Application of Specific Capacity In Monitoring Groundwater Well : A Case Study of Kota Agung Groundwater Well

Maintaining the quality and quantity of the groundwater from the well is important aspect for the well sustainability. Well monitoring is mandatory for sustainable water management especially for the well with high iron and manganese that easily precipitate at well screen and rock surround well screen due to oxidation. Based on daily well flow rate and water level data, which recorded with electromagnetic flow rate and hydrostatic water level sensor, historically specific capacity data could be obtained. The study case in this paper take place at Kota Agung groundwater well on southern slope of Mount Tanggamus. The well has confined aquifer with lithology sandstone, fractured andesite lava and volcanic breccia as its aquifer and high iron and manganese concentration that enough to precipitate and clog the well screen and rock surround the well screen that impacted well efficiency. Based on historical specific data of the well, well efficiency that impacted by iron and manganese clogging can be predicted without knowing the visual condition of well screen. Decreasing of specific capacity has direct correlation with the well screen clogging and validated by the video logging. By using specific capacity data we don’t need to perform video logging borehole camera to know well condition. In addition to that, by monitoring specific capacity data, well efficiency can be predicted and well maintenance schedule can be defined to restore well to its initial condition.