---
kind: "range"
citation: "40 C.F.R. §§ 125.59–125.68"
title: "40"
from: "125.59"
to: "125.68"
count: 10
url: "https://uscodex.org/cfr/40/125.59..125.68"
---

# §125.59. General.

- (a) **Basis for application.** An application under this subpart shall be based on a current, improved, or altered discharge into ocean waters or saline estuarine waters.
- (b) **Prohibitions.** No [section 301(h)](/cfr/40/301.md?p=h) modified permit shall be issued:
  - (1) Where such issuance would not assure compliance with all applicable requirements of this subpart and [part 122](/cfr/40/part122.md);
  - (2) For the discharge of sewage sludge;
  - (3) Where such issuance would conflict with applicable provisions of State, local, or other Federal laws or Executive Orders. This includes compliance with the Coastal Zone Management Act of 1972, as amended, [16 U.S.C. 1451](/usc/16/1451.md) et seq.; the Endangered Species Act of 1973, as amended, [16 U.S.C. 1531](/usc/16/1531.md) et seq.; and Title III of the Marine Protection, Research and Sanctuaries Act, as amended, [16 U.S.C. 1431](/usc/16/1431.md) et seq.;
  - (4) Where the discharge of any pollutant enters into saline estuarine waters which at the time of application do not support a balanced indigenous population of shellfish, fish, and wildlife, or allow recreation in and on the waters or which exhibit ambient water quality below applicable water quality standards adopted for the protection of public water supplies, shellfish, fish, and wildlife or recreational activities or such other standards necessary to assure support and protection of such uses. The prohibition contained in the preceding sentence shall apply without regard to the presence or absence of a causal relationship between such characteristics and the applicant's current or proposed discharge; or
  - (5) Where the discharge of any pollutant is into the New York Bight Apex.
- (c) **Applications.** Each applicant for a modified permit under this subpart shall submit an application to EPA signed in compliance with [40 CFR part 122](/cfr/40/part122.md), [subpart B](/cfr/40/subpartB.md), which shall contain:
  - (1) A signed, completed NPDES Application Standard form A, parts I, II, III;
  - (2) A completed Application Questionnaire;
  - (3) The certification in accordance with [40 CFR 122.22(d)](/cfr/40/122.22.md?p=d);
  - (4) In addition to the requirements of [§ 125.59(c)](#c) (1) through (3), applicants for permit renewal shall support continuation of the modification by supplying to EPA the results of studies and monitoring performed in accordance with [§ 125.63](/cfr/40/125.63.md) during the life of the permit. Upon a demonstration meeting the statutory criteria and requirements of this subpart, the permit may be renewed under the applicable procedures of [40 CFR part 124](/cfr/40/part124.md).
- (d) **Revisions to applications.**
  - (1) POTWs which submitted applications in accordance with the June 15, 1979, regulations (44 FR 34784) may revise their applications one time following a tentative decision to propose changes to treatment levels and/or outfall and diffuser location and design in accordance with [§ 125.59(f)(2)(i)](#f-2-i); and
  - (2) Other applicants may revise their applications one time following a tentative decision to propose changes to treatment levels and/or outfall and diffuser location and design in accordance with [§ 125.59(f)(2)(i)](#f-2-i). Revisions by such applicants which propose downgrading treatment levels and/or outfall and diffuser location and design must be justified on the basis of substantial changes in circumstances beyond the applicant's control since the time of application submission.
  - (3) Applicants authorized or requested to submit additional information under [§ 125.59(g)](#g) may submit a revised application in accordance with [§ 125.59(f)(2)(ii)](#f-2-ii) where such additional information supports changes in proposed treatment levels and/or outfall location and diffuser design. The opportunity for such revision shall be in addition to the one-time revision allowed under [§ 125.59(d)](#d) (1) and (2).
  - (4) **POTWs which revise their applications must—**
    - (i) Modify their NPDES form and Application Questionnaire as needed to ensure that the information filed with their application is correct and complete;
    - (ii) Provide additional analysis and data as needed to demonstrate compliance with this subpart;
    - (iii) Obtain new State determinations under §§ [125.61(b)(2)](/cfr/40/125.61.md?p=b-2) and [125.64(b)](/cfr/40/125.64.md?p=b); and
    - (iv) **Provide the certification described in paragraph (c)(3) of this section.**
  - (5) Applications for permit renewal may not be revised.
- (e) **Submittal of additional information to demonstrate compliance with §§ 125.60 and 125.65.**
  - (1) On or before the deadline established in [paragraph (f)(3)](#f-3) of this section, applicants shall submit a letter of intent to demonstrate compliance with §§ [125.60](/cfr/40/125.60.md) and [125.65](/cfr/40/125.65.md). The letter of intent is subject to approval by the Administrator based on the requirements of this paragraph and [paragraph (f)(3)](#f-3) of this section. The letter of intent shall consist of the following:
    - (i) For compliance with [§ 125.60](/cfr/40/125.60.md): (A) A description of the proposed treatment system which upgrades treatment to satisfy the requirements of [§ 125.60](/cfr/40/125.60.md).
      - (B) A project plan, including a schedule for data collection and for achieving compliance with [§ 125.60](/cfr/40/125.60.md). The project plan shall include dates for design and construction of necessary facilities, submittal of influent/effluent data, and submittal of any other information necessary to demonstrate compliance with [§ 125.60](/cfr/40/125.60.md). The Administrator will review the project plan and may require revisions prior to authorizing submission of the additional information.
    - (ii) For compliance with [§ 125.65](/cfr/40/125.65.md): (A) A determination of what approach will be used to achieve compliance with [§ 125.65](/cfr/40/125.65.md).
      - (B) **A project plan for achieving compliance.** The project plan shall include any necessary data collection activities, submittal of additional information, and/or development of appropriate pretreatment limits to demonstrate compliance with [§ 125.65](/cfr/40/125.65.md). The Administrator will review the project plan and may require revisions prior to submission of the additional information.
    - (iii) **POTWs which submit additional information must—**
      - (A) Modify their NPDES form and Application Questionnaire as needed to ensure that the information filed with their application is correct and complete;
      - (B) Obtain new State determinations under §§ [125.61(b)(2)](/cfr/40/125.61.md?p=b-2) and [125.64(b)](/cfr/40/125.64.md?p=b); and
      - (C) **Provide the certification described in paragraph (c)(3) of this section.**
  - (2) The information required under this paragraph must be submitted in accordance with the schedules in [§ 125.59(f)(3)(ii)](#f-3-ii). If the applicant does not meet these schedules for compliance, EPA may deny the application on that basis.
- (f) **Deadlines and distribution—**
  - (1) **Applications.**
    - (i) The application for an original 301(h) permit for POTWs which directly discharges effluent into saline waters shall be submitted to the appropriate EPA Regional Administrator no later than December 29, 1982.
    - (ii) The application for renewal of a 301(h) modified permit shall be submitted no less than 180 days prior to the expiration of the existing permit, unless permission for a later date has been granted by the Administrator. (The Administrator shall not grant permission for applications to be submitted later than the expiration date of the existing permit.)
    - (iii) A copy of the application shall be provided to the State and interstate agency(s) authorized to provide certification/concurrence under [§§ 124.53 through 124.55](/cfr/40/124.53..124.55.md) on or before the date the application is submitted to EPA.
  - (2) **Revisions to Applications.**
    - (i) Applicants desiring to revise their applications under § [125.59 (d)(1)](#d-1) or [(d)(2)](#d-2) must:
      - (A) Submit to the appropriate Regional Administrator a letter of intent to revise their application either within 45 days of the date of EPA's tentative decision on their original application or within 45 days of November 26, 1982, whichever is later. Following receipt by EPA of a letter of intent, further EPA proceedings on the tentative decision under [40 CFR part 124](/cfr/40/part124.md) will be stayed.
      - (B) Submit the revised application as described for new applications in [§ 125.59(f)(1)](#f-1) either within one year of the date of EPA's tentative decision on their original application or within one year of November 26, 1982, if a tentative decision has already been made, whichever is later.
    - (ii) Applicants desiring to revise their applications under [§ 125.59(d)(3)](#d-3) must submit the revised application as described for new applications in [§ 125.59(f)(1)](#f-1) concurrent with submission of the additional information under [§ 125.59(g)](#g).
  - (3) Deadline for additional information to demonstrate compliance with §§ [125.60](/cfr/40/125.60.md) and [125.65](/cfr/40/125.65.md).
    - (i) A letter of intent required under [§ 125.59(e)(1)](#e-1) must be submitted by the following dates: for permittees with 301(h) modifications or for applicants to which a tentative or final decision has been issued, November 7, 1994; for all others, within 90 days after the Administrator issues a tentative decision on an application. Following receipt by EPA of a letter of intent containing the information required in [§ 125.59(e)(1)](#e-1), further EPA proceedings on the tentative decision under [40 CFR part 124](/cfr/40/part124.md) will be stayed.
    - (ii) The project plan submitted under [§ 125.59(e)(1)](#e-1) shall ensure that the applicant meets all the requirements of §§ [125.60](/cfr/40/125.60.md) and [125.65](/cfr/40/125.65.md) by the following deadlines:
      - (A) By August 9, 1996 for applicants that are not grandfathered under [§ 125.59(j)](#j).
      - (B) At the time of permit renewal or by August 9, 1996, whichever is later, for applicants that are grandfathered under [§ 125.59(j)](#j).
  - (4) **State determination deadline.** State determinations, as required by §§ [125.61(b)(2)](/cfr/40/125.61.md?p=b-2) and [125.64(b)](/cfr/40/125.64.md?p=b) shall be filed by the applicant with the appropriate Regional Administrator no later than 90 days after submission of the revision to the application or additional information to EPA. Extensions to this deadline may be provided by EPA upon request. However, EPA will not begin review of the revision to the application or additional information until a favorable State determination is received by EPA. Failure to provide the State determination within the timeframe required by this [paragraph (f)(4)](#f-4) is a basis for denial of the application.
- (g)
  - (1) The Administrator may authorize or request an applicant to submit additional information by a specified date not to exceed one year from the date of authorization or request.
  - (2) Applicants seeking authorization to submit additional information on current/modified discharge characteristics, water quality, biological conditions or oceanographic characteristics must:
    - (i) Demonstrate that they made a diligent effort to provide such information with their application and were unable to do so, and
    - (ii) Submit a plan of study, including a schedule, for data collection and submittal of the additional information. EPA will review the plan of study and may require revisions prior to authorizing submission of the additional information.
- (h) **Tentative decisions on section 301(h) modifications.** The Administrator shall grant a tentative approval or a tentative denial of a [section 301(h)](/cfr/40/301.md?p=h) modified permit application. To qualify for a tentative approval, the applicant shall demonstrate to the satisfaction of the Administrator that it is using good faith means to come into compliance with all the requirements of this subpart and that it will meet all such requirements based on a schedule approved by the Administrator. For compliance with §§ [125.60](/cfr/40/125.60.md) and [125.65](/cfr/40/125.65.md), such schedule shall be in accordance with [§ 125.59(f)(3)(ii)](#f-3-ii).
- (i) **Decisions on section 301(h) modifications.**
  - (1) The decision to grant or deny a [section 301(h)](/cfr/40/301.md?p=h) modification shall be made by the Administrator and shall be based on the applicant's demonstration that it has met all the requirements of [§§ 125.59 through 125.68](/cfr/40/125.59..125.68.md).
  - (2) No [section 301(h)](/cfr/40/301.md?p=h) modified permit shall be issued until the appropriate State certification/concurrence is granted or waived pursuant to [§ 124.54](/cfr/40/124.54.md) or if the State denies certification/ concurrence pursuant to [§ 124.54](/cfr/40/124.54.md).
  - (3) In the case of a modification issued to an applicant in a State administering an approved permit program under [40 CFR part 123](/cfr/40/part123.md), the State Director may:
    - (i) Revoke an existing permit as of the effective date of the EPA issued [section 301(h)](/cfr/40/301.md?p=h) modified permit; and
    - (ii) Cosign the [section 301(h)](/cfr/40/301.md?p=h) modified permit if the Director has indicated an intent to do so in the written concurrence.
  - (4) **Any section 301(h) modified permit shall—**
    - (i) Be issued in accordance with the procedures set forth in [40 CFR part 124](/cfr/40/part124.md), except that, because [section 301(h)](/cfr/40/301.md?p=h) permits may be issued only by EPA, the terms “Administrator or a person designated by the Administrator” shall be substituted for the term “Director” as appropriate; and
    - (ii) Contain all applicable terms and conditions set forth in [40 CFR part 122](/cfr/40/part122.md) and [§ 125.68](/cfr/40/125.68.md).
  - (5) Appeals of [section 301(h)](/cfr/40/301.md?p=h) determinations shall be governed by the procedures in [40 CFR part 124](/cfr/40/part124.md).
- (j) **Grandfathering provision.** Applicants that received tentative or final approval for a [section 301(h)](/cfr/40/301.md?p=h) modified permit prior to February 4, 1987, are not subject to [§ 125.60](/cfr/40/125.60.md), the water quality criteria provisions of [§ 125.62(a)(1)](/cfr/40/125.62.md?p=a-1), or [§ 125.65](/cfr/40/125.65.md) until the time of permit renewal. In addition, if permit renewal will occur prior to August 9, 1996, applicants may have additional time to come into compliance with §§ [125.60](/cfr/40/125.60.md) and [125.65](/cfr/40/125.65.md), as determined appropriate by EPA on a case-by-case basis. Such additional time, however, shall not extend beyond August 9, 1996. This paragraph does not apply to any application that was initially tentatively approved, but as to which EPA withdrew its tentative approval or issued a tentative denial prior to February 4, 1987.

# §125.60. Primary or equivalent treatment requirements.

- (a) The applicant shall demonstrate that, at the time its modification becomes effective, it will be discharging effluent that has received at least primary or equivalent treatment.
- (b) The applicant shall perform monitoring to ensure, based on the monthly average results of the monitoring, that the effluent it discharges has received primary or equivalent treatment.
- (c)
  - (1) An applicant may request that the demonstration of compliance with the requirement under [paragraph (b)](#b) of this section to provide 30 percent removal of BOD be allowed on an averaging basis different from monthly (e.g., quarterly), subject to the demonstrations provided in paragraphs [(c)(1)(i)](#c-1-i), [(ii)](#c-1-ii) and [(iii)](#c-1-iii) of this section. The Administrator may approve such requests if the applicant demonstrates to the Administrator's satisfaction that:
    - (i) The applicant's POTW is adequately designed and well operated;
    - (ii) The applicant will be able to meet all requirements under [section 301(h)](/cfr/40/301.md?p=h) of the CWA and these [subpart G](/cfr/40/subpartG.md) regulations with the averaging basis selected; and
    - (iii) The applicant cannot achieve 30 percent removal on a monthly average basis because of circumstances beyond the applicant's control. Circumstances beyond the applicant's control may include seasonally dilute influent BOD concentrations due to relatively high (although nonexcessive) inflow and infiltration; relatively high soluble to insoluble BOD ratios on a fluctuating basis; or cold climates resulting in cold influent. Circumstances beyond the applicant's control shall not include less concentrated wastewater due to excessive inflow and infiltration (I&I). The determination of whether the less concentrated wastewater is the result of excessive I&I will be based on the definition of excessive I&I in [40 CFR 35.2005(b)(16)](/cfr/40/35.2005.md?p=b-16) plus the additional criterion that inflow is nonexcessive if the total flow to the POTW (i.e., wastewater plus inflow plus infiltration) is less than 275 gallons per capita per day.
  - (2) In no event shall averaging on a less frequent basis than annually be allowed.

# §125.61. Existence of and compliance with applicable water quality standards.

- (a) There must exist a water quality standard or standards applicable to the pollutant(s) for which a [section 301(h)](/cfr/40/301.md?p=h) modified permit is requested, including:
  - (1) Water quality standards for biochemical oxygen demand or dissolved oxygen;
  - (2) Water quality standards for suspended solids, turbidity, light transmission, light scattering, or maintenance of the euphotic zone; and
  - (3) **Water quality standards for pH.**
- (b) **The applicant must—**
  - (1) Demonstrate that the modified discharge will comply with the above water quality standard(s); and
  - (2) Provide a determination signed by the State or interstate agency(s) authorized to provide certification under §§ [124.53](/cfr/40/124.53.md) and [124.54](/cfr/40/124.54.md) that the proposed modified discharge will comply with applicable provisions of State law including water quality standards. This determination shall include a discussion of the basis for the conclusion reached.

# §125.62. Attainment or maintenance of water quality which assures protection of public water supplies; assures the protection and propagation of a balanced indigenous population of shellfish, fish, and wildlife; and allows recreational activities.

- (a) **Physical characteristics of discharge.**
  - (1) At the time the 301(h) modification becomes effective, the applicant's outfall and diffuser must be located and designed to provide adequate initial dilution, dispersion, and transport of wastewater such that the discharge does not exceed at and beyond the zone of initial dilution:
    - (i) All applicable water quality standards; and
    - (ii) All applicable EPA water quality criteria for pollutants for which there is no applicable EPA-approved water quality standard that directly corresponds to the EPA water quality criterion for the pollutant.
    - (iii) For purposes of [paragraph (a)(1)(ii)](#a-1-ii) of this section, a State water quality standard “directly corresponds” to an EPA water quality criterion only if:
      - (A) The State water quality standard addresses the same pollutant as the EPA water quality criterion and
      - (B) The State water quality standard specifies a numeric criterion for that pollutant or State objective methodology for deriving such a numeric criterion.
    - (iv) The evaluation of compliance with [paragraphs (a)(1)](#a-1) (i) and (ii) of this section shall be based upon conditions reflecting periods of maximum stratification and during other periods when discharge characteristics, water quality, biological seasons, or oceanographic conditions indicate more critical situations may exist.
  - (2) The evaluation under [paragraph (a)(1)(ii)](#a-1-ii) of this section as to compliance with applicable [section 304(a)(1)](/cfr/40/304.md?p=a-1) water quality criteria shall be based on the following:
    - (i) **For aquatic life criteria—** The pollutant concentrations that must not be exceeded are the numeric ambient values, if any, specified in the EPA [section 304(a)(1)](/cfr/40/304.md?p=a-1) water quality criteria documents as the concentrations at which acute and chronic toxicity to aquatic life occurs or that are otherwise identified as the criteria to protect aquatic life.
    - (ii) **For human health criteria for carcinogens—**
      - (A) For a known or suspected carcinogen, the Administrator shall determine the pollutant concentration that shall not be exceeded. To make this determination, the Administrator shall first determine a level of risk associated with the pollutant that is acceptable for purposes of this section. The Administrator shall then use the information in the [section 304(a)(1)](/cfr/40/304.md?p=a-1) water quality criterion document, supplemented by all other relevant information, to determine the specific pollutant concentration that corresponds to the identified risk level.
      - (B) For purposes of [paragraph (a)(2)(ii)(A)](#a-2-ii-A) of this section, an acceptable risk level will be a single level that has been consistently used, as determined by the Administrator, as the basis of the State's EPA-approved water quality standards for carcinogenic pollutants. Alternatively, the Administrator may consider a State's recommendation to use a risk level that has been otherwise adopted or formally proposed by the State. The State recommendation must demonstrate, to the satisfaction of the Administrator, that the recommended level is sufficiently protective of human health in light of the exposure and uncertainty factors associated with the estimate of the actual risk posed by the applicant's discharge. The State must include with its demonstration a showing that the risk level selected is based on the best information available and that the State has held a public hearing to review the selection of the risk level, in accordance with provisions of State law and public participation requirements of [40 CFR part 25](/cfr/40/part25.md). If the Administrator neither determines that there is a consistently used single risk level nor accepts a risk level recommended by the State, then the Administrator shall otherwise determine an acceptable risk level based on all relevant information.
    - (iii) **For human health criteria for noncarcinogens—** For noncarcinogenic pollutants, the pollutant concentrations that must not be exceeded are the numeric ambient values, if any, specified in the EPA [section 304(a)(1)](/cfr/40/304.md?p=a-1) water quality criteria documents as protective against the potential toxicity of the contaminant through ingestion of contaminated aquatic organisms.
  - (3) The requirements of paragraphs [(a)(1)](#a-1) and [(a)(2)](#a-2) of this section apply in addition to, and do not waive or substitute for, the requirements of [§ 125.61](/cfr/40/125.61.md).
- (b) **Impact of discharge on public water supplies.**
  - (1) The applicant's modified discharge must allow for the attainment or maintenance of water quality which assures protection of public water supplies.
  - (2) The applicant's modified discharge must not:
    - (i) Prevent a planned or existing public water supply from being used, or from continuing to be used, as a public water supply; or
    - (ii) Have the effect of requiring treatment over and above that which would be necessary in the absence of such discharge in order to comply with local and EPA drinking water standards.
- (c) **Biological impact of discharge.**
  - (1) The applicant's modified discharge must allow for the attainment or maintenance of water quality which assures protection and propagation of a balanced indigenous population of shellfish, fish, and wildlife.
  - (2) A balanced indigenous population of shellfish, fish, and wildlife must exist:
    - (i) Immediately beyond the zone of initial dilution of the applicant's modified discharge; and
    - (ii) In all other areas beyond the zone of initial dilution where marine life is actually or potentially affected by the applicant's modified discharge.
  - (3) Conditions within the zone of initial dilution must not contribute to extreme adverse biological impacts, including, but not limited to, the destruction of distinctive habitats of limited distribution, the presence of disease epicenter, or the stimulation of phytoplankton blooms which have adverse effects beyond the zone of initial dilution.
  - (4) **In addition, for modified discharges into saline estuarine water—**
    - (i) Benthic populations within the zone of initial dilution must not differ substantially from the balanced indigenous populations which exist immediately beyond the boundary of the zone of initial dilution;
    - (ii) The discharge must not interfere with estuarine migratory pathways within the zone of initial dilution; and
    - (iii) The discharge must not result in the accumulation of toxic pollutants or pesticides at levels which exert adverse effects on the biota within the zone of initial dilution.
- (d) **Impact of discharge on recreational activities.**
  - (1) The applicant's modified discharge must allow for the attainment or maintenance of water quality which allows for recreational activities beyond the zone of initial dilution, including, without limitation, swimming, diving, boating, fishing, and picnicking, and sports activities along shorelines and beaches.
  - (2) There must be no Federal, State, or local restrictions on recreational activities within the vicinity of the applicant's modified outfall unless such restrictions are routinely imposed around sewage outfalls. This exception shall not apply where the restriction would be lifted or modified, in whole or in part, if the applicant were discharging a secondary treatment effluent.
- (e) **Additional requirements for applications based on improved or altered discharges.** An application for a [section 301(h)](/cfr/40/301.md?p=h) modified permit on the basis of an improved or altered discharge must include:
  - (1) A demonstration that such improvements or alterations have been thoroughly planned and studied and can be completed or implemented expeditiously;
  - (2) Detailed analyses projecting changes in average and maximum monthly flow rates and composition of the applicant's discharge which are expected to result from proposed improvements or alterations;
  - (3) The assessments required by [paragraphs (a) through (d)](#a..d) of this section based on its current discharge; and
  - (4) A detailed analysis of how the applicant's planned improvements or alterations will comply with the requirements of [paragraphs (a) through (d)](#a..d) of this section.
- (f) **Stressed waters.** An applicant must demonstrate compliance with [paragraphs (a) through (e)](#a..e) of this section not only on the basis of the applicant's own modified discharge, but also taking into account the applicant's modified discharge in combination with pollutants from other sources. However, if an applicant which discharges into ocean waters believes that its failure to meet the requirements of [paragraphs (a) through (e)](#a..e) of this section is entirely attributable to conditions resulting from human perturbations other than its modified discharge (including, without limitation, other municipal or industrial discharges, nonpoint source runoff, and the applicant's previous discharges), the applicant need not demonstrate compliance with those requirements if it demonstrates, to the satisfaction of the Administrator, that its modified discharge does not or will not:
  - (1) Contribute to, increase, or perpetuate such stressed conditions;
  - (2) Contribute to further degradation of the biota or water quality if the level of human perturbation from other sources increases; and
  - (3) Retard the recovery of the biota or water quality if the level of human perturbation from other sources decreases.

# §125.63. Establishment of a monitoring program.

- (a) **General requirements.**
  - (1) **The applicant must—**
    - (i) **Have a monitoring program that is—**
      - (A) Designed to provide data to evaluate the impact of the modified discharge on the marine biota, demonstrate compliance with applicable water quality standards or water quality criteria, as applicable, and measure toxic substances in the discharge, and
      - (B) Limited to include only those scientific investigations necessary to study the effects of the proposed discharge;
    - (ii) Describe the sampling techniques, schedules and locations (including appropriate control sites), analytical techniques, quality control and verification procedures to be used in the monitoring program;
    - (iii) Demonstrate that it has the resources necessary to implement the program upon issuance of the modified permit and to carry it out for the life of the modified permit; and
    - (iv) Determine the frequency and extent of the monitoring program taking into consideration the applicant's rate of discharge, quantities of toxic pollutants discharged, and potentially significant impacts on receiving water quality, marine biota, and designated water uses.
  - (2) The Administrator may require revision of the proposed monitoring program before issuing a modified permit and during the term of any modified permit.
- (b) **Biological monitoring program.** The biological monitoring program for both small and large applicants shall provide data adequate to evaluate the impact of the modified discharge on the marine biota.
  - (1) Biological monitoring shall include to the extent practicable:
    - (i) Periodic surveys of the biological communities and populations which are most likely affected by the discharge to enable comparisons with baseline conditions described in the application and verified by sampling at the control stations/reference sites during the periodic surveys;
    - (ii) Periodic determinations of the accumulation of toxic pollutants and pesticides in organisms and examination of adverse effects, such as disease, growth abnormalities, physiological stress, or death;
    - (iii) Sampling of sediments in areas of solids deposition in the vicinity of the ZID, in other areas of expected impact, and at appropriate reference sites to support the water quality and biological surveys and to measure the accumulation of toxic pollutants and pesticides; and
    - (iv) Where the discharge would affect commercial or recreational fisheries, periodic assessments of the conditions and productivity of fisheries.
  - (2) Small applicants are not subject to the requirements of [paragraph (b)(1)](#b-1) (ii) through (iv) of this section if they discharge at depths greater than 10 meters and can demonstrate through a suspended solids deposition analysis that there will be negligible seabed accumulation in the vicinity of the modified discharge.
  - (3) **For applicants seeking a section 301(h) modified permit based on—**
    - (i) A current discharge, biological monitoring shall be designed to demonstrate ongoing compliance with the requirements of [§ 125.62(c)](/cfr/40/125.62.md?p=c);
    - (ii) An improved discharge or altered discharge other than outfall relocation, biological monitoring shall provide baseline data on the current impact of the discharge and data which demonstrate, upon completion of improvements or alterations, that the requirements of [§ 125.62(c)](/cfr/40/125.62.md?p=c) are met; or
    - (iii) **An improved or altered discharge involving outfall relocation, the biological monitoring shall—**
      - (A) Include the current discharge site until such discharge ceases; and
      - (B) Provide baseline data at the relocation site to demonstrate the impact of the discharge and to provide the basis for demonstrating that requirements of [§ 125.62(c)](/cfr/40/125.62.md?p=c) will be met.
- (c) **Water quality monitoring program.** The water quality monitoring program shall to the extent practicable:
  - (1) Provide adequate data for evaluating compliance with water quality standards or water quality criteria, as applicable under [§ 125.62(a)(1)](/cfr/40/125.62.md?p=a-1);
  - (2) Measure the presence of toxic pollutants which have been identified or reasonably may be expected to be present in the discharge.
- (d) **Effluent monitoring program.**
  - (1) In addition to the requirements of [40 CFR part 122](/cfr/40/part122.md), to the extent practicable, monitoring of the POTW effluent shall provide quantitative and qualitative data which measure toxic substances and pesticides in the effluent and the effectiveness of the toxic control program.
  - (2) The permit shall require the collection of data on a frequency specified in the permit to provide adequate data for evaluating compliance with the percent removal efficiency requirements under [§ 125.60](/cfr/40/125.60.md).

# §125.64. Effect of the discharge on other point and nonpoint sources.

- (a) No modified discharge may result in any additional pollution control requirements on any other point or nonpoint source.
- (b) The applicant shall obtain a determination from the State or interstate agency(s) having authority to establish wasteload allocations indicating whether the applicant's discharge will result in an additional treatment pollution control, or other requirement on any other point or nonpoint sources. The State determination shall include a discussion of the basis for its conclusion.

# §125.65. Urban area pretreatment program.

- (a) **Scope and applicability.**
  - (1) The requirements of this section apply to each POTW serving a population of 50,000 or more that has one or more toxic pollutants introduced into the POTW by one or more industrial dischargers and that seeks a [section 301(h)](/cfr/40/301.md?p=h) modification.
  - (2) The requirements of this section apply in addition to any applicable requirements of [40 CFR part 403](/cfr/40/part403.md), and do not waive or substitute for the [part 403](/cfr/40/part403.md) requirements in any way.
- (b) **Toxic pollutant control.**
  - (1) As to each toxic pollutant introduced by an industrial discharger, each POTW subject to the requirements of this section shall demonstrate that it either:
    - (i) Has an applicable pretreatment requirement in effect in accordance with [paragraph (c)](#c) of this section; or
    - (ii) Has in effect a program that achieves secondary removal equivalency in accordance with [paragraph (d)](#d) of this section.
  - (2) Each applicant shall demonstrate that industrial sources introducing waste into the applicant's treatment works are in compliance with all applicable pretreatment requirements, including numerical standards set by local limits, and that it will enforce those requirements.
- (c) **Applicable pretreatment requirement.**
  - (1) An applicable pretreatment requirement under [paragraph (b)(1)(i)](#b-1-i) of this section with respect to a toxic pollutant shall consist of the following:
    - (i) As to a toxic pollutant introduced into the applicant's treatment works by an industrial discharger for which there is no applicable categorical pretreatment standard for the toxic pollutant, a local limit or limits on the toxic pollutant as necessary to satisfy the requirements of [40 CFR part 403](/cfr/40/part403.md); and
    - (ii) As to a toxic pollutant introduced into the applicant's treatment works by an industrial discharger that is subject to a categorical pretreatment standard for the toxic pollutant, the categorical standard and a local limit or limits as necessary to satisfy the requirements of [40 CFR part 403](/cfr/40/part403.md);
    - (iii) As to a toxic pollutant introduced into the applicant's treatment works by an industrial discharger for which there is no applicable categorical pretreatment standard for the toxic pollutant, and the [40 CFR part 403](/cfr/40/part403.md) analysis on the toxic pollutant shows that no local limit is necessary, the applicant shall demonstrate to EPA on an annual basis during the term of the permit through continued monitoring and appropriate technical review that a local limit is not necessary, and, where appropriate, require industrial management practices plans and other pollution prevention activities to reduce or control the discharge of each such pollutant by industrial dischargers to the POTW. If such monitoring and technical review of data indicate that a local limit is needed, the POTW shall establish and implement a local limit.
  - (2) Any local limits developed to meet the requirements of paragraphs [(b)(1)(i)](#b-1-i) and (c)(1) of this section shall be:
    - (i) Consistent with all applicable requirements of [40 CFR part 403](/cfr/40/part403.md) and
    - (ii) **Subject to approval by the Administrator as part of the 301(h) application review.** The Administrator may require such local limits to be revised as necessary to meet the requirements of this section or [40 CFR part 403](/cfr/40/part403.md).
- (d) **Secondary removal equivalency.** An applicant shall demonstrate that it achieves secondary removal equivalency through the use of a secondary treatment pilot (demonstration) plant at the applicant's facility which provides an empirical determination of the amount of a toxic pollutant removed by the application of secondary treatment to the applicant's influent where the applicant's influent has not been pretreated. Alternatively, an applicant may make this determination using influent that has received industrial pretreatment, notwithstanding the definition of secondary removal equivalency in [§ 125.58(w)](/cfr/40/125.58.md?p=w). The NPDES permit shall include effluent limits based on the data from the secondary equivalency demonstration when those limits are more stringent than effluent limits based on State water quality standards or water quality criteria, if applicable, or are otherwise required to assure that all applicable environmental protection criteria are met. Once such effluent limits are established in the NPDES permit, the POTW may either establish local limits or perform additional treatment at the POTW or a combination of the two to achieve the permit limit.

# §125.66. Toxics control program.

- (a) **Chemical analysis.**
  - (1) The applicant shall submit at the time of application a chemical analysis of its current discharge for all toxic pollutants and pesticides as defined in § [125.58(aa)](/cfr/40/125.58.md?p=aa) and [(p)](/cfr/40/125.58.md?p=p). The analysis shall be performed on two 24-hour composite samples (one dry weather and one wet weather). Applicants may supplement or substitute chemical analyses if composition of the supplemental or substitute samples typifies that which occurs during dry and wet weather conditions.
  - (2) Unless required by the State, this requirement shall not apply to any small [section 301(h)](/cfr/40/301.md?p=h) applicant which certifies that there are no known or suspected sources of toxic pollutants or pesticides and documents the certification with an industrial user survey as described by [40 CFR 403.8(f)(2)](/cfr/40/403.8.md?p=f-2).
- (b) **Identification of sources.** The applicant shall submit at the time of application an analysis of the known or suspected sources of toxic pollutants or pesticides identified in [§ 125.66(a)](#a). The applicant shall to the extent practicable categorize the sources according to industrial and nonindustrial types.
- (c) **Industrial pretreatment requirements.**
  - (1) An applicant that has known or suspected industrial sources of toxic pollutants shall have an approved pretreatment program in accordance with [40 CFR part 403](/cfr/40/part403.md).
  - (2) This requirement shall not apply to any applicant which has no known or suspected industrial sources of toxic pollutants or pesticides and so certifies to the Administrator.
  - (3) The pretreatment program submitted by the applicant under this section shall be subject to revision as required by the Administrator prior to issuing or renewing any [section 301(h)](/cfr/40/301.md?p=h) modified permit and during the term of any such permit.
  - (4) Implementation of all existing pretreatment requirements and authorities must be maintained through the period of development of any additional pretreatment requirements that may be necessary to comply with the requirements of this subpart.
- (d) **Nonindustrial source control program.**
  - (1) The applicant shall submit a proposed public education program designed to minimize the entrance of nonindustrial toxic pollutants and pesticides into its POTW(s) which shall be implemented no later than 18 months after issuance of a 301(h) modified permit.
  - (2) The applicant shall also develop and implement additional nonindustrial source control programs on the earliest possible schedule. This requirement shall not apply to a small applicant which certifies that there are no known or suspected water quality, sediment accumulation, or biological problems related to toxic pollutants or pesticides in its discharge.
  - (3) The applicant's nonindustrial source control programs under [paragraph (d)(2)](#d-2) of this section shall include the following schedules which are to be implemented no later than 18 months after issuance of a [section 301(h)](/cfr/40/301.md?p=h) modified permit:
    - (i) A schedule of activities for identifying nonindustrial sources of toxic pollutants and pesticides; and
    - (ii) A schedule for the development and implementation of control programs, to the extent practicable, for nonindustrial sources of toxic pollutants and pesticides.
  - (4) Each proposed nonindustrial source control program and/or schedule submitted by the applicant under this section shall be subject to revision as determined by the Administrator prior to issuing or renewing any [section 301(h)](/cfr/40/301.md?p=h) modified permit and during the term of any such permit.

# §125.67. Increase in effluent volume or amount of pollutants discharged.

- (a) No modified discharge may result in any new or substantially increased discharges of the pollutant to which the modification applies above the discharge specified in the [section 301(h)](/cfr/40/301.md?p=h) modified permit.
- (b) Where pollutant discharges are attributable in part to combined sewer overflows, the applicant shall minimize existing overflows and prevent increases in the amount of pollutants discharged.
- (c) The applicant shall provide projections of effluent volume and mass loadings for any pollutants to which the modification applies in 5-year increments for the design life of its facility.

# §125.68. Special conditions for section 301(h) modified permits.


Each [section 301(h)](/cfr/40/301.md?p=h) modified permit issued shall contain, in addition to all applicable terms and conditions required by [40 CFR part 122](/cfr/40/part122.md), the following:

- (a) Effluent limitations and mass loadings which will assure compliance with the requirements of this subpart;
- (b) **A schedule or schedules of compliance for—**
  - (1) Pretreatment program development required by [§ 125.66(c)](/cfr/40/125.66.md?p=c);
  - (2) Nonindustrial toxics control program required by [§ 125.66(d)](/cfr/40/125.66.md?p=d); and
  - (3) Control of combined sewer overflows required by [§ 125.67](/cfr/40/125.67.md).
- (c) **Monitoring program requirements that include—**
  - (1) Biomonitoring requirements of [§ 125.63(b)](/cfr/40/125.63.md?p=b);
  - (2) Water quality requirements of [§ 125.63(c)](/cfr/40/125.63.md?p=c);
  - (3) Effluent monitoring requirements of §§ [125.60(b)](/cfr/40/125.60.md?p=b), [125.62(c)](/cfr/40/125.62.md?p=c) and [(d)](/cfr/40/125.62.md?p=d), and [125.63(d)](/cfr/40/125.63.md?p=d).
- (d) Reporting requirements that include the results of the monitoring programs required by [paragraph (c)](#c) of this section at such frequency as prescribed in the approved monitoring program.