UPDATE: Illinois EPA NPDES Industrial Storm Water Discharges

January 26, 2023

Attachment 1 of the NPDES Permit No. ILR00 Newly Published

On January 11, 2023, the Illinois Environmental Protection Agency posted the General NPDES Permit for Industrial Storm Water Discharges (NPDES Permit No. ILR00) for public review and comment.

Please note that numerous modifications and additions are proposed for Attachment 1 of the NPDES Permit No. ILR00. The Attachment was just made public by the Illinois Environmental Protection Agency. We are preparing a summary of the changes associated with each subsector.

Modifications and added parts or sections are summarized below:

1. Modification to Part F.1 – Storm Water Controls for permittees to consider stormwater control measure enhancements for major storm events (storm surges).
2. Indicator monitoring (measuring and reporting with no benchmark threshold) for pH, Total Suspended Solids (TSS), and Chemical Oxygen Demand (COD) has been modified in many subsectors for benchmark monitoring, as described in Attachment 1.
3. Indicator monitoring (measuring and reporting with no benchmark threshold) for polyaromatic hydrocarbons (PAHs) have been added for certain subsectors, as described in Attachment 1. This pertains to areas within a property where storm water is exposed to surfaces initially sealed or re-sealed with coal-tar sealcoat.

4. Benchmark threshold values have been updated for aluminum, copper, selenium, cadmium, magnesium, and iron in Attachment 1.
5. The benchmark monitoring schedule has been updated for many subsectors, as shown in Attachment 1. We anticipate that the IEPA will require benchmark monitoring to occur in the permit’s first and fourth years of coverage.

6. Additional implementation measures have been revised for some of the subsectors in Attachment 1.
7. A sign of permit coverage (except in instances where other laws or local ordinances prohibit such signage) must be placed in a safe, publicly accessible location in close proximity to the facility and include the following:

• • The NPDES ID Number
  • Information about how the public can request the facility’s SWPPP
  • And how they contact the facility and IEPA if stormwater pollution is observed.

8. Submit an updated Notice of Intent (NOI) within 150-days of the permit renewal date (to be determined)

All comments on the draft permit and requests for a public hearing must be received by the IEPA no later than February 11, 2023.

Our team of Storm Water professionals in Illinois includes Spencer LaBelle and Scott Knoepke, who are ready to answer your NPDES Permit questions and discuss how the proposed modifications to the permit may impact your operation.