Document ID: chunk:federal_register_of_legislation:F2013C00288:reg:3:p5
Version: federal_register_of_legislation:F2013C00288
Segment Type: reg
Provision Reference: reg 3 (pt 5/8)
Character Range: 108433–111598

should be considered and assessed as appropriate in accordance with Schedule B6 and jurisdictional policies for the protection of groundwater resources.

3.4              Considerations for ecological assessment

    3.4.1          General
Schedule A provides an overview of the site assessment process and the application of investigation and screening levels for human health and ecological risk assessment. While protection of human health often drives the first stages of assessment, protection of the environment (terrestrial and aquatic) should be a consideration for all site assessments.

In assessing the overall risk to the environment from soil contamination the following site-specific aspects should be considered:
    * the location of the contamination in relation to any on-site and off-site sensitive receptors, e.g. watercourses, estuaries, groundwater resources, sensitive ecological areas
    * the existing or proposed land use(s)
    * the presentation of contaminants including areal extent, depth below finished ground level, the presence of barriers or containment that prevents or minimises the migration of contamination or exposure pathways
    * the in situ leaching characteristics of contaminants of concern and the potential for leachate to adversely affect any accessible sensitive on-site and off-site receptors
    * the potential for contaminants to be transported from the site at levels of concern by erosive forces.

    3.4.2          Scope of ecological assessment
The relevance and scope of ecological assessment should be considered early in the development of the conceptual site model and data quality objectives. A pragmatic risk-based approach should be taken in applying EILs and ESLs in residential and commercial/industrial land use settings.

Site soils may have poor structure and drainage, low organic content, minimal topsoil depth and a limited ability to support plant growth and soil micro-organisms. In existing residential and urban development sites there are often practical considerations that enable soil properties to be improved by addition of ameliorants with a persistent modifying effect or by the common practice of backfilling or top dressing with clean soil. In other cases, all of the site soils will be removed during site development works or relocated for the formation of new land forms. Sites may also be backfilled with clean soil/fill and the fate of any excavated contaminated soil should be considered in the process.

Commercial and industrial sites may have large building structures and extensive areas covered with concrete, other pavement or hardstand materials and may have limited environmental values requiring consideration while in operational use.

    3.4.3          Mobility of contaminants
When contamination is in a highly leachable form or is incorporated in exposed readily erodible soil, potentially adverse ecological effects may occur some distance from the contaminant source area. The potential for off-site environmental impacts should be considered in the development of the conceptual site model. Methods for determining leachability are discussed in Schedule