Plant / Station Locator . SIEC Plants - - - - - - - - - - - - - - - - - - - - - Pasay Zamboanga Puerto Princesa Davao . SIEC Buying Stations - - - - - - - - - - - - - - - - - - - - - Zamboanga Puerto Princesa Mindoro Surigao . SIEC Buying Station - - - - - - - - - - - - - - - - - - - - - Tabaco, Albay