ABSTRACT
It is necessary to understand some of the basic principles of groundwater hydrology before a water supply wellfield can be designed and successfully used. An understanding of the processes involved in the natural groundwater system is necessary to successfully develop raw water from any type of aquifer. An aquifer consists of porous rock or sediment that can store and transmit water in sufficient quantities to allow economic development. The type of aquifer and its response to pumping greatly influence the design of any wellfield, particularly one to supply a membrane treatment plant. When a large salinity change must be tolerated, it is necessary to design the membrane plant to treat the worst quality water or to use a different source of water supply during part of the year. If any substantial concentration of organic solvents or petroleum products is drawn into a well feeding a membrane plant, the membranes could be destroyed by the substances.
