The bunded diesel tank in the corner of the yard

5 November 2026

The fuel that matters most on a long international run is the fuel that goes in before the truck leaves the yard. If the bulk tank in the corner is contaminated, the problem travels with the vehicle: blocked filters, rough running, a breakdown somewhere in Europe or somewhere much less convenient further east. Most operators with their own fuel never give the tank a second look until that happens.

What collects at the bottom

Water can collect in storage tanks through condensation or defects around fittings. Water at the bottom of a diesel tank gives microbial growth, the so-called diesel bug, somewhere to live, and the sludge it forms gets drawn into the fuel system. Sediment and rust from older tanks add to the mix. Once debris reaches the dispenser filters, it becomes a problem for the whole yard rather than one lorry.

Cleaning removes the water, sludge and deposits so the tank can stay in use, be inspected or be taken out of service safely. Fuel polishing, where the fuel is filtered and returned, can sometimes deal with contaminated fuel without emptying everything, though it does not replace cleaning a tank with heavy deposits.

Plan the clean around the fuelling

A tank cleaning visit takes the tank out of use for a while. Arrange an alternative: fill vehicles beforehand, use fuel cards for the duration, or plan the work for a weekend when fewer vehicles are going out. Make sure the crew can reach the tank, the bund and the fill point, and that anyone who uses the pump knows it is locked off.

The bund deserves a look at the same time. Rainwater and debris can take up space in a bund and make signs of a leak harder to spot. Oily water in a bund is waste in its own right and needs taking away properly, not pumped out onto the yard.

Tank Cleaning Services covers storage tank and process vessel cleaning for sludge, product residues, inspection preparation, removal and changes of use, with the work based on the actual tank and what it holds.

When the depot moves

Moving depots raises the question of what happens to the old tank. Leaving it full or half cleaned is a liability for whoever takes on the site. Emptying, cleaning and either removing it or making it safe belong on the list alongside handing back the keys and the drainage records. If the tank is moving too, its contents and condition need to be dealt with before transport is arranged.

Whichever way it goes, keep a record of the work with the rest of the site file. The next tenant, buyer or insurer will ask, and a dated note answers the question in seconds.