2017-09-07_PERMIT FILE - C1981019A ‎(4)‎

• Permit No: C1981019A
• IBM Index Class Name: Permit File
• Doc Date: 9/7/2017
• Doc Name: Performance Standards
• Section_Exhibit Name: Volume 15 Rule 4
• Media Type: D
• Archive: Yes

RULE 4 PERFORMANCE STANDARDS
5. MJ -95-03 - Located in the Jubb Creek valley fill just downstream of the confluence of the West and East
Forks of Jubb Creek, this site represents the condition of the valley -fill aquifer downgradient of the proposed
Collom Pit.
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.
12. Trout Creek Well — Located on the northeastern edge of the Collom Pit, this site respresents the regional
aquifer condition of the Trout Creek Sandstone.
For the valley fill groundwater wells and one deep groundwater well, 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 )o Calcium (Ca+z)°
Solids
Magnesium (Mg+2)n
Ammonia (NH3)
Nitrate Phosphate (PO4 as P) Sodium (Na)
Sulfate (SO4)
Arsenic (As)
Iron (Fe) Lead (Pb) Manganese (Mn) ID
Mercury (Hg)
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:
1. MW -95-01 — Located in the Wilson Creek alluvium, this site represents the upstream,
undisturbed background conditions of the valley fill aquifer.
2. MW -05-03 — Located in the Wilson Creek and unnamed drainage alluvium, this site
represents valley fill groundwater quality immediately downgradient from Lower Wilson.
3. 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.
Collom — Rule 4, Page 11 Revision Date: 12/30/16
Revision No.: TR -108