With over 150 years of combined experience, the leadership team at SCI is committed to building and maintaining client relationships and supporting the growth of SCI across the United States.


  • Leadership is the art of getting someone else to do something you want done because he wants to do it.
    Dwight D. Eisenhower
  • A leader is one who knows the way, goes the way, and shows the way.
    John Maxwell
  • Leadership is lifting a person's vision to high sights, the raising of a person's performance to a higher standard, the building of a personality beyond its normal limitations
    Peter Drucker
  • A leader is someone who has the clarity to know the right things to do, the confidence to know when she's wrong, and the courage to do the right things even when they're hard.
    Darcy Eikenberg
  • Be hearty in your approbation and lavish in your praise
    Dale Carnegie


“We are very appreciative and pleased with the work that SCI is doing for us. Kudos to you and your team!"

EM Harris

“I want to take this opportunity to thank you for the excellent work you and your team did as consultants regarding our most recent noise litigation matter. On this case, and the others we have worked with your company on in the past, we are appreciative of your expertise, your responsiveness and your client-oriented attitude in making sure we were able to provide accurate information in a professional manner. Your technical knowledge and skill sets have been most beneficial. I would gladly serve as a reference for you personally or for SCI Engineering, Inc. in the future.”

John J. Diehl, Jr.

Diehl Law Group, LLC


Scott Harding, CPSS/SC
President and CEO

Mobile: 314-581-3553

As President and CEO of SCI, Scott is in charge of the strategic direction of the firm. He advises the board of directors on the impact of long-range planning, financial strategies, performance management, and the day to day operations of SCI. In addition to his role as President, Scott frequently lectures at public outreach events. He joined SCI in 1994, and earned his Master’s degree in Pedology (Soil Classification) and his Bachelor of Science degree in Soil Science from the University of Illinois-Champaign/Urbana. He is a Professional Soil Classifier and a Certified and Professional Soil Scientist. Scott chairs and serves on several prominent committees including Progress 64 West Membership Chair, Society of American Military Engineers Scott Post Scholarship Chair, American Council of Engineering Companies Environment & Energy Committee, East-West Gateway Water Resources Advisory Committee, and the St. Louis Earth Day Water Symposium Planning Committee. His associations include the American Society of Agronomy, Illinois Soil Classifiers Association, Illinois Association of Floodplain & Stormwater Management, Missouri Association of Professional Soil Scientists, American Council of Engineering Companies – Illinois, American Public Works Association, and American Society of Civil Engineers.

Tony Kreutz
Executive Vice President

Mobile: 636-949-8200

Tony joined SCI in 1991 and currently serves as Executive Vice President and Director of Business Development and oversees the efforts of corporate customer service and marketing, including strategic planning and acquisitions expansion. He also is responsible for operations at the Rolla office and serves as a consultant for special inspection services. Tony currently serves on several committees and holds key positions with several organizations including Make-A-Wish Missouri Governing Board, Mercy Foundation Board Chair, American Council of Engineering Companies Transportation Committee, Corps of Engineers – Kansas City Liaison Committee, Downtown Partnership of St. Louis Government Committee, East Central College Foundation Executive Board/Director-at-Large, Urban Land Institute Programs Committee, OneCurveAtaTime Board Member and First State Community Bank Board Member.

David Nolan, P.E.
Vice President, Construction Services

Mobile: 314-575-9546

Dave joined SCI in 1995 and is Vice President of the Construction Services Group. He has 20 years of experience in the field of civil engineering and construction materials testing. His experience and responsibilities include management of the construction services group, including field and laboratory operations. He earned his Master’s degree in Business Administration from Lindenwood University and Bachelor of Science degree in Civil Engineering from Purdue University. He is involved in multiple organizations including the Concrete Council of St. Louis, the O’Fallon Public Works Commission, the Associated General Contractors of Missouri and the HBA of Greater St. Louis.  He is also a past president and the current Certifications Chairman for the Missouri Chapter of the American Concrete Institute.

Shawnna Erter, P.E.
Vice President, Geotechnical Services

Mobile: 314-486-1215

Shawnna joined SCI Engineering, Inc. (SCI) in 2001 and is currently the Vice President of the Geotechnical services group. Her responsibilities include preparation of reports and proposals for subsurface explorations, and foundation design recommendations, including both shallow and deep foundations as well as slope stability, liquefaction and settlement analyses. As a Project Manager, Shawnna reviews geotechnical reports and analysis, provides reviews of project plans and specifications, attends project meetings, and provides technical presentations to clients and other engineers. In addition, she also provides project management for the Construction Services Group. Shawnna served as Past President on the American Society of Civil Engineers (ASCE) Board of Directors and as a Region 7 Governor. She serves nationally on the Site Characterization and Ground Modification Committees for the Geo Institute of ASCE. She is on multiple committees for the Home Builders Association, and serves on a committee for the Women In Transportation. Additional associations include the Association of Engineering Geologists and the American Public Works Association.



Ed Grimmer, P.E.
Vice President, Environmental Services

Mobile: 618-779-1445

Ed joined SCI in 1999 and is Vice President of the Environmental Services department and an Associate of the company. He has over 20 years of experience providing various environmental services and has been responsible for projects throughout the United States. He is a Professional Engineer in Missouri and Illinois and earned his Bachelor of Science degree in Chemical Engineering from the Missouri University of Science and Technology (MS&T). He currently serves as the Society of American Military Engineers St. Louis Post Treasurer and is affiliated with the Air and Waste Management Association.

Michael Hartoin
Vice President, Natural Resource Services

Mobile: 618-779-3039

Mike joined SCI in 1995 and is Vice President of the Natural Resources Services department and an Associate of the company. His experience includes environmental planning, specializing in natural resources including wetland delineations, environmental assessments, environmental impact statements, state and federal permitting, public involvement, threatened and endangered species compliance, wetland and waterbody impact assessments and mitigation planning. He has been integral in working with local, state and federal governments to streamline the mitigation banking review process in Illinois and Missouri. He designed and gained approval of the first wetland mitigation bank ever approved by the St. Louis District Corps of Engineers. He earned a Bachelor of Science degree in Biology from Southern Illinois University at Edwardsville and is affiliated with the Society of Wetland Scientists, the U.S. Green Building Council Missouri Gateway Chapter, and the Midwest Bat Working Group.

Trey Coad, CHMM
Vice President, Client Development

Mobile: 314-575-7404
Texas: 210-660-SCIE (7243)

As Vice President of Client Development at SCI, Trey specializes in identifying growth oriented opportunities and producing strategic solutions.  In addition, Trey’s environmental and construction background has allowed him to demonstrate success by providing consulting and risk management services for a broad spectrum of clientele throughout the country. He is involved in all aspects of business management and development, including but not limited to corporate planning, evaluating and developing business strategies and financial goals and analyzing potential growth models for the firm. He also leads key growth sectors, including SCI’s continued geographic expansion.

Trey’s project management endeavors have included multi-million dollar construction and redevelopment projects that have had unique design and engineering hurdles. He has provided leadership for these projects in which he has evaluated, designed and performed construction oversight. His strengths include using his vast experience to effectively manage high-profile projects that require detailed and dedicated services in order to control the individual risks and liabilities of investors, owners, and project team. His experience using risk based protocols and remedial approaches help provide the most cost-effective recommendations for clients and keep the project financially viable. He also regularly provides technical negotiations with regulatory authorities on a local, state, and federal level and routinely use modern risk management and remedial techniques to manage projects with multi-faceted concerns. He has been successful with mentoring commercial and residential developers and industrial clients in a broad spectrum of development pitfalls

Tonya Sonsteng, P.E.
Regional Manager - Texas

Mobile: 210-850-7782

Tonya joined SCI in 2019 as a Senior Geotechnical Engineer in our Austin, Texas office. Her responsibilities include preparation of geotechnical reports and proposals for subsurface explorations, and providing foundation and site development recommendations. Tonya has experience with AutoCAD, gINT, Wincore and MathCAD. Her expertise lies in geologic formations within Central Texas, shallow slab on grade and footing foundations, deep drilled pier and drive pile foundations, flexible HMAC and concrete pavement solutions, soil stabilization and improvement, infiltration and applied load testing, construction materials review and site development feasibility.

Michelle Eaton, P.E.
Regional Manager - Mountain

Mobile: 720-544-3663

Michelle Eaton, P.E, has over 16 years of experience in the Environmental Engineering field and is responsible for management and oversight of projects in SCI’s Denver, Colorado office. Her expertise includes experience with Spill Prevention, Control, and Countermeasure (SPCC) Plans, remediation planning and oversight, and soil and hazardous waste characterization. Her responsibilities include, but are not limited to, proposal development and review, scheduling, staffing, technical writing, client management, and report delivery coordination.

In addition to her role as an environmental professional, Michelle also supports SCI’s geotechnical, natural resources, cultural resources, and material testing teams.