925.09  SUBSTANCES LIMITED.
   The following described substances, materials, waters or waste shall be limited in discharges to public sewers to concentrations or quantities which will not harm either the sewers or sewage works, will not have an adverse effect on the stream receiving effluent from the sewage works, or will not otherwise endanger lives, limb, public property, or constitute a nuisance.  The Service-Safety Director may set limitations lower than the limitations established in the regulations below if in his opinion such more severe limitations are necessary to meet the above objectives.  Deliberate dilution with unpolluted water to meet the concentrations established in the regulations below shall not be acceptable.  In forming this opinion as to the acceptability, the Director will give consideration to such facts as the quantity of subject waste in relation to flows and velocities in the sewers, materials of construction of the sewers, the wastewater treatment process employed, capacity of the sewage works, degree of treatment process employed, capacity of sewage works, degree of treatability of the sewage in the sewage works, disposal of sludge materials, and other pertinent factors.  The limitations or restrictions on materials or characteristics of sewage discharged to the public sewer which shall not be exceeded without approval of the Director are as follows:
   (a)   Sewage having a temperature higher than 150 degrees Fahrenheit.
   (b)   Any sewage containing solids, liquids or gases in sufficient quantity, either singly or by interaction with other wastes to injure or interfere with any wastewater treatment process, constitute a hazard to humans or animals, create a public nuisance, or create any hazard in the receiving waters of the sewage treatment plant, including, but not limited to cyanides, chromium, copper, zinc, cadmium, nickel and phenols in the sewage as discharged to the public sewer.
   (c)   Sewage containing more than fifty milligrams per liter of petroleum oil, cutting oils, product of mineral oil origin, or floatable oils, fat, wax or grease.
   (d)   Grease in such quantities or concentrations as to create a danger of blockage of the sewers.
   (e)   Biochemical oxygen demand, suspended solids, or phosphorus in concentrations which, in the opinion of the Director, may adversely affect the sewage treatment plant.
   (f)   Flows of a magnitude of variation which, in the opinion of the Director, may adversely affect the sewage treatment plant.
   (g)   No use of the sewer system shall discharge more than the following quantities of heavy metals, phenols, or cyanides, into the City sewer system without a permit to exceed these quantity limitations:
   total cyanide   -      0.02#/day
   total chromium   -   0.5#/day
   copper   -         1.0#/day
   zinc   -         0.6#/day
   cadmium   -      0.1#/day
   nickel   -         0.5#/day
   phenols   -      0.05#/day
   lead   -         0.05#/day
   mercury   -      0.005#/day
   silver   -         0.006#/day
Any exceptions to these limitations shall be made in conformance to Section 925.11.
   (h)   Any sewage containing odor-producing substances exceeding limits which may be established by the Service-Safety Director or any local or State regulatory agencies.
   (i)   Any radioactive wastes or isotopes of such half-life or concentration as may exceed limits in compliance with applicable State or Federal regulations.
   (j)   Quantities of flow, concentrations or both which constitute a "slug" as defined herein.
   (k)   Waters or wastes containing substances which are not amenable to treatment or reduction by the wastewater treatment processes employed, or are amenable only to such degree that the wastewater treatment plant effluent cannot meet the requirements of other agencies have jurisdiction over discharge to the receiving waters.
   (l)   Any water or wastes which by interaction with other water or wastes in the public sewer system, release obnoxious gases, form suspended solids which interfere with the collection system, or create a condition deleterious to structures and treatment processes.
         The limitations set on toxic metal discharges shall be evaluated by the industries discharging the toxic metal and the Service-Safety Director when one of the following conditions exists:
      (1)   One year after implementation of this chapter and every year thereafter.
      (2)   Anytime the effluent from the sewage treatment plant consistently is above or below the water quality standards.
         (Ord. 80-24.  Passed 3-20-80.)