Recent development project initiated by Rio Tuba Nickel Mining Corporation (RTNMC) under its Social Development and Management Program (SDMP) focused on determining the presence of water-bearing materials as potential source of groundwater for the host and neighboring communities of Barangays Rio Tuba and Ocayan in Bataraza, Palawan.
In pursuing this undertaking, RTNMC requested the technical services of the Mines and Geosciences Bureau (MGB) MIMAROPA to conduct a vertical electric sounding (VES) survey in search for potential groundwater resource in Sitio Racub, Barangay Rio Tuba and Sitio Marangres, Barangay Ocayan.
A team of geologists from the Geosciences Division was deployed on January 8-12, 2018 to conduct the said survey in the area which has been identified as relocation site for the fire victims from Sitio Marabajay.
The results of this geophysical study will determine whether it is feasible to conduct more detailed tests in relation to the productivity of a water-bearing layer in the area. This method is simple, cost effective, and reliable in determining the presence of water-bearing materials under the surface.
The VES method is a one-dimensional electrical resistivity surveying technique used to observe variations in resistivity with depth at a single point location. The effectiveness of this method in the detection of aquifers is anchored on the generalization that most aquifers are laterally extensive and fairly homogeneous in composition. Lithologically, the lowland area of Bataraza is mostly comprised of hard, impervious ophiolitic rocks overlain by potentially water-bearing sedimentary units (aquifer). The survey aimed to determine the occurence, thickness, and spatial distribution of these aquifers and to propose recommendations in optimizing drilling programs prior to well construction.
Based on the results of the georesistivity survey, MGB MIMAROPA recommended that both sites have good groundwater potential and that drilling should be conducted for further assessment of the productivity of the aquifers present. Controls regarding the depth of drilling should be imposed to reduce the well’s susceptibility to saltwater intrusion – 100 mbgl depth for the site in Sitio Racub, and 20m for the site in Sitio Marangres. Detailed physico-chemical analysis of water samples was also recommended to determine the possible uses and restrictions for the groundwater.
By: MGB MIMAROPA