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West Elk Mine
<br />sedimentation pond MB -5E for treatment, if necessary, and is discharged into the receiving stream
<br />or to temporary storage in various sumps within the mine. The changed timing of these return flows
<br />to the receiving streams is of no practical consequence, because the inflows via fault systems far
<br />exceed the losses (or consumptive uses) to the North Fork. In addition, the mine fault inflows are a
<br />new, non -tributary source of contributions to the North Fork. Similarly, because losses within the
<br />mine are roughly 5 percent of the total inflow, the annual loss will be 1 acre foot or less. It is also
<br />important to recognize that at those times when inflows (other than those from the fault systems) to
<br />the mine are likely to be at their highest levels (during snowmelt runoff), water users in both basins
<br />should be satisfied rather than "calling" for water.
<br />Streams
<br />Baseline data for streams in and adjacent to the permit area are being obtained as presented in
<br />Section 2.04.7 and, more specifically, in Table 5 of Exhibit 71 and as recommended in Exhibit 71A.
<br />Drainage basins and the resources monitored or proposed for monitoring are shown on Map 34.
<br />Monitoring to determine the hydrologic consequences to streams is by seasonal measurements
<br />(three times per year to correspond to the start of spring runoff, the peak spring runoff, and the fall
<br />low flow) of flow, pH, conductivity, and temperature are taken. Seasonal samples are also obtained
<br />from the Sylvester Gulch and North Fork sites for analysis of TDS Fe, Mn, and TSS. Annually
<br />during the second sampling (except for the North Fork which is during the third sampling), MCC
<br />performs a full -suite laboratory analysis of water solids (TDS), total suspended solids (TSS),
<br />calcium, magnesium, sodium, SAR, hardness, bicarbonate, chloride, nitrate/nitrite, phosphate (PO2 -3
<br />as P), sulfate, iron (total & dissolved), manganese (total & dissolved), aluminum (dissolved) arsenic
<br />(total recoverable), cadmium, copper, lead, mercury (total recoverable), molybdenum, selenium
<br />(total recoverable), and zinc.
<br />A seasonal, rather than quarterly or semi-annual water quality monitoring schedule was instituted
<br />for a variety of reasons. The primary reason for selecting seasonal sampling is that, in many
<br />instances, particularly streamflow and spring flows, these are the only periods of measurable flow.
<br />Most of the streams are ephemeral or intermittent at best, and nearly all of the springs are ephemeral
<br />except in the wettest years. The nine years of baseline data clearly indicate that there is no reason to
<br />attempt to sample these locations in the dead of winter. The adverse conditions encountered in the
<br />remote areas of the West Elk Mine lease area severely hamper sampling procedures and influence
<br />the collection of meaningful data. As a result, by restricting sampling to the periods of flow and
<br />ensuring sample integrity, MCC will be able to provide meaningful data to the agency while
<br />reducing the costs associated with collecting unnecessary data or data that is not meaningful.
<br />MCC has selected the water quality parameters above and in Table 5 of Exhibit 71 for routine
<br />measurement because they are most commonly associated with coal mining impact on water
<br />quality. Annual full -suite monitoring will allow MCC to identify possible mining -induced changes
<br />in water quality. Monitoring data, along with a discussion of any impacts observed or projected,
<br />will be provided in an Annual Hydrology Report to be submitted by June 30 each year.
<br />2.05-194 Rev 06/05- PRIG, 03/06- PRIO, 05/06- PR10, 05/09- TR117, 08/18- PR15
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