PERMFILE130951

• Permit No: C1981022A
• IBM Index Class Name: Permit File
• Doc Date: 9/16/2005
• Section_Exhibit Name: 2.04 Environmental Resources
• Media Type: D
• Archive: Yes

S~csr - 2.04.7
included, az a min~rm~m analysis of surface water samples for pH, electrical conductivity (EC), total
• suspended solids ('I'SS), total dissolved solids ('IDS), total iron (Fe), and total manganese (NII~.
Table 2.04.7-T1, Surface and Ground Water Parameters, lists the analysis parameters for ongoing
operational hydrologic monitoring. Generally, bazeline and operational surface water monitoring have
focused on specific mine disturbance areas, so there have been some changes over time in the
designated surface water monitoring sites.
Table 2.04.7-T5, Iltstoric Surface Water Monitoring Suntnrary, identifies all of the sites for which
surface water monitoring recondc are available and notes the monitoring interval(s) for each. The
following sections summarize water quahry characteristics, based on available monitoring and analysis
infomtation, for each of the identified surface drainages or drainage categories.
North Fork of the Gunnison River -Information on the quality and characteristic of surface water
flows in the North Fork of the Gunnison River is based on sampling and analysis of wacer samples
from monitoring Stations R-1, R-2, G1, G2, NF-1, and NF-2. Bazed on available surface water
quality analysis resulu for the North Fork and az shown on Figure 2.04.7-F12, North Fork of the
Gunnison River Trilinear Diagram, the Nonh Fork surface water is a calciurrrcarbonate chemical
type. Analysa values indicate a neutral to moderately alkaline pH and low to moderate EC, TSS, and
TDS values, az summarized by Table 2.04.7-T6, North Fork of the Gunnison River Surface Water
Quality Surmnary.
In general, surface flows in the North Fork increase significantly following spring runoff, with a lag
corresponding to filling of Paonia Reservoir upstream and initiation of releazes from the reservoir.
Elevated flows continue throughout the summer, during irrigation season, declining in late surruner to
early fall. The increase in spring stream flows is typically accompanied by significant increases in TSS,
minor increases in TDS, and minor to moderate increases in Fe and Mg. Decreases in stream flows in
]ate summer and through the Fall and winter are commonly accompanied by minor to moderate
mcreazes in TDS az dilution effects decline with reduced flows. While the noted changes reflex
general trends, it u important to recognize that the pattern and range of water quality fluctuations are
not consistent over tune. Generally, the quality of the North Fork surface water is good in the
vicinity of the mine permit area. Some degradation of North Fork water quality occurs well
downstream from the mine az a result of imgation return flows.
Hubbard Geek -Information on the quality and characteristics of surface water flows in Hubbard
Geek is based on sampling and analysis of water samples from monitoring Stations H 1 and I-I2.
Bazed on available surface water quality analysis results for the Hubbard Geek and az shown on
Figure 2.04.7-F13, Hubbard Geek Trilinear Diagram, Hubbard Geek surface water it a calcium-
carbonate chemical type. Analysis values indicate a neutral to moderately alkaline pH and low to
moderate EC, TSS, and TDS values, az sunurrari7xd by Table 2.04.7-T7, Hubbard Creek Surface
Water Quality Sunurrary. The general pattern of seasonal water quality variation previously discussed
for the North Fork u ako observed for Hubbard Geek, with fluctuations being slightly more
pronounced and occumng earlier in the year due to a shover flow path for runoff and reduced
dilution effects. Generally, the quality of the Hubbard Geek surface water is good in the mine permit
and adjacent areas.
Intermittent and Ephemeral Drainages -Information on the quality and characteristics of surface
water flows in the numerous small intermittent and ephemeral drainages within the tnine permit and
adjacent areas is based on sampling and analysis of water samples from those monitoring stations
identified on Table 2.04.7-T5, Surface Water Monitoring Surmnary. Based on available surface water
quality analysis resulu for the intermittent and ephemeral drainages and az shown on Figures 2.04.7-
F14 Intermittent Drainages Ttilinear Diagram, and 2.04.7-F15, Ephemeral Drainages Trilinear
• Diagram, surface water in these drainages is typically a calciurrrcarbonate chemical type, with some of
the intemuttent drainages tending toward asodium-carbonate type.
PR04 2.04-69 Revised August 2000