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--> APPENDIX C Case Histories of Representative Remediation Projects1 Frank Bohlen, Peter Shelley, and Kenneth S. Kamlet To develop an understanding of the factors affecting the management of contaminated sediment sites, the committee reviewed a large number of ongoing and recently completed projects. From this group, six projects, which are considered representative of particular site conditions, regulatory constraints, and classes of contaminants, were selected and examined in more detail These case histories yielded graphic illustrations of the complexity of the management process and provided a basis for subsequent committee evaluations of remediation strategies and the protocols affecting their implementation. The criteria used by the committee to select the six projects are shown in Table C-1. The case histories provide examples of coastal, lake, riverine, and estuarine conditions and include both navigation dredging and environmental cleanup (Superfund2) projects. A variety of remediation strategies, and both organic and inorganic contaminants, are represented. The lessons learned are largely subjective, rather than formal, rigorously derived conclusions, such as those presented in the text of the report. The lessons were considered throughout the committee's study along with other evidence. The sites selected for evaluation were Boston Harbor, Massachusetts; Hart and Miller islands, Maryland; James River, Virginia; Marathon Battery, New York; Port of Tacoma, Washington; and Waukegan Harbor, Illinois. 1 This appendix has been edited for grammar and style, accuracy is the sole responsibility of the authors 2 Superfund is the common name for the Comprehensive Environmental Response, Cleanup, and Liability Act
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--> TABLE C-1 Selection and Evaluation Criteria for Six Case Histories Sites Selection Criteria Boston Harbor Hart/Miller Islands James River Marathon Battery Port of Tacoma Waukegan Harbor Navigation dredging Yes Yes No No Yes No Hot spot/Superfund No No Yes Yes Yes Yes Imminent hazard No No Yes Yes No No Remediation end-point Water quality standards Water quality standards FDA action levels Cadmium. nickel concentration ≤100 ppm State sediments quality objective (apparent effects threshold) PCB concentration at 50 ppm Critical technology selected On-site capping CDF Natural restoration Chemical stabilizer Near-shore containment Thermal desorption Natural restoration No No Yes Partial No No Capping Yes Yes No Partial Yes (in containment area) Yes In situ treatment No No No No No No Ex situ treatment No Limited No Yes No Yes Ex situ containment CDFs. confinement Containment islands None Landfill Diked containment Diked containment Examples of beneficial uses Landfill cover and cap; real estate Recreational area, reduced erosion None None Enhanced port and habitat None Institutional/ intangible factors Public involvement Public opposition Fisheries contamination; high costs of remediation Wildlife area Stakeholder cooperation Human health, Superfund
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--> BOSTON HARBOR, MASSACHUSETTS The ongoing project in Boston Harbor involves significant navigation dredging, source controls, and the removal and isolation of a large mass of contaminated sediment. Contained aquatic disposal (CAD) is planned. The harbor supports commercial shipping as well as fisheries and recreational boating. The harbor also has served as a contaminant sink for hundreds of years, receiving municipal and industrial discharges, urban runoff, vessel spills, and flows from several watersheds. Sewage has been discharged in two locations in the harbor for many years. Background Litigation in the early 1980s forced the construction of new sewage facilities to allow for diffused discharge 9.5 miles offshore. The improvements are to come on line between 1996 and 2000; interim remedial projects already have made significant improvements in water-column and sediment quality as well as benthic activity. In 1968, the U.S. Congress directed the U.S Army Corps of Engineers (USACE) to review plans for navigation improvements. The planning eventually led to a 1988 feasibility study for dredging and deepening several channels. The dredged material was to be placed at the Massachusetts Bay Disposal Site (MBDS), some 22 nautical miles east of Boston, in waters 80 to 100 meters deep. Contaminated sediments were to be capped. The dredging project stalled because of a number of factors, including political changes in the state, growing public concern about the offshore placement of dredged material near an area subsequently designated as a national marine sanctuary, and the tightening of sediment characterization criteria. The USACE and the local project sponsor (the Massachusetts Port Authority or MASSPORT) conducted another environmental review in 1992, this time with extensive public participation. More than 37 organizations (including environmental groups, state water quality certification officers, neighborhood organizations, and businesses) were invited to a meeting, with a facilitator from a professional office of dispute resolution. Two technical working groups were established, one focusing on sediment characterization and one on disposal options. During the process leading to the designation, many more people became aware of and involved in the harbor remediation decision process. Remediation Alternatives Considered The screening process began with 312 land-based inland and coastal sites, 21 landfills, and 21 aquatic sites. This list was narrowed to 24, from which four acceptable and preferred alternatives were identified: MBDS, the Boston Lightship site, two near-shore borrow pits, and one CAD site.
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--> The cooperative review led to changes in the decision-making process: (1) the MBDS was dropped from consideration because of uncertainties about the efficacy and durability of capping at the proposed depths and because of persistent concerns about deleterious biological impacts on the nearby marine sanctuary; (2) the use of a cost cap as a screening tool was eliminated, and all alternatives were analyzed primarily on the basis of their technical and environmental merits, with a secondary cost-effectiveness screen; (3) the project team focused on the use of previously impacted areas as placement sites; (4) the USACE agreed to treat all silts as contaminated; and (5) innovative technologies for the handling, treatment, and placement of contaminated marine sediments were evaluated thoroughly. The unit costs of all the alternatives considered ranged from $16/cubic yard (yd3) for open-ocean capping at the MBDS to well over $200/yd3 for various treatment or land and shore-side containment facilities. Strategy Chosen In the end, an entirely new strategy was chosen: in-channel CAD with sand capping. To accommodate the in-channel CAD strategy, portions of the navigation channels were to be overdredged to form a series of deep cells or pits. Contaminated sediments from the remainder of the channel were to be placed in these pits and capped with a layer of sand at least three feet thick. Clean dredged material from the deeper sediments of each pit was to be barged offshore for placement at the MBDS. It was recognized that in-channel placement would limit future capabilities to deepen the waterway to accommodate vessels of increased draft. This was not considered a major impediment, however, because channel depths already were limited effectively by several roadway tunnels passing under the harbor. Dredging costs associated with the in-channel disposal option were estimated at $37/yd3, resulting in a total project cost of approximately $58 million. Overall Assessment It is premature to declare that the project has cleared its last hurdle, but the reactions of the general public, the regional press, and project participants have been positive. Although the project is without question more complicated and expensive than the original proposal, a wider range of stakeholders consider it to be both environmentally preferable and politically implementable. Lessons Learned In a limited number of cases, historically contaminated bottom areas within or close to a dredged navigation channel may represent the optimum location for the disposal or containment of contaminated channel
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--> sediments. The use of these areas is not beyond the capability of existing methodology. Involvement of all key interest groups at the earliest possible stage in the planning process can contribute significantly to ultimate project acceptability. Dispute resolution tools can be helpful in building consensus. When conducting cost-benefit analyses of various management strategies, decision makers need to recognize that considering cost criteria alone is overly restrictive. The most desirable choice appears to be the lowest-cost solution that is politically and environmentally acceptable. HART AND MILLER ISLANDS, MARYLAND The Hart and Miller islands project involves a diked confined disposal facility (CDF) that was constructed specifically to receive all sediments dredged from Baltimore Harbor and its approach channels within the Patapsco River. By state law, these sediments are considered to be contaminated and must be contained. The site was also intended to receive clean sediments from a major deepening project. Baltimore Harbor sediments have been contaminated by a variety of agricultural, industrial, and municipal wastes. Bottom sediments dredged from the harbor and its approach channels were to be placed in the 1, 00-acre CDF and capped with clean material. The facility is adjacent to Hart and Miller islands, which are located in the Chesapeake Bay several miles north of the harbor entrance. Both of these small islands support abundant wildlife. The capacity of the CDF was sufficient to provide 9 to 30 years of service, depending on the number of dredging projects required to use the facility. When filled, the site was to be landscaped for use as a public recreation area. Background In 1970, the U.S. Congress authorized the deepening of the harbor approach channels from 42 to 50 feet, on the condition that nonfederal harbor agencies provide a suitable placement area for dredged material. In the past, materials dredged from the harbor have been placed at open-water sites. Concerns that this practice would have adverse environmental effects led to an extensive environmental review. Approximately 70 disposal sites were considered, 10 of which were subjected to intensive study. The analysis indicated that the construction of a diked area spanning Hart and Miller islands would provide the most environmentally acceptable disposal site. At first, the Hart/Miller project was controversial. Proponents argued that it would reduce the open-water placement of contaminated dredged materials and
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--> help combat serious erosion of the islands. Opponents asserted that environmental impacts, alternative options, and cumulative impacts had not been assessed adequately. A legal challenge to the plan was filed, but the courts eventually ruled against the plaintiffs. A permit was obtained in 1976, but the legal challenge was not resolved until late 1980. The CDF was completed in 1983 and was first used in 1984. Remediation Alternatives Considered In addition to containment at the Hart/Miller site, other strategies that were considered included taking no action, using other diked containment areas (including the use of a larger number of smaller sites), and using dredged material to produce bricks or other ceramics. The range of alternatives was limited when the Maryland General Assembly appropriated $13 million specifically to implement a diked containment strategy. A consultant evaluated 70 sites and concluded that Hart/Miller was the most desirable on the basis of both economic and environmental factors. Strategy Chosen The original plan, dredging and disposal at the Hart/Miller CDF, was carried out, and the CDF was operated under rigorous effluent discharge criteria and subject to external environmental monitoring. Subsequently, the dikes were temporarily raised 10 feet, from 18 to 28 feet, for the 50-foot deepening project because substantial capacity was used to contain clean sediments from the approach channel when no other placement sites were available. A continuing inability to secure consensus on placement has resulted in a state decision to raise the dikes permanently in the facility's north cell another 16 feet, which would add 30 million cubic yards of capacity. Overall Assessment The CDF was expected to be filled by July 1996. The facility's useful life was shortened because the Maryland Port Administration was forced to use the site for backlogged and new dredging work when permits could not be obtained for open-water sites. The state park encompassing the Hart/Miller site has become a fairly popular recreational destination for boaters. Reactivation of an additional small-scale, shoreside industrial CDF is progressing. The state has not been able to establish other sites because of public and environmental opposition to specific sites, including most beneficial use projects. Consequently, the state
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--> has been forced not only to continue to use the CDF for clean sediments but also to increase the CDF capacity despite prior public commitments not to do so. Lessons Learned Stakeholders who do not feel adequately represented in the original decision can delay a project for many years in an effort to ensure that their interests are considered. A high-volume CDF has the potential to be a multiuse facility that not only isolates contaminants from surrounding waterways but also, for example, stabilizes adjoining coastal areas and serves as recreational parkland. The requirement that all sediments dredged from the harbor, regardless of their quality, be disposed of in the CDF shortened the lifetime of the facility. The availability of a large CDF can become a convenient excuse to delay or avoid making politically sensitive, difficult, and controversial decisions to resolve critical dredging problems, shortening CDF capacity for contaminated sediments in the process. JAMES RIVER, VIRGINIA Among the contaminated sediment projects reviewed by the committee, the James River case stands out as a clear example of the utility of natural recovery. The James River drains an area of approximately 25,600 square kilometers (km2) from the hills of West Virginia to the tidal waters of the Chesapeake Bay near Norfolk, Virginia. The river was contaminated as early as 1967 with the pesticide Kepone, which was manufactured until 1975 by a company situated near the upstream limit of the estuarine reach. Commercial fisheries were closed in 1975 because of Kepone contamination. Background This estuarine system had been studied extensively prior to the discovery of the Kepone contamination, and these early investigations not only supported the need for subsequent ecological studies but also helped create a strong scientific basis for making sound management decisions. The Kepone distribution pattern coupled with the hydrophobic nature of this pesticide suggested that contaminant transport was dominated by physical processes affecting the distribution of suspended sediments. The dominance of physical processes favored a progressive decrease in surficial Kepone concentrations as a result of dispersion and dilution, as clean sediments introduced from both upstream and downstream sources were
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--> mixed with contaminated materials, and as a result of sedimentation and burial within the deeper, low-energy regions of the river channel. These natural processes effectively reduced near-surface concentrations and the associated exposure of biota and isolated contaminants in the interior of the sediment column from overlying waters. Remediation Alternatives Considered A variety of options, including dredging, sorption, and stabilization of the surficial sediments using molten sulfur, were considered in a 1978 study. Biological, chemical, physical, and geological aspects of the contamination indicated that remedial actions to remove Kepone would be expensive, time-consuming, and environmentally damaging. Strategy Chosen The high cost of active remediation, combined with the observed decrease in Kepone concentrations in surface sediments, favored the selection of natural recovery as the strategy of choice. No direct costs were incurred, although there were economic costs associated with site studies leading to the selection of this option as well as with the closure of the fishery for 13 years while natural recovery was taking place. Overall Assessment In this case, natural recovery has proven to be an effective management strategy in both economic and environmental terms. Source control was an important factor in the success of this project (the Kepone manufacturing operation was shut down). Commercial fisheries reopened in 1988 when the contamination decreased, the sediments had been covered sufficiently by uncontaminated materials to diminish the Kepone flux back into the water column, and Kepone concentrations in organisms inhabiting the river were below federal action levels. It is assumed that Kepone concentrations are continuing to decline. Lessons Learned Under the right circumstances, natural recovery can represent the most cost effective, environmentally beneficial, and politically acceptable management scheme. Confidence in the decision to allow natural recovery to proceed is contingent on the availability of long-term data concerning the physical, chemical, and biological characteristics of the site.
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--> Close collaboration between scientists familiar with local site characteristics and the agencies responsible for resource management can contribute significantly to the selection of optimum remediation strategies. MARATHON BATTERY, NEW YORK Marathon Battery is an example of the remediation of heavy-metal contamination of a wetland environment within the tidal reach of a river. Marathon Battery is a Superfund site located along the eastern shore of the Hudson River, approximately 80 km north of New York City. The area has a long history of industrial use, first as a foundry producing armaments and then, until 1979, as a plant producing nickel-cadmium batteries. Process waters were discharged into a nearby cove and, through a municipal sewer outfall, into the Hudson, introducing significant quantities of heavy metals, including cadmium, nickel, and lead. Field sampling indicated that the site was contaminated by approximately 50 metric tons of cadmium, the principal contaminant of concern. Background After contamination of the area was recognized in the early 1970s, a volume of 90,000 m3 was dredged and dewatered, and 4,000 m3 of remaining sediment was placed in a sealed vault. In 1981, the Environmental Protection Agency (EPA) placed the site on the National Priorities List of sites requiring investigation and cleanup under Superfund. After the analysis of field data, the EPA decided to use dredging and chemical fixation to remove 95 percent of the contaminants The fixed sediments were to be transported for off-site disposal. To facilitate dewatering, treatment, and transport, a multicelled settling basin was designed by the USACE. Plans were disrupted when an historical gun testing platform was discovered in the area that was to be used for equipment staging and waste stabilization. The archeological features of the site were then reviewed and the plans redesigned. In 1992, just prior to the bidding for the remediation contract, the EPA reached a settlement with the parties responsible for the contamination, who agreed to clean up the site to the criteria established by the EPA. Remediation Alternatives Considered Only one approach—dredging, treatment, and off-site placement—was considered. The eventual solution differed little from the original plan. The EPA's original plan was to rely on gravitational settling for dewatering the sediments and to use a Portland cement-based process for chemical fixing. The responsible parties proposed using a series of graded screens for dewatering and a proprietary stabilizing agent for chemical fixing. This approach would produce a soil-like material in which the metals would be immobilized.
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--> Strategy Chosen Remediation of the site, through dredging, treatment, and containment, began in 1993. Stabilized sediments were placed in rail cars for transport to a placement site in Michigan. Actual project costs are not known but are expected to be less than the EPA's original estimate of $48.5 million. An interesting incentive for cost savings was used. Contractors were encouraged to recommend modifications to the original plan; if any accepted recommendations reduced costs, then the savings would be shared by the contractor (40 percent) and the government (60 percent). Overall Assessment Remediation began in 1993 and was scheduled for completion by late 1994. But a variety of unexpected problems were encountered. Dredging was slowed by tidal conditions, which limited water depths and occasionally grounded the hydraulic dredge used in the confined inshore areas. Because of relatively high concentrations of coarse sand, gravel, and rock in the deeper areas of the Hudson River, the hydraulic dredge was replaced with a clamshell dredge. Initial dewatering operations were very slow because of persistent clogging of the screens by organic materials, so the process had to be redesigned. Neither the final outcome of the project nor the results of post-project monitoring is available at this time. Lessons Learned Site character and history, including archeology, can have a significant effect on project design and can impede project completion. Placement of contaminated sediments at a remote site is both possible and acceptable in some cases. Adequate pre-project site assessments are needed to minimize the possibility of costly surprises after the project has begun. Incentives for cost savings and other innovations can be included in the contract bidding process. PORT OF TACOMA, WASHINGTON The Port of Tacoma project is an example of how stakeholder cooperation and the emergence of a single project advocate can lead to innovative and successful solutions. The Sitcum Waterway, an industrial and commercial shipping channel, is a Superfund site within Commencement Bay in the City of Tacoma. Shorelines of
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--> the bay are urbanized, with heavy industry on former tideflats. Less than 2 percent of the original near-shore wetlands remain. Several fish species (including salmon, steelhead trout, sole, and flounder) seek refuge and feed near shore. The release of hazardous substances into the environment has altered the chemistry of the water and sediments. Studies indicated that Sitcum sediments contained elevated concentrations of several metals, organic chemicals, and other contaminants. Background In 1983, Commencement Bay Nearshore Tideflats were placed on the priority list of sites requiring investigation and cleanup under the EPA's Superfund authorities. The EPA entered into a cooperative agreement with the state Department of Ecology to conduct an investigation and feasibility study at the site. The EPA's Record of Decision (ROD) detailing the cleanup plan for the bay identified eight problem areas, including Sitcum Waterway. The goal was to achieve sediment quality that would support a healthy marine environment and reduce the risk of exposure from the consumption of contaminated seafood caught in the bay. The ROD also set forth sediment quality objectives. It was agreed that EPA would be the lead federal agency for the remediation of contaminated sediments, whereas the state Department of the Environment would take the lead in controlling the sources of hazardous substances. The EPA asked the Port of Tacoma to consider including Sitcum sediment remediation as part of long-standing near-shore fill and waterway dredging projects, and the port agreed, assuming the responsibilities of the principal responsible party. The emergence of a single project advocate contributed significantly to dispute resolution and, ultimately, to project implementation. These projects, which were required under the terms of a legal settlement for both navigational and environmental reasons, involved dredging Blair Waterway and filling more than 70 percent of the Milwaukee Waterway to create 24 acres of land for a marine container terminal and wildlife habitat. Remediation Alternatives Considered The ROD identified four options, including dredging and CAD (at a cost of $11.5 million), dredging and near-shore containment ($4 million), landfill placement ($20 million), and in-place capping, which was considered unacceptable because it would interfere with vessel operations and long-term maintenance of the channel. Strategy Chosen The dredging and near-shore containment option (the least expensive of the four) was selected. The plan satisfied terms of the ROD, which specified that
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--> near-shore placement be used only if it could be combined with fill projects that would be permitted anyway for commercial development. The strategy was made possible, in part, because the EPA broadly interpreted Clean Water Act (CWA) restrictions on avoidable discharges of dredged material in waters regulated under the CWA. By satisfying the intent of the CWA and Superfund rather than focusing rigidly on the specific language, the EPA was able to forge a creative solution to otherwise intractable problems. Overall Assessment The Blair/Milwaukee/Sitcum project was successful in many ways: It settled Superfund liability for contaminated sediments in near-shore areas, provided sufficient depth for navigation to allow the continuation of port activities, provided cleanup and navigational improvements in adjoining waterways, provided for the environmentally acceptable placement of contaminated sediments, facilitated habitat restoration, and generated filled land in the port for productive (industrial) uses. Lessons Learned The success of a project is directly related to the early identification of all interested parties and concerns connected with previous related projects and on the willingness and ability of all parties to satisfy the concerns of affected stakeholders. If the goals of land use, port planning, and resource management can be combined in an environmentally sound and economically attractive plan, then project success is almost assured. The availability of on-site space permitting containment or remediation and treatment of contaminated sediments is a significant benefit; it may facilitate project approval by reducing costs and eliminate the need to justify extending the contamination to remote disposal sites. Interpretation of requirements based on the intent of the underlying law can eliminate complications and delays and contribute to project success. WAUKEGAN HARBOR, ILLINOIS Waukegan Harbor is an example of the ex situ treatment of polychlorinated biphenyls (PCBs). Waukegan Harbor is a Superfund site located on the western shore of Lake Michigan, approximately 37 miles north of Chicago. In the mid-1970s, surveys conducted by the state found significant concentrations of PCBs
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--> in the sediment column of the harbor. The PCBs had been used as hydraulic fluids by the Outboard Motor Corporation (OMC) in its manufacturing operations and had leaked into the harbor from 1961 to 1971. Extensive sampling showed that, in the areas within and adjacent to Waukegan Harbor, PCB concentrations ranged from 50 parts per million (ppm) to 520,000 ppm. Navigation dredging was suspended until a remediation project could be completed. Background Initially, the cleanup project was simple: Sediments would be removed from the harbor and slip areas and adjoining land sites and placed in a landside containment facility. These plans, developed by the EPA and issued in 1983, were contested by OMC on the basis of costs and the company's lack of involvement. The company's subsequent negotiations with the EPA and the associated litigation and delays led to OMC signing a consent decree and assuming responsibility for completing the cleanup. In the meantime, however, Superfund was reauthorized, and the new legislation forced consideration of advanced treatment to achieve significant contaminant removal rather than simple containment. Under the new plans, all sediments with PCB concentrations above 50 ppm were dredged and placed in a nearby slip that had been occupied by a recreational marina, which was relocated to another site acquired and donated by OMC. To contain the sediments, a three-foot-thick slurry wall was constructed around the slip. All sediments with PCB concentrations above 500 ppm (a total of about 16,000 tons) were dewatered and removed for treatment using a rotary thermal desorption kiln technology selected by OMC. Remediation Alternatives Considered Dredging and containment appears to have been the only approach considered until Superfund legislation dictated the use of advanced treatment technologies. It is not clear whether any technologies other than thermal treatment were considered by OMC. Strategy Chosen Cleanup began in 1991. The thermal desorption technology reduced sediment concentrations from 500 ppm to 2 ppm and produced 200 tons of residual PCBs in an oil phase, which required off-site incineration. Cost of the process was approximately $250/yd3, plus fixed costs of $150/yd3. Treated sediments were returned to on-site containment cells with bentonite walls. Once dredging was completed, all containment areas were capped with soils and high-density polyethylene. Post-project monitoring indicated some groundwater infiltration in the containment areas, so periodic pumping is required to maintain inward hydraulic gradients.
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--> Overall Assessment After a convoluted and drawn-out process, the project is now complete. The long delays can be attributed to the litigious nature of the relationship between the EPA and OMC, which stems in part from high costs of thermal treatment and failure to include OMC in the initial planning. Lessons Learned Even seemingly ideal project conditions (e.g., one major contaminant, one responsible party, sediments in accessible sites) do not obviate the need for prudent planning and the development of partnerships among stakeholders. Project implementation is facilitated by incentives that encourage voluntary action. Unencumbered acquisition and transfer of property rights (for relocation of the marina, in this case) can contribute to project completion; such actions obviously are facilitated by partnerships among, and the early involvement of, all affected parties. Monitoring and a long-term commitment to active site management (e.g., through groundwater pumping) are required for permanent remediation.
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