Connecticut’s IGP: Public Comment & Summary of Changes for 2nd Draft Permit

The Connecticut Department of Energy and Environmental Protection (DEEP) Water Permitting and Enforcement Division (WPED) is in the process of reissuing their National Pollutant Discharge Elimination System (NPDES) industrial stormwater general permit (IGP), a general permit that follows the multi-sector format of the United States Environmental Protection Agency’s (U.S. EPA) 2021 national industrial stormwater permit (MSGP). The original 45-day public comment for the reissuance began on March 11, 2024, ahead of the current permit’s expiration date on September 30, 2024.

As discussed in an earlier ALL4 blog, the proposed IGP contains more substantive changes than the previous re-issuances in 2016 and 2021. During the 45-day comment period, WPED received over 100 comments from various groups and U.S. EPA Region 1 on the proposed IGP. As a result of those comments, an updated draft IGP has been issued for a 30-day public comment period beginning on December 30, 2024.

Summary of Changes to the December 2024 IGP:

• Additional documentation has been added in Appendix H to include a flow chart providing guidance for semiannual benchmark monitoring and corrective actions, spanning from July 2025 to June 2030 to assist permittees in determining if a corrective action is required and when sampling is complete.
• Clarifications to Sector C (Chemical and Allied Products Manufacturing and Refining) and Sector O (Steam Electric Power Generation) for stormwater and non-stormwater discharge authorizations and prohibitions. The updated draft includes updated prohibitions to Sector C for runoff from phosphate fertilizer manufacturing coming into contact with storm water and discharges from coal storage piles at steam electric generating facilities for Sector O.
• Additional Control Measures updates to Sector Q (Water Transportation) and Sector R (Ship and Boat Building and Repair Yards) for minimizing the release or discharge of propylene glycol.
• Updates to the schedule for monitoring and data reporting for sector-specific federally required Effluent Limitation Guidelines.
• Sector AF (Federal, State, or Municipal Fleet Facilities) was modified for Sector-Specific Monitoring Requirements to include Federal, State, or Municipal Facilities without Vehicle Maintenance and Repair requirements. Permittees for facilities that do not conduct vehicle repair and maintenance on-site must review the Storm Water Pollution Prevention Plan (SWPPP) and existing stormwater control measures if for any parameter sampled the value is above the benchmark but is less than two times greater than the benchmark threshold or if the value is equal to or greater than two times the benchmark. Upon review of the SWPPP and stormwater control measures, the permittee must implement additional measures to help reduce the parameter exceedance for both exceedance types. When a parameter value exceedance is greater than or equal to two times the benchmark, additional sampling is required following the implementation of additional control measures to demonstrate effectiveness.

What Actions Do You Need to Take?

Additional information concerning the registration and renewal process will be posted by DEEP, however renewal registrations are not yet required at the time of this publication and should not be submitted. Facilities with existing permit coverage under the October 1, 2021, IGP will continue to have permit coverage under this general permit until DEEP has reissued the IGP. Following the issuance of the draft IGP, permittees will have 120 calendar days to renew their facility’s coverage under the general permit. Permittees should review the draft December 2024 IGP to familiarize themselves with sector specific changes and permit condition updates during this current 30-day public comment period.

If you have any questions regarding the draft December 2024 IGP updates or what your next steps should be to prepare for the issuance of the IGP, please reach out to me at cnagel@all4inc.com. ALL4 will continue to track updates to the IGP, and we are here to help with any actions your facility may need to take.