Implementation of categorical pretreatment standards.
Memphis Code of Ordinances § 13-24-42
in effectSec. 13-24-42. - Implementation of categorical pretreatment standards.
A. Compliance with categorical pretreatment standards required. Users must comply with the categorical pretreatment standards found at 40 C.F.R. Chapter I, Subchapter N, Parts 405-471, as applicable. Compliance by existing sources with categorical pretreatment standards shall be within three years of the date the standard is effective unless a shorter compliance time is specified in the appropriate subpart of Subchapter N or the Federal Register promulgation of the Standard. Existing sources, which become industrial users subsequent to promulgation of an applicable categorical pretreatment standard, shall be considered existing industrial users except where such sources meet the definition of a new source. New sources shall install, have in operating condition and, "start-up" all pollution control equipment required to meet applicable pretreatment standards before beginning to discharge. Within the shortest feasible time (not to exceed 90 days), new sources must meet all applicable pretreatment standards.
B. Use of the combined wastestream formula. When wastewater subject to a categorical pretreatment standard is mixed with wastewater not regulated by the same standard, the control authority may impose an alternate limit in accordance with the combined wastestream formula as set forth in Tennessee Rule 0400-40-14-.06(5) or take such other action as necessary to assure compliance with categorical pretreatment standards.
C. Fundamentally different factors variance. A discharger may request a variance from categorical pretreatment standards in accordance with applicable procedures. See, e.g., Tennessee Rule 0400-40-14-.13.
D. Net gross adjustment. A categorical industrial user (CIU) may obtain a net/gross adjustment to a categorical pretreatment standard in accordance with the following subsections:
1. 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 pretreatment standard will be calculated on a "net" basis (i.e., adjusted to reflect credit for pollutants in the intake water) if the requirements of subsections (2) through (5) of this section are met.
2. Criteria.
a. The applicable categorical pretreatment standards contained in 40 C.F.R. 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 pretreatment standards in the absence of pollutants in the intake waters.
3. 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 industrial 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.
4. 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 pretreatment standard(s) adjusted under this section.
5. 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.
E. Implementation of production-based limit.
1. When the limits in a categorical pretreatment standard are expressed only in terms of mass of pollutant per unit of production, the control 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.
2. Any industrial user operating under a control mechanism incorporating equivalent mass or concentration limits calculated from a production-based standard shall notify the control 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 industrial user not notifying the control authority of such anticipated change will be required to meet the mass or concentration limits in its control mechanism that were based on the original estimate of the long-term average production rate.
F. Imposition of equivalent mass or concentration based limits.
1. When a categorical pretreatment standard is expressed only in terms of pollutant concentrations, the control authority may also establish equivalent mass limits so that local, state, or Federal authorities may enforce either concentration or mass limits. In the alternative, an industrial user may request that the control authority convert the concentration limits to equivalent mass limits and include only the equivalent mass limits in the permit. The determination to convert concentration limits to mass limits is within the discretion of the control authority. The control authority may establish equivalent mass limits in lieu of a concentration limit only if the industrial user meets all the conditions set forth in subsections (F)(1)(a) through (e) below.
a. Employ, or demonstrate that it will employ, water conservation methods and technologies that substantially reduce water use during the term of its discharge permit;
b. Currently use control and treatment technologies adequate to achieve compliance with the applicable categorical pretreatment standard and has not previously used or plan to use dilution as a substitute for treatment;
c. 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;
d. 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
e. Have consistently complied with all applicable categorical pretreatment standards during the period prior to the industrial user's request for equivalent mass limits.
2. An industrial user subject to equivalent mass limits must:
a. Maintain and effectively operate control and treatment technologies adequate to achieve compliance with the equivalent mass limits;
b. Continue to record the facility's flow rates with a continuous effluent flow monitoring device;
c. Continue to record the facility's production rates and notify the control authority whenever production rates are expected to vary by more than 20 percent from its baseline production rates. Upon notification of a revised production rate, the control authority may reassess the equivalent mass limit and revise the limit as necessary to reflect changed conditions at the facility; and
d. Continue to employ the same or comparable water conservation methods and technologies as those implemented pursuant to subsection (F)(1)(a) of this section, so long as it discharges under an equivalent mass limit.
3. When developing equivalent mass limits, the control authority may:
a. 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;
b. Upon notification of a revised production rate, reassess the equivalent mass limit and recalculate the limit as necessary to reflect changed conditions at the facility;
c. Retain the same equivalent mass limit in subsequent 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; and
d. Deny or condition equivalent mass limits upon the industrial user also being in compliance with section 13-24-46(C)(4) regarding the prohibition of bypass.
4. The control authority may convert the mass limits of the categorical pretreatment standards of 40 C.F.R. 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 control authority.
5. If only equivalent mass limitations are included in the control mechanism, once included in the control mechanism, the industrial user must comply with the equivalent limitations in lieu of the promulgated categorical standards from which the equivalent limitations were derived.
G. Calculation of categorical limits. 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 under applicable categorical pretreatment standards.
H. Sampling waiver. The control authority may authorize an industrial user subject to a categorical pretreatment standard to forego sampling of a pollutant regulated by a categorical pretreatment standard if the industrial user has demonstrated through sampling and other technical factors that the pollutant is neither present nor expected to be present in the discharge, is present only at background levels from intake water, and there will be no increase in the pollutant due to activities of the industrial user. See Tennessee Rule 0400-40-14-.12(5)(b). This authorization is subject to the following conditions:
1. The waiver may be authorized where a pollutant is determined to be present solely due to sanitary wastewater discharged from the facility, provided that the sanitary wastewater is not regulated by an applicable categorical standard and otherwise includes no process wastewater.
2. The monitoring waiver is valid only for the duration of the effective period of the individual control mechanism, but in no case longer than five years. The user must submit a new request for the waiver before the waiver can be granted for each subsequent control mechanism.
3. In making a demonstration that a pollutant is not present, the industrial user must provide data from at least one sampling of the facility's process wastewater prior to any treatment present at the facility that is representative of all wastewater from all processes.
4. The request for a monitoring waiver must be signed by an authorized representative of the user and include the certification statement in [section] 13-24-30(J)(3). See 40 C.F.R. § 403.6(a)(2)(ii) and Tennessee Rule 0400-40-14-.06(1)(b)2.
5. EPA and TDEC have determined that, where the lowest minimum detection level for a pollutant as set forth in 40 C.F.R. Part 136 has been used in the analysis, it is appropriate to equate a non-detectable sample result as demonstrating that a pollutant is not present.
6. In order for a monitoring waiver approval by the control authority to be effective, it must be included as a condition in the user's discharge permit.
7. Upon approval of the monitoring waiver and revision of the user's control mechanism by the control authority, the industrial user must certify on each report with the statement in section 13-24-30(J)(3) that there has been no increase in the pollutant in its wastestream due to activities of the industrial user.
8. In the event that a waived pollutant is found to be present or is expected to be present because of changes that occur in the industrial user's operations, the industrial user must immediately comply with the monitoring requirements as set forth in section 13-24-30(E) or other more frequent monitoring requirements imposed by the control authority and notify the control authority.
9. This provision does not supersede certification processes and requirements established in categorical pretreatment standards, except as otherwise specified in the categorical pretreatment standard.
(Ord. No. 5793, §§ 3, 5, 8-17-2021)
Source: City of Memphis, Code of Ordinances and Charter and Related Laws (Municode Library, library.municode.com)URL: https://library.municode.com/tn/memphis/codes/code_of_ordinances?nodeId=TIT13PUSE_CH13-24PR_ART3DIPUSASE_S13-24-42IMCAPRSTFetched: 10/28/2026