2016-08-08_PERMIT FILE - C1981019A ‎(3)‎

• Permit No: C1981019A
• IBM Index Class Name: Permit File
• Doc Date: 8/8/2016
• Doc Name: Performance Standards
• Section_Exhibit Name: Volume 15 Rule 4
• Media Type: D
• Archive: Yes

RULE 4 PERFORMANCE STANDARDS
6. Gossard Well — Located within alluvium beneath the rail loop, this site represents the condition of the valley
fill aquifer in the vicinity of the Gossard Coal Loadout Facility.
7. A-6 Well — Located in the Good Spring Creek alluvium, this site represents the condition up -gradient of
proposed and current mining activities.
8. North Good Spring Well — Located in the Good Spring Creek alluvium, this site represents the down -dip
condition below existing and proposed mining activities.
9. MT -95-02 — Located in the Taylor Creek valley fill, this site represents the down -dip condition below current
and proposed mining activities.
10. A-7 — Located in the West Fork of Good Spring Creek alluvium, this site represents a potential down -dip
condition below South Taylor mining activities.
11. A-8 - Located in the West Fork of Good Spring Creek alluvium, this site represents the condition up -gradient
of South Taylor mining activities.
For the valley fill groundwater wells, water levels and field water -quality parameters (Temperature,
Water Level, pH and Conductivity) will be measured quarterly; samples for laboratory analysis will be
collected annually during the second quarter utilizing the paramaters listed below.
Annual Groundwater Laboratory Parameters
pH
Conductivity at 25°C
Total Dissolved Bicarbonate (HCO3 -)°
Solids
Calcium (Ca+2)D
Magnesium (Mg+2)D
Ammonia (NH3)
Nitrate Phosphate (PO4 as P)°
Sodium (Na +)D
Sulfate (SO4)
Arsenic (As)
Iron (Fe) Lead (Pb)
Manganese (Mn)
Mercury (H g)TD
Selenium (Se)
Zinc (Zn)
D = Dissolved
TD = Total Dissolved
T = Total
TR = Total Recoverable
Prior to mining at Lower Wilson, the following three valley fill groundwater monitoring sites will be
added:
MW -95-01 — Located in the Wilson Creek alluvium, this site represents the upstream,
undisturbed background conditions of the valley fill aquifer.
MW -05-03 — Located in the Wilson Creek and unnamed drainage alluvium, this site
represents valley fill groundwater quality immediately downgradient from Lower Wilson.
MW -95-02 — Located in the Wilson Creek alluvium, this site represents the downgradient
conditions below Lower Wilson and the proposed haul road.
It is reasonable to expect potential future monitoring activities for the Lower Wilson locations to mirror
those for the existing operation as it pertains to frequency and specific parameters.
Groundwater Fill Piezometers - Monitoring of the Streeter Fill piezometer and Section 16 Fill piezometer
have been discontinued. The West Pit Fill and West Taylor Fill piezometers will be monitored quarterly
for water levels. One additional piezometers will be installed into the toe of East Taylor Fill, once
constructed, as described in Exhibit 21 Item 1.
A future spoil water monitoring well will be drilled (and water quality monitored) as identified on Map
41 B in the reclaimed Collom Pit area to monitor and measure the potential development of a spoil aquifer.
This location represents the lowest point in the proposed Collom Pit.
Trout Creek Sandstone Monitor Well — One monitor well will be drilled to the Trout Creek Sandstone
north to northeast of the middle of the northern edge of the pit. For this well, water level and field water-
Collom —Rule 4, Page 10 Revision Date: 4/18/16
Revision No.: PR -04