The granting of an approval and a certification of necessity by the department shall only constitute approval to establish, maintain, construct, and operate a sewer system within the proposed service area requested in the initial application for an approval and a certification of necessity, and shall in no way constitute approval or authority to establish, maintain, construct and operate a sewer system in any area which may be annexed at some future time by the applicant water district.

The granting of an approval and a certification of necessity by the department does not constitute approval of the engineering report or plans and specifications of any sewer system, and all plans and specifications and the proposed method of operation and maintenance for any sewer system must be approved by the department pursuant to WAC 246-271-050.