(A) Industrial users shall be required to meet the applicable pretreatment standard as defined in applicable pretreatment standard in § 50.046.
(B) National categorical pretreatment standards. The national categorical pretreatment standards found in 40 C.F.R. Chapter I, Subchapter N, Parts 405 through 471, are hereby incorporated into this subchapter and shall be met by all dischargers of the regulated categories, if more stringent than state or local limits.
(1) Where a categorical pretreatment standard is expressed only in terms of either the mass or the concentration of a pollutant in wastewater, the authority may impose equivalent concentration or mass limits in accordance with divisions (B)(5) and (6).
(2) When the limits in a categorical pretreatment standard are expressed only in terms of mass of pollutant per unit of production, the authority 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.
(3) When wastewater subject to a categorical pretreatment standard is mixed with wastewater not regulated by the same standard, the authority shall impose an alternate limit in accordance with 40 CFR 403.6(e).
(4) A CIU may obtain a net/gross adjustment to a categorical pretreatment standard in accordance with the following divisions of this section.
(a) 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 requirements of division (4)(b) of this section are met.
(b) Criteria.
1. Either:
a. The applicable categorical pretreatment standards contained in 40 CFR subchapter N specifically provide that they shall be applied on a net basis; or
b. 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.
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.
(5) When a categorical pretreatment standard is expressed only in terms of pollutant concentrations, an industrial user may request that the City of Shelbyville convert the limits to equivalent mass limits. The determination to convert concentration limits to mass limits is within the discretion of the authority. The city may establish equivalent mass limits only if the industrial user meets all the conditions set forth in divisions (B)(5)(a)1. through (B)(5)(a)5. below.
(a) To be eligible for equivalent mass limits, the industrial user must:
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 wastestreams, 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 authority whenever production rates are expected to vary by more than 20% from its baseline production rates determined in division (B)(5)(a)3.. Upon notification of a revised production rate, the authority 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 division (B)(4)(a)1. of this section so long as it discharges under an equivalent mass limit.
(c) When developing equivalent mass limits, the authority:
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 discharge 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 division (E). The industrial user must also be in compliance with § 50.0642(C) regarding the prohibition of bypass.
(6) The authority 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 authority.
(7) Once included in its permit, the industrial user must comply with the equivalent limitations developed in this section in lieu of the promulgated categorical standards from which the equivalent limitations were derived.
(8) 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.
(9) Any industrial user operating under a permit incorporating equivalent mass or concentration limits calculated from a production-based standard shall notify the authority 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 authority 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 requirements. State requirements and limitations on discharges to the POTW shall be met by all dischargers which are subject to such standards in any instance in which they are more stringent than Federal requirements and limitations or those in this or any other applicable ordinance.
(D) Right of revision. The authority reserves the right to amend this subchapter to provide for more stringent limitations or requirements on discharges to the POTW where deemed necessary to comply with the objectives set forth in § 50.045.
(E) Dilution. No discharger shall increase the use of potable or process water in any way, nor mix separate waste streams for the purpose of diluting a discharge as a partial or complete substitute for adequate treatment to achieve compliance with standards set forth in this subchapter. The authority 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.
(F) Municipal supplemental limitations.
(1) The authority 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 industrial user shall discharge wastewater containing concentrations of the following enumerated materials, exceeding the following values:
Material | Concentration (mg/l) |
Material | Concentration (mg/l) |
Arsenic | 1.0 |
Cadmium | 1.0 |
Copper | 4.0 |
Cyanide | 1.0 |
Lead | 1.0 |
Mercury | 0.10 |
Nickel | 4.0 |
Hexavalent Chromium | 2.5 |
Total Chromium | 5.0 |
Zinc | 4.0 |
Silver | 1.0 |
PCB's | None |
Phenol | 10.0 |
(3) 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 authority may impose mass limitations in addition to the concentration-based limitations above.
(a) In cases where the standard requires compliance with a best management practice (BMP), the user shall submit documentation as required by the authority or applicable standards to determine compliance with the standard.
(b) These limitations are based on process, boiler, blow-down and cooling water and any combination thereof. Any other waters added prior to the point of monitoring shall reflect lower limitations.
(c) The authority may impose mass limitations on dischargers which are using dilution to meet the pretreatment standards or requirements of this subchapter, or in other cases where the imposition of mass limitations is deemed appropriate by the authority.
(4) The authority may develop best management practices (BMPs), by ordinance or in individual wastewater discharge permits or general permits, to implement local limits and the requirements of § 50.047.
(Ord. 12-2683, passed 8-20-12)