Jusi, Arnel, F.Unpublished Masteral Theses, University of Nueva Caceres, City of Naga, 2001
Keywords: Bio- physical Impact of Mining

The study identified the bio-physical impact of ball clay mining in Del Gallego, Camarines Sur. Specifically it answered the following questions: (1) What are the dimension and characteristics of ball clay quarries? (2) What is the impact of ball clay mining along water and soil? (3) What factors are associated with the impact?

This study used the descriptive and comparative methods. Two types of data were compiled and generated: Secondary and primary data. The secondary data were composed of data coming from the different government and private offices. The primary data consisted of the actual dimension of the bal clay quarries, laboratory results f soil and water samples collected from pre-determined stations that were the selected during the pre-fieldwork phase. Base maps used were the 1:50,000 scale NAMRIA topographic map and available Land sat Images. Water parameters such as pH, temperature, TDS, TSS, TS, Conductivity, Resistivity and DO directly taken from the field utilizing the “SOLOMAT”. Soil and clay types were also determined taking two samples, ball clay and suspended solids, and analyzed for its clay content through X-Ray Defraction method. Vegetative cover verification was further conducted through the aid of available LandSat images. Vis a vis these activities, photo documentation was conducted.

The findings were: (1) An accumulated area of about 21,385 square meters (2.135 hectares) was disturbed by mining with an average quarry area of 1,000 square meters with an average dimension of 61.88 meters length, 30.55 meters width and depth of 3.33 meters. The extracted material (soil and ball clay) was mainly composed of the mineral Smectite and Cristobalite, a variety of Quartz some areas. (2.1) Impact on soil: removal of soil itself and existing flora, displacement / destruction of soil organism's niche and alteration of existing topography; removal of the soil's A – horizontal cuts off the subsurface flow of the water, lessened ground percolation, increased surface runoff and create sudden change in slopes, producing large pit holes and water ponding. (2.2) Impact on water: produced neutral to basic pH, high TDS at the upstream portion of Kilbay river and along Kilbay river; first order stream of Kilbay river had uniform temperature of 30 C and coole temperature at higher order streams than the order streams; increased DO at the lower portion of the river and uniform DO at other stream orders; conductivity range was 8.84 – 14.75 except along Katakian creek and adjacent new pit pond and low. (3.10 Associated environmental factors causing impact were: Rainfall triggered erosion produced high surface runoff and siltation rate; lesser vegetation and the number of stream order caused the dilution or concentration of water bodies. (3.2) Associated Organizational or policy factors causing impact were: poorly maintained and muddy barangay roads add more siltation problems; increased road networks increased quarry production; increased production increased the impact on the environment; other landuse, other than mining, may caused siltation and other impact.

Major conclusions were (1) A total volume of 70,520 cubic meters was quarried and approximately 12,150 cubic meters were accounted for where the difference in volume of 58,370 cubic meters were either uncounted or considered as waste. This unaccounted volume was also composed of Kaolinite with minor amount of Smectite and Cristobalite which is a potential source for siltation due to its fineness.(2.1) the high plasticity and less permeability of ball clay deposits resulted to less plant root penetration; increased surface runoff; created silted ponds (2.2) Ball clay quarries have partially affected the amount of Total Solids on the drainage system; produced slight siltation reaching the lower Kilbay river area; foliage caused variation in temperature; oxidized metallic consisting minerals/ elements in suspension produced high conductivity; high resistivity at lower Kilbay was due to influence of salt water intrusion. (3.1) The interplay of the different associated environmental factors (drainage, topography, vegetation, climate and the type and dimension of deposit) and the triggering mechanism for erosion (unimplemented rehabilitation activities, ore hauling activities and absence of proper mine plan) and poor road condition and related infrastructure contributed to the increase in quantity of suspended solids on the water environment. Environment ; earth moving activities (mining) and top soil alteration (agriculture) produced similar impact on the water environment.