above ground oil tank (insurance, how much, houses)

[KFM1]

I'm looking at a house that currently uses oil heating, and the tank is in the basement. The house was built in the 1940s, so I will check as to whether it ever had an UST (in the front yard for instance). Assuming that it never had an UST, what should I consider with regards to the tank in the basement? Is there a realistic possibility that the fill pipe or vent pipes (or anything else that is outside the house) could leak? I obviously have no interest in buying anyone's environmental problems, so what are the issues to consider with above ground storage tanks that are inside the home.

[totallyfrazzled]

Most houses built in that era, especially if they were not that large, had the tank in the basement. The tank was dropped in place after the basement was poured but before the framing began. Your home inspector should be able to tell you whether the existing tank is in good shape or not (it may not even be the original tank from the late 1940s anyway) and approximately how much useful life it probably has.

I once had to replace an 1948 basement oil tank in a house I owned in the 1990s. Because it was originally "dropped in", it was too big to be brought out intact up the basement stairs, so they first pumped it dry of oil, then cut the tank up with a sawz-all, bagged the pieces, and took them out of the house that way. The stink was considerable and lasted for several days but eventually went away. The new tank was located outdoors.

By the way, don't assume that the tank itself will never corrode simply because it is in a basement rather than exposed to the outdoor elements. Over time any welded steel object will begin to rust and weaken, especially one that is filled with something like heating oil. Most basements are not bone-dry either, so there is dampness which will gradually act upon any metal in a detrimental way.

Trust me, if you have an operational nose you will immediately be able to tell if there is any leakage from a basement oil tank.

[KFM1]

Originally Posted by totallyfrazzled

Most houses built in that era, especially if they were not that large, had the tank in the basement. The tank was dropped in place after the basement was poured but before the framing began. Your home inspector should be able to tell you whether the existing tank is in good shape or not (it may not even be the original tank from the late 1940s anyway) and approximately how much useful life it probably has.

I once had to replace an 1948 basement oil tank in a house I owned in the 1990s. Because it was originally "dropped in", it was too big to be brought out intact up the basement stairs, so they first pumped it dry of oil, then cut the tank up with a sawz-all, bagged the pieces, and took them out of the house that way. The stink was considerable and lasted for several days but eventually went away. The new tank was located outdoors.

By the way, don't assume that the tank itself will never corrode simply because it is in a basement rather than exposed to the outdoor elements. Over time any welded steel object will begin to rust and weaken, especially one that is filled with something like heating oil. Most basements are not bone-dry either, so there is dampness which will gradually act upon any metal in a detrimental way.

Trust me, if you have an operational nose you will immediately be able to tell if there is any leakage from a basement oil tank.

Thanks. I intend on converting to gas before I even move in, so my main concern is whether the tank might have leaked. Do oil tanks in the basement present the same type of environmental risk as buried tanks?

[totallyfrazzled]

Originally Posted by KFM1

my main concern is whether the tank might have leaked. Do oil tanks in the basement present the same type of environmental risk as buried tanks?

No, not at all. When a buried tank or fillpipe leaks it often goes completely unnoticed for quite some time, and in the meanwhile all that oil is migrating into the surrounding soil. Depending on the size of the tank and the speed of the leak, that can present a major environmental and cleanup problem.

With a basement tank, first of all the leak will be noticed very quickly by the residents of the house because the odor will be apparent. And depending on exactly what part of the tank is leaking (fittings, body, etc) there may well also be visible fresh oil stains on the floor near the tank. So unless the house is vacant and unvisited, any leak will be seen/smelled and fixed in short order, before it ever gets within sniffing distance of the surrounding property.

If the floor under and around the basement tank is the original poured concrete (or if covered it can be exposed somehow so that you can look at it) then if there ever was a significant leak in the past the stains will still be visible (just like auto fluid/oil stains on a garage floor). If it just shows normal basement dirt there was probably never any leak issues.

[nycbrooklyn]

The house i am thinking about purchasing has a buried tank. Do you know what's the life span of buried tanks?

[totallyfrazzled]

If it's typical metal, then depending on the soil/water conditions of the place where it's buried (and also depending on who you talk to), it can range anywhere from 15 to 30 years. It's really impossible to say. Everything I've read, though, says that once they pass the 20-25 year mark you're on borrowed time.

If it's a fiberglass tank, you're in luck because those are corrosion resistant and do not deteriorate the same way the metal ones do. I believe they come with anywhere from a 30 to 50 year manufacturer's warranty against leakage. Some insurers who normally won't insure a house with a buried metal tank will do so if you can prove that the tank is fiberglass. It's actually easy to tell because the fill/vent pipe configuration is different for the round fiberglass tanks than for the cylindrical metal ones.

However, it's still possible for a minor leak to occur at the point where the fill/vent pipes are connected to a fiberglass tank... but if it was properly installed and not damaged afterward, that's pretty rare.

[rkk12]

I bought a house with an above-ground oil tank, and everything seems to be ok. I looked into getting insurance for the tank, but the oil delivery company wanted to do a ultra-sonic test to determine the thickness at the bottom of the tank. They could not do it because it was covered with Fiber-glass, and refused to insure it.

My oil delivery company told me it costs about 1600$-2000$ to replace an oil tank in the basement. You can buy insurance for 40$ an year, but this will require a pre-test to make sure the oil tank is not at risk. You can ask an oil delivery company to check the tank out for insurance to understand the risk.

How much does it cost to convert to Gas heating??

[KFM1]

Originally Posted by totallyfrazzled

No, not at all. When a buried tank or fillpipe leaks it often goes completely unnoticed for quite some time, and in the meanwhile all that oil is migrating into the surrounding soil. Depending on the size of the tank and the speed of the leak, that can present a major environmental and cleanup problem.

With a basement tank, first of all the leak will be noticed very quickly by the residents of the house because the odor will be apparent. And depending on exactly what part of the tank is leaking (fittings, body, etc) there may well also be visible fresh oil stains on the floor near the tank. So unless the house is vacant and unvisited, any leak will be seen/smelled and fixed in short order, before it ever gets within sniffing distance of the surrounding property.

If the floor under and around the basement tank is the original poured concrete (or if covered it can be exposed somehow so that you can look at it) then if there ever was a significant leak in the past the stains will still be visible (just like auto fluid/oil stains on a garage floor). If it just shows normal basement dirt there was probably never any leak issues.

Aside from the tank itself, are there any pipes that go from the outside (i.e. in the ground) into the tank that could leak? I assume that there is a pipe that goes into the ground before it gets into the basement. Is there any risk that that pipe could leak?

[totallyfrazzled]

For a basement oil tank, the fill pipe is USUALLY right up against the house at the closest possible point to where the tank itself is located. Basically other than the small area of soil surrounding the visible upper part of the tank and where you see it come through the house wall into the basement, it's not travelling any distance. Maybe through a couple of square feet of soil?

Again that's the usual configuration. I've never seen a basement oil tank that didn't have the fill pipe located as close as humanly possible to the house itself.

IMHO if I were you I wouldn't worry about a basement tank leak problem.

[actank]

You should have the grounds searched by a company like mine for underground tanks. The tank in the basement should be inspected for leaks and a visual of the tank structural integrity. Also you can purchase above ground tank insurance from Pro Guard.