The U.S. Energy Information Administration, Office of Energy Consumption and Efficiency Statistics, estimates there are more than 120 million residential units in the United States using heating oil as their primary heat source. The U.S. Environmental Protection Agency (USEPA) does not regulate heating oil tanks at single-family residences, as home heating oil tank regulation is primarily handled at the state and local levels. State and local governments often require permits for installation or replacement of heating oil tanks and have established regulations for the cleanup of any spills or leaks. Replacing or installing heating oil tanks should always be done by licensed contractors following standard practices for reliable tank service.
While most leaks from heating oil tanks are typically small and can be remediated with a straightforward removal action, when unnoticed or left unattended, large volumes of oil can be released over time. Larger spills can also occur as a result of misdeliveries or overfills during the fuel delivery process, and older tanks occasionally suffer dramatic failure when over-pressurized during fuel delivery. The extent of impacts to soil and groundwater can also be complicated by the age of the home, foundation construction, and the site setting.
Types of Tanks and Their Regulation
Home heating oil tanks are typically 275-gallon capacity but can range in size from 250 up to 1,000 gallons; and they can be either aboveground storage tanks (ASTs) or underground storage tanks (USTs). Contemporary tanks are typically constructed of coated steel, although fiberglass and steel-fiberglass tanks are available as well. Older tanks are almost always found constructed of bare steel. Tank service life ranges from 20 to 25 years; however, many older residences may have tanks twice this age or more.
Although many homeowners have ASTs located at the rear of the residence, they are normally found in a heated or partially heated part of the home since fuel oil tends to “gel”’ at about 20° Fahrenheit. The most common location is in the basement. Although an AST is easily inspected and small leaks can be detected early, leaking oil inside a basement can cause indoor air quality issues and can seep into the ground along foundation lines. Alternatively, USTs are most often situated outside the building footprint, several feet from the foundation wall, and deep enough to be below the frost line. However, USTs are much more difficult to routinely inspect and to detect leakage.
Leaks from heating oil tanks are predominantly caused by corrosion of the tank, transfer lines, or fill line. Partially full tanks contain air at some level of humidity (tanks are vented so the contents are exposed to the local atmosphere). As temperature changes occur, water may condense out of the surrounding air and collect in small volumes in tanks. Since oil is less dense than water, the water ends up residing at the tank bottom and can lead to corrosion along the bottom centerline of the tank. Occasionally, human error can be the cause of oil releases due to improper installation, loose connections of tank penetration lines, or delivery errors (overfills, delivering fuel oil to fill connections no longer in use, etc.). Routine annual or biennial inspection by a certified tank installer of the tank, fill lines, and transfer lines can catch deficiencies early.
Although USEPA does not regulate home heating oil tanks, all states prohibit releasing substances like fuel oil into the soil, surface waters, and groundwater. Many states have detailed regulatory programs for home heating tanks and/or either guidance or reporting requirements. Some offer incentive funding for homeowners to either upgrade their aging heating oil tank or convert to another heating method (like natural gas or electricity).
Managing Home Heating Oil Releases
The majority of home heating oil releases are relatively minor and can be easily addressed during tank removal or replacement by excavating the impacted soil surrounding the old tank. However, depending on the site setting and the duration of the leak, some heating oil impacts may require a complicated and extensive cleanup effort. For example, highly permeable soils like sand can allow the leaking oil to spread over wider areas and to greater depths. Even lower permeable soil, combined with a long ongoing leak, can lead to a wide area of impact that can be more difficult to remediate. The cleanup of some spill sites can be highly complex due to oil leaking under the home’s foundation or into fractured bedrock. Impacts to both surface water and groundwater can add another layer of complexity.
Remediation costs can vary widely depending on the complexity of the cleanup and can range from $25,000 to more than one million dollars. Depending on the homeowner’s financial position, these costs can be devastating and can sometimes match the value of the home itself. Many state programs provide incentives/funding grants to replace aging tanks; or to provide grants or loans for remediation of soil and groundwater impacted by leaking fuel oil. Some states have mandated that homeowners’ insurance policies include some form of coverage for remediation or that insurance companies actively offer riders as available add-ons to homeowners’ policies.
HETI…Here to Help
Replacing aged tanks and sticking to a regular inspection/maintenance program for the heating oil system can minimize leaks or at least catch leaks early before remediation costs spiral. The current regulatory trend is to offer incentives for good tank practices; to offer grants/loans for remediation; and to require that insurance policies cover leaking tanks.
HETI offers a technical staff with extensive experience in home heating oil releases, insurance and regulation. So whether a client is looking for emergency response service, remedial solutions, or regulatory support, our licensed professionals are available to provide expert and efficient service.
To find out more about HETI’s environmental services, please contact us.
Ron Adams, PE, LSP, LSRP Senior Engineer