Our Staff


Jim Henning P.E.

President / director of testing services

Dan Driesenga P.E.

Founder, Chairman

Douglas Snyder

Vice President/Director of Sales

civil engineering

John Tenpas P.E.

Director of Civil Engineering

Tracy Hutchinson P.E.

Senior Civil project manager - Grand Rapids, MI

Annie Gigowski

Civil project manager - Kalamazoo, MI

Julie Townsend, P.E.

Civil project manager - Lansing, MI

Geotechnical / environmental consulting

Randy Pail P.E.

Director of Geotechnical Engineering

Michael Stork

Project Manager - Holland, MI

Moe Nabil

Geotechnical Project Manager - Lansing, MI

land surveying / Construction Staking

Alan Dahl P.S.

Director of Surveying

Marc Lohela P.S.

Survey Group Manager - Holland/Grand Rapids, MI

Matthew Reinking P.S.

Survey Group Manager – Kalamazoo, MI

materials testing

Adam Peterson

Materials Testing Manager

Jake Stocking

Testing Group Manager - Holland, MI

Jesse Reed

Testing Project Manager - Grand Rapids, MI

Beni Traore

Testing Group Manager – Lansing, MI

Andy Anschuetz

Testing Group Manager - Kalamazoo

Dennis Snyder

Testing Group Manager – Ypsilanti, MI


Vince Murray

Accounting Manager

Tricia Henning

Accounting Coordinator

Sarah Bolton

Administrative Assistant - ypsilanti, MI

Allison Jones

Administrative Assistant - Kalamazoo, MI

Ellen Jackson

Administrative Assistant - Grand Rapids, MI

Ahmed ElSadek

Administrative Assistant - Lansing, MI

Driesenga & Associates founded

D&A is founded by Dan Driesenga in the former Chris-Craft manufacturing building in Holland, MI.  The company focused on Geotechnical Engineering, Materials Testing, and Environmental Consulting
Holland Office Relocates

The Holland office is moved into space in the former GE Building on 16th Street to accommodate growth
Growth by Acquisition

Joiner Engineering, a 25 year-old firm in Spring Lake, MI is purchased by D&A to expand services to offer Civil Engineering and Land Surveying
Expansion to Grand Rapids

D&A opens a Grand Rapids, MI office to better serve the firm's growing client and workload base in the area
Holland Office Relocates Again

The Holland office moved into the former Black River Schools Building on 8th Street to accommodate even more growth
Another Strategic Acquisition

Sandel, Chappell Associates, a 20 year-old Civil Engineering & Surveying firm, with offices in Whitehall and Grand Haven, MI is acquired by D&A.
Local Recognition

D&A is reconized as the 2001 Holland Area Chamber of Commerce Small Business of the Year

Grand opening of our Kalamazoo office
More Awards

Dan Driesenga is recognized as the 2002 Entrepreneur of the Year for Michigan by Ernst & Young
Northern Michigan Expansion

D&A opens a new office in Cadillac, MI to help serve the Northern Michigan market
D&A Goes to Detroit

D&A expands East with a satellite office in the metro Detroit area to serve the needs of our Southeast Michigan clients
D&A Targets Indiana

D&A capitalizes on a strategic opportunity by opening an office in Indianapolis, IN.  This marks the company's first office out of Michigan.
Centralizing Lakeshore Operations

As the Lakeshore market continues to grow, the Spring Lake office is merged into an expanded central Holland office
D&A Goes South

Similar to expansion into Indiana, D&A sees opportunities in North Carolina. New offices are opened in Charlotte and Raleigh within the year
Refining Focus in Michigan

The effects of the Great Recession force tough decisions to be made. Operations in Indiana and North Carolina are closed to allow D&A to focus on core clients in Michigan.
Detroit Office Relocates

The metro Detroit office moves west to Ypsilanti in order to centralize services more efficiently in the eastern Michigan region
20th Anniversay Celebration

Driesenga & Associates proudly celebrates 20 years of outstanding client service.

Holland Office Moves

D&A's corporate headquarters and Holland, Michigan operations moved to a new location in the Holland Town Center after more than 10 years in the previous 8th Street location.
Dan Driesenga Retires

Dan Driesenga steps down as President of D&A after nearly 25 years. Jim Henning has been promoted to President after serving multiple roles in the company since it's founding in 1995.
25th Anniversary Celebration

Driesenga & Associates proudly celebrates 25 years of outstanding client service

Expansion to Lansing

D&A opens an office in Lansing, MI to further serve the company's continually growing markets



Keely joined the D&A team in 2023, bringing over 8 years of experience in various administrative and office roles. Her primary duties include providing report processing to all service groups and general administrative support, including directing inquiries and assisting clients. She serves as administrative support for the Holland office.

• Gulf Coast High School, Florida Gulf Coast University - Dual Enrollment
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