2016-02-16_REVISION - M2004031

• Permit No: M2004031
• IBM Index Class Name: Revision
• Doc Date: 2/16/2016
• Doc Name: Objection
• From: Equity Funding LLC
• To: DRMS
• Type & Sequence: AM1
• Email Name: TOD
• Media Type: D
• Archive: No

Environment, Inc. Page 3
February 12, 2016
These graphs show that there has been a marked increase in the
groundwater elevations after the slurry wall was built .
While there are no site specific studies done for the Orr
Property, it is possible to use the best available information to
draw some conclusions on what was going on, the Orr Property
prior to 2005 . According to the Division of Reclamation Mining
and Safety records AI submitted monitoring well data with each of
their annual reports filed from 5/6/2005 to 11/02/15 for the
wells located along the east side of their permit line. Review
of those reports produced the following information. The wells
that provided historic groundwater elevations closest to the Orr
Property are Well #255775 (MW#2) which is immediately west of
the property line; Well # 255788 (MW #11B) is immediately north;
Well # 255776 (MW #3) is east of the Fulton Ditch and Well 255780
(MW #8) is north of the site. All are shown on the attached
photo map plats 11 & 13 from the D.R.M. S . presentation. When
Tetra Tech says there is not enough data to estimate the ground
water historic elevation on the Orr Property, they did not take
time to research the information presented during the 3/18/15
enforcement action hearing taken by the D.R.M. S . In that
presentation slides 9, 10, 15 are examples of what could be
created using AI' s annual report data. These wells could be used
to estimate the pre slurry wall/ Bull Seep move, groundwater
elevations across the Orr Property, or they could establish
targets for AI to work towards to mitigate the groundwater
mounding occurring from their slurry wall .
One way to do this would be to establish the average elevation
for each monitoring well and then connecting the wells with a
straight line to estimate the depth at any point along the line .
For an example of what could be done, I reviewed the drill logs
for MW#2 submitted that run from 2/16/2004 to 1/27/2005 to
establish the average groundwater elevations in MW # 2 prior to
installation of the slurry wall and relocation of Bull Seep.
This average was 6 . 08 feet BELOW the surface at MW#2 for the
first year of data collected If you then did this for the other 3
wells you could create an approximate isopac of the average
groundwater table that could become the target for mitigation of
the impacts to the hydrologic balance.