United States
Environmental Protection
Agency
Office of
Emergency and
Remedial Response
EPA/ROD/R03-91/107
December 1990
v°/EPA
Superfund
Record of Decision
Middletown Air Field, PA
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50272-101
REPORT DOCUMENTATION 11. REPORTNO.
PAGE EPA/ROD/R03-91/107
I ~
3. Recipient'. Acceuion No.
~ T11Ie 8nd ~litle
1UPERFUND RECORD OF DECISION
Aiddletown Air Field, PA
Second Remedial Action
7. Author(.)
5. Repor1 0818
12/17/90
6.
8. Perfonning Org8nlzallon Rapt. No.
8. Perfonnlng Org8lnlza1lon N8me 8nd AdcIresa
10. ProjectlTulllWork Unit No.
11. Contract(C) or Grant(G) No.
IC)
1~ Sponsoring Org8llizatlon N8me 8nd Addre..
U.S. Environmental Protection
401 M Street, S.W.
Washington, D.C. 20460
IG)
13. Type 01 Repor1 & PerIod Covered
Agency
800/000
14.
15. Supplementary Notes
16. Abstract (Umlt: 200 word.)
The SOD-acre Middletown Air Field site is a former military airfield located between
the towns of Highspire and Middletown in Dauphin County, Pennsylvania. Land in the
area is used predominantly for industrial and commercial purposes. Several on site
wetlands areas, as well as the floodplain of a small stream, have been identified
on site. From 1898 to 1917, the site was operated by the U.S. Army as a basic training
camp. Subsequently, the site was used as an airfield by the Army/Air Force from 1918
Jntil all onsite military operations ceased in 1966. Site features include several
private manufacturing companies, an inactive landfill, and the Harrisburg International
Airport (HIA). The site was divided into five distinct study areas where soil,
sediment, ground water, and surface water investigations were conducted. These five
study areas are: '(1) the 3D-acre runway area where, during the mid-1940s through 19S6,
wastes from base operations were either incinerated or placed in a landfill; (2) the
lSD-acre industrial area where industrial operations such as paint stripping and metal
finishing were conducted by the Air Force; (3) the I-acre fire training pit area where
combustible wastes were burned during military training exercises; (4) the 7-acre north
base landfill area where construction debris and miscellaneous drums were disposed of
(See Attached Page)
17. Document Analyel. .. Deecrlptore
Record of Decision - Middletown Air Field Site, PA
Second Remedial Action
Contaminated Media: soil, gw
Key Contaminants: VOCs (TCE), other organics (PAHs), metals (arsenic, chromium,
lead)
b. Idenlifier8lOpen-Ended Tenne
.
c. COSA 11 FlekVGroup
A veilebility SIatement
18. Security Cia.. (Thi. Report)
None
20. Security CI... (Thi. Pege)
None
21. No. 01 Pages
49
I
~ Price
(See ANSI-Z38.18)
See InslrUcuons on ReveIN
-
(Formerly NTl5-35)
Department 01 Commerce
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EPA/ROD/R03-91/107
Middletown Air Field, PA
necond Remedial Action
Dstract (Continued)
from 1950 to 1956; and (5) the Meade Heights housing area where, prior to housing
construction, wastes may have been disposed. Based on identification of onsite soil and
ground water contamination, the remedial action for the site was divided into five
Operable Units (OUs) that were slightly different from the study areas. These OUs and
their respective media of concern are as follows: ground water for the site (OUI); the
industrial area (soil) (OU2); the fire training pit area soil (OU3); the north base
landfill area (ground water) (OU4); and Meade Heights housing area (surface) (OU5).
This ROD provides a final remedy for OUI through OU4, and an interim remedy for OU5,
which requires additional investigations to determine contamination sources. The
primary contaminants of concern affecting the soil and ground water are VOCs .including
TCE; other organics including PAHs; and metals including arsenic, chromium, and lead.
The combined selected remedial action for this site at OUI through OU5 is continuing the
operation of existing drinking water supply treatment systems, which include air
stripping, followed by disinfection, and the current distribution system; monitoring and
treating any additional source of drinking water from new wells and other HIA wells not
used during routine operations; reconfiguring HIA ground water production wells;
monitoring ground water, surface water, sediment, and biota; preparing a health safety
plan for any future activities that may disrupt surface soil; and implementing
institutional controls including deed, land use, and ground water use restrictions
throughout the site. The estimated net present worth cost for the remedial actions for
OU1 through OU4 is $1,327,000. Capital costs for OU1 through OU4 total $118,000. There
are no capital costs for OU5; but a net present worth cost of $55,000. Total net
7esent worth cost for all five OUs is $1,382,000.
PERFORMANCE STANDARDS OR GOALS: Ground water remediation goals for OU1 and OU4 are
based on Federal MCLS, and include lead 5 ug/l (proposed MCL). The State ground water
ARAR for remediating the aquifer to meet background levels has been waived for technical
impracticability, and the aquifer itself will be treated to meet MCLs.
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RECORD OF DECISION
MIDDLETOWN AIRFIELD SITE
DECLARATION
SITE NAME AND LOCATION
Middletown Airfield Site
Middletown, Pennsylvania
STATEMENT OF BASIS AND PURPOSE
This decision document presents the selected remedial action for
the Middletown Airfield site, in Middletown, Pennsylvania, chosen
in accordance with CERCLA, as amended by SARA, and to the extent
practicable, the National Contingency Plan. This decision is
based on the administrative record file for this site.
The state of Pennsylvania has not concurred with the selected
remedy. .
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 ROD, may present an imminent and substantial
endangerment to human health, welfare, or the environment.
DESCRIPTION OF REMEDIES
EPA's overall strategy for protecting human health and the
environment at the Middletown Airfield Site is to:
.
Prevent. the ingestion of groundwater that has
contaminants in excess of regulatory drinking water
Standards or criteria, or in excess of health-based
levels;
.
Prevent human exposure to contaminated soil and dust
during activities that require disturbance of soils at
both the Industrial Area and the Fire Training Pit
Area; and
.
Prevent aquatic organisms living in a stream or river
environment from being adversely impacted by
contaminants.
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In order to accomplish these objectives, the Middletown Airfield
Site has been divided into five operable units:
.
Operable Unit 1:
Harrisburg
Industrial Area--
International Airport (HIA)
Groundwater Production Wells
Industrial Area--Soils
Fire Training Pit Area--Soils
North Base Landfill Area--Groundwater
Meade Heights Area--Surface Water
.
Operable
Operable
Operable
Operable
Unit 2:
Unit 3:
unit 4:
Unit 5:
.
.
.
A final decision has been made in this ROD to mitigate any
imminent or substantial endangerment to human health, welfare, or
the environment for the first four operable units. For Operable
Unit 5, an interim action is proposed as the results of the field
investigation were inconclusive in determining the source(s) of
contaminants and their potential environmental impacts.
The first operable unit prevents the ingestion of groundwater at
the site that has contaminants in excess of regulatory drinking
water standards or criteria, or health-based levels. This remedy
. involves continued operation of the existing drinking water
supply treatment systems and the current distribution system, the
institution of groundwater use restrictions, and additional
, monitoring of the water supply wells. The onsite system is
treating 1.5 million gallons per day. This is one half its
maximum capacity.
The major components of the selected remedy include:
continued operation of the existing drinking water
supply treatment sy~tems for groundwater.
i
I
I
I .
.
Monitoring and tre__ment of any additional source of
drinking water from new wells and other HIA wells not
used during routine operations.
.
A hydrogeologic investigation which will include, at a
minimum, a capture zone analysis for HIA production
wells.
.
Reconfiqpration of the HIA groundwater production
wells.
.
Monthly monitoring for organic and inorganic
contaminants in the HIA wells for a period of one year.
.
Installation of shallow, intermediate or potentially
deep bedrock wells between the North Base Landfill and
Middletown Well (MID 04).
.
Quarterly monitoring of the newly installed wells for
organic and inorganic contaminants for a period of. five
years.
-------
.
Restrictions on permitting of new wells downgradient of
the North Base Landfill Area.
The second and third operable units prevent public or worker
exposure to contaminated soil and dust during activities that
require the disturbance of soils. The major components of the
selected remedy for Operable units 2 and 3 include:
.
Land use and access restrictions.
.
Public and
activities
excavation
site soil.
worker health and safety requirements for
involving construction, demolition, and
or other activities that would disturb the
The fourth operable unit which provides protection of MID 04 from
contaminants found in the North Base Landfill Area has been
integrated with Operable Unit 1 in order to collectively address
the groundwater at the site.
The fifth operable unit provides for the evaluation of water
quality and organisms living in the stream near Meade Heights.
The major components of this selected interim remedy include:
.
Sampling of surface water and sediments.
Sampling of stream invertebrates, aquatic insects, and
fish.
.
STATUTORY DETERMINATIONS FOR OPERABLE UNITS 1, 2, 3, AND 4
The selected remedies are protective of human health and the
environment, comply. with federal and state requirements that are
legally applicable or relevant and appropriate to the remedial
action, and are cost-effective. The existing remedy at the site,
which is an integral part of the overall site remedy, utilizes
permanent solutions to the maximum extent practicable. However,
because additional treatment of the principal threats of the site
were not found to be practicable, these remedies do not satisfy
the statutory preference for treatment as a principal element of
the remedy. Onsite groundwater treatment is the existing remedy
that is currently being utilized on the site. The remedy -
selected for Operable Unit 1 recognizes the existing treatment
and mandates continued treatment of groundwater at the site. The
State of Pennsylvania groundwater ARARs for Operable Unit 1 will
be waived since EPA has determined that it is technically
impractical at this time to remediate groundwater to background
concentrations. The aquifer itself will be treated to Maximum
Contaminant Levels (MCLs).
Because these remedies will result in hazardous substances above
health-based levels remaining onsite, a review will be conducted
within five years after commencement of remedial action to ensure
that the remedy continues to provide adequate protection of hUDa~
-------
health and the environment. At this time, the technical
practicability for meeting the Commonwealths groundwater ARAR
will be reevaluated.
STATUTORY DETBRMINATIONS FOR OPERABLB UNIT 5
Operable unit 5 does not constitute the final remedy and
therefore the statutory requirements for protection of the
environment may not be met. Given the limited scope of this
action, issues such as long-term effectiveness and permanence;
reduction in toxicity, mobility, or volume through treatment; and
cost-effectiveness will not be satisfied by this interim action
and will be addressed at the time of the final response action.
Subsequent actions are planned to address fully the principal
threats posed by this operable unit.
~~ y; ~
L. ~l~(. - L~-
DEC 171990
Edwin B. Erickson
Regional Administrator
Date
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RECORD OP DBCISION
MIDDLBTOWN AIRFIBLD SITB
DECISION SUMMARY
I.
SITE HAME, LOCATION, AND DESCRIPTION
The Middletown Airfield Site is located in Dauphin County,
Pennsylvania. The site is about eight miles southeast of
Harrisburg, Pennsylvania, between the towns of Highspire and
Middletown. The site is situated along Pennsylvania Route 230,
with the southern border on the Susquehanna River.
The site was divided into five distinct study areas for
facilitating the remedial investigation (RI): the Runway Area,
the Industrial Area, the Fire Training pit Area, the North Base
Landfill Area, and the Meade Heights Area. The location of these
areas and the site are shown in Figure 1.
The size of the Runway Area landfill is estimated to be
approximately 30 acres. This consists of about 10 percent of the
total runway and taxiway areas. The Industrial Area of the
, Middletown Airfield Site includes numerous buildings on
approximately a lS0-acre tract of land. The Fire Training Pit
Area located at the northwestern end of the airport runway is
approximately one acre in size. The approximate land area of the
North Base Landfill, which is located three-fourths of a mile
north of the airport, is seven acres. The Meade Heights Area
that was investigated consists of a hillside area of about two
acres and a ravine along a small stream (Figure 2).
The Middletown Airfield Site lies within the Triassic Lowland of
the Piedmont Physiographic Province. The Triassic Lowland is
characterized by a gently undulating topography, which slopes
generally to the south and is traversed by long low ridges and a
few round hills. Altitudes on the site range from 280 feet above
mean sea level (MSL) at the Susquehanna River to approximately
420 feet MSL at the northern boundary.
Very little of the site is an undisturbed natural area because of
industrial/ commercial land uses. Site topography provides a
significant portion of the driving force behind groundwater
movement at the site. Groundwater withdrawals from several
pumping centers also strongly influence groundwater flow at the
site. On the basis of groundwater usage, the subsurface at the
Middletown Airfield Site can be divided into three broad
categories: overburden, shallow bedrock, and the deep bedrock.
Usage of the deep bedrock groundwater (greater than 200 feet) is
extensive. Usage of the shallow bedrock groundwater is less
extensive, while groundwater in the overburden is not used as a
direct water supply source.
The RI has shown that groundwater recharge to the shallow bedrock
carries contaminants from the overburden aquifer. It also
-------
PENNSYLVANIA
FRUEHAUpf
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SOIL BORING AND MONITORING
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~JI~..""«J~..
-------
revealed that groundwater movement through the bedrock occurs in
isolated zones. Once groundwater enters the bedrock from the
overburden, it travels along vertical bedding planes.
A wetlands investigation was also conducted as part of the RI and
the results are presented in Figure 3. The largest wetland area
located at the Middletown Airfield Site is the forested deciduous
wetland which has developed west of the Fire Training Pit Area
(Area A - Figure 3). The other wetlands identified were marsh
type wetlands located north and south of West Main Street (Area
B); offsite immediately adjacent to the eastern end of the site
along the Susquehanna River (Area D); a floodplain for a small
stream located east of Meade Heights (Area E); and a wet meadow
type wetland located east of the Fruehauf parking lot at the
North Base Landfill (Area F).
II. SITE HISTORY AND ENFORCEMENT ACTIVITIES
The property occupied by the Middletown Airfield Site was
initially established by the Army as a basic training camp in
1898. In 1917, the Army Signal Corps established a storage depot
known as the Aviation General Depot consisting of warehouses,
open sheds, and garages. This depot was renamed in 1921 as the
Middletown Air Intermediate Depot. Flying activities at the base
began in 1918 and the airfield was named the Olmstead Field for
Lt. Robert S. Olmstead in 1923. Through World War II various Air
Corps materiel was stored at the site. Activities at the base
consisted of complete overhauling of aircraft including
stripping, repainting, engine overhaul, reassembly, and equipment
replacement as well as general base support maintenance and
operation. In 1947, Olmstead Field was renamed Olmstead Air
Force Base to coincide with the designation of the Air Force as a
separate Department of Defense establishment. In 1956, a major
expansion of existing runways to handle jet aircraft was
undertaken. In the early 1960s, Air Force operations began to
decrease and all operations were ceased by 1966.
The Air Force airfield and many of the Air Force buildings are
now owned by the Pennsylvania Department of Transportation (PA
DOT) and operated by the Harrisburg International Airport (HIA),
several small private manufacturing companies, and the
Pennsylvania Air National Guard. The property north of
Pennsylvania Route 230 is owned by the Fruehauf Company (a truck
trailer production facility), the Odd Fellows Organization, and a
branch campus of the Pennsylvania State University.
Several investigations that have been performed at the Middletown
Airfield Site since 1983 have been summarized below:
The potable water production wells at HIA are sampled frequently
by the Pennsylvania Department of Environmental Resources
(PADER). In September 1983, R.E. Wright Associates (REWAI) was
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PENNSYLVANIA
MIDDLETOWN
i mm
HARRISBURG
INTERNA flONAL
AIRPORT
SWATARA
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ROYALTON
FIGURE 3
WETLANDS LOCATED
ON OR NEAR THE
MIDDLETOWN AIRFIELD
SITE
WETLANDS
Gannett Fleming
»CALt_ I" • 2000'
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asked to investigate a milky water condition which had developed
in the four HIA wells (6, 9, 11, and 12) providing water to the
HIA complex. REWAI determined that the four wells were being
overproduced and had air entrained in them. This overproduction
resulted from the heavy pumping of the four wells to provide 1.6
million gallons per day of water to HIA, which had been
previously served by ten wells. The other six wells (HIA 1
through 5 and 13) had been removed from production due to
trichloroethene and tetrachloroethene contamination. As a part
of this operation, the former landfill located beneath the HIA
runway was investigated to determine if it may be contributing to
the contamination of the HIA production wells. Based on
groundwater test results and the normal groundwater gradient at
the landfill, it was concluded that the Runway Area landfill was
not the source of contamination to the HIA production wells.
Also in 1984, ground penetrating radar and magnetometer surveys
were conducted by Roy F. Weston at the Runway, Industrial, and
North Base Landfill areas. Nine partially exposed 55-gallon
drums were removed from a fill area located along a stream bank
northeast of the Meade Heights housing complex. The drums were
empty except for water and coatings of a hard, black tarry
substance. These contents were sampled and found to be
nonhazardous under the EPA characteristic of EP toxicity.
The Middletown site was proposed for inclusion on the National
Priorities List (NPL) on October 1, 1984 after EPA scored the
site using the Hazard Ranking System. The site was included on
the NPL on June 1, 1986. EPA's initial response centered around
the presence of volatile organic compounds (VOCs) that were found
in the groundwater beneath the site. The remedy selected to
address the contaminated drinking water supply consisted of the
installation of an air stripping system for the removal of VOCs
to meet the drinking water standards. The existing treatment
system consists of two air strippers, an ion exchange unit for
the removal of hardness, and disinfection prior to distribution.
The selected remedy was documented in the December 30, 1987
Record of Decision (ROD).
In order to fully characterize the site and identify potential
public health and environmental concerns, EPA issued a contract
for an extensive study of the site in 1988. The study was
conducted by NUS Corporation (NUS) and Gannett Fleming, Inc.
(GF). The study was conducted in two phases—the RI and the
Feasibility Study (FS).
A potentially responsible party (PRP) search was conducted in
1988 by Development Planning and Research Associates, Inc.
(DPRA). DPRA conducted its research within the information
collection guidelines as specified by EPA under the terms of
CERCLA, as amended by SARA. The work was conducted in two
phases. The first phase consisted of describing the site and
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4
remedial activities; producing results of the title search and
identifying possible PRPs; and making recommendations for
preparing and sending CERCLA 104(e) letters. The second phase
consisted of analyzing the CERCLA 104(e) letter responses and
concluding the search by making appropriate recommendations.
Based upon these recommendations and additional followup
information, EPA identified several potentially responsible
parties (PRPs).
The objectives of the RI were:
.
To characterize the chemical nature of contamination.
.
To determine the approximate lateral and vertical
extent of contamination.
.
To develop an understanding of groundwater flow to
determine contaminant migration.
.
To characterize the potential for environmental impact
to the Susquehanna River, and evaluate the current
environmental condition of Swatara Creek.
.
To evaluate current and potential public health and
environmental risks.
.
To develop appropriate remedial objectives based on the
data collected during. the RI.
Various data collection activities were conducted to meet these
objectives. Data were collected to identify contaminants in
groundwater, surface water, sediments and soil. A total of 21
overburden monitoring wells, 14 bedrock monitoring wells and 39
subsurface soil borings were drilled during the investigation.
Two rounds of groundwater samples were taken at each of the new
wells installed by GF, as well as from 17 existing monitoring and
production well locations. A single round of samples was.
collected from five residential wells and a neighboring community
production well. In addition, one round of surface water and
sediment samples was taken from 24 separate locations on and
adjacent to the site. Groundwater testing was also conducted at
the site to evaluate aquifer characteristics and determine
groundwater flow conditions.
Following the RI, an FS was conducted to evaluate a range of
remedial altern~tives that would protect human health and the
environment from potential risks associated with the Middletown
Airfield Site.
In order to accomplish these objectives, five operable units were
established. The operable units are not the same as the five
-------
5
study areas discussed previously. The five areas of concern in
the RI identified all potentially contaminated media within
distinct and spatially separate areas: whereas the five operable
units identify only those media within a specific area that
require remediation. The five operable units are:
. Operable unit 1: Groundwater for the Middletown site
. Operable unit 2: Industrial Area--Soil
. Operable Unit 3: Fire Training pit Area--Soils
. Operable Unit 4: North Base Landfill Area--Groundwater
. Operable unit 5: Meade Heights Area--Surface Water
III.
COKMUNITY RELATIONS HISTORY
In accordance with Sections 113 and 117 of the comprehensive
Environmental Response, Compensation and Liability Act (CERCLA),
42 U.S.C. Sections 9613 and 9617, EPA held a public comment
period, which was extended due to a request from the public, from
August 13, 1990 through October 13, 1990 for the proposed
remedial actions described in the RI/FS and the Proposed Plan.
The notice of availability of the Work Plan, Project Operations
Plan, Community Relations Plan, Remedial Investigation,
Feasibility Study, and the proposed Plan was published in The
Patriot News on August 13, 1990. These documents were made
available to the" public in the administrative record maintained
in the EPA Region III office and at the Middletown Public
Library. In addition, a public meeting was held on August 29,
1990. At this meeting, representatives from EPA answered
questions about problems at the site and the remedial
alternatives under consideration. A response to the comments
received during the public comment period is included in the
Responsiveness Summary, which is part of this ROD. This decision
document presents the selected remedial action for the Middletown
Airfield Site, in Middletown, pennsylvania, chosen in accordance
with CERCLA, as amended by SARA and, to the extent practicable,
the NCP. The decision for this site is based on the
administrative record.
IV.
SCOPB AND ROLB OP RESPONSB ACTION
EPA's strategy for protecting human health and the environment a:
the Middletown Airfield site is to:
2)
Reduce the mobility and volume of organic and inorganic
contamination in the groundwater as necessary to be
protective of the public health and environment:
continue to prevent the ingestion of groundwater that has
contaminants in excess of regulatory drinking water
standards or criteria, or in excess of health-based levels
for both organic and inorganic contaminants;
1)
-------
6
3)
Prevent human exposure to contaminated soil and dust during
airport construction; and
4)
Prevent aquatic organisms living in a stream or river
environment from being adversely impacted by contaminants.
Operable Units 1 and 4 were developed to address contaminated
groundwater at the site, whereas Operable Units 2 and 3 were
developed to address contaminated soils at the site.
A final decision has been made in this ROD to mitigate any
imminent or ~ubstantial endangerment to human health, welfare, or
the environment for the first four operable units. For Operable
Unit 5, further investigation is proposed as the results from the
field investigation showed a need for further study to determine
the source(s) of contaminants and their potential environmental
impacts. The final remediation will primarily be based on the
results of the interim action.
v.
SUMMARY OP SITE CHARACTERISTICS
The five areas that were investigated for potential soil and
groundwater contamination were the Runway Area, Industrial Area,
Fire Training pit Area, North Base Landfill Area, and the Meade
Heights Area. Samples were collected from groundwater, surface
water, sediments, and soils in or adjacent to the five study
areas. The groundwater and soil sampling locations at the Runway
Area, Industrial Area and Fire Training Pit Area are shown in
Figure 4. The groundwater and soil sampling locations at the
North Base Landfill Area and Meade Heights Area are presented in
Figure 2. Surface water and sediment samples collected at and
adjacent to the site are shown in Figure 5.
Runwav Area
From the mid-1940s through 1956, wastes (sanitary, ash fill,
debris and various chemicals) from base operations were either
incinerated or landfilled in this area. An old Fire Training pit
was also located in this area in the early 1940s before it was
moved to the new location on the westernmost part of the site.
In 1956, a runway construction program was initiated so that the
base could accommodate jet aircraft. This led to the phasing out
of the incinerator landfill area and the use of other base areas
for waste disposal. Presently, this area lies beneath the main
runway of the HIA.
The soil boring locations in the Runway Area along the
Susquehanna,River (BHH-2, BHH-4, and BHH-8) showed the highest
concentrations of volatiles (vinyl chloride, 1,2-dichloroethene
[DCE], trichloroethene [TCE], and chlorobenzene), semivolatiles
(polynuclear aromatic hydrocarbons [PAHs] and dichlorobenzenes) ,
and lead. The groundwater monitoring wells sampled in the Run~a:'
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-jeF-sos-
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FIGURE 4
SAMPLING LOCATIONS
INDUSTRIAL, RUNWAY
AND UHL TRAINING
PIT ARtAS
jt t He-mini
*«•« ODD FELLOWS HOME
MOMTOTONG WELLS
GANNETT FLEMING
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-------
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PENN STATE
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HOME
TRAINING
AREA
INDUSTRIAL
AREA
MIDDLETOWN
ROYALTON
SURFACE WATER AND SEDIMENT
SAMPLING LOCATIONS
MIDDLETOWN AIRFIELD
Gannett Fleming
-------
Area showed raised concentrations of the volatile organics TCE,
DCE, vinyl chloride, carbon tetrachloride, benzene,
chlorobenzene, and tetrachloroethene. The metals detected at
raised concentrations were arsenic, barium, cadmium, chromium,
lead, and nickel. Surface water and sediment samples were
collected from the Susquehanna River adjacent to the runway. The
surface water showed low concentrations of DCE (13 |±g/L) , TCE (8
M9/L) / and 4,4'-DDT (0.27 jig/L) . Aluminum, iron, and zinc
exceeded the Federal Ambient Water Quality Criteria (AWQC). The
presence of contaminants (volatiles, PAHs, a phthalate, and a
polychlorinated biphenyl [PCS]) in the sediments was observed.
Industrial Area
Throughout the operation of the Air Force Base, industrial
operations such as paint stripping, metal finishing, assembly,
and equipment testing were conducted in the industrial shops.
Currently, this area is occupied by several private manufacturing
companies as well as the HIA.
The groundwater contamination in the Industrial Area is
widespread and it encompasses the central area of HIA including
the area east of the Terminal Building parking lot to the eastern
edge of the site near the warehouse buildings. The area between
the Stambaugh Aviation facility (GF-217) and the old base
wastewater sump (GF-218) showed elevated levels of TCE, DCE,
chlorobenzene, dichlorobenzenes, chromium, lead, barium, arsenic,
cadmium, and nickel (Figure 4). Except for chlorobenzene and
dichlorobenzenes, none of the contaminants detected in the
groundwater are present at high concentrations in the soil. HIA
production well 13 is located in close proximity to this area.
Currently, water pumped from HIA-13 for industrial process
purposes is being treated in the wastewater lagoons at the
eastern end of the site. The soil beneath the lagoons do not
seem to be a significant source of volatile organic contamination
to the groundwater since concentrations of volatile organics in
that area were relatively low. Elevated concentrations of
semivolatiles were also found in the soils, however, no adverse
impact to any receptors has been identified.
Fire Training Pit Area
Combustible wastes generated by industrial aircraft maintenance
were burned in this area during fire training exercises. These
materials included fuels with too high a water content, oil and
various waste solvents. Currently, this area is abandoned. The
highest soil contamination in the Fire Training Pit Area was
found in the surface soils (PAHs and lead). The concentrations
at which the contaminants DCE, TCE, bis(2-ethylhexyl)phthalate,
barium, and chromium were observed in this area were relatively
low. Surface water and sediment samples were collected adjacent
to this area from the Susquehanna River (Figure 5). PAHs and
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8
phthalates observed at low concentrations in the sediments may be
site related but do not appear to pose a threat to the
environmental quality of the Susquehanna river. Low
concentrations (1 to 2 M9/L) of three volatile organics were
observed in the surface water.
North Base Landfill
This landfill was used for waste disposal from 1950 to 1956 to
accommodate the runway expansion program. Construction debris
was primarily disposed at this location; however, it was also
noted that some drums were deposited at the site. Thisproperty
is now owned and operated by Fruehauf as a truck trailer
facility. At the North Base Landfill Area location, monitoring
continues to indicate the presence of trichloroethene
contamination in the bedrock groundwater aquifer. The presence
of contamination raises a concern regarding the potential of
contamination reaching the Middletown drinking water supply well
(MID-04), however, no contaminants above drinking water Maximum
Contaminant Levels (MCLs) were found during this investigation at
MID-04. The soils sampled in the Fruehauf parking lot have low
levels of contamination. Surface water and sediment samples were
taken from a small stream at this location (Figure 5). Some
PAHs, phthalates, and a pesticide were detected in the sediments
but do not appear to pose a threat to the environmental quality
of the stream. Iron and lead exceeded the Federal AWQC for
surface waters in isolated samples. The evaluation of
alternatives for groundwater remediation at the North Base
Landfill will be incorporated into the discussion of groundwater
remedies for the Industrial Area.
Meade Heiqhts
As part of a major expansion in 1956, this area was bought and
used for military housing. Based on historical photos provided
by the Environmental Photographic Interpretation Center (EPIC),
there is evidence that shows that this area was used for waste
disposal purposes prior to 1963. Soil borings during the GF
investigation also indicated the presence of fill material.
Currently, this area houses Penn State University students.
The primary contaminants in the only soil boring in the Meade
Heights Area were PAHs. Since these compounds are strongly
adsorbed onto soils, it is unlikely that they would pose a threat
to groundwater resources in the area. Barium, chromium, zinc and
nickel were detected at raised concentrations in the groundwater.
Surface water and sediment samples taken from the stream showed
the presence of bis(2-ethylhexyl)phthalate in the sediments. The
other contaminant observed was methylene chloride. Zinc exceeded
the Federal AWQC for surface waters in one isolated sample.
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9
In order to further assess the presence of contamination, several
surface water and sediment samples were collected along Swatara
Creek (Figure 5). Low concentrations of pesticides (0.0033 to
3.8 ~g/L) were detected in the surface water. other contaminants
(PAHs, phthalates, volatiles, and pesticides) were observed at
low concentrations at several locations in the sediments.
Groundwater movement is the most significant mechanism for
contaminant transport at all of the study areas. The overburden
and bedrock aquifers act as seijarate units but both have a
gradient of approximately 4xlO ft/ft and flow toward the
Susquehanna River. Some contaminants are transmitted from the
overburden aquifer to the bedrock aquifer through fractured beds
that dip north to northwest. This may be one source of
contamination found in the 100-foot bedrock wells and the deep
production wells. Contaminants are dispersed throughout site
soils and the respective aquifers. Few discrete sources of high
concentrations of contaminants were found in site soils.
Consequently, it is difficult to establish quantitative
relationships for contaminant transport from soil to groundwater.
This is important since it makes it difficult to predict the
ability to reduce contamination levels in the groundwater from
any $oil remediation.
Surface water movement is a potentially important contaminant
transport mechanism at the Runway Area, Industrial Area and Fire
Training Pit.. Stormwater flowing through soils in these areas
provides baseflow to the Susquehanna River. This baseflow
contains contaminants found in overburden groundwater and can
potentially affect aquatic life. The Susquehanna River provides
a great deal of dilution after mixing with the stormwater
discharges. However, the presence of contaminants in the river
and river sediments may be the result of precipitation migrating
through contaminated site soils, or other upstream sources may
also be contributing to the contaminants measured in the river or
sediments. '
The effect of stormwater discharges on the river was estimated
through use of a desktop dilution calculation. Based on this
method, it was determined that five metals, two pesticides and a
PCB contained in discharges to the river may affect aquatic life
in a worst-case scenario.
Trackout (the transport of dirt on vehicles from onsite to
offsite) is a minor transport mechanism at the Industrial Area,
North Base Landfill Area and Meade Heights Area. However,
trackout becomes important if subsurface excavation is likely to
occur as a result of commercial/industrial development. This
scenario should be handled by institutional controls involving
appropriate health and safety requirements.
various categories of contaminants found on the site may be
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10
readily transported across media and over significant areas. In
general, monocyclic aromatics and chlorinated aliphatic
hydrocarbons are relatively mobile in groundwater and surface
water. Halogenated phenols, PAHs, phthalate esters, pesticides,
PCBs, and metals are less mobile in groundwater and surface
waters. They may be transported by surface water runoff or
sediment transport; however, many factors influence the
solubility of specific contaminants.
Biodegradation/biotransformation are potentially significant fate
mechanisms for all contaminants, except metals. However,
degradation/transformation is less likely to occur if
macronutrient and/or oxygen availability are limited, or if there
are inhibitory effects from high levels of metals and organic
chemicals. Soil-catalyzed oxidation is a potential fate
mechanism for phenol and monocyclic aromatics. All of the
contaminants, except chlorinated aliphatic hydrocarbons,
monocyclic aromatics, nonhalogenated phenols, and some metals,
are potentially bioaccumulative.
VI. SUMMARY OF SITE RISKS
During the RI/FS, an analysis was conducted to estimate the
potential human health or environmental problems that could
result if contaminated media at the site were not cleaned up.
This analysis is commonly referred to as the baseline risk
assessment. Potential human health problems are identified by
calculating risk levels and hazard indices. Potential
carcinogenic risks are identified by the risk level, and a 1x10 s
level indicates one additional case in 1,000,000 that an
individual will develop cancer above the expected normal rate of
approximately 250,000 per 1,000,000. The hazard index identifies
the potential for the most sensitive individuals to be adversely
affected by noncarcinogenic chemicals. If the hazard index
exceeds one (1.0), there may be concern for potential non-cancer
effects. As a rule, the greater the value of the hazard index
above 1.0, the greater the level of concern. Changes in the
hazard index, however, must be over one or more orders of
magnitude (e.g., 10 times greater) to be significant.
The risk assessment focused on contaminants detected within the
five operable units. Many human exposure pathways were
evaluated. The major concerns are the ingestion of contaminated
water from the HIA production wells and the MID-04 well located
adjacent to the North Base Landfill Area, the inhalation of dust
and the ingestion of soil from the Industrial Area, and the
inhalation of dust and ingestion of soil from the Fire Training
Pit Area. In Table 1, a summary of the calculated carcinogenic
risk and hazard indices is presented.
Based on post-air stripping average contaminant concentrations,
the ingestion of HIA production well water would result in a
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11
hazard index of 2.0 to children. The potential for
noncarcinogenic health effects in children is primarily a result
of antimony, arsenic and cadmium. The average concentrations of
these contaminants, however, are below existing and proposed
drinking water quality criteria. The potential for carcinogenic
risk is within the acceptable range for both adults and children.
Lead is the contaminant that poses the greatest carcinogenic
risk, but the average concentration of lead (5.6 ~g/L) is below
EPA's suggested drinking water criterion of 15 ~g/L.
Ingestion of water from MID-04 would not result in a potential
for noncarcinogenic health effects or carcinogenic risk above
that which are considered acceptable. No contaminants were
detected in MID-04 that are above drinking water quality
criteria. The chemical that poses the greatest carcinogenic risk
is dieldrin (a pesticide), but the source of this contaminant
does not appear to be site related.
Exposure to contaminants in the surface soil or dust in the
Industrial and Fire Training pit areas during construction would
not result in a potential carcinogenic risk outside the range
commonly considered acceptable. In addition, the potential for
noncarcinogenic health effects would not be above that which is
considered acceptable.
Exposure to contaminated water and sediments in the Swatara Creek
or Susquehanna River was analyzed for many pathways~ however, the
only pathway that poses a ri~k is the ingestion of fish. Cancer
risk levels that exceed 1X10. and hazard indices that exceed 1.0
were calculated for this pathway for each body of water. These
risks are based on estimated concentrations of contaminants in
fish, and therefore they may not be accurate and are probably
overestimated. The contaminant responsible for most of the risk
is DDT (a pesticide) based on an ingestion level of 38 grams per
day of fish for adults. This contaminant which was detected at
low concentrations is widespread in the local environment and
does not appear to be site related.
One area in which environmental receptors (e.g., plants, fish,
wildlife) may be adversely impacted by contaminants is the stream
that transverses the North Base Landfill and Meade Heights areas
(Figure 2). Lead, iron and zinc were detected in isolated.
surface water samples at concentrations exceeding federal or
state surface water quality criteria. The source of these
contaminants, however, could not be determined. In the
Susquehanna River, aluminum, iron and zinc were detected at
concentrations that exceeded federal or state water quality
criteria. Aluminum and iron were also found in concentrations
that exceeded the water criteria upgradient from the site. Only
one location had zinc above the water quality criteria.
Additional water quality sampling will be conducted to assure
that site related contaminants are not adversely impacting the
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TABLE 1
SUMMARY OP CALCULATED RISKS FOR AVERAGE CONTAMINANT CONCENTRATIONS
MIDDLETOWN AIRFIELD SITE
AREA
Industrial Area
Fire Training Pit Area
North Base Landfill
Area
MEDIUM
HIA
production well
water
Surface soil
Surface soil
MID-04 well
water
PATHWAY
Ingestion
Ingestion of
dust during
excavation
Inhalation of
dust during
construction
Ingestion and
dermal contact
Inhalation of
dust during
construction
Ingestion
RECEPTOR
Adult
Child
Adult
Adult
Adult
Child
HAZARD
INDEX
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12
Susquehanna River. No federal or state threatened or endangered
species are located in the vicinity of the Middletown Airfield
Site. Actual or threatened releases of hazardous substances from
this site, if not addressed by implementing the response actions
selected in this ROD, may present an imminent and substantial
endangerment to public health, welfare, or the environment.
VII.
DESCRIPTION OP ALTERNATIVES
In accordance with 40 CFR 300.430, a list of remedial response
actions and representative technologies were identified and
screened to meet the remedial action objectives at the Middletown
Airfield Site. The technologies that passed the screening were
assembled to form remedial alternatives.
The FS evaluated a variety of technologies used in the
development of alternatives for addressing the contaminated
groundwater and soil for each of the operable units that have
been defined for the site. The technologies and approaches
contained in the following alternatives were determined to be the
most applicable for this site.
OPERABLE WIT 1:
Alternative 1-1:
Alternative 1-2:
Alternative 1-3:
Alternative 1-4b:
OPERABLE OBIT 2:
Alternative 2-1:
Alternative 2-2:
Alternative 2-3a:
OPERABLE WIT 3:
Alternative 3-1:
Alternative 3-2:
OPERABLE WIT 4:
GROt1NDWATER FOR THE MIDDLETOWN SITE (includes
the North Base Landfill)
No Action--Existing Ion Exchange
SOftening/Air Stripping/ Chlorination for HIA
production wells
Existing Treatment Systems Plus Institutional
Actions
Existing Treatment Systems, Institutional
. Actions Plus Selective Ion
Exchange/Neutralization
Existing Treatment Systems, Institutional
Actions Plus
Coagulation/Flocculation/Filtration/Neutraliz
ation
INDOSTRIAL AREA--SOILS
No Action
Institutional Actions
Institutional Actions Plus Vacuum Extraction
PIRE TRAINING PIT AREA--SOILS
No Action
Institutional Actions
The former Operable unit 4 discussed in the
FS report and the Proposed Plan has been
combined into Operable Unit 1 for all the
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13
groundwater.
OPERABLE UNIT 5:
MEADE HEIGHTS AREA--SURPACE WATER
Alternative 5-1:
Alternative 5-2:
No Action
Institutional Actions
Each of the operable units includes alternatives which are also
contained in the other operable units. The no action alternative
provides a baseline of comparison for each operable unit.
Institutional actions include the continued monitoring of the
areas where contamination remains, deed restrictions, and
mandated compliance with specific health and safety programs.
Where groundwater is contaminated, the objective is to reduce
contamination and prevent the ingestion of well water that has
contaminants in excess of regulatory drinking water standards or
criteria, or health-based levels. For soils, the common
objective is to prevent or minimize human exposure to
contaminants.
A detailed evaluation of the various alternatives is presented in
the FS report. A summary of each alternative's evaluation, by
operable unit, is presented below. For each alternative, the
costs and implementation times that are presented are estimated
values. The capital cost, the operation and maintenance (O&M)
cost, and the present worth cost presented for each alternative
do not include the costs associated with the implementation of
the first Middletown Airfield ROD or other remediation activities
that are not related to this ROD.
OPERABLE UNIT 1:
GROUNDWATER FOR THB MIDDLETOWN SITB
Alternative 1-1:
No Action
Capital Cost:
Annual Operation and
Maintenance (O&M) Costs:
Present Worth
Time to Implement:
o
o
o
None
This alternative is considered in the detailed analysis to
provide a baseline to which the other remedial alternatives can
be compared. This alternative involves taking no further action
at the Middletown Airfield Site to remove, remediate or treat the
groundwater. Currently at the site, an ion exchanger is used fo~
water softening, air stripping towers are used for removing
volatile organics, and chlorination is used for disinfecting the
HIA production well water that is used as the drinking water
supply in and around the airport. Water from extraction well
HIA-13 is currently used by the Chloe manufacturing facility fo~
process water and is subsequently treated in wastewater lagoons
onsite before being discharged to the Susquehanna River. Water
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14
from extraction well HIA-14 is currently used by the HIA as
cooling water and is directly discharged to the Susquehanna
River. The state requires quarterly monitoring for both organic
and inorganic parameters of the HIA production well water. Near
the former North Base Landfill, groundwater is currently being
pumped from the Middletown production well MID-04. After
chlorination, this water is distributed as potable water for the
population of Middletown. The well was sampled during the field
investigation and no contaminants were detected above drinking
water standards.
This alternative provides for no additional reduction in
groundwater contamination over that already accomplished by the
air stripping operation, which was previously addressed in the
first operable unit in the ROD dated December 30, 1987. The
drinking water ARARs for the public water supply are being met by
this Alternative. However, this Alternative may not meet the
remedial objective because it has the potential for inorganic
contaminants to enter the water treatment system without
detection. All ARARs will be met at the drinking water tap.
Alternative 1-2: Existing Treatment systems Plus Institutional
Actions
Capital Cost:
Annual O&M Costs:
Present Worth:
Time to Implement:
$ 98,000
$735,000
$950,000
One year
(first year)
This alternative involves continued operation of the existing
water treatment systems and the institution of groundwater use
restrictions. This includes the following requirements:
.
continued operation of existing water treatment system
for all actively pumping HIA production wells even if
airport operations cease. This includes any new wells
and other HIA production wells that are not now used.
currently 1.5 million gallons a day are treated onsite.
Activities addressing groundwater remediation should be
implemented until MCLs and non-zero MCLGs are shown to
be maintained in the groundwater at the production
wells and at the site boundary;
Monthly monitoring of the HIA production wells for
organics and inorganics for a year;
.
.
A hyd~ogeologic investigation which includes capture
zone analysis for the HIA production wells. After this
study, EPA will issue a notice indicating the expected
restoration timeframe. If restoration is expected to
take a long period of time (e.g. over 100 years), then
EPA may reevaluate the selected remedies;
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15
.
Installation of sentinel wells between the North Base
Landfill and MID-04 well:
.
Quarterly monitoring of the sentinel wells for the
organic and inorganic contaminants for five years;
.
Restrictions on the permitting of new wells and the use
of existing wells between the North Base Landfill Area
and the HIA production well field:
Quarterly sampling of the HIA we~ls and MID-04 well
will continue by PADER as required for all public water
supplies:
.
.
The monitoring results would be evaluated and the
sampling frequency adjusted if necessary on a yearly
basis for a five-year period:
.
Based on these groundwater monitoring data, further
treatment may become necessary. If this occurs, a
modification to this ROD may be issued by EPA in
consultation with PADER outlining the required actions;
and
A separate five-year monitoring program for organic and
inorganic contamination would be instituted for the
susquehanna River adjacent to the site. This
monitoring will include quarterly sampling of surface
water and biannual sediment sampling at four locations
along the Susquehanna River for full target compound
list of organics and target analyte list of in organics.
This alternative provides for a reduction in volume and toxicity
of the groundwater contamination. It will meet the remedial
objective. All drinking water ARARs for the public water supply
will be met. This alternative is protective of both human health
and the environment. The state of pennsylvania groundwater ARAR
of treating contamination to background levels for this operable
unit will be waived since EPA has determined that it is
technically impractical at this time to remediate the groundwater
to background quality. The rationale for the waiver is discussed
in section IX- Selected Remedies under Alternative 1-2. The
technical practicability for meeting the Commonwealth's
groundwater ARAR will be reevaluated during the five-year review.
.
Alternative 1-3: Existing Treatment systems, Institutional
Actions Plus Selective Ion EXchange/Neutralization
capital Cost:
Annual O&M Costs:
Present Worth:
Time to Implement:
$2,639,000
$1,035,000
$8,050,000
One year
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16
This alternative includes the existing unit processes,
institutional actions as listed in Alternative 1-2, plus a
selective ion exchange unit for metals removal, and a
neutralization basin to adjust the pH of the water before pumping
to the distribution system. An ion exchange unit used for water
softening and two air strippers used for volatile organics
removal are already in place and operating at the site.
Selective cation and anion exchange units specifically designed
to meet antimony, arsenic, cadmium, and lead cleanup goals would
be integrated into the existing system. The new units would be
placed between the existing ion exchange unit and the air
strippers. A pH neutralization basin would be installed after
the air strippers and before chlorination.
Reduction in groundwater contamination is provided by this
alternative. The remedial action objectives are met and the
contaminant-specific ARARs for the groundwater aquifer have been
waived. All ARARs will be met at the drinking water tap. This
alternative is protective of human health and the environment.
Alternative 1-4b: Existinq Treatment systems, Institutional
Actions Plus coaqu1ation/Flocculation/Piltration/Neutralization
Capital Cost:
Annual O&M:
Present Worth:
Time to Implement:
$2,127,000
$ 938,000
$6,050,000
Two years
(first year)
In addition to the existing treatment system, this alternative
utilizes coagulation, flocculation, and multimedia filtration to
remove inorganic cont~~inants. The institutional actions listed
in Alternative 1-2 are also included. Ferric chloride, ferrous
sulfate and ferrous sulfide may be considered as effective
coagulants. The aggregated particles that form during
coagulation would be removed by a gravity filter. The filtered
water would then go through the ion exchange softener unit, air
strippers, neutralization, and chlorination prior to
distribution. This alternative provides reliable inorganic
contaminant removal.
Reduction in qroundwater contamination is provided by this
alternative. The remedial action objectives are met, and the
contaminant-specific ARARs for the qroundwater aquifer have been
waived. All ARARs will be met at the drinking water tap. This
alternative is protective of human health and the environment.
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17
OPERABLB UNIT 2:
INDUSTRIAL AREA--SOILS
Alternative 2-1:
No Action
capital Cost:
Annual O&M Costs:
Present Worth:
Time to Implement:
o
o
o
None
This alternative is considered in the detailed analysis to
provide a baseline to which the other remedial alternatives can
be compared. This alternative involves taking no further actions
to remove, remediate, or treat the soil in the Industrial Area.
This alternative provides no additional reduction in soil
contamination and it does not meet the remedial objective. No
chemical-specific ARARs are applicable to this alternative.
Alternative 2-2:
Institutional Actions
capital Cost:
Annual O&M Costs:
Present Worth:
Time to Implement:
$ 10,000
$ 45,000
$195,000
Three months
This alternative would provide for land use and access
restrictions, and public health and safety requirements for
activities involving construction, demolition, and excavation or
other activity that would disturb the site soil. Deed
restrictions would be implemented which would limit property
usage and access and specify special precautions including
protective equipment for excavation, special employee training
and onsite perimeter air monitoring. A system would be
implemented under this alternative to further avoid the
possibility of potentially hazardous exposures. A health and
safety program would be instituted to apprise workers of the
risks to themselves and the public. The program would provide
appropriate measures describing means of prevention and .
containment. Exposures to contaminants would be minimized
through the use of respiratory protection and protective
clothing, along with other site safety measures. Special
construction practices may be required.
Reduction in soil contamination is not provided by this
alternative: however, no adverse impact to the public or
environment has been shown to exist because of their presence.
The objective of preventing public and worker exposure to
contaminated soil and dust is met. This alternative is
protective of human health and the environment and all ARARs are
met. While removal of the soil and debris is not part of this
remedy, any future construction activities at the site, which
disturb the soil and debris, must comply with any applicable
Federal, state, and local requirement in existence at the time of
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18
the disturbance.
Alternative 2-3a: Vacuum Extraction Plus institutional Actions
Capital Cost: $15,010,000
Annual O&M Costs: $ 45,000
Present Worth: $15,195,000
Time to Implement: 18 Months
The institutional actions associated with Alternative 2-2 are
provided. In addition, vacuum extraction is provided for the
removal of VOCs from the vadose zone of the soil. Vacuum
extraction wells would be placed in the soil to shallow depths
ranging down to 30 feet. The effect of vacuum extraction is to
enhance the volatilization of the VOCs by increasing their
partial pressure in the air stream. It is estimated that the
total volume of soil requiring remediation would be 420,000 cubic
yards. Emissions from the vacuum extraction will be required to
meet existing air emission regulations.
This alternative provides a reduction in the total volume of
contaminants found at the site. The remedial action objectives
are met. No chemical-specific ARARs are applicable to this
alternative. This alternative is protective of human health and
the environment.
OPERABLE UNIT 3: FIRE TRAINING PIT AREA—SOILS
Alternative 3-1: No Action
Capital Cost: 0
Annual O&M Costs: 0
Present Worth: 0
Time to Implement: None
This alternative is considered in the detailed analysis to
provide a baseline to which the other remedial alternatives can
be compared. This alternative involves taking no further action
at the Middletown Airfield Site to remove, remediate, or treat
the soil in the Fire Training Pit Area. This alternative
provides no additional reduction in soil contamination and it
does not meet the remedial objective. No chemical-specific ARARs
are applicable to this alternative.
Alternative 3-2: Institutional Actions
Capital Cost: $ 10,000
Annual O&M Costs: $182,000
Present Worth: $182,000
Time to Implement: Three months
The institutional action alternative would provide for property
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19
access restrictions and restrictions on construction activities.
Deed restrictions would be implemented which would limit property
usage and specify any special considerations such as personal
protective equipment for excavation activities. A permitting
system would be instituted under this alternative for
construction-related activities that may cause disturbance of
contaminated soils, resulting in potentially hazardous exposures
to construction personnel. A health and safety program would
have to be addressed in the construction permitting process.
Exposures to contaminants would be minimized through the use of
respiratory protection and protective clothing. Special
construction practices may be required.
Additional reduction in soil contamination is not provided by
this alternative. The objective of preventing public and worker
exposure to contaminated soil and dust is met. While removal of
soil and debris is not part of this remedy, any future
construction activity at the site, which disturb the soil and
debris, must comply with any applicable Federal, State, and local
requirement in existence at the time of the disturbance. During
a wetland survey and subsequent field reconnaissance, no adverse
environmental conditions were noted. Chemical specific ARARs are
not applicable to this alternative since no regulatory standards
exist for contaminants in the soil. This alternative is
protective of human health and the environment.
OPERABLE UNIT 5: MEADE HEIGHTS AREA—SURFACE WATER
Alternative 5-1: No Action
Capital Cost: 0
Annual O&M Costs: 0
Present Worth: 0
Time to Implement: None
This alternative is considered in the detailed analysis to
provide a baseline to which the other remedial alternatives can
be compared. This alternative involves taking no further actions
at the Middletown Airfield Site to remove, remediate, or treat
the surface water in the Meade Heights Area. This alternative
provides no additional reduction in surface water contamination
and it does not meet the remedial objectives of determining the
source(s) of this contamination nor its potential impact on
aquatic life in the stream. The contaminant-specific ARARs are
not applicable.
Alternative 5-2: Institutional Actions
Capital Cost: 0
Annual O&M Costs: $55,000
Present Worth: $55,000
Time to Implement: Six months
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This alternative provides for further investigation of the
surface water in the Meade Heights Area. While no potential
human health threats were identified, the results are
inconclusive for an environmental assessment since the source of
contamination was not identified. A sampling plan has been
developed that addresses these concerns. The plan includes
sampling of surface water and sediments for two storm events and
two non-storm events; and sampling stream invertebrates; aquatic
insects, and fish.
No adverse public health effects have been identified. Reduction
in surface water contamination is not provided by this. .
alternative. The influence of site-related contaminants on
aquatic organisms living in the system was not determined.
Chemical-specific ARARs may not be met; however, initial sampling
results are inconclusive. This alternative is provided to
determine if there is the potential for adverse environmental
impacts. .
VIII.
COMPARATIVE ANALYSIS OF ALTERNATIVES
The remedial action alternatives described above were evaluated
under the nine evaluation criteria described in 40 CFR
Part 300.430{e) (9) as set forth in "Guidance for Conducting
Remedial Investigations and Feasibility Studies Under CERCLA,"
October 1988, and "Guidance on Preparing Superfund Decision
Documents: The Proposed Plan, The Record of Decision,
Explanation of Significant Differences, and the Record of
Decision Amendment," July 1989, Interim Final. These nine
criteria can be further categorized into three groups: threshold
criteria, primary balancing criteria, and modifying criteria.
Threshold criteria
Overall protection of human health and the environment
Compliance with ARARs
Primary Balancinq criteria
.
.
.
Reduction of toxicity, mobility, or volume through
treatment
Implementability
Short-term effectiveness
Long-term effectiveness
Cost
.
.
.
.
ModifyinQ criteria
.
Community acceptance
State acceptance
.
. These evaluation criteria relate directly to requirements in
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21
Section 121 of CERCLA, 42 U.S.C. Section 9621, which measure the
overall feasibility and acceptability of the remedy. Threshold
criteria must be satisfied in order for a remedy to be eligible
for selection. Primary balancing criteria are used to weigh
major trade-offs between remedies. State and community
acceptance are modifying criteria formally taken into account
after public comments are received on the Proposed Plan.
This section profiles the performance of the alternatives against
the nine criteria, noting how each compares to the other options
under consideration. Under each criterion, Operable Unit 1 is
discussed in relation to groundwater; Operable Units 2 and 3 are
discussed together in relation to soils, and Operable Unit 5 for
surface water, is discussed independently. The evaluations are
as follows:
Overall Protection of Human Health and the Environment.
Alternatives 1-2, 1-3, and 1-4 would achieve the groundwater
remedial objectives and thus would adequately protect drinking
water supplies. Alternative 1-2 offers continued groundwater
protection through a program of production well reconfiguration
and groundwater monitoring. In the future, if contamination was
detected that posed an unacceptable risk, the alternatives that
include treatment (Alternative 1-3 or 1-4) could be implemented.
The no action alternative does not provide long-term protection
of human health and the environment, and thus it is not
considered further in this analysis as an option for any operable
unit on the site.
Alternatives 2-2, 2-3a, and 3-2 would achieve the soil
remediation objective of preventing worker exposure to
contaminated soils. Alternative 2-3a would provide the greatest
protection because contaminant volume would be removed by using
vacuum extraction.
There is no immediate overall protection provided by Alternatives
5-1 or 5-2; however, Alternative 5-2 will provide additional data
that can lead to long-term environmental protection.
Compliance with ARARs. Requirements related to specific
contaminants, locations and remedial actions were reviewed. The
Federal Safe Drinking Water Act provides for protection of human
health from contaminants in drinking water by establishing MCLs
and MCLGs. These criteria were established as remediation
requirements since the groundwater is used as a drinking water
source.
Alternatives 1-2, 1-3, and 1-4 meet the contaminant-specific
ARARs at the tap. Location-specific ARARs do not directly impact
the alternatives still under consideration. It is expected that
action-specific ARARs (e.g., Federal Clean Air Act regulations as
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22
they apply to air stripping, state regulations for hazardous
material transport and worker health and safety regulations) can
be met for all of the alternatives. The state of Pennsylvania
groundwater ARAR for the aquifer itself meeting background
quality has been waived as discussed in section IX- Selected
Remedies under Alternative 1-2.
ARARs do not provide a means of distinguishing among the soil
remediation alternatives (Operable units 2 and 3) nor for the
surface water alternatives at Meade Heights. contaminant-
specific ARARs are not applicable to those alternatives involving
no action.
Lonq-Term Bffectiveness and Permanence. Alternative 1-2 provides
a means to maintain reliable protection of human health and the
environment over time. Long-term monitoring will provide an
early indication if a change in contaminant concentrations may be
occurring. Alternatives 1-3 and 1-4 provide for permanent
removal of contaminants through treatment. Only Alternatives 1-J
and 1-4 remove both organic and inorganic contaminants.
Alternatives 2-2 and 3-2 provide long-term protection of
construction workers from exposure to contaminants. Only
Alternative 2-3a provides permanent removal of VOCs from the
soil. This alternative would minimize long-term management and
monitoring requirements for contaminated soil areas. Alternative
5-2 does not provide long-term effectiveness.
Reduction of contaminant Toxicity, Mobility or Volume.
Alternatives 1-3 and 1-4b reduce contaminant volume through
treatment, whereas .Alternative 1-2 prevents potential human
receptor contact with contaminants by utilizing different well
pumping configurations, thereby avoiding use of groundwater with
raised contaminant concentrations.
Alternative 2-3a will reduce contaminant volumes and toxicity by
cleaning up the soil with vacuum extraction. Alternatives 2-2
and 3-2 do not provide reduction in soil contamination.. No
contaminant reduction is provided by Alternative 5-2.
Short-Tera Bff8ctiveness. Alternatives 1-3 and 1-4b include so~e
degree of treatment and, therefore, present a potential risk of
contaminant exposure, although minor, to treatment plant
operators. No short-term impacts are expected from Alternative
1-2. In general, the degree of risk increases with the amount 0:
time necessary to implement the remedial actions.
Alternatives 2-2 and 3-2 will minimize short-term health and
environmental impacts due to construction activities.
Alternative 2-3a may pose a potential risk of contaminant
exposure to site workers, the community and the environment in
the event of treatment system failures.
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23
Short-term effectiveness is not a significant issue for Operable
Unit 5.
Implementability. Alternatives, 1-2, 2-2, 3-2, and 5-2 are all
readily implementable. The proposed institutional actions have
been used singularly or in conjunction with other alternatives at
Superfund sites. Alternatives 1-3 and 1-4b are both
implementable since they involve standard technologies; however,
they are more difficult to implement than the institutional
actions.
Similarly, for soils, Alternatives 2-2 and 3-2 are readily
implementable. Alternative 2-3a contains some uncertainty
regarding its implementability since it is a relatively new
technology. Treatment problems associated with low permeability
soils, interference of utilities and existing structures may make
this alternative more difficult to implement.
No implementation problems are anticipated for Alternative 5-2.
Costs.
below:
The present worth costs of the alternatives are listed
For Operable Unit 1
Alternative
Alternative
Alternative
For Operable Unit 2
Alternative 2-2
Alternative 2-3a
For Operable Unit 3
Alternative 3-2
For Operable Unit 5
Alternative 5-2
1-2
1-3
1-4b
$ 950,000 (*)
$ 8,050,000
$ 6,050,000
~
$ 195,000 (*)
$15,195,000
$
$
182,000 (*)
55,000 (*)
(*)
Selected Alternative
state Acceptance. The Commonwealth of Pennsylvania has not
concurred with the selected remedial actions.
Community Acceptance. The Proposed Plan was released on
August 13, 1990 to solicit public comment regarding the proposed
remedial alternatives. At that time, a 30-day public comment
period was initiated from August 13, 1990 to September 13, 1990
and a public meeting was held on September 29, 1990. A request
for a 30 day extension was received and the public comment peric:
was extended to October 13, 1990. Comments submitted during the
public comment period and issues raised by the community during
the public meeting are referenced in the Responsiveness Summary
attached to this ROD.
IX.
SELECTED REMEDY
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24
Based on the findings in the RI/FS and evaluation of the nine
criteria listed above, the following alternatives in the judgment
of EPA represent the best balance among the evaluation criteria
and satisfy the threshold statutory requirements of protection of
human health and the environment and compliance with ARARs. A
final decision could not be made for Operable Unit 5 because the
results were inconclusive in determining the potential
environmental impacts. No threats to human health were
identified for this operable unit.
The selected remedies for each operable unit are identified and
discussed below: .
OPERABLE UNIT 1:
Alternative 1-2:
Actions .
OPERABLE UNIT 2:
Alternative 2-2:
OPERABLE UNIT 3:
Alternative 3-2:
OPERABLE UNIT 5:
Alternative 5-2:
OPERABLE UNIT 1:
INDUSTRIAL AREA--GROUNDWATER FOR THE MIDDLETOWN
SITE
Existing Treatment Systems Plus Institutional
INDUSTRIAL AREA--SOILS
Institutional Actions
FIRE TRAINING PIT AREA--SOILS
Institutional Actions
MEADE HEIGHTS AREA--SURFACE WATER
Institutional Actions
INDUSTRIAL AREA--GROUNDWATER FOR THE MIDDLETOWN
SITE
The remedial action objective of this operable unit was to
reduce the volume and toxicity of the contaminants in the
groundwater and to prevent the ingestion of HIA production well
water that has contaminants in excess of regulatory drinking
water standards or criteria, or health-based levels. The
remediation of groundwater from the North Base Landfill is
included in this Operable unit as part of the overall remediation
of groundwater addressed by the HIA system. .
Remediation goals for contaminants in HIA production well water
were determined by evaluating numerous parameters including
chemical concentrations, ARARs, the potential for adverse health
effects, and analytical sensitivity. The actions addressing
groundwater remediation should be implemented until MCL and non-
zero MCLG levels are shown to be maintained in the groundwater a:
the production wells and at the site boundary.
The only carcinogenic chemical present in HIA production well
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25
water that poses a potential risk is lead. The current federal
MCL for lead at the source is 50 M9/L, the proposed MCL is
5 ~g/L. Currently, EPA's proposed MCL for lead is 15 ~g/L at the
tap. Sampling of the Odd Fellow's Home, in December, 1989 by
EPA, did not detect the presence of any lead, cadmium, or arsenic
in the drinking water at the tap. Antimony was not analyzed for
during this sampling event. Subsequent sampling in the HIA wells
did not detect antimony in any of the wells expected to be
routinely pumped. All other carcinogenic contaminants present in
the HIA production well water after passing through the air
strippers are below their respective MCLs and non-zero MCLGs and
do not add significantly to the risk. Some noncarcinogenic
chemicals exceed Maximum contaminant Level Goals (MCLGs) in
isolated samples, however the composite untreated well water used
as the public water supply is below the MCLGs. The
noncarcinogenic contaminants that are responsible for most of the
calculated hazard index for adults or children, are antimony,
arsenic, and cadmium. While antimony is the only chemical for
which the calculated risk is of potential concern, it was
detected only once in a total of 22 samples. The concentration
reported for the one detection was below the contract required
detection limit, making the accuracy of the detection suspect.
Continued monitoring is needed to confirm the existence or
absence of lead and antimony before a determination can be made
on the necessity for further treatment.
Alternative 1-2 is the preferred alternative as it appears to
provide the best balance among alternatives with respect to the
nine evaluation criteria.
Alternative 1-2:
Actions
Existinq Treatment systems Plus Institutional
This alternative involves the continued operation of the existing
. drinking water supply treatment system even if airport operations
cease, institution of additional monitoring requirements and
specific groundwater use restrictions. Also included in this
action is the installation of sentinel wells between the North
Base Landfill and the Middletown production well MID-04.
The existing drinking water supply treatment and distribution
systems include the following:
.
An ion exchanger is used for water softening, air.
stripping towers are used for removing volatile
organics, and chlorination is used for disinfecting the
HIA production well water that is used as a drinking
water supply.
Water from extraction well HIA-14 is currently used by
the HIA as cooling water and is directly discharged to
the Susquehanna River.
.
-------
1--
26
.
The state requires quarterly monitoring for both
organic and inorganic parameters.
Additional monitoring requirements and specific groundwater use
restrictions include the following:
.
Requires monitoring and treatment of any additional
source of drinking water from new wells or other HIA
wells. Treatment shall be as effective as that
provided by existing drinking water treatment systems.
Before new wells are brought on-line, a hydrogeologic
analysis should be performed including at a minimum, a
capture zone analysis for HIA production wells.
Based on additional groundwater sampling, further
treatment may become necessary. If this occurs, a ROD
modification may be issued.
.
.
Requires that current National Pollutant Discharge
Elimination System (NPDES) permit requirements in
effect for discharges from Well HIA-13 apply to all
existing and future discharges from other sources of
groundwater pumped from HIA property. HIA-13 should
continue pumping and discharging for treatment by the
wastewater lagoons.
.
Requires monthly monitoring for full TCL organics and
TAL inorganics using Contract Laboratory Program (CLP)
protocol for a period of one year after which the
situation would be reevaluated every year for a period
of five years. Monitoring would be done for all HIA
wells that could be potentially used for drinking water
purposes.
.
Requires a five year review of technologies to
reevaluate technical practicability of complying with
the waived Commonwealth ARAR (25 PA. Code sections
264.97(i)(j) and 264.100 (a)(9).
Overall Protection of Human Health and the Environment. This
alternative provides for the continued reduction in groundwater
contamination. The remedial action objectives of preventing the
ingestion of HIA production well water that has contaminants in
excess of health-based levels is being met by this alternative.
compliance with. ARARs. The remedial action objectives of
preventing the ingestion of HIA production well water that has
contaminants in excess of drinking water standards or criteria
can be met by this alternative. Consequently, the statutory
requirement that the protection of human health and the
environment be achieved can be met by this alternative. The
State of Pennsylvania groundwater ARAR for the aquifer itself
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27
meeting background quality has been waived because of the
following reasons: 1) Volatile organic compounds (VOCs) from the
HIA wells are being treated by the current best available
technology (BAT), air stripping. Even this technology, with
better than 99 percent removal of VOCs, will not be able to
guarantee treatment to background levels that are found
upgradient from the site which are zero for VOCs: 2) The
background groundwater concentrations for the inorganic compounds
would require treating the following chemicals to zero or below
detection limits: antimony, arsenic, beryllium, cadmium, cobalt,
copper, lead, mercury, nickel, selenium, silver, vanadium, and
cyanide. For a number of these chemicals, the best available
technologies (BATs) for their removal would not be good enough to
achieve background levels. A number of the chemicals also do not
have much associated risks to either human health or the
environment to warrant their treatment. In addition, since the
edge of the waste management unit is the Susquehanna River, any
treatment that would be established at this location would be
treating large volumes of water from the river. The addition of
large volumes of water from the Susquehanna River requiring
treatment to background would also be impractical. The
percentages of contaminants removed using BATs were obtained from
the Federal Register dated November 13, 1985, August 18, 1988,
and July 25, 1990. .
Long-term Effectiveness and Permanence. The existing water
supply treatment system consisting of ion exchange, air
stripping, and chlorination are all well- demonstrated, reliable
technologies. The residual generated from the treatment process
is the regenerant solution from the ion exchange softening
process which is discharged to the Susquehanna River. Volatile
organics are monitored periodically to check for process
efficiency as well as compliance with standards. The state
requires quarterly monitoring for both organic and inorganic
parameters for protection of human health and the environment.
~
In addition, this alternative provides for monthly monitoring for
both organic and inorganic parameters of all HIA wells that could
be used for drinking water. Also, any new HIA wells that are
brought on-line for providing drinking water and the sentinel
wells for MID-04 will be monitored and/or treated, as .
appropriate.
Reduction of Mobility, Toxicity, or Volume Through Treatment.
Currently, the extraction of groundwater through wells used for
treating the water reduces the mobility and volume of
contaminated groundwater. The treatment system consisting of ion
exchange softening, air stripping, and chlorination reduces the
toxicity of volatile organics found in the groundwater, but it
does not treat for heavy metals. The residual generated from the
ion exchange softening process is discharged to the Susquehanna
River. This treatment system should be implemented until MCL and
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28
non-zero MCLG levels are maintained in the groundwater at the
production wells and at the site boundary.
Short-term Bffectiveness. During sampling and hydrogeologic
investigations, appropriate personal protective equipment would
be used to protect workers from exposure to potentially dangerous
contaminants. No known impacts to the community or the
environment are expected to occur as a result of this
alternative.
Implementabi1i~y. Implementing institutional controls and
monitoring the groundwater production wells as well as doing a
hydrogeologic investigation are easily implementable. The
effectiveness of this alternative would depend on the enforcement
exercised by the implementing agency.
Cost. The annual cost for monitoring 10 HIA wells at a rate of
one sample/well/month is estimated to be $190,000. The samples
would be analyzed for full TCL organics and TAL inorganics. The
cost also includes the labor requirements for sampling the wells.
Costs for doing a hydrogeologic analysis will be dependent on the
number of new HIA wells to be utilized. An estimated cost for
performing the hydrogeologic analysis is $455,000 for all 10
wells. The total O&M cost for monitoring and hydrogeologic
investigation is estimated to be $645,000. The cost for
monitoring the Susquehanna River on an annual basis is $55,000.
The cost of installing four sentinel wells is estimated to be
$98,000. The annual monitoring cost for these four wells are
estimated to be $35,000. This cost includes sampling labor and
analytical costs. The total present worth cost for this
alternative based on a five percent interest rate is estimated to
be $950,000. A summary of the major cost elements of
Alternative 1-2 is presented in Table 2.
OPERABLE UNIT 2:
INDOSTRIAL AREA--SOILS
The remedial action objective of this operable unit was to
prevent worker exposure to contaminated soil and dust during
activities that require disturbance of soils.
Cleanup goals for near-surface soils in the Industrial Ar~a are
not needed because the concentration of contaminants in the soils
to which construct~on workfrs may be exposed meet risk-based
levels (i.e., a 10. to 10. risk range) based on average
concentrations. All calculated total hazard indices were below
1.0. However, risk scenarios were only run for soils up to five
feet deep. Construction activities are likely to occur in this
area and may require the excavation of soils below five feet.
Exposure to these deeper soils may pose a risk greater than that
. calculated for near-surface soils because the concentrations of
some chemicals increase with depth.
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TABLE 2
SUMMARY OP OOGT ESTIMATES
MXCDLETOttN AIRFIELD
OPERABLE UNIT 1:
Alternative 1-2:
CAPITAL COSTS
INDUSTRIAL AREA—HIA GROUNDRATER PRODUCTION WELLS
Existing Treatment Systems Plus Institutional Actions
Item
Monitoring Well Installation
Cost
$98,000
OPERATION AND MAINTENANCE COSTS
Item
HIA Well Monitoring
Capture Zone and Hydrogeologic Analysis
Susquehanna River Monitoring
North Base Landfill Sentinel Well Monitoring
Five Years, Annual Cost
Subtotal First Year
Cost
$190,000
$455,000
$55,000
$35,000
$735,000
TOTAL COST
Net Present Worth Calculated Using a 5% Discount
Value
$950,000
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TABU!: 2 (oant'cS.)
smDmR! ~ CX8l' E8TIMM'ES
MIIDIBmIIN ADQr.u51D SrrE
P1tGE: 'lW)
OPElWW!: tJNI'l' 2: INDU8'l'RIAL ARE'A-SOUB
Alternative 2-2: Institutional ~ans
CAPITAL cnm;
I~am~n.;~:
OPERATION AND ~CE CDSTS
Cost $10, 000 I
Item Cost
Protective Equipnent $36,000
Monitorinq for Oca.1pational ~ $9,000
SUbtotal $45,000
'!urAL a:sr
.1 Net Present WOrth cala1lated Usn.; a 5t Discoont
Value
$195. 000 I
OPERABU: tJNI'l' 3: FIRB 'l'RADmG PIT ARE'A-SOUB
Alternative 3-2: Institutional ~ans
CAPITAL cnm;
I Item
Legal an:! Ergineerin;J 5etvices
OPERATION AND MA1NI'ENANCE CDSTS
Cost I
$10,000 .
Item Cost
Protective Eqt1;~ $175,000
Monitorin;J for ()(xIJPational Exposure $7,000
SUbtotal $182,000
'!urAL. a:sr
I Net Present WOrth calculated Usn.; a 5t Discoont
Value
$182 ,000 ]
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TABUB 2 (oont'd.)
SUMMARY OP O06T ESTIMATES
MUDLETOWN AIRFIELD BITE
PAGE THREE
OPERABLE UNIT 5: MEAGE HEIGHTS AREA—SURFACE WATER
Alternative 5-2: Institutional Actions
CAPITAL COSTS
Item
None
Cost
$0
OPERATION AND MAINTENANCE COSTS
Item
Monitoring
Cost
$55,000
TOTAL COST
Net Present Worth Calculated Using a 5% Discount
Value
$55,000
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29
Alternative 2-2 is selected as the preferred alternative as it
provides the best balance among alternatives with respect to the
nine criteria.
Alternative 2-2:
Institutional Actions
This alternative would provide for land use and access
restrictions and public health and safety requirements for
activities involving construction, demolition and other
activities that would disturb the site soil. Deed restrictions
would be implemented which would limit property usage and specify
any special considerations such as personal protective equipment
for excavation activities, special employee training and onsite
perimeter air monitoring. A permitting system would be
instituted under this alternative for construction-related
activities that may cause disturbance of contaminated soils, in
order to avoid exposure to potentially hazardous materials~ A
health and safety program would be instituted to apprise workers
and the public, as appropriate, of potential risks associated
with work occurring at the site. Through the use of respiratory
protection and protective clothi~g, exposures to contaminants
would be minimized. Special construction practices may also be
required. .
Overall Protection of Human Health and the Environment.
Currently, there is no public or environmental threat due to site
conditions to anyone transgressing the property. However, if
construction were to occur, the use of personal protective
equipment and deed restrictions would reduce the risk posed to
workers from exposure to contaminated soils. Proper personal
protective equipment, however, would reduce the risk associated
with ingestion, dermal contact, and inhalation of soils and
volatiles. Deed restrictions would limit property usage and
limit exposure frequencies and durations. The magnitude of risk
reduction, however, cannot be quantified.
Compliance with ARARs. Chemical-specific ARARs are not
applicable to this alternative because no regulatory standards
exist for contaminated soils. While removal of the soil and
debris is not part of this remedy, any future construction
activity at the site, which disturb the soil and debris, must
comply with any applicable Federal, State, or local requirement
in existence at the time of the disturbance. Location-specific
ARARs, such as those that pertain to the protection of rare and
endangered species, wetlands, and floodplains are not applicable
to this alternative since this area is used primarily for
industrial/commercial uses. OSHA requirements, which set
standards for personal protective equipment and exposure limits
for volatile chemicals in order to protect workers in the
workplace, are action-specific criteria that may be applicable t:
this alternative.
. -
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30
Consequently, the statutory requirements that protection of human
health and the environment be achieved is met by this
alternative.
Long-term Effectiveness and Permanence. This alternative can be
implemented effectively if the construction permitting process is
reviewed and monitored by the Borough of Middletown. Proper
management would ensure that the remedial action objective of
controlling exposure of construction workers is achieved. Prior
to each proposed construction activity at the site, an
appropriate health and safety plan must be developed that defines
the proper level of protection for various exposure scenarios.
Reduction of Mobility, Toxicity, or Volume. This alternative
does not reduce mobility, toxicity, or volume of contaminants
found in the Industrial Area soils but leaves the contaminants
inplace. However, groundwater beneath the industrial area is
treated and a reduction is mobility and volume is accomplished.
Short-term Effectiveness. The short-term effectiveness of this
alternative would be dependent on the commitment of the
overseeing authority. The permitting process would have to be
enforced, reviewed, and updated to effectively control exposures
to contaminants in the soil. The population at risk would be
limited to construction and utility personnel performing work
that requires soil disturbance or excavation.
Implementability. The implementation of this alternative would
require the designation of an overseeing authority to develop and
implement deed restrictions for construction activities. Deed
restrictions would specify certain legal procedures. An
appropriate health and safety program approved by the Borough of
Middletown and other appropriate agencies would be required to
assure the protection of workers from exposure to contaminants in
the sub soils during construction activities.
Cost. Capital costs to implement this alternative are estimated
to be $10,000, primarily for legal and engineering services that
would be necessary to develop a permitting system for access and
construction restrictions. Costs borne by excavation contractors
would depend on the amount of construction that may take place ir
the area. Assuming that construction activities were to occur
three months a year over a five-year period, the total annual
costs are $45,000 ($36,000 for personal protective equipment and
$9,000 for air monitoring). The total present worth cost is
estimated to be $195,000 based on a five percent interest rate
for a five-year period. A summary of the major cost elements for
Alternative 2-2 is presented in Table 2.
OPERABLE UNIT 3: FIRE TRAINING PIT AREA—SOILS
The remedial action objective of this operable unit was to
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31
prevent the ingestion of soils or inhalation of dust during
future construction or earth-moving activities.
Cleanup goals for the soils in the Fire Training pit Area are not
needed because exposure to these soils is not occurring. In
addition, the risks associated with the concentration of
contaminants to which workers may be pxposed during construction
activities fall within the 10.' to 10. risk range. There is also
a potential for contaminants in the soil to be leached into the
groundwater and be subsequently carried to the Susquehanna River
which is less than a quarter mile away. These contaminants may
have an impact on aquatic organisms in the river; however, no
adverse effects have been documented to date.
Alternative 3-2 is the preferred alternative as it appears to
provide the best balance among alternatives with respect to the
nine criteria used by EPA to evaluate alternatives.
Alternative 3-2:
Institutional Actions
This alternative provides deed restrictions to control
construction activities at the Fire Training Pit Area. The
construction permitting process would involve the preparation of
, a health and safety plan to include personal protective equipment
and air monitoring for protecting workers from exposure to
contaminants in the soil. Access to the area would continue to
be restricted to limit exposure frequencies.
Overall Protection of Human Health and the Environment. An
adequate health and safety plan would protect workers from
exposure to contaminants in the soil. Access restrictions would
limit the number of people allowed in the vicinity of
construction in the area. Monitoring the potential for
contaminants in the Susquehanna River under Alternative 1-2 would
ensure adequate protection of the environment.
Compliance with ARARs. Chemical- and location-specific ARARs are
not applicable to this alternative because no regulatory
standards exist for contaminants in the soil. While removal of
the soil and debris is not part of this remedy, any future
construction activity at the site, which disturb soil and debris.
must comply with any applicable Federal, State, and local
requirement in existence at the time of the disturbance. Action-
specific criteria such as OSHA requirements for the protection of
workers in the workplace would be applicable to this alternative.
Consequently, the statutory requirements that protection of huma~
health and the environment be met is achieved by this
alternative.
Lonq-term Effectiveness and Permanence. The carcinogenic risk tc
construction workers would be reduced provided adequate health
and safety requirements are met. Long-term effectiveness would
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32
depend on continued future enforcement by the overseeing
authority. Monitoring of the contaminants in the Susquehanna
River would ensure protection of the environment.
Reduction in Toxicity, Mobility, or Volume. No reduction in
toxicity, mobility, or volume of contaminants would occur as a
result of this alternative.
Short-term Effectiveness. Construction workers would be
adequately protected through the use of personal protective
equipment. No known adverse impacts to the community or the
environment are expected to occur as a result of this remedial
alternative.
rmplementability. The implementation of this alternative would
require the designation of an overseeing authority to develop and
implement deed restrictions for controlling construction
activities. Access restrictions would require certain legal
procedures and cooperation of state and local agencies to limit
future actions at the site. An appropriate health and safety
program would be effective in protecting workers from exposure to
contaminants in the Fire Training Pit Area soils.
Cost. Capital costs to implement this alternative are estimated
to be $10,000, primarily for legal and engineering services that
would be necessary to develop a permitting system for access and
construction restrictions. Costs borne by excavation contractors
would depend on the amount of construction that may take place in
the area. It was assumed that excavation activities would take
place once every five years and be conducted by a relatively
large work force over a 10-week period. The capital cost of this
alternative is $10,000. The total annual costs are $182,000
($175,000 for personal protective equipment and $7,000 for air
monitoring). The total present worth cost is estimated to be
$182,000. A summary of the major cost elements of
Alternative 3-2 is presented in Table 2.
OPERABLE UNIT 5:
MEADB HEIGHTS AREA--SORPACB WATER
The remedial action objective of this operable unit is to prevent
aquatic organisms living in the stream system near Meade Heights
from being adversely impacted by surface water contaminants.
Aquatic organisms are potentially at risk in the Meade Heights
stream because of the presence of iron, lead, and zinc above
Ambient Water Quality criteria (AWQC). The goal for this
operable unit will be to further investigate, through several
sampling events, the source(s) of these contaminants and the
potential effects that these contaminants may have on aquatic
organisms.
Alternative 5-2 is the preferred alternative as it appears to
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provide the best balance among alternatives with respect to the
nine criteria used by EPA to evaluate alternatives.
Alternative 5-2:
Institutional Actions
In the GF/NUS field investigation, the contaminants iron, lead,
and zinc were detected in the stream that runs through the North
Base Landfill and Meade Heights areas at concentrations exceeding
the AWQC. Due to the limited sampling that occurred, it was not
possible to determine whether these contaminants were site
related as well as their potential impact on aquatic life in the
stream. Further investigation would determine the source(s) of
the contaminants as well as their potential impact on aquatic
organisms in the Meade Heights stream system. A sampling plan
has been developed that addresses these concerns. The plan
includes the sampling of surface water and sediments for two
storm events and two non-storm events: and sampling stream
invertebrates, aquatic insects, and fish. Collecting biological
samples will allow comparisons to be made to the large data base
available on the Swatara Creek and susquehanna River. Also, the
relative water quality within the stream can be assessed.
Overall Protection of Human Health ~d the Environment. A
carcinogenic risk of less than lxlO. and noncarcinogenic hazard
index of less than 1.0 exist for ingestion of the surface water
from the Meade Heights stream system.
Compliance with ARARs. Iron, lead, and zinc exceeded the AWQC.
Iron exceeded the Federal AWQC for the protection of freshwater
aquatic life (chronic criteria) as well as the protection of
human health (ingestion of water and fish). Lead exceeded the
Federal and State AWQC for the protection of freshwater aquatic
life (chronic criteria). Zinc exceeded the federal and state
AWQC for the protection of freshwater aquatic life (both acute
and chronic criteria). consequently, the statutory requirements
that protection of human health and the environment be achieved
is not met by this alternative.
Long-term Bffectiveness and Permanence. No reduction in risk
would occur as a result of this alternative.
Reduction of Toxicity, MObility,
reduction in toxicity, mobility,
as a result of this alternative.
satisfy the statutory preference
or Volume Through Treatment. No
or volume is expected to occur
This alternative does not
for treatment.
Short-term Bffectiveness. Workers would be adequately protected
during the sampling activities by appropriate personal protective
equipment. No impacts to the community or the environment are
expected to occur as a result of this alternative.
Implementability.
Sampling of the surface water, sediments,
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stream invertebrates, and fish is easily implementable. A
focused work plan outlining the sampling activities will be
prepared.
Cost. There is no capital cost associated with this alternative.
The monitoring cost is estimated to be $55,200. A summary of the
major cost elements of Alternative 5-2 is presented in Table 2.
x.
STATUTORY DETERMINATIONS
The selected remedial actions which were previously outlined
satisfy the remedy selection process requirements of CERCLA and
the NCP for the Operable Units 1, 2 and 3. The remedy selected
for these operable units provides protection of human health and
the environment, achieves compliance with applicable or relevant
and appropriate requirements, and is cost effective. The
selected remedies for groundwater build upon the existing
treatment system that is currently in use at the site, and hence
satisfy the statutory preference for treatment as a principal
element. Since remedial action objectives for soils at the site
were met through institutional controls, the selected remedies do
not satisfy the statutory preference for treatment as a principal
element for soils. Onsite groundwater treatment is an existing
remedy that is currently being utilized on the site. The remedy
selected for Operable Unit 1 recognizes the existing treatment
and mandates continued treatment of groundwater at the site. For
Operable Unit 5 further investigation is proposed as the RI
results were inconclusive in determining the source(s) of
contaminants and their potential environmental impacts.
Overall Protection of Human Health and the Environment.
Alternative 1-2 will prevent the ingestion of groundwater
has contaminants in excess of health-based levels through
treatment, institutional controls such as monitoring, and
restrictions.
that
deed
Alternatives 2-2 and 3-2 will prevent public and worker exposure
to contaminated soil and dust during activities that require
disturbance of soil through the implementation of land use and
access restrictions and a health and safety program.
Alternative 5-2 may not be protective of the environment since
iron, lead, and zinc exceeded the AWQC in the Meade Heights
stream system. However, Alternative 5-2 is an interim remedy and
compliance with the statutory requirement of overall protection
of the environment will be addressed at the time of the final
remedy selection.
Compliance with ARARs. The first three operable units will
comply with applicable or relevant and appropriate chemical-,
location-, and action-specific ARARs as described below:
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.
Chemical-specific ARARs--The state of Pennsylvania
ARARs for groundwater at the site have been waived
since EPA has determined that it is technically
impractical at this time to remediate the groundwater
to background quality. The technical practicability
for meeting the Pennsylvania ARARs for groundwater will
be reevaluated during the five year review. The
chemical-specific ARARs are not applicable for
Alternatives 2-2 and 3-2 because no regulatory
standards exist for contaminants in the soil.
Alternative 5-2 does not meet the chemical-specific
ARARs as iron, lead, and zinc exceeded the AWQC
criteria. since Alternative 5-2 is an interim action,
compliance with chemical-specific ARARs will be
addressed if remedial measures are necessary.
.
Location-specific ARARs--No location-specific ARARs
have been identified for the first three operable
units. since Alternative 5-2 is an interim action,
compliance with location-specific ARARs will be
addressed if remedial measures are necessary.
Action-specific ARARs--OSHA regulations (29 CFR
Parts 1904, 1910, and 1926) would be applicable to
Alternatives 1-2, 2-2, and 3-2 during construction or
well drilling activities. OSHA requirements specify
the personal protective equipment and monitoring
requirements for protecting workers from exposure to
potentially hazardous contaminants. Since
Alternative 5-2 is an interim action, compliance with
action-specific ARARs will be addressed at the time of
final remedy selection.
Cost Effectiveness. The estimated present worth costs of the
preferred alternatives are listed below:
.
Alternative 1-2
Alternative 2-2
Alternative 3-2
Alternative 5-2
$950,000
$195,000
$182,000
$ 55,000
For each operable unit, these costs represent the lowest
estimated costs for providing an adequate level of effectiveness
to meet the remedial action objectives. The costs associated
with Alternative 5-2 represent estimated costs for doing further
investigation. .
Utilization of Permanent Solutions and Alternative Treatment
Technologies to the Maximum Extent practicable. EPA has
determined that the selected remedial actions represent to the
maximum extent practicable, permanent solutions and alternative
treatment technologies while providing the best balance among th~-
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other evaluation criteria. Of all the alternatives evaluated
that are protective of human health and the environment and meet
ARARs, the selected remedies provide the best balance in terms of
long-term effectiveness and permanence: short-term effectiveness:
cost: implementability: and state and community acceptance.
Since Alternative 5-2 is an interim action remedy, the
utilization of permanent solutions and alternative treatment
technologies to the maximum extent practicable will be addressed
at the time of the final remedy selection.
Preference for Treatment as a Principal Element. The selected
remedies for the site build upon the existing groundwater
treatment system that is currently in use. The treatment system
is mandated to stay in use at the site as part of
Alternative 1-2. This treatment is an integral part of the
overall remediation for the Middletown Airfield site. Thus, the
volume, toxicity and mObility of hazardous constituents at the
site will continue to be permanently reduced or eliminated from
the groundwater. Since remedial action objectives for soils at
the site were met through institutional controls, the selected
remedies do not satisfy at this time the statutory preference for
treatment as a principal element. Preference for treatment of
soils at the site will be reevaluated during the five year
review.
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