Rio Alto Mining Limited (TSX:RIO) (BVL:RIO) (NYSE:RIOM) (DBFrankfurt:MS2) is pleased to announce that it has received formal notification from the General Bureau of Environmental Affairs of the Ministry of Energy and Mines of Peru Directorial Resolution N degrees 515-2013-MEM/AAM dated December 27, 2013, by which it approves modifications to the current Environmental Impact Study for the La Arena Project Gold Oxide Mine. This EIA modification allows Rio Alto to apply for permits for a future Phase 2 open pit sulphide mine, construct an 18,000 tonne per day copper/gold flotation plant and concentrator, expand the current waste dump facilities to accommodate sulphide waste and to use the Calaorco Pit for tailings deposition once open pit oxide reserves are exhausted.

A feasibility study underway on the Company’s Phase 2 copper/gold sulphide project is currently scheduled for completion in Q2 2014. Study work is focussed on maximizing future financial returns from the project and keeping start-up capital costs as low as practicably possible.

Alex Black, President & CEO commented that “The approval to modify the existing EIA at La Arena took a total of seven months to complete. This is a great achievement by the Rio Alto environmental team and demonstrates their ability to work closely with the various government agencies in Peru to complete this process in the shortest possible time.”