Assessment of Tube Well Pumping Test Performance on Different Geological Formation
Keywords:Well pumping, Aquifer, Alluvium, Fractured Hard-rock
Water supply-demand is increasing in line with the increment in population. Natural water resources are declining due to a few factors of a reduction of water catchment areas, river pollution and drought. This causes the raw water quantity to decrease and its quality to be contaminated and resulting in higher water treatment costs. Groundwater usage is able to solve this problem due to its less pollution and requires minimal water treatment. The groundwater is preserved in aquifer within the geological formations, i.e., in the alluvium and fractured rock. However, the groundwater yield of each formation is unknown unless constructing the tube well and performed the pumping test. The study aim is to evaluate the tube well performance via pumping test on different geological formations. This research focuses on the effect of transmissivity, hydraulic conductivity, and efficiency of the aquifer, which are step-drawdown test, constant-rate test and recovery test in tube well in the geological formation of alluvium and fractured rock. Three well-pumping tests at each formation of alluvium and fractured rock were conducted at IBS Universiti Malaysia Kelantan (UMK), Kelantan, Sekolah Kebangsaan Chantum, Kelantan, Sekolah Menengah Kebangsaan Agama Tok Bachok, Kelantan, FRU Wakaf Tapai, Terengganu, Kampung Dada Kering, Kuala Lipis, Pahang, and Kampung Seri Gunung Pulai, Johor, respectively. The aquifer efficiency is obtained from the relationship between transmissivity and hydraulic conductivity. The suggested value of 75% efficiency is selected for presenting its well efficiency. The wells efficiency indicate that the alluvium formation was constantly higher between 9.39m3/h and 23.38m3/h. Meanwhile in the fractured rock formation were highly varied between 1.00m3/h and 32.33m3/h. The alluvium aquifer showed uniform water production compared to the fractured hard rock aquifer. Meanwhile, the water quantity in the fractured hard rock formation is unpredicted, which is subjected to the fractured rock characteristic.