Document ID: chunk:federal_register_of_legislation:F2013C00288:reg:1850:p28
Version: federal_register_of_legislation:F2013C00288
Segment Type: reg
Provision Reference: reg 1850 (pt 28/117)
Character Range: 424188–427545

assessors should be aware of (and comply with) relevant jurisdictional requirements such as groundwater protection policies and licensing requirements for the construction of monitoring bores and groundwater abstraction.

The collection and assessment of groundwater data and the selection and use of fate and transport models should be undertaken by appropriately qualified and experienced professionals. This is particularly important when applied to fractured and karstic rock environments.

8.1              Groundwater investigation approaches

    8.1.1          Introduction
There are several methods for collecting groundwater data. In general, these methods involve collection of:
    * in situ measurements to calculate hydraulic head, groundwater flow direction and rate
    * in situ measurements of apparent product thickness (NAPL, immiscible with water)
    * in situ physical and/or chemical measurements of groundwater quality, e.g. redox potential, electrical conductivity, pH, and dissolved oxygen
    * collection of groundwater samples for ex situ measurement/analysis.

The main issues that determine the selection of the appropriate method(s) are:
    * the DQOs
    * site-specific conditions such as depth to water table, soil/rock competency
    * analyte-specific characteristics
    * financial and logistical constraints.
Careful consideration and appropriate weighting of each of these issues will assist in determining the most appropriate method(s) of groundwater investigation.

    8.1.2          Scope of investigation
The appropriate scope of the investigation is determined through the development of the site CSM and the DQOs. Generally this will include a preliminary site investigation comprising a desktop review of relevant background and historical information and a site visit followed by one or more intrusive field programs to update and refine the CSM until the objectives of the site assessment are met. The results of any earlier investigations, including soil and soil vapour investigations, should be used to refine the CSM and inform the scope of the groundwater investigation.

Typically this will include consideration of the following:
    * the nature of the contaminant including its mobility and toxicity characteristics
    * the type and location of known and potential contaminant source zones (including off-site) and associated contaminant plumes
    * site geological and hydrogeological conditions (lithology, lateral and vertical extent of aquifers, perched water tables, confining layers, aquifer properties, etc.)
    * depth to the water table and likely seasonal variation
    * potentiometric surface(s)
    * upgradient groundwater quality to assist in determining background groundwater quality
    * hydrogeochemistry of relevant aquifer units
    * direction of groundwater flow and hydraulic gradient
    * location of recharge and discharge areas
    * location of any abstraction wells
    * current and future realistic use(s) of the groundwater resource and nearby surface water resources and water protection zones
    * known and/or perceived risks to the environment and/or human health including the presence of potential pathways between contaminant source(s) and potential receptors.

    8.1.3          Site-specific conditions
Site-specific conditions that may limit or