Quote Originally Posted by Elizabeth Greene View Post
I'd like to understand more about how this system works. Specifically, I read of a person that stole huge amounts of fuel by parking a modified van over (I don't know which port), popping up a hatch cut in the rear of the van floor, and pumping fuel into tanks inside the van. When I've looked at the ports where tankers fill up (with permission) they don't appear to have a direct route into the tank where the thieves could drop in a pump.

How would that type of attack work?
I've had a little experience with underground fuel tanks but have mostly dealt with aboveground models, so could be completely wrong with this answer. Correction is encouraged.


In most cases, the fill port on the underground type is as close to a straight vertical drop to the tank as possible. There may be a slight offset due to available space at the filling station, The line to the dispenser doesn't have to be straight. This allows for the tanks to be filled without interfering with activity at the dispensers. Depending on the layout of the filling station, it can be possible at a busy site for someone to park directly over the fill port and, with a flexible hose, do their modified van thing without attracting much attention. They would be long gone by the time the station checks the inventory.


Regarding leak detection, aboveground tanks are double walled and are supposed to be manually checked every day for interstitial leakage. Newer underground tanks are also double walled but use a more sophisticated system that involves liquid sensors, monitoring wells to detect fuel vapor, and routine pressure and/or vacuum tests.


As an aside, aboveground tanks are mostly filled with concrete between the inner and outer sections due to the tendency of some people to shoot at them. Believe it or not, that actually happens in places that aren't war zones.