Step 1: Applicability - do you need a permit?

Is my facility regulated by the industrial stormwater permit?

This step provides information to help facilities determine if they need industrial stormwater permit coverage. Any facility that is engaged in a Narrative Activity or a Primary SIC Code, as listed in the Multi-Sector General Permit (appendix A) needs to apply for permit coverage or certify for No Exposure.

PDF icon Appendix A: Sectors of industrial activities authorized

Determine your Primary SIC code

How do I know what my SIC code(s) or Narrative Activities are?

Businesses are designated by their SIC code(s) or by Narrative Activities, often for Commerce/Revenue purposes. One way to determine what SIC codes and Narrative Activities are applicable to your facility is to refer to your federal tax form — the codes are typically located on the upper left of the Schedule C or C-EZ for Sole Proprietors, Form 1065 for Partners, Form 1120 for C Corporations, or Form 1120-S for S Corporations. 

How do I look up a SIC codes? What if I have a NAICS code?

Determine if your industrial activities are regulated

Not authorized

  • Co-mingled wastewater & stormwater discharges: this discharge is considered wastewater and a Wastewater Discharge Permit may be required.

Not required

  • NPDES/SDS permit with stormwater requirements: If your individual wastewater discharge permit has stormwater requirements, you do not need to apply for the Multi-Sector General Permit.
  • MNG49 Permit: If your industrial stormwater activities can be covered by the MNG49 Nonmetallic Mining and Associated Activities Permit for sand, gravel, and concrete activities, you do not need to apply for the Multi-Sector General Permit.
  • No Narrative Activities or Primary SIC code: If you do not conduct a regulated narrative activity or regulated Primary SIC code, no permit is required.

Does my Facility have construction sand and gravel, aggregate, hot mix asphalt and/or concrete activities?

Facilities with industrial activities covered under the “Nonmetallic Mining and Associated Activities” Permit (MNG49) do not need to apply for the Multi-Sector General Permit. 

  • Construction sand and gravel mining areas (SIC code 1442) that discharge stormwater and/or pit dewatering wastewater, but no wash water;
  • Dimension stone, crushed and broken limestone, granite or stone mining and quarrying areas (SIC codes 1411, 1422, 1423 and 1429) that discharge stormwater only; OR,
  • Hot mix asphalt production areas (SIC code 2951) that discharge stormwater only.

The MNG49 Permit can cover multiple locations. For more information or to apply for the MNG49 Permit, go to the Nonmetallic Mining and Associated Activities program page. If a facility has additional industrial activities beyond what are listed above, either obtain the Multi-Sector General Permit for the location that has additional activities (such as local trucking, landfill activities) or obtain the Multi-Sector General Permit for portions of the facility with these additional activities.

Grain elevators: I own or operate a grain elevator. Do I need permit coverage?

Establishments primarily engaged in buying and/or marketing grain, or country grain elevators primarily engaged in buying or receiving grain from farmers (as well as terminal elevators and other merchants marketing grain) fall within SIC code 5153, and therefore do not need permit coverage. 

The 29 sectors of industrial activity


Sector description

SIC codes


Timber products

SIC codes: 2411, 2421, 2426, 2429, 2431-2439 (except 2434), 2441, 2448, 2449, 2451, 2452, 2491, 2493, 2499
Narrative activity: A4, Logging-discharges from wet decking storage areas


Paper and Allied Products Manufacturing

SIC codes: 2611, 2621, 2631, 2652-2657, 2671-2679


Chemical and Allied Products Manufacturing

SIC codes: 2812-2819, 2821-2824, 2833-2836, 2851, 2861- 2869, 2873-2879, 2891-2899, 3952
Narrative activity: C1, Runoff from phosphate fertilizer manufacturing facilities that comes into contact with any raw materials, finished product, by-products or waste products


Asphalt Paving and Roofing Materials Manufactures and Lubricant Manufacturers

SIC codes: 2951, 2952, 2992, 2999
Narrative activity: D2, Stormwater runoff from asphalt emulsion facility


Glass, Clay, Cement, Concrete, and Gypsum Product Manufacturing

SIC codes: 3211, 3221, 3229, 3231, 3241, 3251-3259, 3261-3269, 3271-3275, 3281, 3291-3299
Narrative activity: E3, Cement Manufacturing facility, material storage runoff


Primary Metals

SIC codes: 3312-3317, 3321-3325, 3341, 3351-3357, 3363-3369, 3398, 3399


Metal Mining (Ore Mining and Dressing)

SIC codes: 1011, 1021, 1031, 1041, 1044, 1061, 1081,1094, 1099


Coal Mines and Coal Mining-Related Facilities

SIC codes: 1221-1241


Oil and Gas Extraction and Refining

SIC codes: 1311, 1321, 1381-1389, 2911


Mineral Mining and Dressing

SIC codes: 1411, 1422-1429, 1442, 1446, 1455, 1459, 1474-1479, 1481, 1499 


Hazardous Waste Treatment Storage or Disposal Facilities

Narrative activities:
K1, Hazardous waste treatment/storage/disposal facility for discharges not subject to effluent limitations in 40 CFR pt. 445 subp. A
K2, Hazardous waste treatment/storage/disposal facility for discharges subject to effluent limitations in 40 CFR pt. 445 subp. A


Landfills and Land Application Sites

Narrative activities:
L1, Municipal solid waste landfill areas closed in accordance with 40 CFR 258.60
L2, Open or closed non-hazardous waste landfill and land application site not discharging to surface water
L3, Landfill that discharges to surface waters stormwater that has directly contacted solid waste


Automobile Salvage Yards

SIC Code: 5015


Scrap Recycling and Waste Recycling Facilities

SIC Code: 5093


Steam Electric Generating Facilities

Narrative activities:
O1, Coal fired and oil fired steam electric generating facility
O2, Nuclear, natural gas fired, and any other fuel source used for steam electric generation
O3, Runoff from coal storage piles at steam electric generating facility


Land Transportation and Warehousing

SIC codes: 4011, 4013, 4111-4173, 4212-4231, 4311, 5171


Water Transportation

SIC codes: 4412-4499


Ship and Boat Building and Repair Yards

SIC codes: 3731, 3732


Air Transportation

SIC codes: 4512-4581

Narrative activity:  S3: Existing and new primary airports with 1,000 or more annual jet departures that discharge wastewater associated with airfield pavement deicing that contains urea co-mingled with stormwater.


Treatment Works

Narrative activity: T1, Treatment works with design flow of 1 million gallons per day or more or are required to have an approved pretreatment program under 40 CFR pt. 403


Food and Kindred Products

SIC codes: 2041-2048, 2074-2079, 2011-2015, 2021-2026, 2032-2038, 2051-2053, 2061-2068,2082-2087, 2091-2099, 2111-2141


Textile Mills, Apparel, and Other Fabric Products Manufacturing

SIC codes: 2211-2299, 2311- 2399, 3131-3199


Furniture and Fixtures

SIC codes: 2434, 2511-2599


Printing and Publishing

SIC codes: 2711-2796


Rubber, Miscellaneous Plastic Products, and Miscellaneous Manufacturing Industries

SIC codes: 3011-3069, 3081-3089, 3931, 3942-3949, 3951-3955 (except 3952), 3961, 3965, 3991-3999


Leather Tanning and Finishing

SIC code: 3111


Fabricated Metal Products

SIC codes: 3411-3499, 3911-3915, 3479


Transportation Equipment, Industrial and Commercial Machinery

SIC codes: 3511-3599, (except 3571-3579), 3711-3799, (except 3731 and 3732)


Electronic and Electrical Equipment and Components, Photographic and Optical Goods

SIC codes: 3571-3579, 3612-3699, 3812-3873


Additional guidance materials

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