Philex, OceanaGold: Trailblazing world-class tailings management

Upgrade to High-Speed Internet for only ₱1499/month!

Enjoy up to 100 Mbps fiber broadband, perfect for browsing, streaming, and gaming.

Visit Suniway.ph to learn

MANILA, Philippines — As the global mining industry shifts toward more rigorous environmental transparency, two Philippine mining giants – Philex Mining Corp. and OceanaGold (Philippines) Inc. – are leading the way in tailings management.

Both companies have successfully aligned their tailings storage facility (TSF) protocols with international best practices, transforming what was once the industry’s greatest liability into a benchmark for sustainable engineering.

Philex and OceanaGold obtained the highest “AAA” ratings for tailings management in the 2024 and 2025 performance evaluation for Chamber of Mines of the Philippines (COMP) member companies under the Toward Sustainable Mining (TSM) initiative.

A critical safety and sustainability responsibility

Tailings management is among the most critical safety and sustainability responsibilities in mining, as tailings facilities are large, long-lived structures that remain long after a mine closes,” said COMP chairman Michael Toledo.

“When poorly designed or managed, failures can result in loss of life, environmental damage, community displacement and lasting erosion of trust in the industry,” he said.

“Under the TSM framework, tailings management is hence treated as a core obligation, central to protecting people, the environment and the industry’s social license, while managing liabilities that can span generations.”

TSM enhances the durability of tailings facilities through a full life-cycle approach, anchored in the principle of “designing for forever.”

This includes conservative engineering for extreme events, proper materials and construction, rigorous water and drainage control, continuous monitoring with independent review and clear accountability up to senior management. Together, these measures ensure that tailings facilities remain stable and safe over the long term, preserving public confidence well beyond the life of the mine, Toledo said.

Moving beyond compliance

COMP’s adoption of TSM inspires companies to improve their performance.  For Philex, it pushed the company to “strengthen its system, improve accountability and elevate the operational discipline, moving beyond compliance and aiming for excellence, ensuring that our operations are safer, more transparent and aligned with global sustainability standards.

Philex’s Padcal mine manages its tailings facilities through a comprehensive system of engineering controls, monitoring programs and operational procedures designed to prevent leaks and spills.

The Tailings Storage Facility of Philex’s Padcal Mine implements and maintains an integrated management system to comply with the requirements of ISO 14001:2014 and OHSAS 18001:2018; prevent injury and ill health of workers and other stakeholders and prevent pollution of the environment.

“We are committed to achieving and maintaining world-class standards in the design, construction, operation and governance of our tailings facilities,” said Philex president and CEO Eulalio Austin Jr.

Huge investment

Philex has a dedicated team to ensure the safety of its tailings storage facilities.  Over the years, it has invested substantial sums for its three tailings ponds – TSF1, which has been decommissioned and is currently in a closed and stabilized state; TSF2, which is undergoing decommissioning and now hosts the community’s sanitary landfill as part of progressive rehabilitation and land-use planning and TSF3, which is currently receiving tailings and is maintained in accordance with national regulations, ANCOLD guidelines, company standards, and the TSM Tailings Management Protocol.

The company’s TSF3 is characterized by a Spillway-Type Decanting System – a first-of-its-kind and a pioneering structure in mining tailings management, designed by Golder Associates, a nationally and internationally reputed engineering consultant.

The initial construction cost of the spillway was P500 million, with an additional P300 million for upgrades and enhancements. This system allows easier monitoring, maintenance and safer water discharge, designed to safely handle a 10,000-year flood, significantly enhancing operational safety.

TSM: A rigorous benchmark

For OceanaGold’s Didipio mine, COMP’s adoption of TSM provides the company with another set of rigorous benchmarks to compare its performance with, and continuously improve and enhance operations as a responsible mining company.

“Passing the TSM is very important to OceanaGold as this demonstrates our commitment to meeting established international ESG standards. Passing also means continuing to maintain (or exceeding) the requirements of a particular set of standards. It is also vital that we constantly benchmark our performance versus these standards, so we know which areas we need to further refine and develop, if there are,” said Joan Adaci-Cattiling, president and general manager for External Affairs and Social Performance at OceanaGold.

‘Zero harm policy’

OGPI’s policy is to ensure safe, compliant and efficient management of the Didipio Tailings Storage Facility through a robust, integrated framework. The policy is aligned with the OGC Tailings Management Framework, Global Industry Standard on Tailings Management (GISTM), and Philippine regulations.  It emphasizes zero harm, transparency, accountability, and continuous improvement, with clear goals, standards and commitments communicated to all personnel.

‘Valley dam’ tailings

At Didipio, the Tailings Storage Facility is designed as a valley dam with staged raises.

The TSF is managed through strict operational controls, regular inspections, comprehensive monitoring (piezometers, prisms, InSAR, water quality), and a Trigger Action Response Plan.

“There are daily, monthly, quarterly and annual inspections, and maintenance is performed as needed. Emergency response plans are in place for leaks or spills,” Adaci-Cattiling said.

A multidisciplinary team is responsible for keeping the tailings facility in check and safe at all times, which complements the design that could last until the life of the mine.

The tailing pond’s volumes and freeboard are managed to accommodate extreme flood events and could withstand an equivalent magnitude eight earthquake.

OMS manual

The company has also developed an operational and maintenance surveillance manual, which ensures efficient, safe operation, maximizes storage, minimizes environmental impact and meets all regulatory requirements.

The OMS Manual has been instrumental in guiding daily operations, maintenance, inspections and emergency response, and provides clear procedures, assigns responsibilities and supports training and audits.