937.02  NONACCEPTABLE WASTEWATER AND INDUSTRIAL PRETREATMENT.
   (a)    The City shall make and enforce rules and regulations establishing the types and characteristics of sewage, industrial wastes and other matters which shall be discharged into the sanitary sewerage system, the types and characteristics of sewage and industrial wastes admissible to the system only after pretreatment, requisites for pretreatment, and otherwise governing the discharge of sewage, industrial wastes and other matters into the system in the interest of safety and efficient operation of the wastewater treatment plant. Applicable industrial pretreatment conditions and industrial pretreatment regulations, as promulgated under Section 307(b) of the Clean Water Act, are hereby incorporated into this chapter and made a part thereof.
   (b)    An industry shall, upon application for sewer service, present to the City a tabulation of the chemical analysis of the wastes to be discharged to the sewerage system and the volume of such wastes, or if this is not available, the expected waste analysis based upon similar processes now in operation.
   (c)    In cases where the character of sewage or industrial waste from any manufacturing or industrial plant, building or premises is such that it will damage the sewerage system or cannot be treated satisfactorily at the wastewater treatment plant, the City shall compel such users to dispose of such waste and prevent it from entering the sewerage system. 
   (d)    In cases where the character of the sewage or industrial waste from any manufacturing or industrial plant, building or premises is such that it imposes an unreasonable burden upon the sewage collection, pumping or treatment works greater than that imposed by the average sewage entering the sewerage system, the City may: compel such manufacturing or industrial plant, building or premises to pretreat such sewage in such manner as specified by the City before discharging it into the sewerage system; require flow control or equalization of such wastes so as to avoid any "slug" loads or excessive loads that may be harmful to the treatment works; or require payment of a surcharge on any excessive flows or loadings discharged to the treatment works to cover the additional costs of having capacity for and treatment of such wastes.
   (e)    The discharge of nonacceptable industrial wastewater into the sewerage system, whether directly or indirectly, is prohibited. Wastewater shall be deemed nonacceptable when the concentration of harmful or toxic substances in the wastewater exceeds certain prescribed tolerable limits. Toxic or harmful substances include, but are not necessarily limited to, the following:
 
            Tolerable Limits
Toxic or Harmful Substance    (milligrams per liter)
   Arsenic          0.2
   Barium          1.0
   Boron             5.0
   Cadmium          0.1
   Chromium+3       0.5
   Chromium+6       0.5
   Cobalt             1.0
   Copper          0.5
   Cyanide (HCN)       0.5
   Fluoride          5.0
   Iron             5.0
   Lead             0.5
   Mercury          0.02
   Molybdenum          5.0
   Nickel             2.0
   Phenols          5.0
   Selenium          0.10
   Silver             0.03
   Sulfides          50.0
   Total dissolved solids    1, 500.0
   Tungsten          5.0
   Zinc             2.0
   Radioactive substances     Gross beta activity (in the known absence of strontium and Alpha emitters) - 1,000 micro curies per liter.
   The preceding list of toxic or harmful substances is subject to revisions as required to meet current water quality standards or effluent standards imposed by state or federal agencies. In special cases (low volume users), the concentration of toxic or harmful substances in the wastewater may be exceeded if it is determined by the City that the total pounds of toxic or harmful substances discharged to the sewage system are not harmful to or shall not interfere with the sewage treatment process or shall not violate water quality or effluent standards.
   (f)    No person shall discharge or cause to be discharged, either directly or indirectly to the sewerage system, any of the following described substances, materials, waters or wastes:
      (1)    Any liquid or vapor having a temperature higher than 150° Fahrenheit.
      (2)    Any gasoline, benzene, naphtha, fuel oil, mineral oil or other volatile flammable or explosive liquid, solid or gas.
      (3)    Any noxious or malodorous gas or substance which, either singly or by interaction with other wastes, is capable of creating a public nuisance or hazard to life or of preventing entry into the sewers for their maintenance and repair.
      (4)    Any waters or wastes having a pH lower than 5.5 or higher than 9.0, or having any other corrosive property capable of causing damage or hazard to structures, equipment or personnel of the sewerage system.
      (5)    Any ashes, cinders, sand, mud, straw, shavings, metal, glass, rags, feathers, tar, plastics, wood, paunch manure, hair and fleshings, entrails, lime slurry, lime, chemical or paint residues, cannery wastes, bulk solids or any other solid objects or viscous substance capable of causing obstruction to the flow operation of the sewerage system.
      (6)    Any waters or wastes containing a toxic or poisonous substance in sufficient quantity to injure or interfere with any sewage treatment process, constitute a hazard to humans or animals, or create any hazard in the receiving waters of the sewerage system.
      (7)    Any water or wastes containing emulsified oil or grease exceeding, on analysis, an average of fifty milligrams of oil and grease per liter determined as total ether soluble matter.
      (8)    Any garbage that has not been properly shredded to a degree that all particles will be carried freely under the flow conditions of the sewer and  with no particle greater than one-half inch in any dimension.
      (9)    Any water or wastes containing suspended solids of such character or  quality that unusual attention or expense is required to handle such  materials at the sewage treatment plant, or having a chlorine demand  greater than twenty-five parts per million.
    The above list is subject to revisions as required to meet current water quality standards imposed by the state or federal agencies.
   (g)    No statement contained in this section shall be interpreted as preventing any  special agreement or arrangement between the City and any industrial concern whereby an industrial waste of unusual strength or character may be accepted by the City for  treatment. In all such cases, the provisions set forth in establishing sewer service charges shall be governing factors in any contracts entered into.
   (h)    Grease, oil and sand interceptors shall be provided when, in the opinion of the Sanitary Engineer, they are necessary for proper handling of liquid wastes containing  grease in excessive amounts, or any flammable wastes, sand, and other harmful  ingredients; except  that such interceptors shall not be required for private living quarters  or dwelling units. All interceptors shall be located as to be readily and easily accessible  for cleaning and inspection. 
   (i)    Grease and oil interceptors shall be constructed of impervious materials  capable of withstanding abrupt and extreme changes in temperature. They shall be of substantial construction, watertight and equipped with easily removable covers which when bolted in place shall be gastight and watertight. Where installed, all grease, oil and sand interceptors shall be maintained by the owner at his expense, in continuous efficient operation at all times.
(Ord. 13-82. Passed 6-21-82.)