Poster Presentations:
Fate of Phosphorus in a Constructed Wetland for Water Reuse
Thomas W. Shartle, Graduate Research Assistant,
Stephen F. Austin State University
CO-AUTHOR
Kenneth Farrish, Director, Division of Environmental Science Stephen F. Austin State University
In order to meet water demand, Tarrant Regional Water District, in conjunction with Texas Parks and Wildlife, developed the Richland-Chambers constructed wetland to improve water quality from the Trinity River before it is released into Richland-Chambers Reservoir. The use of a constructed wetland for water reuse is a new development and with a steady inflow of nutrient rich water, it is important to determine the fate of the nutrients, particularly phosphorus (P), in order to prevent hydrologic burnout of the wetland cells and eutrophication in the reservoir. An analysis of total P, Mehlich-3 P, water extractable P, and a P sorption index in the soil from active cells and an adjacent wetland, based on ten depth increments, was used to determine the fate of P in the wetland system. In addition, a simulated tillage experiment followed to determine any increase in P fixation potential. Preliminary results will be presented.
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The Temporal and Spatial Breeding Bubble of the Great Egret
Laurissa Noack, Graduate Student, Department of Marine Sciences, Texas A&M University at Galveston
The colonial-nesting Great Egret (Ardea alba) utilizes a distinct 3-dimensional space amongst nest site foliage to build their nests, attract mates, copulate, lay eggs, incubate and hatch eggs, and rear their young. This defined space or Breeding Bubble can fluctuate based on the particular action being performed, but every behavior is accomplished within this nesting site niche. This study uses video analysis of the breeding/nesting behaviors of A. alba on the Heron Island Rookery at Smith Oaks Sanctuary, High Island, Texas from the 2010 nesting season. Measurements derived from their morphology and behavior will determine their spatial breeding habitat requirements or individual Breeding Bubble. When these assorted Bubble requirements are combined, they may provide a better understanding of rookery spatial architecture. Coastal rookery habitats are naturally dynamic environs due to variable seasonal conditions and natural disasters such as flood, drought, or hurricanes. To foster breeding success, rookery managers will often construct simple, single-story, horizontal breeding/nesting platforms for the birds to occupy when additional habitat is needed. By utilizing Breeding Bubble spatial and temporal dimensions in platform design, management of colonial-nesting water birds’ breeding/nesting habitat can be enhanced.
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Repetitive Flood Loss Challenges in Texas and Recommendations for Management
Sarah A. Norman, Center for Texas Beaches and Shores, Texas A&M University at Galveston
CO-AUTHOR
Samuel R. Brody, Wesley Highfield, Center for Texas Beaches and Shores, Texas A&M University at Galveston
The National Flood Insurance Program (NFIP) was established in 1968 to address national flooding issues as a policy-driven mitigation strategy. The NFIP allows properties with repetitive losses to continue to receive coverage, unless the property has sustained damages of 50% or more. This clause has encouraged continued development in flood prone areas and created a challenge for the NFIP to reduce repetitive flood loss claims. Repetitive flood loss claims in Harris County, Texas, from 1978 through 2009 were analyzed regarding date of loss, hurricane-related claims, and claims filed before and after a county-wide floodplain update on June 18, 2007. A total of 9,450 flood claims filed from 2,986 properties were examined and assessed using an including independent samples t-test. Findings include that 34.68% of repetitive flood losses were filed related to a hurricane, 47.4 % of all flood losses were filed on properties outside the floodplain, and 52.60% of all flood losses were filed on properties inside the floodplain. When grouped by claims filed before June 18, 2007 and claims filed after June 18, 2007, 54% of claims were filed inside the floodplain before the floodplain update as opposed to 39% of claims filed inside the floodplain after the floodplain update. In the 31 years of repetitive flood loss claims analyzed, over $350 million in flood insurance was paid through the NFIP to the Harris County properties. Floodplain delineation is a key factor in determining whether a homeowner is required to obtain flood insurance. In this study, implications for utilizing management tools other than floodplain delineations are examined and recommendations for future management alternatives are discussed.
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Heavy Metal Accumulation in Different Growth Forms of Spartina alterniflora
Lindsey McMahan, University of Houston Clear Lake
Spartina alterniflora (smooth cordgrass) is a salt tolerant grass found along the east and southeast coasts of the United States. It is an ecologically important species in numerous marshes as it provides habitat and food and is often used in erosion control or phytoremediation. Three phenotypic growth forms of the species are recognized in Galveston Bay: short, intermediate, and tall. Numerous studies have measured the uptake, accumulation, and excretion of a variety of metals in S. alterniflora, but none appear to have compared these measures among growth forms. The objective of this study was to determine if different growth forms of S. alterniflora vary in: (1) the amount of heavy metals they uptake, or (2) in the locations in which heavy metals are accumulated within the plant. Grasses collected from Galveston Bay were exposed to one of five metal treatments (Cd, Cr, Cu, Pb, or Zn) hydroponically in the laboratory and then each tissue type was analyzed separately to measure heavy metal accumulation and excretion. No significant differences in metal concentrations were found among growth forms in the roots of exposed plants. However, leaves of the short form accumulated significantly more cadmium and lead, while stems and excreted salts of the short form contained significantly more lead and zinc. These results provide evidence of ecotypic variation in the accumulation of several metals, and indicate that taller forms of the species are more likely to restrict heavy metals to belowground biomass and decrease the bioavailability of contaminants.
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Comparison of Glutathione Reductase Activity Among Native and Pollutant-Impacted Spartina alterniflora Marshes in Galveston Bay, Texas
CL Gauthier*, JM Borski, and CL Howard, University of Houston Clear Lake, Texas
Coastal wetland habitats in the Galveston Bay estuary provide many services by functioning as nurseries for juvenile finfish and shellfish, bird sanctuaries, and storm buffers for the Texas coast. The fundamental health of these Spartina alterniflora marsh grass communities and how they tolerate or adapt to environmental and pollution stresses, is still largely unknown. In plants, cellular glutathione (GSH) is essential for defense against a variety of natural and pollutant stressors. The antioxidant enzyme, glutathione reductase (GSR) maintains adequate levels of cellular GSH within plant cells. High levels of heavy metals in the surrounding environment are known to induce glutathione reductase activity (GSR). As part of a large study on biomarkers of stress in S. alterniflora, GSR activity was measured as a biochemical indicator of oxidative stress in 182 individuals from seven sites representing unimpacted native and heavy metal-impacted coastal salt marshes in the Galveston Bay system. At each site, S. alterniflora shoots were collected from nine stations for heavy metal analysis and GSR analysis. GSR activity was determined using the Sigma-Aldrich Glutathione Reductase Assay, which provided colorimetric spectrophotometric results. Individuals collected from the pollutant-impacted sites exhibited twice the GSR activity when compared with those obtained from unimpacted native sites and GSR activity was also correlated with specific heavy metals.
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Electricity Generation Using Municipal Solid Waste in Waste-to-Energy Technologies
Oneida Ana Watson, Rice University
Efforts to boost renewable energy have focused on wind, solar and biomass alternatives; however, electricity from municipal solid waste (MSW) can provide the benefits of alternative renewable fuels while simultaneously reducing the amount of discarded waste. Incineration, the primary WtE technology used in the USA, can cause adverse environmental impacts and is limited in efficiency and electricity generation. In contrast, pyrolysis, gasification (conventional and plasma), and co-combustion of MSW are WtE technologies that can offer higher electricity generation (EG) efficiencies, ranging from 18-45%, while lowering the environmental and landfill costs associated with MSW disposal and incineration. Although these technologies can mitigate air and water quality degradation by lowering NOx, SOx, furan and dioxin emissions and are already used in energy portfolios in the EU and UK, they are not widely used for MSW in the USA. Current research with these WtE technologies is lacking when determining which is more efficient, environmentally sound or economically viable, or to equip municipalities with comprehensive information to determine the optimal WtE technology for their region.
This research uses AspenTech software for both static and dynamic simulations for modeling gasification, pyrolysis, co-combustion and incineration for efficiencies, pollutants and thermodynamic stability of pertinent reactions when varying MSW composition and local environmental conditions. Simulations for combustion processes associated with gasification and pyrolysis include gas engine, steam turbine and combined cycle gas turbine. Expected results of this research include identifying efficacy factors for each WtE technology, promoting landfill disposal reduction, and determining the EG efficiency for each WtE technology as a function of MSW compositions (including moisture content) and operating conditions. Municipalities and local contractors can use these results to determine which WtE technology is best suited for a region. Future research includes quantifying the effect of local environmental regulations and economic conditions on WtE power plant profits and placement.
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Modeling the impact of Inland Wetland Destruction on Flood Hydrology
Brandon Duncan, Rice University
This study uses a distributed hydrologic model, VfloTM, to assess the impact of wetland destruction on watershed response. Conventional wisdom suggests that inland wetlands generally have a much larger impact on watershed response than expected given their area. In light of this, wetlands may have significant flood-mitigation potential. However, two hurdles have generally prevented hydrologist from quantifying this impact: data availability and the lack of the appropriate model.
Over the last few decades wetland delineation and hydrologic data has become increasingly available. From the 1992-2008 approximately 55% of the wetlands in the Deihl Subcatchment of Houston’s White Oak Bayou Watershed were destroyed. Throughout this time period the rain and flow of this watershed have been monitored by the United State Geological Survey and the Harris County Office of Homeland Security and Emergency Management because of its proximity to downtown Houston. As data availability has grown, the capacity of computers has also grown to allow for easy use of distributed hydrologic models. The use of a distributed hydrologic model is critical because they allow for the consideration of finite areas, such as wetlands, on watershed response. This study uses this data and model availability to assess the impact that wetland destruction has had on flood peaks in the Deihl Subcatchment.
Platform Presentations: SESSION 1 ABSTRACTS - SOILS
Successful Use of Passive Soil Gas Survey in Tight Soil
Richard Rexroad, Brown and Caldwell, Inc., Houston, Texas
Previous experiences with active soil gas surveys led to a “rule-of-thumb” conclusion that the effectiveness of soil gas surveys as a site assessment tool is typically limited to sites with relatively coarse-grained, sandy soil. Brown and Caldwell recently completed a passive soil gas (PSG) survey at a site characterized by a heterogeneous mixture of generally tight fine-grained near-surface soil in Rock Springs, Wyoming using equipment and analysis provided by Beacon Environmental Services, Inc. (Beacon). This PSG survey successfully defined the lateral extent of hydrocarbon-impacted soil at two separate site source areas and demonstrated the applicability of PSG surveys as a site assessment tool for hydrocarbon plumes in sites with tight soils.
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A Statistical Approach for Soil Remediation and Site Closure – Former Oilfield Equipment Rental Facility
Yanping Ren, PhD., PE, Brown and Caldwell, Inc., Houston, Texas
Polycyclic aromatic hydrocarbon (PAH) constituents have been detected above Texas Risk Reduction Program (TRRP) protective concentration levels (PCLs) in soil at depths ranging from 0 to 5 feet below ground surface (bgs) at a former oilfield equipment rental facility (the Site). An interim response action was implemented to excavate the impacted soil, treat the impacted soil, and backfill the excavated areas with the treated soil.
To facilitate the soil remediation and to evaluate the effectiveness of the interim response action at the Site, a statistical approach was developed. The solution included utilizing Geographic Information System (GIS) technology to identify areas with chemical of concern (COC) concentrations exceeding the PCLs, predicting COC distributions at the Site using geostatistical methods, simulating soil removal scenarios from the contaminated areas, developing post-excavation representative concentrations, and comparing the representative concentrations to the PCLs to demonstrate compliance with TRRP rules. This statistical approach minimized the client’s overall site liability and positioned the client for a timely and cost-effective site closure.
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Geological and Statistical Lines of Evidence for Site Closure in Determining Site-Specific Arsenic Background Concentration
Richard Rexroad, PG and Yanping Ren, PhD, PE., Brown and Caldwell, Inc., Houston, Texas
Elevated arsenic concentrations have been detected above Texas Risk Reduction Program (TRRP) protective concentration levels (PCLs) in soils at a former oilfield equipment rental facility (the Site). Multiple lines of evidence were employed to demonstrate that elevated arsenic concentrations were due to naturally occurring background. The multiple lines of evidence included:
1. An evaluation of site and regional geology;
2. Graphical analysis with statistics;
3. Mann-Kendall trend analysis; and
4. Geochemical association analysis.
Based on the above multiple lines of evidence, it was determined that elevated arsenic concentrations detected in soils at the Site could be attributed to the naturally occurring presence of arsenic in background soils. This geological and statistical lines of evidence approach minimized the client’s overall site liability and positioned the client for a timely and cost-effective site closure.
Platform Presentations: SESSION 1 ABSTRACTS - INNOVATIVE TECHNOLOGY 1
Solar Power on Landfills
Mark Landress, P.G., Project Navigator, Ltd., Houston, Texas
Landfill space represents an unused asset that typically sits idle with little effective use after closure of the landfill. In an attempt to utilize landfill space more effectively, and to capitalize on what would otherwise be unused landfill space, installation of solar cells is being proposed and implemented at landfills across the nation. Reuse of landfill space is supported by municipalities and by EPA. Tax credits and other financial incentives favor the economics of solar development on landfills. Geographic location, layout and size and other factors also affect the feasibility of solar installations. Because of the issues surrounding operation of landfills, a combination of skills to manage the environmental and solar development is needed for a successful solar installation to be developed. This paper discusses the rise of solar power on landfills and the progress made in the industry in support of solar development.
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Environmental and Economical Opportunities Made Possible by Advanced ATP Monitoring
Dave Tracey and Pat Whalen, LuminUltra Technologies, Ltd., 440 King Street, King Tower Suite 630, Fredericton, New Brunswick, Canada, E3B 5H8. Bill Travis, Thornton, Musso, & Bellemin, P.O. Box 181, Zachary, Louisiana, USA, 70791
One of the biggest barriers associated with wastewater treatment is the lack of information relating to the living biomass population within the process. Operators are limited to solids measurements and various inferred parameters that limit the degree to which the process can be optimized. As such, treatment plants often operate at biomass levels that are well above what is needed in order to minimize the possibility of off-spec effluent. Operating under these conditions, however, requires significantly more power and resources than what is needed to maintain an optimized process.
In order to provide a direct indicator of living biomass, LuminUltra Technologies, Ltd. has developed a rapid and portable test kit concept that measures the total active biomass content in any wastewater sample in less than five minutes. This provides a unique opportunity to optimize wastewater treatment processes to reduce environmental impact while maximizing process efficiency. By decreasing the biomass population to a more reasonable level, the amount of carbon dioxide produced would significantly drop, along with the electricity requirements needed to support this larger population.
This technology is based on the measurement of ATP (Adenosine Triphosphate), the primary energy transfer molecule present in all living cells on Earth. As such, its measurement is a direct indication of the microbial population in water. This technology is already widely utilized to verify disinfection efficacy in the food industry and is also commonly applied in industrial cooling water systems to monitor microbial growth and biocide applications. However, until now, ATP monitoring technology has not been applied to monitor active biomass in wastewater systems.
The proposed session will discuss the background on this 2nd generation ATP monitoring technology, the information that the tests provide, and real-life case studies showing how it has provided invaluable benefit to the wastewater treatment industry in terms of improved efficiency, enhanced stability, cost savings, and environmental benefits.
Platform Presentations: SESSION 1 ABSTRACTS - REMEDIATION
Ex-situ Treatment of Trichloropropane-Impacted Soils
Rick Wenzel, Remediation Lead, The Dow Chemical Company 6519 HWY 225 Deer Park, Texas 77536
Rohm and Haas Chemicals LLC (Rohm and Haas) and Parsons recently completed an EPA-approved corrective measure cleanup at a former Morton International Facility in Moss Point, Mississippi. Cleanup of the North Woods Area will allow that part of the facility to be developed for industrial use.
Prior to the mid-1970’s, the undeveloped, seven-acre North Woods Area was used for management of construction and maintenance materials and some of the Site’s drummed, off-specification batches of polysulfide rubber products which contained trace amounts of 1,2,3-trichloropropane (TCP). Over time, the drums deteriorated leaving a tar/rubber material on the surface, and allowing TCP to leach into the soil. Investigation of the North Woods Area delineated about 7,500 cubic yards of the underlying clayey soils to be impacted to depths of nearly 40 feet over a 150-foot by 180-foot area.
In-situ remedies were evaluated but were deemed to be not practical due to the dense clay nature of the soil matrix. Rather than excavating and disposing of the impacted soil at an approved off-site landfill, the Mississippi Department of Environmental Quality, US Environmental Protection Agency and Rohm and Haas chose to treat the soil on-site via soil aeration (landfarming) using specialized soil remediation equipment (SCARAB) to allow the TCP to dissipate and photo-degrade in the air. The soil was treated using the SCARAB equipment until agency-approved soil clean-up goals were achieved. The clean-up goals were established based on the future land use and the site risk assessment for industrial and construction worker direct contact to surface and sub-surface soils. The treated soils were then returned to the excavated area as backfill, eliminating the need for off-site sources of backfill.
In evaluating the efficacy of this remedial approach, SESOIL and atmospheric dispersion modeling were conducted. Soil borings and SESOIL modeling confirmed the site conceptual model that TCP was not leaching to the water-bearing zone underlying the thick clay which extends to a depth of 65 feet below grade. Air dispersion modeling, based on projected worst-case, full-scale soil treatment conditions, predicted that the remediation could be done while protecting the health of both on-site workers and off-site residents. Air monitoring was conducted with GC/MS and calibrated PIDs to measure the TCP level in air in the treatment area and at the fence line. The measured concentrations of TCP remained significantly below the predicted concentrations and well below regulatory levels.
The remediation of the 7,500 cubic yards of TCP-impacted soil using the SCARAB equipment allowed the soil to be treated on-site over a two-month period; clean-up goals were achieved; and the treated soil was used as backfill in order for the property to be returned to productive industrial use. The remediation was conducted without any safety incidents while being protective of workers and off-site residents.
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Remediation using Alkaline Activated Sodium Persulfate with Case Studies
Douglas D. Carvel, PE, MECX LP, 3203 Audley Street, Houston, TX 77098
Case studies will provide a detailed design process for the use of solid peroxygens and catalysts in the application of alkaline activated sodium persulfate (A-ASP). The presentation presents the effects on soil, groundwater, and NAPL during aggressive chemical oxidation bench and pilot tests and how these effects are used to optimize the remediation performance. The studies present Chemical Oxidation (ChemOX) techniques using solid oxidants both ex-situ and in-situ for the treatment of organics in both soil and groundwater. The solid oxidants that are used are sodium percarbonate, sodium persulfate, and calcium peroxide in combination. The application techniques employed the use transition metal catalysts and pH adjustments as activators to ensure proper deployment of the technology. This study will describe the specific techniques to ensure activation, their applicability in various soils/geologies, saturated conditions, and types of contaminants. It will also discuss specific design considerations for each approach to ensure proper delivery, ensure contact with the contaminant, avoid excessive displacement or migration, and provide a safe work place during application.
Additionally, the study of the A-ASP pilot application of In-situ Chemical Oxidation (ISCO) using alkaline activated sodium persulfate (A-ASP) for the treatment of NAPL and high sorbed mass used a delivery technique which included recirculation of groundwater from the targeted treatment zone to enhance contact and to minimize migration. This study will describe the specific techniques that were used in this alluvial dolomitic geology by MECX to ensure the effective application of this technology. It will also discuss issues that were addressed during design to ensure proper contact with the contaminant without short-circuiting, avoid excessive displacement or migration, and provide a safe work place during application.
This paper presents specific information on proper chemical mixing and handling considerations, the complete understanding of the lithology and hydrogeology, necessity of properly screened well intervals, and the need to real time monitoring of secondary treatment parameters during treatment. This paper also presents a summary of when the specific technology is most likely to be most effective and what specific application techniques should be employed to ensure contact with the contaminants. The paper does not have data with direct comparison of the application of these technologies and will provide a summary of the observed limitations and benefits of each approach that MECX has applied.
Platform Presentations: SESSION 2 ABSTRACTS - AIR / INDOOR AIR
Evaluation of Sub-Slab and Indoor Vapor Data at Petroleum Impacted Site
Deepankar K. Vaidya, E.I.T. and Atul M. Salhotra, Ph.D., RAM Group of Gannett Fleming, Inc. Houston, TX
This paper presents an evaluation of sub-slab and indoor vapor data collected at petroleum impacted site, located about 3,000 feet east of the Mississippi River and covering an area of approximately 150 acres with 600 homes and commercial properties. East and north of the site are oil refineries, petroleum product storage facilities, and related infrastructure. Underground pipelines that run east-west through the site have transported petroleum products to and from these facilities to the Mississippi River. Other pipelines run along the east and west boundaries of the site have transported petroleum products from the refineries to a storage terminal and pumping station north of the site. Several of these pipelines are no longer in use.
This infrastructure has existed since early 1900’s. There have been spills and leaks of petroleum products of various magnitudes, which have resulted in petroleum hydrocarbons beneath the northern portion of the site (approximately 51 acres) in the form of recoverable LNAPL (Light Non-Aqueous Phase Liquid), residual LNAPL, dissolved phase, and vapor phase. Historically, there have been periodic fires attributed to these petroleum hydrocarbons and complaints of gas odors in homes, although no fires attributed to such contamination have been reported since 1990. Numerous mitigation measures have been conducted which include but not limited to (i) in-home monitoring, using Tedlar bags and Summa canisters, (ii) options to reduce potential vapor intrusion, (iii) groundwater monitoring, (iv) vapor extraction system, and (v) LNAPL removal activities.
This paper will present the specifics of the data collected and the analysis specifically related to potential indoor vapor intrusion; and the effect of water fluctuation (due to river fluctuation) on potential vapor intrusion.
The analysis and conclusions from this paper will further help in evaluation of potential vapor intrusion and the development of vapor intrusion guidance for regulatory agencies.
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Effect of Barometric Pressure on Soil Gas Transport and Vapor Intrusion
Bhoom Reddy Korpol and Atul M. Salhotra, Ph.D.,RAM Group of Gannett Fleming
Atmospheric pressure near land surface is constantly changing due to gravitational, diurnal and long term cycles due to weather system. Changes in barometric pressures result in subsurface advective vapor movement in the unsaturated zone, this phenomenon is referred as barometric pumping. As per the barometric pumping effect, subsurface gases move upwards during periods of decreasing atmospheric pressure and atmospheric gases move downwards into the subsurface during periods of increasing barometric pressure.
This study evaluates the effect of barometric pressure on the vapor transport in the vadose zone at a hydrocarbon impacted site in the Midwest. The seasonal and diurnal variation of barometric pressure and hourly subsurface pressure data measured at several wells was evaluated. The correlation between the barometric pressure and the subsurface pressure in various zones (by depth) at nine monitoring well nests for a total of 31 wells was also evaluated. An annual variation of greater than 20 inches of water of barometric pressure was observed during the three years for which the data was evaluated. Barometric pressure varied from day to day but there was very little systematic variation during a day, although one would expect some diurnal variation. Subsurface pressures at several wells followed the trend of barometric pressure, but the data did not indicate a clear correlation at other wells.
The gauge pressure (difference between the subsurface pressure and barometric pressure) in the very shallow zone, and the gauge pressure difference between the shallow and very shallow zone determines the advective vapor transport in these zones there by effecting the vapor intrusion. The data does not indicate a clear trend in the direction of vapor flow in relation with the barometric pressure. Although the subsurface pressures depend on the barometric pressure variation, there is no clear evidence to indicate that the barometric pumping effect is significant at this site. The results of this analysis would help to evaluate indoor vapor intrusion and to design soil vapor collection systems.
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New Oil and Gas Permit By Rule (PB) and Standard Permit
Lisa Swanson, Providence Engineering, Houston, Texas
The Texas Commission on Environmental Quality (TCEQ) has recently shifted a large amount of their attention to the oil and gas industry. Two of the most common air permit authorizations for these types of activities are the oil and gas permit by rule (PBR) and the oil and gas standard permit. Currently, these two authorizations are relatively straightforward, i.e. the current PBR is less than one page long and authorizes typical oil and gas operations. However, the TCEQ has recently proposed a new PBR that is 23 pages long and will require additional effort to authorize these typical operations. This rule is expected to be finalized on December 14. This presentation will be a summary of the new air permitting mechanisms for oil and gas facilities in Texas.
Platform Presentations: SESSION 2 ABSTRACTS - INNOVATIVE TECHNOLOGY 2
Superfund Redevelopment
Mark Landress, P.G., Project Navigator, Ltd.
CO-AUTHORS:
Kris Wachter, Brett Braden, Phoenix International Terminal, LLC
Redevelopment of federal Superfund sites poses a unique challenge to purchasers and developers, particularly where the site remains with impacted soil, landfill cells and ongoing operations and maintenance. Location, market, site conditions and development concepts all impact the ability to develop former Superfund sites. A case study is presented highlighting the actual purchase and sale of a remediated Superfund site in Texas and some of the challenges and successes involved in the transaction from the developer’s perspective.
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Regeneration of Carbon Nano Foam Exhausted in Capacitive Desalination
Sanjay Tewari, Ph.D. Candidate, Environmental & Water Resources Engineering Division and Bill Batchelor, Arthur McFarland Professor, Zachry Department of Civil Engineering, Texas A&M University, College Station, TX 77843
Brackish and salt water is one of the main problems in gulf coast and neighboring area. In this study Carbon Nano Foam (CNF) has been used for desalination as well as removal of heavy metals from brackish and salt water. In the past, carbon has been used in different forms for water treatment including electrochemical desalination. The CNFs are a type of carbon aerogel (CA). These are a new type of material with many of the properties of traditional CAs. They are synthetic foams with very low density, three dimensional framework, nanometer-scale pores, continuous porosity, high surface area and electrical conductivity. They are available in various forms but only paper form was used for these experiments. Electro-sorption based capacitive de-ionization (CDI) technology was used with CNF electrodes. When two oppositely charged electrodes put very close (in this case about 1-2 mm) to each other they act as a capacitor and when placed in the water to be treated, ions are first trapped in the double layers near oppositely charged electrodes and then they are adsorbed onto the porous carbon surface, producing relatively clean water. A DC voltage (1-2 Volts) is applied to the CNF electrodes. CNF electrodes, once saturated with counter ions, lose their adsorptive capacity and would need to be replaced. This increases the cost of the treatment process, because CNFs are expensive. Regeneration and reuse of exhausted CNF will eliminate this problem and will provide an energy efficient, cost effective water purification process. Very little work has been documented on regeneration of the CA/CNF and the proper methods of operation in order to maximize the quantity of clean water produced. Modeling of regeneration behavior of CA electrodes is not available. The goal of this study is to investigate the regeneration of exhausted CNFs and to develop optimal regeneration procedures and the ability to predict performance by examining desorption behavior of adsorbed ions on CNF electrodes and developing a model to describe desorption behavior. Results show that reverse potential plays important part in regeneration of CNF but duration of application of reverse potential is equally important. If reverse potential duration is too short then not many adsorbed ions are pushed out of pores into solution stream but at the same time if it is applied too long then after adsorbed ions are pushed out of pores into solution stream they are re-adsorbed on opposite electrode. Also, the duration of application of reverse potential for maximum regeneration varies with variation in temperature and flow speed. Maximum regeneration of about 98% was achieved for one set of conditions proving CNF can be regenerated successfully and can be used multiple times (about 100 times) in water purification/desalination. Experiments to evaluate the effect of mass, size and the charge of ions on regeneration are complete, interesting data has been collected and being analyzed. Experiments to evaluate the effect of density and pore size of CNF on regeneration are being done.
Platform Presentations: SESSION 2 ABSTRACTS - WASTE MANAGEMENT
Sales or Science – Is Effective Marketing or Good Science and Engineering Controlling the Selection of Remedial Technologies
Douglas D. Carvel, PE, MECX LP, 3203 Audley Street, Houston, TX 77098
A study of various inappropriate In-situ Chemical Oxidation (ISCO) technologies and application techniques that have been selected for treatment at various sites throughout the USA and EU. These approaches were not the optimum for the sites but were selected based on the salesmanship of the chemical vendor or applicator. In all cases, a thorough scientific engineering feasibility evaluation would have selected a more effective and efficient alternative technology for application at the site.
This paper presents a summary of when specific technologies have been recommended and selected even though they are clearly not the optimal solutions. We will demonstrate why they were not the most applicable for the given application based on their incompatibility with the targeted contaminants, geology, or cleanup objectives for the sites and provide information on why the technology was selected based on interviews with the responsible engineers and scientists.
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The Relevancy of Background Concentrations of Polychlorinated Dibenzo-Dioxins (PCDDs) in Toxic Tort and Property Contamination Cases
Randy Horsak, Principal Consultant, 3TM Consulting, LLC, 955 Dairy Ashford, Suite 206, Houston, Texas 77079
The release of toxic chemicals to off-site receptors can impact not only public health but also property values. A major regulatory, scientific, and legal consideration is the level of contaminant measured in various environmental matrixes in receptor samples vis-à-vis background levels. This paper presents a methodology for assessing background levels for Dioxins based on publicly available regulatory and scientific data and 3TM sampling events throughout the United States.
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Optimized Selection of Landfill Sites in Houston Area Using Geographical Information System
Dong Zhai, Student, University of Houston, Clear Lake, TX
CO-AUTHOR:
Chunlong Zhang, Professor, University of Houston, Clear Lake
With the fast economic and population growth in Houston-Galveston area, more and more municipal solid wastes are generated in the region. It is expected that more landfill sites need to be built in the future within the next ten or twenty years in Houston-Galveston area. The objective of this study is to identify the best locations for the future landfill sites in Houston-Galveston area using geographical information system (GIS). Landfill site selection is a very important step before building the landfills. An optimized site selection will maximize the cost saving for waste transportation while minimize the adverse social and environmental impacts. In this study, GIS data of different geographical features in Harris County and Galveston County were collected, including constrains of flood plain, streams, hurricane areas, schools, museums, water bodies, hospitals, parks, natural refugee areas and airports that are prescribed by federal and state regulations on landfill sitting. We customized the GIS and generated a grid system composed of grids with 50 acres size. GIS spatial selection method was used to identify the grids that are out of the impact on various environmental sensitive areas. These selected grids have been evaluated in Google Earth using the KML technology. Preliminary results have identified several best sites for future landfills in the region, mainly in the Northeast Harris County and Northwest Harris County.
Platform Presentations: SESSION 3 ABSTRACTS - BIOREMEDIATION
Substrate Loading Strategies for Enhanced Reductive Dechlorination
Michael R. Sieczkowski, CHMM, and Donovan Smith, P.E. JRW Bioremediation, L.L.C., Lenexa, Kansas
Adding organic substrates to enhance the anaerobic bioremediation of chlorinated solvents has become a widespread remedial option. The general goal of the process is to add sufficient substrate to establish and maintain anaerobic conditions conducive to reductive dechlorination for a period of time sufficient to degrade all constituents of concern and their daughter products. Common substrates used include molasses, lactates, vegetable oil, and solids like wood mulch or whey powder. At issue has always been how much substrate to use for any given site. Early designs were based on a stoichiometric ratio, or the theoretical amount of hydrogen available from the substrate compared to the theoretical amount of hydrogen need to chemically reduce the electron acceptors and the constituents of concern in the treatment zone. It was quickly realized that this method did not provide sufficient substrate to establish and maintain anaerobic conditions so minimal substrate loadings and “additional demand factors” and “safety factors” were added to the calculations. These corrections could represent more than 80% of the calculated mass of substrate required to treat an area.
In many cases where the competing electron acceptors or additional demand factors were high, the systems exhibited reduced microbial activity. The “more-is-better” approach didn’t always help as many of these systems were determined to be negatively impacted by a drop in pH most likely due to an over-abundance of carbon. In theory, when a carbon substrate is fermented, a number of processes are set into motion that can reduce the pH of a system. Carbon substrates are metabolized resulting in the formation of various volatile fatty acids (VFA), hydrogen is produced through fermentation of VFAs, and when chlorine is removed from a chlorinated hydrocarbon through reductive dechlorination, free chlorine is released. All of these can impact pH, especially in a poorly buffered system and if the pH dropped enough to stress the dechlorinating microbial populations, the rate of contaminant degradation could be slowed or even stopped. In addition, reduced pH conditions along with a low reductive-oxidation-potential can result in the formation of errant byproducts such as acetone and butanone. One alternative method of determining the substrate “loading rates” is through a simple calculation of minimum and maximum concentrations of any specific substrate needed in a particular system based primarily on substrate dissolution rate and the minimum and maximum substrate mass required to establish and maintain optimal conditions, with contaminant and competing electron acceptor concentrations as secondary considerations. This presentation reviews the problem and compares the two approaches with both a readily soluble and a slow release substrate.
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Effect of Nano-scale Zero Valent Iron Particles on a Mixed Culture Dechlorinating Trichloroethylene
Zong-ming Xiu, Key Laboratory of Pollution Processes and Environmental Criteria, Ministry of Education, Nankai University, Tianjin 300071, Dept. of Civil & Environmental Engrg., Rice University, Houston, TX
Kelvin B. Gregory and Gregirt V. Lowry, Dept. of Civil & Environmental Engrg., Carnegie Mellon University, Pittsburgh, PA
Pedro J. J. Alvarez, Dept. of Civil & Environmental Engrg., Rice University, Houston, TX
Nano-scale zero-valent iron particles (NZVI) are increasingly being used to treat chlorinated solvents contaminated sites. The effect of NZVI on dechlorinating microorganisms that participate in the anaerobic bioremediation of such sites was investigated. NZVI can have a biostimulatory effect associated with water-derived cathodic H2 production during its anaerobic corrosion (730 ± 30 µmol H2 was produced in 166 h in abiotic controls with 1 g/L NZVI) or an inhibitory effect upon contact with cell surfaces (assessed by Transmission Electron Microscopy). Methanogens, which are known to compete for H2 with dechlorinators, were significantly biostimulated by NZVI and methane production increased relative to NZVI-free controls from 58 ± 5 to 275 ± 2 µmol. In contrast, bacteria dechlorinating TCE were inhibited by NZVI, and the first-order degradation rate coefficient decreased from 0.115 ± 0.005 h-1 (R2=0.99) for controls to 0.053 ± 0.003 h-1 (R2=0.98) for treatments with 1 g/L NZVI. Ethene production from TCE was initially inhibited by NZVI, but after 331 hours increased to levels observed for an NZVI-free system (7.6 ± 0.3 µmol ethene produced in 502 h compared to 11.6 ± 0.5 mmol in the NZVI-free system and 3.8 ± 0.3 µmol ethene for NZVI alone). Apparently, cathodic H2 was utilized as electron donor by dechlorinating bacteria, which recovered following the partial oxidation and presumably passivation of the NZVI. Overall, these results suggest that reductive treatment of chlorinated solvent contaminated sites with NZVI might be enhanced by the concurrent or subsequent participation of bacteria that exploit cathodic depolarization and reductive dechlorination as metabolic niches.
Platform Presentations: SESSION 3 ABSTRACTS - ENVIRONMENTAL SUSTAINABILITY
Environmental Sustainability
Heidi Massin, Sustainability Professional, Massin Consulting Services, LLC
U.S. industries have been embracing the drivers of ‘Environmental Sustainability’ rapidly in the past 5 years. Thousands of articles and papers have been published to date on the subject of sustainability. Today there are still many companies striving to “go green” yet do not know how or even know where to begin the process. The key to environmental sustainability is a combination of educating and allowing the free markets to do what they do best, and that is to offer competitive products that truly do less or no harm to the environment.
The cost of sustainability, or “going green”, generally thought to be too expensive, in reality, is not! This paper will focus on both the educational needs as well as the ‘real’ costs associated with “greening”. Environmental sustainability includes accounting for social costs, those intangibles, that generally do not denote a specific value in dollars, yet are real. In education, comes a shift in consumer behavior. The big difference is now after only 5 short years in the U.S., there are businesses that manufacture, produce and sell true green, sustainable products. These manufacturers and the products they produce today continue to drive business, which in turn, helps keep the balance of the triple bottom line viable. This includes all aspects of environmental sustainability: economic, environment and social.
This paper will discuss the behavioral aspects of sustainability, and how human ingenuity ultimately has shaped the shift in business models by which the over-arching environmental sustainable movement evolves.
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The Growing e-Waste Issue
Clive Hess, Commercial Vice President of CompuCycle, Houston, TX
In August 2010, EPA Chief Administrator Lisa Jackson declared that preventing e-waste and its irresponsible management was one of the US Environmental Protection Agency’s top six newly announced global priorities. While this is not the first time e-waste has been pushed to the forefront of the environmental agenda, the DTV transition was calculated to have increased e-waste by as much as 70%, this new emphasis on creating industry standards for e-cyclers brings forth issues the general public has never considered.
The problem is that most “recyclers” in the U.S. don’t really recycle our old electronics. Instead, they ship them by the container load to developing nations, like China, India, Ghana, and Nigeria. There, the toxic chemicals inside these products cause great harm, contaminating air and water, and exposing workers and communities to horrible, harmful chemicals.
So far, 30 states have passed legislation mandating statewide e-waste recycling. However, a national standard is yet to be passed. Some recyclers have already become certified to follow industry standards set forth by such entities as EPA, Electronics Take Back Association and the Basel Action Network. The vast majority, however, have not. Up to 80% of obsolete TV’s, computers, cell phones and other electronics exported are overseas by unscrupulous recyclers are dumped or burned according to the Basel Action Network.
Platform Presentations: SESSION 3 ABSTRACTS - SURFACE WATER
BIG Ideas for Cleaner Waters – Making Houston Area Waterways Safer for Swimming
Rachel Powers, Houston-Galveston Area Council
The most common water quality impairment in the Houston-Galveston region is the presence of bacteria. When a water body is designated as impaired, the Clean Water Act requires that a Total Maximum Daily Load be developed for each segment of the body of water. A TMDL is a calculation of the maximum amount of a pollutant that a water body can receive and still safely meet water quality standards. Once a TMDL is completed, an Implementation Plan (I Plan) must be developed, which recommends best management practices designed to reduce the pollutant and restore the waterway to its designated use.
The Texas Commission on Environmental Quality (TCEQ) notified the Environmental Protection Agency (EPA) as early as 1996 that some of its streams were impaired for contact recreation due to high levels of bacteria. Section 303(d) of the Clean Water Act requires the TCEQ to adopt TDMLs for all of the affected segments. The ultimate goal of this I Plan is the reduction of bacteria concentrations in the 62 bacteria-impaired segments included in this I Plan for which TMDLs have been adopted by the TCEQ.
The TCEQ adopted 18 TMDLs for bacteria in Buffalo and Whiteoak Bayous and their tributaries on April 8, 2009. Nine TMDLs for bacteria in Clear Creek and its tributaries were adopted September 10, 2008. Eight TMDLs in the Greens Bayou Watershed were adopted on June 2, 2010. TMDLs for 19 segments in Brays, Sims, Halls, and eastern Houston bayous were adopted on September 15, 2010. TMDLs for the Lake Houston area have not been adopted as of October 15, 2010. Reductions range from 25 to 99 percent of the bacteria entering a waterbody.
To address the high levels of bacteria in the project area and to develop the I-Plan, the TCEQ asked that H-GAC form a stakeholder group. The Bacteria Implementation Group, or BIG, includes representatives of city and county governments, resource agencies, business and agriculture interests, conservation and professional organizations, watershed groups, and the public. In November of 2010, the BIG approved a draft plan for the purposes of soliciting public comment. The recommendations in this I Plan represent the work of the BIG and many additional stakeholders who actively participated in the process.
Many of the implementation activities in the I Plan are directed towards reducing bacteria loading from possible point and non-point sources that the TCEQ identified during development of the TMDLs. The activities are intended to achieve the reductions identified in the TMDL reports that are necessary to comply with established water quality standards. The sources of bacteria include wastewater treatment facilities, sanitary sewer systems, on-site sewage facilities, storm water runoff, illicit discharges, agriculture, livestock, wildlife, pets, sediment re-suspension, and bacterial re-growth.
Many of the strategies in the I Plan are new to this region, and limited data is available on their effectiveness and cost-effectiveness locally. Stakeholders developed the implementation strategies based on their best professional judgments through a series of workgroup meetings. The BIG recommends an iterative management approach so that data from early implementation efforts can be used to refine strategies throughout the life of the I Plan. H-GAC staff will track the implementation of activities and monitor water quality data to assess effectiveness of the various efforts.
The presentation will cover:
• H-GAC’s Clean Rivers Program: Regional water quality monitoring
• A brief overview of water quality in the region, with an emphasis on bacterial contamination
• A review of bacteria TMDLs in the region
• An overview of the plan developed by the Bacteria Implementation Group to reduce the amount of bacteria entering waterways
• How the plan might affect how stakeholders manage wastewater and stormwater facilities
• An opportunity to learn more, become involved, and provide comments on the plan
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(Electro) Coagulation Pretreatment for Enhanced Virus Removal During Surface Water Microfiltration
Charan Tej Tanneru, Department of Civil and Environmental Engineering, University of Houston
CO-AUTHORS:
Neranga Gamage, and Shankar Chellam, Department of Civil and Environmental Engineering, University of Houston, Houston
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Microfiltration is an excellent barrier for Giardia lamblia cysts and Cryptosporidium oocysts achieving > 99.9999% removal of these protozoa that are difficult to inactivate using free chlorine. However, viruses penetrate microfilters since they are smaller than the membrane pores. Additionally, membrane fouling can be problematic during surface water treatment, which can be countered by coagulation pretreatment. We have developed a novel electrocoagulation process, which has certain advantages over conventional chemical coagulation such as no alkalinity consumption, reduced sludge production and footprint, and even improved performance under certain circumstances.
This presentation will focus on results from on-going experiments being performed at the University of Houston using both chemical coagulation and electrocoagulation as pretreatment methods for surface water microfiltration. The relative performance of conventional chemical coagulation using alum (Al2(SO4)3) and aluminum electrocoagulation will be discussed. In electrocoagulation, a current is passed through an elemental anode releasing the desired metal ion coagulant. The coagulant dosage is determined by varying the current and time according to Faraday’s law. Our research group has recently demonstrated the poor performance of iron electrocoagulation, which is the reason we have switched to aluminum.
The principal objective of this research is to evaluate simultaneous improvements in virus removal and reductions in membrane fouling during microfiltration of surface waters following electrocoagulation and chemical coagulation pretreatment. Bacterial viruses (bacteriophages) including MS2, PRD1, φX174, Qβ and T7 will be used for this study. Important experimental variables include coagulation pH, coagulant dosage, and effect of natural organic matter (NOM) on virus removal and filtration pressure. This research constitutes a portion of my doctoral work performed under Dr. Chellam’s supervision at the University of Houston.
Results to date demonstrate the production of trivalent aluminum during electrocoagulation as measured quantitatively by Faraday’s law. Fouling was reduced incrementally at low aluminum dosages (< 3 mg/L) but substantial performance enhancements were obtained at higher dosages (~ 10 mg/L). Interestingly, higher dosages did not improve overall fluxes at pH 7.5 and 6.4, which was attributed to floc breakage or increased mass of deposited particles. Blocking law modeling revealed cake formation to be the dominant fouling mechanism for the entire duration of filtration. Specific cake resistances were significantly reduced with following aluminum addition where higher reductions were observed at low doses at pH 6.4. This is due to formation of larger flocs with increasing aluminum concentration, which increased permeability of the filter cake. Additionally, the specific cake resistance increased with pressure due to cake compressibility, which reduced the flux at higher transmembrane pressures at both pH values investigated (6.4 and 7.5).
Ongoing work focuses on enhancing the removal of viruses and precursors to disinfection by-products by electrocoagulation-microfiltration. We are particularly interested in the effects of water chemistry parameters (pH and natural organic matter) as well as operating conditions (aluminum dose and filtration pressure) on virus removals. Further, the effect of aluminum dose on the zeta potential on particle surface will be analyzed to better understand the aforementioned experimental outcomes.
Platform Presentations: SESSION 4 ABSTRACTS - AIR 2
Trends in Texas Air Quality
Karla Kinslow, Senior Toxicologist Texas Commission on Environmental Quality, Austin, TX
Texas has the most extensive air monitoring network in the United States and it is the responsibility of Texas Commission on Environmental Quality (TCEQ) to maintain the network, as well as record and evaluate the results from this network. Results have shown that Texas has made significant improvements in air quality over the past decade. One of the primary indicators of air quality is ambient benzene concentration. Since 1998, we have seen significant decreases in benzene concentrations throughout Texas. Specifically, monitors in the Houston area have shown as much as 84 percent decrease in benzene concentration. Specifically, the San Jacinto Monument monitor in the Houston Shop Channel is one of our greatest success stories. The 84 percent decrease in monitored benzene concentrations in two years (2005-2007) at this location can be attributed to collaboration between the TCEQ, industry and the community. Such collaboration is one of our most effective tools in meeting our goal of continued improvements in Texas air quality.
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North American Dust Influences Airborne Particulate Matter Levels in Houston
Nicholas Spada, University of Houston
Airborne particulate matter affects the health and welfare of humans by inducing disease and causing environmental and aesthetic damage. Aerosols can penetrate deep into the lungs and enter the bloodstream and have been linked to decreased lung function, asthma, heart attacks, and even premature death.
Aeolian suspension and long-range transport of aerosols from North Africa, especially the Sahara-Sahel region, is known to elevate ambient aerosol levels throughout Western Europe as well as Central and Eastern America. The Texas Commission on Environmental Quality (TCEQ) is allowed to exclude such events from regulatory compliance without any calculations of the amount of African aerosols in local ambient particulate matter. Therefore, the principal objective of this research is to quantify the contributions of particulate matter from North Africa (Sahara-Sahel desert) to particulate pollution in Houston, Texas.
Satellite imagery tracked the African aerosols to Houston between July 25 and July 27, 2008. During this period, TCEQ measured higher concentrations of fine particles throughout southeastern Texas (coarse particles were not measured). For example, hourly mass concentrations of fine particles in the Clinton Drive continuous ambient monitoring site were elevated during this 3-day period reaching as high as 41.2 g/m3. In contrast, hourly fine particle concentrations were significantly lower immediately before and after this episode averaging only 12.9 g/m3.
This presentation will focus on ambient fine and coarse particulate matter data from two monitoring stations in the Houston area, viz. Clinton Drive and Channelview. Aerosols were resolved into the coarse (< 10 μm) and fine (< 2.5 μm) size modes and averaged over a 24-hour period. Gravimetric mass was determined for all filters and elemental composition was determined via ICP – Mass Spectrometry. Forty-eight elements, including lanthanoids, were quantified to apportion aerosol concentrations between African aerosols and local sources. 24-hour PM2.5 mass levels rose from 12.4 μg/m3 to 28.9 μg/m3 at one site and from 9.6 to 26.7 μg/m3 at the other. PM10 mass showed an even more substantial rise in mass (18.4 to 78.1 and 27.5 to 125.4 μg/m3). The crustal elements (Al, Na, Mg, Si, K, etc.) consistently increased with mass, indicating association with the transported aerosols. Al and Si followed a similar pattern with mass in both size modes and at both sites. However, anthropogenic metals (Cu, Mo, V, Ni, Zn, etc.) stayed consistent through the dust event at both Houston sites. Elemental ratios also varied independently of the dust event. The ratio of V to La (an important tracer of oil refinery catalyst emissions) five days prior to the event ranged between 9.3 - 35.2 but was only 4.0 – 17.2 during the event. Similar metal ratios demonstrate the simultaneous contributions of local and global sources. These data provide insightful information on the prevalence and nature of these long-transport aerosols, which consistently impact the local atmospheric chemistry. On-going work is focused on performing chemical mass balance calculations and enrichment factor analysis to better quantify the African aerosol contribution to total mass during the episode.
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Air Monitoring Comparison Values and How They Relate to Effects Screening Levels
Carla Kinslow, Senior Toxicologist Texas Commission on Environmental Quality, Austin, TX
This presentation will discuss the new Effects Screening Levels (ESL) guidelines and introduce a new term "Air Monitoring Comparison Values (AMCVs)." Historically, the same short- and long-term ESLs have been used for both air permitting and air monitoring. However, there are significant differences between the procedures used for performing health effect reviews for air permitting and the various forms of ambient air monitoring data. Based on these differences, changes were made to toxicity values that were used in these distinctly different program areas when the Toxicology Division (TD) published their Guidelines to Develop Effects Screening Levels, Reference Values, and Unit Risk Factors (RG-442). ESLs are used in the review of air permitting whereas AMCVs are used in the review of ambient air monitoring data.
Platform Presentations: SESSION 4 ABSTRACTS - GROUND WATER
Innovative Injection Technology Increases in-Situ Remediation Efficacy
Patrick M. Hicks, Ph.D. Vice President, Wavefront Technology Solutions USA Inc., Raleigh , NC
Groundwater at a residential site received a release of chlorinated aliphatic hydrocarbons (CAHs), including 1,1,1-trichloroethane (1,1,1-TCA) and related degradation products including 1,1-dichloroethane (1,1-DCA), 1,1-dichloroethene (1,1-DCE), and chloroethane (CA). A full-scale injection using Primawave technology with a combination of readily-degradable sodium lactate and slow-release EVO was used to sustain a reaction zone. Injections were designed to stimulate anaerobic degradation of CAHs in groundwater. Wavefront Technology Solutions USA, Inc provides Primawave™ technology for pressure pulsing to enhance the introduction of fluid into saturated porous media. Primawave™ technology is applied to environmental remediation projects to increase the effective distribution of remedial products through standard injection wells or direct push rods. The application of a pressure pulse through the injected liquid is modulated by controlling the frequency of the pulsing to maximize injection rates at minimal pressures to minimize blow-by and day-lighting, and also optimize radius of influence and distribution of the injected fluid in the aquifer. Semi-annual groundwater monitoring performed after the full-scale injection indicated that EISB was effective in reducing concentrations of CAHs in groundwater. Concentrations of CA increased following the injections as a result of the sequential dechlorination of 1,1,1-TCA to 1,1-DCA to CA. Concentrations of CA generally declined after 1,1,1-TCA and 1,1-DCA were depleted. Monitoring results 28 months after the full-scale injection indicated that degradation of CA had slowed, and concentrations of CA remained elevated above clean-up criteria throughout the treatment zone. Geochemical data suggested that conditions suitable for the anaerobic degradation of CA were diminishing, and/or a residual source of CAHs may exist in the vadose zone or capillary fringe in the source area. A second full-scale injection was performed to further enhance anaerobic degradation of CA. During the second full-scale injection event, the Primawave™ technology was used in an attempt to increase the injection flow rate, minimize day-lighting, and to reduce field time. The maximum practical injection rate was approximately 3.79 L per minute during the first full-scale injection due to significant day-lighting. The average flow rate achieved during the second full-scale injection was between 7.6 and 11.4 liters per minute without significant day-lighting. Concentrations of most CAHs remained below detection limits or below clean-up goals. At 2 months after the second full-scale injection, CA concentrations had increased in a portion of the source area, but decreased in the majority of the treated area of the plume. In the period from 2 to 7 months after the second full-scale injection, CA concentrations decreased at all locations but still remained above clean-up goals. The persistence of CA at this site is attributed to possible residual sources of parent compounds and a relatively slower degradation rate for CA compared to 1,1,1-TCA and 1,1-DCA. It is anticipated that CA concentrations will continue to decrease over time as there is evidence that the second full-scale injection further remediated residual CAH parent compounds in the source area. Monitoring data is presented to illustrate the ultimate fate of CA at the site.
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Well Design and Method of Application, The Keys to ISCO Success
Douglas D. Carvel, PE, MECX LP, 3203 Audley Street, Houston, TX
A study of various In-situ Chemical Oxidation (ISCO) delivery techniques including gravity delivery, recirculation, and pressure injection and if they can be enhanced using fracing techniques. This study will describe the specific techniques, their applicability in various geologies, saturated conditions, and chemicals, and present case studies provided both by MECX and applicators of these technologies. It will also discuss issues that need to be addressed during design for each delivery technique to ensure proper contact with the contaminant without short-circuiting, avoid excessive displacement or migration, and provide a safe work place during application.
This paper presents an impartial summary of when the specific application techniques and enhancements are proven to be most effective and when they have been ineffective. The paper does not have data in direct comparison applications and will not provide recommendations for specific applications but will provide a contact list of practitioners that supported this evaluation.
Platform Presentations: SESSION 4 ABSTRACTS - WETLANDS AND WATERBODIES
Use of NWI Mapping in Two Counties on the Upper Texas Coast
Timothy Love, Professional Wetland Scientist Associate Environmental Specialist, Water, AECOM 5757 Woodway, Suite 101 West, Houston, Texas
Wetlands identified on National Wetlands Inventory maps are compared with wetland boundaries delineated within a 42 km long 91.44 m wide corridor that spans two counties in the upper Texas Coast. Notable differences were observed between the NWI mapping and the delineated boundaries, especially in forested portions of the corridor. NWI maps should be used with caution for planning purposes when estimating the extent and location of possible wetlands for projects on the upper Texas Coast. The discrepancies and possible solutions when using NWI mapping and interpretation of aerial photography are discussed.
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Stream Mitigation Tools
Jayson Hudson, USACE – Galveston District
33 CFR 332, issued April 2008, states that if further avoidance and minimization of difficult-to-replace resources, such as streams, is not practicable, then the required compensation for the functions and services lost at the impact site should be provided in the form of rehabilitation, enhancement, or preservation. The Galveston District of the U.S Army Corps of Engineers is developing an assessment tool for stream compensation that includes channel morphology, riparian buffer, in-stream habitat, anthropogenic modification, and biological indicators.
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Environmental Mobile Applications for Projects (EMAP): A Modernized Approach to Field Data Collection
Jessica Wilson, Aquatic Ecologist, Environmental Assessments, AECOM
Field surveys and field data collection is one of the most important tasks undertaken in the environmental field. Traditional data collection methods utilizing paper copy notes which later must be input into an electronic data base or agency-required data forms and linked to spatial data in the office are time consuming and often times difficult to manage.
To streamline this process, AECOM developed a new, proprietary environmental information technology known as Environmental Mobile Application for Projects, or EMAP. EMAP combines all of the information that was previously recorded on paper in the field and ties that information to a GPS-captured point, line, or polygon, a comprehensive Geodatabase in ArcGIS. The EMAP application includes domain and relational tables to reduce data input errors and help organize and structure the data. Fields for feature attributes, comments (free text), and photo ID’s have been standardized and allow the data to be quickly rolled up into a master Geodatabase for every project. EMAP greatly improves the efficiency of data collection, editing, and attribution processes associated with field data collection and eliminates the need for using hard copy (paper) forms and multiple data formats and devices in the field.
EMAP has been field tested and applied to a variety of studies, including wetland, fisheries, hydrology, threatened and endangered species and archaeological surveys. EMAP has been successfully deployed on 5 large-scale (850-mile, 743-mile, 302-mile, 231-mile, and 123-mile) interstate pipeline projects, 2 wind farm projects in Colorado and Wisconsin, as well as wetland delineations and surveys for threatened and endangered species across the U.S.
Platform Presentations: SESSION 4 ABSTRACTS - REMEDIATION 2 / REGULATORY
Potential Ecological Impacts of Emerging Carbonaceous Materials Assessed Through Their Interactions with Earthworm Eisenia Fetida
Dong Li, Department of Civil and Environmental Engineering in Rice University, Houston, TX
Carbon fullerenes, including buckminsterfullerene (C60), are increasingly available for numerous applications, thus increasing the likelihood of environmental release. This calls for information about their bioavailability and bioaccumulation potential. Another emerging carbonaceous material, biochar, will probably be widely applied to soils in the near future due to its potential for enhancing soil fertility, sequestering carbon, and enabling beneficial waste disposition. Because of the potential for widespread application, it is essential to proactively assess and mitigate any unintended consequences associated with soil biochar amendment. Earthworms are a useful model organism in ecotoxicological studies because many aspects of their response to environmental perturbations can be assessed and connected to environmental outcomes. We conducted bioaccumulation tests, soil avoidance tests, growth and reproduction tests, and oxidative stress assays with the earthworm Eisenia fetida to assess the potential toxicity of soil amended with emerging carbonaceous materials, including fullerene C60 nanoparticles and biochar. Phenantherene, a known toxic polynuclear aromatic hydrocarbon, was used as positive control in these tests.
Biota-sediment accumulation factors (BSAF) were measured after 24-h depuration in high C60 dosage soils (60, 100 and 300 mg-C60 kg-1 dry soil), which exceed the soil sorption capacity, as well as in soils with a low C60 dose (0.25 mg kg-1) conducive to a high fraction of sorbed molecular C60. The BSAF value for the low-dose soil (0.427) was one order of magnitude lower than for less hydrophobic phenanthrene (7.93). Apparently, the large molecular size of C60 hinders uptake and bioaccumulation. Lower BSAF values (0.065 to 0.13) were measured for high-dose soils, indicating that C60 bioaccumulates more readily when a higher fraction of molecular C60 (rather than larger precipitates) is available. In toxicological studies with biochar, earthworms avoided soils containing 100 and 200 g kg-1 dry biochar at statistically significant levels (p < 0.05), and after 28-d of incubation, these earthworms lost more weight than those in control (unamended) soil. However, biochar did not affect the reproduction of earthworms. Wetting the biochar to its field capacity resulted in statistically undetectable avoidance, suggesting that biochar induced dessication is a potential concern and indicating that moisture is a key factor that may affect earthworm behavior in biochar amended soil.
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Utilizing Ash to Stabilize Arsenic in Chromated Copper Arsenate (CCA) Contaminated Soil
Rachel Blodget, Graduate Assistant, Hans Williams, Kenneth Farrish, Environmental Sciences, Stephen F. Austin State University
From 1970 to 2003, Chromated Copper Arsenate (CCA) was used widely in the industrial and residential wood treatment market. In 2003, CCA was removed from the market as a result of soil, ground water, and surface water contamination resulting from CCA leaching into soils and water. Coal fly ash and wood fly ash have been used to stabilize metals such as arsenic in contaminated soils. In this study, CCA contaminated soils were mixed with 0, 4, 10, 16, and 22% of wood fly ash as well as Class C and Class F ash. Weekly rain simulations were performed over a 7 week period to determine what proportion and type of ash best stabilized arsenic within the contaminated soil. Preliminary results will be presented.
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Whistleblowers Can Now Seek Federal Environmental Penalties and Keep A Cut
Mike Howell, Attorney and Counselor at Law, Howell Law Firm
Whistleblower cases, also known as qui tam cases, have been around since the American Civil War when Congress passed the first law to prevent fraud on the government and counter war profiteering. Usually the whistleblower with the assistance of a lawyer will report the fraud to the government and the government will either decide to take on the prosecution of the case or, if the case is not large enough, allows the whistleblower to proceed with the case with their own private lawyers. Traditionally these cases have been brought by employees of defense contractors or medical providers for over-billing the government for goods and services. Reports indicate that the Federal Government has recovered more than $27,000,000,000 ($27 billion) in qui tam cases since 1986. Not surprisingly, with the 2008 news on financial markets and mortgage markets, the last two years showed the highest ever recoveries under the False Claims Act (FCA) with over $5,400,000,000 ($5.4 billion) recovered. Some States have similar or limited versions of State qui tam laws.
Recent legislative action now allows for recovery of environmental penalties under the Fasle Claims Act. False Claims Act liability is substantial. The government can recover triple damages for the amount it should have received and civil penalties of $5,500 to $11,000 per violation, plus attorney’s fees and costs. If the government handles the case, the whistleblower is entitled to receive between 15 to 25 % of the proceeds of the action unless the whistleblower was not the primary source of the information (government audit etc.) in which case they can receive no more than 10% of the proceeds plus reasonable attorney’s fees.
If the government does not take the lead in litigation, the qui tam relator receives between 25 and 30% of the proceeds, plus attorney’s fees and costs.
A defendant can recover it reasonable attorneys' fees and expenses if the defendant prevails in the action and the court finds that the claim of the person bringing the action was clearly frivolous, clearly vexatious, or brought primarily for purposes of harassment.