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Low Erosivity Waiver from Stormwater Requirements

The Utah Dept of Environmental Quality defines the Low Erosivity Waiver from stormwater requirements as follows:

Submission of this Low Erosivity Waiver Certification constitutes notice that the entity identified in Section B does not require permit authorization for its storm water discharges associated with construction activity in the State of Utah due to the existence of a low erosivity factor (less than 5) at the site of soil disturbance.

This waiver applies only to “small construction activity” which is defined as soil disturbances due to construction activity that are 1 acre or greater but less than 5 acres.

Small construction activity also includes disturbances of less than one acre if it is part of a common plan of development or sale that is less than 5 acres. Remember, disturbances of less than one acre, if it is not part of a common plan of development or sale, is not required to have permit authorization.

Application not relieve the operator of permitting requirements for other regulated activities/discharges which may pertain to the construction activity (e.g. dewatering activities, non-storm water discharges, etc.)

An erosivity factor can be calculated from the EPA calculator at or it can be done by hand using the instructions from the EPA Fact Sheet entitled, Storm water Phase II Final Rule: Construction Rainfall Erosivity Waiver (which is posted on the DWQ construction storm water web page). The EPA fact sheet also explains where the erosivity factor comes from.

The information needed to calculate an erosivity factor is the start and end date of construction activities, and the latitude and longitude for the project site (or another acceptable way of pinpointing the location of the project site – see the EPA calculator).

The waiver is meant for sites that can predictably be completed within the specified time period (the time between the dates used to calculate the erosivity factor).

Completion Date: The date when the site is permanently stabilized (see part 2.6 of the Common Plan Permit):

  • For areas in Utah with annual precipitation over 20 inches, that means all soils have permanent cover (pavement, structures, etc.), or have uniform revegetated cover of at least 70% of indigenous vegetation.

  • For areas in Utah with annual precipitation less than 20 inches, that means all areas that are not covered (paved, structures, etc.) must be seeded. Slopes 5 % to 20% must have energy dissipation for drainage pathways. Slopes over 20% and greater must have nonvegetative surface stabilization (mulch, gravel, erosion blanket, etc.)

If delays or unforeseen circumstances prolong the construction time of completion and the project is not completed by the projected completion date, the operator must immediately submit application for coverage under the Utah Pollutant Discharge Elimination System (UPDES) General Permit for Storm Water Discharges Associated with Construction Activities, or recalculate the erosivity factor and confirm that the newly calculated erosivity factor is less than 5.

The cost for an erosivity waiver is $100. The preferred method for paying is to obtain the waiver on line with Visa/Master Card at, but it can be paid by check/cash if submitted with a paper form and dropped off at DWQ, 195 N. 1950 W., SLC, UT 84116, or via check only with paper form if mailed to PO Box 144870, SLC, UT 84114.

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