Any pressurized distribution system constructed under the authority of section 43-330A, Idaho Code, shall be operated, maintained, repaired and replaced by the district, and the district may levy and collect an assessment against each tract of land served by the distribution system to defray the cost and expense of such operation, maintenance, repair or replacement. The board shall apportion to each tract of land included in the contract a portion of the cost of operation, maintenance, repair and replacement of the distribution system, on the same basis as the cost of construction of the distribution system is apportioned.