Machinery first. Petrol in a diesel tractor, header or telehandler is the same problem as petrol in a diesel ute, modern common rail machines rely on the diesel to lubricate the high pressure pump, and petrol strips that away. It usually happens in the rush, a jerry can grabbed off the wrong shelf, a drum that wasn't what the label said, a contractor filling from the wrong tank. Don't start it, or shut it down as soon as you realise, and call.
Work utes, gensets, fire pumps and other small plant are usually quick jobs, the tanks are small and easy to get at. We drain the wrong fuel, flush the lines and refuel right there at the shed, the paddock or the yard, the same drain and flush we do on the road every week.
On site storage is the other half of it. Old diesel that has gone off over winter, water in the bottom of the tank after rain, sediment stirred into a delivery, or fuel that simply went into the wrong tank. We drain it out, dispose of it under EPA Licence 52359 and leave you ready for a clean fill.
We drive out across regional South Australia, the Barossa, Mid North, Riverland, Murraylands, Yorke Peninsula and the South East, and onto mine and work sites where access allows. Response and price are quoted on the call. For the mechanical detail, see petrol in a diesel and contaminated fuel.