Integrated energy company Semirara Mining and Power Corporation (SMPC) announced Monday it had completed its backfilling operations in Panian.

The Panian facility was once the largest open-pit mine in the Philippines. 

In a statement, SMPC said it spent 11.5 million man-hours to fill the pit with over 452 million bank cubic meters (bcm) of earth material, which is enough to fill 217,000 Olympic-size swimming pools. 

“We are mindful of our twin role as stewards and government contractor. What we accomplished in Panian is proof of that,” said SMPC President and COO Maria Cristina Gotianun. 

Located on Semirara Island, the Panian mine spans 400 hectares with topographic elevations that ranged from 300 meters below sea level (mbsl) to 30 meters above sea level (masl) during its mine life. 300 meters is roughly the height of a 90-story building. 

SMPC covered the pit in six years, way ahead of the original 10-year mine rehabilitation plan. Mine rehabilitation refers to repairing land that was disturbed by mining activities.  

The company is now developing a science-based plan to reforest and restore the biodiversity in the area. 

Panian had a mine life of 16 years and generated P12.7 billion in royalties for the government and SMPC host communities.