How long do aboveground oil tanks last?

The useful life of an aboveground heating oil tank is unpredictable. Experience has shown that newer tanks made with recycled metals often tend to corrode and leak more quickly than tanks installed many years ago.Tanks that have been treated with a liquid corrosion inhibitor will last longer than unprotected tanks. Tank leaks usually start as slow drips, so it is a good practice to check your tank periodically.

Why do oil tanks leak?

Moisture condenses on the inside of all oil tanks and settles to the bottom to form an acidic sludge. Over time, this sludge build-up attacks the metal and can cause the tank to leak from internal corrosion. Internal corrosion typically causes pin hole leaks that drip slowly under the tank.

External rust can also cause tanks to fail. In damp basements, the tank bottom and side next to a cement or stone wall are especially vulnerable. Outdoor tanks are most vulnerable to external rust and should be protected from the weather.

What warning signs should I look for?

The obvious sign of a leak is a stain or puddle on the floor under the tank.Sometimes oil leaks from the top fittings when a tank is filled; in this case there will be an oil streak down the side of the tank.

The extent of internal corrosion is impossible to determine. External rusting is visible unless the tank is close to a wall. Call your oil dealer if you have any concerns about the condition of your tank.

What should I do if there is a leak?

Call your oil dealer immediately if you suspect a leak.

DO NOT TOUCH THE TANK OR WIPE THE AREA OF A SUSPECTED LEAK – YOU MIGHT MAKE THE SITUATION WORSE.

Place a pan under the tank to catch dripping oil. Use speedy dry or kitty litter to absorb spilled oil. Clear the area around the tank to prevent oil damage and to allow technicians access to the tank. In most cases, the technicians will be able to contain the leak with a magnet patch or putty until the tank is replaced.

How much does a replacement tank cost?

The cost today to replace a leaking aboveground heating oil tank ranges from $1,200 to over $1,500.

Regulations require documented disposal of the sludge as a hazardous material and certification of proper disposal of the tank itself. These costs are included in the cost estimate above.

All states require permits for oil tank installations. Permit fees are a source of local government revenue and often they are significant. Permit fees are not included in our cost estimates.

What is involved in replacing an oil tank?

Oil tank removal and installation is subject to state safety codes. For example, in Massachusetts the local Fire Chief is the oversight authority, and permits are required for both the removal of the old tank and the installation of the new tank. The proper permits must be obtained and the work must be performed by a Licensed Technician.

Please refer to the Replacement Checklist page for details to consider when replacing a leaking oil tank.

Can I do anything to protect my oil tank?

Water from condensation is the chief cause of internal tank corrosion. Water is heavier than fuel oil, so it settles to the tank bottom. It is generally impractical to try to remove the moisture. The best solution is to treat the tank annually with a liquid corrosion inhibitor. The corrosion inhibitor chemical reacts only with the moisture on the tank bottom and reduces the corrosive activity. Please refer to the Lincoln Laboratory website for corrosion inhibitor information.

External rusting is usually visible. If the rusting is superficial and the tank is still sound, sanding and painting with a rust resistant paint would be advisable.

We recommend that outdoor tanks should be protected from the weather by some type of enclosure. Plastic secondary containment enclosures for outside tanks are available from heating oil dealers and plumbing supply stores. They are designed to blend with house exteriors.

Check periodically to verify that the proper caps are securely installed on both the fill and vent pipes. Missing caps are a primary cause of excess water in the tank. They also allow dirt into the system and invite bees' nests.