(A) Prohibited discharge standards.
(1) General prohibitions. No user shall introduce or cause to be introduced, directly or indirectly, into the POTW any pollutant or wastewater which causes pass through or interference. These general prohibitions apply to all users of the POTW whether or not the user is subject to categorical pretreatment standards or any other federal, state, or local pretreatment standards or requirements.
(2) Specific prohibitions. No user shall introduce or cause to be introduced 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 degrees F (60 degrees C) using the test methods specified in 40 CFR 261.21;
(b) Wastewater having a pH less than 5.0 or more than 11.5, or otherwise causing corrosive structural damage to the POTW or equipment;
(c) 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 (½") in any dimension;
(d) Pollutants, including oxygen-demanding pollutants (BOD, etc.), released in a discharge at a flow rate and/or pollutant concentration which, either singly or by interaction with other pollutants, will cause interference with the POTW;
(e) Wastewater having a temperature greater than 150 degrees F (66 degrees C), or which will inhibit biological activity in the treatment plant resulting in interference, but in no case wastewater which causes the temperature at the introduction into the treatment plant to exceed 104 degrees F (40 degrees C);
(f) Petroleum oil, non-biodegradable cutting oil, or products of mineral oil origin, in amounts that will cause interference or pass through;
(g) 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) Trucked or hauled pollutants, except at discharge points designated by Director of Utilities in accordance with § 191-03(D);
(i) Noxious or malodorous liquids, gases, solids, or other wastewater which, either singly or by interaction with other wastes, are sufficient to create a public nuisance or a hazard to life, or to prevent entry into the sewers for maintenance or repair;
(j) Wastewater which imparts color which cannot be removed by the treatment process, such as, but not limited to, dye wastes and vegetable tanning solutions, which consequently imparts color to the treatment plant’s effluent, thereby violating the city’s AZPDES permit;
(k) Wastewater containing any radioactive wastes or isotopes except in compliance with applicable state or federal regulations;
(l) 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 Director of Utilities;
(m) Sludges, screenings, or other residues from the pretreatment of industrial wastes;
(n) Medical wastes, except as specifically authorized by Director of Utilities in a wastewater discharge permit;
(o) Wastewater causing, alone or in conjunction with other sources, the treatment plant’s effluent to fail toxicity test;
(p) Detergents, surface-active agents, or other substances which that might cause excessive foaming in the POTW;
(q) Fats, oils, or greases of animal or vegetable origin in quantities that cause or contribute to obstructions;
(r) Wastewater causing two readings on an explosion hazard meter at the point of discharge into the POTW, or at any point in the POTW, of more than 5% or any single reading over 10% of the lower explosive limit of the meter.
(3) Pollutants, substances, or wastewater prohibited by this section shall not be processed or stored in such a manner that they could be discharged to the POTW.
(B) National categorical pretreatment standards.
(1) Users must comply with the categorical pretreatment standards found at 40 CFR §§ 405–471, as amended.
(3) If the limits in a categorical pretreatment standard are expressed only in terms of mass of pollutant per unit of production, the Director of Utilities may convert the limits to equivalent limitations expressed either as mass of pollutant discharged per day or effluent concentration for purposes of calculating effluent limitations applicable to individual industrial users.
(4) If wastewater subject to a categorical pretreatment standard is mixed with wastewater not regulated by the same standard, the Director of Utilities shall impose an alternate limit in accordance with 40 CFR 403.6(e).
(5) (a) A CIU may obtain a net/gross adjustment to a categorical pretreatment standard in accordance with the following paragraphs of this subsection.
(b) Categorical pretreatment standards may be adjusted to reflect the presence of pollutants in the industrial user’s intake water in accordance with this section. Any industrial user wishing to obtain credit for intake pollutants must make application to the city. Upon request of the industrial user, the applicable standard will be calculated on a “net” basis (i.e., adjusted to reflect credit for pollutants in the intake water) if the following requirements are met:
1. Either (i) the applicable categorical pretreatment standards contained in 40 CFR subchapter N specifically provide that they shall be applied on a net basis; or (ii) the industrial user demonstrates that the control system it proposes or uses to meet applicable categorical pretreatment standards would, if properly installed and operated, meet the standards in the absence of pollutants in the intake waters;
2. Credit for generic pollutants such as biochemical oxygen demand (BOD), total suspended solids (TSS), and oil and grease should not be granted unless the industrial user demonstrates that the constituents of the generic measure in the user’s effluent are substantially similar to the constituents of the generic measure in the intake water or unless appropriate additional limits are placed on process water pollutants either at the outfall or elsewhere;
3. Credit shall be granted only to the extent necessary to meet the applicable categorical pretreatment standard(s), up to a maximum value equal to the influent value. Additional monitoring may be necessary to determine eligibility for credits and compliance with standard(s) adjusted under this section; and
4. Credit shall be granted only if the user demonstrates that the intake water is drawn from the same body of water as that into which the POTW discharges. The city may waive this requirement if it finds that no environmental degradation will result.
(6) When a categorical pretreatment standard is expressed only in terms of pollutant concentrations, an industrial user may request that the city convert the limits to equivalent mass limits. The determination to convert concentration limits to mass limits is within the discretion of the Director of Utilities.
(a) The city may establish equivalent mass limits only if the industrial user:
1. Employ, or demonstrate that it will employ, water conservation methods and technologies that substantially reduce water use during the term of its individual wastewater discharge permit;
2. Currently use control and treatment technologies adequate to achieve compliance with the applicable categorical pretreatment standard, and not have used dilution as a substitute for treatment;
3. Provide sufficient information to establish the facility’s actual average daily flow rate for all waste streams, based on data from a continuous effluent flow monitoring device, as well as the facility’s long-term average production rate. Both the actual average daily flow rate and the long-term average production rate must be representative of current operating conditions;
4. Not have daily flow rates, production levels, or pollutant levels that vary so significantly that equivalent mass limits are not appropriate to control the discharge; and
5. Have consistently complied with all applicable categorical pretreatment standards during the period prior to the industrial user’s request for equivalent mass limits.
(b) An industrial user subject to equivalent mass limits must:
1. Maintain and effectively operate control and treatment technologies adequate to achieve compliance with the equivalent mass limits;
2. Continue to record the facility’s flow rates through the use of a continuous effluent flow monitoring device;
3. Continue to record the facility’s production rates and notify the Director of Utilities whenever production rates are expected to vary by more than 20% from its baseline production rates determined in subsection (B)(6)(a)3. of this section. Upon notification of a revised production rate, the Director of Utilities will reassess the equivalent mass limit and revise the limit as necessary to reflect changed conditions at the facility; and
4. Continue to employ the same or comparable water conservation methods and technologies as those implemented pursuant to § 191-02(B)(6)(a)3. of this section so long as it discharges under an equivalent mass limit.
(c) When developing equivalent mass limits, the Director of Utilities:
1. Will calculate the equivalent mass limit by multiplying the actual average daily flow rate of the regulated process(es) of the industrial user by the concentration-based daily maximum and monthly average standard for the applicable categorical pretreatment standard and the appropriate unit conversion factor;
2. Upon notification of a revised production rate, will reassess the equivalent mass limit and recalculate the limit as necessary to reflect changed conditions at the facility; and
3. May retain the same equivalent mass limit in subsequent individual wastewater discharger permit terms if the industrial user’s actual average daily flow rate was reduced solely as a result of the implementation of water conservation methods and technologies, and the actual average daily flow rates used in the original calculation of the equivalent mass limit were not based on the use of dilution as a substitute for treatment pursuant to § 191-02(F). The industrial user must also be in compliance with § 191-13(C) regarding the prohibition of bypass.
(7) The Director of Utilities may convert the mass limits of the categorical pretreatment standards of 40 CFR Parts 414, 419, and 455 to concentration limits for purposes of calculating limitations applicable to individual industrial users. The conversion is at the discretion of the Director of Utilities.
(8) Once included in its permit, the industrial user must comply with the equivalent limitations developed in this § 191-02(B) in lieu of the promulgated categorical standards from which the equivalent limitations were derived.
(9) Many categorical pretreatment standards specify one limit for calculating maximum daily discharge limitations and a second limit for calculating maximum monthly average, or four-day average, limitations. Where such standards are being applied, the same production or flow figure shall be used in calculating both the average and the maximum equivalent limitation.
(10) Any industrial user operating under a permit incorporating equivalent mass or concentration limits calculated from a production-based standard shall notify the Director of Utilities within two business days after the user has a reasonable basis to know that the production level will significantly change within the next calendar month. Any User not notifying the Director of Utilities of such anticipated change will be required to meet the mass or concentration limits in its permit that were based on the original estimate of the long term average production rate.
(C) State pretreatment standards. Users shall comply with Arizona State Pretreatment Standards authorized by A.R.S. Title 49, Chapter 2, Article 3.1, as amended, and located in Title 18, Chapter 9, Article 9 of the Arizona Administrative Code (“A.A.C.”), as amended. 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 chapter.
(D) Local limits.
(1) The Director of Utilities is authorized to establish local limits pursuant to 40 CFR § 403.5(c).
(2) The following pollutant limits are established to protect against pass through and interference. No person shall discharge wastewater containing in excess of the following limitations. If and when federal or state regulatory agency regulations require a specific pretreatment concentration for a specific industry, whichever is the more stringent concentration level between these regulations and such federal or state regulations will apply.
Local Limits for Users of the Figueroa Avenue Water Pollution Control Facility (WPCF)
Parameter | Daily Maximum Limit
|
Parameter | Daily Maximum Limit
|
Ammonia | 260 mg/L |
Arsenic | 0.070 mg/L |
Boron | 2.5 mg/L |
Cadmium | 0.072 mg/L |
Chromium (Total) | 4.9 mg/L |
Copper | 1.9 mg/L |
Cyanide | 0.13 mg/L |
Dissolved Sulfide | 0.5 mg/L |
Total Petroleum Hydrocarbons | 100 mg/L |
FOG, Polar | (See note 1) (See note 2) |
FOG, Total | (See note 1) (See note 2) |
Lead | 0.52 mg/l |
Mercury | 0.0002 mg/L |
Molybdenum | 0.20 mg/L |
Nickel | 0.82 mg/L |
Nitrogen (Total) | 150 mg/L |
pH | 5 - 11.5 S.U. |
Silver | 2.9 mg/L |
Selenium | 0.020/0.011 mg/L (See note 3) |
Thallium | 0.027 mg/L |
Biochemical Oxygen Demand (BOD) | Note 4 |
Total Suspended Solids (TSS) | Note 4 |
Total Dissolved Solids (TDS) | Note 4 |
Zinc | 1.8 mg/L |
Note 1: Discharges of oil and grease shall not result in accumulations which either alone, or in combination with other wastes, are capable of obstructing flow or that interfere with the operations or performance of the wastewater collection system or the treatment facilities. | |
Note 2: Dischargers of polar FOG shall minimize free floating polar FOG. Discharge of polar FOG in quantities that cause or contribute to obstructions is strictly prohibited. Dischargers of free floating polar FOG shall be required to install pretreatment devices such as grease removal equipment sized according to city standards and institute other best management practices. | |
Note 3: Industry specific selenium local limit of 0.020 mg/L to identified selenium discharging significant industrial users (SIU). To counterbalance the higher selenium limit for these discharges a lower limit of 0.011 mg/L for other SIUs is required. | |
Note 4: The discharge of wastewater shall not cause the inhibition of wastewater treatment or violation of any ADEQ requirements. | |
The above limits apply at the point where the wastewater is discharged to the POTW. All concentrations for metallic substances are for total metal unless indicated otherwise. The Director of Utilities may impose mass limitations in addition to the concentration-based limitations above.
(3) The Director of Utilities may develop best management practices (BMPs), by ordinance or in individual wastewater discharge permits and/or general permits, to implement local limits and the requirements of § 191-02(A).
(E) City’s right of revision. The city reserves the right to establish, by chapter or in individual wastewater discharge permits and/or general permits, more stringent standards or requirements on discharges to the POTW consistent with the purpose of this chapter.
(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 a discharge limitation unless expressly authorized by an applicable pretreatment standard or requirement. The Director of Utilities may impose mass limitations on users who are using dilution to meet applicable pretreatment standards or requirements, or in other cases when the imposition of mass limitations is appropriate.
(Ord. O2019-007, passed 2-6-2019)