Asbestos Remediation Plan for Forested Areas near Libby, Montana

Transcription

1 Asbestos Remediation Plan for Forested Areas near Libby, Montana Developed for: Lincoln County Port Authority Libby, Montana Final Report September 2012

2 Asbestos Remediation Plan for Forested Areas near Libby, MT Developed for: Lincoln County Port Authority Libby, Montana Project Team: Roy Anderson, Senior Consultant, The Beck Group, Portland, Oregon Greg Frame, Estimating Manager Envirocon, Inc., Missoula, Montana Craig Rawlings, Principal Forest Business Network, Missoula, Montana Project Reviewers: Tony Ward, Assistant Professor University of Montana, Missoula, Montana Bob Rummer, Project Leader Forest Operations Research U.S. Forest Service, Auburn, Alabama Final Report September 2012

3 Table of Contents Page CHAPTER 1 EXECUTIVE SUMMARY Introduction The Operating Environment Landowners Tree Biomass in OU Road System Asbestos Levels The Remediation Plans Standing Tree Remediation Plan Forest Floor Duff Remediation Plan Recommendations... 8 CHAPTER 2 THE OPERATING ENVIRONMENT Existing Tree Vegetation Road Density Topography Asbestos Levels CHAPTER 3 REMEDIATION PLANNING APPROACH CHAPTER 4 STANDING TREE REMEDIATION PLAN Standing Tree Remediation Plan Objectives Timber Harvesting Technology General Discussion of the Technologies Selected Timber Felling Extraction Merchandising Delimbing Truck Loading Hauling Equipment & Operating Modifications Needed for OU3 Plan Implementation General Approach Equipment Modifications Operator Modifications Monitoring... 32

4 Table of Contents CHAPTER 5 FOREST DUFF REMEDIATION PLAN Forest Duff Remediation Technology Remediation of Northern Europe Forests Combination Industrial Vacuum System and Portable Conveyor Beneficial Land Cover CHAPTER 6 MATERIAL UTILIZATION General Utilization Concepts Establish a Permanent Utilization Structure Site Control Specific Products That Might Be Produced Sawlogs Pulp Chips Hog Fuel Logging Slash Firewood Budgetary Capital Cost Estimates Estimated Required Staffing Levels... 41

5 CHAPTER 1 EXECUTIVE SUMMARY 1.1 INTRODUCTION The forest surrounding the former W.R. Grace vermiculite mine near Libby, Montana has been found to be contaminated with asbestos fibers. Since exposure to those asbestos fibers can reasonably be expected to be a health risk for humans and since wide spread exposure to humans could occur during a wildfire event, the Lincoln County Port Authority (LCPA), in consultation with the U.S. Forest Service (USFS) and the Montana Department of Natural Resources and Conservation (DNRC), seek a timber harvesting technical plan for removing asbestos contaminated standing trees and forest floor duff from the forests in an area identified by the United States Environmental Protection Agency (USEPA) as Operable Unit 3 (OU3 see Figure 1). Timber harvesting was selected as the focus of the study because of the high per acre fuel volumes in OU3, the well-developed state of timber harvesting technology, and the desire to identify a practical approach that also offers the opportunity to offset remediation costs with saleable products produced by the effort. FIGURE 1 AERIAL PHOTO OF CURRENT OU3 AREA To develop the technical plan, LCPA retained the services of a consulting team that included The Beck Group; Forest Business Network; and Envirocon, Inc. (the project team). The combined expertise of the project team includes timber harvesting, wood/biomass utilization, and environmental remediation. The objective of the team s work was to develop a preliminary technical plan for remediating the forest in OU3. THE BECK GROUP Page 1

6 Chapter 1 Executive Summary The OU3 area is part of the Libby Asbestos Superfund site that was established in It surrounds the former W.R. Grace vermiculite mine near Libby, Montana, and it is approximately 35,000 acres in size. According to the USEPA, expansion of the OU3 perimeter is under consideration as further testing has shown asbestos contaminated trees outside the current OU3 boundary. At this point, the extent of the potential expansion is not known. Implementation of the technical plan developed as part of this project is expected to reduce the amount of biomass in OU3, which in turn would reduce the danger of wildfire in OU3, which in turn would mitigate the risk of the asbestos currently contained in the trees and forest floor duff from becoming airborne and spreading and contaminating a much broader area during a wildfire event. Implementation of the plan is also expected to allow the public to maintain some amount of access to OU3. The following sections of the executive summary provide a description of the project team s plan, as well as a summary of the project team s recommendations and conclusions. The team appreciates the opportunity to assist on this important project. 1.2 THE OPERATING ENVIRONMENT Landowners At the current time OU3 is about 35,000 acres. The major landowners in OU3 include the U.S. Forest Service, State of Montana, Plum Creek Timber Company, and Kootenai Development Company (W.R. Grace). Table 1 shows the estimated acreage owned by each. TABLE 1 ESTIMATED DISTRIBUTION OF LANDOWNERSHIP IN LIBBY OU3 AREA Landowner Estimated Acres Owned United States Forest Service 23,973 Plum Creek Timber Company 5,433 Kootenai Development Company (W.R. Grace) 3,629 Other Miscellaneous Private Owners 1,325 State of Montana 640 Total 35,000 THE BECK GROUP Page 2

7 Chapter 1 Executive Summary Tree Biomass in OU3 No inventory of the trees in OU3 was completed as part of this study. However, based on the US Forest Service s FIA timber inventory database, for the area covered within a 20 mile radius of the mine site, there is estimated to be an average 611 trees per acre. When this per acre average for the region is applied to the 35,000 acres of OU3, the resulting estimate of total merchantable standing tree volume (for all trees greater than 5 inches in diameter at breast height) in OU3 is 65.4 million cubic feet, or 850,000 bone dry tons, or about 425 million board feet. This translates to a per acre average volume of about 1,900 cubic feet, 25 bone dry tons, or 12.4 thousand board feet. About 270,000 bone dry tons (or about 44 percent) is estimated to be found in pulpwood size trees (those less than 11 inches in diameter at breast height). About 455,000 bone dry tons is estimated to be found in trees larger than 11 inches in diameter at breast height. The balance of about 125,000 bone dry tons is estimated to be the bark of the trees. In addition to the merchantable volumes described in the preceding paragraph, there is also biomass volume in the limbs and tops of the trees. During typical logging operations, the limbs and tops (i.e., logging slash) are either left scattered across a logging unit, or piled at a landing. For this project, an effort would be made to collect and utilize all logging slash. The project team estimates that in OU3 there are 425,000 bone dry tons of limbs and tops. Table 2 summarizes the volume of various materials estimated to be found in OU3. TABLE 2 ESTIMATED VOLUME OF BIOMASS IN OU3 Material Type Bone Dry Tons Sawlogs 455,000 Pulp Chips 270,000 Bark 125,000 Logging Slash 425,000 Total 1,275,000 THE BECK GROUP Page 3

8 Chapter 1 Executive Summary Road System The existing road system within OU3 is fairly well distributed, with the exception of the southern portion of the area, which has relatively few roads. While the project team did not inspect the existing road system within OU3 first hand, we did, however, view the area from the perimeter and we viewed and analyzed aerial photos and topographic maps of the area. The project team estimates that the road density in OU3 is 1.75 (95 miles of forest road per 54.7 square miles of land area in OU3). Importantly, for our recommendations about how the biomass can be utilized, the mine site is centrally located within OU3 and appears to be accessible from most points in OU3 without the need for log trucks to travel on Highway 37. Please note, however, that if OU3 is expanded, it may become necessary for log trucks loaded with asbestos contaminated logs to travel on major public highways. The project team has not investigated this possibility in detail, but log trailers have been developed that have curtain sides 1. Thus, it is possible that the logs can safely be transported on major public roads so long as it is done using the enclosed log trailers. More research on the feasibility and safety of material transport is needed if the area of OU3 is expanded. While the project team did not have an opportunity to tour the interior of OU3, it is readily apparent from topographic maps of the region that the terrain within OU3 is very challenging, especially in the western portion of the area. The steepness of the terrain limits the choices of equipment available for timber harvesting operations, but it does not prevent timber operations altogether. Specific equipment considerations are discussed in greater detail in the body of the report Asbestos Levels Asbestos levels on the trees in OU3 have been documented in several studies. For example, the US EPA completed a study 2 in which transects from 3 miles to nearly 10 miles long were run radially from the mine site. Tree bark samples were taken at regular intervals along each transect. The results indicate that no fibers were detected along some transects, while on others as many as 50 asbestos fibers were found per 1 See: Log-Chip Trailer Offers Flexibility accessed at 2 Libby OU3 Phase I Sampling and Analysis Plan. USEPA. Completed 9/7/11. THE BECK GROUP Page 4

9 Chapter 1 Executive Summary sample. Another study 3 completed by a University of Montana team in 2004 found trees close to the mine site contained between 14 million and 260 million amphibole fibers per square centimeter of bark surface area. Another study 4 was completed by Tetra Tech EM, Inc. for the Montana Department of Environmental Quality. That study was completed on the Upper Flower Creek Timber Sale located south of Libby, Montana. The site is owned by the State of Montana and managed by the Department of Natural Resources and Conservation. The study found that Libby Amphibole fibers (asbestos) concentrations ranged from no detection to nearly 283,000 structures per square centimeter of tree bark. Samples were also taken from forest duff and were found to range from no detection to 12 million structures per gram of dry weight of duff. 1.3 THE REMEDIATION PLANS The project team organized its work into two distinct plans. The first is a remediation plan for treating standing trees, and the second includes recommendations for treating forest floor duff. Please note that for the standing tree remediation plan, the approach taken was that identifying the silvicultural treatment (e.g., clearcut, seed-tree harvest, shelterwood harvest, thinning, etc.) applied during timber harvesting was beyond the scope of this study. Instead, each landowner within OU3 will have to determine for themselves the most appropriate silvicultural prescription at the time of harvest Standing Tree Remediation Plan With regard to the standing tree remediation plan for OU3, the project team recommends at this time that a mechanized, whole-tree harvesting system be used to carry out timber harvesting operations. More specifically, trees will be felled with a tracked feller buncher, then brought to a landing with either a grapple skidder or cable yarding system (depending on the terrain). Each tree will then be delimbed and topped at the landing with either a stroke-boom delimber or a processor and be loaded onto conventional log trucks with a tracked loader. The log trucks will transport the logs to either a landfill, or to a utilization facility. To control and contain the asbestos fibers on the trees during such timber harvesting activities, a number of modifications to normal timber harvesting and transport 3 See: Amphibole Asbestos Fibers in Tree Bark A Review of Findings for this Inhalational Exposure Source in Libby, Montana. In: Journal of Occupational and Environmental Hygiene. 4 See: Final Data Report for DNRC Tree Bark ahnd Duff Smapling for the Upper Flower Creek Timber Sale, Task Order No. 93, DEQ Contract Accessed at: DuffSampling-UpperFlowerCreekTimberSaleAreaFeb pdf THE BECK GROUP Page 5

10 Chapter 1 Executive Summary procedures will be required. The following list provides a brief description of each modification: To mitigate the potential for the asbestos on trees to become airborne during logging operations, it is recommended that timber harvesting activities in OU3 be restricted to certain times of the year. The optimal time for mitigating asbestos fiber release during timber harvesting is during the winter months when the ground and trees are frozen. It is expected that the asbestos fibers during these conditions will largely remain frozen to the bark and therefore will be less likely to become airborne. Since the extent of the remediation effort is very large and since there is concern about the limited amount of time that freezing weather conditions will exist, the project team also recommends testing timber harvesting operations during the shoulder seasons of spring and fall. The testing would measure the extent of asbestos fiber release at the timber harvesting site at times when air temperatures are cooler, the relative humidity is higher, (i.e., during conditions which are expected to be less likely to create airborne asbestos as a result of timber harvesting). The USEPA conducted tests in OU3 during the late summer of 2012, measuring the impact on air quality of timber harvesting operations. The results of those tests were not available at the time of this study. However, those results should be considered in assessing the timing of remediation efforts in OU3. To the extent possible, all timber harvesting equipment operators and log truck drivers will work only from within the enclosed cab of their machines. The cab of each machine will be equipped with positive air pressure HEPA filter systems. This type of equipment is readily available. To eliminate the possibility of recontamination, the sequence of remediation efforts will be to first harvest trees in an area. After all trees scheduled for harvest have been removed, the area will be reentered, and the forest floor duff remediation plan will be completed. A site safety and health plan (SSHP) will be developed for work that occurs in contaminated areas. This SSHP will include all requirements for working within contaminated areas of OU3. For certain timber harvesting activities (i.e., cable yarding), workers will have to work outside of an enclosed, air controlled cab environment. These activities will include workers setting chokers on logs and hooking the logs to the yarder/carriage. These workers will be working in the harvest unit, while other workers will be working on the landing unhooking the logs from chokers. All of THE BECK GROUP Page 6

11 Chapter 1 Executive Summary these workers will wear personal protective equipment (PPE) during logging operations, as defined in the SSHP. All procedures, as defined in the SSHP, will be followed while working in contaminated areas of OU3. To meet the activity based air quality standards that are expected to be established as part of the OU3 timber harvesting remediation process, engineering controls may be needed to be implemented. These controls may include reduced work speed, application of water to key site areas, or application of crusting agents to control dust. A sampling and analysis plan (SAP) will be developed for use during the logging activities to determine the levels of PPE and engineering controls that will be required to be implemented to meet air emission standards. Monitoring may indicate airborne asbestos levels during logging that are higher than allowed limits. The project team recommends that the USFS, EPA and other stakeholders negotiate an agreement for acceptable emission standards for logging activities within OU3. Given the limited amount of time available each year for operation and the possibility that the equipment may need to operate at less than maximum production rates, the remediating of OU3 will be a lengthy process. The project team estimates it may take 10 years (or more) to complete the work. Therefore, it is recommended that an implementation plan be developed, which prioritizes the areas to be treated within OU3. All biomass material (logs, limbs, tops, etc.) resulting from timber harvest operations in OU3 can either be disposed (landfilled) at the mine site (or other area) or processed in a permanent utilization structure that could be located within OU3 at the former mine site. The permanent facility will have equipment for unloading log trucks, and the primary operation within this permanent utilization structure will be debarking the tree stems. The resulting bark will either be used as boiler fuel (at a boiler location to be determined) or landfilled at the mine site. The debarked stems will be cleaned with water and tested for levels of asbestos fibers. At this point, the effectiveness of debarking and water treatment in removing asbestos fibers is unknown. Neither is there a known, cost-effective test for identifying asbestos levels on debarked and water-cleaned stems. If/when such protocols are developed, the cleaned stems that meet the specifications for maximum levels of asbestos can then be certified by the landowner as being acceptable for sale to commercial users. For example, the sawlogs could be sold to sawmills in the region. Also, the smaller pulpwood size stems could be chipped into pulp chips on site or sold THE BECK GROUP Page 7

12 Chapter 1 Executive Summary as stems and chipped at a location of the buyer s choosing. Similarly, hog fuel (ground bark, limbs, tops, etc.) could be utilized by biomass boilers in the region Forest Floor Duff Remediation Plan The project team considered several technologies with respect to removing forest duff from OU3. They included machines developed and tested in Europe for removing topsoil from forests contaminated by a nuclear accident and a combination industrial vacuum and portable conveyor system for moving forest duff from the forest to a central collection area. The project team concluded that none of these technologies seem promising for application in OU3 for the following reasons: The very steep terrain in OU3 will limit the ability of the equipment to operate as designed. The large area of very steep terrain in OU3 means after the removal of forest duff, severe erosion and perhaps contamination of areas outside of OU3 is possible in run-off coming from OU3. The forest duff (and underlying soils) in OU3 are likely to be shallow and rocky in many areas. To the extent these conditions exist, it will limit the ability of some equipment to perform as expected. There is an unknown level of asbestos that is likely to be naturally occurring in the minerals soils in the region. Thus, efforts to measure the amount of asbestos in the soils and forest duff before and after forest duff remediation treatments are likely to be confounded by naturally occurring asbestos. Given the preceding considerations, the project team recommends that the strategy for developing a forest duff remediation plan follow the lead of the US EPA in making recommendations for institutional controls (administrative and legal controls that help minimize the potential for human exposure to contamination and/or protect the integrity of the remedy). The individual landowners within OU3, will then be able to use the established institutional controls in developing their own remediation plans. 1.4 RECOMMENDATIONS The following is a list of conclusions and recommendations: The plans presented here are judged to be technically feasible based on the project team s experience and on research conducted as part of this study. However, given the unique nature of OU3, the remediation plans have not been THE BECK GROUP Page 8

13 Chapter 1 Executive Summary proven in the field. Therefore, field testing is recommended to confirm the feasibility of the remediation plans recommended in this report. The tree inventory estimates for OU3 presented in this report are broad estimates based on regional average per acre volumes. A more accurate inventory of tree volume in OU3 is needed. Therefore, a silvicultural inventory (timber, stand composition, fuel type, other vegetation, etc.) of OU3 is recommended. A detailed analysis of the existing road system in OU3 is needed. Key parts of this analysis should include the ability of trucks to deliver materials from all parts of OU3 using the existing forest road system rather than having to use Highway 37. Also, given the recommendation to haul stems from landings to the central processing facility in lengths as long as possible, an assessment of the maximum log length that can be transported on the existing road system using conventional log trucks is needed. A system for identifying the highest priority areas for treatment should be developed. Potential criteria for selecting high priority areas are: 1) those found to have the highest concentrations of asbestos fibers; 2) those already readily accessible by existing roads; 3) those areas judged to have the greatest potential for wildfire or where broad areas of trees have been killed by insects or disease. Research and field level testing are needed to determine the effectiveness of reducing the release of asbestos fibers by operating logging equipment under the controls proposed in the remediation plan. USEPA testing efforts up to this point have only determined that asbestos is found on the bark on the main stem of the tree. While it stands to reason that the fibers would also be found on other parts of the tree (e.g., limbs, tops, needles, etc.) testing should be completed to confirm this assumption. A program for providing the residents of the region with firewood from OU3 should be considered. This program would allow existing firewood contractors to gather and provide firewood that is dry and certified to be free of asbestos fibers. This effort is expected to eliminate what is believed to be a current and common practice among residents of the area going into the OU3 area, cutting firewood, bringing it back to town, and burning it in their stoves, which potentially results in recontamination of areas that have already been cleaned of asbestos. More research is needed to determine whether it is preferable to install a boiler and turbine generator within OU3 (e.g., at the former mine site), which would allow utilization of biomass for hog fuel without the additional transport cost and THE BECK GROUP Page 9

14 Chapter 1 Executive Summary risk of contamination in areas outside OU3. Or would it be preferable to utilize the hog fuel at an existing (or to be developed boiler) that would require the transport and storage of asbestos contaminated biomass on roads and at a location outside the borders of OU3? More research is needed to determine the environmental impacts associated with shipping asbestos contaminated logs, chips, barks, etc. in specially designed covered trucks. Testing is needed to determine the effectiveness of sprayed water in removing asbestos fibers from debarked logs. Testing and research are needed to identify procedures that can be employed to quickly and accurately assess the presence of asbestos fibers on the surface of materials (i.e., debarked logs). Testing is needed to determine if the use of a water misting system on a landing to encase tree stems in a sheath of ice is effective in controlling asbestos. If such a system proves to be effective, additional testing should be conducted to determine if it is feasible to use equipment similar to the snow making equipment used at ski resorts to encase entire standing trees in a sheath of ice that will serve as protection against the release of asbestos fibers during timber harvesting operations. THE BECK GROUP Page 10

15 CHAPTER 2 THE OPERATING ENVIRONMENT The purpose of this section is to describe the physical features of the area surrounding the mine site, including the terrain, road systems, and density of existing tree vegetation. In addition, the levels of asbestos found during EPA testing in OU3 are described Existing Tree Vegetation For this study, no inventory of trees in OU3 was completed. Instead, the team used data from the USFS Forest Inventory and Analysis (FIA) database to estimate average tree densities by species and diameter class (on a per acre basis) in the forests in the OU3 area. FIA data is based on permanent inventory plots that were established over 80 years ago. There is roughly 1 plot for every 6,000 acres of forest land in the United States. Each plot is revisited about once every 10 years, at which time measurements of tree growth, mortality, harvest, etc. are taken. The most recent measurements taken in Montana were completed between 2003 and Data from the FIA website was retrieved using the mine site as the center of a 20 mile radius area. The specific information collected included the number of timberland acres in that region, total number of trees, and total volume. That data was converted to averages per/acre. The per/acre values were then applied to the 35,000 acres in OU3. It is important to note that this process is likely to overstate the number and volume of trees in OU3 since it is based on the assumption that all of the acres in OU3 are the same as the average of the broader region from which the FIA sample was taken. In other words, it does not account for areas within OU3 that may have been harvested recently and therefore do not reflect the average forest conditions, or areas on the southern part of OU3 that have little tree vegetation because they are located on south facing slopes. Completing a more accurate inventory of OU3 was beyond the scope of this project. As shown in Table 3, there is estimated to be, on average, 611 trees per acre. Of that amount, on average, about 440 (or about 72 percent) are trees that are less than 5 inches in diameter at breast height. Douglas fir and Western Larch are the most common species. About 4 percent of the total standing trees are standing dead trees. Given that OU3 is about 35,000 acres in total size, the estimated total number of trees in the area is about 21.0 million (after excluding about 1 square mile or about 640 acres for the mine site where there are no trees). Of that amount, about 6.0 million are greater than 5 inches in diameter at breast height and about 1.3 million are greater than 11 inches in diameter at breast height (or what would often be considered a sawlog size tree). THE BECK GROUP Page 11

16 Chapter 2 The Operating Environment TABLE 3 ESTIMATED AVERAGE NUMBER OF STANDING TREES PER ACRE IN OU3 BY SPECIES AND DIAMETER CLASS Species 1.0 to to to to to 10.9 Tree Diameter Class 11.0 to to to to to to Total DF PP TF HM WP ES LP WL RC Other Total NOTE: DF = Douglas fir; PP = Ponderosa Pine; TF = True firs; HM = Hemlock; WP = Western White Pine; ES = Engelmann Spruce; LP = Lodgepole Pine; WL = Western Larch; RC = Western Red Cedar; and Other = all other miscellaneous species In terms of volume, rather than number of trees, Table 4 shows that there is an estimated 65.4 million cubic feet of standing trees in OU3. Note that at the bottom of the table, the cubic volumes have been converted into a total of roughly 850,000 bone dry tons (BDT). The conversion is based on a factor of 26 bone dry pounds per cubic foot. In addition, the cubic volume has been converted into board feet. When the volume is expressed in board feet it is estimated to be about 425 million board feet (MMBF) of standing trees in OU3. Please note that this estimate is based on a rough conversion factor between cubic feet and board feet that does not account for different conversion factors as tree size changes. About 38 percent (317,000 bone dry tons) of the total volume is in pulpwood size trees that are less than 11 inches in diameter at breast height. Note the 317,000 ton total includes an estimated 47,000 bone dry tons of bark. Douglas fir and Western Larch trees account for about 60 percent of the volume. Given that OU3 is about 35,000 acres in size, the estimated average per acre volume of standing trees is about 1,900 cubic feet, 25 bone dry tons, or 12.4 thousand board feet. THE BECK GROUP Page 12

17 Chapter 2 The Operating Environment Species TABLE 4 ESTIMATED CUBIC FOOT VOLUME OF STANDING TREES IN OU3 BY SPECIES AND DIAMETER CLASS (CUFT MILLIONS) 5.0 to to to to 12.9 Tree Diameter Class 13.0 to to to to to Total DF PP TF HM WP ES WL LP RC Other Total CUFT Total Converted to BDT 73, , , , , ,172 59,426 51,755 55,409 21, ,572 Total Converted to MMBF Road Density As shown in Figure 2, the existing road system in OU3 is fairly well distributed throughout the northern portion of the area, but relatively few roads exist in the southern portion of the area. Based on the project team s cursory analysis, there are approximately 95 miles of road in OU3, excluding the main highway on the southern boundary of OU3 and any roads directly within the mine area. This means that the road density in OU3 is an estimated 1.75 (road density = miles of road per square mile of land area). As will be described later in the report, the project team has recommended that all material harvested in OU3 be processed for utilization (or disposed of) at the former mine site. Based on a review of the aerial photos of OU3, it appears that the road system in the northwestern part of OU3 does link directly to the mine site, but a portion of that road system is outside the OU3 boundary. The project team recommends that all material harvested in OU3 be transported to the mine site on the existing forest road system rather than along the eastern and southern boundaries of OU3 parts of which are a major state highway (Highway 37). This policy/procedure/strategy will mitigate increased log truck traffic on the highway and reduce the cost of containing loads for transport on public roads. The project team recommends a more detailed analysis of the road system in OU3 in a later phase of study. Note, however, that if OU3 is expanded, then hauling contaminated material THE BECK GROUP Page 13

18 Chapter 2 The Operating Environment on major public roads may become necessary. More research is needed to determine how effective specially designed log trucks with curtain sides to enclose the logs might be in limiting the release of asbestos fibers during transport Topography The project team was unable to visit and tour the OU3 area. However, a preliminary analysis of the topography of the site (see Figure 3) shows that the terrain in OU3 is very challenging, especially in the western portion of the area. Note that the areas shaded in blue are those judged to be where the terrain is less challenging. As shown in Figure 3, generally only the valley bottoms and mountain tops contain the gentler sloped areas. The ability of logging equipment to operate on slopes is discussed in greater detail in Chapter Asbestos Levels In November 2004, a research team from the University of Montana collected samples from standing trees at seven locations in the vicinity of the W.R. Grace mine site and one from a control tree in Albany, NY. The results were published in a study 5 and are shown in Table 5, which indicates that the number of Amphibole fibers per square centimeter of bark ranged from a low of zero for the control tree in New York and one tree tested in Libby at the Asa Wood Elementary School to a high of 260 million fibers per square centimeter of bark on a lodgepole pine tree near the former pump house at the W.R. Grace mine site. TABLE 5 CONCENTRATIONS OF ASBESTOS FIBERS IN TREES IN AND NEAR OU3 Sample Point Location Description Type of Tree Amphibole Fibers/cm2 of Bark Location 1 - Sample 1A Near the former pump house at the W.R. Grace mine Lodgepole Pine 100 million Location 1 Sample 1B Near the former pump house at the W.R. Grace mine Lodgepole Pine 260 million Location 1 Sample 1D Near the former pump house at the W.R. Grace mine Larch 40 million Location 2 Just outside the mine property along Raney Creek Road Lodgepole Pine 110 million Location 3 Sample 3B Near the mine access gate on Raney Creek Road Ponderosa Pine 14 million Location 4 Albany, NY Pine None detected Location 5 Sample 11 Along railroad ~ 7 miles east of Libby, Montana Ponderosa Pine 5.8 million Location 7 Sample 18 Libby Middle School Track Douglas fir 0.25 million Location 8 Sample 23 Asa Wood Elementary School Larch None detected 5 Trees as Reservoirs for Amphibole Fibers in Libby, Montana. Tony J. Ward, et al Science of the Total Environment. August 15, 367(1): THE BECK GROUP Page 14

19 Chapter 2 The Operating Environment In addition to the University of Montana study, the Montana Department of Environmental Quality and the Montana Department of Natural Resources and Conservation commissioned a study to measure the levels of asbestos contamination in tree bark and forest duff in a timber sale area. The study was completed by Tetra Tech EM, Inc. and was located in the Upper Flower Creek Timber Sale Area, which is located south of Libby, Montana on land owned and managed by the State of Montana. Samples were collected from 10 trees and 10 areas of forest duff in November The results are shown in Table 6. TABLE 6 CONCENTRATIONS OF ASBESTOS FIBERS IN TREES AND FOREST DUFF AS MEASURED AT A TIMBER SALE LOCATION Sample Type Sample Number Asbestos Fiber Count Asbestos Concentration Unit of Measurement Tree ,298 structures/cm2 Tree 1 ND < DL structures/cm2 Tree 2 ND < DL structures/cm2 Tree 3 ND < DL structures/cm2 Tree 4 ND < DL structures/cm2 Tree ,862 structures/cm2 Tree ,793 structures/cm2 Tree ,873 structures/cm2 Tree ,436 structures/cm2 Tree ,287 structures/cm2 Tree 9 ND < DL structures/cm2 Duff 1 ND < DL structures/gram of dry weight Duff 2 2 5,700,000 structures/gram of dry weight Duff 3 1 7,300,000 structures/gram of dry weight Duff 4 ND < DL structures/gram of dry weight Duff 4 ND < DL structures/gram of dry weight Duff 5 ND < DL structures/gram of dry weight Duff 6 ND < DL structures/gram of dry weight Duff 7 ND < DL structures/gram of dry weight Duff 9 ND < DL structures/gram of dry weight Duff 8 ND < DL structures/gram of dry weight Duff ,000,000 structures/gram of dry weight *DL refers to Detection Limit Finally, the USEPA completed a study that measured the levels of asbestos in forest soil, tree bark, and forest duff material along a number of transects extending radially from the mine site. The results are shown in Table 6A THE BECK GROUP Page 15

20 Chapter 2 The Operating Environment Transect ID TABLE 6A ASBESTOS FIBER LEVELS - USEPA TESTING Number of Structures Tree Bark Surface Loading (M s/cm2) Number of Structures Duff Material Concentration (M s/gram) SL SL SL SL SL SL n/a n/a SL SL SL SL SL SL Figure 1A shows the locations of each transect. FIGURE 1A LOCATION OF USEPA TREE BARK AND FOREST DUFF MEASUREMENT TRANSECTS (THE CENTER POINT IS THE FORMER MINE SITE) THE BECK GROUP Page 16

21 Chapter 2 The Operating Environment FIGURE 2 IMAGE OF EXISTING ROAD SYSTEM IN OU3 AREA (WHITE SHADED AREA = OU3; RED LINES = EXISTING ROADS) THE BECK GROUP Page 17

22 Chapter 2 The Operating Environment FIGURE 3 TOPOGRAPHY IN OU3 (BLUE SHADED AREAS ARE WHERE THE SLOPE IS ESTIMATED TO BE LESS THAN 15 PERCENT TO 20 PERCENT) W.R. Grace Mine Site Operational Unit 3 Libby, Montana THE BECK GROUP Page 18

23 CHAPTER 3 REMEDIATION PLANNING APPROACH The project team has organized the remediation plan into two distinct planning efforts: 1. Standing Tree Remediation Plan all activities associated with remediating areas contaminated with standing trees containing asbestos fibers on the bark. 2. Forest Duff Remediation Plan all activities associated with remediating the forest floor (the organic duff layer). Given the unique requirements of this remediation effort and the limited budget for this phase of the project, the approach taken was to develop remediation plans based on a combination of the project team s experience and project specific research completed during the course of the study. Thus, the plans presented here are being considered theoretical because while the procedures and technologies recommended in this study have been used in other applications, they have not to our knowledge been used for the remediation of asbestos from standing trees and forest duff. In other words, the procedures and technology recommendations made in this report have not yet been tested and proven in the field for the specific purpose of asbestos remediation from standing trees and forest duff. Therefore, throughout the report, the project team has made recommendations about issues that, in the team s judgment, need validation based on field testing. THE BECK GROUP Page 19

24 CHAPTER 4 STANDING TREE REMEDIATION PLAN 4.1 STANDING TREE REMEDIATION PLAN OBJECTIVES The purposes of the standing tree remediation plan are to: 1. Develop a remediation alternatives list that identifies a number of possible remediation approaches; 2. Analyze these alternatives to determine the best approach for this application, (i.e., the one that captures and removes the most contamination); 3. Plan out the best approach for the remediation process in a step-by-step format ; 4. Describe any required modifications to processing equipment and processing techniques to ensure worker safety and maximize containment of the asbestos fibers; 5. Identify all other necessary best management and safe remediation practices. The goals of this effort are that plan implementation will result in: 1. Reduction of fuels in the event of a wildfire in OU3; 2. Utilization (if possible) of contaminated material; 3. Continued public forest use of OU3 with minimal restrictions. 4.2 TIMBER HARVESTING TECHNOLOGY Figure 4 illustrates the processing steps (areas shaded in light green) involved in harvesting and processing trees. Listed below each processing step area variety of the technology option(s) that can be used to complete the processing step (the white boxes). Each of the technology options shown at each step were considered as part of this study. However, the blue arrows indicate the technology options judged to be best suited for removal of the asbestos-impacted standing trees in OU3. Note that debarking is generally not a common processing step in timber harvesting. It is included here because removing the bark within the OU3 area reduces the probability of contaminating other areas during transport. Following Figure 4 is a general discussion section about the various technologies selected for consideration. The next section describes the modifications needed to be THE BECK GROUP Page 20

25 Chapter 4 Standing Tree Remediation Plan made to the equipment or operating procedures in order to perform the procedures in OU3 to achieve the safest work environment for the workers, while also capturing and containing the asbestos to the greatest extent possible. FIGURE 4 DIAGRAM OF THE TIMBER HARVESTING PROCESS AND TECHNOLOGY OPTIONS FOR EACH STEP Tree Felling Hand felling with Chainsaw Tracked or Walking Feller Buncher Tracked Harvester Wheeled Feller Buncher Wheeled Harvester Extraction Cable Logging Wheeled Ground-Based Skidding Tracked Ground-Based Skidding Wheeled Forwarding Merchandising (Delimbing) Stroke-Boom Delimber Processor Truck Loading Tracked Excavator Hauling Conventional Log Truck General Discussion of the Technologies Selected Regarding Figure 4, it is important to note that whole-tree harvesting is the logging system that would be employed. Whole-tree harvesting refers to the practice of felling trees and then moving the entire tree (i.e., limbs and top still intact) to a central processing area where the limbs and top are removed and the tree is merchandised into logs. The other common logging system is known as cut-to-length, and it involves the processing of the tree into logs (i.e., removing the limbs, tops, and cutting logs to length) at the area the tree is felled. A key difference between whole-tree harvesting and cut-to-length is that most of the limbs and tops accumulate at the centralized processing site (i.e., the landing) when using whole-tree, rather than being scattered across a large area when using cut-tolength. Therefore, an advantage of whole-tree for this application is that much of the material to be reclaimed will already be concentrated in one location. THE BECK GROUP Page 21

26 Chapter 4 Standing Tree Remediation Plan Timber Felling The process of timber felling is simply severing a standing tree at the base of the stem so that the tree falls to the ground. In the past this process was commonly completed by a person using a chainsaw in an activity called hand felling. While hand felling allows for a great deal of flexibility in the types of terrain and tree sizes that can be processed, use of hand felling is less productive than mechanized tree felling systems. It is also the most hazardous timber harvesting activity because workers can be injured by falling branches, tree tops, or the tree itself, as well as sustaining injuries by the chainsaw itself. In addition, the hand Figure 5 a dangle-head harvester which is typically used for felling, delimbing, and cutting logs to length. felling application could potentially increase asbestos exposure to workers as the tree is felled and hits the ground. Therefore, given the danger with hand felling and the increased potential to asbestos exposure by workers, hand felling was not considered a viable option for OU3. In most modern logging operations, the timber felling step is accomplished by a mechanized piece of equipment with a machine operator controlling a cutting device and the direction of the tree s fall from an enclosed cab. The two basic types of machines are harvesters and feller bunchers. Harvesters: In cut-to-length systems, the machine that accomplishes timber felling is called a harvester because it not only cuts the tree down, it also delimbs the tree, and cuts logs to specified lengths from the tree. Figure 5 shows a wheeled harvester at work, although harvesters can also be mounted on tracked vehicles. Some harvesters are equipped with self-leveling cabs. A knuckle boom is used to reach out to individual trees, rather than driving up to each tree. One disadvantage of harvesters is that they cannot effectively process trees with multiple stems. One benefit of using harvesters is that the process of delimbing and topping trees right at the stump creates a bed of slash on which the harvesters and forwarder can operate. Operating the equipment on the slash bed rather than bare ground reduces soil disturbance. However, given the likelihood of asbestos being on the limbs and needles and therefore, the increased potential for asbestos to be in the slash mat, the action of the equipment would probably cause the asbestos particles to become airborne. Therefore, a harvestor system has not been considered further for this technology assessment. The project team recommends that additional testing be THE BECK GROUP Page 22

27 Chapter 4 Standing Tree Remediation Plan completed to determine definitively whether asbestos is also found on the limbs and needles. Feller Bunchers are the second type of commonly used mechanized tree felling equipment. The key differences between harvesters and feller bunchers are that feller bunchers are only used for cutting, holding, and placing stems on the ground. Feller Bunchers are typically mounted on either wheeled vehicles or tracked vehicles (see Figure 6). When mounted on tracked vehicles, feller bunchers often have self-leveling cab capabilities to ensure that the machine can be safely operated on steep slopes. Another advantage of tracks is that the weight of the machine is distributed over a relatively large surface area, which means that ground pressure levels are low, and therefore, the machines can operate on loose and wet soils while causing little soil disturbance. In addition, when feller bunchers are mounted on tracked vehicles, they typically have a swing-boom that reaches out to each tree rather than driving the machine to each tree in order to fell it (see Figure 6). Note from Figure 6 that feller bunchers have accumulator arms in which several stems can be collected (i.e., a bunch ). Wheeled feller bunchers can only be operated on gentle terrain (less than 25% slopes). Tracked feller bunchers with self-leveling cabs can operate on much steeper slopes (up to 50%) and therefore would be best suited to the rugged terrain found in OU3. Another advantage of feller bunchers for this application is that the machine can control the direction and speed with which trees are felled. Therefore, since the operators will probably be instructed to more carefully place the trees on the ground, they can operate the equipment in such a way as to reduce the chances for the asbestos fibers to become airborne. The project team recommends that a tracked feller buncher be used to harvest trees in OU3. THE BECK GROUP Page 23

28 Chapter 4 Standing Tree Remediation Plan FIGURE 6 - SWING BOOM FELLER BUNCHER FIGURE 7 Figure 7 - John Deere Prototype Walking Forest Machine THE BECK GROUP Page 24

29 Chapter 4 Standing Tree Remediation Plan Please note that while a tracked feller buncher has been recommended as the preferred technology for OU3, the project team has also made inquiries to John Deere about using one of their prototype walking forest machines (see Figure 7). These machines were developed in the early 1990s, and only two were ever built. They were designed to be able to navigate in very difficult (steep, rocky) terrain. One of the prototype machines has accumulated over 2,000 working hours during machine testing. One of the potential advantages to John Deere of using this machine to fell the timber in OU3 is giving John Deere a high profile application to demonstrate the capabilities of their machine. Depending on the terms of any agreement reached with John Deere, it might reduce or eliminate the costs associated with purchasing equipment needed to complete remediation efforts in OU3. In addition, the walking forest machine is more likely to be able to operate in the extreme terrain areas that a tracked feller buncher might have difficulty navigating Extraction Extraction is the process of moving the tree from the forest area (i.e., stump) to a central processing area (i.e., landing). The following describes each type of extraction process. Forwarding is the process of moving logs from the forest to a landing by carrying them completely off the ground. The machine used to complete that process is called a forwarder (see Figure 8). Forwarders are typically wheeled machines with an enclosed operator cab and a log bunk for storing logs. The machines are usually self-loading and are designed to carry the logs completely off the ground. While the off-the-ground aspect of forwarding could be considered advantageous because it creates less forest duff disturbance and thereby reduces the amount of airborne asbestos, the advantage is minimal in OU3. First, the very steep terrain in the vast majority of the area limits their use only to areas with less than 40 percent slope. Second, these machines are most frequently designed to work in tandem with a cut-tolength harvester. While some forwarders are designed to move tree-length stems, these machines are very large and not well suited to operating on steep slopes. Thus, given the project team s recommendation of a whole-tree logging system, a typical forwarder machine would not be well matched with the project team s other technology selections for processing the timber in OU3. THE BECK GROUP Page 25