Scope_of_Work_RDM_Baseline_Monitoring_2026-27.pdf

Statement of Work

Red Devil Mine - Alaska Baseline Monitoring

A. Introduction The Bureau of Land Management (BLM) is conducting response action at the Red Devil Mine (RDM), located on the Kuskokwim River in southwest Alaska (Figure 1). The project is being performed using the process defined under the Comprehensive Environmental Response, compensation and Liability Act (CERCLA). The Remedial Investigation and Feasibility Study (RI/FS) phase of the process is complete and resulting documentation can be downloaded from the project administrative record using the following url:

https://www.blm.gov/programs/public-safety-and-fire/abandoned-mine-lands/regional-information/alaska/projects/red-devil-mine Baseline monitoring work plans and reports for 2019-2024 can be downloaded from the administrative record web page using the URL listed above. Note that there is no work plan addendum for 2024. Monitoring performed in 2024 is based on the 2023 work plan addendum.

This scope of work describes baseline monitoring activities to be performed in 2026 with an option to conduct monitoring in 2027. In general, the 2026-27 baseline monitoring program at RDM is similar to previous phases of baseline monitoring. Dedicated bladder pumps have been installed in all monitoring wells to be sampled in 2026-27. Sampling methods, locations, timing and analytes are identical to previous years.

B. Background

The Red Devil Mine (RDM) was once the leading mercury producer in Alaska. The mine has been inactive since the early 1970’s and the site is currently being managed by the BLM. Extensive ore processing was performed at the mine site, leaving large volumes of tailings adjacent to Red Devil Creek. The processed tailings are the primary contaminant source at Red Devil Mine.

Data analysis performed as part of the RI indicate that groundwater in the vicinity of Red Devil Creek, where the tailings and waste rock are prevalent, contains elevated concentrations of the three primary contaminants of concern (COCs): arsenic, mercury and antimony. Monitoring wells were installed and sampled in the vicinity of the tailings piles as part of the initial RI to define the nature and extent of contamination. No monitoring wells were installed in the higher elevations of the watershed because surface sampling results demonstrated that tailings and waste rock were absent outside of the area adjacent to ore processing buildings.

Multiple remediation alternatives evaluated through the Feasibility Study (FS) include an onsite repository located on the northern edge of the Red Devil Creek watershed. Because groundwater was not evaluated in the vicinity of the proposed repository location as part of the RI, additional monitoring wells were installed to characterize the bedrock aquifer upgradient of the tailings. Initial samples were collected from the new wells while the FS was in progress and those results were initially reported in the Supplemental Feasibility Study Report (2019).

Because CERCLA RI/FS was conducted over a 9 year period, groundwater and surface water data were initially documented in multiple reports making it difficult to access the data and discussion of related analysis. Recognizing that groundwater and surface water quality will be key metrics in https://www.blm.gov/programs/public-safety-and-fire/abandoned-mine-lands/regional-information/alaska/projects/red-devil-mine https://www.blm.gov/programs/public-safety-and-fire/abandoned-mine-lands/regional-information/alaska/projects/red-devil-mine evaluating future remedial action, the BLM consolidated the groundwater data and analysis performed as part of the RI and FS in a single report titled, The Final Red Devil Mine Groundwater and Surface Water Report (June 2019). The compiled groundwater/surface water can be downloaded from the online administrative record.

The RI/FS extended through 2018, and a preferred remedial alternative was selected in 2019.

Selecting a preferred remedial alternative provided a framework to identify data needed to support remedial action. The baseline monitoring program was initiated in 2019 when the formal work plan was submitted for regulatory review. The initial round of baseline monitoring was performed in 2020.

The tasks described below are a continuation of the baseline monitoring program and the methods to be used are detailed in the 2019 work plan.

C. Base Scope of Work The RDM baseline monitoring program is structured in three tasks: planning, field data collection and reporting. Deliverables are required for the planning and reporting tasks. The 2026-27 baseline monitoring approach is limited to groundwater and surface water monitoring within the mine site. No water or sediment samples are to be collected from the Kuskokwim River.

C.1 Task 1 –Planning The contractor shall be responsible for technical and logistical planning in coordination with the BLM. The contractor shall accomplish the following as part of the planning task:

1. Developing a project schedule that defines all field work and deliverables

2. Meeting planning milestones as defined in the project schedule

3. Developing an addendum to Final Work Plan, Groundwater and Surface Water Monitoring, Red Devil Mine Alaska, June, 2019 (2019 plan) for BLM review and comment

4. Procuring services to support logistics and provide laboratory data

The work plan addendum shall reference the 2019 plan. The addendum shall describe all differences between the 2019 and 2026 sampling events. The administrative record contains 2020 and 2021 addenda to the 2019 plan. The contractor shall format the 2026 addendum in the same manner as earlier addenda.

C.2. Task 2 – Field Data Collection Groundwater characterization results clearly show that groundwater levels increase consistently across the site in the spring, shortly after breakup. Similarly, groundwater levels begin to decrease in all wells at approximately the same time that seasonal baseflow recession in Red Devil Creek begins in late fall. A key objective of baseline monitoring is to identify and track seasonal variability in groundwater flow patterns and related variability in COC concentrations. Consequently, it is important that a sampling event be performed as soon after spring breakup and as late in September as site conditions allow. Field data collection shall be planned sampling events in late May and late September. Site conditions and weather have been determining factors in past sampling events.

The locations of all monitoring wells and surface water sampling stations are illustrated in Figures 2 and 3 (attached). Static water level measurements are to be made in all wells within a 24-hour period during both sampling events in 2026. Only those monitoring wells highlighted in yellow in Table 1 are to be sampled in 2026. All surface water monitoring stations listed in Table 2 are to be sampled in 2026.

The contractor shall be responsible for providing all labor, materials, equipment and logistics necessary to:

1. Mobilize to the project site all personnel, equipment and material needed to perform monitoring activities

2. Ensure that all samples are transported to the laboratory under chain of custody such that laboratory analysis is performed within holding times prescribed for all analytical methods

3. Coordinate with the BLM at least once a week while data collection is ongoing

4. Demobilizing personnel, equipment and material from the site at completion of field data collection period At the time the static water level is measured in each well, the contractor shall measure the elevation difference between the top of casing and adjacent ground surface. The measured difference shall be reported with water table elevation results as a check on impacts of seasonal frost on well casing elevation.

The contractor shall be responsible for arranging lodging, food and, field transport for the field crew during the data collection period. Seasonal lodges are available in both Red Devil and Sleetmute. The contractor is not responsible for providing lodging, food or field transport for any government employees as part of this task order.

2026 Groundwater Monitoring The contractor shall collect depth to static water level measurements in all monitoring wells listed in Table 1. Depth to water is to be measured in all wells within a 24-hour period during both the spring and fall sampling events.

Groundwater samples shall be collected using methods and protocols defined in the 2019 Baseline Monitoring Work Plan. Water samples are to be collected for laboratory analysis only from the monitoring wells highlighted in yellow in Table 1.

Table 1 Baseline Groundwater Monitoring Well Summary

Base Scope of Work

Monitoring Well ID

Year Monitoring Well Status

Northing Easting Latitude Longitude

MW01 2011 Active 6848472.892 588897.3617 61.75889973 -157.315908 MW03 2011 Active 6848581.065 588979.8349 61.7598512 -157.3142933 MW04 2011 Active 6848564.133 588907.3826 61.75971611 -157.3156735 MW06 2011 Active 6848656.18 588995.1024 61.76052164 -157.3139673 MW07 2011 Active 6848393.712 588891.9008 61.75819052 -157.3160502 MW08 2011 Active 6848354.155 588997.7221 61.75781096 -157.314066 MW09 2011 Active 6848491.702 588970.2143 61.75905157 -157.3145193 MW10 2011 Active 6848470.815 588950.2887 61.75886879 -157.3149068 MW11 2011 Active 6848454.172 588935.993 61.75872278 -157.3151857 MW12 2011 Active 6848354.269 588742.4843 61.75787129 -157.3188986 MW13 2011 Active 6848408.425 588879.97 61.75832531 -157.3162689 MW14 2011 Decommissioned 6848508.596 588912.2571 61.75921664 -157.3156084 MW15 2011 Decommissioned 6848524.636 588918.9663 61.75935901 -157.3154735 MW16 2011 Active 6848553.57 588947.871 61.75961191 -157.314912 MW17 2011 Active 6848551.484 588948.1433 61.75959313 -157.3149079 MW18 2011 Active 6848531.638 588988.1867 61.75940574 -157.3141594 MW19 2011 Active 6848571.165 589025.1547 61.75975182 -157.31344 MW20 2011 Active 6848592.8 588967.1091 61.75995945 -157.3145285 MW21 2011 Active 6848622.174 589000.2127 61.76021533 -157.3138872 MW22 2011 Active 6848638.537 589022.4639 61.76035697 -157.3134579 MW23 2011 Active 6848688.27 589038.5637 61.76079947 -157.3131286 MW24 2011 Active 6848641.681 588975.4127 61.76039613 -157.3143472 MW25 2011 Active 6848629.149 588940.7024 61.76029175 -157.3150107 MW26 2011 Active 6848622.444 588918.9978 61.76023664 -157.3154249 MW27 2011 Active 6848587.889 588919.2896 61.75992651 -157.3154364 MW28 2011 Active 6848585.43 588917.8712 61.75990477 -157.3154644 MW29 2011 Active 6848700.653 588897.0048 61.76094352 -157.315803 MW30 2011 Active 6848630.777 588855.5862 61.76032614 -157.3166216 MW31 2011 Active 6848717.532 588561.9681 61.7611727 -157.322139 MW32 2011 Active 6848725.007 589122.1639 61.76110964 -157.3115275 MW33 2011 Active 6848780.504 589096.4901 61.7616136 -157.3119863 MW34 2011 Active 6848558.6 589074.0454 61.75962768 -157.3125204 MW35 2011 Active 6848567.313 589075.9173 61.75970543 -157.3124807 MW36 2011 Active 6848564.717 589084.2718 61.75968019 -157.3123238 MW39 2015 Active 6848849.533 588651.3045 61.76233646 -157.3203827 MW40 2015 Active 6848767.128 588726.9626 61.76157949 -157.3189904 MW42 2015 Active 6848618.255 588792.7568 61.76022838 -157.3178174 MW43 2015 Active 6848605.028 588834.4352 61.76010001 -157.3170347

Monitoring Well ID

Year Monitoring Well Status

Northing Easting Latitude Longitude

MW44 2017 6848863.449 588738.0061 61.76244122 -157.3187341

MW45 2017 Active 6848923.057 588700.9894 61.76298466 -157.3194059 MW46 2017 Active 6848994.838 588631.5805 61.76364486 -157.3206852 MW47 2017 Active 6849057.39 588604.4875 61.76421241 -157.3211676 MW48 2017 Active 6848841.96 588787.3862 61.76223694 -157.3178095 MW49 2017 Active 6848819.986 588882.4892 61.76201767 -157.3160193 MW50 2017 Active 6848912.827 588629.5502 61.76290944 -157.3207637 MW51 2017 Active 6848980.258 588580.2529 61.76352592 -157.3216643 MW52 2017 Active 6849032.846 588522.5802 61.76401115 -157.3227308 MW53 2017 Active 6848849.577 588568.7948 61.76235596 -157.3219452 MW54 2017 Active 6848903.625 588517.9083 61.76285272 -157.3228824 MW55 2017 Active 6848988.233 588449.4053 61.76362777 -157.3241383 MW56 2017 Active 6848851.666 588696.7599 61.76234506 -157.3195209 MW57 2017 Active 6848793.412 588612.8689 61.76184178 -157.321138 MW58 2017 Active 6848819.169 588496.7913 61.76209978 -157.3233235 MW59 2017 Active 6848851.296 588656.2038 61.76235113 -157.3202891

Notes:

1. Groundwater samples shall be collected from monitoring wells highlighted in yellow

2. Northing and easting are provided as Alaska State Plane coordinates.

Surface water monitoring in Red Devil Creek Surface water monitoring shall be performed to evaluate discharge rate and surface water quality at seven locations on lower Red Devil Creek. The locations of the five sampling stations are illustrated in the attached figure. The five surface water sampling station identifiers and coordinates are summarized in Table 2. Note that due to action taken in 2014 to prevent tailings/waste rock from migrating downstream in Red Devil Creek, the current surface sampling locations may not be the same as those described in the RI report (November 2014).

No stream sediment samples will be collected. Northing and easting are Alaska State Plane coordinates.

Table 2 Baseline Surface Water Monitoring Locations

Based Scope of Work

Location ID Decimal Degree Latitude

Decimal Degree Longitude

Northing Easting

RD10SW 61.75814 -157.319 588731.8 6848384

RD15SW 61.7555 -157.321 588644.3 6848088

RD05SW 61.7618 -157.312 589100.3 6848801

RD06SW 61.76143 -157.311 589135.7 6848761

RD08SW 61.76169 -157.311 589133.4 6848790

Laboratory Analysis The parameters demonstrated as most significant contributors to overall risk at RDM are the primary focus of baseline monitoring.

The number of samples to be sent off site for laboratory analyses and the analytical methods to be applied to those samples are summarized in Table 3.

Table 3 Surface Water and Groundwater Analytical Summary

Base Scope of Work

Media Analysis Method Primary Samples

Field Duplicate

Rinsate Blank

Field Blank

Trip Blank

Total Samples

Surface Water

Total TAL Metals EPA 6010B/6020A 5 1 2 1 9 Total Low-Level Mercury EPA 1631 5 1 2 1 1 10

TSS EPA 160.2 5 1 1 7

TDS EPA 160.1 5 1 1 7

Inorganic Ions (Cl, F, EPA 300.0 5 1 2 1 9

Nitrate-Nitrite as N EPA 353.2 5 1 2 1 9 Alkalinity as CO3/HCO3 EPA 310.1 5 1 2 1 9

Groundwater

Total TAL Metals EPA 6010B/6020A 28 3 3 3 37 Total Low-Level Mercury EPA 1631 28 3 3 3 1 38 Dissolved Low-Level Mercury EPA 1631 28 3 3 3 1 38

C.3. Task 3 – Documentation The contractor shall submit four deliverables to the BLM as part of this scope of work:

1. A project schedule

2. Draft and Final addendum to the 2019 plan covering both sampling events during the base year

3. A Data Summary Report for the spring 2026 sampling event

4. Draft and Final Annual Data Summary Report summarizing results for both sampling events during the bases year.

Draft versions of the Baseline Monitoring Work Plan and the Annual Data Summary Report shall be submitted to BLM in PDF for review and comment. The draft text shall also be submitted as a MS Word file. The BLM will provide comments in the draft Word file using track changes.

The contractor project manager shall participate in one conference call with the BLM to resolve comments and define final responses. The contractor shall incorporate all changes resulting from BLM comments into a final version of each document. A table with comments and final responses shall be submitted along with the final document.

The contractor shall submit 3 hard copy of the final work plan, final data summary, and the final annual report. The draft plan, draft reports and all final documents should be submitted in PDF. The final documents shall be bookmarked. All final reports (both electronic and hard copy) shall include an electronic submittal of all information received from the analytical laboratory and complete versions of all quality assurance review reports.

C.3.1 Project Schedule The project schedule will specify beginning and end of the period of performance, the projected beginning and end dates for each sampling event, and all submittal milestones. The project schedule shall be submitted to BLM as a PDF Gant Chart within 4 weeks of receiving authorization to proceed. The Gant Chart should include a table listing all milestone dates and duration of all sampling events.

C.3. 2 Baseline Monitoring Work Plan Baseline monitoring methods and procedures generally follow those developed for the RI. The contractor shall develop a letter work plan addendum for 2026 by referencing the 2019 plan regarding all methods and protocols applicable to the 2026 baseline monitoring program scope of work. All planned variances from the 2019 work plan (other than schedule) shall be described in the 2026 work plan addendum. The format of the 2026 work plan addendum shall be consistent the format of previous addenda.

C.3.3 Data Summary Report The spring 2027 monitoring results shall be submitted to the BLM in a letter report. The letter report shall consist of:

• A brief narrative of activities completed during the sampling event, including discussion of any deviations from methods and procedures in the work plan

• Tables of depth to static water data with associated elevations and Red Devil Creek discharge data collected in spring 2026

• Tables of analytical data for groundwater and surface water samples organized by parameter and sampling location.

• A potentiometric surface map showing the depth to static water elevation for each well and interpolated water table contours using data collected in spring 2024 (2026?)

The analytical data summarized in the letter report shall have been subjected to a quality assurance review and flagged as appropriate.

C.3.4 Annual Summary Report An annual data report summarizing monitoring results for both 2026 sampling events shall be submitted to BLM and regulatory agencies for review and comment. The format and content of the 2026 annual data report shall be consistent with 2021 Annual Baseline Monitoring Report, Red Devil Mine, Alaska (March 2022). Discussion shall summarize data trends observed in 2026 data and how they relate to historical data. All tables and figures contained in previous annual reports shall be extended to include 2026 data and included in the annual data report. The report shall also discuss unexpected site conditions that could impact monitoring results and recommendations for future baseline monitoring.

The annual data report shall contain the following attachments:

• Field documents, including observations pertinent to sampling pump performance

• A photo log illustrating:

o The condition of all damaged wellheads o Conditions along the section of Red Devil Creek where surface water samples are collected, highlighting sampling locations o The condition of all structures constructed on Red Devil Creek as part of the 2014

Interim Action o Conditions at the mouth of Red Devil Creek, the adjacent barge landing (also referred to as the Red Devil Creek Delta) and current stage of the Kuskokwim River o Condition of the small area known as the Dolly Suice, located just downstream of the barge landing o Conditions of the reclaimed section of Red Devil Creek in the vicinity of the demolished reservoir dam (upstream of the mine) o The presence and condition of all beaver dams on the reach of Red Devil Creek extending from the reclaimed section to the mine

• Analytical laboratory reports

• Data Validation Reports

C.3.5 Submittal Format All final tables and graphs of analytical data shall be submitted in Excel 2010 format, and all maps shall be submitted as shape files in ESRI compatible electronic format. An electronic copy of the draft and final deliverables shall be provided in a Portable Document Format (PDF) generated using Adobe Acrobat version 10 or later. The text for all draft deliverables shall be submitted and in Word format. With the exception of the analytical laboratory submittal and full quality assurance review reports, the PDF formatted draft and final versions shall all comply with Section 508 of the Rehabilitation Act. Section 508 requires that Federal agencies' electronic and information technology is accessible to people with disabilities to assure accessibility by the visually impaired using assistive technology such as screen readers and refreshable Braille displays. Guidance on

Section 508 compliance is available at http://www.section508.gov/. No submittal shall be considered “508 compliant” until it has been reviewed and approved by the BLM. It is recommended, but not required, that the contractor use the following checklist for making submittals “508 compliant”:

1. Document file name does not contain spaces or special characters.

2. Document file name should be concise, generally be limited to 20-30 characters, but make the content of the file clear in the context in which it is presented.

3. Document properties for Title, Author, Keywords, and Language are properly filled out.

4. If the edit function of Adobe Acrobat was used, all Comment and Markup items must be deleted.

5. A visual check has been done to ensure no hidden data from MSWord or other applications used to create the original document are present.

6. All images and/or non-text elements have alternative text descriptions (see Note 4 below).

7. All charts and graphs have an alternative text description and provide a description in the text immediately below the chart/graph.

8. Files of 10 pages or more have internal bookmarks.

9. Color is not used to convey important information, e.g., "See red text below."

10. Data tables identify row and column headers.

11. Layout tables do not identify row and column headers

12. Data cells in tables are associated with row and column headers.

13. All tables read from left to right and top to bottom.

14. All hyperlinks use the full Web address, e.g., http://www.blm.gov/ (not simply www.blm.gov).

15. Pages with multi-column text, tables, or call-out boxes have been checked for reading order using the Acrobat Professional "Read Aloud‟ function.

16. All needed accessibility tags have been added and a full Accessibility Report has been run in Adobe Acrobat Professional 10* or higher showing no errors present.

17. A separate text-only version has been provided when there is no other way to make the content accessible. (Example: An organizational chart must have a text- only version).

Checklist Notes:

1. If content will be available as html or text, it is not required that the accompanying PDF file be Section 508 accessible.

2. A PDF created by scanning a paper document in TIFF or another image format is not 508 compliant. Either a text-only version must be provided or, for complicated figures and maps, "Map Title Description. If you need help in using the data or information, the ALT tag must have title and description and a point of contact person as defined in the following: here, please contact the Alaska State Office Public Information Center at 907-271-5960. Adobe provides Accessibility best practices at: http://www.adobe.com/accessibility/best_practices.html#acrobatx

3. PDF forms require a specialized accessibility review because they present an additional degree of complexity.

http://www.section508.gov/ http://www.section508.gov/ http://www.blm.gov/ http://www.blm.gov/ http://www.adobe.com/accessibility/best_practices.html#acrobatx

4. If a graphic is purely decorative or included for spacing purposes (such as a 1 pixel gif spacer), an ALT tag is not required. If the graphic is not referenced at a specific point in the text, it’s best to include it in the reading order at a convenient point, for instance, at the end of a paragraph.

Additional guidance on DOI policy for complying with Section 508 of the Rehabilitation

Act can be found at: http://www.hhs.gov/web/policies/checklistpdf.html. Please contact the Alaska State Office Public Information Center at 907-271-5960 with questions. Adobe provides Accessibility best practices at: http://www.adobe.com/accessibility/best_practices.html#acrobatx

3. PDF forms require a specialized accessibility review because they present an additional degree of complexity.

4. If a graphic is purely decorative or included for spacing purposes (such as a 1 pixel gif spacer), an ALT tag is not required. If the graphic is not referenced at a specific point in the text, it’s best to include it in the reading order at a convenient point, for instance, at the end of a paragraph.

Additional guidance on DOI policy for complying with Section 508 of the Rehabilitation Act can be found at: http://www.hhs.gov/web/policies/checklistpdf.html.

D. Optional Scope of Work The methods, sampling event planned schedule and reporting requirements for the optional scope of work are identical to the base scope of work. The optional scope of work applies to sampling events in spring and fall 2027. The optional scope of work shall be exercised at the discretion of the contracting officer subject to availability of funding.

D.1 Task 1 –Planning Planning requirements for the optional scope of work are identical to those described in Section C.1.

D.2. Task 2 – Field Data Collection Field data collection will be performed in two sampling events during 2027; one in late May and one in September. All other requirements are identical to those described in Section C.2.

Groundwater Monitoring Groundwater monitoring shall be performed at the 28 monitoring wells highlighted in yellow in Table 4. The depth to static water level will be measured in all the wells listed in Table 4 at least once during each sampling event, within a 24- hour period.

Table 4 Groundwater Monitoring Well Summary

Optional Scope of Work

Monitoring Well ID

Year Monitoring Well Status

Northing Easting Decimal Degrees Latitude

Decimal Degrees

Longitude MW01 2011 Active 6848472.892 588897.3617 61.75889973 -157.315908 MW03 2011 Active 6848581.065 588979.8349 61.7598512 -157.3142933 MW04 2011 Active 6848564.133 588907.3826 61.75971611 -157.3156735 MW06 2011 Active 6848656.18 588995.1024 61.76052164 -157.3139673 MW07 2011 Active 6848393.712 588891.9008 61.75819052 -157.3160502 http://www.hhs.gov/web/policies/checklistpdf.html http://www.adobe.com/accessibility/best_practices.html#acrobatx http://www.hhs.gov/web/policies/checklistpdf.html

Year Monitoring Well Status

Northing Easting Decimal Degrees Latitude

Decimal Degrees

Longitude MW08 2011 Active 6848354.155 588997.7221 61.75781096 -157.314066 MW09 2011 Active 6848491.702 588970.2143 61.75905157 -157.3145193 MW10 2011 Active 6848470.815 588950.2887 61.75886879 -157.3149068 MW11 2011 Active 6848454.172 588935.993 61.75872278 -157.3151857 MW12 2011 Active 6848354.269 588742.4843 61.75787129 -157.3188986 MW13 2011 Active 6848408.425 588879.97 61.75832531 -157.3162689 MW14 2011 Decommissioned 6848508.596 588912.2571 61.75921664 -157.3156084 MW15 2011 Decommissioned 6848524.636 588918.9663 61.75935901 -157.3154735 MW16 2011 Active 6848553.57 588947.871 61.75961191 -157.314912 MW17 2011 Active 6848551.484 588948.1433 61.75959313 -157.3149079 MW18 2011 Active 6848531.638 588988.1867 61.75940574 -157.3141594 MW19 2011 Active 6848571.165 589025.1547 61.75975182 -157.31344 MW20 2011 Active 6848592.8 588967.1091 61.75995945 -157.3145285 MW21 2011 Active 6848622.174 589000.2127 61.76021533 -157.3138872 MW22 2011 Active 6848638.537 589022.4639 61.76035697 -157.3134579 MW23 2011 Active 6848688.27 589038.5637 61.76079947 -157.3131286 MW24 2011 Active 6848641.681 588975.4127 61.76039613 -157.3143472 MW25 2011 Active 6848629.149 588940.7024 61.76029175 -157.3150107 MW26 2011 Active 6848622.444 588918.9978 61.76023664 -157.3154249 MW27 2011 Active 6848587.889 588919.2896 61.75992651 -157.3154364 MW28 2011 Active 6848585.43 588917.8712 61.75990477 -157.3154644 MW29 2011 Active 6848700.653 588897.0048 61.76094352 -157.315803 MW30 2011 Active 6848630.777 588855.5862 61.76032614 -157.3166216 MW31 2011 Active 6848717.532 588561.9681 61.7611727 -157.322139 MW32 2011 Active 6848725.007 589122.1639 61.76110964 -157.3115275 MW33 2011 Active 6848780.504 589096.4901 61.7616136 -157.3119863 MW34 2011 Active 6848558.6 589074.0454 61.75962768 -157.3125204 MW35 2011 Active 6848567.313 589075.9173 61.75970543 -157.3124807 MW36 2011 Active 6848564.717 589084.2718 61.75968019 -157.3123238 MW39 2015 Active 6848849.533 588651.3045 61.76233646 -157.3203827 MW40 2015 Active 6848767.128 588726.9626 61.76157949 -157.3189904 MW42 2015 Active 6848618.255 588792.7568 61.76022838 -157.3178174 MW43 2015 Active 6848605.028 588834.4352 61.76010001 -157.3170347

MW44 2017 6848863.449 588738.0061 61.76244122 -157.3187341

MW45 2017 Active 6848923.057 588700.9894 61.76298466 -157.3194059 MW46 2017 Active 6848994.838 588631.5805 61.76364486 -157.3206852 MW47 2017 Active 6849057.39 588604.4875 61.76421241 -157.3211676 MW48 2017 Active 6848841.96 588787.3862 61.76223694 -157.3178095 MW49 2017 Active 6848819.986 588882.4892 61.76201767 -157.3160193

Year Monitoring Well Status

Northing Easting Decimal Degrees Latitude

Decimal Degrees

Longitude MW50 2017 Active 6848912.827 588629.5502 61.76290944 -157.3207637 MW51 2017 Active 6848980.258 588580.2529 61.76352592 -157.3216643 MW52 2017 Active 6849032.846 588522.5802 61.76401115 -157.3227308 MW53 2017 Active 6848849.577 588568.7948 61.76235596 -157.3219452 MW54 2017 Active 6848903.625 588517.9083 61.76285272 -157.3228824 MW55 2017 Active 6848988.233 588449.4053 61.76362777 -157.3241383 MW56 2017 Active 6848851.666 588696.7599 61.76234506 -157.3195209 MW57 2017 Active 6848793.412 588612.8689 61.76184178 -157.321138 MW58 2017 Active 6848819.169 588496.7913 61.76209978 -157.3233235 MW59 2017 Active 6848851.296 588656.2038 61.76235113 -157.3202891

Notes:

1. Groundwater samples shall be collected from monitoring wells highlighted in yellow

2. Northing and easing are Alaska State Plane coordinates

Surface water monitoring in Red Devil Creek Surface water monitoring shall be performed to evaluate discharge rate and surface water quality at five locations along the stream section that flows through the main mine area (see attached figure). The five sampling station identifiers and coordinates are summarized in Table 5. Note that due to action taken in 2014 to prevent tailings/waste rock from migrating downstream in Red Devil Creek, the current surface sampling locations may not be the same as those described in the RI report (November 2014). No stream sediment samples will be collected. Northing and easing are Alaska State Plane coordinates.

Table 5 Baseline Surface Water Monitoring Locations

Location ID Decimal Degree Latitude

Decimal Degree Longitude Northing Easting

RD010SW 61.756 -157.321 6848130.277 588623.0283

RD15SW 61.759775 -157.315041 6848571.616 588940.384

RD05SW 61.759865 -157.315003 6848581.629 588942.3573

RD06SW 61.760513 -157.313342 6848656.05 589028.137

RD08SW 61.761693 -157.311282 6848790.359 589133.4419

Laboratory Analysis The parameters demonstrated as most significant contributors to overall risk at RDM are the primary focus of baseline monitoring. The number of samples to be sent off site for laboratory analyses and analytical methods to be applied to those samples are summarized in Table 6.

Table 6 Surface Water and Groundwater Analytical Summary

Base Scope of Work

Media Analysis EPA Method Number

Primary Samples

Field Duplicate

Rinsate Blank

Field Blank

Trip Blank

Total Samples

Surface Water

Total TAL Metals 6010B/6020A 5 1 2 1 9 Total Low-Level Mercury 1631 5 1 2 1 1 10

TSS 160.2 5 1 NA 1 7

TDS 160.1 5 1 NA 1 7

Inorganic Ions (Cl, F, SO4) 300.0 5 1 2 1 9 Nitrate-Nitrite as N 353.2 5 1 2 1 9 Alkalinity as CO3/HCO3 310.1 5 1 2 1 9

Groundwater

Total TAL Metals 6010B/6020A 24 4 4 4 36 Total Low-Level Mercury 1631 24 4 4 4 1 37 Dissolved Low-Level 1631 24 4 4 4 1 37 Mercury

NA – Not Applicable

E. Period of Performance The base period of performance consists of a spring and fall sampling events in 2026. Should a second year of baseline monitoring be authorized, the spring and fall sampling events in 2027 The BLM anticipates that the contractor shall receive authorization to proceed well before May 2027, allowing sufficient time to complete tasks defined in Section C.1. Because the baseline monitoring program is designed to produce a consistent data set over an extended period of time, it is important that spring data collection begin in mid-late May, depending on timing of spring breakup. It is anticipated that all work will be accomplished under the base scope by March 1, 2027. Should the optional task be authorized, all work shall be completed no later than March 1, 2028.

F. Cost Proposal The contractor shall provide a technical proposal describing appropriate technical capability, past project experience and capacity to perform the work. The technical capability summary shall include:

• A list of equipment and material required to accomplish the scope of work

• Project resumes for key personnel that defines their role on the project and highlights the education, training and pertinent experience that qualifies them for that role

• At least three examples of company experience demonstrating successful execution of a monitoring effort of similar magnitude at a remote location. At a minimum, the project manager and field team leader should be able to show that they have played a similar role on at least one of the three project examples.

All subcontractors shall be listed in the technical proposal along with a description of the role they will play on the project. A summary shall be provided for each subcontractor that clearly defines the capability that qualifies them to fulfill their assigned role.

The cost proposal shall include a line item breakdown of cost for all labor, expenses, material and services to be used in meeting the requirements described in Section C. The line item estimate shall include unit costs, number of units and total cost for each line and a total cost to complete the base scope of work. Assumptions made in estimating project costs shall be included in the cost proposal.

The cost proposal shall include a cost estimate for the optional scope of work described in Section D.

The line item estimate shall include unit costs, number of units and total cost for each line and a total cost to complete the base scope of work. Assumptions made in estimating project costs shall be included in the cost proposal. Award of the optional task is subject to available funding and will not be concurrent with the base scope of work.

G. Government Supplied Equipment The government shall provide: dedicated bladder pumps for each monitoring well to be sampled, and keys to locks on the site access gates and to locks on the monitoring wells. All other equipment, material and services required to complete this scope of work shall be provided by the contractor.

H. BLM Points-of-Contact:

Points of contact for the contract are:

The BLM Project Manager is Frank Marley (fmarley@blm.gov, 907-267-1226).

The Contracting Officer is Patrick Euler (peuler@blm.gov, 907-271-4136).

mailto:peuler@blm.gov

Figure 3

Well Construction and Groundwater Depth Information

Reported Well Total Depth As

Constructed (feet bgs)

Reported Screened

Interval (feet bgs)

Surveyed Ground

Elevation (feet

NAVD88)

Surveyed Top of Casing

Elevation (feet

NAVD88)

Measured Well Total

Depth (feet below

TOC)

Well Inner Casing

Stick-up at drilling

Well Inner Casing

Stick-up Surveyed

Ground Water Elevation

(feet NAVD88)

Average of Historical GW Elevation

Range of Historical

GW

Elevation

Comments

MW01 29.5 19.0 - 29.1 254.51 257.51 29.76 3.05 3.00 238.95 237.50 4.71

MW03 25.5 15.0 - 25.0 228.37 230.77 27.75 2.30 2.40 211.81 210.39 7.54

MW04 30.5 20.0 - 30.0 239.92 242.12 32.83 2.00 2.20 217.26 215.86 8.59

MW06 23.5 13.0 - 23.0 214.99 217.49 26.12 2.30 2.50 199.33 198.88 3.04

MW07 21.5 11.0 - 21.0 278.39 280.89 23.47 2.20 2.50 260.76 259.48 3.98

MW08 16.0 5.0 - 15.0 328.92 331.32 17.63 2.20 2.40 318.37 317.63 3.40 Frost-jacking observed May 2017, inner casing has pushed up.

MW09 31.0 20.0 - 30.0 274.88 277.28 34.62 2.30 2.40 250.38 249.28 4.17

MW10 61.0 50.0 - 60.0 274.31 276.21 63.53 2.08 1.90 250.18 247.28 7.90 3-4" of frost jacking observed fall 2017

MW11 23.0 12.0 - 22.0 268.70 271.30 25.42 2.55 2.60 250.04 247.14 3.60

MW12 15.0 4.0 - 14.0 263.22 265.62 17.39 3.70 2.40 260.81 260.73 4.52 Inner casing sticking out of outer casing about 2” due to possible frost jacking observed fall 2017.

MW13 32.0 21.0 - 31.0 274.30 276.70 31.65 2.10 2.40 250.80 247.70 14.99

MW16 22.0 11.0 - 21.0 226.09 228.09 24.08 1.77 2.00 217.77 215.56 9.02

MW17 52.5 41.5 - 51.5 226.36 228.66 54.77 2.02 2.30 216.48 214.18 9.08 3-4" of frost jacking observed May 2017. Outer casing is tilted to south

MW18 40.0 29.0 - 39.0 241.33 243.83 41.14 1.46 2.50 218.17 215.40 9.83

MW19 43.0 32.0 - 42.0 237.70 240.00 45.50 1.50 2.30 224.10 220.04 7.93 Black mark was not at north so took measurement at north fall 2017

MW20 15.5 4.5 - 14.5 212.90 215.20 17.47 2.27 2.30 208.88 208.28 3.78

MW21 17.5 6.5 - 16.5 208.23 210.13 19.39 2.75 1.90 202.00 201.43 1.54 Approx. 4" of frost jacking observed May 2017.

MW22 15.5 4.5 - 14.5 203.10 205.10 17.50 2.35 2.00 197.87 196.49 4.78

MW23 29.0 18.0 - 28.0 201.96 204.16 30.58 1.30 2.20 188.30 188.03 2.32 Frost jacking. Sand above well cap observed May 2017.

MW24 30.0 19.0 - 29.0 221.41 223.51 31.97 1.70 2.10 207.55 206.35 4.43 Minor frost jacking observed May 2017.

MW25 42.0 31.0 - 41.0 237.56 239.76 44.44 1.80 2.20 208.77 207.78 2.99

MW26 43.0 32.0 - 42.0 244.03 245.93 45.01 1.80 1.90 212.73 210.47 4.48

MW27 34.0 23.0 - 33.0 241.04 242.94 35.65 2.00 1.90 214.11 212.72 8.26

MW28 64.0 53.0 - 63.0 239.94 241.94 65.58 2.00 2.00 214.89 213.94 5.94

MW29 70.0 59.0 - 69.0 280.35 282.25 71.52 1.50 1.90 223.89 220.90 14.24 Frost jacking. Sand above well cap. Both observed May 2017

MW30 53.0 42.0 - 52.0 275.71 277.41 55.35 1.60 1.70 223.14 223.64 0.04 Silt on sensor tip when measured TD May 2017. Depth to water measured only

MW31 44.8 33.8 - 43.8 495.79 497.99 47.07 2.00 2.20 462.77 458.77 10.83 Sand at halfway from ground surface to inner casing observed May

MW32 25.0 14.0 - 24.0 194.38 196.58 26.70 1.85 2.20 178.58 177.57 4.62

MW33 23.0 12.0 - 22.0 176.62 178.92 24.40 2.00 2.30 172.25 171.36 5.14

MW34 NR NR 290.95 294.25 65.5 3.2 3.30 264.22 270.18 34.31

MW35 NR NR 285.76 289.26 54.95 3.38 3.50 252.92 246.73 11.75

MW36 NR NR 286.33 290.03 22.60 3.85 3.70 274.57 260.00 25.59

MW39 84.0 63 - 83 432.83 435.26 85.89 2.00 2.43 350.36 349.92 0.14 No sand in inner casing observed May 2017. Depth to water measured only twice because well is typically dry.

MW40 140.0 119 - 139 392.86 395.18 142.35 1.90 2.32 266.46 264.41 4.39 Frost jacking observed May 2017 MW42 140.0 119 - 139 339.85 342.34 142.45 2.40 2.49 215.74 214.29 3.86 No sand in inner casing observed May 2017

Reported Well Total Depth As

Constructed (feet bgs)

Reported Screened

Interval (feet bgs)

Surveyed Ground

Elevation (feet

NAVD88)

Surveyed Top of Casing

Elevation (feet

NAVD88)

Measured Well Total

Depth (feet below

TOC)

Well Inner Casing

Stick-up at drilling

Well Inner Casing

Stick-up Surveyed

Ground Water Elevation

(feet NAVD88)

Average of Historical GW Elevation

Range of Historical

GW

Elevation

Comments

MW43 118.5 98 - 118 300.87 303.69 120.78 2.55 2.82 215.86 215.86 DTW measured only once. No sand in inner casing observed May 2017.

MW44 69 48-68 378.92 381.59 71.73 2.7 2.67 349.08 349.08 N/A DTW measured only once MW45 82 61-81 397.70 400.37 79.78 2.8 2.67 355.31 355.31 N/A DTW measured only once MW46 57 36-56 399.62 402.50 60.04 2.8 2.88 370.69 370.69 N/A DTW measured only once MW47 67 46-66 380.67 383.67 70.2 2.8 3.00 347.79 347.79 N/A DTW measured only once MW48 44.5 23-43 348.87 351.51 46.76 2.8 2.64 332.28 332.28 N/A DTW measured only once MW49 61.7 40-60 301.15 303.78 64.14 2.7 2.63 275.97 275.97 N/A DTW measured only once MW50 92 71-91 439.58 442.6501 96.71 3.0 3.07 392.18 392.18 N/A DTW measured only once MW51 77 56-76 422.38 425.05 80.4 2.7 2.67 386.36 386.36 N/A DTW measured only once MW52 56 35-55 383.91 386.83 59.72 3.2 2.92 357.16 357.16 N/A DTW measured only once MW53 62 41-61 460.82 463.7785 65.6 3.0 2.96 433.88 433.88 N/A DTW measured only once MW54 50 29-49 423.01 425.7406 53.5 3.0 2.73 395.94 395.94 N/A DTW measured only once MW55 27 10-20 341.26 344.09 23.92 2.9 2.83 331.82 331.82 N/A DTW measured only once MW56 76 55-75 408.55 411.329 79.72 2.8 2.78 378.63 378.63 N/A DTW measured only once MW57 60 37.5-57.5 461.00 463.8141 61.45 2.8 2.81 433.16 433.16 N/A DTW measured only once MW58 58 36.62-56.62 469.84 472.7246 60.63 2.9 2.88 443.88 443.88 N/A DTW measured only once MW59 161.5 140-160 432.63 435.4785 167.67 2.7 2.85 297.71 297.71 N/A DTW measured only once

Notes Elevation datum: NAVD88 calculated using GEOID09. Top of casing (TOC) refers to the top of PVC inner casing.

Key GW Groundwater N/A Not Applicable NR Not Recorded