Position paper against mining in Rapu-Rapu


A. Acid Mine Drainage (AMD) as a consequence of mining activities in sulphide-bearing rocks is confirmed both at Pagcolbon (present mining exploration) and upper slopes of Sta. Barbara (formerly known as Carogcog Saday representing past and abandoned mining site of Hixbar Mining Co.).

AMD is water polluted with high levels of iron, aluminum and sulfuric acid. It appears orange or yellowish-orange or orange-brown in color due to high levels of iron content. It also smells like rotten egg which is due to the emitted sulfur dioxide. AMD occurs when the mineral iron pyrite (FeS2) is exposed to air and water.

  2FeS2 + 7O2 + 2H2O    ---->     2 FeSO4 + 2H2SO4   

Thus, the reaction forms iron sulfate (FeSO4) and sulfuric acid (H2SO4). Such reaction is hastened by the presence of a bacteria (Thiobacillus thiooxidans) and converts sulfur in a reduced form to sulfate (Jackson and Jackson, 1996).

Research Associates of the INECAR conducted a scientific study on the potential for AMD in the island of Rapu-Rapu during the second week of May, this year. Two professors and two college teachers composed the team. The two professors are: Dr. Emelina G. Regis (the undersigned) and Dr. Melanio M. Regis. The two other teachers are: Engr. Irma Medrano and Ms. Au Azurin. A brief educational background and their expertise are provided in Annex C. In this study, three sites were investigated: a) Creeks at the Hixbar mining Area (Carogcog Saday) and immediate surroundings representing impact of past and abandoned mining activities, b) Creek at Pagcolbon and surrounding area representing impact of the present Lafayette mining exploration and c) Creek at Sta. Barbara and the adjacent barangay proper. This creek (c) is not directly connected to the contaminated creek from the Hixbar mining area and represents clear water creek. [please see Figures 1, 1a), 1b) and 1c) in attached map]


Fig. 1 Location of the Study Sites: 1.) Creeks at Hixbar mining Area 2.) Creek in Lafayette mining area 3.) Creek at Sta. Barbara
 

Fig. 1b) Mina creek at Hixbar in Carogcog Saday/ #1 in Map

Fig. 1a) Creek at Pagcolbon just below the field office and processing area of Lafayette. #2 in Map

 

Fig. 1c) Part of the clear water creek at Sta. Barbara. #3 in Map

 

 
 

The findings of the study show acidic water and soil in both the Hixbar (Site 1) and Pagcolbon (Site 2) creeks; neutral pH was recorded for the creek at Sta. Barbara (Site 3). [Please see Annex A for the values: neutral pH is 7.0; the lower the number the more acidic the material, the higher the number, the less acidic but the more basic/alkaline the material]. Thus, the initial suspicion of Acid Mine Drainage (AMD) occurring in the area is confirmed. AMD is occurring in the 2 creeks originating from the Hixbar area; AMD is also occurring in the creek at Pagcolbon which is located just below the field office and processing area of Lafayette Mining Company. [Please see Figures 2 to 6a) below]

 

Fig. 2: Contaminated creek (Pulang Salog) at Hixbar 120 meters above sea level (asl)

Fig. 3: Contaminated pond at Hixbar mining 300 meters asl.

Fig. 4: Orange-Brown water and silt indicating AMD, coming out of a canal inside the field office of Lafayette Mining company (taken Jan. 23, 2000)

Fig. 5: View of the field office (indicating by a red arrow) of Lafayette Mining Co. just above the contaminated creek (picture taken May 9, 2000)

Fig. 6: Contaminated creek at Pagcolbon just below the field office and processing area of Lafayette Mining Company at 70 m asl. (picture taken May 9, 2000)

Fig. 6a Part pf the contaminated creek mentioned in Figure 6. Note the yellowish-orange-brown condition of the creek's botton sediments and coating on rock surfaces.

 

 
 

As reported earlier, AMD is a "perpetual pollution machine" because of its potential for long term devastating impacts on rivers, streams, and aquatic life (http://www.miningwatch/ emcbc/library/amd_water.htm). This acid dissolves the heavy metals such as lead, zinc, copper, arsenic, mercury and cadmium, found in waste rocks and tailings. The presence of certain bacteria is able to increase the rate of the reaction (http:/biology.usgs.gov/s+t/SNT/ noframe/co115.htm; http://www.wsn.org/miningpledgefacts.html)

At present, the first world countries maintain that there is no effective treatment of AMD with existing technology (Environmental Management Council of British Columbia on line: http://www/miningwatch.org/emcbc/library/amd_water.htm) . Below are some examples of proposed treatments/remediation and their problems.

  1. The proposed treatment by seawater enhances the released of heavy metals. Hamelink (1994) reported for instance that in the dredged mud of Hamburg Harbor, 1.3% of the total Copper (Cu) was released upon the addition of seawater. Likewise, in a experiment using seawater treatment, 9.1% of the total Zinc (Zn) was also released to the surroundings.
  2. In the case of Deep Sea Tailings Placement (DSTP) which is the intended method of Lafayette [ TVI Press Release October 13, 1999], the effect is on the biodiversity of marine organisms.

    In the report provided by Environment Canada (Briefing Document on Metal Mine Submarine Tailings Disposal [March 22,1996]), to the Environmental Mining Council of British Columbia, Canada, the BHP Minerals' Island Copper Mine near Port Hardy had been using marine dumping for its wastes for years until its closure in 1996. The effect on the aquatic life of the sea floor at the site was low abundance and diversity of organism (http://www.miningwatch.org/emcbc/library/amd_water.htm).

    With the present situation of dwindling fishery resources in the Philippines, we cannot afford to risk destroying what is left of our marine resources because food security is a basic necessity. Even in the absence of jobs, when food is abundant in a resource, our people could still survive.

  3. If the method is to prevent exposure to oxygen by submerging the waste rock or tailings under water, the water cover and structure of the dam must be made strong enough to withstand geologic hazards such as an earthquake. In high seismic area, the potential for breaking the dam structure and cover is very likely (http://www.miningwatch.org/emcbc/library/amd_water.htm). Figure 7 shows that the island of Rapu-Rapu has one existing fault in the area crossing Binosawan-Malobago points between the Western Deposit and Main Deposit. Any seismic activity strong enough to move this fault can break the cover and dam structure and release toxic metals to the surroundings and eventually to the sea. Perhaps this method is possible in Australia and other large continents that do not experience earthquakes.

  4. Other covers (wet and dry) being proposed by Nick Currey (1998) is still in the trial stage. Wet cover is done by placing acid producing rocks under water to reduce contact with oxygen. However, this method also promotes an anoxic (no oxygen) condition that encourages the growth of anaerobic bacteria forming H2S. As a consequence, another environmental problem is created which is pollution (both air water and soil, the latter two are by wet deposition) through the release of atmospheric sulfur. (Manahan, 1994). Furthermore, where sulfide formation occurs, the sediments become black due to the formation of FeS. (Figures 8 and 9)

    Fig. 8: Black coating on the surface of exposed rocks at about 300m. asl in Hixbar Mining area.

    Fig. 9: Black coating on a man-made structure at the bank of Pulang Salog in Sta. Barbara at 120 m. asl



  5. The use of Sulfate Reducing Bacteria (SRB) for active treatment of contaminated groundwater (from mines) [Robertson, 1998] cannot solve the problem of heavy metal contamination. SRB is able to methylate heavy metals such as mercury (Manahan, 1994; Jackson and Jackson, 1996) making them readily absorbed by plants and eventually remobilized through the food chain. The methylation of mercury in aerobic and anaerobic forms for instance increases its toxicity, posing a danger to living organisms including man.
  6. Lastly, remediation is very expensive so that mining companies tend to disappear after mining ceased.

 

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Ateneo de Naga University