If a project will serve two or more municipalities, the applicant shall submit the executed intermunicipal agreement, contract or other legally binding instrument necessary for the financing, building and operation of the proposed treatment works. This instrument must set forth the basis upon which costs are allocated, the formula by which costs are allocated and the manner in which the system of allocating costs will be administered.
Nev. Admin. Code § 445A.772
NRS 445A.135