Driesenga & Associates, Inc. (D&A) is a full service professional engineering firm providing civil and geotechnical engineering, land surveying, land planning, construction materials testing and inspection, and environmental consulting.

The professional services offered by D&A can be grouped into five (5) general categories: Civil Engineering, Land Surveying, Geotechnical Engineering, Construction Materials Testing, and Environmental Consulting. In support of these areas, the firm is equipped with engineering laboratories to perform soil, concrete, masonry, and asphalt testing.