REP24228

• Permit No: C1981044
• IBM Index Class Name: Report
• Doc Date: 3/30/1984
• Doc Name: ANNUAL HYDROLOGIC REPORT text
• From: EMPIRE ENERGY CORP
• To: MLRD
• Permit Index Doc Type: HYDROLOGY REPORT 1983
• Media Type: D
• Archive: No

-2-
1.1 Ground Water Quantity
l.l.l Trout Creek Sandstone
The Trout Creek Sandstone is the first regional aquifer unit below the
entire coal zone. It is separated from the overlying F seam (the
lowermost seam presently being mined) by 320 to 360 feet (permit
application document, page III-44). This unit is being monitored
from two wells within the permit area: The No. 5 Mine well and the
Okie Plaza well. Presently, only field and laboratory water quality
monitoring is reported for the Trout Creek Sandstone, as part of
EEC's hydrologic monitoring plan. Therefore, no information is
available within the annual hydrologic report on water levels of the
Trout Creek Sandstone wells.
1.1.2 Middle Sandstone
The Middle Sandstone lies approximately 61 to 267 feet above the F
seam and from 165 to 266 feet below the overlying Twentymile
Sandstone (permit application, page III-45). Plots of water levels
from three monitor wells completed in this unit are presented in the
1983 annual hydrologic report. These plots (Figures 3, 4 and 5)
cover the cumulative period of water level monitoring, from 1981
through the end of 1983. Due to the location of drawdowns in the
Middle Sandstone, the observed head declines are inferred to be due
to dewatering by the underlying No. 5 Mine (permit application, Page
III-46). The plots indicate that water levels in the Middle
Sandstone continued to decline at about the same rate during 1983,
except for Well TR-4, which declined at a steeper rate. This may be
due to the advance of the No. 5 Mine to the east during the year.
Overall declines for these monitor wells since water level monitoring
began are approximately 45, 35, and 50 feet for Wells TR-4, TR7a, and
81-O1, respectively. The December, 1983 piezometric surface map for
this unit (Figure 10 of the report) shows a gradient of about 350
feet per mile to the west-northwest, as opposed to 450 feet per mile
as is stated on Page 2 of the report. The observed water level
declines for the Middle Sandstone are well within the maximum
predictions of decline made in the permit application. (Section
3.4.7.3).
7.1.3 Twentymile Sandstone
The Twentymile Sandstone is located 165 to 246 feet above the Middle
Sandstone, and between 370 to 380 feet below the P seam (mined in the
No. 9 Mine) (permit application, Page III-47). Two monitor wells are
completed in this unit, Well 259 and the No. 9 Mine Well. During
1983, water levels were only measured in Well 259. A cumulative plot
for this well is presented on Figure 6 of the report