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PAGE 6
<br />• Slug tests performed by J.F. Sato & Associates (1983, p. 53Jj: and Table 16) in Coal Gulch, 25 miles
<br />northwest of Cameo, produced an average transmissiviry for the Cameo coal bed, there 23.5 ft thick,
<br />of 3 ft /day, for a hydraulic conductivity of 0.11 ft/day. An average of 556 ft of overburden was
<br />subject to similar testing, producing a transmissivity of 4 ft /day, with a resultant conductivity of
<br />0.007 ft/day. Fractured sandstone in the overburden, on the other hand, had a transmissivity 538
<br />ft /day, producing hydraulic conductivity of 19.39 ft/day. It should be pointed out that Coal Gulch
<br />is on the apex of a broad, low-amplitude anticline; many such folds in the Piceance basin exhibit
<br />substantially greater fracturing than is found in monoclinal areas such as the vicinity of the Roadside
<br />Mine.
<br />Water inflow into the Roadside Mine can originate from gravity or pressure-driven drainage from
<br />overlying rocks through cave areas and both natural fractures and those resulting from mining; from
<br />dewatering of the coal bed being mined; and by hydraulic head drainage and subsequent recharge
<br />inflow from underiying rocks. According to Brooks, there is no structural gradient along the length
<br />of the Rapid Creek drainage basin sufficient to induce "much" groundwater flow (1986, p. 4). He
<br />also states that "...any water in the Rollins Sandstone ...likely is not under large pressure in the
<br />basin." (Brooks, 1986, p. 18). His comments concerning rechazge in the area of the Roadside Mine
<br />are given on page 4 above.
<br />According to a letter and accompanying maps dated January 26, 1996, from L. M. Reschke,
<br />Engineer, average discharge from Roadside South is 250 gallons per minute (gpm). Of this total,
<br />approximately 100 gpm originates in the southeast part of the mine (5 East Mains, 11 West). The
<br />remaining 150 gpm originates in other parts of the mine above the level of the Colorado River,
<br />below which the mine is flooded. Water in the southeast part of the mine, originates from
<br />overburden sources in caved areas (8 and'9 West, total 4.5 gpm); a couple very minor roof drips
<br />along fractures and floor "water holes" which may also be fracture-related (6 East, 2 South Mains,
<br />quantities too small to measure), and three larger sources, all apparently from the floor (11 West,
<br />20 gpm; No. 5 East Mains, 50 gpm; and 6 East, 20 gpm; all amounts approximate}. Given the dip
<br />and nature of bottom heave found in this part of the mine it is possible that the flows in the northeast
<br />comer of No. 5 West Mains and 6 East are related. It is also likely that the water flowing in the 2
<br />South Mains was in part emanating from the 11 West and 5 East Mains and is now in part flowing
<br />through the floor and ending up in 6 East, down dip. In 6 East, water could be seen originating from
<br />"springs" in the floor, traveling up to 100 ft, disappearing for a crosscut, and reappearing in another
<br />low spot. There is thus no doubt that water is traveling in heaved rock beneath the mine floor. In
<br />any case, with an apparent discharge of 250 gpm, assuming that each source is independent
<br />(unlikely), and a total exposed area (including interior pillars) of 1,250 acres, the Roadside South
<br />Mine is discharging 0.20 gpm/acre, or 0.32 acre-ft per year per acre.
<br />The Roadside North Portal discharges an average of 110 gpm, of which 40 gpm originates from
<br />Colorado River alluvial material and is pumped from underdrains in the portal area. The workings
<br />of Roadside North essentially surround the flooded portion of the adjacent abandoned Cameo Mine,
<br />and it can assumed that virtually all of the inflows from the roof, rib, and floor of entries abutting
<br />• the barrier between the two mines originates from the Cameo Mine. The open area (including
<br />interior pillars) of the Roadside North Portal workings is 170 acres, and that of the Cameo Mine 780
<br />acres. The discharge from Roadside North is thus 0.07 gpm/acre, not including alluvial drainage,
<br />or 0.12 acre-ft per year per acre.
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