“Significant industrial user” means any industrial user of the city's wastewater disposal system who (i) has a discharge flow of twenty-five thousand gallons or more per average work day, or (ii) has a flow greater than five percent of the flow in the city's wastewater treatment system, or (iii) has in his wastes toxic pollutants as defined pursuant to Section 307 of the Act of (State) Statutes and rules or (iv) is found by the City, (State Control Agency) or the U.S. Environmental Protection Agency (EPA) to have significant impact, either singly or in combination with other contributing industries, on the wastewater treatment system, the quality of sludge, the system's effluent quality, or air emissions generated by the system. (Ord. No. 1038, § 1 (part).)