In 1989, the Urban Regeneration Agency commissioned Mott MacDonald to investigate the extent of contamination on the 63ha former Royal Dockyard site at Chatham, Kent and advise on a remediation scheme. The agency needed the site 'to be of a standard sufficient to permit residential and/or commercial development'.
The Royal Dockyard operated for 400 years and the site was known to contain a number of contaminants including asbestos, lead and other heavy metals.
Following site investigations, Mott MacDonald advised that 363,000m3 of contaminated material be removed to landfill at a cost of £23M. But as work progressed, more contamination was identified. In the end, more than 1.1M.m3 was removed at a cost of £67.6M.
The agency sued for more than £50M. Mott MacDonald lost and the high court made a provisional award of £18.5M damages, with the final figure to be assessed at a later hearing. The firm is appealing.
The case highlights three key lessons.
First, consultants should understand the client's requirements. Mott MacDonald used a risk assessment approach to evaluate the contamination and remediation of the site, whereas the client was concerned about public perception that if any hazard remained, even if buried, it would affect home and land values.
Mott MacDonald argued that the agency was trying to impose a 'squeaky clean' approach with a higher standard of remediation than necessary but the judge ruled that the agency's concerns about public perception if contaminated material was left on site were reasonable.
'A consultant must provide clear and comprehensive advice in a way that enables the client to appreciate all the factors influencing any proposed remediation. This includes the results of any site investigations and the reasons for any professional judgment exercised and for each recommendation made,' he said.
The judge also emphasised the need for consultants to ensure that clients understand the nature and shortcomings of concepts used, in this case threshold trigger levels, action trigger levels, risk assessment and gradation with depth.
The second lesson is to make sure that the best techniques are used. Consultants need to keep up with the latest developments and guidance. If not, they may face potentially catastrophic financial penalties.
In this case, the judge ruled that Mott MacDonald made substantial errors in site investigation and in its responses to the results of the investigation. He also decided that when measured against guidance available in 1989, the firm had not used state of the art methods as it had claimed.
Finally, environmental consultants should make sure their role is clearly defined, laying down what it will and will not do with regard to the client's instruction.
If the client is reluctant to spend time and money on certain aspects of remediation, the consultant must explain the risks of cutting corners and in some cases it may even be wiser for the firm to refuse to carry out work.
Gabor Kovacs, environmentalist specialist lawyer at Blake Lapthorn