PERMFILE133316

• Permit No: C1980003
• IBM Index Class Name: Permit File
• Doc Date: 12/11/2001
• Doc Name: Previous Findings and Conclusions
• Section_Exhibit Name: 1996 Appendix F
• Media Type: D
• Archive: No

V. Geology -Rules 2.04.5 and 2.04,6(1) '
• The geology sections of the permit application, found in Section 2.04,6 of
Volume I and Appendix D, Volume III, have been reviewed by the Division for
compliance.
The data provided in Appendix D, Section 1 (mass spectrometry analysis) of the
application indicate that the overburden and lnterburden contain some chemical
constituents at suspect (abnormally high) levels. The parameters of
particular concern consist of lead, cadmium, molybdenum, zinc, copper, nickel,
manganese, boron and sodium.
The disturbance of these overburden materials could impact the quality of the
ground water and surface water as a result of leaching of the overburden
materials in the pit and in the excess spoil pile. High concentrations of
lead, molybdenum and sodium have been observed in a spoils spring. The
significance of the potential for degradation of the quality of the water will
be discussed in a later section of this document (Section IX).
Another potential impact is related to the suitability of the overburden
material as a plant growth medium. Topsoil depths range from 6 inches to
20 inches and rooting depths could exceed these thicknesses. High levels of
soluble salts are suggested by high values of electrical conductivity (see
Appendix D, page 2 of Accu-Lab Data and see page 2 of Report No. 73-89194, in
Volume III). High sodium levels as well as high SAR's indicate sodic
conditions. Sodium in the soil tends to break down soil structure,
particularly 1n soils of predominantly clay texture. The result of this
• breakdown is a decrease in water holding capacity and a decrease in water
availability for plant growth.
Rased on growth observed at the mine, however, the sodic nature of the
material is not a significant problem. There are areas of the excess spoil
pile which have several years growth of vegetation on them.
The operation is in compliance with the requirements of this section.
VI. Hydrologic Balance - Rules 2.04.5, 2.04.7, 2.05.3(4), 2.05.6(3), and 4,05
A. Surface Water
The surface water Quantity and quality portions of the permit application can
be found in Section 2.04,7 (Volume I), Appendix I (Volume IV), Appendix L
(Volume V) and Appendix S (Volume VIII). Surface water quality data for the
smaller drainages are given in Exhibit AA and CC of the volume entitled
Exhibit II. The HPDES permit and baseline monitoring plan are compiled in
Appendix !C (Volume IV). The monitoring plan is found in Section 2.05.6(3).
Surface water impacts may occur in the Hayden Gulch watershed as a consequence
of backfilled spoils springs and in the Dry Creek watershed as a result of
leaching from the loadout facility. This is discussed in greater detail in
Section IX of this document.
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