Closed landfills contaminating groundwater, World Bank warns

The leachates coming from the closed San Mateo landfill in Rizal and Carmona landfill in Cavite continue to contaminate ground water, a recent World Bank (WB) study showed.

The World Bank also warned that aside from Carmona and San Mateo landfills, the Payatas dumpsite in Quezon City and Smokey Mountain in Manila, continues to pose significant environmental risks to adjacent communities.

Because of these, the World Bank urged the Philippine government, particularly the local government units (LGUs) concerned, to immediately take up measures to contain the landfill sites.

"There is an urgent need to properly contain these sites and the numerous open dumps to prevent leachate contamination of water bodies," the World Bank report said.

The World Bank added that the San Mateo and Carmona landfills, which were both closed, contain over 23 million cubic meters of degrading waste.

"Recent studies indicate that the biochemical oxygen demand (BOD) quality of effluent from leachate treatment plants of both sites exceeded permissible standards, San Mateo with 10,000 mg/l; and Carmona, 3,500 mg/l. This indicates that the treatment employed on both sites are not functioning properly," the World Bank noted.

The World Bank explained that normally when sanitary landfills are closed or capped, the facility owner is required to implement a post-closure program.

"This includes storm water drainage, leachate treatment and monitoring and gas flaring or recovery and landscaping. Although it is a regulatory requirement, such a program is not in place at either of the sites. While these sites had landfill gas vents, there were no gas recovery facility," the World Bank said.

The World Bank said that the poor construction and faulty operation of the sites resulted in negative perception of sanitary landfills among the general public.

"This, combined with the NIMBY (not-in-my-backyard) syndrome, has caused problems in the siting of landfills in the country, especially for Metro Manila, where the problem is particularly acute," World Bank said.

The World Bank said rehabilitation of San Mateo and Carmona landfills could benefit from on-site power generation.

The World Bank added that based on recent estimates, the waste contained in the San Mateo and Carmona landfills is capable of producing enough power to supply 5,500 homes.

"The use of landfill gas for energy could supplement the costs of implementing urgently needed rehabilitation plans for both sites," it said.