The purpose of the chapter is to present alternatives for supplying drinking water to a municipality when its normal supply is contaminated. The term alternative refers to any alternate source and includes both new supplies or treatment of the existing supply. The technological approaches described are often used when an existing supply is found to be contaminated. Among the various alternatives that might be considered are: (1) development of new or existing water resources; (2) blending of a new and contaminated water supply to achieve safe levels; (3) treatment at the well head or each point of consumption; (4) connection to alternative existing municipal or private supplies; (5) oversized community storage facilities to compensate for loss of existing system capacity; and (6) alteration of existing groundwater flows.