RPS worked with Heathgate Resources to develop and use a detailed four-layer computer model of the aquifer and wellfield systems at Beverley.
Predictive groundwater modelling is essential for assessing the transport and locations of flows in the groundwater system, and also to visualise what is happening underground. In the case of Beverley it was used to optimise the Beverley wellfield operations and to demonstrate the location and extent of disposal fluid and mining solution flows.
Model development began in mid-2003. Initial development involved a calibration (or history-match) to monitoring data from December 2000 to December 2002, followed by use in compliance reporting, as well as for week-to-week operational reviews.
RPS completed regular updates of the tool with new drilling and pumping information. For example, in April 2004 the model was run with data from January 2003 to March 2004, including information from commissioning of the Central wellfield, and Northern wellfield data, which had not been used for the history match calibration. Again, a good history match was achieved to most of the monitoring information, validating the model’s capability.
Prediction runs showed the expected extent of the disposal fluid in the future extending on from model plots of historical flowpaths, as required by the compliance reporting process. Reports on the model development and results were submitted to government agencies, and presentations were to the community and agencies. Model refinement incorporating re-interpretation of geological data and re-calibration is an ongoing task, and RPS delivered training to Heathgate staff to undertake some of the model development and updating work in-house.