Keeping the city dump stable kept officials and engineers busy on Monday after the facility failed to withstand heavy rains dumped by Typhoon “Mina” on Saturday.
But they also had to deal with the anger of the community on Asin Road in Tuba, Benguet, which lies below the decommissioned dump. This is the same community, along with residents of Barangay (village) Irisan, that forced the city government to close the dump in 2008, believing it had become a danger to them.
This mountain of garbage stands 20 meters high and looms over communities on Asin Road.
On Monday, Asin residents went to the City Hall to confront officials.
A portion of the dump collapsed on Saturday, burying at least three houses perched on the sides of the dump and killing five people.
Over 18,000 cubic meters of compacted trash now block access to Asin Road. Since Sunday, employees, traders and residents have been walking through this mound of trash to get a ride to Baguio City.
Faye Apil, chief geologist of the Mines and Geosciences Bureau (MGB) in the Cordillera, said the trail of garbage from the dump uphill to the road below spans 350 meters, covering workshops of local woodcarvers on Asin Road’s Kilometer 5.
No evacuation alert
“No one alerted us to evacuate on Saturday [when Typhoon Mina brought strong rains to Baguio] … I was with my two daughters and a grandchild when a huge ball of trash rolled in front our our house. It was like a monster had crossed our path,” said Elizabeth Bagyan, 48.
Some of Bagyan’s neighbors went to Barangay Irisan and blocked the path of garbage trucks, which were sent by the city government to Asin Road to haul the trash to a landfill in Tarlac.
The village leaders told Mayor Mauricio Domogan that they were certain the trash would simply be hauled back to the dump, “and our cycle of falling trash will never end.”
Domogan pacified the villagers. But while negotiations took place at City Hall, government engineers sat down to study why the dump fell apart.
Cordelia Lacsamana, city environment officer, said the dump was unstable while rains continued to pour in the city. She said experts would need clear skies to inspect the mountain of trash and find out what had gone wrong.
DENR supervision
Under the supervision of the Department of Environment and Natural Resources (DENR), Lacsamana said the government had to undertake a five-year stabilization process that required it to shape the wall of garbage into terraces of compacted trash, which would be held in place by an 8-m high and 1.5-m thick concrete retaining wall at its base, documents showed.
Because the facility needs to be enclosed to prevent trash and leachate (liquid from decaying garbage) from leaking out into the area, the city government was required to develop artificial pathways that would channel runoff rainwater away from the dump.
Fountains of water
Residents said they saw fountains of water shoot out from the concrete wall on Saturday noon, on the day the typhoon dumped 225 millimeters of rain on Baguio, Lacsamana said.
Within minutes, the retaining wall burst from what appeared to be high water pressure, followed immediately by mounds of garbage that rolled down the mountainside, she said.
“We are still uncertain why water still crept into the dump [given the measures taken to divert runoff water] so engineers need time to inspect the facility,” Lacsamana said.
Brigitte Ancheta, a government engineer, traced the water that rolled down the Naguilian Road toward the dump on Saturday to a government road construction project.
Road work
“Due to the ongoing excavation [by work crews to install new drain tunnels] along the second road of Barangay Quezon Hill, runoff water had been diverted to the road’s concrete surface [because] the existing drainage system [has been blocked by debris from ongoing repairs there],” Ancheta said.
She said this may explain the cascading water seen rolling down Naguilian Road.
Clarence Baguilat, DENR Cordillera director, said the compacted garbage strewn over Asin Road appeared “super saturated,” based on a report by Paquito Moreno, Cordillera director of the Environmental Management Bureau (EMB).
Lacsamana said photographs of the rehabilitated Irisan dump before the collapse showed portions of the facility’s retaining wall to be swollen, suggesting that it could have been storing water for some time now.
But defects like those were repaired and reinforced months before the accident occurred, she said.
Mina dumped up to 225 millimeters of rain over the city from 8 a.m. to 8 p.m. on Saturday, which meteorologists here describe as “extensive” for the summer capital. The dump collapse happened at 12:30 p.m. on Saturday, amid heavy rains here.
Domogan said the huge amount of rainfall would be a factor when the city reviews the facility’s design.
Because of the collapse, a new wall would have to be built around the dump, which would take the government another four years to complete, Lacsamana said.