1993-05-26_REVISION - M1977378

• Permit No: M1977378
• IBM Index Class Name: REVISION
• Doc Date: 5/26/1993
• Doc Name: Reclamation Issues
• From: Welborn Dufford Brown & Tooley, P.C.
• To: CDH-WQCD
• Type & Sequence: TC1
• Media Type: D
• Archive: No

WELBORN DUFFORD BROWN & TOOLEY, P.C.
Mr . J. David Holm
May 26, 1993
Page Three
plug would cut off approximately 2/3 of the mine water
presently flowing from the American Tunnel, and is expected to
create an effective seal with minimal, if any, seepage around
that seal . This is the point to which Sunnyside Gold has
requested that its NPDES discharge point be moved upon
completion of the plugging.
The plug in the American Tunnel is proposed in a
location of stable and competent rock and will dam the
naturally in-flowing ground water. The water level in the mine
workings behind the plug will rise until an equilibrium is
reached between water moving toward the mine workings and water
moving away from the flooded mine workings through naturally
occurring fractures in the rock. Due to the physical and
chemical characteristics of the ground water and wall rock, the
water behind the proposed plug is expected to be better than
the water which currently discharges from the American Tunnel
prior to treatment. In effect, installation of the plugs is
expected to return the hydrologic system to an approximation of
the natural, pre-mining conditions .
As a result, over time water which previously
entered the mine workings will likely find its way through
natural structures to surface. In our view, such waters would
not constitute point source discharges. Rather, they would be
a return to the historic natural conditions of hydrologic
flow. Additionally, there would be no discharge of pollutants,
or addition of pollutants, by any activity of man. Whatever
the natural constituents of the water moving through the
geologic environment, that would reflect the historic natural
conditions . Therefore, C.R.S. 25-8-501 and the statutory
definitions of "discharge of pollutants" , "point source" ,
"pollutant" , and "pollution" would not require an NPDES permit
for any surface springs or seeps which occur. We request the
Division' s confirmation of that status .
Additionally, if water backed up sufficiently, there
is a theoretical possibility that it could exit from historic
mine workings such as the Mogul Mine. If additional water were
to flow from that historic portal, it would be primarily from
the reversal of hydraulic gradient to the historical flow
path. The Simon Hydro-Search report (dated March 12, 1993,
S S 8 .2 and 8 .3) estimates that, after 16 years from plugging,
only about 4 gpm would flow from the Mogul Mine after flowing