Cordillera mines start review of mine tailings, waste disposal

BAGUIO CITY, Philippines—Mining firms operating in the Cordillera have begun reviewing their waste-management facilities, including the designs of their tailings dams, in the aftermath of the tailings pond leak at the Benguet facility of Philex Mining Corp. in August.

The reviews not only address the waste disposal system of the country’s oldest mines, but are also meant to assure outlying communities that the facilities are safe, said Maria Mignon de Leon, vice president for administration of Benguet Corp.

Officials of the Benguet Corp., the Itogon Suyoc Resources Inc. (ISRI) and the Cordillera Exploration Company Inc. held a news conference on Tuesday to address the impact on their ventures of the Philex leak.

The accident has cost Philex more than P1 billion in penalties.

Asked if the tailings leak had discouraged new investors, De Leon said: “So far, it has not. They [businessmen] saw there was really no proof that Philex was negligent. [Philex] took care of their tailings pond. [The accident, however] was more of a wake-up call for many of us not to be complacent.”

Tailings Pond No. 3 of Philex’s Padcal Mine in Itogon town was built in 1992 with a design capacity to impound 177 million cubic meters of mill tailings from the 26,000 tons per day mining operation of Philex, a document from the Mines and Geosciences Bureau in the Cordillera said.

The leak was found near an underground tunnel, beneath a penstock which channels rainwater out of the dam and toward the closest waterway, the Balog Creek.

Using huge concrete balls wrapped in steel, Philex had been able to plug the leak.

Lawyer Eduardo Aratas, Philex legal officer, said on Tuesday that 61 meters of concrete now line the damaged rainwater tunnel. He said the company has been using a second penstock tunnel to remove rainwater from the tailings facility while it builds a new spillway for run-off rainwater.

This second underground tunnel will be condemned or sealed once the spillway is completed, Aratas said.

“What happened to Philex affects us because it…gives the community a bit of uneasiness. If you talk about a dam, the picture of [the accident] can always come to mind, so we [the mine industry] have to double-time to deliver information to residents to express what we are doing now,” De Leon said.

Benguet Corp. has applied for government permission to process its mine tailings using technology that would allow the country’s oldest mine to recover gold mixed with the mine waste.