United Statet
Environmental Protection
Agency
Office of
Emergency and
Remedial Retponee
EPA/ROO/ROJ-SMWfl
December 1907
&EPA
Superfund
Record of Decision
Middletown Air Field, PA
-------
DECLARATION FOR THE RECORD OF DECISION
Site Name and Location
Pennsylvania.
Statement of Purpose
r, Drinking Water Supply Operable Unit, Middletown,
This decision document represents the selected remedial action for this
Site developed In accordance with CERCLA, as amended by SARA, and to the
extent practicable, the National Contingency Plan.
The State of Pennsylvania has concorred on the Selected Remedy.
Statement of Basis
This decision is based upon the Administrative Record (index attached).
The index identifies the items which comprise the Administrative Record
upon which the selection of a remedial action is based.
Description of the Selected Remedy
This Is an interim remedy which focuses on the drinking water supply as
an operable unit. The remainder of the site is under investigation and
will be addressed at a later date.
The selected remedy consists of providing a potable water supply to those
served by the Harrisburg International Airport system. This will be accomp-
lished by constructing a central treatment plant. Water from 10 of the
on-site wells will be collected and then treated via a 2-tower air stripping
unit. _
Declaration
The selected remedy is protective of human health and the environment,
attains Federal and State requirements that are applicable or relevant and
appropriate, and is cost-effective. This remedy satisfies the preference
for treatment that reduces toxicity, mobility, or volume as a principal
element. Finally, it is determined that this remedy utilizes permanent
solutions and alternative treatment (or resource^ recovery) technologies to
the maximum extent practicable.
Date
J
Jamis M. Self/ <
Regional Administrator
-------
ROD DECISION SUMMARY
I. SITE NAME. LOCATION. AND DESCRIPTION
The Middletovn Air Field Site covers what is now the Harrisburg International
Airport (HIA), and is located between the towns of Middletown and Highsplre,
in Dauphin County, Pennsylvania, on the east bank of the Susquehanna River
(Figure 1 & 2). Geographically it is located at latitude 40° 12' N and
longitude 76° 45' W.
Prior to its use as a commercial airport, the Middletown Air Field site .
was used from the early 1900s to 1962 by the Federal Government a military
property. It was assigned the name Olmsted Air Force Bate in 1947. The former
location of the base is now occupied by the HIA and several other entities,
including the Fruehauf Truck Trailer Manufacturing facility, Penn State
University Branch Campus, and several small manufacturing facilities. The
airport is owned and operated by the Commonwealth of Pennsylvania, Department
of Transportation (PennDOT). The area surrounding the base is characterized
as mixed residential/industrial. Middletown, located southeast of the
Site, has a population of approximately 10,200.
II. SITE HISTORY
The property formerly occupied by Olmsted was initially established by the
Army as a basic training camp in 1898. Vithin that same year, following
the Spanish-American War, the land was reverted back to farmland. In May
1917, the Army Signal Corps established a storage depot on 47 acres of this
area, which was known an the Aviation General Depot. Warehouses, open sheds
and garages were constructed on the site beginning in 1918 for materiel
storage. The depot was renamed in 1921 as the Middletown Air Intermediate
Depot.
Flying activities at the base began in 1918 with Curtis'M-4 aircraft and
balloons. At that time, a canvas hanger housed the aircraft maintenance
activities. The airfield was named the Olmsted Field for Lt. Robert S.
Olmsted following his death in a balloon race in 1923.
The functions of the base were increased following World War I to include
aircraft and accessory repair. Aircraft overhaul facilities were expanded
and made permanent to accommodate increasing activity, which by 1931 had
reached a peak of one plane per day.
From 1931 to 1939, the Middletown Air Depot operations remained stable, and
the main functions were supply and maintenance of Army Air Corps materiel.
During World War*II, facilities were expanded. In 1943, the facility was
assigned to the Middletown Air Depot Control Area Command. The Command was
redesignated the Middletown Air Technical Service Command in 1944 and was
changed again in 1946 to Middletown Air Materiel Area (MAAMA). Activities
during World War II included overhaul of P-40, P-38, and B-25 type aircraft.
To accommodate the extreme increase in the load of aircraft overhaul activities,
-------
? I*•"Wl'vt*'* \ '
^wte/)-^
j^ttMlw
FioniUSGS 75'Oiimhwigle*.
Sleetton «Hl MNhNetown. Pa (1972)
I
•O
i
Reproduced from
best available copy.
SITE LOCATION MAP
FIGURE 1
-------
HavisbUrg International Airport
*** ?
LE-3ENO
HIA-1: Pcoduclion Wtll
•»••• Induslriil Area
btc lnM,iH4tion n»<.if)i»tMi«t r
fwm ^Ijqc I ritt.il ni-i»uil A««
Susquettanna River
FIGURE 2 GENERAL SITE MAP SHOWING
INDUSTRIAL AREA AND
PRODUCTION WELLS
Ojl
-------
- 4 -
activities, the base used the Farm Show Building in Harrisburg, Pennsylvania,
for aircraft engine repair between 1943 and 1945. In 1945, building T-160
was converted to a POW camp; it was deactivated in February 1946.
In September 1947, Olmsted Field was renamed Olmsted Air Force Base to
coincide with the designation of the Air Force as a separate Department of
Defense establishment.
In 1948, four engine test cells were converted for overhaul of jet engines,
marking the introduction of jet aircraft to the base* From 1950 to 1955,
improvements were made to maintenance hangars, engine test cells, and
other maintenance and test buildings to properly handle engineering of Jet
engine accessories, and radio and electronic components.
In 1951, MAAMA materiel storage operations included 28 different buildings
at Olmsted and were supported by 6 locations remote to the base, using a
total of 1,739,000 square feet space.
In 1956, a major expansion of the existing runways to handle jet aircraft
was undertaken. As part of this program, a tract of land encompassing
Sunset Hill (i.e., Sunset Golf Course) was purchased. Additional property
was purchased in 1956 to accommodate facility expansion, Including property
for military housing (Meade Heights), property west of the facility for
runway expansion, and property north of U.S. Route 230 for additional bulk
warehousing.
By the early 1960s Air Force operations at Olmsted began to decrease. The
industrial portion of the installation was declared excess to the Air
Force in November 1964, and all Air Force operations were ceased by 1966.
The primary mission of the former Olmsted AFB was to provide support to
the MAAMA in conducting its procurement and production assignments.
Logistical support of Air Force operations for 11 northeast states con-
sisted primarily of supply services and engineering maintenance. Activities
at Olmsted throughout its history included:
* Warehousing and supply of parts, equipment, general supplies, and
petroleum, oil and lubricants (POL) for the northeast procurement
district
• Complete aircraft overhaul, including stripping, repainting, engine
overhaul, reassembly, and equipment replacement
* Engine and* aircraft testing
" General base support maintenance and operation
III. CURRENT SITE STATUS
This Record of Decision (ROD) focuses on the provision of a safe drinking
-------
- 5 -
water supply for the HIA. The remainder of the site is being investigated,
and the findings of the complete Remedial Investigation/Feasibility Study
will be presented at a later date.
In March 1983, trichlorethylene (TCE) contamination caused six of the ten
onsite production wells supplying HIA to be taken out of service. Because
of the Air Force's past involvement with the installation, the Air Force
initiated investigations at the Middletown Air Field Site under the Depart-
ment of Defense Installation Restoration Program (IRP). In accordance
with the IRP, Phase I investigations were completed in April 1984 (JRB
Associates, 1984) and Phase II studies were completed in April 1986 (Roy
F. Ueston, 1986). Additional studies were also completed for PennDOT in
April 1984 (R.E. Wright Associates Inc., 1984). These studies identified
six areas of potential concern. These were:
Lisa Lake
Landfill/Runway Area
.- North Base Landfill
Meade Heights
Industrial Area
Fire Training Pit
The findings of these confirmation studies indicate that while volatile
organic compound contamination of ground water resources exists, the exact
source(s) of contamination cannot be clearly defined. The results Indicate
contamination of the ground water (which feeds the production wells) by
volatile organic compounds (VOCs) from one or more, possibly current, sources
in the "Industrial Area" (Figure 2).
One of the recommendations of the Phase II study (Weston, 1986) was the
development and implementation of a ground water withdrawal and treatment
system for the industrial area to remove volatile organic compounds from
the HIA drinking water supply wells. The Phase II study also contained
a number of recommendations concerning the other sites at HIA (Lisa Lake,
Meade Heights, North Base Landfill, and the Incinerator/Landfill Disposal
Area).
To date, HIA has been able to temporarily meet the water requirements of
the facility by taking the most contaminated well off-line as a -potable
water source and by blending potable water from a number of wells. The
well taken off-line is now a dedicated purge well pumped for cooling water
supply only. However, in view of the water supply contamination problem,
long-term remedial action is necessary to assure a continued and reliable
potable water supply.
The VOCs detected in the airport wells are listed in Table 1. Shown are the
highest average concentrations of each VOC at each well over the sampling
period from March 1983 to June 1985 along with the well In which the highest
average concentrations occurred. In addition, Table 1 shows the concentration
of two additional VOCs that were detected in Well No. 13 during the sampling
for Hazardous Substances List (HSL) compounds on May 26, 1987. Non-volatile
organics have not been detected in the ground water, based on the sampling
and analysis of Wells No. 2, 3, 4, 5, 6, 9, 11 and 13 on May 26, 1987, for
the HSL compounds.
-------
- 6 -
TABLE 1
VOCS DETECTED IN AIRPORT WELLS
VOC
Highest average
influent concentrations
(uq/L)
Highest
single
concentration Well
number
Chlorome thane
Carbon Tetrachloride
1 , 1-Dichloroe thane
trans-1 , 2-Dichloroethene
1,1, 1-Tr ichloroethane
Vinyl Chloride
1 , 1-Di chloroethene
Trichloroethene
Tetrachloroethene
Benzene
Chlorobenzene
Toluene
2.0
0.25
3.35
73.3
4.46
1.20
1.74
81.67
6.25
4.80
8.2
17.0
4.0
1.0
5.3
140
19
2.6
1.74
311
25
4.80
15
17
12
13
13
13
6
13
13
13
11
2
13
2
Source: Buchart-Horn, Inc. and Halcoln Pirnie, Ground Water Remediation at
Harrisburg International Airport, Draft Engineering Report, March 1986.
cis-1,2-Dichloroethene1
1,2-Di chlorobenzene
1,4-Dichlorobenzene
149.3
189
27
149.3
189
27
13
13
13
Source: USEPA, Region III, Analytical Results from Ground Water Samples
Collected on Hay 26, 1987 at Harrisburg International Airport.
1 cis-1,2-Dichloroethene was tentatively identified in the nontarget conpound
report
-------
- 7 -
The most prevalent volatile organic* In the airport wells are trichloro-
ethylene (TCE) and tetrachloroethylene (PCE), which have been found In all
the wells sampled. Although TCE and PCE are the most common VOCs, the
other VOCs shown in Table 1 are also being addressed. Well No. 13 has
consistently had the highest concentrations of many of the volatiles
(see Table 1). VOCs have also been detected in Wells No. 2, 3, 4, 5, 6,
9, 11 and 12.
Present EPA and Pennsylvania Department of Environmental Resources stand-
ards and guidelines for the volatile organics are given in Table 2.
The volatile organic compounds for which final Maximum Contaminant Level
Goals (MCLGs) and final Maximum Contaminant Levels (MCLs) have been
adopted by EPA are shown in Table 2. Of the eight MCLs, only 1,2-
dichloroethane has not been detected in the airport wells. Six other
organic compounds (chloromethane; 1,1 dichloroethane; 1,2-dichlorobenrene;
trans-1,2-dichloroethylene; chlorobenzene; and toluene) have also been
detected in the airport wells. Of these six compounds, proposed MCLGs
have been published by EPA for toluene (2,000 ug/1), 1,2-dichlorobenzene
(620 ug/1), chlorobenzene (60 ug/1), and trans-1,2-dichlorethylene (70
ug/1). These are shown in Table 2. Tetrachloroethylene is carcinogenic
and has been included in Table 2; 1,1-dlchloroethane and chloromethane are
non-carcinogenic.
The carcinogenic risk from consumption of volatile organic chemicals is
the major health risk at the site. Potential receptors are the customers
of the HIA Water Supply System. Using maximal ground water contamination
values for six volatile organic carcinogens found In the HIA wells (assuming
no blending of water) the carcinogenic risk to users of that water assuming
no remedial action is conducted, is as follows.
CARCINOGENIC RISK
Chemical
Concentration
(ppb) IP"6 ppb/10"6
Trichloroethylene 311 1.84 169
Tetrachloroethylene 25 1.0 25
Carbon tetrachloride 0.47 0.27 2
Vinyl chloride ^ 4.1 0.015 273
Benzene - 4.8 0.66 7
1,1-Dichloroethylene 1.74 0.033 53
Total carcinogenic risk x 10~& « 529
529 x 10~6 - 5.3 x 10"4
*ppb which gives risk for one cancer per million lifetime consumers
-------
- 8 -
TABLE 2
GUIDELINES AND STANDARDS FOR SELECTED VOLATILE ORGANICS
Contaminant
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
II.
12.
13.
14.
15.
Chlorome thane
Carbon Tetrachloride
1 ,1-Dichloroethane
trans-1 ,2-Dichloroethene
cls-1 ,2-Dichloroethene
1,1, 1-Trichloroethane
Vinyl Chloride
1 , 1-Dichloroethene
Trichloroethene
let rachloroethene
Benzene
Chlorobenzene
Toluene
1 ,2-Dichlorobenzene
1 ,4-Di chlorobenzene
USEPA
MCL
(ug/1)
—
5.0
-
-
-
200
2.0
7.0
5.0
-
5.0
-
-
-
75
USEPA
MCLG
(ug/1)
—
0
-
70
70
200
0
7.0
0
-
0
60
2000
620
75
USEPA
10-6
level
(ug/1)
—
0.27
-
-
-
-
0.015
0.033
1.84
1.0
0.66
-
-
1.8
-------
- 9 -
The risk which derives is 5.3 x 10~* lifetime risk for developing cancer,
assuming consumption of 2 liters per day for 70 years.
The amount of water being pumped from each well is shown below:
WELL I RATE (GPM)) DESCRIPTION DEPTH (FT) COMMENT
2
3
4
5
6
9
11
12
13
14
270
130
140
170
500
150
600
700
430
340
Domestic/Potable
Domestic/Potable
Domestic/Potable
Domestic/Potable
Domestic/Potable
Domestic/Potable
Domestic/Potable
Domestic/Potable
Non Pota./Indust,
Use
Non Pota./Indust.
Use
450 Used Sparingly
450 Used Sparingly
459 Used Sparingly
776 Used Sparingly
500 Used 24 hours/
day, 7 days a
week
451 Used Sparingly
600 Not Used
600 Used 24 hours/
day, 7 days a
week
800 United Piece
Dye Well
800 Passenger
Terminal HVAC
In the current distribution system, water is pumped from the wells directly
into the distribution system. The distribution system is a complex network
of approximately 21 miles of pipe, varying in size from 6 to 18 inches.
If water is not required by a customer, it is stored in one of the three
elevated storage tanks (65,000 gallons, 200,000 gallons, and 400,000 gallons)
in the low pressure area. A 1-mi 11ion gallon tank located in the area
north of the airport is supplied with water by a pumping station located
on the eastern end of the airport. This tank supplies water to Fruehauf
Corp., Pennsylvania State University at Harrisburg, and the Odd Fellows
Home. The approximate daily consumption of water at the airport ranges
between 1,400,000 gpd to 1,800,000 gpd. United Piece Dye uses a large
percentage of this amount for manufacturing purposes. The HIA new passenger
terminal building also uses 500,000 gpd of the foregoing amount for the
HVAC system. The water system is interconnected with Middletown Royalton
water system at one operable location. The interconnection Is normally
closed, and designated for use only in the event of an emergency. It is a
one-way connection with the airport being the supplier.
iv. ALTERNATIVE'S EVALUATION
This ROD recommends the appropriate remedial actions for the water supply
contamination problem found in the Industrial Area of HIA through a process
of screening, developing, and evaluating applicable control measures. The
selection of the preferred remedial action is based on its ability to satisfy
the primary objective.
The primary objective is to provide a potable water supply (i.e., one that
meets federal and state standards) to HIA that can satisfy present and
future needs. A collateral and ancillary benefit of achieving this objective
is to remediate ground water contamination in the industrial area by reducing
volatile organic compound concentrations and controlling contaminant migration.
-------
- 10 -
A. Screening Of Alternatives
The following Table 3 lists all the control technologies which were screened
in the focused feasibility study for development as remedial action alter*
natives. The focus of the screening is to determine which control measures
have the potential for satisfying the primary objective, i.e., to provide
a potable water supply. Only those measures which have this potential
were retained for development as remedial action alternatives. Control
measures are screened on the basis of technical feasibility, cost, environ-
mental impacts, and public health effects.
The National Contingency Plan (NCP) requires that, to the extent possible
and appropriate, at least one remedial alternative be developed as a part
of a feasibility study in each of the following categories:
(1) Alternatives for treatment or disposal at an off-site facility
(2) Alternatives that attain applicable or relevant and appropriate
Federal public health and environmental requirements
(3) Alternatives that exceed those requirements
(4) Alternatives that do not attain the requirements above, but will
reduce the likelihood of present or future threat and that pro-
vide significant protection to public health, welfare and the
environment
(5) No action
The only potential alternative that involves disposal at an off-site facility
that could be a candidate for further evaluation is excavation of the
contaminated soil followed by transportation and disposal at a RCRA landfill.
This alternative would involve the excavation of a potentially large and
deep area through existing pavement, and would not be cost effective because
of the large amounts of material to be transported and disposed, coupled with
the relatively low concentrations of contaminants that would be removed.
Accordingly, no alternative in this category is judged to be appropriate
for further analysis.
A centralized treatment plant using either activated carbon adsorption
or air stripping can meet or exceed Federal requirements.
Because the no-action alternative involves continuing to pump well HIA-13
to waste, it reduces the likelihood of present or future threat. However,
in the long term,* the no-action alternative will not attain the applicable
Federal requirements in times of mechanical failure or increased demand.
Therefore, based on the technology screening evaluations, the following
remedial action alternatives have been selected for development and detailed
evaluation:
-------
- 11 -
TABLE 3
COMPARISON or CONTROL TECHNOLOGIES
Technology
Ground Mater Control
Capping
Pumping (w/o treatment)
t
Containment Barrier
Soil and Sediment Control
E>cavation and Removal
In-Situ Treatment of Soil
Direct Mater Treatment
Separation
o Air Stripping
o Activated Carbon
Adsorption
o Polymeric (Resin)
Adsorption
Destruction
UV-Catalyzed Ozonation
Detoiffication
Dye-Sensitized Photo
Oxidation
Time to
Achieve
Primary
Objective
Mill not
achieve
objective
Mill not
achieve
objective
Mill not
achieve
objective
2-4 yrs
Could be
many yrs.
2 years
2 years
2-3 years
2-3 years
2-3 years
Difficulty
in Imple- Ability
mentation to Satisfy
and Opera- Quantity Proven Relative
tion Demand Technology Cost
Low Low Yes Low
Low Low Yes Low
Low Low Yes Low
High Low Yes High
High Low No High
Low High Yes Hoderate
Low High Yes High
Moderate Low No High
High High No High
Hoderate High No High
Public Result of
Envmt'1 Health Initial
Impact Protection Screening
Low Poor Eliminated—
•ill not pro-
vide potable
•ater
Moderate Poor Eliminated—
•ill not pro-
vide potable
•ater
Low Poor Eliminated—
•111 not pro-
vide potable
•ater
High Poor Eliminated—
poor technical
feasibility
Moderate Poor Eliminated—
unproven
technology
Low Good Consider further
Low Good Consider further
Moderate Good Eliminated—
not proven at
this scale
Low Fair Eliminated—
unproven
technology
Low Fair Eliminated—
unproven
-------
- 12 -
TABLE 3 (cent.)
COMPARISON OF CONTROL TECHNOLOGIES
Technology
Simple Chemical Addition
Management Methods
Eiisting Utter Supply
0 Central, Treatment
o Me 11 Head Treatment
o Poin.t-of-U$e Treatment
Alternative Water Supply
o Connection to Public
System
o Susquehanna River
o Ne« Ground Hater
Supply Mel Is
o Bottled Mater
Time to
Achieve
Primary
Objective
Hill not
achieve
objective
2 years
3-4 years
1 year
3-4 years
4-6 years
4-6 years
<1 year
Difficulty
in Imple-
mentation
and Opera-
tion
Low
Low
High
High
Low
Moderate
Moderate
LOW
Ability
to Satisfy
Quantity Proven Relative Envmt'l
Demand Technology Cost Impact
High No Low High
High res Moderate Low
High Yes High Low
High Yes Moderate Low
Low Yes Moderate Low
High Yes Moderate Moderate
Low Yes High Moderate
High Yes High Moderate
Public Result of
Health Initial
Protection Screening
Poor Eliminated--
will not remove
VOC'i
Good Consider further
Good Eliminated—
high cost and
poor feasibility
Fair Eliminated—
unreliable
performance
and monitoring
problems
Good Eliminated—
adequate public
supply not
available
Fair Eliminated due to
cost, raw water
quality and time
to implement
Good Eliminated due to
lack of available
sites for
development
Fair Eliminated due to
economic, and
practical
considerations •
-------
- 13 -
Category
Attains Federal requirements
Exceed Federal requirements
Alternative
Centralized plant using air stripping
Centralized plant using activated carbon
adsorption
Centralized plant using air stripping
Centralized plant using activated carbon
adsorption
No action
Does not attain Federal
requirements
No action No action
B. Detailed Analysis of Alternatives
After screening the alternatives, three emerged as warranting further con-
sideration: central treatment plant, air stripping treatment, and carbon
adsorption treatment. The no-action alternative is also evaluated. For the
purpose of this analysis, treatment via air stripping or carbon adsorption
assumes treatment at a central facility. The alternatives will be compared
in relation to the following factors: engineering feasibility, cost, environ-
mental impact, public health effects, and regulatory compliance.
1. CENTRAL TREATMENT PLAN
A central treatment facility is technically feasible and implementable.
The 10 affected wells would have to be manifolded to a central location and
then hydraulically redistributed after treatment. Treatment with air
stripping or granulated activated carbon. (GAC) can readily be accomplished
in this manner. If more of the existing wells developed unacceptable levels
of volatile organics they would be automatically treated. Public health
would be protected on a continuous basis with only nominal monitoring
required.
The cost for a central treatment facility including pipelines and well pump
renovation should be competitive with the other identified alternatives for
using the existing supply. The environmental impact of this option relates
to construction of the treatment building and waste by-products generated
in the treatment process. Environmental impact from construction should be
nominal since the plant can be built on airport property at a location
which is presently cleared and level. The plant by-products, depending on
treatment process selected, could be a moderate atmospheric discharge from
an air stripping system or spent granular activated carbon which would have
to be handled and reactivated or disposed of appropriately. Both treatment
technologies are in common use and waste by-products are not considered a
major problem except at very contaminated sites.
-------
- 14 -
2. AIR STRIPPING
Air stripping relies upon the natural volatility of volatile organic
compounds to remove compounds from the water into an air stream. A
high removal efficiency (99 percent) is required to remove VOCs found
at maximum concentrations observed in the well field to date. To
achieve this removal efficiency, a packed tower air stripper would be
required. In the packed tower configuration, water and air are brought
into contact in a column packed with one of several commercially
available packing materials. Water trickles down through the packing,
while a counter-current flow of air is forced upward.
Figure 3 shows a conceptual diagram for a typical packed tower air stripper.
The installation of air stripping will consist of pumps, clearwell, packed
towers and chlorination equipment. Water would be pumped directly from
the wells to the top of the tower where it would cascade over the packing
as forced air carries the volatiles from the water. After stripping, the
water would enter an intermediate clearwell where booster pumps would
provide system pressure. The water would be chlorinated in the clearwell.
In the future, softening could be added to the system, if desired. There
are many operating air stripping systems in Pennsylvania removing the same
type and level of organ!cs.
The estimated capital cost for a complete air stripping installation is
about $3,700,000 including 30 percent for contingencies and 13 percent
for engineering. Air stripping operating costs would average $161,000
per year or $0.15 per thousand gallons. Capital cost for a six contactor
carbon system would be about $8,900,000 including the same contingency
and engineering percentages. The capital costs for both technologies
are much higher than normally expected for a plant of this size because
more than $2,000,000 (including contingency) is needed to repipe the wells.
The environmental and public health impacts from the air stripping
towers relate to construction activities and air emissions. The plant
site is level and cleared. Construction activities would be typical and
normal for a water plant and generally confined to the immediate limit
of work with the exception of the pipelines conveying water from the
wells.
3. GRANULAR ACTIVATED CARBON ADSORPTION
Activated carbon has been successfully used to remove VOC contaminants
from drinking water supplies. Granular activated carbon can reduce
organics in drinking water to immeasurable levels. However, the mechanism
by which GAC removes organics is molecular adsorption to the surfaces
of the internal micropores. Consequently, the capacity of GAC is finite
and limited by the type, concentration, and mixture of organics compared
to available adsorption sites.
-------
AIR STRIPPING UNIT
( PACKED TOWER )
EXHAUST AIR
DEMISTOR
WATER DISTRIBUTION
NOZZLES OR
DISTRIBUTION PLATE
AIR BLOWER
TO ATMOSPHERE
OR TREATMENT
INFLUENT WATER
FROM
'CONTAMINATED
SUPPLY
TREATED WATER
FIGURE 3
-------
- 16 -
The cost of such treatment it mostly determined by the quantity of
carbon- required to achieve the desired removal. The annual carbon
consumption at 3.0 mgd is estimated at 1,643,000 pounds per year.
At an approximate cost of $1.54/kg for virgin carbon ($9.70/lb),
this translates to $1.15 million per year in carbon replacement cost
alone. Power, labor, and maintenance would be additional costs, but
insignificant compared to that for carbon replacement.
A GAC facility at Harrisburg would consist of six pressure contactors.
Each pressure contactor would contain 20,000 pounds of carbon. In
order to meet the projected quality guideline, the CAC would require
replacement every 28 to 30 days (calculated for design influent
conditions). Replacing carbon this frequently is generally considered
excessive. Using the carbon for 6 months is more practical. However,
to achieve a 6-month replacement schedule would require installation
of 36 contactors (containing a total of 720,000 pounds of carbon).
This is an impractical number of contactors.
Operating and maintenance costs for the GAC system based on constant
influent VOCs at design levels are estimated at $1,300,000 per year or
$1.18 per thousand gallons. Even a cursory review of the cost breakdown
supports the air stripping towers as being considerably less expensive
to build and operate than the carbon contactors. However, a major
factor in the operating cost for the carbon is the actual VOC influent
levels. As the levels decrease, and ultimately they should, replacement
cost for the carbon should decrease proportionately. Since the levels
of VOCs will not directly affect the stripping tower operating costs,
as the influent levels decrease the carbon will tend to be more
competitive with the air system. However, information is not presently
available that will allow a reasonable prediction of aquifer cleanup
duration.
Construction of the carbon contactors would require more land area
(perhaps 10,000 ft?) than the strippers. The pipeline construction
would remain the same. There would be no atmospheric discharge from the
GAC but the spent carbon along with the adsorbed volatile organics would
have to be handled and disposed of in an appropriate manner, either by
thermal regeneration or by land disposal. Backwash water from the carbon
contactors would have to be disposed of in an approved manner as would
the carbon transport water. Discharge of backwash water to the
Susquehanna River, without treatment, could have an adverse impact on
river water quality.
GAC treatment will result in two discharge streams: backwash water from
the carbon contactors and carbon transport water. Backwash is water
that is produced daily during routine filter maintenance to keep the
filters from becoming clogged. Carbon transport water is the water that
is used to produce a slurry with the spent activated carbon in order to
flush the spent carbon from the contactors. This process is carried out
every six months. Since this system is not proposed to be operated in
combination with air stripping, contaminated carbon will be present in
the carbon transport water.
-------
— 17 -
Compared to the air stripping alternative, GAC treatment is slightly
more desirable from the standpoint that there would be no atmospheric
emissions at all. However, disposal, regeneration, and transportation
of the spent carbon is a potential public health concern.
Air stripping is sometimes followed by carbon adsorption to increase
carbon longevity and reduce costs. Air stripping, followed by carbon
adsorption, is typically effective when the influent water contains a
mixture of volatile and nonvolatile organics. The advantage of using
these treatments together is that air stripping can remove VOCs at a
low cost and carbon can adsorb the remaining VOCs as well as non-VOCs.
Combining air stripping and carbon adsorption at Harrisburg would not
prove economically beneficial since no non-volatile* have been reported
in the well water, the air stripping towers do not require air emission
control, and two-stage air stripping can meet the proposed EPA MCLs and
Pennsylvania DER guidelines.
4. NO ACTION ALTERNATIVE
The no action alternative would continue current (May 1986) water supply
operations at HIA. HIA wells No. 8, 10, 14, 16, 17, and 18 would remain
closed. HIA well No. 7 would remain plugged and abandoned. HIA well No.
13, which is the most productive well in the system, would continue to be
used as an interceptor/purge well pumped for cooling water supply only.
HIA wells No. 2, 3, 4, 5, 6, 9, and 12 would continue to be blended to meet
the water requirements of the facility (wells No. 11, 13 and 14 not used).
In the no action alternative, no treatment for volatile organic compound
removal would occur. Instead, reliance would be placed on the ability to
continue blending water from the production wells in use to meet state and
federal drinking water standards for VOCs. Water from the potable supply
wells would continue to be chlorinated prior to general use.
In terms of engineering feasibility, the main concern with the no-action
alternative is the effectiveness of this alternative in satisfying the
primary or secondary objectives. Currently, the seven wells in use are
able to meet facility supply requirements and the blended water meets
drinking water standards with chlorination. However, future contaminant
migration could cause an increase in VOC levels in one or more of these
wells. If the level is high enough to cause even one well to be taken off
line, available water supply could fall below demand. Or, if future demand
increases subsfantially or in a drought condition, the unavailability of
well No. 13 for potable supply could cause a potable supply quantity
problem.
»
Additionally, HIA No. 13 is a productive operable well in the Harrisburg
International Airport system. Presently it is used as a purge well; the
water is used for Industrial cooling. This constitutes waste of a
valuable water resource. This could be avoided through treatment.
-------
- 18 -
Since the no action alternative is defined as current operations,
i.e., pumping, blending and chlorination, compared to the action
alternatives, there are no capital costs associated with this alter-
native. Annual operation and maintenance costs over and above current
levels are approximately $12,000. This cost reflects additional
monitoring and analysis that would be prudent if the current system
were to be implemented indefinitely. Note that O&M costs such as
chlorination which are common to both the action alternatives and
the no action alternative have not been included in this comparison.
Annual chlorination costs under the no action alternative would be
slightly higher than the action alternatives because of the greater
operating and maintenance requirements of ten individual chlorination
systems compared to a central chlorination system.
Because the no-action alternative does not reasonably assure continued
potable water supply from the HIA wells, a potential exists for environ-
mental (socioeconomic) impacts should the wells have to be abandoned and
emergency alternative supplies have to be provided.
If the wells were abandoned, the volatile organic contaminants in the
ground water would be expected to migrate with the general ground
water flow and eventually discharge to the Susquehanna River. The
impact on the Susquehanna River would be slight because of the relatively
small quantities of contaminant involved and the type of contaminants
(i.e., volatile organics susceptible to river aeration). Continuation
of the pumping of well No. 13 as cooling water supply has air quality
(cooling tower) and river water quality (cooling water discharge)
impacts due to the VOCs present in the water.
As long as the current method of blending produces water that meets
drinking water standards, no unacceptable health effects should
result.
In assessing the risk of the no-action alternative for providing safe
drinking water to the 3500 personnel presently served by the system
the exposure route is ingestion. Using the EPA protocol (Superfund
Public Health Evaluation Manual, 1986) for the presence of two
carcinogenic compounds (TCE and PCE) and assuming a 2 liter/day
consumption by a 70 kg male, the 10~6 cancer risk level was calculated.
The target concentrations that correspond to a cancer risk level of
10 for TCE and PCE from the same source are 2.1 ug/1 and 0.3 ug/1,
respectively. By reviewing the data, it is apparent that at some
point in time each well has exceeded not only the 10~° cancer risk
level but also the enforceable standards. It is apparent that the
public health would be best served by an alternative that assured a
potable water aupply that met the enforceable standards. The two
action alternatives will accomplish this. The lack of certainty
regarding the future ability to meet drinking water standards through
blending is a potentially significant public health disadvantage of
the no action alternative compared to the alternatives of treating
water with known, proven technology. In particular the ability to
dilute current levels of TCE and PCE to acceptable concentrations on
a continuous basis is tenuous. The risks of downtime of the least
contaminated wells, dry years and increased demand will increase the
-------
- 19 -
likelihood,of more contamination in the potable water. Either action alternative
will assure a drinking water supply that meets federal and state standards.
If in the future other contaminants are detected, potential public health impacts
may have to be evaluated at that time.
Permits required for the no-action alternative are those associated with the
current water system. Since this is an ongoing operation, no additional permits
are necessary and, therefore, no time is required prior to implementation.
However, should water quality conditions change, compliance with federal and state
drinking water regulations could become a significant problem requiring some form
of mitigation or response to maintain compliance.
Summary
Table 4 summarizes in chart form the evaluation of the alternatives.
TABLE 4
SUMMARY OF ALTERNATIVES EVALUATION
Alternative
No Action
Cost ($1,000)
Annual
Capital O&M
0 12
(baseline)
Central Treat-
ment Plant
with Air
Stripping
Central Treat-
ment Plant
with Granular
Activated
Carbon Ad-
sorption
3,700 160
8,900 1,300
Engineering
Feasibility
Does not
assure
potable
water sup-
ply to
meet future
needs
Environmental
Impacts
Loss of
adequate
potable water
supply could
have socio-
economic
impacts
Public
Health
Effects
Does not
reasonably
assure
future
supplies
will meet
drinking
water
standards
Regulatory
Compliance
May Cause
future non-
compliance
with state
and federal
drinking
water
standards
Proven,
effective
technology
No
unavoidable
significant
adverse
effects
Provides
high level
of assur-
ance of
safe water
supply
Meets all
regulatory
requirements
Proven
effective
technology
No
unavoidable
significant
adverse
effects
Provides
high level
of assur-
ance of
safe water
supply
Meets all
regulatory
requirements
-------
- 20 -
V. SELECTED REMEDY
The chree alternatives that were included in the final analysis were no
action, central treatment with air stripping, and central treatment with
granular activated carbon. Treatment with granular activated carbon is
considerably more expensive to construct and operate and does not have any
clear environmental or public health advantages over air stripping. The no
action alternative does not ensure future protection of public health and
does not account for water supply quantity deficiencies which are already
evident. Therefore, central treatment with air stripping is selected as the
most effective, economical and environmentally sound alternative.
The operable unit which this Record of Decision addresses is only part of
the total remedy for the site. It addresses provision of a potable water
supply to users of the HIA system. The remainder of the site is being
investigated as part of an RI/FS, the results of which will be presented at
a later date. A Record of Decision which addresses this second phase of
site evaluation will also be forthcoming.
A. Engineering Description
The air stripping facility would consist of two packed towers, three forced
air centrifugal blowers (one standby), clearwell with 30-minute detention
time, gas chlorination, small laboratory, booster pumps and associated
pipelines. All the existing well pumps would have to be replaced with new
low-lift equipment and a new booster station constructed downstream of the
treatment plant.
The towers would be 10 feet in diameter, approximately 30 feet tall (28 ft.
of packing) and constructed of either aluminum or fiberglass. Each tower
would have a capacity of 3.0 mgd and could be operated in series or parallel.
The packing would be 2-inch size and the volumetric air-to-water ratio
would be 50 to 1. When the towers are operating in series the expected
volatile organic removal would be in excess of 99.5 percent. This level of
removal efficiency will handle the contamination levels found in the ground
water to date and substantially higher levels (see Table 9). The operating
range of VOC removal available with the dual towers would allow tie-in of
additional purge wells that may be developed. The towers would sit directly
on a baffled concrete clearwell designed for a minimum chlorine contact
time of 30 minutes. _ Provision would be made to chemically clean the packing
as necessary. Each tower would be equipped with demisters and redistribution
rings as required.
-------
- 21 -
Overall'dimensions of Che plant structure would be approximately 60 ft.
by 80 ft. and would be constructed on airport property. The most likely
location would be on a site between the airport circumferential road and
the existing railroad tracks. Connection of the ten wells to the plant
will require over 10,000 feet of ductile iron pipe. Centrifugal or verti-
cal turbine pumps will lift the water from the plant clearwell to the system
gradient. During operation, approximately 40 hours per week of routine
operator attendance will be necessary to document performance, change
charts and attend to the chemical feeders. Air emissions from the tower
during routine operation at the average influent VOC level are expected to
be minimal and within allowable Commonwealth of Pennsylvania guidelines.
B. Cost
The estimated project cost for construction is $3,750,000 including en-
gineering and 30 percent contingencies. Of this estimate over half is
required for the piping and new pumping equipment at the existing wells.
Consequently, the cost for the 3.0 mgd towers is.higher than might typi-
cally be expected. Projected operating costs for series towers is estimated
at $160,000 per year or about $0.15 per 1000 gallons. The operating cost
components are power for pumps and blowers, analytical monitoring (assuming
monthly VOC samples at each well and at key plant check locations), chlorine
and operating labor. The operating cost of $0.15 per 1000 gallons compares
favorably with costs at other facilities of this type.
The duration of operation cannot be estimated at this time. However the
duration will probably be on the order of years and, therefore, should be
assumed as indefinite.
C. Public Health Evaluation
There are two potential health effects from the air stripping process.
First, because an air stripper theoretically cannot remove 100 percent of
contaminants from water, there is a need to estimate the ingestion health
risk of the low concentrations remaining in the treated water. Second,
because the contaminants are transferred from the water to the air, it is
necessary to also estimate the inhalation health risk of the air discharge
to potential receptors. In order for these risks to be estimated, a most
probable and worst case contamination scenario consistent for both inhala-
tion and ingestion was developed.
The worst case contamination scenario used the highest average effluent
concentrations which provide a margin of conservatism over the most probable
cases. Based on the projected performance of the facility established by
Buchart-Horn and Malcolm Pirnie, a highest average effluent concentration
was established as the worst case for both the inhalation and ingestion
risk assessment (See Table 5).
-------
- 22 -
TABLE 5
HIGHEST AVERAGE CONCENTRATIONS
Contaminant
Chlorome thane
Carbon tetrachloride
1 , 1-Dichloroe thane
cis-1 , 2-Dichloroethene
trans-1 , 2-Dichloroethene
1,1, 1-Tr i chloroe thane
Vinyl chloride
1,1-Di chloroe thene
Trichloroethene
Te t rachl o roe thene
Benzene
Chlorobenzene
Toluene
1 , 2-Dichlorobenzene
1 , 4-Di chlorobenzene
Highest
average
influent cone.
-------
- 23 -
Since'the highest average effluent concentrations were taken prior
to blending to represent a worst case scenario, a aost probable
(more realistic) scenario was also evaluated to identify potential
risks associated with ingestion and inhalation. The projected average
composite effluent concentrations for each of three operational well
groupings were evaluated to identify the most probable potential risks
that are likely to be present when the wells are blended. These group-
ings were selected on the basis that they met the projected demand for
approximately 3 MGD of water based on their historic yields (See Table
6). Well 13 shows the highest concentration levels and has been included
in all three well groupings to add an element of conservatism to the
most probable cases.
HEALTH RISK FOR INGESTION OF WATER
The potential carcinogens .identified as being present in the water are
carbon tetrachloride, vinyl chloride, 1,1-dichloroethene, trichloroethene,
tetrachloroethene, benzene and chloromethane. The lifetime cancer risk
posed by ingestion of the potential carcinogens detected in the water are
presented in Table 7. The total risk associated with ingestion of the
water for the most probable case for the three pumping scenarios is 6 x 10~8
for pumping scenario one, 7 x 10~8 for pumping scenario two and 7 x 10~8
for pumping scenario three. The worst case scenario (assuming no blending
of the water) poses a 3 x 10~7 lifetime cancer risk. These lifetime cancer
risks are all less than 10~6 which is the recommended "safe" limit according
to EPA guidelines.
The noncarcinogens detected in the water were 1,1-dichloroethane, trans-
1,2-dichloroethene, cis-1,2-dichloroethene, 1,1,1-trichloroethane,
chlorobenzene, toluene, 1,2-dichlorobenzene, and 1,4-dichlorobenzene. A
chronic daily intake was calculated for the noncarcinogens and compared
where available to the EPA acceptable intake for chronic exposure or
risk reference dose (RFD). For the noncarcinogens which do not have
an RFD, the maximum contaminant level goals (MCLGs) were compared to
the effluent concentration. Evaluation of the noncarcinogens indicated
the potential hazard to human health is unlikely, with an adequate
margin of safety.
HEALTH RISK ASSOCIATED WITH AIR EMISSIONS
The total risk due to air exposure has been estimated assuming health
risks from the various compounds are additive. The estimated worst
case health risk is 2 x 10~7, or two in 10 million, and 2 x 10~8,
or two in 100 million, for the most probable case air exposure (See
Table 8).
In addition to the risks associated with inhalation of carcinogenic
compounds, health impacts may occur due to exposure to noncarcinogens.
As with carcinogens, chronic low-level exposure to noncarcinogens is
the principal public health concern. Exposure calculations revealed
no potential for significant health impact from exposure to noncar-
cinogenic contaminants is expected.
-------
TABLE 6
COMPARISON OF WORST CASE INFLUENT
CONCENTRATIONS TO HOST PROBABLE INFLUENT CONCENTRATIONS
1
Well Group 1
Well Group 2
Well Group 3
Volatile organic compound
Chlorome thane
Carbon Tetrachlorlde
1 . 1-Dichloroethane
cis'l.Z-Oichloroethene
trans 1.2-Oichloroethene
1.1,1-Trichloroe thane
Vinyl Chloride
l.l-Oichloroethene
Trichloroethene
Tetrachloroethene
Benzene
Chlorobenzene
Toluene
1.2-Dichlorobenzene
1 ,4-Dichlorobenzene
W^ • • * «. f
-------
TABLE 7
COMPARISON OF PROJECTED RISKS FROM INGESTION OF WATER
FOR ALTERNATIVE EFFLUENT SCENARIOS
Contaminant
Carbon tetrachlorxd*
Vinyl chloride
1 , 1-Dichloroethene
Trichloroethene
Tetrachloroethene
Benzene
Worst
case
scenario
5 x 10"J
8 x 10"'
5 x 10"'
2 x 10"'
3 x ICT*
3 x 10"'
Pumping
scenario
one
8 x 1
-------
- 26 -
TABLE 8
COMPARISON OF PROJECTED RISKS FROM INHALATION
FOR ALTERNATIVE INFLUENT SCENARIOS
Host probable scenarios
Contaminant
Benzene
Carbon tetrachloride
Chlorome thane
Vinyl chloride
1 , 1-Dichloroethene
Trichloroethene
Tetrachloroethene
Total risk
High
average
scenario
9.0 x 10"'
2.4 x 10"'
NA
2.2 x 10"'
1.5 x 10"'
2.7 x 10"'
7.7 x 10"l°
1.9 x 10"'
Pumping
scenario
one
8.3 x 10"l°
3.8 x 10"10
NA
7.2 x 10'10
1.3 x 10"'
5.7 x l
-------
- 27 -
D. Ad&ptability of the Treatment System
Because the highest average concentrations used to assess risk have
been defined as conservative, the technical judgment made for this
evaluation is that the raw water concentrations are unlikely to exceed
the highest average concentrations and extremely unlikely to exceed the
design concentrations. Regardless, unexpectedly high raw water
concentrations may be unlikely, but are not impossible.
As long as the actual influent concentration of contaminants to the pro-
posed facilities remains at or below the design influent concentration,
one tower would operate with the second tower serving as a stand-by
unit. The parallel mode, with the flow equally split to each unit,
would only be used if the system performance for a specific compound(s)
needs to be enhanced over the performance of a single unit. The parallel
mode can enhance performance for some compounds while saving the cost
of repumping the entire process flow. This enhanced performance results
from a doubling of the air-to-water ratio induced by having only half
the design flow flowing through each tower. The series mode, requiring
the repumping of all flow through the second tower, would only be used
if the influent concentration to the facility for any compound increased
to the point where a single unit or both units in the parallel mode
were incapable of acceptable performance (Buchart-Horn, 1987). Therefore,
the treatment system is adaptable and is capable of achieving higher
levels of performance than in a conventional single unit operating mode.
Table 9 summarizes the improved performance that could be expected from
series and parallel operation and references this improved operation to
the highest average concentrations used throughout this risk assessment
and to a number of applicable standards.
E. Regulatory Compliance and Consistency with other Environmental Laws
On July 8, 1987, EPA published a final rulemaking pertaining to eight
VOCs, seven of which have been found at Harrisburg International Airport.
These regulations, otherwise known as Maximum Contaminant Levels (MCLs),
are scheduled to have the force of law on January 9, 1989. Based on
the air stripping tower design parameters and the worst case and most
probable case influent concentrations, the air stripping tower should
not have any foreseeable problems remaining in full compliance with the
MCLs and therefore with the Safe Drinking Water Act. These MCLs are
applicable to alt public water systems in the United States of which
the HIA treatment facility is an example. Therefore, once this facility
is constructed, these MCLs are the standards by which the Owner, PennDOT,
will be monitored by the Pennsylvania Department of Environmental
Resources (PA DER). (See Table 9 for comparison of EPA standards and
guidelines with effluent concentrations.) Air emissions will be within
PA DER recommended guidelines.
-------
TABLE 9
COMPARISON OF MOftST CASC TREATMENT .
PERFORMANCE TO APPLICABLE GUIDELINES AND STANDARDS*
Single Unit
3.0 MOO
Contaminant * '
1.
2.
3.
4.
S.
6.
7.
a.
9.
10.
11.
12.
1).
14.
IS.
Chlorate thane
Carbon Tetrachlorlde
l.l-Otchtoroethane
trans- 1 ,2-Otchloroethene
ci$-l ,2-Dlchloroethene
l.l.l-Trichloroe thane
Vinyl Chloride
I . 1-Oichloroethene
Trichloroethene
Tetr achl oroethene
Benzene
Chlorobenzene
Toluene
1 .2-Dichlorobenzene
I .4-Dichlorooenzene
Highest
average
Influent
2
0.2S
3.3S
73.3 .
149.3*
4.46
1.2
1.74
81.67
6.2S
4.8
8.2
17 *
1894
27*
Eff.
cone.
ug/1
0.014
0.001
O.T92
l.>6
3.18
0.036
<0.001
0.003
O.S47
0.023
0.017
0.060
0.122
6.16
0.689
I
Rewval
99.31
99.44
97.24
97.87
97.87
99.20
99.99
99.82
99.33
99.63
99.64
99.27
99.28
96.74
97.45
Parallel
Units
1.5 NGO Each
Eff.
cone.
ug/1
0.011
0.001
0.069
1.17
2.39
0.027
<0.001
0.002
0.466
0.021
0.010
0.039
0.078
3.38
0.424
S
Removal
99.45
99.50
97.95
98.40
98.40
99.40
>99.99
99.86
99.43
99.67
99.80
99.53
99.54
98.21
98.43
Series Units'
3.0 HGO Each
Eff.
cone.
ug/1
<0.001
<0.001
0.004
0.037
0.075
<0.00l
<0.001
<0.001
0.004
<0.001
<0.001
<0.001
<0.001
0.302
0.024
Total S
rewval
>99.99
>99.9
99.90
99.95
99.95
>99.99
>99.99
>99.99
>99.99
>99.99
>99.99
>99.99
>99.99
99.84
99.91
Guidelines and Standards2
USEPA
NCLS
ug/1
.
5.0
-
-
-
200
2.0
7.0
5.0
-
5.0
-
-
-
75
USEPA
NCLG
ug/1
.
0
-
-
-
200
0
7.0
0
-
0
-
2000
620
75
USEPA
10-6
level
ug/1
.
0.27
-
-
-
-
0.015
0.033
1.84
1.0
0.66
-
-
-
*
Affluent concentrations shown for series units, the percent removal of the second air stripper tower 1s assumed equal to that df the first
tower.
Guidelines and standards presented were verified with Bruce Molholt, Ph.D.. Toxtcotoeist. Hazardous Haste Enforcement Branch. USEPA Region
III.
andtiB to Will la* Koskl of CON. Sept. 28. 1987.
JTah1e adapted froa Buchart-Horn
4USEPA. Region III. Analytical Results fro* Ground Mater Samples Collected on Nay 26. 1987 at Hanrlsburg International Airport.
-------
- 29 -
F. Operation and Maintenance
Under the Safe Drinking Water Act Amendments of 1986, EPA promulgated
monitoring requirements for the MCLs pertaining to the volatile organic
chemicals as part of its publication in the July 8, 1987, Federal Register:
Ground water systems shall sample at points of entry to the
distribution system representative of each well. Sampling
must be conducted at the same location or a more representative
location each quarter. Ground water systems must sample every
three months for each entry point to the distribution system...
(FR, Vol. 52, No. 130, p. 25712.)
Compliance is based on a .yearly running average of the quarterly finished
water samples. In addition, simultaneous with the collecting of the re-
quired finished water samples, air stripper influent samples will also
be collected. Comparison of observed concentrations in the finished
water and raw water will assist in monitoring the performance of the
air stripper, assist in monitoring the air emissions, and assist in
monitoring the aquifer.
Ultimately, the concentrations of contaminants will decline. Eventually
the concentrations in the raw water may decline to a level that may
indicate that treatment is no longer needed. The criteria for ceasing
treatment would be evidence that the raw water contamination has declined
to below the applicable MCLs for four consecutive quarterly samplings.
Monitoring will be continued indefinitely in accordance with the Safe
Drinking Water Act regardless of whether treatment for volatile organics
continues to be provided.
Air emissions monitoring can be performed by a similar methodology as was
used to generate the emissions data for this study. Essentially, air
emission data can be based on a calculation from the water flowrate,
air flowrate, and contaminants' concentration in the water.
-------
30
RESPONSIVENESS SUMMARY
MIDDLETOWN AIR FIELD SITE
DAUPHIN COUNTY, PENNSYLVANIA
DECEMBER 29, 1987
This community relations responsiveness summary is required by
the National Contingency Plan (NCP) to document, for the public
record, any public concerns or issues expressed during remedial
planning or the public comment period. It also documents the
EPA's responses to the issues and concerns that were expressed.
The document is divided into the following sections.
1.0 Overview
2.0 Background of Community Involvement and Concern
3.0 Summary of Major Public Issues and Concerns
4.0 Remaining Concerns
1.0 Overview
The public comment period for the Middletown Air Field Site, a
hazardous waste site at the Harrisburg International Airport
(HIA), began on November 25, 1987, and extended to December 25,
1987. During this time, the U.S. Environmental Protection
Agency Region III (EPA) solicited comments regarding the Focused
Feasibility Study (FFS) Report. The report was prepared to
outline remedial alternatives for providing a safedrinking water
supply to HIA and members of the community who are supplied by
the HIA water system.
The preferred alternative is a combination of two of the options
proposed in the FFS Report, 1) direct water treatment and
2) water supply management. If this alternative is selected,
water from all of the HIA wells will be brought to one location
on site and treated, using a two-tower air-stripping unit to
reduce the concentration levels of volatile organics to safe
levels.
On December 8,' 1987, the EPA conducted a public meeting at the
Middletown Community Center; 60 West Emmaus Street; Middletown,
Pennsylvania. EPA representatives explained that the FFS Report
and the comment period were intended to address the drinking water
supply, not long-term groundwater remediation. However, they
stated that some of the options that were rejected as ways to
-------
31
provide safe drinking water in the long term will continue to
be considered for use as potential groundwater remediation
technologies.
Approximately twenty-five people attended the meeting. Of that
number, most were present in official capacities, including
representatives of the local news media, local government, and
HIA. Also attending in official capacities were spokesmen for
PennDOT and the USAF.
Following the EPA presentations, questions and comments were
solicited from the audience. The question and answer session
lasted approximately 35 minutes. Participants included a
newsperson and a local, elected official. No questions were
asked of the PennDOT or USAF representatives.
At the close of the meeting, the audience was reminded that
site related documents are available locally at the Middletown
Public Library on North Catherine Street. Those who are unable
to devote time to actually reading the file materials were told
that they may contact the EPA project manager, Laura Boornazian,
or the EPA community relations coordinator, Ray Germann, for a
summary of the FS and FFS reports.
2.0 Background of Community Involvement and Concern
When the groundwater problem at HIA was first brought to public
attention in 1983, several public meetings and press conferences
were held. In general, the meetings were well attended,
particularly by local, state, and federal elected officials and
by the news media. Private citizens were less involved, except
for Londonderry Township residents, whose water supply wells
were shown to be contaminated by the Sunset Golf Course site,
and Pennsylvania State University Capitol Campus (PSU) students,
who were also concerned about their water supply, which was
provided by HIA.
By the spring of 1984, the EPA had extended a waterline from
Middletown Borough to the Londonderry Township residents in need
of a new water source, and HIA was blending water from its
supply wells to achieve reduced contaminant levels that met
established he-alth standards. The USAF had agreed to reimburse
the EPA for the waterline extension and had also removed exposed
drums from an area near PSU student housing units. Two additional
areas on site were the subjects of removal actions conducted by
the Pennsylvania Department of Environmental Resources (PADER).
-------
Since mid-1986, the EPA, the USAF, and PennDOT have cooperated
to keep the public informed by holding three additional public
meetings. Although the news media and officials from Middletown
and Lower Swatara Township remain actively interested in the site,
the general public's participation has been significantly reduced.
Throughout the site's history, the primary concerns expressed by
residents and officials regarding the Middletown Air Field Site
have been associated with securing safe drinking water and
remediating the groundwater. As residents became satisfied that
the drinking water supply they were receiving was within acceptable
standards, the emphasis of concern shifted from safe drinking water
to permanent groundwater remediation.
3.0 Summary of Major Public Issues and Concerns
Comments received during the public comment priod and the EPA's
responses to them are summarized below.
1. Long-term remediation of the ground-water and the time frame
to achieve it seemed to be a primary concern of people
attending the December 8, 1987, meeting. The preferred
alternative was labeled a "band-aid" by one speaker.
Because the HIA wells supply several entities in Lower Swatara
Township, including PSU, Fruehauf Trucking, the Odd Fellows Home,
and HIA itself, and because many people located along Route 230
are, reportedly, concerned that contaminants will migrate to
their wells, one speaker suggested the EPA focus on a
permanent cleanup of the groundwater. He pointed out the main
airport is not the only local site with groundvater contamination
related to USAF activities at HIA, and asked whether the EPA
will address the USAF dump sites at Lisa Lake, the Fruehauf
property, and the supply well for Middletown and Londonderry,
because these locations adjoin the HIA property. The same
speaker inquired whether the community would have to deal
with the USAF for the remediation of these locations if they
are not part of the current remedial program. Also, it was
pointed out that the groundwater has been contaminated for a
long time. The speaker stated that the community deserves
to know how-long groundwater remediation will take; he suggested
fifty years as a possibility.
EPA Response; The FFS under discussion addresses a safe
drinking water supply for HIA and the HIA water supply system,
only. The other locations mentioned are not part of this
operable unit remedy but will be investigated as part of the
RI/FS for the entire site.
-------
33
'It is impossible to say how long groundwater remediation
will take, because the present extent of contamination and its
sources are not known. Thus, a full Remedial Investigation
(RI) is required. If a pumping and treating alternative is
eventually selected as the preferred alternative to remediate
the groundwater, it could take a number of years; the FFS
assumes indefinite operation.
2. A related concern was expressed by another speaker regarding
the effects of HIA plans for future expansion upon long-term
remedial efforts. The speaker reported that the HIA Master
Plan includes the extension of the airport at the south end
of the site (nearest to Middletown) by the turn of the century.
The plan requires the property involved to be excavated to
runway height. This creates concern that excavating to a
depth of 25 feet to 35 feet may destroy EPA constructions, if
groundwater containment barriers or surface caps are employed
as remedial measures. It was pointed out that such measures
are treatments for symptoms rather than cures and that, at the
pace bureaucracies generally move, the technologies may
barely be in place when HIA expansion begins.
EPA Response; The objective at this time is to provide an
acceptable drinking water supply for the public to use until
the balance of the problem can be addressed. Eventually, EPA
hopes contamination will be reduced or eliminated at its
source.
That bureaucracies take a long time to implement plans is a
fact. However, a decision on an alternative to provide a
short-term drinking water supply will be_made within the next
30 days. Hopefully, that alternative will be in place within
li to 2 years, depending on the duration of construction.
3. Installing a safe drinking water supply is also a primary
public concern, because consumers are worried about the
long-term reliability of the current method of achieving
acceptable drinking water standards by blending water from
the various HIA wells. A speaker stated that if the Middletown
Air Field Site is a priority site, as inclusion on the National
Prioritie's List (NPL) suggests, there shouldn't be any delay
in providing safe drinking water. The speaker wanted to know
the expected time span required to install the preferred alter-
native arfd whether the HIA water supply is safe to use.
EPA Response: If work can begin soon, the water treatment
system can probably be in place in li to 2 years. Every effort
-------
34
w'ill be made to act as quickly as possible and to continue to
progress with the long-term remedial program as well.
Water quality at some of the wells is below state drinking
water standards. Water from 7 of the production wells is being
blended to achieve acceptable concentration levels. Consequently,
the water currently being provided by HIA is safe. There is
no need, at this time, for immediate action, but if such a
need becomes apparent, emergency action could be taken.
Since there is no health problem now, but groundwater
contamination is present, a long-term solution is required.
Over time, demands on groundwater supply will increase. The
goal of the remedial program at the Middletown Air Field Site
is to develop a reliable solution that willbe able to accomodate
future airport expansion and other increases in need.
A task force, including representatives of local governments
and commerce, is considering taking over the operation and
ownership of HIA, but the biggest deterrent to a takeover is
concern about the water supply. The task force wonders what
guarantee they might have that the water is safe and whether
the USAF will be required to pay operation and maintenance
(O&M) costs for water treatment, if the task force takes over
the airport.
EPA Response; It would be a good idea to read the Feasibility
Study (FS) Report and the FFS Report. These documents contain
a discussion of the risks involved in consuming HIA drinking
water, assuming worst-case and most probable scenarios after the
treatment system is in place. The system will be monitored on
a quarterly basis.
In the worst-case, the risk will be about 10~ . This is one
order of magnitude lower than the 10" level which is generally
established as the acceptable or "safe" level of cleanup.
In the interagency agreement being drafted by EPA, USAF, and
PennDOT, USAF and PennDOT are responsible for 0 & M costs.
Several questions were asked about the air-stripping unit.
The main concern regarding the unit was that it could discharge
contaminants removed from groundwater into the air, possibly
creating a*n increased health risk. It was pointed out that the
area will have two locations venting contaminants into the air,
if an air-stripper is installed: the Middletown Air Field
Site and Three-Mile Island. One speaker asked to know the cost
-------
35
•of the air-stripper and its life expectancy. The speaker
also asked whether it is a proven technology and how the
safety of the treated water supply will be guaranteed.
EPA Response; Just as the FFS Report discusses the risks
associated with water contamination, it also includes a risk
assessment addressing the health effects of the^air discharges.
The potential risk was calculated to be 2 x 10" , which is an
order of magnitude lower than the 10* level EPA sets as its
goal.
The cost of installing the unit will be approximately $3.7
million, and estimated yearly operating costs are about
$160,000. The USAF and PennDOT will assume these costs.
Water quality and air quality related to the air-stripping unir
will be monitore.
-------
36
7. An opinion was expressed that the public comment period is
'just a legal exercise required for the record. -The commentor
suggested that the EPA and PennDOT have already made their
decision.
EPA Response; The public comment period is not treated lightly
by the EPA. The law requires that a responsiveness summary be
prepared and that all comments received must be considered,
and a response must be made to the comments. When the preferred
alternative is presented to EPA management, it must be explained,
and the rationale for selecting it must be given. Information
regarding other alternatives, including any suggested during the
comment period, must also be provided, and a case for or against
each must be presented. There is always the possibility that
an alternative other than the preferred alternative may be
chosen.
The alternative recommended by the FFS Report is the preferred
alternative; EPA plans to make its decision after all public
comments have been received.
8. A final comment was made by a local politician regarding the
trust-worthiness of many government agencies. The speaker
suggested that many promises were made to local communities
in the aftermath of the Three-Mile Island accident (by unident-
ified government entities) and that most were broken.
Consequently, the speaker said it was hard to trust the EPA now.
EPA Response; Please continue to watch our performance,as you
have all along, and see what is accomplished.
4.0 Remaining Concerns
No concerns related to the Superfund remedial activities at the
Middletown Air Field Site remain unaddressed.
-------
37
MIDDLETOWN AIR FIELD
SARA ADMINISTRATIVE RECORD *
INDEX OF DOCUMENTS
Site Identification
1) Report: Site Inspection of Olmstead Air Force Base, 8/10/84.
2) Letter to Lieutenant Colonel Robert A. Lombard fron Mr. John B.
Moyer re: consultant's suggestions for site, 5/31/84.
3) Letter to Mr. Don Bryan fron Mr. John B. Moyer re: closure plans for
building 267, 5/31/84.
4) Letter to Lieutenant Colonel Robert Lombard from Mr. Michael Steiner
re: study and actions at Harrisburg International Airport, 5/30/84.
5) Memorandum to Mr. Edward Simmons from Mr. Timothy Alexander re:
history and industrial waste activities at site, 4/9/84. History
and diagrams are attached to the memorandum.
6) Memorandum to Mr. Joseph Kozlosky from Mr. Francis Fair re: inspection
of Stanbaugh's Air Service, 3/21/84. Pick-vp locations and map are
attached to the memorandum.
7) Memorandum to all maintenance personnel from Mr. Ron Kaylor re:
fluids in holding tank, 1/30/84.
8) Letter to Mr. Garth Glenn from Mr. L. W. Walsh re: site inspection
and-sampling plan, 12/15/83.
9) Site Safety Plan, 12/B/83.
10) Report: Potential Hazardous Waste Site Identification and Preliminary
Assessment, 11/15/83.
11) Report: Potential Hazardous Waste Site Identification and Preliminary
Assessment, 11/4/83.
12) Report: Field Trip Summary Report, 10/4/B3. Sampling, data graphs,
and maps are attached to the report.
•
13) Letter to Colonel Klingensmith from Mr. Michael Steiner re: private
drinking well contamination, 8/9/83. Letter regarding citizens with
temporary water storage bladders is attached to the letter.
14) EPA Notification of Hazardous Waste Site (undated).
*Administrative Record available 9/16/87.
-------
38
Remedial Response Planning
1) Letter to Mr. Bruce Smith from Colonel Donald Kane re: final Focused
Feasibility Study. 7/24/87.
2) Report: Harrlsburg International Airport Focused Feasibility Study,
7/87.
3) Report: Harrlsburg International Airport Focused Feasibility Study,
Addendum I, 7/87.
4) Memorandum to Mr. J. Winston Porter from Mr. Stephen Wasseriug re:
delegation of remedy selection, 6/9/87. Delegation briefing Is attached
to the memorandum.
5) Sampling Plan for Mlddletown Air Field, 5/26/87.
6) Report: Quality Assurance Project Plan, 11/86.
7) Letter to Ms. Paula Luborsky from Mr. Andy Szllagzl re: transmittal
of engineering report, 4/21/86. Report: Ground Water Remediation
at Harrlsburg International Airport, by Malcolm Pirnle Is attached
to the letter.
8) Report: Installation Restoration Program Phase II -
Confirmation/Quantification Stage I Final Report for. Harrlsburg
International Airport, by Roy F. Weston, 4/86.
9) Report: Joint Presentation to the United States Environmental
Protection Agency, by the United States Air Force and Commonwealth
of Pennsylvania Department of Transportation, 3/25/86.
10) Memorandum to Mr. Francisco Barba from Ms. Libby Rhoads re: Impact
on wetland areas, 3/21/86.
11) Report: Health and Safety Program Installation Restoration Program,
by E. C. Jordan Co., 3/86.
12) Memorandum to Mr. Abraham Ferdas from Mr. Jeffrey Pike re: immediate
removal consideration, 9/26/85.
13) Record of communication to Mr. Charley Samuels from Mr. Jeffrey Pike
re: possible emergency condition, 6/3/85.
14) Letter to Mr. John Moyer from Mr. Robert Lombard re: statement of
work, 8/29/84. Statement of work is attached to the letter.
15) Report: Hydrologlcal Investigation into the Possible Contamination
of Harrlsburg International Airport Water Supply Wells by the Dump
Located Under the Main Runway, by R.E. Wright Associates, Inc., 5/84.
16) Report: Installation Restoration Program Phase I - Records Search,
by J. R. B. Associates, 4/84.
-------
39
Community Involvement
1) Letter to Mr. Bruce Smith from Mr. Edwin Bedker re: response to a
congressional inquiry, 7/21/87. Letter to Honorable John Heinz
regarding action at the site is attached to the letter.
2) Memorandum to Ms. Carol Stokes from Mr. David Green re: public
meeting, 8/19/86. Meeting attendance sheet is attached to the
memorandum.
3) Letter to Senator Arlen Specter from Mr. James Seif re: contamination
of well 13, 8/12/86.
4) Letter to Senator John Schumaker from Mr. James Seif re: contamination
of well 13, 8/12/86.
5) Memorandum to Ms. Janet Viniski from Mr. Bete Bentley re: public
meeting, 8/5/86.
6) Transcript of a public meeting, 7/31/86.
7) Letter to Mr. James Seif from Mr. John Shumaker re: request for a
progress report, 7/25/86. Resolution Seeking Relief from Hazardous
Substance Exposure for the Year 1986 is attached to the letter.
8) Ccrmunication to the U. S. EPA from Senator Arlen Specter re: inquiry
from a constituent about detoxification, 7/24/86. Letter regarding
detoxification and resolution for the year 1986 are attached to the
communication.
9) Letter to Senator Arlen Specter from Mr. James Seif re: well sampling
results, 6/30/86.
10) Communication to the U. S. EPA from Senator Arlen Specter re: inquiry
frcm a constituent about well contamination, 6/18/86. Letter regarding
contamination is attached to the communication.
11) Letter to Representative George Gekas frcm Mr. James Seif re: well
contamination, 6/5/86.
12) Letter to Honorable John Heinz from Mr. Jack McGraw re: comments on
the listing of the site on the National Priorities List, 7/29/85.
13) Letter to Honorable Lee Thomas from Senator John Heinz re: addition
of the site to the National Priorities List, 7/2/85.
14) Letter to Senator John Heinz re: drinking water contamination,
6/25/85.
-------
40
15) Letter to Mr. Cbn Welsh from Senator John Heinz re: concerns expressed
by'a constituent, 6/6/85. Letters regarding home well contamination
are attached to the letter.
16) Letter to Mr. James Seif from Representative George Gekas re: well
contamination* 5/14/85.
17) Letter to Ms. Susan Sides from Representative Rudy IsicJ Dininni re: town
meeting, 5/7/85.
18) Letter to Representative Rudolph Dininni from Ms. Susan Sides re:
hone well contamination, 4/30/85.
19) Letter to Mr. George Merkel from Mr. Bruce Smith re: drinking water
for residents, 9/30/83.
20) Press release re: private well sampling (undated).
Data Summary Documents*
1) Memorandum to Mr. Gregg Crystall from Mr. Rick Dreisch re: analytical
reports for sample numbers 870625-06, and 870625-07, 7/28/87. Further
analyses and data regarding sample numbers 870625-06 and 870625-07
are attached to the memorandum.
2) Memorandum to Mr. Gregg Crystall from Mr. Rick Dreisch re: analytical
reports for sample numbers 870527-06-12, 14-17, 6/9/87. Further
analyses and data regarding sample numbers 870527-06-12 and 14-17
are attached to the memorandum.
3) Memorandum to Mr. Francisco Barba from Ms. Lori Davis re: sample
analysis of well 113, 8/12/86. Laboratory analysis reports are
attached to the memorandum.
4) Letter to Mr. Jerry Heston from Mr. Michael Shmcokler and Ms.
Catherine Ward re: sample numbers SR8644-1 to SR8644-11, 9/30/83.
5) Memorandum to Mr. Daniel Donnelly from Mr. Rick Dreisch re: 'sample
numbers 830915-01-08, 9/21/83. Data analysis sheets and traffic
reports are attached to the memorandum.
*Data supporting the Sumnary Sheets is located at the EPA Region III
Central Regional Laboratory in Annapolis, Maryland.
-------
41
CES'ERAL GUIDANCE DOCL'KENTS *
1) "Promulgation of Sites from Updates 1-4," Federal Register, dated 6/10/86.
2) "Proposal of update 4," Federal Register, dated 9/18/85.
3) Memorandum to U. S. EPA from Mr. Gene Lucero regarding community relations
at Superfund Eqforcement sites, dated 8/28/85.
4) Groundvater Contamination and Protection, updated by Mr. Donald V.
Feliciano on 8/28/85.
5) Guidance on Remedial Investigations under CERCLA, dated 6/85.
6) Guidance on Feasibility Studies under CERCLA, dated 6/85.
7) "Proposal of Update 3,V> Federal Register, dated 4/10/85.
8) Memorandum to U. S. EPA from Mr. Jack McGraw entitled "Community Relations
Activities at Superfund Sites - Interim Guidance," dated 3/22/85.
9) "Proposal of Update 2," Federal Register, dated 10/15/84.
10) EPA Groundvater Protection Strategy, dated 9/84.
11) Memorandum to U. S. EPA from Mr. William V. Reckman, Jr. entitled
"Transmittal at Superfund Removal Procedure* - Revision 2," dated 8/20/84.
12) "Proposal of Update 1," Federal Register, dated 9/8/83.
13) Community Relations in Superfund: A Handbook (interim version), dated
9/83.
14) "Proposal of first National Priority List," Federal Register, dtted
12/30/82.
15) "Expanded Eligibility List," Federal Register, dated 7/23/82.
16) "Interim Priorities List," Federal Register, dated 10/23/81.
17) Uncontrolled Hazardous Vaste Site Ranking System; A User's Manual
(undated).
18) Field Standard Operating Procedures- Air Surveillance (undated).
19) Field Standard Operating Procedures- Site Safety Plan (undated).
*Located in U. S. EPA Region III office.
-------
MiddLetow.i \lr Field-Water Supply Operable 'Jni:
Enforcement Susnary & Reconreendations
Summary:
°rovisions for a potable water supply for the Harrisburg International
Airport became necessary due to increased airport usage and was aided by
significant pressures froa the PennDOT. Throughout the late 1970s and
early 1980s, the U.S. Air Force, recognizing the potential for adverse
environmental impacts fron past practices at the site, initiated their
Installation Restoration Program (IRP). The IRP was tailored in such a
•«-•- *-u .- *. »u». *J*ii*;Ni2«\m«^n*> *%f i Fnftt^f-^A fpocfHi'lirtr efitHu frtf" ''h* W3 f"P t"
supply operable unit was quickly prepared front existing IRP reports.
Throughout ROD preparation, EPA has been negotiating an Interagency
agreement (IAG) with the Air Force and PennDOT to implement the ROD remedy,
(i.e., the Air Force to fund construction, PennDOT to oversee construction
Additionally, EPA is negotiating with the Air Force and PennDOT to
conduct the "subsequent" RI/FS activities necessary to fully characterize
the site and determine clean-up remedies. EPA wants to and expects that
we will take the lead in this project. The Air Force and PennDOT feel
the work will go along smoother and more expeditiously if EPA has the
lead.
We are also conducting a thorough PR? search at the site since the
Air Force and PennDOT have leased different buildings and areas of the site
to industrial users who may have contributed to the contamination. This
PRP search will coincide with the subsequent RI/FS project and we expect
to be negotiating for clean-up with numerous other parties besides the Air
Force and PennDOT after this work is done.
Recomaendations:
It is recommended that the ROD be signed as presentee to cne RA. EPA
will continue to negotiate an IAG for ROD implementation with the Air Force
and PennDOT.
Reproduced from
best available copy.
------- |