List of Tables

• Table 1 Monitoring Well Construction Details- Winston Thomas Facility
• Table 2 Elevations - Winston Thomas Facility
• Table 3 Condition of Existing Monitoring Wells- Winston Thomas Wastewater Treatment Plant
• Table 4 Groundwater Analytical Results - Winston Thomas Facility
• Table 5 Groundwater Sample Results, Field Parameters and Low-Flow Purge Measurements - Winston Thomas Wastewater Treatment Plant
• Table 6 Winston Thomas Area - Clear Creek Water Sample Results
• Table 7 Winston Thomas Outfall Water Samples
• Table 8 Winston Thomas Springs- PCB Sample Results
• Table 9 Winston Thomas Tertiary Lagoon Spring, Southeast Sump and Outfall Sampling by Viacom
• Table 10 Winston Thomas Site - Clear Creek Sediment Samples
• Table 11 Summary of Nonsplit Samples Collected

List of Figures

• Figure 1 Site Location Map
• Figure 2 Location of Surface/Groundwater Monitoring Stations
• Figure 3 Portion of a CBU GIS Topographic Map
• Figure 4 Topographic Map of Lagoon Area, Winston Thomas Site

Introduction

1.1 Site Background

The Winston Thomas site (WT) is owned by the City of Bloomington and was operated as the main sewage treatment plant for the city from 1933 to 1982. PCBs were discharged to the facility by the fommer Westinghouse capacitor plant from 1958 to 1978. The discharge ceased when the Westinghouse plant stopped using PCBs and the sewer lines discharging from the Westinghouse plant were cleaned. The WT sewage plant was shutdown in 1982. After shutdown, the City of Bloomington maintained the plant process units in a holding mode (units full of water and sludge) awaiting remedial efforts for PCB contamination. The primary source of contamination at the site was the stored water and sludges in the process units.

In 1985, a consent decree was agreed to by Viacom (fommerly CBS and Westinghouse), the City, State, Monroe County and EPA (collectively known as the parties) that addressed the remediation of various sites including the WT site. The remedy called for closure and removal of PCB contaminated materials from all contaminated site process units and from underlying soils. Along with the removal activities, the consent decree also required long term Groundwater monitoring and the provision of alternate drinking water to any resident with a contaminated drinking water well within a 5000-foot radius of the site boundary.

In 1987, a number of interim remedial measures were undertaken in accordance with the consent decree. These included removal of sediments from Clear Creek, maintaining existing warning signs and security fencing around the site and additional pumping capacity to maintain the freeboard in the tertiary lagoon. An interim storage facility for temporary storage of materials removed from several streams and landfills in the area was also constructed on the site.

In 1997, under a separate administrative order on consent entered into between EPA and Viacom, soils and sludges were removed on the west bank of Clear Creek in an area that received contaminated sludges. In 1997, the parties agreed to modify the original consent decree remedy for the site digesters and sludge drying beds and Viacom began cleanup. In 1998, the parties agreed to modify the consent decree remedy for the trickling filter, abandoned lagoons and the tertiary lagoons.

Removal activities were substantial and were concluded in 1999. They included removal and washing of all stone from the trickling filter, removal of water and sludge from the digesters, removal of sludge from the drying beds, removal of water and sludge from the tertiary lagoon, and removal of sludge from the abandoned lagoon area. All areas where sludges were removed included removal of underlying soils if they were contaminated above the agreed upon cleanup requirements for each unit. In addition to the process unit cleanup, a number of areas where contaminated sludge had been historically disposed of, on the grounds of the site were also cleaned. The removal actions are summarized in several final reports. References 1 through 5.

Viacom proposes this plan for long term Groundwater monitoring as the final remedial component of work for the site.

1.2. Site Location

1.3 Summary of Site Conditions

Contaminated materials were removed from the site as set forth in requirements associated with the various cleanup measures described in Section 1.1. Most of the process unit shells remain and are gradually being or have been filled by the City of Bloomington with soils and construction debris. The site is currently not occupied by any permanent workforce or residents. The City of Bloomington is maintaining it in its current inactive condition. In discussions with the City, there have been several potential long-temm uses proposed for the site including light industrial or commercial use. The City of Bloomington, State of Indiana and EPA are to establish the appropriate deed restrictions for the site. The site will likely remain inactive for at least the next few years except for the presence of city workers dumping construction debris on various parts of the site as fill material.

1.4 Geology and Hydrogeology

The site geology and hydrogeology have been studied and summarized previously. See Reference 6 for the most complete summary. A brief review of the major findings is included here for convenience.

The site is located in the Mitchell Plain physiographic region, a low plateau developed on limestones of the Mississippian Blue River and Sanders Group. The topography of the site varies from nearly level to moderately sloping. Steep slopes occur on the berms of the former tertiary lagoon. The geology of the site consists of unconsolidated materials underlain by Mississippian Age limestone interbedded with shale and siltstone. The unconsolidated material at the WT Facility consists of fill materials and soil. The predominant soil present throughout the site is a red/brown/yellow/gray silty clay and clayey silt that ranges in thickness from 2.5 to 9 feet. Sand and gravel associated with the flood plain and streambed deposits of Clear Creek and the former channel of Clear Creek, respectively, were also encountered at some locations.

There are three types of fill materials at the site:

• General fill placed at the site during the various periods of original plant construction and expansion
• Soil backfill placed during remedial efforts in 1997-1999
• Construction debris fill placed by the City of Bloomington to fill process unit shells after remediation

The general fill, ranging in thickness from approximately 0.9 to 10 feet, consists of clay and silt mixed with asphalt, ash, rocks, concrete, gravel, nails, and roots. This fill was placed during construction of the tertiary lagoon bottom and berms in the mid 1960s. The tertiary lagoon berm consists of silty clay. Backfill placed during remediation is a silty clay. Backfill during remediation was placed in areas of the tertiary lagoon, abandoned lagoons, drying beds and on the west side of Clear Creek. Construction debris fill being placed by the City appears to be mostly road construction soil/rock and other general fill materials.

The bedrock units encountered at the site are the Harrodsburg Limestone and the Ramp Creek Formations of the Sanders Group underlain by the Edwardsville Formation of the Borden Group. During site investigations, the contact between the Harrodsburg Limestone and the Ramp Creek Formation could not be detemmined; therefore these two stratigraphic units are discussed as one unit. This unit is primarily a group of interbedded gray limestone and shale that ranges in thickness from 22 to 36 feet. A few fracture zones were found in the limestone bedrock however, most of the fractures were filled with calcite, silica, or mud. Siltstone and dolomite lenses also occur throughout the upper bedrock encountered at the site. The dip of the rocks is expected to be to the west or southwest following the regional trend. The limestone bedrock at this site is prone to karst development and karst features/hydrogeology are present.

The Edwardsville Formation of the Borden Group is a dark gray silty shale with pyrite specks. This unit is considered a hydraulic confining layer below the Harrodsburg Limestone and Ramp Creek Formation. In the Bloomington area, the Borden Group can range from 650 to 700 feet in thickness.

The Groundwater flow system at the site consists of three components including recharge areas, flow areas and discharge areas. Recharge is believed to occur in the topographically higher areas east of the site. Recharge may also have occurred historically from process units that had leaky boundaries such as the tertiary lagoon, digesters, trickling filter, and clarifiers. The flow areas are primarily subsurface in water bearing zones. There appears to be several main discharge areas, a line of springs on the eastern margin of the former tertiary lagoon, a spring along the southwest boundary of the abandoned lagoons and springs along the banks of Clear Creek.

There appears to be two water-bearing zones. One zone is in the overburden. This overburden zone receives water from direct infiltration from the rain, from leakage associated with theformer tertiary lagoon and from Clear Creek backflooding during periodic high stage events. Flow may be concentrated in zones of more pemmeable overburden and/or at the top of rock in fractures and low spots. It discharges to Clear Creek and possibly the underlying upper bedrock zone. Fillipi and Krothe (Reference 9) studied the flow in the unconsolidated deposits immediately adjacent to Clear Creek and detemmined that flow was into the creek during low flow and out of the creek into bank storage during high flow periods.

The second water-bearing zone is in the upper portion of the bedrock, the Harrodsburg Limestone/Ramp Creek Formation. This zone receives water from the overburden bow in the form of diffuse infiltration and concentrated swallet flow (sinks) and from subsurface areas hydraulically upgradient.

Since this zone is developed in ancient limestone, the flow in this zone is most likely concentrated in conduits. In karst, the interpretation of well water levels and well contaminant data is confounded by conduit flow. Beneath the site, groundwater in the bedrock is believed to flow predominantly in bedding planes, fractures, and solution enlarged joints. While the overall direction of karst groundwater in conduits will typically follow a regional trend (which can usually be discerned by well water levels) the specific direction at any one point can be highly variable and influenced by micro-stratigraphic features such as fractures, compositional changes, sinks, and site process units. Interbedded shale lenses are also important as perching layers.

The flow direction in the upper bedrock zone was evaluated with monitoring wells and appears to be to the southwest following the regional trend of flow in Clear Creek. It appears that this zone discharges to Clear Creek during low flow periods. Some reversal of flow (backflooding) may occur during periodic high stage events. Additionally, recharge in multiple directions could have occurred from leaking process units such as the tertiary lagoon when these units were filled with water.

1.5 Surface Water Features

The site is located within the north-south trending valley of Clear Creek. Clear Creek flows to the south along the western edge of the site. Clear Creek is a stream, which flows on limestone/shale bedrock. It appears that it serves as the Groundwater and surface discharge point for the site area as well as the entire southern portion of the City of Bloomington. Prior to construction of the tertiary lagoon in 1967, Clear Creek was rerouted to its present location from an area located beneath the former tertiary lagoon.

There are four stormwater and/or surface water drains that discharge to Clear Creek in the immediate vicinity of the site. These are:

• A small stream like channel just north of the northern berm of the former tertiary lagoon. This channel appears to take storm water and surface water and possibly some resurging Groundwater from areas to the north and east of the site.
• A large 48 inch concrete culvert which nuns under the fommer tertiary lagoon. This culvert is located about 300 feet north of the southern berm of the lagoon (outfall is marked item 9 on Figure 2) and carries storm water from the commercial area to the east of the site.
• A culvert installed at the southwest comer of the former tertiary lagoon (outfall is marked item 11 on Figure 2). This culvert drains excess water from the fommer tertiary lagoon.
• A small surface channel running east-west along the southern boundary of the abandoned lagoon area and between the fommer sludge drying beds (outfall for this channel is marked item 7 on Figure 2). This channel appears to take some surface Runoff from areas east of the site, some site runoff and some resurging Groundwater from the Abandoned Lagoon Spring. The latter is shown on Figure 2 located between the fommer abandoned lagoon and the digesters.

There are also a number of springs at the site. In the area of the former tertiary lagoon, the eastern boundary of what was the lagoon berm was excavated to below bedrock elevation during initial construction in the mid-1960s. In 1999, the tertiary lagoon was drained and all sludge was removed. This exposed much of the cut into bedrock in the eastern bemm area. This uncovered a number of springs visible along the old excavation face. These springs are in the Harrodsburg/Ramp Creek Formation and appear to be perched on a shale bed. These springs also appeared to be located along solutionally enlarged joints in the limestone as would be expected in a karst aquifer. The springs along the eastern bemm of the fommer tertiary lagoon area were temporarily sumped and pumped to a sanitary sewer connection during and after site remediation. Six springs that discharged into the sumps along the eastern berm of the romper tertiary lagoon were identified by CBU during a reconnaissance in June 2000. Sampling of these springs by CBU has shown them to have acceptable quality for direct discharge (Reference 14). IDEMhassince approved direct discharge to Clear Creek so this water is no longer Bumped and pumped to the sanitary sewer connection. Figure 2 shows the location of the SE sump along the east berm. Figure 4 shows a topographic map of the SE sump and the eastern collection trench. Figures 3 and 4 show the location of these six springs.

There is one other perennial spring at the site. This spring is located on the southern boundary of the former abandoned lagoon area. Figure 2 shows the location on site of this perennial spring. During remediation excavation of the Abandoned Lagoon in 1998 the swampy discharge area for this spring was dugout; the sump collection area was filled with gravel, and piped out to the small surface channel running east-west along the southern boundary of the abandoned lagoon area, which was mentioned above. The sump and pipe run were covered with dirt fill, with the discharge of the pipe exposed to the surface channel.

There are also several wet weather seeps that are sometimes visible flowing along the eastern bank of Clear Creek during the receding limb of stomm flows. The flow in these springs are most likely a mixture of storm water that infiltrated small swallets on the site and Clear Creek water that has infiltrated the banks during high flow periods.

1.6 Site Historical Water PCB Data

1.6.1 Groundwater Monitoring Wells

Groundwater monitoring wells in karst terrane are difficult to interpret and of highly questionable use. This is because most of the Groundwater in karst moves in relatively small conduits. Unless the well just happens to intercept one of these conduits, the data from the well cannot be used as an overall indicator of Groundwater quality at the site or the transport of contaminants from the site.

The EPA has recognized this situation. EPA guidance for groundwater monitoring in karst is contained in Groundwater Monitoring in Karst Terranes: Recommended Protocols and Implicit Assumptions. (Reference 7), and FULCRA 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.

At this site the monitored locations are the various process units and land disposal sites where PCBs were located. Given the type of process units present, the tertiary lagoon and the abandoned lagoons are the areas with the greatest potential for Groundwater contamination. This is because these areas/units had PCB sludge in contact with soils/bedrock with limited or no barriers to prevent migration and/or water contact. All the other areas/units on site have concrete barriers and/or engineered drainage systems between the contamination and the Groundwater.

Eleven groundwater-monitoring wells were installed at the site in 1987. The rationale for the location of each well was~provided in previous Westinghouse plans, most notably the Supplemental Hydrogeologic Plan submitted in August 1986 (Reference 10). While some of these wells were located on fracture traces, no follow up dye tracing has been performed to establish the significance of these locations. Viacom and general industry experience is that attempting to locate conduits in karst and intercept them with monitoring wells is an extremely difficult and uncertain task. Short of this effort, the value of monitoring well data both past and future cannot be established.

Tests conducted in these wells included packer tests, gamma ray logging, water level measurement and PCB sampling. Results of these investigations were presented in Data Evaluation: Winston Thomas Facility", dated March 1989 (Reference 6).

The details of the monitoring well construction are shown in Table 1. Well locations are indicated on Figure 2. A summary of the water level measurements and the current conditions of the existing wells are included in Tables 2 and 3. PCB results from these wells are included in Tables 4 and 5. The interpretation of the level data is that the flow is towards the southwest into Clear Creek in the upper bedrock zone.

In evaluating the PCB results, it should be noted that the sample data on 3/2/88 for wells MW-1, MW-2, MW-6, MW-7, and MW-8 are invalid due to cross contamination of the sample pump from a previous sampling event at Bennett's Dump. PCBs were reported in two of the monitoring wells (MW-3S and 7) in each sampling event. Monitoring wells MW-31 and MW~6 had detectable levels of PCBs on two occasions, and monitoring wells MW-1, MW-2, MOO-4, MW-51 and MW-8 each had detectable levels of PCBs on only one occasion. PCBs were not detected in monitoring well MW-3D.

Ten wells at WT were purged and sampled by Viacom in 2001 according to the June 25, 2001 Field Sampling Plan addendum to the QAPP, Volume X)(VII (Reference 12). Table 3 provides the condition of the wells at the time, including the Groundwater elevations. Table 5 lists the PCB sample results as well as the field parameters and low-flow purge measurements for the 2001 monitoring well sampling. Five wells were BDL at a detection limit of 0.1 ppb. The other five wells varied from 0.1 to 0.41 ppb (Reference 13).

The best interpretation of the historical monitoring well PCB data for the site is that in some locations there were detectable PCBs and at others there was not. No overall evaluation of Groundwater quality at the site or of the contribution of PCBs to Clear Creek from Groundwater can be made from the well data.

The exception to the ambiguity of well data may be well 3S. This is the only well onsite located in the overburden of the sands and gravel associated with the former Clear Creek channel which ran through the present location of the former tertiary lagoon. The creek bed under the fomier lagoon was filled with PCB contaminated sludge. This well was most likely in a seepage area for water leaving the tertiary lagoon and flowing into Clear Creek. As such, this well should show PCB contaminated water leaking from the tertiary lagoon while the lagoon was still full of sludge and water. The historical data for this well showed consistent levels of PCBs.

The creek bed under the former tertiary lagoon was sampled and excavated in 1999. Some of the grids in the fommer creek channel were excavated to the top of rock. This area was backfilled with soils from the lagoon/berm area that had less than 25 ppm PCB content. In areas where the excavation went to the top of rock, a foot of clean clay was first placed on top of rock. With the removal of sludges and water from the entire tertiary lagoon in 1999, and the installation of a surface water drain from the lagoon, the amount of Groundwater at the MW 3S location and its utility in monitoring PCB loading to Clear Creek from the former tertiary lagoon are now questionable.

1.6.2 Surface Water

1.6.2.1 Clear Creek

Clear Creek is the main surface water body associated with the site. All known springs and surface water storm drains flow into Clear Creek, as did the discharge from the sewage plant before it was shut down. Surface water samples have been collected in Clear Creek on several occasions over the years. Table 6 presents a summary of all known PCB samples in Clear Creek near the site.

Historically, the PCB loading to Clear Creek from the WT site was much higher prior to the shutdown of the sewage plant in late 1982 (References 11 and 15). For example, note the samples taken at Gordon Pike (immediately downstream of the WT Site) in 1976 through 1978 (41, up to 69 and 23 ppb). This data translates to a mass loading of over 2 pounds per day of PCB to the creek from the plant. After shutdown of the sewage plant, the two downstream samples have been less than 1 and .1 ppb, respectively.

Of note is the data of November 1997. This data, for an upstream and downstream location (Country Club Road and Gordon Pike, respectively), shows that there was still some very low loading of PCBs to Clear Creek from the site area under low flow conditions. Compared to the 1976 data, the PCB loading to the creek from the site area is more than four orders of magnitude lower. However, this data should be viewed with caution since it represents single grab samples that were not integrated over the width of the discharge and which were analyzed from a non-standard PCB method (not an IDEM or EPA approved method) modified to produce a detection limit less than 0.1 ppb. This low detection limit data is viewed as an estimate at best.

A water sample was collected by CBU on September 10, 2000 from Clear Creek at Winslow Road (Country Club Rd), upstream of the WT site. The sample analytical result was non-detect at a detection limit of 0.1 ppb. (Reference 14)

In November 1999 and again in November 2000 Viacom collected water and sediment samples at Country Club road during fish sampling events along Clear Creek. Water samples were 0.019 ppb in 1999 and <0.1 ppb in 2000 (References 17 and 18).

1.6.2.2 Winston Thomas Site Ouffalls

There are a number of outfall pipes and storm surface drainages that discharge to Clear Creek. All but one of these was sampled in 1998 by CBU personnel. These water results are shown on Table 7. Tetra Tech sampled the water from Outlet #7 on August 27,1998. The analytical result was 0.78 ppb as shown in Table 11.

Some of these ouffalls have had no visible flow both during the July 1998 CBU sampling observations and in a wet weather survey/inspection performed by Viacom in February 2000. The ouffalls with no flow in either survey are listed as numbers 4,6 and 10 on Figure 2. The PCB data for the sediments associated with these outfallsare shown on Tables 10 and 11 and are discussed with the Clear Creek sediment data below.

Outfall 11 was constructed in 1999 by Viacom and functions as the stormwater outlet for the fommer tertiary lagoon area. The City of Bloomington sampled this outfall monthly, seven times from July 12, 2000 to January 17, 2001. The results of all seven samples are listed in Table 7 as non-detect for PCBs at a detection limit of 0.1 ppb. (Reference 14).

1.6.2.3 Winston Thomas Perennial Springs

There are a number of perennial springs at the site. These are shown on Figure 2. Note that the springs are on the eastern half of the site and discharge to Clear Creek via surface drainage ways. The perennial springs have been sampled concurrent and subsequent to the remedial activities at the site. Table 8 presents a summary of PCB data for water samples taken by Viacom from April 1999 to'January 2000 in three sumps along the eastern berm of the tertiary lagoon where the east berm site spring water discharges were collected. It also lists the results for the Viacom quarterly samples from the Abandoned Lagoon Spring from October 1998 to September 2001.

CBU performed monthly sampling of the six individual springs that were identified along the tertiary lagoon east bank during their June 2000 reconnaissance. These springs were sampled for six months from August 2000 to January 2001. Table 9 lists the results of all these samples as non-detect at a detection limit of 0.1 ppb (Reference 14).

Based on the Viacom and CBU sampling, the PCB levels in the springs along the east bank of the former tertiary lagoon have decreased to essentially non-detectable levels since the draining and removal of sludge from the former tertiary lagoon. Based on this sampling, IDEM has approved direct discharge of the spring water from the east bank of the former tertiary lagoon to Clear Creek.

The spring within the former abandoned lagoon area is still showing PCB levels slightly above the limit of quantitation. The PCB data appears to show a slight downward trend.

1.6.3 Sediments

Tables 10 and 11 present a summary of the sediment samples taken from Clear Creek over the years. It should be noted that all the sediments from the section of the stream adjacent to and 500 feet downstream of the site were removed by Viacom in 1987. Again, the sediment data shows that Clear Creek sediments were contaminated at a much higher level prior to the shutdown of the WT Plant. Since the shutdown of the sewage plant and the removal of the sediments in Clear Creek along the site, the sediments tested near the detection limit both upstream and downstream of the plant (see samples for 11/91 for just above the tertiary lagoon and Gordon Pike). This indicates that there was not a significant loading of PCBs to the creek from the plant site area.

Between drying beds 2 and 3 there is a low-lying area which has a culvert drain under the road. This culvert, outfall 6 on Figure 2, drains this low area to Clear Creek. Sediments were removed from this area in 1999 and the culvert was replaced. The area was backfilled with trickling filter stone by the City.

1.6.4 Residential Wells

In 1986, Indiana University conducted a residential well user survey. They found 40 wells within a 5000-foot radius of the site boundary in use. Most (29) of these wells were sampled and analyzed for PCBs by Indiana University. The only well sampled within this radius that had detectable PCBs (detection limit of .001 ppb)was north of Country Club Road and west of Clear Creek. This location is considered significantly upgradient of the site. In 1996, this survey was updated and there were found to be 5 private wells still in use within a 5,000-foot radius of the site. AU these wells were sampled for PCBs in 1996. No PCBs were detected (detection limit of .1 ppb). Based on these sampling events, there appears to be no historical contamination of residential wells from the WT site.

2.0 Long-term Monitoring Approach

The consent decree contained provisions and requirements for the long-term groundwater monitoring at this site. It was based on the model of porous media flow and required a suite of onsite and offsite wells. This model is not appropriate for this karst site. These original groundwater-monitoring provisions were deleted from the requirements in the stipulation agreed to by the parties for the removal action at the tertiary lagoon, abandoned lagoon and trickling filter.

The SOW for the site, negotiated in 1998, requires the submittal of a long term Groundwater Monitoring Plan by Viacom. The stated purposes of the long term monitoring plan in the SOW are to detemmine whether groundwater contamination has occurred, and to ensure that no offsite migration of contaminated groundwater is occurring. A review of this monitoring plan and data will occur in December of 2004 at which time the parties will decide if the 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 site is located in karst. As such the most accurate indicator of groundwater conditions will be springs or stream water samples. The existing wells are of highly questionable utility in determining groundwater conditions.
• Clear 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.
• PCB loading to Clear Creek was relatively heavy prior to shutdown of the sewage plant in 1982. This loading was not from site groundwater but from the plant discharge.
• After plant shutdown in 1982 and Clear Creek sediment removal in 1987, the water and sediment samples in Clear Creek indicate a much lower loading of PCBs to Clear Creek from the site with all samples taken downstream of the site near or below detectable limits
• The remediation of the site was substantial. All materials greater than 25 ppm were removed. All contaminated liquids were removed. There is little potential for additional groundwater contamination from the materials left onsite.
• There is or was some historical PCB contamination of site groundwater based on well samples and spring water samples prior to remediation. After remediation, PCB levels in site groundwater, based on spring and stream water samples, are reducing to levels near or below detection.

1.6.4 Residential Wells

In 1986, Indiana University conducted a residential well user survey. They found 40 wells within a 5000-foot radius of the site boundary in use. Most (29) of these wells were sampled and analyzed for PCBs by Indiana University. The only well sampled within this radius that had detectable PCBs (detection limit of .001 ppb)was north of Country Club Road and west of Clear Creek. This location is considered significantly upgradient of the site. In 1996, this survey was updated and there were found to be 5 private wells still in use within a 5,000-foot radius of the site. All these wells were sampled for PCBs in 1996. No PCBs were detected (detection limit of .1 ppb). Based on these sampling events, there appears to be no historical contamination of residential wells from the WT site.

2.0 Long-Term Monitoring Approach

The consent decree contained provisions and requirements for the long-term groundwater monitoring at this site. It was based on the model of porous media flow and required a suite of onsite and offsite wells. This model is not appropriate for this karst site. These original groundwater-monitoring provisions were deleted from the requirements in the stipulation agreed to by the parties for the removal action at the tertiary lagoon, abandoned lagoon and trickling filter.

The SOW for the site, negotiated in 1998, requires the submittal of a long term Groundwater Monitoring Plan by Viacom. The stated purposes of the long term monitoring plan in the SOW are to detemmine whether groundwater contamination has occurred, and to ensure that no offsite migration of contaminated groundwater is occurring. A review of this monitoring plan and data will occur in December of 2004 at which time the parses will decide if the 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 site is located in karst. As such the most accurate indicator of groundwater conditions will be springs or stream water samples. The existing wells are of highly questionable utility in determining groundwater conditions.
• Clear 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.
• PCB loading to Clear Creek was relatively heavy prior to shutdown of the sewage plant in 1982. This loading was not from site groundwater but from the plant discharge.
• After plant shutdown in 1982 and Clear Creek sediment removal in 1987, the water and sediment samples in Clear Creek indicate a much lower loading of PCBs to Clear Creek from the site with all samples taken downstream of the site near or below detectable limits
• The remediation of the site was substantial. All materials greater than 25 ppm were removed. All contaminated liquids were removed. There is little potential for additional groundwater contamination from the materials left onsite.
• There is or was some historical PCB contamination of site groundwater based on well samples and spring water samples prior to remediation. After remediation, PCB levels in site groundwater, based on spring and stream water samples, are reducing to levels near or below detection.

Based on the above, and the SOW goals, the groundwater monitoring plan should be structured to confirm that there is no significant transport of PCBs to Clear Creek and that the PCB levels in site groundwater continue to drop or stay at the existing very low levels.

EPA guidance for karst sites (Reference 7) is to focus on springs for routine groundwater monitoring rather than monitoring wells because of the difficulties interpreting individual well results. This is because the springs 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. At this site, since the groundwater flows into Clear Creek, sampling Clear Creek water itself would be an excellent indicator of overall groundwater quality and PCB transport to the creek.

2.1 Spring Sampling

The perennial springs at the site are along the eastern berm area of the former tertiary lagoon and the abandoned lagoon spring. As discussed in Section 1.6.2 the City has performed extensive sampling of the eastern berm area springs and has shown that they meet IDEM requirements for direct discharge.

Viacom will sample the abandoned lagoon spring semi-annually to monitor the PCB trend of this water until the end of 2004. Half of these sampling events will be performed during high flow periods. The high flow sampling is planned for the spring and the low flow sampling for the fall.

Viacom, CBU and EPA will perform a reconnaissance along the east bank of Clear Creek, adjacent to the WT site, during a stomm event in the spring of 2002. IDEM is to be notified when the reconnaissance is to occur and may choose to participate. The three parties are to select representative flowing springs that will be sampled for PCBs during a 2002 storm event and during subsequent annual spring storm sampling events to the end of 2004.

When sampling springs, a qualitative and /or quantitative estimate (if reasonably practical) of spring flow should be made. TSS and conductivity will also be measured.

2.2 Clear Creek Sampling

To provide an indication of any significant PCB transport to Clear Creek from the myriad bank springs and old ouffalls, low flow monitoring of the creek water upstream and downstream of the site will be done. Semiannual low flow monitoring is proposed at a site immediately upstream of the fommer tertiary lagoon and at Gordon Pike. Additionally, an annual high flow sample upstream and downstream in the creek will be done on the receding limb of a major spring stomm event.

During all creek sampling, the flow in the creek should be estimated. To facilitate flow measurement during high flow events a flow gauging station with a staff gage will be installed at the Gordon Pike location. A rating curve will be developed for this gauging station. During the low flow biannual sampling events a hand held velocity probe will be used to estimate flow in the creek. TSS and conductivity will also be measured during each sampling event

As discussed in Section 4.3, a composite sample will be obtained across the width of the creek using a US DH-81 style sampler in an attempt to obtain a representative sample.

Sampling in the creek will be done until the end of 2004.

If at the end of 2004, PCBs are below the level of quantitation downstream of the site or essentially equal to upstream levels, then monitoring will cease. If PCBs are both above the level of quantitation and higher than the upstream levels, monitoring will continue and an investigation to identify the source of PCBs will be proposed.

2.3 Monitoring Well Sampling

As indicated in Section 1.6.1, the ten wells at WT were purged and sampled by Viacom in 2001 according to the approved June 25, 2001 Field Sampling Plan addendum to the QAPP, Volume XXVII (Reference 12). For this long-term monitoring effort, Viacom has agreed to sample three monitoring wells, MW-3S, 31 and 7, semi-annually until the end of 2004. PCB, level, TSS and conductivity will all be measured. Section 4.1 specifies the low purge method to be used to sample the wells.

Monitoring wells MW-4, ED, 6 and 8 will be abandoned according to Indiana Department of Natural Resources regulations, 312 IAC 13-10-2, as discussed in Section 10.0.

3.0 Data Analysis and Reporting

Once the plan is implemented, long term Groundwater monitoring reports will be provided to the CD parties twice yearly. Viacom will work with the parties to develop a process to provide stage, flow and water level data and water quality data in an electronic format.

Long-term monitoring at WT will be done until the end of the review period, which has been established to be the end of 2004. At the end of the review period, the CD parties will evaluate all the monitoring data and decide if monitoring will cease, continue as is, or continue in a modified fomm. Also, during the base monitoring period, changes to the plan may be proposed and the plan changed with the consent of all the parties.

4.0 Sample Collection

4.1 Monitoring Well Sampling

Monitoring wells will be sampled using the low purge methods with either a peristaltic pump and dedicated tubing or the dedicated submersible pump per the sampling procedures approved in Volume XXVII of the Bloomington QAPjP, Field Sampling Plan for Winstcn Thomas Wells, June 25, 2001 (Reference 12).

The samples will be sent for total PCB and TSS analysis.

In addition to PCBs, field parameters will also be taken at the well at the time of sampling. The field parameters include:

1. Monitoring well Groundwater elevation
2. Water temperature in the well
3. Specific conductivity
4. pH
5. Turbidity

The field parameters will be taken per FP~6 and FP-7 of the QAPjP.

To sample springs, an unfiltered grab sample will be taken by hand dipping a 1 liter bottle into the main exit point of the spring orifice or center of the stream as applicable. The samples will be sent for total PCB and TSS analysis.

4.3 Surface Water Sampling

During the biannual low flow sampling of Clear Creek, an attempt will be made to obtain a composite sample across the width of the creek. Based on previous velocity measurements made at low flow, velocities are not expected to be sufficient to allow an isokinetc sample to be taken (ret: National Field Manual for the Collection of Water-Quality Data TWRI, Book 9 Chapters A1-9 ). Therefore, an equal discharge increment sample will be attempted across the width of the stream. The sample will be taken with a US DH-81 style sampler if the depth of water is sufficient. This type of sampler is used to take a depth-integrated sample. If water depth is not sufficient to allow use of the sampler at low flow, a hand-dipped bottle may be used instead. The key is to take sufficient samples across the stream that represents the same flow increment and then composite equal volumes per flow increment for one composite sample. At the same time the flow will be estimated by using a hand held velocity probe so that a total mass flow of PCB can be calculated.

For the annual receding limb high flow sample, isokinetic conditions may exist. If possible equal width increment sampling will be attempted. Again, the DH-81 sampler will be used and the goal will be to obtain a depth integrated sample of varying volumes based on the flow at the width increment. The subsample from each equal width increment will be composited into one sample for analysis. The downstream gauging station at Gordon Pike will also be used to obtain a flow estimate for the creek.

See Bloomington Project QAPjP Volume 1, Appendix B. Field Procedure FP-4.

4.4 Quality Assurance Sampling

During each sample cycle, a duplicate sample and field blank will also be taken. The duplicate will be a second sample of water taken from one of the sample points. The field blank willbe an identical sample bottle filled with deionized water at the site while taking the samples. During sample collection, enough volume of sample will be obtained and sent to the laboratory to allow MS/MSD analysis to be performed per the approved Bloomington QAPjP.

4.5 Laboratory Analysis of Samples

The PCB analysis of water will be to a detection level of 0.1 ppb at an approved lab for this project whose procedures will be in accordance with the requirements of Test Methods for Evaluation of Solid Waste: PhysicaUChemical 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.

5.0 Sample Custody Procedures

5.1 Sample Identification System

A sequential sample numbering system will be used to identify each sample, including duplicates and blanks. Each sample will be assigned a unique sample number. The field activityleader will maintain a listing of sample identification numbers in the field logbook. Each sample number will consistof six digits as illustrated by the following example: WT0001.

The "WT" is the site code and refers to Winston Thomas. 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 National Enforcement Investinations Center (NEIC) Policies and Procedures, EPA-330/~DDI-R, Rev. June 1985 (Reference 16), 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 pemmanent site file. The field logbook wil 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 Leadefs name
• Sequential book number
• Project start date
• Project end date

It is important that this document be maintained to provide a record of field activities. Daily entries will be made during periods of site activity. Entries will include the following:

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

At the beginning of each entry, the date, start time, weather conditions, and names of the site personnel and visitors present will be recorded. Each page will be initialed. Enbries 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 followed.

In addition entries, field data sheets will be used to record field parameters such as well depths, flows, purge rates, etc. These field data sheets will be included in the official sampling record and project files.

5.4 Sample Shipment and Transfer of Custody

Sample hiandling and shipping procedures and transfer of custody procedures are provided in Section 5.0 and FP-12 of the QAPjP.

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 USEPA Specifications and Guidance for Obtaining Contaminant-Free Sample Containers. December, 1992. Bottles used for the sampling activity will not contain target organic and inorganic contaminants exceeding the level specified in this 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 monitoredfor 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, contacting 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, an educated detemmination of whether the bottles and data are still usable must be made.

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

6.2 Sample Preservation and Holding Time

Samples will be stored on ice to 4øC for preservation. Maximum holding times until extraction will be seven days for water samples. Maximum holding times until analysis of extract from water samples will be forty days.

6.3 Sample Handling, Packaging, and Shipment

Sample Handling and Transporting instructions are listed in Section 8.2.6 of FP~ for Groundwater samples. Sample packing and transportation requirements are described in FP-12.

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 plastic sheets
• Drums or carboys for 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

Sample bodes or containers filled in the field will be decontaminated before being packed for shipment or handled by personnel without demmal hand protection as follows:

1. Wipe container with a paper towel dampened with potable water.
2. Dispose of used paper towels as specified in the Section 9.

Field team members will refer to the field procedures in the QAPjP or the manufacturers' instrument manuals for the appropriate preventive maintenance procedures for the field equipment used at the site. Section 11.0 of the QAPjP discusses Preventive Mair,tenance Procedures.

9.0 Investigation-Derived Waste

The waste material generated during a field investigation is known as Investigation Derived Waste (IDW). At this site, there is a very low potential to generate IDW that has any significant level of contamination on it. This is because all high level contamination has been removed from the site.

9.1 Types of Investigation-Derived Waste

• Personnel protective equipment (PPE). This includes disposable coveralls, gloves, booties, respirator canisters, etc. It is expected that nominal work clothes will be used by samplers with disposable gloves and booties where appropriate.
• Disposable equipment (DE). This includes plastic ground and equipment covers, aluminum foil, Teflon tubing, broken or unused sample containers, sample container boxes, tape, etc.
• Groundwater obtained through well development or well purging.
• Cleaning fluids such as spent solvent and wash water.

9~2 Management of Investigation-Derived Waste

In general there will be a small quantity of IDW generated during the sampling related to this plan. Disposal booties and gloves should not be heavily contaminated and can be disposed of with normal site bash. Any spent hazardous cleaning liquids will be disposed of in accordance with EPA regulations. Waste generated will be properly contained and labeled at the site. The waste will be manifested and shipped to a permitted treatment or disposal facility in accordance with EPA regulations. In the case of purge water, it will be taken to the Neal's Landfill Spring Treatment Facility for beatment and disposal.

10.0 Well Abandonment