Document ID: chunk:federal_register_of_legislation:F2013C00288:reg:20:p10
Version: federal_register_of_legislation:F2013C00288
Segment Type: reg
Provision Reference: reg 20 (pt 10/14)
Character Range: 1319972–1323340

data for a contaminant, toxicity data derived by models like QSARs or QAARs and the equilibrium partitioning approach should not be used. However, if there is insufficient terrestrial toxicity data available to meet the SSD requirements, the modelled data should be used in combination with measured toxicity data. The minimum data requirements to use the SSD and AF methods are the same when using a data set containing both measured and modelled toxicity data as when using only measured toxicity data. However, only low reliability EILs can be generated using modelled toxicity data (Section 2.4.11).

Table 10. The taxonomic groups for terrestrial species
Taxonomic group  Examples of species in this group
Mollusca         Snails, slugs
Annelida         Enchytraeids, earthworms
Nematoda         Nematodes
Hexapoda         Insects, springtails
Myriapoda        Centipedes, millipedes
Chelicerata      Mites, spiders
Crustaceans      Woodlice
Algae            Algae
Plantae          Plants
Fungi            Fungi
Bacteria         Bacteria
Protozoa         Amoebas, ciliates, flagellates
Tardigrada       Water bears
Chordata         Reptiles, mammals, birds

Table 11. The nutrient groups for soil (i.e. microbial and fungal) processes
Nutrient group  Soil process                     Examples of end points
C cycle         Aerobic decomposition            Basal respiration, substrate-induced respiration
N cycle         N mineralisation/ammonification  Urease activity, NH4 production
                Nitrification                    NO3 production, substrate-induced respiration
                Denitrification                  Nitrate reductase
                Nitrogen fixation                Nitrogenase activity
P cycle         P mineralisation                 Phosphatase, Py-phosphatase
S cycle         S mineralisation                 Aryl-sulfatase

2.4.5         Calculation of the added contaminant limit using a species sensitivity distribution approach
The SSD approach is a statistical method to calculate a soil concentration that theoretically protects a specified percentage of species and/or soil processes. The SSD method used to derive the Australian and New Zealand WQGs (ANZECC & ARMCANZ 2000) was the Burr Type III method (Shao 2000), which was incorporated into the BurrliOZ program (Campbell et al. 2000) that is available from: www.cmis.csiro.au/Envir/burrlioz/
Download1.htm.

If there are screened toxicity data values for a contaminant to at least five species or soil processes for three taxonomic or nutrient groups, then there is sufficient data to calculate an ACL using the Burr Type III SSD method.

All SSD methods use a single numerical value to describe each species or soil process for which toxicity data is available. The means by which a single value was obtained for each species or soil process (Van de Plassche et al. 1993) are set out below:
    * if there were only one toxicity datum, that was taken to represent the species or process
    * if there were several toxicity values for the same end point, the geometric mean of the values was calculated and was taken to represent the species or process
    * if there were several toxicity values for different end points (e.g. mortality or reproduction), the end point with the lowest geometric mean was taken to represent the species or process.

SSD methods