Stormwater Program for Industrial Activity: Steps to Compliance
Step 2: Consider certifying for No Exposure
How do I figure out if I can qualify for No Exposure?
No materials or industrial activities outside? Apply for No Exposure! A key component of the rules is sheltering pollutant-containing (significant) materials from exposure to stormwater. Facilities that shelter all significant materials and activities from stormwater may be eligible for No Exposure.
Step 2a: Review the benefits of certifying for No Exposure:
What are the benefits of certifying for No Exposure?

- 5-year exclusion from the requirements of the industrial stormwater permit
- No Stormwater Pollution Prevention Plan to create
- No application fee or no annual fee to pay
- No annual reports to fill out
- No monitoring to conduct
No Exposure is good for business—and our water
Some facilities may need to take simple actions in order to qualify for the exclusion. Others will need to make more extensive efforts to qualify. All facilities will benefit by removing significant materials from exposure to stormwater, even those requiring a permit. These benefits include increased efficiency through pollution prevention, improved employee health and safety, simplified regulatory compliance, and protection of Minnesota’s waters. Facilities may choose to store materials and conduct activities indoors or within a storm-resistent shelter.
Step 2b: Determine if your activities and materials are within a storm-resistant shelter:
What is a storm-resistant shelter?
Facilities with uncovered scrap bins, trash compactors or other significant materials exposed to the elements need to complete a Stormwater Pollution Prevention Plan, and then apply for permit coverage.
Storm-resistant shelters include completely roofed and walled buildings or structures, as well as structures with only a top cover but no side coverings, provided the material under the structure is not otherwise subject to any run-on and subsequent runoff of stormwater, such as berming the area or sloping the land inward to prevent spills from running out of the area.
Step 2c: Determine if you have any outdoor significant materials
Significant materials
No Exposure means that rain, snow, and runoff do not contact pollutant containing materials. These “significant” materials and activities can be found in raw materials, intermediate products, byproducts, final products, waste products, material-handling operations, and manufacturing equipment. Pollutants of concern can include metals, oil and grease, organics, sediments, nutrients, and other chemicals. Materials are considered significant if they contain pollutants that could be transferred to stormwater. Significant materials include:
- Fuels, solvents, coolants, lubricants and cleaners
- Metallic materials
- Raw, intermediate, and final products
- Machining fluids
- Wastes and scrap materials
- Dust or residuals
- Processing or production operations
- Hazardous substances
Step 2d: Reduce exposure to stormwater
The following Stormwater Control Measures can help you prevent exposing pollutants to stormwater. See Step 5 for more information about Stormwater Control Measures:
- Move significant materials and activities under cover
- Optimize maintenance practices
- Control spills and leaks
- Manage wastes
- Optimize operations
For specific BMP options that fit within these control measures, read the
Manufacturers: Reduce your exposure to stormwater regulations (stormwater-noexposurebrochure) fact sheet.
Step 2e: Review the application questions and examples of outdoor exposure:
Are any of the following materials or activities exposed to precipitation, now or in the foreseeable future? These questions are for your entire facility.
- Using, storing or cleaning industrial machinery or equipment, and areas where residuals from using, storing or cleaning industrial machinery or equipment remain and are exposed to stormwater. Example: Equipment or vehicle wash areas
- Materials or residuals on the ground or in stormwater inlets from spills or leaks. Example: Vehicles needing repair, areas of hydraulic fluid/fuel spillage
- Materials or products from past industrial activity. Example: A new owner takes over a facility and the previous owner had industrial materials/products stored or managed outside
- Material handling equipment (except adequately maintained vehicles). Example: Leaking forklifts, trolleys, automated machinery
- Materials or products during loading or unloading or transporting activities. Example: Totes, drums, raw materials needed for process (with the potential to have a release into stormwater) , or fueling of vehicles and equipment
- Materials or products stored outdoors (except final products intended for outside use, such as new cars, where exposure to stormwater does not result in the discharge of pollutants). Example: broken or contaminated pallets, salt, coal
- Materials contained in open, deteriorated or leaking storage drums, barrels, tanks and similar containers. Example: raw materials or intermediate products materials from process
- Materials or products handled or stored on roads or railways owned or maintained by the discharger. Example: stockpiles of materials, land applied by-product
- Waste materials (except waste in covered, non-leaking containers like a covered dumpster). Example: oily rags, sawdust, spent equipment, containers of used oil
- Application or disposal of process wastewater, unless otherwise permitted (If currently unpermitted, obtain NPDES/SDS permit coverage or authorization from your local Wastewater Treatment Facility). Example: land application
- Particulate matter or visible deposits of residuals from roof stacks and/or vents not otherwise regulated (i.e., under an air quality control permit) and evident in the stormwater outflow. Example: Bag-house dust, smokestack residue, where the materials have fallen on the ground
Step 2f: Review the common violations at No Exposure facilities
Not all facilities who certify for No Exposure can qualify. Based on application reviews, phone calls and inspections, here are common sources of exposure at facilities attempting to certify for No Exposure:
- Open/unplugged dumpsters: can leak out “garbage juice” when stormwater gets in them.
- Storing significant materials outdoors: corrodible metals, used appliances, etc.
- Industrial activities being conducted outdoors: fueling of vehicles/equipment, mixing of wastes, loading/unloading of products, etc.
- Dust/Particulates: facilities operating under an air permit but having particulate matter or visible deposits of residuals on the ground.
- Pollutants Potentially Mobilized by Wind: windblown raw materials cause a condition of exposure. Materials sheltered from precipitation can still be deemed exposed if the materials can be mobilized by wind.
- Facilities with “partial” No Exposure: The No Exposure Exclusion requires a facility to shelter 100% of its significant materials and activities.
- Metal processing facilities: large bins outside that are uncovered and contain scrap metal in them
- Trash compactors: exposure occurs from hydraulic leaks, contents falling out of seams in equipment, or during loading or unloading
- “Bag houses” or other particulate matter collection devices: particulate matter exposure frequently occurs
Step 2g: Take the steps to achieving No Exposure
- Develop a plan to ensure maintenance of No Exposure conditions.
- Take actions needed to achieve No Exposure.
- Certify for No Exposure Exclusion by completing the
Industrial Stormwater Muti-Sector General Permit Application (PDF Version) (wq-strm3-52w) form - Receive confirmation of your No Exposure Exclusion status; post coverage card that you receive from the MPCA in an area of the facility that provides highest visibility to employees and visitors.
- Monitor for and address changes resulting in exposure of materials or activities to stormwater.
- Maintain condition of No Exposure. If condition changes, apply for permit coverage by filling out a new
Industrial Stormwater Muti-Sector General Permit Application (PDF Version) (wq-strm3-52w) form.
Step 2h: Review additional guidance materials
-
No Exposure: Qualifying For, and Maintaining, the Exclusion (wq-strm3-13) (10/10) -
Manufacturers: Reduce your exposure to stormwater regulations (stormwater-noexposurebrochure) -
Industrial Stormwater Best Management Practices Guidebook (wq-strm3-26) (Chapters 4 & 5) -
Guidance Manual for Conditional Exclusion from
Storm Water Permitting Based On “No Exposure” of Industrial Activities to Storm Water (U.S. EPA) 
