Document ID: chunk:federal_register_of_legislation:F2013C00288:reg:2:p15
Version: federal_register_of_legislation:F2013C00288
Segment Type: reg
Provision Reference: reg 2 (pt 15/21)
Character Range: 80461–83378

agricultural soils, which need evaluation in relation to crop toxicity, plant contaminant uptake and detailed consideration of soil type.

    2.5.4          Levels of protection
The protection levels for the generic land use settings are:
    * 99% for areas of ecological significance
    * 80% for urban residential areas and public open space
    * 60% for commercial and industrial land uses.
These protection levels are increased by 5% when biomagnification may occur (refer Schedule B5b).

    2.5.5          Ecotoxicity data
The NEPM has adopted lowest observed effect concentration (LOEC) or effective concentration 30% (EC30) data to derive EILs for the land use scenarios.

The LOEC is the lowest concentration used in a toxicity test that causes a toxic effect that is significantly different from the control. EC30 data is the concentrations of contaminants that cause an effect on 30% of the test group of an organism after a specified exposure time. The data is drawn from a range of species to derive individual EILs.

For further information see Schedule B5b.

    2.5.6          Depth of application
EILs apply principally to contaminants in the top 2 m of soil at the finished surface/ground level which corresponds to the root zone and habitation zone of many species. In arid regions, where the predominant species may have greater root penetration, specific considerations may result in their application to 3 m depth.

    2.5.7          Ambient background concentration
The methodology assumes that the ecosystem is adapted to the ambient background concentration (ABC) for the locality and that it is only adding contaminants over and above this background concentration which has an adverse effect on the environment.

The ABC of a contaminant is the soil concentration in a specified locality that is the sum of the naturally occurring background level and the contaminant levels that have been introduced from diffuse or non-point sources by general anthropogenic activity not attributed to industrial, commercial, or agricultural activities, for example, motor vehicle emissions. Methods to estimate background levels are provided in Schedule B5b.

Three methods for determining the ABC are presented in Schedule B5b. The preferred method is to measure the ABC at an appropriate reference site. This approach is essential in areas where there is a high naturally occurring background level such as will occur in mineralised areas.

In other situations where an appropriate reference site cannot be determined, the method based on urban metal levels in Olszowy et al. (1995) or the method from Hamon et al. (2004) may be used.

In the method of Hamon et al. (2004), the ABC varies (depending on the element) with the soil iron and/or manganese concentration; for example, the ABC for zinc varies from
3 to 62mg/kg in soils with soil iron concentrations between 0.1% and 20%. Alternatively,