How will the mine use and affect our water?
The Elandsfontein phosphate deposit lies below the water table within the Elandsfontein aquifer. In order to mine the phosphate deposit, the mining area will be temporarily dewatered. To dewater the mine pit, Elandsfontein will install a set of borehole pumps to divert the water around the mining area, through a network of closed pipes, to be reintroduced to the aquifer downstream from the mining area.
Extensive ground water studies have been carried out by Geoss Ground Water Consultants and SRK Consulting. Geoss developed a regional ground water model, looking at the underground water from the Berg River to the Langebaan Lagoon. As part of a ground water impact assessment, they confirmed that the impact on the lagoon from the mining activities would be low, if any. SRK created a groundwater model focussing on the mining area, to allow correct design of the borehole dewatering pumps and the aquifer recharge system. Their findings confirmed that the mine would have negligible impact on the lagoon.
The water studies have been reviewed by a number of specialists, including consultants to SANParks and to Cape West Coast Biosphere, who were in agreement with Geoss’ and SRK’s model inputs and subsequent findings.
Elandsfontein has also sought guidance from the Department of Water and Sanitation, to understand the nature of the aquifers and any potential impact its operation could have on the ground water in the area.
From previous research, examples of similar case studies where the successful discharge of aquifers has been implemented for the dewatering of mining operations include:
- Finsch Diamond Mine, South Africa;
- Kolwezi Copper Mines, DRC;
- Mosaic Phosphate Mine, USA;
- Robinson Copper, Molybdenum, Gold Mine, USA;
- Premier Coal Mine, Australia.
Blue Science water specialists completed a surface water study. There is no surface water within the mining area, or on the Elandsfontein properties. The surface water study considered the impact on the Groen and Sout Rivers and the Langebaan Lagoon. It was concluded that there will be negligible impact on any surface water by the mine, especially considering the distance of the mine from any surface water.
Kropz is a member of the Saldanha Bay Water Quality Forum Trust. Kropz’s contribution this year funded the purchase of a logger that will be installed in the lagoon at Geelbek, as well as a macrobenthos study on the shores of the lagoon. This information will serve as a baseline, and will be updated annually to prove that Kropz’s activities will not have an impact on the lagoon in anyway. The results of the information gathered will be published as part of Saldanha Bay Water Quality Forum Trust’s ‘State of the Bay’ report (and presentation), which is shared with all interested and affected parties on the West Coast. The publication will be released in October.