Document ID: chunk:federal_register_of_legislation:F2013C00288:reg:2:p4
Version: federal_register_of_legislation:F2013C00288
Segment Type: reg
Provision Reference: reg 2 (pt 4/4)
Character Range: 1510144–1512416

for the potential to leach in deriving practical SQGs at a generic level, rather this should be done as part of a more detailed site-specific ecological risk assessment.

Given the available data, the most complete set of SQGs was derived for each of the eight contaminants. A summary of what SQGs could be derived is presented below.

    * For chromium (III), copper, nickel and zinc, it was possible to derive a set of soil-specific SQGs using each of the three types of toxicity data for each of the three land uses for both fresh and aged contamination.
    * For arsenic and lead, it was possible to derive generic (not soil-specific) SQGs using each of the three types of toxicity data for each of the three land uses and for both fresh and aged contamination.
    * For DDT and naphthalene, it was possible to derive generic (not soil-specific) SQGs using each of the three types of toxicity data for each of the three land uses but only for fresh contamination.

In addition, SQGs that account for the potential of contaminants to leach (and therefore should protect aquatic ecosystems) were derived for arsenic and zinc. This was only done for these contaminants to illustrate how this is done and what effect it has on the resulting SQGs compared to the SQGs that do not account for leaching.

2.1              Precision of estimates and rounding of added contaminant limits
In order to increase the readability and ease of use of this report the ACL, ABC and SQG values presented in the various tables have all been rounded off using the following scheme:
    * all values <1 were rounded off to the nearest 0.1
    * all values between 1 and 10 were rounded off to the nearest whole number
    * all values between 10 and 100 were rounded off to the nearest multiple of 5
    * all values between 100 and 1000 were rounded off to the nearest multiple of 10
    * all values greater than 1000 were rounded off to the nearest 100 units.
Figure 2. Schematic of the methodology for deriving soil quality guidelines (SQGs) (modified from Heemsbergen et al. 2008). Green arrows show the path when the preceding question was answered with a 'yes' while the red arrows indicate the path when the answer was 'no'. Blue arrows indicate the path when there is no choice.