Document ID: EPA-HQ-SFUND-1994-0009-0002
Agency: epa
Document Type: Rule
Title: National Oil and Hazardous Substances Pollution Contingency Plan; National Priorities List; Direct Final Notice of Deletion of the Army Materials Technology Laboratory Superfund Site from the National Priorities List
Posted Date: 2006-09-22T12:22:21Z

[Federal Register: September 22, 2006 (Volume 71, Number 184)]
[Rules and Regulations]               
[Page 55319-55326]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr22se06-10]                         

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 300

[Docket ID No. EPA-HQ-SFUND-1994-0009; FRL-8221-6]

 
National Oil and Hazardous Substances Pollution Contingency Plan; 
National Priorities List

AGENCY: Environmental Protection Agency.

ACTION: Direct Final Notice of Deletion of the Army Materials 
Technology Laboratory Superfund Site from the National Priorities List.

-----------------------------------------------------------------------

SUMMARY: EPA Region 1 is publishing a direct final notice of deletion 
of the Army Materials Technology Laboratory Superfund Site (Site), 
located in Watertown, Massachusetts, from the National Priorities List 
(NPL). The NPL, promulgated pursuant to section 105 of the 
Comprehensive Environmental Response, Compensation, and Liability Act 
(CERCLA) of 1980, as amended, is Appendix B of 40 CFR part 300, which 
is the National Oil and Hazardous Substances Pollution Contingency Plan 
(NCP). EPA is publishing this direct final notice of deletion with the 
concurrence of the Commonwealth of Massachusetts, through the 
Department of Environmental Protection (MADEP), because EPA determined 
that all appropriate response actions under CERCLA--other than 
operation and maintenance and five-year reviews--have been completed 
and further remedial action pursuant to CERCLA is not appropriate.

DATES: This direct final deletion will be effective November 21, 2006 
unless EPA receives adverse comments by October 23, 2006. If adverse 
comments are received, EPA will publish a timely withdrawal of the 
direct final deletion in the Federal Register informing the public that 
the deletion will not take effect.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-HQ-
SFUND-1994-0009, by one of the following methods:
     http://www.regulations.gov: Follow the on-line instruction for 

submitting comments.
     E-mail: keckler.kymberlee@epa.gov.
     Fax: (617) 918-0385.
     Mail: Kymberlee Keckler, Remedial Project Manager, U.S. 
Environmental Protection Agency, Region 1, 1 Congress Street, Suite 
1100 (HBT), Boston, Massachusetts 02114-2023.
     Hand delivery: 1 Congress Street, Suite 1100 (HBT), 
Boston,

[[Page 55320]]

Massachusetts 02114-2023. Such deliveries are only accepted during 
normal hours of operation, and special arrangements should be made for 
deliveries of boxed information.
    Instructions: Direct your comments to Docket ID No. EPA-HQ-SFUND-
1994-0009. EPA's policy is that all comments received will be included 
in the public docket without change and may be made available online at 
http://www.regulations.gov, including any personal information provided, 

unless the comment includes information claimed to be Confidential 
Business Information (CBI) or other information whose disclosure is 
restricted by statute. Do not submit information that you consider to 
be CBI or otherwise protected through http://www.regulations.gov or e-mail. 

The http://www.regulations.gov Web site is an ``anonymous access'' system, 

which means EPA will not know your identity or contact information 
unless you provide it in the body of your comment. If you send an e-
mail comment directly to EPA without going through http://www.regulations.gov, 

your e-mail address will be automatically captured and included as part 
of the comment that is placed in the public docket and made available 
on the Internet. If you submit an electronic comment, EPA recommends 
that you include your name and other contact information in the body of 
your comment and with any disk or CD-ROM that you submit. If EPA cannot 
read your comment because of technical difficulties and cannot contact 
you for clarification, EPA may not be able to consider your comment. 
Electronic files should avoid the use of special characters, any form 
of encryption, and be free of any defects or viruses.
    Information Repository: All documents in the docket are listed in 
http://www.regulations.gov index. Although listed in the index, some 

information is not publicly available, e.g., CBI or other information 
whose disclosure is restricted by statute. Certain other material, such 
as copyrighted material, will be publicly available only in hard copy. 
Publicly available docket materials are available either electronically 
at http://www.regulations.gov or in hard copy at the U.S. Environmental 

Protection Agency, Region 1, Superfund Records Center, 1 Congress 
Street, Suite 1100, Boston, Massachusetts 02114-2023 and at the 
Watertown Free Public Library, 123 Main Street, Watertown, MA 02472. 
The EPA Superfund Records Center is open Monday through Friday from 9 
a.m. to 5 p.m. and the Watertown Free Library is open Monday through 
Thursday from 9 a.m. to 9 p.m., Friday and Saturday from 9 a.m. to 5 
p.m., and Sunday from 1 p.m. to 5 p.m. The EPA Superfund Records 
Center's telephone number is (617) 918-1440 and the Watertown Free 
Library's telephone number is (617) 972-6431.

FOR FURTHER INFORMATION CONTACT: Kymberlee Keckler, Remedial Project 
Manager, U.S. Environmental Protection Agency, 1 Congress Street, Suite 
1100 (HBT), Boston, Massachusetts 02114-2023, (617) 918-1385, Fax (617) 
918-0385, E-mail: keckler.kymberlee@epa.gov.

SUPPLEMENTARY INFORMATION:

Table of Contents

I. Introduction
II. NPL Deletion Criteria
III. Deletion Procedures
IV. Basis for Site Deletion
V. Deletion Action

I. Introduction

    EPA, Region 1, is publishing this direct final notice of deletion 
of the Army Materials Technology Laboratory Superfund Site from the 
NPL.
    The EPA identifies sites that appear to present a significant risk 
to public health or the environment and maintains the NPL as the list 
of those sites. As described in 40 CFR 300.425(e)(3) of the NCP, sites 
deleted from the NPL remain eligible for remedial actions if conditions 
at a deleted site warrant such actions.
    EPA is taking this action without prior publication of a notice of 
intent to delete because it considers this action to be non-
controversial and routine. This action will be effective November 21, 
2006 unless EPA receives adverse comments by October 23, 2006 on this 
notice or the parallel notice of intent to delete published in the 
Proposed Rules section of today's Federal Register. If adverse comments 
are received within the 30-day public comment period on this direct 
final notice of deletion, EPA will publish a timely withdrawal of this 
direct final notice of deletion before the effective date of the 
deletion and the deletion will not take effect. EPA will, as 
appropriate, prepare a response to comments and continue with the 
deletion process on the basis of the notice of intent to delete and the 
comments already received. There will not be an additional opportunity 
to comment.
    Section II of this document explains the criteria for deleting 
sites from the NPL. Section III discusses the procedures that EPA is 
using for this action. Section IV discusses the Army Materials 
Technology Laboratory Superfund Site and demonstrates how it meets the 
deletion criteria. Section V discusses EPA's intent to delete the site 
from the NPL unless adverse comments are received during the public 
comment period.

II. NPL Deletion Criteria

    Section 300.425(e) of the NCP provides that releases may be deleted 
from the NPL where no further response is appropriate. In making a 
determination to delete a release from the NPL, EPA shall consider, in 
consultation with the State, whether any of the following criteria have 
been met:
    (i) Responsible parties or other persons have implemented all 
appropriate response actions required;
    (ii) All appropriate Fund-financed (Hazardous Substance Superfund 
Response Trust Fund) response under CERCLA has been implemented, and no 
further response action by responsible parties is appropriate; or
    (iii) The remedial investigation (RI) has shown that the release 
poses no significant threat to public health or the environment and, 
therefore, taking of remedial measures is not appropriate.
    Even if a site is deleted from the NPL, where hazardous substances, 
pollutants, or contaminants remain at the deleted site above levels 
that allow for unlimited use and unrestricted exposure, CERCLA section 
121(c), 42 U.S.C. 9621(c) requires that a subsequent review of the site 
will be conducted at least every five years after the initiation of the 
remedial action at the deleted site to ensure that the actions remain 
protective of public health and the environment. In the case of this 
Site, a five-year review is necessary because not all hazardous 
substances, pollutants, and contaminants have been removed from the 
Site. If new information becomes available that indicates a need for 
further action, EPA may initiate remedial actions. Whenever there is a 
significant release from a site deleted from the NPL, the deleted site 
may be restored to the NPL without the application of the hazard 
ranking system.
    In the case of the Army Materials Technology Laboratory, the 
selected remedies are protective of human health and the environment. 
The Army will maintain the institutional controls and will perform 
annual inspections. The first five-year review was conducted by EPA, 
the MADEP, and the Army in January 2002. The second five-year review 
was completed in March 2006. Copies are located at the repository noted 
previously. The remedies were deemed protective. Reviews will be 
conducted every five years hereafter.

[[Page 55321]]

III. Deletion Procedures

    The following procedures apply to deletion of the Site:
    (1) EPA consulted with the Commonwealth of Massachusetts on the 
deletion of the Site from the NPL before developing this direct final 
notice of deletion.
    (2) The Commonwealth of Massachusetts concurred with the deletion 
of the Site from the NPL on September 8, 2006.
    (3) Concomitantly with the publication of this direct final notice 
of deletion, a notice of the availability of the notice of intent to 
delete the Site from the NPL will be published in a major local 
newspaper of general circulation at or near the Site and will be 
distributed to appropriate federal, state and local government 
officials and other interested parties. The newspaper notice announces 
the 30-day public comment period concerning the notice of intent to 
delete the Site from the NPL.
    (4) EPA and the Army placed copies of the documents supporting the 
deletion in the Site information repositories identified above.
    (5) If adverse comments are received within the 30-day public 
comment period on this notice or the companion notice of intent to 
delete also published in today's Federal Register, EPA will withdraw 
this direct final notice of deletion before its effective date and will 
respond to comments and continue with the deletion process on the basis 
of the notice of intent to delete and the comments already received.
    Deletion of a site from the NPL does not itself create, alter, or 
revoke any individual's rights or obligations. Deletion of a site from 
the NPL does not in any way alter EPA's right to take enforcement 
actions, as appropriate. The NPL is designed primarily for 
informational purposes and to assist EPA management. Section 
300.425(e)(3) of the NCP states that the deletion of a site from the 
NPL does not preclude eligibility for future response actions, should 
future conditions warrant such actions.

IV. Basis for Site Deletion

    The following information provides EPA's rationale for deleting the 
Site from the NPL:

Site Location

    The Army Materials Technology Laboratory (Site) lies in Middlesex 
County, Massachusetts, 6 miles northwest of Boston, and occupies 
approximately 48 acres within the town of Watertown, MA. The 
surrounding city population is approximately 34,000. Developed land 
adjacent to the Site is a mix of residential and commercial uses. The 
Site borders the Charles River to the south.

Site Background and History

    The AMTL facility was established in 1816 and was originally used 
for the storage, cleaning, repair, and issuance of small arms. During 
the mid-1800s, the mission was expanded to include ammunition and 
pyrotechnics production; materials testing and experimentation with 
paints, lubricants, and cartridges; and the manufacture of breech 
loading steel guns and cartridges for field and siege guns. The 
mission, staff, and facilities continued to expand until after World 
War II, at which time the facility encompassed 131 acres, including 53 
buildings and structures, and employed 10,000 people. Arms 
manufacturing continued until an operational phasedown was initiated in 
1967 and much of the property was transferred to the General Services 
Administration (GSA). In 1968, GSA sold approximately 55 acres to the 
Town of Watertown. This property was subsequently used for the 
construction of apartment buildings, the Arsenal Mall, a public park, 
and a playground. AMTL contained fifteen major buildings and fifteen 
associated structures. In 1960, the Army's first material research 
nuclear reactor was completed at AMTL. The reactor was used actively in 
molecular and atomic structure research activities until 1970 when it 
was deactivated. The research reactor was decommissioned under the 
jurisdiction of the Nuclear Regulatory Commission in 1992 and the 
structure was demolished in 1994. In 1987, the U.S. Army Toxic and 
Hazardous Material Agency initiated preliminary site studies, the first 
stage of the facility's closure plan. In late 1993, Congress 
recommended the closure of the facility. On September 29, 1995, AMTL 
was officially closed and reverted to a caretaker status.
    The AMTL was placed on the EPA National Priorities List (NPL) as a 
Superfund Site in May 1994 and in 1995 the Army signed an Interagency 
Agreement with the EPA stipulating that site investigations and cleanup 
actions would follow CERCLA/Superfund Amendments and Reauthorization 
Act, under the regulatory guidance of the National Contingency Plan 40 
CFR part 300. A Technical Review Committee was formed at the time that 
has subsequently become the Restoration Advisory Board. In 1994, AMTL 
was placed on the Base Realignment and Closure list.
    In August 1998, 36.5 acres of the 48-acre CERCLA site were 
transferred from the ownership of the U.S. Army. At that time, the 
Watertown Arsenal Development Corporation (WADC) acquired 29.44 acres 
of the Site. The Town of Watertown took ownership of 7.21 acres. In 
March 2005, the remaining 11 acres of the Site were transferred to the 
Commonwealth of Massachusetts, Department of Conservation and 
Recreation (DCR). The DCR was formed in 2003, when the Metropolitan 
District Commission, or ``MDC'' merged with the Massachusetts 
Department of Environmental Management, or ``DEM.'' As set forth below, 
the MDC has managed a portion of the site since the 1920s. At the time 
of each transfer, the United States of America, acting by and through 
the Secretary of the Army, granted the MADEP a Grant of Environmental 
Restriction and Easement for each appropriate zone of the AMTL Site. 
The purpose of the grant is to provide a mechanism for the creation and 
enforcement of the necessary land use controls as required by the 
CERCLA Records of Decision (RODs) for the Site (September and July 
1996). The first grant re-designated areas into lots for property 
transfer and future deed tracking. Environmental Zones 1, 2, and 3 (the 
parcel initially transferred to WADC) were designated as Lot 1. Lot 1 
was sold to Charles River Business Center Associates (CRBCA) in 
December 1998. CRBCA sold the Lot 1 property to the President and 
Fellows of Harvard College (Harvard) in May 2001. Environmental Zone 4 
(the parcel transferred to the Town of Watertown) was designated as Lot 
2. Zones 1, 2, 3, and 4 were deleted from the NPL through the partial 
deletion process on November 22, 1999.
    Zone 5, the Charles River Park, is the subject of the second grant. 
Although this park was AMTL property, it was managed by the MDC since 
the 1920's under a lease from the Army. Since then, the land has been 
maintained as open and recreational space. In 1948, the MDC leased 
approximately two acres of the riverfront property to the Watertown 
Yacht Club.
    Because of the complexity of this industrial facility, the Site was 
divided into three areas for investigation. EPA designated these three 
areas as operable units. The operable units are described in detail 
below.
OU1--Outdoor Areas
    Operable unit 1 (OU1) addresses most outdoor soils and all 
underlying groundwater. The indoor areas and petroleum related cleanups 
are

[[Page 55322]]

addressed under the Commonwealth of Massachusetts cleanup authority. 
Environment Zones 1-5 (Areas A, B, C, D, E, F, G, H, J, K, L, M, N, O, 
P, Q, T, and metal hot spots) are all included in the OU1 ROD. These 
areas exceeded expected future use and/or ecological risk levels for 
metals, polycyclic aromatic hydrocarbons (PAHs), polychlorinated 
biphenyls (PCBs) and pesticides. The ROD required soil excavation and 
off-site disposal/reuse of contaminated soils exceeding cleanup goals 
and was signed on September 26, 1996. The ROD for OU1 also documented 
that no further action was necessary under CERCLA for the groundwater 
at the entire AMTL site. Two Explanations of Significant Differences 
(ESD) have been signed for OU1. The first ESD addressed Lot 1 and was 
signed on January 12, 1998. The second ESD addressed the Charles River 
Park and was signed on June 7, 2001. The ESDs changed the subsurface 
PAH cleanup levels to levels protective of construction workers. The 
first ESD revised PAH cleanup goals were applied at Areas B, E, G, and 
L4. These cleanup goals were also applied to the Charles River Park 
(Zone 5: Areas M, N, O, P, and Q) as part of the second ESD.
OU2--Charles River
    OU2 encompasses approximately two miles of the Charles River 
adjacent to the AMTL property. This area of the river has received 
contaminants from the AMTL site via storm drainage, direct discharges, 
and erosion. The ROD for this operable unit documented that no further 
action was necessary under CERCLA for these sediments because the 
contaminants are present at levels that are indistinguishable from the 
concentrations associated with exposure to urban background conditions 
in the Lower Charles River Basin. The OU2 ROD was signed on September 
29, 2005.
OU3--Area I
    Area I is located northeast of Building 131 at the intersection of 
Talcott Street and Kingsbury Avenue (Zone 3). The ROD for OU3 was 
signed before the OU1 ROD for residential cleanup of soils contaminated 
with PAHs and pesticides above cleanup levels. This area was segregated 
from OU1 to enable faster redevelopment. The OU3 ROD was signed on June 
28, 1996.

Remedial Investigation/Feasibility Study (RI/FS) Results and Record of 
Decision (ROD) Findings for Operable Units 1 and 3

OUs 1 and 3--RI/FS Results
    Remedial Investigations of these two operable units were conducted 
between 1987 and 1995 and generally found the following contamination 
across the facility.
    Groundwater: With the exception of one well, all upgradient wells 
showed detectable quantities of chlorinated solvents, suggesting that 
off-site sources have caused or aggravated on-site groundwater 
contamination. Based on a site water table map, groundwater flow paths 
indicate the potential for groundwater to flow away from the site in an 
area in the northwestern part of the site before flowing toward the 
Charles River. No evidence of on-site contamination migrating off-site 
was found in groundwater samples collected from on-site wells because 
the majority of contamination was detected in the upgradient wells. The 
on-site, and farthest downgradient, wells bordering the Charles River 
showed the lowest levels of contamination. Although some contamination 
is present in certain areas of on-site groundwater, this does not pose 
a current or future risk because the groundwater is not used as a water 
supply, and no significant migration of contamination is occurring. The 
site groundwater meets the Commonwealth of Massachusetts definition of 
a non-drinking water aquifer (GW-3) as defined in 310 C.M.R. Part 40. 
Therefore, there is no risk to human receptors. Groundwater does 
discharge from the site into the Charles River. A model of contaminant 
contribution via groundwater to the Charles River was developed. This 
model, as presented in the FS, shows that no significant concentrations 
of contaminants are migrating to the river from the site groundwater. 
Hence, there is no risk to human health or the environment from site 
groundwater and no further action was documented in the OU1 ROD for all 
groundwater across the AMTL facility.
    Surface soils: Semi-volatiles, pesticides, polychlorinated 
biphenyls (PCBs), and metals were detected at levels exceeding the 
Massachusetts Contingency Plan (MCP) S-1/GW-1 standards (the most 
protective). These detections were scattered and in hot spots, as 
opposed to site-wide distribution. PCBs were detected at levels above 
the EPA action level. The analytical results showed that the total 
uranium activity in all soils was below the Federal maximum allowable 
standards.
    Sub-surface soils: Volatile organics, semi-volatile organics, 
polycyclic aromatic hydrocarbons (PAHs), pesticides, and metals were 
found at many sampling locations above MCP S-1/GW-1 standards.
    Surface water and sediments: Surface water contained arsenic and 
lead exceeding human health Ambient Water Quality Standards. Sediments 
were contaminated with low levels of metals and pesticides above 
sediment screening values.
    A summary of the contaminants of concern for soil and the 
corresponding cleanup levels follows:

----------------------------------------------------------------------------------------------------------------
                                                         ROD cleanup
                                                         level (mg/   ESD cleanup
                                            Maximum          kg)       level (mg/     Zone where cleanup level
      Soil contaminant of concern        concentration  (surface and      kg)                pertains**
                                             (mg/kg)     subsurface   (subsurface
                                                           soils)     soils only)
----------------------------------------------------------------------------------------------------------------
Benzo(a)anthracene.....................          32.0           8.5        1760.0  2, 3, 4 & CRP.
Benzo(a)pyrene.........................          37.0           2.0         154.0  2, 3, 4 & CRP.
Benzo(b)fluoranthene...................          15.0           7.9        1760.0  2, 3, 4 & CRP.
Benzo(k)fluoranthene...................          24.0           6.2       17600.0  2, 3, 4 & CRP.
Chlordane..............................           9.4           1.4*  ...........  4 & CRP.
Chrysene...............................          34.0          11.1      176000.0  3, 4 & CRP.
DDD....................................           3.5          13.7   ...........  4 & CRP.
DDE....................................           6.3           0.14  ...........  4 & CRP.
DDT....................................           5.2           0.17  ...........  4 & CRP.
Dibenzo(a,h)anthracene.................           3.3           0.27        154.0  3 & CRP.
Dieldrin...............................           4.0           0.35  ...........  4 & CRP.
Indeno(1,2,3-cd)pyrene.................          14.0           3.0        1760.0  2, 3, 4 & CRP.
Arochlor 1260 (PCB)....................           4.9           1.0   ...........  3 & 4.
----------------------------------------------------------------------------------------------------------------
*Cleanup goal for chlordane in Zone 3 was 1.5 mg/kg based on human health risk.
**No cleanup goals were developed in the ROD for Zone 1.

[[Page 55323]]

    Human health risks for both OU1 and OU3 were evaluated for current 
use and for future use. The future use included a residential scenario, 
which is the most protective assessment for human health. Risks were 
unacceptably high under the residential conditions (maximum cancer 
risks 3E-05 and maximum Hazard Index 0.4) and therefore remediation was 
required. Some areas were remediated to commercial risk levels and 
required a Grant of Environmental Restriction.
    Ecological risk scenarios include exposure to site groundwater in 
the Charles River and exposure to site soils in the limited open space 
areas. Although contaminants in groundwater could migrate toward the 
Charles River, the level of contamination is not expected to adversely 
affect aquatic organisms. Most of the AMTL Site is not prime 
terrestrial habitat owing to the lack of open space. Suitable habitat 
for terrestrial vegetation and wildlife is restricted to the 
southeastern corner of the site. Major risk drivers were metals and 
pesticides. Receptors evaluated in the risk assessment with 
unacceptable hazard indices were: Northern short-tailed shrew, white-
footed mouse, American robin, song sparrow, and earthworms. Cleanup 
goals were not determined for metals because on-site metals were found 
to be generally consistent with normal background levels. Any areas 
with metals contamination posing an unacceptable localized risk were 
co-located with pesticides and remediated.
OU2-RI Results
    Various investigations were performed between 1979 and 2005. In 
1979, the Army completed a study to verify where storm water pipes were 
located and identified seven storm water pipes at AMTL that discharged 
either directly or through the storm water system into the Charles 
River. In 1994, 1998, and 2003 surface water and sediment samples were 
taken upstream and downstream of the outfalls. The 2003 sampling event 
also included biological and toxicological studies of the river 
conditions. The Charles River was divided into four reaches for the 
purposes of evaluation in the baseline ecological risk assessment.
    There are numerous existing and historical sources of pollutants to 
the Charles River, an urban riverine system. Chemicals detected in 
surface water at the Charles River OU were found at low concentrations 
that were either below human health based risk screening levels, 
consistent with upstream background conditions, or indistinguishable 
from the urban background conditions of the Charles River.
    Sediments were found to be contaminated by PAHs, inorganics, low 
levels of pesticides and PCBs, and extremely low levels of several 
radionuclides.
    Potential human receptors included the people engaging in water-
related activities along and on the river or eating fish caught from 
the river. These activities were considered for resident adults and 
children and park visitors. Based on the nature of contamination and 
anticipated activities, the exposure routes evaluated for this portion 
of the Charles River included:

--Ingestion and dermal contact with river water and sediments;
--Ingestion of contaminated fish; and
--External exposure to radiation released from radionuclides in 
sediments.

    An advisory concerning the consumption of fish was issued by MDPH 
in 1996 for the Lower Basin of the Charles River owing to elevated 
PCBs.

    Results of the HHRA revealed that all cancer and non-cancer risk 
levels were within the acceptable thresholds specified in the National 
Contingency Plan. The estimated excess chemical carcinogenic risk to 
adults ranged from 1 x 10 -\10\ for ingestion of surface 
water to 2 x 10 -\6\ for ingestion of sediment. The excess 
carcinogenic risk from radionuclides ranged from 5 x 10 
-\11\ for ingestion of surface water to 8 x 10 
-\10\ for ingestion of fish. Chronic hazard index values for 
children ranged from 0.00003 for ingestion of surface water to 0.01 for 
ingestion of fish and for dermal exposure to sediment.
    Based on all of the site data, EPA concluded that the potential for 
ecological risks contributed by the former AMTL facility are 
indistinguishable from the anthropogenic urban background conditions 
that characterize the Lower Charles River Basin. EPA considered (1) the 
weight assigned to each measurement endpoint; (2) the magnitude of the 
response observed in each measurement endpoint; and (3) the summation 
of the degree of agreement among the outcomes of each measurement 
endpoint. There are elevated levels of many constituents (and a 
potential for ecological risk) present in all four reaches and the 
majority of these compounds are present at concentrations consistent 
with upstream reference locations. In general, the potential for 
ecological risk to benthic invertebrates was found to be low to 
moderate, with an even lower potential risk to finfish and vertebrate 
wildlife, respectively.
    A No Further Action ROD was signed for OU2 because of consistency 
of the AMTL site conditions with urban background and the similar 
potential for ecological risks across sampling reaches.

OU1, OU2, and OU3 ROD Findings

OU1 ROD Findings
    On September 26, 1996, the Army and EPA signed a Record of Decision 
documenting the remedial action selected for OU1. The MADEP concurred. 
The major components included:
     Excavation of areas with contaminated soils above cleanup 
goals;
     Confirmatory soil sampling after contaminated soil 
removal;
     Off-site landfill disposal or reuse of the excavated soil;
     Backfilling with clean soils;
     Institutional controls to limit future use and to restrict 
site access; and
     Five-year reviews.
    Two Explanations of Significant Difference (ESD) were signed for 
this OU. The first ESD addressed Lot 1 and was signed on January 12, 
1998. The second ESD addressed the Charles River Park and was signed on 
June 7, 2001. Both ESDs changed the subsurface PAH cleanup levels to 
levels protective of construction workers. The revised PAH cleanup 
goals were applied at Areas B, E, G, and L4 with the first ESD. These 
cleanup goals were also applied to the Charles River Park (Zone 5: 
Areas M, N, O, P, and Q) with the second ESD.
OU2 ROD Findings
    A No Further Action ROD was signed on September 29, 2005 because 
the potential for risks contributed by the former AMTL facility were 
indistinguishable from urban background conditions. MADEP concurred.
OU3 ROD Findings
    The ROD for OU3 was signed on July 28, 1996. The major components 
include:
     Excavation of areas with contaminated soils that were 
above cleanup goals;
     Confirmatory soil sampling within excavations after 
contaminated soil removal;
     Off-site landfill disposal or reuse of the excavated soil;
     Backfilling of clean fill soils into the excavations.
    There are no institutional controls in place that are applicable to 
OU3. The MADEP concurred.

[[Page 55324]]

Response Actions for OU1 and OU3

OU1 Remedial Action
    Soil clean-up goals were established in the ROD for different zones 
at AMTL based on their intended future use. The clean-up goals were 
developed to allow a mix of future uses at the site, including 
residential, commercial, and recreational scenarios. The only exception 
was for the contaminants of concern and for the Zone 3 where the 
residential cleanup level was slightly higher than the ecologically 
protective level for chlordane. In addition, during remediation and 
excavation activities, the Army and regulators determined that a 
construction worker scenario was a more realistic and appropriate 
exposure scenario for soils at a depth greater than one foot below 
ground surface (bgs) at Zones 1 and 2. Because the Baseline Risk 
Assessment did not include the construction worker exposure scenario, 
additional risk assessment work was performed. The construction worker 
exposure scenario recognized that periodic maintenance and/or 
installation of subsurface utilities/structures would be required in 
the future. In general, the construction worker exposure scenario 
differs from the commercial exposure scenario by evaluating risks from 
contaminated soils below one foot bgs using an exposure duration that 
mimics the potential need to perform periodic subsurface utility work. 
The top one foot of soil meets the appropriate risk-based clean-up 
goals and no changes were made to the cleanup goals in the surface 
soils. In addition, the subsurface soil construction worker exposure 
scenario is recognized as an appropriate risk scenario for the public 
benefit reuse areas (Zone 4) because the open space user will not 
likely excavate below one foot and will be protected by the one foot of 
soil meeting its risk-based clean-up goals. The Revised clean-up goals 
were documented in an ESD, dated January 12, 1998. Remedial action 
objectives remained the same--mitigate the risks to human health and 
the environment posed by direct contact with and incidental ingestion 
of contaminated soils. The revised cleanup goals were applied at Areas 
B, E, G, J, and L. The confirmation samples taken before the revision 
of the clean-up goals indicated that the soils below one foot met these 
goals and the excavations were considered complete.
    Remedial Action for the northern zone of the AMTL site was started 
on November 20, 1996, and completed on July 27, 1998. All soils were 
disposed off-site in accordance with state and federal requirements. 
Implementation of the required Institutional Controls took place during 
the transfer.
    In 1997, the Army began remedial activities within the Charles 
River Park parcel. Two areas (Areas N & O) within the 11-acre Park 
parcel were remediated but work in the remainder of the Park was 
suspended. The excavation volumes required to achieve soil clean-up 
levels specified in the ROD were significantly larger than previously 
estimated. This resulted in a significant potential increase in 
estimated costs of the remedy for the Charles River Park parcel.
    The Army applied the revised cleanup goals (previously documented 
in the January 1998 ESD) to the Charles River Park parcel at elevations 
greater two foot bgs level since several areas required the removal of 
the top two feet of soil in order to address elevated ecological risks. 
This change was documented in an ESD dated June 7, 2001.
    Riverbank excavations at areas P, Q, and M were terminated at two 
feet bgs since no revised clean-up goals were exceeded. A terraced 
wetland was constructed in Areas P and Q to provide protection from 
boat wakes and wind-driven waves. A breakwater structure was 
constructed at the toe of the bank. Vegetated plugs, shrubs, and trees 
were planted above the breakwater and erosion matting was placed on the 
slope.
    The entire Charles River Park zone was mulched, seeded, and 
fertilized. Remedial Action for the Charles River Park zone was 
completed on December 22, 2003. All soils were disposed off-site in 
accordance with state and Federal requirements. Implementation of 
Institutional Controls for this zone took place during the transfer 
process.
    In August 1998, 36.5 acres were transferred from the ownership of 
the U.S. Army. The Watertown Arsenal Development Corporation (WADC) 
acquired 29.5 acres of the site and the Town of Watertown took 
ownership of 7 acres. In March 2005, the remaining 11 acres of the 
site, the Charles River Park parcel, were transferred from the Army to 
the Commonwealth of Massachusetts, Department of Conservation and 
Recreation (DCR). At the time of each transfer, the Army issued a Grant 
of Environmental Restriction and Easement for each appropriate zone of 
the AMTL Site to the MADEP. The purpose of the Grants is to provide a 
mechanism for the creation and enforcement of the necessary land use 
controls as required by the CERCLA RODs for the site (July and 
September 1996). The WADC and Town of Watertown parcels were deleted 
from the NPL through the partial deletion process on November 22, 1999.
    The Charles River Park parcel is the subject of the second grant 
and this deletion process. Although the park was site property, it has 
been managed by the DCR since the 1920's under a right of way (ROW) 
from the Army. Since then, the land has been maintained as recreational 
space and a portion as a road. The ROW gave the right to use the 
property for a park, to construct improvements on the property that are 
reasonably related to park purpose, and to care for and manage the 
property. The ROW also gave the DCR police jurisdiction of the 
property. In 1948, the DCR's predecessor, Metropolitan District 
Commission, leased approximately two acres of the riverfront property 
to the Watertown Yacht Club for the hauling and storage of boats. A 
clubhouse and a three-bay maintenance garage with a boat winch 
currently occupy the area not used to store boats. The DCR and the club 
are currently negotiating a permit to continue boating operations at 
the site.
    The Army submitted the Final Project Close-Out Reports (dated May 
1998 and March 2002, respectively) and they were approved by both EPA 
and Massachusetts DEP. The joint EPA and MADEP inspection required by 
the NCP pursuant to 40 CFR 300.515(g) was conducted on June 23, 2003. 
As a result of the inspection, EPA determined that the remedy was 
``operational and functional'' under 40 CFR 300.435(f)(2).
OU3 Remedial Action
    Remedial Action (RA) for Area I started on August 26, 1996, and was 
completed on January 10, 1997. The Final Project Close-Out Report 
(December 1996) was approved by EPA and Massachusetts DEP. All soils 
were disposed off-site in accordance with state and Federal 
requirements. No institutional controls were needed as the ROD 
specified clean-up goals (Zone 3) were protective of residential 
exposure to soils.

Operation and Maintenance Activities

    The Army is responsible for conducting annual inspections of the 
institutional controls and ensuring that erosion control and bank 
stabilization project remains effective over the long-term.

Five-Year Reviews

    CERCLA requires a five-year review of all sites with hazardous 
substances remaining above health-based levels for unrestricted use of 
the site. Since hazardous substances will remain on-

[[Page 55325]]

site above levels allowing unlimited use and unrestricted exposure, a 
statutory five-year review will be conducted by the Army pursuant to 
CERCLA section 121(c) and as provided in OSWER Directive 9355.7-03B-P, 
Comprehensive Five-Year Review Guidance.
    The five-year review process will evaluate whether human health and 
the environment remain protected by the remedies. The first five-year 
review was performed in 2001 and documented in March 2002 by the Army. 
The Army completed its second five-year review in March 2006. EPA and 
MADEP concurred with the Army's assessment that the remedies were 
protective of human health and the environment. For future five-year 
reviews, EPA will review the Army's annual reports and conduct a five-
year review inspection. The Army will provide the next five-year review 
in March 2011.
    The first 5-year review, dated March 7, 2002 concluded:
     For OU1, the remedy was determined to be protective of 
human health and the environment as long as a limited amount of soil in 
Area E exceeding the applicable cleanup goals was removed. The soils 
were since excavated at Area E, shipped offsite, and used as landfill 
daily cover. All confirmation samples met the ROD criteria. The 
excavation was backfilled with clean soils and new benchmarks were 
installed to identify the area.
     The protectiveness of OU2 was not determined because the 
remedy had not yet been chosen.
     For OU3, the remedy was determined to be protective of 
human health and the environment.

----------------------------------------------------------------------------------------------------------------
             Restricted area                   Inspection description                     Frequency
----------------------------------------------------------------------------------------------------------------
Charles River Park Open Area............  Inspect to determine that the     Annually in June.
                                           use does not allow residential,
                                           daycare or school activities
                                           except those incidental to
                                           recreational park activities.
                                          Inspect area to ensure no
                                           excavation, drilling or
                                           otherwise disturbance of the
                                           soils located two feet or more
                                           below surface grade have
                                           occurred.
                                          Inspect benchmarks for eroded
                                           areas and reduction in grade
                                           and repair as necessary. Ensure
                                           that benchmarks remain visible.
                                          Breakwater Treatment Inspection:
                                           Inspect rock toe for
                                           separation and/or settlement.
                                           Inspect coir fascine
                                           for proper anchoring.
                                           Inspect for scour
                                           between plant carpets and coir
                                           fascine.
Charles River Park Wooded Area..........  Inspect to ensure use does not    Annually in June.
                                           allow residential, daycare, or
                                           school activities except those
                                           activities incidental to
                                           recreational park activities.
Watertown Yacht Club Open Area..........  Inspect to ensure use does not    Annually in June.
                                           allow residential, daycare, or
                                           school activities except those
                                           activities incidental to
                                           recreational park activities.
                                          Inspect benchmarks for eroded
                                           areas or reduced grade and
                                           repair as necessary. Ensure
                                           that benchmarks remain visible.
                                          Inspect area to ensure no
                                           excavation, drilling or
                                           otherwise disturbance of the
                                           soils located two feet or more
                                           below surface grade have
                                           occurred.
Structures at the Watertown Yacht Club..  Inspect to ensure use does not    Annually in June.
                                           allow residential, daycare, or
                                           school activities except those
                                           activities incidental to
                                           recreational park activities.
                                          Inspect area to ensure no
                                           excavation, drilling or
                                           disturbance of the soils below
                                           the building foundations and
                                           slabs have occurred.
                                          Inspect area to ensure no
                                           excavation, drilling or
                                           disturbance of the building
                                           foundations and slabs in a
                                           manner that would likely result
                                           in human contact with
                                           underlying soils has occurred.
North Beacon Street.....................  Inspect to ensure use does not    Annually in June.
                                           allow residential, daycare, or
                                           school activities except those
                                           activities incidental to
                                           recreational park activities.
                                          Inspect area to ensure no
                                           disturbance of the roadway or
                                           sidewalk pavement that would
                                           compromise their integrity or
                                           would be likely to result in
                                           human contact with the
                                           underlying soils has occurred.
North Beacon Street Wooded Area.........  Inspect to ensure use is          Annually in June.
                                           restricted to no residential,
                                           daycare, or school activities
                                           except those activities
                                           incidental to recreational park
                                           activities.
Buildings: 142, 244, 245, & 111.........  Inspect to ensure use does not    Annually in June.
                                           allow residential, daycare or
                                           school uses.
                                          Inspect to ensure that no
                                           transportation, disposal, or
                                           deposition of soils from within
                                           the parcel occurs, unless in
                                           compliance with the Soil
                                           Management Protocol set forth
                                           in Paragraph 4 of the Grant.
                                          Inspect area to ensure no
                                           excavation, drilling or
                                           otherwise disturbance of the
                                           building foundations and that
                                           would likely result in human
                                           contact with underlying soils
                                           has occurred.
Areas: L4, E, B & G.....................  Inspect to ensure use does not    Annually in June.
                                           allow residential, daycare or
                                           school (children under 18 years
                                           old), hotel, motel, community
                                           center (children under 18 years
                                           old), and/or recreational/
                                           activities uses.
                                          Inspect benchmarks for eroded
                                           areas and reduction in grade
                                           and repair as necessary. Ensure
                                           that benchmarks remain visible.
                                          Inspect to determine no soils,
                                           located at a depth of one foot
                                           or more below the surface
                                           grade, were removed unless
                                           disposed as required in the
                                           Grant.
Buildings: 97, 60, 652, & 312...........  Inspect to ensure use does not    Annually in June.
                                           allow residential, daycare or
                                           school (for children under 18
                                           years of age), hotel, motel,
                                           community center (for children
                                           under 18 years of age), and/or
                                           recreational uses or activities
                                           uses.
                                          Inspect to determine that no
                                           transportation, disposal, or
                                           deposition of soils from within
                                           the parcel occurs, unless in
                                           compliance with the Soil
                                           Management Protocol set forth
                                           in Paragraph 4 of the Grant.
                                          Inspect area to ensure no
                                           excavation, drilling or
                                           otherwise disturbance of the
                                           building foundations and slabs
                                           in a manner that would likely
                                           result in human contact with
                                           underlying soils have occurred.

[[Page 55326]]

Building 39.............................  Inspect to ensure that use does   Annually in June.
                                           not allow residential, daycare
                                           or school (children under 18
                                           years old), hotel, motel,
                                           community center (children
                                           under 18 years old), and/or
                                           recreational uses or activities
                                           uses.
Buildings 131, 117, & 313-S.............  Inspect area to ensure no         Annually in June.
                                           excavation, drilling or
                                           otherwise disturbance of the
                                           building foundations and slabs
                                           that would likely result in
                                           human contact with underlying
                                           soils have occurred.
----------------------------------------------------------------------------------------------------------------

    The second five-year review, completed in March 2006, concluded 
that the remedy at OU1 (the only site where hazardous materials remain 
on-site) is protective of human health and the environment in the 
short-term because there is no evidence of exposure. However, there was 
concern that some bank erosion occurred along the Charles River 
adjacent to Charles River Park (in areas where the Army was not 
required to remediate). In order for the remedy to remain protective in 
the long term, the Army must stabilize the riverbank adjacent to Areas 
P and Q before the next five-year review. While the integrity of the 
two-foot soil coverage required by the ROD and ESD remains intact along 
the riverbanks, the Army will undertake preventive measures to ensure 
long-term site integrity. This work began in September 2006 and is 
expected to be completed before the end of the year.

Community Involvement

    In addition to the regular community meetings discussed below, 
community relations activities for the Army Materials Testing 
Laboratory NPL Site have included the following: development of a 
community relations plan, public meetings and site tours during the RI 
and remedy selection process, public comment periods on proposed plans, 
and publication and distribution of fact sheets updating the status of 
site cleanup.
    In 1989, the Army established a Technical Review Committee (TRC) to 
enhance community involvement. In 1993 the TRC transitioned into a 
Restoration Advisory Board (RAB). The purpose of the TRC and RAB was to 
serve as a forum where representatives of the community, regulators, 
and the Army could discuss and exchange information on environmental 
cleanup issues and progress at the Site. The TRC and RAB provided an 
opportunity for stakeholders to participate in the decision-making 
process by reviewing and commenting on documents and proposed remedial 
actions. Through the TRC and RAB, cleanup decisions were discussed and 
approved.
    During fiscal year 2006, a fact sheet that discussed the intention 
to delete the site from the NPL was distributed to the RAB. EPA will 
also announce the deletion of the Site from the NPL once the deletion 
has been completed with fact sheet and public notice.

V. Deletion Action

    EPA, with concurrence from the Commonwealth of Massachusetts, has 
determined that all appropriate responses under CERCLA have been 
completed, and that no further response actions under CERCLA are 
necessary. Therefore, EPA is deleting the Site from the NPL.
    Because EPA considers this action to be non-controversial and 
routine, EPA is taking it without earlier publication of a notice of 
intent to delete. This action will become effective November 21, 2006 
unless EPA receives adverse comments by October 23, 2006 or a parallel 
notice of intent to delete is published in the Proposed Rule section of 
today's Federal Register. If adverse comments are received, EPA will 
withdraw this direct final notice of deletion before the effective date 
of the deletion and it will not take effect. EPA will respond to 
comments, as appropriate, and continue with the traditional deletion 
process on the basis of the notice of intent to delete and the comments 
already received. There will be no additional opportunity to comment. 
If EPA receives no adverse comment(s), this deletion will become 
effective November 21, 2006.

List of Subjects in 40 CFR Part 300

    Environmental protection, Air pollution control, Chemicals, 
Hazardous waste, Hazardous substances, Intergovernmental relations, 
Penalties, Reporting and recordkeeping requirements, Superfund, Water 
pollution control, Water supply.

    Dated: September 12, 2006.
Robert W. Varney,
Regional Administrator, U.S. EPA--New England.

0
For the reasons set out in this document, 40 CFR part 300 is amended as 
follows:

PART 300--[AMENDED]

0
1. The authority citation for part 300 continues to read as follows:

    Authority: 33 U.S.C. 1321(c)(2); 42 U.S.C. 9601-9657; E.O. 
12777, 56 FR 54757, 3 CFR, 1991 Comp.; p. 351; E.O. 12580, 52 FR 
2923, 3 CFR, 1987 Comp., p. 193.

Appendix B--[Amended]

0
2. Table 2 of Appendix B to part 300 is amended by removing the entry 
for ``Materials Technology Laboratory (US ARMY), Watertown, MA.''

[FR Doc. 06-7966 Filed 9-21-06; 8:45 am]

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