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

Brandon EllefsonBrandon Ellefson joined LimnoTech as an environmental engineer in 2010 after graduating from Michigan Technological University with master’s and bachelor’s degrees in Environmental Engineering. Brandon’s areas of expertise include surface water quality modeling, watershed modeling, sediment flux analysis, database development, and data management and evaluation. His graduate and post-graduate studies included utilizing nitrogen and oxygen as a method to prevent methyl mercury releases from highly contaminated sediments.  His wide-ranging field experience includes Great Lakes monitoring and buoy deployment, mapping lake bathymetry, wet weather event sampling, airport deicing sampling, bed load sampling, and water quality sampling.
Tel: 734-332-1200

Amanda FlynnAmanda Flynn is an environmental scientist with expertise in nutrient cycling, fate, and transport in rivers, lakes and estuaries; watershed and surface water quality modeling and assessment; ecosystem assessment; and environmental issues related to agriculture. Ms. Flynn’s project experience has included the development and application of several watershed (HSPF, AnnAGNPS, SWAT), water quality-eutrophication (WASP5, CE-QUAL-ICM), and hydrodynamic (FEQ, EFDC) models in support of TMDLs, CSO LTCPs, and watershed and surface water quality management programs. Ms. Flynn has co-authored several literature reviews on various nutrient and ecosystem topics and has published two peer-reviewed papers on estuarine nutrient cycling. Ms. Flynn’s current responsibilities at LimnoTech include model development and application, data analysis and management, technical review, report writing, and project management. 
Tel: 734-332-1200

Paul FreedmanPaul Freedman, P.E., BCEE, is co-founder and CEO/President of LimnoTech. Since 1975 Paul's 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 a past President of the Water Environment Federation (WEF), an international organization of more than 35,000 water quality professionals. He has also been honored by WEF by being named one of the first recipients of its WEF Fellow Recognition Program, and has also been granted “Fellow” status by the American Society of
Civil Engineers (ASCE).
Tel: 734-332-1200

Nick GreweNick Grewe is an environmental engineer at LimnoTech. He completed his B.E. in Environmental Engineering at the University of Minnesota – Twin Cities and a B.A in Environmental Studies at Saint John’s University. Nick’s areas of interest are in watershed engineering, stream restoration, and hydrologic/hydraulic modeling. He has extensive field experience in many areas of water resources including water quality monitoring, contaminated soils, Rosgen stream assessments, erosion control, and watershed monitoring. He helps develop models (FLUX, HEC-HMS, HEC-RAS, HSPF, SWMM, SEDCAD) for watersheds around the country to aid in the preparation of permits and TMDLs. Nick is also proficient in ArcGIS, and he uses his skills to support a diverse set of project-specific needs.
Minneapolis/St. Paul regional location
Tel: 651-330-6038

Jeremy GrushJeremy Grush is an environmental engineer at LimnoTech with expertise in surface water hydrodynamics and water quality. His project work has included development and application of a variety of hydrodynamic models of widely varying complexity that have been used for various purposes such as developing conceptual site models of hydrodynamics and sediment transport, estimating the footprint of a suspended solids release into a large waterbody, aiding in the design of a new floodway in Toronto, assessing receiving water quality, and supporting remedial investigations in riverine and estuarine systems. Jeremy's current responsibilities include model design and application, surface water quality assessments, data analysis and interpretation, and report writing.
Tel: 734-332-1200

Kathy HallKathy Hall, 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

Joseph 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

Dan HerremaDaniel Herrema, P.E., is an Associate Vice President and Regional Manager of the Mid-Atlantic office in Washington D.C.  He is a Professional Engineer with two decades of experience in contaminated sediment and wastewater/stormwater projects.  Dan manages all aspects of contaminated site projects for a variety of industrial clients, including site investigations, feasibility studies, remedial design and site management.  For municipal clients his work has focused on developing and implementing stormwater management programs, watershed management and restoration projects, and hydrology and hydraulic modeling tasks. Mr. Herrema also leads and manages regulatory compliance and due-diligence projects for multiple commercial and industrial clients.
Mid-Atlantic regional office
Tel: 202-833-9140

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. With nearly 30 years of experience at LimnoTech, Scott has developed and applied models to evaluate toxic organic chemicals, metals, eutrophication, and dissolved oxygen problems. His major roles at LimnoTech include providing advice, support, and technical review of complex water quality modeling applications.
Austin, Texas location
Tel: 512-231-1575

Hans HolmbergHans Holmberg, P.E., BCEE, is an Associate Vice President and senior environmental engineer at LimnoTech. Hans provides leadership for LimnoTech’s service area addressing Clean Water Act compliance, and he manages the Minneapolis/St. Paul regional office located in Oakdale, Minnesota. Hans has served clients facing complex technical and regulatory challenges related to a broad range of environmental issues since 1994. These clients include industries in the mining, chemical, pulp and paper, manufacturing, and agricultural sectors; municipalities; attorneys; state and federal agencies; and nonprofit organizations. He provides assessment, compliance, and planning services for clients needing to address wastewater, stormwater, contaminated sediment, soil, and groundwater issues. Hans has expertise in NPDES permit negotiations, TMDL development and review, water quality standards review and revision, and watershed and wet weather program planning. Hans’ experience involves all phases of projects, including monitoring and modeling, remedial and restoration design, and implementation and construction oversight.
Minneapolis/St. Paul regional office
Tel: 651-330-6038

Justin IbershoffJustin Ibershoff, P.E., is a project engineer in our Los Angeles regional office with expertise in environmental database development, environmental monitoring and modeling, and statistical analysis. He has studied water and sediment quality, hydraulics, and hydrologic issues throughout the United States using modeling tools (HSPF, CORMIX, HEC-RAS, EPANET), spatial/drafting tools (ArcGIS, AutoCAD, Microstation), and programming languages such as VBA and SQL.
Southern California office
Tel: 310-939-7293

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 KlaverPeter 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

R. LambertRenn Lambert joined LimnoTech in June 2012. He has contributed to a number of projects, performing tasks including setting up and running linked hydrodynamic/sediment transport models for a river oil spill, contributing to a report to determine Lake Erie phosphorus loading targets, and setting up and running watershed and water resources models for the electric power industry. Before joining LimnoTech he took part in a number of studies as a student including examining the bioavailability of phosphorus loads to the Great Lakes and Onondaga Lake. He has presented the results of his studies at professional seminars.
Tel: 734-332-1200

Wendy LarsonWendy Larson is an Associate Vice President and senior project scientist with extensive technical and project management experience through a wide variety of project work. Her responsibilities at LimnoTech are currently focused on water sustainability consulting for a range of clients, addressing corporate water stewardship and water footprinting assessments. Over the past 18 years she has also directed several basin-scale studies related to Great Lakes water quality and quantity issues; conducted research directed at improvements to the TMDL process; and managed a range of projects involving ecosystem, conventional, and toxic chemical modeling and analyses. Wendy's varied project experience also includes assessment of contaminated sediment sites, and impacts of aquatic nuisance species on freshwater systems. She brings her strong synthesis and communication skills to every project.
Tel: 734-332-1200

John LentersJohn D. Lenters, Ph.D., is a recognized expert in observation networks, lakes, watersheds, and climate science. He has been involved in a variety of research projects related to the impacts of climate on lakes, particularly in Alaska, Nebraska, and the Great Lakes region. Lenters has been leading a global initiative to study the long-term warming of lakes worldwide, and he is also working with a number of institutions to establish a coordinated observation network for Great Lakes evaporation. Lenters is a member of the International Association for Great Lakes Research, American Geophysical Union, American Meteorological Society, and the Global Lake Ecological Observatory Network. His work has been featured in the Journal of Great Lakes Research, Water Resources Research, and Journal of Climate, as well as popular literature such as Smithsonian Magazine and National Geographic's "Water Currents." Before joining LimnoTech, Lenters was an associate professor in the School of Natural Resources at the University of Nebraska-Lincoln (UNL). He has also worked at Lake Superior State University, the University of Wisconsin-Madison, and Cornell University, where he received his Ph.D. in atmospheric science.
Tel: 734-332-1200

Dendy LoftonDendy Lofton, Ph.D., is an aquatic biogeochemist and ecologist with expertise in carbon and nutrient cycling. Interested in the influence of climate change on aquatic ecosystems, Dr. Lofton conducted her doctoral research in Arctic Alaska where she studied methane production and oxidation in lakes. Dr. Lofton also provided support on a multi-year project that evaluated nitrogen cycling and primary production in response to experimental whole-lake nitrogen isotope additions. In North Carolina, Dr. Lofton examined the effectiveness of denitrification to mitigate excess nitrate in a stream receiving wastewater effluent and runoff from adjacent agricultural lands. Since joining LimnoTech, Dr. Lofton has provided technical support to numerous projects including the development and implementation of TMDLs, watershed management plans, in addition to stream restoration and sediment remediation projects.
Minneapolis/St. Paul regional office
Tel: 651-330-6038

Brian 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 MarrJohn Marr, P.E., is our Chief Operating Officer 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’s experience features over 30 years with LimnoTech working on hundreds of projects and water systems in over two dozen states. His primary engineering expertise is assessment and modeling of water quality, and hydraulic and hydrologic processes of receiving waters, sewers, tunnel hydraulics, and agricultural and urban watersheds. John pioneered the development and use of complex runoff, sewer conveyance, tunnel surge, 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

Ric 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 a wide range of clients.  She has directed or conducted watershed assessment and planning studies in over 80 watersheds nationwide, including TMDL implementation plans and the nation’s first watershed-based plans to address sewer overflows.  She is experienced in all phases of watershed assessment, including modeling, and has written several protocols and guidance documents for watershed assessment and TMDLs. Penelope’s work is currently focused on assessing trends in water resources and assisting clients with water footprinting assessments and water sustainability.
Tel: 734-332-1200

Ryan O'BanionRyan O'Banion is an environmental scientist with LimnoTech who makes maximum use of the capabilities of geographic information systems (GIS) and research to help clients make informed decisions about water resources. Ryan has worked extensively to show how green infrastructure and best management practices can offset controls on sewer overflows. He also has experience with advanced geospatial analysis in support of watershed modeling. Ryan’s wide-ranging field work has included sampling water and sediment. He has served in field oversight roles for drilling, sampling, and construction projects. Ryan is a graduate of Duke University with a master’s degree in Environmental Management and a certificate in Geospatial Analysis.
Mid-Atlantic regional office
Tel: 202-833-9140

Cullen O'BrienCullen O'Brien, P.E., is a project engineer with LimnoTech. He has extensive experience in the collection of environmental media samples including groundwater, surface water, soil, and sediments. Cullen also conducts surface water monitoring activities which involve the installation and maintenance of remote monitoring instruments. He performs oversight during construction activities and conducts the operation and maintenance of remediation systems. He assists with the production of reports and databases. He uses a computer-aided drafting program and GIS to construct various maps, geologic cross-sections, boring logs, and design drawings.
Tel: 734-332-1200

Julie PJulie Padilla joined LimnoTech in January 2014 with a master’s degree in Environmental Engineering from Michigan Technological University and a bachelor’s degree in Geological and Environmental Science from Stanford University. Her areas of expertise include watershed management, stream habitat ecology, and environmental data management and evaluation. She is also proficient with several types of environmental modeling software. She was the recipient of numerous academic honors and awards during her undergraduate and graduate studies.
Tel: 734-332-1200

Greg 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

Todd RedderTodd 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

Kat RidolfiKat Ridolfi is an aquatic ecologist with expertise in assessing and managing contaminated aquatic ecosystems. She specializes in assessments at Superfund and other contaminated sediment sites, development of Total Maximum Daily Loads (TMDLs), and all phases of watershed assessment.  She is also experienced in field sampling of water, tissue and sediment, GIS, project management, development of sampling plans, habitat suitability analysis for fish, and green infrastructure practices. Previous professional experience focused on biological research and watershed management throughout California, with a focus on San Francisco Bay and its tributaries.
Mid-Atlantic regional office
202-833-9140

Daniel Rucinski, Ph.D., 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 RutynaJason Rutyna, P.E., is an environmental engineer with LimnoTech. Jason has a master's degree in Civil and Environmental Engineering from Wayne State University with a focus on water resources and environmental engineering. Jason has experience with providing clients with scientific and engineering analyses in a variety of projects that involve hydrodynamic/hydraulic models, hydraulic transient/pneumatic models, water quality models, TMDL modeling and analysis, mixing zone modeling, water quality data analysis, and three-dimensional geostatistical interpolations. Jason also has the ability to post-process field data from the ADCP to produce summary statistics and graphics of flows and velocities. Jason is also skilled in developing client-deliverable databases and compiling water quality, biological, habitat, continuous monitoring, meteorological, and point source data. 
Tel: 734-332-1200

A. SavineauAnouk Savineau is a senior project engineer with over 10 years of experience working in the field of water resources. She provides technical and programmatic support on a variety of projects including the characterization and modeling of surface water, stormwater, and sewer collection systems; protection and management of watersheds; and analysis and selection of green infrastructure and low-impact development. Anouk is well versed in a variety of software applications, including MikeUrban, SWMM, WASP, and the HEC models, and is also a proficient user of GIS for performing spatial analysis for watershed and sewershed characterization. Anouk hails from Belgium and speaks French, Dutch and English.
Mid-Atlantic regional office
Tel: 202-833-9140

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Derek SchleaDerek Schlea joined LimnoTech in June 2011 with a master’s degree in Ecological Engineering from The Ohio State University. Two of his areas of expertise at LimnoTech are green infrastructure development and agricultural watershed modeling. Derek has project experience in NPDES permit support, hydrologic and water quality model development, data analysis, database management, processing and evaluation of model results, and environmental field sampling activities. He has also worked on conceptual designs for green infrastructure projects and developed a hydrologic performance monitoring plan for stormwater best management practices. Areas of work experience during his graduate studies included stormwater management using rain gardens and rainwater harvesting systems, and development of sustainable remediation and energy-efficiency tools.
Tel: 734-332-1200

Tim 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

Pranesh SelvendiranPranesh Selvendiran, Ph.D., has been an Environmental Engineer with LimnoTech since 2008. Pranesh’s engineering experience includes watershed modeling and assessment, evaluation of mercury dynamics, contaminant fate and transport assessments, water footprinting and hydrodynamics. Pranesh has been responsible for development and application of watershed and hydrodynamic models for various environmental investigations. Pranesh also has extensive experience in data analysis and interpretation, database management and developing technical reports. Pranesh has been involved in mercury research with a focus on wetland and lake ecosystems. His research findings have been published in various peer-reviewed scientific journals. Pranesh received his doctorate in Civil Engineering from Syracuse University.
Tel: 734-332-1200

Steve SkripnikSteve Skripnik, P.E., is an environmental engineer with expertise in stormwater runoff and watershed management issues, surface water hydrology, and low-impact development.  Steve’s project experience has included the development and application of a variety of watershed hydrology, storm and sanitary sewer collection system, and receiving water models.  His diverse project experience includes watershed planning, stormwater quality and conveyance, and water supply planning. Steve has experience in a wide range of open-source and proprietary modeling tools to support the development and review of TMDLs, permits, planning documents, and infrastructure design and planning projects.
Mid-Atlantic regional office
202-833-9140

Tad SlaweckiTad 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 design and implementation of a GIS-based viewer of detailed habitat and fisheries data to support use attainability analyses. Tad chairs the Water Environment Federation's Watershed Management Committee.
Tel: 734-332-1200

Evren SMehmet Evren Soylu, Ph.D., joined LimnoTech in March 2014 with a Ph.D. in Natural Resource Sciences in hydrology specialization. His general study areas include hydrology, ecohydrology and hydrogeology. Specifically, his research focus is linkages between groundwater, land surface processes, and climate, with a particular emphasis on incorporating field observation and numerical models to understand the interrelations of surface/subsurface hydrological processes and vegetation dynamics under changing climate, land cover, and human activities, and analyzing their impacts on quality and quantity of water resources. He has been involved with research projects related to water sustainability and climate impacts on natural and agroecosystems. He has published numerous papers and abstracts in his areas of expertise. He speaks English and Turkish.
Tel: 734-332-1200

Hua TaoHua Tao, Ph.D., graduated from Tufts University with a Ph.D. in Environmental Engineering. Before receiving his degree, he acquired valuable relevant experience working on various environmental engineering projects in China. Dr. Tao’s areas of specialization include surface water quality modeling, model calibration, sensitivity and uncertainty analyses, and proficiency in GIS software applications. He also co-authored the EPA-sponsored river and stream water quality model QUAL2K. Dr. Tao is proficient in a number of types of software, including FORTRAN 90/95, Visual Basic 6, VBA, C++, and Matlab. He has also completed EPA BASIN/TMDL specialized training.
Tel: 734-332-1200

Tim ToweyTimothy Towey, P.E., has over ten years of experience as an environmental professional. His engineering experience includes CSO control planning, the application of a variety of water quality models, sediment remediation planning, and the use of multivariate statistical analysis. Tim has managed projects and tasks on several water quality modeling efforts in support of CSO Long-term Control Plans, provided engineering support for the remediation of contaminated sediments, and applied statistical tools to better understand both chemical and ecological data. Tim holds Master's and Bachelor's degrees in Environmental Engineering.
Tel: 734-332-1200

Carrie TurnerCarrie 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 UdvardyBrad Udvardy, P.E., is a senior 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

Ed 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

Scott WadeScott Wade is a planner and the geographic information systems (GIS) manager at LimnoTech. He combines expertise in geography, GIS, cartography, and urban planning to support clients as they work to manage watersheds, remediate contaminated sediments, and protect water quality and habitats. Scott uses the power of GIS to support LimnoTech’s modeling of watersheds, surface waters, and sediments. He compiles spatial datasets from diverse sources and integrates them into project-specific geographic information systems. He uses GIS to characterize watersheds and to provide clients a thorough understanding of the interaction between the landscape and surface waters. Scott constructs maps to help make complex model results accessible to clients, project team members, and the public.
Tel: 734-332-1200

Jeremy WalgraveJeremy Walgrave, P.E., CFM, joined LimnoTech’s Minneapolis-St. Paul regional office in February 2012. He earned a bachelor of science degree in Civil Engineering from the University of Nebraska-Lincoln, and has over 12 years of experience in Water Resources Engineering. Jeremy has worked with public and private clients throughout the Upper Midwest and has experience in all levels of engineering from planning and permitting to design and construction. Jeremy is a licensed Professional Engineer and a Certified Floodplain Manager.  He is involved in the Minnesota Association of Floodplain Managers and is currently serving as the Executive Board Chair.
Minneapolis/St. Paul regional office
Tel: 651-330-6038

Laura WeintraubLaura Weintraub, P.E., is a senior project engineer and project manager with over 18 years of experience in hydrologic analysis, water quality modeling and watershed management. Her expertise includes water resources and water quality analyses and the development of decision-support systems for public, private, and research clients. Ms. Weintraub’s project experience includes TMDL development, watershed planning, source water protection, loading analyses, and corporate water stewardship. She responds to the needs of stakeholders by using data, modeling tools, and sound science to identify water quantity and quality issues, develop potential management alternatives, and evaluate the feasibility and benefit of various options. Ms. Weintraub has particular interest in water issues faced by the electric power industry and has conducted numerous projects for electric power generators and EPRI on water use issues such as water availability planning, 316(b) compliance, corporate water stewardship, TMDLs, water quality trading, watershed management, and decision-support tool development (e.g., Water Prism, WARMF).
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 WolfeJohn R. Wolfe, Ph.D., P.E., BCEE, is a Vice President at LimnoTech, managing corporate efforts to expand scientific and technical capacity through innovation and training. He has managed 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, energy-water issues, and environmental economics. He has extensive expertise in surface water quality modeling, including contaminated sediments, wastewater treatment, and permitting; and groundwater protection, and is a Board Certified Environmental Engineer in the specialty area of Hazardous Waste Management. Prior to his career in engineering, John worked for 13 years as an economist, including 11 years as a university professor. He served as a member of the Committee on Sediment Dredging at Superfund Megasites of the National Research Council of the National Academies. John also now resides in the Los Angeles, California area, and is seeking to expand LImnoTech's services to West Coast clients.
Southern California office
Tel: 310-939-7293

Matt ZelinMatt Zelin, P.E., is a hydraulic and water resources engineer with experience in hydrologic and hydraulic modeling, urban hydrology, and fluvial geomorphology. Much of his academic background focused on hydrology and hydraulics, water quality of natural waters, and stream restoration. Matt’s project experience has included the development and application of hydrologic and hydraulic models, analysis of stormwater quality and quantity, and the design of green infrastructure and stream restoration practices. Matt also has experience leading FEMA NFIP hydrologic and hydraulic modeling tasks, and he is a Certified Floodplain Manager.  Matt has field experience in stormwater and stream water quality sampling, topographic surveying, and geomorphic assessments.
Mid-Atlantic regional office
Tel: 202-833-9140

Greg ZuknickGreg Zuknick is an environmental scientist with LimnoTech. He has a Bachelor of Science degree in environmental sciences from the University of Maryland Baltimore County, and specializes in watershed hydrology, fluid dynamics, advanced geographic information systems, and AutoCAD. Greg’s project experience covers a wide array of tasks including the design of digital data collection forms for field work, wet and dry weather sampling, evaluation of best management practices’ effectiveness, advanced GIS tasks, AutoCAD drafting, and performance of biological sampling tasks. He has also had significant work experience with stream restoration in the areas of site assessment, design components, and plan drafting.
Mid-Atlantic regional office
Tel: 202-833-9140

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Administrative Staff

Patti Fosbender
Controller
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

Nicole Robinson
Accounting Specialist
Tel: 734-332-1200

Marcia Brown
Receptionist
Tel: 734-332-1200

Elizabeth Ubelacker
Mid-Atlantic Office Manager
Tel: 202-833-9140

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