It is the intent of this chapter to assure an adequate supply of potable water for use on an individual lot, and to protect the public health by providing sanitary methods for the disposal of sewage on an individual lot. It is the general policy that connections must be made to community water supply and sewerage systems when such systems abut the lot, except when sewer or water service is unavailable by policy determination as stated in the county's comprehensive water supply and sewerage systems plan. It is intended that permits for individual water supply and sewage disposal systems will be issued only when community systems are unavailable, inadequate or connections are not economically feasible. (1979 L.M.C., ch. 46, § 8.)