Superfund and Mining Megasites Lessons from the Coeur d'Alene River Basin (2005) / Chapter Skim
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8 Remediation Objectives and Approaches
8 Remediation Objectives and Approaches
Pages 327-410
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From page 327... ...
(EPA 2002) represents the next step in a long and contentious path for all concerned with human health and the environment in the Silver Valley of northern Idaho, Lake Coeur d'Alene, and the Spokane River down to Upriver Dam.
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From page 328... ...
process and is intended to interact with and take advantage of remedial actions taken under the RODs for OU-1 and OU-2. In essence, the ROD for OU-3 was the next step in addressing basin-wide human health and environmental issues caused by past mining operations.
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From page 329... ...
blood lead level" (EPA 2004a, p.
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From page 330... ...
9-1) : · Protection of human health in the populated and community areas of the upper basin and lower basin · Protection of ecologic receptors in the upper basin and lower basin · Protection and restoration of Lake Coeur d'Alene · Protection of human health and ecologic receptors for the Spokane River from the Idaho-Washington State line to Upriver Dam in eastern Washington Remedial alternatives are analyzed and described only to the level needed to support development of a proposed plan for cleanup, which is then expanded after the selection of alternatives in the ROD.
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From page 331... ...
parison with alternative remedial actions. Consideration of a "no-action" alternative is necessary to ensure that there is a benefit to proposed remedial actions and that remedial actions "do no harm." Alternatives for the protection of human health that address exposure pathways through soil, house dust, drinking water, and aquatic food sources are summarized in Box 8-1.
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From page 332... ...
. Soils The remedial alternatives considered for controlling human health risks from lead-contaminated soils include the following: S1, no action; S2, information and intervention; S3, information and intervention and access modifications; S4, infor mation and intervention and partial removal and barriers; and S5, information and intervention and complete removal.
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From page 333... ...
Aquatic Food Sources Three alternatives were developed to protect recreational fishermen, and per haps subsistence fishermen, from risks associated with eating fish caught in con taminated areas of the Coeur d'Alene River basin: F1, no action; F2, information and intervention; and F3, information and intervention and monitoring. The alternatives for protection of individuals from the risks associated with the consumption of contaminated fish caught in the Coeur d'Alene River, lateral lakes, and Lake Coeur d'Alene heavily focus on educating fishermen and recreational users about the potential health risks involved.
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From page 334... ...
. Appendix AA of the FS (URS Greiner, Inc.
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From page 335... ...
Min ing companies did not prepare an alternative. Alternatives developed for the Spokane River are similar in concept to those proposed for the upper and lower basin of the Coeur d'Alene River, ranging from institutional controls, to containment and removal, to aggressive removal and dis posal.
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From page 336... ...
336 $0 $0 $0 $428,000 cost $5,410,000 $2,900,000 $1,380,000 $4,290,000 $1,418,000 $2,900,000 $2,210,000 $81,000,000 $10,000,000 $123,000,000 Estimated total utility barriers Basin extensive and water program/ River removal program/dust sources loan public groundwater modifications removal loan capping/more treatment d'Alene access partial complete vacuum source, source, and alternative and and and and vacuum Coeur removal, residential alternative alternative multiple the and and and and for intervention intervention intervention intervention intervention intervention, source and and and and and and interior mats information information information information information Developed Action action action dust mats, cleaning Description No Information Information Information Information No Information Information No Public Public Public Public Public Costs and a a Alternative designation S1 S2 S3 S4 S5 D1 D2 D3 W1 W2 W3 W4 W5 W6 Alternatives of water dust Summary Media/Area Soils House Drinking 8-4 TABLE Focus Human health protection
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From page 337... ...
337 $0 $0 $0 >700 $230,000 $910,000 $900,000 and $1,300,000 $8,800,000 $1,800,000 $6,500,000 $28,000,000 $370,000,000 $257,000,000 $194,000,000 $1,300,000,000 $2,600,000,000 ts-of-way) barrier.
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From page 338... ...
Human Health Risk in Communities Comparative analysis of the alternatives led EPA to decide that the best balance of trade-offs would be represented by Alternative S4 for soil, D3 for house dust, W6 for drinking water, and F3 for food sources, as described above in Box 8-1. Ecologic Receptors in Upper and Lower Basin As described in Chapter 9 of the ROD (EPA 2002)
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From page 339... ...
that could include capping of contaminated sediments, riverbed sediment removal, and possibly sediment removal from Upriver Dam. Evaluation of EPA's Comparison of Alternatives In the statement of task, the committee was asked to assess whether EPA adequately characterized "the feasibility and potential effectiveness of
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From page 340... ...
of most of the alternatives EPA considered have been demonstrated at other sites and within the Coeur d'Alene River basin in the cleanups conducted within OU-1 and OU-2. However, as discussed in Chapter 5, the evidence regarding the effectiveness of yard remediations for decreasing blood lead levels (BLLs)
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From page 341... ...
Spokane River There are no remedial actions for Lake Coeur d'Alene, however, because a lake management plan (Coeur d'Alene Basin Restoration Project 1996, 2002; IDEQ 2004) is proposed, which is intended to be implemented outside of the Superfund process.
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From page 342... ...
Ecologic protection Approximately 30 years of prioritized actions $250,000,000 in the upper basin Including: and lower basin Upper basin tributaries $100,000,000 Lower basin riverbanks and bed $71,000,000 Lower basin floodplains $81,000,000 Lake Coeur d'Alene Not included in the selected remedy Spokane River Combination of elements of Spokane River $11,000,000 Alternative 3, 4, and 5 Monitoring Basin-wide monitoring $9,000,000 Total Cost $360,000,000 NOTE: costs are rounded to two significant figures. aIncludes costs for residential soil, street rights of way, commercial properties, and common areas, 31 recreational areas in the lower basin, and house dust.
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From page 343... ...
The agency, however, has not established any clear criteria for when these discretionary supplemental activities will occur. 1This approach of using less-protective remedies in areas where the contamination is lower results in an apparent anomaly that the residual risks from contaminated yard soils facing children in homes with lower initial soil contamination levels will likely end up higher than those for children living in homes with high initial levels of yard soil contamination.
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From page 344... ...
, or removal/ replacement." · Remediation of commercial properties and common use areas: Depending on the location, use, and levels of contamination in these areas, remedial actions will include soil removal and replacement, barriers (such as vegetation or a cover of clean gravel or other material) , and access restrictions.
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From page 345... ...
This lack of any quantitative, measurable, indicator of success is troublesome. Feasibility and Potential Effectiveness of Remediation Plans Coeur d'Alene River Basin EPA has already implemented remedies like these in the box and at other Superfund sites and has demonstrated that they are feasible.
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From page 346... ...
. As presented in the OU-1 5-year review, "Given the financial status of the Bunker Hill Superfund Site cities and residents, it seems unlikely that cleanup from the Milo Creek flood would have occurred so efficiently, or at all, without FEMA funds" (TerraGraphics 2000, p.
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From page 347... ...
Consumption of lake fish represents an exposure pathway to metals, but limited information was available to assess the health risks of such exposures when the human health risk assessment was initially prepared. To address this data gap, EPA funded a special study to characterize the concentrations of arsenic, cadmium, lead, mercury, and zinc in the tissues of bass, bullhead, and kokanee in Lake Coeur d'Alene (URS Greiner, Inc.
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From page 348... ...
Selected Remedy for Ecologic Protection The selected remedy is not one of the alternatives considered in the FS (URS Greiner, Inc.
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From page 349... ...
CERCLA allows EPA to select an interim remedy, if it is part of the total remedial action that will attain all ARARs. The EPA National Remedy Review Board recommended interim remedial actions for protection of ecologic receptors in the basin, because of the magnitude of contamination to be addressed, the significant costs associated with a basin-wide remedial strategy, and the uncertainties associated with predicting the effectiveness of the basin-wide ecologic alternatives (NRRB 2001)
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From page 350... ...
. As described in Chapter 3 of this report, groundwater contamination by metals has been detected at locations throughout the river basin.
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From page 351... ...
The water in the Spokane River meets safe drinking water standards for metals. The estimated average concentrations of total lead and dissolved zinc in surface water are 2.1 and 58 µg/L, respectively; dissolved cadmium was not detected (EPA 2002, p.
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From page 352... ...
. The sediments in this stream segment are stratified vertically, with sediments containing high lead concentrations buried deeper, covered by sediments with lower lead concentrations (see Figure 3-9 in Chapter 3 of this report)
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From page 353... ...
and mixed with approximately 25,400 tons of sediment from the North Fork (URS Greiner Inc. and CH2M Hill 2001d, Figures 3.2-4 and 3.2-5)
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From page 354... ...
354 SUPERFUND AND MINING MEGASITES Ecologic Risks: Adaptive Management and Determining Levels of Remediation The situation with respect to remediation levels for ecologic risks is similar to, but more complicated than, the situation with respect to human health risks. One major reason for the increased complexity is that the current ROD (EPA 2002)
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From page 355... ...
As discussed further below, EPA has proposed a reasonable set of biological indicators for evaluating responses of fish communities to remedial actions intended to improve water quality but has not proposed an equivalent set of indicators for evaluating the effectiveness of sediment removal actions. Implications of 3This discussion is based on principles developed by the British Columbia Forest Service (BC Forest Service 1999, 2000)
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From page 356... ...
The agency presumes that it can accurately predict the effectiveness of the alternatives it evaluates, which supports the passive adaptive management approach, and at most Superfund sites this approach is adequate. However, several of the actions proposed for protecting fish and wildlife in the lower Coeur d'Alene River basin appear to have many of the characteristics of experiments, and an explicit active adaptive management approach might be more effective in the long run.
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From page 357... ...
Monitoring blood lead concentrations in waterfowl and songbirds is clearly essential for documenting whether the remedial actions are reducing 4Benchmarks (actions and criteria) are near-term objectives that serve as "landmarks and measures" to evaluate the progress of prioritized actions to achieve long-term goals of risk reduction (EPA 2002, 8-1 to 8-3; EPA 2001a, pp.
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From page 358... ...
358 and con- × more between Inc. or resident 2004)
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From page 359... ...
359 and Inc.
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From page 360... ...
Instead, the BEMP states the target as being a statistically significant decline in blood lead concentration. A small, but statistically detectable decline in blood lead concentrations might not substantially reduce the number of birds adversely affected by lead exposures.
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From page 361... ...
EPA's approach to ecologic protection in the Coeur d'Alene River basin includes many of the components of adaptive management, but it has not been established in an explicit, structured manner that establishes unambiguous links between management objectives, management actions, performance benchmarks, and monitoring indicators. The biggest weakness is that the agency often has not established a series of quantitative indicators, particularly short-term indicators that can be monitored to unambiguously determine the success or failure of the proposed remedial actions.
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From page 362... ...
Only 5 percent of the impacted area in the Lower Basin is estimated to have lead concentrations between 530 mg/kg and background. For these reasons, EPA believes that selection of 530 mg/kg lead as the benchmark cleanup criterion for soil and sediment is technically the best alternative available at this time" (EPA 2002, p.
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From page 363... ...
For instance, nonnative fish species artificially introduced into the lateral lakes, Lake Coeur d'Alene, and the Coeur d'Alene River probably have permanently altered the fish communities of the basin and may impede or even prevent the reestablishment of viable populations of native species, even if water quality standards were achieved. Moreover, even if remediation improved water quality sufficiently to protect the health of fish, habitat restoration still would be needed to support macroinvertebrate and fish populations (see discussion in Chapter 7)
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From page 364... ...
364 SUPERFUND AND MINING MEGASITES to achieve the ARARs, and, even if they are achieved, improved water quality alone may not be sufficient to ensure the viability of the fish populations of concern. EPA could exempt the cleanup from meeting water-quality standards if the agency could demonstrate that fish and aquatic life can be protected without achieving these standards.
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From page 365... ...
· Will the cleanup be effective in meeting the agency's goals or benchmarks? These questions are addressed for the following five topographical areas of the basin: · Upper basin, which includes the high-gradient streams that flow into the South Fork Coeur d'Alene River · Middle basin, which extends from Wallace to Cataldo · Lower basin, which extends from Cataldo to Lake Coeur d'Alene · Lake Coeur d'Alene · Spokane River EPA uses a probabilistic model to quantify the certainty that a proposed remedy could meet cleanup goals (URS Greiner, Inc.
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From page 366... ...
and the ROD (EPA 2002) , was to quantify the effect that remedial measures would have on surface-water concentrations and metal loadings and the certainty and time frame that a remedial alternative or a proposed remedy would meet cleanup goals, which may be AWQC or interim benchmarks (URS Greiner, Inc.
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From page 367... ...
associated with this model and its use in extrapolating the effect of proposed remediation to 1,000 years, including the assumption that the impact of remedial strategies on the release of metals from source material to surface waters is known. In essence, the probabilistic model estimates relative loading potentials based on estimated total volume of contaminated material, estimated concentration of available zinc, and estimated effectiveness of various remediation methodologies in reducing metal loading.
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From page 368... ...
Remedial Actions Proposed for Upper Basin Tributaries: Ninemile Creek, Canyon Creek, and Pine Creek Areas slated for cleanup in the upper basin encompass Ninemile Creek, Canyon Creek, and Pine Creek. Many of the primary sources (for example, mine workings, waste rock, and tailings)
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From page 369... ...
369 of million Cost (Present $36 ) a to million million million Estimated Cleanup Worth $13.5 $35 $14 $16 Streams not and treat- dumps in- protect do with removal cap Rex to mine and the passive stream; hot-spot sites added.
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From page 370... ...
The committee fully supports the agency's plan to undertake the removal of sources contributing metals to surface water, encourages stabilization actions, and endorses actions that couple fish habitat restoration with remedial actions. Without habitat restoration, achieving the goal of reestablishing a resident fishery is doubtful.
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From page 371... ...
It is unclear, however, how much of the groundwater contamination in lower Canyon Creek is attributable to the Hecla-Star tailings impoundments, because no definitive studies have been carried out. Erosion is observed along the side of the ponds (URS Greiner, Inc.
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From page 372... ...
would be necessary to achieve the benchmark of 50% reduction of dissolved metal loading. In verbal discussions with EPA during the committee's tour on April 14, 2004 (EPA 2004c)
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From page 373... ...
. Remedial Actions Proposed for the Middle Basin (Wallace to Cataldo)
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From page 374... ...
2002) could prove useful in the middle and upper basin as tools for determining source areas contributing dissolved metals (also see Chapter 4 of this report)
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From page 375... ...
. Remedial Actions Proposed for the Lower Basin (Cataldo to Harrison)
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From page 376... ...
376 Cost million million Estimated $71 $81 Basin in is by acres) acres)
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From page 377... ...
· It is estimated that only 4% of the lead in the depositional environment of the lower basin resides in the riverbanks (Figure 8-3)
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From page 378... ...
Further, highly contaminated sediments are buried in the lower basin riverbed and they are susceptible to scouring and transport during flood events. The volume, lead concentration, and potential for transport make riverbed sediments a key component of any remedial strategy.
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From page 379... ...
(2004) , "the dredged river channel probably would re-fill with relatively dilute metal-bearing sediment, transported from the confluence of the North and South Forks, and containing about 2000 ppm of Pb." One thing is for certain -- until contaminated sources that exist both upstream and in the lower basin riverbed are removed or otherwise stabilized, particulate lead transport down-river is inevitable.
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From page 380... ...
of wetlands and lateral lakes in the lower basin that waterfowl use during their migration through the basin.12 RI studies indicate that more than 18,000 acres of waterfowl habitat exceed the adverse-effects level of 530 mg/kg. Because the total contaminated floodplain area in the lower basin is so large, it was recognized that all areas needing long-term cleanup could not be addressed completely in the interim action.
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From page 381... ...
Although it has not been described which lands will be acquired, their level of contamination, or how effective such efforts may be in directing the waterfowl from contaminated areas, reestablishing wetlands in these areas is a laudable effort, particularly if these areas are less susceptible to contamination from flooding. The other major efforts to protect waterfowl involve removing contaminated sediments from the bed and banks of the lower reach of the Coeur d'Alene River to reduce the likelihood that the cleaned-up areas will become recontaminated as well as to possibly reduce the transport of contaminated sediment through Lake Coeur d'Alene to the Spokane River.
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From page 382... ...
Regardless, decisions about remedial actions proposed in the floodplain of the lower basin need to seriously consider the impact and potential of recontamination as it can quickly undo costly, time-consuming, and resource-intensive remedies. Lake Coeur d'Alene Lake Coeur d'Alene is not included in the interim action, because its cleanup is to be addressed via a lake management plan (Coeur d'Alene Basin Restoration Project 1996, 2002; IDEQ 2004)
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From page 383... ...
Another concern of the committee is that EPA primarily used average conditions in designing remedies. For example, average mass loadings were used, despite the fact that metal concentrations at low flows are higher, and, therefore, conditions at low flows are more toxic to aquatic life.
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From page 384... ...
Clearly, a great deal of new information has been collected by USGS, the Idaho Department of Environmental Quality, the Coeur d'Alene tribe, EPA, and others on sediment dynamics in the South Fork, the North Fork, and the lower basin. Much of this information has become available since the RI was released in 2001 and the ROD was issued in 2002.
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From page 385... ...
. Under this process, EPA developed a range of remedial alternatives, presented in the FS (URS Greiner, Inc.
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From page 386... ...
. The proposed remedies will not lower the amount of surface-water contamination (particularly from dissolved zinc)
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From page 387... ...
This recommendation was based on the results of applying the integrated exposure uptake biokinetic model with the "default parameters." In OU-3, a higher screening level was selected with site-specific parameters (see Chapter 6) , which is consistent with EPA guidance.
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From page 388... ...
It is also unclear whether the interim remedies focused on cleaning up the wetlands and lateral lakes in the lower basin will provide adequate protection for the migratory bird species to satisfy the requirements of the Migratory Bird Treaty Act ARAR. Several new rules, which probably will qualify as ARARs, have been adopted since the ROD was prepared.
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From page 389... ...
It is not clear what effect these standards would have on the proposed remedies, particularly in that they apply only to the southern portion of Lake Coeur d'Alene. EPA does not claim to have satisfied all the ARARs with its interim measures, stating that The remedial actions selected in this ROD are not intended to fully ad dress contamination within the Basin.
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From page 390... ...
Many have the potential to be undone by floods, which are common in the valley and most selected remedies will require continued monitoring and maintenance to retain their effectiveness. These issues were discussed earlier in this chapter (see "Feasibility and Potential Effectiveness of Remediation Plans")
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From page 391... ...
As mentioned, it has not been demonstrated that removing selected floodplain materials would decrease inputs of dissolved zinc. Implementing some of the lower basin remedies will substantially disrupt the wildlife habitat being "remedied," giving them a negative effectiveness in the very short term.
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From page 392... ...
In comparison, the approximately 256 acre CIA contains 24.2 million cubic yards of material (URS Greiner, Inc. and CH2M Hill 2001h, Appendix J, Table A-8)
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From page 393... ...
In the Coeur d'Alene River basin, however, some of these judgments are very difficult, for -- at least in the case of environmental protection-none of the alternatives considered is expected to provide the amount of protection required by law. The agency is not particularly clear about how it made these judgments but asserts that "the Selected Remedy achieves a significant reduction in residual risk relative to its cost.
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From page 394... ...
However, it is not clear that improved cost estimates would affect the relative attractiveness of the different alternatives identified in the FS, although substantially higher costs might cause EPA to reduce its expectations of what it can afford to do in the valley. Perhaps more problematic are the externalities or indirect costs associated with many of the proposed remedial actions.
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From page 395... ...
could well be higher given the narrow, twisting roads that are typical in the valley. This issue is addressed briefly in the FS in the evaluation of the short-term effectiveness of the ecologic alternatives (URS Greiner, Inc.
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From page 396... ...
In projects as large as this, they are sufficiently significant that the committee concludes they should be explicitly considered when comparing alternative approaches and remedial actions even if they are not included in the quantitative cost estimates. State Acceptance As indicated earlier in this chapter, EPA has apparently made substantial efforts to coordinate its plans and proposals with other governmental organizations.
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From page 397... ...
The effectiveness of the remedial actions for human health protection, where they have occurred, needs to be further evaluated. The agency has implemented similar measures in OU-1 and OU-2 and at other sites.
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From page 398... ...
In addition, a strategy is needed for evaluating the performance and efficiency of the selected remedies. Conclusion 4 The lack of repositories for contaminated soils and sediments is particularly problematic and is a primary concern to the committee regarding the feasibility and implementability of the proposed remedial actions in the basin.
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From page 399... ...
Conclusion 7 Ultimately the contamination problems in the Coeur d'Alene River basin, Lake Coeur d'Alene, and the Spokane River will be solved only when the contaminated sediments in the river basin have been removed or stabilized. Efforts to remove contaminated sediments in the lower basin are likely to be of limited value until the problems of sediment transport from the upper and middle basins have been adequately addressed.
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From page 400... ...
The committee supports measures such as restoring wetlands on agricultural lands in the lower basin and upgrading the quality of the habitat in existing wetland areas that have the least likelihood of being recontaminated. Many of the wetland and lacustrine areas in the lower basin are likely to be recontaminated by the first major flood that occurs after their remediation, and the likely effectiveness of some of the measures proposed to reduce such recontamination is very uncertain.
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From page 401... ...
Monitoring has demonstrated that, during flood events, lead concentrations increase in the river downstream of Cataldo and that riverbed sediments in the lower basin are redeposited on the banks and adjacent wetlands. It is estimated that the riverbed of the lower basin is the source of 70-80% of the particulate lead entering Lake Coeur d'Alene.
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From page 402... ...
of the dissolved zinc in the lower basin results from groundwater seepage through the box area, but EPA has excluded this area from consideration in OU-3. It appears unlikely that the agency will be able to achieve waterquality standards downstream from the box without reducing the amount of zinc coming from this source.
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From page 403... ...
The probabilistic model is used to estimate relative loading potentials based on estimated total volume of contaminated material, estimated concentration of available zinc, and estimated effectiveness of various remediation methodologies in reducing metal loading. There are no leach test data from sediments or tailings that would provide rates and quantities of metal release over time, allowing extrapolation of relative loading potential.
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From page 404... ...
Recommendation EPA should support the development of a predictive tool based on sound scientific principles and supported by site-specific information on leaching potential, groundwater movement, and other such factors to allow them to accurately assess the likely effectiveness of remedial actions on dissolved metal loadings from various sources along the river. Conclusion 14 The transport of contaminated sediment through the basin and the rest of the project area is a key factor in determining the likely effectiveness and durability of proposed remedies.
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From page 405... ...
Recommendation In establishing priorities for designing and implementing remedial actions, EPA should consider the potential indirect costs and environmental impacts of the remedies being considered. Conclusion 16 The large uncertainties in the present understanding of the mechanisms of release of metals and nutrients from Lake Coeur d'Alene sediments and their transport and fate after release will limit development of an effective lake management plan.
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From page 406... ...
2000. Relation of water fowl poisoning to sediment lead concentrations in the Coeur d'Alene River Basin.
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From page 407... ...
Presentation at the Second Meeting on Superfund Site Assessment and Remediation in the Coeur d'Alene River Basin, April 15, 2004.
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From page 408... ...
2004. Presentation at the Third Meeting on Superfund Site Assessment and Remediation in the Coeur d'Alene River Basin, June 17, 2004, Coeur d'Alene, ID.
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From page 409... ...
Environmental Protection Agency Region 10, Seattle, WA, by URS Greiner, Inc., Seattle, WA, and CH2M Hill, Bellevue, WA. October 18, 1999.
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From page 410... ...
2001e. Probabilistic Analysis of Post-Remediation Metal Loading Technical Memorandum (Revision 1)
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