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Categories of Industrial Activity that Require Permit Coverage

The federal regulations, in 40 CFR 122.26(b)(14)(i)-(xi), identify 11 categories of stormwater discharges associated with industrial activity required to be covered under an NPDES permit (unless otherwise excluded). One category, Category 10, is construction sites that disturb five acres or more; however, because of the significant difference in the nature of those activities, construction sites are permitted separately. More information about permitting stormwater discharges from construction activities is available.

In general, the 10 categories of industrial activities are as follows:

  • Category One (i): Facilities subject to federal stormwater effluent discharge standards in 40 CFR Parts 405-471
  • Category Two (ii): Heavy manufacturing (for example, paper mills, chemical plants, pretroleum refineries, and steel mills and foundries)
  • Category Three (iii): Coal and mineral mining and oil and gas exploration and processing
  • Category Four (iv): Hazardous waste treatment, storage, or disposal facilities
  • Category Five (v): Landfills, land application sites, and open dumps with industrial wastes
  • Category Six (vi): Metal scrapyards, salvage yards, automobile junkyards, and battery reclaimers
  • Category Seven (vii): Steam electric power generating plants
  • Category Eight (viii): Transportation facilities that have vehicle maintenance, equipment cleaning, or airport deicing operations
  • Category Nine (ix): Treatment works treating domestic sewage with a design flow of 1 million gallons a day or more
  • Category Eleven (xi): Light manufacturing (For example, food processing, printing and publishing, electronic and other electrical equipment manufacturing, and public warehousing and storage).

EPA has issued a Multi-Sector General Permit (MSGP) that addresses stormwater discharges from 29 sectors of industrial activity.

The 29 sectors are defined by either the facility's Standard Industrial Classification (SIC) code Exit EPA Site or a general description of the facility’s industrial activities. The North American Industry Classification System (NAICS) will eventually replace the SIC system. The U.S. Census Bureau has a conversion table Exit EPA Site to bridge the two systems. For more information on each of the 29 sectors, view the Industrial Fact Sheet Series for Activities Covered by EPA's MSGP.

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Last updated on March 25, 2009 4:18 PM