Document ID: chunk:federal_register_of_legislation:F2013C00288:reg:2:p20
Version: federal_register_of_legislation:F2013C00288
Segment Type: reg
Provision Reference: reg 2 (pt 20/21)
Character Range: 93868–97019

on and off the site of origin and potential effects on groundwater resources.

The Groundwater investigation levels (GILs) are based on the Australian Water Quality Guidelines 2000 (AWQG), Australian Drinking Water Guidelines 2011 (ADWG) and Guidelines for Managing Risk in Recreational Waters 2008 (GMRRW). The GILs are adopted in the NEPM as investigation levels in the context of the framework for risk-based assessment of groundwater contamination (refer Schedule B6) i.e. levels above which further assessment is required.

The AWQG provide tabulated values based on percentage species protection for various aquatic environments and water uses. The appropriate settings for current and potential uses of groundwater need to be identified for the aquifer undergoing assessment. The guideline documents should be consulted for appropriate interpretation of guideline values, in consultation with relevant regulatory authorities if necessary.

Table 5.  Groundwater environmental values and guidelines for their protection
Environmental value to be protected  Guidelines to apply
Raw drinking water source            ADWG
Agricultural use – stock watering    AWQG
Agricultural use – irrigation        AWQG
Fresh water aquatic ecosystem        AWQG
Marine water aquatic ecosystem       AWQG
Recreational use                     GMRRW

The GILs provided in Table 1C at the end of this Schedule, define acceptable water quality for various contaminants at the point of use.  Table 1C provides frequently used values for drinking water and protection of fresh and marine ecosystems. Additional GILs applicable to industrial use (aquaculture), agricultural use (stock watering and irrigation) and recreational waters are provided in the referenced documents.

The GMRRW recommend applying a multiplication factor of 10 to 20 to the ADWG for assessment of the acceptability of recreational water quality. GILs for other receptors should be obtained directly from the 'primary industries' section of the AWQG where relevant. Note that the recreational and aesthetics sections of the AWQG have been superseded by the GMRRW.

2.9              'Management limits' for petroleum hydrocarbon compounds
In addition to appropriate consideration and application of the HSLs and ESLs, there are a number of policy considerations which reflect the nature and properties of petroleum hydrocarbons:
    * formation of observable light non-aqueous phase liquids (LNAPL),
    * fire and explosive hazards and
    * effects on buried infrastructure e.g. penetration of, or damage to, in-ground services by hydrocarbons.
The CWS PHC includes 'management limits' to avoid or minimise these potential effects and these values have been adopted as interim Tier 1 guidance. The values are included in Table 1B(7) at the end of this Schedule. A site-specific assessment (Tier 2 or 3) may be preferred where relevant site-specific information is available.

Application of the management limits will require consideration of site-specific factors such as the depth of building basements and services and depth to groundwater, to determine the maximum depth to which the limits