Marine Corps Air Station Yuma or MCAS Yuma is a United States Marine Corps air station. It is the home of multiple squadrons of AV-8B Harrier IIs and F-35B Lightning IIs of the 3rd Marine Aircraft Wing, Marine Aviation Weapons and Tactics Squadron 1 (MAWTS-1), Marine Operational Test and Evaluation Squadron 1 (VMX-1) and Marine Fighter Training Squadron 401 (VMFT-401), an air combat adversary squadron of the 4th Marine Aircraft Wing of the Marine Corps Reserve. It is a designated Superfund site due to a number of soil and groundwater contaminants, including asbestos.