§ 18-56. Use of the public sewers.
   (a)   Prohibited Discharges Into Sanitary Sewer. No person shall discharge, permit or cause to be discharged, any stormwater, surface water, groundwater, roof runoff, or substance drainage to any sanitary sewer. Further, no person shall discharge, permit or cause to be discharged any noncontact cooling waters to any sanitary sewer, unless granted written authorization by the superintendent.
   (b)   Discharge Stormwater or Cooling Waters. Stormwater and all noncontact cooling waters, except where authorization is granted by the superintendent to discharge into the sanitary sewer, shall be discharged to such sewers as are specifically designated as storm sewers, or to a natural outlet approved by the superintendent. Under no circumstances shall sanitary waste water be discharged into a storm sewer.
   (c)   Prohibited Discharges to Public Sewers. No user shall discharge or cause to be discharged, directly or indirectly, any pollutant or wastewater which will interfere with performance of the POTW or cause pass-through of a pollutant(s) to the receiving stream. These general prohibitions apply to all such users of a POTW whether or not the user is subject to national categorical pretreatment standards or any other national, state, or local pretreatment standards or requirements. A user shall not contribute the following substances to the POTW:
      (1)   Any gasoline, benzene, naphtha, fuel oil, or other flammable or explosive liquid, solid, or gas.
      (2)   Any waters or wastes containing priority pollutants or hazardous chemicals, liquids, or gases in sufficient quantity, either singly or by interaction with other wastes, to injure or interfere with any sewage treatment process, constitute a hazard to human or animals, create a public nuisance, or create any hazard in the receiving waters of the sewage treatment plant.
      (3)   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 and personnel of the sewage works.
      (4)   Solid or viscous substances in quantities or of such size capable of causing obstruction to the flow in sewers, or other interference with the property operation of the sewage works such as, but not limited to ashes, cinders, sand, mud, straw, shaving, metal, glass, rags, feathers, tar, plastics, wood, unground garbage, whole blood, paunch manure, hair and fleshings, entrails, and paper dishes, cups, milk containers, etc., either whole or ground by garbage grinders.
      (5)   Ignitability and explosivity. Pollutants which create a fire or explosive hazard in the POTW, including, but not limited to, wastestreams with a closed up slashpoint of less than one hundred forty (140) degrees Fahrenheit or sixty (60) degrees Celsius using the test methods specified in 40 CFR 261.21.
      (6)   Reactivity and fume toxicity. Toxic gases, vapors, or fumes within the POTW in a quantity that may cause acute worker health and safety problems,
      (7)   Oil and grease. Petroleum oil, nonbiodegradable cutting oil, or products of mineral oil origin in amounts that will cause interference or pass-through.
      (8)   All others. Any pollutant, substance, compound, solid liquid or gas that will either interfere with the POTW or pass through the POTW to cause toxicity in the POTW effluent.
      (9)   Any waste which does not meet applicable categorical industrial standards.
      (10)   All trucked or hauled wastes unless authorized by the superintendent in writing.
      (11)   Use of dilution as a means of treatment to meet categorical standard except when expressly authorized to do so by an applicable categorical pretreatment standard and as applicable to section 18-64(h)(2) of this chapter.
   (d)   Discharge of Potentially Harmful Wastes. No person shall discharge or cause to be discharged the following described substances, materials, waters or wastes if it appears likely in the opinion of the superintendent that such wastes can harm either the sewers, sewage treatment process, or equipment; endanger life, limb or public property; or constitute a nuisance. In forming his opinion as to the acceptability of these wastes, the superintendent will give consideration to such factors as the quantities of subject wastes in relation to flows and velocities in the sewers, materials of construction of the sewers, nature of the sewage treatment process, capacity of the sewage treatment plant, degree of treatability of wastes in the sewage treatment plant, and other pertinent factors. The substances prohibited are:
      (1)   Any liquid or vapor having a temperature higher than one hundred fifty (150) degrees Fahrenheit (sixty-five (65) degrees Celsius). However, the temperature of sewage at the point of entry into the sewage treatment plant shall not exceed one hundred four (104) degrees Fahrenheit, and in the event of such occurrence, the superintendent shall have appropriate authority to determine the cause of major causes of such excessive temperature and shall have the authority to exercise those procedures and remedies set forth in subsection (f).
      (2)   Any water or waste containing fats, wax, grease, or oils whether emulsified or not, in excess of one hundred (100) milligrams per liter or containing substances which may solidify or become sufficiently viscous to obstruct flow in the sewers at temperatures between thirty-two (32) degrees Fahrenheit and one hundred fifty (150) degrees Fahrenheit zero (0) and sixty-five (65) degrees Celsius.
      (3)   Any garbage that has not been properly shredded.
      (4)   Any waters or wastes containing chemical constituents and/or objectionable or toxic substances that exceed the limits set forth below or limits as set forth in the Federal Pretreatment Standards contained in Title 40 of the Code of Federal Regulations, Part 403, or such other federal standards and regulations as may from time to time be enacted.
      (5)   Any waters or waste containing phenols or other taste and/or odor-producing substances, in such concentrations exceeding limits which may be established by the superintendent as necessary, or exceeding the limits set forth in the federal pretreatment standards mentioned in paragraph (4), or any other requirements or standards of the state, federal, or other public agencies of jurisdiction for such discharge to the receiving waters.
      (6)   Any radioactive wastes or isotopes of such half-life or concentration as may exceed limits established by the superintendent in compliance with applicable state or federal regulations.
      (7)   Materials which exert or cause:
         a.   Concentrations of inert suspended solids exceeding three hundred fifty (350) milligrams per liter, such as, but not limited to, fuller's earth, lime slurries, and lime residues; or of dissolved solids in quantities sufficient to have a detrimental effect on the treatment process;
         b.   Excessive discolorations exceeding three hundred (300) standard color units, such as, but not limited to, dye wastes and vegetable tanning solutions, unless approved by the superintendent.
         c.   Unusual chemical requirements which constitute a significant load on the sewage treatment works, unless specifically permitted by special permit.
         d.   Unusual volume of flow or concentration of wastes constituting slugs as defined in this division.
      (8)   Waters or wastes containing substances which are not amenable to treatment or reduction by the sewage treatment processes employed, or are amenable to treatment only to such degree that the sewage treatment plant effluent cannot meet the requirements of other agencies having jurisdiction over discharge to the receiving waters.
      (9)   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.
   (e)   Industrial Discharge Limits. The superintendent of the WWTP is authorized to establish local limits pursuant to 40 CFR 403.5(c). These limitations are for characteristics of any wastewaters to be discharged into the municipal sewer system, subject to any compliance schedule as established in the industrial user permit. All significant industrial users must comply with these discharge limitations where they are more stringent than applicable state and federal regulations. Based upon the sampling program at the Danville Wastewater Treatment Plant, the discharge limitations may be adjusted to reflect the POTW's needs. The following individual waste limitations are provided in addition to others set forth in this division:
Industrial Discharge Limits
Monthly Average*
Maximum Day*
Monthly Average*
Maximum Day*
Total Chromium
Chromium, Hexavalent
Total Oil and Grease
Cyanide, Amenable
Liquid or Vapor Flashpoint
Oil and Grease, Hydrocarbon
*Values in milligram per liter (mg/l)
**s.u.= standard units
   (f)   Actions Regarding Potentially Harmful Wastes. If any waters or wastes are discharged, or are proposed to be discharged to the public sewers, which waters contain the substances or possess the characteristics enumerated in this section and which in the judgment of the superintendent may have a deleterious effect upon the sewage works, processes, equipment, or receiving waters, or which otherwise create a hazard to life or constitute a public nuisance, the superintendent may:
      (1)   Reject the wastes.
      (2)   Require pretreatment to an acceptable condition for discharge to the public sewers.
      (3)   Require control over the quantities and rates of discharge.
      (4)   Require payment to cover the added cost of handling and treating the wastes not covered by existing taxes or sewer charges under the provisions of subsection (k).
   If the superintendent permits the pretreatment or equalization of waste flows, the design and installation of the plants and equipment shall be subject to the review and approval of the superintendent, and subject to the requirements of all applicable codes, ordinances and laws.
   (g)   Grease, Oil, Sand Interceptors. Grease, oil, and sand interceptors shall be provided when, in the opinion of the superintendent, they are necessary for the proper handling of liquid wastes containing grease in excessive amounts, or any flammable wastes, sand or other harmful ingredients; except that such interceptors shall not be required for private living quarters or dwelling units. All interceptors shall be of a type and capacity approved by the superintendent and shall be located as to be readily and easily accessible for cleaning and inspection. In the maintaining of these interceptors, the owner shall be responsible for the proper removal and disposal by appropriate means of the captured material and shall maintain records of the dates and means of disposal which are subject to review by the superintendent.
   (h)   Preliminary Treatment; Flow-Equalizing Facilities. Where preliminary treatment or flow equalizing facilities are provided for the wastes or waters, they shall be maintained continuously in satisfactory and effective operation by the owner at his expense.
   (i)   Control Manhole. When required by the superintendent, the owner of any property serviced by a building sewer carrying industrial wastes shall install a suitable control manhole together with such necessary meters and other appurtenances in the building sewer to facilitate observation, sampling and measurement of the industrial wastes. Such manhole, when required, shall be installed by the owner at his expense and shall be maintained by him so to be safe and accessible at all times.
   (j)   Measurements, Testing, Analysis. All mea- surements, tests, and analysis of the characteristics of waters and wastes to which reference is made in this division shall be determined in accordance with 40 CFR 136 or other applicable standard or authority, and shall be determined at the control manhole provided, or upon suitable samples taken at such control manhole. If no special manhole has been required, the control manhole shall be considered to be the nearest downstream manhole in the public sewer to the point at which the building sewer is connected. Sampling shall be carried out by customarily accepted methods to reflect the effect of constituents upon the sewage works and to determine the existence of hazards to life, limb, and property. The cost of having tests run on industrial waste shall be at the expense of the industrial user.
   (k)   Special Agreements Between City and Industrial Users. No statement contained in this section shall be construed 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, subject to payment therefor by the industrial concern. However, any such special agreement the city and any industrial user cannot be less stringent than any applicable federal pretreatment standard or categorical regulation pursuant to Section 307 of the Clean Water Act and must be approved by the office of the Pretreatment Section KPDES Branch Division of Water.
   (l)   Emptying Septic Tanks or Grease Traps Outside City Limits Into Sewer System. Before any person shall empty the contents of septic tanks or grease traps located outside the city limits into the sewer system of the city, he shall first secure a permit from the superintendent and shall pay a fee in accordance with the schedule maintained by the superintendent. In addition, no such matter shall be emptied into the sewer system except at such locations as designated by the superintendent. Furthermore, the content of such matter shall not violate the requirements and restrictions set forth in this section.
   (m)   National Categorical Standards. The City of Danville has received authority through the U.S. EPA and state statutes to enforce the requirements of 40 CFR Chapter I, Subchapter N, parts 405-471 and 40 CFR part 403. All users shall comply with the requirements of those regulations. The WWTP superintendent and/or his designee may require the development and implementation of best management practices (BMPs), by ordinance or in individual wastewater discharge permits to implement local limits and the requirements of this ordinance.
(Ord. No. 1331, § II, 7-10-84; Ord. No. 1277, Art. VI, 7-8-80; Ord. No. 1450, § 3, 4, 8-27-91; Ord. No. 1630, 7-8-02; Ord. No. 1640, 11-25-02; Ord. No. 1803, § 2, 2-27-12; Ord. No. 1903, § 1, 9-25-17; Ord. No. 1911, § 1, 2-26-18; Ord. No. 1923, §1, 10-8-18)