(A) Prohibited discharge standards.
(1) General prohibitions. No user shall contribute or cause to be contributed into the POTW, directly or indirectly, any pollutant or wastewater which causes interference or pass through. These general prohibitions apply to all users of a POTW whether or not the user is a significant industrial user or subject to any national, state or local pretreatment standards or requirements.
(2) Specific prohibitions. No user shall contribute or cause to be contributed into the POTW the following pollutants, substances or wastewater:
(a) Pollutants which create a fire or explosive hazard in the POTW, including, but not limited to, waste streams with a closed cup flashpoint of less than 140°F (60°C) using the test methods specified in 40 C.F.R. § 261.21;
(b) Solid or viscous substances in amounts which will cause obstruction of the flow in the POTW resulting in interference but in no case solids greater than one-half inch in any dimension;
(c) Petroleum oil, nonbiodegradable cutting oil or products of mineral oil origin, in amounts that will cause interference or pass through;
(d) Any wastewater having a pH less than 5.0 or more than 10.0 or wastewater having any other corrosive property capable of causing damage to the POTW or equipment;
(e) Any wastewater containing pollutants, including oxygen-demanding pollutants, (BOD and the like) in sufficient quantity, (flow or concentration) either singly or by interaction with other pollutants, to cause interference with the POTW;
(f) Any wastewater having a temperature greater than 150°F (66°C), or which will inhibit biological activity in the POTW treatment plant resulting in interference, but in no case wastewater which causes the temperature at the introduction into the treatment plant to exceed 104°F (40°C);
(g) Any pollutants which result in the presence of toxic gases, vapors or fumes within the POTW in a quantity that may cause acute worker health and safety problems;
(h) Any trucked or hauled pollutants, except at discharge points designated by the POTW Director in accordance with division (I) below;
(i) Any noxious or malodorous liquids, gases or solids or other wastewater which, either singly or by interaction with other wastes, are sufficient to create a public nuisance or hazard to life or are sufficient to prevent entry into the sewers for maintenance and repair;
(j) Any substance which may cause the POTW’s effluent or any other product of the POTW such as residues, sludges or scums, to be unsuitable for reclamation and reuse or to interfere with the reclamation process. In no case, shall a substance discharged to the POTW cause the POTW to be in noncompliance with sludge use or disposal regulations or permits issued under § 405 of the Act, the Solid Waste Disposal Act, the Clean Air Act, the Toxic Substances Control Act or state criteria applicable to the sludge management method being used;
(k) Any wastewater which imparts color which cannot be removed by the treatment process, including, but not limited to, dye wastes and vegetable tanning solutions, which consequently imparts sufficient color to the treatment plant’s effluent to render the waters injurious to public health or secondary recreation or to aquatic life and wildlife or to adversely affect the palatability of fish or aesthetic quality or impair the receiving waters for any designated uses;
(l) Any wastewater containing any radioactive wastes or isotopes except as specifically approved by the POTW Director in compliance with applicable state or federal regulations;
(m) Storm water, surface water, ground water, artesian well water, roof runoff, subsurface drainage, swimming pool drainage, condensate, deionized water, noncontact cooling water and unpolluted industrial wastewater, unless specifically authorized by the POTW Director;
(n) Fats, oils or greases of animal or vegetable origin in concentrations greater than 100 mg/l;
(o) Any sludges, screenings or other residues from the pretreatment of industrial wastes;
(p) Any medical wastes, except as specifically authorized by the POTW Director in a wastewater discharge permit;
(q) Any material containing ammonia, ammonia salts or other chelating agents which will produce metallic complexes that interfere with the municipal wastewater system;
(r) Any material that would be identified as hazardous waste according to 40 C.F.R. Part 261 if not disposed of in a sewer except as may be specifically authorized by the POTW Director;
(s) Any wastewater causing the treatment plant effluent to violate state water quality standards for toxic substances as described in 15A NCAC 213.0200;
(t) Wastewater causing, alone or in conjunction with other sources, the treatment plant’s effluent to fail a toxicity test;
(u) Recognizable portions of the human or animal anatomy;
(v) Any wastes containing detergents, surface active agents or other substances which may cause excessive foaming in the municipal wastewater system; and
(w) At no time, shall two successive readings on an explosion hazard meter, at the point of discharge into the system (or at any point in the system) be more than 5% nor any single reading over 10% of the lower explosive limit (LEL) of the meter.
(3) Pollutants, substances, wastewater or other wastes. Pollutants, substances, wastewater or other wastes prohibited by this section shall not be processed or stored in such a manner that they could be discharged to the municipal wastewater system. All floor drains located in process or materials storage areas must discharge to the industrial user’s pretreatment facility before connecting with the system.
(4) POTW Director action. When the POTW Director determines that a user(s) is contributing to the POTW, any of the above enumerated substances in such amounts which may cause or contribute to interference of POTW operation or pass through, the POTW Director shall:
(a) Advise the user(s) of the potential impact of the contribution on the POTW in accordance with § 51.058(A); and
(b) Take appropriate actions in accordance with § 51.054 for such user to protect the POTW from interference or pass through.
(B) National categorical pretreatment standards. Users subject to categorical pretreatment standards are required to comply with applicable standards as set out in 40 C.F.R. Chapter 1, Subchapter N, Parts 405 through 471 and incorporated herein.
(1) Where a categorical pretreatment standard is expressed only in terms of either the mass or the concentration of a pollutant in wastewater, the POTW Director may impose equivalent concentration or mass limits in accordance with 40 C.F.R. § 403.6(c).
(2) When wastewater subject to a categorical pretreatment standard is mixed with wastewater not regulated by the same standard, the POTW Director shall impose an alternate limit using the combined waste stream formula in 40 C.F.R. § 403.6(e).
(3) A user may obtain a variance from a categorical pretreatment standard if the user can prove, pursuant to the procedural and substantive provisions in 40 C.F.R. § 403.13, that factors relating to its discharge are fundamentally different from the factors considered by EPA when developing the categorical pretreatment standard.
(4) A user may obtain a net gross adjustment to a categorical standard in accordance with 40 C.F.R. § 403.15.
(C) Local limits.
(1) An industrial waste survey is required prior to a user discharging wastewater containing in excess of the following average discharge limits.
Arsenic | 0.003 mg/l |
BOD | 250 mg/l |
Cadmium | 0.003 mg/l |
Chromium | 0.05 mg/l (total chromium) |
Copper | 0.061 mg/l |
Cyanide | 0.015 mg/l |
Fluoride | 2.00 mg/l |
Lead | 0.049 mg/l |
Mercury | 0.0003 mg/l |
NH3 | 25 mg/l |
Nickel | 0.021 mg/l |
Oil and grease | 100 mg/l |
Silver | 0.005 mg/l |
TSS | 250 mg/l |
Zinc | 0.175 mg/l |
(2) Industrial waste survey information will be used to develop user-specific local limits when necessary to ensure that the POTW’s maximum allowable headworks loading are not exceeded for particular pollutants of concern. User-specific local limits for appropriate pollutants of concern shall be included in wastewater permits. The POTW Director may impose mass based limits in addition to, or in place of, concentration based limits.
(D) State requirements. State requirements and limitations on discharges shall apply in any case where they are more stringent than federal requirements and limitations or those in this subchapter.
(E) Right of revision. The city reserves the right to establish limitations and requirements which are more stringent than those required by either state or federal regulation if deemed necessary to comply with the objectives presented in § 51.050 or the general and specific prohibitions in division (A) above, as is allowed by 40 C.F.R. § 403.4.
(F) Dilution. No user shall ever increase the use of process water or, in any way, attempt to dilute a discharge as a partial or complete substitute for adequate treatment to achieve compliance with the limitations contained in the national categorical pretreatment standards, unless expressly authorized by an applicable pretreatment standard, or in any other pollutant-specific limitation developed by the city or state.
(G) Pretreatment of wastewater.
(1) Pretreatment facilities. Users shall provide wastewater treatment as necessary to comply with this subchapter and wastewater permits issued under § 51.054(B) and shall achieve compliance with all national categorical pretreatment standards, local limits and the prohibitions set out in division (A) above within the time limitations as specified by EPA, the state or the POTW Director, whichever is more stringent. Any facilities necessary for compliance shall be provided, operated and maintained at the user’s expense. Detailed plans showing the pretreatment facilities and operating procedures shall be submitted to the city for review, and shall be approved by the POTW Director before construction of the facility. The review of such plans and operating procedures shall in no way relieve the user from the responsibility of modifying the facility as necessary to produce an effluent acceptable to the city under the provisions of this subchapter. Any subsequent changes in the pretreatment facilities or method of operation shall be reported to and be approved by the POTW Director prior to the user’s initiation of the changes.
(2) Additional pretreatment measures.
(a) Whenever deemed necessary, the POTW Director may require users to restrict their discharge during peak flow periods, designate that certain wastewater be discharged only into specific sewers, relocate and/or consolidate points of discharge, separate sewage waste streams from industrial waste streams, and such other conditions as may be necessary to protect the POTW and determine the user’s compliance with the requirements of this subchapter.
(b) The POTW Director may require any person discharging into the POTW to install and maintain, on their property and at his or her expense, a suitable storage and flow-control facility to ensure equalization of flow. A wastewater discharge permit may be issued solely for flow equalization.
(c) Grease, oil and sand interceptors shall be provided when, in the opinion of the POTW Director, they are necessary for the proper handling of wastewater containing excessive amounts of grease and oil, or sand; except that such interceptors shall not be required for residential users. All interception units shall be of type and capacity approved by the POTW Director and shall be so located to be easily accessible for cleaning and inspection. Such interceptors shall be inspected, cleaned and repaired regularly, as needed, by the user at his or her expense.
(d) Users with the potential to discharge flammable substances may be required to install and maintain an approved combustible gas detection meter.
(H) Accidental discharge/slug control plans.
(1) The POTW Director shall evaluate whether each significant industrial user needs a plan or other action to control and prevent slug discharges and accidental discharges as defined in § 51.051. All SIUs must be evaluated within one year of being designated an SIU. The POTW Director may require any user to develop, submit for approval and implement such a plan or other specific action. Alternatively, the POTW Director may develop such a plan for any user.
(2) All SIUs are required to notify the POTW immediately of any changes at its facility affecting the potential for spills and other accidental discharge, discharge of a non-routine, episodic nature, a non-customary batch discharge, or a slug load. Also see § 51.055(E) and (F).
(3) An accidental discharge/slug control plan shall address, at a minimum, the following:
(a) Description of discharge practices, including non-routine batch discharges;
(b) Description of stored chemicals;
(c) Procedures for immediately notifying the POTW Director of any accidental or slug discharge, as required by § 51.055(F) of this subchapter; and
(d) Procedures to prevent adverse impact from any accidental or slug discharge. Such procedures include, but are not limited to, inspection and maintenance of storage areas, handling and transfer of materials, loading and unloading operations, control of plant site runoff, worker training, building of containment structures or equipment, measures for containing toxic organic pollutants, including solvents and/or measures and equipment for emergency response.
(I) Hauled wastewater.
(1) Septic tank waste may be introduced into the POTW only at locations designated by the POTW Director, and at such times as are established by the POTW Director. Such waste shall not violate this section or any other requirements established by the city. The POTW Director may require septic tank waste haulers to obtain wastewater discharge permits.
(2) The POTW Director shall require haulers of industrial waste to obtain wastewater discharge permits. The POTW Director may require generators of hauled industrial waste to obtain wastewater discharge permits. The POTW Director also may prohibit the disposal of hauled industrial waste. The discharge of hauled industrial waste is subject to all other requirements of this subchapter.
(3) Industrial waste haulers may discharge loads only at locations designated by the POTW Director. No load may be discharged without prior consent of the POTW Director. The POTW Director may collect samples of each hauled load to ensure compliance with applicable standards. The POTW Director may require the industrial waste hauler to provide a waste analysis of any load prior to discharge.
(4) Industrial waste haulers must provide a waste tracking form for every load. This form shall include, at a minimum, the name and address of the industrial waste hauler, permit number, truck identification, names and addresses of sources of waste, and volume and characteristics of waste. The form shall identify the type of industry, known or suspected waste constituents, and whether any wastes are RCRA hazardous wastes.
(2009 Code, § 51.37) (Ord. passed 2-27-2007)