Olathe-based Terracon Consultants Inc has purchased RGA Environmental Inc. RGA is based in Emeryville, CA, and is the second acquisition in California for Terracon this year. RGA specializes in hazardous materials, industrial hygiene, safety, emergency response, litigation and environmental construction management services. The company will continue to operate as RGA Environmental, A Terracon Company, and will retain its 65 employees. Terracon is an engineering consulting firm with more than 3,000 employees in 140 offices across the country. Terms of the acquisition were not disclosed.