Guidance for Residential Home Heating Oil Tank Leaks


Report any leak from a tank and/or piping to the DEEP Emergency Response and Spill Prevention Division at 866-337-7745.  If heating oil is in surface water or a drinking water well, also report it to the Remediation Division at DEEP at 860-424-3705.

Insurance Information

The Connecticut Department of Insurance requires that homeowner’s policies include liability coverage and funds for the clean-up of a fuel oil release, though exceptions may exist.  Homeowners should consult with their insurance agent to determine if the release is covered under their policy.  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.  

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. 

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.
  • E-mail the Department of Insurance at:

Financial Assistance and Financing Programs for Heating Systems and Oil Tank Replacement 

See Appendix A of the Connecticut Council on Environmental Quality's Report, Fuel for Thought:  Recommendations to Reduce the Incidences and Severity of Accidental Releases of Home Heating Oil, for a list of programs related to paying for heating system replacements, some of which include financing for oil tank replacement.

Underground or Outside Aboveground Storage Tanks Leaks

Your heating oil supplier may be able to help you find a registered contractor to remove leaking underground tanks and/or piping and a permitted spill cleanup contactor to perform the necessary remedial actions.  The remedial actions include removal of any petroleum-stained soil to the extent possible.  Remove any heating oil that is floating on the water table.  Remove any heating oil that collects in drains around the house or flows into streams, drainage ditches, ponds, etc.  Prevent contamination from going off-site.  You are responsible for restoring neighboring properties to pre-leak conditions. 
After excavating the stained soil, the permitted spill cleanup contactor should collect soil samples to make sure they removed all of the pollution possible.  Soil samples should be collected from the bottom and each side of the excavation.  Samples should be collected from discrete locations nearest where stained soil had been.  Do not mix soil samples from different locations (composite sampling), as that will skew the data.  If groundwater is present in the excavation, the sidewall samples should be obtained at the level of the water and a water sample must be collected.  Send collected samples to a Connecticut certified lab for analysis for Extractable Total Petroleum Hydrocarbons (ETPH) using the CT DEEP Reasonable Confident Protocols.  Permitted spill cleanup contractors usually have certified labs with whom they work.
Remove additional soil if the ETPH concentrations exceed 500 ppm (parts per million or mg/kg).  Collect and analyze additional samples to show the cleanup is complete.  Soil venting can be used to clean up areas with residual staining that cannot be excavated, such as beneath structural footings.

Aboveground Storage Tank Leaks Inside a Building

Keep oil from reaching sumps or floor drains.  If oil gets into sumps or floor drains, it will spread farther and will be harder to clean up.
Close the door(s) between the tank and the rest of the house.  Open windows and doors to the outside to allow vapors to escape.  Use window fans facing out to exchange the air and reduce heating oil odors.  Turn off forced air heaters or air conditioning to keep odors out of the rest of the house.  Removing and properly disposing of any oil stained items (cardboard, wood, drywall, etc.) will also improve indoor air quality.  Use deodorizing cleansers to clean oil-stained concrete. 
Pollution located under a garage or basement floor presents a difficult situation.  With your contractor, try to determine how much oil escaped by checking oil delivery records and/or sampling soil from beneath the floor.  If the contamination is severe or if drinking water wells are within 500 feet, excavation may be necessary.  The DEEP Corrective Action Unit can help determine the best course of action in such circumstances ( or 860-424-3376).

Drinking Water Wells/Groundwater Sampling

In areas without drinking water wells, if you removed all floating oil, you do not need to sample groundwater.
If a drinking water well(s) is within 500 feet of the leak, call the Remediation Division District Supervisor for advice on appropriate well water sampling and cleanup.  Your local health district may also be able to offer assistance. 
A Significant Environmental Hazard report is required by law if:
  • a drinking water well is within 500 feet of the leak and groundwater contains any petroleum component over the Groundwater Protection Criteria (for ETPH 250 parts per billion [ppb or µg/l]), or
  • there is any petroleum component detected in a drinking water well at any level. 

Heating Oil Odors/Soil Venting

If heating oil odors remain in the house after soil removal, a passive soil venting system could help.  A passive soil venting system is made of perforated plastic piping in a buried stone-lined trench near the pollution.  This provides airflow near the pollution, allowing the remaining oil to evaporate into the air and exit through the pipe, instead of into the house. 
If heating oil pollution near or under the house is more severe or the pollution is near drinking water wells, you may need an active soil venting system.  Active soil venting uses an electric blower to pull air through the system faster, removing pollution more quickly. 
If there is no petroleum odor in a building, soil venting may not be necessary.


Contractors should produce a letter report detailing the tank removal and the excavation of contaminated soil.  The report should include photos, a sketch of the excavation area showing all sample locations, and all laboratory analytical results.  Send copies of that report to DEEP Emergency Response and Spill Prevention Emergency Response Unit and the local Fire Marshal.
Homeowners should keep that report with their other important property related documents, as questions regarding contamination from heating oil tanks can arise during home sales.  Potential homebuyers and lenders are typically interested in tank leaks, but are reassured if homeowners can document that cleanup is complete. 
Content last updated November 2023