§ 50.023  LOCAL LIMITS.
   (A)   The following pollutant limitations are established to protect against pass through and interference.  No person shall discharge wastewater containing in excess of the following daily maximum concentrations based upon a 24-hour composite sample.
   (B)   Additionally, no person shall discharge wastewater containing in excess of the following maximum concentrations times a multiplier of one and one-half based upon samples needed for compliance verification purposes.  The one and one-half sample multiplier does not apply to Hex. Chromium, Cyanide and Oil and Grease in that analytical procedures do not allow for composite techniques to be applied to these parameters. For Hex. Chromium, Cyanide and Oil and Grease, three sample results shall be analyzed with results not to exceed the following noted limitations:
      (1)   Arsenic, 0.08 mg/l (total);
      (2)   BOD5, 500 mg/l (daily maximum);
      (3)   Cadmium, .7 mg/l (total);
      (4)   Hex. Chromium, .93 mg/l;
      (5)   Chloride, 2,000 mg/l;
      (6)   Total Chromium, 32 mg/l;
      (7)   Total Suspended Solids, 500 mg/l (daily maximum);
      (8)   Copper, 4.24 mg/l;
      (9)   Cyanide, .23 mg/l (total);
      (10)   Lead, 1.57 mg/l (total);
      (11)   Mercury, .038 mg/l (total);
      (12)   Molybdenum, 1.2 mg/l;
      (13)   Nickel, 5.75 mg/l;
      (14)   Oil and Grease, 100 mg/l;
      (15)   Selenium, .40 mg/l;
      (16)   Silver, 1.26 mg/l;
      (17)   Zinc, 38 mg/l (total);
      (18)   Ammonia, 500 mg/l.
   (C)   As an alternative to the total oil and grease limitations established by this section, the control authority may establish in an IWP a limitation of 100 mg/l for non-polar grease.  The alternative limitation is subject to the following conditions:
      (1)   The user submits an application for the alternative limit;
      (2)   The user provides information regarding the user’s products, processes and operations that shows to the control authority’s satisfaction that the oil and grease discharged by the user is predominantly of animal or vegetable origin;
      (3)   The user shows that the oil and grease in the user’s discharges is not visible, free or floating at 50°F at anytime;
      (4)   The user has sampling facilities that allow for both visual inspection of the user’s discharge and using the equipment necessary for collection samples for floatable oil and grease;
      (5)   The oil and grease in the user’s discharge is not related to past instances of obstruction, interference or pass through;
      (6)   Users subject to the alternative limit shall continue to operate and maintain grease traps and any other oil and grease separation and treatment equipment and shall continue all existing practices that reduce discharges of oil and grease;
      (7)   If the control authority determines that a user subject to the alternative limit has caused, alone or in conjunction with other discharges, obstruction, interference or pass through, then the user shall comply with the total oil and grease limitation or another appropriate limitation established by the district in the user’s IWP; and
      (8)   Any other appropriate conditions set forth in the user’s SIU.
   (D)   (1)   The above limits apply at the point where the wastewater is discharged to the POTW.
      (2)   All concentrations for metallic substances are for “total” metal unless indicated otherwise.
      (3)   The Town Manager may impose mass limitations in addition to, or in place of, the concentration-based limitations above.
   (E)   (1)   Upon the promulgation of the national categorical pretreatment standard for a particular user, the standard, if more stringent then the limitations imposed under this chapter for sources in that category, shall, when effective, immediately supersede the limitations and conditions imposed under this chapter.
      (2)   The Town Manager shall notify all known affected users of the applicable permitting and reporting requirements under 40 CFR 403.12.
(Ord. 14-2000, passed 8-7-00; Am. Ord. 4-2012, passed 1-17-12; Am. Ord. 16-2012, passed 6-18-12; Am. Ord. 2-2013, passed 3-4-13)