Document ID: chunk:federal_register_of_legislation:F2013C00288:reg:2:p1
Version: federal_register_of_legislation:F2013C00288
Segment Type: reg
Provision Reference: reg 2 (pt 1/15)
Character Range: 1252047–1254995

2                   EIL derivation methodology

2.1              Overview of the EIL derivation methodology
The methodology was developed being cognisant of both the methods used in other jurisdictions and of the existing methods used in Australia to derive water and sediment quality guidelines (ANZECC & ARMCANZ 2000; Simpson et al. 2005; Simpson & Batley 2007). The methodology is flexible and can deal with a variety of different land uses, risk pathways and toxicity data. It could be used to derive not just EILs but also other soil quality guidelines (SQGs) that have different purposes and/or different land uses. Examples of other SQGs include negligible risk target values, clean-up guidelines (goals that a site remediation must meet), intervention values (guidelines that, if exceeded, require immediate action in the form of remediation), and agricultural guidelines (guidelines to protect the long-term sustainability of agricultural land). The same basic methodology could also be used to derive guidelines for contaminants in products that are added to soil such as soil amendments, biosolids, fertilisers and re-use of wastes or by-products. In fact, guidelines for cadmium, copper and zinc for Australian biosolids applied to agricultural land have been developed using a very similar method (Warne et al. 2007, Heemsbergen et al. 2009). While the methodology can be used to derive other SQGs, this guideline will henceforth only focus on EILs.

An overview of the EIL derivation methodology is given in Figure 1. It consists of three main steps:
    1. choosing the level of protection desired for the site
    2. assessing exposure pathways
    3. collating appropriate data for the selected exposure pathways and deriving EILs.

Figure 1. Overview of the methodology for the derivation of EILs.

2.2              Levels of protection
Selecting the level of protection to be provided to a site or soil is one of the most important steps in the EIL derivation methodology.

The level of protection provided will depend on:
    1. The species and ecological functions that should be protected—every land use has specific functions and species that should be protected in order to ensure the land can continue to be used for that purpose. These functions and species include plants, soil microbial processes, soil and terrestrial invertebrates and vertebrates. For example, it would not be expected that all terrestrial species would be protected in an urban residential setting but it would be in national parks and areas of high ecological value.
    2. The exposure pathways that are relevant for the land use—for terrestrial ecosystems in general, there are multiple potential exposure pathways. However, not all exposure pathways will be relevant for any particular land use. For example, exposure pathways that involve biomagnification are unlikely to be relevant to small industrial sites, as their surface area is limited.