This Big Mac is one of the largest engineering design companies in the US. MACTEC provides a full range of infrastructure and environmental engineering services to federal agencies, municipalities, transportation, energy, and industrial customers, including construction management and facilities operation and management. A specialist in hazardous waste cleanups, the group provides decommissioning and demolition of nuclear facilities and remediation of brownfield sites. MACTEC, which has grown dramatically through acquisitions, operates 80 locations throughout the US. It is majority-owned by private equity firm Nautic Partners, but UK-based engineering group AMEC is buying MACTEC for some $280 million.