Page 51-52 Final EIS (charts did not come across too well ...)
2.8 Agency Mitigated Alternative
The Agency Mitigated Alternative addresses potential impacts to water quality, water quantity,
and the location of the proposed water treatment facility.
2.8.1 Water Quality and Groundwater Monitoring
BHJV’s proposed water monitoring program was described in Section 2.5.4.1. Under the
Agency Mitigated Alternative, BHJV would be required to add two additional surface water
quality monitoring sites, plus three stream flow monitoring sites and four additional monitoring
wells for the purpose of monitoring the effects of mine dewatering on groundwater elevations
and stream flows.
Two of the four additional monitoring wells would be located in the upper Fish Creek drainage,
one would be just west of the Range Front Fault near Moose Creek, and one would be west of
the historic Highland Mine adit near Basin Creek (Figure 2.8-1). A list of additional groundwater
and surface water monitoring locations proposed in the agency-mitigated alternative is provided
in Table 2.8-1 and 2.8-2. All water quality monitoring sites and the chemical and physical
parameters which will be analyzed from samples collected at these locations are provided in
Appendix B.
Table 2.8-1. Butte Highlands Mine Water Monitoring Sites Added As Part of the Agency-Mitigated
Alternative.
Surface Water 1
Monitoring Site Parameter Suite Monitoring Frequency
Added as Part of the
Agency-Mitigated
Alternative
WS-3 See Table B3 Monthly Yes
WS-9 See Table B3 Monthly Yes
WS – 10 2 Stream Flow Monthly Yes
WS – 11 3 Steam Flow Monthly Yes
WS – 12 3 Stream Flow Monthly Yes
Emerald Lake Aqueduct
Fish Creek Flow Augmentation Outfall
007 Flow Monthly Yes
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MPDES Outfalls
Number Numeric Discharge
Limits by Parameter
Monitoring
Requirements
001 See Table B-4 See Table B-8
002 See Table B-5 See Table B-8
003 See Table B-6 See Table B-8
004 See Table B-7 See Table B-8
005 See Table B-6 See Table B-8
006 See Table B-6 See Table B-8
1 Metals analysis for surface water samples will be for total recoverable concentrations except for aluminum which will be for dissolved concentrations
2 Proposed Basin Creek Flume Site
3 Proposed Fish Creek Flume Site
Table 2.8-2. Butte Highlands Mine Proposed and Agency-Mitigated Water Monitoring.
Groundwater
Monitoring Site Parameter Suite Monitoring Frequency
Added as Part of
the Agency-
Mitigated
Alternative
MW15-001 1 Water Level Monthly Yes
MW15-002 2 Water Level Monthly Yes
MW15-003 3 Water Level Monthly Yes
MW13-001 4 Water Level Monthly Yes
1 Proposed monitoring well Fish Creek, between WS-11 and WS-12
2 Proposed monitoring well adjacent to proposed Fish Creek augmentation outfall
3 Proposed monitoring well Moose Creek Basin, above LAD 1 site
4 Proposed monitoring well west of the Historic Highland mine portal
2.8.2 Monitoring and Management of Post-closure Seeps
BHJV proposed to conduct post-closure surveys within one mile of the new mine portals to
detect the formations of springs and seeps that may develop following groundwater level
recovery within the mine area. DEQ would require that this survey area be expanded to the
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BHJV Mine FEIS 53
December 2014
east to encompass additional area within the headwaters of Fish Creek that are beyond one
mile of the portals, including surface water monitoring sites WS-3 and WS-5.
DEQ will require the mine to monitor seeps and springs post closure for at least one year after
water levels have returned to pre-mining water levels (estimated to take about 8 years). DEQ
will evaluate water quality data at downstream monitoring sites (including WS-3 and WS-5 in
Fish Creek, WS-7 in Basin Creek, and WS-6 in Moose Creek) to determine whether streams
show degradation compared with baseline water quality data. If streams do not show
degradation, monitoring could cease. If streams show degradation, monitoring would continue
and, as outlined in Section 2.6.3.1, water would be directed into the subsurface LAD system (or
other options as described in BHJV’s proposal, see Section 2.6.3.1 above) which would allow
attenuation of any elevated parameters (metals, nitrates, TSS) via flow through soils within the
LAD area. This water management plan could be adapted to include passive water treatment
methods such as absorptive media or wetlands, if determined appropriate.
2.8.3 Moving the Water Treatment Plant to the Surface
Water from dewatering the mine workings would be discharged to surface water at the approved
MPDES outfalls or within the LAD sites. This water would likely need to be treated prior to
disposal. The water treatment plant would be located on the surface, rather than installed
underground as proposed by BHJV, in the area of the other mine facilities. This location would
facilitate access to the plant during mine operation and post-closure (as needed).
2.8.4 Mitigation for Flow Reductions
DEQ has consulted with Montana Fish, Wildlife, and Parks on the potential impacts from flow
reductions on resident populations of westslope cutthroat trout (Oncorhynchus clarki lewisii) in
Basin Creek and on wetland habitat in upper Moose Creek (FWP, 2014).
Basin and Blacktail Creek
After mining ceases, it is likely that flows may be reduced in Basin Creek by approximately 105
gpm due to the plugging of the historic Highland Mine adit. BHJV proposes to plug the adit to
remove the potential need for treatment of water discharging from the mine post-closure.
Therefore, this potential flow decrease is expected to be a permanent change. After
groundwater level recovery, some renewed inflow to the adit below the plug is expected, so
long-term flow reduction would likely be less than 75 gpm on average.
To compensate for potential flow reductions in Basin Creek after mining ceases, BHJV would be
required to replace three culverts and improve sediment control at two other culverts along
Roosevelt Drive (Figure 2.8-1), These improvements would benefit aquatic organism passage
and reduce sediment impacts to Blacktail Creek, of which Basin Creek is a tributary. The culvert
replacements and road improvements would have long-term positive benefits for the fishery in
Blacktail Creek.
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BHJV Mine FEIS 54
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Figure 2.8-1. Proposed Culvert Improvement and Sediment Control Upgrade Sites along Roosevelt Drive
in the Blacktail Creek Drainage, Silver Bow County, Montana.
Moose Creek
Although flow reductions in Moose Creek are not predicted by the groundwater model, there is
some potential for reduced flow during the groundwater level recovery phase. BHJV would be
required to improve five stream crossings along lower Moose Creek on Highland Road to
compensate for the potential changes to wetland extent and duration during the period of
recharge (Figure 2.8-2). These improvements would provide long-term benefits to wetland
habitat and potentially improve aquatic organism passage and are also part of the Forest
Service Plan of Operation.
Table 2.8-3 summarizes the components of the Agency Mitigated Alternative related to water
quality, water treatment, groundwater, and stream flows. Table 2.8-4 summarizes information on
the proposed outfalls, monitoring wells, and receiving waters addressed under the Agency-
Mitigated Alternative.
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Figure 2.8-2. Proposed Culvert Improvement and Sediment Control Upgrade Sites along Highland Road
in the Moose Creek Drainage, Silver Bow County, Montana.
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December 2014
Table 2.8-3. Under the Agency-Mitigated Alternative, the following Components Would Become Stipulations of the Butte Highlands Mine
Operating Permit.
Resource Area
Issues or Comments
Addressed
Mitigation Duration Location
Water Quality Request for expansion
of water quality
monitoring
BHJV would expand its proposed water
quality monitoring plan and add 4
monitoring wells.a
Throughout active mining
and continuing post closure
until DEQ approves
discontinuing monitoring
Please see Figure
3.6-1 for water
quality monitoring
locations
Water Treatment Remove the need to
maintain access to the
inner workings of the
mine after mine closure.
Desire for more
frequent assessment of
the water treatment
equipment.
The water treatment facility, originally
planned to be housed underground in the
mine workings, would be relocated to a
structure adjacent to the mine portal near
the other support facilities on the existing
portal pad.
Throughout active mining.
Treatment would cease after
pumps are shut off.
At existing portal
pad (Figure 2.4-1)
Stream Channel
Stability
Concern that increases
in flows from mine water
discharge may
destabilize the channels
of Basin Creek and
Moose Creek
BHJV would monitor stream channel
dimensions and bed composition near
mine discharge outfalls on an annual
basis, in June or July after peak run-off.b
Beginning once discharge
occurs at an outfall and
continuing until data are
conclusive or for duration of
discharge.
Basin Creek,
Moose Creek, Fish
Creek
Fish Creek
Groundwater Concern that the
groundwater pumping
and the resulting cone
of depression as
modeled may result in
dewatering of Fish
Creek
BHJV would install 2 additional monitoring
wells in the upper Fish Creek basin. a
These would provide an early indication of
groundwater drawdown that might
influence streamflow, allowing for timely
implementation of mitigations (flow
augmentation).
Wells would be installed
before mining commences
and be monitored throughout
mining and recharge
Well 1: east of the
mine on private
land (Stratton
family-Humbug
claim)
Well 2: on private
land (Stratton
family-Highland
flume claim) near
WS-3
Stream Flow
Supplementation:
Fish Creek
Concern that mine
dewatering may affect
base flow conditions in
Fish Creek. Dewatering
is predicted to reduce
flows in Fish Creek by
BHJV would secure up to 25 gpm of water
from the Butte-Silver Bow Emerald Lake
aqueduct that crosses Fish Creek. BSB
will complete a change application to
request this POU from DNRC. The water
would be used to supplement flows in
During mining and post
closure until the groundwater
recharges to elevation of
historic Highland adit at
7,339 ft (Estimated at 7 to 8
years post-closure)
A short pipeline
would be built on
patented land near
WS-3 to carry
water from the
aqueduct to Fish
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Resource Area
Issues or Comments
Addressed
Mitigation Duration Location
14 gpm and 12 gpm at
stations WS-3 and WS-
5, respectively.
Fish Creek if reductions occur. a Creek
Basin Creek
Groundwater Need for information on
how mine dewatering
will affect groundwater
in the vicinity of Basin
Creek
Installation of well BHMW-13-001 and
monitoring of groundwater levels and
periodic water quality sampling.c
New well is currently in
place. During mining and
post closure until the
groundwater recharges to
elevation of historic Highland
adit (Estimated at 7 to 8
years post-closure)
NW corner of the
Northern Claims
parcels
Stream Flow in
Basin Creek
Concern that installing
the hydraulic plug in the
historic Highland adit
will reduce surface
flows in Basin Creek in
the upper Basin Creek
drainage.
Compensatory mitigation on Blacktail
Creek along Roosevelt Drive would
include improving three to five stream
crossings to reduce sediment input and 3
crossings to provide aquatic organism
passage. a,d
BHJV would install one monitoring flow
weir on Basin Creek. a
Stream crossing and
sediment control structures
would be designed as
permanent features of the
roadway.
Weir would be monitored per
the water quality monitoring
plan throughout life of the
mine.
Please see Figure
2.8-1 for culvert
and stream
crossing
improvement
locations.
Weir would be
installed one mile
downstream of the
historic Highland
Adit on patented
land
Moose Creek
Groundwater
impacts to
Moose Creek
Concern that mine
dewatering may affect
base flow conditions in
Moose Creek
Installation of one additional monitoring
well to verify groundwater
compartmentalization due to the Range
Front Fault. a This would provide an early
indication of groundwater drawdown that
might influence streamflow
During mining and post
closure until the groundwater
recharges to elevation of
historic Highland adit at
7,339 ft. (Estimated at 7 to 8
years post-closure)
Immediately below
the mine surface
facilities, on east
side of Fish Creek
Road (FSR 8520),
west of the Range
Front Fault.
Potential impacts
to Surface Water
in Moose Creek
Concern that mine
dewatering may affect
the extent of the Moose
Creek wetlands in the
upper Moose Creek
Compensatory mitigation. BHJV would
replace five stream crossings along the
Highland Road within the broader Moose
Creek basin. Two crossings would
increase stream connectivity and aquatic
Improvements to the
Highland Road would
become permanent.
Please see Figure
2.8-2 for culvert
locations.
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BHJV Mine FEIS 58
December 2014
Resource Area
Issues or Comments
Addressed
Mitigation Duration Location
basin. organism passage, while three would
maintain wetland integrity. a,d
Outfalls 003 and 004 will release as much
as 60 gpm and 140 gpm, respectively
during mine dewatering per the MPDES
permit.b
During mine dewatering Outfall 003 is on
Middle Fork of
Moose Creek and
Outfall 004 is on a
tributary to the
Middle Fork of
Moose Creek
Documentation:
a BHJV Proposed Mitigation Memo October 7, 2014
b MPDES permit MT0031755 (Appendix A)
c BHJV Flow Mitigation Memo July 22, 2014
d Letter from FWP September 16, 2014
Table 2.8-4. A Summary of the Outfalls, Receiving Waters, and Associated Monitoring Sites.
Water body Basin Creek Fish Creek Middle Fork Moose
Creek, south branch
Middle Fork Moose
Creek, north branch
Outfall Outfall 001 Outfall 002 Outfall 004/Outfall 005 Outfall 003/Outfall 005
Issue
Surface Water Monitoring
(listed from upstream to
downstream position)
WS-1, WS-7 WS-5, WS-3 WS-9 WS-8, WS-6
Groundwater Monitoring New well installed 2013 BHJV would install 2
monitoring wells in upper
Fish Creek. One near WS-
3 and one farther upstream
near the Fish Creek Road
crossing.
New well to be installed Same as Moose Creek
Water Quantity during
Mine Dewatering
Outfall discharge
up to 350 gpm per MPDES
permit
BHJV would only construct
the MPDES Outfall in Fish
Creek if and when mine
dewatering requirements
Outfall discharge
Up to 140 gpm at Outfall
004 per MPDES permit, no
discharge at Outfall 005
Outfall discharge
Up to 60 gpm at Outfall
003 per MPDES permit
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Water body Basin Creek Fish Creek Middle Fork Moose
Creek, south branch
Middle Fork Moose
Creek, north branch
Outfall Outfall 001 Outfall 002 Outfall 004/Outfall 005 Outfall 003/Outfall 005
exceed 550 gpm. If
dewatering reduces
streamflow prior to
construction of the outfall,
streamflow would be
augmented from the
Butte-Silver Bow Emerald
Lake aqueduct as needed
Stream channel stability Annual monitoring Annual monitoring Annual monitoring
Water temperature MPDES suggests no
mitigation needed
MPDES suggests no
mitigation needed
MPDES suggests no
mitigation needed
MPDES suggests no
mitigation needed
Water quantity during
groundwater recovery
phase
Compensatory mitigation
on Blacktail Creek
crossings on Roosevelt
Drive
Water from Butte-Silver
Bow Emerald Lake
aqueduct as needed
Compensatory mitigation
on Moose Creek crossings
on Highland Road
Same as Moose Creek
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2.9 Related Future Actions
Currently, the only related future action that has the potential to affect the alternatives under
consideration is the parallel NEPA process that the Forest Service is completing for the portion
of the proposed haul route that crosses Forest Service lands. The Forest Service has issued its
Draft EA, but has not finalized a decision on the Plan of Operations. DEQ is in consultation with
the Beaverhead-Deerlodge National Forest, but DEQ’s approval of BHJV’s operating permit is
not contingent upon the Forest Service selecting a preferred haul route. The two agencies and
their respective environmental review processes are independent. DEQ is not aware of any
other relevant actions under review by another state agency with the potential to affect the
cumulative impacts of this action.
The City of Butte has discussed the potential for changes to the Basin Creek Reservoir and its
surface water intake and water treatment plant. This reservoir supplies part of Butte’s public
water supply. A new water treatment plant is currently being designed. MEPA requires that
related future actions may only be considered in an agency’s cumulative impacts analysis when
these actions are under concurrent consideration by any agency through pre-impact statement
studies, separate impact statement evaluations, or permit processing procedures (75-1-208(11),
MCA). This EIS will discuss the Forest Service EA’s review of the proposed haul routes as part
of the cumulative impacts assessment in Chapter 4.
2.10 Alternatives Considered But Dismissed
Under MEPA, a reasonable alternative is one that is practical, technically possible, and
economically feasible. In addition, any alternative under consideration must be able to meet the
purpose and need of the Proposed Action. During scoping, alternatives to the Proposed Action
were suggested and discussed by agency representatives and the BHJV. Alternatives covered
in this section include alternatives or alternative components that were considered and
eliminated from detailed study. For each alternative discussed, the agency includes a synopsis
of the changes proposed and a discussion of why the alternative or component was dismissed.
2.10.1 Determination of Ore Haulage Route
Several ore haul route alternatives were evaluated for moving ore from the mine to an off-site
milling facility where ore would be processed (Table 2.1-1). Three alternative haul routes were
carried forward and analyzed. Alternative routes that were considered but dismissed included:
1. Using the existing Highland Road in its entirety to access the Feely interchange at
Interstate 15;
2. Forest Service Road 668 (Fish Creek Road) northeast to Highway 2; and
3. Numerous other alternate routes using Forest Service, county, and private roads out of
the Highland Mountains.
BHJV has proposed using the Highland Road to Interstate 15 ore haul route. However, this
route was modified as it crossed private property west of the Forest Service boundary and east
of the highway due to easement restrictions of the existing county road. The modified route is
described in the Proposed Action and included in the operating permit application (BHJV, 2013).
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BHJV Mine FEIS 61
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Pertinent details of the dismissed routes are described below and the reasons for their removal
from consideration are provided.
2.10.1.1 Using the Existing Highland Road to Access the Feely Interchange
This route would have directed the ore haul trucks down Highland Road (and along the county
road) to the proposed transfer facility and on to Interstate 15 at the Feely Interchange. Because
BHJV was unable to resolve a conflict related to the road easement agreement among the
landowners and Butte-Silver Bow County, this alternative was removed from consideration.
2.10.1.2 Forest Service Road 668 (Fish Creek Road) to Highway 2
Proposed ore hauling on this route used 30-ton center-articulated trucks from the mine site via
Forest Service Road 8520 (Camp Creek Road), then Forest Service Road 668 (Fish Creek
Road) to a private ranch. Inside an existing ore transfer facility at the ranch, the ore would have
been off-loaded and reloaded onto highway-legal trucks. Highway-legal trucks would have
followed Cedar Hills Road, then Montana Highway 41 north to reach Montana Highway 2. This
route is about 45 miles in length.
Originally ore haulage out Forest Service Road 668 (Fish Creek Road) directly to Montana
Highway 2 was proposed; however, the Forest Service requested BHJV to haul across a ranch
on a private road and then on Cedar Hills Road. From April 2011 through June 2012 BHJV held
a lease with the ranch owners for ore haulage and transfer facilities. The lease was dropped
when it became obvious that this route would not be used.
Forest Service Road 668 (Fish Creek Road) was proposed to be widened to 16 feet with 22-foot
wide turnouts where needed for passing. The road surface would have been raised in areas
where it is lower than the surrounding ground and collects water. The road surface would have
been capped where boulders protrude through the existing road surface. Culverts and bridges
would have been replaced to meet aquatic criteria and Forest Service standards. All upgrades
would have been achieved by widening to the uphill side of the road, thus avoiding impacts to
the flood plain.
Cedar Hills Road, a dirt and gravel road, would have been rebuilt and maintained to
accommodate daily truck traffic. Dust control and road maintenance by BHJV would have been
required on the Forest Service Road 8520 (Camp Creek Road), Forest Service Road 668 (Fish
Creek Road), private roads, and Cedar Hills Road. Environmental impacts would have included
effects from road reconstruction. Road upgrades and repairs were roughly estimated at
$1,000,000 to $2,000,000. Haulage costs were estimated at $25 per ton. This route was
dropped due to a combination of length of travel, complexity of securing the route across
multiple public and private lands, potential environmental impacts to extensive wetlands and
streams, and high construction and haulage costs.
2.10.1.3 Other Ore Haul Routes
A number of other haul routes were considered but dismissed. The routes headed in various
directions away from the mine site. These routes were each dismissed on the basis of a number
of factors. These factors included but were not limited to:
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· The current poor condition, undersized, or otherwise inadequate roads;
· The relative amounts of sufficient road improvements to allow heavy truck traffic;
· The number of stream crossings (with suitable culverts to be installed); and
· The length of wetlands, streams, and riparian habitat that those roads traversed or
travelled alongside.
2.10.2 Highland Mine Adit Left Open
As an alternative to plugging the historic Highland Mine Adit that feeds into Basin Creek, leaving
the adit open and allowing mine water to flow out unimpeded was considered. However, BHJV
would be required to monitor water quality and to provide for long-term water treatment to
ensure that the water would meet nondegradation standards. Basin Creek is classified A-Closed
to protect the city of Butte water supply (ARM 17.30.621); This alternative was removed from
consideration because of the level of uncertainty related to water treatment needs.
2.10.3 Highland Mine Adit Plugged, but with Regulation Valve
Another alternative to plugging the adit with a concrete hydraulic plug would be to plug it with an
adjustable regulation valve. This alternative would allow BHJV to close off the adit if water
quality monitoring indicated that the outflow did not meet nondegradation standards. However,
the technology that would support such a valve has not been proven to be reliable, and if the
valve was not able to close off the entire flow, then additional excavation or retrofitting would be
needed to close off the adit completely. In addition, the Highland Mine adit is not currently
accessible from the surface. The historic adit would require great expense to access it from the
surface, while access would be available from the new mine workings after it is dewatered.
Because the adit plug would only be accessible from deep inside the mine workings, it would
not be accessible after mine closure or flooding. Therefore, adjusting the valve after mine
closure would not be possible. The uncertainty related to the reliability of this option led to its
dismissal. |
