Does my facility need an industrial stormwater permit?

This image shows a flowchart to decide if facility needs an ISW permit
Flowchart used to decide if facility needs an Industrial Stormwater permit

Introduction

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
Link to this table

Is the facility’s industry type listed? What to do
Primary SIC code Secondary SIC code Narrative activity
Scenario 1 Listed Listed or not Listed or not Apply for permit or certify No Exposure
Scenario 2 Not listed Listed Not listed No stormwater permit required
Scenario 3 Listed or not Listed or not Listed 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.

Warehouses

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.”

No Exposure

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.

On-site activities

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.


Off-site activities

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.

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