Homes face demolition as Akzo Nobel tackles contaminated site

Chemical manufacturer Akzo Nobel has told three Coventry households that it wants to demolish their homes to enable it to complete the clean-up of an adjacent contaminated site. The controversial multi-million pound project is attempting to deal with chemical contamination which the company unknowingly inherited when it acquired dozens of sites from Courtaulds in 1998.

The disruption, which is being caused by the remediation project in Coventry, is not on the scale of the recent episode involving Weston village in Cheshire, where ICI ended up demolishing some three dozen properties and buying up 250 after an old hazardous waste dump was found to be emitting chlorinated chemicals into some residents' homes (ENDS Report 342, pp 5-6 ).

Nevertheless, residents of 17 properties along one side of a street in the Foleshill area of the city have already faced several months of disruption and uncertainty - and three households are now under pressure to move out.

The one-acre contaminated site was previously owned by the Courtaulds chemicals and textiles group, which used it to store carbon disulphide (CS2) - a raw material in the manufacture of viscose rayon at a factory nearby. The storage use ceased in 1967, and the site was covered with tarmac shortly afterwards and has since been used as a car park.

Akzo Nobel inherited the site along with several dozen others when it acquired Courtaulds in 1998. But a detailed examination of the site was not carried out until late last year, after the car park flooded.

Investigations with ground radar revealed five large buried structures at five metres depth which turned out to be former storage tanks for carbon disulphide set in concrete bunds. The tanks had been emptied and backfilled, but three were found to contain CS2 residues. More of the chemical was found beneath the tanks.

Akzo Nobel does not believe that the contamination posed any threat to groundwater - there is no aquifer close by, and the site is underlain by a layer of clay - and monitoring yielded no evidence that any carbon disulphide had reached a nearby canal. Nevertheless, the company decided to remove the structures and excavate the contaminated soil.

This proved a major exercise which ran for four months. Some 200 tonnes of bentonite were used to absorb the liquid CS2 before the contaminated soil was dug out and landfilled.

The operation did nothing for the company's popularity with its neighbours. Carbon disulphide volatilises readily and is highly odorous, and Akzo Nobel's project coordinator, Mike Peters, acknowledges that at times there was a "terrible stink" as the soil was excavated. But air monitoring around the site perimeter produced no readings of health significance, he says.

The excavation was not the end of the story. Both the site and the gardens of the 17 neighbouring homes contain numerous underground structures from historic uses of the land, and Akzo Nobel was concerned that these might have provided preferential pathways for CS2 to migrate towards the houses.

In July, the company asked residents for permission to dig trenches and sink a series of small boreholes in some of the gardens. Householders were offered £500 per day while the trenches were being dug.

The results are being treated as confidential to the householders. According to Mr Peters, 15 of the gardens were found to contain either no CS2 or only "minute traces" of the chemical. One contained an elevated level of CS2, but the reading was obtained at four metres depth and was not high enough to pose an immediate health risk, he says.

Nevertheless, Akzo Nobel contends that it has a "duty of care" which requires the removal of the contaminated soil around this property. However, the need to excavate to several metres depth means that the building will suffer severe structural damage, along with two others in the same block.

It is these three properties which the company wants to demolish. It has offered the owners removal expenses, independent valuation of their homes and, says Mr Peters, a "very generous" premium on top of this to buy them out.

Negotiations on this offer continue. Meanwhile, the other residents have been offered £1,000 to allow CS2 monitors to be fitted inside their homes for 12 months, starting this autumn.

All this has gone on outside the scope of the statutory contaminated land regime under Part IIA of the Environmental Protection Act 1990. Coventry City Council says it sees no need to designate the site under Part IIA. A spokeswoman commented: "We're happy with the way that Akzo Nobel are dealing with things. They've involved us and kept us informed, and are doing the right thing by the residents so far."

The interesting question is whether the people who are being asked to leave their homes as a self-proclaimed "ethical company" seeks to clean up a liability would have faced the same prospect under Part IIA. As far as human health is concerned, a site must be designated as contaminated under Part IIA only if it is causing "significant harm" or there is a "significant possibility" of such harm - and Akzo Nobel has insisted throughout that there is no such risk to the residents.