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

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Stockpile itself is not a major source. Removal of a large portion of the mineralized rocks located on this area,will reduce the loading to the environment, but more importantly the reclamation of the area will reduce the amount of infiltration down previously unreclaimed features such as the American Shaft and collapses adjacent to the Shaft. Drainage from this facility will either report to the Water Tunnel, or flow overland to the South Mosquito Creek monitoring location. Quarterly reporting will demonstrate the benefits of the work. b) The London Mine drainage effluent is not acidic.The pH of the discharge from the Water Tunnel is 7.8 and even when the site was abandoned by the Estate from 2010-2016 the pH never became acidic(below pH 6.5) in the untreated discharge. c) Geologic conditions:The London Water Tunnel and the London Fault is the primary containment facility for the Site. The direction of all water to the Leadville Limestone/Dolomite formation is ordered by CDPHE since August 3, 2016, and the collection of water from that formation results in non-toxic, non-acidic water. Operation of the Lower Well (LM2.5) at flows of around 700 GPM has created a regional containment surrounding the Well so that the groundwater table is lowered nearly 1700 feet vertically (from around 12,100 feet, to near 10,400 feet AMSL) for a radius of more than 5,000 feet outward from the Lower Well. These facts were verified by the drilling investigation under the NO1 (P2016-020). a. Division One(Greeley)Water Decree 8314-76 provides the following statement of facts: 11 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, sometimes 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 nor be fed by it. The waters in the syncline are in a geologic trap, and are non- tributary waters. d) The Permittee under CDPS Permit No. CO0038334 monitors the London Water Tunnel and the discharge therefrom weekly. Under the Consent Order, the discharge Permittee also conducts monitoring of locations within and downstream of the Water Tunnel to better isolate and manage the treatment of water from the Water Tunnel. These locations include: 0210 Drift, 0205 Drift, Water Raise, Water Tunnel, Water Tunnel outfall after sediment control pond (WT001), and at SMC003 in the creek at the Site boundary downstream. Methods of sampling include weekly grab samples. Reporting is by Discharge Monitoring Reports monthly. Parameters monitored include pH, arsenic, cadmium, copper, iron, lead, manganese, mercury (quarterly), nickel, selenium, sulfide,sulfate, and zinc.