Viacom Inc.1 1 Stanwix StreetPittsburgh, PA 15222-1384

EPA Region 5 RecortsCtr.

Environmental Affairs in257165

July 20, 2001

VIA OVERNIGHT MAIL

VIACOMMr. Thomas Alcamo Ms. Jessica HuxholdU.S. EPA, Region V Indiana Department of Environmental Mgmt.77 West Jackson Boulevard 100 North Senate AvenueChicago, IL 60604 Indianapolis, IN 46204

Mr. Dennis WilliamsonMonroe County Health Department119 West Seventh StreetBloomington, IN 47404

Subject: Groundwater Investigation Plan for the Neal's Landfill Site

Viacom completed remedial activities at the Neal's Landfill site in October 1999.Interim groundwater monitoring was initiated before the remediation and hascontinued to the present. On June 5, 2001, Viacom sent to the parties its proposedLong-term Groundwater Monitoring Plan for review. Interim monitoring will continueuntil the Long-term Groundwater Monitoring Plan is implemented. In addition to themonitoring to be done under the long-term plan, Viacom also plans to do thisinvestigative effort.

The consent decree parties are to engage in negotiations in an attempt to resolveissues over the need for additional remedial measures for groundwater contaminationrelated to Neal's Landfill. Viacom has decided to voluntarily undertake theinvestigation work in this plan to increase the understanding of the Neal's Landfillhydrogeology to support these discussions. The attached investigation plandescribes the work Viacom will be doing.

If you have any comments or questions on this plan, please call Russ Cepko on412-642-2569.

Sincerely yours,

Dorothy M. AlkeDirector, Bloomington ProjectBP:01-0064

Attachment

cc: John Langley, City of BloomingtonRaj Rajaram, Tetra TechJohn Bassett, Earth TechJim Patrick, ViacomMike McCann, ViacomRuss Cepko, ViacomMike Hessling, PSARARichard McCandless, PSARAKen Kilbert, BCCZRay Taylor, PSARABP File

O:\LEA\Bloom\SHAREDIR\BP01-0064.doc

GROUNDWATER INVESTIGATION PLAN

NEAL'S LANDFILL

July 2001

Meal's LandfillGroundwater Investigation Plan

TABLE OF CONTENTS

Page No.

1.0 Introduction 1.1.1 Long-term Groundwater Monitoring Plan 1

2.0 Investigation Plan Objectives 1

3.0 Investigation Plan Details 23.1 Investigation of Peak Storm Flows 23.2 Storm Event Monitoring in Conard's Branch 33.3 Investigation of Lateral Flow under the RCRA Cap 4

4.0 Reporting 6

References .7.

LIST OF TABLES

1. History of Piezometer PZ-01

LIST OF FIGURES

1. As-Built Subsurface Features of the Landfill2. Meal's Landfill PZ-01 Summary Graph

1.0 Introduction

Remedial activities were completed at the Meal's Landfill site in October 1999.Interim groundwater monitoring was initiated before the remediation and hascontinued on a quarterly basis to the present per the requirements of the Statementof Work (SOW) (Reference 1).

The results from the interim monitoring program along with all previous hydrologicand groundwater data were comprehensively analyzed. This analysis is reported inthe draft Long-term Monitoring Plan (Reference 5). The analysis indicates thatvarious hydrogeologic conditions may have changed from pre-remedial conditions.Peak storm flow rates have apparently been attenuated and PCB levels ingroundwater appeared to have risen during the remedy and immediately thereafterand now appear to have decreased to values lower than typical pre-remedy levels.

Viacom has volunteered to undertake an investigation, in addition to those proposedin the Long-term Groundwater Monitoring Plan, to increase understanding of thepresent Meal's Landfill site hydrogeology and to detect further changes from the pre-remedial conditions.

This document describes the plan for that investigation.

1.1 Long-term Groundwater Monitoring Plan

Viacom has proposed a Long-term Groundwater Monitoring Plan (LTMP) for Meal'sLandfill. Elements of the plan include:

• Sampling of the Northwest Spring System, North and South Springs and theOverflow Springs has been proposed to continue to evaluate trends in PCBlevels under normal and storm flow conditions. Monthly low flow and annualstorm monitoring was proposed.

• Continuous monitoring of groundwater elevations under the consolidated wasteto determine the effectiveness of the cap system to prevent wetting of theconsolidated waste. The five shallow piezometers and one phreatic well (5A)were proposed for monitoring.

• Fish and sediment sampling of Conard's Branch and Richland Creek are alsoproposed to determine how PCB content is decreasing. Viacom proposed asingle sampling of the fish and sediments late in the first five year period.

The LTMP contains the data and analysis that is the basis for the additional studiesdetailed below.

2.0 Investigation Plan Objectives

The goal of this investigation plan is to supplement the data gathered in the LTMPfor the first few years after the completion of remediation to aid in evaluating the

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impact of the remedy on water flows and PCB transport at the site. In someinstances, the data gathered as part of this investigation might be the same as thatgathered in the LTMP but the frequency of data gathering may increase. In otherinstances, different data may be collected over a fewer number of years to look atcertain aspects of the remedy.

The specific individual objectives of this investigation are to:

1. Evaluate the causes of the apparent drop in peak storm flows at theNorthwest Spring System and determine if there are other cost effectivemanners to further reduce storm flows.

2. Monitor additional storm flows and PCBs at the Northwest Spring System athigher frequencies than specified in the LTMP to build a more robustdatabase to determine the impact of the remedy on storm flow PCB transport.

3. Determine if lateral flow of perched water under the landfill significantly wetsthe capped consolidated waste. If so, determine the sources and flow paths.

3.0 Investigation Plan Details

3.1 Investigation of Peak Storm Flows

The recent analysis of storm flows versus rain (see Reference 5) shows that therehas been a substantial drop in storm flows for comparable rainfall since the early1990s. The reasons for this are not entirely clear.

To evaluate the causes of the apparent flow drop at the Northwest Spring System,the following steps will be conducted.

• Previous basin studies will be identified. The estimates of the basin size from theprevious studies will be assimilated/reviewed.

• Changes over time in the drainage basin will be identified and their impact onstorm flows estimated.

• Viacom will also be monitoring flow and rain on an hourly basis throughout theinitial five year monitoring period covered in the LTMP. Annually, the regressionsfor flow and rain will be updated.

The final cap and surface water control remedy was designed to route some waterfrom swallets to surface streams and reduce storm flows. It was expected that asmuch as 100 acres of drainage would be diverted from the swallets of the old CattailPond area to the Southwest Seep Branch and that this would reduce storm flows.However, the magnitude of the reduction in storm flows is larger than expected.

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To facilitate this effort, aerial photos from the early 1990s will be compared withaerial photos from the late 1990s and post remedy photos. Large changes in landuse and drainage will be noted. Persons knowledgeable about drainage issues andchanges in the area will be consulted. Field surveys of potential impact areas will beperformed to identify specific features that have changed.

Initial work done in this area indicates that a large retention basin (Field StoneReservoir) was installed in the Cave Creek watershed. A walk of the Cave CreekStream area was done in April 2001 with the government parties. No obviousswallow holes were identified except at the terminus of the stream where the waterwas known to sink. While a dye trace previously performed on this stream did notshow a connection to the site, there is some question about the accuracy of thetrace based on the timing of the dye injection versus flow peaks. Because of thesize of this watershed and the magnitude of the apparent storm flow reductions, thenew retention basin in this watershed remains a prime candidate as a cause ofsignificant flow reductions. At this time Viacom is not proposing to perform a moredefinitive dye trace. However, if this remains the most likely basin change thatimpacted flows and the issue remains relevant, a new dye trace may be performed.

There also has been substantial enlargement in the nearby Rogers Quarryoperations. Quarry dewatering activities could impact flows at the site.

As part of this work any other subbasin areas that may be a significant contributor tothe spring system storm flows will be identified. Field surveys will be conducted inknown drainage ways to identify swallets. The impact of any identified subbasinareas on further reducing storm flows will be estimated again based on drainagearea. If there are any significant areas identified, an initial feasibility estimate basedon conceptual level cost and property issues may be made.

3.2 Storm Event Monitoring in Conard's Branch

The long term monitoring plan contains provisions to monitor one large storm eventper year over the initial five year long term monitoring period. In order to establish abetter database for long term comparisons, Viacom has monitored a number ofstorms since the completion of the remedy. Seven storms have been monitoredfrom April 7, 2000 to February 25, 2001 (including two storms in 2001).

Viacom will continue to monitor storms until a significant storm database has beenaccumulated. As a minimum, Viacom will attempt to monitor five storms in 2001.The storms chosen for monitoring will be biased towards larger events (greater than2000 gpm). At least one significant (greater than 5000 gpm peak flows) storm eventwill be monitored at Conard's Branch in the spring and the fall.

During storm monitoring, flows will be monitored at Conard's Branch. Rainfall will belogged onsite and well EPA 5A level will be continuously logged. Water samples willbe taken in Conard's Branch just upstream of the culvert near South Spring. This

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will be the combined flow of the headwaters of Conard's Branch, the overflowsprings and any overflow from the South Spring collection basin. Water samples willbe taken hourly with an ISCO autosampler as 500-ml grab samples. Samples willbe analyzed for Aroclor PCBs, total suspended solids (TSS) and conductivity.

Peak flows will be measured and regression equations will be generated for flowversus rainfall. Total PCB loading will be calculated during storms to determine ifthe PCB loading is declining overtime.

At the end of 2001, the cumulative data will be reviewed and an additionalassessment made on any further data needs beyond those that will be obtained aspart of the LTMP (one storm event per year).

3.3 Investigation of Lateral Flow under the RCRA Cap

Sampling conducted within the landfill in 1998 (pre-remedy) showed that in somelocations the waste was saturated. To evaluate this, 10 piezometers were installedin 1998 and these piezometers were evaluated prior to and after storm events. Itwas found that piezometers at location PZ-60 and PZ-61 responded with a level riseafter a significant storm event (Reference 6). It was not known if this response wascaused by direct precipitation infiltration through the old interim soil cover or if itrepresented lateral inflow from higher elevations to the east and west of the site.

To determine if lateral inflow would be significant after the final cap was installed,five piezometers were installed within the waste consolidation area under the RCRAsubtitle C cap after the 1999 remedial action. These piezometers were located inareas that were found to contain saturated waste and/or low spots that may be moresusceptible to backflooding. Figure 1 shows the location of the piezometers andcontains a table showing the elevations of the surface and bottoms of the wells. Aspart of the LTMP these piezometers will be monitored to determine if groundwater isreaching the consolidated waste.

When the piezometers were installed, only PZ-01 had appreciable water in it. PZ-01was placed near the locations of the old PZs-60/61. PZ-03 was reported to have2-3 inches of water in the bottom. The others were dry. Consequently, investigationcentered on PZ-01 to determine whether this water had previously infiltrated andwas trapped, or if there was active groundwater flowing there.

Table 1 summarizes the history of PZ-01 measurements and observations. In lateNovember of 1999, 4.92 feet of water was measured in the piezometer. Dataloggingequipment was ordered and in early March 2000 was operating. The logger ranfrom March 7 to October 26, 2000, but water levels were not hand checked duringthis period. Figure 2 shows the logger data for this period. On October 26, 2000,the logger was stopped and the hole was observed to be dry by use of a hand waterlevel probe. The data logger never indicated a dry hole. The data logger was pulledand mud was found to be coating the instrument. This may have clogged the sensor

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preventing accurate measurements or the faulty indication may have been causedby a calibration problem.

It was decided to place an insert in the piezometer so a new Mini-Troll continuouswater level monitor could be installed and the calibration maintained within a sump.On February 20, 2001, measurements were taken for the sump and at 15:35 hoursthe piezometer was dry. When personnel returned the next day 3.28 feet of waterwas discovered in the piezometer and no rain had occurred for a week. Viacom hasno explanation for the discrepancy of the piezometer being dry one day and havingwater the next with no intervening precipitation.

Crest gage indicators were installed in the other four piezometers on April 12, 2001and checked on June 14, 2001. PZ-03 had a depth to bottom of 18.79 feet and adepth to water of 18.52 feet. There was an apparent movement of % inch on thePZ-03 crest gage, while the crest gauges in the other three piezometers showed noapparent movement.

The Mini-Troll was installed in PZ-01 and began logging at 11:00 hours onFebruary 2, 2001. Figure 2 shows the level data from February 21, 2001, to July 3,2001, along with the cumulative rain plot. Based on the PZ-01 response as shownon Figure 3, Viacom does not believe there is significant lateral infiltration under thelandfill. The piezometer level declined from February to early May, as would beexpected since only about four inches of rain fell during that period. However, fromearly May through the heavy storms of early June an additional eight inches of rainfell and yet PZ-01 levels still continued their decline. If laterally infiltrating epikarsticwater were feeding the PZ-01 area, a closer correlation to rainfall and level would beexpected. Note that prior to the remedy the old PZ-60 and PZ-61, which were bothnear the location of the present PZ-01, both showed level increases after stormevents. Evidently the new cap has been effective in eliminating this response.

Viacom proposes to continue to record the level in PZ-01 through one completehydrologic cycle (through the end of June 2002). The other piezometers will alsohave their crest gauges checked at least once a quarter during this time. If anypiezometer is observed to show a significant upward response during this timeperiod, then the potential impact of lateral infiltration must be evaluated.

The evaluation of the impact of any indicated lateral infiltration will be conducted byobserving for any subsidence near the responding piezometer or any unexplainedincrease in PCB levels at the Northwest Spring System. If there is a small increasein the water level of a piezometer but no noticeable subsidence or unexplainedincreases in PCB levels in the spring discharges, then no further investigation of thepotential lateral inflow may be warranted.

If lateral inflow is occurring as evidenced by an increase in a piezometer water leveland this increase is large and/or appears to be causing either subsidence or anincrease in PCB discharges to the springs, then Viacom will formulate and submit a

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plan to investigate the source, extent and rate of the inflow. Some of the followingwould be considered as means to determine the source and flow path of the influentwater:

• Evaluate aerial photos and perform field reconnaissance for fracture tracelocations.

• Perform shallow geophysics with electrical resistivity in areas of likely lateral flow.• Drill shallow piezometers to identify flow paths and water levels.• Review data and determine if fresh water can be re-routed.

The parties will be consulted before finalizing any conclusions on lateral inflowand/or investigation plans.

Well EPA-5A will also be continuously monitored for water level as part of the LTMP.This well has been shown to closely match the response of the Overflow Springs atthe site. This indicates it may be an accurate indication of the water potential of themain conduit under the site. Its level will also indicate any potential for backflooding.In the four inch storm of October 4, 2000, EPA-5A reached a peak elevation of760.62 feet, which is still well below the refusal elevation of 769.95 feet at PZ-01,and shows no groundwater backflooding has occurred.

4.0 Reporting

Interim reports providing raw data will be sent out on a quarterly basis. A final reportwith an analysis of all data will be prepared several months after sufficient data iscollected to support conclusions. It is anticipated that the report will be issued byAugust 2002.

Based on the data evaluation and conclusions, Viacom may recommend additionalinvestigation tasks. Therefore, a "phased" investigation of the groundwaterconditions at Meal's Landfill may be performed by Viacom.

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References

1. Statement of Work (SOW) for the Source Control Remedial Design andRemedial Action at Meal's Landfill, Monroe County, Indiana, March 5, 1999

2. Consent Decree, Civil Action No. IP 83-9-C, USA and the State of Indiana v.Westinghouse Electric Corporation and Monsanto Company, and Civil Action No.IP 81-448-C, The City of Bloomington and Monroe County, Indiana v.Westinghouse Electric Corporation and Monsanto Co., entered August 1985

3. Remedial Design / Remedial Action Work Plan, Neal's Landfill, Monroe County,Indiana, CBS Corp., April 23, 1999

4. Final Report - Remediation of Neal's Landfill, Bloomington, Indiana, CBS Corp,December 2000

5. Draft- Long-term Groundwater Monitoring Plan for Neal's Landfill, BloomingtonProject, Viacom Inc., June 2001

6. Draft Data Evaluation Report for the Remedial Investigation/Feasibility StudySampling and Analysis Activities Neal's Landfill Site Monroe County, Indiana,Tetra Tech EM Inc. May 1998

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Date

9/20/99

11/23/99

12/10/99

2/29/00

3/7/00

10/26/00

11/2/00

2/20/01

2/21/01

3/6/013/20/014/24/015/8/015/23/016/8/01

6/22/017/3/01

Table 1History of Piezometer PZ-01

Event

Piezometer initially installed to refusal and flush mountwith reference point (RP) at 798.39 ft. amsl

first hand measurement DTW - 23.07' (RP 798.39')and DTB - 27.99

hand DTW - 23.08' (RP 798.39')

Troll 4000 installed, hand DTW - 23.69' (RP 798.39')DTB - 27.69', logger not turned on

Troll 4000 turned on to begin logging, hand DTW- 23.75'(RP 798.39') logger was downloaded once per month but

water levels were not hand checked

Troll 4000 turned off, noticed that hole was dry

Troll 4000 removed, noticed that it was stuck in black muck

At 15:35 hrs hand measured as dry, flush mount to beraised to stick-up and new mini-Troll to be installed

At 10:15 hrs hand measured DTW- 26.80' from new RP of800.41' amsl. No rain during intervening hours. DTB - 30.08'

Started mini-troll at 1 1 :00 hrs.

Series of Hand Measurments Taken From RP 800.41' amslhand DTW - 26.75hand DTW - 26.80hand DTW -27.03hand DTW -27. 16hand DTW -27. 15hand DTW - 27.24hand DTW -27. 30hand DTW -27.41

OriginalPI Number

19

J

4t,

SiteNorthing

1 427723.911 427730.<M_1427248.581427169241 427742.22

NeafsL(Instatei

GrinEasting

3078256.123077999.353078110.863078530.393Q7S553.7

ondfill P/ez<1 Fall 1 999 In F,

[lev. AtSurface(ft amsl)79839795.06817.5791.38820.17 j

metersla/Cap)

Efev.TopofInner Casing

(ftamsl)797.9479459816.99790.91819.5

Depth toBottom

27.99/18816.7530.3525J8

ffev. A/Bottom

769.95•780.7180024760.56794.32

3

1

l

£o

C/QPQO

NOTE: IWOR>UTiaH REPRESENTED ON THIS SHEETHAS KEN OBTAINED IT SUITH HEUKCIER 1 ASSOC. IIT« FIELD. MS AND PSARA TECHHXOC1 HAVEPROVIDED ADDITIONAL INFORMATION FIX SWSURFACE

8 womuTioN SUCH AS CAS van PIPINC. TIC DRAM" TEES AND KNDS. t' DRAIN ON TOP OF CAP.

5

2865S«ET

OF

'11/01/99

FIGURE 1

Figure 2Neals Landfill Piezometer 01 Data for 2000

774.10

774.00

773.50

773.401/25/000:00 3/15/000:00 5/4/000:00 6/23/000:00 8/12/000:00 10/1/000:00 11/20/000:00

774.00

773.80

™ 773.60o>o

o773.40

773.20

s

773.00

772.80

Figure 3Neals Landfill PZ-01 Summary Graph

PZ-01 elev rain

18-Feb 4-Mar 18-Mar 1-Apr 15-Apr 29-Apr 13-May 27-May 10-Jun 24-Jun 8-Jul