The Phase I stormwater regulations created 11 categories of Stormwater Discharges Associated with Industrial Activity. Facilities in these categories must have an NPDES permit for their stormwater discharges. Categories i through ix and category xi are commonly called the Stormwater NPDES Industrial Program. Category x and the new Phase II requirements for Small Construction Sites together are called the Stormwater NPDES Construction Program.

• Category i: Facilities that are subject to Stormwater Effluent Limitation Guidelines, New Source Performance Standards, or Toxic Pollutant Effluent Standards under 40 CFR subchapter N.
• Category ii: Facilities with Standard Industrial Classifications as follows:
  • 24 - Lumber and Wood Products (except 2434 - Wood and Kitchen Cabinets)
  • 26 - Paper and Allied Products (except 265 - Paperboard Containers and Boxes and 267 - Converted
  • Paper and Paperboard Products, except Containers and Boxes)
  • 28 - Chemical and Allied Products (except 283 - Drugs)
  • 29 - Petroleum and Coal Products
  • 311 - Leather Tanning and Finishing
  • 32 - Stone, Clay, Glass, and Concrete Products (except 323 - Glass Products, Made of Purchased Glass)
  • 33 - Primary Metal Industries
  • 3441 - Fabricated Structural Metal
  • 373 - Ship and Boat Building and Repairing
• Category iii: Facilities with Standard Industrial Classifications as follows:
  • 10 through 14 - Mineral Industry (including active and inactive mining). Non-metallic mineral mining is covered exclusively by another NPDES program area under general permit SCG730000.
• Category iv: Hazardous waste treatment, storage, or disposal facilities, including those that are operating under interim status or a permit under subtitle C of RCRA.
• Category v: Landfills, land application sites, and open dumps that have received any industrial waste including those that are subject to regulation under subtitle D of RCRA.
• Category vi: Facilities involved in the recycling of materials, including metal scrap yards, battery reclaimers, salvage yards and automobile junkyards, including but limited to those classified as SIC 5015 (motor vehicle parts, used) and 5093 (scrap and waste material - this includes auto wreckers engaged in dismantling automobiles for scrap).
• Category vii: Steam electric power generating facilities, including coal handling sites.
• Category viii: Transportation facilities which have vehicle maintenance shops, equipment cleaning operations, or airport deicing operations and which have Standard Industrial Classifications as follows:
  • 40 - Railroad Transportation
  • 41 - Local and Interurban Passenger transport
  • 42 - Trucking and Warehousing (except: 4221 - Farm Product Warehousing and Storage, 4222 -
  • Refrigerated Warehousing and Storage, and 4225 - General Warehousing and Storage)
  • 43 - U.S. Postal Service
  • 44 - Water Transportation
  • 45 - Transportation by Air
  • 5171 - Petroleum Bulk Stations and Terminals (this does not include service stations or facilities that sell
  • only packaged products)
• Category ix: 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 sludge, including land dedicated to the disposal of sewage sludge that are 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 the federal regulations.
• Category x: Construction activity including clearing, grading and excavation activities except: operations that result in the disturbance of less than five acres of total land area which are not part of a larger common plan of development. This language has been modified by the current version of SCR000000 to further separate the Stormwater NPDES Industrial Program from the Construction Program.  Per 1.1.4.2 of SCR000000:
  • Stormwater discharges associated with construction activity disturbing one acre or more, statewide, or disturbing 0.5 acres or more in Horry, Georgetown, Berkeley, Charleston, Dorchester, Colleton, Beaufort, or Jasper County are not eligible for coverage under this permit. These discharges are subject to the requirements found in the NPDES General Permit for Stormwater Discharges from Large and Small Construction Activities (SCR100000).
• Category xi: Facilities under Standard Industrial Classifications as follows and which are not otherwise classified within categories ii through x. and which have "stormwater exposure":
  • 20 - Food and Kindred Products
  • 21 - Tobacco Products
  • 22 - Textile Mill Products
  • 23 - Apparel and Other Finished Products Made From Fabrics and Similar Material
  • 2434 - Wood Kitchen Cabinets
  • 25 - Furniture and Fixtures
  • 265 - Paperboard Containers and Boxes
  • 267 - Converted Paper and Paperboard Products, except Containers and Boxes
  • 27 - Printing, Publishing, and Allied Industries
  • 283 - Drugs
  • 285 - Paints, Varnishes, Lacquers, Enamels, and Allied Products
  • 30 - Rubber and Miscellaneous Plastic Products
  • 31 - Leather and Leather Products (except 311 - Leather Tanning and Finishing)
  • 323 - Glass Products, Made of Purchased Glass
  • 34 - Fabricated Metal Products (except 3441 - Fabricated Structural Metal Products)
  • 35 - Industrial and Commercial Machinery and Computer Equipment
  • 36 - Electronic and Other Electrical Equipment and Components, except Computers
  • 37 - Transportation Equipment (except 373 -Ship and Boat Building and Repairing)
  • 38 - Measuring, Analyzing, and Controlling Instruments; Photographic, Medical and Optical
  • Goods; Watches and Clocks
  • 39 - Miscellaneous Manufacturing Facilities
  • 4221 - Farm Product Warehousing and Storage
  • 4222 - Refrigerated Warehousing and Storage
  • 4225 - General Warehousing and Storage