Sulfuroxides Emission Control Measures at Calaca Coal-Fired Thermal Power Plant in the Philippines

Abstract

Funded by Japanese Exim Bank, Calaca Coal-Fired Thermal Power Plant Unit 1 in Calaca City, 115 km south from Metro Manila, Philippines started operation in 1984. Poor operation of the unit 1, such as overstocking of coal, resulted in fly ash and offensive odour over a neighboring village. In addition, noise and water pollution annoyed local people. Municipal assembly of Calaca City requested the NPC to stop operation of the unit 1.

In 1986, Philippine Government requested Japanese Government a concessional yen loan to establish unit 2. Having concern that local environment would further worsen, local people protested the establishment of the unit 2. Overseas Economic Cooperation Fund (OECF), Japanese implementing agency of yen loans, sent back the NPC's request for approval for the contract of construction of the once-approved project.

Philippines' emission standard system is complicated. If it is economically or technically impossible for the sources to meet the emission standards, which are equivalent to or even more stringent than that of developed nations, they are exempted from the standards. In such cases, the sources are required that concentration of pollutants in ambient air meet environmental quality standard. Calaca is this case, and this leads to misunderstanding of Japanese NGOs and mass media. They accused the Japanese government that the sulfurdioxides emission of unit 1 exceeded the emission standard and had violated the law, although the unit 1 and unit 2 in fact met Philippines' regulations. Japanese Government insisted on installation of flue gas desulfurizarion (FGD) equipment to the unit 2, which NPC strongly rejected.

Borrowing additional yen loans, NPC implemented its environmental improvement project, which did not include installation of FGD equipment. In 1992, Department of Environment and Natural Resources clearly stated that FGD was not necessary. OECF finally approved the contract of construction without FGD in 1993. Construction of unit 2 was completed in 1995 after overall delay in project implementation at 41 months. Simulation of sulfuroxides concentration in ambient air carried out by OECF in 1998 showed that the maximum concentration would not exceed the environment quality standard.