•< ipcrfund Records Cente 1

WELCOME ^ J M

PUBLIC HEARING

FOR THE

FINAL SUPERFUND ACTION

AT

BENNINGTON LANDFILL SUPERFUND SITE

AUGUST 11, 1998

SDMS DocID 7027

PURPOSE: The purpose of this meeting is to provide an opportunity for the public to offer formal comments regarding the EPA proposed final Superfund Action for the Bennington Landfill Site.

All comments will be recorded as part of the hearing transcript.

Questions regarding EPA Proposed Action, Site activities and the proposed reclassification of the groundwater by the State of Vermont will be answered after the close of the comment session.

B-4-3 EXTENT OF NTCRA CAP

AND GAS MANAGEMENT

SYSTEM / UNDERDRAW OUTFALL MW-5

LEACHATE COLLECTION SUMP

TREATED LEACHATE INFILTRATION GALLERY

SITE LOCATION

UPGRADIENT GROUNDWATER

ISOLATION TRENCH

g?8_1 NETIAND AREA

LEACHATE TREATMENT

TRANSFER STATION

TRANSFER STATION ACCESS

ROAD B-6-1 :=====: ROAD

ill WETLAND AREA

E£S7a PCB IMPACTED SOIL (EXCAVATED AND Sf^fl PLACED IN LANDFILL UNDER NTCRA CAP).

MONITORING WELL HOUGHTON LANE

600

SCALE. FEET

800

FIGURE 1

NTCRA

COMPONENTS

Site Contacts

EPA Project Manager:

Edward Hathaway U.S. EPA New England ME/VT/CT Superfund Section mailcode: HBT JFK Federal Building Boston, MA 02203 Phone (617) 573-5782 Fax (617) 573-9662

• HATHAWAY.ED@epamail.epa.gov

EPA Community Involvement Coordinator:

Sarah White U.S. EPA New England mailcode: RAA JFK Federal Building Boston, MA 02203 Phone (617) 565-9260 Fax (617) 565-3415 WHITE.SARAH@epamail.epa.gov

VT DEC Project Manager:

John Schmeltzer VTDEC 103 South Main Street/West Building Waterbury, VT 05671-0404 Phone (802) 241-3886 Fax (802) 241-3296

Town of Bennington Contact:

Stuart Kurd • Town Manager

205 South Street P.O. Box 469 Bennington, VT 05201 Phone (802) 447-9700

Site Information

The Administrative Record and Site Reports and Data are available for review at:

Office of Town Manager 205 South Street Bennington, VT Contact: Stuart Kurd

and

EPA Record Center 90 Canal Street Boston, MA 02114 (617)573-5729

Please call Edward Hathaway, Sarah White, John Schmeltzer, or Stuart Kurd if you have any problems obtaining Site information or if you have any questions.

Site Background:

15 Acre Solid Waste Landfill

Currently used as a Transfer Station

Operated from 1969 - 1987

Industrial wastes disposed from 1969 - 1975

Underdrain system installed in 1976

Solid waste closure 1989 - 1990

Placed on Superfund List in 1989

Superfund Investigations 1991-1997

First Cleanup Decision 1994

Construction of First Cleanup began 1997

i Groundwater Component

Draft Rl Report Submitted to EPA

I Initial Human Health and Ecological Risk Assessment 1995

Low Stress Groundwater Sampling 1994-1997

Revised Groundwater Risk Assessment and Addendum 1997/1998

Final Rl Approved by EPA -1997

Summary Assessment Report 1998

I Proposed Plan/Public Comment

Summer 1998

Bennington Landfill Site History

1969-1987 Landfill Operational

1989

• Landfill Closed

Site Listed on NPL

1 1991

EPA and PRPs Agree to Conduct RI/FS

1094

initial bite onaractenzation uompietea

' Project Subdivided to Expedite Remediation

* Source Control Component

Approval Memorandum to Perform EE/CA Signed January 1994

Engineering Evaluation/Cost Analysis (EE/CA) Jury 1994

Fact Sheet/Public Comment Jury-August 1994

Action Memorandum Selecting Non-Time Critical Removal Action (NTCRA)

1994

NTCRA Negotiations July 1995-August 1997

NTCRA Design 1996 -1997

NTCRA Implementation September 1997-1998

( FIGURE 2~")

Results of Superfund Investigations

Landfill is the primary source of groundwater and sediment contamination;

High levels of PCBs were detected in the soils of the drainage pond;

Two groundwater systems at the Site (shallow and deep)

Shallow system is mostly sand and gravel. Shallow system is most contaminated;

Shallow system discharges to wetlands that feed Hewett Brook;

Superfund Investigations (cont'd)

Deep system is both a bedrock and sand and gravel unit. A very tight layer of till separates the two systems.

Low levels of contamination (below drinking water standards) were detected in deep system.

More information regarding the investigations and results can be found in the RI Report portion of the Administrative Record. Previous fact sheets also summarized the results.

EXTENT OF GROUNDWATER CONTAMINATION PLUME.

s= ROAD

ilt WETLAND AREA PCB IMPACTED SOIL (EXCAVATED AND

UffSpl PLACED IN LANDFILL UNDER NTCRA CAP). 4" MONITORING WELL HOUGHTON

^DIRECTION OF GROUNDWATER LANE

FIGURE 3 EXTENT OF GROUNDWATERREMEDIAL INVESTIGATION.

CONTAMINATION PLUME BASED UPON

LOCATION OF GROUNDWATER

CONTAMINATION PLUME

EAST

UPGRADIENT GKUUNUWAltK , AMP.,-,, , ,,Mr,rorsDAiM ISOLATION TRENCH /-LANDFILL UNDERDRAIN

DRAINAGE POND i

POND B

HEWITT BROOK WETLANDS

600

LEGEND

LOCATION OF INFERRED GEOLOGICAL CONTACT

SCALE. FEET •PREDICTED STEADY-STATE PHREATIC SURFACE POST-CAP/TRENCH CONDITION - DAMES it MOORE, HORIZONTAL 1997, GRdUNDWATER FLOW MODEL, BENNINGTON LANDFILL, BENNINGTON. VERMONT, FIGURE 12

NOTE: FIGURE 4ADAPTED FROM PLATE XI, REVISED DRAFT SURFACE. APRIL 1994 REMEDIAL INVESTIGATION REPORT, ESTIMATED BEDROCK AQUIFER POTENTIOMETRIC BENNINGTON LANDFILL SITE, BENNINGTON.

INFERRED GROUNDWATER FLOW DIRECTION VERMONT. McLAREN/HART ENVIRONMENTAL GEOLOGIC CROSS-SECTION AND BR-12 ENGINEERING CORPORATION, WARREN, NEW

MONITORING WELL SCREENED INTERVAL JERSEY, 1995. CONCEPTUAL HYDROGEOLOGIC MODEL

800

PROPOSED FINAL ACTION

No Further Cleanup Action

Long-Term Monitoring

BASIS FOR NO FURTHER ACTION

Previously approved cleanup actions will control the contamination at the Site;

No groundwater contamination is detected outside of the property owned by the Town of Bennington

Deed restrictions and the reclassification of the groundwater will prevent any future use of the contaminated groundwater;

The adverse health effects from the contamination in the groundwater are not of sufficient magnitude to require groundwater extraction.

Previously Approved Cleanup Actions:

EPA selected an initial Site cleanup action in 1994.

This action was called a Non-Time-Critical Removal Action or NTCRA.

A public comment period for the NTCRA was held in July/August 1994.

The NTCRA is being implemented by a group of companies under a legal agreement signed in 1997.

The NTCRA Includes:

Excavation of all soils and sediments with PCB concentrations above 1 part per million or mg/kg. (Completed in May 1998)

Collection and Treatment of leachate that was discharging from the landfill through an underdrain system. The collection system was completed in December 1997. The treated leachate is discharged into the ground through an infiltration gallery. The treated water meets federal and state drinking water standards.

Interception of upgradient groundwater and surface water and diversion of that water around the landfill. The upgradient diversion trench was installed in fall 1997.

Installation of a multi-barrier landfill cap over the waste material. The cap construction began in May 1998 and should be completed by November 1998.

Institutional controls to protect the cap and prevent use of groundwater. A Deed Restriction to prevent future use of the property was completed in July 1998. The reclassification of the groundwater is being evaluated by the VTDEC.

DRAIN NET

40-MIL THICK FLEXIBLE MEMBRANE PRIMARY BARRIER LAYER

GEOCOMPOSITE CLAY SECONDARY BARRIER LAYER

LANDFILL CAP NOT TO SCALE

GAS VENT LAYER

BARRIER LAYERS FIGURE 5 6" 0 PERFORATED

GLACIAL TILL HOPE DRAIN PIPE STONE nil

CROSS GRQUNDWATER INTERCEPTOR TRENCH

SECTIONS NOT TO SCALE

PROPERTY OF VERMONT TOWN Of 8ENNINGTON J

•< }

EXTENT OF ! NTCRA CAP

AN£> GAS MANAGEMENT

SYSTEM

SHE UXXTON

UPGRADIENT GROUNDWATER

5OIATK3N TRENCH

PROPERTY OF TOWN OF BENNINCTON

TRANSFER STATION ACCESS'

ROAD

= ROAD

il* WETLAND AREA nzgra PCB IMPACTED SOU. (EXCAVATED AND E2«21 PLACED IN LANDFILL UNDER NTCRA CAP). —?— TOWN OF BENNINCTON PROPERTY LJNE HWCHTON LANE­prr̂ ri GROUNDWATER RECLASSinCATION ii-̂ d AREA •

RGURE X

GROUNDWATER

RECLASSIFICATION AREA

What is the effect of the NTCRA?

The NTCRA will accomplish the following:

1. The placement of the PCB contaminated soils and sediments under the landfill cap will prevent any future contact with this material.

2. The upgradient diversion system will prevent water from flowing under the landfill and mixing with leachate to become contaminated water.

3. The leachate collection and treatment system will stop the discharge of the contaminated leachate into the groundwater. The contaminated leachate is replaced by clean water.

4. The multi-barrier landfill cap will prevent any future contact with waste material and will significantly reduce the amount of water that enters the landfill waste material to form leachate.

5. The Deed Restrictions and Groundwater Re-Classification will assure that no one will use the contaminated groundwater or damage the cap.

6. The control technologies implemented as part of the NTCRA will substantially improve the groundwater quality downgradient of the landfill.

In addition to the NTCRA, EPA evaluated the need to restore the contaminated groundwater at the Site using extraction and treatment technologies.

This evaluation was performed by assessing the potential adverse health effects or risks from exposure to the contaminated groundwater.

There are three groundwater risk assessments at the Site.

Risk Assessment 1 was completed in 1995. This risk assessment assumed that someone could ingest water up to the edge of the landfill. It was also assumed that someone would ingest 2 liters of water per day for 30 years.

Risk Assessment 2 was completed in June 1997. Changes in groundwater sampling techniques provided a more accurate data base for the assessment of the risk to groundwater. In addition, as a result of the NTCRA it was determined that two wells close to the landfill that will be within the limits of the NTCRA should not be included in the risk assessment.

Risk Assessment 3 was completed in February 1998 to use a recent revision in the calculation of the maximum concentration for each contaminant.

Risk Assessment 1 predicted significant adverse health impacts from ingestion of the groundwater adjacent to the landfill.

Risk Assessments 2 and 3 predicted a much lower level of potential adverse exposure. The final risk assessment (February 1998) predicted a risk of 5 x 10-5 or a potential increased cancer risk of 5 cancer cases per 10,000 exposed individuals and non-cancer hazard quotients of 2.

The level at which EPA believes an action should be taken is when the risk level is greater than 1 x 10-4 or the hazard quotient is above 1. However, risks in the range of 1 x 10-4 to 9 x 10-4 and hazard quotients between 1 and 10 warrant further consideration.

Other Factors Considered:

Groundwater quality will improve as a result of the NTCRA.

The Deed Restrictions and Groundwater Reclassification will effectively prevent any future use of contaminated groundwater.

Based upon the review of all existing data and the cleanup actions previously implemented EPA is Proposing that No Further Action is required for the Bennington Landfill Superfund Site

The Proposal also includes 30 years of monitoring

Estimated costs $1.5 million

Opportunity for Public Comment

Public Comment Period:

July 22, 1998 - August 21, 1998

Public Hearing:

August 11, 1998

How you can make a formal comment. ^^ During the 30-day formal

/& comment period, EPA will y)r accept formal written comments ( and hold a hearing to accept \ formal verbal comments. EPA uses

public comments to improve the cleanup proposal.

To make a formal comment you need only speak during the public hearing on August 11, 1998 or submit a written comment during the comment period.

Federal regulations require EPA to distinguish between "formal" and "informal" comments. While EPA uses your comments throughout site investigation and cleanup, EPA is required to respond to formal comments in writing only. EPA will not respond to your comments during the formal hearing portion of the August 11 information session.

The fact that EPA responds to formal comments in writing only does not mean that EPA can not answer questions. Once the meeting moderator announces that the formal hearing portion of the meeting is closed, EPA can respond to informal questions.

EPA will review the transcript of all formal comments received at the hearing, and all written comments received during the formal comment period, before making a final cleanup decision. EPA will then prepare a written response to the all formal written and oral comments received.

Your formal comment will become part of the official public record. The transcript of comments and EPA's written responses will be issued in a document called a Responsiveness Summary when EPA releases the final cleanup decision.

Where you can go for more detailed information...

AH of the technical and public information publications prepared to date for the Bennington Landfill site are available at the at the following site information repositories:

Bennington Town Office EPA Records Center South Street 90 Canal Street Bennington, VT 05201 Boston, MA 02114 Hours: (617) 573-5729 Monday-Friday Hours: 8:00am-5:00pm Monday-Friday

10:00 am-noon 2:00 pm-5:00 pm

Attention Internet Users! Visit EPA's Superfund web page at: http://www.epa.gov/region01/superfund

Send Comments to:

Edward Hathaway US EPA Mailcode: HBT JFK Federal Building Boston, MA 02203

Groundwater Reclassification

VTDEC Seeks Comments Regarding Reclassification of Groundwater

In order to ensure that no one will withdraw groundwater from the contaminated plume extending from under the landfill to Hewitt Brook, the State of Vermont has taken two institutional initiatives. The first is to consider the ^classification of the contaminated groundwater under the landfill and dowrtgradient to Hewitt Brook to Class IV; that is non-potable. This reclassification means that the groundwater should not be used for drinking or other domestic purposes. It prohibits the State from permitting the use of that water for those purposes under its water supply regulations. Records of this classification will be placed on the State inventory maps, which are available through the Vermont geographic information system ' ' ' " "

;The State of \^ermont has also accepted an iEnyirpnmehtal lEasement graiiiited by i^e Town of Bennington j^r'the projpierj^ contajiniiri^t^^ ;

grouiadwater contaminant pjiilme; This gives the IS t̂e the right to inspect the &&*$ Activities on it th^t jfiiay effect the rethedy for tfcie hazardous: Waste

isjlte, iincjlia^ing c^nstr^ the withdrawal of grouittdwat^r,: ;This >yjin ; provide J^rther ass^ consume groundwater contaminated by the landfill, (See Figure 6 for the area that wiH have both the Environmehtal Easement and the Reclassification to Class IV.

The Vermont Agency of Natural Resources (ANR) invites public comment on its proposal to reclassify the groundwater at the Benningtoh Landfill site. : A ; representative from Vermont ANR will attend the meetings scheduled at the Ben hington Free Library on July 21 and August 11 to explain both the reclassification and the environmental easements, and to answer questions. . Written comments should be sent to Elizabeth Hunt, Groundwater Coordinating Committee, Water Supply Division, Department of Environmental Conservation, 103 South Main Street, Waterbury, Vermont 05671-0403, by August 21, 1998. Phone number for information (802) 241-3409.

GROUNDWATER RESULTS

Location .As Mn Fe Ba VC B PCB (ug/1)

Cleanup Level 50 840 none 1000 2 5 0.5/0.008?

Downgradient ug/1 ug/1 ug/1 ug/1 ug/1 ug/1 ug/1 wells

1-1 <1 795 4035 155 nd nd nd

1-2 <1 77 10,000 201 nd nd nd

B-16 <1 997 36,548 114 nd nd nd

B-17 <1 26 223 27 nd nd nd

Plume wells

2-1 <1 70 393 211 nd nd nd

2-2 13.4 1,422 9,728 1,361 <1 nd 0.3

5-1 21 730 13,133 1339 1.5 1.6 5.2

5-2 16 600 17,473 3,439 6.2 3.5 8.6

B-15 16 1,121 8,385 1,592 2 .8 1 3

Landfill wells

B-14 8 4,146 36,040 1,255 9 19 19

B-6 2 2,338 4,378 973 23.2 5.3 nd

Background wells

8-1 3 739 3,112 280 nd nd nd

7-1 <1 21 375 93 nd nd nd

3-1 <1 <1 <1 31 nd nd nd

B-12 <1 959 239 83 nd nd nd

VC =vinyl chloride, B = benzene