Copyright (c) 2009 University of Massachusetts Amherst All rights reserved. http://scholarworks.umass.edu/intljssw Recent documents in International Journal of Soil, Sediment and Water en-us Thu, 08 Oct 2009 08:46:18 PDT 3600 http://scholarworks.umass.edu/intljssw/vol2/iss2/6 http://scholarworks.umass.edu/intljssw/vol2/iss2/6 Mon, 03 Aug 2009 12:37:29 PDT The discovery of chlorinated volatile organic compounds (CVOCs) in the aquifer underlying a manufacturing facility prompted the initiation of an aggressive voluntary site wide soil and groundwater cleanup. Given a large number of potential source areas within the plant, delineation of CVOC impacts to the unsaturated zone was performed by the installation of an innovative soil vapor extraction system, rather than performing extensive soil sampling within the operating manufacturing facility. The system was designed with a pneumatically actuated valve manifold system to cycle the 120 extraction points which allowed for delineation of impacts, targeting hot spot source area removal, and overall contaminant reduction while remaining below regulatory discharge requirements, thereby eliminating the need for more costly air treatment. The innovative system design reduced equipment size by 80% while improving system recovery by operating in the most productive range of the removal curve. The groundwater remediation system, consisting of 6 extraction wells and 7 injection wells, is capable of extracting up to 600 gallons per minute (gpm) of groundwater. Up to 200 gpm of the extracted groundwater is treated by shallow tray air strippers with subsequent discharge via NPDES permitted outfall and re-injection of up to 400 gpm of substrate augmented groundwater into the upgradient portion of the plume. The net loss from the NPDES discharge provides capture and treatment of offsite groundwater downgradient of the site. The groundwater remediation system operates as a closed loop bioreactor allowing downgradient microbial seed to be recycled into the up gradient heart of the plume to increase the rate and effectiveness of CVOC removal via reductive dechlorination. Operations have so far have removed over 900 pounds of CVOCs from the unsaturated zone and over 1500 pounds CVOCs from the groundwater within the treatment zone. Groundwater treatment is ongoing. http://scholarworks.umass.edu/intljssw/vol2/iss2/5 http://scholarworks.umass.edu/intljssw/vol2/iss2/5 Mon, 03 Aug 2009 12:37:23 PDT Managing of sediments coming from dredging operations in ports, harbor areas and navigation waterways has to deal with huge quantities of highly contaminated material. As a matter of fact, due to routine operations, to the need of deepening fairways and ports and, eventually, to remediation activities, every year more than 200·106 m3 of dredged materials are produced throughout Europe. Chemical-physical treatments are generally used in order to separate a contaminated fraction from a clean one in order to reduce the quantity of sediments to be disposed of. Within this research work, carried out by the Department of Chemical Material Environment Engineering of Sapienza University of Rome and ISPRA (High Institute for Environmental Protection and Research), former ICRAM, sediments coming from a harbor area characterized by metal contamination have been treated adopting three different technologies: sieving, hydro-cycloning and flotation. Results show that sieving, hydro-cycloning and flotation are able to separate products in which metal contaminants generally present lower concentration compared to that of untreated dredged sediments. Nevertheless, in order to further reduce metal content in the cleaned fraction, the examined treatment cannot stand alone as a single step, but a multi steps or a combination of treatments have to be considered. http://scholarworks.umass.edu/intljssw/vol2/iss2/4 http://scholarworks.umass.edu/intljssw/vol2/iss2/4 Mon, 03 Aug 2009 12:37:16 PDT Hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) is a secondary high explosive that has been identified as a contaminant of concern in groundwater and soil as a result of military training activities (Wani et al., 2002). Remediation technologies that have been proposed for use on these training ranges include in situ techniques. An obstacle to using in situ approaches for the treatment of RDX contaminated soils and groundwater is the lack of information concerning the biogeochemical factors that influence transformation. This research compares paired (biotic and poised abiotic systems) RDX degradation experiments in which Eh-pH conditions conducive to RDX degradation were established. Degradation of RDX under iron-reducing conditions was studied in biological and chemical systems. The redox conditions created by the biological systems were simulated by poised chemical systems in order to compare RDX transformation. The poised chemical systems used an iron-ligand complex to achieve the necessary Eh values for RDX degradation. RDX degraded in both biological and chemical systems and final reaction solutions from both systems were analyzed to determine which degradation pathway was followed. The results from this effort will expand the basic knowledge of energetic transformation over a range of biologically-induced conditions, by isolation of enzymatic pathways from abiotic redox mechanisms. http://scholarworks.umass.edu/intljssw/vol2/iss2/3 http://scholarworks.umass.edu/intljssw/vol2/iss2/3 Mon, 03 Aug 2009 12:37:11 PDT <p>A sudden heating oil release occurred below a concrete slab of a residence in Massachusetts. The oil entered an open sump in the basement and migrated to a nearby stream. Remediation included deployment of absorbent booms, limited soil excavation, and in-situ treatment with hydrogen peroxide. Soil, sediment, groundwater, and indoor air samples were analyzed to delineate the extent of contamination, verify that remedial efforts were successful, and determine if a vapor intrusion pathway existed. Indoor air samples were collected on three events: at the time of release, after remedial activities, and four months later.</p><p>Indoor air analytical results were compared to the new draft Threshold Values published by the MassDEP Indoor Air Working Group (June 2008). In each sampling event, various compounds were detected above the applicable Threshold Values. As suggested by the MassDEP, multiple lines of evidence were investigated to determine whether the exceedances were attributable to the release. The presence of mothballs, the construction and operation of the home heating system, analytical evidence of a potential historical release, and soil and groundwater analytical data were used as lines of evidence that a vapor intrusion pathway did not exist.</p> http://scholarworks.umass.edu/intljssw/vol2/iss2/2 http://scholarworks.umass.edu/intljssw/vol2/iss2/2 Mon, 03 Aug 2009 12:37:05 PDT Arsenic is often present in soils naturally or from historical anthropogenic activities. Arsenic is commonly a constituent of potential concern at environmental remediation sites, even where there is no reason to suspect a release. Site risks are frequently driven by arsenic, and risk-based screening levels below background are not uncommon. However, determining whether arsenic concentrations are consistent with background typically requires an extensive background data set. The ability to gain access to representative background locations owned by third parties is problematic at best in any characterization study. Consequently, many sites undergo characterization and potentially remediation for arsenic concentrations in soil that may in reality be representative of background (natural or anthropogenic). This study examines a large soil arsenic background data set to provide insight on typical concentrations of arsenic that are naturally occurring or represent anthropogenic background.Between 1995 and 2001, over 1,600 background soil samples were collected from 189 sites in Kentucky, Maryland, New York, Ohio, Pennsylvania, Virginia, and West Virginia. Samples were collected using strict Quality Assurance/Quality Control procedures under a United States Environmental Protection Agency (USEPA) Superfund Administrative Order on Consent (AOC) and were analyzed by USEPA-approved laboratories. All data were verified and 10% underwent detailed data validation. Arsenic concentrations in samples retained for statistical analysis ranged from 1.1 mg/kg to 89 mg/kg. Data are evaluated by state and by geology and are compared to USEPA and state risk-based screening levels (RBSLs). Some standard background threshold values (BTVs) are derived for each state and distinct geology. The BTVs are greater than RBSLs. This extensive, regional data set should be considered by all stakeholders involved in relevant risk-based decisions related to arsenic in soils. The consideration of this data set and the BTVs may aid in the appropriate identification of arsenic in soils below typical background concentrations. In turn, the use of BTVs may aid in identifying where risks are truly elevated relative to background, and thus where remediation may or may not be appropriate. http://scholarworks.umass.edu/intljssw/vol2/iss2/1 http://scholarworks.umass.edu/intljssw/vol2/iss2/1 Mon, 03 Aug 2009 12:36:59 PDT A major aspect of lead hazard control is the evaluation of soil lead hazards around housing with lead-based paint applied to specific exterior surfaces. The use of field-portable X-ray fluorescence (FPXRF) to do detailed surveying, with limited laboratory confirmation, can provide lead measurements in soil (especially for planning and monitoring abatement activities) in a more timely manner than laboratory analysis. To date, one obstacle to the acceptance of FPXRF as an approved method of measuring lead in soil has been a lack of correspondence between field and laboratory results. In order to minimize the differences between field and laboratory results, a new protocol has been developed for field drying and sieving of collected samples for field measurement by FPXRF. To evaluate this new protocol, composite samples were collected in the field following both HUD Guidelines and American Society for Testing and Materials (ASTM) protocols, measured after drying and sieving by FPXRF, and returned to the laboratory for confirmatory inductively coupled plasma atomic emission spectroscopy (ICP-AES) analysis. Evaluation of study data from several diverse sites revealed no statistical difference between paired FPXRF and ICP-AES measurements when samples were dried and sieved to less than 250 µm particle size. http://scholarworks.umass.edu/intljssw/vol2/iss1/5 http://scholarworks.umass.edu/intljssw/vol2/iss1/5 Tue, 10 Mar 2009 05:47:02 PDT PCB and Heavy Metal Soil Remediation, Former Boat Yard, South Dartmouth Massachusetts. Michael E. Martin & Marc J. Richards, Tighe & Bond Consulting Engineers. Heavy metals have been added to marine paint for more than 100-years to protect boats from biological, chemical and physical degradation. Polychlorinated biphenyls (PCBs) were added to marine paint starting in the 1940's to give the paint better adhesive properties and to provide anti-corrosion protection from moisture, chemicals and flames (approximately 2% composition of paint). The nature of the contamination at this project Site was primarily heavy metals and PCBs in soil and heavy metals in sediment. The source of soil contamination was from marine paint chips from repainting and maintenance activities conducted at the boatyard since the early 1900s.The source of sediment impacts is believed to be stormwater discharges to the Apponagansett Bay from routine boatyard activities, including power washing of boats. The overall goal of the soil remediation was to reduce PCB and metals exposure point concentrations at the Site to levels that do not pose a risk to human health and the environment. The work had to be conducted during the winter months, so the remedial and construction activities did not interfere with daily marina operations. This paper describes the remediation activities performed at the Site to achieve the overall remediation goal, which included: the chemical treatment of soil to stabilize the soil (bind leachable lead), excavation and off-site disposal of impacted soils and the construction of a multi-layer asphalt cap containment system to restrict access to residual PCBs and heavy metals. Additionally, this paper will discuss the applicable environmental regulations governing the remediation. As a measure to minimize the potential for future contamination, this project also included the construction of a boat wash/washwater collection system to prevent future paint chip debris from entering the environment. http://scholarworks.umass.edu/intljssw/vol2/iss1/4 http://scholarworks.umass.edu/intljssw/vol2/iss1/4 Tue, 10 Mar 2009 05:46:58 PDT The potential health risk from exposure to chemically contaminated soil can be assessed from bioavailability studies. The aims of this research were: (a) to determine the dermal bioavailability of contaminants in soil for representatives of the polycyclic aromatic hydrocarbon class of chemicals, namely, benzo(a)pyrene and naphthalene, and (b) to examine the relative contribution of soil matrix and chemical sequestration in soil with time ("aging") on their bioavailability. In vitro flow-through diffusion cell studies were performed utilizing dermatomed male pig skin and radioactive chemicals to measure dermal penetration. Volatilization of naphthalene was predominant in reducing the amount of chemical available for dermal penetration. Immediate contact with either of two soils reduced volatilization, however, only the soil with higher clay content resulted in reduced penetration. Aging in higher sand content soil and higher clay content soil further reduced skin penetration by 23 and 70 fold, respectively, versus naphthalene in the absence of soil. Benzo(a)pyrene penetration was reduced >88% following immediate contact with either soil with further reductions occurring after aging. While aging in either soil reduced the dermal penetration of both naphthalene and benzo(a)pyrene, the effect on naphthalene was much greater. The results of this study suggest that the bioavailability from dermal exposure to the polycyclic aromatic chemicals examined can be significantly reduced by soil matrix and aging in soil, resulting in reduced potential health risk following dermal exposure. http://scholarworks.umass.edu/intljssw/vol2/iss1/3 http://scholarworks.umass.edu/intljssw/vol2/iss1/3 Tue, 10 Mar 2009 05:46:54 PDT Restoration of natural resources is the ultimate goal of natural resource damage assessment (NRDA). According to the U.S. Department of Interior regulations for NRDA (43 CFR Part 11), Trustees of natural resources develop alternatives that will "restore, rehabilitate, replace, and/or acquire the equivalent of the injured resources." Identification, scaling, and evaluation of groundwater restoration projects has proven challenging. This paper describes potential categories of groundwater restoration projects, including: 1) Generating clean water, 2) Conserving water, 3) Storing water for times of scarcity, and 4) Accessing new sources of water that were previously inaccessible or unusable. Examples of specific types of projects within these broad categories are provided, together with discussion of the particular challenges associated with scaling and evaluating these projects. http://scholarworks.umass.edu/intljssw/vol2/iss1/2 http://scholarworks.umass.edu/intljssw/vol2/iss1/2 Tue, 10 Mar 2009 05:46:50 PDT A large amount of groundwater quality monitoring data has been collected in connection with solid waste landfills regulated by the New York State Department of Environmental Conservation. Although sampling personnel and analytical laboratories are different for each site, a high degree of uniformity in methods is assured by state regulations which govern environmental monitoring at the landfills. In this study, data for selected parameters was pooled from upgradient, presumably uncontaminated, monitoring wells installed in different rock formations at a large number of sites in order to characterize regional variability in ambient groundwater quality. Parameters selected for this study are those considered to be most useful in detecting landfill-derived groundwater contamination and include alkalinity, ammonia, arsenic, chloride, chemical oxygen demand, hardness, iron, manganese, total phenols and total dissolved solids. Comparisons are made with data from monitoring wells downgradient of the landfills and with other available data sets. Emphasis is placed on whether parameters exceed applicable water quality standards in ambient groundwater and whether the parameters selected are reliable indicators of landfill-derived groundwater contamination. This study should be particularly useful in cases where topography, property boundaries or other site constraints make it impossible to site a valid upgradient monitoring point or where groundwater quality impact assessments must be made using a single monitoring point.