Document ID: chunk:federal_register_of_legislation:F2013C00288:reg:5:p5
Version: federal_register_of_legislation:F2013C00288
Segment Type: reg
Provision Reference: reg 5 (pt 5/10)
Character Range: 158296–160954

(silt, 2<4 m)
         F1   F2   F3    F4   B    T   E   X
Soil GM  130  160  1100  260  1.5  80  70  60
HSL A    100  NL   N/A   N/A  1.0  NL  NL  NL

Notes
   NL indicates the HSL is not limiting (see Footnote 5, Table 1A(3)).
   N/A not applicable as these fractions are not volatile and hence are not of concern for vapour intrusion
   Shaded and bold font for sample value indicates relevant HSL exceeded
Groundwater (site maximum concentration) values mg/L, refer Table 1A(4) for groundwater HSLs (silt, 4 m to <8 m)
       F1   F2    F3    F4    B     T     E     X
MW1    1.3  0.9   <LOR  <LOR  7     16    12    35
MW2    0.5  <LOR  <LOR  <LOR  <LOR  <LOR  <LOR  4
MW3    2.7  1.1   <LOR  <LOR  8     17    23    42
HSL A  6    NL    N/A   N/A   5     NL    NL    NL

Notes
   LOR is the limit of reporting.
   NL indicates the HSL is not limiting (see Footnote 4, Table 1A(4)).
   N/A not applicable as these fractions are non-volatile and hence are not of concern for vapour intrusion
   Shaded and bold font for sample value indicates relevant HSL exceeded
Step 2: Tier 1 risk assessment
    1. Are site values greater than soil and groundwater HSLs for assessing vapour intrusion risks?  YES, elevated F1 and benzene in soil and elevated benzene in groundwater.
    2. Is biodegradation applicable?  YES (from consideration of likely slab size for a typical residential house and oxygen content of soil vapour at 1m) Adjust soil HSLs x10 (soil depth 2 – 4 m) and groundwater HSLs x100 (depth to groundwater 6 m) (see Notes Table 1A(3) and Table 1A(4)and Friebel & Nadebaum 2011a).
Adjusted HSL values for soil and groundwater –biodegradation factors applied
 HSL         F1  F2  F3   F4   B   T   E   X
Soil 2-4 m   NL  NL  N/A  N/A  10  NL  NL  NL
Groundwater  NL  NL  N/A  N/A  50  NL  NL  NL
4 m to <8 m

Notes
   Confirmation of soil oxygen > 5% at 1 m depth allows a biodegradation factor of x10 for vapour sources from 2 m<4 m. Similarly, a biodegradation factor of x100 applies to groundwater vapour sources >4 m which takes adjusted HSLs to above the non limiting threshold value except for benzene in the example above.
   NL indicates the HSL is not limiting (see Footnote (5) Table 1A(3) and Footnote (4) Table 1A(4) .
   N/A not applicable as these fractions are non-volatile and hence not of concern for vapour inhalation
  3.       Are site values greater than adjusted HSLs for vapour intrusion? NO
  4.       Are direct contact HSLs relevant? YES (proposed low density residential land use) however there is no soil contamination at surface (95% UCL for all the identified contaminants of concern was less than the appropriate