Oceana Gold New Zeland Limited Hydrogeology Support for WKP Underground Updated Conceptual Model 500m). The ancillary hanging wall veins (HW-EG-West Veins), where present, form barriers to flow and isolate the deeper rock aquifer from shallow groundwater. Shallow groundwater occurrence is variable at the two points investigated. At WKP-01, located west of the HW-EG-West Veins, the deeper piezometer is dry, perhaps reflecting the influence of the veins on as barriers to groundwater flow. At WKP-02, there is a downward vertical gradient, although the lower piezometer is in the contact zone of the rhyolite flow dome which has enhanced permeability. In other areas, water levels and water losses during drilling suggest an unsaturated zone between shallow and deeper groundwater. All these results indicate that shallow groundwater conditions are locally variable and should be investigated more broadly across the site. In the absence of significant weathering and veining, the rhyolite flow dome and rhyolite volcaniclastics have low permeability. Packer water levels and VWP data from WKP-P03D indicate that the T-Stream vein is dry. 4.5. Work undertaken to data has been sufficient for preliminary characterization of the EG and TStream vein systems. The following processes are not described in this report, or are described in limited detail and/or in specific areas: Surface water-groundwater interactions. Expected connections between shallow and deeper groundwater. Expected interactions between the underground mine during development and shallow groundwater and streams. The nature and extent of surface water-groundwater interactions relies, in part, on information on permeability and hydraulic properties of the streambed and the shallow subsurface underlying and surrounding the streams, or direct measurements of these processes (i.e. via in-stream seepage meters). To date these data have not been collected. In this report we have provided examples of the lack of connection between deeper groundwater and shallow groundwater in specific areas (i.e. EG vein aquifer and shallow groundwater west of the HW-EG-West Veins). However, we are not able to comment on these interactions at a sitescale due to lack of information on shallow groundwater occurrence, levels, and aquifer properties in many areas of the site. Due to access constraints, there is currently no information on the shallow groundwater system directly overlying the EG vein.
RkJQdWJsaXNoZXIy MjE2NDg3