(A) The following maximum weekly average pollutant limits are established to protect against pass through and interference. No person shall discharge on a weekly average wastewater containing in excess of the following:
Arsenic | 0.20 mg/l |
Cadmium | 0.12 mg/l |
Chromium (total) | 9.52 mg/l |
Copper | 2.72 mg/l |
Cyanide | 3.72 mg/l |
Lead | 1.28 mg/l |
Mercury | 0.07 mg/l |
Molybdenum | 0.11 mg/l |
Nickel | 0.92 mg/l |
Selenium | 0.07 mg/l |
Silver | 1.41 mg/l |
Zinc | 1.53 mg/l |
(B) Weekly average shall mean the arithmetic mean of all 24-hour daily results, whether composite or grab, collected in a one-week period from Sunday through Saturday.
(C) At no time shall the pollutant concentration of a 24-hour composite or grab sample exceed one and one-half times the weekly average limit listed above for the pollutant. Should these limits be exceeded, it shall constitute a daily violation under this chapter.
(D) The above limits apply at the point where the wastewater is discharged to the POTW. All concentrations for metallic substances are for “total” metal unless indicated otherwise. The Industrial Pretreatment Coordinator may impose mass limitations in addition to, or in place of, the concentration- based limitations above. All test procedures shall conform to an approved analysis method as indicated in 40 C.F.R. part 136.
(E) For the pollutants listed in the table above, where multiple grab samples are collected during the same day, the average would be used for determining compliance with the daily maximum limit, while compliance with the instantaneous maximum limit would be determined based on each individual grab sample result.
(Res. 1998-10-18-A, passed 10-19-1998; Ord. 180, passed 12-21-1998; Ord. 211, passed 8-2-2004; Ord. 252-2011, passed 7-5-2011; Ord. 285-2021, passed 9-7-2021)