(a) Discharges from each separate discharge of a user, as measured under the provisions of this chapter, shall not contain in excess of the following concentrations, based upon a twenty-four hour composite sample or a grab sample as noted. Multiple industrial wastewater discharges from a permitted facility may be combined in a flow weighted manner to determine compliance with the following limitations for a twenty-four-hour composite.
Pollutant Maximum Concentration
Arsenic 0.25 mg/l
Barium 1.0 mg/l
BOD5 250 mg/l
Cadmium 0.15 mg/l
Chromium (T) 3.5 mg/l
Copper 1.34 mg/l*
Cyanide (grab) 0.50 mg/l*
Lead 0.60 mg/l
Manganese 15.0 mg/l
Mercury 0.02 mg/l
Molybdenum 0.42 mg/l*
Nickel 1.21 mg/l*
Oils (hexane soluble or equivalent) (grab) 50.0 mg/l
pH (grab) (5.0 to 9.5 units)
Phenols (grab) 0.30 mg/l
Silver 0.60 mg/l
Total suspended solids 250 mg/l
Zinc 2.10 mg/l
(b) The initial period of compliance with the revised (*) provisions of this section shall be no later than 180 days after the effective date of this chapter, except that compliance with the manganese provision of this section shall begin immediately after April 3, 2023. The above limits apply at the point where the wastewater is discharged to the POTW. All concentrations for metallic substances are for total metals unless otherwise indicated. The Department of Public Works - Water and Sewer Division may impose mass limitations in addition to concentration-based limitations above.
(c) The City Council may develop Best Management Practices (BMP's), by ordinance or in individual wastewater discharge permits, to implement local limits and the requirements of Section 1046.09.
(Ord. 96-68. Passed 10-7-96; Ord. 2020-11. Passed 3-2-20; Ord. 2023-14. Passed 4-3-23.)