A district, acting through its board of directors, shall have the power in connection with a domestic water system undertaken under this act: (a) to establish periodic tolls and charges for domestic water service adequate to meet its contract obligations, all other expenses incurred in the construction, operation and maintenance of such a system, and to maintain such reserves as are reasonable to assure continuous and efficient domestic water service; (b) to require the payment of such tolls and charges in advance of the delivery of water; (c) to fix the delinquency dates for tolls and charges and the penalties for failure to pay before delinquency, penalties not to exceed twelve per cent (12%) per annum of the delinquent amounts; and (d) to handle and account for the domestic water system funds in such manner as may be required by contract with the United States.