I have been approached by a filling station in my area who have decided to no longer store fuel and wish to close the site. I would like some guidance on the correct procedure for making a disused tank safe.

The filling station was developed about 17 years ago and has double wall tanks with the glycol leak detection with a black header tank installed in each of the manholes.

I have heard that these require special treatment. Can you advise please?

As you will probably be aware that around 5 years ago tanks using Glycol in the interstitial space (known as Class 2 leak detection) are no longer permitted to be installed in the UK and Europe due to the high risk of pollution to groundwater if the tank leaked. It was decided that tanks already installed with Class 2 leak detection could continue to be used as the leak detection system would warn the occupier if the tank leaked.

Guidance on making tanks safe is provided in Chapter 12 Decommissioning in The Blue Book.

In this case, however, the tanks cannot be made safe in situ, they would need to be fully removed to ensure that the risk of pollution from the leaking Glycol is no longer present.

Specialist firms carrying out this work are listed in the Yearbook and listed in the Contact Directory on the publications page of the APEA website at www.apea.org.uk.