PB98-963126
                                EPA 541-R98-117
                                March 1999
EPA Superfund
      Record of Decision Amendment:
      Tibbetts Road
      Harrington, NH
      9/28/1998

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           DECLARATION FOR THE AMENDED RECORD OF DECISION

                            Tibbetts Road Superfund Site
                             Barrington, New Hampshire

STATEMENT OF PURPOSE

This decision document amends the selected remedial action for the Tibbetts Road Superfund
Site (Site) located in Barrington, New Hampshire, as outlined in the September 29, 1992 Record
of Decision, and is developed in accordance with the Comprehensive Environmental Response,
Compensation and Liability Act of 1980 (CERCLA), 42 USC $ 9601 et seq.. as amended, and to
the  extent practicable, the National Oil and Hazardous Substances Contingency Plan (NCP), 40
CFR Part 300 et seq.. as amended.  The Director of the Office of Site Remediation and
Restoration has been delegated the authority to approve this Amended Record Of Decision
(ROD).

The State of New Hampshire concurs with the selected remedy.

STATEMENT OF BASIS

This decision is based on the Administrative Record which has been developed in accordance
with Section 113(k) of CERCLA and which is available for public review at the Barrington
Public Library in Barrington, New Hampshire and at the US EPA - Region I Office of Site
Remediation and Restoration Records Center in Boston, Massachusetts.  The Administrative
Record Index (Appendix F to the Amended ROD) identifies each of the items comprising the
Administrative Record upon which the selection of the remedial action is based.

ASSESSMENT OF THE SITE

Actual or threatened releases of hazardous substances from this Site, if not addressed by
implementing the response action selected in this Amended ROD, may present an imminent and
substantial endangennent to the public health or welfare or to the environment.

DESCRIPTION OF THE SELECTED REMEDY

This decision document amends a portion of EPA's 1992 Record of Decision.  The 1992 ROD
called for the extraction and treatment of contaminated ground water from the overburden and
weathered bedrock aquifers beneath the Site using vacuum extraction and pump-and-treat,
respectively.  The vacuum extraction component of the 1992 ROD remedy was implemented
from 1995 through 1997 removing a significant amount of contamination from the subsurface.
At the time the vacuum extraction system was shut down in 1997, contaminant removal rates had
decreased to the point where there was limited progress being made towards achieving the clean
up levels identified in the 1992 ROD. After evaluating the available alternatives, EPA selected
natural bioremediation and phytoremediation as the means of treating the remaining

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contamination found in the overburden and bedrock aquifers. The selected remedy is a
comprehensive approach which addresses all current and potential future risks caused by soil and
groundwater contamination at the Site and will attain clean up levels within a reasonable time
frame.

The selected remedy includes these major components:

1.      attainment of clean up levels in the overburden aquifer through the use natural
       bioremediation and phytoremediation;

2.      attainment of clean up levels in the bedrock aquifer through natural bioremediation;

3.      the development and implementation of a revised environmental monitoring plan tailored
       to assess the progress of bioremediation and phytoremediation;

4.      the possibility of hot spot  remediation using existing vacuum extraction equipment; and

5.      a review of site conditions every five years.

In addition, human health and the environment will continue to be protected through the
expansion and upgrading of the existing alternate water supply, as needed for new users, and
enforcement of a local ordinance restricting ground water use by the Swain's Lake Village Water
District.

DECLARATION

The selected remedy is protective of human health and the environment, attains Federal and State
requirements that are applicable or relevant and appropriate for this remedial action and is cost-
effective.  This remedy utilizes permanent solutions and alternative treatment technology, to the
maximum extent practicable, and  satisfies the statutory preference for remedies that employ
treatment that reduces toxicity, mobility, or volume as a principal element.

As this remedy will result in hazardous substances remaining on-site above health based levels, a
review will be conducted within five years after commencement of remedial action to ensure that
the remedy continues to provide adequate protection of human health and the environment.
Patricia L. Meaney, Director                                          Date
Office of Site Remediation and Restoration
US EPA - Region 1

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 AMENDED RECORD OF DECISION
      US Environmental Protection Agency
              Region I

TIBBETTS ROAD SUPERFUND SITE
       CERCLIS No. NHD989090469

      BARRINGTON, NEW HAMPSHIRE
           September 28, 1998

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             TIBBETTS ROAD SUPERFUND SITE
             AMENDED RECORD OF DECISION

                   TABLE OF CONTENTS
I.    SITE NAME, LOCATION, RATIONALE FOR AMENDMENT & SITE
     DESCRIPTION  	1

II.    SITE HISTORY AND ENFORCEMENT ACTIVITIES	2

III.   COMMUNITY PARTICIPATION	2

IV.   DESCRIPTION OF CHANGES TO THE 1992 ROD	3

V.    SUMMARY OF SITE CHARACTERISTICS	8
     Soil	8
     Air	9
     Surface Water and Sediments	9
     Ground Water	10
         Flow Path 51S to SOS  	11
         Flow Path SOS to 79S  	12
         Flow Path 57S to 69R	13

VI.   SUMMARY OF SITE RISKS	14

VII.  COMPARATIVE ANALYSIS OF THE ORIGINAL REMEDY AND
     AMENDED REMEDY	15
     Overall Protection of Human Health and the Environment	17
     Compliance with Applicable  and Relevant and Appropriate Regulations ..17
     Long-term Effectiveness and Permanence	18
     Reduction of Toxicity, Mobility, and Volume through Treatment  	19
     Short-term Effectiveness	20
     Implementability	20
     Cost 	20
     State Acceptance	22
     Community Acceptance	23

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VIII. THE SELECTED REMEDY	23
     A.    Interim Cleanup Levels	25
     B.    Description of Remedial Components	26

IX.  STATUTORY DETERMINATIONS  	29
     A.    The Selected Remedy is Protective of Human Health and the
           Environment	30
     B.    The Selected Remedy Attains ARARs	31
                Chemical Specific	32
                Location Specific	33
                Action Specific	34
     C.    The Selected Remedial Action is Cost-Effective 	34
     D.    The Selected Remedy Utilizes Permanent Solutions and Alternative
           Treatment or Resource Recovery Technologies to the Maximum
           Extent Practicable	35
     E.    The Selected Remedy Satisfies the Preference for Treatment Which
           Permanently and Significantly reduces the Toxicity, Mobility or
           Volume of the Hazardous Substances as a Principal Element	36

X.   DOCUMENTATION OF NO SIGNIFICANT CHANGES	37

XI.  STATE ROLE	37


LIST OF APPENDICES

APPENDIX A -   Figures and Tables
APPENDIX B -   State of New Hampshire Letter of Concurrence
APPENDIX C -   Applicable and Relevant and Appropriate Requirements
                (ARARs) Analysis
APPENDIX D -   Calculation of Biodegradation  Cleanup Rates, and other
                technical data
APPENDIX E -   Responsiveness Summary
APPENDIX F -   Administrative Record Index

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             TIBBETTS ROAD SUPERFUND SITE
         AMENDED RECORD OF DECISION SUMMARY
                        SEPTEMBER 28,1998


I.     SITE NAME, LOCATION, RATIONALE FOR AMENDMENT &
      SITE DESCRIPTION


SITE NAME: The Tibbetts Road Site (the "Site").


SITE LOCATION: The Site is located in the Town of Bamngton, Strafford County,
New Hampshire, approximately eight miles west of the City of Dover and two miles
northeast of the junction of New Hampshire Route 4 and Hall Road.  The Site is located
on the US Geological Survey map of the Bamngton Quadrangle at longitude 71ฐ2' and
latitude 43ฐ 11". Figure 1, which can be found in Appendix A, provides a map showing
the location of the Site.

RATIONALE FOR AMENDMENT: Based on the data gathered over the past three
years during the testing and full scale operation of the vacuum extraction component of
the remedy described in the 1992 Record of Decision (1992 ROD), EPA has determined
that further implementation of the 1992 ROD would yield very little benefit to furthering
the clean-up of ground water beneath the Site. Three years of operating the full scale
vacuum extraction component of the 1992 ROD remedy has removed more than 800
pounds of contaminants from the subsurface. Contaminant removal rates have reached
an asymptote, declining from a maximum of 3.5 pounds of contaminants per day to
approximately one ounce per day. However, ground water contamination still remains in
both the overburden and bedrock aquifers.  Following further investigation of the Site
and consideration of emerging technologies, EPA believes that phytoremediation and
natural bioremediation will restore ground water to cleanup levels in a time frame similar
to any active ground water remedy. Phytoremediation, or the use of plants for
environmental clean up, will be implemented at the Site through the planting of
approximately 1,400 poplar trees.  The trees will alter the subsurface environment,
thereby slowing and reducing the flow of contaminants away from the Site. Natural
bioremediation will use the native microbes, unaided by any manmade inputs, to destroy
ground water contaminants. The combined effect will be to reduce contaminant
mobility, toxicity and volume and reach cleanup levels set in the 1992 ROD in a
reasonable time frame, approximately fourteen years.

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TIBBETTS ROAD SUPERFUND SITE                                              2
AMENDED RECORD OF DECISION	September 28,1998

SITE DESCRIPTION: The Site is located in a rural residential area. It was the
former residence of the late Alexander Johnson. The property, during much of the 1960's
through 1995, consisted of two acres that were lightly wooded with white pine and birch,
bordered by grasses, and possessing an under story of various shrubs. The surrounding
neighborhood, now on a paved road, has six occupied residential homes within 100 feet
of the Site boundary.  Figure 2 shows an aerial photograph of the Site during the 1985
soil removal operation and also shows the approximate boundaries of the Ground Water
Management Zone within which ground water will be restored.  A more detailed
description of the area and the geology beneath the Site are contained in the 1992 ROD.

II.    SITE HISTORY AND ENFORCEMENT ACTIVITIES

      Details of the Site History and Enforcement Activities are presented in the 1992
ROD. The most significant enforcement activity since the ROD has been the entry of a
Consent Decree. The Consent Decree between EPA, the State, the Potentially
Responsible Party at the Site Ford Motor Company (Ford), and the Swain's Lake Village
Water District (the Water District) was entered on March 20, 1995. Among other items,
Ford agreed under the Consent Decree to conduct the cleanup of the Site as specified in
the ROD. The Water District agreed to operate and maintain an alternate water supply
for affected residences and pass a local ordinance restricting the use of groundwater in
the impacted area.


III.   COMMUNITY PARTICIPATION

      A history of community participation is contained in the  1992 ROD. Since that
time, Ford has kept the neighbors informed of the clean up progress at the Site through
annual on-site meetings, including an on-site cookout in June of 1997.  During
significant construction activities EPA has mailed letters  to the neighbors informing them
of the status of work.

      A Proposed Plan for the changes set forth in this Amended ROD was sent to the
public in June of 1998. The EPA and State held a public hearing and informational
meeting on June 24, 1998. A document, titled "Responsiveness Summary", attached to
this Amended ROD as Appendix E, contains all verbal and written comments regarding
the Proposed Plan and EPA's and the State's response to those comments.

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TIBBETTS ROAD SUPERFUND SITE                                              3
AMENDED RECORD OF DECISION  	   	September 28,1998
IV.   DESCRIPTION OF CHANGES TO THE 1992 ROD

      In the 1992 ROD EPA determined that the following actions needed to be
performed to protect public health and the environment:

      ฎ Prevent contaminated ground water from migrating away from the Site with
      wells or trenches placed to intercept any contaminants.
      
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TIBBETTS ROAD SUPERFUND SITE                                               4
AMENDED RECORD OF DECISION	September 28.1998

      ฎ To provide the Institutional controls required by the 1994 Consent Decree, a
      local ordinance was enacted to prevent the use of ground water at the Site and
      within the impacted area surrounding the Site. That area is depicted as
      Attachment B in the 1994 Consent Decree. The Swain's Lake Village Water
      District enacted the ordinance and complied with the statutory requirements under
      the State's Groundwater Management Zone regulations Env-Ws 410. The
      prohibition on ground water use within the area of drinking water supply service
      of the Swain's Lake Village Water District will be maintained.
      ฉ In the event that additional hot spots are discovered at the Site, vacuum
      extraction may be required at such locations.

The four changes that this Amended ROD makes are:

      ฎ Ground water cleanup levels will be attained in the overburden aquifer through
      the use of natural bioremediation and phytoremediation, not by vacuum
      extraction.
      ฎ Ground water cleanup levels will be attained in the weathered bedrock through
      the reduction of contaminant flux from the overburden by the methods described
      in (D above and by natural bioremediation in the weathered bedrock, not by an
      active pump-and-treat system.
      ฎ Environmental monitoring will be tailored to properly assess natural
      bioremediation and phytoremediation.
      ฎ The treatment of the ground water recovered during implementation of the
      vacuum extraction remedy was by carbon filtration rather than ultraviolet
      oxidation for removal of VOCs and did not require chemical precipitation for
      metals removal.

      The largest apparent physical change at the Site under the Amended ROD will be
to its appearance. During the implementation of the vacuum extraction  component of the
1992 ROD remedy, the Site was paved to enhance to the performance of the vacuum
extraction system. Under the Amended ROD remedy the pavement will be removed, the
Site will be re-planted with trees and its  appearance will revert to a more natural
condition. It is anticipated that phytoremediation and bioremediation will restore the
ground water at the Site at the same rate as the remedy described in the  1992 ROD,
thereby reducing the risk to public health and the environment. A more detailed
description of the four changes from the 1992 ROD to this Amended ROD and the
reason for those changes follows.

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TffiBETTS ROAD SUPERFUND SITE                                               5
AMENDED RECORD OF DECISION	September 28,1998

      O The greatest difference between the 1992 ROD remedy and the remedy
      outlined in the Amended ROD is that the 1992 ROD specified that
      contaminated ground water in the weathered bedrock aquifer would be
      extracted and treated, whereas the remedy described in the Amended ROD
      depends on the use of natural bioremediation to achieve the same clean up
      goals in a similar time frame.

      Contamination of the weathered bedrock is due to the migration of contaminated
ground water from the overburden aquifer. During the design process it became apparent
that removal of ground water from the weathered bedrock aquifer would likely draw
more contaminated ground water down from the overburden aquifer into the weathered
bedrock.  This would make the contamination worse in the weathered bedrock and allow
contaminated ground water to escape from the overburden aquifer. Figure 4 depicts the
condition of the weathered bedrock and anticipated affects of the remedy.

      Dr. John Wilson of EPA's Laboratory in Ada, Oklahoma, also reviewed the
situation and recommended that any pumping of the weathered bedrock be held in
abeyance to allow ongoing, natural bioremediation to have a chance at treating
contaminants.  Dr. Wilson was concerned that by pumping the weathered bedrock there
would be an increase in the hydraulic gradient which in turn would cause contaminants
to flow too quickly through the overburden aquifer.  The rapid movement of
contaminants through the overburden aquifer would limit the time available for bacteria
to adequately treat contaminants.  Ultimately, this would allow additional contaminants
to enter the weathered bedrock aquifer. To a certain extent this process may have been
seen during the recent monitoring of weathered bedrock well 69R. At a pumping rate of
less than a gallon-per-minute the preliminary data from April 1998 appears to show an
increase from previous sampling rounds in contaminant concentrations,  perhaps
validating the  concerns with regards to pumping this aquifer.

      Instead of the remedy outlined in the 1992 ROD, ground water will be monitored
to assess the progress of natural bioremediation and phytoremediation in the overburden
aquifer. Bioremediation occurring in the overburden aquifer will reduce the amount of
contamination that migrates into the weathered bedrock. Phytoremediation will reduce
the rate at which ground water and contaminants flow into the weathered bedrock.
Lastly, natural bioremediation is also occurring in the weathered bedrock which will help
to reduce contaminant concentrations in that aquifer.

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TIBBETTS ROAD SUPERFUND SITE                                               6
AMENDED RECORD OF DECISION	September 28.1998

      0 The 1992 ROD specified that the method of attaining final cleanup levels
      in the overburden aquifer would be achieved through vacuum extraction of
      the contaminants and flushing of the aquifer. The Amended ROD remedy
      will attain cleanup levels through natural bioremediation and
      phytoremediation of the overburden aquifer.

       The 1992 ROD remedy predicted that it would take approximately twenty years
to attain cleanup levels in the overburden aquifer. However, during the three years the
vacuum extraction system was operated, a significant reduction in the amount of
subsurface contamination was achieved. Approximately eight hundred pounds of
hydrocarbon contaminants, of which three hundred pounds were hazardous compounds
listed with cleanup levels in Table 16 of the 1992 ROD and in Table 3 of this Amended
ROD, were extracted, captured, and destroyed during the systems operation. During
peak operation the vacuum extraction system removed 3.5 pounds of contaminants per
day. Operation of the vacuum extraction system in the waning months of 1997 removed
less than one ounce per day.

      The reduction of recovery efficiency led EPA to consider other cleanup
alternatives including bioremediation and phytoremediation. Bioremediation uses native
microbes to degrade contaminants while phytoremediation uses plants to change the
physical properties of the subsurface environment. Modeling of bioremediation indicated
that cleanup levels could be attained at the Site in approximately fourteen years at
removal rates of approximately one ounce per day or greater, a time frame and removal
rate equivalent to that estimated for vacuum extraction.   Phytoremediation, using poplar
trees, will dewater the Site, thereby minimizing the contaminant flow off-site. The trees
also appear to have the ability to breakdown chlorinated compounds such as those found
at the Site although the exact mechanism is not clearly understood. In summary, the
removal efficiency of bioremediation and phytoremediation compares favorably to the
vacuum extraction remedy. The application of bioremediation  and phytoremediation at
the Site is explained in greater detail later on in this  document.

      ฉ Environmental monitoring will need to be altered to  assess the conditions
      in the aquifer.

      Since the 1992 ROD there  has been a gradual decrease  in the frequency and size
of sampling events for ground water and surface water at and/or nearby the Site. This
reduction is the result of the accumulation of sufficient data over the years to identify
important trends related to the implementation of the 1992 ROD.  Since the Amended
ROD will involve new approaches (e.g., natural bioremediation and phytoremediation) it

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TIBBETTS ROAD SUPERFUND SITE                                               7
AMENDED RECORD OF DECISION	September 28,1998

is likely that the sampling frequency and parameters of interest will have to be increased
again. The installation of additional monitoring wells may also be needed to document
the effectiveness of the remedy called for in the Amended ROD.

      Although a change in monitoring may appear to be a point of little consequence,
bioremediation and phytoremediation are new technologies which will need to be
carefully observed.  The degradation kinetics of bioremediation are sensitive to the
presence of electron acceptors such as iron and oxygen, and other nutrients.  The ability
of poplar trees to lower the ground water is proven but the contaminant removal abilities
of these trees is still under investigation. The sensitivity of either of these processes to
other environmental conditions is not well known. Therefore, the monitoring will be
tailored to assess function and progress of the phytoremediation and bioremediation
remedies.

      O This Amended ROD also documents minor process changes made during
      the pilot testing and full-scale operation of the vacuum extraction system.
      The vacuum extraction system  was used from 1995 through 1997 to remove
      contaminated air and ground water from the subsurface.  The 1992 ROD
      specified that volatile organic contaminants (VOCs) in the extracted ground
      water would be destroyed using ultraviolet oxidation and that inorganic
      compounds present in the groundwater would be removed using
      precipitation.  Instead, the treatment system used carbon to remove VOCs
      from the air stream  and ground water. Concentrations of inorganic
      compounds were low enough to not require any treatment with precipitation.
      No contaminants from the air or ground water were released to the
      environment at the Site.

      The 1992 ROD chose precipitation to remove inorganic contaminants (e.g.,
metals) from the extracted ground water, followed by UV-oxidation to destroy VOC
contaminants.  During the pilot test it was determined that the recovery method, vacuum
extraction, caused geochemical changes in the aquifer which removed the metal
contaminants while still in the aquifer.  Also, the introduction of air into the aquifer and
recovery well stripped the VOC contaminants from the ground water.  The result was an
air stream contaminated with VOCs and a stream of extracted ground water that met
EPA's cleanup levels established in the 1992 ROD before any treatment. The vacuum
extraction system rarely recovered more than five gallons  of water per minute during the
remedy and usually recovered three gallons or less.

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TIBBETTS ROAD SUPERFUND SITE                                                8
AMENDED RECORD OF DECISION	September 28.1998

      Therefore, it was only necessary to treat the air stream with vapor-phase granular
activated carhon. This change resulted in the construction of a much smaller treatment
system.  As a precaution, Fords consultant at the Site, G&M filtered the recovered
ground water through carbon prior to discharge to the overburden aquifer.  Changing the
treatment method saved some money but it also allowed the constructed system to fit in
better with the surrounding residential neighborhood. The change yielded the same
results, the capture of contaminants, and no impacts to the public and the environment.

V.    SUMMARY OF SITE CHARACTERISTICS

      This summary of Site characteristics, including soils and the surface, air,
sediments and surface  water, and ground water is derived from the 1990 Remedial
Investigation (RI), the  1993 Treatability Study, and investigations performed by G&M.
The discussions herein will focus on those elements of each characteristic which is
pertinent to this change. A more detailed discussion of each of the media are contained
in the above referenced volumes and the 1992 ROD.

Soil:
      The soils at the  Site consist of a thin (approximately six inches or less), organic-
rich top, underlain by a fifteen to twenty-foot thick layer of mineral soil consisting
primarily of sand with interlayered gravel.  This type of soil is typical of glacial till.
Similar to many tills it is extremely variable in its grain size and type. Variable grain size
causes ground water to flow slowly and makes contaminant recovery difficult and time-
consuming.

      The Site is at the top of a ridge. Therefore, the water table fluctuates on a
seasonal basis. During the spring, the water table may be as little as one foot below the
surface, while in the late summer it may be ten feet below the surface. This oscillation of
the water table is an important means of contaminant transport and distribution in ground
water and soil, because it continually brings contaminated ground water into contact with
different intervals of soil.  This causes some of the contaminants, generally VOCs, to
sorb to the soil particles and to be caught in the unsaturated zone by capillary forces.

      Soil has been the focus of early remedial efforts. Prior to the RI in 1990, 405
cubic yards of VOC and PCB contaminated soil were excavated from two areas and
transported off-site for disposal. Also 3.5 yards of dioxin and PCB contaminated soil
were excavated, treated and disposed. Following the RI, efforts again focused primarily
on removing contamination from the soil. In 1993, a Treatability Study was completed
using vacuum extraction.  The Study proved to be effective and the full-scale system

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TIBBETTS ROAD SUPERFUND SITE                                                9
AMENDED RECORD OF DECISION	September 28.1998

described in the 1992 ROD remedy was implemented at the Site from 1995 through
1997. More detailed information regarding past soil removals is contained in the 1992
ROD and the  1992 Remedial Investigation.

Currently, following removal of the cap for vacuum extraction, the two-acre Site has
been planted with approximately 1,400 four-foot tall poplar trees and a ground cover,
and is therefore well vegetated. The Site is a local topographic high; however, winds are
abated by surrounding trees.  Surface water erosion is also not expected to be a factor in
contaminant migration, as no well-defined channels exist on-site, and drainage is limited
to minor sheet flow to low lying areas. The overall effect is that little erosion is seen in
close proximity to the Site.  Therefore, the migration of any Site contaminants adsorbed
to soil is unlikely. As a further note, contamination appears to be found primarily in the
subsurface environment decreasing the likelihood of off-site transport of contaminated
soils.

Air:
      Due to the extremely low concentrations of volatile contaminants in soil and
surface water, significant concentrations of contaminants in air due to volatilization are
not expected, nor were they observed by air monitoring.  During all field activities for the
RI, air monitoring exhibited fewer than five parts per million (ppm) total organic vapors
above background. Therefore, since no source areas are exposed at the surface, and
since qualitative sampling detected no contaminants above background, it has been
concluded that there are no significant air quality impacts resulting from VOCs on the
Tibbetts Road Site.

Surface Water and Sediments:
      Surface water and sediment samples collected from Swains Lake in 1991 showed
no detectable levels of contaminants from the Site. A summary of surface water and
sediment sampling is contained in the 1992 ROD.

      Swains Lake is the surface water body of primary concern, due to its proximity to
the Site (approximately 900 feet north of the Site) and the fact that it is used as a drinking
water supply for residents in the area.  Surface water and sediment samples were taken
from this lake at a number of locations in  1991. Sampling locations included a point in
the lake closest to the Site (the southern end of the lake), at the Swains Lake Village
Water District treatment plant, and in the Bellamy River. The sampling results from these
locations revealed no detectable contamination. Moreover, the ground water samples
from monitoring wells closest to the lake have not shown the presence of Site

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TIBBETTS ROAD SUPERFUND SITE                                              10
AMENDED RECORD OF DECISION	September 28,1998

contaminants, indicating no quantifiable impact on the water quality of the lake from
contaminants originating at the Site.

Tributaries of both the Oyster and Bellamy Rivers, both class "A" drinking water bodies,
drain the area surrounding the Site and the State of New Hampshire has found them
suitable for fishing, swimming and drinking water use. The Bellamy and Oyster Rivers
are sources of drinking water for municipalities down gradient from the Site.
Sediment/soil transport from the Site to the lake and rivers is not viewed as a significant
pathway, because surficial soil contamination is not significant and the Site is a relatively
flat topographic high with no developed flow pathways in the areas of contamination.

Ground Water:
      The Site sits on a drainage divide as identified in Figure 5.  This creates two
ground water flow directions. The uppermost aquifer which is very heterogeneous,
consists of glacial till, a mix of silt, sand, and gravel otherwise termed "ground moraine".
This upper till and the saturated portions thereof is referred to as the "overburden
aquifer". The overburden aquifer is approximately twenty to thirty feet thick and is
underlain in the general vicinity of the Site by what is called a "lodgment till." The
lodgement till is a compacted silt/clay material resembling a dense concrete. The
lodgement till is practically impervious to ground water and actually serves to limit the
flow of ground water into the underlying bedrock aquifer. The bedrock is fractured and
formerly served as a drinking water aquifer, supplying local residents with drinking
water prior to the identification of Site contamination.

      Ground water in both the overburden and bedrock aquifers on the southwestern
portion of the Site flows to the west into the Oyster River watershed, and on the
northeastern two-thirds of the Site flows to the east into the Bellamy River watershed.

      Ground water contamination at the Site exists in both the overburden and bedrock
aquifers. The overburden aquifer, directly beneath the source areas, is the most heavily
contaminated of the two. Mass balance calculations performed in the 1992 Remedial
Investigation calculated that approximately 570 pounds of VOCs existed in the
overburden aquifer in 1990, while only a little  more than two pounds of VOCs existed in
the weathered bedrock and competent bedrock together. This compares well with the
removal of 300 pounds of chlorinated VOCs (800 pounds of total VOCs, including
chlorinated and non-chlorinated) during the vacuum extraction pilot-test and full-scale
application of the 1992 ROD remedy. Subsequent calculations estimate that
approximately 100 pounds of contaminants remain in the aquifer (Appendix D).

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TIBBETTS ROAD SUPERFUND SITE                                              11
AMENDED RECORD OF DECISION	September 28,1998

      Contaminant migration in the overburden aquifer mirrors the flow of ground
water from the Site. Those contaminants released from the drum storage areas at the Site
entered the uppermost overburden aquifer and migrated horizontally either to the west or
to the northeast, depending upon where the release occurred in relation to the drainage
divide. The horizontal migration of contaminants is a function of the lodgement till
acting as an aquitard, severely restricting vertical flow. Horizontal flow continues to the
west and northeast until the underlying aquitard pinches out This aquitard accounts for
the low concentrations of contaminants in bedrock wells on-site. In areas where the
aquitard thins out, such as northeast of the Site, we see evidence of heavier
contamination of the weathered bedrock. With no aquitard, a component of vertical
migration of contaminants develops, thereby introducing contaminants to the bedrock.
Originally this area was termed the "weathered bedrock"; however, following additional
investigation it was determined that what was thought to be a moderate amount of
weathered bedrock  is actually a localized fracture zone of the bedrock.  Three sets of
wells convey the flow paths and tenor of the contamination at the Site.  Those three  sets
are shown in Figure 6 and discussed further below.

Flow Path 51S to SOS:

      The Western portion of the Site in the vicinity of monitoring well 5 IS was used as
a fuel storage site.  Reportedly the Site owner maintained a large aboveground storage
tank in this area and only a few drums. However, this was the area into which the owner
would mix various solvents with gasoline to fuel his vehicles. Therefore, the spillage
here was long-term and consisted mostly of gasoline components such as benzene,
toluene, ethyl benzene, and xylene. Neither the EPA nor State removed any soil from
this area. Early sampling results indicated the presence of solvents; however, those
compounds have not been found since  1990. The contaminated ground water in this area
flows in a westerly  direction from monitoring well 5 IS to well SOS.

      During vacuum extraction this area was identified as Treatment Cell 3.  One
vacuum extraction well was operated in Cell 3 beginning in 1996 in the immediate
vicinity of well 5 IS.  Because concentrations of fuel component contaminants kept
increasing, G&M conducted a drilling program to find a suspected source area.  High
concentrations of toluene and the other fuel components were found approximately eight
feet away and a new vacuum extraction well was positioned. The new well operated
over the summer of 1997. The sampling results presented in Table 1  of Appendix A,
showed significant  concentrations of all fuel components in both 5 IS and SOS in 1997,
and preliminary data for March 1998 show that concentrations are decreasing
and approaching cleanup levels.

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TIBBETTS ROAD SUPERFUND SITE                                               12
AMENDED RECORD OF DECISION	September 28.1998
      It is clear that arsenic and manganese remain elevated in concentration; however,
this is most likely a product of disequilibrium. As a result of natural degradation
processes, the subsurface environment went from aerobic to anaerobic conditions,
thereby increasing the solubility and mobility of arsenic and manganese.  It is likely that
the concentrations of these compounds in the near future will continue to be in a state of
flux while degradation processes continue. It is expected that as bioremediation
continues to reduce the concentrations of VOCs in this flow path the tendency for the
subsurface environment will be to return to its normal aerobic conditions.  As this
process occurs we believe that the concentrations of arsenic and manganese will also
decrease and approach their respective cleanup levels.  A goal of the remedial efforts
described in this Amended ROD will be to attempt to have this portion of the  aquifer
become aerobic throughout its thickness as soon as possible.

To help monitor the  progress in achieving this goal,  ground water monitoring shall be
directed at assessing normal ground water parameters as well as special parameters
related to the anaerobic/aerobic processes such as measurement of electron acceptors and
oxidation potential.

Flow Path SOS to 79S:

      The area in the southeast portion of the Site nearby ground water monitoring well
SOS was one of the drum storage areas. The EPA and State removed significant
quantities of solvent contaminated soil following the initial spill, which was believed to
have occurred in 1984.  Early ground water sampling results had high concentrations of
solvents (trichloroethylene 1,000 parts per billion) and fuel components (toluene 98,000
parts per billion).  However, the ground water gradient in this area is not as high as that
seen in the vicinity of wells 5 IS and SOS; therefore, the contaminants did not travel as
far. The combined effects of slow ground water velocities, ongoing natural
bioremediation, the soil removal, and approximately three years of vacuum extraction
treatment have acted to clean this flow path to the cleanup standards set in the 1992
ROD.

      During vacuum extraction this area was referred to as  Treatment Cell 2. One
vacuum extraction well operated in Cell 2 beginning in 1996 in the immediate vicinity of
well SOS and was discontinued early in 1997.  Sampling results presented in Table 2 in
Appendix A of the Amended ROD, did not detect any contaminants in 1996.  In 1998 an
adjacent well, 84S, was sampled and showed that all contaminants met cleanup levels
except for arsenic and manganese.

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TIBBETTS ROAD SUPERFUND SITE                                              13
AMENDED RECORD OF DECISION	September 28,1998

      Although arsenic and manganese still exceed their cleanup levels their
concentrations are decreasing over time and appear to be following a trend similar to
what is described above in the flow path 5 IS to SOS section (i.e., as the solvents and fuel
components are reduced and the aquifer returns to aerobic conditions we should see a
decrease in arsenic and manganese concentrations). Arsenic and manganese levels were
measured at this location at 446 and 17,400 parts per  billion, respectively, in 1995 prior
to vacuum extraction.  In 1998,  after a couple of years of soil treatment, the
concentrations of arsenic and manganese had declined to 160 and 2,200 parts per billion,
respectively. Although this relationship needs to be investigated further to establish the
properties of the various species and to document trends, it does show a positive trend.

Flow Path 57S to 69R:

      The central area of the Site in the vicinity of ground water monitoring well 57S
was the largest drum storage area and probably the area of greatest spillage. The EPA
and State did remove significant quantities of solvent contaminated soil following the
initial spill. Early ground water sampling results had high concentrations of solvents
(trichloroethylene 27,000 parts per billion) and fuel components (toluene 140,000 parts
per billion). Ground water and  contaminants flowed  slowly to the northeast in this area.

      During vacuum extraction this area was referred to as Treatment Cell 1.  Cell 1
had five vacuum extraction wells placed around it based on 1992 ROD information and
later information derived from a drilling investigation. The sampling results for this area
appear to show limited progress in achieving the cleanup levels identified in the 1992
ROD. Many of the wells (72S,  70S, 52S, 37D, 53S, and 35R) may not be in the same
direct groundwater flow path, therefore it is difficult to evaluate what any increases or
decreases in contamination in the well means.  Probably the most direct connection is
between 57S to 69R.  There also appears to be a hydraulic connection  in this area to 35R
which may represent the groundwater flow path into the bedrock aquifer from 69R.
Therefore, for brevity in the table the other wells have been omitted. The full table and
the data are contained in Appendix D.

      Along this flow path it is apparent that there are still some residual pockets of
contamination which continue to leach into the aquifer over time. There are obviously a
number of questions which still need to be answered including whether the Amended
ROD remedy will be able to achieve the mandated cleanup levels throughout this entire
area.  The ensuing monitoring program will attempt to answer questions  such as these
and determine whether more active measures such as  the continued application of
vacuum extraction will be necessary.

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TIBBETTS ROAD SUPERFUND SITE                                              14
AMENDED RECORD OF DECISION	September 28.1998

      An additional item of interest for this area is the large declines in
trichloroethylene, benzene, and toluene from 1985 to 1995 and a corresponding increase
in the 1,2 cis-dichloroethylene concentration. The difference was dramatic enough for
EPA to collect samples for other metabolic products, gases, and microcosm studies in
1992 and 1993. These data indicated a significant anaerobic reduction of contaminants
to nonhazardous compounds. It is also interesting to note that during the vacuum
extraction test, when the aquifer became aerobic in this area,  the concentrations of
trichloroethylene and other chlorinated solvents remained relatively constant while
concentrations of 1,2  cis-dichloroethylene declined. This would support the expectation
based on existing literature and studies that under aerobic conditions the degradation of
TCE to 1,2 cis dichloroethylene would cease. Again, this confirms that the ensuing
monitoring program will have to  be tailored to help us better understand the natural
processes taking place beneath the Site.

      A complete discussion of the geology and hydrogeology at the Site is presented in
more detail in Sections 1 and 3 of the 1992 RI.  Much of the data and calculations used
as the basis for this discussion are found in Appendix D of the Amended ROD.

VI.   SUMMARY OF SITE RISKS

      The 1992 ROD summarizes the risks at the Site and additional details are
provided in Appendix I of the Remedial Investigation. Since that time the contaminants
of concern have remained unchanged, although the overall concentrations in ground
water have declined.  Exposure scenarios have not been changed from the 1992 ROD.
The findings of the 1992 ROD were that exposure to Site soils and surface waters in
streams surrounding the Site do not incur an unacceptable risk for children or adults.
The only unacceptable risk to human health that exists is associated with the
consumption of ground water for drinking purposes. However, because drinking water is
supplied to the area through a municipal supply system and a local ordinance places
further restrictions on ground water use, there is not a current risk. A more detailed
accounting of risk at the Site is contained in the 1992 ROD and Remedial Investigation.

      The Ecological Risk Assessment conducted during the Remedial Investigation
measured the potential ecological impacts of contaminants from the Site on surrounding
locations including Swains Lake, the intermittent brook southwest of the Site, and
identified wetland areas to the west and northeast  of the Site.

      The only surface water apparently affected by the Site, as determined by 1990 and
1991 analytical data, was the intermittent stream southwest of the Site. Contaminants of

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TIBBETTS ROAD SUPERFUND SITE                                             15
AMENDED RECORD OF DECISION	       September 28,1998

concern were not detected in the same intermittent stream in 1991, thus reinforcing the
assessment that the intermittent stream is a limited exposure pathway for environmental
receptors. This intermittent stream is the result of ground water in the overburden
aquifer discharging to the surface. The intermittent nature of the stream is likely to result
in limited bioavailability of contaminants and limited exposure pathways. Thus, the
detected surface water and sediment contaminant concentrations are not expected to pose
significant risks to aquatic components of this stream.

      At this Site, hazardous substances have been released into the environment and
response action is necessary to protect public health, welfare and the environment. Actual
or threatened releases of hazardous substances from this Site, if not addressed by
implementing the response action selected in this Amended ROD, may present an
imminent and substantial endangerment to public health, welfare, or the environment.
The potential use of contaminated ground water, as well as the migration of groundwater,
in both the overburden and bedrock aquifers, from the Site poses a potential threat to
public health.


VII.  COMPARATIVE ANALYSIS OF THE ORIGINAL REMEDY
      AND AMENDED REMEDY

      Section 121(b)(l) of CERCLA presents several factors that at a minimum EPA is
required to consider in its assessment of potential remedies.  Building upon these specific
statutory mandates, the National Contingency Plan articulates nine evaluation criteria to
be used in assessing the individual remedies.  The following is a comparison of the 1992
ROD remedy and the Amended ROD remedy, contrasting each remedy's strength and
weakness with respect to the nine evaluation criteria. These criteria are as follows:

      Threshold Criteria

      The two threshold criteria described below must be met in order for a remedy to
      be eligible for selection in accordance with the NCP.

            1.     Overall protection of human health and the environment
                  addresses whether or not a remedy provides adequate protection and
                  describes how risks posed through each pathway are eliminated,
                  reduced or controlled through treatment, engineering controls, or
                  institutional controls.

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TIBBETTS ROAD SUPERFUND SITE                                              16
AMENDED RECORD OF DECISION	September 28,1998

            2.     Compliance with applicable or relevant and appropriate
                  requirements (ARARS) addresses whether or not a remedy will
                  meet all of the ARARs of other Federal and State environmental
                  laws and/or provide grounds for invoking a waiver.
      Primary Balancing Criteria

      The following five criteria are utilized to compare and evaluate the elements of
      one alternative to another that meet the threshold criteria.

            3.     Long-term effectiveness and permanence address the criteria that
                  are utilized to assess remedies for the long-term effectiveness and
                  permanence they afford, along with the degree of certainty that they
                  will prove successful.

            4.     Reduction of toxicity, mobility, or volume through treatment
                  addresses the degree to which remedies employ recycling or
                  treatment that reduces toxicity, mobility, or volume, including how
                  treatment is used to address the principal threats posed by the site.

            5.     Short term effectiveness addresses the period of time needed to
                  achieve protection and any adverse impacts on human health and the
                  environment that may be posed during the construction and
                  implementation period, until cleanup goals are achieved.

            6.     Implementability addresses the technical and administrative
                  feasibility of a remedy, including the availability of materials and
                  services needed to implement a particular option.

            7.     Cost includes estimated capital and Operation Maintenance (O&M)
                  costs, as well as present worth costs.

      Modifying Criteria

      The modifying criteria are used on the final evaluation of remedial alternatives
      generally after EPA has received public comment on the RI/FS and Proposed
      Plan.

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TIBBETTS ROAD SUPERFUND SITE                                               17
AMENDED RECORD OF DECISION	September 28,1998

             8.    State acceptance addresses the State's position and key concerns
                  related to the Amended ROD remedy and the 1992 ROD remedy,
                  and the State's comments on ARARs or the proposed use of waivers.

             9.    Community acceptance addresses the public's general response to
                  the remedy change described  in the Proposed Plan.

      An assessment of 1992 Rod and the Amended ROD remedy according to the nine
criteria and an assessment of the relative performance of each remedy against the nine
criteria follows.

1.    Overall Protection of Human Health and the Environment

      This criterion considers whether a remedy,  as a whole, will protect human health
and the environment.  This includes an assessment of how public health and
environmental risks are properly eliminated, reduced, or controlled through treatment,
engineering controls, or institutional controls.

      There are two primary considerations at this Site: the first is that contaminated
ground water does not discharge to surface water;  and the second is that measures,
including the construction of an alternate water supply and enactment of a local
ordinance restricting the use of ground water, have been taken to prevent residences near
the Site from drinking and using contaminated ground water.  Therefore, there is no
present exposure, nor anticipated future exposure,  to Site contaminants under either
remedy. Because the  time to attain cleanup levels for both remedies is dependent upon
the same physical property of soil (e.g.,desorption rates) the time to attain cleanup levels
and comply with all ARARs,  is the same for both remedies.

      There are currently no exposures to contaminants at the Site to either the public or
the environment. Moreover, both remedies would either eliminate or collect residual
contamination in the ground water.  Therefore, both remedies are equally protective of
human health and the environment.

2.    Compliance with Applicable and Relevant and Appropriate Regulations

      This criterion addresses whether or not a remedy complies with all state and
federal environmental and public health laws and requirements that apply or are relevant
and appropriate to the conditions and remedy at a specific  site. If an Applicable or

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TIBBETTS ROAD SUPERFUND SITE                                              18
AMENDED RECORD OF DECISION	September 28,1998

Relevant and Appropriate Requirement (ARAR) cannot be met, the analysis of a remedy
must provide the grounds for invoking a statutory waiver.

      Both of the remedies will meet the requirements of all ARARs within a reasonable
time frame.  The only ARARs the Site is not in compliance with are the chemical specific
ARARs that pertain to drinking water standards.

      The period over which either of the two remedial alternatives will achieve
compliance with all of the chemical-specific ARARs will be in approximately the same
time frame, 14 years. Volatile organic compounds and arsenic concentrations in the
ground water violate the drinking water standard, if the ground water were to be used as
a drinking water source. Based on the results of ground water modeling, EPA expects
that natural bioremediation and phytoremediation will diminish contaminants at the Site
within a reasonable time frame, therefore there is no need to invoke an ARAR waiver for
ground water cleanup.  Pumping and treating or vacuum extraction of contaminated
ground water will not hasten the cleanup process because the rate at which contaminants
can be leached from the soil by these processes is limited by the same physical properties
(e.g., desorption) which limit the rate at which natural biodegradation can take place. A
more thorough discussion of cleanup times is contained in Section VIII.A., and
Appendix D of this document.

3.    Long-term Effectiveness and Permanence

      This criterion refers to the ability of an alternative to maintain reliable protection
of human health and the environment over time once the remedial action objectives and
cleanup levels have been met.

      Both remedies, once implemented and maintained over a number of years will be
equally effective and permanent. Vacuum extraction would be effective because it
would prevent the migration of contaminants from the Site through the extraction and
treatment of contaminated soil vapors and ground water. The bioremediation and
phytoremediation remedies will be equally effective in preventing the migration of
contaminants by using natural processes (e.g., natural biodegradation and
phytoremediation) to reduce the concentration, toxicity, and mobility of contaminants.
The trees performing the phytoremediation will minimize water infiltration,  lessening
ground water and contaminant flow, and microorganisms involved with biodegradation
will transform the contaminants to nonhazardous materials and permanently reduce the
risk posed to human health and the environment.

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TIBBETTS ROAD SUPERFUND SITE                                               19
AMENDED RECORD OF DECISION	September 28,1998

      Vacuum extraction or pumping and treating will reduce contamination.  However,
there is typically a point reached during treatment where the amount of contamination
removed decreases  because of physical limitations associated with the soil and
contaminants.  Contaminants at that point can not diffuse from the soil and/or water at a
rate sufficient to keep up with the rate the media around them is being removed. As a
result the system is typically shut down and run intermittently to allow contaminants time
to equilibrate with their surroundings. This process can continue over long periods and
still not necessarily achieve the desired cleanup levels as was seen at the Site during the
full-scale application of vacuum extraction. Whereas, if cleanup levels are attained
through natural biodegradation, the remedy will be permanent because equilibrium
conditions will have been maintained throughout the cleanup process.

4.    Reduction of Toxicity. Mobility, and Volume through Treatment

      This criterion contains three measures of the overall performance of a remedy.
The  1986 amendments to the Superfund statute emphasize that, whenever possible, EPA
should select a remedy that uses a treatment process to permanently reduce the level of
toxicity of contaminants at the Site, inhibit or eliminate the spread of contaminants away
from the source of contamination, and reduce the volume, or amount, of contamination at
the Site.

      Both remedies reduce contaminant mobility by reducing the mobility of ground
water. Vacuum extraction uses a cap and active removal of ground water and air to
reduce the water table and ground water flow.  The natural bioremediation and
phytoremediation remedy will lower the water table through the transpiration of plants
and their resultant water uptake. The overall effect of phytoremediation is to have each
plant act as a small  pump to remove ground water from the subsurface.  The transpiration
of ground water will be limited primarily to the growing season. However, the density of
the trees has been designed to reduce the infiltration of ground water to such a degree
that it will likely yield the same effective mass of ground water removed, if not greater
than, that removed by the vacuum extraction system over an annual cycle.

      Toxicity and volume are diminished by both remedies.  Vacuum extraction
removes the contaminants, captures them and then treats them off-site. Natural
bioremediation will reduce the contaminants, trichloroethylene, benzene, toluene, and
others to carbon dioxide and nonhazardous acids and salts on-site.

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TIBBETTS ROAD SUPERFUND SITE                                               2 0
AMENDED RECORD OF DECISION	September 28,1998

5.    Short-term Effectiveness

      This criterion refers to the likelihood of adverse impacts on human health or the
environment that may be posed during the construction and implementation of an
alternative until remedial action objectives and cleanup levels are achieved.

      Short-term effectiveness addresses the risks posed to workers and neighbors
during the construction and implementation of the remedy. In this regard, vacuum
extraction poses some minor risks such as the on-site storage of carbon filters
contaminated with recovered VOCs and truck traffic. Natural bioremediation and
phytoremediation would see occasional traffic to conduct environmental monitoring and
maintenance of the trees.

6.    Implementability

      This criterion refers to the technical and administrative feasibility of a remedy,
including the availability of materials and services needed to implement the alternative.

      Both remedies are implementable with standard technologies that are readily
available. As vacuum extraction was used previously at the  Site, it is easily
implementable because the vacuum unit and extraction wells will be maintained at the
Site for treatment of any hot spots that EPA believes may be warranted in the future.
Phytoremediation is  also easily implementable and has already been implemented with
the planting of approximately 1,400 poplar tress to establish a cover over the Site.
Natural bioremediation was occurring at the Site as early as  1990 and continues today.
Natural bioremediation requires no addition of nutrients or electron acceptors and
therefore has already been implemented at the Site.

7.    Cost

      This criterion includes the capital (up-front) cost of implementing each remedy as
well as the  cost of operating and maintaining that remedy over the long-term.  The costs
described below only reflect those costs that would be incurred henceforth and do not
include previous costs which are substantial.  The cost of the vacuum extraction test and
full-scale implementation was greater than $2 million and included clearing the surface
of the Site,  paving the Site, designing and purchasing the equipment, and operating the
equipment for a period of approximately three years.  Using the present as time zero for
costs, the comparison is surprisingly close. This is because the only practical difference
between the two remedies is the $140,000 difference between planting trees and the

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TIBBETTS ROAD SUPERFUND SITE                                               21
AMENDED RECORD OF DECISION	September 28,1998

electrical operating costs for vacuum extraction. The cost of sampling for the
bioremediation and phytoremediation remedy will most likely be more than that of
vacuum extraction because the technology is still new and less well defined. The
potential exists that following additional research in the field and examination of the
data, these costs could decrease. Because many of the costs are the same, or in the case
of the vacuum extraction system, front loaded, there is no calculation of net present
worth of both capital and operation and maintenance costs as it would yield no practical
information.

      The EPA has developed the costs using reasonable assumptions more fully
outlined in the Feasibility Study and adapted to the situation. The length of time has
been adjusted to account for the time for cleanup, fourteen years, three years of
compliance monitoring and an additional two years as a contingency. The cost for
implementing each remedy and monitoring over 20 years is:

            Vacuum Extraction Remedy:
                  Running the vacuum extraction system: Electricity, maintenance,
                  carbon filters ($4,000 per month x 5 months per year x 14 years),
                  adjusting recovery (new wells)	  $280,000

                  Technical support: additional investigations to assist recovery,
                  environmental monitoring 2x per year,  meetings with State and
                  EPA, evaluation of data and preparation of reports (approximately
                  $30,000 per year x 20 years)	$600,000

                  Site work: cost of samples ($4,000 per  round x 2 per year x 20
                  years), other miscellaneous such as cap maintenance, fence repair,
                  and repair of neighbors property	$200,000
                  TOTAL:                                           $1,080,000

            Natural Bioremediation & Phytoremediation:
                  Operating and maintaining the trees: Inspections, insect control,
                  culling ($2,000 per year x 20 years)  	$40,000

                  Technical support: additional investigations, environmental
                  monitoring 3x per year, meetings with  State and EPA, evaluation of
                  data and preparation of reports (approximately $30,000 per year x
                  20 years)	$600,000

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TIBBETTS ROAD SUPERFUND SITE                                              2 2
AMENDED RECORD OF DECISION	September 28,1998

                  Site work: cost of samples ($5,000 per round x 3 per year x 20
                  years), other miscellaneous such as fence repair and repair of
                  neighbors property	$300,000
                  TOTAL:                                            $940,000

CONCLUSION AFTER ANALYSIS OF SEVEN OF THE CRITERIA

      An analysis of the data gathered over the three years of conducting the vacuum
extraction component of the 1992 ROD remedy led EPA to select natural bioremediation
and phytoremediation for presentation to the public as EPA's proposed change to the
1992 ROD Remedy during the public participation process.  The EPA selected this
remedy because under the natural bioremediation and phytoremediation remedy, public
health and the environment continue to be protected while doing so in a more cost-
effective manner. An alternate public drinking water supply has already been provided
to nearby residences, eliminating the greatest potential risk of exposure for the public.  In
addition, a local ordinance further restricting the use of ground water at and nearby the
Site has been enacted by the Swain's Lake Village Water District. Ground water
modeling indicates that cleanup levels and ARARs will be met within a reasonable time
frame using natural bioremediation and phytoremediation. Due to the physical properties
of the soils and chemicals found at the Site there is presently no active remedy which will
restore  the aquifer in a time frame faster than what can be achieved using natural
bioremediation and phytoremediation. Because of these factors, the Amended ROD
remedy will have minimal impact on cleanup times, will make the remedy less costly, and
have greater public acceptance.

8.    State Acceptance

      This criterion addresses whether, based on its review of the data derived from the
Site and the Proposed Plan, the State concurs with, opposes, or has no comment on the
remedy change EPA has selected for the Site.

      The State has participated in discussions related to the proposed remedy change
and has indicated its support for the use of bioremediation and phytoremediation at the
Site. In addition, the State has also had an opportunity to review the technical data
supporting this change. The New Hampshire Department of Environmental Services has
provided EPA with a letter of concurrence with the remedy change. This letter is
attached as Appendix B.

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TIBBETTS ROAD SUPERFUND SITE                                              2 3
AMENDED RECORD OF DECISION	September 28.1998
9.    Community Acceptance

      This criterion addresses whether the public concurs with EPA's proposed remedy
change.  Community acceptance of this cleanup proposal was evaluated based on
comments received at the public hearing.

      All of the residents and neighbors nearby the Site appeared to support natural
bioremediation and phytoremediation at the public meeting held to discuss the change.
The one written and oral comment received during the public comment period, which is
included as part of the Responsiveness Summary in Appendix E to this document, had to
do with removing the fence at the property. The front fence has since been removed to
address the concern of the nearby resident.

VHI. THE SELECTED REMEDY

      Natural bioremediation and phytoremediation are selected as the remedy in this
Amended ROD based on the following findings:

                  Contaminants in the soil and ground water are capable of being
                  effectively remediated by natural bioremediation and
                  phytoremediation.

                  Although transformation products will be formed, none are more
                  hazardous than the parent compound.

                  The nature and distribution of sources of contamination have been
                  adequately reduced by vacuum extraction over the previous three
                  years and will be controlled by the natural  bioremediation and
                  phytoremediation remedies.

                  The contaminated ground water plume is stable and does not appear
                  to be migrating.

                  Vacuum extraction over the three prior years reduced contamination
                  such that natural bioremediation will be able to maintain and
                  eventually shrink the plume of contaminated ground water.

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TIBBETTS ROAD SUPERFUND SITE                                               2 4
AMENDED RECORD OF DECISION	September 28.1998

                  The surface water source for the drinking water supply, Swains
                  Lake, will not be affected by the contaminated ground water.

                  The natural bioremediation and phytoremediation remedy will attain
                  cleanup levels in approximately the same time frame, fourteen years,
                  as the continued operation of vacuum extraction due to desorption
                  limitations.

                  The water supply district is capable of maintaining service to all
                  drinking water users in the area of affected ground water.

                  Pursuant to the  1994 Consent Decree, the water district passed an
                  ordinance restricting the use of ground water within its service area.
                  The water district inspects and enforces this ordinance vigorously
                  due to its concerns over cross-connections.

                  No current unacceptable risk is posed to public health or the
                  environment.

                  The natural bioremediation and phytoremediation remedies will
                  attain cleanup levels and will meet all ARARs within a reasonable
                  time frame.

                  The natural bioremediation and phytoremediation remedies will
                  permanently reduce mobility, toxicity and volume.

                  Past activities, soil removals and vacuum extraction, have acted to
                  reduce mobility and toxicity of contaminants at the Site, making
                  cleanup through natural bioremediation and phytoremediation more
                  amenable.

                  The remedy will pose no short-term risks.

                  The cost is less  than vacuum extraction, yet cleanup levels will be
                  attained in approximately the same time frame.

      Combined with the vacuum extraction remedy performed under the 1992 ROD
from 1995 to 1997, natural bioremediation and phytoremediation will provide for a
comprehensive remedy. Municipal drinking water is already supplied to the area.

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TIBBETTS ROAD SUPERFUND SITE                                              2 5
AMENDED RECORD OF DECISION	September 28,1998

Institutional controls restricting the use of contaminated ground water have been
established pursuant to the 1992 ROD through the enactment of a local ordinance by the
Swain's Lake Village Water District. The area of the Ground Water Management Zone
for which this local ordinance provides usage restrictions is depicted in Figure 2.

      A.   Interim  Cleanup Levels

      Interim cleanup  levels that were established in the 1992 ROD as the performance
standards are retained for this Amended ROD remedy.  Those cleanup levels were
established for all contaminants of concern identified in the Baseline Risk Assessment
found to pose an unacceptable risk to either public health or the environment. These
protective levels shall constitute the cleanup levels for this Amended ROD and shall be
considered performance standards for any remedial action for the Site.

      Periodic assessments of the protection afforded by the Amended ROD remedy
will be made as the remedy is being implemented and at the completion of the remedial
action. These periodic assessments will be made based on available data and may involve
a risk assessment. If, after review of the risk assessment or available data, the remedial
action is not determined to be protective by EPA, the remedial action shall continue until
either protective levels  are achieved, and are not exceeded for a period of three
consecutive years, or until the remedy is otherwise deemed protective by EPA. EPA,
after its review, may also require further implementation of the vacuum extraction
remedy in the event mat it is determined that protective levels can not be achieved by the
remedy described in the Amended  ROD.

      Once the interim cleanup levels are attained and all ARARs are complied with
over a three-year period a final risk assessment will be performed.  Such risk assessment
of the residual ground water contamination shall follow EPA procedures and will assess
the cumulative carcinogenic and non-carcinogenic risks posed by the ingestion of ground
water and surface water used for drinking water purposes.  The risk assessment will
determine if conditions both on-site and off-site are such that no current or future risk is
posed to either the public health or the environment for any exposure pathway. The
interim cleanup levels established for ground water are presented in Table 3 of Appendix
A. The 1992 ROD also describes how those cleanup levels were selected. This Amended
Record of Decision will retain those cleanup levels.

      Because the aquifer at and beyond the Site is a Class II aquifer which is a potential
source of drinking water, MCLs and non-zero MCLGs where more stringent than MCLs,
established under New  Hampshire's Water Quality Standards are ARARs.

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TIBBETTS ROAD SUPERFUND SITE                                               2 6
AMENDED RECORD OF DECISION	         September 28,1998
      These interim cleanup levels which are consistent with ARARs or suitable To-Be-
Considered (TBC) criteria for ground water, attain EPA's risk management goal for
remedial actions and are determined by EPA to be protective. However, the true test of
protection cannot be made until residual levels are known. Consequently,  at the time that
Interim Ground Water Cleanup Levels identified here in the Amended ROD and newly
promulgated ARARs and modified ARARs which call into question the protectiveness of
the remedy have been achieved, and have not been exceeded for a period of three
consecutive years, a risk assessment will be performed on residual ground  water
contamination to determine whether the remedial action is protective. The  EPA has
estimated that these levels will be attained in approximately fourteen years.

      B.    Description of Remedial Components

      The selected remedy consists of monitoring the progress of natural bioremediation
and operating and maintaining a phytoremediation system to achieve the natural
restoration of the ground water and to protect surface water quality. This remedy will
meet, through natural processes, cleanup levels in ground water, and act to address any
contamination in ground water or surface water which might threaten public health or the
environment.  The selected remedy consists of the following remedial components:

      1.    Natural bioremediation and phytoremediation of contaminated
            ground water in the overburden aquifer.

       The natural bioremediation mechanism consists of natural, in-situ  degradation
processes being performed by anaerobic microorganisms primarily in the overburden
aquifer.  EPA first came to suspect that bioremediation was occurring in the overburden
aquifer in  1992. These suspicions were based on shifts in the concentrations of some
species of chlorinated compounds (e.g.,  trichloroethylene being supplanted by the less
chlorinated 1,2 cis-dichloroethylene). To further confirm whether bioremediation was
occurring, EPA collected samples and conducted laboratory microcosm studies, the
results of which have been presented as  a paper (Wilson, et al., Design and
Interpretation of Microcosm Studies for Chlorinated Compounds).  These  studies
demonstrated that a wide variety of compounds, including benzene and toluene, were
being degraded in ground water at the Site by anaerobic microorganisms. During vacuum
extraction it appears that anaerobic degradation processes were slowed or halted as
portions of the aquifer became aerobic.  With the cessation of vacuum extraction
treatment the saturated portion of the subsurface environment was able to revert back to

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TIBBETTS ROAD SUPERFUND SITE                                               2 7
AMENDED RECORD OF DECISION	September 28,1998

anaerobic conditions, thereby allowing the anaerobic microorganisms to continue
metabolizing and degrading the contaminants.

      Calculations, including analysis with EPA's Bioscreen model, have shown that the
cleanup levels for VOCs will be attained in approximately fourteen years.  Those same
calculations show that the destruction rate by bioremediation is greater than the one
ounce per day removal rate of the vacuum extraction system when it was shut down in
1997. The environmental monitoring program will be designed to confirm these
calculations and modeling results.

      It is believed that the cleanup levels for inorganic contaminants, especially arsenic
and manganese, will be achieved shortly after the aquifer becomes aerobic. The aquifer
will become aerobic through two mechanisms. The first mechanism is based on the
consumption by microbes of a majority of the organic contaminants in the aquifer, after
which the oxygen levels should increase  and return the aquifer to aerobic conditions.
The second mechanism will be through the extension of roots from the trees involved
with the phytoremediation. As the root zone moves downward and enters the anaerobic
zone it will gradually extend the aerobic  zone to this area.

      As mentioned previously, the phytoremediation component will consist of the
planting of approximately 1,400 poplar trees at the Site. Migration of contaminants from
the Site would be slowed if not halted by the uptake and transpiration of water by these
poplar trees. The active pumping during the vacuum extraction removed at most 5
gallons per minute or 7200 gallons per day from the aquifer.  Research has shown that an
individual poplar tree can transpire or use approximately 25 to 50 gallons per day.
Considering the number of trees to be used at the Site, it is possible that upwards of
35,000 gallons of ground water per day will removed by the trees, an amount greater than
achieved during vacuum extraction.

      An additional benefit of the phytoremediation process  appears to be the plants
ability to withdraw contaminants from the soil. Recent research has shown that poplars
grown in media containing 50 parts per million trichloroethylene (the Site maximum is 7
parts per million) were able to consume large amounts of the  trichloroethylene,
metabolize the majority, and transpire very small amounts of trichloroethylene (Newman,
et al., Uptake and Biotransformation of Trichloroethylene by Hybrid Poplars, 1997). The
environmental monitoring program will attempt to evaluate this process as well, since the
mechanism for this activity is not well understood at this time.

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TIBBETTS ROAD SUPERFUND SITE                                               2 8
AMENDED RECORD OF DECISION	September 28,1998

      There is also a synergistic effect that the poplars and natural bioremediation have.
Bioremediation requires that ground water travel times be reduced to metabolize as much
of the contaminants as possible.  By reducing the hydraulic gradient, the poplar trees will
also slow down ground water flow. Also, it has been shown that root growth of poplars
into aquifers fosters a rich environment for the production of microbes, molds, and fungi,
all of which may help to degrade contaminants.

      2.    Natural bioremediation of contaminated ground water in the
            weathered bedrock aquifer.

      The remedy in the "weathered bedrock aquifer," henceforth termed the north
fracture zone, is dependent upon the success of the overburden aquifer natural
bioremediation and phytoremediation remedy. The success of the overburden remedy
would reduce the flow of contaminants to the north fracture zone. Reducing the amount
of contaminants will enable the microbes and other attenuating processes in the north
fracture zone to reduce contamination. Monitoring ground water in the weathered
bedrock will allow an assessment of the cleanup progress. EPA will evaluate future
monitoring results to determine whether other measures are necessary.

      3.    Implementation of Long Term Monitoring Plan

      A detailed plan for monitoring the performance and effectiveness of the remedial
action will be developed and submitted by Ford to the State and EPA for approval or
modification. The ground water and surface water monitoring components of the plan
will provide the data necessary to monitor the effectiveness of natural bioremediation and
phytoremediation. Because bioremediation and phytoremediation are new technologies
it is likely that specialized sampling plans, focusing on the contaminants of concern as
well as parameters which measure the success of the processes will be necessary. To
help fully characterize the Site and these processes it may also be necessary to install
additional monitoring wells. The installation of such wells, if needed, and their
monitoring will conform with the substantive requirements of the State's Groundwater
Protection Rules Env-Ws 410.

      Monitoring will focus on the appropriate parameters to determine the progress of
natural bioremediation and phytoremediation. Such parameters include the measurement
of ground water levels, terminal electron acceptors, degradation products, field
parameters (ORP, pH, DO, etc.), and sampling of root zone soils. The ground water
levels will be measured on a frequency sufficient to build a data base that shows levels
over a year and can be compared from year-to-year to assess the success of

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TIBBETTS ROAD STJPERFUND SITE                                               2 9
AMENDED RECORD OF DECISION	September 28.1998

phytoremediation in lowering the water table. Terminal electron acceptors shall be
measured, either through redox products or through hydrogen concentration or other
appropriate methodology.  Such measurements will be at a frequency sufficient to
determine what is being reduced at the Site and how that affects the mobility of arsenic.
Contaminants and their metabolic products will be measured on a basis sufficient to
determine the end-products of the natural bioremediation process.  Field parameters will
be measured during the other sampling events and compared to the terminal electron
acceptors to determine the environment of the aquifer and how that affects the
degradation of contaminants. Root zone soils shall be sampled periodically to determine
the extent and mass of the root zone and to determine the ability of the phytoremediation
remedy to assist and augment the bioremediation remedy.

      The results of the above monitoring and sampling will be used to provide inputs
into models to determine the progress of the natural bioremediation and
phytoremediation remedy at the  Site.  Monitoring shall also be  conducted to assess the
protectiveness of the remedy and to meet the substantive requirements of New
Hampshire's Groundwater Protection Rules,  Env-Ws 410.  The EPA and State will
review all sampling data. The results of sampling and other work will be presented to the
public on a periodic basis.

      4.    Five Year Reviews

      The  1986 CERCLA amendments require review of conditions every five years at
NPL sites if any hazardous substances, pollutants or contaminants remain to assure that
the remedial action continues to protect human health and the environment. All data
obtained in the monitoring program will be further evaluated and discussed in the five-
year reviews. These reviews will consider all relevant data, any significant trends, and
determine if additional remedial actions, adjustment to the  monitoring plan, or other
actions, are necessary.

DC.   STATUTORY DETERMINATIONS

      The remedial action selected for implementation at the Tibbetts Road Superfund
Site is consistent with CERCLA and, to the extent practicable, the NCP. The selected
remedy is protective of human health and the environment, attains ARARs and is cost
effective. The selected remedy also satisfies the statutory preference for treatment which
permanently and significantly reduces the mobility, toxicity or volume of hazardous
substances as a principal element. Additionally, the selected remedy utilizes alternate

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TIBBETTS ROAD SUPERFUND SITE                                              3 0
AMENDED RECORD OF DECISION	September 28,1998

treatment technologies or resource recovery technologies to the maximum extent
practicable.

      A.    The Selected Remedy is Protective of Human Health and the
            Environment

      The natural bioremediation and phytoremediation remedy at this Site will continue
to permanently reduce the risks posed to human health and the environment by
eliminating, reducing or controlling exposures to human and environmental receptors
through the implementation of the remedy and the use of engineering controls and
institutional controls already in place

      The protection of human health and the environment is the first and most
important criterion. This criterion is met because there is no exposure to contaminants
from the Site. Exposure to contaminated ground water  is prevented by five items:

      > The provision of an alternate public drinking water supply to affected
      residences in 1987. The water supply has been operated since then by the Swain's
      Lake Village Water District.

      >• A prohibition established by the Water District for the Ground Water
      Management Zone on the use of ground water for drinking water purposes. The
      prohibition was enacted in compliance with the requirements of State's
      Groundwater Protection Rules.

      > Hydraulic containment by the vacuum extraction system stopped contaminants
      from migrating from the Site and greatly reduced the contaminant mass remaining
      in the soil.

      > Phytoremediation will effectively stop contaminants from migrating by
      lowering the water table and thereby lessening the rate of ground water flow.

      > Natural bioremediation will continue to destroy contaminants in the ground
      water at the Site in an time frame estimated to be similar to that of active
      remediation.

      Moreover, the selected remedy will achieve potential human health risk levels that
attain the 10"4 to IQ"6 incremental cancer risk range and  a level protective of

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TffiBETTS ROAD SUPERFUND SITE                                              31
AMENDED RECORD OF DECISION	September 28,1998

noncarcinogenic endpoints, and will comply with ARARs and to-be-considered criteria.
At the time that the Interim Ground Water Cleanup Levels identified in the 1992 ROD,
and carried over into this Amended ROD, and newly promulgated ARARs and modified
ARARs which call into question the protectiveness of the remedy have been achieved
and have not been exceeded for a period of three consecutive years, a risk assessment
shall be performed on the residual ground water contamination to determine whether the
remedial action is protective.  This risk assessment of the residual ground water
contamination shall follow EPA procedures and will assess the cumulative carcinogenic
and non-carcinogenic risks posed by drinking ground water.  If, after review of the risk
assessment, the remedial action is not determined to be protective by EPA, the remedial
action shall continue until protective levels are achieved and have not been exceeded for
a period of three consecutive years, or until the remedy is otherwise deemed protective.
These protective levels shall constitute the cleanup levels for this Amended ROD and
shall be considered Performance Standards for any remedial action.

      B.    The Selected Remedy Attains ARARs

      This remedy will attain all applicable or relevant and appropriate federal and state
requirements that apply to the Site. All ARARs for the Site are listed in tabular form in
Appendix C,  Tables 1 through 3 of this document. Environmental laws from which
ARARs for the selected remedial action are derived include:

                  New Hampshire Drinking Water Quality Standards
                  New Hampshire Surface Water Quality Rules
                  New Hampshire Groundwater Protection Rules
                  Federal Fish and Wildlife Coordination Act, 40 CFR 6.0302(g)
                  Executive Order 11990 (Protection of Wetlands)

      Because natural bioremediation and phytoremediation are of a more passive
nature, with the exception of monitoring, the impacts of ARARs are few.  New
Hampshire's  Hazardous Waste Rules (RCRA Authorized), Executive Order 11988
(Floodplain Management), and New Hampshire's Wetlands Program do not apply. The
only air emission that may occur is the venting of air from a small vacuum extraction
system if it is turned on for any hot spot mitigation. Such gases will be treated with
activated carbon to remove all contaminants. The RCRA Land Ban requirements do not
apply to the selected remedy as no excavation, placement, or disposal of Land Ban waste
will occur as a result of the remedial action.  The Federal Safe Drinking Water Act and
the Clean Water Act are supplanted by the delegated State programs.

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TIBBETTS ROAD SUPERFUND SITE                                              3 2
AMENDED RECORD OF DECISION	September 28,1998

      The following policies, criteria, and guidance will also be considered (TBCs)
during the implementation of the remedial action:

                  EPA Health Advisories
                  EPA Guidance to Management of Investigation-derived Wastes
                  EPA Policy for low-stress sampling

A brief narrative summary of the ARARs and TBCs follows.

      CHEMICAL SPECIFIC

      New Hampshire Drinking Water Quality Standards Maximum Contaminant
      Levels (MCLs). These are standards for metals, pesticides, VOCs, radionuclides,
      and other classes of contaminants. The state drinking water program is authorized
      and these regulations have been adopted as enforceable standards for public
      drinking water systems identical to the Safe Drinking Water Act (SDWA).  MCLs
      for non-carcinogens are based in part on the allowable lifetime exposure to the
      contaminant for a seventy kilogram (154 pound) adult who is presumed to
      consume two liters of water per day.  The basic jurisdictional prerequisite for
      MCLs and non-zero Maximum Contaminant Level Goals (MCLGs), where more
      stringent than MCLs, is that they apply to "public water systems," defined as
      systems for the provision of piped water for human consumption with at least
      fifteen service connections.  Although not directly applicable to activities at the
      Site, the potential exists for residential drinking water use of ground water at the
      Site. Therefore, these standards are considered to be relevant and appropriate.

      To attain this requirement, ground water at and beyond the Site will attain MCLs
      and non-zero MCLGs at the completion of the remedy.  These levels will be
      attained by natural bioremediation and phytoremediation. In the overburden and
      bedrock aquifers MCLs and non-zero MCLGs are expected to be attained off-site
      in approximately fourteen years.

      New Hampshire Surface Water Quality Rules Water Quality Criteria Water
      quality criteria relating to surface water are developed under the State's Surface
      Water Quality Rules.  They are used by the State of New Hampshire, in
      conjunction with a designated use for a stream segment, to establish water quality
      standards.  The appropriateness of the WQC guidelines are dependent on site-
      specific circumstances. These regulations apply to point and non-point sources

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TIBBETTS ROAD SUPERFUND SITE                                               3 3
AMENDED RECORD OF DECISION	September 28,1998

      and include sediments.  Ground water discharges to surface water at Swains Lake
      and surrounding small streams, therefore AWQC are applicable.

            To date, there has not been any evidence of Site-related impacts on the
      surface water and sediments.  Monitoring will continue under the Amended ROD
      to ensure that contaminants do not affect surface water bodies and sediments.

      New Hampshire Groundwater Protection Rules The substantive rules provide
      quantitative limits on contaminants in ground water and the use of that ground
      water, regardless of whether it is used as a drinking water source or not.
      Therefore, these standards are considered to be applicable.

            Ground water within and beyond the Site will attain State standards at the
      completion of the remedy. These  levels will be obtained by natural
      bioremediation and phytoremediation. The time to achieve these standards is
      expected to be fourteen years.

      LOCATION SPECIFIC

      There are few location-specific ARARs because there will be no action at the site
      other than sampling. Therefore the only ARARs are:

            Federal Protection of Wetlands Executive Order 11990 - 40 CFR Part 6
      Appendix A is an ARAR for any undertaking or new construction located in a
      wetland.  Although the activities occurring at the Site (e.g., natural bioremediation
      and phytoremediation) will not occur in or have an impact on any nearby wetland
      there is the potential for discharges of ground water from the Site to enter into
      Swain Lake, a nearby surface water. In this case the potential for discharge of
      contaminated ground water to surface waters will require monitoring to ensure
      that there are no impacts to any nearby wetland. Compliance with the Executive
      Order will be ensured by ground water, surface water,  and sediment monitoring.

            Federal Fish and Wildlife Coordination Act - 40 CFR 6.0302(g) which is
      also an ARAR for any pollutants discharged to surface water from ground water.
      In this case the potential for discharge of contaminated ground water to surface
      waters will require  monitoring to ensure that there are  no impacts to fish or
      wildlife.

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TIBBETTS ROAD SUPERFUND SITE                                              3 4
AMENDED RECORD OF DECISION	September 28,1998

            New Hampshire Groundwater Protection Rules - Env-Ws 410.26 (a - g) is
      an applicable ARAR which establishes a state ambient ground water quality
      standards (AGQSs) which shall not be exceeded and requires that all ground
      waters be suitable for use as drinking water without treatment. For Sites at which
      the AGQSs are exceeded there is the requirement to establish a Groundwater
      Management Zone (GMZ), provide an alternate water supply for impacted
      residences, and/or restrict further use of the groundwater.  All property owners
      within the impacted area have been connected to an alternate water supply. The
      Swain's Lake Village Water District has also enacted a local ordinance further
      restricting the use of ground water in the GMZ. Ground water within and beyond
      the Site will attain State standards at the completion of the remedy and migration
      of contaminants will not be allowed to occur.

      ACTION SPECIFIC

      There are also few action-specific ARARs because of the  passive nature of the
      remedy selected in the Amended ROD. Therefore the only ARARs are:

                  Federal Guidance to Management of Investigation-Derived Wastes
            provides guidelines in the handling of contaminated media and equipment.
            Because this is a guideline, it is to-be-considered.

                  September 23. 1996 Memorandum from Linda Murphy. Director.
            Office of Site Remediation and Restoration New Procedure for collecting
            Ground water samples for the determination of organic and Inorganic
            contamination establishes the low-stress method of sampling as the only
            method to collect valid samples. All ground water samples, with noted
            exceptions, will be collected using this technique.  Because this is a
            guideline, it is to-be-considered.

      C.    The Selected Remedial Action is Cost-Effective

      In the Agency's judgment, the selected remedy is cost effective, i.e., the remedy
affords overall effectiveness proportional to its costs. In selecting this remedy, once EPA
identified remedies that are protective of human health and the environment and that
attains ARARs, EPA evaluated the overall effectiveness of each  remedy by assessing the
relevant three criteria in combination:

            long term effectiveness and permanence;

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TIBBETTS ROAD SUPERFUND SITE                                             3 5
AMENDED RECORD OF DECISION	September 28.1998

            reduction in toxicity, mobility, and volume through treatment; and
            short term effectiveness,

      The relationship of the overall effectiveness of this remedy change was
determined to be proportional to its costs.  The costs of this remedy change is
approximately $140,000 less than the 1992 ROD remedy over a twenty-year period.
Although the remedy performed at the Site, vacuum extraction, is cost effective as well,
it was determined that it would not clean up ground water any faster than the remedy
selected in this Amended ROD.

      D.    The Selected Remedy Utilizes Permanent Solutions and
            Alternative Treatment or Resource Recovery Technologies to the
            Maximum Extent Practicable

      Once the Agency determined the remedy change will attain ARARs and will be
protective of human health and the environment, EPA examined the remedy change to
determine if it utilizes permanent solutions and alternative treatment technologies or
resource recovery technologies to the maximum extent practicable. This determination
was made by deciding whether the 1992 ROD remedy or the Amended ROD remedy
provides the better balance of trade-offs in terms of:

      1) long-term effectiveness and permanence;
      2) reduction of toxicity, mobility or volume through treatment;
      3) short-term effectiveness;
      4) Implementability; and
      5) cost.

      The balancing test emphasized:
            long-term effectiveness and permanence; and
            the reduction of toxicity, mobility and volume through treatment.

      The balancing test considered as principal elements:
            the preference for treatment;
            the bias against off-site land disposal of untreated waste; and community
            and state acceptance.

The selected remedy for this Amended ROD provides the better balance of trade-offs as
compared to the 1992 ROD.

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TIBBETTS ROAD SUPERFUND SITE                                              3 6
AMENDED RECORD OF DECISION	September 28,1998

      Although a preference for treatment exists, the EPA and State believe that no
treatment system will achieve cleanup levels in the ground water any faster than natural
bioremediation and phytoremediation can. The cleanup time at the Site is dependent
upon and limited by desorption processes that will not be influenced greatly by the
application of engineered recovery systems such as vacuum extraction. The EPA and the
State also believe that any active treatment system may also generate hazardous residues
that will require management and off-site disposal. Therefore the only remaining criteria
to evaluate was cost. The Amended ROD remedy will cost slightly less and better
address neighborhood concerns. The neighboring community believes that natural
bioremediation will provide a better remedy than pump and treat because it will preclude
intensified traffic and the generation and storage of potentially hazardous materials. The
local residents also maintain that they wish the Site to fit into the neighborhood rather
than contrast, as it has for the past fourteen years.

      E.    The Selected Remedy Satisfies the Preference for Treatment
            Which Permanently and Significantly reduces the Toxicity,
            Mobility or Volume of the Hazardous Substances  as a Principal
            Element

      Continuation of the vacuum extraction system may arrest migration; however, it is
believed that phytoremediation may be equally as successful in controlling the migration
of contaminants from the Site.  It is even possible based on the estimated volume of
water that the plants will take up that phytoremediation will exceed the performance of
vacuum extraction system. The volume of hazardous substances would be reduced under
both the 1992 ROD remedy and the Amended ROD remedy. However, both remedies
are  limited by the desorption of contaminants from the soil and will therefore both
achieve cleanup levels in approximately the same time, fourteen years. The 1992 ROD
remedy relies on collecting contaminants from the subsurface so that they may be taken
off-site and destroyed.  The natural bioremediation and phytoremediation remedy will
permanently destroy contaminants in-situ by transforming them to nonhazardous
products.

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TIBBETTS ROAD SUPERFUND SITE                                             3 7
AMENDED RECORD OF DECISION                 	        September 28.1998
X.    DOCUMENTATION OF NO SIGNIFICANT CHANGES

EPA presented a proposed plan with a preferred remedy change for the Site on June 24,
1998. The change included:

      Rely on natural biodegradation of contaminants, assisted by phytoremediation,
      rather than vacuum extraction and pumping and treating, to restore ground water
      quality in the overburden aquifer and halt migration of contaminated ground
      water.

      Rely on natural biodegradation, assisted by the reduction of contaminants flowing
      from the overburden aquifer, to restore ground water quality in the weathered
      bedrock aquifer and not perform an active, engineered remedy to restore ground
      water quality.

      Ensure the functioning of the biodegradation and phytoremediation remedies
      through a modified program of sampling of ground water and surface water.

      This amended Record of Decision contains all of those components and remains
substantially unchanged from the presentation given in the Proposed Plan.

XL   STATE ROLE

      The New Hampshire Department of Environmental Services has reviewed the
remedy change and has indicated its support.  The State has also reviewed the technical
data generated to determine if the selected remedy is in compliance with applicable or
relevant and appropriate State Environmental laws and regulations. The State of New
Hampshire concurs with the selected remedy for the Tibbetts Road Site.  A copy of the
declaration of concurrence is attached as Appendix B .

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   APPENDIX A




FIGURES AND TABLES

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Figure 1. Location of the Site in Harrington, New Hampshire. The Site lies on Tibbetts Road
which is off Hall Road, north and west of the Lee Circle (the intersection of New Hampshire
Routes 4 and 125).

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Figure 2. General details of the Site. The aerial photo is of the Site in 1985. The center of
the photo is the house where the former Site owner lived.  The source areas, where drums
were stored and their contents used, are circled in yellow.   A fence is seen as a faint outline
around the  Site.  Houses surround the Site, and the trailer-like figure to the right of the house
is an incinerator EPA brought on  the Site to destroy dioxins in soil.  Figure 5 shows the
geology, each of the aquifers,  ground water flow and rough contaminant locations.  Below
the aerial photo is a diagram of the Site and the Ground Water Management Zone. A water
supply service provides drinking water to all the residents in the photo and an additional 70
residences that lie within the area of influence and may be contaminated if ground water
were pumped from the bedrock aquifer. A municipal ordinance prevents the use of ground
water within its service area. That area is shown in the 1994 Consent Decree between the
EPA, State of New Hampshire, Ford, and the Swains Lake Village Water District.

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Figure 3a. The pre-remedial stage. The photo shows one
of the three drum storage areas behind the Site owner's
house during Site discovery. The three areas in which 337
drums were stored prior to EPA removing them are outlined
in yellow in Figure 2.
               Figure 3b.  The remedy as outlined in the
               1992 ROD. The house is to be removed, the
               Site is capped to minimize infiltration (dark
               blue), vacuum extraction wells operate to
               recover contaminants in the subsurface (light
               blue), contaminated ground water migrating
               from the Site is intercepted and collected with
               either wells or two trenches (red lines).
               Contaminants in the weathered bedrock are
               pumped from the aquifer (red dots) and treated
               Figure 3c. The remedy performed by G&M
               from 1995 to 1997. The house is gone, the Site
               is paved, vacuum extraction is used more
               widely over the Site to maximize recovery.
               The requirement for intercepting contaminants
               migrating in the aquifer is met by  positioning
               the vacuum extraction wells in an  appropriate
               manner and paving the entire site.  A small
               amount of pumping in the weathered bedrock
               did occur in 1997.
                   A photo of the Site taken in May 1996,
                   during the 1992 ROD remedial Action. The
                   view is from the Tibbetts Road end of the
                   Site looking roughly northward at the
                   vacuum extraction pump and treatment area.

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                                       Figure 4
         A cross-section through the Site prior to vacuum extraction (1948 - 1995)
         uthern and northern Site Bo
 I'XXXXXXXXXXX^*-.- .> * * ^XXX>*ป^
 •xxxxxxxxxxxxxxxxxxxxxxxxxxx
 'XXXXXXXAHI i WBW ซ• 'XXXXXXXXXX
Figure 4a. This shows a north-south cross-section
of the Site (looking westward), before remediation
began in 199S. Although contaminated soil was
removed, significant ground water contamination
existed in the water table and served as a source of
more wide-spread ground water contamination. In
1992 EPA found that naturally occurring microbes
were active in the ground water, however, because
there was too much contamination and ground
water flow was too fast, the microbes were unable
to degrade all of the compounds and contaminated
ground water continued to flow off-site.
         A cross-section through the Site during vacuum extraction (1995 - 1997)
         iDthem and northern Site Bo
                   Vacuum Extraction Wells

                     Cap   ซ
                  Former SonrcJ
  XXXXXXXXXXXXXXXXXXXXXXXXXXX,
                          xxxxxxxxxx,
  xxxxxxxx.ซป;?? u?g ••xxxxxxxxxx.
 i xxxxxxxx/TV VV7 V™ xxxxxxxxxx,
Figure 4b. This shows the same cross-section
(again looking westward); however, this is after
remediation began in 199S.  Up to ten vacuum
extraction wells operated, removing both ground
water and air,  to reverse the flow of contaminated
ground water so that it flowed back to, rather than
away from, the Site. Vacuum extraction removed
the majority of the contaminants in the source
area.
 Cross-section during proposed Phytoremediation and Natural Attenuation (1998 and on)
        uthern and northern Si
                                 'Weathered
                                   Bedrock
                  'Former Source
XXXXXXXXXXXX*-.. -r	XXX*^?XX
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
! XXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
   Figure 4c. The cap and vacuum extraction
   system are gone and the poplar trees are
   planted.  The fence remains to protect the trees
   from deer damage. Although small at first, the
   poplars will grow very quickly. In the second
   year of growth the trees are expected to begin
   depressing the water table, ultimately acting in
   the same fashion as the cap and vacuum
   extraction system. During this phase and until
   the Site is taken off the Superfund list, ground
   water will be monitored to determine the
   success of phytoremediation and natural
   attenuation.

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 Overburden
 Aquifer - consists of a poorly
 sorted grove, sand, silt,
 glacial till that is 16 to
 in fiy
Lodgement
Till - consists of a
highly compacted, fine-
grained material.  This
material is so dense
that it is dry. except for
minor, secondary porosity.

 Ground water flow - indie
 by the blue arrows.  In the overbn
  Areas of present ground water
  contamination are outlined on
  the ground surface in yellow.
 aquifer the water flows norm on the
 north side of the drainage divide, south
 on the southern. Bedrock ground water
 flow appears to be generally northeast
               Zone of weathered
               Bedrock - was found
               during design investigations
               to not be significant in
               extent.       	
Bedrock- consists of a quartz monzonite with
some pegmatites. There are few fractures;
however, those few transmit large volumes of
ground water.
Figure 5.  Geology and Hydrogeology at  the Site.   The house at
the  Site is  visible.   Tibbetts  Road lies  just to  the south of
the  house.   The two  remaining areas of  contamination are
outlined in  yellow.   The ground water and contaminant flow in
the  smaller,  southernmost area  of contamination is to the  south
and  well SOS.   The flow in the  larger,  northernmost area of
remaining contamination is to the north in the overburden
aquifer.  Flow is also into the bedrock.   The flow of ground
water in the bedrock is generally to the  north; however,  is
very susceptible to  pumping.  Contaminated ground water will
migrate to the area  of any pumping along  fractures which  are
very transmissive.

-------
Figure 6. Three sets of wells depict the flow of ground water and contamination at the Site.
Each of these sets of wells will be discussed separately in the context of what contaminants
are present and the characteristics of the flowpath.
       Flowpath51Sto50S
Flowpath SOS to 79S
                  Dense, Grey Till
                                Flowpath 57S to 69R
          Dense, Grey Till
                                                                     76R

-------
Table 1 - Contaminant Concentrations along flow path 51S to 50S
(Flow is from 51S to SOS)
Well
51S
SOS
Concentration (in parts per billion) of
Benzene / Toluene
Ethyl benzene / Xylene
Arsenic / Manganese
1997
<2500 / 12000
1600 / 10000
110/5000
44/34
620 / 1200
not analyzed
1998
<100 / 1200
780/4700
210 / 6600
<25 / 590
310 / 590
370 / 7100
Cleanup Level
5 / 1000
700/10000
50 / 3650

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    Table 2 - Contaminant Concentrations along flow path S7S to 69R to 35R
   (Flow is postulated to be from S7S to 72S to 70S to S2S to 37D to 53$ and 69R, lastly 35R)
Well
   Concentration (in parts per billion) of
        Trichloroethylene / Toluene
         Benzene / Ethyl benzene
          4-methyl-2-pentanone
           Arsenic I Manganese
                1995
                              1998
                       Cleanup Level
57S
69R
3SR
   7200/250
    100 / 760
     no data
   113/14000
  6500 / 28000
  <1000 / 2400
     <1000
   170 /19000
  <1000 / 7300
  2700/<4000
     51000
   135 / 5300
  <1000 /12000
   3600 / <700
     26000
   120/4600
25 / not detected
290 / not detected
      790
   31 / no data
<50 / not detected
130 / not detected
      1000
    30 / 870
                                                            5/1000
                                                             5/700
                                                              1825
                                                            50 / 3650

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TABLE 3
CLEANUP LEVELS FOR THE TIBBETTS ROAD SUPERFUND SITE
NON-CARCINOGENIC COMPOUNDS
Non-carcinogenic
Contaminants of Concern
(class)
1,2 Dichloroethene - (cis) (D)
- (trans) (D)
Ethylbenzene (D)
4-Methyl-2-Pentanone (D)
Styrene (C)
Toluene (D)
1,1,1 Trichloroethane (D)
Xylene (D)
Naphthalene (D)
Chromium (D)
Manganese (D)
Nickel (D)
Vanadium (D)
Interim
Cleanup
Level
(M8/D
70
100
700
1825
100
1000
200
10000
1460
100
3650
100
256
Basis
MCLG
MCL
Risk
MCL
MCLG
MCLG
MCLG
Risk
MCLG
Risk
MCLG
Risk
Target
Endpoint
of
Toxicity
Blood
Kidney & Liver
Kidney & Liver
Blood & Liver
Kidney & Liver
Liver
CNS-DBW
DBW
No effect
CNS
DBW
No effect
Hazard
Quotient
0.19
0.14
0.19
1
0.014
0.14
0.06
0.14
1
0.55
1
0.14
1
•••• ••'• ;•. : v. .:/;;'ifeAizi^ '. '
TOTCENDPQINT V;S:^: •' : •••••.•: "•'•'" V/". • . . .TOTAL
Blood 0.344
Kidney 1.33
Liver 1 .404
Decreased Body Weight (DBW) 1 .28
Central Nerve js System (CNS) 1.14

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TABLE 3, continued
CLEANUP LEVELS FOR THE TIBBETTS ROAD SITE
CARCINOGENIC COMPOUNDS
Carcinogenic Contaminants of
Concern (class)
Benzene (A)
Tetrachloroethylene (B2)
Trichloroethylene (Bj)
Styrene (C)
Bis(2-ethylhexyl)phthalate (B2)
Arsenic (A)
Interim
Cleanup
;: Level (jigA)
5
5
5
100
4
50
Basis
MCL
MCL
MCL
MCL
MCL
MCL
Levelof
Risk
1.7 xlO"6
3.1x10*
6.4 xlO'7
3.5 xlO'5
6.6 x lO'7
8.8 x ID"4
                              Sum:
9.2 x 10'4
     1   Standard  exposure parameters  from OSWER Directive  9285.6-
03 for residential ingestion of potable water (i.e.,  adult of
seventy kilogram body weight drinks two liters of water per day
for 350 days for a thirty year duration) are the basis for
calculation of risk-based cleanup level, hazard quotient,  and
level of risk.

     2   Toxicity  values  (i.e.,  RfD or CPF)  used  for calculation
of risk-based cleanup level, hazard quotient, and level of risk
are from either the on-line IRIS or FY 1997 HEAST.

-------
      APPENDIX B

STATE OF NEW HAMPSHIRE
LETTER OF CONCURRENCE

-------
                                     State of New Hampshire
                       DEPARTMENT OF ENVIRONMENTAL SERVICES
                            6 Hazen Drive, P.O. Box 95. Concord, NH 0330?
                                 (603) 271 -2900    FAX (603) 271 -2456

                                             September 23,  1998
       Patricia L. Meaney, Director
       Office of Site Remediation and Restoration
       US EPA - Region I
       John F. Kennedy Federal Building (HBO)
       1 Congress Street
       Boston MA 02203-2211

       SUBJECT:  HARRINGTON,  NEW HAMPSHIRE •  Tibbetts  Road  Superfund  Site,
                   Amended Record of Decision Declaration of Concurrence

       Dear Ms. Meaney:

             The New Hampshire Department of Environmental Services (Department) has reviewed and
       concurs with the "Amended Record of Decision" (Amended ROD) for the Tibbetts Road Superfund
       Site in Harrington, New Hampshire.  The Amended ROD addresses the remedial action necessary
       to address potential threats to human health, welfare and the environment at Tibbetts Road which
       resulted from releases of hazardous substances. The Amended ROD documents the changes in the
       cleanup plan and in the 1992 ROD to protect human health and the environment.

             The primary difference between the 1992 ROD versus the remedy performed and the remedy
       outlined in the Amended ROD is that the 1992 ROD specified that contaminated ground water in the
       weathered bedrock aquifer would be extracted and treated. During the performance of the remedy
       from 199S to 1997. and as outlined in the Amended ROD, the weathered bedrock will instead be
       monitored. The 1992  ROD specified that the method of attaining final cleanup levels would be from
       vacuum extraction and flushing of the aquifer. The Amended ROD directs that cleanup levels will
       be attained through natural phytoremediation and bioremediation.

             EPA prepared the Tibbetts Road Amended ROD in accordance with the provisions of the
       Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA) as
       amended by the Superfund Amendment and Reauthorization Act of 1986 (SARA). The Department
       has participated in the oversight of EPA's Remedial Investigation, Risk Assessment, Feasibility
       Study  and  in the implementation of the remedial actions performed  in the  1992 ROD.   The
       Department has reviewed the proposed changes in the Amended ROD and has indicated its support
       to finish the groundwater cleanup using natural processes. The elements of the proposal are:

       •      Discontinue recovery of contaminants from the weathered bedrock

       •      Establish a tree and vegetative cover on the site

       •      Continue monitoring groundwater quality to determine if contamination continues  to
             decrease
hซp7/www.$tate.nh.us                                                      TDD Accew: Rซ1ay NH 1-800-735-2964

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                                    I t nur
Patricia L. Meaney, Director
Barrington, NH - Tibbetts Road Superfund Site
Page 2

       Vacuum extraction in the overburden aquifer greatly reduced the amount of contamination
flowing into the bedrock. The weathered bedrock below the site is an area of intensely fractured
bedrock where contaminants have collected over time. The bedrock yields little groundwater. In
addition, EPA determined that even minimal pumping of the weathered bedrock would increase flow
from the overburden aquifer and cause additional contaminants to flow into the weathered bedrock
zone. Phytoremediation will be employed to cost-effectively remove the remaining contaminants in
the overburden aquifer, EPA and the Department anticipate that concentrations in the weathered
bedrock will decline through natural attenuation processes.

       Phytoremediation is a newly recognized technology that  uses vegetation  to remove or
concentrate contaminants from the soil and groundwater.  The installation of the Phytoremediation
system at the Tibbetts Road Site began in the spring of 1998. The Phytoremediation system uses a
hybrid poplar  tree in a planting area approximately 1.1  acres of a 2-acre site.  The system also
incorporates understory crops which consist of clover and perennial rye grass. The understory offers
quick erosion control and water uptake.

       The trees are primarily used to lower the water table, minimizing the groundwater flow away
from the site. The active pumping during the vacuum extraction, removed at most 5 gallons per
minute or 7,200 gallons per day from the aquifer. A mature poplar tree has been shown to transpire,
or use, 25 to 50 gallons per day.  Considering that more than 1,500 trees are planted at the site, it is
possible that they may pump a minimum of 37,000 gallons of groundwater from the subsurface per
day. A secondary purpose is to actively treat the organic contaminants in the groundwater. As the
trees (root system) lower the water table and contain the off-site flow of contaminants, the native
microbes have greater time to destroy contaminants.

       An irrigation system was installed at the site to ensure a reliable source of water throughout
all weather conditions and facilitate optimum  tree health during the first three growing seasons.
Removal of the irrigation system is anticipated after the first three-year establishment period. An
on-site bedrock well is being used for irrigation.

       The Phytoremediation system is being  maintained  and  monitored by the Potentially
Responsible Party (PRP). They will perform periodic visits to the site to monitor and review tree
growth. As these hybrid poplar trees reach the end of their life expectancy  of 30 or more years,
natural colonization of slower growing and longer-lived trees will occur which is the  beneficial end
use sought by the PRP, the regulatory agencies and the neighborhood.

New Hampshire's Groundwater Protection Rules

       The Department has been actively involved in the oversight of EPA's environmental response
activities at the Tibbetts Road site and has worked with EPA to ensure that all  actions that are taken
comply with state regulations and policies. EPA has designated the State's  groundwater quality
criteria and ambient groundwater quality standard's Env-Ws 410.03 and 410.05 as applicable to the
groundwater response action.  These  provisions establish numeric criteria  for groundwater

-------
Patricia L. Meaney. Director
Harrington, NH - Tibbetts Road Superfund Site
Page 3

restoration. EPA also designated the Oroundwater Management Zone (GMZ) provisions (Env-Ws
410.26) as an applicable ARAR. Under Env-Ws 410, a GMZ is established to manage the use of
contaminated groundwater until the groundwater quality standards  are met.   The relevant
requirements of Env-Ws 410 applicable to the Tibbetts Road remedy are as follows:

       GM,ฃ Establishment:  The Amended ROD includes Env-Ws 410,26  as an ARAR; this
       provides for the establishment of a GMZ and containment of groundwater contamination
       within the GMZ.

•      Eventual Achievement of Groundwate^ Quality Standards: The Amended ROD includes
       Env-Ws 4lO's numerical groundwater quality standards as an ARAR and the NCP requires
       that these standards be met within a reasonable lime frame (March 8,1990 Federal Register,
       P, 8732). The requirement that groundwater quality will be restored within the reasonable
       time frame of the NCP  is functionally equivalent to Env-Ws 410's expectation that
       groundwater quality will eventually be restored.

•      Qroundwater Restoration: The remedial action must restore groundwater quality to meet the
       groundwater quality criteria contained in Env-Ws 410.03. A high priority is given to source
       control, high value groundwater or groundwater that will be used as a water supply.

•      Institutional Controls: The Description of Changes to the 1992 ROD section in the Amended
       ROD requires establishment of institutional controls to restrict the use of groundwater for
       consumptive purposes  within the GMZ. The  1994 Consent Decree  mandated that  an
       ordinance be enacted to prevent the use of groundwater within the impacted area surrounding
       the Tibbetts Road site. The Swain's Lake Village Water District enacted the ordinance and
       complied with the statutory requirements under the State's Groundwater Management Zone
       regulations Env-Ws 410.

•      Long-Term Monitoriny of the GMZ and Remedy Performance: The description of the
       Environmental Monitoring Program in the Amended ROD provides for monitoring of the
       performance and effectiveness of the remedial actions as well as the  groundwater quality at
       the GMZ boundary.

       The remedy as discussed in the text of the Amended ROD  is consistent with the State's
"Draft Guidelines for Selection of Natural Attenuation for Groundwater Restoration under Env-Ws
410" in that it meets the guidance for implementation of natural attenuation at contaminated sites and
for monitoring of the natural attenuation process.  The Amended ROD, consistent with the guidance,
includes a contingency remedial method that could be implemented if it fails to achieve remedial
goals and cleanup levels. In the event that these cleanup levels cannot be achieved through the use
of biorcmediation and Phytoremediation. or the time frame to achieve these cleanup levels is
significantly greater than estimated in the Amended ROD, EPA and the Department may direct that
active remedies again be implemented. The active remedy may include pumping contaminated
groundwater from the weathered bedrock or localized vacuum extraction to reduce groundwater
contaminants to acceptable levels. Under such circumstances, the ARARs as described in the 1992
ROD would apply.

-------
Patricia L. Meaney, Director
Harrington, NH - Tibbetts Road Superfund Site
Page 4
       After the remedy  is implemented,  the long-term monitoring  plan  will ensure future
consistency with Env-Ws 410's substantive requirements and other key ARARs. A comprehensive,
detailed review of all environmental monitoring data will be conducted on a periodic basis by EPA
and the Department in order to ensure that  the remedial action provides adequate protection of
human health and the environment and complies with applicable regulations.

       The Department reviewed all information in the Tibbetts Road Administrative  Record,
evaluated the cumulative  risks associated  with current and future potential exposures to  the
contaminants whose presence is associated with a CERCLA release and determined the actions set
forth  in the Amended ROD  are consistent with State applicable or relevant and  appropriate
requirements.  Acting as agent for the State of New Hampshire, the Department concurs with the
remedial decision selected  under CERCLA for Tibbetts Road.

       In striving to achieve the maximum benefit with limited public (and private) resources, the
Department continues to seek reasonable and practical solutions to the often costly and complex
environmental challenges associated with contaminated site cleanups. Through the partnership  and
dedication exhibited by all parties, the rapid implementation of the actions necessary to protect
human health and  the environment will serve to  expedite  the  achievement of our mutual
environmental goals and facilitate efforts to restore the local economy in order to protect the welfare
of those in communities surrounding the Tibbetts Road site.  As always, the Department stands ready
to provide the guidance and assistance EPA  may require in order to take the actions necessary to
protect human health and the environment in a complete and cost-effective manner.
                                         Sincerely,
                                         Philip J. O'Brien, Ph>
                                         Director
AATIBBETS2.WPD
cc:     Carl W. Baxter, P.E., DES-WMD
       Richard H. Pease, P.E., DES-WMD
       John Regan, DES-WMD
       Michael Walls, Esq., NHDOJ
       Richard Boynton, P.E., EPA-New England
       Neil Handler. EPA-New England
                                                                                   TOTftL P.02

-------
              APPENDIX C

APPLICABLE AND RELEVANT AND APPROPRIATE
     REQUIREMENTS (ARARs) ANALYSIS

-------
                             ARARs DETERMINATION

       The purpose of this section is to identify the ARARs which may apply to the remedy
described in the Amended ROD and where appropriate, briefly describe how the remedy will
achieve these ARARs. The remedy as discussed further in the text of the Amended ROD
consists of the use of natural bioremediation and phytoremediation to achieve the clean-up levels
identified in the 1992 ROD. In the event that these clean-up levels can not be achieved through
the use of bioremediation and phytoremediation, or the time frame to achieve these clean-up
levels is significantly greater than estimated in the Amended ROD, or additional hot spots are
discovered at the Site, then EPA may require that vacuum extraction as described in the 1992
ROD be further implemented. Under such circumstances the ARARs as described in the 1992
ROD would apply.

-------
                                               AMENDED ROD REMEDY
                       TABLE 1 - NATURAL BIOREMEDIATION AND PHYTOREMEDIATION
                                                 CHEMICAL-SPECIFIC ARARs
AUTHORITY
         REQUIREMENT
      REQUIREMENT
         SYNOPSIS
    ACTION TO BE TAKEN TO
    ATTAIN REQUIREMENTS
STATUS
    Federal
     State
     State
     State
SDWA-Maximum Contaminant Levels
(MCLs) and Maximum Contaminant
Level Goals (MCLOs) (40 CFR 141.11-
141.16)
State of New Hampshire Safe Drinking
Water Act, Env-Ws 316 and 317 of the
Water Quality Standards.
State of New Hampshire Safe Drinking
Water Act-Env-Ws 319.01 of the Water
Quality Standards
State of New Hampshire Oroundwater
Protection Rules, Env-Ws 410.03 (a),(b)
and Env-Ws 410.05
MCLs and MCLOs have been
promulgated for a number of
common organic and inorganic
contaminants to regulate the
concentration of contaminants in
public drinking water supply
systems.
Establishes MCLs and MCLOs to
regulate the concentration of
contaminants allowed in public
water supplies in the State of New
Hampshire . These regulations are
generally equivalent to SDWA
MCLs and MCLOs.
These are secondary standards
established for public water
supplies which are based on
aesthetic criteria.
These regulations establish state
ambient ground water quality
standards. Section 410.03
requires that all ground waters
shall be suitable for use as
drinking water without treatment
and shall not contain any
contaminant that exceeds the
standards set forth in Ws 410.05.
MCLs and non-zero MCLOs were used in      Relevant and
determining the clean-up levels for            Appropriate
contaminants found in the aquifer beneath
the Site as it is a potential drinking water
source. A number of compounds still
exceed these standards but it is anticipated
that the remedy will attain them in
approximately fourteen years.

New Hampshire MCLs and non-zero          Relevant and
MCLOs were used in determining             Appropriate
acceptable clean-up levels for contaminants
found in the aquifer beneath the She where
they were more stringent than federal
MCLs and non-zero MCLOs  The remedy
is projected to attain these standards in
approximately fourteen years.

A number of compounds still exceed their        To-Be-
rcspectivc SMCLs in the aquifer beneath        Considered
the Site but h is anticipated that the remedy
will return these compounds to compliance
within approximately fourteen years.

 Ground water beneath the Site continues to      Applicable
exceed the groundwater quality standards
for arsenic, vinyl chloride,
trichloroethylene,  tctrachlorocthylene, and
benzene . The remedy is projected to attain
these standards in approximately fourteen
years.

-------
                                           AMENDED ROD REMEDY
                     TABLE 1 - NATURAL BIOREMEDIATION AND PHYTOREMEDIATION
                                             CHEMICAL-SPECIFIC ARARs
AUTHORITY
        REQUIREMENT
     REQUIREMENT
        SYNOPSIS
   ACTION TO BE TAKEN TO
    ATTAIN REQUIREMENTS
STATUS
     State
     State
State of New Hampshire Oroundwatcr
Protection Rules, Env-Ws 410.03 (c)
State of New Hampshire Surface Water
Quality Standards, Env-Ws 430-437
Ground water shall not contain
any contaminants that will cause
an exceedence of the surface water
quality standards.

Establishes water quality criteria
for toxic substances and rules for
determining acceptable point- and
non point- source discharges to
the State's surface waters.
Although no surface water standards are        Applicable
currently being violated, continued surface
water monitoring will occur as part of the
remedy.

Although no surface water standards arc        Applicable
currently being violated, continued surface
monitoring will occur as part of the
remedy.

-------
                                             AMENDED ROD REMEDY
                      TABLE 2 - NATURAL BIOREMEDIATION AND PHYTOREMEDIATION
                                                LOCATION SPECIFIC ARARs
AUTHORITY
         REQUIREMENT
     REQUIREMENT
         SYNOPSIS
   ACTION TO BE TAKEN TO
    ATTAIN REQUIREMENTS
 STATUS
    Federal
     State
    Federal
Federal Fish and Wildlife Coordination
Act -16 USC 661 - 666,40 CFR
6.0302(g)
State of New Hampshire Groundwater
Protection Rules, Env-Ws 410.26 (a - g)
andRSA485-C:6-a
Protection of Wetlands Executive Order
11990 (40 CFR 6, Appendix A)
Requires the protection offish or
wildlife resources related to
actions that control or modify
water bodies.
Requires the establishment of a
Oroundwatcr Management Zone
(OMZ) at sites with contaminated
groundwater exceeding ambient
ground water quality standards
(AOQSs).  It also requires that an
alternative water supply service be
provided to the affected area and
certain restrictions be placed on
the use of ground water.

Requires Federal Agencies to
avoid impacts associated with the
destruction or loss of wetlands and
to avoid support of new
construction in wetlands if a
practical alternative exists.
Although H does not appear that
groundwater beneath the Site is impacting
any nearby surface -water bodies,
monitoring of water quality will continue
as part of the remedy.

Ground water usage within the GMZ has
been restricted by the provision of an
alternative drinking water supply to
residences within the impacted area and the
passage of an ordinance by the Swain's
Lake Village Water District.
Although there is no evidence of any Site-
related impact to nearby wetland areas,
monitoring of the surface water will
continue as part of the remedy.
Relevant and
Appropriate
 Applicable
Relevant and
Appropriate

-------
                                            AMENDED ROD REMEDY
                    TABLE 3 - NATURAL BIOREMEDIATION AND PHYTOREMEDIATION
                                                ACTION SPECIFIC ARARs
AUTHORITY
         REQUIREMENT
   REQUIREMENT
      SYNOPSIS
    ACTION TO BE TAKEN TO
    ATTAIN REQUIREMENTS
STATUS
     State
Federal Guidance
     State
State of New Hampshire Groundwatcr
Protection Rules, Env-Ws 410.30 (a - i)
September 23,1996 Memorandum from
Linda Murphy, Director, Office of Site
Remediation and Restoration, New
Procedure for Collecting Ground Water
Samples for the Determination of Organic
and Inorganic Contamination

State of New Hampshire Oroundwater
Protection Rules, Env-Ws 410.31 (a), (b)
Defines where ground
water and surface water
will be sampled and for
what parameters.

Establishes a standard
ground water sampling
methodology using the low
stress method.
Defines how ground water
wells will be installed and
who may install them.
Monitoring of the ground water and surface
water will comply with the substantive
requirements of these regulations .
Ground water sampling will be performed
using the low-stress methodology.
Additional ground -water wells, if required,
will be installed in compliance with the
substantive portions of these regulations.
Applicable
  To-be-
considered
Applicable
Federal Guidance
Federal Guidance
Federal Guidance to Management of
Investigation-derived Wastes
Use of Monitored Natural Attenuation at
Superfund, RCRA Corrective Action, and
Underground Storage Tank Sites,
Directive 9200.4-17, December 1, 1997.
Establishes guidelines for
the handling of
contaminated media
(sediment, ground water)
and contaminated
equipment.

Sets criteria for the
selection, application, and
monitoring of natural
attenuation remedies.
All monitoring activities will dispose of           To-be-
purge water and disposable sampling            considered
equipment in an appropriate manner.
Components of this remedy are                 To-be-
implemented, monitored, and managed in a      considered
manner similar to natural attenuation
remedies.

-------
                APPENDIX D

CALCULATION OF BIODEGRADATION CLEANUP RATES,
         AND OTHER TECHNICAL DATA

-------
        Attachment A
Mass Balance and Clean Up Time
         Calculations

-------

-------
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-------
                Attachment B
Application of Bioscreen, a R.S. Kerr Laboratory
   Hydrocarbon Degradation Screening Tool

-------
                     Tlbtetts Road
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-------
4.314
4.314
4.314
7.000
2.698
2.274
2.698

1.813
1.298
1.813
1.000
1.338
0.829
1.338

0.990
0.644
0.990

0.694
0.346
0.694

0.421
0.195
0.421

0.217
0.095
0.217

0.097
0.041
0.097

0.037
0.015
0.037

0.012
0.005
0.012

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0.055
0.055
0.055
7.000
0.035
0.029
0.035

0.025
0.017
0.025
1.000
HMMBI^M
0.020
0.011
0.020

0.017
0.008
0.017

0.015
0.006
0.015

0.014
0.005
0.014

0.014
0.004
0.014

0.013
0.003
0.013

0.013
0.002
0.013

0.013
0.002
0.013

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                       Tibbetts Road
                                                            Recalculate This
                                                               Sheet
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-------
0.791
0.791
0.791
1.000
0.584
0.180
0.584

0.424
0.040
0.424
0.500
0.333
0.010
0.333

0.275
0.002
0.275

0.235
0.001
0.235

0.205
0.000
0.205

0.181
0.000
0.181

0.161
0.000
0.161

0.143
0.000
0.143

0.125
0.000
0.125

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0.440 1 0.325
0.440
0.440
1.000
0.100
0.325

0.236
0.022
0.236
0.500
0.185
0.005
0.185

0.153
0.001
0.153

0.131
0.000
0.131

0.115
0.000
0.115

0.103
0.000
0.103

0.094
0.000
0.094

0.086
0.000
0.086

0.080
0.000
0.080

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0.310
0.310
0.310
1.000
0.229
0.071
0.229

0.166
0.016
0.166
0.500
0.130
0.004
0.130

0.108
0.001
0.108

0.092
0.000
0.092

0.081
0.000
0.081

0.073
0.000
0.073

0.066
0.000
0.066

0.061
0.000
0.061

0.056
0.000
0.056


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                      Tibbetts Road
                                                         Recalculate This
                                                             Sheet
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 IHHl^^BMMi
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-------
1.497
1.497
1.497
28.000
0.990
0.668
0.990

0.726
0.330
0.726
0.500
0.617
0.189
0.617

0.567
0.117
0.567

0.546
0.076
0.546

0.543
0.051
0.543

0.552
0.035
0.552

0.571
0.025
0.571

0.597
0.017
0.597

0.628
0.012
0.628

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-------
                Attachment B
Application of Bioscreen, a R.S. Kerr Laboratory
    Hydrocarbon Degradation Screening Tool

-------
                       Tlbbotts Road
                                                           Recalculate This

                                                              Sheet
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Dispersivities, R, lambda, other

-------
4.314
4.314
4.314
7.000
2.698
2.274
2.698

1.813
1.298
1.813
1.000
1.338
0.829
1.338

0.990
0.544
0.990

0.694
0.346
0.694

0.421
0.195
0.421

0.217
0.095
0.217

0.097
0.041
0.097

0.037
0.015
0.037

0.012
0.005
0.012

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-------
2.659
2.659
2.659
7.000
1.696
1.412
1.696

1.182
0.820
1.182
1.000
0.944
0.546
0.944

0.808
0.391
0.808

0.717
0.292
0.717

0.648
0.224
0.648

0.586
0.174
0.586

0.522
0.135
0.522

0.452
0.104
0.452

0.376
0.078
0.376

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                     Tlbbefo Road
                                                        Recalculate This
                                                            Sheet
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-------
0.440
0.440
0.440
1.000
0.325
0.100
0.325

0.236
0.022
0.236
0.500
0.185
0.005
0.185

0.153
0.001
0.153

0.131
0.000
0.131

0.115
0.000
0.115

0.103
0.000
0.103

0.094
0.000
0.094

0.086
0.000
0.086

0.080
0.000
0.080

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-------
0.310 I 0.229
0.310
0.310

0.071
0.229

0.166
0.016
0.166
n cnn
0.130
0.004
0.130

0.108
0.001
0.108

0.092
0.000
0.092

0.081
0.000
0.081

0.073
0.000
0.073

0.066
0.000
0.066

0.061
0.000
0.061

0.056
0.000
0.056

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                     Tibbetts Road
                      uena
                                                        Recalculate This
                                                           Sheet
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-------
             Attachment C
Preliminary Monitoring Data from the Site

-------
  ARCADIS  GERAGHTY& MILLER
                                                                               ARCAOIS Geragmy i MHIer. inc.
                                                                               warmaiancn orftce ana
                                                                               TeennotoCT Center
  TELEFAX                                                                      :7ฃ Caoot Smm Sune =03
                                                                               lowen
                                                                               Maisacnusans 0185ซ
                                          Coamr.                                 Tel 978 937 9999
                                                                               rax 978 937 7555


                                                                               environmental
 "•*  Lri_ ,          Oaป:
rouuoaqes:
                                                  \ \J
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 if you do noc receive an pages, please call to let us know as soon as posaiote.
                          "l^r^
THIS MESSAGE IS INTENDED ONLY FOR THE USE OF THE INDIVIDUAL OR ENTrTY TO WHICH IT IS ADDRESSES AND MAY
CONTAIN INFORMATION THAT IS PRIVILEGED. CONFIDENTIAL AND EXEMPT FROM DISCLOSURE UNDER APPLICABLE LAW.
W ซhe reader of ttm message ซ not the mended redpwra. or (tie employee or agent iซsponsabto far delivenng th* message tfl ine iniendefl
ซteip.ent. you are hereby nodded mat any dissemnaoon. datnbuoon. or copying of this communKabon is stnoty prortibrtea. If you have
weeived this commumcaoon ซ error, please notfy us immeaiaterr oy setephone and nsum the ongmal message to us at me aoove aadress

     -  9sป,,e^e.              ARCADIS GERAGHTY4MILLER

    tOci                             W-SO  SIQVOHV*   IMdSC^SO   3S-22-9O

-------
            Table _. Summary of Groundwater Data Collected in April !998,Tibbetts Road, Barrington, New Hampshire
                                                                                                                                              Page 1 of 5
0
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Well Designation
Sample ID
Sample Date
Metals (mg/L)
Arsenic
Chromium
Iron
Manganese
Nickel
Vanadium
VOCs(ue/L)
4-Methyl-2-pentanone (MIBK)
Acetone
Benzene
cis- 1 ,2-Dichloroethene
Ethylbenzene
Methylene chloride
Tetrachloroethene
Toluene
Trichloroethene
Xylene (total)


184SD
184SD-0498
!6-Apr-98

NA
NA
NA
NA
NA
NA

...
...
...
5.3
...
...
...
—
...
9.3


35R
35R-0498
21-Apr-98

0.03
<0.02
1.2
0.87
<0.02
<0.02

1000
—
130
...
—
...
<25
...
<50
...


37D
37D-0498
20-Apr-98

0.36
<0.02
40
3.1
<0.02
<0.02

...
...
...
7.8
...
...
7.6
...
14
...


/50S
5JDS-0498
2l-Apr-98

0.37
<0.02
66
7.1
<0.02
<0.02

...
...
<25
...
310
...
<25
...
<50
590


'i
51S
f 1SL-0498
7-Apr-98

0.21
<0.02
29
5.8
<0.02
<0.02

...
...
<100

-------
   Table	. Sumnury of Groundwater Data Collected In April l998,Tibbetts Road, Barrington, New Hampshire

Metals (mg/L)
Arsenic
Chromium
Iron
Manganese
Nickel
Vanadium
VQCi(ug/L)

-------
       Page 2 of 5
Table	. Summary of Groundwater Data Collected in April l998,Tibbetts Road. Bairington. New Hampshire
  84SL
84SL-0498
16-Apr-98
   0.16
  <0.02
    68
    2.2
  <0.02
  <0.002
    7.7
84SM 84SV
84SM-0498 84SV-0498
)6-Apr-98 16-Apr-98
Metals (mg/L)
Arsenic 0.16 <0.005
Chromium 0.06 0.067
Iron 74 0.029
Manganese 2.3 <0.02
Nickel <0.02 <0.02
Vanadium <0.002 <0.002
VOCs (ug/D
4-Methyl-2-pentanone (MIBK)
Acetone
Benzene
cis-l,2-Dichloroethene — 5.4
Ethylbenzene
Methylene chloride
Tetrachloroethene
Toluene
Trichloroethene
Xylene (total) 7.8 10
EW-01
W1DM-049
17-Apr-98

0.0037
<0.02
0.03
O.005
<0.02
<0.02

980
...
<100
140
600
—
<100
2500
<100
3100
EW-01
EW1DV-049
17-Apr-98

<0.002
<0.02
0.033
<0.005
<0.02
<0.02

390
—
<100
130
620
—
<100
2500

-------
                    Page 3 of 5
                                                                          Page 4 of 5
                                                                                           Table	.  Summary of Groundwater Data Collected in April  1998
•V-03S      EW-04S
3S-0498  EW4S-0498
Apr-98    20-Apr-98
).027
;0.02
 6.5
 1.6
iO.02
:0.002
                               FB      Trip Blank   Trip Blank
                              B-0498   TB-041698    TB-0498
                              -Apr-98    !6-Apr-98   20-Apr-98
0.52
<0.02
 250
  3
<0.02
<0.02
              16

              12
 <0.02
,<0.02
 <0.005
,<0.02
'<0.02
|<0.02
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
                                                                                              Trip Blank
                                                                                         Trip Blank (4/17/98)
                                                                                              17-Apr-98
Metals (mg/L)
Arsenic
Chromium
Iron
Manganese
Nickel
Vanadium

VOCs (ug/L)
4-Methyl-2-pentanone (MIBK)
Acetone
Benzene
cis-1,2-Dichloroethcne
Ethylbenzene
Methylene chloride
Tetrachloroethene
Toluene
Trichloroethene
Xylene (total)
NA
NA
NA
NA
NA
NA
                                                                                                     Bold indicates value exceeds cleanup levels.
                                                                                                     < indicates that reporting limit exceeds cleanup levels.
                                                                                                     NA - Not analyzed.
                                                                                                     — = Not detected and delected unit is less than cleanup
                                                                                                     mg/L - Micrograms per liter.
                                                                                                     ug/L - Kilograms per liter.

-------
I 1998,Tibbetts Road, Barrington, New Hampshire                                           Page 5 of 5

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-------
Contaminant Concentrations along flowpath 57S to 35R
(Flowfc fiiom 57$ to 72$ to 70S to 52S to 37D to 533 
-------
             Contaminant Concentrations along flowpath 57S to 35R
          (How is from 57S to 72$ to 70S to S2S to 37D to53S and 69R, lastly 35R)
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  Concentration (ia parts per billion) of
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                            1998
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 3600 / <700
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  120/4600
35R       25 / not detected
          290 / not detected
                790
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                      <50 / not detected
                      130/not detected
                            1000
                           30 / 870

-------
      APPENDIX E




RESPONSIVENESS SUMMARY

-------
                     RESPONSIVENESS SUMMARY
                              Tibbetts Road Site
                          Harrington, New Hampshire

                                  Prepared by

        U.S. ENVIRONMENTAL PROTECTION AGENCY NEW ENGLAND
                     Office of Site Remediation and Restoration
                                  Boston, MA

                                August 31, 1998

      The Amended ROD changes the remedy from active, remedial measures to passive
natural processes. Since the completion of a water treatment plant and distribution system
in 1987, the public's main concern has been the physical appearance of the Site.

      Following Site discovery (1985) until active cleanup by Ford (1995) the Site
consisted of two overgrown acres, a boarded up, partially burned out, dilapidated house,
piles of debris and tires, all surrounded by an eight-foot chain-linked fence topped with
three strands of barbed wire.  The Site contrasted quite starkly with the surrounding
residential neighborhood. Meetings with the public were attended primarily by neighbors
abutting the Site, who stressed that their primary concern was the appearance of the Site
as well as its potential as an attractive nuisance for children.

      During Ford's remedial activities the debris, house, and vegetation were removed
from the Site. The portion of the fence facing the neighborhood was replaced by a less
obtrusive six-foot horse fence.  Ford paved the Site to enhance the vacuum extraction
remedy and landscaped the perimeter. Landscaping efforts by Ford included the hiring of
an arborist to prune a large sugar maple, to improve the appearance of the Site. During
the Site remediation, EPA held meetings or sent letters at appropriate junctures to let the
public know what was occurring. In June of 1997, Ford hosted a picnic at the Site to
discuss their future remediation plans with nearby residents. At the June 1997 meeting,
Ford stated that they hoped to finish the ground water remedy using a combination of
natural processes (e.g., bioremediation and phytoremediation). All of the neighbors

-------
concurred with this proposal, including one neighbor who expressed a desire for Ford to
clear some brush so that she might better see the Site from her house once the
phytoremediation remedy was in-place.

      On June 24, 1998 EPA held a public meeting and hearing where EPA identified to
the public that it was considering changing the remedy for the groundwater from vacuum
extraction and pump-and-treat to bioremediation and phytoremediation, to complete the
cleanup process.  One oral and written comment was received at the hearing. Both of the
comments were from the same person, a resident located across the street from the Site.
The comments were about the fence at the Site and requested that "the fence must come
down."  EPA had originally proposed that the fence be retained to protect the
phytoremediation remedy, young poplar trees, from marauding deer. After conferring
with Ford a compromise was reached, and EPA asked that the fence closest to the street
be taken down. Based on subsequent conversations with the individual who had the
comment his concerns appear to have been addressed.

      In trying to keep with the concerns of surrounding neighbors the pavement over
the Site was removed. As of August 31, 1998 approximately 1,400 poplar trees, four to
six feet in height, were planted at the Site. A thin ground cover has also been planted and
the trees and ground cover are being watered through an irrigation system. The Site is
surrounded on three sides by a fence.  The fence on the south side which immediately
faces a residence has been removed. Ford will continue to monitor the trees and if deer
predation becomes a problem Ford has agreed to install a three-rail wooden fence which
would fit in better with the surrounding neighborhood.

      The transcript of the public meeting and hearing is attached as Attachment A. The
single comment letter has been attached as Attachment B.

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ATTACHMENT A

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                    TIBBETTS JIOAD SUPERFUND SITE
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                            ORIGINAL
                         Banington, New Hampshire
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12                         Public Meeting/Hearing

                              June 24,1998
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    Darryl Luce, U.S. Environmental Protection Agency
    Thomas Andrews, N.H. Department of Environmental Services
    Peter Jalajas, Arcadis, Geraghty & Miller, Inc.
    THE LYNN REPORTING AGENCY  CERTIFIED AUDIO TRANSCRIBER
                M NOHTII WAKIJ li:i.l) KOAIX WOl.H-IIOttO. N II

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                 PROCEEDINGS
                MR. LUCE: Good evening. My name is Darryl
and I'm with the EPA, and what we're here for tonight is to discuss
site progress at the Tibbetts Road site and where we hope to go in
the future.
                This isn't a project mat's just been EPA'd, as you're
probably well aware.  Also been involved is Tom Andrews of the
Department of Environmental Services. The State's been involved
with us in site discovery. Also along with him tonight is Carl
Baxter on the right side and Paul Lincoln on the left, more as an
observer.
                Okay, let's see.  There is going to be the person
doing most of the work there, Geraghty & Miller, Peter Jalajas. I
know several of you have dealt with him on many occasions.
They've done the site  work since approximately 1994. Let's see.
                In 1992 we had a similar public meeting, I think
in this building, but not in this part, where we outlined what we
     •
were going to do in terms of a remedy, or what we hoped to do at
that time for a remedy. I hope this can all be seen, but essentially,
this is Hall Road right here, Tibbetts Road. I'm sure you're well
familiar with how the site is laid out. Norm is at the top of the map.
The fence Fve sort of done in pencil around here.
                And the remedy, as we proposed it at that time,
was going to be a set  of interception trenches because this is a
hilltop right here with groundwater flowing to either crest, off of
either crest, so we were going to put interception trenches on either
    THE LYNN REPORTING AGENCY   CERTIFIED  AUDIO TRANSCRIBER
                   .M NORTH WAKI:FII-I.I) ROAD. WOI.H'UOKO. N II <  (UK) S6')-SSH7

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side or wells sufficient to keep groundwater from migrating off the
                 site.
               At the same time, we were going to put in a
vacuum extraction system which would pump water and air,
cleaning up both groundwater and the air in the soil, taking the
contaminants out of it. And I've put these three, A, B, C, here.
These were, as I'm sure again you're all very familiar with, the three
main drum storage areas. B was perhaps the one that was the most
active and the most contaminated where most of the contaminants
were stored and men eventually spilled.
               In cross-section, Fve drawn a little cross-section,
here's the hilltop, and I should have put Tibbetts Road over on one
side or the other, but the trenches were going to be going, like I said,
on the flanks of the hill, the vacuum extraction in the center, the
idea being to lower the water table so that we wouldn't have off-site
migration contamiaants and then we'd also have recovery in the
center.
               This water table was bounded at the bottom by this
what I've labeled as dense till.  And, actually, I've brought some of it
because atthe time I was very taken with it When we drilled down
about twenty feet through the water table, we got into that dense till
and this stuff was like concrete. I mean this was essentially
underneath the water table  and very resilient material like concrete
and in dropping a three hundred pound hammer on it we were only
going about one inch for every hundred blows of the hammer. I
remember it was very tough. I talked to a couple of people in terms
    THE LYNN REPORTING AGENCY   CERTIFIED AUDIO TRANSCRIBER
                   Al NORTH WAKIWI'I.I) HOAO. WOI HIIIORO. N It OW>1 (6OJ) Srt'/SSH?

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of what this was because Tm from the mid-west and Fd never seen
anything like that.  It's a lodging till, so that the glacier could
literally ground into a pocket of the bedrock. So thafs what was the
bounding layer underneath to keep me contamination from going
deeper down into the bedrock at mat point
               And then in 1994 EPA settled with Ford Motor
Company and Ford Motor Company, through their contractor,
Geraghty & Miller, began doing work at the site. And what they
did, again, as Fm sure you're familiar with, is removed a lot of the
surface material, two hundred and thirteen tons of non-hazardous
debris, rubble, that was at the site, four hundred tires, a number of
drums that contained things like ซh that was from the incineration,
the PCB contaminated soil mat was located in that area, just
miscellaneous waste; for instance, some of me activated carbon
filters mat were going to be used, I guess, for me alternative to the
water treatment plan before mat was the final remedy there.  So they
took all those materials off site.
               Eventually, we also got the house off site, I
imagine much to many of your pleasure, and the lead contaminated
wood from  there, the lead-painted wood, was taken to a separate
facility for disposal there.
               Tom and I at that time, when we were doing the
oversight, we were going up there on a monthly basis and also
reviewing the reports that they had submitted regarding the progress
at the site.
                hi 1995 they started the vacuum extraction pilot
    THE LYNN REPORTING AGENCY  CERTIFIED AUDIO TRANSCRIBER
                   Jl NORTH WAKI-FlliM) KOAO. WOI.H-HOKO. N II I) WM (/*<) V,<)-5SW7

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test.  And what that was to do, what that did, was not only right
here, but also in Area A and C there were wells installed that
pumped both air and water in as fast a rate as we could at that site
because it doesn't yield much water.  Five gallons a minute was
pretty much all we were getting for the whole area. And what mat
did was it approximated pretty much what these trenches would
have done; namely it de-watered, kept contaminants from migrating
from the site.
               And the vacuum extraction that they were doing,
as we saw, the site was capped, it was paved, essentially, with
asphalt, the one point nine acres, and if turned out to be a very
efficient system, so we let mem run it at full speed to test this
system and see what it would do and it operated real well. It took
out eight hundred pounds of contaminants from the subsurface, as
you've seen in the write-up of the proposed plan.  And at its peak
operation, which I think was in late '95, it was taking out about three
and a half pounds of contaminants a day.
                Now, towards the end we were only recovering
about an ounce per day and mat was with the best positioning that
had been done. Geraghty & Miller had gone in there and positioned
these wells based on hydropunch and geoprobes;  mainly, they've
gone in there and dug some temporary holes or drilled very small
temporary holes to measure the contaminants and see where things
were lying.  And so mat way they optimized the system and really
got just about all that could be got
                So with the vacuum extraction system having been
     THE LYNN REPORTING AGENCY  CERTIFIED AUDIO TRANSCRIBER
                    31 NORTH WAKKIIIXI) ROAD. WOII l-:iซORO. N II O3K94 <6OA) 569 5SH7

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 so successful, the surface debris removed from the site, you're
 saying why are we here tonight.  And what it comes down to is there
 is still contamination at the site and in the groundwater and the
 vacuum extraction is really not any more efficient in collecting it
 Like I said, an ounce a day, that*s not something that you can easily
justify keeping the site paved, running a fifty horse motor in mere,
and even driving up there, you almost would cause as much
pollution as what we'd be recovering out of the groundwater.
                So what we're looking to do and what you've  seen
out there is using phytoremediation and bioremediation at the site.
Now, I know you see out there there's already the trees planted and
you're saying well, it looks like they've already really made up  their
minds, but that*s not the case there; because what we can do  is  if
there's any localized concentrations, regardless of whether we say
yes, we have to do something active or if we say eventually we'd say
yes, well do the phytoremediation, men if there is a localized
concentration that we find to be hazardous, a threat to health, then
well go in and do a spot removal, mainly put down a temporary cap,
sort of like what we did in 1992,wken we did the first pilot test of
the vacuum extraction system, put down plastic with gravel on  top
of it, a well in the center that would be withdrawing the
contaminants, and in that way reduce the contamination in that very
local area.
               Now, what the trees do, and this is something that's
relatively new. In fact, when it was first brought up, it wasn't
brought up so much for any reduction in contaminants, rather the
    THE LYNN REPORTING AGENCY  CERTIFIED AUDIO TRANSCRIBER
                   M NORTH WAKi:H|-:i.l) KOAD. W()| I CHOKO. N II 
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idea of planting all these trees was to reduce the elevation of the
water table. Now, you see on this diagram right here, again it's a
cross-section, Fve shown the root zone going down through these
very schematically what I've labeled as Water Table One and Water
                  Table Two.
                                 Water Table One is the usual water table and can
fluctuate through the column. As many of you know up there, in
spring time usually the water table is just a part of the surface and
then in the winter time there can be as much as — or early fall there
can be as much as eight feet down. So if s a fluctuating water table,
but with the trees growing into this zone now, the idea is that they
will reduce the amount of water in there and take the water table
down to this zone. Now, when the leaves are not on the trees during
the winter time, it can be expected that the water table will recover
in part, maybe even as high as here. But during the summer time,
again, it will de-water probably more efficiently, as you saw in the
proposed plan, de-water more efficiently than the vacuum
extraction.
               Now, since mis was first counted as something to
be done just to reduce the water table, and when you reduce the
water table, as I said before, men the migration of the contaminants
is less, simply because mere's not as much driving force to push
them off. Now, when there's not as much driving force to push
them off, that gives the bacteria, the microbes mat are in there,
longer times to work on the contaminants. I don't want to jump too
far ahead.
     THE LYNN REPORTING AGENCY   CERTIFIED AUDIO TRANSCRIBER
                    31 NORTH WAKI-HI-I.I) ROAIX WOI.FI-HOKO. N.M. 
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               Now, to stay with the phytoremediation for a
minute, there's a couple of processes.  You might ask well, if these
trees pumping the water are contaminated, what happens to those
contaminants in the water. Well, there's several papers I've read on
the use of poplars, or, actually, I believe those species are
cottonwood trees, and they've shown that the respiration that occurs,
the transpiration, is simply nothing more than the oxygen and water,
that the contaminants aren't seen at the leaf because they're
metabolized by the tree itself when it takes it up.  If s, I guess, a
useable product  So they've never seen accumulation or
transpiration from leaves and they haven't seen any accumulation of
any contaminants in wood, other man possible low concentrations
of iron and manganese. Fve tried to approximate the color of
poplar, but I mink I've failed mere.
                The next zone, the next element of remedy, is not
only phytoremediation, but bicremediation. In '92 when Tom and I
first started working on the site, it was noticeable that there were
some contaminants that were disappearing and other contaminants
being produced.  Those disappearing included the more heavily
chlorinated ones like trichloroemylene and those being produced
included the less chlorinated, like dichloroethane, I, 2
dichloroethane.  And at the time I had no idea what that meant and I
had contacted some people in EPA's risk reduction laboratory out in
Ada, Oklahoma. They had me collect samples in '92 back when we
did that one vacuum extraction test and I took core samples down in
this zone right here near the dense till. Those cores were taken into
    THE LYNN REPORTING AGENCY  CERTIFIED AUDIO TRANSCRIBER
                   31 NORTH WAKLHI-LI) ROAD. WOI.FI-UOKO. N If 0.5894

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the laboratory there in Oklahoma and put through a microcausing
test where they were kept in little viles.  First of all, they were left
for six months, I believe, just to let them equilibrate again
               And after that time, Doctor Wilson down there, he
would drip in a certain amount of tagged trichloroethylene and other
contaminants, too, from the site, benzene and the like, to see what
would happen mixing with that material and, indeed, he saw
percentage reductions of the contaminants per week. So that
necessarily cant be extrapolated back to this situation entirely
because travel times are much slower through here than they are in a
laboratory setting because they want to see the results in a hurry.
But they did see those results.
               And so we knew we had phytoremediation going
on here, probably sometime in '94. The thing is, at the  time, though,
the contamination was so plentiful that it was able to overwhelm,
there were just too many Indians for the cowboys and they were
able to run past the boundaries of die site. Hopefully, with the
vacuum extraction at the time, we thought that we would be able to
reduce mat contaminate mass and thafs indeed what happened; eight
hundred pounds of contaminants were removed.  So that will
give the microbes there a little bit more of a foothold to reduce what
remains.  But now with  the trees coming in here and reducing the
water table, that will slow down the rate of groundwater flow off
the site and give the microbes even more time to work.
               There will be the aerodegradation that occurs up
here above the water table where oxygen can get to it and where the
    THE LYNN REPORTING AGENCY  CERTIFIED AUDIO TRANSCRIBER
                   31 NOKTII WAKI-HI-LI) KOAD. WOI.H-IIOKO. N II O.WM (6
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L
		      10
 trees can - they'll have a root — in the root zone, there's called
 a rhizosphere and a number of bacteria in there will be able to
 degrade some of the contaminants.
                Down here, out of reach of the roots, what will
 happen is the bioremediatioo that was occurring naturally before we
 started any of this. Like I said, ifll just be more efficient now, and
 what that will be doing is it will be taking apart some of the
 contaminants like the toluene, gasotioe components.  And when it
 does that, there will be an enzyme produced and that* s what destroys
 the trichloroethylene and die other chlorinated solvents and reduces
 that
                Just to give you an idea where things lie right now,
 the area of contamination, I couldn't think of really a good way to
 present this, but the area of contamination, as you all were aware of
 back in '85 through '90, really was flowing off of the top of the hill
 in each direction. The concentrations were very high, especially on
 mis side where you saw concentrations as  high as a hundred
 thousand parts per billion of trichloroethylene in 1986 and lower,
 but still plentiful concentrations on this side.
                After the vacuum extraction, many of these areas
 were greatly reduced in concentration, but like I said, there are still
 some contaminants there. This area over here, on the second
 diagram I believe well see, this area now meets the cleanup levels,
 the drinking water standards.  And I've just put in a few wells right
 here just more or less to orient, but 84S is the tip of the well right ui
 the center and was the most contaminated and mat well and the
    THE LYNN REPORTING AGENCY  CERTIFIED AUDIO TRANSCRIBER
                   31 NORTH WAKI-|-'ll-:i.r> KOAD Wi >l I-THOIซ >  \> ll n; />..iซ> ซ/:ซ•"•—

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	;	  n
               .                                       ~~      I
 wells downgradient of it, 79S, probably should be more over in this
 direction, but I arted it in badly.
                Those wells, like I said, meet the drinking water
 standards.  These areas don't. However, the ideas with the planting
 of the trees, die contaminants will then be, like I said, degraded
 further and hopefully the concentrations mere will be returned to the
 drinking water standards approximately within the time frame that
 we had talked about back in 1992.  In 1992 we had said that the
 cleanup levels would be reached in twenty years and I use that as
 an upper sealing now. I know I put in the proposed plan there the
 seven to eight year figure, but mat could be viewed as maybe an
 optimistic figure.
                Now, Pete Jalajas of Geraghty & Miller just came
 in a few minutes ago and if you have any questions, well be happy
 to entertain those.  Yes?
                AUDIENCE: What do the little wet yellow flags
                 indicate?
                MR. LUCE: Pete, could you come up here?
                MR. JALAJAS: The question was, what are the
 little wet yellow flags on part of the property there. Those represent
 locations where we hammered in six inch pieces of the poplar trees,
 which are then hand drilled. Other than plant the four foot width,
 which would be inside of the fence in a nice little grove, that was
 kind of an irregular area and those just mark it
                MR. LUCE:  Yes?
                AUDIENCE: I notice you have a proposed plan
    THE LYNN REPORTING AGENCY  CERTIFIED AUDIO TRANSCRIBER
                  Al N()HTIIWAKi:HI-:i.l)K()AO. WOI>|.:iK)H(). Nil

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    that talks about a prohibitation established by the district on the use
    of the groundwater for drinking puiposes. How was that
    implemented, was that deed restrictions or just a zoning ordinance
    of some sort?
                   MR. LUCE:  Just an ordinance to the -
                  AUDIENCE:  Just a local ordinance?
                  MR. LUCE: Correct
                  AUDIENCE:  How is that monitored, verified,
   ensured it's not violated?
                 MR. LUCE:  In terms of drinking water, the
  district itself; they do inspections, they now have meters, I believe,
  on all the houses.  Ifs something that they're made aware of under
  the State's Groundwater Management Zone Rules. There's
  notification required so those people will know that they're not
  supposed to use it for drinking water purposes. I mean, it would be
  difficult to go out there and inspect, and I wouldn't want to do it.
  •aspect people's yards to make sure there are no wells, but I know
  the water district would be very interested in possible cross-
 connections if there were something like that.
                AUDIENCE: And on developing the natural
 accumulation process that you're going to use, did you follow the
 guidelines put forth in the latest EPA guidance on monitor natural
 accumulations and all those protocols?
               MR. LUCE: Yes. Those are still draft and I
know they may not be marked entirely. The last copy out is draft.
And the guidelines involved in there are very - they're suggestive.
                                                                     12
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                                                                                   13
There are no definitive guidelines proposed in there. Now, in this
situation right here, there will be monitoring very specifically
tailored to that, and in particular looking at water levels because
phytoremediation is a key component of it, lowering the water
                 table.
               There's a lot of things that that draft guidance
doesn't talk about. For instance, I had talked some about just very
generally, and I'm no biologist and I know most biologists would
probably scream, but anaerobic degradation in this zone is
important. If mat zปne were to be aerobic, turned aerobic for some
reason, men there wouldn't be any degradation or it certainly
wouldn't be a quick degradation of contaminants and so some may
migrate off site there.  What turns in our favor there is the fact that
usually down at those sort of depths, eighteen to twenty feet below
the ground, the situation is anaerobic.
                AUDIENCE:  On me vapor extraction system,
I noticed in the paper and you mentioned that efficiency had
dropped off so it would be unique for a flat slope line or efficiency
of operation, although maybe the clean-up goals or objectives
weren't reached.
                MR. LUCE: In the three areas they positioned a
number of wells and repositioned wells based on geoprobe surveys
to make sure that they were in the proper area, that namely you
didn't have to drag the contaminants over a whole lot of the aquifer
to withdraw them.  So they were continually out there.  I can think
of two occasions of drilling just to  find the better places to put them.
    THE LYNN REPORTING AGENCY   CERTIFIED AUDIO TRANSCRIBER
                   31 NORTH WAKIiFII-LI) KOAO. W( H.M-KORO. Nil (HH94 (69 SSH7

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                                                                 14
               And, like I said, three and a half pounds per day
 was pretty much the maximum that they reached, that's a good
 recovery, and at the tail end of it about an ounce per day is what
 they were recovering in the flow rates and I cant remember exactly
 what the flow rate was at that point, but it reached an optimum point
 that several - there were other EPA experts that I had consulted
 with before Gcraghty & Miller was involved with this in terms of
 drawing up the scope of work with Ford Motor Company where
 what we did was look at where is really the pit of efficiency, where
 will you no longer be efficient And what they had given me at that
 time was a figure of around a half a pound per day per hundred
 standard cubic foot removed and we were well underneath that for,
actually, a year before we turned it off. Ifs just that Geraghty &
Miller went out there and optimized it one more time, I believe, in
terras of putting in some additional wells and operating others, such
that they would draw out the most amount of contaminants.
               AUDIENCE:  The approach you're taking, I do
concur with that, it's a rational evolution that you go ahead and try
to remove the mass of the contaminants using the best means
available, but once that becomes an inefficient operation, the next
step in the process is monitoring, so it's a natural and I think it's a
good evolution for clean-up, so don't get me wrong there, I think
that's a positive approach.
               MR. LUCE:  Geraghty & Miller had first posed
 that to Tom and I in terms of saying well get out the mass and
although I like snakes, they said we're going to cut off the head of
    THE LYNN REPORTING AGENCY  CERTIFIED AUDIO TRANSCRIBER
                   31 NORTH WAKH-'iu.n UOAI>. w<-i I-TMOHO NII IKH<>; ,t.iu\w**~

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	.	     15
 the snake and then essentially the phytoremediation will be the
 polishing effort. Yes?
                AUDIENCE: The water you're using for your
 irrigation system, that's the contaminated water that you're bringing
 back up?
                MIL LUCE: That well is right over in this
 location and what that well represents is that well is drilled down
 two hundred and ten feet and the water down there is slightly
 contaminated, just barely above drinking water limits; however,
 the reason why it's contaminated isn't because of the bedrock down
 there, and this was seen when we did a geophysical test, is that
 there's a leak on one of the casings where it goes down through the
 sandy interval up above, before it gets in the bedrock there's a leak,
 so that that small trickle is what we've been sampling, that's what
 we believe. And so yes, it was slightly contaminated when it's
 brought out on the surface like that and put through the sprinklers.
 I mean there's really nothing much left of it
                AUDIENCE: So, I mean, could people open up
 their wells and use it to wash cars and water lawns and stuff with?
                MR. LUCE: That1 s something that I think the
 district would be concerned with in terms of, again, potential cross-
 connections, and under the Groundwater Management Zone Rules,
 I'm not sure how that applies, either. I mean that1 s the  operational
 regulation there is the State's Groundwater Management Zone and I
 mean, you know, in terms of operating a well like that, at any point
 you have to ask yourself you know, what am I doing,  will I hit a
    THE LYNN REPORTING AGENCY  CERTIFIED AUDIO TRANSCRIBER
                   II NOKTII WArCI-:i-'ll-:i.l> ROAD. MM>|.| i;il< >KO. N II. (HHVi

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 lucky fracture and draw the contaminants from the site in some
 fashion.  I mean, you're right/ watering, washing a car, it's not likely
 to be a big draw on the system, but it's the fact that you don't know
 what you're doing to the system right now.
                Most of the contaminants are all in this area and
 the bedrock really doesn't hold much right now, but it's still
 something that I'd question, what am I pulling over and what's
 the value of that versus just using water that's supplied anyway.
                AUDIENCE:  But as long as you're using it on
 site, you don't mink that it's being drawn into any other areas, then.
 up?
                AUDIENCE: How long is the fence going to be
                MR. LUCE: We had hoped to drop the fence and
 then the tree guy, Lou, who I guess you met last June, he said the
 deer will eat the trees up and so that's one of the reasons why we
 want to leave part of it up. I got Mr. Runde's comment regarding
 the fence and what I've talked to Pete Jalajas about is in terms of
 leaving up the three sides, the back, the two sides, and putting
 in something that's more aesthetically pleasing, a three railed fence
 or something up front so mat it looks like a nursery, which is what it
 looks like now, and men a wooded lot in a couple years from now.
 And I don't know if that's something that would be possible,
 acceptable to you and acceptable to Ford. That's something we have
 to work out.  I know when I went up there, mere were a couple of
 other things that I talked to Pete about in terms of just more or less
 hiding things and he has no problem with mat in terms of neating up
    THE LYNN REPORTING AGENCY  CERTIFIED AUDIO TRANSCRIBER
                   31 NORTH WAKi:i-li;i.l) ROAD. WOLHiHORO. NH 03894 (ซM)S69.SW7

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	.	.	____^  17
 the site a little bit.
                MR. JALAJAS: All those things that Danyl
 mentioned here, our field people are doing their quarterly ground
 monitoring through the end of June here in the second quarter, so
 they're all really close.  So come July we should see all  these things
 happening.
                MR LUCE: Yes?
                AUDIENCE:  How far from the site do you have
 monitoring wells? I'm wondering if they've shown any  changes
 with the incredibly hard rain that we've had which has caused a lot
 more groundwater. That's one question. I have a second, a
 different question.
                MR LUCE: Well, the first part is I know we've
 had some  hard rains and I wouldn't expect to see anything right
 now. We have wells that are almost a half mile from the site.
 Whether they're effective wells, that Fm not certain of.  I mean
 they've shown no contamination or very light contamination from
 what I believe may have been other sources. There's a well way
 down here that had benzene a long time ago mat was not above the
 drinking water standards, but still benzene can come from a lot of
 other things, the main component of gasoline.
                And then I know mere was the  Vances' house
 down here that was contaminated because principally there was a
 fracture that lies - I believe it dips down this way and then runs
 along almost Hall Road and the campground down there at the time
 was pumping for all the residents and I think that was pulling in a
    THE LYNN REPORTING AGENCY   CERTIFIED AUDIO TRANSCRIBER
                  31 NORTH WAKIiKII'Ll) ROAD. WOI.H-HORO, N.H  03K94 (6m) Vป9 5S87

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lot of contaminants and so they had low contamination. They did
have some that was over the drinking water standard and we haven't
sampled that in some time. That's something that we will look to do
in the future because we saw no reason to sample right now with no
one drinking it and we wanted to concentrate our sampling efforts in
here while we were doing the vacuum extraction to make sure that
we were, again, optimizing the recovery there; again, removing the
mass here so hopefully we don't see anything in the future.
               Now, with the hard rain I wouldn't expect it to
immediately affect this particular zone right here, simply because
the rate of ground water movement, approximately twenty feet per
day at its very highest in this material right here. So that wouldn't
have a big effect there.  In the bedrock, in areas where it may
outcrop, you would see a more immediate effect there, yes, and in
terms of what that  may do to the contaminants; because there's not
much in the way of bedrock contamination, I don't think it would be,
again, a lot. If there were to be any effect, I would think mere
would be a lag time after — maybe a couple months after landing up
here and having to get through this material and then out.
               And the second part?
               AUDIENCE:  How long does it take the  trees to
get big enough to have the desired effect of decreasing the  ground-
water?
               MR. LUCE: Well, I have a vague idea, but Pete,
would you say two years?
                MR. JALAJAS:  More like three years to get big
    THE LYNN REPORTING AGENCY  CERTIFIED AUDIO TRANSCRIBER
                  31 NORTH WAKI-MI-I.I) ROAD. WOLFLHOKO. N.H. O.WX <ซM) 569 5587

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		19
 enough roots (inaudible).
                MR. LUCE: They'll be water this year, so
 right, they won't be lowering the water table this year. I don't think
 anything could lower the water table this year.  But in the future
 as the trees do start competing and moving down, that's what Lou
 Litka talked about, two to three years before we start seeing
 effective removal. Are mere any other questions?
                The next segment of this is what's going to be the
 public hearing portion. Typically, what we've done in the past for
 these sort of things is we have a public meeting and then a couple
 weeks after that a public hearing where we take comments.  As
 described in the proposed plan there, with the comments what we're
 doing is just soliciting your ideas and input.
                You not only have this opportunity to just
 comment out loud, but also you can send in your comments. Mr.
 Runde has already sent me one on the portion of the proposed plan
 that can just be mailed in to either Tom or I, but it would be nice to
 have it just come to me so mat we've got just the one central area.
 Again, too, you can call us at any time. I know Mr. Boucher and
 Mr. Swier and Ms. Judwell have my phone number and Tom's, as
 well, so if there are any comments mat anyone would like to make,
 though, we now formally open the public hearing; please step
 forward and state your name and what your comment is.
                MR. RUNDE: I have a couple comments.  Mr.
 Runde from Tibbetts Road. I'd like to know if the road that was
 damaged between my property and Stan's is going to be repaired. It
    THE LYNN REPORTING AGENCY   CERTIFIED AUDIO TRANSCRIBER
                  31 NORTH WAKKHI-LI) ROAD. WOLFLUOKO. N.H. O.W;4 (603) 569 5SH7

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	_.              	     20
 was damaged this spring by the trucks coming in and out of the site.
                 I don't believe that there are going to be enough
 deer in that area to warrant leaving that fence up. That is a
 populated area and you don't have that many deer running through
 there. I think that's just a bunch of baloney. I think it's a ploy to
 keep the fence  up and keep it as a test site.  I'd just like to make that
 comment. I think it's a ploy for the EPA and these people to keep
 the fence up, to keep it as a test site longer than it should be.  I don't
 believe it. I can't believe it. I don't see that many deer out there.
                And those poplars, because I've worked with the
 forest service and I've planted many of those trees, even if they did
 eat a few of those leaves and branches, they will bounce right back
 the next year and actually help them to grow; because every place
 where you cut one of those branches,  it will just branch off and
 make it better.
                MR. LUCE: I should also state, too, that with the
 commentary we don't — EPA and the  State don't engage in —  it's not
 a question and  answer. Well take these comments and we will -
 I should have stated this earlier — and we'll put those in as an
 official response. So those comments that Mr. Runde made will be
 officially recorded in the record decision and we'll respond to it in
 writing in that same document.  And once that document is done, it
 will be put in the Bamngton Town Library. Thanks. Any other
 comments? Well, again thank you for coming mis evening and,
 again, if you have any questions, please give me a call or Tom a
 call. We're usually around to take any questions.
    THE LYNN REPORTING AGENCY  CERTIFIED AUDIO TRANSCRIBER
                   .M NORTH WAKHFII'I.I) ROAD. WOLWHOKO. N.H. 0.^894 (6Ot) 569-5587

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1
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    I, Linda M. Lynn, do hereby certify that the foregoing instrument, numbered 1

    through 20, contain a true and correct transcript, to the best of my knowledge, of
5
    tape recorded proceedings at the Barrington Elementary School, Banington, New
6
7
B
                                                                              21
                                CERTIFICATE
     Hampshire, hereinbefore set forth, transcribed by me, from tapes identified as

     follows:
                              Linda M. Lynn, RPR
                              Notary Public
 9
                               TAPE NO. 98-027
10
     Dated at Wolfeboro, New Hampshire, this 26th day of June, 1998.

12

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                               My commission expires:  10/18/2000
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16   C:\WPWIN60\WPDOCS\EPA.HRG

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   THE LYNN REPORTING AGENCY   CERTIFIED AUDIO TRANSCRIBER
                 31 NORTH WAKKFItLD ROAD. WOLFliBORO, N.H 03K94 ((SO}) 569 5587

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ATTACHMENT B

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Use This Space to Write Your Comments

EPA wants your written comments on the options under consideration for dealing with the
contamination at the Tibbetts Road Superfund Site.  You can use the form below to send written
comments. If you have questions about how to comment, please call EPA Community Involvement
Coordinator Sarah White at 6177 565-9260. Send this form, or any other written comments,
postmarked no later than July 24, 1998 to:
             Darryl Luce
             Remedial Project Manager
             U.S. Environmental Protection Agency
             Region I, (HBO)
             JFK Federal Building
             Boston, MA 02203
Comment Submitted

bv:
Address:

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        APPENDIX F




ADMINISTRATIVE RECORD INDEX

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         Tibbetts Road
            NPL Site

    Administrative Record
            for the
 Amended Record of Decision

             Index
    Compiled: September 28, 1998
           Prepared by
         EPA-New England
Office of Site Remediation and Restoration

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                                  INTRODUCTION

      This document is the Index to the Administrative Record for the remedial action at the
Tibbetts Road Superftind Site. The citations in the Index are for those documents that EPA relied
upon in selecting a response action at the Site.  Site-specific documents are cited in Section I of the
Index, and EPA guidance documents are cited in Section II. Documents cited in Section I of the
Index are ordered by the Document Number that appears at the end of each citation.

      The Administrative Record is available for public review at the EPA Region I Office of Site
Remediation and Restoration (OSRR) Records Center in Boston, Massachusetts [(617) 573-5729],
and the Barrington Public Library, Star Route, Barrington, NH 03285.  This Administrative Record
includes documents in the September 29,1992 Administrative Record for this Site. EPA guidance
documents cited in Section II are available for review only at the OSRR Records Center. The Staff
of the OSRR Records Center recommends that you set up an appointment prior to your visit.

      Questions concerning the Administrative Record should be addressed to the Project Manager
for the Tibbetts Road Superfund Site.

      An Administrative Record is required by the Comprehensive Environmental Response,
Compensation and  Liability Act (CERCLA), as amended by the Superfund Amendments and
Reauthorization Act (SARA).

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Section I

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                       ADMINISTRATIVE RECORD INDEX
                              TIBBETTS ROAD
                            All Operable Units
  09/28/98
Page     1
04.09   FEASIBILITY STUDY - PROPOSED PLANS FOR SELECTED REMEDIAL ACTION

        Title:Proposed Plan to Amend the Cleanup Plan at the
                    Tibbetts Road Superfund Site.
        Authors:    ENVIRONMENTAL PROTECTION AGENCY REGION 1
        Date:       June 1998
        Format:      FACT SHEET,  PRESS RELEASE    No. Pgs:   12
        AR No.       04.09.1                      Document  No.  000007
05.04   RECORDS OF DECISION - RECORD OF DECISION

        Title:       Amended Record of Decision.
        Authors:    ENVIRONMENTAL PROTECTION AGENCY REGION 1
        Date:       September 28, 1998
        Format:     REPORT, STUDY
        AR No.       05.04.1                      Document No.  000008
06.04   REMEDIAL DESIGN - REMEDIAL DESIGN REPORTS

        Title:Overburden Aquifer Pilot Testing Program Results.
        Addressee:  ENVIRONMENTAL PROTECTION AGENCY REGION 1
        Authors:    GERAGHTY & MILLER, INC.
        Date:       April 1996
        Format:      REPORT,  STUDY                No. Pgs:   393
        AR No.       06.04.1                      Document No.  000001
        Title:      Results of Pulsed Operation Phase.
        Addressee:  ENVIRONMENTAL PROTECTION AGENCY REGION 1
        Authors:    GERAGHTY & MILLER, INC.
        Date:       December 1996
        Format:     REPORT, STUDY                No. Pgs:  48
        AR No.      06.04.2                      Document No.  000002

        Title:      Final Remedial Action Construction Report for
                    Overburden Remedial System.
        Addressee:  ENVIRONMENTAL PROTECTION AGENCY REGION 1
        Authors:    GERAGHTY & MILLER, INC.
        Date:       June 1997
        Format:     REPORT, STUDY                No. Pgs:  75
        AR No.      06.04.3                      Document No.  000003

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                       ADMINISTRATIVE RECORD INDEX              09/28/98
                              TIBBETTS ROAD                   Page     2
                            All Operable Units

        Title:      Phytoremediation Design Report.
        Addressee:  DARRYL LUCE - ENVIRONMENTAL PROTECTION AGENCY
                    REGION 1
        Authors:    ARCADIS GERAGHTY & MILLER
        Date:       April 1998
        Format:     REPORT, STUDY                No. Pgs:   187
        AR No.      06.04.4                      Document No.  000004
17.07   SITE MANAGEMENT RECORDS - REFERENCE DOCUMENTS

        Title:      Design and Interpretation of Microcosm Studies
                    for Chlorinated Compounds.
        Authors:    BARBARA H. WILSON, JOHN T.  WILSON, DARRYL LUCE -
                    ENVIRONMENTAL PROTECTION AGENCY
        Format:     REPORT,  STUDY                No. Pgs:   8
        AR No.      17.07.1                      Document No.  000006

        Title:      Uptake and Biotransformation of Trichloroethylene
                    by Hybrid Poplars.
        Authors:    LEE A. NEWMAN,  STUART E. STRAND, NAMI CHOE, JAMES
                    DUFFY
        Date:        1997
        Format:     REPORT,  STUDY                No. Pgs:   6
        AR No.      17.07.2                      Document No.  000005

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Section II

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                            GUIDANCE DOCUMENTS
The EPA guidance documents listed below were considered during the process of selecting the
response action for the Tibbetts Road Superfund Site.  These EPA guidance documents may be
reviewed at the EPA Region I Office of Site Remediation and Restoration Records Center, 90
Canal Street, Boston, MA 02114.

1.     CERCLA Compliance with Other Environmental Statutes, Porter. J.W. OS WER #9234.0-2.
      October 2, 1985.   [3001]

2.     CERCLA  Compliance  with Other Laws (Draft).  Office of Emergency and Remedial
      Response.  OSWER #9234.1-01.  August 8,  1988.   [3002]

3.     Considerations in Ground Water Remediation at Superfund Sites. OSWER # 9355.4-03.
      October 18, 1989. [2410]

4.     Ground-Water Protection Strategy. Office of Ground-Water Protection.  (EPA/440/6-84-
      002). August 1,  1984.   [2403]

5.     Guidance  on Remedial  Actions  for Contaminated Ground Water at Superfund Sites.
      OSWER #9283.1-2. December 1, 1988.  [2413]

6.     Suggested ROD Language  for Various Ground Water Remediation Options, Longest
      II, Henry, Office of Emergency and Remedial Response. OSWER # 9283.1 -03. October 10,
      1990.   [C206]

7.     Use of Monitored  Natural  Attenuation at Superfund.  RCRA  Corrective Action,  and
      Underground Storage Tank Sites.  OSWER# 9200.4-17. December 1, 1997.   [C473]

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