Didipio project mine waste management system
At a glance
OceanaGold Philippines Inc. engaged GHD to design a Tailings Storage Facility (TSF) and Waste Rock Dump (WRD) for the Didipio gold-copper mine located on the island of Luzon, approximately 270 km north of Manila in the Philippines.
The challenge
One of the key challenges our team faced was the terrain. The TSF and WRD are located in a steep-sided valley, prone to landslides over a significant river with a wet tropical climate that averages 3.3 m annual rainfall. The target storage volume for the TSF included a large stormwater retention capacity to manage flood inflows and a tight timeframe for construction.
Our response
GHD developed a design featuring an innovative flow-through zone within the WRD to pass mean river flows, and a WRD landform to manage and retain flood peaks upstream. The TSF was incorporated into the WRD, which provided an economic method of construction as well as a conservatively safe, stable, structure suited to long-term sustainable closure.
Our team carried out geotechnical site investigations for the mine waste facility (and the mill site), followed by TSF detailed design and documentation for the TSF in 2011. We are currently (2017) providing an ongoing role with design advice including on-site technical inspections and QA/QC throughout the construction of the TSF and WRD.
We have worked closely with the Didipio team to plan and accommodate all materials from the open pit to the TSF/WRD - in order to maximise utilisation of resources and facilitate continuous construction in a challenging environment.