5.3. PCSR 08-24-2004 - Laserfiche WebLink

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J&B Mining Page 2 be evaluated to develop an effective monitoring system. It is understood that the majority of the ditch will be excavated, however, the monitoring program should be developed to coincide with the excavation phasing plan to ensure that potential groundwater (surface water) impacts that could occur during site development are adequately evaluated. It is suggested that a higher degree of confidence in the groundwater flow analysis be supported by the installation of additional piezometers located along the downgradient east side of the property. Considering the direct connection between groundwater and surface water, the monitoring plan should include collection of surface water samples within the ditch at the location of the east property boundary. The monitoring schedule should identify that at least three monitoring wells on the property be initially monitored for the listed parameters for two sampling events within a four week period to provide baseline of data for ongoing monitoring at the site. The annual groundwater sampling should include the sampling of two downgradient wells and one upgradient well at a minimum. This will enable comparisons of water quality between upgradient and downgradient points at the site to assess the significance of water quality data. Field parameters of pH, temperature and conductivity should be reported and interpreted with the analytic monitoring results for groundwater sampling. Contingencies related to assessment of surface water quality should be included in the Plan due to the location of the surface water ditch through the property. Contingency (in the event of an environmental release) sampling in the ditch would occur near the east property boundary where surface water flows from the Site. The City of Elk River should be notified ASAP if water quality monitoring data indicates groundwater impacts and the potential occurrence of an environmental release. Water quality for groundwater sampling for the Schuer Site monitoring should be incorporated into the assessment provided with the annual monitoring report. Storm Water Pollution Prevention Plan The Storm Water Pollution Prevention Plan (SWPPP) has been developed with an acceptable general outline. The SWPPP should state that surface water runoff will drain to the surface water ditch passing through the Site. The ditch should be identified as a major surface water discharge point for the site at the east property boundary. The SWPPP states that predevelopment runoff rates will be maintained. A reference to the analysis which supports this statement should be provided. A no disturb buffer area should be established along the ditch until such time that the ditch does not provide surface water conveyance through the site. Similarly, no disturb buffer areas should be established around wetlands until such time they are mitigated and approved for excavation based on the mining phasing plan. There should be no equipment traffic allowed within the buffer area. 2