Lt. Gen. Thomas P. Bostick, former commander of the U.S. Army Corps of Engineers, has joined Intrexon Corp., a Germantown, Md., bioremediation and biomedical technology firm, as senior vice president and leader of its environmental unit. He served in numerous Army command and staff assignments in the U.S. and abroad in a 38-year military career, from which he retired in May. Bostick previously led the Corps division in Baghdad in 2004-2005 and was a special assistant to the Secretary of Veterans Affairs. The U.S. Senate held up Bostick’s Corps nomination for more than a year before his 2012 confirmation.

Intrexon was founded in 1998 and went  public in 2013. With more than 800 employees, it reported $173.6 million in 2015 revenue, says a spokeswoman. Intrexon’s development of a genetically modified mosquito to counter the Zika virus helped to boost its stock value by 15% in May, said Wall Street analyst Sean Williams in a June review in financial services website The Motley Fool. But he said the firm’s development of genetic product RheoSwitch “could be a game-changer in terms of treating cancer.”

Former engineering firm CEOs Kevin McMahon and William Siegel have formed a consulting firm, McMahon|Siegel Group, based in Colorado Springs, Colo. It will specialize in strategic and operational consulting, training and development, and ownership transition. McMahon was chairman and CEO of design firm Edwards and Kelcey and, after its 2007 purchase by industry giant Jacobs Engineering, group vice president of that firm. Siegel was chairman and CEO of Kleinfelder, an ENR Top 50 firm, where he led its global expansion.

Quality-assurance firm Intertek-PSI has elevated Dan Dixon to senior vice president, based in West Monroe, La. He will oversee Louisiana operations and Mississippi special projects.

Mary Cay O’Malley has joined engineer Mott MacDonald as a Cleveland-based senior vice president, leading its alternative transportation project delivery. She is formerly vice president of engineering design services at Parsons Corp. O’Malley played key roles in projects that include Seattle’s East Link light-rail extension, Denver’s T-REX highway and light-rail expansion, and the upgraded I-64 in St. Louis.

Woodard & Curran, a Portland, Maine, engineer-operations firm, has named Phyllis Brunner president of its consulting business. She returns to the firm from a previous role as West regional manager and senior vice president at Brown and Caldwell.