Revisiting the Boac River:
Clear Waters Now, More Dangers Lying Ahead

Thousands of farmers and fisherfolk in Marinduque woke up one day five years ago to find the river of their life gone. By what a mining firm said was an accident, toxic mine tailings began to defile the Boac and, later, Makulapnit Rivers for several kilometers and since then, the tragedy has changed their lives. The company promised some compensation and a rehabilitation plan. However, the issue is far from being solved as environmentalists, scientists and local folk are not satisfied with the way the river’s rehabilitation is managed – a concern even the United States Geological Survey has confirmed. Bulatlat.com revisited the rivers and villages affected last week and filed this report.

By Zelda Soriano

Five years after it messed up the Boac and Makulapnit Rivers in Marinduque, the controversial multinational mining firm, Placer Dome, Inc., is currently gearing up efforts to clean up the rivers. The Canadian firm, which was in a partnership with the local Marcopper Mining Corporation (MMC) when the disaster happened, is now working with the Mines and Geosciences Bureau (MGB) to haul the remaining mine tailings back to where it came from – the Tapian Pit.

Although the clean-up strategy is yet to be announced by the Department of Environment and Natural Resources  (DENR), preparations are underway as the MGB submits to the latter its latest tailings inventory.

Based on the inventory, the volume of mine tailings is now down to 703,228 cubic meters from the original 1.3 million cubic meters. Some non-government organizations (NGOs) had earlier estimated the original tailings volume at about 3.5 million cubic meters. Most of the tailings have been washed out to the nearby Tablas Strait by natural processes, no thanks to the mining firm.

Today, the MGB describes the tailings volume at the Marinduque rivers as “manageable” while Placer Dome brushes aside any potential danger it could pose to the island folks.

But both the DENR and the mining firm may be speaking too soon – or they could just be showing the brighter side of the picture. Some groups of scientists and environmentalists continue to raise environmental concerns and long-term negative effects of the 1996 tailings spill at the Boac River. Although the waters at the Boac River appear to be clearer now than when disaster struck five years ago, many Marinduqueños are still worried about its safety.

Looking back

On March 24, 1996, about three million cubic meters of mine tailings from an open pit of the MMC spilled over Boac - the biggest river in the island province of Marinduque.

The whole stretch of the 30-kilometer river was buried with slurry materials claimed by MMC as “a harmless mixture of sand and water.” Soon, however, the company’s efforts to dispel any environmental threat collapsed as the magnitude of the damage began to show. An environmental investigative mission conducted weeks later by a Quezon City-based NGO, the Center for Environmental Concerns (CEC)-Philippines, found toxic minerals, various chemical reagents and other effluents in the tailings.

Mud and dirt virtually killed the river – once Marinduqueños’ source of irrigation, kangkong farming, fishing, laundry and bathing.

Initially, Marcopper-Placer Dome constructed  a kilometer dredge channel at the Boac River delta to minimize the dispersion of tailings. But that was it. Since then, no river clean-up had been made as most Marinduque farmers and other residents rejected the mining company’s plan to reroute the tailings to the Tablas Strait by a sophisticated-sounding method - managed submarine placement (MSP).

The disaster ruined the lives of the 31,000 farming and fishing families living in 25 barangays (villages) along Boac and the intersecting Makulapnit River. To prevent public shock from turning into fury, the mining firm promised compensation to many of the affected families.

The facilitating NGO, Marinduque Center for Environmental Concerns (MACEC), however, complains of delayed and incomplete payments. Beth Manggol of MACEC says that only the 1996 and 1997 damages were computed and being paid for by Placer-Dome - by installment. The prolonged impact of unrehabilitated rivers from 1998 up to now were unaccounted.

Placer-Dome insists on paying only the 1996-97 damages saying that the prolonged impact of the dirty river in not its fault. “We were ready to clean up the river by managed submarine placement method but the people refused,” a company spokesman explained.

New life?

Meanwhile, “signs” of new life are beginning to show in the Boac River. Once more, small fishes could be seen in what appear to be clear waters. Although the river remains shallow in most parts and hardened tailings mixed in natural sediments are definitely present in river banks and beds, a thin vegetation is growing along the river.

In an ocular inspection by Bulatlat.com last week, some Boac residents were seen using the river again for laundry and bathing.

A recent tailings inventory by the MGB says that “a relatively manageable amount of tailings are scattered throughout the whole stretch of the rivers. The bulk of the tailings are concentrated inside the dredge channel and at the north and south estuaries. Most of the tailings along the Boac and Makulapnit Rivers are concentrated in spill-overs, levees and patches.”

Asked if these manageable tailings could still endanger human and marine life, Mining Engineer Rodolfo L. Velasco, Jr. of the MGB”s Mining Environment and Safety Division (MESD), answered: “If the tailings are under water as in the case of Boac River at present, and so, the tailings are not exposed to sun and air, then the tailings would not be oxidized and these will not cause the acidity of the river.”

He also said that the discharges at the Boac River are covered by a layer of soil materials which secure the tailings from oxidation.

Based on the inventory, the DENR recommends that the remaining tailings be diverted back to Tapian Pit and sealed with very strong structures.

With these developments, a Placer Dome Technical Services official commented that the 1996 spillage had only become an emotional issue. Now, he said, there is no more danger of any kind in the Boac River and that it can be tapped again for agricultural and domestic purposes.

The company official appears to be singing a different tune, however. In random interviews, many Boac residents still doubt the river’s safety.

Toxic

To verify their concerns, Bulatlat.com asked some scientists of the National Institute of Geological Sciences of the University of the Philippines (UP-NIGS) in Diliman, Quezon Ciry. Contrary to Placer Dome and MGB’s opinions, UP NIGS Director Joselito P. Duyanen says oxidation is possible in the underwater tailings of the Boac River.

“As long as there is pyrite, the mineral that could combine with oxygen in air, a chemical process of oxidation occurs,” explains Duyanen. “It is simply iron in minerals, iron as in rust plus oxygen equals iron sulfate.”

He adds that oxygen, although absent under water, could be brought in by rainfall since rains carry dissolved elements of oxygen. Rains mixed with waters in Boac River could contain the oxygen elements necessary to oxidize the embedded pyrite in the tailings.

Deputy Director Victor B. Maglambayan of UP NIGS validated the methods used in the MGB tailings inventory and said that “nature has its own way of recuperation.” Tailings are a long-term source of acidity, he added. “When the waters of a river become acidic, fish, plants and also human beings could be toxicated,” he also said.

Earth science publications say that in many mineral deposits like Marcopper’s, which contain sulfide minerals such as pyrite (an iron sulfide) or chalcopyrite (a copper-iron sulfide), a primary concern is the formation of acid rock drainage (ARD). When sulfide-bearing mineral deposits are exposed to the atmosphere by mining (or naturally by erosion), the sulfides react with oxygen and water to form ground and surface waters having elevated concentrations of sulfuric acid (and correspondingly lower pH values).

Mining can greatly accelerate the formation of ARD in waters that fill open pits after mining, and that drain sulfide-bearing underground mine workings, mine waste dumps or mill tailings deposits.

Environmental mission

As early as 1996, concerns on the toxicity of the tailings had been raised primarily by the CEC. In its investigative mission in May 1996, it debunked Marcopper’s claims that its “mill residue was largely inert materials and that chemicals used in the recovery process was in small quantity”.

The CEC mission reported: “The nature and character of the ore are sulfides of copper (chalcopyrite), iron (pyrite), zinc (sphalerite), lead (galena), and cadmium. The mineral content of their tailings comprises a wide range of sulfide minerals that are not subjected to any recovery process because their primary concern is to recover the copper from the ore through the flotation process. Roughly 25 percent or more of these sulfide ores are left in the mine tailings. While it is true that silicates may be present as inert materials in the mine tailings, the sulfides are oxidized producing acid salts which are toxic.”

It went further: “The claim that chemical reagents used in the flotation process is not toxic is deceptive. If amount used is reckoned based on the daily tonnage of their concentrator which ranges from 23,000-25,000 MT per day, then on the average, Marcopper is consuming 192 kilos of dithiophosphate and 144 kilos of Xanthates daily. At this volume, the chemical reagents become toxic. Aside from this, these chemicals are used as ‘collectors’ which are discharged along with the mill tailings since there was no mention about recovery of these reagents. Once exposed to the environment, chemical reaction of these reagents with other elements present in the surrounding environment will likely produce carbon disulfide, both considered to be highly toxic. The stench emanating from the mine tailings which resembles that of a rotten egg confirms the presence of hydrogen sulfide.”

Five years later, the United States Geological Survey (USGS) raised the same environmental concern on possible leaching of acid and metals from the tailings into the Boac River. In May last year, the USGS team carried out a simple leach test, acidity and conductivity measurement as well as chemical analysis. Results revealed that the leach waters are acidic (pH3.72) and have very high levels of a variety of heavy metals such as copper, aluminum and manganese.

The USGS also reported  that extensive soluble salts observed in the tailings deposit can dissolve quite easily, and could therefore potentially cause an environmentally damaging flush of acid and metals from the tailings into the river during rain storms. Little or no fish and invertebrate aquatic life was visible in the Boac River in its middle stretches.

“This lack of aquatic life indicates that the repeated flush of acid, metals and sediments from the tailings during rainy periods is having a detrimental impact on the river system,” the American team said.

The tailings deposits are also a potential source of acid and metals into ground water near the river, according to the USGS. Following this, then it has also potential danger on food crops and on the marine environment.

“It is possible,” says USGS, “that the clear, deep green color of the Tapian and San Antonio Pit waters is indicative of high levels of dissolved ferrous iron and copper.”

Although water is still accumulating in the pit lakes, the USGS feared that “that acid ground waters are also migrating down gradient from the pits along fractures and other zones of permeability. These waters are a potential concern if they are migrating far enough away from the mine site to affect ground water quality in domestic wells, or if they discharge via springs into local surface waters.”

However, Orlando Cruz, Vice President for Corporate Affairs of the Placer Dome Technical Services, former partner of Marcopper during the 1996 spill, dismissed the USGS allegations.

In a Bulatlat.com interview, he said: “We don’t use the toxic chemicals like cyanide and mercury. In the first place, these chemicals are used only in further refining processes to produce gold for one or to produce 99 percent copper. These processes are being done in Japan and elsewhere; definitely, not in Marinduque.”

Cruz also added that Marcopper and Placer Dome have been constantly conducting water tests and monthly inspection of acidity as well as chemical analysis in water samples of the Boac River. “There is no danger of any kind as shown in our monthly monitoring results,” he stressed.

Back to Tapian

Placer Dome, he also said, stands by the managed submarine placement as the safest and practical way to clean up Boac and Makulapnit Rivers. Although he admitted that the mining firm is preparing for the new option recommended by the MGB, he finds the idea of returning the tailings back to Tapian Pit as simply “silly.”

“Doon na nga galing ‘yung tailings, doon pa rin ibabalik? May potential dangers din ang hauling process at isipin mo napakalawak ng bundok na hahawanin to build roads to transport the tailings. Ang Tapian Pit kasi ay nasa taas ng bundok at ang bundok na iyon ay very steep (Why to you remove the tailings back to where it came from? There are potential dangers of this process given that the mountains are so steep on which to build roads to transport the tailings),” explained Cruz.

He clarified, however, that these are his personal opinions. If the latest option is the most acceptable among Marinduqueños, then Placer Dome will comply, said Cruz.

The new method is yet to be approved by DENR’s top officials. Since it is unannounced yet, Marinduque folks are unprepared to give any comment.

The USGS, contracted last year by the Marinduque provincial government to conduct a comprehensive and in-depth study on the state of the Boac and Makulapnit Rivers as well as the mining impact in Marinduque at large, is hindered by lack of funding sources.

Placer-Dome refuses to fund the USGS missio, maintaining that the company’s only responsibility is to what is approved by government agencies - referring to the MGB and the DENR - and limited to the Boac and Makulapnit Rivers rehabilitation, not to the whole island province.

Meantime, some natives are already using the river - unaware of the hazards posed by oxidation and other chemical processes in its waters.

Maglambayan of UP NIGS reflects on the broader implications of the problem: “Ang talagang problema kasi sa ganitong mga isyu, walang malawak at malalim na scientific knowledge ang mga tao. Paano maiintindihan ang potential danger tulad ng kaso sa Boac at paano mapipili ang tamang solusyon sa problema kung hindi alam ng mga tao  ang mga basic scientific concepts? Sana huwag tumagal ulit ng five years bago magkasundo sa best option at di matulad sa nakaraan na sa dinami-dami ng nakialam sa isyu, wala ngang nangyaring clean-up (The problem is the people cannot understand the issue scientifically. Without this, the people are unaware of the potential dangers at Boac and can’t come up with the correct solution. I hope agreeing on the best solution won’t take five years. Despite the fact that several groups are involved in the issue, no clean-up has ever taken place).” Bulatlat.com