General Pretreatment Permit for Significant Industrial User -4/28/25
Notice of Tentative Determination of Intent to Reissue the General Pretreatment Permit for Significant Industrial User Discharges to Publicly Owned Treatment Works
1.0 Tentative Determination
The Commissioner of the Department of Energy and Environmental Protection (“DEEP”) hereby gives notice of a tentative determination to reissue and administer the General Pretreatment Permit for Significant Industrial User Discharges to Publicly Owned Treatment Works (SIU GP) (“the General Permit” or “general permit”) under the authority of Sections 22a-430 and 22a-430b of the Connecticut General Statutes (“CGS”).
2.0 Commissioner’s Findings
The current general permit was issued on October 30, 2020, and expires on October 30, 2025. The purpose of the general permit is to protect the waters of the state from discharges from Significant Industrial Users (“SIU”) to publicly owned treatment works (“POTWs”).
In accordance with applicable federal and state law, the Commissioner has made a tentative determination that discharges authorized under the general permit will not cause pollution to the waters of the state. The proposed general permit, if reissued as drafted, contains effluent limits, discharge monitoring requirements, best management practices, and permit conditions established in accordance with Section 22a-430 of the Regulations of Connecticut State Agencies (“RCSA”) necessary to protect the waters of the state.
3.0 General Permit Regulatory Conditions
The general permit authorizes the discharge from SIUs to POTWs. Any discharge of water, substance, or material into the waters of the state other than the ones specified in the general permit are not authorized
by this general permit.
3.1 Registration
The general permit as drafted does not require a Registration Form for the General Pretreatment Permit for Significant Industrial User Discharges to Publicly Owned Treatment Works (“Registration”) for Emergency Discharges, Temporary Discharges, or Short-term Discharges occurring as a result of petroleum Underground Storage Tank (“UST") replacements lasting no more than thirty (30) consecutive days. All other new and existing discharges seeking authority under this general permit are required to file a complete Registration for the Commissioner’s written approval prior to initiating the discharge. For sites that have existing authorization to discharge under the 2020 SIU, Permittees continue to have interim permit coverage under this general permit as long as a complete Registration is submitted within ninety (90) days after the issuance date of the general permit to allow time for existing Permittees to submit a complete renewal Registration and obtain coverage under the reissued permit.
3.2 Effluent Limitations & Best Management Practices (“BMPs”)
The general permit establishes numeric parameter limitations and permit conditions. Limits are based on state and federal regulations and those developed using best professional judgement. General and sector specific BMPs are identified and referenced. Permit conditions and limits are included to ensure the authorized discharges will be protective of the waters of the state.
4.0 Proposed Changes
•The general permit will incorporate indirect discharges of Dewatering and Remediation Wastewater.
•Limits for Metal Finishing Wastewater discharges will be updated to include additional parameters.
•The limits for pH will be narrowed to 5.5 S.U. to 10.0 S.U. and include a two (2) year compliance for
Existing Permittees to transition to the more narrowed limits.
•A temperature limit will be added for all discharges.
•Flow reporting requirements will be updated requiring Permittees to report all flows in NetDMR.
•The general permit will incorporate DEEP’s new online noncompliance reporting tools.
•Per- and polyfluoroalkyl substances (“PFAS”) screening, monitoring, and, as applicable, minimization requirements will be added.
5.0 Commissioner’s Authority
The Commissioner is authorized to issue this general permit pursuant to Sections 22a-430 and 22a-430b of the CGS and Sections 22a-430-3 and 4 of the RCSA. The Commissioner is authorized to approve or deny any Registration under this general permit pursuant to CGS Section 22a-430b.
6.0 Public Comment
Interested persons may obtain a copy of this public notice, the draft general permit and fact sheet on the DEEP website at www.ct.gov/deep/publicnotices..The general permit materials are also available for inspection at the DEEP Bureau of Materials Management and Compliance Assurance, Water Permitting and Enforcement Division, 79 Elm Street, Hartford, CT from 8:30am – 4:30pm, Monday through Friday. Questions may be directed to the Pretreatment Group at DEEP.pretreatment@ct.gov or Brittany Bendel at brittany.bendel@ct.gov.
Prior to making a final decision to reissue the proposed general permit, the Commissioner shall consider written comments from interested persons that are received within 30 days of this public notice. Written comments should be directed to: Pretreatment Group, Water Permitting and Enforcement Division, Bureau
of Materials Management and Compliance Assurance, Department of Energy and Environmental Protection, 79 Elm Street, Hartford, CT 06106-5127 or may be submitted via electronic mail to: DEEP.pretreatment@ct.gov or Brittany Bendel at brittany.bendel@ct.gov. Electronic mail is recommended.
6.0 Petitions for Public Hearing
The Commissioner may conduct a public hearing if the Commissioner determines that the public interest will be best served thereby or shall hold a hearing upon receipt of a petition signed by at least twenty-five (25) persons. Petitions should include the name of the general permit noted above and also identify a contact person to receive notifications. Petitions may also identify a person who is authorized to engage in discussions regarding the proposed general permit and, if resolution is reached, withdraw the petition. Original signed petitions may be scanned and sent electronically to deep.adjudications@ct.gov or may be mailed or delivered to: DEEP Office of Adjudications, 79 Elm Street, 3rd floor, Hartford, CT 06106- 5127. All petitions must be received within the comment period noted above. If submitted electronically, original signed petitions must also be mailed or delivered to the address above within ten days of electronic submittal. If a hearing is held, timely notice of such hearing will be published in a newspaper of general circulation.
/s/Emma Cimino
Deputy Commissioner
Published on April 28 in the Hartford Courant, Connecticut Post, New Haven Register, Waterbury Republican-American, New London Day and The Chronicle.
Draft General Permit
Fact Sheet
The Connecticut Department of Energy and Environmental Protection is an Affirmative Action and Equal Opportunity Employer that is committed to complying with the Americans with Disabilities Act. To request an accommodation contact us at 860-418-5910 or deep.accommodations@ct.gov.