Below ground seems more dangerous from an exposed tank point of view. A car could run into it, debris from a wind storm or natural disaster, foul play. These could be mitigated with some kind of containment structure but then you require more land area and investment.

s/Below/Above/ ?

yes thanks, edited

> I never understood the move of gas tanks from above ground to underground. The few stations left with above ground tanks were forced to bury them ages ago.

> To me, you can easily detect leaks if above ground and correct. The local Gov can even hire someone to check above ground tanks. Seems oil companies did the move to avoid inspections.

Above-ground tanks might be better for detecting leaks, but I'd imagine they're much more vulnerable to catastrophic accidents (e.g. a truck slamming into one and causing a giant fire).

Do you not consider contaminating a city's water supply catastrophic

No, because that's not something that actually happens due to underground storage. The leaks are local, and cause minimal long term harm. They are not "contaminating a city's water supply", that's simply not true.

Its absolutely true, one of my city's primary aquifers is directly under ground. Future underground tanks will not be permitted because they've been leaking into the groundwater, especially if and when they're abandoned because the business failed.

So make failed businesses empty their fuel tanks? Seems like a dumb reason to regulate tanks for active businesses.

Failed businesses don't often fail because they executed things perfectly. When you bankruptcy and shut down, you don't necessarily sell property immediately.

That’s demonstrably false. Google the red hill fuel tanks

A truck slamming into an above-ground tank could easily contaminate a city's water supply, so I'm not sure you've got a valid argument here.

Heh, I did some work on a pretty cool tank monitoring hardware/software solution with a major fuel supplier here about a decade ago. They have facilities with about a dozen large vertical 40-80,000L above-ground fuel tanks for agricultural use. One of the features I was working on was leak detection, and we got the sensors and statistical analysis down to the point where, when testing with water, I could accurately detect the rate of evaporation from a smaller indoor tank.

Anyway, we’re in an area that doesn’t have a whole lot of “acts of God” kind of destruction; no hurricanes or earthquakes, high winds occasionally but tornados are quite rare, etc. They reported to me that the number one cause of leaks on their above-ground tanks was bullet holes. Just… people randomly shooting at the tank farms. They don’t catch fire when this happens generally, they just spill out from the hole until someone catches it and transfers all of the fuel out of the tank.

>Anyway, we’re in an area that doesn’t have a whole lot of “acts of God” kind of destruction

Are you in the US? And if so... mind sharing your vague region? I'd love to know where to actually avoid tornadoes.

One example: much of Pennsylvania has none of these.

Philly doesn't count as a natural disaster?

Saskatchewan in Western Canada. Just north of North Dakota and Montana. What we do get is wild amounts of cold and snow some years, but those don't generally harm fuel tanks a whole lot :).

Move to the Southwest. I moved to northern New Mexico and I love it. Nobody to bother me and miles of space for whatever I need to do. Gets hot though.

I have been to many industrial sites, and oil/gas/diesel tanks have been above ground. Some had bollards to block physical bumps. Many had spill containment knee walls.

There are probably regulations depending on type of tank and contents to allow these private tanks. Above ground does make identification of a leak more rapid.

Above ground tanks also have the benefit of being gravity fed, so you can use them in rural areas without a power supply or complex pumping equipment.

The tanks for fresh product (gas/diesel) which I saw had 220v electric pumps and were outside. Some had meters like a gas station to track usage to a machine. Fresh oil tanks were pneumatic. Used oil tanks were pumped out by the service truck. OSHA regulated.

Free-standing tanks for fresh product which are in rooms (drifts/bays) underground (mines) seem to be pneumatic with small tanks using a rotational hand pump simply because not a lot of whatever is being used. MSHA regulated. (Never call used oil "contaminated".)

Maybe farmers use gravity?

As an aside, I happened to recently see a setup 2/3 mile underground with two free-standing used oil tanks. One was marked "abandoned in place" because someone realized if both tanks fail when full, the retaining wall would not contain all of the used oil.

Does this happen? Here in NJ underground is now banned, finding a buried tank on your property is an expensive nightmare.

I believe that's only true for heating oil, but not for gas stations' storage of gasoline.

A small airport I used to fly out of switched to an aboveground tank when the old underground one was found to have a leak. The permitting and construction costs for an underground tank were much higher with double walls and I believe sensors to detect leaks.

The rationale was exactly as you say -- with an aboveground tank you can easily see fuel leaking out and fixing a leak is also very easy by comparison.

Underground tanks are best thought of as indoor tanks these days. They build an underground room, put the tanks in and then inspect them visually, and the room collects any leaks.

Not always of course, but that is a common way to do them.

Tornadoes are more likely to ruin an above ground tank.

Tornadoes are very uncommon in the west coast of US (also, much of the Northeast and the rest of the world)[1][2]

[1] https://hazards.fema.gov/nri/Content/Images/StaticPageImages... [2] https://64.media.tumblr.com/64f5e2b83554ea3342a609c64bd8b4dc...

Oil companies don’t own the gas stations.

I mean, you probably answered your own question. Easier to obfuscate or straight up ignore if its completely outta sight, outta mind.