Miss. Code § 77-5-33
The authority shall not be operated for gain or profit or primarily as a source of revenue to the state. The authority shall, however, prescribe and collect reasonable rates, fees or charges for the services, facilities and commodities made available by it, and shall revise such rates, fees or charges from time to time whenever necessary so that the authority shall be and always remain self-supporting, and shall not require appropriations by the state to enable it to carry out its purpose. The rates, fees, or charges prescribed shall be such as will produce revenue at least sufficient (a) to pay when due all bonds and interest thereon, for the payment of which such revenue is or shall have been pledged, charged or otherwise incumbered, including reserves therefor, and (b) to provide for all expenses of operation, maintenance or improvement of the system or systems acquired by the authority, including reserves therefor. Any surplus thereafter remaining shall be devoted solely to the reduction of rates.
Miss. Code § 77-5-33