Contaminated Land and Bio-Remediation - Environmental Biotechnology: Theory and Application - page 90

5
Contaminated Land
and Bio-Remediation
Contaminated land is another example of a widely appreciated, yet often poorly
understood, environmental problem, in much the same way as discussed for pol-
lution in the last chapter. That this should be the case is, of course, unsurprising,
since the two things are intimately linked, the one being, in essence, simply
the manifestation of the other. The importance of land remediation in cleaning
up the residual effects of previous human activities on a site lies in two spheres.
Firstly, throughout the world, environmental legislation is becoming increasingly
stringent and the tightening up of the entire regulatory framework has led to both
a real drive for compliance and a much greater awareness of liability issues within
industry. Secondly, as the pressure grows to redevelop old, unused or derelict
so-called 'brown-field' sites, rather than develop previously untouched 'green-
field', the need to remove any legacy of previous occupation is clear. A number of
technologies are available to achieve such a clean-up, of which bio-remediation,
in its many individual forms, is only one. Though it will, of course, provide
the main focus of this discussion, it is important to realise that the arguments
presented elsewhere in this topic regarding the high degree of specificity which
governs technology selection within biotechnological applications also applies
between alternative solutions. In this way, for some instances of contamina-
tion, expressly non-biological methods of remediation may be indicated as the
best practicable environmental option (BPEO). It is impossible to disassociate
contextual factors from wider issues entirely. Accordingly, and to establish the
relevancy of the wider setting, alternative remediation techniques will be referred
to a little later in this chapter.
The idea of 'contaminated land' is something which is readily understood, yet,
like pollution, somewhat more difficult to define absolutely. Implicit is the pres-
ence of substances which, when present in sufficient quantity or concentration,
are likely to cause harm to the environment or human health. Many kinds of
sites may give rise to possible contamination concerns, such as asbestos works,
chemical works, garages and service stations, gas works, incinerators, iron and
steel works, metal fabrication shops, paper mills, tanneries, textile plants, timber