REMEDIAL ACTION WORK PLAN OPERABLE UNIT 2, LANDFILL ...

10. Comment:
This section is inadequate to describe the activity which will be the major determinate of the quality
of the closure. No material or construction specifications are referenced, and no quality control plan
is described. Please reference the applicable specifications. Additionally, the text implies that liner
seaming could be adequately performed by extrusion in place of fhsion. What is the basis for
extrusion being an acceptable altmnative?
Response:
This section of the RAWP is not intended to be the specification or the quality control plan.
Specification Section 02271 Flexible Membrane Liner, will be used as the basis for bidding and
selecting a supplier and installer. A third party subcontractor will be used for quality control during
manufacture and installation.
The text mentions fusion and extrusion welding, both of which are used for the installation of
polyethylene geomembrane. Panel welding is done using a hot-wedge fusion welder, however
extrusion welding is used for patching panels and pipe penetrations, i.e. in areas where a fusion
welder will not work. There was no implication intended to substitute fusion welding for extrusion
welding.
Action:
Section 2.7.1, last paragraph, delete and replace with:
“A specialty liner installation company will be subcontracted to famish and install the FML. Part
of the acquisition process requires submittal of company and personnel experience before award
of a subcontract.”
11. Comment:
During placement of the first lift of cover over the flexible membrane liner, this section states:
“Material will initially be placed. . . . a track mounted excavator. . . . a Low Ground Pressure (LGP)
dozer” . . . This equipment is not listed in the equipment lists on Tables 7-1 through 7-3. Please
explain or list this equipment.
Response:
The track-mounted excavator is listed in Table 7-2 under the heading “Excavator”. A Cat 225
excavator is a track-mounted excavator.
The low ground pressure dozer is the D6 dozer. Table 7-3, Support Equipment does not include
major earthmoving equipment.
Action:
Table 7-1 will be revised to include the excavator. The LGP dozer will be clarified on Tables 7-1
and 7-2.
SJ/4-23-96/SACTERC/FTORDOU2/USEPA
B-6