letter transmits attached settling defendants bmfou ... · on september 2, 2016, the fou raar draft...

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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

FOURTH QUARTER, 2017

The Settling Defendants1 continue to implement the remedial action requirements of the Butte Mine Flooding Operable Unit (BMFOU) specified in the Statement of Work to the Consent Decree. This report summarizes those activities conducted during the fourth quarter of 2016 as required under Section X. Reporting Requirements, Paragraphs 31and 35 of the Consent Decree. The headings a) through g) in the following report sections correspond to the categories identified in Paragraph 31. The sections captioned h) Issues Encountered and i) 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 Appendix C of the Consent Decree. These seven components and the remedial action activities undertaken by the Settling Defendants (hereinafter referred to as “SDs”) in the fourth 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, and monthly sampling of the Granite Mountain Mine shaft. Water level measurements of the Granite Mountain Mine shaft have not been completed since July 2016 due to an obstruction in the shaft at the depth of 420 feet and safety concerns with accessing the area around the shaft. The MBMG is currently working with the SDs to develop a plan to find an alternative means for measuring. Installation of pressure transducer are being considered with direct read cable to avoid entering the immediate area around the shaft on a monthly basis. In addition, MBMG is also developing a plan to install pressure transducers with direct read cables to the Anselmo, Kelley, Pilot Butte, Lexington, Marget Ann, and Steward mine shafts in early 2017.

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.

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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 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. However this drone boat requires entry to the pit for deployment of the boat; therefore the SDs are currently discussing with Montana Tech modifying the sampling platform from a remotely controlled boat to a remotely controlled amphibious vehicle (e.g.an ARGO). During Q4 2016 no significant slope failures occurred within the Berkeley Pit.

The SDs provided access to the MBMG personnel to conduct monitoring. A grab surface water sample was collected by MBMG on December 7, 2016. Results of the surface sample were reported to the Agencies by MGMA via email and included in the MBMG Butte Mine Flooding Consent Decree 02-350BU-SHE 2016-Data Summary (MBMG, 2017) submitted to the Agencies on February 2, 2017.

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.PITWATCH.ORG. These are the primary vehicles for educating the public about BMFOU status and activities. A PITWatch meeting was held on October 21, 2016 in which the SDs participated.

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 Record of Decision (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.

http://www.pitwatch.org/

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During the quarter, approximately 21,888,000 gallons of HsB flow was bypassed to the Berkeley Pit from October 15, 2016 to October 20, 2016 due to a planned plant shut down to clean accumulated sediments from the influent wet well. Significant maintenance activities completed during the quarter include:

Influent wet well cleaned; New influent pump installed for pump No. 115; New check valves installed in influent pumps No. 114 & 115; Stage 2 lime addition valve replaced; Actuator for Stage 2 lime addition valve replaced; Stage 1 recycle pump replaced; Base cone on south silo replaced; Blowdown lines for Stage 1 and Stage 2 separated to allow each stage to

be operating and not restrict the other. Top end of air compressor rebuilt. Stage 1 was bypassed to drain the Stage 1 reactor to view the mixer and to

check the amount of buildup in the reactor.

Control of groundwater levels in the vicinity of the HsBWTP continued. Engineering controls operated during the fourth quarter and regulated the groundwater level in the area of the HsBWTP. Fourth quarter 2016 reporting of these activities is included in the HsBWTP Groundwater Level Reduction Project Quarterly Report (SDs, 2017) attached as Attachment 1 to this report.

4. HsB Water Treatment Plant Upgrade/Sludge Repository – The SDs have initiated the HsBWTP Remedial Action Adequacy Review (RAAR) to ensure that ongoing and future remedial activities will meet the requirements of the CD. The preliminary draft schedule for the BMFOU RAAR was submitted on June 30, 2014 and approved by the Agencies on September 11, 2014. The RAAR contractor has updated the detailed schedule provided to the Agencies during October 4, 2016 Quarterly BMFOU Progress Meeting, and also attached to this report as Attachment 2. 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.

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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. On April 20, 2016, a Final BMFOU RAAR HsBWTP Short-term Optimization Work Plan (Golder, 2016) was submitted to the Agencies. The SDs anticipate submitting the Draft HsBWTP Short Term Optimization Review Technical Memorandum to the agencies in Q1 or Q2 2017. On September 2, 2016, the BMFOU RAAR Draft Final Water Balance Work Plan (SDs, 2016) was submitted to the Agencies. Comments from the Agencies have been received. It is anticipated that responses to Agency comments and the BMFOU RAAR Final Water Balance Work Plan will be provided Q1 2017. The Explanation of Significant Differences, Appendix A to the CD allows for placement of sludge into the Berkeley Pit. During Q4, 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 BMFOU RAAR schedule.

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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, 2013) and consult Mr. Terrence E. Duaime, Project Manager of the MBMG 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.

b) Summary 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 4, 2016 and in total for the year to date:

Period Influent

(MG) HsB Plant

Water2 (MG)

Sludge Wasted (MG)

Lime Delivered

(tons)

Average Influent Flow

(MGD)

Average Lime Usage

(mg/L)

Quarter 1 427 469 17 3,745 4.7 2,117 Quarter 2 410 444 21 4,613 4.5 2,705 Quarter 3 420 430 24 4,213 4.6 2,407 Quarter 4 416 426 20 3,792 4.5 2,202

YTD 1,673 1,769 81 13,364 4.6 2,364 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. The Horseshoe Bend Water Treatment Plant Groundwater Level Reduction Project Quarterly Report (SDs, 2017) is attached as Attachment 1 to this report.

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.

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c) Identify all work plans and other deliverables required by this Consent Decree

completed and submitted in the previous quarter

The following deliverables required by the Consent Decree were completed or submitted in Q4 2016: 1. SD BMFOU Quarterly Report CD for the Butte Mine Flooding Site CD, CV 02-35

Bu-RFC Remedial Action – Implementation of the Remedy Quarter 3, 2016 (SDs, 2016) was submitted to the Agencies on November 15, 2016.

2. September 2016 Berkeley Pit Migratory Waterfowl Mitigation Monthly Report (SDs, 2016) submitted to the Agencies on October 24, 2016.

3. October 2016 Berkeley Pit Migratory Waterfowl Mitigation Monthly Reports (XXX, 2016) to the Agencies on November 18, 2016.

4. MBMG BMF Monthly Report BMFOU CD 02-35-BU-SHE Remedial Action-Monitoring Program Contract No. 415008-TO-2 September 2016 (MBMG, 2016) was submitted by MBMG on behalf of the SDs on November 15, 2016.

5. MBMG BMF Monthly Report BMFOU CD 02-35-BU-SHE Remedial Action-Monitoring Program Contract No. 415008-TO-2 October 2016 (MBMG, 2016) was submitted by MBMG on behalf of the SDs on November 15, 2016.

6. MBMG BMF Monthly Report BMFOU CD 02-35-BU-SHE Remedial Action-Monitoring Program Contract No. 415008-TO-2 November 2016 (MBMG, 2016) was submitted by MBMG on behalf of the SDs on December 15, 2016.

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 first quarter 2017 anticipated activity summary is as follows:

1. The Monitoring Program will continue to be implemented during the next quarter, with the exception of sampling the Berkeley Pit and Granite Mountain Mine shaft. 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. MBMG and the SDs will continue to develop a plan to find alternative means of sampling of the Granite Mountain Mine shaft. In addition, MBMG will continue to develop a plat

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to install pressure transducers with direct read cables to the Anselmo, Kelley, Pilot Butte, Lexington, Marget Ann, and Steward mine shafts in early 2017.

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 flow emanating from the HsB area. The Inflow Control requirement will continue to be met with the HsBWTP treated water being integrated into the mining and milling operations. The SD BMFOU Annual Report Consent Decree for the Butte Mine Flooding Site CD, CV 02-35 Bu-RFC Remedial Action – Implantation of the Remedy HsBWTP 2016 Annual Report is being submitted as Attachment 3 to this report. 4. Operation of the dewatering system around the HsBWTP will continue.

5. The Draft HsBWTP Short Term Optimization Review Technical Memorandum will be prepared anticipated for submittal in Q1 or Q2 2017.

6. It is anticipated that SD response to Agency comments regarding the BMFOU RAAR Draft Final Water Balance Work Plan (SDs, 2016) will be submitted to the Agencies in Q1. The BMFOU RAAR Final Water Balance Work Plan is anticipated to be submitted in Q1 of 2017.

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

8. Pumping from WCP-1 will continue to maintain West Camp water levels below the CWL. 9. Waterfowl mitigation efforts will be continued 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. SDs are continuing to investigate the waterfowl incident that occurred in late November and early December 2016. The SDs are providing a combined November and December 2016 Berkeley Pit Migratory Waterfowl Mitigation Monthly Report that contains additional information about the incident. In addition the SDs are preparing interim modifications to the Berkeley Pit Migratory

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Waterfowl Mitigation Plan in advance of the spring migration season, while a full review and update to the plan will be completed prior to the fall 2017 migration season.

10. 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 stipulations of Section IX. Access and Institutional Controls of the CD.

11. The BMFOU RAAR schedule will be followed and modified, as needed, with modifications approved by the Agencies.

12. The Fourth Five-Year Review Report for Silver Bow Creek/Butte Area Superfund Site (EPA, January 2016) was issued by the EPA on August 30, 2016, is currently under review by the SDs.

e) Include information regarding unresolved delays encountered or anticipated that

may affect the future schedule for implementation of the Work.

Following a series of landslides in the Berkeley Pit, in 2013 EPA approved a variance to the Waterfowl Mitigation Plan that waived the requirement of putting personnel on the pit water, due to safety concerns with future landslides. This exclusion of on the water activities effected entry onto the pit for water sampling, waterfowl hazing, mortality counts, and waterfowl retrieval. The Settling Defendants are monitoring slope stability and working to develop remotely controlled equipment that can be used to safely allow these activities to resume without placing personnel at risk. See the discussion in Section a.1 above, regarding the agreement entered into between the SDs and Montana Tech.

f) 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.

BMFOU RAAR schedule updates are ongoing. MBMG is not currently monitoring the Granite shaft due to safe access as discussed above.

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g) 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 above in Section a. Actions Taken Toward Achieving Compliance, Subsection 2. Public Education and Involvement for details to the answers to this reporting requirement.

h) Issues Encountered

On November 28, 2016, thousands of snow and Ross’s geese landed in the Berkeley Pit, as discussed above. Hazing operations pursuant to the Berkeley Pit Migratory Waterfowl Mitigation Plan were implemented. Further information about this incident is contained in the combined November-December 2016 Berkeley Pit Migrating Waterfowl Monthly Mitigation Report. Safety concerns have led to the temporary suspension of water-level monitoring at the Granite Mountain Mine as discussed above. AR and MBMG personnel inspected all mine sites to identify potential future safety issues that may impact the long-term monitoring program. No immediate problems beyond the Granite Mountain site were identified; however, installation of pressure transducers with direct read cables to the Anselmo, Kelley, Pilot Butte, Lexington, Marget Ann, and Steward mine shafts are being planned to increase reliability of monitoring.

i) Other

The following information is included in this report at the request of the Agencies and is not part of the BMFOU RA. MR continued operations during the fourth quarter 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, Section IX. ACCESS AND INSTITUTIONAL CONTROLS, part 26b., p. 39).

Attachment 4 is a report for Q4 titled “Berkeley Pit Slope Stability Quarterly Summary” produced by MR’s Engineering Department. The report summarizes activities conducted during the quarter related to monitoring and dewatering of the alluvium in the Concentrator, Southeast Corner and Pittsmont Sectors of the Berkeley Pit.

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MR implemented 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 was completed in Q4 2016.

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

Q4 2016

ATTACHMENT 1:

Horseshoe Bend Water Treatment Plant Groundwater Level Reduction Project Quarterly Report

A Washington Company

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

MEMORANDUM TO: Mark Thompson

FROM: Amanda Griffith

DATE: February 15, 2017

SUBJECT: HsBWTP GWL Reduction-2016 4th Quarter Summary

Overview

The Horseshoe Bend groundwater dewatering system was operated continuously through the fourth quarter. Individual wells were shut down for less than ten minutes apiece to reconnect outgoing pipes following weekly manual flow measurements. Two weeks of flow rate measurements were skipped over the Christmas and New Year holidays. Flow rates can be seen in Table 1. Two new monitor wells were installed during the fourth quarter. Locations of the wells around the plant can be seen in Figure 1. Deeper wells H14-4, H14-5, and H14-6 are not currently being pumped so that their influence on the shallower water system can be assessed. Water levels and pumping rates were monitored weekly to determine their effect on the dewatering of the area. The water levels in the pumping and monitor wells remained relatively steady over the quarter.

The water level in monitor well H14-3 decreased by 0.20 feet over the quarter. The water level in monitor well H15-9 decreased 0.52 feet over the quarter. Changes in water level over the fourth quarter can be seen in Table 2.

Two monitor wells were installed during the fourth quarter. The well completion logs for H16-13 and H16-14 are attached as Figures 3 and 4. The wells were completed as pumping wells should they be needed. The water levels are very similar to those seen in pumping wells H15-7 and H15-8. The water levels in H16-13 and H16-4 are both a little over ten feet lower than those seen in H15-9.

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.

HsB

WT

P GW

L R

eduction-2016 4th Quarter Sum

mary

Page 2 of 7

A Washington Com

pany

9/29/2016 10/6/2016 10/13/2016 10/20/2016 10/27/2016 11/3/2016 11/10/2016 11/23/2016 12/1/2016 12/12/2016 12/20/2016 1/10/2017

Pump Average Average Average Average Average Average Average Average Average Average Average AverageH14-1 43.7 47.1 45.3 43.7 44.8 44.2 44.7 46.9 44.9 43.2 42.1 39.2

H14-2 12.9 19.3 17.7 14.2 17.5 13.6 17.0 18.6 14.4 13.8 14.4 14.2 +

H14-4 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

H14-5 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

H14-6 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

H15-7 3.6 3.2 3.4 11.3 4.5 3.2 3.3 3.2 3.5 3.2 3.0 2.9 **

H15-8 14.7 13.0 12.3 11.5 11.2 13.0 13.1 12.3 11.7 12.9 11.5 11.5 *

H15-10 5.4 4.4 4.5 4.0 4.7 4.3 4.6 4.6 4.5 4.9 4.1 4.3 *

H15-11 8.6 7.7 7.9 7.3 7.7 7.5 7.9 7.8 7.7 7.5 7.5 8.0 *

H15-12 11.1 11.8 12.3 11.5 11.4 11.6 11.7 11.2 10.7 10.4 10.4 9.6 *

* indicates an overall decrease in flow

+ indicates an overall increase in flow

** valve shut before testing on 10/20/2016 resulting in false high

Table 1. Pumping rates for HsBWTP dewatering wells.

HsB

WT

P GW

L R


mary

Page 3 of 7

A Washington Com

pany

Figure 1. Site map of HsBWTP and surrounding dewatering and monitor wells.

HsB

WT

P GW

L R


mary

Page 4 of 7

A Washington Com

pany

5,490

5,500

5,510

5,520

5,530

5,540

5,550

5,560

5,570

9/2

9/2

01

6

10

/30

/20

16

11

/30

/20

16

12

/31

/20

16

H2

O E

LEV

ATI

ON

S (U

SGS

CO

OR

DIN

ATE

S)

DATE

4th Quarter HsBWTP Water Levels

H14-1

H14-2

H14-3

H14-4

H14-5

H14-6

H15-7

H15-8

H15-9

H15-10

H15-11

H15-12

H16-13

H16-14

Figure 2. HsBWTP dewatering and monitor well levels for 4th quarter of 2016.

HsBWTP GWL Reduction-2016 4th Quarter Summary Page 5 of 7


Well

1/1/2017

Water

elevation

(USGS ft)

1/1/2017

Water

elevation

(ACM ft)

Change from

9/29/2016 (ft)

Screened

interval

(ACM ft)

H14-1* 5537.85 5590.48 1.01 5562-5582

H14-2* 5537.05 5589.68 0.30 5561-5581

H14-3 5523.87 5576.50 -0.20 5555-5575

H14-4** 5535.81 5588.44 -0.44 5538-5558

H14-5** 5499.16 5551.79 0.55 5515-5535

H14-6** 5509.94 5562.57 0.75 5535-5555

H15-7* 5547.74 5600.37 0.14 5593-5623

H15-8* 5546.47 5599.10 0.19 5592-5602

H15-9 5558.68 5611.31 -0.52 5597-5507

H15-10* 5530.33 5582.96 0.21 5572-5592

H15-11* 5536.14 5588.77 0.42 5576-5596

H15-12* 5539.63 5592.26 0.14 5582-5612

H16-13 5546.69 5599.32 NA 5579-5599

H16-14 5547.93 5600.56 NA 5579-2289

* Pumping well

** No longer pumping

Table 2. Pumping and static water levels of the HsBWTP dewatering and monitor wells 9/29/2016 through 1/1/2017.



Figure 3: Well completion diagram for monitor well H16-13 (previously referred to as H16-1).



Figure 4: Well completion diagram for monitor well H16-14 (previously referred to as H16-2).


Q4 2016

ATTACHMENT 2:

BMFOU RAAR Schedule Updated on 9/30/16

ID Task Name Duration Start Finish Predecessors

1 HsBWTP O&M Optimization 520 days Thu 5/14/15 Wed 5/10/172 HsBWTP Short Term Optimization 680 days Thu 5/14/15 Wed 12/20/173 Phase 1 Work Plan Development 6.5 mons Thu 5/14/15 Wed 11/11/154 Issue Draft Work Plan to Agencies 0 days Fri 11/13/15 Fri 11/13/155 Agency Review 3.4 mons Fri 11/13/15 Tue 2/16/16 46 Issue Final Phase 1 Work Plan 0 days Tue 3/29/16 Tue 3/29/16 5FS+10 days7 Develop Hydraulic Model and Process Evaluation 8 mons Thu 4/14/16 Wed 11/23/16 58 Issue Draft RAAR HsBWTP Optimization Tech Memo to Agencies 0 days Wed 11/23/16Wed 11/23/16 79 Agency Review 1 mon Thu 11/24/16Wed 12/21/16 810 Issue Final RAAR HsBWTP Optimization Tech Memo 0 days Wed 1/18/17 Wed 1/18/17 9FS+20 days11 HsBWTP Optimization Improvements 12 mons Thu 1/19/17 Wed 12/20/17 1012 Short Term Optimization - Phase 2 12 mons Thu 1/19/17 Wed 12/20/17 1013 Water Management Alternatives 660 days Fri 8/7/15 Thu 2/15/1814 Water Balance 660 days Fri 8/7/15 Thu 2/15/1815 Phase 1 Work Plan Development 14 mons Fri 8/7/15 Fri 9/2/16 16SF16 Issue Draft Work Plan to Agencies 0 days Fri 9/2/16 Fri 9/2/1617 Agency Review 1.5 mons Fri 9/2/16 Thu 10/13/16 1618 Issue Final Phase 1 Work Plan 0 days Thu 11/10/16Thu 11/10/16 17FS+20 days19 Develop Phase 1 Water Balance 5 mons Fri 11/11/16 Thu 3/30/17 1820 Issue Draft RAAR Water Balance Tech Memo to Agencies 0 days Thu 3/30/17 Thu 3/30/17 1921 Agency Review 1 mon Fri 3/31/17 Thu 4/27/17 2022 Issue Final RAAR Water Balance Tech Memo 0 days Thu 5/11/17 Thu 5/11/17 21FS+10 days23 Water Balance - Phase 2 10 mons Fri 5/12/17 Thu 2/15/18 2224 Current Design Review Evaluation 440 days Thu 4/27/17 Wed 1/2/1925 Alternatives Evaluation 8 mons Thu 4/27/17 Wed 12/6/1726 Pilot Studies (e.g., pump from Kelley, mech evap, etc) 15 mons Thu 8/17/17 Wed 10/10/18 25FS-4 mons

27 Performance Testing (inc. WET testing) 12 mons Thu 6/22/17 Wed 5/23/18 25FS-6 mons

28 Evaluation of Cd treatment requirements 8 mons Thu 12/7/17 Wed 7/18/18 27FS-6 mons

29 Evaluation of the need for acidification 6 mons Thu 12/7/17 Wed 5/23/18 27FS-6 mons

30 Evaluation of scaling in discharge waters 8 mons Thu 12/7/17 Wed 7/18/18 27FS-6 mons

31 Current Design Review Tech Memo 3 mons Thu 7/19/18 Wed 10/10/18 30,29,28

32 Design Report (Preliminary, Draft Final, Final) 18 mons Thu 8/17/17 Wed 1/2/19 31FF+3 mons

33 Sludge Disposal/Repository Evaluation 360 days Thu 7/19/18 Wed 12/4/1934 Sludge Disposal Tech Memo 8 mons Thu 7/19/18 Wed 2/27/19 28,29,30

35 Final Design Report or Reclamation Plan 10 mons Thu 2/28/19 Wed 12/4/19 34

36 Final RAAR Tech Memo 180 days Thu 7/18/19 Wed 3/25/2037 Prepare Final RAAR Tech Memo 8 mons Thu 7/18/19 Wed 2/26/20 32FF+3 mons,338 Agency Review 1 mon Thu 2/27/20 Wed 3/25/20 3739 Upgrade Construction 840 days Thu 3/26/20 Wed 6/14/23 32FS+3 mons

40 HsBWTP Upgrades (if necessary) 360 days Thu 3/26/20 Wed 8/11/2141 Upgrades (incl. polishing) 18 mons Thu 3/26/20 Wed 8/11/21 36

42 Acidification 8 mons Thu 3/26/20 Wed 11/4/20 36

43 Pump Station and Piping 12 mons Thu 3/26/20 Wed 2/24/21 36

44 Sludge Disposal Modifications (if necessary) 200 days Thu 3/26/20 Wed 12/30/2045 Construction (if necessary) 10 mons Thu 3/26/20 Wed 12/30/20 35FS+3 mons,36

46 Shakedown Period of Operations 24 mons Thu 8/12/21 Wed 6/14/23 41,42,43

47 East Camp Bedrock CWL Prediction (2012) 0 days Mon 7/3/23 Mon 7/3/23

11/13

3/29

11/23

1/18

9/2

11/10

3/30

5/11

7/3

H2 H1 H2 H1 H2 H1 H2 H1 H2 H1 H2 H1 H2 H1 H2 H1 H2 H1 H2 H1 H2 H12014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

Task

Split

Milestone

Summary

Project Summary

External Tasks

External Milestone

Inactive Task

Inactive Milestone

Inactive Summary

Manual Task

Duration‐only

Manual Summary Rollup

Manual Summary

Start‐only

Finish‐only

Deadline

Progress

Manual Progress

PRELIMINARY DRAFT

Project: CWL_Schedule_v2016100Date: Fri 9/30/16


Q4 2016

ATTACHMENT 3:

HsBWTP 2016 Annual Report

SILVER BOW CREEK/BUTTE AREA NPL SITE MINE FLOODING OPERABLE UNIT

Settling Defendants BMFOU Annual Report Consent Decree for the Butte Mine Flooding Site CD, CV 02-35 Bu-RFC Remedial Action – Implementation of the Remedy Horseshoe Bend Water Treatment Plant 2016 Annual Report

Submitted by the Settling Defendants: Atlantic Richfield Company And Montana Resources LLP. February 28, 2017

SILVER BOW CREEK/BUTTE AREA NPL SITE MINE FLOODING OPERABLE UNIT

Settling Defendants BMFOU Annual Report Consent Decree for the Butte Mine Flooding Site CD, CV 02-35 Bu-RFC Remedial Action – Implementation of the Remedy Horseshoe Bend Water Treatment Plant 2016 Annual Report

Submitted by the Settling Defendants

Atlantic Richfield Company 317 Anaconda Road Butte, Montana 59701

And

Montana Resources LLP. 600 Shields Avenue Butte, Montana 59701

February 28, 2017

HSBWTP 2016 Annual Report Page i February 28, 2017

TABLE OF CONTENTS Page

HORSESHOE BEND WATER TREATMENT PLANT 2016 ANNUAL REPORT ............. 1

OPERATIONS AND MAINTENANCE MANUAL/PLANS.................................................... 1

SYSTEM PERFORMANCE........................................................................................................ 2 2016 System Component Performance Summary .............................................................. 2 2016 System Statistics ........................................................................................................ 3

HSBWTP 2016 OPERATION SUMMARY ............................................................................... 3 Plant Management Structure ............................................................................................... 3 Safety …. ........................................................................................................................... 3

HSBWTP Operations Personnel ......................................................................................... 4 2016 General Plant Performance ........................................................................................ 4 Plant Operation ................................................................................................................... 5 Plant Maintenance ............................................................................................................... 5 2016 Notable Maintenance Activity ................................................................................... 6

SUMMARY ................................................................................................................................... 8

REFERENCES .............................................................................................................................. 8

LIST OF ATTACHMENTS

ATTACHMENT 1: Stage 1 Reactor and Clarifier Inspection Reports ATTACHMENT 2: Stage 2 Reactor and Clarifier Inspection Reports

HSBWTP 2016 Annual Report Page 1 February 28, 2017

HORSESHOE BEND WATER TREATMENT PLANT 2016 ANNUAL REPORT

The Settling Defendants1 (SDs) continue to implement the remedial action requirements specified in the Statement of Work to the Consent Decree. This report summarizes system performance and operation and maintenance activities for 2016.

No water has been discharged to Silver Bow Creek from the Butte Mine Flooding Operable Unit (BMFOU). Other than infrequent and short-duration bypass events to the Berkeley Pit, all Horseshoe Bend (HSB) flows have been used within the mine permitted area for a water supply purpose. Pursuant to the Consent Decree, Exhibit 3 Statement of Work and Attachment 1 to Exhibit 3, these flows are not subject to compliance with any Interim or Final Standards. When there is a point source discharge of treated HSB or Berkeley Pit water to Silver Bow Creek, the requirements contained in Exhibit 3 to the Statement of Work, “Performance Standards…” and Attachment 1 to Exhibit 3 “Detailed Performance Standards for Point Source Discharges from HSB Water Treatment Plant…” (including Annual Reports) will be applicable. In response to a request by the Agencies, the SDs are submitting this Report for 2016 that contains information described in the Operations and Maintenance (O&M) Manual Horseshoe Bend Wastewater Treatment Plant (HSBWTP) (SDs, 2014). OPERATIONS AND MAINTENANCE MANUAL/PLANS

The HSBWTP has been operated as designed since November 2003 as a two stage, high density sludge (HDS) lime precipitation plant. There have been three revisions of the HSBWTP O&M Manual:

1. Horseshoe Bend Wastewater Treatment Facility, Operations Manual, prepared by Veolia Environmental in 2003, was the original manual that was used to train the initial Montana Resources (MR) Plant operators. It was not submitted to the Agencies as a deliverable.

2. Horseshoe Bend Water Treatment Facility, Operations Manual, prepared by the SDs in 2012, updated the original document standard operating procedures based on experience learned from nine years of Plant operating experience. This document was not submitted to the Agencies as a deliverable.

3. O&M Manual for HSBWTP (SDs, 2014) again updated the previous document based on Plant operating experience. This document was submitted to the Agencies as a deliverable on December 12, 2014, and approved by the Agencies on August 17, 2015. The major variation included instructions to operate the Plant periodically in a single

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.


stage configuration with HDS precipitation in order to accommodate necessary annual maintenance and cleanout of the reactors and clarifiers.

SYSTEM PERFORMANCE

The Consent Decree specifically requires that the Annual Reports contain information as described in the O&M Manual for HSBWTP. The “System” includes the following components:

1. The Ditch System, which transports water to the concrete diversion (the Diversion) and provides short-term influent storage in conjunction with the Equalization Basin.

2. The Diversion, which directs HSB influent either into the Equalization Basin or to the Berkeley Pit.

3. The Equalization Basin with a working volume of approximately 2,000,000 gallons. 4. The Influent Wet Well and influent pumps. 5. The HSBWTP and all components contained therein. 6. The HSB treated water pipeline that transports the high pH, HSB Plant Water (formerly

referred to as effluent) to MR’s Return Water Line for use in the milling process. 7. Utility infrastructure that includes electricity and natural gas supply lines and three

sources of water for use in the operation of the HSBWTP: municipal (Butte) water, MR’s service water (i.e., pH 7), and process (i.e., ~pH 10.5) water.

Since 2003 and including 2016, 100% of the HSB treated water has been incorporated into MR’s mining process (more aptly into the “milling circuit”) pursuant to the U.S. Environmental Protection Agency BMFOU Record of Decision dated September 29, 1994 (EPA, 1994), and Appendix C to Consent Decree, Statement of Work. The remedial action has been effective in meeting this requirement and no water has been discharged to Silver Bow Creek. 2016 System Component Performance Summary

The following summarizes the system component performance in 2016:

There were no issues with the ditch system in 2016. Improvements to the Montana Bureau of Mines and Geology (MBMG) flow monitoring structure and ditch cleanout upstream from the weir were conducted in 2015 and documented with the correspondence from the SDs to the Agencies (Re: MBMG Weir Upgrades Summary and the 2015 HSBWTP Underground Piping Upgrades Summary Memoranda (SDs, 2016)].

There were no significant issues with the Diversion in 2016. The Equalization Basin was dredged in 2016 to remove built-up sedimentation as

discussed below in the Plant Maintenance section. The culvert from the Equalization Basin to the inlet sump was jetted in 2016. There were no issues with the culvert that


feeds the Equalization Basin nor were there any issues with the Equalization Basin in 2016.

There was normal routine maintenance with the influent wet well and influent pumps during 2016 as discussed below in the Plant Maintenance section.

Component maintenance and clean out work detailed in the Plant Maintenance section occurred throughout the HSBWTP during 2016.

There were no issues with the HSB Plant Water Pipeline or the interconnection with MR’s Return Water Line in 2016.

There were no issues with the utility feeds components (e.g., natural gas, water system, and electrical power) of the infrastructure system during 2016. NorthWestern Energy planned several power outages for the Precipitation Plant Substation that feeds the HSBWTP.

2016 System Statistics

The following list contains the monthly flow, lime, and utilities data and the annual totals for 2016.

HSBWTP 2016 OPERATION SUMMARY

Plant Management Structure

MR operates the plant on the behalf of the SDs.

Safety ….

The document that establishes safety protocol at the HSBWTP is the Site Specific Health and Safety Plan HSBWTP (SDs, 2014), submitted to the Agencies on December 12, 2014. The Safety Plan incorporates the site’s safety policies and procedures and Best Management Practices. Safety regulatory authority for the site is under the U.S. Department of Labor, Mine Safety and Health Administration (MSHA) and the MSHA regulations are also incorporated into


the Safety Plan by reference and must be strictly adhered to by the operators. There were no reportable incidents at the HsBWT in 2016.

The MSHA issued two citations during 2016:

1. An extension cord that was not ground checked; and 2. A variable frequency drive (VFD) cabinet with two latches unsecured.

HSBWTP Operations Personnel

The HSBWTP components are monitored by computer process controls and displayed on computer monitors in both the HSBWTP control room and at MR’s Concentrator Control Room. Motor drops, high or low level indications, out of specification situations, and other key operational functions result in alarms that alert operators of problems, which are then addressed. The Concentrator Control Room is manned 24-hours per day and the operator immediately dispatches supervision to the HSBWTP when an alert is received. One full-time operator, one contract operator, and one full-time maintenance technician are assigned to the HSBWTP during the week on dayshift. Each of MR’s four operating crews also has at least one operator trained to operate and troubleshoot the HSBWTP during night shifts and weekends. Crew foremen assign additional operations personnel when required. The operation of the Plant and coordination of maintenance are the responsibility of the MR Mill Superintendent and the MR Mill General Foreman. 2016 General Plant Performance

For 2016, approximately 24.1 million gallons were bypassed from the HSBWTP to the Berkeley Pit. The 2016 bypasses of the HSBWTP resulted in the equivalent of approximately 5.3 days of inflow to the Pit. Nearly 1.7 billion gallons of surface water were treated at the HSBWTP in 2016; therefore, the percentage of water bypassed was 1.3% for 2016. The following is a brief discussion by quarter of the HSBWTP bypasses to the Berkeley Pit.

First Quarter - During the quarter, approximately 81,000 gallons of HSB flow were bypassed to the Berkeley Pit during a planned MR mill shutdown requiring a planned HSBWTP shutdown. Second Quarter - During the quarter, approximately 340,000 gallons of HSB flow were bypassed to the Berkeley Pit.

Approximately 120,000 gallons were bypassed on May 11, 2016, due to an

obstruction in the inlet pipe to the equalization basin. Approximately 220,000 gallons were bypassed on May 19, 2016, due to a planned

shutdown of the mill requiring a shutdown of the HSBWTP.


Third Quarter - During the quarter, approximately 1,774,500 gallons of HSB flow were bypassed to the Berkeley Pit:

Approximately 155,000 gallons were bypassed on July 13, 2016, to modify power

supply to the WTP. Approximately 160,000 gallons were bypassed on July 17, 2016, resulting from flow

limitations during clean out. Approximately 1,306,500 gallons were bypassed on August 24, 2016, due to a

planned mill shutdown requiring the shutdown of HSBWTP. Approximately 153,000 gallons were bypassed on September 21, 2016, due to a

power outage.

Fourth Quarter - During the quarter, approximately 21,888,000 gallons of HSB flow were bypassed to the Berkeley Pit due to a planned shutdown to clean accumulated sediments from the influent wet well.

Plant Operation

Since the HSB Plant Water2 is incorporated into MR’s milling circuit, the compatibility of the Plant Water with MR’s Return (or reclaimed) Water establishes the important treatment parameter for the level of treatment required. The Plant set point for this water is pH 10.5. Deviations from this parameter can cause conduit scaling problems in the Concentrator. There have not been other compound-specific standards set for incorporating this Plant Water with Return Water but future evaluations are under consideration.

The Plant operators are responsible for following the standard operating procedures, field monitoring, data recording, and sample collection at the Plant and performing routine daily, preventative, and breakdown maintenance. This work was routine in 2016 and progressive improvements were made during the year.

Conduit scaling and gypsum formation requires annual downtime per stage for clean out and maintenance activities. Single stage treatment to pH 10.5 allows for adequately treated Plant Water for milling purposes. In 2016, shortened cleanouts and optimization activities helped refine the pH control to optimize lime addition and reduce scale buildup.

Plant Maintenance

2 The treated HSB water that is used in MR’s milling process as required by the Consent Decree is 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 Consent Decree Statement of Work and plant water that is treated to standards amenable for inclusion into MR’s milling process.


A Maintenance Technician is assigned full time to the HSBWTP. In addition, MR’s Mill Maintenance Department assigns instrumentation technicians, electricians, and other mechanical and welding technicians when required. The Maintenance Electrical Superintendent also provides valuable computer information technology (IT) support for the HSBWTP. The operation and the maintenance of the Plant greatly benefits from this management situation, which results in efficient operation and exceptional Plant reliability. 2016 Notable Maintenance Activity

The notable 2016 HSBWTP maintenance activity, by quarter, is summarized as follows:

First Quarter: Completed punch list items from Swank Enterprises’ work to implement piping

maintenance to increase HSBWTP flow capacity. The work was documented and reported to the Agencies on August 10, 2016, in the correspondence Re: MBMG Weir Upgrades Summary and the 2015 HSBWTP Underground Piping Upgrades Summary Memoranda (SDs, 2016).

Replaced Stage 2 sludge pump. Replaced automated flush water valve on the north lime sump. Replaced motor on polymer system disperser. Replaced 2.5-inch Red Valve on the Stage 1 alkalization tank south slurry supply

line. Replaced disperser on polymer system. Replaced mixer motor on the #2 polymer system mix tank. Replaced bearings and auger in north lime feeder. Replaced knife gate on north lime silo. Replaced south slaker lime slurry return line. Replaced mixer gear box on polymer system #2 mix tank. Replaced 6-inch Red Valve on Stage 2 recycle line. Replaced booster pump on south slaker. Installed new motor on influent pump #114. Rebuilt south slaker grit conveyor (new shafts, bearings, sprockets, paddles, and

chain).

Second Quarter: Stage 2 of the HSBWTP was bypassed and taken out of service for annual

maintenance on May 19, 2016. During the Stage 2 cleanout, Veolia Environmental was contracted to remove the scale from the Stage 2 reactor walls using high pressure water. After the scale was removed from the Stage 2 reactor, repairs were made to the liner. Lawrence Hunter inspected the concrete in the Stage 2 clarifier and reactor


on July 27, 2016 (see Attachment 1 for inspection reports). A small area of delaminated concrete was found in the Stage 2 clarifier. The delaminated concrete was removed and the area repaired.

Replaced motor on south slaker paddle shafts. Replaced motor on south slaker feeder. Installed new motor on effluent pump #113. Replaced north slurry pump # 2. Descaled discharge line from the Stage 1 alkalization tank. Installed new pinch valve on the downstream side of the Stage 2 recycle line flow

meter. Installed new pressure gauges on the influent and effluent pumps. Rebuilt grit conveyor on north slaker (new bearings, shafts, sprockets, chain and

paddles). Installed new drive on polymer pump No. 1. Jetted the line entering the equalization pond.

Third Quarter:

Cleaned the Equalization Basin using a dredge to remove built up sedimentation. The dredging started on July 20, 2016, and was completed on July 26, 2016.

Stage 2 was brought back on-line August 1, 2016, at which time Stage 1 was bypassed and taken out of service for annual maintenance. Stage 1was brought back online on September 1, 2016, and the HSBWTP operated in dual stage mode for the remainder of the year. Lawrence Hunter inspected the concrete in the Stage 1 clarifier and reactor on August 25, 2016 (see Attachment 2 for inspection reports). Two small areas of delaminated concrete were found on the floor of the reactor. The delaminated concrete was removed and the areas repaired.

Rebuilt grit conveyor on north slaker. Replaced pinch valve on north slurry tank return line. Cleaned effluent flow meter. Installed two new valves on south lime slurry tank discharge. Replaced Stage 2 sludge pump. Replaced Stage 1 sludge pump. Replaced the south slaker paddle shaft, end bearings, and seals. Replaced flow meter on Stage 2 blower line. Replaced screen on south slaker PLC panel. Cleaned scale from Stage 2 reactor walls. Repaired coating on Stage 2 reactor walls. Dewatering wells re-routed and no longer discharging within plant.


Fourth Quarter: The HSBWTP was shut down October 17, 2016, to October 20, 2016, to clean

accumulated sediments from the influent wet well. Installed new influent pump for pump No. 115. Installed new check valves in influent pumps No. 114 & 115. Replaced Stage 2 lime addition valve. Replaced actuator for Stage 2 lime addition valve. Replaced Stage 1 sludge pump. Replaced base cone on south silo. Separated blowdown lines for Stage 1 and Stage 2 to allow each stage to be operating

and not restrict the other. Rebuilt top end of air compressor.

SUMMARY

In 2016, all the HSB treated water was incorporated into MR’s milling circuit pursuant to the BMFOU Record of Decision dated September 29, 1994, and Appendix C to Consent Decree, Statement of Work. REFERENCES

EPA, 1994. U.S. Environmental Protection Agency BMFOU Record of Decision, Silver Bow

Creek/Butte Area. EPA ID: MTD980502777 OU 03 Butte, MT. EPA/ROD/R08-94/102, dated September 29, 1994 https://semspub.epa.gov/work/HQ/188195.pdf.

SDs, 2016. MBMG Weir Upgrades Summary and the 2015 HSBWTP Underground Piping

Upgrades Summary Memoranda. Letter from Settling Defendants to Agencies, 2016. SDs, 2014. Operations and Maintenance (O&M) Manual Horseshoe Bend Wastewater Treatment

Plant (HSBWTP). Settling Defendants manual dated 2014.

https://semspub.epa.gov/work/HQ/188195.pdf

HSBWTP 2016 ANNUAL REPORT

ATTACHMENT 1:

Stage 2 Reactor and Clarifier Inspection Reports

HSBWTP 2016 ANNUAL REPORT

ATTACHMENT 2:

Stage 1 Reactor and Clarifier Inspection Reports


Q4 2016

ATTACHMENT 4:

Berkeley Pit Slope Stability Quarterly Summaries


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

MEMORANDUM TO: Stephen Walsh

FROM: S. Huckeby

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

DATE: February 7, 2017

SUBJECT: Berkeley Pit Slope Stability Fourth Quarter Summary 2016

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

Table 1. Berkeley monitoring network Fourth Quarter 2016.

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).

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BERKELEY PIT

HIGHWALL STABILITY

Bird Watch Sector

Concentrator Sector

Southeast Sector

Pittsmont Sector

Berkeley Slope Stability Quarterly Summary Oct - Dec 2016 Page 2 of 6


Three survey points in the Bird Watch Sector were checked weekly and one survey point was checked daily. Survey points in the Southeast Sector and Concentrator 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. TDR wells were read weekly. Water levels can be measured in both TDR wells and Inclinometers. These water levels as well as standalone piezometers were measured either daily or monthly (TDR wells). Berkeley Pit - Active Sectors Sector nomenclature for the Berkeley pit is detailed on Plate II (attached).

Figure 1. TDR Well locations. Bird Watch Sector: The Bird Watch Sector monitor points did not exhibit any abnormal movement during the Fourth 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 TDR cable in Well B06-1 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. TDR 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 Fourth Quarter of 2016. 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 Fourth Quarter of 2016. The backup pumps installed in PZF15-1 and PZF 15-6 did not operate during the quater.

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

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 25.8 99% 25.4 100% 25.9 99% 22.6 91%PZF15-3 110.6 99% 113.4 100% 113.5 99% 111.8 90%PZF15-4 14.6 99% 15.0 100% 15.2 99% 14.9 91%PZF15-5 9.5 99% 14.8 100% 15.4 99% 13.7 91%PZF15-6 0.0 0% 0.0 0% 0.0 0% 0.0 0%LP-15 40.6 99% 40.3 100% 40.4 99% 40.5 91%

December Fourth Quarter 2016October NovemberDewatering

Wells



Pittsmont Sector: Prisms on the Pittsmont dump were surveyed approximately once a week during the quarter. No slope movements were detected during the quarter. The TDR 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 unexpected fluctuations of note during the quarter in the Bird Watch, Concentrator, or Pittsmont Sectors.

Figure 4. Hydrographs Bird Watch Sector.



Figure 5. Hydrographs Concentrator Sector.

Figure 6. Hydrographs Southeast Sector inclinometer wells.



Figure 7. Hydrographs Southeast Sector pumping wells

Figure 8. Hydrographs Pittsmont Sector.

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letter transmits attached settling defendants bmfou ... · on september 2, 2016, the fou raar draft...

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