2010-07-13_HYDROLOGY - C2009087

• Permit No: C2009087
• IBM Index Class Name: HYDROLOGY
• Doc Date: 7/13/2010
• Doc Name: Water Age Report for COV23 and Implications for Additional Bedrock Monitoring Wells
• From: Peabody Energy
• To: DRMS
• Permit Index Doc Type: Correspondence
• Email Name: JDM
• Media Type: D
• Archive: No

CONCLUSIONS
FIGURE 6- SUMMARY OF WATER AGES, SAGE CREEK MINE
YAMPA RIVER,
MODERN WATER,
<65 YEARS
i
MONITOR WELL COV23i
ANCIENT WARt
0 500,000 1,000,000 1,500,000 2,000,000
Minimum Apparent Age, years
1. The Yampa River water sample was modern water, younger than 65 years
(Figures 3 and 6).
2. The Williams Fork Formation water sample was ancient water, at least
1,150,000 years old and could be older (Figure 5 and 6).
3. The surface water sample and the Williams Fork Formation sample came
from different hydrologic systems due to their vastly different ages.
4. From the monitor well water age and Darcy Equation calculations, it was
determined that there was some type of hydraulic boundary between the
Williams Fork Formation outcrop on the surface and Monitor Well COV23.
9