Identification of Potential Sites
The objective of this task is to identify a site and determine if it is likely
to require further study.
The following information sources are useful to help identify potentially contaminated
At this stage no assumptions have been made about the need to conduct an
RA or decide any actions for a site, but will inform the
next stage of preliminary site characterisation.
Preliminary Site Characterisation
The objective of a preliminary site characterisation is to determine two main points:
- Might there be any contaminants with the potential to cause
adverse effects to human health and ecological values?
- Are there any people or ecological values that have the potential to be
In order to do this, you should record the following basic information about each
individual site of concern:
- Site location
- Site history the major historical site uses
- Current land use
- Surrounding land uses residential/industrial/rural, streams/rivers, wetlands,
parks/schools, reserves, etc.
- Main potential contaminants historic and current uses, and the processes in which
they are/were used (Note: many industrial processes have changed
substantially over time and may formerly have used compounds that
are now banned or no longer necessary),
- Potential ecological receptors of concern,
- People who might potentially be receptors.
Each site should be mapped in relation to
its surroundings and potential contaminants of concern. Several useful information sources
can help in this task:
obtained from the preliminary site characterisation will not usually be sufficient to
decide any course of action for the site, unless, for example, the information shows conclusively that potential
contaminants were never used at a site.
Site classification is simply a method of categorising sites based on the information
you have collected about the potential for contamination and the possible
ecological values present. The three basic classifications are:
- probably contaminated
- possibly contaminated or unknown
- probably uncontaminated.
The three basic categories for human receptors and ecological values are:
- probably human receptors and/or ecological values present
- possibly human receptors and/or ecological values present
- probably human receptors and/or no ecological values present.
You may need to undertake an issues-identification exercise to
determine which specific ecological values are important, (e.g.,
wetlands, rivers, indigenous vegetation, reserves). Likewise you may
need to determine whether people resident or working in the area might
be exposed to contaminants.
The result will be a matrix to highlight the sites of most concern:
You may decide that other categories are appropriate as a means of dividing the sites
into groups. However, at this stage the purpose of site classification is simply to assist
with the next step of prioritising the sites.
||Follow this link to an example of the
type of information a typical site classification might include.
A site manager may be dealing with more than one potentially contaminated
site, in which case, some form of prioritisation based on the site
classification step above may be necessary. This is to ensure that resources for
further site investigation are focused on those sites with the greatest
There are several methods available to prioritise sites. Many regulatory authorities in New Zealand use the
Rapid Hazard Assessment System
(RHAS), which is predominantly human-health based. This method as been
updated by the Classification
and Information Management Protocols prepared for The Ministry for the
Environment in 2001. The method you use to prioritise the sites for an
ERA should provide an outcome appropriate for the circumstances, for example, taking into
account financial and resourcing constraints.
Once a site has been identified as requiring an assessment, the
RA framework process should then be followed.
||Follow this link to an example of the type
of information a typical preliminary site prioritisation might include.
This diagram shows how the above
steps are used: