Riverlands scheme is on a former landfill site – this can cause problems, says Professor

Jan 8 2008 by David Bartlett, Liverpool Daily Post

PROF Bradshaw believes there are a number of considerations that need to be taken into account because of the site’s past as a landfill site.

In his written evidence to the public inquiry, he said: “This site is a large and deep landfill. It is well appreciated that this can lead to serious problems from the point of view of building construction.

“1. The site will be covered with poor load bearing ground material likely to continue to compact even after careful treatment, so that all normal buildings will require extensive, and expensive, pile foundations to hard material below.

“2. Decay processes in the ground material will lead to continuous production of methane, capable of being an explosive gas at low concentrations.

“3. This decay will be likely to lead to further subsidence.

“4. Pockets of serious polluting material, such as asbestos, from disposal at random in the original landfill materials are possible.

“These considerations mean that careful soil surveys must be undertaken, foundations of all buildings must be appropriate, a high class gas proof so that any stray gas emissions cannot enter buildings.”

He said that all building works “must be carried out with great care so that any disturbed ground does not, and cannot, provide gratuitously easy access for methane emissions, or exposure to polluting material.

“These problems can be treated, but at mostly considerable expense, and will need to be carefully monitored.”