Environmental Engineering Reference
In-Depth Information
reserves, as much information about a site as possible should be obtained from
the nature conservation agency websites (i.e., Natural England, Countryside
Council for Wales, Joint Nature Conservation Committee). These websites will
also provide information on assessment endpoints; for example, 'favourable
condition' for SSSIs, or 'favourable conservation status' for Natura 2000 sites.
For local reserves and BAP habitats species information can be obtained from
the local record centres, Local Authority ecologists or the site managers (such
as the local wildlife trust or RSPB office).
There is a range of ecological survey (ecosurveys) types, and careful
consideration needs to be given to what is required of the survey, which will
depend on (among other things) the receptor, the exposure pathway, the
contaminant's mode of action and the type of habitat. Examples of ecosurvey
types (Hill et al.
2005
) that may be undertaken include:
size or number of individuals;
community composition (presence of particular species/overall diversity);
population age structure, recruitment or mortality;
population density etc.
Whichever method is used, the ecosurvey must be adapted as appropriate to
the site and type of contamination and should be specifically tailored to the
features and sensitivities of the site, e.g., grassland or bat population. Consider-
ations might include (after Environment Agency
2008b
):
General issues
Contaminant pathway
How many years of data are required
Contaminant mode of action
Time of year surveys need to be made
Contaminant distribution
Are there cumulative impacts
Receptor distribution
How much detail is required
Scales of natural variation
Is expert judgement required
External influencing factors
Practicality issues
Safety issues (personnel health and safety)
Access to the site
Are licenses required
In addition to the considerations outlined above regarding surveying specific
receptors, ecological functioning of the site should also be considered. Ecological
functioning includes a great many factors, and some of those that might be
considered in an ecosurvey at Tier 2 of the ERA are listed in
Table 9.3
(Environment
Agency
2008b
). More information is available from IEEM (
2006
).
Distribution of the contaminant is another important consideration when
planning an ecosurvey: the contaminant may not affect the entire site, and
may move offsite via wind or water; and the habitat on the site is unlikely to
be homogenous. Furthermore, offsite contamination must also be considered
