17 East Main St. PO Box 431

White Sulphur Springs, MT 59645 Tel: (406) 547-3466

M E M O R A N D U M

DATE: October 29, 2018

TO: Rainie DeVaney

Jeff May

FROM: Jerry Zieg

SUBJECT: Addendum to Integrated Discharge Permit Application for the Black Butte

Copper Project

Tintina Montana, Inc. (Tintina) is submitting this memorandum as an addendum to the Integrated

Discharge Permit Application (Permit Application) for the Black Butte Copper Project (Project).

This addendum adds a contingency to the water management plan for storage of treated water

during the seasonal period when the total nitrogen standard is applied (July 1 to September 30,

for Middle Rockies Ecoregion). Below is a description of the water management plan for the

storage contingency, a description of the TWSP, and an update to the Storm Water Discharge

Systems.

Water Management Storage Contingency

Tintina is proposing to discharge water as described in the Integrated Discharge Permit

Application Narrative (Hydrometrics, 2018) if the discharge water meets the seasonal effluent

limits for total nitrogen in the MPDES permit. However, if the total nitrogen concentration is

greater than the effluent limit, the treated water will be discharged to the Treated Water Storage

Pond (TWSP) from July 1st to September 30

th. Starting October 1

st, the stored water will be

routed back to the WTP and blended with the WTP effluent prior to discharge to Outfall 001.

Prior to discharge the blended water will be sampled/monitored as required in the MPDES

permit. In the event that storage is necessary, the average seasonal discharge (October 1st to June

30th

) to Outfall 001 will be 531 gpm (133 gpm from the TWSP and 398 gpm from the WTP). An

updated water balance schematic (revised Figure 3.8) and contingency discharge schematic

(Figure 3.8A) is provided in Attachment A.

Treated Water Storage Pond Description

The TWSP will be located southeast of the WTP and west of Brush Creek as shown the revised

Figure 1.3 included in Attachment 1. The design of the TWSP was based on an average seasonal

flow rate from the WTP of 405 gpm. The average seasonal flow rate is slightly larger than the

average annual discharge due to minor differences in seasonal flows from Mill Catchment

Runoff associated with the seasonal precipitation and evaporation at the site. The TWSP has

been designed to store up to 53.7 million gallons of treated water, providing enough temporary

storage for treated water from July 1 to September 30 at an average flow rate of 405 gpm. The

pond will be lined with a 60 mil HDPE geomembrane liner installed over a 12 oz/yd2 non-woven

geotextile cushion. Treated water from the water treatment plant will be pumped through a 6-

inch (150mm) diameter HDPE pipeline to the TWSP. Water stored in the TWSP will then be

pumped back to the water treatment plant via a 6-inch (150mm) diameter HDPE pipeline, where

it will be mixed with the WTP effluent and allow for the blended water to be sampled prior to

being discharged per the MPDES permit.

Storm Water Discharge Systems Update

The addition of the TWSP requires updates to the site drainage controls and storm water permit.

The additional storm water controls include a runon control berm on the northwest portion of the

pond, drainage ditches along the remainder of the facility, and two storm water outfalls (Outfalls

012 and 013). An update to Figure 3.1 shows the storm water controls and outfalls for the

project. Storm water flows to each of the new outfalls were simulated using the same methods

and modeling software for the other outfalls (See Section 4.2 of permit). In addition, storm

water quality is assumed to be similar to that summarized in Section 4.3 of the permit. Below is

a description of the new drainage controls and a summary of the changes to the permit

application.

Storm water Outfall 012 discharges water from approximately 8.75 acres from areas south and

west of the TWSP. Discharge will include storm water from native lands and a portion of the

TWSP embankment (constructed from non-waste rock materials). Diversion ditches collect

runoff from the drainage areas and directs flow to the outfall. The storm water simulations

indicate that peak flow will be 9.72 cfs with a total runoff volume of 0.5 acre-feet during a 10-

year/24-hour storm event. A summary of the flow calculations and SEDCAD4 output are

provided in Attachment B.

Storm water discharges to Outfall 013 originate from 2.6 acres of the southern and western

portion of the vegetated TWSP embankment. Diversion ditches collect runoff from the drainage

areas and directs flow to the outfall. Storm water modeling simulated a peak flow of 1.76 cfs

with a total runoff volume of 0.1 acre-feet from a 10-year/24-hour storm event.

There is a small area (0.4 acres) of sheet flow from the vegetated embankment on the northeast

corner of the TWSP. The simulated peak flow for this area is estimated at 0.27 cfs with a total

volume of 0.01 acre-feet from a 10-year/24-hour storm event.

Outfalls 012 and 013 share a runon control structure along the northwest side of the TWSP. The

runon control structure will consist of a berm above the cut slope of the northwest portion of the

pond. The northeast corner of the TWSP embankment extends into a natural drainage channel.

The embankment will be protected from scouring via a riprap covering on the northeast corner

and a modified drainage channel as shown on revised Figure 3.1. The geometry of the diversion

channel will be similar to that shown on Figure 4.2 in the permit application.

The information for the two additional outfalls (012 and 013) required for Form 2F is provided

below:

I. Outfall Location

Outfall No. Latitude Longitude Receiving Water

012 46° 45' 58.68" 110° 54' 22.68" Brush Creek

013 46° 46' 2.28" 110° 54' 16.92" Brush Creek

II. Improvements

No additional information

III. Site Drainage Map

A revised Site Drainage Map (Figure 3.1) is included with this memorandum

IV. Narrative Description of Pollutant Sources

Outfall No. Area of Impervious Surface Total Drained Area

012 No Impervious Surface 8.75 acres

013 No Impervious Surface 2.60 acres

No additional information for Parts B and C.

V. Nonstormwater Discharges

Not Applicable

VI. Significant Leaks or Spills

ATTACHMENT A

REVISED FIGURES

1800

1805

1810

1745

1735

1725

1750

1740

1730

1795

1785

1775

1765

1755

1790

1780

1770

1760

1865

1855

1845

1835

1825

1870

1860

1850

1840

1830

1815

1820

1815

1805

1795

1785

1775

1765

1755

1745

173518

20

1810

1800

1790

1780

1770

1760

1750

1740

1730

1785

17751765

1790

17801770

1735

1740

1730

1795

1785

1775

1800

1790

1780

17601765

1770177517801785

1755

N 5,178,500E 5

10

,0

00

N 5,181,000E 5

08

,5

00

N 5,178,500E 5

08

,5

00

N 5,181,000E 5

06

,0

00

N 5,178,500E 5

06

,0

00

N 5,181,000E 5

10

,0

00

2019

24

29

30

25

36

31

32

T12N

R

6E

T12N

R

7E

STRAWBERRYBUTTE

RECLAMATIONMATERIALSSTOCKPILE

SOUTH

FIBER-OPTIC VAULT LOCATION

PORTAL

PORTAL PAD(EL. 1785 m)

ADIT ALIGNMENTPROJECTED TO SURFACE

NON-CONTACT WATERRESERVOIR (NCWR)

CEMENT TAILINGSFACILITY (CTF)

CTF DIVERSION DITCHING

FIBER-OPTIC VAULT LOCATION

CONTACT WATER POND (CWP)

POWER LINE AND PIPINGTO WATER WELL (PW-6)

TOPSOILSTOCKPILE

SUBSOIL STOCKPILE

BURIED SOLID PIPE (TYP.)

BURIED PERFORATED PIPE (TYP.)

APPROX. TOP OF CUTOR TOE OF FILLS (TYP.)

POWER LINE

VENT RAISE (TYP.)

CULVERT CROSSING 5

CULVERTCROSSING

CULVERT CROSSINGCULVERT CROSSING

ACCESS ROAD

PROCESS WATERPOND (PWP)

SERVICE ROAD

CONSTRUCTION ACCESSROAD AND CULVERT

ACCESS GATE

CULVERT CROSSING

COPPER-ENRICHEDROCK STOCKPILE

TEMP. WASTE ROCK STORAGE(EL. 1792.98 m)

MILL PAD(EL. 1785 m)

EXTEND EXISTINGROAD TO VENT RAISE

CONNECT EXISTINGROAD TO VENT RAISE

NCWR DIVERSIONDITCHING

SERVICE ROADPWP DIVERSION

DITCHING

APPROXIMATE AREA FORRECLAMATION MATERIAL

STOCKPILE NORTH

TEMP. POWDER MAGAZINEFOUNDATIONDRAIN POND

FOUNDATIONDRAIN POND

CORE SHACKS

COON CREEK

SPILLWAY

US 89

MINE PERMIT BOUNDARY(APPROXIMATE)

CTF ROAD

MINE PERMIT BOUNDARY(APPROXIMATE)

FENCING

ALLUVIAL UIG

SEPTIC DRAINFIELD

METEOROLOGICAL STATION

SHEEP CREEK

LITTLE SHEEP CREEK

SHEEP CREEK COUNTY ROADBUTTE CREEKCOUNTY ROAD

BRUSH CREEK

SECONDARY ESCAPEWAYACCESS ROUTE TOWATER WELL (PW-6)

BURIED PERFORATEDUIG PIPE (IN CLOSURE)

JAW CRUSHERCONVEYOR

TEMP. CONSTRUCTION STOCKPILE

UCZ PROJECTED TO SURFACE

LCZ PROJECTED TO SURFACE

CULVERT CROSSING

CULVERTCROSSING

CULVERT CROSSING

TREATED WATERSTORAGE POND (TWSP)

FOUNDATION DRAININFILTRATION POND

WET WELL PIPELINE

BURIED WET WELL PIPELINE

FIGURE 1.3Facilities Site Plan

Black Butte Copper Project

Mine Operating Permit Application

Meagher County, Montana

0 250Scale: 1: 15 000 (metres)

500

N 1,000E 1

,0

00

LEGEND

Prepared by Tetra Tech Inc. (Revised October 2018 to include alluvial UIG as included in the December 2018 Integrated Discharge Permit Application Narrative Report by Hydrometrics that was revised in February 2018; Completeness Determination by MT DEQ on May 25, 2018.)

STREAMS

WETLANDS

POWER LINE ROUTEAPPROX. TOES / TOP OF CUT

CULVERT CROSSING

MINE PERMIT BOUNDARY (APPROX.)

NEW FENCE

BURIED ALLUVIAL CONVEYANCE PIPELINE

COUNTY ROAD

NEW MINE ROAD

VENT RAISEWATER WELL

UTM Z12N NAD83 COORDINATES

US ROUTE 89

DIVERSION DITCH

WETLANDS (OUTSIDE PROJECT BOUNDARY: SEENOTE BELOW)

Some streams and wetlands shown outside of the project boundarywere determined via photo-interpretation and were not delineatedaccording to USACE methodology. These features are presented fordisplay purposes only and do not represent jurisdictional features.

Streams within the project boundary represent jurisdictional featuresthat were determined during field inventory to have an ordinary highwater mark (OHWM) consistent with 33 CFR § 328.3.

Topographic base map from US Geological Survey (2011):Strawberry Butte 7.5 Minute Quadrangle.Map Projection: UTM Zone 12NMap Datum: NAD83Contour Interval: 5m

SECTION NUMBER32

SECTION LINEPRIVATE ROAD

BURIED WATER LINE

FOUNDATION DRAIN POND

Scale: 1" = 1250'0 1250625

STREAMS (OUTSIDE PROJECT BOUNDARY: SEENOTE BELOW)

ALLUVIAL INFILTRATION TRENCH

BURIED UNDERGROUND INFILTRATION GALLERY(UIG) - SOLID PIPE IN CLOSURE

WET WELL PIPELINEBURIED WET WELL PIPELINE

DRY

WATER TANK

5,000 GAL

OFFICE

SHOP

PARKING

WPDSL

LAYDOWN

AREA

WATER WELL

EQUIP

PRKG

CO

NE

X

PASTE PLANT

TRUCK SHOP COMPLEX

W.T.P.

THICKENER

MOBILE GEN

SETS

BATCH

PLANT

OFF/WASH DRY

CONC.

THICKENER

CONC.

STORAGE

PROCESS

PLANT

FLY ASH/SLAG SILOS

DIESEL STORAGE 50kL CAP.CONTAINMENT BERM

REFUELING STA

PROC. WAT. TANK

FRESH/FIRE WAT. TANK

POTABLE WAT. TANK

SURGE BIN

EMERGENCYGENSETS

CONVEYOR

SUB

STATION

RECLAMATIONMATERIALSSTOCKPILE

SOUTH

FIBER-OPTIC VAULT LOCATION

PORTALPORTAL PAD(EL. 1785 m)

ADIT ALIGNMENTPROJECTED TO SURFACE

NON-CONTACT WATERRESERVOIR (NCWR)

CEMENT TAILINGSFACILITY (CTF)

CTF DIVERSION DITCHING

FIBER-OPTIC VAULT LOCATION

CONTACT WATER POND (CWP)

POWER LINE AND PIPINGTO WATER WELL (PW-6)

TOPSOILSTOCKPILE

SUBSOILSTOCKPILE

APPROX. TOP OF CUTOR TOE OF FILLS (TYP.)

VENT RAISE (TYP.)

CULVERT CROSSING 5

CULVERTCROSSING 4

CULVERT CROSSING 1CULVERT CROSSING 2

ACCESS ROAD

PROCESS WATERPOND (PWP)

SERVICE ROAD

CONSTRUCTIONACCESS ROAD

CULVERT

ACCESS GATE

CULVERT CROSSING 3

COPPER-ENRICHEDROCK STOCKPILE

TEMP. WASTE ROCKSTORAGE

(EL. 1792.98 m)

MILL PAD(EL. 1785 m)

EXTEND EXISTINGROAD TO VENT RAISE

CONNECT EXISTINGROAD TO VENT RAISE

NCWR DIVERSIONDITCHING

SERVICE ROAD

PWP DIVERSIONDITCHING

APPROXIMATE AREA FORRECLAMATION MATERIAL

STOCKPILE NORTH

TEMP. POWDER MAGAZINE

FOUNDATIONDRAIN POND

FOUNDATIONDRAIN POND

CORE SHACKS

SPILLWAY

CTF ROAD

MINE PERMIT BOUNDARY(APPROXIMATE)

E 5

10

,0

00

N 5,178,500E 5

08

,5

00

N 5,178,500E 5

06

,0

00

SEPTIC DRAINFIELD

METEOROLOGICAL STATION

SHEEP CREEK

SHEEP CREEK ROADBUTTE CREEK ROAD

29

30

25

36

31

32

T12N

R

6E

T12N

R

7E

ACCESS ROUTE TOWATER WELL (PW-6)

STRAWBERRYBUTTE

TEMP. CONSTRUCTIONSTOCKPILE

CULVERTCROSSING

CULVERTCROSSING

ROCK-LINEDCHANNEL

ROCK-LINEDCHANNEL

ALLUVIAL UIG

B

R

U

S

H

C

R

E

E

K

L

I

T

T

L

E

S

H

E

E

P

S

H

E

E

P

C

R

E

E

K

S

H

E

E

P

C

R

E

E

K

L

IT

T

L

E

S

H

E

E

P

C

R

E

E

K

004

002

007

006

003

009

010

005

C

O

O

N

C

R

E

E

K

2

5

.

1

1

5

.

7

1

.

2

9

.

3

4

.

3

4

9

.

2

1.4

1.3

0.7

28724.638

1.3

4

.

0

2

.

1

6

.

3

1.5

2

.

4

1

.

7

8.0

7.5

7.0

3

1

.

3

1.3

1.7

1

0

.

0

2.0

0.9

7

.

7

0.3

0.4

0.5

6

.

2

3

.

4

CULVERTCROSSING

C

R

E

E

K

008

011

001

BURIED SOLIDPIPE (TYP.) BURIED PERFORATED

PIPE (TYP.)

APPROX. TOP OF CUTOR TOE OF FILLS (TYP.)

MINE PERMIT BOUNDARY(APPROXIMATE)

BURIED PERFORATEDUIG PIPE (IN CLOSURE)

JAW CRUSHER

CONVEYOR

TREATED WATERSTORAGE POND (TWSP)

FOUNDATION DRAININFILTRATION POND WET WELL PIPELINE

BURIED WET WELL PIPELINE

RUNONCONTROL

BERM

RUNOFFCONTROL

DITCH

2

.

6

2

.

7

6

.

0

0

.

4

012

013

NO

RT

H

LEGENDMINE PERMIT BOUNDARY (APPROX.)

BURIED ALLUVIAL CONVEYANCE PIPELINEDISTRIBUTION PIPE UNDER WETLAND INFILTRATION TRENCH

EROSION CONTROL DRAINAGE

DITCH

CTF DIVERSION DITCH

CATCHMENT BOUNDARYUS 89US 89

CULVERTMPDES OUTFALL

STORMWATER OUTFALL

INTERNAL DRAINAGE TO WATERN 5,178,500TREATMENT PLANT (WTP)STORM WATER CAPTURE AREAS DRAINAGE DIVIDE AND FLOW DIRECTIONROAD SEGMENT OR STOCKPILE ACRES DRAINAGE AREA ACRESGENERAL DRAINAGE FLOW DIRECTION

MPDES and Storm Water Discharge Systems

Black Butte Copper Project

Meagher County, Montana

Figure 3.1

7

.

8

1.2

SCALE0

(In Feet)

1050

Mine Portal

Water TreatmentPlant

Process Water Pond(PWP)

Mill

Water with Concentrate

Tailings PastePlant Underground

Infiltration Galleries

UndergroundTailings Storage

Cemented TailingsFacility (CTF)

MillCatchment

Runoff

86.4 gpm 103 gpm

Ore Water24.1 gpm

7.0 gpm

13.1 gpm

5 gpm

42.2 gpm

8 gpm

Treated Water397.7 gpm

189.4 gpm

Mill Water42.4 gpm

UndergroundDewatering500 gpm

1,912.1 gpm

Foundation Drain

20 gpm

RO Brine83 gpm

24.6 gpm

Recycle 14.6 gpm

FreshwaterUses

2,042 gpm

(~90% Recycled)

PrecipitationTransfer

42.2 gpm

NOTES:1. WATER IN TAILINGS PASTE IS ASSUMED TO BE UNRECOVERABLE.2. SEEPAGE IS ASSUMED TO BE ZERO AS THE FACILITIES ARE LINED.3. THE NUMBERS IN THE BOXES CORRESPOND TO TABLE V-1 IN APPENDIX V.Reference: Modified after Knight Piesold (2017a): Report No. VA101-46-/3-2

Unused Freshwater4.5 gpm

8 gpm

FreshwaterLosses5.5 gpm

9

10

12

1

15

17

16

13

2

14 768

5 4

18

19

gpm acre-ft/year

PWP Evaporation 8 13

CTF Void Loss 103 166

Underground Tailings Void Loss 86 139

Water Loss to Concentrate 7 11

Freshwater Losses 6 9

Total Consumptive Use 210 339

Estimated Groundwater Consumptive Use Components

Water use

Consumptive Use

Runoff Precipitation Evaporation

Precipitation

Treated WaterStorage Pond

Details shown on Figure 3.8A

FIGURE 3.8Annual Water Balance Schematic for Mean Case - Year 6

Mine Operating Permit ApplicationBlack Butte Copper Project

Meagher County, Montana

Direct Discharge to UIG Storage with Seasonal Discharge

Treated Water3397 gpm

1333

gpm

Total Discharge3530 gpm

Water TreatmentPlant

UndergroundInfiltration Galleries

(UIG)

Treated Water1397.7 gpm

FIGURE 3.8AMPDES Discharge

Mine Operating Permit ApplicationBlack Butte Copper Project

Meagher County, Montana

Water TreatmentPlant

UndergroundInfiltration Galleries

(UIG)

Treated WaterStorage Pond

(TWSP)

3972gpm

NOTES:1. If effluent total nitrogen concentration is < seasonal effluent limit water will be discharged to UIG continuously.2. If effluent total nitrogen concentration is > seasonal effluent limit water will be stored in TWSP from 7/1 to 9/30.3. Water will be discharged from TWSP by blending water with WTP effluent at an average rate of 530 gpm.

ATTACHMENT B

FLOW CALULATIONS AND SEDCAD4 OUTPUT

SF-03

Drainage Areas 1 2 3 1 2 1

Total Acres 6.01 1.95 0.79 0.90 1.70 0.40

Channel Flow*

Slope % 15.3 21.1 10.7 11.4 5.6Horizontal Distance (ft) 392.0 202.0 299.4 317.0 750.0Vertical Distance (ft) 60.0 42.6 32.0 36.0 42.0Time (hr) 0.1 0.0 0.0 0.0 0.0

Hydraulic Soil Group P(D) CF (B) CF (B) CF (B) CF (B) CF (B)Vegetation Type Shrubland Grass Cover Grass Cover Grass Cover Grass Cover Grass Cover

Upland Flow ***

CN 83 73 73 73 73 73

Slope % 7.6 33.3 31.4 30.8 25.9 32.8Horizontal Distance (ft) 105.0 64.0 68.0 64 57 65Vertical Distance (ft) 8.0 21.3 21.3 20 15 21S (in) 2.0 3.7 3.7 3.699 3.699 3.699Time (hr) 0.029 0.013 0.014 0.013 0.013 0.013Tc (Total) 0.084 0.021 0.030 0.030 0.033 0.013

Time of Concentration

Compacted Fill

Outfall 012 Outfall 013

Soil Type (1)Poin Compacted

FillCompacted

FillCompacted

FillCompacted

Fill

Subwatershed Hydrology Detail:

Stru#

SWS#

SWS Area

(ac)

Time ofConc

(hrs)

Musk K

(hrs)Musk X

Curve

NumberUHS

PeakDischarge

(cfs)

RunoffVolume

(ac-ft)

#1 1 6.010 0.084 0.085 0.346 83.000 S 9.18 0.447

2 1.950 0.021 0.000 0.000 73.000 S 1.32 0.073

3 0.790 0.030 0.000 0.000 73.000 S 0.54 0.027

8.750 9.72 0.547

#2 8.750 9.72 0.547

Filename: S012.sc4 Printed 10-24-2018

SEDCAD 4 for WindowsCopyright 1998 -2010 Pamela J. SchwabCivil Software Design, LLC 1

Subwatershed Hydrology Detail:Stru#

SWS#

SWS Area

(ac)

Time ofConc

(hrs)

Musk K

(hrs)Musk X

Curve

NumberUHS

PeakDischarge

(cfs)

RunoffVolume

(ac-ft)

#1 1 0.900 0.030 0.000 0.000 73.000 S 0.61 0.033

2 1.700 0.033 0.000 0.000 73.000 S 1.15 0.064

2.600 1.76 0.097

#2 2.600 1.76 0.097

Filename: S013.sc4 Printed 10-24-2018

SEDCAD 4 for WindowsCopyright 1998 -2010 Pamela J. SchwabCivil Software Design, LLC 1

013

Subwatershed Hydrology Detail:Stru#

SWS#

SWS Area

(ac)

Time ofConc

(hrs)

Musk K

(hrs)Musk X

Curve

NumberUHS

PeakDischarge

(cfs)

RunoffVolume

(ac-ft)

#1 1 0.400 0.013 0.000 0.000 73.000 S 0.27 0.011

0.400 0.27 0.011

#2 0.400 0.27 0.011

Filename: SF-3.sc4 Printed 10-24-2018

SEDCAD 4 for WindowsCopyright 1998 -2010 Pamela J. SchwabCivil Software Design, LLC 1

SF-0