letter transmits attached butte mine flooding site consent ... · a bp affiliated company mr....

Montana Resources

600 Shields Ave. Butte, Montana USA 59701 59701 (406) 496-3200 (406) 723-9542 fax www.montanaresources.com

August 11, 2016

Certified Mail Mr. Henry Elsen, Esquire U.S. EPA Region VIII, Montana Office

Baucus Federal Building IO West 15th Street, Suite 3200 Helena, Montana 59626

Certified Mail Mr. Nikia Greene, Remedial Project Manager US EPA Region VIII, Montana Office

Federal Building 10 West 151h Street, Suite 3200

Helena, Montana 59626

bp

Certified Mail

317 Anaconda Road Butte, MT 59701

Main (406) 782-9964 Fax (406) 782-9980

A BP affiliated company

Mr. Jonathan Morgan, Esquire Legal Counsel

Mine Flooding CERCLA Site Montana Department of Environmental Quality P.O. Box 200901 Helena, Montana 59620-0901

Ce11ified Mail Mr. Daryl Reed, State Project Officer Montana Department of Environmental Quality

State of Montana

Phoenix Building, P.O. Box 200901

Helena, Montana 59620-0901

Re: BUTTE MINE FLOODING SITE CD, CV 02-35 Bu-RFC, 2016 Second Quarter Report

Dear Mr. Morgan, Mr. Elsen, Mr. Greene and Mr. Reed:

The Settling Defendants (Atlantic Richfield Company and the MR Group, as defined in the Consent Decree) continue to implement the remedial action requirements as specified in the Statement of Work to the Consent Decree. The attached report summarizes those activities conducted during the second quarter of 2016.

Please contact us if you would like to discuss this BMFOU Quarterly Report.

On behalf of the Settling Defendants,

;#1~ Mark Thompson ~ Manager of Environmental Affairs

Montana Resources LLP

600 Shields A venue

Butte, MT 59701

Tim Hilmo, P.E.

Operations Project Manager

Remediation Management Services Company

An affiliate of Atlantic Richfield Company

317 Anaconda Road

Butte, MT 59701

Lhallaue

Text Box

1551569 - R8 SDMS

CC: Rebecca Summerville, Esq. Datsopoulos, MacDonald, and Lind P.C. (email copy) Steve Walsh, MR (email copy)

File

Cord Harris, AR (email copy) Lorri Birkenbuel, AR (email copy) Irene Montero, AR (email copy) Jean Maitin, AR (email copy) John Davis, Esq. Poore, Roth and Robinson P.C. (email copy) Bill Duffy Esq., Davis Graham and Stubbs, LLP (email copy) Terence E. Duaime, MBMG (email copy) Jim Jonas, Copper Environmental (email copy) Don Booth, Booth Consulting (email copy) Joe Vranka, EPA (email copy)

[email protected]

Attachments

SETTLING DEFENDANTS BMFOU QUARTERLY REPORT CONSENT DECREE FOR THE

BUTTE MINE FLOODING SITE CD, CV 02-35 Bu-RFC REMEDIAL ACTION -IMPLEMENTATION OF THE REMEDY

QUARTER 2, 2016

The Settling Defendants 1 continue to implement the remedial action requirements specified in the Statement of Work to the Consent Decree. This report summarizes those activities conducted during the second quarter of 2016 as required under section X. Reporting Requirements, Paragraphs 31and 35 of the Consent Decree. The headings (a-g) in the following report correspond to the categories identified in paragraph 31. The sections captioned Issues Encountered and Other have been added at the request of the EPA.

a) Actions Taken Toward Achieving Compliance with the Consent Decree

To achieve compliance with the Consent Decree, the Settling Defendants conducted remedial action activities under the seven components identified in the Statement of Work for Remedial Design/Remedial Action ("SOW") which is part of the Consent Decree. These seven components and the remedial action activities undertaken by the Settling Defendants (hereinafter referred to as "SDs") in the second quarter of this year include:

1. Monitoring Program -The Montana Bureau of Mines and Geology ("MBMG") conducted monitoring activities as required by the SOW with the exception of the semi-annual Berkeley Pit water quality sampling program. A rotational slump of the highwall in the southeast sector of the Berkeley Pit occurred on February 8, 2013. This slope failure and the potential of continuing slope instability in the eastern sector of the Berkeley Pit has created a safety issue for persons entering the Berkeley Pit including persons who enter the Pit to collect water quality samples and conduct other components of the Remedial Action. At the request of the Agencies, the SDs are evaluating the necessity for near-term water quality sampling of the Berkeley Pit and potential safe alternative sampling methods and migratory waterfowl mitigation efforts. The SDs have entered into an agreement with Montana Tech to investigate and construct a remotely operated "drone" sampling platform for the Berkeley Pit. Field testing of this technology is currently being undertaken.

1 The term Settling Defendants as used in this report collectively refers to Atlantic Richfield Company, Montana

Resources, Inc., Montana Resources LLP, and Dennis Washington.

BMFOU Quarterly Report Quarter 2, 2016 August 11, 2016

Page 2

Further infonnation about slope stability has been developed by the STRATA Geotechnical consulting firm. STRATA completed the scope of work for the BMFOU Berkeley Pit Slope Stability Evaluation ("Evaluation") and the Report was submitted to the agencies on August 15, 2014. The SDs received Agency

comments on the Evaluation on November 6, 2014. The SD's response document was submitted on October 22, 2015. The agencies issued final approval of the report on April 11, 2016.

During Q2 2016 no significant slope failures occurred within the Berkeley Pit.

The SDs are continuing to formulate the concepts to safely enable resumed water sampling, and potentially on-water waterfowl mitigation activities, while mitigating risk to personnel, as discussed above.

No1mal waterfowl mitigation efforts continue according to plan; only on-water inspections have been suspended.

The SDs provided access to the MBMG personnel to conduct monitoring.

2. Public Education and Involvement - The SDs are represented on the Berkeley Pit Public Education Committee which directs the publication of the PITWatch and the

website www.PITW ATCH.ORG. These are the primary vehicles for educating the public about BMFOU status and activities. A PITWatch magazine was published during Q3 2015.

3. Horseshoe Bend ("HsB") Inflow Control- The SOW requires integration of the HsB flow into mine operations and/or release of treated water into Silver Bow Creek.

Since the issuance of the ROD in 1994 and integration of treated HsB water into the mining and milling process on April 15, 1996, the flow has become an integral part of

the water balance for efficient active mining and milling operations at Montana Resources, LLP ("MR"). Treated HsBWTP water has been integrated into MR's milling water circuit since the HsBWTP was commissioned in November 2003.

During the quarter, approximately 340,000 gallons of HsB flow was bypassed to the

Berkeley Pit:

• Approximately 120,000 gallons on May 11, 2016 due to an obstruction in the

inlet pipe to the equalization basin;


Page 3

• Approximately 220,000 gallons on May 19, 2016 due to a planned shutdown of the mill requiring a shutdown of the HsBWTP.

Stage 2 of the HsBWTP was bypassed and taken out of service for annual maintenance on May 19, 2016. The WTP operated in single stage mode for the remainder of the quarter.

In 2015, the SDs in consultation with MBMG perfonned maintenance on the HsB Drainage weir directly upstream of the HsBWTP diversion structure. The maintenance increased the accuracy of the weir. A summary memorandum

documenting the maintenance activities completed is anticipated to be submitted to the agencies on August 11, 2016.

Punch list items from Swank Enterprises' work to implement piping maintenance to increase the WTP flow capacity were completed in QI 2016. A summary memorandum documenting the piping maintenance activities completed is anticipated to be submitted to the agencies on August 11, 2016. Significant maintenance activities completed during the quarter include:

• Motor replaced on south slaker paddle shafts;

• Motor replaced on south slaker feeder;

• New motor installed on effluent pump #113;

e North slurry pump # 2 replaced;

• Discharge line from the 1st stage alkalization tank descaled;

• New pinch valve installed on the downstream side of the 2nd stage recycle

line flow meter;

• New pressure gauges installed on the influent and effluent pumps;

• Grit conveyor on north slaker rebuilt (new bearings, shafts, sprockets,

chain and paddles);

• New drive installed on polymer pump No. 1;

e Line entering the equilization pond jetted;

Efforts continue to control groundwater levels in the vicinity of the HsBWTP.

Engineering controls operated during the second quarter and continued to regulate the groundwater level in the area of the HsBWTP. Please refer to Attachment 1 of this

report for the Groundwater Level Reduction Summary Report.

4. HsB Water Treatment Plant Upgrade/Sludge Repository- The SDs have initiated

the Horseshoe Bend Water Treatment Plant Remedial Action Adequacy Review to


Page4

ensure that ongoing and future remedial activities will meet the requirements of the CD. The Draft Site Activity Schedule for the HsBWTP Remedial Action Adequacy Review ("RAAR") was submitted on June 30, 2014 and approved by the Agencies on September 11, 2014. The Scope of Work ("SoW") for the RAAR was subsequently prepared to evaluate four primary tasks with appropriate subtasks. The comprehensive list of activities in the schedule was identified to meet the milestones required in the CD and also to complete important precursor activities to meet those requirements to ensure continued protectiveness of the remedy. The schedule and scope of work also respond to the issues raised by the Agencies in the February 20, 2014 letter to the SDs regarding the Agencies response to the BMFOU Five-Year Review Issues. The RAAR contractor will periodically update the detailed schedule as needed.

The primary tasks in the RAAR include:

Task 1. HsBWTP O&M Optimization:

• Short term optimization;

• Long term optimization; and,

• Optimization with various source water quality and quantity. Task 2. BMFOU Site-wide Water Balance Study:

• Base case - current and historical conditions;

• Future conditions - predictive analysis; and,

• Integrate water quality into predictive water balance. Task 3. Potential Pilot Studies Evaluation:

• Sludge disposal alternatives;

• Alternate influent sources; and,

• Alternative treatment enhancements. Task 4. Technical Memorandum Preparation.

The SD's selected Golder as the RAAR consulting firm in May 2015 and provided a statement of qualifications to the Agencies of the firm selected. On May 20, 2015, the Agencies approved Golder as a "Supervising Contractor" pursuant to the Consent Decree, Section VI. PERFORMANCE OF THE WORK BY THE SETTLING DEFENDANTS, Paragraph 10, Selection of Supervising Contractors. Golder submitted, on behalf of the SD's, on November 13, 2015 the HsBWTP Short-term Optimization Work Plan. The agencies approved the work plan on February 16, 2016.


Page 5

The Explanation of Significant Differences, Appendix A to the CD allows for placement of sludge into the Berkeley Pit. During Q2, all of the sludge generated by the HsBWTP was placed into the Berkeley Pit (see Table in Section 7b). The evaluation of sludge disposal in the Berkeley Pit is also included as an activity on the RAAR schedule.

5. West Camp System - During the second quarter of 2016, approximately 16.9 million gallons of water were pumped from the West Camp pump station to the Lower Area One (LAO) for treatment in the Butte Treatment Lagoons (BTL) system. Operators of the BTL maintained normal operating levels the entire quarter. The water level at the end of the quarter was 5420.95 (NGVD29).

6. Waterfowl Mitigation - During the repo1iing period, the SDs conducted monitoring, active and passive hazing efforts and reporting as required by the Berkeley Pit Migratory Waterfowl Mitigation Plan, (Exhibit 5 to the CD), but did not perform any on-water activities. The SDs continued to perform waterfowl mitigation efforts under the variance from this requirement of the Waterfowl Mitigation Plan.

The SDs submitted the March, April and May, 2016 Berkeley Pit Migratory Waterfowl Mitigation Monthly Reports, which included the Observation and Hazing logs as attachments to the report letters. Please see these reports for a description of the detail of mitigation efforts.

7. Institutional Controls -Full SD compliance with this component of the RA SOW was completed by funding provided in 2002 by the SDs past and future cost cash out provisions of the Consent Decree. The Butte Alluvial and Bedrock Controlled Ground Water Area ("BABCGWA") was established by the MT DNRC in October 2009 with Butte-Silver Bow as the petitioner. Implementation and monitoring of the BABCGWA was assigned to the MBMG and funding from the SDs cash out amount that was provided in 2002. The outer perimeter of the area was determined and covers approximately 8.11 square miles. Please see the Butte Mine Flooding Operable Unit, Water-Level Monitoring and Water-Quality Sampling, 2012 Consent Decree Update, 1982-2012 (MBMG, September 2013) and consult Mr. Terrence E. Duaime, Project Manager of the Montana Bureau of Mines and Geology for more detailed information.

Access - The SDs have fully complied with the CD requirement to provide access to the Agencies.


The SDs provided access to the MBMG personnel to conduct monitoring.

Page 6

b) Summarv of all results of sampling and tests and all other data generated in the previous quarter

The following table summarizes the performance of the HsBWTP in Quarter 2 2016 and in total for the year to date:

Period Influent HsB Sludge Lime Average Average (MG) Plant Wasted Delivered Influent Flow Lime Usage

Water2 (MG) (tons) (MGD) (mg/L) (MG)

Quarter 1 427 469 17 3,745 4.7 2,117 Quarter2 410 444 21 4,613 4.5 2,705 Quarter3

Quarter4

YTD 837 913 38 8,358 4.6 2,411

HsBWTP water is sampled at multiple locations including the HsBWTP influent and, Stage 1 Clarifier overflow (during 2 stage operation), and Plant Water (Mill influent formerly named plant effluent). These data will be utilized in the RAAR HsBWTP Optimization currently ongoing. The testing demonstrates that the current operation of the HsBWTP satisfactorily complies with the requirement of the CD to treat HsB water that is to be incorporated in MR's milling circuit.

In the vicinity of the HsBWTP, engineering controls associated with groundwater monitoring and dewatering to manage the groundwater elevation continued to operate. Please see Attachment 1 to this report.

c) Identify all work plans and other deliverables required by this Consent Decree completed and submitted in the previous quarter

No work plans were completed or submitted in the previous quarter.

2 The treated HsB water that is used in MR's milling process as required by the CD will be referred to as "HsB Plant Water" instead of the previously used term "effluent." This semantics change has been made to distinguish between effluent that will be treated to the discharge standards stipulated in the CD SOW and plant water that is treated to standards for inclusion into MR's milling process.


Page 7

d) Describe all actions, data collection and implementation or work plans that may be required under this CD scheduled for the next quarter and provide other information relating to the progress of the work

RA Activity - The RA activity required in this section is congruent with that reported at the beginning of this document and is aligned with the seven general components of the SOW and RA. The inclusion of an eighth component to follow the RAAR required by the SOW has been added as an additional activity for the next quarter. The second quarter 2016 anticipated activity summary is as follows:

1. The Monitoring Plan will continue to be implemented during the next quarter, with the exception of sampling the Berkeley Pit, and the SDs will continue to provide access, cooperation and any assistance to the MBMG requested in performing this task. SDs will continue to pursue safe methods of sampling the Berkeley Pit by progressing the remote sampling platform.

2. The SDs will provide information to the Agencies as requested and participate in any public education meetings or activities that the Agencies deem necessary to fulfill this requirement of the CD.

3. The HsBWTP will continue to operate in the next quarter with the goal of capturing and treating all of the flow emanating from the HsB area. The Inflow Control requirement will continue to be met with all of the HsBWTP treated water being integrated into the mining and milling operations.

It is anticipated that the annual maintenance for both HsBWTP Stages will be completed during Q3 2016.

4. Operation of the dewatering system around the HsBWTP will continue.

5. The HsBWTP Short-term Optimization draft Technical Memo will be prepared for submittal in Q3.

6. It is anticipated that the RAAR Work Plan for the Water Balance will be submitted to the Agencies in Q3.

7. Sludge from the HsBWTP will continue to be placed into the Berkeley Pit during the next quarter.


Page 8

8. Submittal of memoranda summarizing the completed maintenance activities on the MBMG weir and the underground ping at the HsBWTP.

9. Pumping from WCP-1 will continue during Q3 of2016 to maintain West Camp water levels below the CWL.

10. Waterfowl mitigation efforts will be continued during Q3 as required by the Berkeley Pit Migratory Waterfowl Mitigation Plan, Exhibit 5 to the CD (with the approved exemption from bi-monthly surface inspections) with frequency of observations commensurate with the migratory season. Monthly reports will continue to be submitted to the Agencies.

11. The Institutional Controls required by the CD will continue to be met with full access provided to the Agencies, the MBMG and all SDs at all reasonable times. MR plans to continue to operate the active mining and milling operation within the 70,000 tpd crushing and concentration of ore and active leaching of dumps at less than 350-acres stipulations of IX. Access and Institutional Controls section of the CD.

12. The RAAR Site Activity Schedule will be followed and modified, as needed, with modifications approved by the Agencies. The HsBWTP optimization, BMFOU sitewide water balance update and alternatives study will continue according to the RAAR Schedule.

13. The Q3 2016 deliverables include: 1. MBMG Weir Maintenance Summary Memorandum;

11. HsBWTP Underground Piping Summary Memorandum; 111. Draft BMFOU Site-Wide Water Balance Work Plan will be submitted for

agency comment; and 1v. Draft HsBWTP Short-term Optimization draft Technical Memo.

e) Include information regarding unresolved delays encountered or anticipated that may affect the future schedule for implementation of the Work.

Unresolved delays include in part, on-water waterfowl mitigation and water quality sampling of the Berkeley Pit due to safety issues and resumption is contingent upon determination of near term necessity of pit water sampling, additional slope stability monitoring and risk assessment study or adoption of an alternative san1pling monitoring


Page 9

technique. (Please see the discussion in section 1 of this report regarding the agreement entered into between the SDs and Montana Tech.)

e) Include any modifications to the RA or RD Work Plans or other work plans or schedules that Settling Defendants have proposed to EPA or that have been approved by the EPA.

There are no current, requested modifications to the RA or RD Work Plans or schedules

proposed to the agencies.

f) Describe all activities undertaken in support of the Community Relations Plan during the previous quarter and those to be undertaken in the next quarter

Please see the response in Actions Taken Toward Achieving Compliance, 2. Public Education and Involvement for details to the answers to this rep011ing requirement.

g) Issues Encountered

No new issues were encountered during the quarter.

h) Other

The following information is included in this report at the request of the Agencies and is

not pat1 of the BMFOU RA.

MR continued operations during the second qumter in compliance with State-issued permits and the description in the CD that allows for the recovery of ore, crushing, concentration, leaching and the importation of water as needed for mining (Consent Decree, IX. ACCESS AND INSTITUTIONAL CONTROLS, pat1 26b., p. 39).

Attachment 2 is reports for Q 1 and Q2 2016 titled "Berkeley Pit Slope Stability Quarterly Summary" produced by MR's Engineering Department. The reports summarize activities conducted during the qumier related to monitoring and dewatering of the alluvium in the Concentrator, Southeast Corner and Pittsmont Sectors of the Berkeley Pit.

MR intends to implement a stability enhancing effort along the Concentrator section of

the Berkeley Pit to secure MR's haul road. The work includes the installation of soil nails ( also referred to as micro-piles) and is anticipated to be initiated in Q3 2016.


Page 10

Submission of this report does not constitute a statement by AR or MR concerning responsibility between them for any identified tasks or a statement by AR or MR that any specific task is required to comply with any existing agreement.


BMFOU QUARTERLY REPORT

Q2 2016

ATTACHMENT 1:

Horseshoe Bend Water Treatment Plant Groundwater Level Reduction Project

Page 11

TO:

FROM:

DATE:

Montana Resources

MEMORANDUM

Steve Czehura, Mark Thompson, and Tim Hilma

Amanda Griffith

July 21, 2016

Montana Resources, LLP 600 Shields Ave. Butte, Montana USA 59701 (406) 496-3200 (406) 723-9542 fax www.montanaresources.com

SUBJECT: HsBWTP GWL Reduction-2016 2nd Quarter Summary

Overview

The Horseshoe Bend groundwater dewatering system was operated continuously through the quarter except for two short intervals when the power was out. Individual wells were shut down for less than ten minutes a piece to reconnect outgoing pipes following weekly flow measurements. Results of the flow rate tests can be seen in Table 1. Locations of the wells around the plant can be seen in Figure 1. The pump in HI 5-4 was shut down for three weeks from 4/14/2016 to 5/5/2016 to assess its effectiveness within the overall dewatering system.

No new wells were installed during the second quarter. The water levels in the pumping wells remained fairly steady over the quarter except in the three deep wells, H14-4, H14-5, and H14-6. In H 14-4 and H 14 -6 the pumps decreased in flow and increased the amount of amperage drawn by the pump. The pump in H14-4 is still pumping, but the water level has risen 25.7 feet since 3/28/2016. The pump in H14-6 seized and will no longer pump water. The pump in H14-5 was shut down because the well was pumped dry. The water level in the two monitor wells has not increased due to the cessation of pumping in the deeper levels, indicating that the pumping of the deep wells is not having an impact on the shallower groundwater around the WTP foundation. The cessation of pumping from H14-6 has not had any immediate effect on the other wells in the area. The water levels in the monitor wells will continue to be monitored over the next several weeks to confirm that the deeper wells are not substantive to the dewatering program.

The water level in monitor well H14-3 fluctuated from week to week, but increased by 0.15 feet over the quarter. The water level in monitor well H15-9 increased 0.56 feet over the quarter. Changes in water level over the second quarter can be seen in Table 2.

No maintenance was performed on the pumping wells during the second quarter of 2016. During the first quarter the scale on the pumps was sampled. This scale was analyzed by NALCO and several inhibitors were suggested to keep the scale from clogging the pumps and motors. NALCO is concerned that the scale may be affecting the sediment around the wells that is near

A Washingto11 Company

HsBWTP GWL Reduction-2016 2°d Quarter Summary Page 2 of 6

the air/water interface. The NALCO scientists suggested collecting more scale samples and testing them with several weak acids to see if any inhibitors could lessen the scale without potentially causing damage to the tanks or other HsBWTP infrastructure.

The Static Water Level (SWL) and Pumping Water Level (PWL) elevations of all wells can be seen in Table 2. A graphical plot of the elevations can be seen in Figure 2.

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Table I. Pumping rates for HsBWTP dewatering wells.

HsBWTP Flow Rates

3/28/2016 4/6/2016 4/11/2016 4/21/2016 4/26/2016 5/3/2016

Pump Average Average Average Average Average Average H14-1 38.0 39.0 39.0 38.7 38.4 38.8 H14-2 6.5 6.2 6.3 6.3 6.4 6.6 H14-4 3.7 3.2 3.2 0.0 0.0 0.0

H14-5 3.0 3.0 3.1 2.9 2.9 3.0 H14-6 8.3 8.2 7.9 8.2 8.5 8.3 H15-7 1.6 1.5 1.6 1.8 1.9 2.2 H15-8 8.8 9.3 8.6 9.0 8.9 9.6 H15-10 3.5 3.9 3.7 3.7 3.6 3.7 H15-11 5.4 5.4 5.6 5.8 5.9 5.8 H15-12 7.4 7.9 7.8 8.1 8.4 8.6

* indicates an overall decrease in flow

+ indicates an overall increase in flow

t outgoing pipe was rerouted for tank cleaning and cannot be accessed to measure flow rate

:,.,

: "' :::-r,~·

~ ::,

~ :::: 'i5 "' ~

5/12/2016 5/18/2016 5/26/2016 6/2/2016

Average Average Average Average 41.0 39.0 40.2 38.4

6.6 6.7 6.7 6.7 2.3 2.6 2.4 2.6

2.8 3.0 2.9 2.2 8.4 8.3 8.4 8.4 2.3 2.5 2.5 2.4 9.7 9.9 9.4 9.6 3.7 3.7 3.7 4.0 6.1 5.7 0.0 0.0 9.8 9.9 10.1 9.2

6/7/2016 6/16/2016

Average Average 38.0 39.1

6.6 6.4 2.0 1.9

0.0 0.0 8.6 8.9 2.3 0.0 9.4 0.0 4.0 3.4 0.0 0.0 9.4 9.3

6/23/2016

Average 38.8

6.4 1.8 * 0.0 * 8.6 2.1 +

8.9 3.5 0.0 t

8.9

I

= [I}

~

~ ~ ~

C')

~ ~ Q. = ('l) --· 0 = I N ~ ,... 0-,

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00 = 9 9 ~

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Figure 1. Site map ofHsBWTP and surrounding dewatering and monitor wells.

HsBWTP GWL Reduction Dewatering and Monitor Wells Existing wells

I ii& I t

= tl'J

i:i:i

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2nd Quarter HsBWTP Water Levels 5,580 ··~, ---------------------------~-~

s,s6o t=::::;:=:::;:==::;;::;,::=~;;::1=H;::::~:~=~:::::;ii;=+:;iii===t==-'==::::.~==+~==:::::;i.====::J:.:===J

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5,480

5,460 ·!-·--·----------·----·-···--··-- ' ..... _______ , ________ , _______ ... , ........ ----··-: ----·-···--"·---.. -----------------.·-----!----..----.,

DATE

Figure 2. HsBWTP dewatering and monitor well levels for 1st quarter of 2016.

-fl-H14-1

I --+-H14-2

H14-3

·-+,-H14-4

....,_H14-5

-O-Hl4-6

·....;/Jl,-HlS-7

--HlS-8

HlS-9

HlS-10

·-*-HlS-11

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HsBWTP GWL Reduction-2016 2°d Quarter Summarv Page 6 of 6

Table 2. Pumping and static water levels of the HsBWTP dewatering and monitor wells 3/28/2016 through 6/30/2016.

6/30/2016 6/30/2016 Water elevation Water elevation Change from Screened

Well (ACM ft) (USGS ft) 3/28/2016 (ft} interval

H14-1* 5590.51 5534.28 0.03 5562-5582

H14-2* 5589.68 5533.45 -0.02 5561-5581

H14-3 5576.46 5520.23 0.15 5555-5575

H14-4* 5571.43 5515.20 25.70 5538-5558

H14-5* 5548.75 5492.52 27.78 5515-5535

H14-6* 5546.34 5490.11 -0.95 5535-5555

HlS-7* 5600.42 5544.19 0.04 5593-5623

HlS-8* 5598.85 5542.62 -0.21 5592-5602

HlS-9 5610.94 5554.71 0.56 5597-5507

HlS-10* 5582.72 5526.49 0.00 5572-5592

HlS-11 * 5590.97 5534.74 2.87 5576-5596

HlS-12* 5592.12 5535.89 -0.26 5582-5612

* Pumping well

A Washington Company


BMFOU QUARTERLY REPORT

Q2 2016

ATTACHMENT 2:

Berkeley Pit Slope Stability Quarterly Summaries

Page 12

Montana Resources

MEMORANDUM

TO: Stephen Walsh

FROM: S. Czehura and S. Huckeby

COPY: Mark Thompson, MR; Tim Hilmo, ARCO/BP

DATE: May 12, 2016


SUBJECT: Berkeley Pit Slope Stability First Quarter Summary 2016

Summary

Monitoring of the Berkeley Pit highwall slope stability continued throughout the First Quarter of 2016 (Table 1).

Monitoring

Table 1. Berkeley monitoring summary First Quarter 2016.

BERKELEY PIT

HIGHWALL STABILITY

Bird Watch Sector

Concentrator Sector

Southeast Sector

Pittsmont Sector

No Installation

ID Imminent Danger

V) V) .... ... C (I/

·o V) .... E (I/

0... E '- .!a 0 0 .... ·.;; .... 0... ·2 oil C

(I/ 0 .... 2 X

LIJ

s -s s s s s -

S Stable

V) V) .... V) bl) <ii (I/ (I/ C ... :a ·;: .,, > (I/ Q. .!:l E Ill (I/

E .... 0 u Ill .... C ex: :: ~ (I/

0 .... u (I/ Ill

I- 0 3: .E

- s - s - s - s s - s s - s - s

M Moving F Failing

The established monitoring network was maintained throughout the quarter (Plate I). Repairs, replacements, and adjustments were completed promptly, as needed, to ensure coverage in areas with a high Probability of Instability (POI).


Berkeley Slope Stability Quarterly Summary Jan - Mar 2016 Page 2 of7

Four survey points in the Bird Watch Sector, three survey points in the Concentrator Sector, eight survey points in the Southeast Sector and three prisms in the Pittsmont Sector were monitored throughout this period. Survey points in the Bird Watch Sector were checked weekly. In the Concentrator Sector, the western two survey points were monitored weekly, and the eastern point was monitored daily during the First Quarter.

Eight survey points in the Southeast Sector and three prisms in the Pittsmont Sector were monitored daily. Wire extensometers in the Concentrator Sector were checked several times per day. Wire extensometers in the Southeast Sector are instrumented and these were monitored continuously. All inclinometers were read daily. All TOR wells were read weekly (Figure 1 ).

Berkeley Pit - Active Sectors

Sector nomenclature for the Berkeley pit is detailed on Plate II (attached).

Figure 1. TOR Well locations.

Bird Watch Sector: The four "Bird Watch Sector" monitor points did not exhibit any abnormal movement during the First Quarter of 2016. These points were surveyed once a week.

A Washingto11 Company


Slow displacement of the outer portion of the dump continues at a rate of less than 0.6 inches per month. The TOR cable in Well B06-1 did not reveal any progressive distress during this period.

Concentrator Sector: Four survey points were checked in this sector throughout the quarter with no significant movement being indicated. Two of the monitor points were surveyed daily, and two of the monitor points were surveyed once a week. On February 15th 2016, use of monitoring of point A37131 was discontinued, due to road conditions and hazardous mud accumulation that prevented surveying.

There was no significant movement indicated by the three wire extensometers in the Concentrator Sector during the First Quarter of 2016. Minor movements appeared to be random and not progressive. No repairs to the extensometers were performed during this time period.

TOR cables were read weekly throughout the First Quarter in three wells in this sector and no progressive movement was detected.

Southeast Sector: No significant movement was detected with the monitoring array during the First Quarter 2016.

The eight Southeast Sector monitor points did not show any significant progressive movement during the First Quarter of 2016. Four monitor points were replaced during the first quarter. The last day the four "old" PZF Monitor Points were surveyed was on February 15th 2016. The points were replaced due to road conditions and mud accumulation that prevented surveying.

Below is a list of the "old" PZF Monitor Pts. that were surveyed during this quarter before replacement (ending February 161

\

• A37152 • A37153 • A37132 • A37159

The list of new PZF Monitor Pts. is shown below (starting February 161h):

• A37239 • A37245 • A37222 • A37227 • A37244

A Wasltington Company


Although the Southeast Sector extensometers are instrumented, they continue to be inspected three times per shift and readings recorded once a shift. If an automated data collector should go down, manual readings are taken three times per shift concurrent with the inspections.

One extensometer repair was made during the quarter due to deer traversing the area.

Dewatering pumps in the Southeast Sector were operated throughout the First Quarter of 2016. The small pump installed in PZF15-1, was not run.

Table 2. Average flows for the PZF15 Dewatering Wells (First Quarter 2016).

Dewatering January February March First Quarter 2016

Well Flow(gpm) Availability Flow (gpm) Availability Flow (gpm) Availability Flow (gpm) Availability

PZF15-1 0.0 0% 0.0 0% 0.0 0% 0.0 0%

PZF15-2 26.7 100% 26.3 99% 25.7 100% 26.2 100%

PZF15-3 123.3 100% 124.6 99% 122.5 100% 123.4 100%

PZF15-4 10.2 100% 10.7 99% 11.5 100% 10.8 100%

PZF15-5 20.9 100% 21.1 99% 20.6 100% 20.9 100%

PZF15-6 3.9 100% 1.6 99% 1.3 100% 2.3 100%

LP-15 41.8 100% 41.5 99% 41.5 100% 41.6 100%

Pittsmont Sector: Three prisms on the Pittsmont dump were surveyed with a total station approximately five days per week during the quarter. No slope movements were detected during the quarter.

The TOR cables in Wells PZF13-1, PZF14-1A, and PZF14-1 B were read weekly during the quarter with no indicated distress.

Hydrographs

Water levels are tracked in all sectors. Hydrographs detailing the piezometric surface in each sector are provided for comparison in Figures 2 through 6. No unusual trends were noted during the quarter in the Bird Watch, Concentrator, or Pittsmont Sectors.

A Waslti11gto11 Company


Figure 2. Hydrographs Bird Watch Sector.

1st Quarter Concentrator Sector TOR Wells s;,;o I

I

5320

Date

Figure 3. Hydrographs Concentrator Sector.



i 11

I ~ a. ! g .!l

! sa %

1st Quarter 2016 Berkeley SE Sector Inclinometer Wells

-PZF12·S _..,..PZFl2-4

-,-PZF12.S

··•-PZF12-ll I-------C----·-..C---·--·------------·-··----····--f·-·-··---·-·----7·--·-1 -llerkH20

Figure 4. Hydrographs Southeast Sector inclinometer wells.

bt Quarter 2016 Berkeley SE Sector Pumping Wells 5600

5500

s.wo

5300

sioo

5100

5000 l!I l!I ~ l!I l!I

~ l!I

! Ii g Ii -Ii i ~ ~ ~ ~ ~ 0,1te

Figure 5. Hydrographs Southeast Sector pumping wells

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-fl-PZf 1:2-2

-4-PZf 12-3

-LP16

-lktttuO

.-+-PZF 15-1

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Berkeley Slope Stability Quarterly Summary Jan - Mar 2016

1st Quarter 2016 Berkeley Plttsmont Sector PZF Wells

::: "' !!;! i, i; i ,f

~ ~ ~

Oate

Figure 6. Hydrographs Pittsmont Sector.

Other

--.PZf13-1

~PZF1t..1A1 -?&-PZf14,.1A2

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Page 7 of7

Relocation of the Rim Haul Road in the Concentrator and Southeast Sectors was completed in January. Construction of a new Pittsmont Ramp is still underway; completion of this project is expected during the Second Quarter of 2016.


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Montana Resources

MEMORANDUM

Stephen Walsh

S. Czehura and S. Huckeby

Mark Thompson, MR; Tim Hilmo, ARCO/BP

July 17, 2016


SUBJECT: Berkeley Pit Slope Stability Second Quarter Summary 2016

Summary

Monitoring of the Berkeley Pit highwall slope stability continued throughout the Second Quarter of 2016. The monitoring network is illustrated in Plate I and summarized in Table 1.

Table 1. Berkeley monitoring network Second Quarter 2016.

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Concentrator Sector 3 3 - 3 - 5

Southeast Sector 8 3 4 - 6 11

Pittsmont Sector 3 - - 4 - 3

Monitoring

The monitoring network was maintained throughout the quarter and repairs, replacements, and adjustments were completed promptly, as needed, to ensure uninterrupted coverage in areas with a high Probability of Instability (POI).

A Waslti11gton Company

Berkeley Slope Stability Quarterly Summary Apr - Jun 2016 Page 2 of7

Survey points in the Bird Watch Sector were checked weekly. In the Concentrator Sector, the western two survey points were monitored weekly, and the eastern point was monitored daily during the Second Quarter. Survey points in the Southeast Sector and in the Pittsmont Sector were monitored daily.

Wire extensometers in the Concentrator Sector, were checked several times per day. Wire extensometers in the Southeast Sector are instrumented and were monitored continuously.

Inclinometers in the Southeast Sector were measured daily.

TOR wells were read weekly.

Water levels can be measured in both TOR wells and Inclinometers. These water levels as well as standalone piezometers were measured either daily or monthly (TOR wells).

Berkeley Pit - Active Sectors

Sector nomenclature for the Berkeley pit is detailed on Plate II (attached).

Figure 1. TOR Well locations.


Berkeley Slope Stability Quarterly Summary Apr - Jun 2016 Page 3 of 7

Bird Watch Sector: The Bird Watch Sector monitor points did not exhibit any abnormal movement during the Second Quarter of 2016.

Slow displacement of the outer portion of the dump continues at a rate of less than 0.6 inches per month. The TOR cable in Well 806-1 did not demonstrate any progressive distress during this period.

Concentrator Sector: Survey points were checked in this sector throughout the quarter with no significant movement being indicated.

There was no significant movement indicated by the wire extensometers in the Concentrator Sector during the quarter. Minor movements appeared to be insignificant and not progressive.

Two extensometer repairs were made during the quarter due to deer traversing the area.

TOR cable readings did not demonstrate any progressive movement during the quarter.

Southeast Sector: The Southeast Sector monitor points did not show any significant progressive movement during the Second Quarter of 2016. One monitor point was replaced due to damage caused by heavy equipment during the Second Quarter.

Although the Southeast Sector extensometers are instrumented, they continue to be inspected up to three times per shift and readings recorded once a shift. If an automated data collector should go down, manual readings are taken three times per shift concurrent with the inspections.

There was no significant movement indicated by the wire extensometers in the Southeast Sector during the quarter. Minor movements appeared to be insignificant and not progressive.

One extensometer repair was made during the quarter due to deer traversing the area.

Dewatering pumps in the Southeast Sector of the Berkeley pit continued to operate throughout the Second Quarter of 2016. The pump installed in PZF15-1, did not operate during the quater.



Table 2. Average flows for the PZF15 Dewatering Wells (Second Quarter 2016).

Dewatering April May June Second Quarter 2016

Well Flow (gpm) Availability Flow (gpm) Availability Flow (gpm) Availability Flow (gpm) Availability

PZF15-i 0.0 0% 0.0 0% o.o 0% 0.0 0%

PZF15-2 25.6 100% 25.6 100% 23.2 99% 24.8 100%

PZF15-3 123.2 100% 122.5 100% 119.8 99% 121.8 100%

PZF15-4 12.2 100% 12.6 100% 13.3 99% 12.7 100%

PZF15-5 20.7 100% 20.4 100% 19.0 99% 20.0 100%

PZF15-6 0.8 100% 0.5 100% 0.3 100% 0.5 100%

LP-15 41.2 100% 40.5 100% 40.4 100% 40.7 100%

Pittsmont Sector: Prisms on the Pittsmont dump were surveyed approximately five days per week during the quarter. No slope movements were detected during the quarter.

The TOR cables were read weekly during the quarter with no indicated distress.

Hydrographs

Water levels are tracked in all sectors. Hydrographs detailing the piezometric surface in each sector are provided in Figures 4 through 8. There were no fluctuations of note during the quarter in the Bird Watch, Concentrator, or Pittsmont Sectors.

A Waslti11gto11 Company


2nd Quarter Bird Watch Sector TOR Wells 5350

5345

5340

j 5335

i ~ V

~ 5330

;. I! i 5325

' Sl %

5320

5315

Figure 4. Hydrographs Bird Watch Sector.

2nd Quarter Concentrator Sector TOR Wells 5460

5440

5420

i 5400

I "' i; 5380

! z 9 :;

5360

i 0 S!

5340

5320

5300 ~ ~ ~ ii ! 1 ~ s:

Figure 5. Hydrographs Concentrator Sector.



2nd Quarter 2016 Berkeley SE Sector Inclinometer Wells

S420

S400

SHO

i 1i

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~ a ti 5!140

! 0 ix!

suo

noo

52SO .,

i ! ~ l 1 "' l!l )\I l!l l!l i l ~ I: i

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N

Figure 6. Hydrographs Southeast Sector inclinometer wells.

2nd Quarter 2016 Berkeley SE Sector Pumping Wells

5500

S400

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HOO -6""'H20

~ _.PZf tS.1

a --PZF15.2

§ ·-,·•PZF tS.3

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ill

~ 5100

5000

I :::

Figure 7. Hydrographs Southeast Sector pumping wells


Berkeley Slope Stability Quarterly Summary Apr - Jun 2016

2nd Quarter 2016 Berkeley Pittsmont Sector PZF Wells

:!l :!l i :!l :!l :!l :!l .. li. ! ~ ! > ;. 1 ! ~ ! ! 2 N N

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Figure 8. Hydrographs Pittsmont Sector.

Other Activities:

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Page 7 of 7

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Relocation of the Rim Haul Road in the Concentrator and Southeast Sectors was completed in January. Construction of a new Pittsmont Ramp was completed in June.

Initiation of the soil nail/micro pile haul road stabilization project will commence in midAugust 2016.


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·nsN, Steve Czehuro. DTL1 So.ro.h Huckeby 7/19/2016

letter transmits attached butte mine flooding site consent ... · a bp affiliated company mr....

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