CTL is a full service consulting engineering, testing, inspection, and analytical services company. Formerly known as Columbus Testing Laboratory, the company was established in 1927 as a privately held independent engineering and testing laboratory serving the local community. During its early years, the company focused mainly on soils, foundation engineering, and construction testing and inspection services. The successes, experience, equipment, and expertise gained in these areas led to a natural expansion into the metallurgical, non-destructive testing, mechanical, mining, roofing, and environmental service industries. CTL maintains a staff of over 250 employees, including registered engineers, chemists, environmental engineers & scientists, geologists, hydrogeologists, non-destructive testing specialists, certified welding inspectors and technicians.