August 11, 2023

NPDES General Industrial Permit
Industry sectors must update site-specific SWPPPs to comply with the 2023 NPDES General Permit. Here’s how.


On July 1, 2023, the Illinois Environmental Protection Agency (IEPA) posted and updated General NPDES Permit No. ILR00 for Industrial Storm Water Discharges (2023 General Permit). The 2023 General Permit is effective July 1, 2023, through June 30, 2028.

Multiple industry sectors must now update their site-specific Storm Water Pollution Prevention Plan (SWPPP) to comply with the 2023 General Permit. Three key updates in the 2023 General Permit are:

1-Permittees are required to submit a Notice of Intent (NOI) for renewal no later than 150 days after the 2023 General Permit is issued (i.e., by November 28, 2023).

2-Permittees must place a sign of permit coverage (except in instances where other laws or local ordinances prohibit such signage) 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 to contact the facility and IEPA if stormwater pollution is observed.

3-Benchmark sampling requirement updates, varying based on the industry sector’s Standard Industrial Classification (SIC) Code classification:

      • Certain SIC Code groups will be required to re-evaluate existing benchmark sampling constituent thresholds (See the list of these SIC Code groups below, titled List 1); and
      • Certain SIC Code groups will have new reporting requirements associated with constituents for which a benchmark threshold has not been established (See the list of these SIC Code groups below, titled List 2).


List 1 – SIC Code Groups with Updated Benchmark Sampling Constituents

Subsector C1 & C2

  • Agricultural Chemicals (SIC Code 2873-2879)
  • Industrial Inorganic Chemicals (SIC Code 2812-2819)

Subsector E1 & E2

  • Clay Product Manufacturers (SIC Code 3251-3259; 3261-3269)
  • Concrete and Gypsum Product Manufacturers (SIC Code 3271-3275)

Subsector F1 & F2

  • Steel Works, Blast Furnaces, and Rolling and Finishing Mills (SIC Code 3312-3317)
  • Iron and Steel Foundries (SIC Code 3321-3325)

Subsector H1

  • Coal Mines and Related Areas (SIC Code 1221-1241)

Subsector L1

  • All Landfills, Land Application Sites, and Open Dumps (Industrial Activity Code “LF”)

Subsector M1

  • Automobile Salvage Yards (SIC Code 5015)

Subsector Q1

  • Water Transportation Facilities (SIC Code 4412-4499)

Subsector AA1

  • Fabricated Metal Products, except Coating (SIC Code 3411-3499; 3911-3915)


List 2 – SIC Code Groups with New Benchmark Sampling Requirements for Reporting Purposes Only

Subsector B2

  • Pulp Mills (SIC Code 2611); Paper Mills (SIC Code 2621); Paperboard Containers and Boxes (SIC Code 2652-2657); Converted Paper and Paperboard Products, Except Containers and Boxes (SIC Code 2671-2679)

Subsector C5

  • Medicinal Chemicals and Botanical Products; Pharmaceutical Preparations; in vitro and in vivo Diagnostic Substances; and Biological Products, Except Diagnostic Substances (SIC Code 2833-2836); Paints, Varnishes, Lacquers, Enamels, and Allied Products (SIC Code 2851); Industrial Organic Chemicals (SIC  Code 2861-2869); Miscellaneous Chemical  Products (SIC Code 2891-2899); Inks and Paints, Including China Painting Enamels,  India Ink, Drawing Ink, Platinum Paints for  Burnt Wood or Leather Work, Paints for  China Painting, Artist’s Paints and Artist’s Watercolors (SIC Code 3952 (limited to list of inks and paints)); Petroleum Refining (SIC Code 2911)

Subsector D2

  • Miscellaneous Products of Petroleum and Coal (SIC Code 2992, 2999)

Subsector E3

  • Flat Glass (SIC Code 3211); Glass and Glassware, Pressed or Blown (SIC Code 3221, 3229); Glass Products Made of Purchased Glass (SIC Code 3231); Hydraulic Cement (SIC Code 3241); Cut Stone and Stone Products (SIC Code 3281); Abrasive, Asbestos, and Miscellaneous Nonmetallic Mineral Products (SIC Code 3291-3299) Miscellaneous Products of Petroleum and Coal (SIC Code 2992, 2999)

Subsector F5

  • Primary Smelting and Refining of Nonferrous Metals (SIC Code 3331-3339); Secondary Smelting and Refining of Nonferrous Metals (SIC Code 3341); Miscellaneous Primary Metal Products (SIC Code 3398, 3399)

Subsector I

  • Crude Petroleum and Natural Gas (SIC Code 1311); Natural Gas Liquids (Sic Code 1321); Oil and Gas Field Services (SIC Code 1381-1389)

Subsector J3

  • Clay, Ceramic, and Refractory Materials (SIC Code 1455,1459); Chemical and Fertilizer Mineral Mining (SIC Code 1474-1479)

Subsector L2

  • All Landfills, Land Application Sites, and Open Dumps, except Municipal Solid Waste Landfill (MSWLF) areas closed in accordance with 40 CFR 258.60 (Activity Code LF)

Subsector N2

  • Source-separated Recycling Facility (SIC Code 5093)

Subsector O1

  • Steam Electric Generating Facilities, including coal handling sites (SIC Code SE)

Subsector P1

  • Railroad Transportation (SIC Code 4011, 4013); Local and Highway Passenger Transportation (SIC Code 41114173); Motor Freight Transportation and Warehousing (SIC Code 4212-4231); United States Postal Service (SIC Code 4311); Petroleum Bulk Stations and Terminals (SIC Code 5171) Steam Electric Generating Facilities, including coal handling sites (SIC Code SE)

Subsector R1

  • Ship and Boat Building or Repairing Yards (SIC Code 3731, 3732)

Subsector T1

  • Treatment Works treating domestic sewage or any other sewage sludge or wastewater treatment device or system, used in the storage, treatment, recycling, and reclamation of municipal or domestic sewage, including land dedicated to the disposal of sewage sludge that is located within the confines of the facility, with a design flow of 1.0 mgd or more, or required to have an approved pretreatment program under 40 CFR Part 403. Not included are farmlands, domestic gardens, or lands used for sludge management where sludge is beneficially reused and which are not physically located in the confines of the facility, or areas that are in compliance with section 405 of the CWA (Activity Code TW)

Subsector U3

  • Meat Products (SIC Code 2011-2015); Dairy Products (SIC Code 2021-2026); Canned, Frozen, and Preserved Fruits, Vegetables, and Food Specialties (SIC Code 2032-2038); Bakery Products (SIC Code 2051-2053); Sugar and Confectionery Products (SIC Code 2061-2068); Beverages (SIC Code 20822087); Miscellaneous Food Preparations and Kindred Products (SIC Code 2091- 2099); Tobacco Products (SIC Code 2111-2141)

Subsector V1

  • Textile Mill Products (SIC Code 2211-2299); Apparel and Other Finished Products Made from Fabrics and Similar Materials (SIC Code 2311-2399); Leather and Leather Products (note: see Sector Z1 for Leather Tanning and Finishing) (SIC Code 3131-3199)

Subsector W1

  • Wood Kitchen Cabinets (SIC Code 2434); Furniture and Fixtures (Sic Code 2511-2599)

Subsector X1

  • Printing, Publishing, and Allied Industries (SIC Code 2711-2796)

Subsector Y2

  • Miscellaneous Plastics Products (SIC Code 3081-3089); Musical Instruments (SIC Code 3931); Dolls, Toys, Games, and Sporting and Athletic Goods (SIC Code 3942-3949); Pens, Pencils, and Other Artists’ Materials (SIC Code 3951-3955 (except 3952 – see Sector C)); Costume Jewelry, Costume Novelties, Buttons, and Miscellaneous Notions, Except Precious Metal (SIC Code 3961, 3965); Miscellaneous Manufacturing Industries (SIC Code 3991-3999)

Subsector Z1

  • Leather Tanning and Finishing (SIC Code 3111)

Subsector AB1

  • Industrial and Commercial Machinery, Except Computer and Office Equipment (see Sector AC) (SIC Code 3511-3599 (except 3571-3579)); Transportation Equipment except for Ship and Boat Building and Repairing (see Sector R) (SIC Code 3711-3799 (except 3731, 3732))

Subsector AC1

  • Computer and Office Equipment (SIC Code 3571-3579); Measuring, Analyzing, and Controlling Instruments; Photographic and Optical Goods, Watches, and Clocks (SIC Code 3812-3873); Electronic and Electrical Equipment and Components, Except Computer Equipment (SIC Code 3612-3699)


Our authors are available to answer questions about the Illinois stormwater regulations. You will find state professionals for updates or filing requirements local to your operation here.  


Spencer LaBelle serves as a Senior Project Engineer for our Upper Midwest Team. Spencer has prepared SWPPPs for multiple, diverse industries and operations throughout Illinois and assisted clients with SWPPP inspections from the Illinois EPA. He has diverse experience in civil/environmental consulting for stormwater and erosion control management systems, site development, and regulatory compliance.

Betsy Powers serves as a Vice President/Senior Project Manager for our Upper Midwest Team. She has over 25 years of experience in civil/environmental consulting, including erosion control and stormwater management, site development, regulatory compliance, landfill design and permitting, landfill construction, material recovery facility design, and compost facility design and permitting.


Additional NPDES and Stormwater Resources:




Posted by Diane Samuels at 6:00 am

September 29, 2021

SCS Engineers Chicago

New Chicago office location at 40 Shuman Boulevard, Suite 216, Naperville, IL 60563

SCS Engineers continues expanding its environmental team in its Chicago, Illinois office to meet environmental engineering and consulting needs focusing on waste management and the needs of the electric utilities. Driving demands are industries and municipalities seeking to reduce their environmental footprint while providing essential services and products.

Scott KnoepkeLeading the Chicagoland team, Professional Engineer and Professional Geologist Scott Knoepke. Knoepke serves clients needing remediation and site redevelopment. This includes commercial dry cleaners, retail petroleum sites, and heavy industries such as steel, rail, coal, mining, manufacturing, metal cutting, and plating.

Meet the Crew!

Richard SouthornRichard Southorn, PE, PG, with 20 years of experience, joins Knoepke supporting solid waste and electric utility sectors. Southorn began his career in the field performing CQA oversight, environmental monitoring, and soil core/rock core logging at landfill sites. He moved into landfill design and modeling, primarily to support landfill expansion projects. Richard has extensive experience with site layouts, geotechnical stability, stormwater management, and leachate generation analyses.


Brett Miller is a Senior Designer with over 20 years of experience and proficiency in AutoCAD Civil 3D and Maya. Brett is capable of any production drafting and is highly skilled in understanding 3D space. This helps him support designs that fit into site-specific, real-world environments. Brett also creates 3D models and animations that illustrate the benefits of a design to our clients.


Niko Villanueva, PE, joins SCS with eight years of experience. Niko provides engineering and drafting support and is experienced in designing various landfill systems such as stormwater management, leachate and gas control, and foundation analysis. He has also prepared cost estimates and construction bid quantities for various projects and construction quality assurance services at multiple facilities.


Meet Spencer LaBelle, with six years of experience. Spencer provides solutions for stormwater-related projects, including stormwater management system design, permitting, and compliance. He provides a diverse portfolio of clients and industries with stormwater-related services and environmental compliance.


Zack Christ, PE, comes to SCS with 15 years of experience in solid waste and CCR landfill sectors. Zack has experience performing CQA oversight and CQA management of landfill final cover, base liner, and GCCS; environmental monitoring; and logging soil borings. He also has extensive landfill design and CAD experience in developing landfill siting and permitting application projects. Zack’s areas of expertise include geotechnical analyses, stormwater management, leachate management design, GCCS design, and cost estimating.





Posted by Diane Samuels at 6:00 am