2015-09-24_REVISION - C1982056 (2)

Home Browse Search

adjustment. From a practical standpoint, the only acreage figures that are of significance are the surface disturbance and affected area acreages, which are normally carried out to one decimal point, since they relate to reclamation obligations under the Permit. The following discusses TC's response to the Division's second adequacy letter dated May 5, 2015. According to Exhibit 7K and the revised permit text, flooding/ponding resulting from subsidence will increase Foidel Creeks surface area by 5 acres and Fish Creek surface area a maximum of 70 acres under high water conditions. Please update section 2.06.8(5) of the permit to include a narrative that addresses all of the applicable items required by Rule 2.06.8(5) associated with mining of the WCR under the Fish Creek and Foidel Creek Alluvial Valley Floor. a. TC's response: Section 2.06.8 of the currently approved PAP has been reviewed and revised to address the proposed mining activities under PR10 and their relationship and effect on any overlying AVF areas. b. Division's response: Revised Page 2.06-205.9 indicates that water quality is monitored at Station 900 on Foidel Creek downstream of previous mining in the Eastern Mining District and the proposed mining in the WCR. This station appears to be upstream of the proposed mining in the WCR. Please revise this page accordingly. c. TC's Response: Given that Station 900 now falls within the eastern limits of the planned WCR mining area, TC will utilize existing Site 29 downstream of Middle Creek (as shown on Map WC23) as the down -gradient surface monitoring site. d. Division's Response: Site 29 is past the confluence of Middle Creek and Foidel Creek. Given this, it would be difficult to assess the impacts mining in the WCR will have on Foidel Creek since Site 29 measures flow received from both Foidel and Middle Creek. The Division believes a new surface water monitoring site should be established along Foidel Creek upstream of the confluence of Middle Creek. Please revise this page accordingly and update Exhibit 4E- 11 and Exhibit 14 as necessary to add this additional monitoring point. e. TC's Response: Based on current mining plans, Site 900 would not be impacted until mid -year 2022. TC proposes to move the Site 900 surface water monitoring station and equipment downstream to the prior location of Site 304 in either fall 2020 or spring 2021 so that one -full year of monitoring data can be collected at the new location prior to any impacts at the present Site 900 location. The referenced pages and exhibits, along with Map 13A, have been reviewed and revised to reflect these plans, and copies of the revised materials accompany these responses for replacement in the PAP. 8. Please submit an environmental monitoring program that includes hydrologic monitoring, vegetation monitoring and subsidence monitoring similar to the one submitted as Exhibit 4e-7 (Fish Creek AVF Monitoring Program) for mining in the NMD. This plan should be designed based on mining of the Wolf Creek Reserve and the projected impacts on the AVFs of Foidel and Fish Creek. a. TC's response: Please recognize that extensive resource and impact monitoring and analyses were completed to validate the initial mining activities and related subsidence effects for the Fish Creek AVF. The results of these extensive monitoring and related analysis efforts confirmed that the projected surface subsidence and related subsidence effects on surface and ground water hydrology and vegetation communities were consistent with actual measured subsidence and subsidence effects. All subsequent mining, subsidence evaluations, monitoring requirements, and impact analyses tiered off and were built on this foundation of confirmed mining and impact results. Given these considerations, very limited monitoring is considered necessary for the mining activities proposed under PR10. A brief summary of the proposed monitoring is provided for inclusion in Exhibit 4. b. Division's Response: Site 900 appears to be upstream of the WCR affected area along Foidel Creek. Given this, it would not serve as an appropriate downstream monitoring station for Foidel Creek. Please revise the monitoring plan to monitor a site that is downstream of the WCR affected area.