KASAMA Vol. 13 No. 3 / July-August-September 1999 / Solidarity Philippines Australia Network

There are sulfuric deposits on Pinatubo. From a natural vent on its slope, sulfuric white steam is continuously emitted. Near this sulfuric mine, the Philippine National Oil Company (PNOC) had bored three test wells. All three holes were closed after the acidity level of the steam emissions were found to be too high for the piping system of the conduits.

Q. Was it geologically advisable to put up a geothermal project on the slopes of an active volcano?

The PNOC constructed a 30-kilometer road that cut through the rainforest of Pinatubo. On many points along this road heavy landslides and erosion were noted by a team of environmentalists in Mach 1990 who were on a fact-finding mission in the area.

Q. Should not PNOC be held ecologically liable for the damage to the mountain's flora and fauna, ecosystems, temperature gradients and climatic conditions?

The ranges and slopes of Pinatubo are the source of life and livelihood for the thousands of Aytas living in the vicinity.

Q. Was it constitutionally valid for PNOC to start a project in the area without wide and proper consultation with the Ayta community?

When the geothermal project was in operation, the Aytas were forbidden to enter restricted areas delineated by the PNOC for security and other reasons beyond the comprehension of the Aytas to whom the mountain is both spiritual heritage and ancestral domain.

Q. Was it morally right for PNOC to lay its claims on a mountain sacred to a cultural community?

Although several quarters have denied the possibility of linking the geothermal drilling with the hydrothermal explosion as a cause-and-effect chain of events, reservations have been made pending a thorough investigation.

Q. Should a positive and direct relationship between the two activities be established, would PNOC be held legally liable for the displacement of thousands of Aytas from their villages and settlements?

While science seeks to settle the question, the Aytas know in their hearts that, somehow, someone had intruded into the domain of their ancestral spirits and the sanctuary of Apo Namalyari (God the Creator).


Mount Pinatubo is located at 15008.20'N and 120021.35'E on the boundaries of three provinces - Pampanga, Zambales and Tarlac. It is one of 21 active volcanoes in the Philippines.

Pinatubo is part of the chain of volcanoes bordering the western side of the Zambales Range, a mountain belt that extends 220 Km from Lingayan Gulf in the north to Bataan in the south. The other major volcanic centers forming the chain are Mts Natib and Mariveles. Eruptive activity of the Zambales Range started 7 million years ago. Mt Pinatubo last erupted in 1380.

Among the three major volcanic centers, Mt Pinatubo is the highest, towering to about 1,745 meters above sea level. From its depths and its heights spring the life-giving and life-sustaining rivers that flow down the valleys and plains of the three provinces.

The Philippine Institute of Volcanology and Seismology (Philvocs) were only aware that the mountain was showing signs of restiveness on the fifth day after the initial hydrothermal explosion at the volcano's crater when, on April 4, 1991 a LAKAS representative travelled to the Philvocs national office to report their sightings. On June 12, 1991, Philippine Independence Day, seismic activity intensified and three major explosions occurred in the morning. This was accompanied by rumbling sounds and ejection of a huge, grey mushroom-shaped cloud. The major eruptive episodes on 12-15 June spewed out 35 km high columns of ash, steam and pyroclastic materials. Scientists estimate that it could take some 50 years before the forest of Pinatubo recovers.

Sources: Illustrations at top of page: Ayta Villages (left) and Map of Zambales (right), Eruption and Exodus; Luzon (centre), CPCA.
Bottom of page: Areas at Risk of Lahar Flow (left), Philippine Daily Inquirer, 17/9/91; Lahar fills the valleys of Pinatubo's western slopes, photo CPCA, 1993.
Text Above: Eruption and Exodus, LAKAS, 1991.