Under Republic Act 9003, open and controlled dumpsites are no longer allowed to operate. Only Sanitary Landfills (SLFs) are permitted to receive domestic waste for final disposal. These engineered facilities are designed to prevent garbage leachate from contaminating groundwater. They have various layers of protection that includes clay and plastic linings.
Landfills are expensive to construct and operate. Sites for putting up these facilities are also difficult to find. Several factors must be considered like technical requirements, cost of land and public acceptance. Their use must be maximized. Ideally, only residual waste should be ‘buried’ in these facilities. All recyclable, reusable and compostable wastes should not be put there to extend their useful life.
But after an SLF is filled to capacity, what is it good for? The huge track of land it occupies is wasted if not used for other purposes. For obvious reasons, no permanent structure can be built on top of it. One possible use is for recreation, like a public park. This is what is being done in the once-largest landfill site in the world, the 890-hectare Fresh Kills Landfill on Staten Island in New York City.
The SLF on Staten Island opened in 1948 and it was the principal landfill for New York City’s garbage. It was closed in 2001 partly in response to Staten Island residents who had complained about being the city’s dumping ground. Now a portion of the covered landfill, around 8.5-hectare, will be turned into a park. It will have pedestrian and cycling paths, an overlook deck, bird viewing tower and composting restroom that uses no water.
In Quezon City here in the Philippines, the Payatas dumpsite is being redeveloped into an urban park for cycling activities. It will be recalled that on July 10, 2000, the garbage dump collapsed destroying houses and killing around 200 people. It was closed and rehabilitated. This incident led to the passage of RA 9003.
In addition to their use as a park, the biogas in SLFs can be harvested. One of the design requirements of an SLF is to bury a network of pipes that will be used later for pumping out the biogas, a byproduct of the decomposition of organic materials. The gas can be used as fuel for cooking or heating. It can even run a power plant if the volume is sufficient.
During the time of Governor Ed Panlilio, the Pampanga Provincial Solid Waste Management Board of which I was a member visited an SLF in Montalban (now Rodriguez), Rizal. We were shown a closed SLF with biogas recovery pipes. The harvested biogas goes to the Montalban Methane Power Plant which uses it as fuel to generate electricity.
While there are beneficial uses for closed SLFs, we cannot go on using these facilities in the future. Soon, we will run out of land to construct them. Other technologies in disposing residuals must be utilized. Waste avoidance and reduction techniques like the 3R’s (reduce, reuse, recycling) and composting must strictly followed. With the right attitude and technology, zero waste is even possible.