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Final TO42 Site Survey Report
Well Upgrades
Upgrades are planned for four existing wells so they can be incorporated into the CSSA overall groundwater monitoring strategy. The wells include two existing monitoring wells that will have 3-inch diameter casing and screen installed into currently open boreholes (see CS-MW1-LGR and CS-MW2-LGR described above). The remaining two wells are older agricultural wells that require rehabilitation. In addition, three existing CSSA water supply wells were examined for possible future upgrades for monitoring purposes utilizing pressure transducers.
Location and Purpose - CS-G is near the center of the western half of the North Pasture, in the Outer Cantonment. Work at CS-G will upgrade the well to conform to the monitoring capabilities of current CSSA monitoring wells. Upgrade items include removal of adjacent windmill remnants (i.e. old sucker rods), replacement of surface completion to comply with current standards, well development, and installation of a new low-flow pump.
Accessibility - The well site is accessed by gravel and narrow dirt roads from the Gate 6 entrance to the North Pasture. Workspace around the well is adequate but there are several large, low overhanging oak limbs that may require trimming.
Personnel requiring access to the site are Parsons field teams and vehicles, drilling subcontractor with pump rig, and surveyors with a vehicle.
Utilities - No utilities were observed at the CS-G work site.
Other Site Issues - Existing surface casing is 6-1/8-inch outer diameter and 4-7/8-inch inner diameter. A well cover and a QED pump cap larger than the currently employed sizes will be required at the upgraded CS-G wellhead. Material removed from site will need to be disposed in an appropriate manner. Operations at CS-G will involve welding, and use of cutting torches and jackhammers. Work at CS-G will cause increased traffic through Gate 6, which is normally secure.
Location and Purpose - CS-H is located in the northwest corner of the Outer Cantonment. Non-operational tubing and hardware must be removed from the well. A new high capacity submersible pump is to be installed and the well re-developed. If the old apparatus cannot be removed from the well, then the well may be plugged and abandoned, and a replacement well installed. The abandonment and replacement of CS-H is not currently funded.
Accessibility - The well site is accessed by gravel and narrow dirt roads from the Gate 6 entrance to the North Pasture. These roads are nearly impassible during and after rain events. Workspace around the well appears to be adequate, but a large dead tree and fallen limbs next to the existing well will need to be removed. An old, raised concrete foundation on the northwest side of the well site will inconvenience some vehicle maneuvering, but should not prevent planned work activities. There is sufficient area nearby to site and install a replacement well, if that option is exercised.
Personnel requiring access to the site are Parsons field teams and vehicles, drilling subcontractor with pump rig, and surveyors with a vehicle. If a replacement well is drilled, then a roll-off truck, larger drill rig, and geophysical logger with van would also be on site at various times.
Utilities - An overhead electric line runs from the north to a panel at the existing CS-H location. Power will need to be off for electrical hook-up of any new pump. Lock-out/tag-out procedures should be followed and verified by a CSSA licensed electrician. Basic electrical hook-ups can be completed by the pump installers, but the CSSA electrician must check the electrical box wiring, etc. upon completion of the task to ensure that all codes are met.
Other Site Issues - Torch cutting and jack hammering may be conducted at the site. There will be increased contractor traffic through the normally secure Gate 6.
Location and Purpose - These wells are on hillsides in the west-central portion of the Inner Cantonment. CS- 9, CS-10 and CS-11 serve as water supply wells for CSSA. The wells were inspected to determine accessibility for electronic monitoring devices, which will be installed in the future. These wells were upgraded with monitoring tubes in July 2001 in support of pumping tests. At this time Parsons is not considering any further upgrades to these wells. Accessibility and utility issues are discussed for completeness.
Accessibility - The wells are easily approached by maintained gravel roadways. If the conduits for monitoring apparatus were replaced, the roof of each well house would have to be temporarily removed.
Personnel requiring access to well locations would be Parsons field team with vehicle and the drilling subcontractor with pump rig.
Utilities - Similar work was performed in the summer of 2001 during pumping tests without hindrance from existing utilities.
Other Site Issues - The current water level monitoring tubes have diameters of 1-inch, which requires miniaturized equipment. Several manufacturers, including (In Situ and Solinst) manufacture transducers with less than a 1-inch diameter. The In Situ models were used during the July 2001 pumping test with the existing monitoring tubes. Solinst offers a conductivity measurement parameter in its small-diameter probe that In Situ does not.
This site was not surveyed as an original drilling location. Since the DQOs, this well has been added to the program. The description has been generalized from prior experience and general site knowledge.
Location and Purpose - The existing CS-16 water well will be upgraded with screen and casing, and will be re-designated as CS-MW16-LGR. The location is in the northeast quadrant of the Inner Cantonment. It lies approximately north of the intersection of North Outer Road and Moyer Road. The purpose of this work is to eliminate the hydraulic connection between the LGR and CC water-bearing zones in the existing open-borehole completion.
Accessibility - The CS-MW16 site is accessed from North Outer Road. There is limited space for rig, vehicle, and equipment placement. The building that houses well CS-16 and the CSSA GAC unit limit the size of the work site. In addition, some of the space will be occupied by roll-offs for groundwater treatment during the drilling phase.
Personnel requiring access to the site are Parsons field teams and vehicles, drilling subcontractor with rigs and trailers, water and vacuum trucks, backhoes, geophysical well logger with van, roll-off delivery truck, and surveyors with a vehicle.
Utilities � Known utilities in this area include water, electrical, and communication lines. All utilities will need to be identified by the CSSA craft team, and a digging permit issued.
Other Site Issues � None at this time.