If an area of territory is so situated that the construction, maintenance, and operation of a trunk sewer system and of a plant or plants for the treatment of sewage and the maintenance of one or more outlets for the drainage of it, after having been so treated, will be conducive to the public health, comfort, convenience, or welfare, the area may be incorporated as a sanitary district in the manner set forth in this chapter. Areas of contiguous or noncontiguous territory may be incorporated in a sanitary district.