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I Meeting these ARARs and, by extension, achieving
2 RAOs, can be accomplished by reducing concentrations
3 (or activities) of contaminants to remediation goal
4 levels or by eliminating potential exposure pathways.
5 Contaminant-specific, numeric soil PROs for direct
6 exposure and protection of groundwater and the
7 Columbia River are typically presented as
8 concentration (mg/kg) or activities (pCi/g).
9 SUMMARY OF REMEDIAL ALTERNATIVES
10 The 221-U Facility final feasibility study addressed
llI five alternatives for interim-remedial action. The
12 Phase I feasibility study Identified two other
13 alternatives that were not recommended for further
14 study. These were Alternatives 2 (Decontaminate and
15 Leave in Place) and S(Close in Place - Standing
16 Structure). Only Alteraatives 0 (as a baseline), 1. 3.4.
1^ and 6 were carried forward into the final feasibility
1 study and this Proposed Plan.
19 These alternatives are as follows:
20
21
22
23
24
25
26
27
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29
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31
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3
3
4
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4
4
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4
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• Alternative 0: No Action
• Alternative 1: Full Removal and Disposal
• Alternalive 3; Entombment with Internal Waste
Disposal
• Alternative 4: Entombment with InternaVExternal
Waste Disposal
• Alternative 6: Close in Place - Collapsed Structure.
With the exception of the No Action baseline
(Alternative 0), the remaining active alternatives
consist of common elements to achieve the 221-U
Facility RAOs. The common elements include
components within the response action, in.aitutional
rnntrols. and, for Alternatives 3, 4, and 6, a u a
barrier nost-elosure monitoring. These are
summarized in Table 4. The foomrint of the surface
Alternative 0: No Action Alternalive
DOFJRl.2001-29
Draft D RedlindStrikeout D
50 The "National Oil and Nazardous Subsunees103
SI Contingency Plan" (NCP) (40 CFR 300) requires that
52 a No Action alternative be evaluated as a baseline for
53 comparison with other remedial alternatives.
54 Alternative 0 represents a situation where no legal
SS restricbons, access controls, or active remedial
56 measures are applied to the site. No Action implies
57 "walking away" from the 221-U Facility and allowing
S8 the wastes to remain in their current configuration,
59 affected otily by natural processes and without benefit
60 of surveillance or maintenance acdvities. Selecting
61 Ahernative 0 as the preferred alternative would require
62 that the 221-U Facility poses no unacceptable threat to
63 human health or the environment.
64 Alternatlve 1: Full Removal and Disposal
65 In this alternative, the 221-U Facility structure and
66 contents would be decontaminated and demolished.
67 Demolition of the structure would involve cutting it
68 into large blocks. Structural material, facility contents.
69 and associated soil above tieaoW>-leve{R-yj,l^y3gQ
70 st,indards would be disposed at the ERDF. An
71 estimated 78,OOD ms (102,000 yd) of debris and soil
72 would be disposed to the ERDF. Most wastes would
73 be expected to meet the criteria established for ERDF
74 waste acceptance. If the ERDF waste acceptance
75 criteria cannot be achieved, waste treatment or
76 disposal at an offsite disposal facility would be
77 required. Material to be disposed of would be
78 segregated, evaluated for reuse or recycle, and
79 packaged and shipped to the disposal facility. The
80 demolition excavation would then be backfilled to
81 surrounding grade, and the disturbed area would be
82 reseeded or otherwise resurfaced consistent with future
83 land-use decisions. Institutional controls to mainuin
84 industrial land use would be required if unrestricted
85 cleanup levels are not achieved by this alternative.
86 Alternative 3: Entombment with Internal
87 Waste Disposal
88 This alternative would involve decontimination of the
89 221-U Facility in preparation for intemal placement of
90 wastes from other CERCLA actions on the Flanford
91 Site. Approximately 3A00 ms (4A00 yds) of exi.sting
92 contaminated equipment from the canyon eperating
93 dcck would be reduced in size and volume and then
94 disposed to process cells of the facility. Approximately
95 10.100 ms (13.200 yds) of waste from other CERCLA
96 actions would also be disposed in available remaining
97 spaces within the 221-U Facility, resulting in a total
98 waste disposal volume of 13500 tns (17.600 yd').
99 These wastes would be grouted to minimize the
100 potential for void spaces. A eross section of the
101 interior waste fill plan under Alternative 3 is shown in
102 Figure 4.
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