Britain’s AEA Technology Group plc this week said it has acquired Eastern Research Group (ERG), an environmental and health and safety consulting firm that is expanding its presence in the defense and health areas, for $83 million in cash and stock.

ERG, which is based in Massachusetts, provides economic and policy analysis, engineering, science, information technology and communications consulting primarily to the Environmental Protection Agency and Occupational Safety and Health Administration. ERG has a key role with the EPA as the prime contractor on the agency’s water scarcity program.

ERG has been expanding its footprint with the United States government by growing its presence in other agencies such as the Departments of Defense and Health and Human Services and the Centers for Disease Control.

AEA is a global consulting firm focused on climate change, energy and environment. The company said the acquisition furthers its strategy of building a business with high-level consulting services to the U.S. government, and then extending those services into the U.S. and U.K. private sectors.

Houlihan Lokey served as ERG’s financial adviser on the deal.