VIACOM - FINAL GROUNDWATER INVESTIGATION …Viacom Inc. 11 Stanwix Street EPA Region 5 Records Ctr....
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Viacom Inc.11 Stanwix Street EPA Region 5 Records Ctr.Pittsburgh, PA 15222-1384
Environmental Affairs 26S313
November 21, 2001
Mr. Thomas Alcamo Ms. Jessica FlissU.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: Final Groundwater Investigation Plan for the Neal's Landfill Site
Attached please find the subject final document. This plan has been revisedaccording to the comments received from the government parties and as discussedat the August 13 and October 18, 2001 meetings.
Viacom is also sending the final revised Long-term Groundwater Monitoring Plan tothe parties under separate cover.
In addition to the monitoring to be done under the long-term plan, Viacom hasdecided to voluntarily undertake the investigation work in this plan to increase theunderstanding of the Neal's Landfill hydrogeology.
The attached investigation plan describes the work Viacom will be performing.
Dorothy M. AlkeDirector, Bloomington ProjectBP:01-0106
cc: John Langley, City of BloomingtonRaj Rajaram, Tetra TechJohn Bassett, Earth TechMike McCann, ViacomRuss Cepko, ViacomJim Patrick, PSARARichard McCandless, PSARARay Taylor, PSARABP File
GROUNDWATER INVESTIGATION PLAN
BLOOMINGTON PROJECTMonroe County, Indiana
Viacom Inc.Bloomington Project
11 Stanwix StreetPittsburgh, PA 15222-1384
Meal's LandfillGroundwater Investigation Plan
TABLE OF CONTENTS
1.0 Introduction 11.1 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 43.3 Investigation of Lateral Flow under the RCRA Cap 5
4.0 Reporting 7
LIST OF TABLES
1. History of Piezometer PZ-01
LIST OF FIGURES
1. As-Built Subsurface Features of the Landfill2. Meal's Landfill Piezometer 01 Data for 20003. Meal's Landfill PZ-01 Summary Graph
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 fromthe previous studies will be assimilated and 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 throughoutthe initial five year monitoring period covered in the LTMP. Annually, theregressions for flow and rain will be updated. Storms monitored during thenext year will be compared with storm events that were monitored during1983-1985 and 1993 to identify historical monitored storm events thatcompare to present day storm events. Conard's Branch flows will becompared between the present day storm event and comparable historicalstorm events to identify changes in peak storm flows.
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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.
To facilitate this effort, aerial photos from the early 1990s will be compared withaerial photos from the late 1990s and post remedy photos. Available 2000 aerialphotos will be used from the Monroe County website. Viacom will also complete anover-flight taking new aerial photos of the area during the fall of 2001. These aerialphotos will be taken after most of the leaves have fallen from the trees to allowbetter visibility of the ground surface. Large changes in land use and drainage willbe noted. This aerial photo analysis will be completed by the end of 2001.
Landowners, other persons knowledgeable about drainage issues and changes inthe area and storm water operators will be consulted. Field surveys of potentialimpact areas will be performed to identify specific features that have changed.
The following data will be sought or will be developed by the end of January 2002:
• USGS data from the overflow springs and the North Spring for 2001• Spring treatment facility inflow records for select periods in 2001 will be
developed.• Flow data from the new Viacom weir installed in Conard's Branch will be
recorded. The new weir is a combination low flow / high flow weir that willallow measurements over the full range of flow under both normal conditionsand storm conditions.
• Available literature will be collected on drainage in the area.
Discussions will be held with the following parties:
• Monroe County Drainage Board members• Field Stone Reservoir operators• Rogers Quarry Operations Personnel
There has been substantial enlargement in the nearby Rogers Quarry operations.Quarry dewatering activities could impact flows at the site. Contact has been madewith Rogers Quarry and discussions initiated regarding current and past groundwater pumping rates from their Bloomington Crushed Stone Company quarry onOard Road.
Initial investigations of the drainage basin indicate that a large retention basin (FieldStone Reservoir) was installed in the Cave Creek watershed. A walk of the CaveCreek Stream 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 not
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show 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.
Records of the opening and closing of the Field Stone Reservoir retention basis for2001 will be requested from the reservoir operators or the Monroe County DrainageBoard. Data from both large and small storms for 2001 will be compared to theavailable historical records. The analysis will be completed by mid-February 2002.
Some continuous stage monitoring may be performed at the sinks of Cave Creek inconjunction with storm event sampling at Meal's Landfill to determine correlationsbetween Cave Creek and the Northwest Spring System.
At this time Viacom is not proposing to perform a more definitive dye trace.However, if this remains the most likely basin change that impacted flows and theissue remains relevant, a new dye trace may be performed.
A determination will be made as to whether the Field Stone Reservoir could accountfor all the observed changes in large storms. Impact of changes made by Viacom indrainage patterns around the landfill will also be estimated to determine if they canaccount for the observed changes for small storms. If the known changes at FieldStone and the landfill can account for the observed changes for both large and smallevents, and the timing of the Field Stone Reservoir closing correlates with observedflow/conductivity patterns at Meal's Landfill, then a new dye test may not be needed.
A decision on whether to conduct a new dye test will be made shortly aftercompletion of the above analysis in time for planning and conducting a new dyetracer test in the spring of 2002.
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 significant areas identified, an initial feasibility estimate to divertadditional groundwater from the Northwest Spring System based on conceptual levelcost 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. Nine storms have been monitored fromApril 7, 2000 through October 2001 (including four storms in 2001).
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Viacom will continue to monitor storms until a significant storm database has beenaccumulated. The storms chosen for monitoring will be biased towards largerevents (greater than 2000 gpm). At least one significant (greater than 5000 gpmpeak flows) storm event will be monitored at Conard's Branch in the spring and thefall.
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. Thiswill 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.
If sample results are obtained below the detection limit (BDL) at the proposeddetection limit of 0.3 ppb for storm samples, two 500 ml sample bottles, instead ofone, will be filled sequentially at each sample time. The larger sample quantity willallow lower detection limits to be reached.
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.
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After the piezometers were installed, only PZ-01 collected an appreciable amount ofwater. PZ-01 was placed near the locations of the old PZs-60/61. PZ-03 wasreported to have two to three inches of water in the bottom. The others were dry.Consequently, investigation centered on PZ-01 to determine whether this water hadpreviously infiltrated and was trapped, or if there was active groundwater flowingthere.
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 sensorpreventing 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 3 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.
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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. Manualmeasurements of water level in the piezometer will be made twice a month, whenthe datalogger data is downloaded, to verify the calibration of the piezometer.
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 aplan 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.
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.
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Based on the data evaluation and conclusions, Viacom may recommend additionalinvestigation tasks. Therefore, a "phased" investigation of the groundwaterconditions at Neal's Landfill may be performed by Viacom.
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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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Table 1History of Piezometer PZ-01
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
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Figure 2Neals Landfill Piezometer 01 Data for 2000
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
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