When the Director receives any information (for example, inspects the facility, receives information submitted by the permittee as required in the permit (see § 122.41 ), receives a request for modification or revocation and reissuance under § 124.5 , or conducts a review of the permit file) he or she may determine whether or not one or more of the causes listed in paragraphs (a) and (b) of this section for modification or revocation and reissuance or both exist. If cause exists, the Director may modify or revoke and reissue the permit accordingly, subject to the limitations of § 124.5(c) , and may request an updated application if necessary. When a permit is modified, only the conditions subject to modification are reopened. If a permit is revoked and reissued, the entire permit is reopened and subject to revision and the permit is reissued for a new term. See § 124.5(c)(2) . If cause does not exist under this section or § 122.63 , the Director shall not modify or revoke and reissue the permit. If a permit modification satisfies the criteria in § 122.63 for "minor modifications" the permit may be modified without a draft permit or public review. Otherwise, a draft permit must be prepared and other procedures in part 124 (or procedures of an approved State program) followed.
(a)Causes for modification. The following are causes for modification but not revocation and reissuance of permits except when the permittee requests or agrees. (1)Alterations. There are material and substantial alterations or additions to the permitted facility or activity (including a change or changes in the permittee's sludge use or disposal practice) which occurred after permit issuance which justify the application of permit conditions that are different or absent in the existing permit. Note: Certain reconstruction activities may cause the new source provisions of § 122.29 to be applicable.
(2)Information. The Director has received new information. Permits may be modified during their terms for this cause only if the information was not available at the time of permit issuance (other than revised regulations, guidance, or test methods) and would have justified the application of different permit conditions at the time of issuance. For NPDES general permits (§ 122.28 ) this cause includes any information indicating that cumulative effects on the environment are unacceptable. For new source or new discharger NPDES permits §§ 122.21 , 122.29 ), this cause shall include any significant information derived from effluent testing required under § 122.21(k)(5)(vi) or § 122.21(h)(4)(iii) after issuance of the permit.(3)New regulations. The standards or regulations on which the permit was based have been changed by promulgation of amended standards or regulations or by judicial decision after the permit was issued. Permits may be modified during their terms for this cause only as follows:(i) For promulgation of amended standards or regulations, when:(A) The permit condition requested to be modified was based on a promulgated effluent limitation guideline, EPA approved or promulgated water quality standards, or the Secondary Treatment Regulations under part 133; and(B) EPA has revised, withdrawn, or modified that portion of the regulation or effluent limitation guideline on which the permit condition was based, or has approved a State action with regard to a water quality standard on which the permit condition was based; and(C) A permittee requests modification in accordance with § 124.5 within ninety (90) days after FEDERAL REGISTER notice of the action on which the request is based.(ii) For judicial decisions, a court of competent jurisdiction has remanded and stayed EPA promulgated regulations or effluent limitation guidelines, if the remand and stay concern that portion of the regulations or guidelines on which the permit condition was based and a request is filed by the permittee in accordance with § 124.5 within ninety (90) days of judicial remand.(iii) For changes based upon modified State certifications of NPDES permits, see § 121.10 of this chapter.(4)Compliance schedules. The Director determines good cause exists for modification of a compliance schedule, such as an act of God, strike, flood, or materials shortage or other events over which the permittee has little or no control and for which there is no reasonably available remedy. However, in no case may an NPDES compliance schedule be modified to extend beyond an applicable CWA statutory deadline. See also § 122.63(c) (minor modifications) and paragraph (a)(14) of this section (NPDES innovative technology).(5) When the permittee has filed a request for a variance under CWA section 301(c), 301(g), 301(h), 301(i), 301(k), or 316(a) or for "fundamentally different factors" within the time specified in § 122.21 or § 125.27(a) .(6)307(a) toxics. When required to incorporate an applicable 307(a) toxic effluent standard or prohibition (see § 122.44(b) ).(7)Reopener. When required by the "reopener" conditions in a permit, which are established in the permit under § 122.44(b) (for CWA toxic effluent limitations and Standards for sewage sludge use or disposal, see also § 122.44(c) ) or 40 CFR 403.18(e) (Pretreatment program).(8)(i)Net limits. Upon request of a permittee who qualifies for effluent limitations on a net basis under § 122.45(g) .(ii) When a discharger is no longer eligible for net limitations, as provided in § 122.45(g)(1)(ii) .(9)Pretreatment. As necessary under 40 CFR 403.8(e) (compliance schedule for development of pretreatment program).(10)Failure to notify. Upon failure of an approved State to notify, as required by section 402(b)(3), another State whose waters may be affected by a discharge from the approved State.(11)Non-limited pollutants. When the level of discharge of any pollutant which is not limited in the permit exceeds the level which can be achieved by the technology-based treatment requirements appropriate to the permittee under § 125.3(c) .(12)Notification levels. To establish a "notification level" as provided in § 122.44(f) .(13)Compliance schedules. To modify a schedule of compliance to reflect the time lost during construction of an innovative or alternative facility, in the case of a POTW which has received a grant under section 202(a)(3) of CWA for 100% of the costs to modify or replace facilities constructed with a grant for innovative and alternative wastewater technology under section 202(a)(2). In no case shall the compliance schedule be modified to extend beyond an applicable CWA statutory deadline for compliance.(14) For a small MS4, to include an effluent limitation requiring implementation of a minimum control measure or measures as specified in § 122.34(b) when: (i) The permit does not include such measure(s) based upon the determination that another entity was responsible for implementation of the requirement(s); and(ii) The other entity fails to implement measure(s) that satisfy the requirement(s).(15) To correct technical mistakes, such as errors in calculation, or mistaken interpretations of law made in determining permit conditions.(16) When the discharger has installed the treatment technology considered by the permit writer in setting effluent limitations imposed under section 402(a)(1) of the CWA and has properly operated and maintained the facilities but nevertheless has been unable to achieve those effluent limitations. In this case, the limitations in the modified permit may reflect the level of pollutant control actually achieved (but shall not be less stringent than required by a subsequently promulgated effluent limitations guideline).(17)Nutrient Management Plans. The incorporation of the terms of a CAFO's nutrient management plan into the terms and conditions of a general permit when a CAFO obtains coverage under a general permit in accordance with §§ 122.23(h) and 122.28 is not a cause for modification pursuant to the requirements of this section.(18)Land application plans. When required by a permit condition to incorporate a land application plan for beneficial reuse of sewage sludge, to revise an existing land application plan, or to add a land application plan.(b)Causes for modification or revocation and reissuance. The following are causes to modify or, alternatively, revoke and reissue a permit: (1) Cause exists for termination under § 122.64 , and the Director determines that modification or revocation and reissuance is appropriate.(2) The Director has received notification (as required in the permit, see § 122.41(l)(3) ) of a proposed transfer of the permit. A permit also may be modified to reflect a transfer after the effective date of an automatic transfer (§ 122.61(b) ) but will not be revoked and reissued after the effective date of the transfer except upon the request of the new permittee.48 FR 14153, Apr. 1, 1983, as amended at 49 FR 25981, June 25, 1984; 49 FR 37009, Sept. 29, 1984; 49 FR 38050, Sept. 26, 1984; 50 FR 4514, Jan. 31, 1985; 51 FR 20431, June 4, 1986; 51 FR 26993, July 28, 1986; 54 FR 256, 258, Jan. 4, 1989; 54 FR 18784, May 2, 1989; 60 FR 33931, June 29, 1995; 64 FR 68847, Dec. 8, 1999; 65 FR 30909 , May 15, 2000; 70 FR 60191 , Oct. 14, 2005; 73 FR 70485 , Nov. 20, 2008; 88 FR 66666 , Sept. 27, 2023