OceanaGold (Philippines) Inc. said Monday it rehabilitated 55 hectares of the 345 hectares of land disturbed by its Didipio Mine as of June 2025, using a new, lower-cost approach.
The company said its "Harmony in Diversity (HiD) Effect" program, implemented in 2024, accelerated ecosystem recovery and cut rehabilitation costs to P1.3 million per hectare from P3.5 million in 2023. The new approach shifts away from conventional hydroseeding to a more holistic, ecosystem-based method.
"Through the HiD Effect, we can transform a disturbed mining area into a self-sustaining forest in just three to five years, compared to at least 15 years under the conventional method," said Donna Del Moro, the acting superintendent for environment at OceanaGold (Philippines) Inc.
It said the HiD Effect combines four distinct techniques: Japan's Miyawaki Method, Burkina Faso's Zai Pit Technique, the use of mycorrhiza fungi for soil enrichment and decomposing twigs or trees to create mini-ecosystems.
The method aims to restore native biodiversity by replicating the area's original ecosystem and fostering symbiotic relationships among endemic plants and species.
The Mines and Geosciences Bureau (MGB) issued a memorandum in February promoting rehabilitation methods that align with natural succession. OceanaGold's HiD Effect, launched ahead of the order, is now being considered as a model for the industry.
MGB officials and representatives from the Ecosystem Research and Development Bureau (ERDB) visited the Didipio Mine in April as part of a nationwide assessment.
"We value the opportunity to collaborate with DENR's principal research arm, combining their institutional knowledge with our on-the-ground innovation," said Nericel Langres-Daulayan, manager of OceanaGold's Mine Environmental Protection and Enhancement Office.
Monthly monitoring has shown faster biodiversity recovery, with native birds such as Pacific swallows, swiftlets and wagtails returning to rehabilitated areas and native plants naturally spreading through seed dispersal by wildlife, the company said.
OceanaGold said it has invested $2.5 million in progressive rehabilitation since 2013.