Baca_Haystack_SDV_SOW_1.pdf

Scope of Work

Baca and Haystack Sheep Dip Vat (SDV) Sampling/Removal

McKinley County, Prewitt, New Mexico

INTRODUCTION

The Bureau of Indian Affairs (BIA) Navajo Regional Office (NRO), Branch of Environmental

Management (BEM), is initiating a remediation and restoration project for three former sheep dip vat sites located in Prewitt, New Mexico, under the jurisdiction of the Baca Chapter. The purpose of this project is to eliminate environmental hazards associated with these abandoned sheep dip vats and restore the affected areas to their natural condition. The selected contractor will be responsible for performing comprehensive site assessments, remediation of contaminated materials, and restoration activities. This includes removal of all remaining structures and remnants of the vats, excavation and proper disposal of contaminated soils, and final site restoration through backfilling and reseeding with a native plant species mix consistent with surrounding undisturbed areas.

The three sites included in this project are:

• Baca #1 SDV (SDV007): 35°22'15.88"N, 108°05'17.58"W

• Baca (New) SDV (SDV008): 35°22'16.18"N, 108°05'04.86"W

• Haystack SDV (SDV060): 35°21'15.38"N, 107°58'31.60"W

These sites have been identified on the Navajo Nation Brownfields Inventory and are known to contain toxaphene contamination in soil and potentially in water. Due to the potential persistence of regulated contaminants in soil, BEM is requesting that the entire site be resampled to confirm that no hazardous substances remain. Historically, sheep dip vat operations have been associated with various regulated chemicals; therefore, comprehensive sampling is necessary to identify and address any contaminants requiring cleanup.

BACKGROUND

BIA NRO BEM is conducting a voluntary cleanup of sheep dip vat sites across the Navajo

Nation reservation under the authority of the Comprehensive Environmental Response

Compensation and Liability Act of 1980 (CERCLA) which requires sampling, site characterization and complete removal of all SDV structures and contaminated soil. The primary soil screening value for toxaphene is set for 0.49 parts per million (ppm) as required by the

Navajo Nation Environmental Protection Agency (NNEPA) Superfund Program to protect human health and the environment. BEM is working in conjunction with the NNEPA Superfund

Program to clean up and remediate former SDV sites across the Navajo Nation reservation.

Toxaphene solutions were primarily used at these SDV sites as a pesticide to eradicate skin conditions and parasites on livestock. A typical SDV included an entrance corral, vat or trough, post-dip corral, heating system, discharge pit and a discharge area. The corrals were commonly constructed with wood. A typical vat was made of concrete and approximately five feet deep and thirty feet long and built at or below grade. The livestock were herded into the entrance corral that had a concrete pad at the entrance to the vat. The livestock were prodded through a pesticide solution and exited into a post-dip corral. The pesticide solution was a mixture of water and toxaphene solution. The water for the dip solution was routinely supplied by a nearby well by way of underground piping. Occasionally, an aboveground heating system was plumbed to the well and vat to warm the water. At the end of a dipping event, the remaining pesticide solutions were typically discharged into unlined pits or pumped out onto the ground.

The Baca #1 SDV is located approximately 200 feet north of well 16K-317 in Prewitt, New

Mexico. The sheep dip vat is buried under windblown soil, with remnants of fencing constructed from railroad ties and wooden posts. Many of the wooden posts are broken or reduced to stumps.

The trough structure measures approximately 50 feet in length and 4–5 feet in width. Concrete fragments, rock debris, and discarded tires are scattered in the immediate vicinity of the vat. No distinct fire pit or discharge pit was observed during the site visit. The surrounding land is undeveloped and sparsely vegetated, with the SDV situated within 15 feet of an existing dirt road. Residential housing was observed approximately 300 feet west of the SDV.

The Baca (New) SDV is located approximately 0.2 miles northeast of well 16K-317 in Prewitt, New Mexico. The sheep dip vat is buried under windblown soil, with remnants of fencing constructed from railroad ties and wooden posts. Many of the wooden posts are broken or reduced to stumps. There are remnants of chain link metal posts sticking up. The trough structure measures approximately 50 feet in length and 4–5 feet in width. Concrete fragments, rock debris, car parts, and trash are scattered in the immediate vicinity of the vat. No distinct fire pit or discharge pit was observed during the site visit. The surrounding land is undeveloped and sparsely vegetated, with the SDV situated within 85 feet of an existing dirt road. Residential housing was observed approximately 400 feet southwest of the SDV.

The Haystack SDV site is located approximately 90 feet west of water well 16T-552 in Prewitt, New Mexico. Visible structures include the concrete vat, entrance pad, exit pad, and remnants of perimeter fencing. According to the Navajo Nation Preliminary Assessment Report (June 1999), laboratory analysis detected toxaphene at 25 ppm in soil west of the trough, likely due to surface release. The trough, entrance pad, and exit pad were originally constructed with rocks and a cement mixture; however, only the rock remains at the entrance pad, and most of the cement has deteriorated. Two metal pipes, likely part of the former gate, remain in place. The concrete trough measures approximately 50 feet long and 5 feet wide and is in fair condition with no visible dirt accumulation. Due to the trough’s poor design, pesticide solutions may have leaked beneath it, and similar leakage may have occurred beneath the exit pad. Portions of the chain-link fence posts remain standing. No distinct fire pit or discharge pit was observed. The surrounding land is undeveloped and is an open, sparsely vegetated area.

Due to the design and construction of the troughs and entrance and exit pads, pesticide solutions may have leaked beneath for three sheep dip vats.

PERIOD OF PERFORMANCE: The period of performance shall be 120 calendar days from the issuance of the Notice to Proceed. Please note that delays may occur due to coordination with external program offices to ensure compliance with the National Environmental Policy Act

(NEPA).

TASK 1: Pre-Work Submittals

A. The contractor shall prepare a work plan for the project and include a project schedule for

BIA’s review and approval prior to commencement of work. The plan should document the proposed work, project work schedule, soil sampling plan including a quality assurance/quality control plan. The sampling plan will include a grid to outline the sampling area. The work plan shall include proposed excavation plan, disposal activities, and restoration activities. The work plan shall also address traffic routes, dust control, and a hazard communication plan for the public or residences living near the site. The project schedule can be adjusted for applicable external program timelines.

B. The contractor shall provide a Health and Safety Plan (HASP) to address worker protection in accordance with 29 CFR 1910.120. The HASP shall contain certifications/licensures of all workers involved in the project. HAZWOPER training will be mandatory for all workers involved. The plan shall identify all required personnel protective equipment (PPE) for all tasks and provide procedures for proper usage. The plan will address any known and potentially occurring environmental and biological hazards that may be encountered at the site. Biological hazards include stinging insects, snakes/reptiles, and airborne pathogens such as the Covid-19 virus.

C. The contractor shall prepare a notification letter on behalf of the BIA to the NNEPA

Superfund Program located in Window Rock, Arizona. The letter will describe the proposed work and proposed schedule.

D. The contractor shall consult with the Navajo Nation Historical Preservation Program for a cultural review and the Navajo Nation Fish and Wildlife department for a biological review. The program offices are located in Window Rock, Arizona and have an established clearance process to meet the National Environmental Policy Act (NEPA). An approved Cultural Resource

Compliance Form Section 106 and Biological Resource Compliance Form Section 7, Endangered Species Act are required to determine action for NEPA compliance. The NRO

Branch of Environmental Quality Act Compliance Review (BEQACR) can be a resource for guidance with any NEPA requirements.

E. The contractor shall utilize an accredited and certified laboratory to analyze the soil samples using the US Environmental Protection Agency (EPA) Method 8081A. The contractor shall provide the name and certifications of the selected laboratory in the work plan.

TASK II: Coordination/Sampling/Analyses

A. The contractor shall arrange a meeting with the NNEPA Superfund point of contact to review the work plan and schedule, and to obtain guidance and recommendations. Contractors shall be available to participate in meetings and present project findings. Additional sampling requests may be required following consultation with the NNEPA Superfund Program. In such cases, sampling protocols will be identified, and a bid submittal will be sent to the BIA Contracting

Officer for inclusion in the SOW without further advertisement.

B. Soil sampling shall be done to determine the horizontal and vertical extent of contamination at each SDV site. The contractor shall fully characterize the horizontal and vertical extent of toxaphene in soils. Cleanup planning will consider potential receptors identified during the assessment.

1. Determine the vertical extent of soil contamination by taking a minimum of three (3) samples at the maximum depth of 12 inches around the entrance and exit pads, the heating unit, the trough, the discharge area, the disposal pit, and if no pit is found, sampling shall be conducted at the nearest stream down gradient from the SDV site.

2. Water samples shall be collected from the nearest pond at or near the SDV site, or from any available water source. If an operational downgradient pump, cistern, or adjacent water source is present, samples shall be collected. For cistern sampling, the cistern shall be purged of at least three times its volume, allowed to recharge, and then sampled. If no water is available, the contractor shall document this in the final report.

All purge water generated during sampling shall be containerized, characterized, and disposed of in accordance with EPA and applicable state regulations for Investigation-

Derived Waste.

3. Decontamination of sampling equipment shall be in accordance with the approved

Sampling and Analysis Plan. Sampling the locations outlined shall be conducted to define the horizontal and vertical extent of toxaphene contamination.

4. Utilize a sampling grid and provide a table showing the Global Positioning System

(GPS) to show the assessment area and locations exceeding the RSL of 0.49 mg/kg.

C. Confirm the extent of contamination through laboratory analysis of soil samples for organochlorine pesticides using EPA Method 8081A.

TASK III: Soil Sampling – SDV perimeter with RSL exceedance

A. Based on initial sampling results, if soil sampling exceeds the RSL for toxaphene, additional sampling is required. If confirmation samples indicate exceedances, it is assumed that the contamination extends an additional 10 feet beyond the investigation area. The recommended sampling grid shall consist of 10 feet by 10 feet cells. Place one (1) soil boring at each corner and one in the center. Soil samples will be collected at depths of 0.5-1 feet, 1-3 feet, and 3-5 feet, for total of three (3) samples per boring. Extend the sampling grid until results confirm clean soil.

B. Soil samples shall be submitted to an accredited laboratory for toxaphene analysis using EPA

Method 8081A. The complete analytical data reports from the laboratory shall be provided to the BIA in the final report.

C. All contaminated soil requires excavation and disposal. Site of excavation shall be backfilled with clean soil.

D. The Contractor will provide detailed mapping to illustrate excavation boundaries, areas of soil removal, and locations where confirmatory samples were collected.

TASK IV: Removal

A. The contractor shall remove and properly dispose of all structural components and debris associated with the SDV site, including wooden posts, metal fencing posts, fencing wire, concrete debris, concrete pads, and rocks used in the construction of the vat and pads.

Additionally, all solid waste materials in the immediate vicinity of the SDV site, such as tires, car parts, and other debris, shall be removed and disposed of in accordance with applicable regulations.

B. All contaminated soils shall be removed by contractor and backfilled with clean soil.

C. The contractor shall prepare a map of the SDV’s existing structures and associated developments before removal/demolition.

TASK V: Excavation

A. The soil removal action for each SDV site shall be conducted based on the sampling results as defined in Tasks 2 and 3, along with the site investigation by the contractor. The contaminated soil and concrete shall be sent to a Subtitle D landfill unless the contamination is not acceptable at Subtitle D landfill.

B. The contractor shall submit to the BIA BEM the volume of contaminated soil to be excavated, along with the estimated weight of concrete, associated piping and other solid waste/other debris to be disposed of.

C. If the site identifies contaminated soil outside the initial sampled area and the perimeter sampled area of RSL exceedance, the contractor shall update the BIA CO and BEM Contracting

Officer Representative (COR) of any revised cost estimates. The contractor shall provide a map of the extended sampling grid with results for the BIA BEM and recommended excavation area.

The contractor shall provide cost estimates for the additional work before work is conducted.

D. During excavation activities, care shall be taken due to protect the public and livestock in the area. Perimeter fencing shall be installed and maintained for the duration of the work to prevent unauthorized entry and restrict livestock access. The contractor shall select and provide the fencing that is suitable for livestock and public safety.

E. The contractor shall apply dust control when the public is within proximity of the work area.

Contractor shall utilize secondary containment during excavation to prevent the spread of contaminated soil.

F. The excavated areas will be backfilled with clean soil. Contractor shall fill all voids and excavated areas with clean fill and compact the area to 90% proctor density; grade and contour the area to prevent ponding or subsidence and meet the existing grad elevations contours.

Backfill sources shall be provided to BIA prior to use by the contractor.

G. Upon completion of the excavation and backfill, the contractor shall reseed any disturbed area with a native species mix that matches the species in the surrounding non-disturbed areas.

H. A project manager or equivalent must be present to supervise, direct, assist, and ensure the safety of the technicians and the public for the entire duration of the work.

TASK VI: Disposal

A. The contractor shall provide a traffic plan during transport of the contaminated soil and concrete debris. The removal of all concrete dip vat, entrance pads, exit pads, and associated piping/concrete structures shall be excavated and disposed of in a Subtitle D landfill unless the contamination is not acceptable at Subtitle D landfill. The contractor shall provide the name and address of the disposal facility for the soil and concrete to be transported to. All governing laws shall be adhered to during transportation of the material.

B. Contractor shall ensure that all documentation for the disposal is maintained and shall be made record and provided in the final report. The contractor may not sign the manifest on behalf of the BIA. When a signature is required, the contractor will inform the BIA in advance via a phone call or email and the BIA BEM will provide arrangements. Any variation to this task will be pre-approved by the BIA NRO BEM Regional Environmental Scientist.

TASK VII: Reports

The contractor will provide a draft of the final report to the BIA BEM and the Navajo Nation

Superfund program within 15 business days upon completion of the project. The report will contain:

A. A description of the work performed.

B. Figures of all drawings/maps showing the sampling locations and results and tables with GPS coordinates and any figures of extended sampling area and results shall be included. Sample log, field forms, boring logs, and photographic logs suitable for an explanation of findings/work will be presented in the report.

C. Full documentation shall be maintained for all field testing, results, and project completions.

During field settings, the contractor shall maintain a daily log and record all events relevant to a task order. Any additional subcontractors shall do likewise. The logs will be signed and closed daily. The logs shall be included in the final report and shall become the property of BIA.

D. Excavation/disposal logs and all transportation documents shall be included in the final report.

E. The draft report shall be submitted to BIA BEM for review within 15 business days upon completion of the project for approval.

F. When the draft is approved to finalize, the contractor shall prepare a final version of the report in Adobe Acrobat pdf format for distribution and two (2) electronic file copies in

Microsoft Word® format one read-only and one writeable version marked for “BIA Use Only”.

The BIA shall be the owner of all documents prepared by the contractor. The contractor shall not copyright or write protect any documents or utilize any data from the project without written consent from the government.

Environmental Professional Certification: The final report shall be stamped and certified by an environmental professional that the work was conducted in accordance with work plan and applicable environmental federal regulations.

Acceptance Requirements: The COR, in consultation with the BEM and possibly representatives of USEPA and NNEPA, will determine the acceptability of work performed. In the event, any agent of the Navajo Nation communicates with the contractor, the NRO BIA BEM

COR shall be immediately informed.

INSTRUCTIONS, CONDITIONS AND NOTICES TO CONTRACTORS

Special conditions:

The contractor shall adhere to all applicable federal and tribal laws and regulations and payment of tribal taxes.

The contractor shall participate in project meetings during both phases of the project and be readily available to present updates and progress on the project as requested by BEM to any regulatory agency.

The contractor must furnish electrical power and procure water to perform remedial actions for cleanup. All available existing roads shall be used during the project to the greatest extent possible.

Contractor shall not distribute concrete or any materials to the local public due to potential liability issues for BIA and the contractor.

The contractor is responsible for any sub-contractors employed during the project and shall ensure proper training and certifications are maintained for the project. Certifications and any necessary training shall be included in the work plan.

All contact with the public, private and regulatory community shall be made through BIA CO and the BIA BEM COR. The contractor shall not communicate any project work on behalf of the federal government to the public. No information may be released without written consent from the Bureau of Indian Affairs, Navajo Region.