May 11, 2017 Ms. Margaret Medellin, P.E. Utilities Portfolio Manager City of Aspen Utilities 130 South Galena Aspen, Colorado 81611 Re: Mine Storage Evaluation in Aspen, Colorado; D&A Job No. CG-0687.001.00 Dear Ms. Medellin: This letter report describes our evaluation of the potential to store raw water in the Smuggler Mine and Aspen Mountain Mines in Aspen, Colorado. Per your request, we performed a scoping meeting with the City Manager and other planning personnel on January 25, 2017, and then conducted a site visit to the Smuggler Mine and other sites the following day. The approximate extent of the mine workings in the Leadville Limestone is shown on Figure 1 along with our site visit points of interest and locations of potential geothermal wells tapping into the Leadville Limestone. A mine section is presented on Figure 2 showing the extents of the mines in Smuggler Mountain, Aspen Mountain, and beneath the Roaring Fork River Valley. To understand the extent of the mine workings and to further inform the evaluation, we reviewed available geologic and mine information in the vicinity. This document summarizes the data review, the observations made during our site visit, and our analysis on the potential to store water underground mine workings, focusing on the pros and cons. Our conclusion is that the cons generally outweigh the pros, primarily due to problems and/or costs of maintaining dominion and control over water stored in the mine workings. DATA REVIEW We obtained published geologic and topographic data, as well as mining maps and reports available at the Colorado School of Mines. In addition to these documents, we also reviewed the City’s geothermal investigations and water quality data collected by the City from select mines. A list of these references follows below: Bryant, B., 1971, Geologic Map of the Aspen Quadrangle, Pitkin County, Colorado, U.S. Geological Survey Map GQ-933, Department of the Interior, Scale 1:24,000. Colorado Division of Water Resources, State Engineer’s Office (SEO), 2013, Well Construction and Test Report for Well Permit No. 50240-MH (Geothermal Test Well), Submitted by Anna Nahlik, Dans’s Water Well & Pump Service to SEO on September 2, 2013. 600 S. Airport Road, Building A, Suite 205 Longmont, CO 80503 Phone: 303-651-1468 ● Fax: 303-651-1469 Ms. Margaret Medellin, P.E. May 11, 2017 Page 2 Rocky Mountain Water Consultants, LLC. (RMWC), 2010, Conceptual Model of Aspen Geothermal Resources, March 2010. Rocky Mountain Water Consultants, LLC. (RMWC), 2015, City of Aspen Geothermal Test Well Drilling Construction and Geophysical Logging, March 2015. SGS Accutest, 2016, Technical Report for City of Aspen Mine Sampling, Data Report, Submitted by Scott Heideman to the City of Aspen on November 2, 2016. Smuggler and Aspen Mountain Mine maps and sections of various dates obtained from the Colorado School of Mines Arthur Lakes Library. These resources, including Volin and Hild have been provided to the City in digital format. Spurr, J.E., 1898, Geology of the Aspen Mining District, Colorado, U.S. Geological Survey Monograph 31, Department of the Interior, 260 p. plus plates. U.S. EPA, 2017, National Primary Drinking Water Regulations, Available at https://www.epa.gov/ground-water-and-drinking-water/national-primary-drinking-waterregulations, Accessed on 4/26/2017. Volin, M.E. and Hild, J.H., 1950, Investigation of Smuggler Lead-Zinc Mine, Aspen, Pitkin County, Colorado, U.S. Bureau of Mines Report of Investigation 4696, Department of the Interior, 47p. GEOLOGIC SETTING The geologic setting in Aspen is complex, but well studied. The outcrop patterns described below are well mapped by Bryant (1971) and by Spurr (1898). Bryant’s map and parts of sections B and C are included as Figure 3. Also shown on Figure 3, are our select points of interest described in the site visit summary and the approximate extent of the mines. The City is located within the Roaring Fork River valley where Hunter Creek, Castle Creek, and Maroon Creek confluence with the Roaring Fork River. The Roaring Fork valley contains thick alluvial deposits (Qal), as well as glacial moraines (Qma, Qmb, Qmc) and glacial outwash terraces (Qga, Qgb). Smuggler Mountain, composed of Precambrian aged granitic rocks (pCq), rises east of Aspen in the Sawatch uplift. Per RMWC (2015), the Sawatch Shear Zone was encountered while drilling the City’s geothermal test well. Sedimentary rocks representing Cambrian through Cretaceous time are intensely folded and faulted up against the Sawatch uplift. The outcropping sedimentary strata on Aspen Mountain, south of the City, represent a tight syncline that plunges to the north (see Section C on Figure 3). Indeed, this structure has resulted in numerous landslides that have affected the City in the past. North of Aspen is Red Mountain, so named because of the red colored sedimentary rocks of the Pennsylvanian/Permian aged Maroon Formation (PPm). Due to the steep northward plunge of the Aspen Syncline, the Paleozoic sedimentary rocks exposed on Aspen Mountain are buried thousands of feet below Red Mountain. The western part of Aspen is underlain by the Castle Creek Fault Zone where vertical to overturned Permian through Cretaceous sedimentary rocks make up the Ms. Margaret Medellin, P.E. May 11, 2017 Page 3 bedrock. The youngest sedimentary rock in the area is the Mancos Shale (Kmu, Kmf, Kml) cropping out as overturned beds in the Castle Creek Fault Zone and in areas to the west of Maroon Creek. The geothermal conceptual model by RMWC (2010) provides a thorough description of the geologic and mining history in the Aspen area in addition to laying out a conceptual geothermal resources program from the Paleozoic Carbonate Aquifer. This aquifer includes the Mississippian Leadville Limestone (Ml) and the dolomitic Devonian Chafee Formation (Dcd, Dcp). It dips about 55 degrees to the west into the Aspen Syncline, where it becomes confined by thousands of feet of lower permeability sediments of the Pennsylvanian and Permian Gothic (Pg), Belden (Pb), and Maroon (PPm) Formations. During drilling of the City’s geothermal test well, the Sawatch Shear Zone was encountered within the Belden Formation. Because the limestones outcrop in the eastern part of Aspen, this unique structure provides the geometry for the carbonate aquifer to be recharged by precipitation and alluvial groundwater. The seven sites that would be involved in the geothermal resources concept either as pumping wells or injection wells are shown on Figure 1. The Leadville Limestone also hosts the famous silver and zinc sulfide mines in the Aspen Mining District, which includes mines both on Smuggler Mountain and on Aspen Mountain. The approximate extent of the mines shown on Figure 1 is based on Spurr (1898) and several mine plans reviewed from the Colorado School of Mines. A longitudinal section of the mine workings between Smuggler Mountain and Aspen Mountain is shown on Figure 2 along with projections of select points of interest and an estimated potentiometric surface of the groundwater within the Leadville Limestone. The dark hachured areas on the section represent the stopes of mined ore. Note the complexity of the mine workings, stopes and faults on the section. Also, note that the main contact fault runs parallel to and along the entire mine section. The sulfide ore was deposited in the brecciated (or broken) parts of the limestone, primarily occurring along a contact fault between the Leadville Limestone and the overlying shales of the Pennsylvanian Belden (or Weber) Formation. Cross-cutting faults through the limestone also formed breccia. After the limestone was broken by faulting, the intruding mineral-rich hydrothermal fluids deposited the sulfide ore in the voids between the limestone clasts. Depending on the intersection of the various faults, the ore bodies would have different shapes, but generally, they trend along the stratigraphic top of the Leadville Limestone, and within limestone cut by the east-west cross-cutting faults. The ore was accessed by both tunnels and shafts, and employed stope mining methods. A “stope” is an open void within a rock formation from which ore has been extracted. In Aspen’s case, tunnels were driven at different levels and the ore was stoped upward so that ore could be removed via the tunnels below. As a result, the various levels of the mines are complexly interconnected by shafts, tunnels, stopes, and likely exploration bore holes. During mining, much of the waste rock was simply dumped back into the lower levels of the mined-out stopes. Because the rich sulfide ore is located within the Leadville Limestone, the mine workings on Smuggler Mountain are connected to those on Aspen Mountain underneath the Roaring Fork Valley (Figure 2). The deepest workings are about 2,700 feet below Smuggler Mountain. During the early 1900s, when silver mining was near its peak in Aspen, it is reported that 3,250 gallons per minute (gpm) were being pumped from the mine workings beneath the City (Volin and Hild, 1950). Ms. Margaret Medellin, P.E. May 11, 2017 Page 4 In 1918, a dispute between the two principal miners resulted in shutdown of the pumps and flooding of the mines by groundwater. Since then, the water levels in the mines have risen and are assumed to be in equilibrium. Therefore, this evaluation considers groundwater in the mines to be hydraulically connected to the groundwater in the Roaring Fork alluvial aquifer. SITE VISIT On January 25, 2017, we met with City staff to discuss the study and its potential alternatives of storing water in the Smuggler Mine, in the Aspen Mountain mines. We outlined how mine bulkheads are generally designed and installed as reclamation alternatives in mine adits to back water up in abandoned mines. Bulkheads are essentially cork-shaped reinforced concrete plugs installed in sound quality rock, with ring grouting of the surrounding rock mass. The size of a bulkhead depends on anticipated water pressures that could build up behind it. Often times several bulkheads are used in different adits at various elevations in attempt to maximize the volume of stored water in abandoned mines. We noted that there is no real precedence in Colorado for storing raw water in underground hard rock mines for municipal use. The location and use of some of the City’s water rights were also discussed. We understand the City has a direct flow water right amounting to about three cubic feet per second (cfs) from the Durant Mine portal. Finally, we discussed the recent installation of a geothermal test well for the City, as well as the State Engineer’s Office (SEO) rules requiring augmentation of tributary groundwater. On January 26 we accompanied City staff into the Smuggler Mine to gain an understanding of the conditions of the mine, its stopes, and tunnels. Following the mine tour, we also were shown the locations of the Mollie Gibson Shaft, the Cowenhoven Tunnel alignment, the Salvation Canal, the City’s geothermal test well, Glory Hole Park, the Durant Tunnel portal, and the water treatment plant. These sites are shown as points of interest on Figures 1 and 2 along with the approximate extent of the mines in the Leadville Limestone subject to this evaluation. Smuggler Mine At the Smuggler Mine we toured Tunnel No. 2, the Clark Tunnel, and even accessed Tunnel No. 1 using a large open stope. We observed the rock mass and structure, ore shoots, large open stopes with waste piles in them, and smaller open stopes extending hundreds of vertical feet above the tunnels. A photograph of Tunnel No. 2 is shown below: Ms. Margaret Medellin, P.E. May 11, 2017 Page 5 Photo 1 – Tunnel No. 2 leading into the Smuggler Mine. Note the character of the limestone breccia on the left. The stopes seem to form a labyrinth of open voids within the mine. Some are a mere three feet wide, but extend for hundreds of feet up and along the fault structures. Others are about 100 feet wide and 100 feet high, partially filled with rock from mining operations. Examples of the types of stopes we observed are shown in the following photographs: Photo 2 – Open stope extending from Tunnel No. 2 down towards Tunnel No. 1. Note ladders for scale. Ms. Margaret Medellin, P.E. May 11, 2017 Page 6 Photo 3 – A large open stope with an extensive waste pile used to access Tunnel No. 1 during our site visit. Photo 4 – Open stopes supported by timbers extending up hundreds of feet above Tunnel No. 2. Again, note the ladders for scale. Ms. Margaret Medellin, P.E. May 11, 2017 Page 7 In addition, we observed some of the mineralization within the rock mass. This included barite, realgar, and orpiment. Barite is barium sulfate, realgar and orpiment are arsenic sulfides. Barite is white, realgar is generally red, and orpiment is orange. These are the minerals that can leach barium and arsenic into the groundwater when they are oxidized by water and oxygen. Photographs of these minerals are included on the following page. Photos 5 and 6 – Localized barite mineralization (left) and realgar and orpiment mineralization (right) in the rock mass. When similarly oxidized, other sulfide minerals in the rock mass including galena (lead sulfide) and sphalerite (zinc-iron sulfide) can also leach their heavy metals into the groundwater, and create acidic water conditions as the free sulphur goes into an aqueous solution. Mollie Gibson Shaft, Cowenhoven Tunnel and Salvation Canal We briefly visited the location of the Mollie Gibson Shaft and looked at the area where the Cowenhoven Tunnel is located. We also saw the Salvation Canal roughly where it crosses the Cowenhoven Tunnel alignment. These features are important when considering storing water in the Aspen mines. Ms. Margaret Medellin, P.E. May 11, 2017 Page 8 The Mollie Gibson Shaft is located below the Tunnel No. 2 access. It is 1,200 feet deep and would need to be completely rehabilitated to access the lower levels of the mines. It apparently leaks groundwater from its collar, suggesting the groundwater level in the mine is higher than the elevation of the top of its collar. As part of the geothermal resources concept, the shaft would be retrofitted to be an injection well for return water from the City’s proposed geothermal resources (RMWC, 2010). The Cowenhoven Tunnel is a roughly 10-foot diameter, approximately three-mile-long drainage and haulage tunnel driven between 1889 and 1892. Its vertical position lies just below Tunnel No. 1 (see Figure 2). We understand that it is collapsed near its portal and that it drains some water into lower Hunter Creek. As shown on Figure 1, the approximate location of the portal is about 1,500 feet from the main mine workings. This is because it was driven through the Gothic and Belden (Weber) Formations. The tunnel would have to be reopened, supported and a bulkhead would have to be installed in it to allow water storage in the Smuggler Mine. The Salvation Canal takes water off the Roaring Fork River, just east of Aspen, and delivers it to irrigated lands on the north side of the valley between Aspen and Woody Creek. Because the canal crosses over the mine workings, it could be a potential source of water to fill a storage vessel in the mines. For example, it could potentially deliver water by gravity into the Mollie Gibson Shaft. This delivery method would only work if water is stored below the level of the canal. Aspen Geothermal Test Well, Glory Hole Park and Durant Portal We also briefly visited the site of the City’s geothermal test well, Glory Hole Park, and the Durant Portal. These are other important features in the City that could affect how potentially stored water is withdrawn from the mine workings. The geothermal test well was installed in July 2013 and is 1,532 feet deep. It encountered 256 feet of alluvium in the Roaring Fork valley, 1,226 feet of Belden shale, and taps into 38 feet of the Leadville Limestone at the bottom. At about 600 feet deep, the well encountered the Sawatch Shear Zone (RMWC, 2015), which produced about 1,000 gpm of water from the well. The water pressure in the limestone was artesian, equilibrating at 16 feet above the ground. Following completion, the artesian flow was measured at 10 gpm from the limestone. The test well is permitted as a monitoring well through a Notice of Intent with the SEO, so it does not have any associated water rights, and cannot be converted to a production well. Nevertheless, a larger well of this type of well would be one way that water could be withdrawn from storage in the Leadville Limestone. Based on its proximity to the Roaring Fork River and the fact that it subcrops below the alluvium, the limestone is in hydraulic connection with the river. Therefore, an approved augmentation plan would be required to pump stored water from the mines. Glory Hole Park is located between Aspen Mountain and the Roaring Fork River. It is so named because during the mining boom a sinkhole opened-up at that location and swallowed a locomotive and two box cars. The locomotive was apparently never removed. Ms. Margaret Medellin, P.E. May 11, 2017 Page 9 We visited the Durant Portal at the base of Aspen Mountain. Presently about 0.5 cfs of water flows out of the portal, under a large house with a glass floor and into a swale that runs through the City. The City owns about 3 cfs of water rights from the portal. If water could be stored in the mines, this water right would represent another means of withdrawing it from storage. ANALYSIS Our analytical work included an estimate of the volume of water that could be stored in the mines, as well as identification of the pros and cons to storing water in old mine workings. We focused on the potential of the mines to maintain control and dominion over any raw water stored in them, possible geologic hazards, environmental effects, and water quality. Storage Volume Estimate We performed a cursory analysis to estimate the volume of water that could potentially be stored in the Smuggler and Aspen Mines. To do this, we simply measured the approximate dimensions of the mine workings shown on Figure 2 and assumed an average stope width of 10 feet. Considering potential karst voids, waste piles and rock mass storage, we estimate the mines to yield a volume of approximately 1,000 to 2,000 acre-feet if every void was filled, both above and below the water table. By preliminary inspection of Figure 2, approximately one-third of that volume could be stored in the workings above the water table. Pros of Raw Water Storage in the Mines The pros of storing raw water in the mines include the following: 1. 2. 3. 4. Proximity to useful water rights and infrastructure Ability to withdraw water using deep wells during drought conditions Good baseline water quality May reduce the need for above grade storage or other water supply resources The proximity of the Smuggler and Aspen Mountain mines to existing water rights and infrastructure is good. Water could potentially be diverted by the Salvation Canal and gravity fed into the Mollie Gibson Shaft (Figure 1), as long as the water storage was below that level. Additionally, bulkheads could be installed deep within Aspen Mountain to raise water levels and ensure longer term and potentially larger flows from the Durant Portal. Alternatively, a horizontal boring could be drilled into the Durant Tunnel to allow larger flows to be discharged from the mine. These infrastructure concepts could optimize the use of the City’s Durant Mine water right. If water can be stored above the groundwater level, discharges to the Roaring Fork River could be good augmentation sources. Pipelines would be needed to deliver water roughly three miles across town to the water treatment facility. Ms. Margaret Medellin, P.E. May 11, 2017 Page 10 Assuming water could be stored in the mine workings below the groundwater level, relatively deep wells, or pumping from the 1,200-foot deep Mollie Gibson Shaft, would allow water to be diverted during virtually any drought condition. Although the geothermal well concept would be to circulate the water without consumption, if those pumping wells could be added to an augmentation plan, the water may be able to be used as a domestic supply after its thermal energy has been consumed. Acid mine drainage and mine water quality does not currently appear to be a major problem for the Aspen mines because they exist within a carbonate (limestone) formation, which buffers the production of acidic water. We reviewed some water quality data provided by the City taken from the Durant Mine, the Mocklin Mine, and the Rio Grande Mine. These samples were tested for general water chemistry, including calcium, alkalinity, corrosivity, hardness, total dissolved solids, pH, and temperature. Additionally, inorganic constituents were found including fluoride, sulfate, nitrate, and metals such as arsenic, barium, nickel, sodium and thallium. Uranium was the only radionuclide measured in the waters. The sample from the Rio Grande Mine had some chloroform and trihalomethanes. In general, the waters have neutral pH values, and are representative of hard, alkaline water from a carbonate aquifer. None of the inorganic constituents appear to be above published U.S. EPA maximum contaminant levels (MCLs) for drinking water (EPA, 2017). The concentration of uranium appears closest to the 0.030 milligrams/liter (mg/L) MCL, with values of 0.026 and 0.020 mg/L in the Mocklin and Rio Grande mines, respectively. This baseline water quality could likely be maintained if storage in the mines was limited to that below the groundwater table. Finally, storing water in the underground mine workings may reduce the need for above grade storage or development of other water supply sources, such as new deep wells. Cons of Raw Water Storage in the Mines The cons of storing raw water in the mines include: 1. 2. 3. 4. 5. 6. Maintaining dominion and control of the water Potential for other geologic hazards Low storage volume and high cost infrastructure Augmentation requirements Potentially poor water quality Mine ownership and operation status Maintaining dominion and control over water stored in the mines would be incredibly challenging, if not impossible. Many bulkheads would have to be installed at virtually every level in the mines, and the water could still potentially leak out through the natural faults, shear zones and fracture zones, especially if these features subcrop beneath the alluvial aquifer. Further, because the stopes are aligned with the stratigraphy of the rock, water could bypass bulkheads by flowing through open stopes in higher levels. Water lost to seepage out of the mine would be even more likely if stored above the natural groundwater table, especially upon first filling. In the case of Aspen Mountain, many other tunnels and adits enter more mine workings above Castle Creek. These “back doors” Ms. Margaret Medellin, P.E. May 11, 2017 Page 11 would likely need to be closed as well. An extensive network of monitoring equipment would likely need to be installed in order to understand how much water is being lost to seepage. Storing water in the mines could also have the potential to cause other geologic hazards, such as shallow groundwater, landslides and land subsidence. These hazards would have an increased likelihood of occurrence if water is stored in the mine workings above the natural groundwater table. Rising groundwater to shallow depths can cause basement flooding, differential settlement of foundations, increase river flooding hazards, and increase the available habitat for mosquitos. Where unstable or over-steepened slopes exist, higher groundwater levels almost always result in additional slope instability. Aspen has plenty of steep slopes with homes built on them and has historically had landslide problems on Aspen Mountain. Storing additional water could easily exacerbate existing landslide hazards and potentially create new ones. Land subsidence is another potential geologic hazard that could result during pumping the water out of the mines. As evidenced by Glory Hole Park, the potential exists for additional sinkholes to open if alluvial or other soil materials inadvertently cave into open mine workings while water is being extracted. Because the host rock is limestone, there is the potential for karst solution cavities and associated sinkhole hazards. There is evidence of paleokarst features in the limestone on Aspen Mountain (RMWC, 2010). Finally, higher water levels would almost certainly result in more widespread damage due to liquefaction during an earthquake. This is because previously dry sediments would be saturated, and then densify during shaking. All these geologic hazards already exist in Aspen, and have differing but relatively low likelihoods of occurrence. Higher groundwater levels would simply increase their likelihood. Although we have not estimated the costs of infrastructure required to store water in the mines, they are likely to be high. Construction costs would include construction dewatering, which historically required around 3,250 gpm of pumping, excavation and disposal of mine waste from the lower levels, installation of bulkheads, rock support and rock mass grouting. The project would also require capital investment into water delivery infrastructure, including diversion structures, pumping wells or pumping stations, pipelines to the water treatment plant and into the upper levels of the mines. Additional water treatment methods may need to be implemented to remove certain metals and other inorganic constituents resulting in higher treatment costs. The risk of losing dominion and control of water pumped into the mines should also be considered a capital cost. In the context of the relatively low storage volume, the unit costs per acre-foot foot of storage are likely to be very high. Another problem with storing water in the mines is that they are likely hydraulically connected to the alluvial aquifer and the Roaring Fork River. Therefore, any pumping required to withdraw water from the mines (even during construction) may require an augmentation plan. Although the limited water quality testing shows that the existing raw water is of decent quality, if water is to be stored above the groundwater table, its presence would leach additional metals out of the oxidized rock and make the water more acidic. Under a storage scenario above the exiting water table, fluctuating water levels in the mine during withdrawal and recharge operations may exacerbate metal leaching and acidification. Because of the difficulties associated with dominion Ms. Margaret Medellin, P.E. May 11, 2017 Page 12 and control of water storage in the mine, the potential may exist for metal-laden acid mine drainage to affect alluvial groundwater and/or surface water in Hunter Creek, Castle Creek or the Roaring Fork River. This scenario could have adverse environmental effects to any aquatic life or riparian areas of these streams. The extent of the buffering capacity of the limestone to keep the water neutral during storage operations is unknown. If water levels are raised well above the existing groundwater table, the best practice may be to allow them to equilibrate before drawing them back down. This equilibration would give the limestone more time to buffer the degrading water quality. CONCLUSIONS The potential to store raw water in the Smuggler and Aspen Mountain Mines was evaluated through discussions with the City of Aspen, performing a site inspection, reviewing available data, and performing a cursory analysis focusing on the pros and cons of such a project. Based on our analysis it appears that the cons generally outweigh the pros. In our opinion, the problems with maintaining dominion and control of the City’s raw water, the potential for multiple adverse effects to the City, and high costs associated with mine storage infrastructure make mine storage a highrisk alternative. Please do not hesitate to call if you have any questions or comments. Sincerely, DEERE & AULT CONSULTANTS, INC. Victor G. deWolfe, P.E., P.G. Associate Don W. Deere, P.E. Principal VGD:sp DWD:sp Attachments U:\0687 City Of Aspen\0687.001 Mine Storage Evaluation\Report\Mine Storage Evaluation.Rpt.Docx 00 78 0 2,000 4,000 Feet Topography from USGS DEM, C.I. = 100 feet Aerial Image from NAIP (2015) 82 00 Mine Section (Figure 2) 8500 8100 Fo rk R Sa lv a iver 8700 ti o nC an 9300 r in g 80 00 al 940 0 0 910 910 0 Ro a rC Hunte re e k er o lt Cowenhoven Vent Smuggler Tunnel No. 2 00 79 Di tch 9900 Geothermal Test Well 9800 9600 Herron Park 0 920 Mollie Gibson Shaft Rio Grande Park 10 00 101 0 00 M Smuggler Mine Cowenhoven Tunnel 1020 0 ¥ 82 00 810 0 Wagner Park 00 84 00 82 Glory Hole Park 8700 Water Treatment Facility Millionaire Mine 0 970 Durant Portal Cree k 0 950 Legend s Geothermal Well Sites 00 88 Points of Interest 94 00 9600 9500 970 0 Approximate Extent of Mine Workings Mine Workings Under Roaring Fork Valley 10 10 0 0 990 Colorado Index Map 93 00 0 20 10 0 30 10 10 40 0 0 830 00 88 Aspen Mountain Mines 91 00 0 1000 Aspen Pitkin County, Colorado 9200 0 105 9000 0 980 0 Mine Section (Figure 2) FIGURE NO. 111 00 JOB NO: 10700 0 90 10 0 00 11 0 80 10 ASPEN UTILITIES 10900 00 86 Streams and Canals 00 90 State Highway 82 10600 U:\0687 City of Aspen\0687.001 Mine Storage Evaluation\GIS\Mine Eval Fig 1 - Site Plan.mxd Tuesday, May 09, 2017 09:39 AM t le 00 89 Ca Mine Storage Site Plan 0687.001.00 SCALE: 8900 1 inch=2,000 feet 1 U:\0687 City of Aspen\0687.001 Mine Storage Evaluation\GIS\Mine Eval Fig 2 - Mine Section.mxd Monday, May 08, 2017 01:31 PM Northeast Smuggler Mountain Smuggler Tunnel No. 2 Glory Hole Park Durant Portal Roaring Fork Valley Mollie Gibson Shaft (1200') Cowenhoven Tunnel Geothermal Test Well (1520') Aspen Mountain Estimated Potentiometric Surface in the Leadville Limestone ASPEN UTILITIES MAY 2017 SCALE: Southwest JOB NO. 0687.001.00 1 inch=1,000 feet 2 FIGURE NO. Smuggler and Aspen Mountain Mine Section DATE: U:\0687 City of Aspen\0687.001 Mine Storage Evaluation\GIS\Mine Eval Fig 3 - Geologic Map and Sections.mxd Tuesday, May 09, 2017 02:58 PM Qgb Water Treatment Facility Section B (Scale 1"=3000') Section C (Scale 1"=3000') ASPEN Cowenhoven Tunnel Smuggler Tunnel No. 2 Mollie Gibson Shaft Geothermal Test Well Glory Hole Park Durant Portal Legend Points of Interest Approximate Extent of Mine Workings 2,000 nB nC JOB NO. 0687.001.00 Feet 4,000 Sec tio Secti o Mine Workings Under Roaring Fork Valley 0 ASPEN UTILITIES Geology from Bryant (1971) Hillshade from USGS DEM SCALE: Sources: 1 inch=2,000 Esri, USGS,feet NOAA 3 FIGURE NO. Geologic Map and Sections MAY 2017 µ DATE: