2015-04-23_REVISION - C1981014 ‎(2)‎

• Permit No: C1981014
• IBM Index Class Name: Revision
• Doc Date: 4/23/2015
• Doc Name: 2nd Adequacy Review
• From: DRMS
• To: Energy Fuels Coal, Inc.
• Type & Sequence: TR43
• Email Name: LDS
• Email Name: DIH
• Media Type: D
• Archive: No

George V. Patterson, Energy Fuels Coal, Inc.
Page 5
April 23, 2015
in 2003 for this purpose. MWNW has been described as a monitoring well throughout the
PAP and other documents, which is inaccurate; really it is simply a cased hole, open to
the mine workings. Nevertheless, and as stated on page 2.05.6 -53, the purpose of this
monitoring point is to:
"...track progressive mine flooding, water levels and water quality."
EFCT Drill holes SR-14 and SR61 have been confirmed as being sealed and reclaimed.
Concerning MW -NW, the DRMS approved MW -NW for the groundwater monitoring
program and DRMS needs to support the approval
DBMS: On page 2.05.641 the mine inflow rate is estimated as 330 Acre feet per year.
Using the previously quoted figure of 5,700 Acre feet as the maximum volume of the
mine cavity, the mine would be expected to refill completely in 17 years. It is noted that
the analysis of BBA suggests that the rate of mine inflow was overestimated. Without a
data point in the mine workings none of the assumptions that underlie any of the
estimates or models can be verified, and the rate at which the mine is refilling will remain
a matter of conjecture.
EFC1: The DRMS' above reference to 330 acre feet per year of mine inflow and that the
mine would be expected to completely refill in 17 years is out of context. The calculations
shown on Page 2.05.6 -41 of the PAP (permit) were generated from data compiled in the
early years of the mining operations at Southfield. Mining records from the Annual
Hydrology Reports (AHR's) document that approximately 85% of the mine inflow was
pumped and metered for accuracy throughout the mining operations at Southfield.
Review of the records from 1985 through 2000, which was the active mining period of
EFCI at Southfield, document that the highest recorded mine inflow during any one year
was 135.3 acre feet, which occurred in 1985. During subsequent years, the inflow rate
steadily decreased down to 10.3 acre feet at the close of mining operations in Year 2000.
DBMS: i) Please provide monitoring data from MWNW, in accordance with the
approved water monitoring plan described in Exhibit 25. This data should be used in
a detailed analysis of the impact of the Southfield Mine on groundwater quantity. The
analysis should also include the data collected from the other groundwater monitoring
points and be used to validate any modeling conclusions. (If it is determined that
MWNW must be replaced, the Division would appreciate the opportunity to discuss
an alternative location for the new monitoring well)
EFCT Monitoring well MW -NW is being monitored within 20 vertical feet of the Southfield
mine workings (353 bgs). Given the weak roof conditions in the Is` North mine section,
where MW -NW is located, it is likely that the 20 vertical foot reach is an open void, (a roof
fall, typical of the 1 s` North Section) if so, the 20 foot void would be part of the mine
workings in the area of MW -NW. Nonetheless, it has been proven that MW -NW is open to
water flow to the mine workings at a flow rate exceeding 100 gallons per minute.
Concerning the Division's comment about the possibility of a new well in a new location,
installing another monitor well at Southfield would be contradictory to the Boulay June