Developing Realistic Assessment Criteria for Your Site
Tier 1 – Initially, environmental site assessment generally involves consideration of collected data against pre-determined NEPM screening criteria to provide an indication of whether further assessment, remediation, and/or management may be required.
Tier 2 – NEPM screening criteria are based on a wide range of assumptions that tend to be somewhat conservative and able to be applied to a broad variety of sites. By understanding these assumptions and adjusting them relative to your particular situation it is possible to derive site-specific criteria that are more appropriately targeted to the site and generally less conservative.
Tier 3 – A more detailed risk assessment involves fully characterising the nature of the contaminants of concern, the specific site transport, and attenuation processes and developing a detailed understanding of how contaminants impact final site receptors (persons, plants, animals etc.). Typically a Tier 3 detailed risk assessment may require some form of fate and transport modelling and/or detailed toxicity assessment.