Tenn. Comp. R. & Regs. 0400-40-05-.08 - EFFLUENT LIMITATIONS AND STANDARDS

(1) Effluent standards and limitations shall be formulated in accordance with the following requirements:
(a) For existing sources, other than publicly owned treatment works, technology-based effluent limitations shall be designed to require application of the best practicable control technology currently available or application of the best available technology economically achievable, as applicable in accordance with requirements of Section 301 (b)(2)(A), Federal Water Pollution Control Act, PL 92-500.
(b) For new sources, technology-based effluent limitations shall require the greatest degree of effluent reduction achievable through application of the best available demonstrated control technology, which shall be new source performance standards, if available.
(c) (Reserved).
(d) Toxic effluent limitations shall be based on consideration of the toxicity of the pollutant, its persistence, its degradability, the usual or potential presence of the affected organisms in any waters, the importance of the affected organisms, and the nature and extent of the effect of the toxic pollutant on such organisms.
(e) Pretreatment standards shall be designed to prevent the introduction into publicly owned treatment works of those pollutants that may interfere with, pass through, or otherwise be incompatible with such works.
(f) All effluent limitations or standards shall be at least as stringent as any minimum standards promulgated by the Administrator and currently effective under the Federal Water Pollution Control Act, P.L. 92-500 as amended or any subsequent applicable acts.
(g) All pollutants shall receive treatment or corrective action to ensure compliance with effluent limitations established by the U.S. Environmental Protection Agency pursuant to Sections 301 and 302 and standards of performance for new sources pursuant to Section 306, effluent limitations and prohibitions and pretreatment standards pursuant to Section 307 of the Federal Water Pollution Control Act as amended, PL 92-500; also to ensure compliance with any approved water quality standard, or avoid conflict with an approved area-wide waste treatment management plan prepared according to Section 208 of the Federal Water Pollution Control Act as amended, PL 92-500.
(h) Any schedules of compliance under this rule shall require compliance as soon as possible, but not later than the applicable statutory deadline under the federal law. When the Division establishes a compliance schedule, it shall consider the technical and economic feasibility of waste treatment, recovery, or adjustment of the method of discharge. Any such schedule of compliance shall require compliance with an enforceable final effluent limitation as soon as possible and include a final compliance date. If compliance will take longer than one year, the schedule of compliance shall establish enforceable interim requirements, establish dates for compliance with these requirements that are no longer than one year apart, and require reporting of interim compliance actions within 14 days of the applicable deadline. If the time necessary for completion of any requirement is more than one year and the requirement is not readily divisible into stages for completion, the permit shall require, at a minimum, specified dates for annual submission of progress reports on the status of interim requirements.
(i) Best management practices to control or abate the discharge of pollutants when numeric effluent limitations are infeasible and the practices are reasonably necessary to achieve effluent limitations and standards or to carry out the purposes and intent of TWQCA.
1. When a permit is renewed or reissued, effluent limitations, standards or conditions shall be at least as stringent as the effluent limitations, standards, or conditions in the previous permit unless:
(i) The circumstances on which the previous permit was based have materially and substantially changed since the time the permit was issued and would constitute cause for permit modification or revocation and reissuance;
(ii) Material and substantial alterations or additions to the permitted facility occurred after permit issuance which justify the application of a less stringent effluent limitation;
(iii) Information is available which was not available at the time of permit issuance (other than revised regulations, guidance, or test methods) and which would have justified the application of a less stringent effluent limitation at the time of permit issuance;
(iv) Technical mistakes or mistaken interpretations of law were made in issuing the permit;
(v) A less stringent effluent limitation is necessary because of events over which the permittee has no control and for which there is no reasonably available remedy; or
(vi) The permittee has installed the treatment facilities required to meet the effluent limitations in the previous permit and has properly operated and maintained the facilities but has nevertheless been unable to achieve the previous effluent limitations, in which case the limitations in the reviewed, reissued, or modified permit may reflect the level of pollutant control actually achieved.
2. In no event may a permit be renewed, reissued, or modified to contain an effluent limitation which is less stringent than required by effluent guidelines in effect at the time the permit is renewed, reissued, or modified.
3. In no event may a permit be renewed, issued, or modified to contain a less stringent effluent limitation if the implementation of such limitation would result in a violation of a water quality standard.
(k) All permit effluent limitations, standards, and prohibitions shall be established for each outfall or discharge point of the permitted facility, except as otherwise provided for best management practices (BMPs) where limitations on effluent or internal waste streams are infeasible.
(l) In the case of POTWs or domestic wastewater treatment plants, permit effluent limitations, standards, or prohibitions shall be calculated based on design flow.
(m) For continuous discharges, all permit effluent limitations, standards, and prohibitions shall be expressed as maximum daily, weekly average (for POTWs only), and monthly average, unless impracticable.
(n) Non-continuous discharges shall be limited in terms of frequency, total mass, maximum rate of discharge, and mass or concentrations of specified pollutants, as appropriate.
(o) Any permit limitations, standards, or prohibitions based on production shall be based upon a reasonable measure of actual production.
1. For new sources or dischargers, actual production shall be estimated from projected production.
2. The time period of the measure of production shall correspond to the time period of the resulting permit limits. For example, monthly production levels shall be used to calculate monthly average permit limits.
(p) All permit effluent limitations, standards, or prohibitions for a metal shall be expressed as "total recoverable metal" unless a promulgated effluent guideline or an applicable, water quality criterion specifies otherwise.
(q) When permit effluent limitations or standards imposed at the point of discharge are impractical or infeasible, effluent limitations or standards for discharges of pollutants may be imposed on internal waste streams before mixing with other waste streams or cooling water streams. In those instances, the monitoring required shall also be applied to the internal waste streams. Limits on internal waste streams will be imposed only when the rationale sets forth the exceptional circumstances which make such limitations necessary, such as when the final discharge point is inaccessible (for example, under water), the wastes at the point of discharge are so diluted as to make monitoring impracticable, or the interferences among pollutants at the point of discharge would make detection or analysis impracticable.
(r) Instantaneous maximum concentration or similar limitations may be imposed in permits when:
1. Toxic or harmful parameters are present in such significant amounts or concentrations as to represent a threat to the possibility of maintaining receiving waters in accordance with established classifications; and
2. The discharge is characterized as irregular, such as high peak, short duration flow.
(s) Any discharge or activity authorized by a permit that is not a minor facility discharge or activity, or the Regional Administrator requests, in writing, be monitored, or contains a toxic pollutant for which an effluent standard has been established shall be monitored by the permittee for the following:
1. Flow (in million gallons per day); and
2. Any of the following pollutants:
(i) Pollutants (either directly or indirectly through the use of accepted correlation coefficients or equivalent measurements determined to be applicable to the discharge to which they are applied) that are subject to reduction or elimination under the terms and conditions of the permit;
(ii) Pollutants that the Commissioner finds, on the basis of information available, could have a significant impact on the quality of waters;
(iii) Pollutants specified by the Administrator, in regulations issued pursuant to the Federal Water Pollution Control Act, as subject to monitoring; and
(iv) Any pollutants, in addition to those identified in subparts (i) through (iii) of this part, that the Regional Administrator or the Commissioner request be monitored.
(t) If a toxic effluent standard or prohibition (including any schedule of compliance specified in such effluent standard or prohibition) is established for a toxic pollutant that is present in the permittee's discharge and such standard or prohibition is more stringent than any limitation upon such pollutant in the permit, the Commissioner shall revise or modify the permit in accordance with established procedure to include the toxic effluent standard or prohibition and so notify the permittee.
(u) The Commissioner may require flow monitoring in other situations where necessary to comply with the Act.
(v) If non-potable reuse of reclaimed wastewater is utilized in association with an NPDES - authorized discharge, the NPDES permit shall impose conditions in accordance with the requirements of Rule 0400-40-06-.10, unless the reuse is separately governed by a state operating permit.
(2) All discharges authorized by the permit shall be consistent with the terms and conditions of the permit. Facility expansions, production increases, or process modifications that result in new or increased discharges of pollutants shall be reported by submission of a new application or, if such discharge does not violate effluent limitations specified in the permit, by submission to the Commissioner of notice of such new or increased discharges of pollutants. The discharge of any pollutant more frequently than or at a level in excess of that authorized by the permit shall constitute a violation of the terms and conditions of the permit.


Tenn. Comp. R. & Regs. 0400-40-05-.08
Original rule filed November 20, 2013; effective February 18, 2014. Amendments filed May 24, 2018; effective August 22, 2018. Amendments filed February 14, 2022; effective 5/15/2022.

Authority: T.C.A. §§ 4-5-201, et seq. and 69-3-101, et seq.

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