The pump worked for 14 hours/day and the total water discharge that could be produced was 12,202.96 m3/day. Accordingly, the recommendation that can be given to the company is changing the broken pumps with 4 units of multi fall 420 pumps having operating speed 1,300 rpm and actual discharge yielded by the pump 871.64 m3/hour. The pump at the research site could not be operated anymore (broken).
Pit-1 Site Semambu had a catchment area around 469,317.15 m2 and a water discharge totally 61,238.81 m3/day derived from rainwater discharge of 48,530.48 m3/day and runoff water discharge 12,708.33 m3/day, whereas the capacity of the temporary accommodating pond (Sump) was 39,539.55 m3. The intensity of rainfall at the research site was 82.5 mm/hour having a rain duration averagely of 3.1 hours/day. The result of data analysis demonstrated that referring to the daily rainfall in 2010 – 2019 through the distribution of Log Person Type III, the maximum rainfall being planned was 508.019 mm/day within the return period of 5 years. The drainage system is applied at the Pit-1 Site Semambu is mine-dewatering carried out by draining the water into the sump so that it can be pumped out of the mining area and prevent the runoff from coming inside through an open drainage system (ditch). This sort of method will create a large basin that can accumulate water inside the mining pit. Tebo Agung Internasional Ltd is one of the companies in coal mining that employs the open-pit mining method. Based on this result, the PS-01 is the best point to make a well-exploitation on South Pandansari Pamsimas Project. Afterthat, we run 2D-pseudosection to know the distribution of groundwater layer in subsurface and get the thickness of groundwater is 20-50 meter with depth 40-80 meter. On PS-03, the water layer is indicated on the depth 30-60 meters with resistivity values equal than 52.8-70 ?m.
On PS-02, the water layer is indicated on the depth 50-100 meters with resistivity values equal than 18.7-40 ?m. After the acquisition on 3 points at Pandansari Village (PS-01, PS-02, PS-03), we get the result on PS-01, the water layer is indicated on the depth 60-80 meters with resistivity values equal than 36.7-50 ?m. From the results of current and potential difference measurements for each electrode spacing (AB/2) different then be lowered resistivity variations in the value of each layer below the measuring point (sounding points). VES Resistivity method is one of the active methods in geophysical study based on electrical properties of the subsurface rock by injecting electric current (I) into the earth and record the potential difference (?V) produced to the surface. In this case, we try to applied Vertical Electrical Sounding (VES) resistivity method with Schlumberger configuration on one of Pamsimas Project to answer that parameter. To obtain a good quality of groundwater, several parameter must be specified such as the depth of groundwater, thickness of the source, and resistivity value of rock. The demand of fresh water to develop of life community is very important, where almost all construction activities is required a water such as irrigating rice fields, building infrastructure, and to daily consumption.