For any lot, parcel of land or premises from which connection is made with the city sanitary sewerage system, or which begins to discharge sewage or industrial waste into the city sewerage system, either directly or indirectly after this chapter becomes effective, the charges and rates for the first payment period after the beginning date of sewage discharge into the city sewerage system shall be based upon the per diem pro rata amount of the established minimum charge per month or shall be based upon the water consumed at the established rates, whichever is the larger. (Prior code § 38-4-4)