Oil tank questions

HeatingHelp

This discussion was created from comments split from: How long should a 275 gallon oil storage tank last?.

briggs

Hello, This question regards a 275 gallon tank. Tag info is 10 10 275. This is an old tank.

Tank has dry bottom want to adjust delivery schedule so that a minimum of oil is stored in tank.

Thinking tank should not be filled to more that 1/4 of capacity. Even at this it's still 70 gallons. Too much oi to have in an old tank.

What delivery schedule should be requested to have as little oil in tank & not run out of oil during winter?

A slow fill has been requested. Will a low oil level cause the sludge to be dislodged & churned up on delivery ?

Is it possible that the sludge is sealing pin holes in tank ? Don't want sludge clogging filters.

Does anyone know of a method of containment that can be used on this tank ? How would this containment system seal tightly around the 4 leggs & bottom discharge pipe to contain the ever rising level of oil inside the containment as tank drains out ? Is there a company that makes such a containment ? Thank You.

briggs

Is it a good idea to use a biocide in an old tank that has never been treated in the past?

pecmsg

https://forum.heatinghelp.com/discussion/comment/1827792#Comment_1827792

O Kay !

mrcoder

If I am reading your post correctly, the tank is currently not leaking, How old?

It is just a question of being pro-active "what if it leaks?". The big concern is the cost of a cleanup, which can be insanely expensive, esp. if the Fed or a local authorities are involved. It is a bit like getting your car towed by a towing company forced on you by law enforcement. They will charge you whatever they feel like and you have no or little recourse. I have seen houses supported on columns, while 8 foot of soil was removed from underneath. 100K plus cost. If you have to pay for such cleanup, you may lose your house, or go bankrupt.
You may also take a hit in your property's equity, as potential buyers may get scared away if they find the property had an environmental cleanup issue.

Homeowners insurance typically will exclude the cost of cleanup, unless you have a rider for that specifically. Getting a rider will require a tank inspection. Residential steel tanks typically only last ~20 years, although I have seen some much older. It would make a lot of sense to limit your exposure by replacing an old tank on your terms, or to get an insurance rider that covers tank leak cleanup cost. In recent years, getting such rider has become easier, as insurance companies are mandated to offer this type of coverage in most US states. A tank leak rider is typically not super expensive, compared to your homeowners policy. maybe and extra 5-15% of top of that cost. YMMV.

A pinhole leak can be usually stopped using a purpose made Rectorseal magnetic tank patch, look for it on Amazon. About 40 USD each. Or, a diy version of this, a flat disk rare earth magnet, with a tire rubber patch between it and the tank. I have just used both of these on a 50+ year old tank that sprung 7 pinhole leaks. The magnetic patches held for 4 weeks until we lined up a replacement tank. The tank was inspected and declared sound a month before it started leaking. So color me skeptical about tank inspection. I suspect the inspection involved a glance at the bottom outside.

It is good to have a few magnetic patches on hand. A word on the Rectorseal patch: In the the middle, there is a neoprene rubber cylinder, the actual plug, which is a bit too tall when brand new, for the 2 strong magnets on the sides to "grab on" to the tank. These have to be "broken in" which involves compressing the rubber cylinder a bit, I do this by pressing them against a magnetic surface for a few minutes to accomplish this, and then storing them "latched on". They get better after they are used, so they are worth keeping after use. The DIY bicycle tire patch does not have this issue.

If you have one, or a few of these patches on hand you may be able to limit the amount that leaks out to nothing, or a tiny amount you can easily manage. Perhaps you are better off dealing with a small cleanup yourself, than any of the alternatives.

Of course use your own sound judgement, and follow the rules and regulations applicable to your situation.

The patch is not a 100% guaranteed solution, but worked on all the leaks I have seen. All were pinholes, varying from dripping to spraying oil. I expect the leaks to be pinhole, because of the way tanks corrode. Condensation or contamination water accumulates at the tank bottom, then bacteria (algae?) get into the water, which then turns it acidic, and slowly corrodes the tank from the inside.

Of course I could be wrong, I have only seen 9 of these, on tanks aged 20 to 50 years. All of them were 1 or more pinhole leaks, and they all could be temporarily stopped using the rubber + strong magnet patching method.

I am not aware of any "Containment retrofit" systems, other than some plastic tubs you can put under the
tank. Nothing that would hold 200-400 gallons, the purpose built ones I have seen would hold maybe 70 gallons, costing $300- $500 These are not a good long term solution, since you have to deal with the smell, the leaked oil would be out in the open.

mrcoder

How much oil?
On a cold day you can easily burn 10-15 gallons, so 70 gallons in the tank may not go very far.

If the tank springs a gusher, even 70 gallons may cause a significant cleanup problem, so I am not sure what the partial fill buys you. If there is a pin hole, full or partial fill will not make much difference to whether a leak manifests or not.

Long Beach Ed

If you are this uptight about the age of your tank,replace it.

I ran a bunch of rental homes with 50+ year old tanks and none ever leaked and I slept like a baby. When old age finally forced some wisdom into my skull and a few dollars into my wallet, I converted them all to gas.

mrcoder

@Briggs:
In general, it is a good idea to use a water dispersant and biocide on any Home heating oil tank.
Inside an older tank there may be accumulated water at the bottom, and bacteria/mold/fungi stuck to the walls.
If you use an effective biocide at a "curative" dose, it may dislodge and emulsify [some of] this layer.

Biocides: Commercially, CMIT, MIT and Cyanate compounds are popular and effective. Tradenames: Kathon, Bellicide. Those who store large amount of diesel or heating oil, where biological growth could be a big problem, tend to use additives that work. ( e.g. fuel bunkers of ocean going ships, refineries, oil
vendors, large farms..)

It is a reasonable question if bio crud may be to some degree protective against pinhole leaks. My thinking is, even if it is, you should not rely on any slime or crud in the tank for protecting against leaks. If you have a pinhole, it is best if you know about it, and line up a replacement tank.

When the slime and crud gets dispersed, it will likely show up in the filter(s) you have so it may be a good idea to change filter(s) after a biocide treatment. It will be obvious on and old school filter, and a cartridge filter can be cut open to look.

Another reasonable line of inquiry: asking your oil supplier if they already dose their oil with some biocides.
Not unthinkable, as they store large quantities, and condensation water and biological growth would be a problem for them as well.