Statement of Work.pdf

Statement of Work (SOW) Project: Technical Review/Geophysical Assessment of Phase I of the Groundwater Transfer and

Injection Pilot Project

GENERAL INFORMATION

1.0 Scope of Work: A technical review of the Groundwater Transfer and Injection Pilot

(GTIP) project by an independent expert is needed to assess engineering, environmental, hydrogeological, and geophysical conditions that influence and are affected by operation of the facility. Work will encompass review of Government furnished hydrologic, geophysical, and facility operation data collected from January 2020 to June 2023 as well as a draft report on Phase I of the GTIP project. Based on the review, the expert will (1) determine the adequacy of data to assess operational success of the facility, (2) draw conclusion on technical feasibility of combining riverbank filtration with groundwater transfer and injection to increase the volume of groundwater in the Mississippi River Valley alluvial aquifer (MRVAA) in the Delta region of Mississippi, and (3) recommend potential directions for expansion of the system beyond the pilot scale.

2.0 Background: In 2015, the Agricultural Research Service (ARS) National Sedimentation Laboratory (NSL) presented to the Governor’s Delta Sustainable Water Resources Task Force an idea for a managed aquifer recharge (MAR) project to pilot test technology to potentially mitigate long-term groundwater level declines in the MRVAA. The MRVAA is a highly productive, shallow surficial aquifer system consisting of coarse sand and gravel generally 60 to 160 ft thick, semiconfined by a surficial layer of silt and clay generally varying from <10 to 100 ft thick. Lithologic variations are substantial over short distances both laterally and vertically, owing to the complex depositional history of fluvial sediments from the meandering Mississippi River system that compose the aquifer. Sediments composing the semiconfining layer and the aquifer itself may be only loosely consolidated, and within and near river floodplains further instabilities may occur such as soil piping. The MRVAA is hydraulically connected to the underlying Sparta aquifer where the MRVAA subcrops or the intervening confining unit is thin or absent.

The GTIP project was proposed to withdraw groundwater from an area near the Tallahatchie River where groundwater levels are relatively high and the MRVAA would more likely be recharged quickly, transport the groundwater several miles through a pipeline, and re-inject it through injection wells into a region of the aquifer where water levels are lower. Planning, design, and construction of the GTIP project was conducted 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 focus on the responses in the MRVAA, with some data collected for 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 project demonstrate the technical feasibility of increasing groundwater levels in the MRVAA using the tested technology. Results have also shown the need for increasing the capacity of the system so that more filtered river water can be extracted for recharging the aquifer.

CONTRACTOR REQUIREMENTS

3.0 Technical Requirements/Tasks: The contractor shall review provided data and documents (listed in section 4.0.) and address the following objectives in a written report:

(1) Determine the adequacy of data to assess operational success of the facility;

(2) Draw conclusion on technical feasibility of combining riverbank filtration with groundwater transfer and injection to increase the amount of groundwater in the Delta region of Mississippi; and

(3) Recommend potential directions for expansion of the system beyond the pilot scale, including modifications of or alternatives to current extraction and injection technologies.

The GTIP project was initiated to determine if MAR could be an environmentally and hydrologically sustainable strategy for increasing groundwater levels in the MRVAA in the Delta region of Mississippi. To begin answering this broad question, more specific questions must be answered with respect to conditions near (1- to 2-mile radius) the extraction and injection wells. Key consideration must be given to the influence of the complex geological setting of the GTIP project, consisting of a shallow (<200 ft), unconsolidated, variably confined aquifer system of fluvial origin as described in Section

2.0. The contractor shall consider the following questions when addressing the preceding objectives:

(1) What are the key factors controlling how much recharge the Tallahatchie River can supply to the extraction well for both steady state and seasonally variable river flow conditions?

(2) What is the impact of facility operation on water levels in the Tallahatchie River, MRVAA, and Sparta aquifer?

(3) What is the quality of captured riverbank filtration water?

(4) What groundwater quality changes occur in the MRVAA and Sparta aquifer, and can changes in water quality be attributed to extraction/injection?

(5) How do backflush requirements and possible well-screen fouling affect the sustained flow capacity of the injection wells?

(6) What permitting and compliance issues may be expected during facility operation at the pilot scale or potential future expansion?

Work can be performed at the Contractor’s location, with the exception of travel described in Section 6.0.

4.0 Government Furnished: ARS NSL will provide, in electronic form, the data and documents listed below. All data are from monitoring sites within approximately 2 miles of the facility’s extraction or injection wells, with the exception of river stage and flow data as noted below.

(1) Groundwater levels measured hourly in 17 observation wells (14 MRVAA, 3 Sparta aquifer; starting January-June 2020) and a Geographic Information System shapefile of all well locations;

(2) Groundwater quality field parameters (temperature, specific conductance, pH, dissolved oxygen; starting September 2020) measured at semi-monthly to monthly intervals at six MRVAA observation wells;

(3) Groundwater quality measured by an analytical laboratory and field parameters (temperature, specific conductance, pH, dissolved oxygen) for 13 monthly sampling events (1 event during pre-operation, 3 events during the 3-month test injection period, 2 events between test injection periods, 6 events during 6-month test injection period, and 1 event during post-operation), consisting of major ions (alkalinity, Cl, SO4

2–, Na, Ca, Mg, K), metals (Fe, Mn, As), nutrients (NO3

NO2

–, NH3 + NH4

+, TKN, total P, and TOC), sulfide, silica, and solids (total, total suspended, and total dissolved solids) from all observation wells, extraction and injection wells, Tallahatchie River, Lake Henry, and injection well backflush discharge; and, for a subset of sampling events, water samples for a large suite of pesticides, herbicides, and trace elements from 4 observation wells, extraction and injection wells, and the Tallahatchie River;

(4) Tallahatchie River stage and flow data (stage and flow are measured 5 miles upstream of extraction well starting 1995, stage only is measured at the extraction well starting July 2021, and stage only is measured 14 miles downstream of extraction well starting 2005);

(5) Facility operation data (extraction and injection well flow rates, wellhead pressures, water levels, and injection well backflush flow rates);

(6) Borehole geophysical logs (natural gamma, spontaneous potential, and 8-, 16-, 32-, and 64-inch normal resistivity) for 7 boreholes located near the injection and extraction wells;

(7) Continuous Standard Penetration Test data including lithologic descriptions for a test borehole located near each of the extraction and injection wells;

(8) Final ARS NSL report, Groundwater Transfer and Injection Pilot Project (GTIP), Shellmound, MS, Monitoring & Analysis Plan, describing planned data collection activities; and

(9) Draft ARS NSL report, Interim report on the Groundwater Transfer and Injection Pilot project – Phase I, describing results from preliminary interpretation of water level, water quality, and facility operation data from pre-operation period, 3- and 6-month test injection periods, and post-operation period.

ARS NSL is responsible for reviewing and approving Contractor’s draft and final reports.

5.0 Deliverables / Schedule: The primary deliverables for this project will be a draft and final review report that evaluates the GTIP project performance consistent with objectives described in Section 3.0. Government furnished information will be provided no later than the Notice to Proceed (NTP) date. Draft review report shall be provided 57 calendar days after the NTP date. Final review report shall be provided 98 calendar days after the NTP date. Reports shall be delivered in electronic format (Word or PDF file). 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.

6.0 Travel: Contractor shall travel to the ARS NSL in Oxford, MS, for two in-person meetings, each with an expected 3 nights duration. During the first meeting, the review team will meet with ARS NSL personnel and make a field visit to view the GTIP system components and hydrogeological setting. The second meeting will include a day trip to Stoneville, MS, to meet with GTIP project stakeholders and provide a summary presentation of review findings. Travel will be reimbursed by the Contractor.

7.0 Contractor’s Key Personnel: The services of three personnel are expected with the following qualifications:

(1) Senior Hydrogeologist/Groundwater Engineer – Serves as the review team lead.

Team lead 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 hydrogeological and engineering evaluation of managed aquifer recharge system operations, including Class V injection wells, in diverse hydrogeological settings including alluvial aquifers.

Individual must possess professional geologist and professional engineer certifications, and appropriate doctoral degree in geoscience, civil engineering, or related field confirming expertise in hydrogeology. Experience must include drilling and geophysical exploration and interpretation of hydraulic and geotechnical characteristics of shallow (<200 ft) unconsolidated aquifer systems of fluvial origin.

(2) Senior Hydrogeologist/Project Manager – Serves as review team member.

Individual possesses at least 10 years of experience in the evaluation of managed aquifer recharge system performance, including Class V injection wells, and hydrogeologic changes that occur during system operation. Individual must possess professional geologist and/or professional engineer certification and demonstrated project management experience. Experience must include drilling and geophysical exploration and interpretation of hydraulic and geotechnical characteristics of shallow (<200 ft) unconsolidated aquifer systems of fluvial origin.

(3) Report/Administrative Specialist – Experience preparing draft and final technical (science or engineering) reports, including editing, layout, and publication, and experience providing other administrative assistance services.

a b c d a b c d a b c d a b c d 1 2 3 Cummulativ e calendar day s at end of w eek 7 14 21 28 35 42 49 56 63 70 77 84 91 98 105

Review of Government furnished information 8 8 Kickoff meeting (in person) - site visit 24 24 Data review and analysis - preliminary 120 40 Midpoint meeting (virtual) 4 4 Draft report due (first week day) 2 Draft report due; revisions per Gov't review (last week day) 16 Data review and analysis - final 60 20 Final report preparation 40 Final report due (first week day) 2 Final report due; revisions per Gov't review (last week day) 20 Wrap-up meeting (in person) - presentation to stakeholders 24 24

Total hours 240 120 80 Personnel:

#1 - Senior Hydrogeologist/Groundwater Engineer #2 - Senior Hydrogeologist/Project Manager #3 - Report/Adminstrative Specialist

1 2 3 4 Personnel Months and weeks

Task Hours

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.