PERMFILE126870

• Permit No: M2001046
• IBM Index Class Name: Permit File
• Doc Date: 7/18/2001
• Doc Name: Concerns Regarding Application
• From: Sage Hill Farm
• To: DMG
• Media Type: D
• Archive: No

Ms. Cynthia Parker
July 13, 2001
Page 4
external elements interfere with the groundwater level and the aquifer properties are
homogeneous and uniform. A simplified form of the Theis equation (Freeze and Cheny,
1979) is as follows:
4h=264Q1o 0.3Tt2
g
T y2S
Where:
0h =change in water table elevation (ft)
Q =pumping rate (gpm)
T = transmissivity (gpd/ft)
r =distance from pumping well (ft)
S =storativity
t =time (days)
Aquifer Properties
The following reports were reviewed in order to develop an understanding of
groundwater conditions at the location of concern:
• Hydrogeologicat Characteristics of the Valley Fill Aquifer in the Brighton Reach
of the South Platte River Valley, Colorado. 1972. R.T. Hurr and P.A. Schneider.
USGS Open File Report 73-124.
Geohydrology of Shallow Aquifers in the Fort Lupton -Greeley Area, Colorado.
2000. S.G. Robson. J.S. Heinv. and L.R. Arnold. USGS Atlas HA 746c.
Based on information contained in these reports, aquifer properties were estimated as
follows:
Transmissivity (T)
storativity {S)
Depth to Bedrock
Water Table Elevation
Saturated Thickness
Results and Discussion
50,000 - 200,000 gpd/ft
0.2
20 - 60 feet below ground surface
less than 10 feet below ground surface
10 - 400 feet
The Theis equation described above was used to estimate the effects of groundwater
pumping during mining operations on the Nix property. The predicted theoretical
drawdowns are based on the assumption that a single well is located 500 feet north of the
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