371815 - 07 - SOW_Well Maintenance.pdf

SCOPE OF WORK

MONITORING WELL NETWORK MAINTENANCE & SEALING

JULY 21, 2025

Fermi National Accelerator Laboratory (Fermilab) is looking to reset the protective covers of 8 monitoring wells, and seal and abandon 11 monitoring wells, at its facility in Batavia, Illinois (Figure 1). The protective covers of the eight monitoring wells have either settled or heaved from the ground, which is creating access issues. The 11 monitoring wells that need to be sealed and abandoned are no longer required and their condition is deteriorating. Additional information and requirements are presented below.

Background

Fermilab is a Department of Energy Office of Science facility that is managed and operated by Fermi Forward Discovery Group, LLC (Fermi Forward). A network of approximately 120 monitoring wells and piezometers are installed to evaluate groundwater conditions throughout the site. As the network ages, some monitoring wells require maintenance to fix protective covers that have settled or heaved from the ground and well pads that have deteriorated. Other monitoring wells may become obsolete due to operational changes at Fermilab and must be sealed and abandoned to prevent contamination of the underlying aquifers.

Work Location

The monitoring well locations are located throughout the property as depicted on Figure 1 and can generally be accessed by asphalt paved roads and two-track pathways. The well sealing and abandonment portion of the work will be conducted in DuPage County; consequently, the Driller must submit appropriate well sealing forms (i.e., Water Well Sealing Application, Water Well Sealing Form/Well Location on Site) to the DuPage County Health Department. The well sealing work area is located within a high-quality restored prairie; disturbance to the plants and soil must be minimized during mobilization, sealing, and demobilization.

Scope of Work

The scope of work consists of resetting protective covers at 8 monitoring wells and sealing 11 different monitoring wells as outlined below.

Reset Protective Covers

The project consists of work to reset eight existing protective well covers to the proper heights and install concrete pads around the reset covers. The Driller will remove material around existing wells, reset the protective well covers to the proper height, install concrete pads around the reset protective covers, restore sites, and produce material summary forms. The eight wells are located as shown in Figure 1 and the planned resets are detailed in the table below.

Well ID Estimated Pro Cover Elevation Change Since Installation (ft)

Planned Pro Cover Reset (ft)

BB-2 2.7 -2.5

S-1265 1.0 -1.0 S-1423 -0.5 0.5 S-1426 0.5 -0.5

The final reset adjustment for each well will be determined in the field based on observation of well riser elevation, access clearance inside the pro cover, etc.

This work will involve:

1. Removal of near-surface materials around the existing well protective covers to allow the reset of the pro covers and to install concrete pads around each pro cover.

a) Well construction must be finished with a concrete surface pad (see the Fermilab Groundwater Management Plan) up to 2 feet by 2 feet laterally, extending to a depth of at least two feet in the borehole annulus around the base of the pro cover and tapering to at least 4 inches thick at the edges of the surface pad, if included. Sonotube construction may also be used to the required depth.

2. Fermilab will conduct eJULIE clearance and mark estimated field locations immediately prior to well repair work. If the eJULIE permit process identifies that a monitoring well utilities within the Exclusion Zone of a subsurface utility, the excavation and material removal must be performed by hand (no tools) or by vacuum excavation. This situation is not anticipated.

3. Fermilab will furnish the disposal container(s) at a central location for the removed material.

4. The material construction log information must be submitted to Fermilab no later than 15 days following completion of the drilling work.

Driller will provide an estimate of the anticipated volume of solid and liquid investigation-derived waste.

Monitoring Well Sealing

The Driller will prepare and submit all necessary water well sealing applications and forms to the DuPage County Health Department. The locations of monitoring wells that require sealing are depicted on Figure 1.

Each of the designated monitoring wells will be sealed and abandoned in accordance with Title 77 of Illinois Administrative Code (IAC) Section 920.120. The well sealing activities will be conducted by an Illinois-licensed water well driller, pursuant to the Illinois Water Well and Pump Installation Contractor's License Act.

In general, the monitoring wells will be sealed by grouting from the bottom up using neat cement grout or other bentonite product manufactured for water well sealing. The bentonite product must not contain PFAS chemicals. A tremie pipe must be used to ensure the sealing material does not bridge. This material shall be applied the full depth of the well and shall terminate within two feet of the ground surface.

Concrete grout may be used in the upper part of the well if the upper part of the well is dry. Fermilab is not aware of contaminants of concern in the groundwater at these locations.

Well ID Estimated Pro Cover Elevation Change Since Installation (ft)

Planned Pro Cover Reset (ft)

PD2-6 1.5 -1.5

PD2-5 0.5 -0.5

PD2-1/BMW-4 1.0 -0.5

S-1280/MS-1 1.9 -1.5

Furthermore, this scope of work will require:

1. Driller will provide an estimate of the anticipated volume of solid and liquid investigation-derived waste (including decon water) and Fermilab will furnish the disposal containers. Fermilab will stage the disposal containers at a central location; Driller is responsible for transporting the investigation-derived waste to the containers.

2. The Health Department sealing form shall be completed by the Driller and submitted to the Fermilab ESH Section within 7 days of completion of the well sealing.

Responsibilities

The Driller responsibilities include:

1. Driller will be responsible for submitting the Water Well Sealing Application form and all necessary fees to the DuPage County Health Department prior to conducting the work.

2. Driller personnel will not have access to any buildings on-site and should make arrangements for portable washroom facilities to be delivered and removed from the property.

3. Driller personnel must attend site orientation prior to beginning work activities. Fermi Forward estimates the orientation and badging will last approximately two hours.

4. Driller must don appropriate Level D personal protective equipment (PPE) including hard hat, safety glasses, hearing protection, cut resistant work gloves, nitrile or latex gloves, and steel- or composite-toe work boots. Driller is responsible for providing its personnel with PPE.

5. IDW including soil cuttings, concrete debris, PVC well materials, etc. must be contained for off-site disposal. Driller must provide Fermi Forward with an estimated volume of IDW that will be generated when completing the scope of work.

6. Driller will be responsible for coordinating all appropriate permits and notifications to state and local officials necessary to complete the scope of work.

Fermi Forward Responsibilities

1. Fermi Forward will mark subsurface utilities.

2. Fermi Forward will manage the profiling and disposal of investigation derived waste (IDW). Driller will be responsible for transferring IDW from the drilling locations to the disposal containers (i.e., lined roll-off boxes, totes) to be staged in a central location.

Figure 1: Entrance and Monitoring Well Locations

KEY

RESET PROTECTIVE WELL COVER AT THIS LOCATION

WELL SEALING AREA

tzei Callout Wilson Street Entrance tzei Polygon tzei Oval tzei Oval tzei Oval tzei Oval tzei Oval tzei Oval tzei Oval tzei Oval tzei Oval tzei Rectangle