Breaking new ground
The contaminated land market is about to receive a major boost from legislative and fiscal changes as well as the government inspired drive to use more brownfield sites for housebuilding. A major beneficiary will be Eco-Smart, the newly launched contaminated ground specialist which is part of the Roger Bullivant group, as Nick Barrett reports from a major Eco-Smart clean up site.
Eco-Smart's general manager, David Bower, explained: "We negotiated with the Environment Agency on Powergen's behalf, obtained a licence, designed a solution, assembled plant and carried out the project. We found heavy metal salts condensed in silts over the years of operation of the power station. Water was being pumped out of the Trent and when it was held in the cooling ponds, the heavy metals settled on the bottom. When the cooling ponds were drained the silt was left behind."
The site was some 100 acres, with about 23 acres involved in the contamination issue. About 35,000 tonnes of material was contaminated, located in three distinct areas and mostly spread on the surface, although contaminants were found as deep as 5.5 metres below ground level. The remediation process involved solidification/stabilisation with cementitious binders which were spread over the site and mixed with the silt. The cementitious material introduced was up to five per cent of the total volume of material. We first excavated the material to be treated and took it to our treatment area on site and placed it in two stockpiles. One was left to stand and dry out while the other had timber and hardcore screened out. Hardcore was crushed and blended back into the silt while the timber went to landfill.
The material was then blended back in layers of 300mm. Rotovators were used and the material was finally compacted. The site is now ready for redevelopment.
"All the investigations and analysis necessary for the project was carried out in house," says Bower, "It wasn't a typical site, although it was typical perhaps of cooling tower sites. The tonnages involved were much bigger than have been treated before in the UK with a heavy metal stabilisation technique. The alternative would have been to cart it all off to landfill, which would have been prohibitively expensive and time consuming as well as environmentally unsatisfactory. We are not of the simply 'bung your problems in another hole in the ground' philosophy. We were off the site within three weeks, which is a strong message to deliver to developers involved with sites like this.
Eco-Smart's mobile plant licence means it can treat any wastes in soil, with a few exceptions like acids which would be isolated and taken off site or a treatment technology would be imported to deal with them on site. "Our role is consultants and project managers," says Bower, "so we are happy to bring in other expertise as the project requires. We can design the solution, negotiate with the relevant authorities and execute the project where appropriate. We aim to be a one stop solution for property and land owners. We take the risk away for developers. We understand the problems facing developers because we have faced them ourselves."
One stop shop
Eco-Smart forecasts an upsurge in contaminated land work as a result of the implementation of the Contaminated Land Act from 1 September this year. In addition, an increasing amount of brownfield sites will have to be made suitable for housebuilding.
"Solutions for contaminated sites are going to be in big demand, and developers
want the one-stop-shop service which we offer," says Bower. "The government
has made 150 per cent tax relief available on the cost of treatment, which will
give another boost to demand. About 50 per cent of the UK market will be within
a few hours of our base in Burton and we aim to capture at least a five per
cent market share."