Infiltration Pond Location Single Proposed Downgradient Monitoring - PowerPoint PPT Presentation

Infiltration Pond Location Single Proposed Downgradient Monitoring Well

Groundwater Contours ‐ GHD

Comments on GW contours • GHD groundwater contours are limited by a lack of borehole data to the West and East of the site. • Aquifer conditions and hydraulic gradient to the East of site are poorly understood. • GWS modelled the hydraulic gradient using all available groundwater elevations. Our analysis does NOT match that of GHD. • Proposed MW location may not actually be downgradient of infiltration pond.

GHD Hydraulic Gradient Infiltration Pond GWS Hydraulic Gradient MW location proposed despite little understanding of hydraulic gradient Groundwater Contours – GW Solutions

Bedrock Topography Contours ‐ GHD

Comments on GW Monitoring • There is insufficient characterization of the groundwater regime at both the eastern and western property boundary. • Groundwater transiting the property has the potential to “daylight” approximately 2 km east of the site in wetlands and small tributaries to Quinsam River. • Due to the high permeability of the aquifer, the recommended groundwater quality monitoring wells may be inadequate in number and location to intercept a potential plume emanating from the site.

Groundwater Divide? Infiltration Pond/Recharge Local Groundwater Water Table Discharge? “Regional” Groundwater Unsaturated Discharge? Rico Lake Saturated BH1 ‐ 16 MW2a ‐ 16 Hydraulic Gradients

Test Boreholes and Monitoring Wells Needed Water Quality/Monitoring Well Array Needed