Tier 2 Receptor Characterisation
Tier 2 Receptor Characterisation will involve identifying the
potential human receptors and ecological values to be protected, including identifying the
people and species known to
be present at or visiting the site. This should also include identification of
species frequenting other sites that are adversely affected by contaminants. You may want to consider
undertaking a preliminary biological survey to confirm these details, but this
may not be necessary until Tier 3.
For any species or populations that are particularly sensitive or valuable
for other reasons (e.g. rarity), the following information should be obtained
- basic life history patterns
- habitat requirements
- food web interactions where it is possible to discern
With regard to a specific population, the following information may be
obtained where possible:
- preliminary estimates of population density, age-class structure, etc.
- preliminary estimates of the percentage of mature females, female
fecundity and other measures of the health of the population of the species
For habitats, communities and ecosystems, obtain more detail regarding what
potential adverse effects may be manifested by the contaminant of concern.
Tier 3 Receptor Characterisation
If not undertaken previously, a biological survey will need to be undertaken
at the site and surrounding areas. This should confirm key ecosystems, processes
and species, sensitive land uses and ecological values, and the protection
status of ecological values and the basis of the protection decisions. Estimates
of biodiversity, estimation of ecosystem functions and potential successional
patterns following remediation may also be required.
Environment Canada (1994) considers that the following
information may need to be
- ecosystem characteristics
- measures of biodiversity and biomass
- functional groups and trophic linkages (e.g.
- measures of basic function including primary production, respiration,
decomposition, nutrient and energy cycling, etc.
- habitat characteristics
- local topography, 3-D configuration of at-risk habitat
- catchment characteristics including surface cover, soils, etc.
- surface water and groundwater hydrology
- weather/climate data especially affecting population levels
- particularly sensitive locations
- community characteristics
- indicator species
- migratory species that are likely to be affected
- overall population density
- number and distribution of populations
- age-class structures
- species or populations of interest
- body tissue/fluid analysis to determine contaminant
- behavioural aspects (e.g. avoidance behaviour)
- food requirements, ingestion rates
- natural variability in life cycle or other aspects.
Note: this list is not exhaustive, and the appropriate information may
be different and/or more or less extensive depending on previous information
obtained and the nature of the receptor.