Contaminated Land and Bio-Remediation - Environmental Biotechnology: Theory and Application - page 91

treatment plants, railway yards and waste disposal sites. This list is not, of course,
exhaustive and it has been estimated that in the UK alone something in the region
of 360 000 ha (900 000 acres) of land may be affected by contamination in one
form or another (BioWise, 2001). Much of this will, of course, be in prime urban
locations, and therefore has the potential to command a high market price, once
cleaned up.
Since the whole question of contaminated land increasingly forms the basis
of law and various professional codes of practice, there is an obvious need for
a more codified, legal definition. The version offered in Section 57 of the UK
Environment Act, 1995 is a typical example:
any land which appears ... to be in a condition that ... significant harm is being
caused or there is a significant possibility of significant harm ... (or) ... pollution
of controlled waters
In this, 'harm' is expressly defined as to 'human health, environment, property'.
As was mentioned earlier, land remediation continues to grow in importance
because of pressures on industry and developers. The motive force is, then, a
largely commercial one and, consequently, this imposes its own set of conditions
and constraints. Much of environmental biotechnology centres on the 'unwanted'
aspects of human activity and the clean up of contaminated land is no exception
to this general trend. As such, it is motivated by necessity and remedies are
normally sought only when and where there is unacceptable risk to human health,
the environment and occasionally to other vulnerable targets. In broad terms it is
possible to view the driving forces on remediation as characterised by a need to
limit present or future liability, increase a site's value, ease the way for a sale or
transfer, comply with legislative, licensing or planning requirements or to bolster
corporate image or public relations. Generally, one or more of these have to be
present before remediation happens.
Having established the need for treatment, the actual remedies to be employed
will be based on a realistic set of priorities and will be related to the risk
posed. This, of course will require adequate investigation and risk assessment
to determine. It is also important to remember in this context that, since the
move to remediate is essentially commercial, only land for which remedia-
tion is either necessary or worthwhile will tend to be treated and then to a
level which either makes it suitable for its intended use or brings it to a condition
which no longer poses an unacceptable risk.
It should be apparent, then, from the preceding discussion that the economics
of remediation and the effective use of resources are key factors in the whole
contaminated land issue. Hence, in purely economic terms, remediation will only
take place when one or more of the driving forces becomes sufficiently com-
pelling to make it unavoidable. It will also tend towards the minimum acceptable
standard necessary to achieve the required clean-up. This is not an example of
industrial self-interest at its worst, but rather the exercise of responsible manage-
ment, since resources for remediation are typically limited and so their effective
use is of great importance. To 'over' remediate any one given site could seriously