Our people

The heart of our organization is our people. Their initiative and curiosity motivate them every day to tackle our clients' problems and to provide what our clients need for informed decisions based on sound science. The descriptions below offer just a brief look at the talented people who help LimnoTech provide its clients with exceptional service every day.

Staff are located in the Ann Arbor office, unless otherwise noted.

A-D | E-L | M-R | S-Z | Administrative Staff

Amanda FlynnAmanda Flynn is an environmental scientist with expertise in nutrient cycling, fate, and transport in rivers, lakes and estuaries; watershed modeling and assessment; and surface water quality monitoring, modeling, and assessment. Ms. Flynn joined LimnoTech in 2005, shortly after receiving her Master’s degree in Oceanography from Rutgers University. Her project experience has included the development and application of several watershed (HSPF), water quality-eutrophication (WASP5), and hydrodynamic (FEQ, EFDC) models in support of TMDLs, CSO LTCPs, and watershed and surface water quality management programs.  Her experience has also entailed co-authoring several literature reviews on various nutrient and ecosystem topics. Ms. Flynn’s current responsibilities include technical modeling work, surface water quality assessments, data analysis and validation, database management, and report writing. 
Tel: 734-332-1200

Paul Freedman, P.E., BCEEPaul Freedman, P.E., BCEE, is co-founder and President of LimnoTech. Paul's 35 year career has encompassed the full history of progress under the Clean Water Act, constantly emphasizing quality, innovation, and service. He has particular technical expertise in the use of models to assess and solve surface water, watershed, and groundwater challenges, as well as creating innovative policy and program approaches. He has been a leading innovator in user interactive models, as well as watershed management, sustainability, wet weather control programs and adaptive management. Paul has taught, presented, and lectured throughout the U.S., with over 200 conferences, workshops, presentations and papers to his credit. Paul has contributed to the advancement of water science and engineering through participation and leadership in numerous professional groups. He is currently Vice President of the Water Environment Federation (WEF), an international organization of more than 35,000 water
quality professionals.
Tel: 734-332-1200

Carrie Graff, Ph.D.Carrie Graff, Ph.D., is an environmental scientist in our Washington, D.C. office who has gained a variety of experience since receiving her doctoral degree in soil science from the University of Minnesota. Her technical skills include use of spatial statistical methods to evaluate spatial datasets; environmental forensics for source allocation and source composition of contaminated sites; watershed modeling design and application; environmental data collection, monitoring, and evaluation; and project management. Some of her projects have included applying 3-D geostatistical analysis to define cleanup volumes for dioxin-contaminated soils; indicator kriging of PCBs in sediments; applying fingerprinting analysis such as PCA and PVA to determine source allocation of PCB and dioxin-contaminated sediments among multiple PRPs; and modeling the fate and transport of nonpoint source pollution from agricultural lands using watershed models. Dr. Graff also has experience applying SWAT and AnnAGPS to agricultural
watersheds to determine BMP implementation strategies that will maximize benefits for water quality.
Mid-Atlantic regional office
Tel: 202-833-9140

Jeremy GrushJeremy Grush is an environmental engineer at LimnoTech with expertise several fields of civil and environmental engineering with an emphasis on surface hydraulics and groundwater hydrology. He recently completed a Master's Degree in Civil Engineering at the University of Michigan. His project work has included a variety of one- and two-dimensional hydrodynamic model applications that have been used to evaluate bank erosion, develop conceptual site models of hydrodynamics and sediment transport, aide in the design of a new floodway in Toronto, and support remedial investigations in riverine and estuarine systems. Jeremy also has experience using geostatistics to interpolate environmental data.
Tel: 734-332-1200

Joseph HelfandJoseph Helfand is a senior project engineer whose expertise is in environmental engineering and project management of modeling and computer simulation of streams, lakes, estuaries, sediments, groundwater and collection systems for toxic and conventional pollutants. He has contributed to a wide variety of projects that have advanced the state of the art in model development and application, and in the analysis and display of water quality data. He has been a principal contributor in the development of computer programs for various types of water quality modeling, including several developed for the EPA. Joseph also has extensive experience in the statistical analysis of water quality data, often involving support of legal cases.
Tel: 734-332-1200

Daniel A. Herrema, P.E.Daniel Herrema, P.E., is a senior project engineer and project manager with extensive environmental engineering and consulting experience. His responsibilities focus on project management and coordination of remedial and watershed projects. He has designed and managed remedial efforts for numerous sites with contaminated soil and groundwater. This work has been performed under various regulatory frameworks including state leaking underground storage tank (LUST) programs, state hazardous waste programs, RCRA facility closures and corrective actions, CERCLA (Superfund) sites, and voluntary actions. Dan has provided regulatory compliance services to industrial and commercial clients involved in a variety of business sectors. He provides stormwater management services and has prepared dozens of stormwater pollution prevention plans. Dan has demonstrated experience in watershed restoration and implementation of stormwater best management practices (BMPs).
He has also worked on the design of streambank stabilization measures and stormwater detention
retrofit projects.
Tel: 734-332-1200

Scott HinzScott Hinz is a senior environmental scientist at LimnoTech with extensive experience in developing and applying water quality, hydrologic, and hydrodynamic models to systems throughout the United States. His particular expertise and training are in the areas of water quality and hydrologic assessments of natural systems. Scott is conversant in a wide range of programming languages and computer software. As a Senior Environmental Engineer with LimnoTech, Scott has developed and applied models to evaluate toxic organic chemicals, metals, eutrophication, and dissolved oxygen problems. His major role at LimnoTech is providing advice, support, and technical review of complex water quality modeling applications.
Austin, Texas location
Tel: 512-231-1575

HolmbergHans Holmberg, P.E., BCEE, is a senior environmental engineer at LimnoTech with several years of experience serving clients facing complex technical and regulatory challenges related to environmental issues. Hans' experience includes more than 50 projects covering a range of environmental issues. Hans has managed state- and national-level projects, addressing development of appropriate water quality standards, Total Maximum Daily Load implementation, nutrient loadings, wet weather impacts on water quality, and Use Attainability Analyses. Hans has also supported the federal and state agencies in developing policy and technical guidance, and implementing requirements of the Clean Water Act and state regulations.
Minneapolis/St. Paul regional location
Tel: 715-549-6740

HoughZaneta Hough is a Project Scientist in Washington, D.C. Zaneta's areas of expertise include stream and wetland ecology and assessment, as well as watershed assessment, education and public outreach. She has contributed to projects addressing the biological integrity and habitat quality of streams and rivers, resilience of aquatic systems to disturbance, fisheries population studies, wetland hydrology and functional assessment, and Endangered Species Act consultation. Zaneta has a wide range of field experience, including surface water chemical quality and biological sampling; wetland characterization and delineation; wetland and upland plant identification; riparian condition assessment; surveying; fish and stream macroinvertebrate identification; coordination of various field projects and field team training.
Mid-Atlantic regional office
Tel: 202-833-9140

Volker JanssenVolker Janssen is a civil engineer at LimnoTech in our Washington, D.C. office with specialized experience in hydrology, hydraulics, hydrogeology and GIS. He graduated at the technical university of Braunschweig, Germany. Mr. Janssen has spent significant time with hydrologic and one- and two-dimensional hydraulic modeling. The projects he has worked on include watershed-models and floodplain estimations as well as flood-protection-concepts and sewer studies. He has acted both as a project engineer and project manager.
Mid-Atlantic regional office
Tel: 202-833-9140

Peter R. Klaver, P.E.Peter Klaver, P.E., is a senior project engineer at LimnoTech's Ann Arbor office, with many years of experience in pollution control issues. He is well-versed in the design, construction and operation of wastewater treatment systems. His experience in the NPDES permitting process includes the application of a variety of regulator-approved models for waste load allocations and other impacts, the preparation of permit applications, and an extensive background in the negotiation of permit limits. His river and stream modeling experience includes one-, two- and three-dimensional hydrodynamic models as well as water quality, sediment transport and particle tracking. Peter's involvement in wet weather issues includes program development support to regulators in CSOs, SSOs, and blending.
Tel: 734-332-1200

Wendy M. LarsonWendy Larson is an senior project scientist with extensive technical and project management experience through a wide variety of project work. Her responsibilities as a Project Manager and Environmental Scientist at LimnoTech have involved several basin-scale studies related to Great Lakes water quality and quantity issues; research directed at improvements to the TMDL process; and ecosystem, conventional, and toxic chemical modeling and analyses. Wendy's varied project experience includes the assessment of ecological impacts of water withdrawals in the Great Lakes Basin, assessment and management of contaminated sediment sites, and review of impacts of aquatic nuisance species on freshwater systems. She brings her excellent synthesis and communication skills to every project, to help clients interpret the data and analyses that are the foundation for sound decision-making.
Tel: 734-332-1200

LautenbachDan Lautenbach, P.E., is a civil and environmental engineer. Dan has employed his expertise in hydrodynamic modeling, water quality modeling, sediment transport, and stormwater management on a variety of projects. Dan has developed two-dimensional hydrodynamic models on river and estuary systems; namely, developing model domains, calibrating the models, and developing simulations that relate system hydrodynamics to sediments deposited throughout the modeled systems. Dan has developed and applied an innovative stormwater/sewage model that predicts how large storage tunnels will fill during storm events, and how surge waves and transients will propagate through these systems as they fill, to aid in identifying locations where high hydraulic grade lines and air pockets could affect infrastructure. Dan has also developed one-dimensional, unsteady-state flow models of river systems that simulate
river flow for a range of conditions, and include the operation of controls such as dams, weirs,
bridges and other structures.
Tel: 734-332-1200

Brian D. LordBrian Lord is a Geographic Information Systems (GIS) specialist, with several years of experience. His primary area of expertise is using GIS to characterize sediment distribution and modeling remediation scenarios. He also has extensive experience using CAD for generating accurate, readable and information-rich, project-related maps, drawings, and figures. With broad field experience, Brian also has extensive expertise in air, groundwater and soil sampling techniques for environmental site investigations, remediation investigation/feasibility studies, remediation pilot studies, and monitoring programs for permit compliance and remediation system performance.
Tel: 734-332-1200
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John Marr, P.E.John Marr, P.E., is our Executive Vice President for corporate operations and a principal involved in municipal and industrial surface water assessments for NPDES permitting, waste load allocations, TMDLs, CSO, and stormwater issues. John brings nearly 30 years of experience on hundreds of water quality projects and systems in two dozen states. His primary engineering expertise is assessment and modeling of water quality, and hydraulic and hydrologic processes of receiving waters, sewers, and agricultural and urban watersheds. John pioneered the development and use of complex runoff, sewer conveyance, and water quality models advancing the confidence in forecasting the costs, benefits and risks of control programs over the full range of environmental conditions and variability.
Tel: 734-332-1200

McCullochRichard McCulloch, CPA, is an environmental engineer with LimnoTech. His broad engineering experience includes mathematical modeling, field investigations, and laboratory bioremediation studies. Before his work as an engineer, Ric worked six years as a CPA. At LimnoTech, he uses his accounting and financial experience for economic analyses related to engineering and regulatory projects, including economic benefit of noncompliance evaluations. Ric has experience with a variety of models including hydrologic, hydrodynamic, sediment transport, and water quality. He has applied these models to combined sewer overflow, watershed, contaminated sediment, and groundwater projects.
Tel: 734-332-1200

Penelope MoskusPenelope Moskus is an Environmental Scientist and project manager providing watershed management and TMDL expertise to clients ranging from watershed associations to municipalities and states. She has extensive experience directing and conducting watershed assessment and planning studies, and has worked on over 70 watersheds located nationwide. She is familiar with issues specific to urban and rural watersheds and has expertise conducting problem assessment, watershed characterization, source identification and quantification, watershed and water quality modeling, source prioritization and assessment of implementation options. Penelope has applied her watershed expertise to the development of watershed management plans and TMDL implementation plans.
Tel: 734-332-1200

Adrienne D. Nemura, P.E.Adrienne Nemura, P.E., is a Vice President and manages LimnoTech's services for providing creative solutions for permits and water quality regulations. She has 23 years of experience evaluating impacts of pollutant sources on watersheds and waterways, is active in several national organizations, and is a frequent speaker at national conferences on water quality issues. Adrienne's work includes NPDES permits, Consent Decrees and Agreed Orders, wet weather discharges, water quality standards, TMDL reviews, and receiving water and collection system monitoring and modeling. Her expertise also includes expert witness services and negotiating agreements over surface water quality issues between local, state and federal entities.
Tel: 734-332-1200

OBrienCullen O'Brien is a project engineer with LimnoTech with experience in environmental soil and groundwater sampling. Cullen has extensive field experience through performing numerous, diverse tasks on a variety of projects. He has conducted surface water flow monitoring and sampling on several rivers, lakes, and streams. Cullen also uses a CAD program and GIS to construct various maps, geologic cross sections, boring logs, and design drawings.
Tel: 734-332-1200

Gregory W. PetersonGregory Peterson is a Vice President and responsible for emerging environmental issues. Greg has extensive environmental engineering experience at more than 200 sites nationwide. He has managed projects for industrial, legal, and government clients in a variety of technical areas including contaminated sediment management; hazardous waste site assessments; remedial investigations and feasibility studies; RCRA facility investigations and corrective actions; remedial action planning, design, and implementation; hydrogeologic investigations; underground storage tank remediation; site assessments for property transfers; regulatory compliance; permit development and review; contaminant fate and transport modeling; exposure and risk assessment; and nonpoint source assessment.
Tel: 734-332-1200

JPetersonJohn Peterson is a Project Scientist with extensive experience in environmental investigations and remediation at more than 40 sites in the Midwest. He has extensive experience in environmental monitoring at CERCLA, Act 307, and LUST sites, RCRA facilities, and industrial and commercial properties. He has implemented all phases of soils, sediment, groundwater and surface water sampling programs, including design and construction of specialty monitoring equipment; monitoring well installation, development, and sampling; soil boring sampling; slug tests; aquifer performance analyses; NAPL investigations; free product recovery; surface water and sediment sampling; geophysical testing; hazardous waste sampling; effluent sampling; feasibility pilot studies; and test pit sampling and surveying.
Tel: 734-332-1200

Todd Redder, P.E.Todd Redder, P.E., is a senior environmental and water resources engineer whose principal expertise is the development and application of mathematical models for the evaluation of hydrodynamics, water quality, sediment transport, contaminant fate and transport, and ecosystem response in watersheds, rivers, lakes, and estuarine systems. He has served as the technical lead on numerous projects, including a wide range of complex, multi-dimensional modeling applications. Todd has also applied his computer programming and database skills to develop an extensive collection of modeling and data analysis tools and database/GIS applications for both internal use and client use, and he serves as a company-wide resource for modeling and computer programming needs.
Tel: 734-332-1200

Daniel K. RucinskiDaniel Rucinski is an environmental engineer with LimnoTech with expertise in the development and application of water quality models. Dan has experience developing models for the evaluation of eutrophication processes, hydrodynamics, sediment transport, and ecosystem responses in river, lake, and estuarine systems. As a visiting engineer at the National Institute of Water and Atmospheric Research of New Zealand, he recently applied his expertise in modeling by developing hydrodynamic models for several applications in diverse situations.
Tel: 734-332-1200

Jason M. Rutyna, P.E.Jason Rutyna, P.E., is an environmental engineer with LimnoTech.  Jason finished a Master's of Science in Civil Engineering at Wayne State University with a focus in water resources and environmental engineering in 2006.  Jason has experience with providing clients with scientific and engineering analysis in a variety of projects that involve hydrodynamic/hydraulic models, water quality models, TMDL modeling and analysis, mixing zone modeling, and water quality data analysis.  Jason is also skilled in developing client-deliverable databases and compiling water quality, biological, habitat, continuous monitoring, meteorological, and point source data.  In addition to his sound analytical skills, Jason is an integrated team member in a variety of field operations.  Prior to joining LimnoTech, Jason developed system-wide computer models for several municipal clients.  The models included water distribution systems and wastewater collection/conveyance systems.  These models provided the clients with a comprehensive understanding of their systems and helped them identify specific issues and solutions in their systems. 
Tel: 734-332-1200

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SchmittTim Schmitt has experience in multiple areas of wet weather, wastewater, and water studies, including NPDES permitting, combined sewer overflow and stormwater management, monitoring and Best Management Practices, Clean Water Act and Safe Drinking Water Act compliance, and water and wastewater security. He also has specialized experience in experimental design, data analysis and data management. Tim has expertise in technology transfer, and has authored more than a dozen fact sheets on wastewater, CSO, and stormwater technologies and management techniques for EPA. Mr. Schmitt has also supported large data collection and interpretation projects for EPA, including efforts for the Clean Watersheds Needs Survey, the national CSO program, and the Clean Water Act Indian Set-Aside Program. Tim has also supported data collection, interpretation, and writing for several Reports to Congress.
Mid-Atlantic regional office
Tel: 202-833-9140

SelvendiranPranesh Selvendiran is an environmental engineer who joined LimnoTech in March 2008. Pranesh received a Master's degree in Environmental Engineering at Syracuse University. He is completing his Ph.D. degree in Civil Engineering at Syracuse University. Pranesh's studies covered several specialized areas of environmental engineering and science, including water quality, hydrology and hydrogeology, contaminant transport, environmental toxicology, hazardous waste management, and biogeochemistry. He has extensive experience in data analysis, data management, field monitoring and laboratory work. He has authored or co-authored several peer-reviewed papers in various journals.
Tel: 734-332-1200

Tad Slawecki  Senior EngineerTad Slawecki is a senior engineer with background in computer engineering and environmental health sciences, both contributing to his expertise in the use of appropriate information technology in environmental resource management. Tad's project experience focuses on the application of database tools, GIS, models, and visualization to move from data analysis and evaluation to decision-making in a rigorous and defensible manner. Current work includes the development and application of a watershed-focused water quality risk model for optimization of wet weather management strategies, and integration of low-flow analysis tools into the US EPA BASINS watershed modeling system.
Tel: 734-332-1200

sullivanMichael Sullivan is a Vice President and Manager of LimnoTech's Office in Washington, D.C. Mike is the liaison with federal agencies and other LimnoTech clients in the Mid-Atlantic region. He has over 30 years of experience in a wide variety of urban hydrology, water quality, and related environmental and water resource management areas. His principal area of expertise is evaluation and management of point and nonpoint sources of pollution and their impact on receiving waters. He has directed and participated in numerous water quality investigations of rivers, lakes and estuaries. Mike has managed watershed, CSO, SSO, stormwater, WWTP, and source water assessments studies, including specialized studies to support NPDES requirements for permittees.
Mid-Atlantic regional office
Tel: 202-833-9140

Kathy Sweet, QEPKathy Sweet, QEP, has been an Environmental Scientist with LimnoTech since 1991. Her work focuses primarily on waste load allocations, effluent permitting for point sources, and Total Maximum Daily Load (TMDL) evaluations. Kathy performs water quality-based effluent limit evaluations for both regulatory agencies and regulated communities, with emphasis on NPDES permit evaluations and negotiations for regulated discharges. She has conducted more than 80 NPDES permit reviews, focusing primarily on evaluating effluent limits for toxics; assessing water quality criteria and bioavailability issues; developing dissolved metal translators; and advocating less stringent yet scientifically sound limitations. Kathy has also evaluated the effects of stormwater and combined sewer overflows (CSOs) on water quality and has conducted more than a dozen TMDL evaluations.
Tel: 734-332-1200

Timothy ToweyTimothy Towey is an environmental engineer with experience in numerous aspects of environmental engineering. Tim's engineering experience includes the development and application of water-quality models, contaminated sediment management, multivariate statistical analysis, and environmental data management. In addition to his technical skills, he is also experienced in curricula development, workshop supervision, advisory committee coordination, and project management related to a variety of environmental topics.
Tel: 734-332-1200

Carrie Turner, P.E.Carrie Turner, P.E., is a senior project engineer specializing in developing affordable and sustainable solutions for wet weather pollution-related issues. She has many years of experience evaluating impacts of pollutant sources on watersheds and in waterways using innovative data and modeling analyses that build on her extensive work in environmental chemistry before joining LimnoTech. Carrie’s technical expertise includes developing and applying models to support combined sewer overflow evaluations, total maximum daily load assessments, contaminated sediments, waste load allocations, and watershed characterizations. She also has extensive experience with data management and analyses, using her chemistry background to design and implement sampling programs, conduct laboratory audits, validate data, write Quality Assurance Project Plans, and develop customized databases and data management frameworks that integrate spatial, physical and chemical data by
linking them with GIS systems for analysis and visualization.
Tel: 734-332-1200

Brad Udvardy, P.E.Brad Udvardy, P.E., is a project engineer with LimnoTech. He is an experienced user of DHI's MIKE URBAN package of hydrologic and hydraulic models, including its Real-Time Control module for modeling dynamic controls. He has experience with the Stormwater Management Model (SWMM), and has been involved with several SWMM-based modeling efforts. His participation in various aspects of modeling efforts include rainfall analysis, model calibration and validation, flooding studies, peak flow analysis, and capacity assurance studies. Brad has supported integration of modeling efforts with GIS technology. He has also managed NPDES permit databases, and has provided regular reports on the status of various permit data sets.
Mid-Atlantic regional office
Tel: 202-833-9140

Edward M. VerhammeEdward Verhamme is a Project Engineer with LimnoTech and has been involved on a variety of water quality projects including hydrodynamic modeling (EFDC, HEC-RAS, and FEQ) and application of existing water quality models (RCA, LOTOX2, Bathtub, and WASP) since joining the firm in June 2005. He has had a significant role in numerous LimnoTech projects involving literature reviews, data analysis, data collection, development of various models, database development, and a variety of field engineering tasks.
Tel: 734-332-1200

R. Scott WadeR. Scott Wade is a planner and geographic information systems (GIS) manager at LimnoTech. He has over 25 years of experience as a planner, geographer, and cartographer, including extensive experience applying GIS for environmental, transportation, and research projects. Scott inventories and analyzes watershed features, including land use patterns, stream networks, topography, and pollutant sources, to help clients develop an understanding of watershed-wide impacts on receiving water bodies. He also helps clients apply water quality models during the land and water management process, as they work to create and implement plans to reach surface water quality goals.
Tel: 734-332-1200

WeintraubLaura Weintraub, P.E., is a senior project engineer with over 10 years of experience in hydrologic analysis, water quality modeling and watershed management. Her work includes managing and executing water resources and water quality analyses, as well as the development of decision support systems for public, private, and research clients. Her project experience has involved TMDL development, watershed planning, source water protection, loading analyses, and stormwater management. She is experienced in responding to the needs of stakeholders by using data, modeling tools, and sound science to identify water quality issues, develop potential management alternatives, and evaluate the feasibility and benefit of various options.
Tel: 734-332-1200

Cathy WhitingCathy Whiting is a senior project engineer and project manager with more than 20 years of environmental engineering and consulting experience. Her recent area of focus is the design and implementation of field sampling plans. Cathy experience includes the management of numerous large surface water investigations. These projects have involved oversight and coordination of project activities including data review and display, model selection, data evaluation and analysis, sampling plan preparation and implementation. She also has experience in environmental remediation, including site investigation, feasibility analysis, remedial technology selection, system design, and site management.
Tel: 734-332-1200

John W. Wolfe, Ph.D., P.E., BCEEJohn W. Wolfe, Ph.D., P.E., BCEE, is a Vice President at LimnoTech, managing projects involving fate and transport of contaminants, site investigation, discharge to surface waters under NPDES and industrial pretreatment permits, effects of CSOs on water quality, and environmental economics. He has extensive expertise in surface water quality modeling, including contaminated sediments, wastewater treatment, and permitting; hazardous waste management, including groundwater protection, and has worked as a project engineer on diverse environmental investigations involving bioremediation of groundwater and sediment contaminants. Prior to his career in engineering, John worked for 13 years as an economist, including 11 years as a university professor. He is a member of the Committee on Sediment Dredging at Superfund Megasites of the National Research Council of the National Academies.
Tel: 734-332-1200
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Support Staff

Administrative Staff

Tammy Bailey
Accounting
Tel: 734-332-1200

Jenni Partyka
Human Resources Director
Tel: 734-332-1200

Tim Bertsos
Proposal Coordinator/
Technical Writer
Tel: 734-332-1200

Dar Pifer
Accounts Payable
Tel: 734-332-1200

Ruth Blum
Office Manager, Ann Arbor
Tel: 734-332-1200

Danielle Rutt
Office Manager,
Mid-Atlantic regional office
Washington, D.C.
Tel: 202-833-9140

Patti Fosbender
Controller
Tel: 734-332-1200

Mary Vath
Receptionist, Ann Arbor
Tel: 734-332-1200

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