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(a) It shall be unlawful to discharge water from cooling systems, pools, spas, fountains, boilers and heat exchangers to the storm drain system.
(b) No person shall discharge or add to the sanitary sewer system or storm drain system, or add to a cooling system, pool, spa, fountain, boiler or heat exchanger, any substance that contains any of the following:
(1) Copper in excess of 2.0 mg/liter;
(2) Any tri-butyl tin compound in excess of 0.10 mg/liter;
(3) Chromium in excess of 2.0 mg/liter;
(4) Zinc in excess of 2.0 mg/liter; or
(5) Molybdenum in excess of 2.0 mg/liter.
The above limits shall apply to any of the above-listed substances prior to dilution with the cooling system, pool, spa or fountain water.
(c) Cooling System Discharges.
(1) For the purposes of this section the average daily flow shall be determined by dividing the total cooling system blowdown volume from April through October by the number of days of operation for the same period.
(2) The maximum allowable limit for discharge of copper for cooling systems discharging an average daily flow of less than 2,000 gallons per day shall be 2.0 mg/liter.
(3) The maximum allowable limit for discharge of copper for cooling systems discharging an average daily flow of greater than 2,000 gallons per day shall be 0.25 mg/liter. The superintendent may impose a higher alternative maximum allowable copper limit when the cycles of concentrations routinely exceed ten. The alternative requirement may consist of an alternative limit, a mass limit or a specified maintenance program, or a combination of these.
(4) New cooling systems commencing discharge with an estimated average daily flow greater than 2,000 gallons per day shall comply with the maximum allowable copper limit of 2.0 mg/liter and shall not be required to comply with the 0.25 mg/liter maximum allowable copper discharge limit specified in subsection (c)(3), until one year after the date of such commencement.
(d) Cooling System Cleaning. Wastewater from cleaning of cooling systems, boilers, heat exchangers and associated piping where a chemical cleaner or physical scouring is used in the cleaning process shall be sampled prior to discharge to the sewer. The maximum allowable limits for discharge of copper shall be 2.0 mg/liter. For purposes of this section, “physical scouring” does not include the use of water at typical water supply pressure; and “associated piping” shall mean piping associated with a heating or cooling system through which water or another heat transfer fluid passes during operation of the system. The wastewater shall be analyzed for copper and any other constituents specified by the superintendent. The results of such analysis shall be reviewed by the cooling system operator prior to discharge.
(e) Devices using electricity to dissolve copper or silver into water distribution systems, cooling systems, pools, spas or fountains are prohibited.
(Ord. 5084 § 2 (part), 2010)