Water Resources and Environmental Engineering

Research Project Abstracts: 2001 - 2002

A Global Assessment of Recycling Policy and Markets
M. A. Barlaz and D. H. Loughlin
Environmental Research and Education Foundation
1/01 to 9/02
The past decade has witnessed explosive growth in the public's interest in recycling. In some countries, the government has encouraged local recycling programs through the use of subsidies. To create new markets for recyclables and to strengthen existing markets, governmental mandates have been used. The objectives of the proposed research are to (1) develop an understanding of the policies and markets that are controlling recycling activity in the US and abroad, and (2) use this understanding to make recommendations on how to strengthen recycling markets and how to finance recycling programs under various regulatory climates.

Long Term Nitrogen Management in Bioreactor Landfills: Mechanisms for Denitrification
M. A. Barlaz
Waste Management Inc.
12/99 to 12/01
Landfill leachate contains high ammonia concentrations after it is stable with respect to organic and metal concentrations. This will likely influence the time of the post-closure monitoring period. The objective of this research is to develop an understanding of the chemistry and microbiology of denitrification in landfills so that operating strategies can be designed for leachate denitrification. Specific factors to be evaluated include (1) the availability of decomposed refuse as an electron donor, (2) the suitability of methanogenic leachate as an electron donor, and (3) the potential for nitrate reduction to ammonia as a consequence of excess degradable organic carbon.

Production of Non-Methane Organic Compounds (NMOCs) and Volatile Organic Compounds (VOCs) During Refuse Decomposition
M. A. Barlaz
Waste Management Inc.
3/01 to 4/02
The overall project objectives are to develop a better understanding of (1) the production of NMOCs and VOCs during refuse decomposition and (2) the relationship between NMOCs and VOCs. During this project an ultimate yield (Lo) for NMOCs and selected VOCs in individual components of MSW will be measured during anaerobic refuse decomposition. In addition, the significance of household hazardous waste (HHW) as a contributor to VOCs and NMOCs during anaerobic refuse decomposition will be evaluated. Finally, the effects of aerobic and nitrate-reducing conditions on NMOC and VOC production will be tested.

The Effects of Aging and Sorbent Decomposition on the Bioavailability of Toluene and Xylene in Solid Waste
M. A. Barlaz and D. R. U. Knappe
US Environmental Protection Agency
10/98 to 2/02
Priority pollutants are being released to groundwater from unlined landfills, and strategies must be developed to manage these sites in a manner that is both cost-effective and protective of the environment. The objective of this research is to develop an understanding of factors controlling the bioavailability and fate of organic contaminants sorbed to components of municipal solid waste (MSW) in landfills. After characterization of the major organic components of MSW, single-solute batch isotherms will be conducted for each material in fresh and decomposed form. This will be followed by work on the effect of leachate on contaminant partitioning and on the effects of aging on the bioavailability of toluene and xylene to anaerobic consortia.

The Implications of Greenhouse Gas Limits for the Waste Management Industry
M. A. Barlaz
Research Triangle Institute
3/02 to 6/02
There is growing pressure on society to reduce emissions of greenhouse gases (GHGs). This pressure is prompting many industries to evaluate GHG emissions associated with their processes. Such an evaluation can include an inventory of emissions based on current practices as well as an evaluation of strategies that could be used to reduce GHG emissions. The objective of this research is to evaluate the impact of alternate municipal solid waste management strategies on greenhouse gas emissions.

Sequestration Mechanisms & Bioavailability of Tetrachloroethene and Toluene in Solid Waste
M. A. Barlaz, D. R. U. Knappe, and M. A. Nanny (Univ. of Oklahoma)
National Science Foundation
09/01 to 08/04
The overall objective of the proposed research is to study factors that control the fate and bioavailability of tetrachloroethene (PCE) and toluene in landfills with a specific focus on contaminant sequestration and biodegradation as influenced by the presence of (1) humic substances in solid matrices and (2) acidogenic and methanogenic leachate. A series of tests will be conducted to characterize the composition of sorbent organic matter and its effects on PCE and toluene sorption and sequestration. Using 13C-labeled compounds, spectroscopic techniques (13C-CP/MAS NMR and pyrolysis GC/MS) will be employed to determine whether covalent binding or noncovalent interactions control contaminant sequestration.

Closing the Gaps in the Regulation of Municipal Solid Waste Landfills: Defining the End of the Post-Closure Monitoring Period and the Stability of Leachate Reticulation Landfills
M. A. Barlaz and M. A. Gabr
US Environmental Protection Agency
9/99 to 9/01
The objective is to develop a plan to establish the scientific basis for defining the end of the post-closure monitoring period at municipal solid waste (MSW) landfills. Current regulations specify terminating the post-closure monitoring period 30 years after closure. While emissions are likely to continue well beyond 30 years, regulatory agencies and landfill owners lack the scientific basis to define an appropriate endpoint. In addition, the increased use of leachate recycle to enhance MSW decomposition will result in changes in the properties of decomposed refuse, increased methane emissions, more precise water management, enhanced settlement, and a need to reconsider cover stability and design.

Development of Permeable Reactive Barriers (PRBs) using Edible Oils
R. C. Borden
Department of Defense, Strategic Environmental Research and Development Program
1/01 to 1/05
PRBs are expected to cost less than active pumping systems. As solvents or other contaminants migrate through the barrier, they are removed or degraded, leaving uncontaminated water to emerge from the downstream side. We propose to develop and evaluate an alternative barrier system for controlling the migration of chlorinated solvents. An oil-in-water emulsion, prepared with food-grade edible oils, will be injected into the contaminated aquifer in a barrier configuration using either conventional wells or Geoprobe points. As the emulsion passes through the aquifer, a portion of the oil will become entrapped within the pores leaving a residual oil phase to support long-term reductive dehalogenation of chlorinated solvents that enter the barrier.

Use of Soybean Oil and Soybean Products for Groundwater Bioremediation
R. C. Borden
United Soybean Board
4/02 to 12/02
Emulsified soybean oil can be used to treat groundwater contaminated with a variety of pollutants including rocket fuel (perchlorate), heavy metals (chromium), acid mine drainage (sulfate, iron, manganese, copper, zinc) and nitrate from agricultural and waste management operations. The overall objective of this proposal is to evaluate the use of soybean oil and soy-based products for use in treating these pollutants.

Development and Characterization of an rRNA-Targeted Oligonucleotide Hybridization Probe for Bacillus licheniformis
F. L. de los Reyes III
Sybron Chemicals Inc.
3/01 to 8/01
The main objective of this project is to develop rRNA-targeted probes that will track the fate of an environmentally versatile strain of Bacillus licheniformis. The specific objectives of the project are: (1) to design one or two strain-specific oligonucleotide probes targeting the 16S rRNA of B. licheniformis, (2) to thoroughly characterize the specificity and sensitivity of the designed probes for membrane hybridization, and (3) to perform initial quantification of B. licheniformis in select environmental samples.

Molecular and Engineering Approaches for Analyzing Microbial Selection in Activated Sludge: Competition between Filaments and Floc-formers
F. L. de los Reyes III
National Science Foundation CAREER
7/01 to 6/06
Fundamental activated sludge microbiology will be examined using novel molecular techniques. The research component of this project will combine molecular, modeling, and reactor studies to integrate theories of microbial selection of floc-formers over filaments and develop design guidelines for reactor design and operation. The education component involves the training of undergraduate and graduate students in the principles and practices of molecular techniques, the integration of treatment process modeling and full-scale treatment plant exposure experiences in courses, the development of a teaching module on applications of molecular methods in environmental engineering, and participation in the Video-Based Engineering Education program.

Fundamental Analysis of a Novel Swine Wastewater Treatment Technology
F. L. de los Reyes and J. Cheng (Biolog. & Agr. Engr. Dept.)
US Department of Agriculture- National Research Initiative Competitive Grants Program
8/01 tp 7/04
In this project, we will identify, quantify, and monitor the nitrifying, denitrifying, and other nitrogen-removing populations in a novel single-reactor system using molecular techniques based on 16S rRNA (ribosomal ribonucleic acid) sequence analysis. These techniques, which will include oligonucleotide probe hybridizations, PCR (polymerase chain reaction) amplification, cloning, and nucleic acid sequence analysis, are not limited by cell morphology or cultivation conditions and are therefore not subject to the limitations and biases of traditional methods. The microbial community structure will be related to reactor operation in order to optimize the performance of the reactor system.

Needs Assessment and Troubleshooting of Municipal Wastewater Treatment Systems in North Carolina
F. L. de los Reyes
University Extension Grants Program
06/00 to 06/01
This project aims to address the needs of municipal wastewater treatment facilities in North Carolina by (1) establishing collaborative linkages with treatment plants, assessing their technological needs, and identifying common problem areas and successful solutions, and (2) establishing a database of microbial communities in treatment plant bioreactors. The assessment of needs, problem areas, and solutions will be conducted using surveys of over 200 full-scale facilities across the state. The second component involves the sampling of biological reactors in treatment facilities to establish a database of microbial community structures that will aid in reactor troubleshooting.

Modeling Activated Sludge Population Dynamics
F. L. de los Reyes
Unsponsored
2001, ongoing
Population models of filaments and floc-formers in activated sludge are being developed using STELLA and MATLAB. These models will explore the effects of varying growth rates, kinetic parameters, load fluctuations, and storage on the outcome of microbial competition. The results of this modeling effort will allow the initial testing of several hypotheses on microbial competition and may impact the design and operation of full-scale treatment plants. In another modeling project, an undergraduate student is developing a model of simultaneous nitrification and denitrification (SND) within activated sludge flocs. This model will test the hypothesis that SND occurs inside flocs because of diffusion limitations.

CAREER: A Unified Approach to Understanding, Education, and Design of Disinfection Processes using Computational Fluid Dynamics
J.J. Ducoste
National Science Foundation
9/01 to 8/06
Computational fluid dynamics (CFD) will be used to develop and evaluate alternative disinfection models for predicting effluent microbial inactivation through continuous flow systems and assessing the impact of disinfectant injection methods and multiple disinfectant injection points on microbial inactivation and DBP formation. The educational plan involves the development of a CFD disinfectant training module. It will be designed around a graphical user interface (GUI) that will be the primary mode of communication between the user and the CFD model. It's three sections are: power point/video-based disinfection process-lecture series, solved disinfection problems and simulated tracer tests, and team-based disinfection design problems.

CFD Modeling of Disinfection Contactor Hydraulics Under Uncertainty of Model Input Parameters
J. J. Ducoste
Unsponsored
9/99 to 12/01
The principle objective of this project is to evaluate the predictive capabilities of CFD models of disinfection contactor hydraulics under uncertainty of model input parameters. The project consists of modeling the transport of a chemical tracer in a full-scale contactor and predicting the effluent-residence time distribution curve. An uncertainty analysis using Monte Carlo statistical techniques will then determine the model's sensitivity to uncertainty in the input parameters. Input parameters that will be tested include the influent turbulence intensity, the turbulent Schmidt number, the wall roughness height, the influent turbulent length scale, and the turbulence model selection.

Hydraulic Characterization of UV Reactors
J.J. Ducoste and Karl Linden at Duke University
American Water Works Research Foundation
8/01 to 7/03
The overall goal is to enhance the ultraviolet (UV) disinfection design process, including prediction of performance and scale-up, through innovative experimental and numerical techniques that assess dose distribution, hydraulic characterization, and microbial inactivation levels. The results of this research will be used for the development of a UV disinfection design framework (UVDDF) protocol. The focus of the experimental work will involve pilot- and full-scale closed-conduit reactors. Novel numerical models developed during this study will be tested with both closed-conduit and open-channel reactors to bridge previous open-channel numerical modeling research.

Improved Chemical Mixing through Computational Fluid Dynamics
J. J. Ducoste
Unsponsored
1/00 to 5/03
The principal objective of this research is to develop an enhanced chemical mixing design protocol for low energy in-line mixers that better predicts downstream mixture uniformity using computational fluid dynamics (CFD). Specific objectives are to (1) evaluate the predictive capabilities of CFD models for different in-line mixing configurations; (2) establish relationships between in-line mixer configurations and downstream chemical mixture uniformity; (3) determine the impacts of process flow, conduit size, and conduit shape on mixer design selection; (4) apply the enhanced mixing protocol at a full scale facility; and (5) compare cost savings and mixing performance for designs produced by enhanced mixing protocol and traditional mixing protocol.

Modeling Heterogeneous Turbulent Induced Flocculation in Water Treatment Processes
J. J. Ducoste
Unsponsored
9/00 to5/03
The proposed research project seeks to develop a numerical tool that will assist environmental engineers to better optimize the full-scale flocculation process in preparation for meeting future stringent water quality goals. The project will combine powerful population balance models (PBM) that simulate flocculation kinetics for a broad range of particle sizes with Computational Fluid Dynamics (CFD) models that will simulate the complex fluid mechanics and particle transport within any reactor system.

Numerical Modeling of Sedimentation Clarifiers
J. J. Ducoste
Unsponsored
9/99 to 12/01
The objective of this study is to model several basin designs that include the use of perforated baffles to reduce the impact of temperature driven density current effects on basin hydraulics. Model results will be compared to published experimental results on a pilot scale sedimentation basin. The overall goal of this study consists of demonstrating the predictive capabilities of CFD to simulate the impact of density current effects on sedimentation basin designs.

RARE: Reconfigurable Computing VIA the Internet
J.J. Ducoste and Clay Gloster at Howard University
Foundation
7/01 to 6/02
Remote Adaptive computing Resource (RARE) comprises a comprehensive set of routines that have been optimized for high performance on a reconfigurable computer. This research will demonstrate how processing some or all of the code on hardware that has been optimized to perform a particular task can reduce a computationally intensive simulation of the growth and breakup of colloidal aggregates in a drinking water flocculation process. Recent experiments conducted by the principal investigator verify that remote hardware versions of several algorithms (implemented on a reconfigurable computer) can complete execution significantly faster than local software versions of the same algorithm (implemented on a typical desktop computer).

Analysis of Drinking Water Treatment Dynamic Simulator: An Undergraduate Research Award
J. J. Ducoste
NC State University
05/02 to 9/02
The objective of this research is to evaluate the performance of a new Water Treatment Plant (WTP) simulator by collecting process data from a WTP in NC, developing a model of this plant using operational data, calibrating the model with a portion of the time history process data from the plant, and comparing the model predictions of the remaining time history process data from the plant. Research will provide the WTP with some "what if" scenarios, which may enable the WTP to cut operational costs. This research also will benefit students by evaluating a software tool that could be used in capstone design courses.

Analysis of Computational Fluid Dynamics Results for Ultraviolet Reactor Design: A Subcontract to UV Disinfection for Large Water Treatment Plants: No. 2768
J. J. Ducoste
Black & Veatch
09/02 to 8/04
The principal objective of this research is the analysis of the Computational Fluid Dynamics (CFD) modeling data generated in the proposal entitled "UV Disinfection for Large Water Treatment Plants: No. 2768." Data analysis will include ensuring accurate assessment of the following: velocity and turbulence distribution within the reactor, particle tracks that display movement of simulated organisms, calculation of dose distribution using information from particle tracks, computed microbial inactivation of target microorganism using particle track data, and simulated tests conducted at multiple flow rates and with different fluence rates in the reactor.

REU Supplement to Career: A Unified Approach to Understanding, Education, and Design of Disinfection Processes using Computational Fluid Dynamics
J. J. Ducoste
National Science Foundation
09/01 to 09/02
The proposed REU research program will enable two of my undergraduate students to work along side M.S and Ph.D. students and conduct the following experimentation: a) bench-scale disinfectant formation studies for chlorine and combined chlorine species to determine the kinetic rate constants in the CFD model and b) bench-scale disinfection studies involving the impact of sequential disinfectants on fluorescence microspheres.

Development and Application of Optimal Design Capability for Coal Gasification Systems
H. C. Frey
US Department of Energy, Federal Energy Technology Center, via Carnegie Mellon University
1997 to 2003
The objective of this project is to develop system analysis tools useful in evaluating energy systems and in addressing the complex problems of environmental management. This project includes the development of a guideline document describing methods for identifying and characterizing key technical and economic uncertainties that are required as inputs for stochastic modeling of energy technologies. This project will include development of new computer simulation models that shall predict the performance, emissions, and cost of advanced fossil fuel power generation and pollution control technologies specified by the US Department of Energy.

Development and Demonstration of a Methodology for Characterizing and Managing Uncertainties in Emission Inventories
H. C. Frey, D. Loughlin, M. Houyoux (MCNC), S. Fine (MCNC)
US Environmental Protection Agency - STAR Grants Program
1/99 to 1/03
The objectives of this work are: (1) to develop and refine methods for quantitative analysis of variability and uncertainty in Emission Inventories (EIs); (2) to demonstrate the methods via application to a detailed case study of an EI; and (3) to characterize the benefits of the techniques for environmental and research management. The key aspects of our work are methods and case studies for quantification of uncertainty in the inputs to an EI, propagation of uncertainty in EI inputs to predict uncertainties in air quality model (AQM)-ready emissions, and identification of key sources of uncertainty in the model-ready emissions estimates.

Identification and Application of Methods for Sensitivity Analysis of Complex Food Safety Process Risk Models
H. C. Frey
US Department of Agriculture
10/00 to 9/02
Sensitivity analyses of risk models can help identify the most significant exposure or risk factors, aid in developing priorities for risk mitigation, aid in identifying the importance of uncertainties in the model for the purpose of prioritizing additional data collection or research, play an important role in verification and validation of a model, and enable insight into the robustness of model results when making decisions. Sensitivity analysis can also aid in identifying the most sensitive or important decision variables, which some may refer to as "control points." This project focuses on identification and application of methods for sensitivity analysis of complex food safety risk models.

NSF CAREER Award: New Methods for Systems Analysis of Environmental Technologies
H. C. Frey
National Science Foundation
6/97 to 5/03
The research program features several major activities: (1) the development of detailed engineering-economic models of clean technologies for the purpose of understanding trade-offs among process performance, emissions, and cost; (2) the development of new methods for quantitative analysis of uncertainty and variability in environmental technologies; (3) the combination of probabilistic analysis with optimization capabilities to yield approaches for optimizing technologies in the face of uncertainties; and (4) detailed case studies to illustrate the use of systems models and the benefits of the probabilistic and optimization methodologies. The educational program will include the development of modular instructional materials in air pollution control, air quality engineering, systems engineering, and related topics.

Probabilistic Modeling of Variability and Uncertainty in Urban Air Toxics Emissions
H. C. Frey
US Environmental Protection Agency - STAR Grants Program
10/98 to 9/02
Our objectives are: (1) to develop methods for quantifying variability and uncertainty in urban air toxics emissions; (2) to develop methods for identifying key sources of variability and uncertainty in assessments of urban air toxic emissions and exposures; (3) to develop probabilistic process engineering models for making realistic estimates of emissions of, and the effects of control measures for, urban air toxics; (4) to demonstrate the methods via a detailed case study of urban air toxics emissions and exposures; and (5) to characterize the benefits of the methods with respect to environmental and research management.

Methodology for Developing Modal Emission Rates for EPA's Multi-Scale Motor Vehicle & Equipment Emission System (MOVES)
H.C. Frey
U.S. Environmental Protection Agency, Office of Transportation and Air Quality
5/02 to 8/02
The objective of this project is to develop and demonstrate an analytical approach for estimating vehicle exhaust modal emission rates and distributions for the Multi-Scale Motor Vehicle & Equipment Emission System (MOVES). The main tasks of this work are to develop pilot modal emission rates from multiple data sources, to perform validation of the developed model against an independent data set, and to recommend specific methodologies for developing modal emission rates for MOVES.

New Methods for Assessment of Pollution Prevention Technologies
H. C. Frey and M. A. Barlaz
National Science Foundation and US Environmental Protection Agency
10/98 to 09/02
The objectives are to develop novel assessment methodologies for evaluating the risks and potential pay-offs of new technologies that avoid pollutant production; demonstrate the methodology via a detailed case study of one promising new pollution prevention technology; and utilize a tiered approach including process simulation and design optimization, probabilistic analysis, life cycle analysis, and assessment of selected regional environmental impacts to provide insights regarding the risks and pay-offs of the pollution prevention approach. The focus will be on pollution prevention in power generation, waste management, and selected aspects of related industries using waste gasification as an example.

Development of a Module for Statistical Analysis of Variability and Uncertainty
H. C. Frey
US Environmental Protection Agency, Office of Research and Development
8/01 to 1/02
This project features the development and evaluation of a computer-based module for fitting parametric probability distribution models to environmental data, visualizing the fitted distribution compared to the data, calculating confidence intervals for the cumulative distribution of the fitted distribution using bootstrap simulation, calculating uncertainty in selected statistics of the fitted distribution, evaluating the goodness-of-fit of the fitted distribution both visually and using standard statistical tests, and outputting results for use in environmental analyses. The software will be verified and quality assured by comparison to known solutions. The algorithms will be documented in a technical report and a user's manual will explain how to use the software.

Recommend Strategy for On-Board Emissions Data Analysis and Collection for New Generation Model
H. C. Frey
US Environmental Protection Agency, Office of Transportation and Air Quality
10/01 to 1/02
Recommendations will be developed regarding procedures that EPA should use to analyze on-board emissions measurement data and regarding design of future data collection efforts. A conceptual analytical methodology will be illustrated for modal and macroscale emission rates for on-road and off-road vehicles and equipment for use in the New Generation Model (NGM). The methodology will be demonstrated on example data sets. Recommendations will be made regarding the role of alternate emissions data in developing exhaust emission rate estimates. A testing strategy for on-board data gathering over the next five years will also be developed.

Recoding and Uncertainty Analysis of the SHEDS/Pesticides Model
H. C. Frey
US Environmental Protection Agency, Office of Research and Development
5/02 to 4/03
The objectives of this project are to recode the existing Stochastic Human Exposure and Dose Simulation (SHEDS) Pesticides (SHEDS/P) model from its existing SAS implementation into C++. NCSU will develop a Graphical User Interface (GUI) and incorporate new algorithms for quantification of variability and uncertainty in model inputs and propagation of variability and uncertainty to model outputs. NCSU will compare the recoded version of SHEDS/P with the SAS version of SHEDS/P for purposes of verification. The new SHEDS/P model will be applied to a multimedia risk assessment case study based upon data provided by the Environmental Protection Agency (EPA).

Effects of Activated Carbon Surface Chemistry and Pore Structure on the Adsorption of Methyl Tertiary-Butyl Ether and Trichloroethene from Natural Waters
D. R. U. Knappe
American Water Works Association Research Foundation
1/99 to 4/02
The objective of this research is to evaluate the effects of activated carbon surface chemistry and pore structure on (1) the adsorption of methyl tertiary-butyl ether (MTBE), trichloroethene (TCE), and natural organic matter (NOM); (2) the simultaneous adsorption of organic micropollutants and NOM; and (3) the sequential adsorption of NOM and micropollutants. The approach involves the preparation of a matrix of activated carbon fibers with 3 pore structure and 4 surface chemistry levels. The expected results of this research will provide a rational framework for the selection of activated carbons for water treatment.

Employing Artificial Neural Networks and Genetic Algorithms to Optimize Turbidity and Natural Organic Matter Removal In Drinking Water Treatment
D. R. U. Knappe and J. Ducoste
Unsponsored
ongoing
Many drinking water treatment plants conduct pilot studies to optimize treatment. These pilot studies typically result in a wealth of data that is difficult to interpret. This study showed that artificial neural network models can describe pilot study results that were obtained over a wide range of treatment conditions and raw water qualities. Pilot studies were conducted by the City of Philadelphia, PA. Artificial neural network models are currently used to determine optimal treatment strategies that consistently produce desired water quality criteria at minimum cost.

Enhancements to the Strategy Development Tool to Support Regulatory Analysis
D. H. Loughlin, J. W. Baugh, E. D. Brill, and S. R. Ranjithan
NC Department of Environment and Natural Resources - Division of Air Quality
9/98 to 8/01
The Strategy Development Tool (SDT) is a prototype decision support system for air quality management. Components of the SDT include tools for: 1) visualizing emissions inventories, 2) designing and testing control strategies, 3) modeling the costs and impacts of incentive-based control approaches such as emissions trading programs, and 4) identifying low-cost management alternatives through optimization. The goal of this project is to upgrade the features of the SDT so that it can be used by the State of North Carolina in developing state implementation plans towards meeting the Federal air quality standards.

System-Wide Optimization of Wastewater Treatment Plants Using Genetic Algorithms
D. H. Loughlin, J. Ducoste, and F. de los Reyes
Hydromantis, Inc. and the National Science Foundation Research Experiences for Undergraduates (REU) Program
10/00 to 12/01
In this project, we are using a genetic algorithm (GA) to perform system-wide optimization of wastewater treatment unit processes. The GA simultaneously selects efficient unit processes and optimizes their design parameters with the goals of minimizing cost and ensuring that effluent standards will be met. The GA-based optimization approach will be used for single and multi-objective optimization, as well as for reliability-based design.

An Assessment of Modeling Tools for the Delineation of the NC Ocean Erodible Area
M. F. Overton and J. S. Fisher
NC Division of Coastal Management (NC DCM)
3/01 to 6/02
The Ocean Erodible Area (OEA) was delineated more than 25 years ago. The methods used to conduct these analyses were simplistic, and newer, more comprehensive models have since that time been developed and applied to similar problems. It is therefore important to investigate the utility of these models in the assessment of the currently defined OEA. This update and potential re-definition of the Ocean Hazard AEC would help ensure that coastal development occurs in lower risk locations. The updated analysis would also assist NC DCM and the North Carolina Division of Emergency Management, as well as local governments, in identifying structures and infrastructure at risk to storm damage.

Shoreline Monitoring at Oregon Inlet
M. F. Overton and J. S. Fisher
NC Department of Transportation
1989, ongoing
The purpose of this ongoing project (1989 to present) is to monitor and evaluate the response of a six-mile stretch of shoreline just south of the terminal groin constructed to protect the bridge at the north end of Pea Island. The purpose of phase one was to establish the "historical erosion rates" for the study area since the change in dredging operations in the inlet in 1984 and before the March 1989 storm. The continuing phases of the project consist of determining the position of the shoreline from air photography every two months and evaluating the response of the shoreline in the context of the historical erosion rates.

Coastal Hazards Building Inventory
M. Overton and S. Rogers
NC Sea Grant
8/01 to 8/02
This research involves a pilot study to assemble and analyze a detailed community building inventory (with damage assessment data) to evaluate the causes and severity of structural damage from Hurricanes Bertha, Fran, Bonnie, and Floyd in North Topsail Beach. Data will be assembled in a GIS (ArcView) from existing datasets, including a complete building inventory of the community conducted by FEMA. A detailed description of each building will be combined with flood insurance damage claims data from each of the hurricanes.

North Carolina Erosion Rate Analysis
M. F. Overton and J. S. Fisher
NC Division of Coastal Management (NC DCM)
9/01 to 9/02
This study will provide the State of North Carolina with an update of the long-term ocean shoreline erosion rate. The rate will be based upon controlled aerial photography collected for the Division of Coastal Management (DCM) by the NC Department of Transportation. Digital orthophotos and terrain models will be provided by the DCM via a third party contractor. The PIs will use these digital data to compute the erosion rates using procedures developed in conjunction with the DCM. In addition to the erosion analysis, this contract will provide technical assistance to DCM in the areas of coastal risk analysis in the vicinity of inlets.

Coastal Highway Vulnerability
M. F. Overton and J. S. Fisher
NC Department of Transportation
7/01 to 6/03
This project proposes to refine and update the highway vulnerability study prepared by the PI's for NCDOT in 1991 by making use of more recent topographic data and by improving the methodology to include short term storm events. This update will be based upon the most recent (1998) aerial photographs available of the entire North Carolina coast for the base maps and the determination of long term erosion rate. In addition, the project will make use of high-resolution digital terrain models that reflect the topographic changes that have occurred in the 1990's. Finally, the revised study will incorporate a statistical method to evaluate the risk of the combination of long-term erosion and storm damage to the NC coastal highway system.

NSF CAREER Award: Development of a Computer-Based Methodology to Assist in Environmental Systems Analysis and Decision Making and Its Applications in Watershed Management
S. R. Ranjithan
National Science Foundation
5/98 to 4/03
This project will: 1) investigate ways to enhance the capabilities of genetic algorithms (GAs) for complex environmental systems analysis, 2) develop and integrate into existing courses an interactive training module to assist in teaching the fundamentals of GAs and their uses in environmental systems analysis, 3) explore applications of the methodology in watershed management, and 4) integrate the applications and their findings in courses related to environmental systems analysis. The academic plans include the development of teaching modules and interactive techniques for both students and practitioners. To demonstrate the practical applicability, an array of realistic watershed management applications will be investigated, including a case study of the Neuse River Basin in North Carolina.

Development of an Integrated Systems Model to Explore Environmentally Beneficial Alternatives for Product Manufacturing and Waste Management
S. R. Ranjithan and M. A. Barlaz
National Science Foundation
10/98 to 10/01
As societies become more focused on minimizing the impact of human activity on the environment, many industries are trying to move towards environmentally responsible manufacturing practices. The objective of this work is to develop a model, integrating a product life-cycle inventory (LCI) with a newly developed life-cycle model of waste management alternatives to examine how the combined LCIs are important and can be influential in product decision making. An integrated systems model will be developed to represent life cycle considerations of products from manufacturing through waste management. The model will then be illustrated through a series of case studies.

Design of Animal Waste Management Strategies to Achieve Regional Environmental Objectives
S. Ranjithan and S. K. Liehr and J. J. Classen (Biological and Agricultural Engineering)
Unsponsored
ongoing
The replacement of anaerobic lagoons that are currently used for swine waste management in North Carolina is expected to be expensive. Identification of the most effective solution to achieve collective target reductions in discharge levels needs an integrated approach that examines and searches among these technology alternatives at all farms simultaneously. The objective of this research is to develop collective or regional management strategies that will aid policy makers, planners, and farmers in making cost effective lagoon replacement decisions to achieve desired treatment and public protection goals. A major component of this activity is the implementation of a cost and treatment efficiency assessment tool (CAWSST) to evaluate alternative animal waste treatment technologies.

Urban Watershed Management Tools
S. Ranjithan
US Environmental Protection Agency (US EPA)/MCNC
10/01 to 9/03
The processes associated with urban storm water runoff and wastewater discharge are to be available for simulation in the US EPA's Multimedia Integrated Modeling System (MIMS). The simulation models are to be coupled with systems analytic methods (including uncertainty analysis and optimization-based search procedures) to explore and identify efficient strategies to manage the urban runoff related problems. In addition, decision-makers require cost/benefit tradeoffs and reliability associated with different strategies. The objective of this project is to integrate urban watershed decisions support tools into MIMS, and demonstrate their use.

Improving Performance of Water Treatment Plant Operations
S. Ranjithan, D. R. Knappe, and J. J. Ducoste
Unsponsored
ongoing
The primary focus of this research is to develop and test computer-based decision support tools to assist in improving the performance of drinking water treatment plants in the presence of variability and uncertainty. Two aspects of plant operations are targeted: the unit process choices at the plant design stage and the process control settings during daily operations. This investigation attempts to identify, based on pilot studies, these choices such that the overall reliability in meeting effluent conditions is increased.

Decision-making under uncertainty: A New Quantitative Method
S. Ranjithan
Unsponsored
ongoing
Our understanding of environmental processes is fraught with uncertainty. Nevertheless, environmental decision-makers must decide a course of action to follow. Of the methods for decision-making under uncertainty that are available, nearly all are either not theoretically sound or are applicable only to the simplest of problems. This research focuses on a new method for decision-making under uncertainty that addresses many of the limitations of existing approaches. The method, Bayesian Programming (BP), utilizes optimization techniques for an efficient search of the alternatives and incorporates Bayesian methods to model uncertainty reduction as data is collected.