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Alternative medicine

ENVIRONMENTAL GEOTECHNICS

A new study aims to identify and break down barriers to wider use of innovative remediation methods. Its authors, Rob Evans and Rachel Mansfield of the Geohazards Group at Nottingham Trent University, describe its remit.

Assessment and remediation of contaminated and derelict land is a prime concern for the geotechnical engineering community. Several factors have encouraged this, including legislation such as Part IIa of the Environmental Protection Act and the Groundwater Regulations (1998), as well as the government target of 60% of new homes to be built on brownfield sites by 2008.

Reuse of brownfield sites depends on successful remediation: the removal or treatment of any contaminants. Traditional civil engineering remediation methods sever the pathway between the contamination source and the receptors (humans, plants, animals or building materials that could be harmed by the contaminant) by removing material to landfill, or by creating a barrier around and/or over the site.

Another option is process-based technologies, which treat contamination directly by destroying, denaturing or stabilising it. These can be used either insitu or exsitu, depending upon the nature of the contamination and other site characteristics. Process based technologies can involve biological, chemical, physical or thermal treatments, or can involve the stabilisation or solidification of contaminated soil.

UK remediation has mostly been by traditional engineered methods, relying heavily on removal and disposal to landfill.

A 2000 survey of UK remediation projects by Petts et al showed that civil engineering techniques were used on 94% of sites, compared with 16% of sites that used insitu process-based techniques and 5% involving exsitu processbased techniques (some sites used a combination of methods).

Excavation and off-site disposal was overwhelmingly the most popular technique, used on 76% of sites surveyed.

With the increasing emphasis on sustainability, it is clear that reliance on engineered methods, which do not remove the source of the problem and may limit the future use of sites, is often not environmentally sound.

A study focusing on the use of innovative technologies in contaminated land remediation is being carried out at Nottingham Trent University.

In 1996, the Royal Commission on Environmental Pollution commented that most remedial methods used in the UK were 'less satisfactory environmentally' than treatment methods that remove contaminants from the soil.

It recommended that 'greater emphasis be placed on the commercial application of treatment technology that is environmentally friendly, competitively priced, and can be applied easily to sizeable areas of land, with a particular emphasis on bioremediation techniques'.

The commission's findings underlined the importance of developing alternative remediation methods capable of effectively treating increasingly complicated contamination problems without excessive cost.

The term 'innovative', when used in reference to remediation technologies, can vary in meaning according to context, but generally refers to a relatively new technology that has yet to become fully established and accepted.

Although some new technologies introduced to the UK can now be considered generally accepted, some available innovative technologies are not used as widely as they might be, and the uptake of them has been slow.

Lack of widespread use of available innovative technologies does not encourage the further development of new methods, thus limiting the options for remediation projects.

There are several possible reasons behind the slow adoption of innovative technologies. A report by the United States Environmental Protection Agency in 2000 classified possible barriers into four broad categories: institutional; regulatory and legislative;

technical; and economic and financial.

The study being carried out at Nottingham Trent will attempt to assess the effects of these factors in UK remediation, and follows on from previous work on the evaluation of land remediation methods (Mansfield and Moohan, 2002).

Other issues that will be considered include behavioural reasons for selection of traditional methods - the extent to which those involved in design of remediation projects prefer to use familiar methods, or to which decision processes favour selection of engineered techniques.

Other potential hindrances to the use of innovative technologies include concerns over the awareness, and availability, of the methods. An additional problem is that process-based technologies are generally highly contaminant-specific and may be unsuitable for use under certain site conditions.

Pressures from other parties may also hinder the use of innovative methods. A large number of stakeholders, including the public, pressure groups, clients and financiers, have an interest in contaminated land remediation projects and their effect on the selection of remedial process may favour well-developed methods.

It is possible that the public in particular may be concerned about the use of new methods that do not have a long history of use, perceiving them to be less reliable, safe or effective than traditional methods.

As the study progresses, it is intended to establish the effects of the involvement of different stakeholder types.

The perceived importance of innovative remediation technologies is illustrated by the number of initiatives that have been created to encourage their use.

The full range of initiatives is extensive, including schemes that:

linvestigate and develop new remediation methods ldisseminate knowledge of innovative methods (eg Envirowise, formerly the Environmental Technology Best Practice Programme, and Biowise).

ldemonstrate the effectiveness of innovative methods under UK site conditions.

Economic measures are another approach to encouraging the development and application of innovative technologies. These may be used by either positive financial encouragement of new technologies, or by increasing the expense of more traditional methods (for example by the landfill tax).

In any commercial operation financial issues are of utmost importance, so the use of economic incentives to avoid dig-anddump, or other less sustainable options, will clearly play an important role in encouraging the wider use and quicker adoption of alternative methods.

The study will assess the effectiveness of these schemes, and suggest other ways that barriers to use of the newer methods could be minimised or eliminated.

The increasing complexity of contamination problems and a growing requirement for sustainability indicates the need for a large portfolio of effective and environmentally acceptable remediation techniques.

For this need to be met, it will be necessary for new and emerging remediation methods and techniques to be developed, accepted and adopted more quickly.

However, significant barriers exist to innovative technology adoption, including (but not limited to):

lconcerns over availability lconcerns over reliability lreal or perceived increased costs associated with innovative methods llack of awareness of the methods available lfear of litigation following unsuccessful remediation.

The study, which will be completed later this year, aims to establish perceptions of innovative technologies, the reasons for their lack of widespread use and the most appropriate ways to encourage their application. Anyone with an interest in the study, or wishing to contribute their views, is welcome to contact the authors.

References

The Environmental Protection Act (1990).

Part IIa: Contaminated land.

The Groundwater Regulations (1998).

Statutory Instrument 1998, No 2746.

Mansfield RM and Moohan JAJ (2002). The evaluation of land remediation technologies, land contamination and reclamation, 10 (1), 25-32.

Petts J, Rivett MO and Butler B (2000).

Survey of remedial techniques for land contamination in England and Wales, R&D Technical Report P401, Environment Agency, Bristol.

Royal Commission on Environmental Pollution (1996). Sustainable use of soil, HMSO, London.

United States Environmental Protection Agency (2000). An analysis of barriers to innovative treatment technologies: summary of existing studies and current initiatives, EPA 542-B-00-003, USEPA Office of Solid Waste and Emergency Response, Washington, DC.

Contact details

Rob Evans and Rachel Mansfield Geohazards Group Nottingham Trent University robert. evans@ntu. ac. uk rachel. mansfield@ntu. ac. uk

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