THE PROJECT

The Shire of Peppermint Grove’s Grove library utilises a shallow geothermal system for heating and cooling.

The geothermal system comprises a production bore, an injection bore, several monitoring bores and associated above-ground infrastructure.  About 4 L/s of water at 22 ⁰C is extracted from the Superficial Aquifer for operation of the geothermal system.

Rockwater has developed a monitoring system that addresses both regulatory and operational requirements.

We established a remote telemetry system for the measurement of water levels in the production bore, the injection bore and one monitoring bore.  Water levels in another monitoring bore and a decommissioned injection bore are measured manually.

This telemetry system includes titanium PT12 In-Situ loggers, non-vented Kevlar cabling and a YDOC adaptor that utilises the 4G network to record and store real-time, barometrically-corrected data on a remote database.

Since 2013, Rockwater’s involvement at Peppermint Grove has focussed on presenting cost-effective and practical solutions to support the system’s operation.  Apart from the telemetry system, this has included redevelopment of the injection bore to improved is efficiency, and improvements to the particulate-filtration system.

We also prepare annual compliance reports for regulator.

• Groundwater flow modelling
• Geothermal system performance assessment and optimisation
• Field investigation reporting
• Annual compliance reporting

THE PROJECT

The Forrestania Nickel Operations, operated by Western Areas, includes two active underground mines, and two inactive pits that have recently been used for groundwater disposal.  The project also includes three injection bore fields, two large evaporation basins, a tailings storage facility and a small freshwater borefield.

Rockwater prepared the Groundwater Licence Operating Strategy for Forrestania, and prepares annual and triennial reports that assess groundwater extraction, discharge and recirculation across the entire dewatering and water supply network.

We also have prepared and implemented groundwater recovery plans for the Forrestania TSF and the evaporation ponds.

• Annual compliance reporting
• Groundwater modelling
• Field investigation reporting

THE PROJECT

The Kwinana Alumina Refinery was commissioned in 1963 and was the first of Alcoa’s three Western Australian alumina refineries.  It has an annual nameplate production capacity of 2.2 million metric tons and produces non-metallurgical alumina and smelter-grade alumina.  Approximately 75 per cent of the refinery’s total production is exported, and the remaining 25 per cent is shipped to Alcoa’s Portland Aluminium smelter in Victoria.

The refinery occupies approximately 1,500-hectares within the Kwinana Industrial Area.  Over 500 bores and other sampling points are regularly monitored for changes in water level and water quality that may result from Alcoa’s operations.  The data are collected by Alcoa and submitted to Rockwater for the preparation of annual compliance reports.

Rockwater has been preparing the annual compliance reports for the Kwinana Alumina Refinery since 2014.

Owing to the scale and complexity of the Kwinana operations, the compliance reports prepared by Rockwater are very comprehensive, typically running to over 100 pages of text plus 60 figures and 27 appendices.

Rockwater also prepares compliance reports for Alcoa’s Pinjarra and Wagerup Alumina Refineries, and has prepared the reports for Pinjarra since 2006.

We have also designed and supervised the construction of production, recovery and monitoring bores at the refineries to depths of 6-265 m, and we continue to provide Alcoa with hydrogeological advice for its various projects.

• Annual aquifer monitoring summaries
• Triennial aquifer monitoring reviews
• Mine closure planning