Attachment 1 Statement of Work.pdf

Statement of Work (SOW) Project: Hydrogeophysical site selection and most probable cost estimation for the Groundwater

Transfer and Injection Project (GTIP) Phase 2

GENERAL INFORMATION

1.0 Scope of Work: Technical experts will provide advice and counsel to the Groundwater

Transfer and Injection Project (GTIP) Phase 2 team at Agricultural Research Service (ARS) National Sedimentation Laboratory (NSL), collaborators, and stakeholders in selecting appropriate sites and creating a most probable cost estimate for the project. During GTIP Phase 2, the project will be expanded by establishing a distributed network of extraction and injection wells that combine riverbank filtration and groundwater transfer and injection. Technical expertise concerning engineering, environmental, hydrogeological, hydrogeophysical, operational, cost, and logistical considerations will be provided to the project team through periodic virtual and on-site meetings with ARS personnel, collaborators, and stakeholders, including reviewing and assessing documentation necessary for developing the plans. Onsite hydrogeophysical investigations of sites of interest identified in the planning process will also be conducted.

2.0 Background: In 2015, ARS NSL presented the concept of a MAR project aimed at testing the feasibility of mitigating the declining groundwater levels in the Mississippi River Valley Alluvial Aquifer (MRVAA) to the Governor’s Delta Sustainable Water Resources Task Force. The MRVAA is a highly productive, shallow surficial aquifer system consisting of coarse sand and gravel that is approximately 60 to 160 ft thick and is semiconfined by a surficial layer of silt and clay that ranges from <10 to 100 ft thick.

Lithologic variations are substantial over short distances both laterally and vertically, owing to the complex depositional history of Mississippi River sediments that compose the aquifer. Sediments composing the semi-confining layer and the aquifer itself may be only loosely consolidated, and within and near river floodplains, further instabilities such as soil piping may occur. The MRVAA is hydraulically connected to the underlying Sparta Sand aquifer, and the confining unit between the aquifers is thin or absent in some areas.

2.1 GTIP Pilot Phase: The GTIP Pilot Phase was proposed to withdraw groundwater from an area near the Tallahatchie River where groundwater is shallow and the MRVAA would likely be recharged quickly, then transport groundwater several miles in a pipeline, and re-inject it through injection wells into an area experiencing aquifer depletion. Planning, design, and construction of the GTIP Pilot Phase was conducted in 2017-2020, and 3- and 6-month test injection periods were conducted in April-July 2021 and February-August 2022, respectively. Substantial amounts of data (water level, water quality, geology) were collected during the testing, and an interim report of analysis was produced by ARS NSL.

Groundwater data collection activities focused on the responses in the MRVAA, with some data collected from the underlying Sparta Aquifer as well as the Tallahatchie River and Lake Henry (receiving water body for injection well backflush discharge). Initial findings of the GTIP Pilot Phase demonstrated the technical feasibility of increasing groundwater levels in the MRVAA using groundwater injection. Results have also shown the need to increase the capacity of the system so that more filtered river water can be extracted for recharging the aquifer. These findings were reviewed by Collier Consulting and documented in an independent engineering report “Technical Review and Geophysical

Assessment of Phase I of the Groundwater Transfer and Injection Pilot (GTIP) Project” dated May 2024.

2.2 Anticipated GTIP Phase 2 Scope: The size and scope of the GTIP Phase 2 expansion is anticipated to include 5-8 riverbank filtration extraction wells and 10-15 injection wells.

Extraction wells are anticipated to be located in 1-2 modules along both the Tallahatchie and Mississippi Rivers. Injection wells are anticipated to consist of 2-4 modules with 3-5 wells per module. Design considerations may be adjusted during initial stakeholder meetings.

CONTRACTOR REQUIREMENTS

3.0 Technical Requirements/Tasks: The contractor shall utilize available data and documents, including the GTIP engineering review report, and meetings with stakeholders to clarify expectations for the project, select several suitable locations for wells, and prepare a most probable cost estimate for implementing GTIP Phase 2 as described below:

Part 1 – Planning and preliminary site selection:

1. Coordination and attendance of a series of virtual and/or in-person meetings with GTIP stakeholders and ARS NSL Phase 2 team members to discuss and decide on various goals, objectives, and initial design and operational considerations for GTIP Phase 2 expansion.

2. Utilize data and analyses previously collected by the U.S. Geological Survey (USGS), ARS, and others for research and preparation of summary reports and joint planning report with ARS NSL personnel. Perform simulations utilizing the USGS Delta numerical groundwater model to predict potential injection and extraction well impacts on groundwater levels.

3. Preliminary site selection for identification of several potential sites that meet subsurface and surface criteria incorporating input from stakeholders and examination of previously collected aerial electromagnetic survey data.

4. Interim presentation of preliminary sites and selection of potential sites that should undergo additional hydrogeophysical investigations to provide a higher fidelity characterization of the subsurface prior to final selection of sites for GTIP Phase 2 expansion.

Note: Two or three iterations of Tasks 1-2 are expected to properly define all the various aspects of the Phase 2 expansion.

Part 2 – Final site selection and most probable cost estimate:

5. Conduct on-the-ground hydrogeophysical investigations of sites identified in Task 4 to inform final selection of the best sites for extraction and injection wells. A total of four

(4) site investigations of parcel sizes between 50-200 acres is expected.

Hydrogeophysical investigations are expected to consist of up to four days of field investigation at each site utilizing a combination of towed time domain electromagnetic and electrical resistivity tomography technologies.

6. Produce a most probable cost estimate for implementation of GTIP Phase 2 based on the findings gathered in Tasks 1-5.

7. Present a preliminary conceptual design that includes the number and locations of extraction and injection wells and pipeline routes necessary to transfer the water from extraction to injection sites, including system operation and maintenance scenarios.

8. Present the final report to the stakeholder group.

9. Coordination and attendance of a series of virtual and/or in-person meetings with GTIP stakeholders and ARS NSL Phase 2 team members to discuss and decide on any modifications to various initial design and operational considerations for GTIP Phase 2 expansion.

4.0 Government Furnished: Government furnished information will be provided no later than the Notice to Proceed (NTP) date. ARS NSL will provide, in electronic form, data from the GTIP Pilot Phase, the independent engineering report, and additional data obtained subsequent to the independent engineering report. Data include groundwater levels, groundwater quality, Tallahatchie River stage and flow, facility operation data (such as pumping rates and injection rates), and borehole geophysical logs. Results of the USGS Mississippi Alluvial Plain Regional Water-Availability Study, including geophysical survey data and MODFLOW-6 files for the Delta groundwater model, are available from the USGS ScienceBase Digital Repository at https://www.sciencebase.gov/catalog/item/58a5d9c5e4b057081a24f3fd

ARS NSL is responsible for reviewing and approving any reports developed by the Contractor.

5.0 Deliverables / Schedule: The primary deliverables for this project will be (1) periodic summary reports developed jointly with ARS NSL personnel that address the considerations needed to develop a plan and most probable cost estimate for GTIP Phase 2 as described in Section 3.0; and (2) a draft and final report developed jointly with ARS NSL personnel. Periodic summary reports shall be provided at meetings with ARS NSL collaborators and stakeholders. The final report shall be provided 60 calendar days after a draft plan is approved by ARS NSL personnel. Reports shall be delivered in electronic format (draft as Microsoft® Word document, final as Adobe® PDF). The Government will provide review comments for the draft and final reports within 7 calendar days of receipt of the respective document. The Contractor shall provide revised versions of each report within 7 calendar days of receipt of the Government’s comments.

Contractor shall follow the timeline below or propose an alternative timeline. Adjustments that are mutually agreeable between the Contractor and Government may be made no less than 14 calendar days in advance.

1. Base Year:

a. Months 1 – 3: Conduct Tasks 1 – 4

b. Months 4 – 8: Conduct Tasks 5 – 8

c. Months 9 – 12: Conduct Task 9

2. Option Year 1:

a. Months 1 – 12: Based on results of Task 9 during the Base Year, repeat

Tasks 1 – 9 (as needed) for up to four (4) additional extraction or injection site investigations.

3. Option Year 2:

https://www.sciencebase.gov/catalog/item/58a5d9c5e4b057081a24f3fd

a. Months 1 – 12: Based on results of Task 9 during Option Year 1, repeat Tasks 1 – 9 (as needed) for up to four (4) additional extraction or injection site investigations.

6.0 Travel: It is expected that most correspondence between the Contractor and ARS personnel, collaborators, and stakeholders will be handled virtually. As needed, however, the Contractor shall travel to Mississippi to meet with ARS personnel, collaborators, and stakeholders or to visit selected sites to verify suitability. Travel will be reimbursed to the Contractor.

7.0 Contractor’s Key Personnel: The following qualifications will be required:

(1) Senior Project Manager and Geologist – Serves as the team lead. Individual possesses at least 15 years of experience in the evaluation of groundwater flow and groundwater quality in unconfined and confined aquifer systems. Individual has experience in geological evaluation and development of planning documents of managed aquifer recharge system operations, including Class V injection wells, in diverse hydrogeological settings including alluvial aquifers. Individual must possess professional geologist certification, an appropriate degree in geoscience, civil engineering, or related field confirming expertise in geology, and demonstrated project management experience. Experience must include drilling and hydrogeophysical exploration and interpretation of hydraulic and geotechnical characteristics of shallow (<200 ft) unconsolidated aquifer systems of fluvial origin.

(2) Senior Hydrogeologist/Engineer – Serves as team member. Individual possesses at least 15 years of experience in the evaluation of managed aquifer recharge system performance, including Class V injection wells, and hydraulic and operation/maintenance conditions that affect system operation. Individual must possess demonstrated project management experience. Experience must include drilling and hydrogeophysical exploration and interpretation of hydraulic and geotechnical characteristics of shallow (<200 ft below ground surface) unconsolidated aquifer systems of fluvial origin.

(3) Geophysicist – Serves as team member. Individual possesses professional geologist certification, and an appropriate degree in geoscience or related field confirming expertise in geophysics. Experience must include hydrogeophysical exploration and interpretation of hydraulic and hydrogeophysical characteristics of shallow (<200 ft) unconsolidated aquifer systems of fluvial origin.

(4) Hydrogeologist – Serves as team member. Individual possesses professional geologist certification, and an appropriate degree in geoscience, civil engineering, or related field confirming expertise in hydrogeology. Experience must include drilling and hydrogeophysical exploration and interpretation of hydraulic and hydrogeophysical characteristics of shallow (<200 ft) unconsolidated aquifer systems of fluvial origin.

8.0 Security Requirements: No specific security requirements are required. Contractor will only need access to Government buildings as a visitor at facilities in Oxford and Stoneville, MS.

9.0 Data Rights: Government furnished data and information described in Section 4.0 may be used by the Contractor only for the purposes of fulfilling the work described in Sections 3.0 and 5.0. No data or information, furnished by the Government or produced by the Contractor, during the execution of this work may be released in any form to any person outside the Contractor’s personnel expressly assigned to this project without the written permission of ARS NSL.

10.0 Section 508 – Electronic and Information Technology Standards: Deliverables need not conform to Section 508 requirements.