Data and information required to assess groundwater quality in the Gwydir subregion are primarily held by the NSW Office of Water, part of the NSW Department of Primary Industries, in its groundwater works database (NSW Office of Water, 2014). Additional data are also available from the Bureau of Meteorology (Bureau of Meteorology, 2014). The information that would be required for a groundwater quality assessment includes:
- location information for all groundwater monitoring points, including the aquifer(s) from which the samples were collected
- information on the time of groundwater sample collection and analysis
- laboratory results of groundwater quality analysis.
An assessment of groundwater quality in the Gwydir subregion would include an assessment of temperature, electrical conductivity, pH and total dissolved solids at least, and these would be compared to water quality guidelines provided by the Australia and New Zealand Environmental and Conservation Council and Agriculture and Resource Management Council of Australia and New Zealand (ANZECC and ARMCANZ, 2000). Data available for any other parameters, such as dissolved oxygen, major and minor cations and anions, trace elements and total petroleum hydrocarbons, should also be included if available.