The tank was well used.
I went ahead and bought it. $150 for a 1000 gallon diesel tank, including a 6' stand, hose, nozzle, and fuel filter, and hopefully I'll get him to toss in the 4 concrete blocks it was sitting on. The hose and all may be used for other projects.
Once I get most of the sludge washed out, the residual diesel in the tank should be minimal, and may leach out a bit over time. How much in 1000 gallons?
As far as petroleum. There are soil microbes that will aerobically break it down. Once rinsed, I'll likely have less total residual oil in the entire tank than one season's application of petroleum based dormant spray in my home orchard (except I'm now using canola based spray).
This winter, I'll try to run a few thousand extra gallons of water through the tank, but will consider it as a non-potable water storage system.
My pressure washer died this spring, so I may pick up a new one (or try to figure out what went wrong with the old one). Right now I'm trying to break up and rinse out the sludge, as well as rinsing a few hundred gallons of water+detergent through it. I thought about rinsing with gasoline, but don't want more contamination, and the water+detergent seems to be working fine, except getting all the rusty sludge out is a bit of a pain.
I like the stand this came with, and once clean, it should be relatively easy to weld should I choose to modify it such as adding a level indicating tube, or changing filling/discharge ports.
It is setup horizontal. I thought about reorienting it vertical (which would require a new stand). But, the 6 feet or so in the air for the horizontal tank should give me adequate pressure for my low pressure needs, and the pressure will be more constant than I would get if I had oriented it vertical.
