It all depends on the lift volume per stroke. some are steady and low volume, some are longer stroke (higher volume) and intermittent.
New wells might be flowing, nad not need a pump at all.
24,000 gallons of gas--about 8 semi-loads if iirc.
I don't mess around with the downstream end of the industry much, I am in exploration.
Either that was a very large facility with a lot of fuel islands, or the tanks were dry while you were putting the pumps in.
Not knowing what sort of arrangement the distributor had with the owner, whether the station was under new management, or what, I can't say one way or the other.
That fuel may have been paid for and waiting for y'all to finish installing the pumps. I don't know.
A gasoline shortage doesn't mean that crude storage tanks won't be full if the bottleneck in the supply chain is in the refining process.
So you could well have seen crude tanks full, and there still have been a gas shortage.
FYI, fuel trailers are most commonly ~9,000 gal, some up to 12,000.
http://www.truckpaper.com/listings/forsale/list.asp?bcatid=28&catid=64&ParentCategoryID=28