1.0 Introduction

The purpose of the Long-term Groundwater Monitoring Plan is to monitor for the presence of PCBs in the Groundwater related to the site. Per the SOW, Groundwater monitoring is to occur quarterly until completion of a five-year review to be done under CERCLA Section 121(c) and Section 300.430(fl(4)(ii) of the National Contingency Plan.

The SOW specifies that ~ review will occur five years after construction began at Bennett's Dump. The remedial action at Bennett's Dump began in August 1999. Interim Groundwater monitoring which was initiated before the remedial action has continued to the present. The interim monitoring will continue until the Long-term Groundwater Monitoring Plan is implemented. This plan will be reviewed in August 2004. At that time, the Consent Decree (CD) parties will review the monitoring data and decide to maintain, reduce or eliminate the Groundwater monitoring. Also, during the base monitoring period, changes to the plan may be proposed and the plan changed with the consent of all the parties.

1.1 Site Location

Bennett's Dump is located in a rural setting in the central portion of Monroe County, Indiana. It is approximately 2.5 miles northwest of the City of Bloomington, as shown in Figure 1. The site consists of two areas. The main area is 3.5 acres in size and is located adjacent to Stout's Creek. The adjacent land to the west of the site, across from Stout's Creek, is agricultural.

Another area, referred to as the satellite area, is located approximately one hundred feet to the east of the main area. The satellite area is approximately one half-acre in size. The main area is bounded by Stout's Creek to the west and quarry access roads to the south and east. Figure 2 shows a plan view of Bennett's Dump.

A third small area (approximately 30 by 60 feet), 750 feet north of the main area was to be remediated under the original CD. A 1992 EPA sampling effort of this area showed no presence of PCBs. Based on these results, the CD parties agreed that no further action was necessary at this location.

1.2 Site History

The quarry produced a finished building stone whose source was the Salem Limestone. Quarries in this area also produced crushed stone for road construction, low-magnesium limestone for cement, and high magnesium limestone for steel production and agricultural application. There is an inactive stone mill within 50 feet of the southwest comer of the main site. The site contains large surface and subsurface limestone quarry blocks and stone rubble, which were abandoned during quarry operations.

In the 1960s (exact dates unknown), a portion of the quarry was used as a landfill for industrial wastes. These wastes included Westinghouse electrical capacitors, which contained PCBs.

1.2.1 ~ On-scene Coordinator's Report

On May 12, 1983, Ron Lillich, the USEPA on-scene coordinator, conducted the initial site assessment of Bennett's Dump at the request of the Monroe County Health Department. The report of this site assessment is contained in the "On-scene Coordinator's Report", USEPA, June 1983, (Reference 1).

The initial condition of this site indicated that it was an uncontrolled dumping and salvaging ground for electrical parts. Most of the electrical parts visible at the site had been crushed, burned or otherwise tom open, with insulator wrapping paper, ceramic bushings, and other electrical parts scattered about the surface. The existence of stained soil was also evident on the landfill surface.

The on-scene coordinator's report also describes: 1) a small pond, possibly a spring, on the eastside of the fill, 2) an adjoining pond draining west toward Stout's Creek, and 3) a small pond along the west border of the site, situated between the fill and the railroad tracks. This small pond flowed via two routes directly into Stout's Creek. The EPA sampled the water from the pond at the time of the inspection in 1983. The 1983 sample was analyzed at 7 ppb PCB Aroclor 1242.

1.2.2 Consent Decree

The removal actions are summarized in the following sections.

1.2.3 Interim Remedial Measures (IRMs)

The second phase of IRMs was specified in the CD. It began in late 1987 and was completed by Westinghouse in 1988. The second phase included installing an additional area at the edge of the main site, posting warning signs and removing sediment from Stout's Creek.

In September 1988, Viacom removed sediment along 1,600 feet of Stout's Creek. The creek was hydrovacuumed from 25 feet upstream of the site to 500 feet downstream of the site. Sediment was also removed from Stout's Creek 30 feet downstream and upstream of Hunter Road and further downstream at Acuff Road.

The sediments were transported to the Interim Storage Facility at the Winston Thomas site or storage. They were subsequently shipped by Viacom in early 1998 to a TSCA-pemmitted landfill in Belleville, Michigan, for final disposal.

All lRMs that were implemented by Viacom were conducted with oversight and approval from the CD parties. Maintenance of the site by Viacom began in 1985. Viacom personnel regularly inspected the site to assure there was no disturbance of the site and to verify that the security fences and cap remained intact.

1.2.4 1999 Remedial Action

The remediation was performed to satisfy the requirements of the SOW for removal of soils and wastes containing concentrations greater than or equal to 50 ppm PCBs with an average concentration across the excavation that does not exceed 25 ppm. The excavation was backfilled with a minimum of 12 inches of clean cover, graded to drain, and vegetated.

Site activities began in mid-August 1999, and were completed in early November 1999. The project involved:

• Shipping a total of 36,157 tons of TSCA material to the Environmental Quality Company's Wayne Disposal Landfill.
• Shipping a total of 1,756 capacitors weighing 118.72 tons to Onyx Environmental in Port Arthur, Texas for incineration.
• The arithmetic average of all residual confirmation sample results was 11.3 ppm compared to the 25 ppm requirement of the SOW.
• The site was backfilled with approximately 25,000 cubic yards of clean clay, graded for drainage and seeded.

Samples were taken of dirt at the bottom of the excavations that probably sifted down from above as the boulders were removed. Each of these areas produced sample results from the bottom of the excavation that exceeded the SOW allowable limit of 50 ppm. The locations and sample results of the subgrids that exceed the 50 ppm limit are:

The satellite area presented a similar situation. A pit encompassing portions of grids S2 and S8 was discovered that was filled with capacitor carcasses, capacitor parts and large amounts of ash. The capacitors, and the soil and ash containing the capacitor parts were removed to a depth of about 13 feet. Capacitors, capacitor parts and stained soils were chased and excavated out of the sidewalls in all directions. Sidewall samples were taken until the cleanup criteria was met in the north, east and south directions. The west sidewall of the satellite area was removed down to a depth of 7 feet below grade and 10 feet westward into the road to a point where all capacitors, capacitor parts, ash and soil were removed from the excavation. The bottom and western sidewall consisted of only large boulders and rock debris all the way up to the gravel roadbed. No appreciable soil or ash remained. The CD parties concurred that no further sampling or excavation was warranted in this area. Figure 4 shows that the final configuration of the bum pit excavation extended across grids S2, S8, S3 and S7.

The remedial action is documented in the "Final Report - Completion of Removal Action for Bennett's Dump, CBS Corp, Febnuary 7, 2000", (Reference 10).

1.2.5 Interim Groundwater Monitoring Program

The SOW for the 1999 remedial action at Bennett's Dump called for an Interim Groundwater Monitoring Program. Prior to the start of excavation activities and every 60 days during remediation, the following locations were to be sampled:

The SOW also called for the implementation of a Long-term Groundwater Monitoring Program. The Interim Groundwater Monitoring Program was to continue on a quarterly basis until the Long-temm Groundwater Monitoring Program was approved and implemented.

In February and March of 2000 the Middle Spring and the Mound Spring, as shown on Figure 5, were added to the interim monitoring program.

The results of the Interim Groundwater Monitoring Program are discussed in Section 1.6 and listed in Table 1.

1.2.6 ~ 2000 Stout's Creek Bank Soil Removal

On September 8 and 9, a depth of at least one inch of soil was removed for a width of about six feet along each of these 50 foot lengths. This material was consolidated on the Bennett's Dump site in Grid G8, as shown in Figure 3. The consolidated material was capped with at least one foot of clean clay backfill.

1.3 Summary of Site Conditions

Star Stone Company is the present owner of the site. The site is currently inactive and not occupied by any permanent workforce or residents. No long term use of the land has been indicated by Star Stone. The site will likely remain inactive for at least the next few years except for the presence of Star Stone employees working in other parts of the quarry.

Viacom has proposed the appropriate deed restriction for the site to USEPA and IDEM, but they are not in place. Viacom has continued to maintain the site.

Viacom performed erosion repair work at Bennett's Dump during the week of September 5, 2000. A diversion berm was installed below the groveled parking area to prevent further erosion. Areas were graded to prevent pending. Filled areas, which had sunk over the winter, were refilled to grade. Hydroseeding and mulching of the regraded areas are incomplete and will be done this season as weather permits.

Interim Groundwater monitoring is continuing on a quarterly basis.

1.4 Geology and Hydrogeology Summary

1.4.1 Site Geology

Very compact gravel used as ballast for the old railroad bed was encountered in the upper three feet of unconsolidated material in the western portion of the site, along Stout's Creek. This gravel fill ranged in thickness from 1.4 to 3 feet. Other fill materials consisting of a mixture of clay, limestone, and coal were encountered to the southern boundary of the main fill area. The predominant soil encountered at the site is a yellow/red/brown, stiff silty clay that ranges in thickness from approximately 2.5 to 5.5 feet. This silty clay grades with a red/gray, stiff clayey silt that ranges in thickness from 1.6 to 4 feet. The area around the site contains large surface and subsurface limestone quarry blocks, which were abandoned during quarry operations.

The Crider silt loam (CrC) is found north of the main Bennett's Dump site beneath a planted field. This soil consists of silt to a silty clay loam. Permeability values are reported to range from 0.6 to 2 inches per hour. Bedrock beneath this soil is usually encountered at a depth of approximately five feet (Reference 4).

The bedrock unit present in the study area of Bennett's Dump is the Mississipian Age Salem Limestone of the Sanders Group. The St. Louis and Ste. Genevieve Limestone of the Blue River Group overlie the Salem Limestone and outcrop at elevations higher than the Bennett's Dump study area. The Harrodsburg Limestone and Ramp Creek Formation of the Lower Sanders Group underlie the Salem Limestone and outcrop at lower elevations near the site. Regionally, the bedrock dips in a southwest direction at approximately 30 feet per mile; however, local deviations may occur.

The Salem Limestone is the first bedrock unit beneath the site ranging from 90 to 100 feet in thickness (References 5, 6). This limestone unit is composed of three lithologies: a light colored limestone that is quarried for dimension stone, a similar limestone not used as dimension stone, and impure limestone (References 5, 6). A gradational contact separates the Salem Limestone from the underlying Harrodsburg Limestone; however, in some places in Monroe County, a few feet of shale is present at the base of the Salem Limestone (References 5, 6). This shale may provide a marker bed to distinguish between the Salem and Harrodsburg

As indicated in the Supplemental Hydrogeologic Investigation Plan (SHIP), five borings which ultimately became monitoring wells were installed in 1987 to provide compositional data on the unconsolidated material (soil and silt) and lithological and structural infommation on the bedrock at the site. Continuous core sampling of the unconsolidated material and the bedrock was performed from the ground surface to an average depth of 42 feet at five locations (Wells MW-1, MW-2, MW-3, MW-4 and MW-6D as shown in Figure 2).

The average thickness of the rock cored was approximately 35 feet. No significant stratigraphic changes could be correlated and no useful marker beds were identified in the cores examined from the site.

Weathered and fragmented limestone was encountered during the installation of wells MW-1, MW-2, MW-4, and MW-6D. Gray/black shale less than 3 feet thick was encountered during the installation of wells MW-3 and MOWED. This shale may represent the Somerset Shale member that separates the Salem Limestone from the underlying Harrodsburg Limestone. Honeycomb weathering was noted in the cores obtained at the locations of wells MW-1, MW-4, and MW-6D.

Horizontal and vertical fractures were noted in some of the bedrock core samples. Most of the fractures were filled with either calcite or mud. Few enlarged solution features were noted in the cores collected at the site. The deeper bedrock is composed of finer-grain calcite particles.

Packer tests perfommed during well installation indicated that these fractures did not transmit water. The subsurface logs for the borings/corings are provided in Appendix 2 of Reference 3. The test borings and rock corings were performed during the months of June, July, August and October of 1987.

At the completion of the boring/coring and well installation activities at the locations of wells MW-1, MW-2, MW-3 and MW-4, the coreholes/wells were caliper logged and gamma-ray logged. No geophysical logging was conducted at wells MW~I and MW-5. No large voids were measured in the wells that were caliper logged. In general, only small changes (~0.5 inches) in the well diameter were measured in the wells logged.

Because of the lack of information on the connection of the wells to any major water bearing conduits, video logging was conducted in 1993. Unfortunately, heavy corrosion of the surface casing in the open-hole wells had occurred, which resulted in rust flakes that partially obscured the camera view. Nevertheless, solution conduits about an inch or so in diameter could be noted in several wells just below where the surface casing was seated into bedrock, and within the first 10 to 15 feet of bedrock. This also coincides with packer test results that indicate the lower part of the wells to be less transmissive. Therefore, no major conduit connections to any of the existing monitoring wells were discovered.

The details of the monitoring well construction are shown in Table 2 (Part 2). Well locations are indicated on Figure 2. Water elevations measured in the monitoring wells are shown on Table 3.

1.4.2 Site Hydrogeology

The Groundwater flow system associated with the site is composed of recharge areas, flow areas, and discharge areas. Recharge to the Groundwater flow system occurs in the topographically higher areas east and south of the site through open water-filled quarries (pits) and through old quarries that have been backfilled with rubble. Although surface water runoff is a contributing source of water to the quarries, the predominant origin of the water in the quarries is believed to be Groundwater.

Groundwater from the Bennett's Dump site is believed to primarily discharge to Stout's Creek. Based on the Groundwater elevation data collected from the monitoring wells in August and November 1987, and March, June, September and December 1988, Groundwater flow is generally to the west-northwest towards Stout Creek for all measurement periods (see Figures 5A through 5F of Reference 3). In the southern portion of the site, the groundwater flow direction trends more directly west toward Stout's Creek. In the central and northern areas of the site, the groundwater flow direction trends west-northwest toward Stout's Creek. Horizontal groundwater gradients varied from approximately 0.05 feet/foot to 0.03 feet/foot in the southern portion of the site and from approximately 0.03 feet/foot to 0.02 feet/foot in the central and northern portions of the site.

The Salem Limestone and the unconsolidated deposits are integrated to comprise one hydrogeologic system. The depth to groundwater at the site ranges from about 2.5 to 14 feet below ground surface. The groundwater flow in the bedrock occurs in solution enlarged joints and fractures. Several seeps located within the limit of the main fill area at the site may also be local groundwater discharge points.

1.5 Topography and Surface Water Features

INDOT is currently building a highway within a mile south and southeast of the site. As part of this construction, some of the water filled quarries were filled during the year 2000. The water in the quarries was not removed as the quarries were filled. This may have temporarily raised the groundwater elevations in the area.

The main area of the site is on a gently westward sloping hillside east of Stout's Creek. Elevations at the site range between 710 and 750 feet above mean sea level. To the south of the site, two streams join forming Stout's Creek, which flows north from the site area. Stout's Creek is joined just north of the site, from the west by the stream referred to as the West Branch, as shown in Figure 5.

There are four springs within the Bennett's Dump site that have been sampled as part of the Bennett's Dump Interim Groundwater Monitoring Program. Two perennial springs at the site, the Middle Spring and the Mound Spring are within the main excavated area. These two springs emerge from within the excavated and backfilled area and run into Stout's Creek. Two other intermittent springs on the perimeter of the excavated area are the North Spring and Mid- north Spring. A 24 inch culvert exists at the North Spring and drains under the rail road tracks to Stout's Creek. The locations of these springs and the culvert are shown on Figure 5. North Spring has not been observed flowing since before the remedial action excavation.

The on-scene coordinator's report from 1983, discussed in Section 1.2.1, describes:

1. A small pond, possibly a spring, on the eastside of the fill.

2. An adjoining pond draining west toward Stout's Creek.

3. A small pond along the west border of the site, situated between the fill and the railroad tracks. This small pond flowed via two routes directly into Stout's Creek.

The report contains a site plan that shows that the first pond on the east side of the fill corresponds to the Mound Spring currently being sampled in the interim monitoring program. The third spring along the west corresponds to the Middle Spring, which is also being sampled as part a! the interim monitoring program.

There are also several wet weather springs that are visible flowing to Stout's Creek from north and west of the middle spring during and after rain events.

1.6 Historical PCB Data

1.6.1 Groundwater Monitoring Well Samples

The EPA has recognized this situation. EPA guidance for groundwater monitoring in karst is contained in "Groundwater Monitoring in Karst Terrain: Recommended Protocols and Implicit Assumptions", (Reference 7), and "RCRA Ground-Water Monitoring Technical Enforcement Guidance Document", (Reference 8). These documents state that the proper locations for monitoring the status of Groundwater in karst areas are springs, cave streams and monitoring wells that have been proven by dye tracing to intercept conduits carrying water from the monitored location.

As discussed in section 1.4.1, seven monitoring wells were installed at the Bennett's Dump site in 1987 and 1988, as shown on Figure 2. Six of the wells surrounded the main fill area of Bennett's Dump where capacitors were known to exist. Four of the wells were positioned between the main fill area and the adjacent Stout's Creek. One well, MW-44 , was located in a small satellite area to the north of the main site, which has since been evaluated as not containing any PCB contamination. MW-4 was abandoned during the remedial action in early August 1999, along with MW-2, which was abandoned to allow access to the site.

The monitoring wells were sampled quarterly during 1988 for PCBs. Additional PCB samples were taken from the monitoring wells since 1999 for the Interim Groundwater Monitoring Program.

During 1988, PCBs were detected during each of the four quarterly sampling events in wells MV\t 61 and MW-6D, and once in well MW-3. The maximum total PCB concentration detected in Groundwater was 27.3 ug/L for MW-6I. The use of well MW-5 was discontinued in March 1988 due to the presence of free PCB product within the well. The sample analytical results are included in Table 4.

From August 25, 1999 until present, monitoring wells MW-3, MW-6I and MW-6D have been sampled for PCBs nine times under the interim monitoring program. These interim sample results are listed in Table 1. MW-3 has been consistently BDL. MW-1 results were up to 1.2 ppb.

MW-6D was sampled at 58 ppb on August 25, 1999, before remediation. A field duplicate sample of MW-6D, taken and analyzed at the same time was reported as 2.6 ppb. The samples were visibly different, with the 58 ppb sample reported to contain a larger amount of sediment. It was concluded that field conditions were not stable during the time that these duplicate samples were obtained. The validation report on these duplicate sample results calls for this data to be flagged as estimates only. The sample results since for MW-6D have been between 5.9 and 15 ppb.

Also, since November 1999, all sample results for well MW-6D have identified Aroclor 1221 as the main constituent. Straight Aroclor 1221 was not used by Westinghouse in capacitors and this Aroclor is not seen in the Stout's Creek downstream samples. It is not clear how to interpret the appearance of this Aroclor at the site.

The boring logs, packer tests, caliper logs and gamma-ray logs from the installation of these Bennett's Dump monitoring wells, as discussed in Section 1.4.1, indicate that none of the Bennett's Dump wells intercepted major Groundwater conduits.

1.6.1.1 Investigation of DNAPL in MW-5

1.6.2 Surface Water

1.6.2.1 Stouts Creek Surface Water Sampling

1.6.2.3 April 1998 Storm Event Sampling

Sample locations in Stout's Creek were upstream of the site, downstream of the site at Hunter Road and in the West Branch entrance to Stout's Creek. Figure 7 shows the PCB concentration and water flow versus time during the storm event. PCB content of the water upstream of the site was typically BDL before the stomm. As the flow in Stout's Creek increased, the PCB content in the water upstream of the site consistently rose to between 0.1 and 0.3 ppb until the storm flow peaked. On the receding limb of the stomm event, the PCB content of the upstream samples resumed to BDL.

The PCB content of the Stout's Creek downstream water samples during the storm event started out at levels typical of the low flow data. Figure 7 shows that during the rising limb of the storm the downstream PCB levels stayed about the same as the upstream PCB levels rose. This could be explained by a lag in the flow increase of the springs compared to the flow increase in the stream during the stomm. Previous surface water monitoring has shown that the springs have higher PCB content but lower flow rates than Stout's Creek, especially during storm conditions. The downstream Stout's Creek flow is a combination of the upstream creek flow and the spring flows that enter the creek from the site. As the creek flow increases during the storm, the effect of the spring flows into the creek become insignificant until the spring flow rates also increase.

Figure 7 shows that on the receding limb of the creek flow curve, as the creek flow decreases, the PCB level in the downstream samples stays about the came or increaser. even though the PCB level of the water upstream of the site has resumed to BDL. During the period of the receding limb of the storm, the flow from the springs may have increased. Since the springs have a much higher PCB content than the water coming from upstream in Stout's Creek, the spring flows are most likely causing the downstream PCB levels in Stout's Creek to remain high.

The downstream PCB levels in Stout's Creek become non-detectable late on the receding limb most likely because flow in the springs recedes and the much higher flow of clean water from upstream dilutes the spring flows.

1.6.3 Sediment Sampling

In April and May 1998 sediment and fish samples were taken under low flow conditions in Stout's Creek. In all, 28 sediment samples were taken from just upstream of the site to just upstream of the confluence with Bean Blossom Creek. Two sediment samples were taken in the West Branch of Stout's Creek just upstream of the confluence with the east branch. Sediment samples were taken at 100 foot spacing from Hunter Road south to the site boundary, then at 50 foot spacing to an area adjacent to MW-6, then at 100 foot spacing again to the southern site boundary. A sample was also taken further downstream at Acuff Road and just upstream of the confluence with Bean Blossom Creek. Figures 8 and 9 show the sediment and water sample locations. All samples were grab samples taken from the approximate center of the stream or in the most abundant sediment pool at that location. Sediment sample results varied from less than 0.1 ppm to 3.2 ppm as shown in Table 7. Generally, only samples downstream of the middle spring and upstream of the West Branch confluence with Stout's Creek showed PCBs greater than 1 ppm.

On June 27 and 28, 2000, sediment samples were taken in accordance with the approved May 15, 2000 Work Plan. Fourteen 50 foot lengths along the creek were sampled for both creek sediments and bank soils as shown in Figure 6. For each 50 foot length, five creek sediments were compositedand five bank soil samples were composited. Individual sample aliquots were taken approximately every 10 feet along the 50 foot length.

Creek sediment samples were taken from under water within the creek. Bank soil samples were taken at an elevation of about one half to two feet above the water level of the creek.

The sample results are tabulated in Table 8. Three of fourteen creek sediment samples were above 1.0 ppm PCB. The highest value was 1.7 ppm for Segment 7. The average of all fourteen creek sediment samples taken was 0.64 ppm. Six of fourteen bank soil samples were above 1.0 ppm. The highest bank soil result was 2.7 ppm for Segment 6. The average of all fourteen~bank soil samples taken was 1.05 ppm.

Based on the June 2000 sampling results, no creek sediments were removed, and only certain areas of bank soils were removed. The objective of the remedial work was to clean up the bank soil for the three creek sections with sample results > 2.0. The three segments, as shown on Figure 6 are Segment 6 with 2.7 ppm, Segment 9 with 2.4 ppm and Segment 13 with 2.0 ppm.

A depth of at least one inch of soil was removed for a width of about six feet along each of these 50 foot lengths. This material was consolidated on the Bennett's Dump site in Grid G8 and capped with at least one foot of clean clay backfill.

1.6.4 Fish Sampling

1.6.5 Residential Wells

As shown in Table 9, one residential well at 4005 Woodyard Road had PCB levels at 0.407ug/L. This value approaches the MCL of 0.5 ug/L. This well was disabled and the residents now use only city water. Table 9 shows six other wells with detectable PCB levels between 0.002 and 0.007 ug/L, which are well below the MCL. It is not known if the source of the PCBs in the well at 4005 Woodyard Road was Bennett's Dump or some other location.

IDEM and Monroe County performed additional residential well sampling in 1988. Three Stout's Creek samples were taken at the same time. Seven residential wells were sampled and all found to be non-detect (<0.1 ug/L). Table 9A lists the results of the residential well and Stout's Creek water samples taken in 1988. This sampling included one of the seven residential wells which had detectable PCB levels in 1986. Viacom took split samples at four of the wells. Three samples were analyzed at non-detect (<0.1 ug/L) and one sample was lost due to an extraction error.

2.0 ~ Long-term Monitoring Approach

The SOW for the site negotiated in 1999 required the implementation of an Interim Groundwater Monitoring Program as discussed in section 1.2.5. The SOW also requires the submittal of a Long-term Groundwater Monitoring Plan by Viacom. The purpose of the long term monitoring plan as stated in the SOW is to determine that the remedy is functioning as set forth in the amended ROD. A review of this monitoring plan and data will occur in August 2004, at which time the CD parties will decide if the prescribed monitoring will be maintained, reduced or eliminated. Also, during the base monitoring period, changes to the plan may be proposed and the plan changed with the consent of all the parties.

A review of the site history, hydrogeology and historical PCB data shows that:

• The remediation of the site in 1999 was substantial and met the intent of the original CD, the SOW and amended ROD. A total of 36,157 tons of TSCA material were removed and disposed offsite. The final site average for the remediated area is 11.3 ppm.
• PCB contaminated light oils were found within the rock in buried quarries at the site. These oil/water mixes were pumped out but some residuals remain in contact with groundwater in these areas.
• The site is located on the Mitchell Plain karst terrain. Stout's Creek is the regional groundwater sink in the area with all upper level water bearing zones at the site appearing to discharge to the creek. The most accurate indicator of groundwater conditions will be springs and/or stream water samples.
• There are two main springs at the site and several smaller seeps that appear only in wet weather. The two main springs have been sampled and have PCB contamination. These springs enter Stout's Creek at the location where the past sediment contamination in the Creek has been the highest.
• The existing wells were installed randomly with respect to karst features and have not been detemmined to be in contact with major groundwater flow paths.
• There still remains an undetermined amount of free phase product at the bottom of MW-5 mixed with sediment. Over the time period of the September 2001 examination, free phase product did not appear to increase.

Based on the above and the SOW goals, the groundwater monitoring plan should be structured to primarily monitor site springs and the water of Stout's Creek. The springs and the creek naturally integrate the groundwater from a broader area and provide a more comprehensive view of the status of groundwater and contaminant transport at the site.

The two perennial springs at the site within the main excavated area are the Middle Spring and the Mound Spring as shown on Figure 5. These two springs emerge from within the excavated and backfilled area and run into Stout's Creek. Viacom is currently sampling these springs as part of the Interim Groundwater Monitoring Program.

Although it is not clear how data obtained from monitoring wells MW-61 and MW-6D will be used to better understand Groundwater at the site, at the request of the government parties, Viacom has agreed to monitor these two wells for PCBs semi-annually until the end of the review period.

Viacom has also agreed to remove the free product and sediment from MW-5 and observe if free product returns.

2.1 Long-term Monitoring Details

1. Sampling of the two perennial springs, the Middle Spring and the Mound Spring, will be done quarterly. for PCBs until the end of the review period. Flow measuring, datalogging weirs are being installed at Middle Spring and Mound Spring to obtain continuous flow data for these two springs. The spring flows will be monitored continuously for one year. At that time the flow data will be reviewed and a decision will be made by the CD parties on extending the
2. Sampling of any other spring onsite that is flowing will be done quarterly for PCBs. For the long-term sampling of these springs, a qualitative and /or quantitative estimate of spring flow will be made, if possible, when the sample is taken.

   Figure 5 shows the Mid-north Spring and North Spring, which are intermittent springs on site and which will be sampled quarterly when they are flowing. Efforts will be made to sample the intermittent springs during times when the intermittent springs would be flowing, such as after significant rainfalls or during wet periods. A flow-measuring weir will be installed at Mid-north Spring to provide manual flow readings.

3. Quarterly low flow PCB sampling of Stout's Creek water will be done at locations immediately upstream and downstream of the site. The upstream sample will be taken at the same location used for the interim monitoring as shown on Figure 5. The downstream sample will be taken just upstream of the West Branch entrance to Stout's Creek. A datalogging gauging station will be located at this location to continuously estimate the creek flow. Specific flow measurements will be recorded at the time the water samples are obtained. These two samples will provide an indication of any significant PCB transport to Stout's Creek from any bank seeps or springs.

   Sampling of the springs and the creek will be done at the same time so that data can be correlated. Temperature and conductivity data will also be recorded for these samples.

4. Annual high flow sampling events of Stout's Creek will be planned for the receding limb of a major spring storm event. Data from the April 1998 storm event shows that the downstream PCB samples are the highest during the receding limb. The same upstream and downstream locations used for low flow monitoring discussed above will be sampled. The flow in the creek will be measured continuously using a datalogger at the gauging station as shown in Figure 5. PCB sampling and flow data logging will also be performed at the Middle Spring and Mound spring during the storm event. Any other onsite springs flowing during the storm event will also be sampled. Estimates of these flows will be made when the water samples are taken.
5. Near the end of the monitoring period, in 2003, fish and sediment will be sampled in Stout's Creek. Fish and sediments will be sampled in the same locations as sampled in 1998.
6. Monitoring wells MW-61 and MW-6D will be sampled for PCB analysis semi-annually. Water elevations, temperature, conductivity, pH and turbidity data will also be measured for these samples. The monitoring well samples will be taken during every other sampling event for spring and stream samples so that data can be correlated.
7. MW-5 will be purged of PCBs and then observed quarterly for one year to detemmine if free product returns. See 2.1.1 and 2.1.2, below for further discussion of MW-5.

2.1.1 MW-5 Purging Procedure

1. Measure depth to water and depth to bottom.
2. Calculate one well volume
3. Using jet pump, remove sediment and water in well.
4. Let well recover and repeat procedure until 5 volumes are purged.
5. All purge material will be discharged into dedicated 5-gallon carboys and disposed of in an approved manner.
6. Allow well to settle overnight and measure depth to bottom.
7. Repeat purge if any measurable sediment remains in well.
8. Allow well to sit undisturbed for a week.
9. Then slowly lower a dedicated 2" bailer to the bottom of the well. Slowly withdraw the bailer and observe the contents. Especially note if any globules of oil or free phase product is evident.
10. If the bailer sample shows no evidence of any free phase product, then commence the quarterly observations of the well a

2.1.2 Quarterly Observation of MW-5

If after one year of quarterly observations of MW-5, no additional free product is observed in the well, then observation will continue on a semi-annual basis. If free product is observed to be accumulating in the well at the end of the first year, Viacom will submit a plan for further assessing the well. If at the end of the base monitoring period no additional free product has accumulated in MW-5, then Viacom will submit a closure and abandonment plan for the well.

3.0 Data Analysis and Reporting

At the end of the five year period, the CD parties will evaluate all the monitoring data and decide if monitoring will cease, continue as is, or continue in a modified form.

4.0 Sample Collection

For creek surface water and springs at non-storm conditions, an unfiltered grab sample will be taken by hand dipping a ~ liter bottle into the main exit point of the spring orifice or centroid of the stream flow as applicable. The samples will be sent for total PCBs and TSS analysis. The PCB analysis will be to a detection level of 0.1 ppb to an approved lab for this project whose procedures will be in accordance with the requirements of "Test Methods for Evaluation of Solid Waste: Physical/Chemical Method" (EPA SW-846, latest edition) analytical method 8082. TSS samples will also be sent to an approved lab and analyzed in accordance with procedures that meet the requirements of EPA 160.1 from EPA 600/4-79-030 latest edition.

During each sample cycle, a duplicate sample and field blank will also be taken. The duplicatewill be a second sample of water taken from one of the sample points. The field blank will be an identical sample bottle filled with Dl water at the site while taking the samples. During barnstorm conditions field parameters of conductivity and temperature will also be measured.

During storm conditions, samples may be taken with an ISCO auto sampler. Each sample will be approximately 500 ml and taken into a glass container in the base of the sampler on an hourly basis until 10 hours after the peak flow and then the frequency will be decreased if determined by the sampling crew to be appropriate. When auto samplers are used to collect stomm samples, the sampler will be iced. The maximum amount of time that a sample can be left in the sampler before it is removed, sealed and refrigerated will be limited to 12to 16 hours.

Well samples will be taken with dedicated tubing and a peristaltic pump following low purge techniques. Field parameters of conductivity and turbidity will be used to detemmine when conditions are stable. Conductivity will be stabilized within 10% and turbidity will be less than 5 NTU and stabilized within 20%.

5.0 Sample Custody Procedures

5.1 Sample Identification System

The "BD" is the site code and refers to Bennett's Dump. The four digits are the sequential number. The sample number will be added to the respective field notebook, sample label, and chain-of- custody form.

5.2 Initiation of Field Custody Procedures

For all samples, Region V chain-of-custody protocols, as described in the UNational Enforcement InvesEgabons Center (NEIC) Policies and Procedures, EPA-330/~DDI-R, Rev. June 1985" (Reference 13), will be followed. Custody procedures are described in Section 5.0 of the QAPjP.

5.3 Field Activity Documentation and Logbook

A field logbook, as discussed in FP-1 of the QAPjP, will be initiated at the start of the Field Sampling Program and maintained to record on site activities. The field logbook is a controlled document that becomes part of the permanent site file. The field logbook will consist of a bound notebook with consecutively numbered pages that cannot be removed. The logbook cover will indicate the following:

• Project name
• Project Geologist's and Field Activities Leader's name
• Sequential book number
• Project start date
• Project end

• Summaries of daily site activities
• Arrival and departure of site visitors
• Arrival and departure of equipment
• Start and completion of sampling activities
• Sample pickup including chain-of-custody form number, carrier, date, and time
• Equipment calibration and repair
• Decontamination procedures used
• Health and safety issues
• Levels of personal protection

At the beginning of each entry, the date, start bme, weather conditions, and names of the site personnel and visitors present will be recorded. Each page will be initialed. Enb ies will be recorded in ink, and no erasures are pemmitted. Incorrect entries will be stricken with a single line, initialed and dated.

Section 5.1.2 and FP-1 of the QAPjP on Field Logbook Record Keeping will be adhered to. In addition to field logbooks, data sheets to record specific field parameters will also be used. Copies of the data sheets will be included with all data transmittals and originals will be film in pemmanent project records.

5.4 Sample Shipment and Transfer of Custody

6.0 Sample Container Preparation, Sample Preservation, and Maximum Holding Time

6.1 Bottle Requirements

The contaminant-free sample containers (bottles) used for this sampling effort will be prepared according to the procedures specified in ~USEPASpecifications and Guidance for Obtaining Contaminant-Free Sample Containers, December, 1992r, (Reference 12). Bottles used for the sampling activity will not contain target organic and inorganic contaminants exceeding the level specified in the above mentioned document. Specifications for the bottles will be verified by checking the supplier's certified statement and analytical results for each bottle lot, and will be documented on a continuing basis. This data will be maintained in the project evidence file and will be available, if requested, for review by the government parties.

In addition, the data for field blanks, etc., will be monitored for contamination per Section 3.1 of the QAPjP. Corrective actions will be taken as soon as a problem is identified and include discontinuing the use of a specific bottle lot, contacffng the bottle supplier(s) for retesting the representative bottle from a suspect lot, resampling the suspected samples, and validating the data, taking into account that the contaminants could be introduced by the laboratory (i.e., common lab solvents, sample handling artifacts, etc.). If a bottle QC problem occurs, a determination of whether the bottles and data are still usable will be made.

Amber glass bottles with tenon liners will be used for PCB water samples.

6.2 Sample Preservation and Holding Time

6.3 Sample Handling, Packaging, and Shipment

7.0 Decontamination Procedures

The following equipment will be on site:

• Distilled water
• 10 percent by volume isopropanol and water solution
• Non-phosphate detergent
• Scrub brushes; squirt bottles for alcohol and water; plastic bags and sheets
• Drums or carboysfor disposal of waste

7.1 Sampling Equipment Decontamination

1. Wash contaminated equipment contact surfaces with nonphosphate detergent.
2. Rinse with tap water.
3. Spray rinse with 10 percent alcohol solution.
4. Rinse with distilled water and air dry.

7.2 Sample Bottle Decontamination

1. Wipe container with a paper towel dampened with potable water.

2. Dispose of used paper towels as specified in the Section 9.

8.0 Preventive Maintenance Procedure and Schedule

9.0 Investigation-Derived Waste

9.1 Types of Investigation-Derived Waste