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Large engine in a generator room.

Air emissions

Stationary engines, commonly used as back-up or emergency generators, are regulated by several federal air standards and state air permits. Learn more on the MPCA air quality program page for engines.


Use this emissions calculator to determine if you need a permit for your gasoline, diesel, and natural gas engines:

A permit is required if one of the federal performance standards applies to the engine or if potential air emissions from the entire business are over certain levels. The calculator also provides guidance on the federal standards.


The U.S. EPA has resources to help you comply with federal standards for engines, which includes NESHAP and NSPS. Use their engine regulation navigation tools for a quick assessment and summary of requirements for your engine.

Air permit due dates


Due date

Emission inventory fee for previous reporting year Mailed to permit holders between February and April, due within 30 days
Emission inventory report April 1
Emissions summary review period Begins in August/September

Hazardous waste

You need a hazardous waste identification number if your business produces any amount of hazardous waste.

Businesses generating most types of hazardous waste are required to report annually, pay a fee, and obtain a license for the subsequent year. Facilities in Anoka, Carver, Dakota, Hennepin, Ramsey, Scott, or Washington County are licensed and inspected by their county. Facilities in greater Minnesota are licensed and inspected by the MPCA. If you produce only small amounts of hazardous waste, you probably qualify as a very small quality generator:

See the Hazardous waste identification and management page for information on managing specific types of hazardous waste, such as oil filters and oil-spill cleanup materials. Oily wastes generally don't require a hazardous waste license, but check with your county to be sure.

Hazardous waste due dates


Due date

Hazardous waste generators fee Mailed to license holders in first quarter, due date on invoice
License application Due August 15 for Greater Minnesota businesses;
Twin Cities metro businesses, contact your county

Storage tanks

Report leaks and spills to the Minnesota Duty Officer at 651-649-5451 or 800-422-0798. Most aboveground storage tanks larger than 500 gallons or underground tanks larger than 110 gallons have to be registered with the MPCA. See the storage tanks pages for more information.

Beyond compliance