General Permit for the Discharge of Stormwater Associated with Industrial Activities

Notice of Tentative Determination of Intent to Reissue the General Permit for the Discharge of Stormwater Associated with Industrial Activities

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 Permit for the Discharge of Stormwater Associated with Industrial Activities (“Industrial Stormwater General Permit” or “general permit”) General Permit No.: CTR050000 under the authority of sections 22a-430 and 22a-430b of the Connecticut General Statutes (“CGS”) authorizing point source discharges to surface water.

2.0 Commissioner’s Findings
The purpose of the general permit is to protect the waters of the state from stormwater runoff discharging from industrial facilities. The current Industrial Stormwater General Permit became effective on October 1, 2021, with a permit duration of two (2) years and an expiration date of September 30, 2024. The Commissioner issued a timely notice of tentative determination to reissue the Industrial Stormwater General Permit on March 26, 2024, authorizing an automatic one (1) year extension of the general permit consistent with the provisions of CGS Section 22a-6aa.

DEEP Water Permitting and Enforcement Division staff reviewed the public comments received during the March 2024 public comment period and determined that significant modifications of the initial draft permit were necessary. The draft general permit, as revised in consideration of the comments received, is the subject of this second notice of tentative determination.

In accordance with applicable federal and state law, the Commissioner has made a tentative determination that discharges in accordance with, and authorized under, the Industrial Stormwater General Permit would not cause pollution to the waters of the state. The proposed general permit, if issued as drafted, will require registration for new and existing permittees and the development and implementation of a site-specific Stormwater Pollution Prevention Plan (“SWPPP”).

3.0 General Permit Regulatory Conditions
The general permit authorizes the discharge of stormwater to surface waters of the state of Connecticut.
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 & Stormwater Pollution Prevention Plan
The general permit requires eligible facilities to submit a registration to obtain permit coverage, develop
and implement a SWPPP, perform site inspections and visual assessments, and conduct stormwater outfall monitoring. The SWPPP must include detailed information describing the site, potential pollution sources, structural and non-structural stormwater control measures (“SCMs”), best management practices (“BMPs”), and procedures for performing inspections, stormwater monitoring and corrective actions.

Interim permit coverage for permittees under the current general permit will be maintained for an interim period of time, provided a complete registration for this permit has been submitted to the Commissioner within 120 days after the issuance date.

3.2 Effluent Limitations & Best Management Practices
The general permit establishes numeric and non-numeric permit conditions, such as water quality-based
and technology-based benchmark thresholds and federal Effluent Limitation Guideline limitations. General and sector specific SCMs and Best Management Practices BMPs are identified, and reference is made to the recently amended Connecticut Stormwater Quality Manual for guidance in the design and implementation of SCMs. Permit conditions and benchmarks are included to ensure the authorized discharges will be controlled to protect water quality standards.

4.0 Proposed Updates
Significant changes to the general permit include the following: an updated format that mirrors the 2021 US EPA Multi-Sector General Permit (“MSGP”); sector-specific designations for each permittee; clarifications on stormwater and non-stormwater discharge authorizations and prohibitions; additional sector-specific definitions; additional SCMs and BMPs for certain sectors; the inclusion of, or updates to, federally required Effluent Limitation Guidelines (“ELGs”) for certain sectors; increases in monitoring requirements to align with the MSGP; the inclusion of a new “Corrective Actions” section; utilization of new electronic DMR reporting and a new online noncompliance notification reporting tool; recommendations for the evaluation of resiliency measures; and submittal of an annual report, consistent with the federal MSGP and similar permits in the region.

To comply with the NPDES Electronic Reporting Rule (40 CFR 127), registration and reporting requirements under the general permit will transition completely to electronic filing. The new two-step registration process will combine the use of a simplified version of DEEP’s existing portal with EPA’s NPDES Electronic Reporting Tool (“NeT”). Permittees will then submit their stormwater monitoring data electronically through the NetDMR platform.

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 the Water Discharge Permit Regulations (sections 22a-430-3 and 4 of the Regulations of Connecticut State Agencies). 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 revised draft Industrial Stormwater General Permit and the general permit 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 Karen Abbott at karen.abbott@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 thirty (30) days of this public notice. Written comments should be directed to: Karen Abbott, Water Permitting and Enforcement Division, Bureau of Materials Management and Compliance Assurance, Department of Energy and Environmental Protection, 79 Elm Street, Hartford, CT 061065127 or may be submitted via electronic mail to: karen.abbott@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
741 .-will be best served thereby or shall hold a hearing upon receipt of a petition signed by at least twenty- five 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

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.

Published in the Hartford Courant, Connecticut Post, Waterbury Republican-American, New Haven Register, New London Day and The Chronicle on December 30, 2024.

Draft Permit
Fact Sheet

Appendix A_SECTORS, SIC CODES, and NAICS CODES
Appendix B_Certification of Registration
Appendix C_Aquifer Protection Areas (APAs)
Appendix D_Certification That the SWPPP Meets Permit Criteria
Appendix E_Certification of Non-Stormwater Discharges
Appendix F_Certification That Facility is Inactive or Unstaffed
Appendix G_Corrective Action Measure (CAM) Form
Appendix H_Guidance for Semiannual Benchmark Monitoring and Corrective Action
Appendix I_Certification That Facility Does Not Use Area
Appendix J_BMPs for Concrete Washout
Appendix K_Notice of Termination
Appendix L_No Discharge Codes