Document ID: chunk:federal_register_of_legislation:F2013C00288:reg:3:p3
Version: federal_register_of_legislation:F2013C00288
Segment Type: reg
Provision Reference: reg 3 (pt 3/7)
Character Range: 2941756–2944617

HILs addresses all non-volatile compounds and exposure pathways. The interim soil vapour HILs for VOCCs address the vapour pathway, only for these compounds.

Figure 1. CSM for HIL A  standard residential land use scenario with garden/accessible soil

    3.2.2         HIL B values  residential scenario with minimal opportunities for soil access
The residential land use scenario considered for the HIL B values is high-density residential, not including a private garden. This land use scenario assumes typical residential unit blocks, consisting of multistorey buildings where living areas are on the ground floor (constructed on a ground level slab or above subsurface structures including basement car parks or storage areas).

Occupants of the buildings considered in the development of the HIL B values have access to yard spaces that are largely covered by permanent paving, with some small areas of landscaping or lawns. Opportunities for direct access to soil by residents of these buildings are therefore minimal but there may be some potential for residents to inhale, ingest or come into direct dermal contact with dust (particulates) derived from the soil on the site. Landscaped/playground (including sandpit) areas used for recreation within a high-density development should be assessed on the basis of the more conservative HIL C values.

The occupants of the dwellings are adults, children and infants who spend the majority of their time indoors within the residential properties, with some limited use of communal outdoor areas on site. The residents that are considered to be most susceptible to health risks associated with soil contaminants are the residents of ground floor units, due to the greatest potential for outdoor soil to be tracked indoors and vapour intrusion occurring with residences immediately overlying contaminated soil. The CSM for this land use scenario is provided in Figure 2.

Figure 2. CSM for HIL B  residential land use scenario with minimal opportunities for soil access

It is noted that the derivation of soil HILs addresses all non-volatile compounds and exposure pathways. The interim soil vapour HILs for VOCCs address the vapour pathway only for these compounds.

    3.2.3         HIL C values  public open space scenario
Public open space land use includes a variety of exposure scenarios such as parks and playgrounds (including sandpits), recreational areas and playing fields that are fully accessible to the public and where the public may potentially spend a significant amount of time.

This land use scenario assumes that the open space areas are in areas where young children may have supervised access and use the area outside of the home environment for frequent short periods of time (up to 2 hours a day, 7 days a week). Other users may include older children and adults who may visit