Re-inventing the Nation’s Urban Water Infrastructure (ReNUWIt), Dick Luthy, Stanford University
ReNUWIt is an interdisciplinary, multi-institution NSF research center whose goal is to change the ways in which we manage urban water. Our vision is of safe, sustainable urban water infrastructures enabled by technological advances in natural and engineered systems, and informed by a deeper understanding of institutional frameworks. One example of ReNUWIt activities include research on unit process wetlands and bioinfiltration stations as passive treatment technologies for urban stormwater and water reuse systems. Another example is analysis of long-term groundwater quality challenges associated with water level rises in the San Fernando Valley as a result of changing urban groundwater management policies.
Remaking Civilization on Dirty Sites, Stephen Coyle, AIA, LEED AP, Town-Green
This presentation will review several applications of sustainable design principles to remedial actions in Mongolia and Gabon. Remedial actions in both cases balanced economic viability, conservation of natural resources and biodiversity, and the enhancement of the quality of life in surrounding communities:
- Ulaanbaatar, Mongolia: Advising the city on a planning process for developing interventions to remediate groundwater contamination from low density settlements that lack sanitary waste systems in the coldest (and most polluted) capitol in the world
- Libreville, Gabon: Proposed remediation efforts in Central Africa
Starting a Student Chapter at Stanford University: Challenges and Opportunities, YeoMyoung Cho, Yongju Choi, Chinghong Hsieh, Diana Lin, Jay Thompson
In Fall 2012, several students at Stanford University founded a student chapter of SURF. The group has grown to ten members, most of whom are highly involved with the group. The group typically meets twice a month to discuss business and SURF topics in current literature. This may include working on a case study, discussing academic journals, or presenting the results of independent study. The objectives of this talk will be to briefly describe the Stanford chapter, present the major opportunities we see for SURF student chapters, and discuss some of the challenges we encountered.
We believe that there is substantial opportunity to grow new SURF student chapters. While the remediation industry and regulatory bodies are placing increasing emphasis on secondary environmental impacts, course offerings on this topic are sorely limited. Thus, student SURF chapters can serve an important educational purpose by disseminating knowledge from professionals to students. Further, there are opportunities for independent research within student chapters. We found that emphasizing this potential for professional development and knowledge creation to be the most successful tactic to recruit new members.
The two biggest obstacles to any new student SURF chapter is the limited number of potentially interested students and unfamiliarity with the concept of sustainable remediation. As students interested in remediation are often a small subset of students enrolled in environmental engineering programs, finding directly interested students may be difficult. Active leadership is needed to recruit new members and effort should be made to recruit students from outside the traditional academic disciplines. Many, if not all, of the students joining a new SURF student chapter will not have an understanding of the basic concepts of sustainable remediation. A lack of relevant institutional knowledge within other student groups or the faculty exacerbates this problem. We believe that SURF can best address this problem by creating a “Suggested Reading” list for new chapters and by, where possible, matching local professional SURF members to student chapters to help build institutional knowledge within the student chapter.
Redefining Remediation Goals with Long‐term Monitoring Data, James, R. Hunt, University of California at Berkeley
Remediation of contaminated groundwater is essential when the contaminants have a current or potential impact on human health and compromise ecosystem functioning. After approximately 30 years of site investigations, many lessons were learned on what contaminants are likely to be persistent and transportable in the subsurface. With the implementation of remedial efforts, there is a body of knowledge developing on the effectiveness of natural attenuation and engineered approaches based on in situ and ex situ technologies. This presentation examines the monitoring data available at sites where contaminants were released to the subsurface starting in the 1950s, and site investigations and remedial efforts have continued for more than 20 years. Two related sites had Cr (VI) release to the subsurface from evaporative cooling wastes at natural gas compressor stations in the deserts of southern California. Another site involved the intentional release of dilute radioactive waste streams to seepage basins at a Department of Energy facility. These examples illustrate the advantages of a broader view of remediation as a system that requires data management, data visualization, and the development of models that predict long term effectiveness and permit scaling from one location to another.
Comprehensive Detection of Perfluorochemical Precursors at AFFF-Contaminated Sites for Improved Remediation Strategies; Erika Houtz, Meghan McGuire, Jennifer Field, Chris Higgins, and David Sedlak
Aqueous film forming foams (AFFFs) are complex mixtures of hydrocarbon and fluorocarbon surfactants that have been used by the military, airports, and municipalities since the 1960’s to extinguish hydrocarbon- fuel based fires. At many military bases, extensive remediation for the hydrocarbon contaminants (e.g., BTEX compounds and TCE) has been undertaken without consideration of the AFFF fluorochemical compounds that are concurrently present. Where these foams have been deployed in unlined fire training areas, high concentrations of poly- and perfluorinated substances have been detected in groundwater. Among these contaminants, perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) have received considerable attention due to concerns about their presence in drinking water.
In addition to PFOA, PFOS, and their shorter chained homologs, AFFF formulations contain more complex polyfluorinated compounds that can be converted into perfluorinated acids by chemical or biological transformation. We refer to these polyfluorinated compounds as perfluorinated acid precursors. Because these precursors may be transformed to their more mobile perfluorinated acid forms upon in situ chemical oxidation or enhanced bioremediation, it is important to characterize the precursor contamination prior to commencing remedial exercises. The direct measurement of these precursor compounds and their transformation products in field samples is limited by lack of available standards. In response to this challenge, a method was developed to indirectly quantify the concentrations of potential perfluorinated acid precursor compounds. Samples were exposed to hydroxyl radicals to convert precursors to perfluorinated carboxylic acids, which were then measured by LC-MS/MS. This precursor oxidation assay was used to measure precursor concentrations in groundwater and soil extracts from an AFFF-contaminated fire-training area where fire training occurred from the 1960s until 1990.
High concentrations of precursors were measured by the oxidation assay on soil samples and in groundwater in the fire training area. Only about half of the total precursor content in the AFFF-contaminated groundwater and soil could be identified with reference precursors, suggesting that typical analytical protocols would not capture most of the AFFF-related precursor contamination. Compared to AFFF formulations, there was an overall reduction in the concentration of precursors as a percentage of the total concentration of fluorochemicals. These results suggest that net production of perfluorinated acids has occurred over time in the fire training area from transformation of AFFF-derived precursors. In areas onsite that were extensively remediated with oxygen sparging wells, enhanced production of perfluorinated acids from precursor compounds was observed.
These results may inform subsequent cleanup efforts of AFFF-contaminated groundwater and soil by providing techniques to assess the scope of fluorochemical contamination and providing a model site to observe the consequences of several different remediation approaches on perfluorinated acid precursor transformation.
SURF BRAZIL, Sander Eskes
Since the 1980s, the existence of contaminated sites is an environmental issue that has been increasingly detected by environmental authorities in Brazil. Besides the federal level, the most important level of environmental legislation regarding contaminated land is the state level. The state governments in Brazil are in charge of the environmental management of contaminated sites through their environmental agencies. The most important state-level environmental agency in Brazil is that of São Paulo State, which is called CETESB (Companhia Ambiental do Estado de São Paulo). CETESB is widely considered as one of the more influential environmental agencies in Latin America. Brazil does not have yet a national public policy, approved by law, about contaminated sites or brownfield redevelopment. São Paulo State Law n. 13.577/2009 constitutes the first public policy issued in Brazil about contaminated sites management. This law adopted the risk assessment as an important decision making tool as far as the site intervention will be developed on the terms of the “fitness for use” approach. A specific fund, called FEPRAC, for contaminated sites can be used in cases where the site is considered an orphan site, i.e., where the responsible entity is not identified or localized. A clause was included in the São Paulo State Law that obliges applicants of remediation projects funded by FEPRAC to include a sustainability assessment together with the remediation plan. This can be seen as one of the first examples of a state endorsed initiative towards more sustainable remediation projects in Brazil. Brazil has a forum to promote and discuss sustainable remediation, called “Brazilian Sustainable Remediation Forum” (in Portuguese: Fórum Brasileiro de Remediação Sustentável). The first meeting of the forum was held on October 18. The organization of the forum can be loosely described as based on social networks, organized around discussion groups and without formal organizational structure. The forum closely cooperates with the São Paulo State Environmental Agency (CETESB), but has limited interaction with industries through branch organizations. The interaction with the public is through mouth-to-mouth advertising (advocacy), a blog and social networks. The forum is involved in policy making at the state level, through technical discussion groups and legislative forums.
Risk-informed and sustainable land management: basis for a fourth generation of Contaminated Land Management policy, Dominique Darmendrail, Common Forum on Contaminated Land in Europe
The complexity of contaminated site problems and of the solutions for solving them was not perceived immediately, even after major incidents discoveries (Love Canal /USA, Lekkerkerk / Netherlands). Policy perspectives concerning this contamination issue have changed gradually in the industrialised countries during the last 30 years.
The Contaminated Land policies evolved since the early 80s at the national level. Three types of national policies were successively generated:
- a systematic approach (inventories, protocols) with a drastic control of soil contamination, in the early 80s,
- around 1990, a contaminated land and risk assessment approach, with a real focus on land use as the main criteria for assessing and decision-making
Some European Member States have already decided to implement the RBLM concept in their national legal framework (e.g. the Netherlands, France, Austria) while other are just changing from the source control approach to risk assessment.
The regulatory environment at the European level is evolving rapidly and different European legal documents aim to take soil issues into consideration (i.e. IED, Industrial Emissions Directive or ELD, Environmental Liability Directive). In 2007 a Soil Protection Strategy has been published and a proposal of Directive is being discussed at the time. Hence a couple of Member States having advanced third generation approaches have main concerns on the recent developments of EU legislation related to soil issues and blocked the text at the European Council level.
Moreover besides directives addressing soil protection several other policies introduce further challenges like:
- Additional provisions on soil issues in the revision of policies already in place (e.g. the Waste Framework Directive which deals now with excavated soils management, the Industrial Emissions Directive which now requires soil monitoring and remediation to baseline conditions), which are building a rather prescriptive but less integrative and sustainable system and
- Additional initiatives regarding sustainable development of European societies like e.g. the Environment Action Plan, the new Resource Efficiency roadmap and the climate and energy targets for 2020, which are committing Europe to transforming itself into a highly energy-efficient, low carbon economy, while de-coupling of resource use and waste generation from economic growth.
Therefore a concept for this 4th generation of policy should integrate three key principles: being risk-informed, managing adaptively and taking a participatory approach. It is important to note that sustainability needs to be incorporated alongside effective risk-management. A better integration of sustainability principles looks out to optimise inputs and outcomes in land remediation, thus also avoiding any trade-offs regarding health or environmental safety.
Building a Common Understanding on Sustainable Remediation: the SuRF-UK experience, Jonathan W.N. Smith, Chairman of SuRF-UK steering board
The Sustainable Remediation Forum-UK (SuRF-UK) is a collaborative, multi-stakeholder initiative to develop a framework, guidance and tools that facilitate more sustainable soil and groundwater remediation. SuRF-UK was established in 2007 and has a steering board incorporating members from government, industry, consultancy, academia and CL:AIRE.
In terms of sustainable development, contaminated land remediation has been generally thought to be a positive step, almost automatically considered sustainable. It brought land back into use, dealt with pollution problems and reduced development pressures on greenfield sites. In some countries, such as the UK, there was an idea that remediation should not take place without some regard to its costs, and frameworks and tools for cost benefit assessment were developed. However, the broader impact of the remediation process itself on environment, economy and society was not a major factor in decision making.
A number of formal and informal networks worldwide are now in process of debate on achieving sustainable development when remediating or regenerating of damaged sites or land. In the UK the Sustainable Remediation Forum UK (SuRF-UK) [www.claire.co.uk/surfuk] has published a framework for assessing the sustainability of soil and groundwater remediation. The goals of SuRF-UK’s framework are to:
- Mitigate unacceptable risks to human health and the environment in a manner that derives the greatest overall (sustainability) benefit;
- Demonstrate compliance with public and corporate sustainable development policies and commitments;
- Make discussions and communication with stakeholders easier;
- Make planning applications stronger
The principles of sustainable remediation have recently been included into revised statutory guidance for the Contaminated Land regime in England and Wales (EPA1990 Part IIa). SuRF-UK is now currently engaged in developing more detailed guidance and a series of case studies. SuRF-UK’s approach is very practicable and SuRF-UK has an established track record in sharing and exchanging know-how and knowledge with related interests in other countries.
Assessment of sustainable remediation is defined by SuRF-UK as ‘the practice of demonstrating, in terms of environmental, economic and social indicators, that the benefit of undertaking remediation is greater than its impact and that the optimum remediation solution is selected through the use of a balanced decision-making process’.
This is the first authoritative framework for assessing the sustainability of soil and groundwater remediation in the UK. While legislation and good practice guidance have encouraged remediation to contribute to sustainable development goals, no formal and authoritative framework has previously been published to guide such an assessment. It provides assessors with a means to undertake a sustainability assessment of soil and groundwater remediation, and to ensure that the remediation industry can directly and measurably contribute toward sustainable development goals.
The framework described in this document complements existing UK best practice guidance, such as the ‘Model Procedures for the Management of Land Contamination’ (CLR11), but is sufficiently generic to be applied elsewhere and under different regulatory systems. SuRF-UK believes that its publication and use will lead to more sustainable remediation practice in the UK and elsewhere.
Bardos, R. P., Bone, B. D. , Boyle, R., Ellis, D., Evans, F., Harries, N. and Smith, J.W.N. (2011) Applying Sustainable Development Principles to Contaminated Land Management Using the SuRF-UK Framework. Remediation, Spring 2011, 77-100. www.claire.co.uk/surfuk
CL:AIRE (2009) A review of published sustainability indicator sets: How applicable are they to contaminated land remediation indicator-set development? CL:AIRE, London, UK. www.claire.co.uk/surfuk
CL:AIRE (2010) A Framework for Assessing the Sustainability of Soil and Groundwater Remediation. March 2010 CL:AIRE, London, UK. www.claire.co.uk/surfuk
Sustainable Remediation Planning and Urban Redevelopment, Paul Favara, CH2M HILL
Construction new sporting venues provided the impetus for redevelopment of a large industrial area. The site had historically been used for a range of purposes including light retail and heavy industry. Sustainability was a key central theme to planning the redevelopment and completing the project. This presentation will provide an overview of the site redevelopment and focus on the sustainable remediation elements of the project. Key sustainable remediation topics that will be addressed include carbon dioxide emission avoidance, reuse of contaminated media, recycling of materials from demolished infrastructure, and development of risk-based cleanup levels to protect human health.
Hydrocarbon Sheens – Governing Processes and Innovative Solutions
Background / Objectives. Sheens from petroleum liquids often drive large and expensive remedial actions. In hindsight, these measures can be less effective than desired and can have secondary adverse environmental impacts. The focus of this research is to develop new, more sustainable approaches for preventing petroleum hydrocarbon sheens in surface water. Petroleum liquids in subsurface environments are commonly referred to as Light Non-Aqueous Phase Liquids (LNAPLs). Common LNAPLs include crude oil, diesel, gasoline, jet fuel, and lubricants. LNAPL releases typically move through the unsaturated zone to the water table where they spread laterally. A common release mechanism for surface water sheens is seeps associated with LNAPL movement along the air-water interface above the capillary fringe. Barriers are an emerging strategy for preventing sheens in surface water. Capillary and organoclay barriers are two examples of possible barriers that can be emplaced to intercept migrating LNAPL. Herein, capillary barriers are materials with a capillary rise that is higher than the adjacent formation. Fully saturated capillary barriers preclude LNAPL migration as an intermediate wetting phase. In contrast, organoclay barriers are oleophilic (high affinity for LNAPL) systems that preclude LNAPL migration by sorption.
Approach / Activities / Methods. Efforts to date have focused on laboratory-scale tank experiments filled with medium silica sand. Sand tank dimensions are 181cm by 38.5 cm by 5.3 cm. Fluorescing dyes are added to the water and LNAPL phases to enhance visualization of processes. Fluid levels are controlled using computer controlled pumps. Two computer controlled digital cameras are employed to take pictures at timed intervals. Capillary barrier experiments include a 4 cm thick vertical fine sand wall at the distal end of the tank. Diesel was added to the tank at a flow rate of 6 mL/hour. Concurrently, water levels were cycled through two high and low levels each day. As a second experiment, the above was repeated with the addition of two wells used for hydraulic LNAPL recovery. A third experiment was performed, identical to the first, with the exception of using a barrier consisting of a 1:3 organoclay:sand mix. The organoclay barrier was 20 cm thick. A fourth experiment, similar to the third, was performed with two organoclay barriers. The first barrier had 3 HDPE wedges spaced out in the organoclay barrier. The second organoclay barrier had 2 cm vertical gravel drain lines every 3 cm. The HDPE wedges and gravel drain lines were installed to prevent preferential flow.
Results / Lessons Learned. The first experiment showed that the capillary barrier precluded LNAPL migration for the duration of the experiment. The second experiment had the combined effect of pumping and the capillary barrier which allowed for the removal of LNAPL. LNAPL removal is a complementary approach that has the potential to extend the longevity of capillary barriers. The organoclay barrier, initially prevented LNAPL migration. However, with time, the LNAPL quickly moved across the air water interface in the organoclay barrier. The net result was preferential flow of LNAPL through organoclay barrier. The fourth experiment was constructed with two organoclay barriers, one with HDPE wedges and the other with drain lines. Both approaches improved the performance of the barrier. Preliminary results show that both the fine sand capillary barrier and the organoclay barrier are viable solutions for preventing the transport of LNAPL. The fine sand capillary barrier appears to be more effective than the organoclay barrier based on work to date. Further research is being conducted to improve both types of remedies. Supporting field work is ongoing in Rensselaer, NY, USA and Burnaby, British Columbia, Canada.
Developing monitoring protocols and baseline data for assessment of a novel, full-scale combined sewer overflow treatment wetland pilot project in Syracuse, NY
Background/Objectives. Combined sewer overflow (CSO) is a mixture of sewage and stormwater runoff that discharges into urban waterways when flow through “grey” municipal sewers exceeds conveyance capacity. Pairing different constructed treatment wetland designs in tandem provides a suite of “green” infrastructure alternatives that can be adapted to fit a variety of urban ecological niches.
Approach/Activities. At the behest of Onondaga County, CH2M HILL and CHA conceived plans for a 2-acre, pilot treatment system to mitigate CSO into Harbor Brook, Syracuse. The design showcases three wetland modules (floating wetland island, vertical downflow, surface flow) in three interchangeable flow configurations (series, parallel, series-parallel), following grit and floatables pre-treatment.
Results/Lessons Learned. SUNY-ESF developed a monitoring plan for this novel pilot project. Here, we present our challenges in developing an adaptive monitoring plan with regards to: (1) experimental design, (2) sampling methods, and (3) sampling targets. We also discuss how the pilot project and monitoring program could be used to help institutionalize monitoring protocols and standards for "green" CSO treatment. Our experimental design and monitoring data will be used to recommend future treatment wetland expansion projects in Onondaga County.
CO2 Traps – A New Tool for Measuring Natural LNAPL Loss Rates at Petroleum Impacted Sites
Background/Objectives. Light non-aqueous phase liquids (LNAPLs) are commonly found beneath petroleum facilities. Despite known issues (e.g. cost, limited effectiveness, waste handling), hydraulic LNAPL recovery is a common default remedial action at many LNAPL sites. However, recent studies suggest that natural LNAPL losses are significant and may rival hydraulic recovery technologies. Therefore, it has become clear that accurately estimating natural LNAPL loss rates is a crucial step in developing efficient and effective (i.e. sustainable) remediation strategies at LNAPL sites. In support of a need for simple and robust methods to estimate natural LNAPL losses, and to address issues with several current methods, Colorado State University has developed a novel integral CO2 trap. The device directly measures fluxes of CO2 (the end product of petroleum mineralization) at grade, which are then used to calculate natural LNAPL loss rates. Field surveys using CO2 traps can provide important evidence of natural LNAPL losses in support of developing sustainable remediation strategies at LNAPL sites. This talk will provide an introduction to development of the CO2 traps, present results from laboratory testing and several field surveys, discuss fundamental processes controlling natural LNAPL losses and CO2 flux measurements, and highlight ongoing related research.
Approach/Activities/Methods. CO2 traps utilize a granular sodalime sorbent material that captures CO2 by converting Ca(OH)2 and NaOH to CaCO3 to Na2CO3. Captured CO2 is then quantified by mass loss during acidification. The CO2 trap design consists of two sorbent elements housed in a trap body that is fit to a receiver at grade. The lower element captures soil CO2 efflux. The upper element intercepts atmospheric CO2 to allow pressure equilibration and avoid overestimating soil CO2 efflux. Laboratory tests were performed to evaluate the ability of the sorbent media to quantitatively capture CO2 and to evaluate sorption capacity. Additional laboratory testing was performed to evaluate the ability of the traps to accurately measure CO2 fluxes. Field surveys were performed at seven sites to estimate natural LNAPL losses under a range of LNAPL types and porous media conditions.
Results/Lessons Learned. Seven rounds of closed system sorbent media testing were analyzed by comparing mass captured (CO2/sorbent) to mass delivered (CO2/sorbent) to check for quantitative CO2 sorption and evaluate sorption capacity. Confidence intervals for the slope and intercept of the resulting regression line were not significantly different from 1 and 0, respectively. The data appear linear up to the sodalime manufacturer’s estimated sorption capacity of 30% CO2 by mass. These results indicate that the media is capable of quantitatively capturing CO2. Results of seven rounds of open system tests of the trap design were analyzed by comparing measured CO2 fluxes (from traps) to input CO2 flux through a large soil-packed column (estimated from known gas flow rate and cross sectional area of the column). Confidence intervals for the slope and intercept of the resulting regression line were not significantly different from 1 and 0, respectively. These results indicate that the traps are effective at quantifying CO2 flux. Field surveys were performed at seven LNAPL sites. Deployment locations were selected to survey a broad range of LNAPL types and porous media conditions. Surveys were repeated over several time periods to assess seasonal trends. CO2 traps were deployed over the LNAPL smear zones and unimpacted background locations in order to separate naturally occurring (background) CO2 efflux from that associated with natural LNAPL losses. Calculated LNAPL losses ranged from 100s to 10,000’s of gallons per acre per year. Measured CO2 fluxes and calculated LNAPL loss rates show distinct spatial and seasonal variability.
Pore Network Changes in Shales: Implications to Remediation
Katherine M. Mouzakis, Colorado School of Mines
Background/Objectives. The mechanism of CO2 dissolution is studied in two types of shale, the Gothic shale and the Marine Tuscaloosa shale. This mechanism creates carbonic acid and reduces brine pH which results in a chemical disequilibrium that drives mineral dissolution and/or precipitation. These reactions can change the controlling characteristics of the pore network. Differences in pore shape and size can cause variation in capillary properties and fluid transport. These mechanisms become integral if the shale is used as an impermeable layer to prevent migration of subsurface fluids. Understanding how the pore network of shales and other rock formations react with various fluids and gases is important to industries such as carbon sequestration or remediation that are concerned with movement through pore networks.
Approach/Activities. Laboratory fixed-volume reactor experiments at temperatures of 160˚C and 150 bars were performed on the systems of brine-shale and brine-shale-CO2. Unreacted, reacted samples with brine, and reacted samples with brine and CO2 were analyzed with field emission scanning electron microscopy (FESEM), small angle neutron scattering (SANS), and with gas adsorption techniques to determine physical changes to pore networks.
Results/Lessons Learned. FESEM provided high resolution images supporting dissolution and precipitation of minerals in both samples with a greater occurrence of dissolution and precipitation in the Gothic shale. New circular and slit-like pores were imaged in the Gothic shale, however new pores were not evident with the FESEM in the Marine Tuscaloosa shale. SANS experiments provided information on the porosity, surface area, and pore size distribution of connected and unconnected pores in the shale samples. An increase in porosity in connected pores occurred in the Gothic shale while a decrease in porosity in connected pores occurred in the Marine Tuscaloosa shale. A comparison of unreacted, reacted with brine, and reacted with brine and CO2 samples provided a novel method of determining experimental artifacts from using synthetic brine in the laboratory experiments. This combination of controlled laboratory experiments, neutron scattering and high-resolution imaging provided new detailed information on changes to pore networks of typical shales that lie above geologic carbon sequestration sites. The altered pore network and associated changes to permeability highlight how reactions with multiphase fluids may result in an actual structural change to a geologic system. A better understanding of these changes may be integral in enhancing the sustainability of certain projects.
Dump the Pump: Replacing Pump-and-Treat with an Engineered Attenuation Zone
Mitchell R. Olson and Tom Sale, Colorado State University); Ben McAlexander and Justin Pruis, Trihydro Corp.
Background/Objectives. Colorado State University (CSU), Trihydro, and a corporate sponsor have been collaborating on a field demonstration of an Engineered Attenuation Zone (EAZ). The demonstration is being conducted at a former refinery site in the western US. Although all refinery-related infrastructure has been removed, soils beneath the site remain impacted with petroleum hydrocarbons. Existing remedies in place at the site include a sheet-pile wall and pump-and-treat system. The objective of the EAZ demonstration is to evaluate a passive remediation system that could replace the current pump-and-treat system. The vision is that impacted soils down-gradient of the LNAPL zone could be replaced by clean soils that are engineered to enhance natural attenuation processes. To evaluate this approach, CSU, Trihydro and a corporate sponsor are collaborating on a pilot-scale field demonstration.
Approach/Activities/Methods. The EAZ demonstration comprises three flumes measuring 40-ft long, 2-ft wide, and 6-ft tall. The primary flume backfill material consists of uncontaminated sandy-gravel borrow material collected from the site. Flume 1 contains site materials admixed with gypsum and taconite as supplemental electron acceptors. Flume 2, which was designed to evaluate treatment under aerobic conditions, contains unamended backfill with an oxygen emitter well. Flume 3 contains only unamended backfill material. Source water originates from an on-site monitoring well. A peristaltic pump transmits groundwater directly from the well to the flumes. The inlet water contains approximately 500 µg/L benzene and 10 to 50 µg/L toluene, ethylbenzene, and xylenes. The source water also contains elevated levels (900 mg/L) of sulfate.
Results/Lessons Learned: In Flumes 1 and 3, BTEX concentrations are reduced to detection limits within the first 8 to 24 feet, corresponding to residence times of about 6 to 18 days, respectively. Flumes 1 and 3 have produced similar treatment patterns, indicating that sulfate amendment may not be required when inlet water already contains high sulfate levels. In Flume 1, BTEX concentrations are reduced to detection limits within two feet of the oxygen diffuser well, corresponding to a residence time of less than 1.5 days. However, a concentration rebound, observed in Flume 1 downgradient of the oxygen diffuser well, indicates a possible treatment limitation due to a non-uniform distribution of oxygen within the flume. Finally, results have indicated that the system is sensitive to inlet water temperatures. System upsets have occurred in the aerobic and anaerobic flumes during winter months as inlet water temperatures drop to approximately 8°C.
Results to date indicate that the EAZ approach may provide a viable alternative to the current pump-and-treat system. In addition to the field demonstration, ongoing evaluation activities focus on economics, feasibility, and sustainability of a full-scale implementation.
The Development and Use of Remotely Operated Nutrient Sensors for in-situ Water Monitoring
Background/Objectives. Aquatic ecosystems with high nutrient levels usually contain an abundance of flora and fauna. However, excess phosphorus can lead to wild growth of algae and other plant life. This causes a drastic decrease in dissolved oxygen levels, creating a hypoxic environment. Aquatic species, which are sensitive to dissolved oxygen levels, are severely affected in hypoxic regions. This process is called eutrophication, and is a leading cause of biodiversity loss in aquatic environments. Although eutrophication can occur naturally, anthropogenic factors, such as agricultural runoff and sewage effluent, are leading contributors in most cases.
The existing methods of phosphorus testing can be both time consuming and expensive. Currently, remote nutrient sensors are very expensive and, therefore, it is often not affordable to employ more than one in an area. The goal of this project is to create an inexpensive total phosphorus analyzer that can take real time measurements and be accessed remotely. This would allow for a much more efficient and accurate determination of phosphorus levels over time and make multiple testing points within a site more economically feasible.
Real-time data acquisition can be greatly beneficial to many types of remediation projects. When the reduction of nutrients is the goal of a remediation project, in situ sensors can indicate how successful the project is without the use of invasive soil cores or offsite laboratory tests. Some remediation techniques include chemical reactions that produce phosphorus as a byproduct. If remotely operated sensors are used in these situations, they can provide instant feedback about the creation of excess phosphorus. In both cases, sensors can be a source of information for feedback loops that control a number of variables such as reactant dose and flow rates. Real-time data reporting creates a more sustainable remediation environment by minimizing the use of materials and cost while simultaneously improving efficiency.
Approach/Activities. In order for total phosphorus to be detected, two chemical reactions must take place within the instrument. First, an oxidation digestion reaction converts organically bound phosphorus into orthophosphate. Second, a Molybdenum blue colorimetric reaction occurs, allowing for the photometric detection of light transmittance that inversely correlates with the concentration of orthophosphate. Therefore, the design for the instrument must be two-fold. The digestion reaction takes place in a UV-assisted heater where the sample and reagent are held at 80°C for 10 minutes. The stream is exposed to UV light at 254nm for 30 seconds in order to speed up radical formation. At this point, all of the phosphorus in the sample exists in the form of orthophosphate and will turn blue in the presence of stannous chloride reagents. A small spectrophotometer with a 5cm path length is used to measure the transmittance of light at 660nm. By comparing the transmittance to a calibration curve, the concentration of total phosphorus can be determined.
Results/Lessons Learned. The assembly of the sensor is complete, and the testing phase is under way. Before field tests can be done, the bench model must show high rates of digestion and repeatability. Thus far, the bench model is showing approximately 90% digestion. The range of detection is 20-140 µg P/L. This almost fully encompasses the range of phosphorus levels that exist in natural waters (10-100µg/L) as well as levels that indicate a risk of eutrophication (>100µg/L). A cost and energy efficient nutrient analyzer can help us to understand the impact of environmental projects on natural waters by allowing for multi-point real-time data acquisition. This allows for more accurate modeling of remediation sites as well as point and non-point sources of nutrient pollution.
Decision Support System for Modeling Matrix Diffusion Processes
Jennifer Wahlberg, Colorado Sate University; Shahla Farhat, GSI Environmental Inc.; Azadeh Bolhari, Colorado State University; Tom Sale, Colorado State University; Chuck Newell, GSI Environmental Inc.
Background/Objectives: Groundwater contaminant transport research of the past two decades has advanced the concept of contaminant transport via advection and transverse diffusion in heterogeneous media. This concept is driving new strategies for managing contaminants in source zones and plumes. Unfortunately, models addressing transport via advection and transverse diffusion are not readily available to the practicing community. In response to this need, GSI Environmental, Colorado State University, and Environmental Security Technology Certification Program (ESTCP) are developing a Matrix Diffusion Toolkit that will allow practitioners to model contaminant transport under conditions dominated by advection and transverse diffusion. This poster introduces the Matrix Diffusion Toolkit with emphasis given to a two layer scenario developed in Sale et al., 2008. The toolkit will be available as downloadable public domain software in Fall 2012.
Approach/Activities/Methods: The toolkit has two components, the Square Root Model and the Dandy-Sale Model. The Square Root Model (one-dimensional) builds on work by Parker et al., 1994 and Sale et al., 2007. The Dandy-Sale Model (two-dimensional) is an analytical model in which a low permeability (low k) layer (e.g., clay) is overlain by a more transmissive layer (e.g., sand). A thin pool DNAPL source is introduced at the contact between the two layers upgradient of x=0. The DNAPL source is active for a given amount of time, τ. While the source is active, forward diffusion occurs from the transmissive layer to the low permeability layer. After the source is exhausted (t ≥τ), back diffusion occurs from the low k layer to the transmissive layer.
Results/Lessons Learned: Model applications allow portrayal (as a function of time and position) of:
- Contaminant concentrations (aqueous, sorbed, and total) in transmissive and low k zones
- DNAPL, aqueous, and sorbed contaminant mass in transmissive and low k zones
- Contaminant fluxes across the contact between transmissive and low k zones
- Aqueous contaminant concentrations in wells in transmissive zones
Current and future applications of the toolkit include:
- Sensitivity analyses for seepage velocity, source longevity, retardation, and diffusion/dispersion coefficients.
- Illustration of the evolution of a chlorinated solvent release from a problem of DNAPL in transmissive zones to aqueous and sorbed phases in low k zones.
- Quantifying the benefits of source removal in terms of aqueous concentrations in downgradient transmissive zone wells.
- Resolving the distribution of contaminants in low k zones as a function of source duration, downgradient position, and time.
Optimization of an Anaerobic Membrane Bioreactor for Decentralized Communities
Background/Objectives. Anaerobic digestion has been used to treat various waste streams for decades. Anaerobic biological treatment technologies have recently received significant research interest, as the biogas produced can be a source of energy. In municipal wastewater treatment, traditional aerobic processes are commonly employed due to shorter hydraulic retention times (HRT) and better overall treatment compared to anaerobic treatment options. For decentralized communities however, proper wastewater treatment can be a major issue, which necessitates the development of robust and low-energy treatment processes.
Anaerobic digesters are typically operated with a HRT of 15-30 days which requires a large reactor footprint. AnMBR systems allow for retention of solids in the reactor while allowing the treated water to be removed from the system. This decoupling of the solids retention time (SRT) from the HRT greatly reduces the HRT required for treatment, and subsequently the system footprint. In addition, AnMBRs can produce a superior quality effluent compared to traditional anaerobic digesters. Membrane fouling has been a major issue in AnMBR operation, and in order to mitigate fouling, AnMBR systems have been operated at low permeate flux and have traditionally employed hollow fiber membranes. These membranes are typically sparged with biogas, which requires energy to compress and deliver the biogas to the membrane surface. The objective of this project was to design, optimize and evaluate an anaerobic membrane bioreactor (AnMBR) for the treatment of municipal and food waste. For this project, a ceramic membrane was evaluated due to robustness towards fouling and ability to be cleaned at high pressures without biogas sparging.
Approach/Activities. The AnMBR system employed a ceramic cross-flow micro-filtration membrane with a 0.2 μm nominal pore size. As opposed to backwashing, the membrane was cleaned with frequent high-pressure back-pulses. The reactor was seeded with sludge obtained from the local wastewater treatment plant. The reactor was initially fed at a 30 day HRT and the feeding volume was gradually increased to a 10 day HRT. Biogas production was measured and biogas analyzed for composition to determine the efficiency of methane production. Reactor digestate and the membrane permeate water quality was evaluated to determine treatment efficiency which included routine analysis of chemical oxygen demand, total organic carbon, total nitrogen, and turbidity.
Results/Lessons Learned. The main goal of this project was to determine the optimum reactor HRT for waste treatment and biogas production. The secondary goal was to determine the optimum cross-flow velocity and back-pulsing frequency to combat fouling. Preliminary results indicate that the AnMBR configuration provides good COD removal at short HRTs. This poster will summarize the fabrication of the AnMBR, methods used to evaluate the reactor, and preliminary results from operation including membrane effluent water quality, biogas production, and indicators of membrane fouling.
Zebra Mussels: A nuisance or A Valuable Asset to Aquatic Systems?
Theodore D. Williams, Mario Montesdeoca, Charles T. Driscoll, Department of Civil and Environmental Engineering, Syracuse University, Syracuse NY; Michael Spada, Upstate Freshwater Institute, Syracuse NY
This study investigates the temporary and permanent sequestration of total mercury (THg) from different sampling sites in the Seneca River and Harbor Brook of the Onondaga Lake. Temporary THg concentrations were as high as 106 ng/g and 1426 ng/g in zebra mussels’ tissues in the Seneca River and Onondaga Lake respectively. Zebra mussels (Dreissena polymorpha) are a group of invasive species that are known to be effective filter feeders. These mussels have been acknowledged as valuable monitoring organisms and accumulators of heavy metals (Voets et al. 2009). Zebra mussels (5-25mm length) were collected between 2009 and 2010 from the highly mercury contaminated Onondaga Lake and the channelized Seneca River that flows from west to east before flowing into the Onondaga Lake and continue flowing north.
Because of the disparity of the concentrations among Zebra Mussels’ tissues and shells, a digestion procedure was used followed by cold Vapor Atomic Fluorescence Spectrometry for the shells and total solid analyses by Atomic spectrometry for the tissues. The freeze-milled shells were prepared for a non-sediment based mercury leaching procedure for 15, 30, 90 and 120 days to evaluate the leaching rate and conditions of THg release by zebra mussels’ shells after deposition. The lake water extraction solutions selected the leaching experiment represented normal lake water chemistry and extreme chemistry conditions to allow the most favorable mercury leaching possibilities.
Based on extreme leaching experimental conditions, 92.9 percent of the THg in zebra mussels’ shells was permanently retained. Based on the application of the results, the permanently sequestered Hg by the zebra mussels were at the Seneca River Cut and Onondaga Lake.
Slow Release Permanganate Candles for Sustainable in situ Chemical Oxidation
Gerlinde Wolf and Michelle Crimi, Clarkson University
Background/Objectives: Chemical contamination of the subsurface is a public health challenge worldwide and it is essential that affected areas be addressed through remediation and treatment efforts. Often, chemical contamination exists in widely dispersed, low concentration contaminant plumes, which pose a great challenge to the remediation industry and are very costly to clean up. Common environmental contaminants of this nature are chlorinated solvents such as trichloroethylene (TCE), which pose a threat to human and environmental health. Historically, remediation of TCE has been a difficult and environmentally demanding process due to the compound’s recalcitrant properties. Long-term, low cost in situ treatment options for chlorinated solvents would be highly desirable for many sites with low levels of contamination where traditional oxidant injection is not physically or economically feasible.
Recently there has been great interest in developing sustainable remediation techniques which strive to maximize the environmental, social, and economic benefits of the project. One such sustainable remediation technique combines passive in situ chemical oxidation (ISCO) with sustained release permanganate candles (SRPCs) which degrade contaminants into innocuous byproducts. ISCO using SRPCs has the potential to reduce energy consumption, site disruption, and personnel time spent at the field site. In this passive oxidation system permanganate is distributed throughout the media via diffusion and dispersion, therefore no injecting or pumping of liquid oxidants is required. Additionally, a reactive zone is created and has the potential to destroy contaminants for extended periods (e.g., months to years). Once SRPCs are inserted into the ground they can be left at the site and only periodic monitoring is needed.
The objective of this research is to develop a SRPC design tool to simulate SRPC release kinetics and permanganate reaction and distribution over time to guide full-scale design. Several existing SRP models offer a good starting point to this research; however the potential effects of inner-candle tortuosity on permanganate delivery have not yet been adequately characterized. Our research will investigate how tortuosity could affect permanganate release and therefore oxidation of contaminants and incorporate these effects into the SRPC design tool.
Approach/Activities: The focus of this project is to understand and develop a model of SRPC release kinetics and show how the kinetics may evolve over time due to the change in candle morphology (i.e. tortuosity). Parameters that need to be determined are (1) how tortuosity will affect permanganate flux, (2) how to incorporate permanganate release rate into the advection dispersion reaction equation, and (3) how to model the permanganate natural oxidant demand of the system. Additionally, the model will address other key variables including how a SRPC may behave in a lower permeability media and ways to optimize the initial SRPC radius, reducing the number of candles required and thereby reducing cost.
Expected Results: Our research will expand upon existing models of SPRC release kinetics by including the impacts of candle tortuosity. We expect this research will enhance the understanding of sustained oxidant release and therefore make sustainable remediation efforts more accessible. The outcome of this research will be a user-friendly design too that will aid in full-scale sustainable remediation design and field scale implementation. This tool will help to estimate the radius of influence of permanganate candles, the number of permanganate candles, and lifespan of oxidation processes, and will attempt to provide a cost estimate of the project. Results of this investigation will allow a better understanding of SRP treatment potential in variety of field settings, and will illustrate how permanganate release rates may change over time.
Sustainable Biocover for Methane Oxidation at Landfill Sites
Poupak Yaghoubi, Bala Yamini Sadasivam, Krishna Reddy, Dept. of Civil and Materials Engineering, University of Illinois at Chicago, Chicago, IL
Background. Municipal solid waste landfill sites are one of the largest anthropogenic sources that emit greenhouse gases like CH4 and CO2 into the atmosphere due to anaerobic degradation of organic matter. Thus, mitigation of landfill gases(LFG) is one of the main aspects considered while designing a landfill site in order to prevent pollution and control global warming. Installation of gas collection systems is the most recent technology that is employed to control methane gas emissions from landfill sites. However, it is not economically feasible to install gas collection systems in old or abandoned landfills with low CH4 production and even in new landfill sites with advanced collection systems, fugitive emissions are a problem. Therefore, it is necessary to develop cost-effective methods for mitigating LFG emissions.
In general, landfill cover soils can partially remove CH4 by the oxidation properties of methanotrophic bacteria. The oxidizing capacity of landfill cover soils can be improved by adding organic rich sludge and composts like biochar. Biochar is a carbon-rich product obtained when plant-based biomass is heated in a closed container with little or no available oxygen. Amendment of biochar to landfill cover soil can change the basic physical-chemical characteristics of the landfill cover and affect the transport behavior of gases. An optimum cover soil composition is critical in enhancing the methanotrophic activities for substantial reduction in CH4 emissions. In order to understand the principle mechanisms involved in methane mitigation within a biochar amended landfill cover, it is necessary to establish the characteristics, adsorption and oxidation behavior of biochar by conducting extensive research.
Objectives. The goals of this work were to: 1) Investigate the characteristics that change as a result of amendment of biochar to landfill cover soil, 2) Investigate the landfill gas adsorption capacity of biochar and biochar amended cover soil, 3)Characterize the main factors that affect methane oxidation within the biochar amended landfill cover, 4) Test the adaptability of biochar amended landfill cover to environmental conditions, such as moisture content and temperature, and 5) Study the mechanisms of methane oxidation and adsorption within biochar amended landfill cover to obtain kinetic parameters of the mitigation process.
Approach. Chemical and physical characteristics and geotechnical properties of soil, biochar, and biochar amended soil were determined. An analysis of moisture content, organic content, total organic carbon content, cation exchange capacity (CEC), total nitrogen, phosphate, and potassium (NPK), pH , density, particle size distribution, Atterberg limits, compaction, hydraulic conductivity, compressibility and shear strength analysis were conducted with biochar alone, soil alone, and biochar amended soil. Both column and batch experiments were conducted using soil alone, and soil amended with biochar to quantify the effects of biochar amended on degradation of CH4. The LFG composition was analyzed before and after transport through the columns at different time periods and the material from the columns was transferred into the bottles for batch testing after 4 months. The effect of methane adsorption to biochar and biochar-amended soil was studied, which provided favorable conditions for methanotrophic oxidation to improve degradation within the cover.
Conclusions. The amendment of biochar to soil increased pH, permeability, and organic content of soil, thus facilitating the growth and multiplication of methanotrophs. It increased the shear strength of the soil and decreased its compressibility. Biochar facilitates the oxidation process by enlarging the oxidation layer of landfill cover. The adsorption of methane by biochar amended landfill cover soils together with the degradation of methane by the methanotrophs which live within biochar pores will make this a sustainable process to mitigate LFG emissions.
Green and Sustainable Remedy Selection & Design for Indian Ridge Marsh, Chicago, IL
Erin Yargicoglu, Jennifer Welch, Gregory Bourgon, Dr. Krishna Reddy, Dept. of Civil and Materials Engineering, University of Illinois at Chicago, Chicago, IL
Background. The remediation and restoration of heavily industrialized former wetlands and mesic prairies in the Great Lakes region pose several special challenges due to: 1) the widespread and heterogeneous distribution of contaminants; 2) the variety of contaminant classes present; 3) complex hydrogeologic regimes due to extensive and variable industrial filling and dredging throughout the Calumet region and a lack of proper hydrologic controls on-site; and 4) the presence of sensitive ecological receptors and habitats, including nesting areas for several endangered and threatened bird species (e.g. black crowned night heron).
The study site, Indian Ridge Marsh (IRM), located in southeast Chicago, IL, is one of several degraded wetlands in the Calumet region that are slated for remediation and redevelopment as part of the Calumet Open Space Reserve (COSR) initiative. IRM has significant and widespread historic contamination, including documented impacts to soil, sediments, surface water and groundwater. Multiple contaminant classes are present on-site including: heavy metals, pesticides, volatile organic compounds (VOCs), polycyclic aromatic hydrocarbons (PAHs), and one observed instance of an LNAPL plume containing petroleum hydrocarbons. The contaminated areas that posed the greatest risk to human and ecological health were identified through comparison of measured sample concentrations to risk based screening levels (RBSLs) established in the State of Illinois Administrative Code, Tiered Approach to Corrective Action Objectives (TACO) and the Calumet Area Ecotoxicological Protocol (CAEP). Areas of Concern (AOCs) were established based on the geographic distribution of samples with contaminant levels exceeding established RBSLs.
Objectives. The goals of this work were to: 1) assess historically documented contamination based on data collected for previous Phase I & Phase II ESAs at IRM; 2) identify AOCs on-site that present the greatest risks to human and ecological receptors to determine the extent and intensity of remedial treatments required to meet established cleanup requirements; 3) evaluate the remedial options available based on applicability, cleanup efficiency and sustainability metrics; and 4) recommend an appropriate remedial strategy and present a viable plan for sustainable restoration of IRM to the CPD for consideration.
Methodology. Remedial options for both soil and groundwater treatments were evaluated in terms of: sustainability; cost; applicability to on-site contaminants; overall site disturbance; and potential impacts to existing habitats for sensitive ecological receptors and native plant species. Technologies considered include: excavation, solidification and stabilization, in-situ chemical oxidation, groundwater pump-and-treat, in-situ bioremediation, and enhanced biostimulation in conjunction with phytoremediation. Appropriate remedial options were subjected to a detailed evaluation using two models for Green and Sustainable Remediation (GSR): SiteWise™ and the Sustainable Remediation Tool™ (SRT).
Conclusions. Those analyses, coupled with qualitative evaluation of sustainability based on California’s Green Remediation Evaluation Matrix (GREM), lead us to our final remedy selection: phytoremediation in conjunction with enhanced biostimulation in areas with severely degraded soils. Based on site-specific conditions (e.g. hydrogeologic regime, heterogeneous soils and surficial sediments, sensitive wetland habitats) and future site use, several remedial alternatives were disqualified. Best Management Practices obtained from Illinois EPA’s Greener Cleanups Matrix and the Minnesota Pollution Control Board for selected technologies are integrated in our recommended remedial strategy, which incorporates plant species present on-site and restoration of native vegetation with minimal site disturbance.
Integrating Social Aspects into Sustainable Remediation
Pat Serie, EnviroIssues
Renee Dagseth, EPA Region 10
The presenters will share a case study of the Lower Duwamish Waterway cleanup process to illustrate what kinds of social issues arise on a complex, urban-environment cleanup site. The presentation will describe approaches used to engage diverse interests in all stages of the cleanup decision-making process and lessons learned from that 10-year process.
Economic Perspectives on Superfund Site Remediation
Dave White, King County Wastewater Treatment Division
This presentation offers some perspectives on the economic aspects of site remediation. It includes observations on long- and short-term economic benefits and impacts, and concerns and strategies for successful remediation with the regional economy in mind.
Walking the Talk: SURF's Nine-Step LCA Process Tested
Dave Ellis, DuPont
A pilot study to incorporate sustainability analysis in the remedy selection process presented an ideal opportunity to test drive the new nine step process for performing footprint analysis and life cycle assessments. An estimated 154 kilograms of perchlorethylene are to be remediated in approximately 520 cubic yards of soil from multiple locations, primarily located along former wood-lined trenches. Four remedial action options (i.e., dig and haul, aeration, phytoremediation, and in-situ reduction) were identified and evaluated along with a no-action baseline using SimaPro™ life-cycle software. Using the SURF nine step process worked well on this site, providing additional insights into each potential remedy and robust guidance for use during the remedy selection process.
Colorado State University Welcomes SURF
Dr. Wade Troxel, Associate Dean of Engineering and Director of Center for Networked Distributed Energy and RamLab
Dr. Troxel will welcome the SURF organization to Colorado State University and provide and overview of sustainability initiatives at Colorado State University.
Taking the SURF White Paper to the Next Level:
Creation of a Sustainable Remediation Site Database
Steven Murawski, Baker & McKenzie LLP
The purpose of the presentation is to describe the proposed creation of an on-line Sustainable Remediation Site Clearinghouse that will allow users to conduct database searches of sustainability-related elements of remediation projects throughout the United States. The presentation will begin with a brief background of the SURF White Paper and EPA's developing regional and national Green/Sustainable Remediation Policies. Afterward, a discussion of the key differences between the SURF White Paper's goals and EPA's Policies will be explored. Next, the proposed on-line Sustainable Remediation Site Clearinghouse will detailed using representative example from EPA's Green Remediation website. Finally, the presentation will end with an outline of suggested next steps to complete this project.
"Our Common Future"...
Addressing the other half of the sustainability challenge
Carl Hammerdorfer, Director, Global Social & Sustainable Enterprise (GSSE) MBA, Executive Director, Center for Advancement of Sustainable Enterprise (CASE)
The Bruntdland report addressed not only environmental and climate concerns, but also linked progress in that sphere to the challenge of economic and social development. Business has tended to view sustainability almost exclusively through the energy and environment lens. More recently, thought leaders and leading business schools have begun to include the other 4 billion in their strategies for building a more sustainable model for global commerce. CSU's Global, Social & Sustainable Enterprise MBA prepares a new generation of students to change the world using enterprise solutions. Its partner organization, Center for Advancement of Sustainable Enterprise (CASE), creates a framework for success of social entrepreneurs, and acts as a bridge between CSU research and commercial actors.
The Multiple Meanings of Sustainability: Values and the Triple Bottom-Line
Michele Betsill, Colorado State University
Sustainability and the related quest to balance environmental, economic, and social goals has become a guiding principle for myriad activities in the public and private spheres from the global to the local level. Yet we find considerable variation in the types of activities that are considered "sustainable" when this principle is translated into practice. This talk will provide a framework for understanding the multiple meanings of sustainability with a particular focus on the role of values in shaping different perspectives. Ultimately, the search for a sustainable future must involve processes by which societies can confront and reconcile these competing values.
The Role of Yellow Iron in Sustainable Remediation
Scott Denson, SunPro Services
Yellow Iron has played a pivotal role in the remediation business over the last 50 years. As methods have progressed and waste minimization and energy reduction techniques refined, yellow iron continues to be a staple even as it enters a new marriage with sustainability. We will explore the vantage an environmental contractor witnesses and discuss some in the field examples where it gets put to action. This will all be conveyed while reflecting back on some of the obstacles sustainability faces along with looking forward to the inspirations of the science and the people.
Remedial Process Optimization (RPO) for Green Remediation: Air Force Plant 4, Texas
Rick Wice, Shaw Environmental and Infrastructure Group
To achieve timely and cost-effective site closures, the Air Force Center for Engineering and the Environment developed RPO guidance. The Army and Navy have similar programs. RPO helps reduce energy and materials use. RPO principles can be used to help green a remediation project, and many of us have been doing this for several years. Air Force Plant 4, a large aircraft manufacturing facility in Ft. Worth, Texas, will be presented as a case study showing how RPO is a tool for performing green remediation.
Improving the Sustainability of Source Removal
Ralph S. Baker, Ph.D., and Tim Burdett (TerraTherm, Inc., Fitchburg, Massachusetts); Steffen Griepke Nielsen (Niras A/S, Aarhus, Denmark); Maiken Faurbye, Niels Ploug and Jesper Holm (Krüger A/S, Søborg, Denmark)
A third-party Life Cycle Analysis (LCA) (Pfeilschifter, et al., 2007) was conducted at a DNAPL site in Reerslev, Denmark where Soil Vapor Extraction (SVE) and In Situ Thermal Desorption (ISTD) were compared with excavation/off-site treatment, and where several years of SVE operation were followed by rapid implementation of ISTD to protect one of the major municipal water supply well fields serving Copenhagen. The LCA performed for the site-specific conditions concluded that SVE would consume more energy, produce more waste and generate more greenhouse gases (GHG) than ISTD, while requiring an indefinite period of time (>100 yr) to remove sufficient contaminant mass to achieve site closure. Whether or not excavation/off-site disposal or treatment compared well with ISTD depended primarily on the transport distance to a suitable disposal or treatment site. The LCA selected ISTD as the most preferable alternative, as it offered the reduced neighborhood (i.e., social) impacts of an in situ remedy (no need to move families and demolish homes), combined with the least overall environmental and economic impacts. Subsequent implementation of ISTD at the site, completed in 2009 and treating 12,560 m3 of contaminated soil to attain the treatment goals actually consumed less energy, produced less GHG, took less time and cost less than the LCA had assumed, i.e., it proved to be even more sustainable than estimated in the LCA. The GHG associated with digging and hauling the soil approx. 140 km (85 mi) equates to the GHG associated with electrically heating the soil for the 5.5 months remediation period, meaning that transport distances exceeding approx. 140 km would be expected to have larger GHG impacts than ISTD.
Status and Direction of Alpha Student Chapter of SURF
Kevin McCoy, MS candidate Civil and Environmental Engineering
Dr. Tom Sale, Associate Professor, Civil and Environmental Engineering
Today’s science and engineering students are broadly integrating sustainability themes into their education and emerging careers. Building on this, students with interests in remediation at CSU have formed the alpha student chapter of SURF. In the spring of 2010 student initiatives led to Colorado State University recognition of SURF as an official student organization. Content of this presentation will address the current plans for the student organization and solicit input from the parent organization regarding the mission of the student chapter and future collaborations with SURF.
Sustainable Remediation at the Bell Landfill Superfund Site, Pennsylvania: Remedy Selection, ROD Change, and Implementation
Dave Ellis, DuPont
The Bell Landfill site is a Superfund site located in northeastern Pennsylvania that contained mixed municipal and industrial waste. The site and ROD were reexamined with sustainability in mind. The original remedy specified a soil cap with a leachate collection system. The tank trucks that collected the leachate and transported it to a POTW for treatment caused several problems: noise and disturbance for neighbors and severe rutting of unpaved roads during wet periods. Over time, the leachate composition changed to the point where it no longer contained organic contaminants. After a sustainability analysis, a spray irrigation system was proposed in lieu of trucking the leachate for treatment. Following laboratory and field testing, the system was approved by the state and USEPA Region 3. An ESD was issued and the spray irrigation system began operation in 2009. A side benefit is that the vegetation on the cap no longer dies during the summers.
Using an Economic Model to Estimate Cross-Media Pollution: SF Bay Area Superfund Sustainable Remediation Case Study
L. Maile Smith, Northgate Environmental Management, Inc.
Regulatory agencies routinely establish risk-based cleanup goals for remediation projects. Although risk assessments provide a means to develop health-protective cleanup goals, they rarely consider cross-media impacts resulting from the remedial activities. We developed a simulation model as part of a comprehensive evaluation of the benefits, costs, and impacts of groundwater remediation programs for federal Superfund projects in the San Francisco Bay Area. Cross-media pollution effects are both direct and indirect, arising from lifecycle economic linkages that exist between remediation activity and the rest of the economy. A static multi-regional input-output model of the economy, calibrated to data on economic activity and pollution emissions, was used to estimate the indirect cross-effects of Bay Area Superfund pump-and-treat programs. This model is based on the IMPLAN® commercial computer software model with associated Social Accounting Matrix.
Got Impact? Working Towards Global Change from Inside the University
Dr. Morgan DeFoort / Co-Director CSU's Engines & Energy Conversion Laboratory
Colorado State University is emerging as a leader in the use of enterprise to improve the human condition on a global scale. CSU's Engines & Energy Conversion Laboratory has led the development of numerous clean energy technologies and several of these have now been implemented at large scale. This talk reviews progress on three of these technologies: emissions reduction for the U.S. natural gas pipeline system, clean cookstoves and two-stroke engine retrofits for the developing world, and algae-based biofuels. Large-scale dissemination models were tailored for each application and will be discussed. These technologies have achieved global impact through this entrepreneurial approach and are poised to dramatically increase the impact. This entrepreneurial approach to global impact is now being implemented more widely at CSU through campus-wide research organizations such as the Clean Energy Supercluster and through academic programs such as the Global Social and Sustainable Enterprise program in the College of Business.
Current Remediation Research at Colorado State University
Dr. Tom Sale, Associate Professor of Civil and Environmental Engineering and Director of the Center for Contaminant Hydrology
For more than two decades students and staff at Colorado State University have been working on advancing innovative strategies for subsurface releases of persistent anthropogenic compounds. A common theme in these efforts has been developing novel solutions that are effective and pragmatic. An overview of current research will be presented. This will include: in situ soil mixing, electrolytic reactive barriers, use of tracer in LNAPL, measuring natural attenuation rates of LNAPL, sheen formation processes in porous media, use of waste heat to accelerate natural attenuation, computation chemistry to evaluate the fate of persistent contaminants, and tools for selecting site remedies.