Document ID: chunk:federal_register_of_legislation:F2013C00288:reg:20:p2
Version: federal_register_of_legislation:F2013C00288
Segment Type: reg
Provision Reference: reg 20 (pt 2/4)
Character Range: 1645544–1648252

that should theoretically protect 99, 80 and 60% of species/microbial processes. The resulting ACL(NOEC and EC10) values are only applicable to the Australian reference soil (Table 6). In order to generate soil-specific ACLs the normalisation relationships were applied to the ACL(NOEC & EC10) values in the reverse manner.

A complicating factor for Cu is that there are different soil physicochemical properties (that is, CEC, pH, OC and a combination of pH and log OC) that control the toxicity of Cu depending on the species or microbial process (Table 50). However, these can be rationalised down to two factors that control the ACL, namely CEC (measured using the silver thiourea method, Chhabra et al. 1975) and pH (measured in 0.01M CaCl2, Rayment & Higginson 1992) (see Appendix F for a detailed explanation of this rationalisation). Thus, there are two sets of ACL values for each land use type (that is, a set that vary with CEC and a second set that vary with pH). To determine the ACL that applies to a site, it is simply a matter of measuring the CEC and pH of the soil, looking up the tables for the appropriate ACL and then adopting the lower of the two ACL values. In the majority of cases the pH-based ACL values will limit how much Cu can be added to a soil when the soil pH is less than or equal to 6, while the CEC-based ACL values will limit the amount of Cu that can be added to a soil when the soil pH is greater than 6.

The ACL values for areas of ecological significance, urban residential/public open space and commercial/industrial land uses are presented in Tables 51 to 53, respectively.
Table 51. Soil-specific added contaminant limits (ACLs, mg/kg) based on no observed effect concentration (NOEC) and 10% effect concentration (EC10) toxicity data for fresh copper (Cu) contamination that theoretically protect at least 99% of soil processes, soil invertebrate species and plant species in soils with a pH ranging from 4.5 to 8 and a cation exchange capacity (CEC) ranging from 5 to 60 cmolc/kg and for an area of ecological significance land use. The lower of the CEC- or the pH-derived ACLs that apply to a soil is the ACL(NOEC & EC10) to be used.
Type of ACL     CEC (cmolc/kg)
                5               10   20  30   40   60
CEC-based ACLs  10              20   25  25   25   25
                pH
                4.5             5.5  6   6.5  7.5  8.0
pH-based ACLs   7               15   20  30   65   90

Table 52. Soil-specific added contaminant limits (ACLs, mg/kg) based on no observed effect concentration (NOEC) and 10% effect concentration (EC10) toxicity data for fresh copper (Cu) contamination that theoretically protect at least 80% of soil processes,