A small municipal wellfield is to be developed in an unconfined sand aquifer with a hydraulic conductivity of 59 m/d, saturated thickness of 44 m, and a specific yield of 0.2. A service demand of 137 L/s is required from the wellfield, and the diameter of each well is to be 50 cm. If the drawdown in the aquifer is not to exceed 3 m when the wellfield is operational, develop a proposed layout for the wells. There are no nearby surface-water bodies.
Does this well meet the minimum screen diameter based on USBR 1995? If not, what is the minimum screen diameter? What is the maximum desirable screen entrance velocity based on Walton 1962?
