ON AUG. 1 last year, Tailings Storage Facility No. 3 of Philex Mining Corp. in Itogon, Benguet, leaked and spilled 20 million metric tons of silt into the Balog Creek and Agno River. As of late April, Philex officials said cleanup in the creek was 98-percent complete. RICHARD BALONGLONG
More than 10 months after it stopped operations last year, it is now business as usual for the Padcal mines of Philex Mining Corp. at Barangay Ampucao in Itogon, Benguet.
Since March 8, when the Pollution Adjudication Board granted a four-month temporary permit, the mines’ daily production has gone back to 26,000 metric tons (MT).
Philex, which extracts gold and copper, shut down hours after its Tailings Storage Facility No. 3 (TSF3) leaked, spilling 20 million MT of silt into the Balog Creek and Agno River early dawn on Aug. 1, 2012.
The Department of Environment and Natural Resources (DENR) issued a suspension order against the company the following day “until such time that the integrity and safety of its TSF3 has been assured.”
Philex was also later ordered to pay a P1-billion fine.
The company was temporarily allowed to operate “to implement its pollution control program by filling the void with fresh tailings” and to reconstruct its offset dike.
“Our goal is really for us to be allowed to resume our operations permanently,” says Libby Ricafort, its resident manager and vice president for operations.
“We have permanently plugged the leak, shifted to another decantation method and we have removed the tailings that spilled into the
Sigh of relief
Balog Creek,” he says.
After the sleepless nights and manual labor that he and the more than 2,000 miners had gone through in the last 10 months,
Ricafort can only heave a sigh of relief when he started recalling the details of the disaster his company had experienced.
It started with a loud, eerie sound that had ripped the silence of the rainy dawn, he says. “Like a giant yawning,” he says.
The workers would realize later that it was the sound of tailings rushing down a water tunnel that drains into the creek.
“When the department manager rang me about it, he could not explain what was happening. But I knew something was wrong. So I immediately ordered that we stop operations,” Ricafort says.
By sunrise, the workers saw the whole stretch of the Balog Creek below the TSF3 filled with tailings that escaped from the pond. “I thought it was already the end of the mining industry,” says Roy Mangali,
assistant resident manager.
Plugging the leak
Ricafort says a part of the kilometer-long drain tunnel was breached due to the rains that fell nonstop on the valley for days.
The tunnel, which cuts through the bottom of the TSF3, is connected to a penstock, an inclined structure that takes in excess surface water from the tailings pond.
Ricafort says that because the breach was in the tunnel, plugging it did not come easy. “We tried to throw our old equipment into the sink hole of the pond, but these did not work,” he says.
It would take them more than a month before they figured out a solution. On Sept. 10, a nine-meter concrete ball was pushed into the sinkhole by three bulldozers.
“We thought that because of its diameter, it won’t be able to pass through the tunnel because the tunnel [dimension] is only
5 meters by 5 meters,” Ricafort says.
When the huge ball finally sank days later, the tunnel had stopped discharging silt, he says. But they were still unsure that the leak had been plugged because they could not see it.
Do or die
“We waited for two weeks. And the discharge at the tunnel was already normal. But still we were not sure,” says Ricafort.
On Sept. 15, Mangali and four miners entered the tunnel to see for themselves if the huge ball had reached its target. “It was do or die for us,” says Mangali. “We have to see [the ball] to be sure that it’s there. So we can move on.”
With the ball in place, the miners then drilled above the tunnel to pour in filling materials spanning a 15-meter stretch of the tunnel. They sealed it with concrete up to a span of 65 meters to permanently close it.
“Its factor of safety is 10. The requirement is only 1.5,” Ricafort says.
Cleanup
With the leak plugged, Ricafort says the next job was to remove the silt that had filled the Balog Creek, which runs for about 2.5 km before it converges with the Agno River.
He says the challenge at first was how to access the creek, which is about 100 meters below the TSF3.
“We had no choice but to do it manually, using shovels, and take the silt up to TSF3,” Ricafort says. “All of our workers were mobilized for the cleanup.”
The cleanup was completed in March. Walkways with railings and hanging bridges were built on one side of the river and a gazebo was put up near a mountain spring. Fish began swimming in the river again, Ricafort says.
“It’s now 98-percent complete,” he says, adding that Philex spent at least P500 million in the cleanup activities alone.
What is only left for them to do now, he says, is to pump out the silt deposit that had accumulated at the convergence area of the Balog Creek and Agno River.
“We are now only waiting for the necessary permits for us to build roads and install customized equipment,” Ricafort says.
Spillway
A spillway, where the pond’s surface water will be discharged, is now being constructed at the TSF3. “This way, we will be able to see it 24/7, unlike the underground tunnel, which we cannot see round the clock,” Ricafort says.
With the resumption of the mining operations, he says 3.5 million MT of fresh tailings had to be produced to fill the conical void that was formed in the pond after the leak.
The tailings are also needed to create a beach in the pond that would push the surface water away from the offset dike.
“Excessive amount of water in the pond, which is designed to hold solids, could damage the dike and flood the surrounding areas with sediment and water,” Ricafort says.
More woes
Despite the heroics in saving the company’s interest, Philex’s woes are not about to end yet.
National Power Corp. (Napocor) wants the company to pay at least P6 billion for damaging its watershed that led to generation losses.
On May 10, Napocor sent Philex a letter claiming that the amount of tailings that had found its way to the San Roque Dam in San Manuel, Pangasinan, had “reduced the volume of water to be used for power generation.”
In Dagupan, acting Mayor Belen Fernandez formed a group tasked to study the impact of the spilled mine tailings on the seven rivers that crisscross the coastal city before they empty to the Lingayen Gulf.
The Agno River, which flows to the San Roque Dam, has tributaries in the Pangasinan plains on its way to the Lingayen Gulf.
“We are at the end of the Sinocalan River system [which is connected to the Agno River] and we should be prepared,” city agriculturist Emma Molina says.
Molina says the city government may file a claim in the P1-billion fine that Philex had paid once it is proven that the tailings affected Dagupan’s rivers.