I can't think of a more boring title for an environmental blog, but crawlspace oil tank removal should rank in the top 10. As boring as it is, old metal tanks that store petroleum compounds such as diesel or heating oil are ticking time bombs, as the low sulfur content of these fuels allows interior corrosion of the tank. Exterior humidity/moisture causes the exterior of the tank to corrode, so you have two opposing forces generating rust, and when tank integrity breaches, oil will flow. The average cleanup cost of an oil leak in a basement is $15,000. A crawlspace oil tank leak doubles that cost simply due to the limited access to a crawlspace.
I refer to abandoned tanks as deferred maintenance because it is a project that doesn't get addressed, and when the stored oil leaks, it is now an immediate problem, with a cost much higher than if the tank had been addressed before the leak occurred. Curren has over 30 years of experience managing tank issues and crawlspace tanks while not a favorite, are part of our overall program. Removing a crawlspace tank is less expensive than cleaning up a leak.
Let's walk through the process, a crawlspace no matter how nice yours is it is called a crawlspace because access is limited. The access to the crawlspace to the left is through a small hatch in the floor.
Once you get into the crawlspace, you will see a tank on the other side of the area. The tank was likely installed after the foundation was installed but before the floor was installed, meaning the tank is wedged into the area, a great reason why no one addressed this tank 10 years ago when they converted to natural gas. Of course, Curren got called because an oil smell was permeating the home, because the tank finally started to leak. Fortunately, the tank was on a rough finish concrete floor, but there were still physical issues in trying to remove the tank. As you can see, we had to cut the HEAD or end of the tank off to access the tank for cleaning, and ultimately cut the tank into 8 pieces to remove it.
If you have an out-of-use metal oil tank, call Curren 
The metal is going to rust, oil is going to leak, you will then be forced to address the tank, which is going to cost more now because you have to clean up the oil from that empty tank.