Determination of potential location for deep-groundwater drilling in Kutukan Village, Rejosari, Batur, Malang, East Java

Malang regency especially Kutukan Village, Rejosari, Batur district is one of the areas experiencing drought annually, due to limited groundwater. The purpose of this activity is determining the location of the potential to do well drilling exploration / production in the deep - groundwater based on geophysical and geological data in order to fulfill water needs in the area. This activities involved topographic mapping, geological and hydrogeological mapping, measuring the intensity of radon and geo electric survey. Lithological this area can be grouped into three units namely volcanic breccia unit, Limestone and Sandstone Unit. From the results of radon measurements values obtained ranged from 3 to 66.3 KBq/m³ indicating zones with high values (> 20 kBq) form a NE-SW trending lineament and NW-SE, the two zones intersect and are interpreted as fracture zone. From this data of fracture, then selected location resistivity measurement results with the best aquifers. Sandstone-2 with a resistivity value range 13-19 m expected to be a potential aquifer for allegedly being on the water-saturated conditions. The thickness of the layer of sandstone-2 is more than 29 m deep sandstone aquifer-top 2150 m. Obtained two potential points are located on site measurements RJS-11 (49m 675947mT; 9083547mU; 359.6 masl) with a depth of 163 m and the top aquifer thickness of over 29 meters, and the RJS-15 (49m 675 816; 9083324: 358.7 masl) with a depth of 160.8 meters and a top aquifer over 29 meters thick. (author)