Document ID: chunk:federal_register_of_legislation:F2013C00288:reg:2:p16
Version: federal_register_of_legislation:F2013C00288
Segment Type: reg
Provision Reference: reg 2 (pt 16/21)
Character Range: 83134–85989

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, ABCs for old and new suburbs and high and low traffic areas for New South Wales, Queensland, South Australia and Victoria for Zn, Cu, Ni, Pb, and CrIII are included in  Schedule B5b and are derived from Olszowy et al. (1995). Values for new suburbs would be appropriate to use for new suburbs or in areas with no known history of contamination for that metal. In old-established urban areas (i.e. suburbs more than 20 years old), it would be appropriate to use the 25th percentile of the ABC values from Olszowy et al. (1995).

In some situations the ABC may be comparatively low and have a minor effect on the magnitude of the site EIL.

    2.5.8          Added contaminant limits
An added contaminant limit (ACL) is the added concentration (above the ABC) of a contaminant above which further appropriate investigation and evaluation of the impact on ecological values is required. The EIL is derived by summing the ACL and the ABC.

ACLs are based on the soil characteristics of pH, CEC and clay content. Empirical relationships that can model the effect of these soil properties on toxicity are used to develop soil-specific values. These soil-specific values take into account the biological availability of the element in various soils. In this approach different soils will have different contaminant EILs rather than a single generic EIL for each contaminant.

ACLs apply to chromium III (CrIII), copper (Cu), nickel (Ni) and zinc (Zn) for site-specific EIL determination. The soil properties to be determined for each relevant soil type at the site, are shown in Table 4 below.
Table 4: Soil properties to be measured for site-specific derivation of ACLs for CrIII, Cu, Ni and Zn
Soil physicochemical property  CrIII  Cu  Ni  Zn
pH                                    
CEC                                         
% clay                         

Insufficient data was available to derive ACLs for arsenic (As), DDT, lead (Pb) and naphthalene. As a result, the derived EILs are generic to all soils and are presented as total soil contaminant concentrations in Tables 1B(4) and 1B(5).

    2.5.9          Ageing of contamination and soil properties
In general the toxicity of soil contaminants (both organic and inorganic) will reduce or age over time to a lower and more stable level by binding to various soil components and decreasing their biological availability. Hence, toxicity can be affected by the physicochemical or chemical properties of the soil including clay content, cation exchange capacity (CEC) measured in centi-mole charge/kg (cmolc/kg), pH, iron and organic carbon content.