(1) All purveyors constructing or proposing to construct public water system facilities within the area covered by the coordinated water system plan shall comply with the plan.

(2) At any time after two years of establishment of the external critical water supply service area boundaries, the department may deny proposals to establish or to expand any public water system within a critical water supply service area for which there is not an approved coordinated water system plan. (Individual retail or direct service connections shall not be considered an expansion.) (See WAC 248-56-620 for provisions pertaining to new public water systems in the interim two years.)