Terracon Acquires Mayes Testing Engineers, Inc.

August 04, 2016

Pacific Northwest Expansion Continues with Materials Engineering Powerhouse

OLATHE, Kan. – Terracon, a leading provider of environmental, facilities, geotechnical, and materials services, is pleased to announce the acquisition of Mayes Testing Engineers of Lynnwood (Seattle), Wash. Terracon is retaining all 115 Mayes employees.

Mayes Testing Engineers was formed in 1991 through acquisition of Boss Testing, originally established in 1984. Locally owned and operated for the past 25 years, Mayes is known as one of the largest providers of construction quality assurance services in the Pacific Northwest with in-depth welding, concrete, soils, masonry, asphalt, and non-destructive testing experience.

“This acquisition allows us to significantly expand our presence and service offering in the Pacific Northwest,” said David Gaboury, P.E., president and CEO of Terracon. “We believe Mayes’ materials expertise and local area knowledge complement our existing services and enhance the value and depth of resources we bring to our clients regionally and nationally.”

The transition is effective immediately. The company operates as Mayes Testing Engineers, A Terracon Company.

The Mayes team provides special inspections, materials testing, condition surveys and other materials consulting for owners, developers, architects, contractors, and structural engineers.

“This is a great opportunity for our company, our employees and our clients,” said Michael Mayes, P.E., president of Mayes Testing Engineers Inc. “Joining forces with a nationwide leader like Terracon allows us to provide additional services, including geotechnical, environmental, and building envelope consulting, to our regional clients.”

Terracon’s expansion brings together the acquired resources of Mayes, RGA Environmental, and Argus Pacific all in the Pacific Northwest. Terracon companies now combine to include six Seattle/Tacoma and two Portland, Ore., locations. The move also becomes Terracon’s fifth acquisition in the West in the past two years, having also acquired NORCAL Geophysical Consultants and Neil O. Anderson and Associates.

Terracon is an employee-owned engineering consulting firm with more than 3,500 employees providing environmental, facilities, geotechnical, and materials services from more than 130 offices with services available in all 50 states. Terracon currently ranks 32nd on Engineering News-Record’s list of Top 500 Design Firms. For additional information about Terracon, visit

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