Does my facility need an industrial stormwater permit?
Flowchart used to decide if facility needs an Industrial Stormwater permit
This fact sheet addresses how to determine a facility’s primary Standard Industrial Classification code (SIC code) or narrative activity and related common questions.
The questions and answers in this fact sheet are based on Minnesota’s Questions and Answers, developed with the U.S. Environmental Protection Agency (EPA) to clarify EPA document “National Pollutant Discharge Elimination System (NPDES) Storm Water Program Questions and Answers, Vol. 1 and Vol. 2.”
Q1 How do I know if my facility needs an industrial stormwater permit?
The MPCA’s industrial stormwater permit lists the industries that need a permit. They are listed by SIC code or are explained in a narrative in Appendix D (page 148) of the permit. Listed industries must get a permit or certify that nothing is exposed to stormwater.
For convenience, the regulated primary SIC codes and descriptions of narrative activities are reprinted at the end of this fact sheet starting on page 10.
Q2 What is a SIC code?
SIC codes are a way of classifying industries by 4-digit codes. It is a descriptor of the kind of work being done at a facility, not a number specifically assigned to the facility like a tax ID. Facilities can have several SIC codes but only one Primary SIC code.
The IRS uses SIC codes, so your tax paperwork or accountant may already have the facility’s SIC code. Look on these federal tax forms:
Schedule C or C-EZ for Sole Proprietors
Form 1065 for Partners
Form 1120 for C Corporations
Form 1120-S for S Corporations
A searchable database of the SIC Codes is available here
Example: A company manufactures metal washers and hinges. Searching for the word “washers” on the linked OSHA website returns a few options. One of them – SIC 3452: Bolts, Nuts, Screws, Rivets and Washers – covers the washers, but not the hinges. Searching for “hinges” returns SIC 3429: Hardware Not Elsewhere Classified. Although hinges aren’t mentioned in the title for SIC 3429, they are specifically listed in the description. Be sure to read the descriptions because they frequently offer the SIC codes for related activities.
Q3 What is a Primary SIC code?
If a facility has more than one SIC code, the activity that generates the greatest revenue is the Primary SIC code. If revenue information is unavailable, use the SIC code for the activity with the most employees. If employee information is also unavailable, use the SIC code for the activity with the greatest production.
Q4 Does a facility need more than one stormwater permit if it has more than one SIC code?
No, only one permit or No Exposure certification is required; it will address all the operations at the facility.
Q5 My facility’s Primary SIC code isn’t listed. Do I need a permit?
If the facility fits one of the listed narrative activities, a permit or No Exposure certification is required regardless of whether or not the facility’s Primary SIC code is listed. But if the facility isn’t described by a listed narrative activity and its Primary SIC code isn’t listed, a permit isn’t required even if a Secondary SIC code is listed. See Table 1.
Q6 Do I have to consider my other SIC codes if I get the permit?
Yes, when the facility applies for the permit, list the Secondary SIC codes in the application. Comply with the sector requirements for the all the SIC codes at the facility and any narrative activities.
Q7 What are “narrative activities”?
Certain industries are easier to define by explaining what they do in a narrative paragraph. They are listed as narrative activities.
If a facility fits any of the listed narrative activities, whether for Primary or Secondary operations, it must get an industrial stormwater permit or the No Exposure exclusion.
Summary of when a permit it required based on SIC codes and narrative activity
Is the facility’s industry type listed?
Primary SIC Code
Secondary SIC Code
What to do
Listed or not
Listed or not
Apply for permit or certify No Exposure
Listed or not
No stormwater permit required
Listed or not
Listed or not
Apply for permit or certify No Exposure
Q8 What can my facility store outside and still qualify for No Exposure?
There are a few things a facility can have outside and still qualify for the No Exposure exclusion:
properly maintained vehicles, such as forklifts, industrial vehicles or delivery trucks
dumpsters that are in good condition, covered and not allowed to drain
materials that do not contaminate stormwater, such as products that are designed to be used outside, pallets in good condition or used tires
office buildings, employee parking lots and employees’ personal vehicles
Containers and tanks that are sealed and free from deterioration. They cannot have any taps or valves, because those could result in drips or leaks.
More information is in the MPCA stormwater factsheet #wq-strm3-13, “No Exposure: Qualifying for and maintaining the exclusion.”
Q9 What is a storm-resistant shelter?
A storm-resistant shelter can be:
a completely roofed and walled building
a structure with only a top cover but no side walls, as long as stormwater cannot flow through the structure and rain or snow that are blown in by the wind are prevented from running out, such as by a curb or berm
Q10 What if my facility has a different water permit?
Wastewater discharge permit
If a facility has a wastewater discharge permit that already includes stormwater requirements, a separate industrial stormwater permit is not required.
See Question 19 for wastewater treatment facility information.
Sand and gravel, stone, concrete and hot mix asphalt
Certain sand and gravel, stone, concrete and hot mix asphalt facilities qualify for the nonmetallic mining water permit. The MNG49 permit includes industrial stormwater requirements and has the advantage of covering multiple locations and portable plants under one permit. If a facility has MNG49 and all industrial activities at the facility are addressed in the permit, the facility does not need the industrial stormwater permit.
However, if a facility has MNG49 and there are industrial activities with a listed SIC code or narrative activity that are not addressed in MNG49 (such as local trucking or a landfill), the facility must add an industrial stormwater permit for the location or part of the location that has these additional activities.
For more information or to find out if a facility qualifies for MNG49, see the MPCA’s Nonmetallic Mining and Associated Activities water permit web page at http://www.pca.state.mn.us/iryp90f. Be careful not to confuse it with the air quality permit that has a similar name.
Q11 Do auxiliary operations need a permit?
On-site: On-site auxiliary operations, such as warehouses or vehicle maintenance shops, are considered Secondary SIC code activities. As discussed above in the section about SIC codes, a facility only needs a permit if the Primary SIC code or narrative activity is listed. If it is listed, get the permit and comply with the sector requirements for primary activities, auxiliary/secondary activities and any narrative activities, or certify for No Exposure.
Off-site: For off-site auxiliary operations, first determine whether industrial activities at the off-site facility have a listed Primary SIC code or narrative activity:
· If so, an industrial stormwater permit or No Exposure exclusion is required for the off-site facility.
· If the off-site facility does not have a listed Primary SIC code or narrative activity, the off-site facility takes on the SIC code or narrative activity of the facility it supports. If industrial activities at the main facility have a listed Primary SIC code or narrative activity, separate industrial stormwater permits or No Exposure exclusions are required for the off-site facility and the main facility.
· If neither facility has a listed Primary SIC code or narrative activity, neither facility needs a permit or No exposure certification.
Research and development
Pilot plants and research and development (R&D) facilities follow a similar decision process as other auxiliary operations:
If a pilot plant or research R&D facility is described by a listed Primary SIC code, it must get an industrial stormwater permit or No Exposure exclusion.
If an on-site pilot plant or R&D facility is located at a facility that is required to have a permit, so does the pilot plant or R&D facility.
If an off-site pilot plant or R&D facility doesn’t have a listed Primary SIC code or narrative activity, it takes on the SIC code or narrative activity of the facility it supports. If the main facility is required to have a permit, so does the pilot plant or R&D facility. The pilot plant or R&D facility must have its own permit and follow the sector requirements of the facility it supports, or certify for No Exposure.
If the R&D facility isn’t listed and the main facility isn’t listed, neither location needs an industrial stormwater permit or No Exposure certification.
Facilities primarily engaged in commercial physical and biological R&D on a contract or fee business are described by the Primary SIC code 8731. These facilities are not required to have an industrial stormwater permit or No Exposure certification.
Warehousing businesses that fit into one of the listed warehousing SIC codes (SIC 422x) must have a permit or certify for No Exposure. Warehouses located on-site at a facility that has a listed primary SIC code or narrative activity are included in that facility’s permit. Follow the sector requirements in the permit for Sector P – Land Transportation and Warehousing for the warehouses.
Off-site warehouses of preassembly parts or finished products are not required to have a permit unless they are specifically a warehouse business described by a warehouse SIC code (SIC 422x).
Q12 How is vehicle maintenance regulated?
Vehicle maintenance facilities follow a similar decision process as auxiliary operations unless they are associated with transportation facilities, which is discussed in more detail in the next section.
Independently-operated vehicle maintenance shops are usually described by Primary SIC codes 75xx or 7699. Neither of those SIC codes are listed, so facilities that fit those descriptions do not need an industrial stormwater permit or No Exposure certification.
For vehicle maintenance shops that provide support to a non-transportation facility:
An on-site vehicle maintenance shop supporting a facility that has an industrial stormwater permit is covered by the main facility’s permit.
An off-site vehicle maintenance shop supporting a facility that requires an industrial stormwater permit takes on the SIC code and sector requirements of the main facility. Both facilities require permits or No Exposure certification.
An off-site vehicle maintenance shop supporting a facility that is not required to have a permit does not need a permit or No Exposure certification.
Minnesota considers water from truck washing operations to be wastewater, not stormwater. Washwater cannot be discharged with stormwater.
Vehicle maintenance for transportation facilities
More information is in MPCA stormwater fact sheet #wq-strm3-32, “Guidance on the Industrial Stormwater Permit for Transportation Sectors.”
The No Exposure certification will be difficult to qualify for and maintain at a transportation facility, even if all vehicle maintenance and equipment cleaning is done indoors. Vehicle fueling is a common source of pollutants. Vehicles waiting for maintenance at transportation facilities are unlikely to be in good condition, resulting in potential exposure of pollutants to stormwater. Outdoor storage of materials used in vehicle maintenance or equipment cleaning are common and can contribute pollutants to stormwater. Particulate matter or residuals from roof stacks or vents that are not otherwise regulated (such as by an air quality permit) and are evident in stormwater are also considered a violation of No Exposure.
Vehicle maintenance shops, equipment cleaning facilities and airport de-icing operations located at a facility in one of the transportation categories (Sectors P, Q, R and S) are regulated by the industrial stormwater permit. However, the permit requirements apply only to the areas where vehicle maintenance, equipment cleaning or airport de-icing are being done. If a transportation facility is not doing vehicle maintenance, equipment cleaning or airport deicing, the facility does not need an industrial stormwater permit or No Exposure certification.
Follow Sector P requirements of the permit for local or long distance trucking maintenance or fueling located at a facility with a listed Primary SIC code.
Exception: Facilities with Primary SIC codes 4221-4225 (warehousing) must have an industrial stormwater permit or certify for No Exposure regardless of whether vehicle maintenance shops, equipment cleaning facilities and airport de-icing operations are present.
EPA has determined that most off-site vehicle maintenance facilities are supporting establishments that take on the SIC code of the facility they support. This means facilities that provide local trucking maintenance, fueling or washing take on the SIC code of the facility they support. If the main facility is required to have a permit, so does the off-site facility. The off-site facility takes on the sector requirements of the main facility.
Exception: Industrial stormwater permits or No Exposure exclusions are always required for vehicle maintenance associated long distance trucking, stevedoring (4491) and water transportation (44xx). As noted above, qualifying for the No Exposure certification will be difficult.
School bus maintenance facilities
The SIC code description for school bus transportation (SIC code 4151) excludes operations that are owned or run by a school district; these are instead covered under SIC code 8211, which is not a listed SIC code. This means school bus maintenance facilities that are owned or operated by a municipality or school district are not required to have an industrial stormwater permit or No Exposure certification.
However, private-contract school bus services (SIC code 4151) must have an industrial stormwater permit or certify for No Exposure. As noted above, qualifying for the No Exposure certification will be difficult.
Q13 Are tank farms regulated?
Tank farms need an industrial stormwater permit if stormwater from the tank farm mixes with stormwater from a vehicle maintenance shop or equipment cleaning operation. Tank farms at petroleum bulk storage stations (SIC code 5171) that don’t have vehicle maintenance or equipment cleaning operations are exempted and do not need an industrial stormwater permit.
If the tank farm is located at a facility that has a listed Primary SIC code, the tank farm is considered a secondary activity and is included in the main facility’s permit.
More information is in MPCA stormwater fact sheet #wq-strm3-32, “Guidance on the Industrial Stormwater Permit for Transportation Sectors.”
Q14 Are grain elevators regulated?
Facilities that only warehouse or store farm products are described by Primary SIC code 4221 and must have an industrial stormwater permit or certify No Exposure.
Grain elevators described by Primary SIC code 5153 do not need an industrial stormwater permit or No Exposure certification. They include elevators buying or marketing grain or beans, country grain elevators buying or receiving grain or beans from farmers and terminal elevators and other merchants marketing grain or beans.
Q15 Are wood mulch or animal bedding manufacturers regulated?
Wood mulch or animal bedding manufacturing are described by one of three listed SIC codes:
SIC 2421 – General Sawmills and Planing Mills
SIC 2429 – Special Product Sawmills Not Elsewhere Classified
SIC 2499 –Wood Products Not Elsewhere Classified
Facilities with any of these Primary SIC codes are regulated by the industrial stormwater permit.
Q16 Are military facilities regulated?
The overarching SIC code 9711 (national security) does not apply to industrial activities at a military facility. Each industrial activity on a military base or state reserve facility such as National Guard is considered to be a stand-alone industrial activity. EPA requires a separate permit or No Exposure exclusion for each listed industrial activity. This is unique to federal military facilities.
Section 313A of the Clean Water Act states that federal facilities "shall be subject to, and comply with, all federal, state, interstate, and local requirements... respecting the control and abatement of water pollution in the same manner, and to the same extent as any nongovernmental entity including the payment of reasonable service charges."
Q17 Are municipal or government facilities (non-military) regulated?
State and local municipal facilities follow the same decision-making process as any industrial facility. Start by determining the Primary SIC code and then evaluate on-site secondary and off-site auxiliary activities.
Publicly-owned government facilities usually are described by Primary SIC code 9199 – General Government, because the greatest revenue source and number of employees are from government administration. SIC code 9199 is not a listed SIC code so an industrial stormwater permit or No Exposure certification is not required. Common industrial activities such as police cars, fire trucks and snow plows are covered by SIC codes 9221, 9224 and 9229; dump trucks and heavy equipment used for construction are covered by SIC codes 1611-1629. None of these activities have listed SIC codes or narrative activities so an industrial stormwater permit or No Exposure certification is not required. This also means that secondary activities at these facilities, such as a Sector N recycling center or a warehouse, do not trigger the need for a permit or No Exposure certification. Off-site vehicle maintenance facilities supporting these SIC codes do not need the permit or No Exposure certification.
A vehicle maintenance facility located on-site at a municipal waste water treatment plant or landfill, which are listed narrative activities and require an industrial stormwater permit, is covered by the main facility’s permit.
A separately located recycling center needs an industrial stormwater permit or No Exposure certification; it is not considered to be auxiliary.
Question 20 lists municipal solid waste activities that do not need an industrial stormwater permit or No Exposure certification.
Q18 Are colleges and universities regulated?
Schools follow the same decision-making process as any industrial facility. Start by determining the primary SIC code and then evaluate on-site secondary and off-site auxiliary activities.
Schools without narrative activities
Public or private universities described by primary SIC code 8221 (Colleges, Universities and Professional Schools) that do not have on-site narrative activities are not required to have an industrial stormwater permit or No Exposure certification. On-site secondary activities with listed SIC codes do not trigger the need for a permit or No Exposure certification. Off-site auxiliary activities such as warehouses or vehicle maintenance shops are not required to have a permit or No Exposure certification.
Schools with narrative activities
Public or private university campuses with a narrative activity are required to have an industrial stormwater permit and follow the requirements for the narrative activity’s sector. All industrial activities at the main campus are covered by the permit, including warehouses, vehicle and equipment maintenance facilities, printing presses and recycling centers. Off-site industrial activities supporting the main campus take on the narrative activity and are required to have the permit or No Exposure certification. The main campus and the supporting facility each need their own permit or No Exposure certification. Both follow the requirements of the narrative activity’s sector. A separately located warehouse does not need the permit or No Exposure certification (see section on warehouses for more information).
Schools with off-site listed or narrative activities
An off-site, university-run facility described by a listed Primary SIC code must have an industrial stormwater permit or No Exposure certification. Common examples are off-site, university-run printing presses or recycling centers. They are described by listed Primary SIC codes 27xx and 5093, respectively, and therefore must get a permit or No Exposure certification. The main campus does not need an industrial stormwater permit or No Exposure certification.
An off-site, university-run facility described by a narrative activity must have an industrial stormwater permit or No Exposure certification. If auxiliary activities are conducted at the off-site facility, all of these activities are covered by the permit. The main campus is not required to apply for an industrial stormwater permit or No Exposure certification.
Q19 Are wastewater treatment facilities regulated?
Most wastewater treatment plants are described by the Sector T narrative activity and therefore must have an industrial stormwater permit.
Vehicle or equipment maintenance associated with a wastewater treatment facility (for example, to haul sewage sludge or to move equipment from the maintenance facility to the treatment plant), whether on-site or off-site, takes on the classification of the main facility and is required to have an industrial stormwater permit if the facility does. If the maintenance facility serves multiple wastewater treatment authorities, it is required to have an industrial stormwater permit.
Wastewater treatment facilities that collect their stormwater runoff and treat the stormwater as part of the normal inflow processed through the treatment plant are not required to have an industrial stormwater permit or No Exposure certification. Stormwater mixed with wastewater becomes wastewater and is addressed by the NPDES wastewater permit for the facility.
Off-site areas where sludge (biosolid) is beneficially reused do not need an industrial stormwater permit or No Exposure certification. For the purposes of the industrial stormwater permit, beneficial reuse of sludge is the application of sludge as a nutrient builder or soil conditioner. It can include agricultural or domestic application.
Off-site pumping stations do not need an industrial stormwater permit or No Exposure certification.
Q20 Which solid waste facilities are exempted?
An industrial stormwater permit or No Exposure certification is not required for solid waste facilities that are exempted from solid waste permitting, or, are granted a solid waste permit without applying for it by Minn. R. 7001.3050, subp.2 and subp.3. This includes the following:
Backyard compost sites.
Yard waste compost facilities that are in compliance with Minn. R. 7035.2836, subp. 2 and 3.
Temporary community cleanup events such as household hazardous waste collection events, provided:
the event is sponsored or approved by the municipality
the event is open to residents of the community
the event occurs no more than twice a year
the event, including removal of the wastes, lasts no more than seven days
Solid waste transfer facilities that accept waste directly from individual residents who self-haul, provided:
the county where the facility is located has determined the facility is necessary due to limited availability of solid waste collection services
no more than 40 cubic yards of waste are stored on site at any given time
no more than 40 cubic yards of waste are managed on site per day
All waste is managed and stored in containers or roll-off boxes constructed of impervious material; and,
removal of waste occurs when the capacity of the container is reached or more often as necessary to prevent nuisance conditions
Transfer facilities that move from location to location and receive solid waste directly from other vehicles for consolidation, provided they are not located in an area for more than 12 hours, all waste is delivered vehicle to vehicle and is not dumped and reloaded.
Transfer facilities where all waste is managed and stored in containers or roll-off boxes constructed of impervious material or in a fully enclosed building that meet the standards in Minn. R. 7035.2870, subp. 3 or subp. 4, provided that in either case the facility is in compliance with the requirements of Minn. R. 7001.3050, subp.3, item A.
Beneficial use of solid waste and storage of a solid waste prior to its beneficial use done according to Minn. R. 7035.2855 and 7035.2860.
Demonstration or research projects authorized by Minn. R. 7035.0450.
Disposal of solid waste on the same property where it was discovered if review, investigation and oversight is conducted under Minn. Stat. § 115B.17, subd. 14 and response actions are conducted in accordance with a plan approved under Minn. Stat. § 115B.175.
Demolition debris land disposal facilities that are designed for less than 15,000 cubic yards total capacity, operate less than a total of 12 consecutive months, are not located adjacent to another demolition debris permit-by-rule facility and are in compliance with Minn. R. 7035.2525 to 7035.2655, 7035.2825 and 7035.2855.
Q21 Are facilities with effluent limits or performance standards regulated?
The following facilities are required to have an industrial stormwater permit or certify for No Exposure:
facilities with air emission new source performance standards
facilities with wastewater toxic pollutant effluent standards
facilities with stormwater effluent limits
Standard Industrial Classification (SIC) codes and narrative activities list
Sector A: Timber products
2421 Sawmills and planning mills-general
2426 Hardwood dimension and flooring mills
2429 Special products sawmills, NEC
2435 Hardwood veneer and plywood
2436 Softwood veneer and plywood
2439 Structural wood members, NEC
2441 Nailed and lock corner wood boxes and shook
2448 Wood pallets and skids
2449 Wood containers, NEC
2451 Mobile homes
2452 Prefabricated wood buildings and components
2491 Wood preserving
2493 Reconstituted wood products
2499 Wood products, NEC
Sector B: Paper and allied products manufacturing
2611 Pulp mills
2621 Paper mills
2631 Paperboard mills
2652 Setup paperboard boxes
2653 Corrugated and solid fiber boxes
2655 Fiber cans, tubes, drums, and similar products
2656 Sanitary food containers (except folding)
2657 Folding paperboard boxes, including sanitary
2671 Packaging paper and plastics film (coated and laminated)
2672 Coated and laminated paper, NEC
2673 Plastics, foil and coated paper bags
2674 Uncoated paper and multiwall bags
2675 Die-cut paper, paperboard, and cardboard
2676 Sanitary paper products
2678 Stationary, tablets, and related products
2679 Converted paper and paperboard products, NEC
Sector C: Chemical and allied products manufacturing
2812 Alkalies and chlorine
2813 Industrial gases
2816 Inorganic pigments
2819 Industrial inorganic pigments, NEC
2821 Plastic materials, synthetic resins and elastomers