-2110(2008)). Dissertation at http://www.ufz.de/data/ufzdiss_3_08_8666.pdf

Chung, J. (Arizona State Univ., Tempe); B.E. Rittmann; W.F. Wright; R.H. Bowman.
Biodegradation, Vol 18 No 2, p 199-209, 2007

To examine the capacity of a hydrogen-based membrane biofilm reactor (MBfR) to reduce multiple oxidized contaminants, the authors conducted bench-scale experiments with three ground-water samples collected from California's San Joaquin Valley and on two synthetic ground waters containing selenate (Se[VI]) and chromate (Cr[VI]). The actual ground-water sources had nitrate levels exceeding 10 mg-N/L and different combinations of anthropogenic perchlorate + chlorate, arsenate, and dibromochloropropane (DBCP). For all actual ground waters, the MBfR reduced nitrate to less than 0.01 mg-N/L. Present in two ground waters, perchlorate + chlorate was reduced below the California Notification Level of 6 µg/L perchlorate. Arsenic(V) was reduced substantially to As(III) for two ground-water samples, which had influent As(V) concentrations from 3 to 8.8 µg/L As. DBCP, present in one ground water at 1.4 µg/L, was reduced below its detection limit of 0.01 µg/L, which is well below California's 0.2 µg/L maximum contaminant level for DBCP. For the synthetic ground waters, switching the influent oxidized contaminant from selenate to chromate or from chromate to selenate gave immediate and significant reduction of the new contaminant in MBfRs treating one contaminant, but not having been previously exposed to the new contaminant. These results show that the hydrogen-based MBfR can treat multiple oxidized contaminants simultaneously, which addresses the common ground-water situation of having multiple oxidized contaminants. Paper at http://www.aptwater.com/assets/tech_papers/PAPER-Nitrate_Chung.pdf

Grundmann, S., R. Fuss, M. Schmid, M. Laschinger, B. Ruth, R. Schulin, J.C. Munch, and R. Schroll.
Chemosphere, Vol 68 No 3, p 511-517, 2007

Through transfer of an active microbial community capable of degrading isoproturon, pesticide mineralization could be enhanced in various soils under laboratory and outdoor conditions. After the microbes were extracted from a soil having high native ability to mineralize this chemical, they were established on expanded clay particles and distributed to various soils in the form of microbial "hot spots." Both diffusion-controlled isoproturon mass flow toward these hot spots (6 µg/d) as well as microbial ability to mineralize the herbicide (~5 µg/d) were identified as the main processes enabling a multiple augmentation of the native isoproturon mineralization, even in soils contaminated with heavy metals. Soil pH value appears to exert an important effect on the sustainability of this process.

Conesa, H.M., B.H. Robinson, R. Schulin, and B, Nowack, Inst. of Terrestrial Ecosystems, ETH Zurich, Zurich, Switzerland.
Environmental Pollution, Vol 145, p 700-707, 2007

An esparto grass (Lygeum spartum) is a native species that grows spontaneously on acid mine tailings in semiarid Mediterranean areas. The suitability of this plant for phytostabilization was examined using L. spartum grown from both seeds and rhizomes in acid mine tailings with various fertilizer and lime treatments. Untreated soils had a solution pH of 2.9 with high concentrations of dissolved salts (electrical conductivity 25 dS/m) and zinc (3,100 mg/L). Plants grown on untreated soil had high shoot metal concentrations (>4,000 mg/kg zinc). Liming increased the solution pH to 5.5 and reduced the dissolved salts by more than 75%, resulting in lower shoot metal accumulation. Plants grown from rhizomes accumulated less metal than those grown from seeds. Plants collected in the field had metal concentrations an order of magnitude less than plants raised in the growth chamber. These differences may be due to the higher moisture content and homogeneous nature of the soils used in the pot experiment. Paper at http://www.ito.ethz.ch/people/robinson/JournalArticles/EnvironPoll2007.p
df

Robinson, B.H., S. Bischofberger, A. Stoll, D. Schroer, G. Furrer, S. Roulier, A. Gruenwald, W. Attinger, and R. Schulin, Swiss Federal Inst. of Technology (ETH), Zurich, Switzerland.
Environmental Pollution, Vol 153, p 668-676, 2008

Elements such as lead (Pb), copper (Cu), nickel (Ni), and antimony (Sb) were measured in the leaves of 10 plant species and associated rhizospheric soil on the stop butt of a disused military shooting range. The geometric mean concentrations of Pb, Sb, Cu, Ni in rhizospheric soils were 10,171, 5,067, 4,125, and 917 mg/kg, respectively. Some species contained Pb, Cu, and Ni above concentrations (30, 25, and 50 mg/kg, respectively) shown to be toxic to livestock. Most contaminants in leaves resulted from surface deposition; however, at soil Pb concentrations above 60,000 mg/kg, field horsetail (Equisetum arvense) and coltsfoot (Tussilago farfara) took up >1,000 mg/kg Pb into the leaves. These plants are not hyperaccumulators, as they take up <100 mg/kg Pb in leaves at lower soil concentrations. Removal of soil with more than 30,000 mg/kg Pb, from which one could smelt the metal to offset remediation costs, followed by revegetation, would minimize dust and leaf-borne contaminants. Paper at http://www.ito.ethz.ch/people/robinson/JournalArticles/EnvironPoll2008b.
pdf

Dominguez, M.T., T. Maranon, and J.M. Murillo (CSIC, Seville, Spain); R. Schulin and B.H. Robinson (Inst. of Terrestrial Ecosystems, Zurich, Switzerland).
Environmental Pollution, Vol 152, p 50-59, 2008

Phytomanagement employs vegetation and soil amendments to reduce the environmental risk posed by contaminated sites. Distribution of trace elements in soils and woody plants was examined at a large phytomanaged area in the Guadiamar Valley (SW Spain), seven years after a mine spill contaminated the area in 1998. In the spill-affected sites, topsoils (0 to 25 cm) had elevated concentrations of a wide range of inorganic contaminants, including arsenic (129 mg/kg), copper (115 mg/kg), lead (210 mg/kg), and zinc (457 mg/kg). Trace element concentrations in the studied plant species were, on average, within the normal ranges for higher plants with the exception of white poplar (Populus alba), which accumulated cadmium and zinc in leaves up to 3 and 410 mg/kg respectively. The results of the investigation are discussed with regard to the phytomanagement of sites contaminated with trace elements. Paper at http://www.ito.ethz.ch/people/robinson/JournalArticles/EnvPoll2008.pdf

Robinson, B.H. (Swiss Federal Inst. of Technology (ETH), Zurich, Switzerland); S.R. Green, B. Chancerel, T.M. Mills, and B.E. Clothier (HortResearch, Palmerston North, New Zealand).
Environmental Pollution, Vol 150, p 225-233, 2007

The potential of hybrid poplar (Populus sp.) was investigated for management of boron (B) using a lysimeter experiment and a field trial on B-contaminated wood waste. In both studies, poplars enhanced evapotranspiration from the wood waste, reduced B leaching, and accumulated B in the aerial portions of the tree. When grown in a substrate containing 30 mg/kg B, poplar leaves had an average B concentration of 845 mg/kg, while the stems contained 21 mg/kg B. Leaf B concentrations increased linearly with leaf age. A decomposition experiment revealed that abscised leaves released 14% of their B during the winter months. Fertilizer application enhanced tree growth without decreasing the leaf B concentrations. Harvesting alternate rows of trees on a contaminated site would reduce leaching from the site while removing B. Paper at http://www.ito.ethz.ch/people/robinson/JournalArticles/EnvironPoll2007b.
pdf

Moreno, F.N. (Univ. of Sao Paulo, Sao Paulo, SP, Brazil); C.W.N. Anderson and R.B. Stewart (Massey Univ., Palmerston North, New Zealand); B.H. Robinson (Swiss Federal Inst. of Technology (ETH), Zurich, Switzerland).
Environmental and Experimental Botany, Vol 62, p 78-85, 2008

The authors investigated the removal of mercury (Hg) from solutions by Indian mustard [Brassica juncea (L.) Czern.] grown in hydroponic conditions with solutions containing Hg concentrations from 0 to 10 mg/L. Plants were enclosed in gas-tight volatilization chambers to assess the effect of Hg concentrations on plant transpiration, accumulation, and volatilization. The speciation and site of origin of volatilized Hg were determined. Solution Hg concentrations of 5 and 10 mg/L had a negative effect on transpiration. Roots concentrated Hg 100 to 270 times (on a dry weight basis) above initial solution concentrations. The plants translocated little Hg to the shoots, which accounted for just 0.7 to 2% of the total Hg in the plants. Volatilization from planted vessels increased linearly as a function of Hg concentrations in solutions. Most Hg volatilization occurred from the roots. Volatilized Hg was predominantly in the Hg(0) vapor form. Volatilization was dependant on root uptake and absorption of Hg from the ambient solution. Production of Hg(0) vapor in the solutions may result from the activity of root-associated algae and Hg-resistant bacteria. Phytofiltration removed up to 95% of Hg from the contaminated solutions by both volatilization and plant accumulation. The authors note, however, that Hg(0) vapors released from living roots may have unforeseen environmental effects. Paper at http://www.ito.ethz.ch/people/robinson/JournalArticles/EEB2008.pdf

Huq, H.P., J.-S. Yang, and J.-W. Yang, KAIST, Daejeon, Korea.
Desalination, Vol 204, p 335-343, 2007

A polyelectrolyte-enhanced ultrafiltration (PEUF) process was investigated for perchlorate removal from ground water containing common co-contaminants, such as nitrate and sulfate. Ion exchange can be used to remove perchlorate, but that process has greater complexity than PEUF, especially when applied in the presence of high nitrate and sulfate concentrations. In a study of the effect of cationic polyelectrolyte, poly(diallyldimethyl ammonium chloride) (PDADMAC) concentration, and the effect of nitrate and sulfate in a broader concentration range, the researchers found that a lower amount of PDADMAC (0.5 to 1 mM) can remove more than 90% of perchlorate from the aqueous phase in the absence of other anions. In the presence of 5 mM nitrate, however, perchlorate removal decreased as the available binding sites of PDADMAC for perchlorate were reduced. In the presence of both 1 mM to 10 mM nitrate and sulfate, 60 to 80% perchlorate was removed with 30 mM PDADMAC. The removal of sulfate and nitrate in this case was nearly 75 and 65%, respectively. Other parameters—relative flux, membrane material, and pore size—also were examined to study their effect on perchlorate removal via PEUF. In this study, the PEUF process did remove perchlorate effectively in ground water containing other contaminants. Paper at http://www.desline.com/proceedings/63-2-tc.shtml

Cao, A., A. Carucci, T. Lai, P. La Colla, and E. Tamburini, Univ. of Cagliari, Cagliari, Italy.
European Journal of Soil Biology, Vol 43, p 200-206, 2007

The application of chelating agents during phytoremediation has the potential to reduce the time required for remediation of heavy metal contamination in soils. Two easily biodegradable chelating agents (EDDS and MGDA) were used in two different dosages (4 and 8 mmol/kg of soil) to test their use in an assisted phytoextraction process and to evaluate their effect on soil and bacteria associated with Mirabilis jalapa, which is commonly referred to as the four o'clock plant. In untreated reactors, zinc (Zn) and lead (Pb) accumulated in roots, but only Zn was translocated to shoots. Both chelating agents performed effectively for Pb and Zn mobilization in soil solution. After chelate treatment, accumulation and translocation was unaffected for Zn and enhanced for Pb. The chelating agents seemed to have a positive influence on bacterial communities of bulk soil and rhizosphere by mitigating the selective pressure caused by Pb and Zn, whereas the endophytes were less affected. See paper under 7b Lai - Phytoextraction - chelating agent.pdf at http://www.image.unipd.it/iat/ASA/Dispense%20e%20Articoli/

Bhatt, P., M.S. Kumar, and T. Chakrabarti, National Environmental Engineering Research Institute (NEERI), Nehru Marg, Nagpur, India.
Journal of Hazardous Materials, Vol 143 Nos 1-2, p 349-353, 2007

Hexachlorocyclohexane (HCH) is a broad-spectrum insecticide still used in developing countries, though developed countries have banned or curtailed its use. Even in areas where t-HCH has not been used for many years, all isomers of t-HCH persist in the soil. Few reports on the degradation of t-HCH isomers in soil are present in the literature, and very little information is available on the effects of these t-HCH isomers on soil microflora. The authors compared the microbial diversity in uncontaminated soil with the effect of t-HCH application on soil microflora. Soil spiked with t-HCH was incubated and then analyzed at regular time intervals for microbial diversity and t-HCH isomers residues. The results show that at higher concentrations of t-HCH, microbial populations were inhibited, and the inhibited populations did not reappear even after prolonged incubation. Potential t-HCH-degrading cultures were isolated and subjected to further acclimation to enhance their degradation capacity. The results are presented and discussed in this paper.

Amano, R.S., J.M. Lucci, and K.S. Guntur, Univ. of Wisconsin-Milwaukee.
Collection of Technical Papers: 45th AIAA Aerospace Sciences Meeting, 8-11 January 2007, Reno, Nevada. ISBN: 9781563478901, 2007

Heated Soil Vapor Extraction (HSVE) was developed by Advanced Remedial Technology as a soil remediation process. Combined with air sparging, HSVE can provide effective soil remediation of contaminants such as solvents, fuels, and polycyclic aromatics. The system consists of a heater/boiler that pumps and circulates hot oil through heating wells, a blower that helps to suck the contaminants out through the extraction well, and air sparging wells that extend down to the saturated region in the soil. Both the heating wells and extraction wells are installed vertically in the saturated region in contaminated soil and are welded at the bottom and capped at the top. The heat source warms the soil, and the heat moves through the soil by conduction and convection. This heating of the soil results in vaporization of organic contaminants, which then are pulled into the extraction well. Where SVE cannot remove contaminants from the soil zone that lies below the water table, air can be pumped into the saturated zone to help flush the contaminants up into the unsaturated zone, which allows the contaminants to be removed by SVE. In this analysis, an attempt has been made to predict the behavior of different chemicals in the unsaturated and saturated regions of the soil. The analysis uses the species transport and discrete phase modeling to predict the behavior of different chemicals when it is heated and absorbed by the extraction well. Such an analysis will be helpful in predicting the parameters, such as the distance between the heating and extraction wells, the temperature to be maintained at the heating well, and the time required for removing the contaminants from the soil. A 2006 paper by R.S. Amano et al. provides additional information on this technology at http://www.jgsee.kmutt.ac.th/see1/cd/file/E-024.pdf

Henderson, K.L. (Iowa State Univ., Ames); J.B. Belden (Baylor University, Waco, TX); J.R. Coats (Iowa State Univ.).
Environmental Science and Technology, Vol 41 No 11, p 4084-4089, 2007

Prairie grasses have been used in filter strips to control runoff and are also useful for phytoremediation; however, little is known about the fate of the herbicide metolachlor and its metabolites within a grassed system. Researchers added radiolabeled (C-14) metolachlor to enclosed systems to determine the fate of the parent compound and its metabolites in soil and plants. Mineralization and volatilization monitored over the 97-day study were found to be 1.05 and 0.2%, respectively, for vegetated systems. At the end of the study, soil and plant materials were evaluated for the presence of parent metolachlor and selected metabolites, as well as bound residues. Metolachlor ethane sulfonic acid was the dominant metabolite in soil and plant tissue. Over 7% of applied radioactivity was taken up by the grasses, and plant uptake/metabolism appeared to be the main mechanism for phytoremediation of metolachlor. Vegetation reduced the amount of metolachlor in soil by 9% in 97 days, indicating the potential of phytoremediation.

Bozau, E., T. Bechstedt, K. Friese, R. Frommichen, P. Herzsprung, M. Koschorreck, J. Meier, C. Volkner, K. Wendt-Potthoff, M. Wieprecht, and W. Geller, UFZ-Centre for Environmental Research Leipzig-Halle, Magdeburg, Germany.
Journal of Geochemical Exploration, Vol 92 Nos 2-3, p 212-221, 2007

Researchers began enclosure tests of biotechnological remediation, which accelerates the microbial sulfate and iron reduction at the water/sediment interface, with the addition of lime and straw in an acid pit lake in Germany. The development and stability of reaction products over time and the interaction between the acidic lake water and the anoxic sediment layer have been investigated for three years. Parameters such as pH, redox state, and total reduced inorganic sulfur indicate significant changes in the treated lake sediments. The progress of the remediation can be calculated from the amount of accumulated sulfur species in the sediment and the diffusive exchange between sediments and water of the lake. Hydrogeochemical processes and limnophysical characteristics of the lake are combined to describe the geochemical behavior in greater detail and predict further development. A simple model based on the code AQUASIM illuminates important uncertainties in the remediation strategy: the low sulfate reduction rates in the upper sediment, a slow diffusive exchange at the water/sediment interface, the inflow of ground water, and mineral reactions that inhibit the success of remediation in the lake area of the enclosure under investigation.

Dercova, K., Z. Sejakova, M. Skokanova, G. Barancikova, and J. Makovnikova, Inst. of Biotechnology and Food Science, Bratislava, Slovakia.
Chemosphere, Vol 66 No 5, p 783-790, 2007

Biodegradation of pentachlorophenol (PCP) was studied in three well-characterized soil samples—chernozem, fluvisol, and regosol—with and without the addition of an organomineral complex (OMC) prepared from humic acids bound on zeolite. The soils were sterilized and bioaugmented with the bacterial isolate Comamonas testosteroni CCM 7530. The immobilization effect of OMC in relation to PCP was found to depend on the concentration of humic acids, PCP concentration, and content of organic carbon in soil. Microbial activity and the action of simulated acid rain led to the gradual release and biodegradation of the reversibly bound PCP with no initial toxic effect on the indigenous or augmented microorganisms. The authors conclude that OMC appears to be a good trap for PCP with potential applications in remediation technology.

Mudd, G.M., S. Chakrabarti, and J. Kodikara, Monash Univ., Clayton, Vic., Australia.
Journal of Hazardous Materials, Vol 139 No 3, p 409-412, 2007

An innovative approach was taken to investigate the potential to use leached brown coal ash in engineered soil covers on a mine overburden dump in Australia. The ash has favorable physical characteristics for use in cover systems, such as high storage capacity/porosity, moderately low permeability, and an ability to act as a capillary break layer generating minimal leachate or seepage. Additionally the leachate from the ash is mildly alkaline, which can help to mitigate and reduce the risk of acid mine drainage. The authors review the engineering issues involved in using leached brown coal ash in designing soil covers for potentially acid-forming overburden dumps. This paper presents the results of laboratory work investigating the technical feasibility of using leached brown coal ash in engineered solid waste cover systems. A background paper, Engineering Review of the Use of Leached Brown Coal Ash in Soil Covers, is available at http://civil.eng.monash.edu.au/about/staff/muddpersonal/2005-WasteEng-En
gProp-BrownCoalAsh.pdf

Friis, A.K. (Technical Univ. of Denmark, Kgs Lyngby), E.A. Edwards, H.-J. Albrechtsen, K.S. Udell, M. Duhamel, P.L. Bjerg.
Chemosphere, Vol 67 No 4, p 816-825, 2007

A microcosm study was conducted to evaluate dechlorination of trichloroethene (TCE) to ethene and survival of dechlorinating bacteria after thermal treatment to explore the potential for post-thermal bioremediation. Unamended microcosms containing ground water and aquifer material from a contaminated site dechlorinated TCE to cis-1,2-dichloroethene (cDCE), while lactate-amended microcosms dechlorinated TCE to cDCE or ethene. Thermal treatment was simulated by heating a subset of microcosms to 100°C for 10 days, followed by cooling to 10°C over 150 days. When unamended, the heated microcosms showed no dechlorination, but when amended with lactate, cDCE was produced in two out of six microcosms within 300 days after heating. Dechlorination of TCE to cDCE occurred in fewer heated (2 out of 12) than unheated (10 out of 12) microcosms. The presence of dechlorinating microorganisms, including Dehalococcoides, was confirmed in the unheated microcosms, but dechlorinating microorganisms were detected in fewer microcosms after heating, and Dehalococcoides were not detected in any microcosms after heating. These results indicate that dechlorination after thermal treatment likely will be limited in areas that have been heated to 100°C. Bioaugmention and/or inflow of ground water containing dechlorinating microorganisms may be needed for anaerobic dechlorination to occur after thermal treatment.

Swindell A.L. and B.J. Reid, Univ. of East Anglia, Norwich, UK.
Chemosphere, Vol 66 No 2, p 332-339, 2007

A study was carried out to assess the influence of diesel, applied over a log concentration range, on the loss and extractability of phenanthrene (measured as radiolabeled phenanthrene residues) in two different soils. The influence of diesel on the ability of a cyclodextrin-based extraction method to predict the microbial bioavailability of C-14 residues also was assessed. An increase in loss of C-14 residues with increasing diesel concentration from 0 to 2,000 mg/kg was generally observed over time in both soils. This trend may be attributable to competitive sorption for soil sorption sites, and to a lesser extent, to displacement of C-14 residues from soil sorption sites by diesel, resulting in greater compound availability and therefore greater loss by degradation via the actions of indigenous microorganisms. In the 20,000 mg/kg diesel treatments of both soils, results indicated a delayed loss. This retarded loss potentially was due to the formation of a discrete nonaqueous-phase liquid phase into which C-14/phenanthrene residues partitioned, thereby decreasing their availability and their degradation. Nutrient limitation may have slowed degradation rates as diesel concentrations increased. Comparison between cyclodextrin extractability and microbial mineralization supported the use of cyclodextrin to assess microbial bioavailability of C-14 residues after 50 days or more of aging up to diesel concentrations of 2,000 mg/kg; however, results suggested that at high diesel concentrations (i.e., 20,000 mg/kg), co-extraction of C-14/phenanthrene residues may have occurred as a result of the combined solvating powers of both the cyclodextrin and the diesel. Additionally, mineralization of C-14/phenanthrene residues may have been affected by extreme nutrient limitation in this treatment.

Yang, L., R.J. Donahoe, and J.C. Redwine.
Paper No: LBNL-63522, 15 pp, 2007

This paper reports the results of an experimental study testing a low-cost in situ chemical fixation method designed to reclaim arsenic-contaminated subsurface soils. Subsurface soils from several industrial sites in the southeastern United States are contaminated with arsenic (As) through heavy application of an herbicide containing arsenic trioxide. The mean concentrations of environmentally available arsenic in soils collected from two study sites, FW and BH, are 325 mg/kg and 900 mg/kg, respectively. The soils are sandy loams with varying mineralogical and organic contents. Previous study has indicated that a large portion of the arsenic in both soils is associated with amorphous aluminum and iron oxyhydroxides and shows very slow release against leaching by synthetic precipitation. The soil's amorphous aluminum and iron oxyhydroxides content was found to have the most significant effect on its ability to retain As. Based on this observation, contaminated soils were reacted with different treatment solutions in an effort to promote the formation of insoluble As-bearing phases and thereby decrease As leachability. Ferrous sulfate, potassium permanganate, and calcium carbonate were used as the reagents alone and in combination for the chemical fixation solutions evaluated in three sets of batch experiments. The optimum treatment solutions for each soil were identified based on the mobility of arsenic during sequential leaching of treated and untreated soils using the toxicity characteristic leaching procedure (TCLP) and the synthetic precipitation leaching procedure (SPLP). Both FW and BH soils showed significant decreases in arsenic leachability for all the treatment solutions, compared to untreated soil. While soils treated with a solution of all three reagents showed the best results with subsequent TCLP sequential leaching, SPLP sequential leaching of those treated soils indicated that the lowest As mobility was obtained using ferrous sulfate alone. Treatment with ferrous sulfate alone is considered the best choice for remediation of As-contaminated soil because SPLP sequential leaching better simulates natural weathering. Analysis of treated soils produced no evidence of newly-formed As-bearing phases in either soil after treatment. Sequential chemical extractions of treated soils indicate that surface complexation of As on ferric hydroxide is the major mechanism for the fixation process. Paper at http://repositories.cdlib.org/lbnl/LBNL-63522/

Negri, M.C., J. Quinn, G. Gopalakhrishnan, L. Moos, R. Piorkowski, E. Gatliff, and N. Golchert.
Fourth International Phytotechnologies Conference, 24-26 September 2007, Denver, Colorado: Abstracts, p 50, 2007

The phytoremediation system at Argonne National Laboratory in northeastern Illinois contains over 800 trees. The plant system is designed for a multifaceted phytoremedial approach to dealing with volatile organic compounds (VOCs) and tritium in soil and ground water, including transpiration of contaminants, in situ breakdown in plant tissues and in the rhizosphere, and hydraulic containment. Hybrid willows and poplars comprise the remediation system, with willows in the source area and deep-rooted poplars (TreeWell™) installed to capture the downgradient plume at 26 to 30 ft below ground surface (bgs). The authors discuss the integrated results of all monitoring activities conducted from 1999 to the present and provide an assessment of technology performance and lessons learned. Monitoring data have been collected in the form of transpirate, leaf and branch contaminant concentrations, trunk core samples, continuous water levels, ground-water contaminant concentrations, tree growth (height and trunk diameter), weather parameters, soil and root studies, and other targeted studies. While VOCs were found in the willows growing in the source area as early as two months from planting, their concentration and spatial distribution in the plants has followed different patterns as the trees grew and reached their mature size. Tritium also has been found consistently in tree transpirate in areas of trace ground-water concentrations, serving both as a tracer of rooting depth and a performance indicator parameter. Roots were found in the hydraulic control planting as deep as the capillary fringe, approximately 22 ft bgs in the glacial subsoil. As the plantation approaches maturity, synthesis of the monitoring data is indicating in-plant degradation processes, contaminant mass uptake and removal rates, the effect of existing site infrastructure, and the anticipated overall efficiency of the project.

Phillips, L. and R. Farrell (Univ. of Saskatchewan); C. Greer (NRC-BRI); J. Germida (Univ. of Saskatchewan). Fourth International Phytotechnologies Conference, 24-26 September 2007, Denver, Colorado: Abstracts, p 55, 2007

Phytoremediation systems typically have been composed of mixtures of plant species based upon the theory that combined root types and exudate patterns allow for greater infiltration and stimulation of the underlying microbial communities. The underlying assumption is that the positive benefits of the individual plants will be proportionally cumulative in the mixed plant treatment. To investigate this assumption and further optimize the potential of phytoremediation as a treatment option in prairie ecosystems, a two-year field study was conducted at a flare-pit site in southeastern Saskatchewan. Three plants commonly used in phytoremediation mixes—Altai wild rye, tall wheatgrass, and alfalfa—were grown both singly and as a mix. The remediation potential of each treatment was assessed by examining the degradation potential of rhizosphere and root interior microbial communities at periodic intervals. After the petroleum hydrocarbon degrader populations were quantified, mineralization assays with C-14-labeled hydrocarbons were used to determine the in situ degradation potential. Although significant contaminant reduction occurred in all treatments after two years, degradation rates were greater in the single-plant treatments. For example, petroleum hydrocarbon concentrations decreased by over 50% in wild rye treatments after a single growing season. Although degrader populations in the wild rye rhizosphere were not significantly greater than those of other plants, wild rye did maintain higher numbers of hydrocarbon degraders within their roots, particularly during times of low soil moisture. The ability of wild rye roots to act as a refuge and subsequent source of hydrocarbon degrader communities during times of drought likely contributed to the overall increased degradation potential within this single species treatment. The results of this study suggest that the common practice of using mixed plant species can slow or inhibit the phytoremediation of hydrocarbon-contaminated soils.

Air Force Center for Engineering and the Environment (AFCEE), 302 pp, May 2008

This technical protocol has been produced by AFCEE to provide guidance on the evaluation, design, and implementation of permeable mulch biowalls and bioreactors for the enhanced in situ bioremediation of ground water contaminated with chlorinated solvents and other compounds subject to anaerobic transformation in ground water. Biowall substrates are typically low-cost materials (mulch, compost). The substrates are mixed with common construction materials (sand, gravel) to prevent compaction and maintain permeability. Amendments can be added to stimulate both biotic and abiotic degradation processes, based on the type of contaminant(s) present and the desired degradation pathway(s) to be stimulated. Application of the technology is not limited to passive biowalls to treat dissolved-phase contaminant plumes. The use of recirculation technology to pass contaminated ground water through a permeable mulch bioreactor or infiltration trench provides an alternative method to treat source areas and enables utilization of the technology to address plumes more than 35 feet below ground surface. Appendix F provides three example case studies evaluating system performance for remediation of chlorinated solvent contamination in ground water:
    •   a pilot-scale dual permeable mulch biowall system to address trichloroethene (TCE), cis-1,2-dichloroethene (cis-DCE), and vinyl chloride (VC) at Seneca Army Depot, NY;
    •   a permeable mulch biowall to address TCE and cis-DCE at Altus Air Force Base (AFB), OK; and
    •   a pilot-scale recirculation bioreactor to address TCE, cis-DCE, and VC at Altus AFB.
Available at http://www.clu-in.org/download/techfocus/prb/Final-Biowall-Protocol-05-0
8.pdf

Davis, J.A., U.S. Geological Survey, Menlo Park, CA.
Report No: NUREG/CR-6959, 132 pp, Apr 2008

This report discusses the development of improved methods to describe chemical processes that control radionuclide movement in ground water. Adsorption is a key process that constrains the movement of dissolved contaminants in a soil. In this process, ions associate with solid materials through reactions at the solid surface, and as a result they move more slowly than water moving through the material. The reactions controlling adsorption can vary substantially for different contaminants and can be sensitive to parameters such as pH, ionic strength, and concentrations of other dissolved species. Adsorption is typically described by the distribution coefficient, K_d, which is the concentration at steady state of an ion adsorbed on an associated solid divided by its concentration in solution. The use of surface complexation models (SCMs) allows the calculation of K_d under complex conditions, mechanistically describing how K_d changes as conditions are altered. SCMs employ mass action laws and thermodynamics to describe speciation in solution and on the solid, as well as the reactions between them. The family of SCMs ranges from detailed calculations of surface charge and associated adsorption to the semi-empirical approach of the generalized composite SCM (GC-SCM). This latter approach is applicable to mixed mineral assemblages of natural materials and views the mineral surface sites as generic functional groups with averaged properties. The work described in this report developed GC-SCMs for three cases of contaminant/sediment combinations: neptunium(V) in Naturita aquifer sediment, uranium(VI) in Forty Mile Wash aquifer sediment, and nickel in Cape Cod aquifer sediment. These contaminants provide very different chemistries to test the modeling approach. The models provided good agreement with experimental data and performed satisfactorily in describing adsorption as a function of changing chemical conditions. The GC-SCM is a compromise between the simple constant-K_d approach and more complex SCM, which at present are difficult to apply to the environment. Report at http://www.nrc.gov/reading-rm/doc-collections/nuregs/contract/cr6959/

U.S. EPA, Office of Radiation and Indoor Air.
Report No: EPA 402-R-07-007, 80 pp, Jan 2008

This report describes the likely analytical decision paths that would be required by personnel at a radioanalytical laboratory following a radiological or nuclear incident, such as that caused by a terrorist attack. EPA's responsibilities, as outlined in the National Response Plan Nuclear/Radiological Incident Annex, include response and recovery actions to detect and identify radioactive substances and to coordinate federal radiological monitoring and assessment activities. This document was developed to provide guidance to the radioanalytical laboratories that will support EPA's response and recovery actions following a radiological or nuclear incident of national significance. Report at http://www.epa.gov/narel/reports/WaterReport%20Final%20%20w%20Cover%201-
16-08.pdf

Commission for Environmental Cooperation, Montreal, Quebec, Canada. 4 pp, Sep 2007

The Commission for Environmental Cooperation (CEC) is working on a project that will allow the governments of Canada, Mexico, and the United States to replace their current paper-based system of tracking transboundary shipments of hazardous waste and hazardous recyclable materials with an electronic-based system. As part of this project, the governments are developing common data standards for export requests and consent documents and a method for sharing this information electronically. Importers and exporters must obtain written approvals from national governments to ship hazardous waste or hazardous recyclable material from one country to another. Currently, countries share export requests and consents documents with one another by sending paper copies by mail, fax, or cable. This results in the exchange of hundreds of thousands of documents between North American governments each year. The CEC project will allow governments to exchange this export request and consent information electronically, an innovation that will reduce government administrative burdens, improve data quality, make it easier to provide data to environmental enforcement and border protection agencies, facilitate the adoption of emerging tracking technologies, and help the governments provide more timely and coherent information on what crosses their national borders. This project also will enhance compliance. The new electronic system will include information on shipment requirements, thus enabling comparison of the requirements with the actual shipment information to determine possible violations. Fact sheet at http://www.cec.org/pubs_docs/documents/index.cfm?varlan=english&ID=2200

U.S. EPA, National Center for Environmental Assessment, Washington, DC.
Report No: EPA 600-R-07-045F, 366 pp, May 2008

To accomplish its mission, U.S. EPA must pay close attention to trends in the condition of the nation's air, water, and land, as well as to associated trends in human exposure and health and the condition of ecological systems. Data on environmental trends serve two key purposes: they provide valuable input to EPA in developing its strategic outlook and priorities, and they allow EPA and the public to assess whether the Agency is succeeding in its overall mission to protect human health and the environment. EPA has prepared this report to help to accomplish these purposes. This report compiles in one place the most reliable indicators currently available to answer 23 questions that EPA believes are of critical importance to its mission and the nation's environment. The indicators are supported by data gathered from federal and state agencies and non-governmental organizations. All of the indicators were peer-reviewed to meet exacting standards for accuracy, representativeness, and reliability. This 2008 report presents trends wherever adequate data are currently available, and it establishes reliable national baselines where they are not. Equally important, the report identifies key limitations of these indicators and gaps where reliable indicators do not yet exist. For a more interactive experience, visit the ROE Indicators live site at http://www.epa.gov/ncea/roe
Report at http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=190806

U.S. EPA, Office of Enforcement and Compliance Assurance, Office of Site Remediation Enforcement.
Report No: EPA 330-K-08-002, 112 pp, May 2008

The Revitalization Handbook summarizes the statutory and regulatory provisions of CERCLA (commonly known as Superfund) and RCRA, as well as the policy and guidance documents most useful in managing environmental cleanup liability risks associated with the revitalization of contaminated sites. It is designed for use by parties involved in the assessment, cleanup, and revitalization of sites, and provides a basic description of the tools parties can use to address liability concerns. The main objective of EPA's cleanup enforcement program is to ensure prompt site cleanup and the participation of liable parties in performing and paying for cleanups in a manner that ensures protection of human health and the environment. The Revitalization Handbook addresses environmental cleanup liability risks associated with the revitalization of contaminated property or sites. Congress passed the Small Business Liability Relief and Brownfields Revitalization Act of 2002 (Public Law 107-118), which modified Superfund and further promoted the cleanup, reuse, and redevelopment of sites by addressing liability concerns associated with unused or under-utilized property. EPA works to clarify and address barriers to the timely cleanup and reuse of Brownfield and other contaminated properties. Report at http://www.epa.gov/compliance/resources/publications/cleanup/brownfields
/handbook/index.html

Dermont, G., M. Bergeron, G. Mercier, and M. Richer-Lafleche, INRS-ETE, Quebec, QC, Canada
Journal of Hazardous Materials, Vol 152 No 1, p 1-31, Mar 2008

Soil washing is one of the few permanent treatment alternatives to remove metal contaminants from soils. This review examines the various technology types and pilot/full-scale field applications of soil washing applicable to soils highly contaminated with heavy metals. The physical separation technologies, the chemical extraction processes, and the integrated processes that combine both physical and chemical methods are discussed separately. The authors address basic principles, applicability, advantages and limitations, and methods of predicting and improving the performance of each physical/chemical technology. The discussion is based on a review of 30 recent laboratory investigations and 37 field applications of soil washing systems implemented between 1990 and 2007, mostly in the Unites States. The status of soil washing technology for remediation of soils contaminated with metals is compared for the United States, Canada, and Europe.

Lai, K.C.K. (Univ. of Texas, Austin); R.Y. Surampalli; R.D. Tyagi; I.M.C. Lo; S. Yan.
Practice Periodical of Hazardous, Toxic, and Radioactive Waste Management, Vol 11 No 3, p 132-157, 2007

Performance monitoring of applied remediation technologies involves periodic measurement of site parameters used to determine performance and the termination date of the remediation. Site parameters are selected based on the chosen remediation technologies and objectives. This paper covers mainly the general criteria for establishing site-specific remediation objectives and the key monitoring parameters for various remediation technologies. It is intended to help avoid wasted efforts to collect unnecessary site parameters during performance monitoring. As examples, if the reduction of the mass or volume of a contaminant zone is the prime remediation objective, contaminant concentrations in soil, soil vapor, and ground water within the contaminant zone should be monitored. If the objective is to mitigate contaminant migration, contaminant concentrations in ground water just outside the contaminant zone should be the main monitoring parameter. To ensure proper operation of in situ thermal remediation, subsurface temperature is a unique monitoring parameter. Ground-water oxidant concentration is the monitoring parameter for in situ chemical oxidation technologies.