NPDES Permitting Resources
MS4 Notice of Intent (NOI) Program Compliance
The Illinois Environmental Protection Agency (Illinois EPA) updated their Notice of Intent (NOI) requirements on April 2025. The NOI outlines action’s the permittee will conduct for the next five years to be compliant with the MS4 permit program. Please note the Illinois EPA issued a new version of its General NPDES Permit No. ILR40 (Permit) which went into effect August 1, 2025.
In 2020 the Illinois EPA requested that each Municipal Separate Storm Sewer System (MS4) permittee submit an updated NOI by February 28, 2021, MS4 permittees who submitted before the February 28, 2021 do not need to submit a new NOI. MS4 permittees who did not submit an updated NOI by the deadline have 90 days of the effective date of the reissued permit to submit an updated NOI to renew Permit coverage.
Individual MS4 permittees should contact the Illinois EPA regarding any submittals to confirm compliance acceptance. If the permittee wishes to continue an activity regulated by this permit after the expiration date of this permit, the permittee must apply for and obtain a new permit. If the permittee submits a proper application as required by the Agency no later than 180 days prior to the expiration date, this permit shall continue in full force and effect until the final Agency decision on the application has been made.
Lake County SMC has provided QLP template documents to aid MS4 communities with the new NOI requirements. (https://www.lakecountyil.gov/3850/Notice-of-Intent-NOI). Additional geospatial resources specific to MS4 programs, can be found within the Lake County MS4 Community Information
NBWW Members NOI Spreadsheet
MS4 communities in the workgroup can recognize the NBWW’s in-stream monitoring data (including sediment sampling) for their NPDES permit compliance as a component of Collaborative watershed-scale monitoring. Ashley Strelcheck, NBWW Coordinator, has provided an NOI spreadsheet detailing NBWW’s monitoring strategy. This spreadsheet can be used as an MS4 program reference and can be included as an NOI reference in the WATER QUALITY AND SEDIMENT MONITORING PROGRAMS Section of the NOI. MS4s should reference program participation, include the spreadsheet hyperlink. For more information on how to utilize this NOI spreadsheet please contact Ashley Strelcheck, astrelcheck@lakecountyil.gov.
Spreadsheet: NBWW Notice of Intent Monitoring Strategy
MS4 Storm Water Management Program (SWMP) Compliance
The MS4 Permittee has 12 months from the coverage letter to comply with the new provisions of the recently released General Permit which went into effect August 1, 2025. The Permittee shall update their storm water management program (SWMP) or stormwater management program plan (SMPP). It is the Permitees responsibility to develop, implement, and enforce a designed to reduce the discharge of pollutants from their MS4 to protect water quality, and to satisfy the appropriate water quality requirements. Per correspondence with the Illinois EPA, a majority of MS4 permitees have received their Coverage Letter with the coverage date stamped on the top of the letter. MS4 permittees who have received a Coverage Letter without a date have until April 1, 2027 to comply with the new provisions of the Permit. Individual MS4 permittees should contact the Illinois EPA regarding NOI submittal status to confirm compliance acceptance if they have not received a coverage letter by August 1, 2026.
NBWW Annual Workplan Scorecards
See the NBWW Annual Workplan Scorecards (Reports & Data) strategy tables are specific program activities that can be included as measurable goals to meet the minimum control measures (MCM) of the NPDES ILR40 permit requirements. “Corresponding MS4 MCM” column should be reflected as measurable goals in the Stormwater Management Program Plan (SMPP) as well as annual facility inspection report. “Water Quality (WQ) Requirement” supports Part 5 of the NPDES ILR40 Permit.