Rules for underground and aboveground tanks

Hennepin County and the Minnesota Pollution Control Agency (MPCA) have a Joint Powers Agreement that allows county staff to jointly fulfill many of the state's roles regarding aboveground and underground storage tanks.

Through the agreement, Hennepin County inspects underground tanks and aboveground tanks. The county also works to locate abandoned and unregistered tanks to make sure that any necessary cleanup work is complete and to give tank owners the opportunity to apply for reimbursement.

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Underground tanks

Underground tanks that hold petroleum or a hazardous material (i.e. diesel, gasoline or oil) and those that hold more than 110 gallons and are not used for building heating are regulated.

The Minnesota Pollution Control Agency must be notified about all underground storage tanks (USTs) within 30 days of installation and about changes in tank status. To register a UST, complete and submit the UST Registration Form.

If your tanks are regulated

  • You must have petroleum tank leak detection on all regulated tanks.
  • You must perform line (pipe) leak detection on all regulated tank piping.
  • You must upgrade all regulated tanks with corrosion protection (fiberglass tanks and/or piping do not require corrosion protection).
  • You must have a corrosion protection test done on the tanks every three years.
  • You must keep all records on file to prove you are in compliance.
  • You must have Stage 1 vapor recovery installed on all retail gas tanks (except facilities located in the cities of Hanover and Rockford).

How to prepare for the inspection

  • Know what kind of tank leak detection you use.
  • If you use an automatic tank gauge, know how to use it.
  • Know where your leak detection records are and have them ready.
  • Provide access to all tanks and dispensers for visual inspection.
  • Know where your emergency overfill alarm is and how it works.
  • If you also service cars, know where your waste storage containers are.
  • Know where your corrosion protection testing records are and have them ready.
  • Know whether you have Stage 1 Vapor Recovery installed. To find out, contact the owner or your tank contractor.
  • If you do not own the tanks, provide the owner's name, address and phone at the time of inspection.

Abandoned petroleum underground storage tanks

If you have an old petroleum underground storage tank on your property, you may qualify to have the tank removed for free.

To qualify:

  • A tank is an underground petroleum storage tank that was taken out of service prior to December 22, 1988.
  • If a tank was taken out of service after December 22, 1988, a tank may qualify if you can show that you could not have reasonably known of its existence at the time you first acquired title to the property.

If petroleum contamination from a leak is discovered and the Minnesota Pollution Control Agency requires an investigation, you must agree to proceed with it according to their policies and procedures. Costs associated with completing a necessary investigation are eligible for up to 90 percent reimbursement from the board.

Aboveground tanks

The Hennepin County Tanks Program and the Minnesota Pollution Control Agency must be notified about all aboveground storage tanks (ASTs) within 30 days of installation and about changes in tank status.

Register an AST by completing and submitting the AST registration form to the MPCA. 

Aboveground storage tanks should either be double-wall in construction or have secondary containment capacity equal to the largest compartment of the tank, plus adequate additional capacity to contain precipitation (if the containment area is not covered against rainfall/snowfall).

Tanks that do not need registration

Tanks not requiring registration include:

  • Farm or residential tanks 1,100 gallons or less storing motor fuel for noncommercial purposes
  • Heating oil tanks 1,100 gallons or less
  • Agricultural chemical tanks
  • Tote tanks
  • Temporary tanks
  • Tanks that are less than 500 gallons

If you are not sure whether your tank is regulated, call the Hennepin County Tanks Program or the MPCA.

Tank violations

Hennepin County, the Minnesota Pollution Control Agency, and the City of Minneapolis have various options available to assure compliance with the regulations. These include:

  • Warnings and citations
  • Monetary penalties
  • Court orders
  • Shutdown of the system(s) in violation
  • Loss of restriction of business license

Any work required to bring the tank back into compliance must be completed in addition to any monetary penalties assessed.

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