Final Site Information Package for National Remedy Review Board ...
Final Site Information Package for National Remedy Review Board ...
Final Site Information Package for National Remedy Review Board ...
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TABLE B9-1a<br />
Comparative Analysis of the No Action Alternative and Alternatives 3+(a) through 3+(e)<br />
<strong>Site</strong> <strong>In<strong>for</strong>mation</strong> <strong>Package</strong> <strong>for</strong> <strong>National</strong> <strong>Remedy</strong> <strong>Review</strong> <strong>Board</strong><br />
Criteria No Action<br />
Compliance with ARARs<br />
Chemical-specific ARARs Would not comply with chemicalspecific<br />
ARARs (AWQC) <strong>for</strong><br />
surface water until natural decay<br />
processes reduced loading to<br />
below AWQC levels (see ARARs<br />
summary above).<br />
Location- and action-specific<br />
ARARs<br />
Long-Term Effectiveness and Permanence<br />
Magnitude of residual risk Magnitude of existing ecological<br />
risk may decrease slightly or<br />
remain essentially unchanged <strong>for</strong><br />
several decades or centuries.<br />
Adequacy and reliability of<br />
controls<br />
OU 2 Alternative (a)<br />
Minimal Stream Lining<br />
OU 3 Component<br />
Alternative 3+: More Extensive Removal, Disposal, and Treatment<br />
OU 2 Component<br />
OU 2 Alternative (b)<br />
OU 2 Alternative (c)<br />
OU 2 Alternative (d)<br />
Stream Lining/French Drain<br />
Extensive Stream Lining<br />
French Drains<br />
Combination<br />
OU 2 Alternative (e)<br />
Extensive Stream Lining/French<br />
Drain Combination<br />
Combined Upper Basin Alternative<br />
Alternative 3+(a) Alternative 3+(b) Alternative 3+(c) Alternative 3+(d) Alternative 3+(e)<br />
Would significantly reduce metals<br />
concentrations in surface water, but<br />
would not meet surface water ARARs<br />
following remediation (see ARARs<br />
summary above).<br />
Not applicable Would comply with all action-specific and<br />
location-specific ARARs, including<br />
substantive requirements of CWA<br />
Section 404, Rivers and Harbors Act<br />
Section 10, and Endangered Species<br />
Act.<br />
Potential <strong>for</strong> ecosystem recovery is<br />
limited by contaminants.<br />
Potentially significant residual risks<br />
to humans.<br />
No controls would be implemented<br />
to control residual risks.<br />
Moderate reduction in expected postremediation<br />
mass loadings (estimated<br />
42% reduction). Some smaller loading<br />
sources would receive no action or<br />
limited containment. Low potential <strong>for</strong><br />
mobilization (through erosion) of<br />
contaminated alluvium left in place.<br />
Natural source depletion processes<br />
would further reduce residual risks.<br />
Low residual risk to humans.<br />
Decontamination of structures and<br />
access restrictions would be effective.<br />
<strong>Remedy</strong> could effectively be maintained<br />
through monitoring, maintenance, and<br />
institutional controls. Moderate<br />
maintenance requirements <strong>for</strong> caps,<br />
stream and riparian improvements,<br />
sediment traps, French drains, and<br />
stream liners. High maintenance<br />
requirements <strong>for</strong> passive and active<br />
treatment.<br />
Would significantly reduce metals<br />
concentrations in surface water, but<br />
would not meet surface water ARARs<br />
following remediation (see ARARs<br />
summary above).<br />
Would significantly reduce metals<br />
concentrations in surface water, but<br />
would not meet surface water ARARs<br />
following remediation (see ARARs<br />
summary above).<br />
Would significantly reduce metals<br />
concentrations in surface water, but<br />
would not meet surface water ARARs<br />
following remediation (see ARARs<br />
summary above).<br />
Would significantly reduce metals<br />
concentrations in surface water, but<br />
would not meet surface water ARARs<br />
following remediation (see ARARs<br />
summary above).<br />
See Alternative 3+(a). See Alternative 3+(a). See Alternative 3+(a). See Alternative 3+(a).<br />
See Alternative 3+(a). Additional Large reduction in expected post-<br />
benefits would be achieved through remediation mass loadings (estimated<br />
this alternative by significantly 60% reduction). Some smaller loading<br />
improving water quality in several OU 2 sources would receive no action or<br />
tributaries (Government, Magnet, and limited containment. Low potential <strong>for</strong><br />
Deadwood Creeks).<br />
mobilization (through erosion) of<br />
contaminated alluvium left in place.<br />
Natural source depletion processes<br />
would further reduce residual risks.<br />
Low residual risk to humans.<br />
Decontamination of structures and<br />
access restrictions would be effective.<br />
Low residual risk to humans.<br />
Decontamination of structures and<br />
access restrictions would be effective.<br />
See Alternative 3+(a). See Alternative 3+(a). More linear feet of<br />
French drain are included in this<br />
alternative, although less stream lining.<br />
Page 2 of 6<br />
Large reduction in expected postremediation<br />
mass loadings (estimated<br />
62% reduction). Load reduction<br />
estimates provided are <strong>for</strong> the SFCDR.<br />
Additional benefits would be achieved<br />
through this alternative by significantly<br />
improving water quality in Government<br />
Creek. Some smaller loading sources<br />
would receive no action or limited<br />
containment. Low potential <strong>for</strong><br />
mobilization (through erosion) of<br />
contaminated alluvium left in place.<br />
Natural source depletion processes<br />
would further reduce residual risks.<br />
Low residual risk to humans.<br />
Decontamination of structures and<br />
access restrictions would be effective.<br />
See Alternative 3+(a). More linear feet<br />
of French drain and slightly less stream<br />
lining would be included in this<br />
alternative.<br />
Large reduction in expected postremediation<br />
mass loadings (estimated<br />
66% reduction). Additional benefits<br />
would be achieved through this<br />
alternative by significantly improving<br />
water quality in many OU 2 tributaries.<br />
Some smaller loading sources would<br />
receive no action or limited containment.<br />
Low potential <strong>for</strong> mobilization (through<br />
erosion) of contaminated alluvium left in<br />
place. Natural source depletion<br />
processes would further reduce residual<br />
risks.<br />
Low residual risk to humans.<br />
Decontamination of structures and<br />
access restrictions would be effective.<br />
See Alternative 3+(a). Significantly<br />
more stream lining and French drains<br />
would be included in the alternative, as<br />
well as slurry walls and groundwater<br />
extraction wells.