VertaseFLI has recently secured a contract at the former RAF / USAF airbase at Upper Heyford to de-commission the fuel storage and distribution system.
The works entail the clean and make safe of 67 tanks and over 13 km of fuel pipeline. The tanks cannot be demolished because the site has been designated by English Heritage and must be protected and maintained due to its importance during the Cold War.
Tanks range in size from 55 m3 (55,000 litres) to 4,700 m3 (4,700,000 litres). Total storage capacity of all tanks is over 30 million litres. For comparison, a typical retail fuel filling station might contain 40,000 litre storage capacity.
The 13 km of buried pipework is to be traced, severed at regular intervals, cleaned and will then be filled with inert hardened foam.
The tanks which were primarily used to store aviation jet fuel (JP8) currently contain water heavily impacted by LNAPL (free phase fuel oil) and dissolved phase fuel oil. VertaseFLI will gain access to the tanks to first recover the LNAPL, and then pump out the fuel contaminated water. The contaminated water will be treated in our own water treatment plant to non-detect levels using granulated activated carbon. LNAPL will be exported to a recycling facility whilst the treated tank water will be discharged across the air field under a special authorisation issued by the Environment Agency or used in the manufacture of tank fill.
Once the tanks have been emptied, manned access will be undertaken to clean the inside of the tanks, remove any sludges and to undertake a condition survey. Manned access will be under full confined space procedures using breathing apparatus.
Following cleaning and de-gassing, the tanks are to be filled to render them safe whilst still maintaining their protected status and external appearance. VertaseFLI designed a particularly innovative and sustainable approach whereby the tanks will be filled with a PFA / OPC grout. PFA or pulverised fuel ash is a by-product from coal fired power stations.
VertaseFLI has undertaken design trials in their own laboratory to identify the most appropriate and efficient design mix. VertaseFLI will mobilise a specialist batching plant and manufacture the grout on-site. The manufacture of the grout represents a particularly sustainable approach because it is manufactured on site and the primary constituent will be PFA from a nearby coal fired power station (the PFA is often surplus to requirements and is disposed of to landfill). We will even use treated tank water in the batching process. This approach will significantly reduce the carbon emissions of the project when compared to alternatives. Once filled, the tanks will be stable, environmentally safe and fully preserved.
For further information on this project or any other matter, please contact Michael Longman in our Portishead office. | 
