Facilities that shelter all significant materials and activities indoors or within a storm-resistant shelter at all times can apply for No Exposure. Efforts to minimize your operational exposure to stormwater can help you save money and time, and protect our surface and groundwater resources.

A facility with a storm-resistant shelter for its significant materials

First, please review the definition of "significant materials, as defined in the industrial stormwater permit:

“Significant Materials” includes, but is not limited to: raw materials; fuels; materials such as solvents, detergents, and plastic pellets; finished materials such as metallic products; raw materials used in food processing or production; hazardous substances; any chemical the facility is required to report pursuant to Section 313 of the Emergency Planning and Community Right-to-Know Act; fertilizers; pesticides; and waste products such as ashes, slag, and sludge that have the potential to be released with stormwater discharges. When determining whether a material is significant, the physical and chemical characteristics of the material should be considered (e.g. the material’s solubility, transportability, and toxicity characteristics) to determine the material’s pollution potential.


Need the industrial stormwater permit? Bring materials and activities indoors: think No Exposure first!

No Exposure is good for business — and our water.

Some facilities may need to take only 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 with permit coverage. 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-resistant shelter.

Determine whether your activities and materials are within a storm-resistant shelter

What is a storm-resistant shelter?

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.

Facilities with uncovered scrap bins, trash compactors, exposed dust baghouses, fueling stations or other significant materials exposed to the elements need to complete a Stormwater Pollution Prevention Plan, and then apply for permit coverage.

Guidance materials and resources:

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