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Frequently Asked Questions

What is GrainPTE?

GrainPTE is a grain elevator potential to emit (PTE) calculation tool designed to help owners and operators of grain elevators determine their group classification (Group,1,2,3,or 4). The PTE calculation tool is available free of charge.

Why are grain facilities required to calculate their PTE?

Owners and operators of air pollution sources, including grain elevators, are required to obtain permits and meet applicable air pollution standards. With the passage of the 1990 amendments to the federal Clean Air Act a new operating permit program for major sources of regulated air pollutants was created. As a result the U.S. Environmental Protection Agency required the state to remove restrictions limiting the regulation of grain elevators which necessitated that the Iowa Department of Natural Resources (DNR) review and permit air emissions at hundreds of grain elevators to bring them into compliance with the air construction permitting requirements of rule 567-22.1(455B). The grain elevators’ PTE determines the group classification, associated reporting and/or permitting requirements.

What types of grain handling facilities does the rule apply to?

The requirements of this rule apply only to country grain elevators, country grain terminal elevators, grain terminal elevators and feed mill equipment, as defined in subrule 22.10 (1).

What if my facility was previously classified as group 2 and is no longer classified as such?

Once a facility receives a Group 2 permit the permit remains in effect even if the PTE drops below 15 ton/year PM10.

What if my company has multiple facilities?

With this application you can register and track multiple sites within the same company.

How do I determine which group is applicable?

Your facility’s PM10 PTE must be calculated to determine the group. The method for calculating the PTE is based on the facility type and the calculation tool must be used to determine the facility PTE. The Iowa DNR uses the following emission thresholds to split the grain elevator sector into four groups, characterized by their PTE for PM10 (particulate matter with an aerodynamic diameter less than 10 microns):

Grain Elevator Group PM10 PTE (tons/year)
Group 1 Less than 15
Group 2 Greater than or equal to 15, less than or equal to 50
Group 3 Greater than 50, less than 100
Group 4 Less than or equal to 100

What types of grain should be included?

Grain includes but is not limited to corn, soybeans, wheat, oats, rye, barley, grain sorghum, flaxseeds, sunflower seeds, spelt, and field peas.

How is throughput defined?

Throughput is defined as the amount of grain received.

I have more than one facility in the same town, should the facilities be considered one facility for the purpose of PTE with the PTE Calculation Tool?

Multiple grain elevators located in the same town or close proximity to each other may be considered as one facility if they are under common ownership or control. The Iowa DNR may be contacted at 1-877-247-4692 for assistance in making this determination.

Who developed GrainPTE?

GrainPTE was developed by the Iowa Waste Reduction Center, and funded by the Iowa DNR. Please visit them at http://www.iwrc.org for more information.