ACLOBAN CITY, (PNA) — The Mines and Geosciences Bureau (MGB) has identified 40 hectares of abandoned Bagacay Mines site in Hinabangan, Samar for reforestation starting next year, an official said.
Romulo Babatugon, chief of the MGB regional mines management division, said in 2014, rehabilitation efforts will move to planting, after years of researches and experiments.
“After several studies, we will start covering some mine sites with coco coir to prevent erosions and organic materials and soil. We have to condition the acidic area before planting trees,” Babatugon said.
Among the species up for planting are narra, mahogany, acacia, mangium and ipil-ipil mixed with tiger and tambo grasses.
In 2005, several trees and grasses were planted in the 76-hectare mine waste dumps.
The vegetative measures failed with only one percent survival rate of the tree species planted. All grasses also died due to high level acidity, according to MGB.
“The grasses and trees had grown for a while but stopped when the roots reached the acidic soil beneath,” Babatugon added.
Research activities such as the re-vegetation trials and other environmental parameters have been studied and considered before the preparation of comprehensive final rehabilitation plan.
That included studies to determine proper forest and plant species adaptable to the area, soil amelioration that is conducive for forest and plants growth, final investigation on the characteristics of the acidic rocks and water of the abandoned site as well as the proper neutralization technologies for acidic water.
The mine has been blamed for degrading the quality of the Taft River causing fish kills, siltation, and overflowing leading to the inundation of agricultural land – and the death of crops – along its banks.
Rehabilitation works on the site, abandoned 21 years ago, include reforestation, mitigation of acid drainage, soil stabilization, construction of laboratory building and putting up of structures to stop soil erosion.
From 1956–1985, Marinduque Mining and Industrial Corp., which previously owned the property, operated the mine primarily for copper minerals.
In 1986, MMIC then entered into an agreement with Philippine Phosphate Fertilizer Corp., which in turn tied up with the Philippine Pyrite Corporation, a subsidiary of Philpos, which operated the mine from 1986 to 1992 for pyrite concentrates.
PPC ceased operation in 1992 due to the rising operational cost of recovery and labor dispute.
MGB records show that as of May 1990 the mineable pyrite reserves of the area were estimated at 4.4 million metric tons (mt) with an average grade of 35.27 percent sulfur.
Assuming that PPC extracted about 120,000 MT from 1990 to 1992, the remaining mineable pyrite reserves is estimated at 4,275,485 mt.