Journal Issue: Proceedings of the Annual International Conference on Soils: Volume 14, Issue 1
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2009-01-01
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Comparison Of Naphthalene Ambient Air Sampling & Analysis Methods At Former Manufactured Gas Plant (MGP) Remediation Sites
Fortune, Alyson; Tuday, Michael; Gendron, Leo
Naphthalene is a contaminant of concern at former Manufactured Gas Plant (MGP) and other property redevelopment sites across the country. A major component of coal tar waste and a possible human carcinogen (EPA Group C), naphthalene is a chemical that may adversely affect human health at remediation sites. Due to its boiling point and vapor pressure, naphthalene can exhibit both volatile and semi-volatile characteristics; therefore the question can arise as to how to properly measure naphthalene in ambient air. Two commonly applied methods of measuring vapor phase naphthalene include EPA Method TO-15, which utilizes whole air sampling in passivated stainless steel canisters; and EPA Method TO-13A, which utilizes high volume sorbent based sampling with polyurethane foam/XAD resin cartridges. Analytical differences between these two methods are discussed, keeping reference to naphthalene’s unique chemical & physical properties. This case study presents weekly data spanning a twelve month period (December 2006 – December 2007) from co-located EPA Method TO-15 and TO-13A ambient air samples at the perimeter of two MGP cleanup remediation sites. Distinct trends are noted and discussed in this paper when comparing the concentration results from the two methods.
Forensic NAPL Determination And Plume Differentiation – A Case Study
Stevens, Nathan A.; Moore, Brian D.; Vinch, Carrie A.
Recent developments in laboratory analytical techniques, when combined with application of multivariate statistical analyses allow differentiation and delineation of comingled NAPLs and resultant contaminant plumes. The increase in laboratory expertise and a growing body of relevant studies in case literature have made possible evaluation of petroleum impacted media through relatively standard techniques a reality, and well within the realm of economical site assessments. The application of several methods to determine the number, type, and timing of multiple NAPL releases at a commercial facility in an urban setting will be summarized. The combination of chemical, historical, and statistical techniques has allowed for a more complete evaluation of NAPL sources and release histories than was initially thought possible. In the examined case, overlapping NAPL plumes are defined, delineated, and identified; and source identifications for individual releases are completed. These evaluations resulted in identification of previously unconfirmed sources, improved characterization of the nature of NAPL present, and refined fate, transport, and feasibility evaluations for the conceptual site model.
Off-Grid Photovoltaic System In A Temperate Climate Greenhouse In Virginia
Mose, Douglas; Mandes, Evans; Metcalf, James
Most buildings require power produced by fossil fuels, the extraction and consumption of which contaminate our environment. The Virginia Center of Basic and Applied Science (CBAS, INC) constructed a building in a remote forested area as a plant and fish nursery (and living space for staff) to be operated by solar electrical power. Comfortable summer interior temperature is facilitated by an open design, 15,000 cubic foot interior, ceiling fans, many large windows and doors, with a large sun-screen eave off the 1000 square foot south-facing roof. Comfortable winter temperature is possible because the building has no tree-shade, thick well-insulated walls and roof, a low number of air changes per hour, and when necessary the surrounding forest provides wood stove heat. The energy challenge of the research was to develop a system facilitating 24-hour and year-round use (primarily for lights, fans, pumps, heaters and staff living requirements) that did not need to be connected to the local electrical utility company. On average, the facility uses 3-4 kilowatt hours per day. The solar power is captured by 8 solar panels which charge a bank of deep-cycle batteries, which in turn generate the power for the facility. The complete system (solar panels, charge controller, batteries, DC-to-AC inverter, 110-to-220 transformer) cost about $10,000, about 5% of the total facility cost.
Pulsed Biosparging Of A Residual Fuel Source Emplaced At CFB Borden
Lambert, Jennifer M; Yang, Tianxiao; Thomson, Neil R.; Barker, James F.
Biosparging enhances both aerobic biodegradation and volatilization and is commonly applied to residual hydrocarbon source zone remediation. This technology was applied in pulsed mode to a known source of gasoline contamination in order to quantify the extent of remediation achieved in terms of both mass removed and reduction in mass discharge into groundwater. The gasoline source was created at the groundwater research facility at CFB Borden, Canada. About 40 L of gasoline with 10% ethanol was injected in small volumes from 24 injection points below the water table in 2004. The downgradient plume is still being monitored and the source area was cored in 2007. In 2008, a single-point biosparge system was installed and operated. Water-saturated soils precluded the use of a traditional soil vapor extraction (SVE) system, so an airtight cover was used with soil venting to capture and monitor off-gases. Conservative tracers (He, SF6) and hydrocarbon gas monitoring were intended to assign mass removal to volatilization. CO2 and O2 monitoring in the off-gas confirmed limited biodegradation of hydrocarbons. Post-remediation core analysis and downgradient monitoring of groundwater will be used to define the extent of remediation and decline of mass discharge to the groundwater plume.