Document ID: chunk:federal_register_of_legislation:F2013C00288:reg:60:p2
Version: federal_register_of_legislation:F2013C00288
Segment Type: reg
Provision Reference: reg 60 (pt 2/3)
Character Range: 1530656–1533403

ACL (NOEC & EC10) values for these land uses are presented in Tables 11 and 12.
Table 11. Soil-specific added contaminant limits based on no observed effect concentration and 10% effect concentration toxicity data (ACL(NOEC & EC10), mg/kg) for zinc (Zn) that theoretically protect at least 99% of soil processes, soil invertebrate species and plant species in soils with a pH ranging from 4.0 to 7.5 and CEC values ranging from 5 to 60 cmolc/kg. These values may be used as ACLs(NOEC & EC10) for Zn in freshly contaminated soils for areas of ecological significance.
pH   CEC (cmolc/kg)
     5               10  20  30  40  60
4.0  4               5   5   5   5   5
4.5  6               8   8   8   8   8
5.0  8               10  10  10  10  10
5.5  10              15  15  15  15  15
6.0  15              25  25  25  25  25
6.5  15              25  35  35  35  35
7.0  15              25  45  55  55  55
7.5  15              25  45  60  75  80

Table 12. Soil-specific added contaminant limits based on no observed effect concentration and 10% effect concentration toxicity data (ACL(NOEC & EC10), mg/kg) for zinc (Zn) that theoretically protect at least 60% of soil processes, soil invertebrate species and plant species in soils with a pH ranging from 4.0 to 7.5 and cation exchange capacity (CEC) values ranging from 5 to 60 cmolc/kg. These values may be used as ACLs(NOEC & EC10) for Zn in freshly contaminated soils with a commercial/industrial land use.
pH   CEC (cmolc/kg)
     5               10   20   30   40   60
4.0  30              35   35   35   35   35
4.5  40              50   50   50   50   50
5.0  55              75   75   75   75   75
5.5  75              110  110  110  110  110
6.0  95              160  160  160  160  160
6.5  95              160  240  240  240  240
7.0  95              160  280  350  350  350
7.5  95              160  280  390  480  520

3.6.1.2         Calculation of ambient background concentration values
To convert ACLs to SQGs, the ambient background concentration (ABC) needs to be added to the ACL. Three methods of determining the ABC were recommended in the methodology for deriving SQGs (Schedule B5b). The preferred method is to measure the ABC at an appropriate reference site. However, where this is not possible the methods of Olszowy et al. (1995) and Hamon et al. (2004) were recommended, depending on the situation.

For sites with no history of contamination the method of Hamon et al. (2004) was recommended to estimate the ABC. In this method, the ABC for Zn varies with the soil iron concentration (Table 13). Predicted ABC values for Zn range from 3 to 60 mg/kg in soils with iron concentrations between 0.1 and 20%.

Table 13. Zinc (Zn) ABC calculated using the Hamon et al.