Rough_Rock_SDV_SOW_1-8-2025.pdf

Scope of Work

Rough Rock Sheep Dip Vat Site (SDV) Sampling/Removal

Rough Rock SDV, Apache County, Rough Rock, Arizona

INTRODUCTION

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

Management (BEM) is seeking an environmental contractor to conduct the remediation and restoration of the former Rough Rock Sheep Dip Vat (SDV). The project shall be conducted in two phases. Phase 1 shall require site investigation surrounding the sheep dip vat area to determine the horizontal and vertical extent of toxaphene contamination to soil and water.

Investigation will determine the remediation of the site or if the site requires no further action.

Phase 2 shall require the demolition and removal of all structures and remnants associated with the SDV, an excavation and disposal of all contaminated soils surrounding the dip vat area, the discharge pit area, and any identified drainage area. Highly disturbed area shall be backfilled with clean fill and reseeded with natural vegetation to the area.

The Rough Rock SDV is located on the Navajo Nation Reservation within the jurisdiction of

Rough Rock Chapter. The site is situated approximately seven (7) miles NE of Rough Rock with coordinates of 36° 28' 22.23" N 109° 46'3 3.20" W (Figure 1). The site can be accessed from Navajo Route N59.

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 pesticides 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 too well and vast 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.

A site investigation was conducted on eighty-three (83) selected SDVs throughout the Navajo

Nation Reservation by OA Systems Corporation and BIA in 2003. In Phase I, the selected SDV sites were screened to determine if toxaphene was present at levels above 40 ppm (mg/kg) in the surface soils. In addition, the sites were screened to determine the presence of Lindane or heptachlor. In Phase II, if any samples came back above 40 ppm, additional samples were taken to determine the lateral extent of the toxaphene contamination to a level of 25 ppm.

The 2003 soil sampling results indicated the area next to the exit pad return a reading above the standard at the Rough Rock SDV. Due to the persistence of toxaphene in the soil without any bioremediation, BEM is requesting that entire site be sampled and ensure no hazardous substances are present. Historically in addition to toxaphene, sheep dip vat operations show that arsenic was a common occurrence; it is unknown if arsenic was used at this site.

Visible structures at Rough Rock SDV are the concrete vat, an entrance pad, an exit pad, and the remnants of the wooden fencing. Over the years, the concrete vat has been filled with windblown dirt. The concrete pad for the entrance and exit pads are visible and wooden post from fencing are partially sticking out of the ground. There is no distinct fire pit or discharge pit.

Thus, it is possible the solution was discharged to ground either on the NW or the NE side of the concrete vat. A livestock water tank and well 10R-119 are located approximately 160 feet north of the SDV which may have been used to supply water to the dip vat. Piping may have been plumbed from the well.

The surrounding land is undeveloped and is an open, sparsely vegetated area.

PERIOD OF PERFORMANCE: The period of performance will be 120 calendar days from

Notice to Proceed. Note: There may be delays in accommodating external program offices to comply with the National Environmental Policy Act (NEPA).

PHASE I-Sampling/Site Characterization

TASK 1: Pre-Work Submittals

A. The contractor shall prepare a work plan for Phase 1 and 2 of the projects 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 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 on the work plan and work schedule for guidance and recommendations. Contractors will be available to participate in meetings and present findings of work regarding this project. Other sampling requests may be required following consultation with NNEPA Superfund Program. In these situations, the 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 extent of contamination at the Rough Rock

SDV site. The contractor shall fully define the vertical and horizontal extent of toxaphene in soils. The potential receptors will determine the cleanup plan to be conducted for this SDV site.

1. Determine the vertical extent of soil and sediment 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 trench, 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 or lake near the SDV site or where water is present. If there is an operational downgradient pump or cistern or adjacent water sources samples shall be collected. If water samples are to be taken from cistern, the cistern will be purged at least three times the water volume of the cistern and a water sample than collected following recharge. If no water is available, the contractor shall document this information in the final report.

3. Decontamination of sampling equipment shall be in accordance with the approved sampling and analyses plan. Sampling the locations outlined shall be conducted to define the horizontal and vertical extent of toxaphene.

4. Sampling grid and a table showing the Global Positioning System (GPS) shall be utilized to show the assessment area, drainage area/disposal pit and locations exceeding the RSL of 0.49 mg/kg.

C. Confirmation of the extent of contamination must be verified through laboratory analyses of soil for organochlorine pesticides by EPA Method 8081A.

TASK 3: Soil Sampling – SDV perimeter with RSL exceedance

A. Based on initial sampling results, if the soil sampling results show exceedances further sampling is required. If confirmation samples contain toxaphene in exceedance of the RSL, it is assumed that the contamination extends an additional 10 ft outside the investigation area.

Therefore, the recommended sampling grid shall be by 10 ft by 10 ft rows. The soil boring placement of one (1) boring on each of the corners and in center of each grid of the investigation area. Soil samples will be collected at depths of 0-0.5 ft, 0.5-1 ft, 1-3 ft, and 3-5 ft, for total of four (4) samples per boring. The sampling grid will be extended until results indicate soil is clean.

B. Soil samples taken at the extended area shall be submitted to accredited laboratory to be analyzed for toxphene using EPA Method 8081A. The complete analytical data reports from the laboratory shall be provided to the BIA and show the extent of toxaphene contamination at the perimeter areas.

C. All contaminated soil requires excavation and disposal. If no contamination is found, excavation of the site shall be backfilled with clean soil.

D. The contractor will provide detailed maps to illustrate the requirements for excavation to remove all contaminated soil.

PHASE 2 Removal of Contaminated Soil/Structures

TASK 1: Removal

A. All wooden posts, fencing wire, concrete debris/pads, and associated SDV structures such as piping shall be removed and dispose of accordingly.

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 2: Excavation

A. The soil removal action for the Rough Rock 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 to the BIA BEM and recommended excavation area.

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

D. During excavation, care shall be taken due to the public and livestock in the area. Perimeter fencing shall be installed and maintained for the duration of the work to prevent entry into the site. 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 spread of contaminated soil.

E. 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.

F. 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.

The contractor shall apply best management practices for erosion control and invasive weed prevention and mitigation.

G. 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 3: 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 transport 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 4: 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. A copy of all bills, receipts and time sheets shall be maintained and included in the final report.

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

G. 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 the 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.

Source of Evaluation Criteria:

Proposals from contractors shall contain the following information:

A Summary of:

• Qualifications and related experience for working with the Bureau of Indian Affairs and

Native American Tribes on Trust Lands

• Qualifications and related asbestos, lead based paint remediation experience, hazardous waste disposal, and universal waste disposal.

• Project Manager Resume

• Knowledge of Navajo Communities in Arizona, New Mexico and Utah and on the

Navajo Indian Reservation to allow contractor to work independently in the field

• Best Technical Approach for the remediation of the site.

• A list of all subcontractors, including qualifications and experience.

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 the remedial actions for toxaphene cleanup.

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.