16.09.045   Additional copper limitations for industrial waste.
   (a)   Industrial waste discharges to the sanitary sewer system are subject to the copper limitations contained in Section 16.09.040(q) except for industrial waste from the following facilities, including facilities that are components of larger facilities, which are subject to specific limitations set forth in other provisions of this chapter.
   (1)   Cooling systems, pools, spas, fountains, boilers and heat exchangers as specified in Section 16.09.205;
   (2)   Photo processing facilities as specified in Section 16.09.215;
   (3)   Dental facilities as specified in Section 16.09.220;
   (4)   Vehicle service facilities as specified in Section 16.09.225;
   (6)   Machine shops as specified in Section 16.09.230; and
   (7)   Non-process, non-domestic waste as specified in subsection (c).
   (b)   Industrial waste discharges to the sewer from metal finishing facilities, as defined by the EPA in 40 CFR part 413 and part 433, shall meet either subdivision (1) or (2) of this subsection. These requirements shall apply to process wastes containing copper or nickel prior to dilution by non-metal finishing process wastes, domestic waste, and cooling water.
   (1)   The annual average copper limit for any twelve month period shall not exceed 0.40 mg/liter. In addition, all reasonable control measures specified in accordance with standards published by the superintendent shall be installed and implemented; or
   (2)   The annual average mass of copper shall not exceed an amount specified by the superintendent in the industrial waste discharge permit, which is based upon a pollution prevention review conducted or approved by the superintendent. The limitation shall be based upon those control measures having a simple payback period of five years or less. The annual average mass per day shall be a “rolling” measurement, calculated by multiplying the flow-weighted average copper concentration for all samples taken during any twelve month period by the total flow for that twelve month period. The annual average mass per day limit may be increased by the superintendent in proportion to increases in production at the discharger's facility to the extent that such production increases are within the growth allocation specified in the document prepared by Montgomery Watson, and published by the City of Palo Alto, entitled “City of Palo Alto-Local Limits Development - Proposed Local Limits - April, 1994.”
   (c)   The maximum allowable limit for discharge of copper from non-process, non-domestic waste discharges to the sanitary sewer other than those covered by subsections (a) or (b) shall be 2.0 mg/liter. These waste discharge sources shall be designated by the superintendent upon request and typically consist of infrequent, low volume, or exceptional wastes that are generated during maintenance, repair and cleaning activities.
(Ord. 5084 § 2 (part), 2010)