Director of Ground Freezing, Keller North America
(920) 889-0190
David K. Mueller
Vice President
Keller North America
Gregory Ziegler, P.E.
Executive Vice President
Keller North America
Kenneth E. Wigg, P.E.
Senior Engineer
Keller North America
the definitive ground freezing resource
Joseph A. Sopko, Ph.D., P.E.
Director of Ground Freezing, Keller North America, Inc.
cell: (920) 889-0190
