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Meteorological Monitoring Station
<br />In order to gather updated meteorological information for air quality compliance and permitting, TC will install a
<br />Meteorological (MET) Monitoring Station just to the south of the Area 1 Pit and permitted Overburden Stockpile,
<br />on an area of reclaimed mine spoils, as shown on Map 24 and by Figure 32. The MET Station will consist of a 4 x
<br />4 foot concrete pad for the instrument tower, a 30 -foot steel tower with guy lines and anchors, a 3 x 3 foot concrete
<br />pad for a solar power panel, the solar panel, and a steel box for control and monitoring equipment. Instruments to
<br />monitor wind speed and direction will be mounted on the tower, along with a transceiver to transmit the data to a
<br />remote receiver. The MET Station will be accessed by the existing road to the Overburden Stockpile, and a new
<br />400 -foot, all- season, light -use road. The road, which will be approximately 20 feet wide, and graveled for all -
<br />season access, will end in a 30 x 30 foot pad to provide a vehicle turn - around. Given that the road and pad will be
<br />built during the winter, installation of drainage controls during construction is not necessary or feasible. Soil
<br />material will be stripped from the road and pad disturbance areas, and placed in existing soil stockpile SF -3. The
<br />road and pad areas will be graveled, and drainage from the small disturbance area will continue to flow to the Area
<br />1 Pit and Pond D. It is anticipated that the MET Station will be reclaimed in conjunction with final backfilling and
<br />grading of the Mine Facilities area at the end of the mine life. Instruments and equipment (ie: tower, solar panel,
<br />and control box) will be salvaged for use elsewhere, and the small concrete pads will be removed and disposed of in
<br />the nearby portal fill area.
<br />EMD Water Monitoring Wells (MR13 -267, MR13 -271
<br />TC plans to complete minor maintenance for existing ranch roads, construct a short segment of temporary road„
<br />construct drill -pads, drill and complete two groundwater monitoring wells, and reclaim the drill- sites. The purpose
<br />of the proposed water monitoring wells is to determine the level and extent of groundwater accumulations in the
<br />sealed Eastern Mining District (EMD) mine workings, and to provide for future monitoring of water level and
<br />quality in this area. The proposed activities will occur on lands and will affect minerals owned by the State of
<br />Colorado and controlled by TC (State Lease CO- 3229), as shown on Figure EX33A -F1, EMD Water Monitoring
<br />Wells.
<br />Drill -sites have been selected and located to facilitate access from existing County and ranch roads. Minor
<br />maintenance may be required for portions of the existing ranch roads, including grading to address rills or washouts
<br />rerouting of an 800 -foot segment of an existing two -track road to avoid an identified cultural resource site, and
<br />placement of suitable road -base materials, geotextile, and gravel or other road -base, to assure good access during
<br />any wet conditions and minimize any road damage. Where direct access from existing roads is not feasible, TC
<br />will construct a short segment(s) of temporary road to access the drill pad(s). The maximum length of temporary
<br />road to be constructed will be approximately 1,500 feet, and construction will involve blading existing soil material
<br />to the side (20 -foot road width — maximum disturbance 0.70 acres) and placing and grading road —base material.
<br />Drill pads will be approximately 100 x 100 feet (0.23 acres), with soil material stripping limited to an area around
<br />the drillhole collar, and the area surrounding any mud pits necessary to support drilling operations, in order to
<br />minimize disturbance and facilitate site reclamation. Nominal 14 -inch -inch drillholes will be completed to a 60-
<br />foot depth to set a surface casing, then the holes will be extended by drilling a nominal 10 -inch drillhole to a depth
<br />of approximately 1,710 feet using conventional rotary drilling methods and drilling mud as the circulation medium.
<br />A 12 -inch or slightly larger surface casing will be set in the upper 60 -feet for each well, with 8 -5/8 -inch casing
<br />extending to a depth of 1,610 feet, and 4 -1/2 -inch slotted screen extending from 1,610 to 1,710 feet. All casing will
<br />be fully grouted in the boreholes. On completion of the wells, they will be developed by cleaning and flushing the
<br />wells with fresh water.
<br />For each well, a pit approximately 12' x 12' x 10' will be excavated on the pad to contain the drilling mud and hold
<br />the drill cuttings. Drainage from the drill pads will be controlled using berms and straw wattles. For each well, the
<br />surface casing will extend above the ground surface and will be capped and locked to limit access. On completion
<br />of the drilling and well completion activities, any excess water will be pumped out of the cuttings pits into trucks
<br />and hauled off -site to a suitable disposal area, the cuttings pits will be allowed to dry out, pits will be covered and
<br />excavated material regraded over the pits, pads will be regraded to blend with the surrounding terrain, road -base
<br />material, geotextile, and gravel or other road -base materials will be removed from any temporary roads, soil
<br />material will be replaced on the disturbed areas, and all regraded areas will be seeded with the approved rangeland
<br />seed mix. When the wells are no longer needed for monitoring, they will be plugged and sealed, consistent
<br />MR13 -271 2.05 -65.6 11/14/13
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