Residential Underground Home Heating Oil Tanks Frequently Asked Questions

What is a residential underground storage tank (UST)?

A residential UST stores heating oil used to heat four residential units or fewer.  DEEP does not regulate residential heating oil USTs. 

DEEP does regulate heating oil USTs serving five or more residential units.

What kind of license or registration is a residential UST contractor required to have?

The Department of Consumer Protection (DCP) requires contractors to be registered as Home Improvement Contractors.  Contractors must display their registration numbers in all advertising, including advertising on vehicles.  A homeowner should check the contractor's registration with the DCP prior to entering into a contract.  A licensed plumber must perform any piping installation or replacement.

What should I do when I remove my residential heating oil UST?

Hire a registered contractor.  DEEP recommends that a soil sample be collected from underneath the tank and piping and that it be analyzed for Extractable Total Petroleum Hydrocarbons (ETPH) at a Connecticut certified laboratory.  Most often contractors will collect samples and deliver them to a certified lab for you.  Take photos of the tank and the excavation, if possible.  Have your contractor generate a brief letter report documenting the details of the tank removal, including ETPH reports from the lab.  Keep these documents in a safe place, as homebuyers usually want proof prior to purchasing the house that the tank did not leak or that any leak was cleaned up. If the soil results indicate that the tank leaked, you are responsible for the cleanup of the resulting pollution.

What type of tank should I install?

It is better if residential tanks are aboveground.  UST leaks may go undetected for some time.  With an aboveground storage tank (AST), you are more likely to detect a leak before it becomes severe.  Cleanup of AST leaks are typically easier and less costly than leaks from USTs. The piping should be installed overhead or along a wall, where it is visible.  As with all home projects, check your Town’s municipal codes to make sure you comply. 

Appendix A of the Connecticut Council on Environmental Quality’s December 2019 report Fuel for Thought includes financing assistance programs in that are available for homeowners wishing to upgrade or replace their heating fuel systems and oil tanks.

Is a permit required?

Contact your Town to see if it requires a building permit for tank installation, removal or replacement.

Does DEEP require me to remove my residential heating oil UST by a specific deadline?

No.  Leaking tanks, however, must be promptly emptied and removed.

What do I have to do if my tank leaks?

Report the leak to DEEP Emergency Response and Spill Division.  If pollution has reached a drinking water well or surface water, also call the Remediation Division at DEEP at 860-424-3705.

Take actions to stop the leak immediately.  Your heating oil supplier may be able to help you find a cleanup contractor quickly.  You are required to clean up the resulting pollution promptly.  Prompt cleanup keeps pollution from spreading to nearby drinking water wells, surface water bodies, or drains around your home’s foundation.  If pollution has spread to neighboring properties, you are responsible for cleaning that up, as well.

Insurance Considerations

When a release of any petroleum or chemical occurs to the ground, this means that a release has occurred to the waters of the state.  Water is a public trust.  Thus discharges to soil or water result in third party damage because the waters of the state have been damaged by the release to the ground.


The property owner or the entity that caused any condition which reasonably can be expected to create a source of pollution to the waters of the state is responsible for cleaning up the release and restoring the soil and water.


You may have homeowner’s insurance coverage for an escaped fuel loss. However, insurance coverage depends on the specific facts and circumstances of your loss and the terms, conditions and exclusions in your homeowner’s insurance policy. Not all homeowner insurance companies provide coverage for escaped fuel losses. If you have experienced a fuel loss, fuel spill and any damages, you should discuss the coverage under your policy with your insurance agent or the insurer directly.  If the release is the fault of a heating oil dealer, homeowners should consult with their dealer.  The State requires heating oil dealers to have general liability insurance coverage and insurance to cover any potential environmental damage due to heating oil spills.  Send copies of the cleanup documentation to the DEEP Emergency Response and Spill Prevention Emergency Response Unit. 

Department of Insurance Contact Information
  • Online portal: to file a complaint or ask a question Website:
  • On the home page, look for “Complaints and Questions”·      
  • Call the Consumer Services Division at: 1 (800) 203-3447 or (860) 297-3900.
  • Email the Department of Insurance at:

Can I abandon my heating oil UST in place if it is not leaking and has never leaked?

DEEP discourages homeowners from abandoning USTs in place unless they are inaccessible (under a deck, patio, or addition, etc.) or if removal would endanger a foundation.  Contact your local Fire Marshal to determine if there are any local ordinances about UST abandonment.  Have your contractor collect a soil sample from underneath the UST to verify that it has not leaked before filling the UST with sand or concrete.  If that sample is contaminated, do not fill the tank and report the leak to the DEEP and local Fire Marshal immediately.

Where can records regarding residential UST removals be found?

Since residential heating oil tanks are largely unregulated by DEEP, no specific DEEP program keeps records regarding residential tanks.  Records may be obtained from the following sources (in descending order of likelihood):

  • If you are purchasing a house, ask the homeowner for any records regarding the tank removal. 
  • Some local Fire Marshals keep UST removal reports.
  • If a residential tank leaked, records could be in the DEEP Emergency Response and Spill Prevention Division files.  Some of these files are available through the DEEP Document Online Search Portal and in the Environmental Quality Records File Room (records are arranged by year, so identify the tank removal year before coming to DEEP). 
  • If a residential heating oil UST was removed from July 1, 1999 to December 31, 2001, the owner may have obtained amnesty for the underground tank leak and the address may appear on a list located in the Environmental Quality Records File Room.

What kinds of records do people usually need?

A letter report describing the cleanup, including analytical reports from the lab, is generally accepted by lending institutions, buyers, and realtors for property transactions.

Can I get a “closure letter” from DEEP?

No, the Department does not issue closure letters for residential cleanups. 

For other questions contact:

The Corrective Action Unit by email at or at (860) 424-3376, the Emergency Response & Spill Prevention Division (860) 424-3024 (press “2” after prompt), or the Storage Tank & PCB Enforcement Unit at (860) 424-3374.

Residential Home Heating Oil Tanks

Content last updated October2021