Breaking new ground

One of the most recent entrants to the contaminated ground remediation market,

Eco-Smart, has just completed its first major project, on the site of the former

Drakelow A and B power stations. Drakelow, on the banks of the River Trent near

Burton-on-Trent, was in its day the biggest power station complex in Europe.

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.”

On-site remediation

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.

Project analysis

“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.”