WAT § 13606

If an application states that the applicant is not able to finance the local agency share of the project, the state board shall consider whether the applicant should be required to levy a sewerage service charge. If the state board determines a sewerage service charge is necessary to pay such costs, the state board shall not approve the grant application unless, as a condition to such approval, the applicant agrees to levy a reasonable and equitable sewerage service charge in connection with the proposed project.

Any such applicant, not otherwise authorized, is authorized by this section to levy a sewerage service charge pursuant to such an agreement, and shall levy such charge in the manner provided in the agreement.