Recently, farmers and fishermen in Candaba have complained against the alleged illegal dumping of waste in the Candaba River by a big piggery in San Miguel, Bulacan. The Environmental Management Bureau (EMB) of Region 3 has already acted on the complaint with no less than director Lormelyn Claudio personally visiting the piggery. In Sta Cruz, Porac, residents are launching a crusade dubbed "Krusada Kontra Amoy" to stop the stench emitted by piggery farms in their community.
The world is really getting smaller. Housing projects are advancing into far-flung areas where most large poultry farms and piggeries are located. With such a mix-up, conflicts are bound to happen. Also with the congestion in many rural communities, backyard piggeries are starting to be a nuisance. Around 80 percent of domesticated pigs in the Philippines are still raised in backyard piggeries.
But problems to some are opportunities to others. The waste can actually be put to good use. Using existing technologies like biogas digesters and lagoons, pollution can be controlled.
The lagoon system, a dug-out pond with a 1:5 width to length ratio, is a simple method of treating waste mainly through the actions of microorganisms. The digestion of organic materials by anaerobic bacteria produces methane or biogas, which can be used for cooking, heating or even for generating electricity.
About four years ago, I visited a community waste management project in an exclusive subdivision in Parañaque.
The homeowners association turned their open space into an ecological waste management showcase. In addition to waste segregation and composting systems, they put up a small piggery to take care of their kitchen waste. The hog waste was used to generate biogas, which is used to fire up the stove in the caretaker's kitchen. Simple and inexpensive materials were used. A plastic tarp is used to cover the hog waste pit. Biogas is captured inside the tarp and piped to the kitchen.
The Bureau of Animal Industry (BAI), through its Research Division, has developed a simple and affordable biogas technology, which they call Tubular Polyethylene Digester (TPED). It is popular among small hog raisers with six to 20 pigs. This low-cost system can make backyard hog-raising sustainable and environment friendly. Those interested in this technology may call Mr. Hernando Avilla of the BAI Research Division at (02) 920-5053. I spoke to him last Wednesday and he is very much willing to give more information about TPED. I learned from our conversation that he is also a member of the Recycling Movement of the Philippines.
On a larger scale, Maya Farms which has some 60,000 pigs, was able to harness biogas as a replacement for Liquefied Petroleum Gas (LPG) and to generate electricity for its deep-well water pumps, feed mixers and some other electric equipment. The farm, which is located 40 kms from Manila, started experimenting on the industrial uses of biogas after the oil crisis in 1973. The generation of biogas was so efficient that in 1982 it was able to cut-off its electrical connection from the Manila Electric Company and has since been running on self-generated power resulting in huge savings.
The sludge, a mixture of anaerobically fermented organic waste and water discharged from the digester, was also utilized. Because it is rich in nutrients, the solid portion was turned into animal feeds and commercial fertilizer. Since feed cost usually represents more than half of production cost, using the dried sludge will significantly bring down cost. Around 10-15 percent of this dried sludge was used for pigs and cattle and 50 percent for ducks.
The liquid portion was used in fishponds for tilapia production. The nutrients in the liquid will cause the growth of algae and phytoplankton, which serve as food for fish. The volume of liquid is controlled because excessive algal growth will cause oxygen depletion in water. Maya Farms claimed that with just the plankton and hog feeds as fish food, the fishponds yielded about two tons of tilapia per hectare every three months.
Drawing from these experiences and resources, I'm sure we can come up with a win-win solution to our present piggery waste problem.
