2023-10-30_PERMIT FILE - M2023015 (2)

Home Browse Search

a. The London Fault is a reverse fault with considerable upthrust on the easterly portion. A fault gouge was created, which is impermeable and prevents water originating westerly of the fault from escaping through it to the east. A portion of the precipitation falling in the recharge.areas enters formations dipping towards the London Fault; or generally easterly into the London Syncline. That syncline dips to the, south or southeasterly. In the areas nearer London Mountain, the syncline is overlain with Belden Shale, which is essentially impervious to water. Beneath the Belden Shale is the Leadville Dolomite, sometinies' called Leadville Limestone.' which is highly fractured in the bottom of the syncline, Particularly in close proximity to the London Fault. These fractures permit water to move down gradient from the recharge area of the London Mountain towards South Park and the Arkansas Valley. They do not come to the surface for many miles, and travel for tens of thousands of years before they surface, if at all. Where the syncline crosses South Mosquito Creek, it is overlain by 600 feet of impermeable Belden Shale. The syncline can neither feed the creek -a- for4be.f04 h ttv The waters in the syncline are in a geologic trap and'ace non- ibutary waters. The equilibrium level of water in the syncline is also well below the creek level. Generally, low discharge occurs in May and June, and a high discharge occurs in October and November. Figure 5Water Decree pg 2-3, W8314-76 While there is a groundwater aquifer below the London Mine, MineWater is actively reducing artesian pressure in the non-tributary decreed aquifer through intensive collection efforts and treating and discharging the mine dewatering flow at a rate of about 1.5 MGD through a permitted outfall,and actively controlling the hydrogeology by extracting and providing water to absolute decreed non- tributary water rights to the City of Aurora. Rule 6.4.21(7), a) Site specific conditions: Monitoring of the sources to the Water Tunnel are conducted under Paragraph 39 of the Consent Order IC160803, including identifying sources of electrically conductive water flowing to the Water Tunnel, and then prioritizing remediation efforts toward the most heavily impacted water sources.The Water Tunnel is the dominant drainage feature at the London Mine and has been decreed to be the source of water rights and has been used since 1912 for hydraulic control of the drainage from the Site to South Mosquito Creek. Applicant has identified through repeated surveys of the Water Tunnel that the area beneath the South London Stockpile is the largest load of dissolved zinc to the Water Tunnel, although the South London