PERMFILE101173

• Permit No: C1989074
• IBM Index Class Name: Permit File
• Doc Date: 12/11/2001
• Section_Exhibit Name: 2.05.6.3 PROBABLE HYDROLOGIC CONSEQUENCES
• Media Type: D
• Archive: No

• The specific conductance measures the ability of the water to conduct electricity which
is directly related to the dissolved ion content of the water. All three wells showed an
increase in conductivity during the later part of 1993, probably due to the extremely dry
conditions that existed during this time throughout Colorado. However, in the Spring
of 1994, the conductivity of the Montoya well and Well 29-4 dropped significantly
while that of the USGS well increased significantly. This is difficult to explain since
the Montoya well is located only 1000 feet south of the USGS well and both are north
(downstream) of the permit area. Checking into possible explanations for this TDS at
the USGS well showed that the entire disturbed area was hydromulched for reclamation
in the second quarter of 1994. Mark Kerr reported that 200 Ibs/acre of fertilizer was
used per acre in the hydromulching and seeding process. This is a normal hydromulch
fertilization rate per acre and normal water levels in the USGS well are the shallowest
in the area: usually from 18' to 20' from the surface. Also, the USGS well is located
immediately downstream and to the east of the fertilized area. However, it is not
possible that the fertilization caused an increase in the salts present in the shallow water
of this hole. See discussion in the Conclusions section.
Well pH levels are shown in the following graph for all three wells currently sampled.

Rimrock Mine
Well pH
•
N
10.00
s.7s
9.50
9.25
9.00
8.75
8.50
8.25
8.00
7.75
7.50
7.25
C
J
n
7.00
6/88 8/88 10/88 12/88 3/89 5/69 7/93 9/93 12/93 1194 4/94 7/94 12/94
Well 29-4 ~MOntoya Well u*'~USGS Well
All samples 5/89 and earlier are before mine startup
1/12/95
2.07(11 Page 12
Montoya
Well Dry
12/94
-rF