Date published: 24th June 2015

A leading contaminated land specialist looks at the landfill challenges facing Heathrow expansion


Adrian Marsh - consultant for RSK one the UK’s leading contaminated land consultants:

"As an industry specialist, I can’t help but watch the final stages of the airport expansion debate with interest, particularly when I see Heathrow’s Chief Executive state that a new runway could be delivered there by 2025. 

"As reported this weekend, one of the many challenges to meeting this deadline is the fact that there are numerous landfill sites in place at Heathrow and the assumptions surrounding whether these need to be moved or left in place should be fed into the current review process and properly examined.

"One of the last pieces of work RSK has done is to undertake an independent review for Gatwick Airport of the available information regarding landfills and associated contaminated land at Heathrow. It has long been well known within the industry that resolution of contaminated land issues would be one of the major environmental challenges facing anyone attempting to build a runway there. In contrast, the conditions at Gatwick are benign.

"Over the last 60 years, former gravel workings to the north and west of Heathrow have been filled with London’s wastes and our analysis, based on available records, suggests that by the time construction started on a runway there, as much as 9,000,000m3 of landfill materials would have to be dealt with.

"This would be a huge task and possibly the largest and most costly project of its kind in the UK.  To put the size of the project into context, RSK is dealing with the recovery of a landfill site just outside Reading for housing development which contains about one twentieth of the volume of waste that Heathrow’s third runway will have to contend with. It is likely that - with the levels of control required to protect adjoining residents and the environment - this project will take about five years to deliver.

"At Heathrow, the wastes lie under the site of the proposed runway, along the course of the diverted motorways and river culverts, and where new passenger terminal facilities are shown on Heathrow’s plans. Our report sets out that leaving the landfills in place and trying to build over them is, for the most part, not a sensible proposition.

"Our report formed part of the information provided by Gatwick to the Airports Commission.  I therefore have confidence the Commission has in front of it good advice from RSK regarding the deliverability, cost and environmental effects of expanding Heathrow.  

"I look forward to Sir Howard’s final recommendation with interest."