If the proceedings for exclusion have been initiated by petition, such petition may be granted by ordinance of the board of directors of such district. If such proceedings have been initiated by resolution, the board shall hear all persons interested in the proposed exclusion who appear at the hearing, which may be adjourned from time to time, and after the conclusion of the hearing, the board may determine by ordinance that such area should be excluded from the district. No petition for exclusion may be granted and no ordinance of exclusion adopted by the board if such proceedings have been initiated by resolution unless and until the board finds that neither the persons nor property within the area proposed to be excluded benefit directly or indirectly from the use of or right to use the ground water supplies within the district and the replenishment thereof.