Document ID: chunk:federal_register_of_legislation:F2013C00288:reg:5:p8
Version: federal_register_of_legislation:F2013C00288
Segment Type: reg
Provision Reference: reg 5 (pt 8/10)
Character Range: 165946–168887

and contiguous bituminised area is >15 m wide.
    *
Step 1: Document results and select interim VOCC HILs and soil vapour HSLs
Soil vapour values mg/m3, refer Table 1A(2) for interim VOCC HILs and Table 1A(5) for soil vapour HSLs for 0-1 m (sand)
Sample              TCE   PCE  Vinyl chloride  B  T      E    X    F1
SG1                 22    110  6               7  25     44   60   120
SG2                 30    130  17              9  60     52   40   200
SG3                 7     75   1.5             5  8      18   20   80
SG4                 4     30   1.3             3  10     21   25   70
Interim HIL or HSL  0.02  2    0.03            1  1,300  330  220  180

Note: Shaded and bold font for sample value indicates relevant interim VOCC HIL or HSL is exceeded.

Step 2: Tier 1 risk assessment
    1. Are results greater than the soil vapour HSLs?  YES, benzene exceeds the HSL in all locations and F1 in one location.
    2. Are results greater than the soil vapour interim VOCC HILs?  YES, TCE, PCE and vinyl chloride exceed the interim HILs for VOCCs in all sampling locations.
    3. Are ecological considerations relevant? NO for on-site only (commercial industrial development with no exposed areas of soil and continuing industrial use).
    4. Are petroleum management limits exceeded? No (Compare results to management limits in Table 1B(7). F1 results do not exceed the management limits.)
Outcome      * Results of Tier 1 assessment show exceedences of the HSL for benzene and interim VOCC HILs for TCE, PCE and vinyl chloride. Further assessment (Tier 2) or management action is required for these contaminants.

Evaluation and conclusion
The results indicate a potentially serious human health risk via the vapour inhalation pathway from benzene, TCE, PCE and VOCC derivatives to ground floor occupants of the office building. As the exceedences are 24 orders of magnitude above the interim soil vapour HILs, an immediate response is required to protect human health such as indoor air sampling to determine actual exposure and/or implementing mitigation measures.
This example is limited to consideration of health risks from selected petroleum hydrocarbons and VOCC inhalation exposure. Additional assessment would be required for other petroleum hydrocarbons and also to evaluate any off-site ecological risks for example via infiltration of contaminated groundwater into sewer or stormwater drainage systems and/or discharge into a sensitive receptor.

Case study 5 - Use of HILs and EILs –

redevelopment of an industrial site for residential use

Site Scenario
The site is a former electroplating works and is proposed for residential townhouse development with individual gardens. Prior to industrial use, the whole site was filled from 0 to 1 m with imported clay/soil fill of uniform characteristics.
Response
The site was assessed by a detailed sampling program based on a well-documented site history