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Practice Leaders

These individuals have a unique combination of leading edge expertise and exemplary performance solving our clients' most difficult engineering and operational challenges.


Steve Gress 400x500Steven P. Gress
Wet Weather Treatment Systems

Steve is an accomplished wastewater engineer highly experienced in the planning, design, and implementation of water, wastewater, and wet weather facilities. This includes the planning and design of storage, pumping, and treatment facilities to alleviate combined sewer overflow (CSO) occurrences. Steve has in-depth regulatory experience and is active in the Indiana Department of Environmental Management (IDEM) workgroups to develop Nonrule Policy Documents for CSO Treatment Facilities and E. coli effluent limits. Since 1990, he has provided instruction to over 800 engineers in the areas of hydraulics, hydrology, and water and wastewater treatment plant design.

Steve has an M.B.A. from Indiana University and a B.S. degree in Civil Engineering from Purdue University.


Joe Berktold 400x500Josef A. Berktold
Electrical Systems

Joe has outstanding knowledge and abilities in the evaluation and design of electrical systems for water and wastewater facilities. Areas of expertise include electrical service, power distribution, energy utilization alternatives, emergency and standby power systems, motor control and motor control center design, voltage drop and short circuit analysis, lighting protection and grounding design, lighting design, and code interpretations.

He serves on the National Fire Protection Association’s NFPA 820, Standard for Fire Protection in Wastewater Treatment and Collection Facilities technical committee as the Water Environment Federation (WEF) representative, and assisted with the rewrite of that guideline for the 2016 edition.

Joe has a B.S. degree in Electrical Engineering from the Illinois Institute of Technology.


Bill Marten 400x500William L. Marten
Wastewater Biological Processes and Nutrient Removal

Bill has been involved with biological treatment and nutrient removal for over three decades, beginning as an operator at Madison, Wisconsin’s Nine Springs wastewater treatment plant and conducting graduate research on biological nitrogen and phosphorus removal at the University of Wisconsin. Since then he has worked with municipal and industrial clients to develop cost-effective, creative, and reliable solutions on hundreds of wastewater projects.

A Water Environment Federation (WEF) George Bradley Gascoigne Medal recipient, he is a leader in Donohue’s biological treatment and nutrient removal activities. This includes the use of process models, such as BioWin, and other tools in designing, analyzing, and troubleshooting wastewater treatment systems and in training operating staff in these areas.

Bill has M.S. and B.S. degrees in Civil/Environmental Engineering from the University of Wisconsin and is a licensed treatment plant operator.


Jeff Wills 400x500Jeffrey L. Wills
Energy Recovery and Mechanical Systems

Jeff’s career is centered on the planning and design of mechanical, HVAC, and energy optimization systems for water and wastewater facilities. An expert in biogas conditioning and utilization, Jeff was instrumental in helping the Sheboygan, WI and the Stevens Point, WI wastewater treatment facilities obtain net zero energy status.

He is actively involved in energy master planning and implementation with other communities as they move towards energy independence. This is accomplished through biogas conditioning, management, and utilization; digester heating; effluent heat recovery; heating distribution; and energy modeling and management. Jeff is also skilled in completing energy grant applications to fund energy efficiency projects.

He has a B.S. degree in Mechanical Engineering from the University of Wisconsin.