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. F

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.