Groundwater in fractured granite for water supply to remote areas in Malaysia

Groundwater in fractured granite in Malaysia was found to be an economical source of water supply for various remote industries and communities. The uses include for agricultural processing, mineral water bottling, granite quarry, golf course irrigation and drinking water supply. Forty five tubewells belong to private companies operating in various places in the area were evaluated in terms of the yields and water quality. The wells were drilled using rotary air-percussion method to a maximum depth of 200 m and provided with 6 inch PVC casing and screens.

The productivity of the wells and the characteristics of aquifer were evaluated by pumping tests using a constant discharge rate and step drawdown methods. The average yield of the wells at allowable drawdown of 40 m was found to be 428 m³ per day. Results from water quality analysis indicate that the water is fresh with total dissolved solids (TDS) concentration between 101 and 150 mg/L. The hardness of the water varies from as low as 9.01 mg/L to a maximum of 337 mg /L. On the average the water is moderately hard with the hardness value of 73.17 mg/L. The water facies of the groundwater was found to be of Calcium-Sodium-Bicarbonate water.