Changes in groundwater levels in the indutrial area were seen on ground air maps from the Directorate of Environmental Geology in 2003 and 2010. Digitization of groundwater level maps was carried out and then the changes were analyzed for getting the volume of water used. Time-lapse microgravity is sensitive to density changes. To get the value of density changes of groundwater, we need information such as rock porosity and water density. In this case we assumed that the porosity value is 30% and the water density value is 1 gr / cc, so the value of water density changes is 0.3 gr/cc. The value of density changes is distributed across the entire volume of groundwater changes during 2003 to 2010. The volume of groundwater changes in interval 2003 to 2010 was around 33,971,200 m3. From calculation of time-lapse microgravity for geometry the reduction of groundwater in the Dayeuhkolot industrial area shows the highest value about -125 microGal. The time-lapse microgravity of the Dayeuhkolot industrial area during 2003 to 2010 shows a value -125 microGal which is very detectable with a gravimeter like Scintrex CG-5 which has accuracy up to 1 microGal.

Pangalengan is located between 107 o 29'-107 o 39 'BT and 7 o 19'-7 o 6' LS. Based on its topography and geological condition, Pangalengan has steep slopes and lies between two strike-slip faults. Average annual rainfall of this area is about 1,996 mm with 5.47 mm of average daily rainfall. The area is about 27294.79 hectares with population of 148353 inhabitants. According to these data, Pangalengan has high risk of landslide. Landslide occurred in Pangalengan on 05-05-2015 at 14:00 pm, caused 9 fatalities, 4 people seriously injured, 134 people evacuated, 10 houses buried, geothermal steam flow pipe of Energy Star damaged. It is necessary to analyze slope morphology and study the potential hazard areas of landslide. The result shows that Cibitung which has steep (35o-45o) and very steep (45 o-65 o) slope is prone to landslide with an area of ± 3038 hectares spread to the south.

In open mining systems, the most important problem in mining production activities is surface water management, where surface water management is an integrated water management activity with the aim of minimizing the negative influence of surface water which consists of mine drainage methods, mine drainage, sediment separation and control. Geographic Information Systems (GIS) can be used for hydrological analysis using spatial data, especially in calculating runoff discharges from surface water. The method used in calculating runoff discharge is in the form of daily rainfall data. This rainfall data can show the influence of the catchment area which is useful for knowing precisely and accurately the runoff water discharge. Geographic Information Systems (GIS) are used to calculate variables in rational formula equations by overlay analysis. Information about digital-based hydrological conditions is very useful as a means of decision making and policies undertaken in monitoring hydrological conditions in open mines. By using a geographic information system (GIS) with a geodatabase attribute, it can be used to view general conditions in a mining area in monitoring hydrological conditions. So it is very appropriate to be used as hydrological monitoring in the mining area in making decisions that are fast, precise and accurate. Apart from that the geodatabase attribute can see the actual conditions of a mining area.

Abstract. In its production activities, this company uses 1 unit of Caterpillar 345 GC excavation equipment which has been used for production for 2 years and 3 units of new Hino 500 New Ranger FM 260 JD production for 4 years. The condition of mechanical equipment that is classified as old and unfit for operation due to frequent breakdowns and requiring special maintenance and equipment operating costs are getting bigger, Of course it will affect productivity and production which will decrease. Therefore, so that the mining activities carried out are not disturbed due to equipment problems that often experience damage, it is necessary to replace the equipment. In planning the replacement of mechanical equipment, it is necessary to conduct a technical and economical study. For a technical study, it includes a study of equipment production, and for an economic study it includes operating costs, as well as ownership costs, Present Worth Cost value and Production Unit Cost value. Based on the results of a technical study, the digging tool has a work efficiency of 49.86% with a production of 271,384.18 BCM/Year and the old conveyance has a work efficiency of 86.03 % with a production of 270,996.93 BCM/year, As for the new means of transportation, it has a work efficiency of 86.95% with a production of 305409,91 BCM/Year. Based on the results of the economic study, it was found that the operating costs of the old conveyances were Rp 621,884,172.20 /year, and for the operating costs of the new conveyances, it was Rp 552,566,994.26 /year. In addition, the results of the calculation of Production Unit Cost for old transportation equipment are also obtained, which is Rp 3,100.46/BCM, while for new means of transport it is Rp 2,585.07/BCM. Abstrak. Dalam kegiatan produksinya perusahaan ini menggunakan alat gali-muat Caterpillar 345 GC sebanyak 1 unit yang telah digunakan untuk produksi selama 2 tahun, 3 unit alat angkut baru Hino 500 Ranger FM 260 JD baru yang sudah beroperasi selama 4 tahun. Kondisi dari alat mekanis yang sudah tergolong tua dan tidak layak beroperasi karena sering terjadi kerusakan dan membutuhkan perawatan yang khusus dan biaya operasi alat semakin besar, tentunya mempengaruhi produktivitas dan produksi yang akan semakin menurun. Oleh karena itu agar kegiatan penambangan yang dilakukan tidak terganggu karena masalah alat yang sering mengalami kerusakan maka perlu dilakukan penggantian alat. Dalam merencanakan penggantian alat mekanis maka perlu dilakukan kajian secara teknis dan ekonomis. Untuk kajian teknis meliputi kajian produksi alat, serta untuk kajian ekonomi meliputi biaya operasi, biaya kepemilikan, nilai Present Worth Cost serta nilai Production Unit Cost. Berdasarkan hasil kajian teknis, alat gali-muat mempunyai efisiensi kerja 49,86% dengan produksi sebesar 271.384,18 BCM/Tahun dan alat angkut lama mempunyai efisiensi kerja 86,03% dengan produksi sebesar 270.996,93 BCM/Tahun, Sedangkan untuk alat angkut baru mempunyai efisiensi kerja 86,95% dengan produksi sebesar 305.409,91 BCM/Tahun. Berdasarkan hasil kajian ekonomi didapatkan hasil biaya operasi alat angkut lama sebesar Rp 621.884.172,20 /tahun, dan untuk biaya operasi alat angkut baru adalah sebesar Rp 552.566.994,26 /tahun. Selain itu didapatkan juga hasil perhitungan Production Unit Cost alat angkut lama yaitu sebesar Rp 3.100,46/BCM, sedangkan untuk alat angkut baru yaitu sebesar Rp 2.585,07/BCM.

Bandung basin is the center of the population at West Java, and several Industrial areasis. In supporting its sustainability, water needs is one of the factors that must be fulfilled. The water needs are obtained by taking water directly from groundwater. Excessive extraction of groundwater can cause damage, the impact of which is the more difficult it is to obtain groundwater and cause environmental disaster in the form of land subsidence. Using the vertical gravity gradient technique in the Bandung basin area is expected to map the critical groundwater damage zone. The results from the vertical gravity gradient area of the Bandung basin map, the region of groundwater with critical status are found in almost all cities, except in the Baleendah area to Ciparay and Soreang to the south of Cimahi.