SOW_Tuba_City_BioRemediation_OU1_OU2_OU3.pdf

SCOPE OF WORK

Western Navajo Agency, Bureau of Indian Affairs, Tuba City, Arizona Operational Unit 2 (OU-2)-Tuba City Agency Heating Plant and

Operational Unit 3 (OU-3)-BIA Roads Maintenance Yard

INTRODUCTION

The Bureau of Indian Affairs (BIA, Bureau), Navajo Region (NR), Branch of Environmental Management (BEM) located in Gallup, New Mexico requires the services of environmental contractor experience to conduct sampling, excavation of contaminated waste, the application of bioremediation and reporting. The site consists of three (3) OUs designated as OU-1, the former Tuba City Motors property, OU-2, the former Heating Plant property; and OU-3, the BIA Roads Maintenance Yard property, all located in central area of the Tuba City, Arizona (Figure 1- Vincity). The Tuba City site is located near the northwestern corner of the intersection of Oak Street and Edgewater Drive, and is bordered by Birch Avenue to the north, Edgewater Drive to the south, and encompasses both sides of Oak and Pine Streets. Surrounding the properties are businesses, a hospital, residential area and schools.

For this contract work, the OU-1 former Tuba City Motors property will not be part of this contract. Only the OU-2, the former Heating Plan property and OU-3, the BIA Roads Maintenance Yard property/sites, shall be cleaned up. Past operational activities at the OU-2 and OU-3 contaminated the properties from past release of total petroleum hydrocarbons (TPH), diesel, gasoline, motor oil, NAPL which were confirmed thorough past sampling activities. The OU-2 and OU-3 require direct push chemical injections into shallow soils and groundwater to reduce the contamination concentrations; both properties require the measurement of NAPL south areas to determine remediation of the contamination. For the OU-2, the asbestos contaminated soils not removed shall be excavated and removed, before backfilling, the excavated areas will be treated as part of the bioremediation strategy. The reduction of approximately 33 groundwater wells shall be recommended for liability purposes and to prevent impact to the groundwater within the Tuba City area. Some of these groundwater monitoring wells are damaged or have remained dry for years. There will be remaining groundwater wells remaining for continued monitoring and sampling under another contract.

This project is listed for assessment, cleanup and monitoring in the Department of Interior (DOI) Environmental Disposal Liabilities (EDL). The EDLs are updated quarterly and submitted to DOI. The regulatory agencies monitoring the BIA work for the OU-2 and OU-3 which are Navajo Nation Environmental Protection Agency or U.S. Environmental Protection Agency Region 9.

SITE BACKGROUND

The OU’s sites started in 2011, beginning with the OU-1 former Tuba City Motors, extending to the OU-2, and the OU-3 properties.

OU-2, Former Heating Plant: In 1999, the explosion of the boilers resulted in the release of heating oil. The heating oil was used as the fuel source for the steam plant machinery and equipment in the former Tuba City Heating Plant. The product was stored in two 50,000 gallon above-ground storage tank (AST) adjacent to Building 193. An explosion in one of the boilers occurred resulting in the release of an unknown quantity of healing oil. Soil studies were conducted which identified asbestos contaminated soils, total petroleum hydrocarbons (TPH) in soil and groundwater contamination. BIA hired a contractor to conduct a subsurface investigation which resulted in installations of groundwater monitoring wells and eleven extraction wells. (Figure 2-OU-former Heating Plant)

In 2011, the contractor installed 10 soil borings and collected soil samples. Samples were analyzed for TPH GRO, DRO, and BTEX (Terranext, 2012). In 2015 and 2016, approximately 7,500 CY of petroleum impacted soils were excavated from this property and disposed of. The impacted soils were excavated down to bedrock interface 10-12 feet below ground surface (bgs);

and the base of the excavation was backfilled with 2-foot bed of processed gravel. Perforated pipes were laid on the gravel to provide future injections of bio-amendments fluids. Residual petroleum impacted soils remain at base of the excavation, as well as in some perimeter and inaccessible areas, such as the sewer line and tool shed. The excavated area filled the original overburden that was not impacted. In 2019, the tool shed was removed by BIE. (Wells, 2017)

In June 2022, Rock Gap Engineering LLC (RG), Animas Environmental Services, LLC, (AES) and Emergency Environmental Services, LLC. Emergency Environmental Services provided soil sampling plan intended to determine the remaining volume of petroleum-contaminated soils (PCS) underneath the former tool shed. The estimate provided was 500 CY. EES and AES excavated 21 test pits in OU-2 with the purpose of delineating the area of impacted soils surrounding the former tool shed. The test pits were conducted to take measurement of volatile organic compounds (VOCs) using photoionization detector (PID) organic vapor meter (OVM).

Soil samples were taken from approximately 4 and 8 ft bgs from pits near the edges of the delineated area.

The previous reports described the geology at OU-2 as consisting of overburden soils comprised of sandy silts and clayey silts, which are transitional both laterally and vertically in various locations. These soils extend to depths of approximately 10-15 feet bgs, at which point bedrock is encountered (Wells, 2017). Bedrock has been identified as silty sandstones and mudstones, part of Moenkopi Formation (Peterson & Pipiringos, 1979). AES soil sampling confirmed these descriptions. Groundwater was encountered near the bottom of the test pits at approximately 7 to 8 ft bgs.

EES PID-OVM headspace readings from the soil samples ranged from non-detected to 1,093 parts per million (ppm). Soil samples were analyzed for TPH, GRO, DRO, and motor oil range organics (ORO) per USEPA method 8015 M/D. (EES, 2022)

The test pit excavation samples indicated the remaining area of contaminated soil measures approximately 100 feet (ft) wide by 60 ft long by 8ft deep. The revised estimate volume of soil that would need to be excavated was approximately 1,800 CY, including 500 CY from the original estimate.

AES collected one groundwater sample from Well MW-307, which was submitted to certified laboratory for analysis using USEPA Methods for total/dissolved iron and manganese, sulfate and nitrate and COD. The analytical methods were done to determine the groundwater remediation strategy.

Under a separate contract for groundwater monitoring and sampling for the operational properties, the draft Fourth Semi-Annual Groundwater Monitoring and Sampling Event Report (iina Ba’, 2022), indicated the OU-2 property contains a plume and oriented from the northwest to the southeast along the prevailing ground water flow direction. The plume is centered around the east-central portion of the area. The plume crosses Oak Street and is present within western limits of OU-3 near its southern boundary. There are isolated impacts along the southern boundary as well as two occurrences of NAPL (MW-227 and offsite south of OU-3 at MW-20).

Further review of the iina Ba’ for groundwater monitoring sampling for dissolved phase concentrations data, it appears there are two monitoring wells with residual concentrations above the standards at MW-1 with 7µg/L methyl tert-butyl ether (MTBE) and 8 µg/L naphthalene; and MW-307w with 11 µg/L naphthalene.

OU-3, BIA Road Maintenance Yard: The Roads Maintenance yard has an Office building #199, Supply building #314 and Storage Barn that store heavy equipment, supplies for roads operation. (Figure 3- BIA Roads Maintenance Yard/Roads yard) In 2008-2010, Terranext conducted a site investigation that confirmed through sampling benzene was present in groundwater at concentrations exceeding U.S. Environmental Protection Agency preliminary remediation goal (PRGs) of 0.35 micrograms per liter(µg/L). A groundwater gradient of 0.02 feet per foot (ft/ft). No detectable soil contamination or non-aqueous phase liquid (NAPL) were reported. (Terranext, 2012).

In June 2018, BIA contracted with Cherokee CRC, LLC (CCRC) and Envirotech excavated approximately 2,808 CY petroleum contaminated soil (PCS) from approximately 9 to 12 ft bgs in the central area of the Roads yard of OU-3. During the excavation, suspected asbestos containing materials (ACM) were discovered in the overburden of the stockpile that was created during the petroleum-contaminated soils (PCS). The work was stopped, and the suspected ACM was sampled and confirmed ACM. The source was a former burn pit that was discovered, as no historical information on former activities was available for the contractor to avoid during excavation. Envirotech removed a total of 6,440 CY of ACM soils from the overburden stockpile. It was noted at the time of this work the additional ACM and ACS remaining in place of OU-3, which required further site characterization to determine the vertical and horizontal extent of contamination within the Roads yard. The discovery of ACM changed the scope of work for this project for CRC.

From July–September 2018, the CRC removed the regulated asbestos contaminated soil (RACS), to focus only on removing the excavated soil stockpiles which was completed. (Asbestos Abatement Closure Report Roads Maintenance Yard, June - October 2018). No work on bioremediation was conducted for OU-2 and OU-3.

In 2022, under a new contract with Rock Gap contractors and sub-contractors completed the delineation, excavation and disposal of soils contaminated with ACM, located within the fenced Roads yard. The contaminated soil was located to the south, previously excavated in 2018.

Approximately 500 CY of asbestos impacted soil was excavated and removed from the south area. Further delineation identified other areas in the Roads yard that were impacted by ACM/ACS. This was done to ensure all the ACM/ACS were removed from the Roads yard.

OU-3 excavated from 3 areas (including south area) in the Roads yard which total 2,776 CY of contaminated soil that was removed. During the excavation activities, AES assessed the current conditions of the bioremediation piping system. The bioremediation systems were damaged from the previous work conducted in 2018. The ACM impacted soils were transported to Contract Environmental Services near Aneth in San Juan County, Utah. The excavated areas in the Roads yard were backfilled with clean soil.

Rock Gap, contractor, was tasked to repair the existing bioremediation piping in the OU-1, OU-2 and OU-3 properties, coordination with Navajo Nation Environmental Protection Agency and U.

S. Environmental Protection Agency to select a remediation to enhance in-situ remediation process to reduce diesel fuel and oil-range hydrocarbon contamination in soil and groundwater at all three OU’s, the implementation of the agreed on method.

PERIOD OF PERFORMANCE: OU-2 and OU-3 shall be from Date of Award to August 2026.

As background information, the OU-1, the former Tuba City Motors property, had a release of gasoline and diesel from Underground Storage Tank (UST) resulted in sampling of the soil and groundwater. The confirmation from the sampling results indicated further studies were required through excavating the contaminated soils, installing groundwater monitoring wells to determine the flow of the contamination in ground water. Using the data results the site used bioremediation to treat the levels of gasoline and diesel contamination, BIA BEM is working with U.S. Environmental Protection Agency (EPA) to obtain a “No Further Action” (NFA) to close out this project along with removal of the groundwater monitoring wells which is not part of this contract. The groundwater sampling results show a significant reduction of contamination to pursue NFA from the regulatory agency. OU-1 is not part of the contract and provided in SOW as background information.

Previous contractors recommended indicated bioremediation appears to be effective in site remediation efforts, and additional applications should be effective to treat residual areas of contaminated impacts which remain outside the existing infiltration galleries. Contractor utilized hydrogen peroxide, diluted to safe concentration would provide a chemical oxidation reaction to reduce the contaminated concentrations. Further a more natural injection product, the Regenesis product Petrofix provided a slower biologically mediated reduction in dissolved phase concentration which has been used onsite.

WORK REQUIRED

The successful bidder/contractor awarded this contract shall conduct cleanup work within the OU-2 and OU-3 sites. Previous work conducted in these areas have demonstrated that bioremediation applications have shown to be effective in site remediation efforts with additional treatment to residual areas that are beyond the sites by utilizing infiltration chemical injections to reduce contamination. Several different chemicals can be considered for infiltration injection.

Hydrogen peroxide, diluted to a safe concentration, provides a chemical oxidation reaction that would quickly reduce contaminants concentrations. If a more natural injection product is preferred the Regensis product PetroFix is made from natural sources of carbon (such as coconut husks) and would produce a slower, biologically mediated reduction in dissolved-phase contamination. This natural injection has been utilized within OU-2. (Rock Gap, Final Report 2023).

The work required for OU-2 and OU-3 shall be conducted in accordance with Scope of Work as follows.

Task 1: OU-2: Based on the previous sampling, investigations conducted by the previous contractor in final sampling report by Rock Gap Engineering LLC (RG), Animas Environmental Services, LLC, (AES) and Emergency Environmental Services, LLC.

It is recommended, based on previous work conducted in this area, the recommendation is conducting advanced direct push chemical injections into shallow soils and groundwater in 5 points surrounding the MW-1 and MW-307 for a total of 10 injection points. (Figure 4-OU-2 November 2022 GW map)

• Assess the amount of NAPL in MW-227 (southeast corner of OU-2). Depending on the thickness of NAPL, the depth of the well, install a passive skimmer or an absorbent oleophilic/hydrophobic sock to collect the residual product.

• The removal of the NAPL layer on groundwater at monitoring wells MW-227 and MW- 20, shall be performed to eliminate the possible dissolved phase impact to local groundwater.

• Excavating approximately 1800 cubic yards of petroleum contaminated soils beneath and adjacent to the footprint of the former shed removed in 2019.

• While the excavation is open, treat the sides and bottom of the excavation with remediation product recommended to prevent further influx of total petroleum hydrocarbons via contaminated groundwater into the clean backfill.

This site will require additional removal of contaminated soil remaining and to reduce the residual dissolved concentrations in groundwater by applying bioremediation. The groundwater will also require further assessment on the levels of NAPL that is flowing southeast, by installing additional monitoring well. This area requires further assessment on the geology of the area and extent of contamination within the area and whether the groundwater contamination has pooled on bedrock. The cleanup standard for heating oil is 500 ppm, by Navajo Nation Environmental Protection Agency

Tskk 2: OU-3: To address residual dissolved phase concentrations:

• Advance direct push chemical injections at RMF-MW-2, MW-211, MW235, MW-237 and MW-239 into shallow soils and groundwater in 5 points surrounding each well, for total of 25 injection points. (Figure 4-OU-5 November 2022 Groundwater Monitoring Map)

• Measure NAPL in MW-20 (south of OU-3). Depending on the thickness of NAPL and depth of well, install either passive skimmer or an absorbent oleophilic]/hydrophobic sock to collect residual product.

• To reduce the footprint of the existing, long-term groundwater monitoring well network by plugging and abandoning the groundwater wells with a history of being dry to eliminate these locations from becoming a liability due to direct conduit to the water table; further reduce the number of monitoring wells no longer needed to monitor the plume migration, reduction and or degradation. Based on the monitoring report along with historic report, 40 monitor wells shall be plugged and abandoned based on their history. They are dry or have at least 8 consecutive sampling events with concentrations below applicable standards. The contractor shall review the groundwater monitoring report for the full cumulative data reported.

• The contractor shall determine which remaining flush-mounted groundwater monitoring wells along Oak Street and First Street shall be evaluated for existing conditions and markers or barricades of some sort need to be erected to prevent any more wells from becoming damaged or destroyed.

Task 3: OU-2 and OU-3 Groundwater Monitoring Evaluation/ Removal:

To begin reducing the footprint of existing, long-term groundwater monitoring wells within the OU-2 and OU-3 shall be evaluated for plugging and abandonment with a history of being dry or have had at least 8 consecutive sampling events with concentrations below the applicable standards shall be considered. Currently there are a total of 37 ground water wells. Properties.

(Figure 6 - RGE Remediation Status report, September 2023) Within this contract, contractor shall remove those groundwater monitoring wells based on their evaluation for closure. This may require coordination with Navajo Nation Water Resources to accomplish. By eliminating these groundwater monitoring wells that are no longer needed to lessen or eliminate the liability as direct conduit to the water table in the Tuba City community. The evaluation will provide BIA which ground water monitoring wells should be removed and the number no longer needed to monitor plume migration and reduction. Using the monitoring report under the another contract can determine if all 37-groundwater monitoring shall be considered for plugging and abandonment.

1. PRE-WORK SUBMITTALS

A. Prepare a detailed Work Plan and Work Schedule for BIA review and approval prior to commencement of work. The plan should document sampling, excavation volumes, and the application of the remediation system to be utilized.

B. Health and Safety Plan (HASP). The contractor shall prepare a site-specific HASP in accordance with 29 CFR 1910.120 to allow for the protection of workers, employers, and the general public. The HASP will contain certifications/licensures or workers and describe the use of all and appropriate PPE. Known and potentially occurring environmental hazards are exposure to petroleum hydrocarbons, potentially explosive atmosphere conditions, tripping/falling hazards, presence of heavy equipment, utility lines, biological hazards, chemical hazards, and venomous insects, snakes/reptiles and mold.

The plan shall include the company’s respiratory plan.

The plan shall include the certificates of workers and HAZWOPER certificates.

C. A list of subcontractors, including qualifications and experience.

D. The P.E. shall be licensed in in the State of Arizona and New Mexico as the Navajo Nation Reservation is located, Arizona, New Mexico or Utah. The project is located in Arizona, with the project requirements from BIA BEM, Gallup, NM, should the regulatory agencies have conditions on the work.

E. The contractor will prepare a communication plan and route/traffic plan for work conducted in OU-2 and OU-3 for the safety of the workers and employees with Road Maintenance operations. The plan should provide all necessary signs, barricades, to control ingress or egress at the site.

F. A work plan and schedule for the work and remedial activities. Sampling plans for sample collections at the excavation site to delineate the extent of contamination of petroleum impacted soils to be excavated. Sampling of the plume is located within OU-2 and the southern area of the OU-3.

G. The Work Plan, Schedule, Sampling Plan, Health and Safety Plan, Communications Plan for work will be reviewed/approved by BIA.

H. Quality Assurance/ Quality Control Plan for sampling and analyses for plume and excavation activities within the operational properties.

I. Copy of Laboratory Certification, State or Federal

J. Navajo Nation Water permit from Navajo Nation Water Resources for water used for dust control during work activities and provided to BIA. Contractor to inquire with Navajo Nation Water Resources for any removal or abandonment of the groundwater monitoring wells.

REPORTS

The contractor will develop a draft and final Report containing:

(1) Description of the field work performed.

(2) Description of subsurface lithology.

(3) The nature of extent of contamination in subsurface soils;

(4) Results of bench testing and

(5) Recommendations for corrective actions.

(6) Maps and drawings as described previously with surveyed improvement and sampling locations should be included. GPS coordinates for the four corners of area that is excavated in OU-3 for future information.

(7) Sample logs and subsurface soil cross-sections suitable for an explanation of findings will be presented in the report. Suggested corrective actions, remediation strategies, monitoring requirements, and associated costs of future activities, necessary will be included in the report, as appropriate.

Documentation is available for review at NRO BEM Program Office, 301 West Hill Street, Gallup, NM 87301

-Site Investigation Report, OU-3, BIA Branch of Roads Yard, Western Navajo Agency, Tuba City, Arizona

-draft/final Groundwater Monitoring Reports, Bureau of Indian Affairs, Tuba City, Arizona -Rock Gap Engineering final reports.

-Program files on Tuba City Remediation.

Miscellaneous: Contractor shall bear the cost of duplication of reports if required.

REPORTS: Any reports generated by the contractor shall be initially submitted as a draft for approval/concurrence defined by CO/COR. A copy of all draft reports will be submitted to NRO BIA BEM, NNEPA/LSTP and USEPA for review and comments before finalization of reports.

The contractor shall submit bi-weekly reports or conduct MS teams meetings on the progress of cleanup work. Reports completed shall be reviewed by BEM and the regulatory agencies before the reports are finalized. Final reports will be due within three (3) weeks of the return of a draft.

A copy of the final reports with a cover letter shall be sent to NNEPA-Leaking Storage Tank Program (LSTP) and USEPA Region 9. If reports are lost, the contractor shall re-issue copies at his/her expense. All final reports shall be signed by a Professional Engineer or certified environmental professional. All correspondence shall be protected and secured. It shall not be made available to the public or disaffected employees.

Acceptance Requirements: The CO, in consultation with the NRO BEM COR and representatives of the NNEPA/LSTP and USEPA Region 9, will determine the acceptability of work performed. If, and when, any agent of the Navajo Nation, or any other governmental entity communicates with the contractor, NRO BEM shall be immediately informed.

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

During field situations, the contractor shall maintain a daily log and record all events relevant to a task order. Any additional sub-contractors shall do likewise. The logs will be signed up and closed daily. The logs shall become the property of BIA. A copy of all bills, receipts and time sheets shall be maintained, in case there is a possible claim for cost recovery.

INSTRUCTIONS, CONDITIONS, AND NOTICES TO CONTRACTORS

Special Conditions The contractor will adhere to all applicable federal and tribal laws and regulations and payment of tribal taxes.

The contractor shall be required to furnish electrical power and procure water to perform investigation, sampling and mitigation.

The contractor is responsible for any utilities that are damaged during the work and shall repair them immediately at no cost to the Government. Contractor will complete a utility locate and blue stake at least two weeks prior to scheduled work to ensure buried utilities are not impacted.

Contractor to coordinate with the BIE Facility Manager and the Navajo Tribal Utility Authority (NTUA) for the work within OU-2 and OU-3.

Project notifications and work schedule to BIA, BIE Acting Facility Manager, Navajo Nation Environmental Protection Agency (NNEPA) and the Tuba City Medical Center will be provided or adjacent businesses at least a week before work begins. BIA shall be notified before work commences to ensure any additional coordination is required.

All contact with the public, private or regulatory community shall be made through BIA, Navajo Region. No information may be released without written consent from BIA Navajo Region.

The contractor shall provide a schedule for BIA/BIE Point of contacts.

Attachments:

Figure 1- Vicinity Map Figure 2- former Heating Oil Property Figure 3-BIA Roads Maintenance Yard (Roads yard) Figure 4 (OU-2 November 2022 Groundwater monitoring map) Figure 5 (OU-3 November 2022 Groundwater monitoring map) Figure 6 (RGE Remediation Status report, September 2023)