Different types of water
Water that falls as rain outside the mining operational areas is directed away from the mine site. Rain that falls within the mine site is diverted, collected and retained. Water used in processing operations is directed to a specially constructed tailings dam.
There are several different classes of water encountered on ERA's operations:
• Process water
• Pond water
• Release water
• Potable water
• Water treatment plant permeate.
Each class of water differs according to its composition, which dictates the way it is managed.
The water summary table below provides details of the different water classes and how they are managed.
Water classes summary table
| Water type | Origin | How it is managed | Uses and destination |
| Stormwater | Rain falling on undisturbed areas i.e. catchments outside the mine footprint. | Diverted away from disturbed or operational areas. | Directed to waterways as natural rainwater run-off. |
| Potable water | Brockman and Majela bore fields. | Separate pipe system, strict operational controls and real-time monitoring, non-return valves, unique colour-coded connection fittings. | Bore field water is used for drinking water, wash water, and washroom facilities; septic is captured and transferred to septic tanks and infiltration galleries for disposal. |
| Release water | Rain falling on catchments within the Ranger footprint. | Water quality is the guiding principle used for managing the release of water. The quality of release waters is such that they do not require incorporation into the pond water inventory but are shed and leave the site as stormwater runoff under controlled conditions. | Release water is closely monitored as an integral part of statutory and operational monitoring to ensure that water quality objectives are met in Magela Creek. Specific streams are routed through passive treatment systems or staging points for management and release. |
| Pond water | Rainfall that falls on the active pit catchment and stockpile (waste and ore) catchments, generating water of a quality that requires active management. | All pond water is contained on site and cannot be released unless it has been treated or released via evaporation. Directed to Retention Pond 2 (RP2), Retention Pond 3 (RP3) or Ranger Pit 3. | Pond water treatment is by (a) wetland filtration for uranium polishing followed by land application or (b) through two pond water treatment plants which utilise microfiltration/reverse osmosis and ultrafiltration/reverse osmosis technology. Pond water is used for general dust suppression within the mining area, in the power station as cooling water, in the dust collection systems within the operations, and is also used in the processing circuit. |
| Process water | Process water includes water used in the uranium extraction circuit, and all water that has come into contact with that circuit. | All process water is contained on site and cannot be released unless it has been treated or released via evaporation. Process water is stored in Ranger Pit 1 and the tailings dam. | Process water disposal is through passive evaporation from the tailings dam and Pit 1 as well as treatment via the high density sludge process water treatment plant. |
| Water treatment plant permeate | Permeate is produced by the treatment of pond or process water. | Permeate can be directed to a variety of locations depending on operational requirements. | When specific conditions are met treated process water permeate can be released into the first cell of Corridor Creek constructed wetland. Treated and partially treated pond water can be discharged to constructed wetland filters, recycled for use in operations and/or land application. |
