4.2 Changes to Original Work Plan

4.2.1 Further Delineation of PCB Contamination

In Appendix A, Figures 5 and 8 identify the elevations at which excavation of TSCA (hot spot material) contaminated material stopped. The information on these drawings was used to guide the daily excavation activities. In grids F17, G17, H17 and in the southern half of F16, G16 and H16, the boring results were also the final verification data. All other grids were post-excavation sampled to verify that the clean criteria was meet.

4.2.2 Increased Perimeter Air Monitoring

• Increasing the number of locations monitored and shifting monitor locations based on excavation location (new locations shown on Figure 5).
• Daily analysis was changed to analyze all units or to analyze those next to residents and the down wind units.
• Shorten the analysis turn around time from 48 to 24 hours.

4.2.3 Grid Verification Sampling

The grid system used is represented on Figures 6, 8 and 9 of this report. The lettered grids run east and west and the numbered grids run north and south. The LL WP originally specified that the grids within the hot spot contours west of the 31011 00E survey coordinate line would be sampled on the basis of 100 ft. x 100 ft. grid system. One sample was to be taken from each 50 ft. x 50 ft. subgrid and composited. Instead the grid sampling was done either on 50 ft. x 50 ft. or 25 ft. x 25 ft. grids and samples prepared as described in the previous paragraph.

4.2.4 Site Control Procedures

4.3 Site Preparation

4.3.1 General Site Preparation Activities

The loadout area was located within the exclusion zone and adjacent to the truck scale. The loadout area was graded and lined with 40-mil plastic. The truck scale was directly west of the loadout area. The scale was 35 ft. long and 10 ft. wide and constructed on a concrete foundation. Tractor-trailer dump trucks were loaded while positioned on the scale. A scale house was located just west of the scale. Located in the scale house was a digital readout of the truck weight. The readout was used by WRS personnel to direct the loading of the over-the-road trucks that transported the contaminated solid waste to the TSCA landfill.

The office and equipment trailers were installed in the staging area. This area was also used for material storage. A metered city water supply was installed and run to the site from a fire hydrant at the northeast corner of the site, on Lemon Lane.

Limited clearing and grubbing was required around the perimeter of the interim Hypalon cap to accommodate remediation and construction activities. Several large trees were removed along the northern part of the site on property adjacent to the landfill. The larger pieces of wood were cut and stacked and left for use by the landowner as firewood. Small brush and trees~from around the perimeter of the site were removed as necessary and chipped. The wood chips were stored on site and used as an absorbent on the bottom of the rolloffs that were used to transport capacitors to the TSCA incinerator.

Site survey control was established as discussed in Section 3.5. The borrow area used as the source of clay to backfill excavations was located approximately 500 ft. west of the staging area. The top layer of soil was scraped and stockpiled prior to the start of excavation. This topsoil was used to restore the borrow area at the end of the project. A dirt road was built between the borrow area and the site.

The perimeter fence line on the west side of the landfill was extended further west to include the new access road and the staging area. Gates were installed across the entrance road near the northwest corner of the site and the borrow area on the west.

A security checkpoint was established at the northwest entrance gate along the access road off of Vernal Pike. A guard booth was placed at that location. A second guard booth was set up on the northeastern fence line of the site. A guard service was contracted to provide security 24 hours a day.

The same type of sediment control fence recommended by the Indiana Department of Transportation was selected for use for this project. Sediment control fence was installed around the perimeter of the site and around the borrow area where the slope was away from the site. A trench was dug to anchor the bottom of the fence into the soil.

A water treatment system was installed at the southwest corner of the site within the fence line but outside of the exclusion zone. The location of the treatment system is shown in Figure 2. The treatment system was built as described in the WP. The system was installed to treat all water collected that came into contact with contaminated waste and also water from the decontamination operations.

Five high volume air monitors were located at the perimeter of the site to monitor the air at the fence line for PCB content. The locations were described in the Air Monitoring Plan, Appendix E, of the LL WP. Two days of background samples were taken on April 19 and 20 and analyzed prior to the start of excavation. Background sample results are included in Table 5.

The initial health and safety (H&S) orientation for all Viacom, WRS and PSARA personnel was conducted on May 1. All new workers arriving on site throughout the project were required to attend a H&S orientation.

4.3.2 Site Preparation of Scale, Loadout, and Decontamination Areas

The Hypalonliner and cushion sand were removed from the north central portion of the interim cap to prepare the initial consolidation area inside the LOC. The waste from the initial excavation areas would be consolidated in this location. After the liner was peeled back, the granular cushion sand was removed down to within a few inches of the underlying geotextile. Cushion sand was stockpiled for re-use in an area to the southwest of the landfill within the security fence.

All waste outside of the LOC and under the interim cap was excavated down to native soil and consolidated within the LOC. The residual cushion sand and the underlying geotex+.ile were consolidated with the underlying waste. The native soil under the excavated waste was sampled for verification as specified in the WP.

Verification sampling results after removal of visible waste in the northwest corner of the cap revealed that the proposed location for the truck scales in C7 contained PCBs above the clean up criteria. Subsequent delineation by hand auger and machine borings revealed TSCA material to depths at or near bedrock. The quantity of TSCA material requiring excavation from the grid containing the scales exceeded the limited capacity of the loadout pile. Therefore the decision was made to postpone excavation of this grid. The truck scales were relocated one grid to the south, to C8 as shown on Figure 2. The loadout pile was also extended from D7 to D8, adjacent to the truck scale. Verification sampling showed the new locations to be clean. Grid C9 was excavated to complete the access road to the truck scales. Portions of C9 were excavated to bedrock due to deep PCB contamination. The scale foundation was installed and the scales were calibrated. A scale house was installed next to the truck scale as shown in the site plan, Figure 2. The access road to the scale was completed.

A personnel decontamination trailer was installed on the west side of the landfill, south of the TSCA loadout pile. The trailer included personnel showers with a hot water supply. Access to the exclusion zone was located between the loadout pad and the decontamination trailer. These areas are identified on Figure 2. The exclusion zone entrance included an equipment decontamination pad. Water from the personnel decontamination trailer and the decontamination pad was collected in a holding tank located adjacent to the personnel trailer. From the holding tank contaminated water was pumped to the water treatment system. The capacitor rolloffs were staged just north of the decon pad as shown on Figure 2. Several capacitors were discovered and removed in the area excavated for installation of the decontamination pad, grid C12.

4.4 Excavation Activities

4.4.1 Consolidation Area

Consolidation started on the north central area within the LOG and was placed in lifts approximately 18 in. thick. Each lift was compacted with a sheepsfoot compactor. To help control air emissions the intermediate grades of consolidated material were periodically covered with borrow clay. This was done in areas where consolidation material was not actively being placed. The consolidation of waste material continued until the approximate final landfill elevation was obtained. Colder provided, in Figure 11 of the LL WP, an anticipated top of waste consolidation that was used as a guide by WRS to place the consolidation materials.

4.4.2 Excavation and Loadout Of Material for Off-Site Disposal

The contaminated material was either in the hot spot contour or identified based on post-excavation verification sampling. The excavation of hot spot waste started in the northwest and generally proceeded down the west to the southwest and then across the south to the east edge of the site. Excavation was accomplished using a track excavator. The excavator typically sat on top of the waste and excavated the waste below, creating a vertical working face. The depth of the cut would generally be the thickness of the hot spot waste. The excavator loaded off road articulating dump trucks that would take the waste from the excavation to the TSCA loadout pile. These dump trucks would generally sit at the bottom of the excavation to be loaded.

TSCA material was taken to the loadout area on the west side of the site. The number of trucks loaded per day varied. A total of 3,093 trucks were loaded containing TSCA waste with a total weight shipped of 80,097 tons. Table 4 provides information on the days that trucks were loaded, the number of truck,, I`'adedeach of these days, and associated net weights of material that were shipped to the EQ Landfill in Belleville, Michigan for final disposal. The first trucks of TSCA material were shipped to EQ on June 12, 2000 for disposal.

Capacitors were encountered during general waste excavation throughout the site. When capacitors were encountered, a track excavator was used to uncover the buried capacitors. The excavator removed the capacitors and placed them adjacent to the excavation. Laborers then loaded the capacitors into the bucket of a front-end loader. The loader transported the capacitors to 20-yard capacity roll off boxes that were located near the exclusion zone entrance. Table 3 lists the shipments of capacitors to the Onyx (formerly Chemical Waste Management) incus rater located in Port Arthur, Texas. Two to three rolloffs were on site at any one time. As one was filled, an empty was delivered and the filled one transported to Port Arthur. The first shipment of capacitors to Onyx occurred on July 6, 2000.

The selected route for the filled trucks to follow from the site access road was left onto Vernal Pike and then onto Route 37 on their way to the off site disposal facilities.

4.4.3 Impact of Consolidation, Excavation and Loadout on Air Monitoring Results

4.4.3.1 Operations Shutdown

• Deep excavations of PCB contaminated soil along the western perimeter of the landfill in grids C and D, 10 and 11. In some subgrids the excavations were to bedrock, with free PCB product found at the bottom.
• Grids C, D, E/16, 17 in the southwest were being excavated and over 900 capacitors were recovered from these grids.
• Waste was excavated to depth of native soil in grids L, M, N. O/17, 18 in the southeast. Approximately 165 capacitors were recovered from L17 on July 18.
• Between July 12 and 17 the Hypalon liner and bedding sand used for the interim cap was stripped from approximately 60,000 square feet of ares along the south of the site. This would represent the surface area of twenty-fou' 50 ft. square grids. Later, when this area was excavated, most of the capacitors found at the site were recovered from here

These concurrent operations resulted in large areas that had been excavated but not backfilled. Most of the above listed activities were in highly contaminated areas, areas with free PCB product, and/or large concentrations of capacitors. In most completed excavation areas the bottoms of the excavations had been verified to meet the clean criteria. However, a large sidewall surface area in the hot spot contours remained exposed and contained visible capacitors and capacitor parts.

During these activities beginning on Thursday, July 13, 2000 and extending to Tuesday, July 18, the site experienced six consecutive days during which the air monitoring results again exceeded the action level of 1000 ng/m3. On July 17 the southeast air result rose to the maximum site PUF level experience `] during the project at 5630 ng/m3. Excavation operations were discontinued on I hursday, July 20, when these air monitoring results were reported.

4.4.3.2 Application of Cover Material

4.4.3.3 PCB Transport Mechanism

Following this same reasoning another major contributor to PCB a,, e missions was thought to be the release of PCB that was trapped under the Hypal`,n cover. The LL site had a black Hypalon cover in place since 1987. The temperature under the black cover was most likely elevated because of the black surface. I ice PCB vapor was contained in the porous bedding sand below the cover and was trapped under the Hypalon cover. This PCB trapped under the cover would have teen released when the Hypalon and bedding sand was stripped. As described at~c~ve between July 12 and 17 the Hypalon liner and bedding sand were stripped Am a large highly contaminated area along the south of the site. By mid July, all but a very small portion of the Hypalon had been stripped off of the site.

The cause of the high air monitor results and actions implemented to reduce the levels are discussed more thoroughly.in the report "Review of Probable Causes of Elevated PCB Emissions and Effectiveness of Mitigation Efforts" distributed to the government parties on August 7 2000.

4.4.3.4 Plan for Restart and Measures Implemented

• Minimize the surface area of open excavation faces. Remove cover clay just prior to excavation.
• Start with a low excavation rate and increase gradually while closely reviewing and evaluating air monitoring results.
• Cover all excavations as soon as possible. Use clay cover or heavy white plastic. Secure the edges of the white plastic with sandbags.
• Excavate TSCA in the coolest part of day. Start work at dawn.
• Minimize the quantity of TSCA waste in the loadout pile.
• Build a windscreen berm around the loadout pile using clean clay Have the excavator sit on the clean clay berm of the windscreen to load trucks.
• Use water-misting system at the loadout pile and excavations to reduce temperatures and reduce air borne dust.
• Remove capacitors from excavations as soon as possible. Place capacitors into plastic bags as they are unearthed. Place the bagged capacitors in rolloffs that have covers than seal.

To help evaluate the effectiveness of these controls three new neighborhood high volume air monitors were also installed prior to the re-start of site operations. A work plan addendum was prepared describing these controls and the installation of additional monitors. The addendum was submitted to the government parties on August 14 and discussed at the August 15 weekly project status me eting. The government parties approved the Work Plan addendum and excavation operations were restarted on August 16 2000. The Work Plan Addendum is included in this final report as Appendix C. The site control requirements of this a`~›iendum were implemented for hot spot excavation loadout of TSCA waste and re-excavations that were required based on verification sampling to meet clean up criteria.

4.4.4 Achieving Clean Up Criteria

Verification sampling criteria varied for the hot spot contours in gent Al as follows. Excavated hot spot grids inside the LOC were cleaned so that each grid surface was <100 ppm. This area was then eventually covered with the RCRA subtitle C cap. Excavated grids which were inside the hot spot excavation contours but outside of the final LOC had two levels of cleanup criteria to meet. First the bottom of the hot spot contour (either as defined in the SOW or by additional borings) were sampled to verify that the surface meet the <100 ppm clean up criterion. Material continued to be removed based on analytical results until the cleanup criterion for that particular area outside the RCRA cap was meet.

Verification sampling outside the hot spot contours and outside the LOC was conducted after the visible waste was removed and native soil surface obtained. Again material in this area continued to be removed as required by sample results to meet the final cleanup criteria for that area.

The removal of PCB contaminated material to meet the clean up requirements for the various areas within the LL Landfill site are described in the following sections. The various areas are shown in Figure 3. All depths of excavations were referenced from the original landfill surface. All material excavated from within the hotspot contours was taken to the TSCA loadout pile for disposal. Any whole capacitors were separated from the TSCA material and sent off for incineration Verification sample results were used to determine whether material that needed to be excavated was to be disposed of off site or could be consolidated on site.

Visual Standard

If a large quantity of capacitors or capacitor windings were encounter red the adjacent waste plus an additional bucket width of material was removed This was done to determine if the concentration of capacitors or parts continued beyond the initial excavation.

An inspection of the excavated surfaces was conducted jointly by thr Viacom representative and the government oversite personnel to implement this visual standard. A consensus between these two parties was achieved in each grid or subgrid as to whether it was necessary to remove any additional material.

4.4.4.1 Areas Outside the Limits of Consolidation

Areas 17 & 20

The clean up criteria specified for Area 17 is an arithmetic average elf ~ ppm with a maximum individual grid result of 5 ppm. If ten inches of cover are added then the average can be increased to 5 ppm. For Area 20 the limited access due to the location of the final fence allowed the clean up criteria to be less stringent. An arithmetic average of 10 ppm with a maximum individual grid result of 20 ppm is required.

All of the grids in Area 17 and most of the grids in Area 20 were outside the hotspot contours. The WP called for all the waste in the grids outside of the hotspot contours to be excavated to the native soil and consolidated within thr LOC. The remaining native soil surface was then to be sampled to verify that It met the clean up criteria. As discussed in Section 4.3.2 the initial areas to be excavated were to accommodate the loadout activities in the northwest. This excavation was conducted in Area 17 and 20. As waste was removed and soil exposer d in the remaining soil surface was sampled. Area 17 grid C7 where the t,~'r.k scale was to be located was found to contain TSCA material based on verification sample results. High PCB levels were discovered in several grids including 1:)5 D7 and 014 that are located along the east boundary of the landfill. To exam trite clean up in grid D5 borings were completed to bedrock and the soil sampled. /\ppendix A discusses the boring samples which were used to guide the excavation process. Verification sample results are contained in Table 1.

The northwest corner of the hotspot contours was included in Area :0 as shown in Figure 3. The depth of the hotspot contour in this area was specific ri Is 4 foot deep. The material in this area was excavated and sent off site as TSCA Subgrids of C9 in the northwest corner of the hotspot contour were ultimately excav Ted to bedrock in order to meet the clean up criteria.

Subgrids of C/D-10/1 1 and C12 in Area 20 along the western edge at the landfill contained deep contamination. Subgrids in A20C11 and A20C12 At ret excavated to bedrock at up to 25 foot below the original surface elevation. Two Rumples were taken of the western wall of the C11 bedrock excavation. Analytical results for the sidewall samples were obtained at 660 and 590 ppm. Additional material was removed from the sidewall, which was then resampled at 4.8 ppm.

Groundwater with a heavy surface sheen was observed seeping into tooth the C11 and C12 bedrock excavations. Three foot of pea gravel was placed on top of the bedrock and geotextile was placed over the gravel. The locations of these two bedrock excavations were surveyed and are shown on Figure 6 as PZ-C and PZ-D. The excavations were then backfilled to grade with clean clay from the borrow pit. Initially these will be piezometer locations measuring water levels above bedrock.

At the end of the excavation phase the loadout pile, scales and truck road within Area 17 and 20 were removed and resampled to verify these areas met the clean up criteria. Most of the grids in Area 17 were cleaned up to BDL. The resulting average for all the grids in Area 17 is 0.5 ppm. The resulting average for ail the grids in Area 20 is 1.5 ppm.

Areas Outside the Existing Fence on the North, East and West

Figure 3 of Appendix A of the LL WP shows the results of the perin,eter delineation sampling. Grids D4, D3, J4 and J5 on Figure 3 had sample results .~t~'ve the clean up criteria of 5 ppm. The highest sample result was 13.4 ppm in this 0 to 6 inch sample of D4. These grids were excavated to remove the soil con~,~inir1g PCBs over 5 ppm and then sampled for verification of cleanup. The material ~ xc..~vated was disposed of based on the delineation sample results. Material that Was equal to or greater than 50 ppm PCB was excavated and transported to the Ft' COCA landfill for disposal. Materials over the clean criteria but less than 50 ppm were excavated and consolidated onsite under the RCRA C cap.

The pre-excavation delineation sampling showed that all the 0 to 6 and 6 to 12 inch samples in Area 9, the Sexton property, were below the clean criteria. The SOW, however, required as part of this delineation that one deep boring be placed in each perimeter area. The individual deep boring drilled in the center of Area 9 showed a slightly elevated PCB content of 5.7 ppm at the 36 to 48 inch depth Because of this boring result additional boring sampling was performed in Area 9 just prior to the remediafion. Two manual split-spoon borings were performed to depths of 4 ft. and 5 ft in grids M7 and M8 respectively. The boring results in grid M7 were all BDL. The sample results for gridP9 indicated consolidation material from 0 to 2 foot. M7 was excavated to 2 foot and a volume 10x10x5-ft deep around the original Area 9 boring was removed. Verification results after excavation were BDL.

It had been demonstrated in the pre-excavation delineation sampling that the grids in Area 11 meet the individual clean criteria of c 5 ppm and the average over the surface was also less than the 2 ppm requirement. However Viacorn directed WRS to remove the material in grid P9 since the PCB level was close to the 5 ppm limit. The final grid sample result was BDL and the average for all the Area 11 grids was less than 1 ppm.

The average verification sample results for Areas 5 6 8 and 9 were between 1.0 and 1.9 ppm as shown in Table 1.

Area 22

To better define the PCB content beyond the contours there was In interest in installing borings to sample this material prior to contour excavation. Given that borings were to be installed this provided the opportunity to better define the PCB content within the contours in advance of excavation. The LL SOW states that CBS may segregate materials within the excavation boundaries that it has reason to believe are not contaminated above 50 ppm for consolidation onsite. "Demonstration that the materials are less than 50 ppm through sampling" is called for. Borings were performed in the southeast grids of Area 22 to further delineate this area for segregation. A revised excavation plan based on the southeast borings was agreed to at the July 6 meeting between Viacom and the government party representatives. Appendix A discusses the southeast borings and the resulting revised excavation plan. During the week of July 10, excavation began in the southeast part of Area 22.

The excavation in the Southeast area began in grids MNO/17-18. Except for the northeast part of M17, all of these grids are outside of the LOC in Area 22. The sand overburden was removed to just above the geotextile. The residual sand, the geotextile and the underlying waste was excavated down to the depth of the native soil and was sent off site as TSCA. The southeast boring results had shown that all the waste in these grids, down to native soil, was TSCA material. The data from the borings had also shown that an additional one foot of the native soil in N17, and two foot in N18 and 3 foot in J19 should be disposed of as TSCA. The remaining native soil, down to the excavation contours, was shown by the borings to be suitable for consolidation on site or had low enough PCB levels to remain in place.

In some cases the excavation of the underlying clean native soil down to the excavation contours required the soil to be replaced with clean backfill to build the area back up to the final construction elevations required. As an alternative to excavating, consolidating and replacing clean soil with borrow clay, the government parties agreed to allow the clean native soil to be left in place. In order to leave the clean native soil in place, the soil was verified clean on a subgrid basis (i.e. center of each 25-ft x 25-ft grid) from the top of the final excavation to a depth 6 inches deeper than the applicable contour. Samples were collected at 1-foot intervals in each subgrid. These sample results are reported by sample depth interval in the grid sample log, Table 2.

By the time of the work stoppage on July 20, grids L17 and MNO/1~-18 had been stripped of waste, down to the depth of the native soil. Excavation resumed on August 16 after the work stoppage, as discussed above in Section ~ 2 4. Work resumed in the southwest corner of the landfill in grids CD/18 of Area 22. The remaining grids in areas 22 and 24 were excavated moving from west to east.

Capacitors continued to be recovered in this area after work resunn~d, especially along the south bank of the landfill in grid row 18 and 19 The measures that were agreed to for restarting the excavation operations were implements d A dedicated crew batched the capacitors as soon as they were uncovered. Also the water misting system was employed to reduce temperatures and prevent Lust locally in the excavation area.

The Area 22 grids west of the 3101100E line were excavated per the contours specified in the work plan. In some of these grids waste existed beyond the bottom of the contours. This waste was sampled and characterized for consolidation or disposal. If the analytical result was less than 50 ppm the waste we consolidated into the LOC. If it was greater than or equal to 50 ppm, the waste we sent off as TSCA. Once the waste was removed to the depth of the native soil, a verification sample was taken in the native soil to determine if it met the cleanup criteria of less than 35 ppm and could remain. Table 2 contains the results of the waste characterization as well as the verification sample results.

Excavation of the grids in Area 22, east of the 31011 DOE line, was started during the week of September 18. These grids were excavated according to the southeast boring agreement as discussed in Appendix A. Most of the grids in this part of Area 22 had the waste excavated down to the native soil as TSCA. Additional soil was removed as TSCA based on the boring data. As discussed above, clean native soil above the contours was confirmed clean and left in place rather than excavate and re-fill the area. Figure 4 shows four individual subgrids, N18SE, N18NE, 018SW and J19SE, which are located outside of the new fence. These suhgrids met the clean criteria but had analytical results greater than5 ppm. A minimum of ten inches of clean soil cover was placed over the subgrids.

The southeast boring agreement also specifies three grids in Area 22, 118, J18 and K19 which were to have additional subgrid borings performed to delineate the waste for disposal or consolidation. The original boring in the center of these grids resulted in waste samples that were mostly clean. Appendix A discusses the borings and the sampling performed in grids J18 and K19 for delineation.

Grids MNO/19-20 in the southeast corner of the landfill were specified for excavation to bedrock per the southeast boring results. These grids were excavated to bedrock during the week of October 9 and consequently no verification sampling was performed because of the bedrock.

LF6 Deep Bedrock Excavation

The oil stained rock and the clay from the bottom of the excavation were sent off to TSCA. The government parties agreed to allow the unstained rock to be cleaned dirt and consolidated under the cap. The excavated hole was filled with about 15 feet of pea gravel. A layer of geotextile was placed over the gravel and covert. with clay to grade.

South Perimeter Areas 13, 14 and 15

Perimeter grids along the railroad tracks from 119/20 to 020 in areas 13 to 15 wer to be excavated based on perimeter delineation results presented in Appendix A the LL WP. Cleanup criteria for the southern perimeter, outside of the old fence li was a maximum of 35 ppm PCB for individual grids with an average of all grids in area to be < 20 ppm if ten inches of cover are placed over the grids.

During the week of October 9, the fence was removed and the area to the railroac tracks was cleared. Grids L20 through 020 (Areas 14 and 15) were excavated pE the plan and verified clean. Ten inches of clean cover was placed over these grid The individual grid verification sample results and the average are listed in Table

Per the access agreement with CSX Transportation, the owner of the railroad, a representative from CSX was present to observe the work in the area along the railroad tracks. The CSX representative expressed concern about possibly undermining the rail bed foundation by digging the embankment and riprap that supports the rail bed ballast in grids 120 and J20. Excavating these two perimeter grids would remove some of the foundation for the slope of the railroad bed. Digs to the initially planned depths in the grids further east was not a problem since the soil elevation was higher in that area and excavation would not impact the critical slope of the railroad bed. This issue was discussed at the October 11 meeting wi the government representatives. There was agreement at this meeting not to excavate grids 120 and J20 and to allow Viacom to cover the these two perimeter grids with one foot of compacted clay. A minimum of one foot of clay was compacted over these grids. All the perimeter grids were then covered with topsc and seeded. In the future, if the railroad tracks are abandoned, Viacom in conjunction with the government parties will evaluate the circumstances related tc the contaminated material remaining in grids 120 and J20. Based on this evaluation a determination will be made as to what action is appropriate.

4.4.4.2 Hot Spot Grids Within the Limits of Consolidation

Area 21 was a 25 ft. by 25 ft. square around soil boring SB08 and was within the consolidation area. Boring SB08 was a hot spot area based on sample results obtained during the 1996 soil borings investigation. The excavation contours specified an initial excavation of four feet in this area, based on the 1996 borings. The visual standard was used in inspections of the sidewalls and bottom of the excavation to determine if any additional excavation was required. Ultimately Area 21 was excavated to an eight-foot depth to obtain a visually clean bottom. The average verification results for area 21 was 7.2 ppm compared to an allowable average of 50 ppm.

Capacitors were discovered in the west sidewall of Area 21. Based on the visual standard, the west sidewall of Area 21 was extended out about 60 feet at a depth of 5 to 7 feet. A total of 117 capacitors were recovered from Area 21 and the west extension. Consolidation material was placed the excavated area after the clean up was completed.

Area 23 is the area east of the 3101100E line and inside the LOC. Excavation began in this area during the week of July 10 when the waste was excavated in grids M17 and L17 to native soil depth per the southeast borings agreement as discussed in Appendix A. A cache of capacitors was recovered in L17. Area 23 was essentially completed on October 3. Verification sampling results are shown in Table 2 and Figure 4. This area was covered with consolidation material.

Area 24 consists of the hot spot contours to the west of the 3101100E line (referred to as the 5300E grid line in the SOW), which are contained within the LOC. The northern grids of this area were excavated first. These grids were all within the four- foot excavation contours. The excavation proceeded south within Area 24 where the deeper excavation contours were located from 6 to 12 feet deep. A 30 foot wide strip running north to south within grids G9 to G15, on the east side of this area was left in place to accommodate a truck access road. This haul road was constructed for use by the onsite TSCA trucks to operate between the southern excavations and the loadout pile.

The SOW allowed verification to be performed in Area 24 using 100 square foot grids. It was agreed with the government representatives that verification would be performed in 50 ft. grids instead of 100 ft. grids. This minimized the surface that was exposed during excavation. Reducing the sample area also provided more representative verification results.

Excavation in CD/16-17 started during the week of July 3. Excavation of these grids resulted in the discovery of another large cache of capacitors. Over 400 capacitors were recovered from these grids. The first rolloff of capacitors was shipped to the Onyx TSCA incinerator on July 6, 2000. A cache of non-friable asbestos tiles was recovered in grids C16/17. Approval was received from EQ to ship this material with the other TSCA waste. An asbestos awareness-training course was given to the workers handling this material on July 12. The transits tiles were excavated and shipped to EQ during the week of July 16.

During the week of August 21 the subgrids in grids FGH/16-17 were bored and sampled to better delineate these grids as discussed in Appendix A. Excavation of these grids proceeded per the boring sample results as agreed to with the government representatives at the August 15 weekly meeting. Depth intervals that contained less than 100 ppm PCB were consolidated. The average for Area 24 was maintained below 50 ppm. Excavation stopped at the top of the first depth interval sample below 100 ppm that was not underlain by another layer greater than 100 ppm. This depth interval sample was regarded as the grid verification sample and no further sampling was performed.

During the week of September 11th the grids containing the onsite TSCA haul road from G9-15 and F9 were excavated and confirmed clean. The TSCA excavation in Area 24 for the contours west of the 3101100E line was completed at this time.

The SOW required that the north sidewall of the hot spot excavation east of the 3101100E line be sampled to determine if PCB contamination extended north. This four foot sidewall was sampled in grids 116 through M16.

The SOW called for four grab samples to be taken along each 50 foot sidewall grid and composited for verification of that 50 foot length of sidewall. This was modified in the approved work plan to allow two column samples, 25 feet apart, to be taken along the sidewall for each 50 foot grid. A column sample was not composited with another column but was sampled and analyzed separately. The full length of each column sample was homogenized and a representative sample taken. In addition, this sampling procedure was further modified in the field to sample only waste in the O to 4 foot sidewall depth and not to include any clay fill material in the sample that was part of the interim cover.

The work plan further allowed that each composite column sample could be used separately to verify each 25-foot length of sidewall. In each 50-foot grid two sidewall samples were obtained, an east and a west sample. The cleanup criterion for each individual sidewall sample was less than 100 ppm PCB with the average of all final sidewall samples to be less than 50 ppm.

The initial sidewall sampling along the north excavation face occurred over the sidewall in grids L and M on July 27. Results for all 4 samples were >100 ppm. During the week of September 11, test pits were dug to allow sidewall sampling to be done in i, J and K-16. Two samples per grid were taken of the exposed waste to the depth of the four-foot contour. Results of the sidewall samples were >100 ppm in 5 of 6 samples. As a result, the sidewall was excavated back to the north about 6 to 8 feet in 1, J. and K-16 and resampled during the week of September 18. Sidewall samples continued to not pass the clean criteria.

Eight test pits were dug in grids K-west, L and M to expedite identifying the northern extent of any waste that was >100 ppm. In addition, on October 1 and 2, borings were drilled in 1, J. K, L, M-14 to further facilitate the investigation. Waste material from the boring to the depth of the four-foot contour was composited for each subgrid. Boring continued north until a clean boring location was established for each lettered subgrid going north. During the week of October 2, the government parties allowed all the subgrids to be excavated to the location of the clean borings. After excavation at the clean boring location an inspection per the visual standard was conducted. No further verification sampling was required.

During this same time, City of Bloomington Utilities (CBU) resampled the sidewall in the l-west (IW) subgrid in the north sidewall excavation. The initial sample result was 41 ppm from the initial test pit sampling event on September 18. The validity of the September 18 sample was questioned since the 0 to 4 foot composite sample contained mainly clay fill, rather than waste. CBU took two sidewall samples in the IW excavation, one from the south facing sidewall and the other from the east facing sidewall. Both samples were determined to be above the clean up criteria. The sidewall in IW was subsequently excavated past the east facing sidewall sampling location to a point north of that sampled by CBU and resampled. The new sidewall was then confirmed clean at 39 ppm.

Sample results for all the sidewall sampling and the average of all the clean verification samples are contained in Tables 1 and 2. The final perimeter of the sidewall excavation is shown in Figure 4.

4.5 Water Collection and Treatment

All.excavations and consolidation areas were protected by berms. The berms were to limit run-on water and contain run-off water within the contaminated areas. Approximately 35 batches of contact water were treated during the course of the project. A total of 865,000 gallons of water were collected and treated on site. Table 6 lists the individual batches of water treated, the sample result of the verification sample taken before the water was released and the total gallons of water treated.

The treatment system is described in Section 3.2.7 of the LL WP. Figure 2 of this report shows the location and arrangement of the equipment as installed in the field. Water collected and treated was either discharged to Sargent's Pond or used for dust control within the exclusion zone. At the end of the project all the pool liners, filter media, and carbon were disposed of as TSCA material.