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REMEDIAL DESIGN / REMEDIAL ACTION WORK PLAN

NEAL'S LANDFILL MONROE COUNTY, INDIANA
Spring 1999

Submitted by CBS Corp.

Sequence of Events | Air Monitoring Plan | Health & Safety Plan | Soil Delineation | Stability Evaluation | Post-Excavation Verification Sampling and Analysis Plan

List of Attachments

  • Figure 1  Map of Superfund Sites
  • Figure 2  Cap Configuration
  • Figure 3  B&B Sampling, 1984
  • Figure 4  Subsurface Investigation Locations and Waste Results
  • Figure 5  Map of Work at Neals Landifill
  • Figure 6  Schematic of Water Treatment Plant
  • Figure 7  Decontamination Pad - Construction Details

1.0 Introduction

1.1 General

This Remedial Design / Remedial Action (RD/RA) Work Plan has been prepared by CBS (formerly known as Westinghouse Electric Corporation) to describe the remedial approach for Neal's Landfill. The landfill is located three miles due west of the City of Bloomington, in Monroe County, Indiana, as shown in Figure 1

This Work Plan has been prepared by CBS based on the Statement of Work (SOW) for the Source Control Remedial Design and Remedial Action at Neal's Landfill as agreed to by the parties on March 5, 1999 and submitted to the Federal District Court of Southern Indiana, which is overseeing the implementation of the Consent Decree entered on August 27,1985, in Civil Action No. IP 83-9-C and IP 81448-C. This Work Plan also satisfies the applicable or relevant and appropriate requirements (ARARs) that are listed in the SOW.

This RD/RA Work Plan is being submitted to the Indiana Department of Environmental Management (IDEM), the United States Environmental Protection Agency (USEPA) and Monroe County (collectively, The Consent Decree [CD] Parties") for review and approval.

1.2 Project Overview

Neal's Landfill was operated between 1950 and 1972 as a disposal site for municipal and industrial waste materials. From 1966 to 1967, Westinghouse waste materials containing PCB (polyclorinated byphenyl), including whole capacitors, capacitor parts, filter aids and saw dust were disposed of at Neal's Landfill by contract waste haulers.

The scope of remedial activities for Neal's Landfill includes site preparation; equipment and site layout; stormwater control and water treatment; excavation and removal of contaminated waste materials; material handling and segregation; stockpile sampling, waste loading, transportation and disposal; waste consolidation on-site, verification sampling, backfill, RCRA capping and site restoration.

1.3 Schedule

Mobilization and site preparation activities are scheduled to commence about mid-April, 1999. Installation of surface water controls is planned to be completed by mid-May, 1999, at which time excavation activities will start. Excavation, disposal and consolidation activities are scheduled to be completed by the middle of August 1999. A temporary soil cap will be placed over the on-site consolidated waste as the consolidation progresses. The soil cap will be completed and erosion controls and drainage ditches will be implemented by early September, 1999, to contain and protect the consolidated waste over the winter. A monitoring and maintenance program will be implemented over the winter to assure that the integrity of the consolidated waste and temporary cover is maintained. Periodic inspections will be performed. Any excessive soil cap erosion or drainage way damage or blockage will be repaired.

The final landfill cover will be installed in year 2000 and will meet or exceed the requirements of RCRA Subtitle C landfill covers as specified in 40 CFR 264.310(a).

Specific project milestones are outlined in Section 5.0, Schedule.

1.4 Project Organization

CBS has retain WRS Infrastructure & Environmental Inc., a qualified remediation contractor, to complete the work described in this Work Plan. A separate engineering consultant, CH2M Hill, has been hired to design and oversee the waste consolidation and the installation of the RCRA Subtitle C cap.

Throughout the duration of this project, CBS will have a designated representative onsite who will be responsible for overseeing site activities.

1.5 Remedial Design / Remedial Action (RD/RA) Work Plan Format

The purpose of this Remedial Design / Remedial Action (RD/RA) Work Plan is to provide a general description of the remedial activities to be undertaken at Neal's Landfill in 1999, and to provide a preliminary description and approach of the design of the RCRA Subtitle C Landfill Cover. This generalized approach will form the basis for specific requirements to be implemented by the remediation contractor.

Following this introductory section, Section 2 - Site Description and History, presents a description of the physical characteristics of the Neal's Landfill site and related site history. The next section, Section 3 - Remedial Approach, establishes the general approach which will be used in the execution of the project. Section 4 - Site Controls, describes the measures which will be used by CBS to ensure that the project is properly performed. Section 5 - Schedule, presents schedule milestones associated with this project. Figures and contractor design drawings are included. The RD/RA Work Plan also includes several appendices in support of this narrative, including Appendix A Post-Excavation Verification Sampling and Analysis Plan (SAP); Appendix B- Health and Safety Plan; Appendix C - Air Monitoring Plan; and Appendix D - Transportation Plan. Appendix E contains technical specifications which will be used for this project through the application of the temporary cap. Included in this appendix as part of the technical specifications are drawing sheets 1 through 14. Some of these sheets are referenced in the following Work Plan sections. A list of the planned sequence of site activities is presented in Appendix F.

2.0 Site Description and History

2.1Site Description

Neal's Landfill occupies 17.6 acres and is located in a rural setting approximately three miles due west of the City of Bloomington, in Monroe County, Indiana. Figure 1 provides the General Site Location Map. State Route 48 is located approximately 800 feet directly south of the entrance gate to Neal's Landfill. The areas surrounding the site consist primarily of undeveloped land and woods. There are a few residences located within a one half mile radius of the site. Sheet 3 of the drawings provides a site plan of the landfill.

The site itself is situated on an east-west oriented ridge, which deflects surface water drainage to the northwest and southwest. Karst and subsurface solution features, such as sinkholes, swallowholes, and caves and caverns have been identified in the Neal's Landfill area.

There are two tributaries of Richland Creek, flowing from the landfill, Conard's Branch and Southwest Seep Branch. Conard's Branch flows to the north from the northwest comer of the site. Southwest Seep Branch flows southwest along the southern boundary of the site.

Springs and seeps are present along the perimeter and in the vicinity of the site, including North and South Springs to the northwest, Southwest Seep near the southern perimeter, and Taylor and Branham Springs to the southwest of the site. During normal flow conditions and rain fall events, discharges from North and South Springs and Southwest Seep are treated at the CBS Neal's Landfill Spring Treatment Facility at the rate of 450 gpm. The treated effluent from the facility is discharged to Conard's Branch.

2.2 Site History

Operations at Neal's Landfill began in 1950. Municipal and industrial wastes were deposited at this site until 1972. The site was operated more as a dump and was originally known as VVhitehall Pike Dump. It was later renamed Neal's Landfill after the operator. Municipal waste was the primary form of refuse deposited at the landfill. The landfill was created by "back-dumping" from trucks down the natural grade of the land. Prior to disposal activities the landfill area was a small ridge-line bordered by drainage channels.

Between 1958 and 1965, expansion of the landfill occurred in the topographic low areas adjacent to the east-west oriented ridge. During the 1966 to 1967 time frame, electrical capacitors containing PCBs from the Westinghouse Plant were deposited at Neal's Landfill. During this time period, both areas adjacent to the ridge were being utilized for disposal. Other material deposited at Neal's Landfill from Westinghouse included capacitor parts, filter aids, and sawdust.

Landfill operations were typical of the time period with absence of controls. No liner was used. Dumping was not controlled or recorded. Daily burning of the waste was common. Scavenging was prevalent and the only source of income to a few local residents.

Interim remedial measures, as defined in the August 18, 1983 Stipulation and Order and the CD of 1985, were implemented by Westinghouse at Neal's Landfill in three phases.

The first phase was completed in May of 1984. A security fence was installed around the entire perimeter of the site. Visible capacitors and associated stained soils were removed. Capacitors were reinterred in eight locations on site, as shown on the site plan drawing, sheet 3. An approximately two foot thick, low permeability clay cap was constructed in the primary fill areas. Drainage control features and erosion control measures (i.e. silt curtains and sediment collection traps) were installed. This action removed visibly identifiable areas of concentrated contaminants on the surface of the landfill.

The second phase of interim remedial measures, the excavation of Conard's Branch, began in the summer of 1987. T he stream bank and stream sediment removal project was completed in October, 1988. Sediments were removed from the entire length of Conard's Branch to Richland Creek, 4,500 linear feet, and 300 linear feet of Richland Creek.

In the third phase of interim remedial measures, Westinghouse completed construction and began operation of a spring collection and water treatment system in February 1990. Under a National Pollutant Discharge Elimination System (NPDES) Permit, this facility treats base groundwater flow collected from three springs (North Spring, South Spring, and Southwest Seep). The plant is designed to treat flows up to 1 cubic foot per second (450 gpm) to a discharge level of 1 ppb of PCBs.

Westinghouse began site maintenance in 1985. CBS currently continues this effort on a regular basis. Site inspections ensure continued integrity of the cap, drainage ditches, and sediment control measures. Mowing of vegetation is also performed during the growing season to preserve the integrity of the cap.

All remedial measures, implemented to remove any identifiable hot spots and immediate threat to public health and the environment, were designed and implemented with oversight and approval from the Consent Decree Parties - USEPA, State c, Indiana (IDEM), City of Bloomington (Utilities Service Board), and Monroe County (County Health Board).

2.3 Description of Neal's Landfill Materials

Over burden at the site on top of the bedrock convicts of refuse and fill underlain by silty clayey soil. The cover varies in thickness over `. e 18 acre site from 0 to 31 feet to bedrock. Layers of the cover consist of a 0 to 6 foot day cover that overlies a 0 to 27 foot layer of the waste material. The top cover consists of a grass covered cap of low to medium plasticity clay to silty clay with trace organic material. Waste materials consist of a mixture of wood fragments, clay fill, plastic, paper, glass, construction debris and cinders and ash from the frequent refuse burning that occurred at the landfill while it was in operation. Residual silty clay soil is found throughout the site as fill material making up the landfill cover placed during dumping operations.

A 0 to 11 foot layer of native clay is between the waste fill and the limestone bedrock surface. The native material consists of a stiff to hard, medium- to low-plasticity, fractured silty clay.

2.4 Previous Site Investigations

Various investigations to characterize Neal's Landfill have been completed. Investigation activities include geophysical surveys, aerial photograph analyses, surface water sampling and analyses, soil boring installations and bedrock coring, a magnetometer survey, topographic surveys, installation of monitoring wells, groundwater monitoring, rain gage monitoring, groundwater sampling and analyses, seismic refraction surveys, a gravity survey, air sampling, stream sediment sampling and analyses, high and low flow dye tracer tests, and sampling and analyses of various fish species.

Sampling activities at Neal's Landfill included characterization of PCB and PCDD/PCDF concentrations in soils. In 1984 Blasland & Bouck collected 89 surface soil samples from 0 to 1 foot and one sample from 1 to 2 feet for PCB analysis. Sample locations were generally in the northwest part of the site. Figure 3 shows the sample locations and results. Table 1 lists all the analytical results for PCB.

Biannual groundwater samples have been collected for PCB analysis since 1989. Surface water data for PCBs is also available, as well as bimonthly PCB monitoring of the influent and effluent of the Neal's Landfill Spring Treatment Facility.

Groundwater elevation data has also been recorded. Some of the fill material in the southeast area was found to be below the maximum groundwater elevation measured during a storm event monitored in November, 1993. A maximum ground water elevation of 773 feet amsl was measured in the EPA 1 OS monitoring well at that time.

In March, 1998, Tetra Tech and CBS performed a boring sampling and analysis program to determine hot spot (> 500 ppm PCB) volumes in Neal's Landfill. About 90 soil borings ware drilled over a 100 feet grid system across the site. The volume of material defined to be >500 ppm PCB, was estimated at 7000 CYs. This material will require excavation and off site disposal. Approximately 41,000 CYs surrounding the hot spots will be excavated, stockpiled and sampled to determine if any is > 500 ppm. About 57,000 CYs of additional soil and waste were analyzed at less than 500 ppm PCB and will be consolidated on-site under a RCRA Subtitle C cap.

In December, 1998, CBS performed trenching operations in Neal's Landfill to identify the contents of the landfill material and to locate the edge or waste at various perimeter points around the edge of the landfill. Figure 4 shows the locations of the edge of waste investigations identified as circles with a designator starting with either E, T or S. The table included in this figure lists the elevations and the observations. The edge of waste data help to set the consolidation foot print and identify the extent of cleanup required around the limits of consolidation.

3.0 Remedial Approach

3.1 Overview

This section describes the remedial approach for Neal's Landfill. It should be noted that the approach described herein represents a generalized description of site activities. Specific means and methods employed by WRS, the remediation contractor, may vary from those described in this Work Plan; however, the basic concept and intent will be retained unless otherwise identified by CBS to the government parties during the course of the project. Appendix F contains a listing of the sequence of activities that WRS plans to carry out to complete the remediation. Weekly meetings will be held with the parties and the contractors to discuss progress and any potential changes in approach.

3.2 Site Preparation

Prior to initiating remedial activities, a series of site preparation tasks will be completed as described below. Figure 5 is site layout which reflects site setup and preparation as described herein.

3.2.1 Clearing and Grubbing

Clearing of the site was begun in November, 1998 in order to facilitate the additional investigations which were conducted at the Site (see Section 2.4). This phase of work will be completed prior to initiating any other activities at the site, and will be done independently of any work to be completed by the remediation contractor. Grubbing will occur once the contractor is on site.

Smaller brush and debris from the clearing and grubbing activities will be chipped and will remain on-site. Chips will be used as an absorbent and will be placed on the bottom of the roll-offs, which will receive capacitors. Larger logs and debris will be removed from the site. Below ground material (e.g., stumps) which is removed from within the limits of excavation will be consolidated on-site under the RCRA C cap. Stumps removed during the diversion ditch excavation, outside of the current limits of waste as shown on sheet 3, will also be consolidated under the cap if removed from an area with PCB levels in the soil >1ppm.

Additional trees may need to be removed by the contractor. These trees will be placed in designated areas outside the current limits of waste. These areas will be identified and marked and will be used for cutting and chipping any additional trees that are removed.

3.2.2 Site Access and Security

The site will be accessed via two locations, Vernal Pike to the north and Route 48 to the south, as shown in the Site Plan shown on drawing Sheet 3. The old logging road running from Vernal Pike, past the Spring Treatment Facility (STF), along the west-side of the site will be upgraded to handle truck traffic. This road will be extended at the southwest edge of the site directly south to State Route 48. The old logging road that runs from the STF along the north side of the site will also be upgraded to allow access to the northern area of the landfill, as shown it sheet 3. This work is all located outside of the current fenced area and will be done before mobilization. The road work will require earthwork and placement of roadbed materials along the length of these access roads. Support areas will be graded, stoned and erosion controls will be installed to protect adjacent properties. It is anticipated that the existing driveway to the southeast of the site will also be maintained at this time.

The existing site fencing will serve as the primary site security feature. Also, as required, the existing fencing will be extended. The Site Plan, Sheet 3, shows the fence relocated around support areas and extended out on the west to accommodate the RCRA C cap extension. Other project-related activities may be located outside of the existing fence and will require fencing. The Remediation Contractor- will select and fence these additional locations. The Site Plan, Sheet 3, shows new access/egress routing with two new gates into the facility support area. The Site will remain secured and locked during periods of inactivity. When the site is open during remedial activities, a security guard will be stationed at the main access road gate to prevent unauthorized access to the Site.

3.2.3 Residential Areas

The closest private residences are located about 700 feet south of the site along Route 48. A few residences are about half a mile to the north of the site. Most homes in the vicinity of the site rely on private groundwater for water supplies. An Indiana University School of Public and Environmental Affairs survey in 1986 showed 48 private wells in use within a mile radius of the site. Thirty five of the wells were sampled at the time. Only five wells had detectable levels of PCB ranging from 0.003 to 0.007 ug/L, well below the USEPA drinking water standard of 0.5 ug/L.

3.2.4 Support Facilities

Support areas will be established on the west side of the site at the intersection of the west access road and the present road that runs east to west across the site, as shown in Sheet 3 of the drawings. This area will include placement of office trailers (probably four), and porta-johns. Independent telephone and electrical service will be provided to the office trailers. The fence will be moved to enclose this area and gates installed for the access roads.

3.2.5 Material Handling Areas

Several material handling areas will be established at the site including waste processing areas, stockpile areas, waste loading areas, and water treatment areas. Consolidation of material which will be left on site under the RCRA Subtitle C cap will probably start at the west side of the site near the support facilities and progress toward the east. The material handling areas will move within the fence line as the excavation and consolidation progresses across the site. A proposed site arrangement including the layout of the water treatment system is shown in Figure 5.

Waste processing areas will be established within the fence line next to the current excavation area. This area will be used to stage material removed from the excavation, and allow for segregation and processing of separate waste streams including capacitors, TSCA landfill material, non-PCB debris, material to be stockpiled for sampling and material to be directly consolidated on-site.

In particular, a dedicated area will be identified for capacitor sorting and storage. This area will be used for segregation of capacitor parts, which will be sent to a TSCA landfill, from whole capacitors which will be sent for incineration. A storage area will be specified for roll-offs which will be filled with capacitors and staged for off-site transport.

Approximately 7000 CYs of material have been identified for off-site TSCA landfilling and is designated as Category "A" material. Previous sampling showed this material to have PCB content >500 ppm (hot spots). No additional sampling is required for this material. This material will be staged within the excavation area prior to loading into trucks for transport to an off-site disposal facility.

Two other types of material have been identified for excavation. One type, Category "C", can be excavated and directly placed for onsite consolidation. This material will be staged next to the excavation area until it can be loaded for consolidation on-site.

The other type of waste material, Category "B", requires further evaluation to determine if any of the material is > 500 ppm PCB. Over the course of the project, about 200 stockpiles, each containing approximately 200 cubic yards of Category "B" material will be created and sampled. The sampling will be done to determine if the material can be consolidated on site or if it must be disposed of off-site at a TSCA landfill. After a stockpile has been established colored flags will be placed in each pile to indicate the status of the pile. The color of the flags will indicate whether the pile has been sampled and awaiting results or if the pile has been sampled and is to be consolidated or sent off site.

Various areas within the footprint of the proposed RCRA C cap will be used for placing stockpiles for sampling. As shown in Figure 4, one approach would be to transport the waste from the excavation area and establish stockpiles near the area where material is currently being consolidated. Temporary containment berms would be built around the stockpiles and the face of consolidation to collect stormwater or water that may drain from the material.

If sample results show the material to be <500 ppm PCB, the stockpile can be loaded in to onsite trucks and placed in the consolidation area. Altematively, if the stockpile material is close enough to the consolidation activity the stockpile can be directly spread out, in the consolidation area, without reloading the material into trucks. Any capacitor parts and stained soils/waste found within the stockpile as it is being spread would be segregated for disposal to the TSCA landfill. If the stockpile is >500 ppm it can either be loaded out directly into dump trailers for off site transport or moved to a staging area for subsequent load out into dump trailers. Capacitor parts will not be picked out of stockpiles that are being sent to the TSCA landfill.

As sampling proceeds, if the majority of the stockpiles sampled are found to be >500 ppm PCB, it may be decided that staging the stockpiles near a load out area along an access road is more efficient. This would require that stockpiles found to be <500 ppm PCB be reloaded into onsite trucks for placement in the consolidation area. The Sampling and Analysis Plan, Appendix A, lists to sampling protocols required for stockpile sampling.

Material handling areas will typically be placed within the exclusion zone as the excavation proceeds so that there will not be a potential of contamination from this area migrating into clean areas. Based on the logistics of loading trucks and the flow of truck traffic, it may become necessary to construct waste processing areas outside of excavation areas, on clean surfaces. The areas will be constructed with a granular subbase material overlaid with a HDPE liner. A perimeter berm and water collection sump will also be provided. Materials staged/stored in this area will be covered with poly sheeting during periods of heavy rain.

A bermed, lined storage area will be constructed for storage of any filled drums or other industrial chemical wastes which are discovered during excavation. These wastes will be segregated from the other excavated material and stored in appropriate containers as required. These wastes will ultimately be characterized and disposed of properly according to the applicable regulations.

A waste load out area for Category "A" will be established at the westside of the site adjacent to the exclusion zone. This area will be lined and a berm will be built around the waste loading area to prevent stormwater from eroding contaminated material onto the roadways or into clean areas. The intent would be to have the contaminated waste loading area at the edge of the exclusion zone adjacent to a clean access road. Material to be loaded will be lifted from the exclusion zone, over the perimeter between the exclusion zone and the clean access road and into the lined disposal truck. Any spillage will be contained on plastic placed between the loading area and the truck. A truck scale, truck tarping station and a decontamination station will be provided at the truck exit point.

If loading directly from the stockpile Car the consolidation area, the access will be controlled to minimize the truck contact with the waste. Additional truck cleaning for decontamination will be implemented as required prior to exiting the area.

3.2.6 Storm Water and Erosion Controls

Prior to any excavation work, erosion controls such as nay bales and erosion fencing will be installed around the work areas to protect adjacent surfaces. Existing erosion controls will be maintained and augmented, as necessary, to prevent erosion and runoff from the work area.

Diversion ditches will be used to prevent stormwater from entering the excavation area and coming in contact with potentially contaminated materials. Diversion ditches will be constructed as shown on drawing sheet 5, Stormwater Diversion System, before excavation begins. Most of the diversion ditches used for stormwater diversion during excavation will be maintained after the RCRA C cap is constructed to prevent run on onto the consolidated footprint. A retention area will be located in the ditch line where the southeast ditch turns west out side the fence. This will accommodate any additional water flow off site compared to flows prior to ditch installation.

The ditches around the site will be lined with rip rap and/or geotextile depending on the slopes. In order to improve the integrity of the ditches adjacent to the cap an additional geomembrane liner will be added under the rip rap. This will prevent water carried in the ditch from damaging the ditch and eventually impacting the cap system.

3.2.6.1 Pre-Construction Delineation Sampling of Diversion Ditch Locations

Delineation sampling per the March 5, 1999 Soil Delineation Sampling & Analysis Plan" has been completed in and around the planned location of the diversion ditches. The layout of the ditch around the consolidation area is shown on Sheet 6. Details of the construction of the ditch are provided on Sheet 7.

Samples were collected every 50 feet along the centerline of the ditch inside the fence line and every 100 feet outside of the fence line, prior to excavation. In previously disturbed areas, a composite sample of the material to be excavated was obtained. In these areas samples were taken from the surface to the planned final excavation depth of the ditch. A separate grab sample was taken at 0 to 6 inches below the base of the planned diversion ditch, below the composite sample. The 0 to 6 inch grab sample will be used to confirm that the bottom of the diversion ditch will meet the 1 ppm clean up standard listed in the SOW for drainage/waterway areas.

The sample results of the material to be removed to form the diversion ditch will be used to determine the ultimate destination of the removed material. If the material is <5 ppm PCB, the material will be stockpiled for use as fill in excavations outside of the final limits of the RCRA C cap. The <5 ppm fill would then be covered with soil and seeded. If it is >500 ppm, the material will be sent to the TSCA landfill. If it is >5 but <500 ppm, it will be consolidated on site under the proposed RCRA C cap

In areas where the diversion ditch is located in undisturbed native soil, only a 0 to 12 inch surface sample was taken to determine the disposition of the excavated soil. Undisturbed soil would be soil that had no signs of previous excavation or contain unusual materials.

During the delineation sampling program, areas adjacent to the ditch in the

southeast and northwest areas were also sampled per the March 5, 1999 "Soil Delineation Sampling & Analysis Plan". A 50 by 50 foot grid system was laid out and sampled. The purpose of the sampling is to ensure that the material surrounding the proposed drainage ditches in these areas does not contain PCB, which may impact installation and usage of the new drainage system. Historical information shows that capacitor scavenging may have occurred in the southeast area south of Cattail Pond. The 1984 Blasland & Bouck data shown in Figure 3 for the northwest area, shows PCB contaminated soil in the area of the proposed location of the Northwest ditch.

If a grid inside the fence is shown to contain PCB levels >50 ppm, the grid will be included in the excavation area. Material >500 ppm will be disposed off site as TSCA. Grid sampling continued "outward" until a clean perimeter was determined. For grids that fall outside the fence line, the clean up criteria will be >5 ppm rather than >50 ppm, per the SOW.

The results of the delineation sampling are printed on the figures in Appendix G. These figures will be used by WRS during the excavation to identify the disposition of the material removed. In some locations the elevation of the ditch is above the existing grade. In these cases clean material from the borrow area will be used to obtain the final grades and slopes.

3.2.7 Water Collection and Treatment

A water treatment area will be established as shown in Figure 5 on the northwest part of the site outside the current limits of waste. This area will be constructed with a HOPE liner, perimeter berm and water collection sump. This area will be used to stage water treatment equipment which will include influent and effluent temporary storage tanks, sand and bag filters, organo-clay filter, carbon treatment units, bag filters and associated pumps and piping. A schematic of this system is provided in Figure 6.

The system has been designed to accommodate a two inch rainfall over the construction area. For rainfalls that are greater the site operation would stop until all water collected was properly treated. Treatment rate will be 100 gpm with discharge to Conard Branch. The PCB limit will be 0.3 ppb.

3.2.8 Dust Controls

Dust controls will include covering of waste stockpiles and open excavation areas during periods of inactivity, if necessary. Appendix C, Air Monitoring Plan (AMP), lists procedures used for dust monitoring. Based on these dust monitoring activities, additional dust controls may be employed including water sprays and physical barriers, such as tarps on the stockpiles, open excavations and fences. Treated stormwater can be used for dust control. Untreated stormwater can be used for dust control in known PCB contaminated areas. Water may be pumped from Conard's Branch, Richland Creek or Southwest Seep streams and used for dust control.

Areas uncovered and exposed for excavation, stockpiling and consolidation will be limited in size to minimize dust generation. A small "work area", typically a strip, will have the existing cover. Approximately 6 inches of the existing cap will remain in place when a strip is prepared. This will minimize the potential for dust to be generated. Also it will insure that only clean cap material is removed and stockpiled for future use. The width of the strip will vary based on the operation but could be about 40 ft. wide for consolidation or excavation. The remainder of the site will remain undisturbed with its existing cover in place to minimize dusting and water treatment requirements prior to consolidation.

As material is consolidated in an area to its final grade, the temporary cap will be installed to protect the consolidated material from dusting or coming into contact with rain water. As the small working areas are completed and covered, new areas will be opened for additional consolidation.

Material in the Category "A" staging area and in the stockpiles will be covered in times of inactivity. During weather conditions that do not cause potential dust problems the piles and staging area may be uncovered to promote drying.

3.2.9 Monitoring Well Abandonment

Due to the location of existing groundwater monitoring wells and the proximity to the excavation area it may be necessary to abandon and remove specific monitoring wells. These wells include:

MW-1

EPA-5SS

B-8

5B

EPA-11

EPA-5S

B-10

B-15

Additional wells that may be considered for removal include:

MW-2

EPA-2B

EPA2SS

EPA-1A

EPA-8S

EPA-10SS

EPA-1S

 

These wells have been determined not to be representative of either ambient groundwater chemistry or ambient groundwater levels. Other existing wells are planned to be used for future groundwater monitoring and/or future potentiometric mapping.

A final determination of which monitoring wells will be removed will be made in concurrence with the government parties.

Monitoring well EPA-5A will be retained. As shown in Sheet 3 this well is outside the final limits of waste. CBS will attempt to retain MW-4 This well is located at the edge of the excavation along the southeast . In the event that the location of this well interferes with the excavation or could be damaged it will be abandoned and replaced after restoration in the same approximate location.

3.2.10 Decontamination Area

AN equipment decontamination pad and personnel decontamination area will be on the west side of the site. The equipment decontamination pad, is shown in Figure 7. A decontamination trailer for personnel will be located at the' fence line crossing the exclusion zone to the staging area. The specific details associated with the decontamination area are described in the Health and Safety Plan (Appendix B). All decontamination water will be collected and treated in the site waste water treatment system.

3.3 Excavation Approach

3.3.1 Existing Clay Cap Removal and Stockpiling

The existing clean clay cover which was placed over a majority of the fill on site during the Interim Remedial Measures will be scraped aside as the consolidation and excavation progresses. Approximately 6 inches of this clay will remain over the waste. Data for cover thickness is available from the Tetra Tech sampling program of March 1998 report. The Tetra Tech study showed the clay cover thickness to vary from 0 to 5 feet. Some additional investigation of cover thickness will be done by WRS prior to cover removal. The remaining 6 inches of clay will limit dust and also will insure that only clean clay is removed for future use. The clay will be placed in a stockpile and used for construction of the temporary cap over the consolidated wastes. Top soil will be segregated and stored separately for reuse. As indicated above in Section 3.2.8. smaller "working areas" will be uncovered as needed, to prevent excessive dust problems and storm water contact with uncovered waste. WRS is proposing to remove the cover in 40 ft. strips to match the excavation process. Similarly strips will also be cleared to match the consolidation process.

The clay material will be placed over the consolidated waste to provide protection during the winter. This protective cover will begin to be placed over an area once the consolidated material has reached the final grade, contour and compaction requirements. As needed additional clay will be brought from the borrow area to complete the temporary cap. In the year 2000, the RCRA Subtitle C cap will be installed over this clay cover.

3.3.2 Removal and Segregation

The remedial action which will be implemented during the execution of this Work Plan is to segregate and dispose off site of all capacitors, capacitor parts and other materials which contain a PCB concentration of greater than or equal to 500 ppm PCB. Materials less than 500 ppm will be consolidated on-site under a RCRA C cap in an area of the site which is not prone to backflooding.

Whole capacitors containing PCB, which are discovered during excavation will be segregated and transported to a TSCA incinerator. Sheet 3 of the attached drawings shows eight locations on-site where capacitors were reinterred during the Interim Remedial Measures. The survey coordinates are included in the table on this sheet.

Capacitor parts (paper, wrappings, windings, insulators, empty metal casings) will be loaded out with soils and waste material which is >500 ppm PCB for disposal in a TSCA landfill. Any soils around the capacitors which are stained with PCB oil will be excavated and transported to a TSCA landfill.

Sheet 8 of the drawings, Excavation Category "A" shows the location of approximately 7000 CYs of material which will be excavated and shipped to a TSCA landfill without any additional sampling. Based on the Tetra Tech and CBS sampling of March 1998, this material is all assumed to be >500 ppm PCB.

Sheet 9 of the drawings, Excavation Category "B" shows the location of 41,000 CYs of material which will be excavated, placed into stockpiles of approximately 200 CYs and sampled per the Sampling and Analysis Plan. Stockpiles with PCB concentrations >500 ppm will be sent to a TSCA landfill. Stockpiles with <500 ppm PCB will be consolidated on site. Capacitor parts will be picked out of <500 ppm stockpiles as the pile is spread out for consolidation on site.

Sheets 10 and 11 of the drawings identify the planned excavation limits that will include the removal of approximately 52,000 CYs of additional material in the north and southeast areas. The material removed to obtain these grades is referred to as Category "C" and will be directly consolidated on-site with no additional sampling. This material had previously been identified as <500 ppm from the 1998 Tetra Tech sampling. Final grid sampling will be conducted to achieve the clean up criteria in these areas.

Non-contaminated debris inside the fence line but outside of the limits of the planned RCRA C cap and also around the outside of the current fence line of the site will be gathered as Category "C" material. This material will be consolidated on site under the eventual RCRA C cap. All tires located on-site will either be quartered and consolidated on site or will be collected in roll-offs and disposed of as special waste at a Subtitle D landfill.

Any filled drums or other industrial chemical wastes which are discovered during excavation will be segregated from the other excavated material and stored in appropriate containers if necessary. These wastes will ultimately be characterized and disposed of properly.

Wet material that is excavated for shipment off site to the TSCA landfill will be drained of free liquids prior to load out. Draining will be done at the excavation or in the case of Category "A" in the staging area prior to loadout. Wet material being consolidated on site will also be drained at the excavation or in the stockpiles as necessary for compaction before being consolidated.

The proposed sequence of excavation of the various materials is presented in Appendix F. In developing the excavation sequence, WRS has taken into consideration: minimizing cross contamination; minimizing the surface area of exposed waste for dust and odor control and water management; development of the consolidation area and associated stockpiles; construction of drainage ways and other water controls. The CD parties will be updated on the progress and any changes in the excavation sequence during the weekly meetings.

3.3.3 Limits of Excavation

3.3.3.1 Southeast Area

The six areas in the southeast area designated on Sheet 8 as Category "A" material were previously determined to be > 500 ppm PCB and shall be excavated and disposed of as TSCA material. The areas contained within the contours shown on Sheet 9, except for the >500 ppm PCB category "A" "hot spots", were previously determined to probably be between 50 and 500 ppm PCB. This material is referred to as Category "B" material and will be excavated, stockpiled and sampled per the Sampling and Analysis Plan (SAP) in Appendix A, to determine if any is >500 ppm. Stockpiles with sample results >500 ppm will be disposed of as TSCA. Stockpiles contaminated with less than 500 ppm PCBs will be consolidated on-site.

The remaining volume beneath the Category "B" contours shown in Sheet 9 for the southeast hot spot shall be excavated six inches into native soil. This material will be directly consolidated on site. No stockpile sampling will be required for this material. This material is referred to as category "C" material. Sheet 11 of the drawings shows the expected extent of excavation of Category "C" material to reach six inches into native soil.

The remaining native clay surface will be gridded and verification sampling will be performed per the SAP. A clean up standard of the remaining clay will be 1 ppm PCB in drainage/waterways. In areas not within drainage/waterways the cleanup standard shall be 25 ppm PCB on average over the whole site with no individual grid exceeding 50 ppm PCB.

Grids with sample results >500 ppm PCB will have a lift of material removed and disposed as TSCA. Grids with sample results >50 ppm PCB (1> ppm in drainage/waterway areas) but <500 ppm, will have a lift removed and consolidated within the footprint of the eventual RCRA cap. The thickness of a lift will be at least 3 inches. Thicker lifts may be taken based on previous data and the observed conditions of the material to be removed. Additional confirmation sampling will be performed in the remaining grid surface after the lift is excavated. Confirmational sampling and reexcavation will continue until the clean up level is achieved.

Sheet 11 shows the expected limits of excavation for the Southeast area based on existing information on the limits of waste and assuming that the clean up criteria will be met at six inches into native soil. Sheet 12 shows the planned interim final grade for this area. Stockpiled clean clay cap material, or material excavated from the diversion ditch construction which has been analyzed at <50 ppm or clay from the borrow area will be placed in this area as shown on Sheet 12 to establish the grades shown. Any drainage ditches that are constructed to direct water flow will have a base consisting of material that contains less than 1ppm PCB.

However, after excavation of the Southeast area is completed and confirmed clean, and before any fill is brought in, the bottom of the excavation will be inspected for any obvious signs of sink holes into the Karst bedrock. At that time the final surface water drainage plan for this area will be reevaluated. The option to use any existing sinkholes in the southeast area for surface water collection will be evaluated. In this case the existing diversion system shown in sheet 5 and the planned interim final area grading shown on sheet 12 would be modified. Any changes would be discussed with the CD parties at the weekly meetings. Based on the final configuration, if necessary, calculations will also be made to determine if an additional retention pond is required in the southeast area to limit flow into the southwest. Any changes to the surface water drainage plan will be brought to the attention of the County Drainage Board.

The clean up level of any new surfaces to be used as part of a new drainage ways will be 1 ppm PCB, per the SOW. Any fill material required to build up drainage ways will be from the borrow area and will have been tested for PCB concentration per the SAP. Surface areas remaining after excavation with PCB levels >1 ppm will be covered with at least 6 inches of clean cover. Included in the cover will be some of the stored top soil which will be spread on the remaining surface areas outside of the footprint of the eventual RCRA C Cap and seeded.

The southeast area will be excavated from the east to the west. Where appropriate excavation strips will be established that run roughly north and south. The strips will be used to limit the amount of exposed material. This will help to control dust and minimize collection of water. Survey controls will be used to insure that the location of each category of material is well identified in the strip. Excavation in a strip will proceed until six inches of native soil have been removed. A temporary berm will be constructed. The remaining soil in the strip will be sampled and any soil above the clean criteria will be excavated. Once the cleanup criteria in the strip has been achieved the strip will be graded to drain and covered with clean soil. The temporary berm will be maintained until the clean criteria in the adjoining strip has been achieved. This approach may vary based on the depth of excavation, the quantity of groundwater encountered and the composition of the waste.

3.3.3.2 North Area Located South of Sloped Area

A volume of material in the north area located south of the slope, as shown on Sheet 8, has been identified to be >500 ppm PCB, Category "A" material and will be excavated and directly disposed as TSCA. The remaining material within the contours around the North hotspot as shown in Sheet 9, including the overburden above the hotspot, is classified as category "B" material and shall be excavated, stockpiled and sampled per the SAP. Stockpiles with sample results >500 ppm PCB will be disposed of as TSCA. Stockpiles contaminated with levels <500 ppm PCB will be consolidated on-site.

The surface area remaining after the contour volumes are removed requires no verification sampling since this area will be used to consolidate material and will ultimately be under the RCRA C cap

The excavation will be done in strips as indicated in Figure 5. Survey controls will be used to insure that the location of each category waste is identified and properly handled. Once all the material required has been removed in a strip the strip will be back filled with Category "C" material. A thin layer of clay will be placed over the "C" material if at some point further consolidation is delayed. Excavation in strips will help control dust and minimized the volume of impacted water that will be collected.

3.3.3.3 Sample Point 52

The volume around sample point 52 from 15 to 21 feet as shown in Sheet 8 is classified as category "A" material and will be excavated and disposed of as TSCA. The remaining material within the contours around the sample point 52 as shown in Sheet 9, including, the overburden above the hotspot, will be excavated, stockpiled and sampled per the SAP. Stockpiles with sample results >500 ppm PCB will be disposed off site as TSCA. Stockpiles contaminated with less than 500 ppm PCB will be consolidated on-site.

The surface area remaining after the contour volumes are removed requires no verification sampling since <500 ppm material will be consolidated on this area. This area will ultimately be under the RCRA cap.

3.3.3.4Sloped Area

The sloped area within the final limit of waste (roughly between contour lines 810 ft. and 790 ft.) as shown in the site plan, Sheet 8, will be cleared of trees and vegetation. All visible capacitors will be removed and sent for incineration. All visible capacitor parts and stained soils will be removed and shipped to the TSCA landfill.

Nearly the entire surface area of the slope will ultimately be under the RCRA cap and therefore will require no verification sampling. Any of the surface area of the slope which will not be under the cap will be gridded and verification sampling will be performed per the SAP. A clean up standard of the remaining clay will be 1 ppm PCB in drainage/waterways. In areas not within drainage/waterways the cleanup standard shall be 25 ppm PCB on average over the whole site with no individual grid exceeding 50 ppm PCB. Six inches of clean cover will be applied over any areas the are above 1 ppm. Where grid sample results for PCB's exceed the cleanup standard a lift of material will be removed and either sent to a TSCA landfill if >500 ppm or consolidated under the RCRA cap if <500 ppm. The thickness of the lift will be at least 3 inches and will be based on previous data and observed soil conditions.

Areas of the slope which will not be under the RCRA cap and which have residual PCB levels over 1 ppm will be covered with at least 6 inches of stored cover, including some of the stored topsoil and seeded.

3.3.3.5 North of Sloped Area

North of the sloped area, the volumes designated around SB77, SB80, SB84 and SB92 in Sheet 8 as Category "A" material, > 500 ppm, will be directly excavated and shipped to a TSCA landfill.

Other than the >500 ppm PCB volumes designated around SB77, SB80, SB84 and SB92 for TSCA disposal, as indicated above, the entire area north of the slope, within the "current limits of waste", including the overburden over the four category "A"hotspots has been designated as category "C" material. This material will be excavated to the contours shown in sheet 10 and consolidated on site under the RCRA cap. Surface and near surface debris between the current and final limits of waste as shown on sheet 1 0 will be removed. Capacitors will be sent for incineration. Capacitor parts and stained soil will be sent to the TSCA landfill. Other debris will be consolidated on-site.

The remaining surface area of the native soil within the excavation area and areas where surface debris are removed will be gridded and verification sampling will be performed per the SAP. A clean up standard of the remaining clay will be 1 ppm in drainage/waterways. In areas not within drainage/waterways the cleanup standard shall be 25 ppm PCB on average over the whole site with no individual grid exceeding 50 ppm PCB. Where grid sample results exceed the cleanup standard for PCB, a lift of material will be removed and either sent to the TSCA landfill if >500 ppm or consolidated under the RCRA cap if <500 ppm. The remaining native soil will be resampled and reexcavated if necessary until the clean up limits are satisfied. Once the clean up criteria has be achieved the area will be graded for drainage. At least 6 inches of clean cover will be applied and seeded.

3.3.3.6 Areas Outside Current Fence Line

Any capacitors or visible PCB contamination outside the fence line will be removed. All visible capacitors will be removed and sent for incineration. All visible capacitor parts and stained soils will be removed and shipped to the TSCA landfill. After the visible contamination is removed the resulting soil surface remaining from under the removed contamination will have verification sampling performed per the SAP.

Trash in the sinkhole to the south of monitoring well EPA 3A will be removed. Any capacitor parts and stained soil will be removed and properly disposed. Sampling will be conducted per the SAP if capacitors or parts are found and stained soil is removed. As part of the ditch sampling and construction of the staging area the areas around EPA 3A and MW 5 were sampled and the results were BDL.

3.3.4 Excavation Dewatering and Treatment

It is anticipated that some amount of excavation below the potential groundwater surface will be required. This will require some amount of groundwater removal in order to access and remove soil and other debris that may exist at and below these depths. As the excavation is advanced, groundwater may accumulate in the bottom of the excavation. A pump will be used to remove this water and transfer it to the temporary water treatment system.

In addition, other sources of potentially impacted water will be collected and transferred into the temporary water treatment system including decontamination water, rain water collected in the material handling areas and excavation areas, etc.

The temporary water treatment system will consist of a temporary water storage tank, which will be used for flow equalization and settling. Water collected in this tank will then be pumped through a sand and bag filter system followed by organo-clay filters then through carbon treatment that includes bag filters. The treated water will be transferred into a temporary holding tank where the treated water will be sampled as a batch. CBS will treat all water to a limit of 0.3 ppb PCB. Following receipt of acceptable analytical results, treated effluent will be batch discharged into Conards Branch, SW Seep or another tributary to Richland Creek, in accordance with IDEM and USEPA approval. The discharge flow rate will be limited to avoid stream bed erosion. If the batch analytical result indicates that the discharge limitation has not been met, the water will be re-treated and re-sampled, as necessary. Note,the treated effluent may also be used for dust control when required.

3.3.5 Verification Sampling

Verification sampling will be conducted after excavation over the area extending from outside the footprint of the future RCRA C landfill cap out to the current limits of waste, as shown on the Site Plan, Sheet 3. Grid areas in the southeast and northwest perimeter areas outside of the Current limits of waste" which where found to require excavation during the delineation sampling, as indicated in section 3.2.6.1, will also have verification sampling performed after excavation. Grids already shown to meet clean up standards during the delineation sampling and therefore required no excavation, will not be resampled.

Verification sampling results will be used to determine whether the cleanup levels have been achieved. Areas outside of the "current limits of waste" where contamination has been removed will also have verification sampling conducted. This will include any areas outside of the current fence line where capacitors or obvious PCB contamination is found and removed. Areas that will be under the future RCRA ~ landfill cap will not be sampled for verification.

Verification sampling will consist of composite soil samples from four subgrids collected on a 50-foot by 50-foot grid basis, and analyzed for PCBs.

Approximately 41,000 CYs of material as indicated on Sheet 9 of the drawings, from the southeast area, the area located south of the sloped area and the area around Sample Point 52, will be excavated, stockpiled and sampled for PCB content. If the PCB content is below 500 ppm the stockpile will be consolidated on site under the RCRA cap. If the PCB content is >500 ppm the stockpile will be shipped to the off site TSCA landfill.

The details associated with the verification sampling and stockpile sampling are described in the Sampling and Analysis Plan - Appendix A.

3.3.6 Loading and Transportation for Disposal

Once the waste materials have been excavated, segregated and processed, all materials designated for off-site disposal will be loaded, transported and disposed as described below. A designated transportation and disposal coordinator will be on site during transportation and disposal activities. This individual will be responsible for coordinating and overseeing these activities.

A Transportation Plan, which describes specific aspects of the transportation activities, is included as Appendix D.

The waste materials will be loaded into appropriate transport vehicles/containers for offsite transportation to the designated disposal facility. Load out of Category HAD material will be conducted from the staging area shown in Figure 5. Off road trucks will place Category "A" material in the staging area from the exclusion zone. A dedicated excavator will load the over the road trucks located outside the exclusion zone. The staging area will be carefully controlled to minimize spillage and fugitive dust. As loading is completed, the loaded truck will be brushed off to remove loose materials.

Trucks and roll-offs that are to be loaded with TSCA material will be lined before loading. The liners will be draped over the side of the container to prevent contamination on the outside of the container. Roll-offs used for transporting capacitors will have wood chips on top of the liner to act as an absorbent. Once the container is loaded, the liner will be folded over and secured. A tarp will be secured over the top of the container. Trucks or roll-offs that enter the exclusion zone will pass through a decontamination area to exit the site. Each load will be inspected to insure that it is secure and that the truck has been properly cleaned/decontaminated, as required. The construction of this decontamination area is shown in Figure 7. Any water collected in the decontamination area will be treated in the on site waste water treatment system.

To prevent overloaded conditions, all trucks and roll-offs will be weighed before leaving the site using an on-site portable scale. The tare weight of each truck will be determined and subtracted from the loaded weight to cross-check the disposal facility weights.

Appropriate documentation (including hazardous waste manifests) will be completed and checked. In addition, a truck log will be maintained of loading and transportation information.

Disposal vehicles will enter the site from State Route 48. Once loaded and inspected, the loaded vehicle will exit the site on to Vernal Pike. The vehicle will proceed to the designated disposal facility in accordance with local, state and federal transportation requirements. TSCA soils, capacitor parts and other site remediation related material (e.g., PPE, liners, spent carbon, etc.) will be transported and disposed at the Environmental Quality (EQ) facility in Belleville, Michigan. Whole capacitors will be transported to the approved TSCA incinerator facility at Waste Management (ChemWaste) in Port Arthur, Texas for incineration.

3.3.7 Handling of non-PCB related waste

Tires will either be quartered on site by shearing and placed in the consolidation area or placed in roll-offs for disposal at Southside Landfill. Tires that go to Southside Landfill will have dirt removed prior to shipping. Other non-TSCA debris that is not consolidated on site will be transported to Southside Landfill in Indianapolis, Indiana for landfilling.

Any filled drums or large quantities of other industrial chemical wastes which are discovered during excavation will be retained in a bermed, lined storage area. These wastes will be segregated from the other excavated material and stored in appropriate containers if necessary. These wastes will ultimately be characterized and disposed properly, per applicable regulations.

3.4 Consolidation, Temporary Capping and Winterization

3.4.1 Material Consolidation

Approximately 200 stockpiles, each 200 cubic yards in size, will be formed from the 41,000 CYs of material indicated on Sheet 9 for stockpile sampling. The stockpiles will be sampled per the procedures listed in Appendix A, Sampling and Analysis Plan (SAP) If the PCB content is below 500 ppm the stockpile will be consolidated on site under the RCRA C cap.

Approximately 57,000 CYs of material from the area north of the slope and the volume under the contours in the southeast area will be directly consolidated on site without any stockpile sampling. This material and the stockpiles sampled at <500 ppm PCB will be spread out in lifts over the area of the footprint of the RCRA cap shown in Sheet 3.

As the consolidation proceeds the existing clay cover will be removed prior to placing consolidation waste. Approximately 6 inches of clay will remain to insure that no clay that has contacted the waste is removed and stockpiled for future use. After the clay has been removed the remaining material within the footprint of the RCRA cap will be prepared by proof-rolling to detect soft or loose subgrade before material is placed for consolidated. Proof rolling is to be performed by a Cat CP433 compactor, or equivalent.

The excavated waste to be consolidated will be placed in lifts of 18 inch maximum thickness. Each lift will be compacted using a Cat CP443 compactor, or equivalent. Survey will be used to confirm the material has been consolidated to the planned elevations and slopes shown on Sheet 12.

3.4.2 Temporary Capping and Winterization

Smaller "working areas" will be opened up for material excavation and consolidation to minimize dust and stormwater problems. Typically strips will be open for placing consolidated materials. The width of the strips will be based on the rate of consolidation. A typical width may be 40 ft. As the material is consolidated in a strip and built up to the planned grade, the temporary cover will be installed. The clean cover that currently exists on Neal's Landfill will be placed over the consolidated landfill material to a thickness of approximately one foot. This material will act as a temporary cap for the winter until the RCRA Cap can be installed during the construction season of the year 2000. The temporary cap will remain in place under the final RCRA cap system to serve as a smooth base for installation of the final cap.

If the existing cover on Neal's Landfill is not sufficient to cover the consolidated wastes, material will be excavated from the borrow areas Sheet 4 identifies an area of Conard's farm as a source of borrow material for the Neal's Landfill cap. The borrow area will also be used to provide backfill, cover and topsoil for the southeast area and the area north of the slope which will be outside of the footprint of the RCRA C cap. The Sampling and Analysis Plan describes the sampling of the borrow area for PCB's.

The temporary cap will be placed in multiple lifts and compacted with Cat CP443, or equivalent. Compaction wilt be confirmed based on the requirements of Technical Specifications #02220. The temporary cap and the cover placed outside of the footprint of the future RCRA C cap will be seeded to promote vegetation to hold the soil over the winter. As an alternative crimped straw may be used as a winter cover on the temporary cap. This would minimize the vegetation that has to be removed for final cap placement while providing erosion control.

The surface water and storm water controls (diversion ditches, silt fences, hay bales, etc.) which were installed at the beginning of the excavation will be maintained over the winter to prevent run on / run off and soil erosion. Once the temporary cap is placed and seeded and surface water controls are set, WRS will demobilize for the winter.

The site will be monitored and maintained over the winter to assure that excess soil erosion does not occur. Drainage ditches will be checked to assure they are open. The consolidated material will be observed to determine if material has sagged, or moved appreciably. If any maintenance is required on the cap, drainage ditches or in any of the other construction area, WRS will be on call to address the situation until final cap construction commences. Monitoring wells will continue to be sampled every two months.

3.5 Preliminary Design of RCRA Subtitle C Landfill Cover

3.5. 1 Footprint

The material to be consolidated will be placed in an area of the landfill which has been determined to be stable. This area will also not prone to backflooding or wetting from a rising ground water table. Sheet 12 shows the footprint and the elevations of the proposed RCRA cap. Sheet 13 presents two cross sections through the interim landfill.

3.5.2 Preliminary Technical Description of RCRA Subtitle C Landfill Cover

CBS has chosen CH2M Hill to design the RCRA cap for Neal's Landfill. The final cap for Neal's Landfill will be designed to satisfy the substantive requirements of RCRA Subtitle C as specified in 40 CFR 264.310(a). The landfill cap will serve to prevent direct contact with waste material, minimize erosion, limit infiltration of surface water, and control landfill gas emissions.

A cap system was developed for Neal's Landfill based on a review of EPA guidance on cap systems and Indiana regulations regarding the closure of municipal waste landfills. The system consists of the following components (from top to bottom):

The cap system as described above will be installed in year 2000, on top of the 12 inch thick temporary clay cover installed this year. The final landfill configuration will have slopes no steeper than 33 percent and no flatter than 5 percent. Details of the cap section are shown in Figure 2. As required settlement monitoring devices will be installed

The cap system will be carried beyond the final limits of waste shown on the construction drawings. The exact limit of the cap will depend on the landfill side slope and existing grade.

3.5.3 Design Approach for RCRA Subtitle C Landfill

Final details of the cap system will be developed from a detailed design evaluation. The design will consider the following issues

.

The efficiency of the cover system will be determined using the EPA computer model Hydrologic Evaluation of Landfill Performance (HELP). The HELP model will evaluate the need for and performance of the drainage layer and considers local climatological data and physical site characteristics. Based on the HELP model, a drainage layer may be required in places for stability of the cover system.

A minimum of 12-inches of clay will be placed over the consolidated waste as a temporary cover for the winter. The temporary cover will be constructed using clay from the borrow area shown in Sheet 4. This temporary cover will serve as a bedding layer for the clay barrier layer that will be part of the final capping system.

The clay material used in the barrier layer will meet the following specifications:

A clay borrow site has been identified north of the landfill. Laboratory testing of the borrow site indicates the clay satisfies the requirements and will provide suitable material for the barrier layer. The borrow site will also provide material for the protective cover and vegetative support layers, if sufficient material is not available from on-site activities. Granular drainage materials are available from quarries in the Bloomington area.

The geomembrane will be selected to satisfy slope stability requirements and to accommodate anticipated settlement or collapse of waste material. A textured material may be used on the side slopes if required for stability purposes. The selection of the geomembrane will also be based on the material strength required to handle the potential for localized settlement or subsidence. A geomembrane panel layout plan will be prepared by the geomembrane installer. The installer will be required to meet the following criteria in the development of the panel layout

.

A short-rooted grass mixture will be used as the vegetative cover. The seed will be selected based on local climate and soil types. The short-rooted grass mixture will maintain a relatively shallow root zone minimizing penetration into the final cover system. As vegetative cover becomes established, slight penetration of grass roots into the vegetative support zone will help to further stabilize the soil portion of the cover. Periodic mowing will inhibit growth of unwanted plant species that may damage the cover. The selected grass mixture, used in conjunction with proper construction practices, will support vegetation without continued maintenance. Temporary erosion measures, such as straw bales and silt fences, will be used until vegetation becomes established.

The final cap system will include surface diversion berms and down-chutes to collect stormwater flowing across the surface of the landfill and convey them to the exterior surface water diversion system to limit erosion. Additional erosion control features such as riprap or erosion control matting will be used as necessary in areas of concentrated flow.

A post-closure plan will be prepared to address long-term inspection and maintenance of the landfill cap. The design of the RCRA cap system will be submitted to the parties for approval as required by the SOW.

4.0 Site Controls

4.1 Sampling and Analysis

Verification sampling and analysis will be conducted to determine whether the cleanup standards have been achieved. A Field Sampling and Analysis Plan (SAP) which describes the verification sampling and analysis is included as Appendix A. Appendix A also describes sampling and analysis procedures for the stockpiles of Category "B" materials.

4.2 Health and Safety

Health and safety will be conducted in accordance with the Health and Safety Plan (HASP) included in Appendix B. This HASP has been prepared in accordance with 29 CFR 1910.120 - Hazardous Waste Site Operations

4.3 Air Monitoring

Air monitoring will include perimeter air sampling for PCB, dust monitoring as well as personal air monitoring as part of the health and safety program. These monitoring procedures are described in the Air Monitoring Plan included as Appendix C.

Excavations will also be monitored regularly for any possible chemical vapors which may be released. It will be the responsibility of the Remedial Contractor to protect his workers from any possible chemical release which may occur during excavation.

4.4 Interim Performance Monitoring (Surface and Groundwater Monitoring)

A surface and groundwater monitoring plan will be implemented during the Neal's Landfill remediation to detect any increasing trends in the PCB concentration of monitoring wells, springs and surface water at and near the site.

Prior to the start of excavation activities, grab samples will between at the following locations for PCB analysis per procedures listed in the Sampling and Analysis Plan (SAP):

During excavation and construction of the landfill cap, grab samples will be taken and analyzed for PCB, per the SAP, every two months from the start of construction activities at the following locations:

Springs- South, North, Branham, Taylor, Pig Pen

Residential Wells - Branham, Conard

Monitoring Wells - EPA 3A, MW- 1, MOO-5, EPA-5A

Forty-five days after completion of the final cap, CBS shall submit a separate groundwater monitoring plan, the Long Term Monitoring Plan, to be implemented as part of the continuing Operation and Maintenance Plan for a minimum of five years.

5.0 Schedule

The schedule for completion of the Neal's Landfill activities are listed below. It should be noted that the dates presented herein are approximate and may be subject to change based on conditions beyond the control of CBS.

Submit Work Plan to CD Parties for review and approval

March 8, 1999

Submit revised Work Plan

April 23, 1999

Work Plan Approval

April 28,1999

Contractor Mobilization and Site Preparation

April 19, 1999

Contractor Initiate Excavation Activities

May 19, 1999

Completion of Temporary Cover

Sept. 10,1999

Contractor Closes Site for Winter

Sept. 17, 1999 (Weather permitting)

Maintenance of temporary cap

Until RCRA cap installation

Install RCRA Subtitle C Cap

Year 2000
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