Engineering and construction firm CH2M HILL (named for its founders Cornell, Howland, Hayes, and Merryfield) operates five divisions devoted to serving its five core markets: Environment and Nuclear; Water; Transportation; Oil, Gas and Chemicals; and Industrial and Urban Environments. CH2M Hill's top client is the US Government, which contributes around 20% to its annual revenue. Public sector clients include the US Department of Energy and the Department of Defense. CH2M HILL also works for state and local governments building water and wastewater systems, airports, highways, and other transportation projects. Founded in 1946, the privately held company is owned by private equity firm Apollo Global Management.