White Mountain Apache Tribe Rural Water System Loan Authorization Act - Directs the Secretary of the Interior, acting through the Commissioner of Reclamation, to provide a loan to the White Mountain Apache Tribe to carry out planning, engineering, and design of the Miner Flat Project (defined as the White Mountain Apache Rural Water System) in Arizona.
Requires the zero-interest, 10-year loan to be repaid with funds from the Lower Colorado River Development Fund.
Directs the Secretary to offer to enter into a cooperative agreement with the Tribe for the planning, engineering, and design of the Project, which shall be in accordance with all federal environmental laws and subject to the requirements of the Indian Self-Determination and Education Assistance Act.