United States
Environmental Protection
Agency
Off ice of
Emergency and
Remedial Response
EPA/ROD/R03-91/109
December 1990
&EPA
Superfund
Record of Decision
Whitmoyer Laboratories
(Operable Unit 3), PA
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50272-101
REPORT DOCUMENTATION '- REPORT Na i
PAGE EPA/ROD/R03-91/109
4. TMeendSubMe
SUPERFUND RECORD OF DECISION
Whitmoyer Laboratories (Operable Unit 3) , PA
Third Remedial Action - Final
7. AI0IOM
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U.S. Environmental Protection Agency
401 M Street, S.W.
Washington, D.C. 20460
XRedptenrs Accession No.
S. ReponOete
12/31/90
6.
10. ProlMvTHUWorkUnHNo.
11. CoMneUC)orOnm(G)No.
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13. Type ol Report A Period Covered
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The 22-acre Whitmoyer Laboratories site is an inactive laboratory facility in Jackson
Township, Lebanon County, Pennsylvania. Land use in the area is predominantly
agricultural with adjacent wetlands areas. In addition, part of the site lies within
the 100-year floodplain of the Tolpehocken Creek-Union Canal. An estimated 20
residences in the vicinity of the site use the underlying aquifer as their drinking
water supply. From 1957 to 1964, Whitmoyer Laboratories, Inc., produced organic
arsenicals onsite. In 1964, the new owners, Rohm & Haas, began storing concentrated
wastes in a concrete vault, and until 1971 conducted onsite ground water pumping and
treatment and ocean dumping of wastes. In 1977, sludge from ground water treatment
was placed in lagoons in the eastern area of the site. Between 1978 and 1982, the
site changed ownership twice, and then in 1985, a RCRA site closure plan was filed.
In 1986, EPA began providing bottled water to residents with ground water
contaminated by site activities. A public water supply line extension is currently
being designed and will be constructed as part of a removal action. When the site
was abandoned in 1987, very little of the RCRA closure plan had been implemented.
From 1988 to 1990, EPA removed approximately 800 abandoned drums and laboratory
(See Attached Page)
17. I
Record of Decision - Whitmoyer Laboratories (Operable Unit 3), PA
Third Remedial Action - Final
Contaminated Media: soil, sediment, gw
Key Contaminants: VOCs (benzene, PCE, toluene, xylenes), other organics (phenols)
o. kfcnmera/open-EncMTenne metals (arsenic)
c. COSATlFWd/Oroup
10. Security CteM (This Report)
None
20. Security O«ss(Thl*Pege)
None
21. No. of Page*
84
22. Pita*
(Set ANSU30.18)
See DufructfofM on fltwrae
OPTIONAL FORM 272 (4-77)
(FormMty NtlS-H)
DoputrnMit of Conviwrov
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EPA/ROD/R03-91/109
Whitmoyer Laboratories (Operable Unit 3), PA
Third Remedial Action - Final
Abstract (Continued)
wastes offsite. A 1989 Record of Decision (ROD) provided for remediation of hazardous
concentrated liquids, including laboratory wastes, abandoned at the site as Operable
Unit 1 (OU1). A December 1990 ROD provided a remedy for vault and lagoon wastes,
miscellaneous products and feedstocks, tanks, process vessels, and other onsite
structures as OU2. This ROD addresses contaminated onsite soil, sediment, and ground
water as OU3. The primary contaminants of concern affecting the soil, sediment, debris,
and ground water are VOCs including benzene, TCE, and PCE; other organics including PAHs;
and metals including arsenic.
The selected remedial action for this site includes excavating and fixation of
approximately 61,000 cubic yards of soil/sediment with contaminant concentrations above
the "principal threat" action levels using an iron-based or other fixation process,
followed by offsite disposal; using biological treatment for approximately 5,600 cubic
yards of soil/sediment with organic concentrations above the "principal threat" organic
chemical action levels for the heavily contaminated soil either prior to or following
fixation, followed by offsite disposal; excavating and consolidating onsite in the vadose
zone approximately 39,000 cubic yards of soil/sediment having contaminant concentrations
below the "principal threat" action levels but above ground water-based unsaturated soil
clean-up targets, followed by capping with low-permeability materials; placing onsite in
the vadose zone approximately 16,000 cubic yards of soil/sediment with concentrations
below the ground water-based unsaturated soil action levels; soil capping any remaining
contaminated surface soil that contains arsenic concentrations greater than 21 mg/kg and
other disturbed areas, as needed; backfilling, grading, and revegetating the excavated
areas; demolishing onsite structures, followed by salvaging non-hazardous debris and
offsite disposal of unsalvaged debris; onsite pumping and treatment of contaminated
ground water using physical, chemical, and possibly biological treatment, followed by
either onsite discharge to surface water, reinjection into the aquifer, or both methods;
disposing of any treatment residuals offsite; conducting long-term ground water
monitoring; and implementing Institutional controls Including deed restrictions for the
remaining contaminated areas. Additionally, this ROD provides a contingency for ground
water if it becomes technically impracticable to achieve cleanup goals. The contingent
remedy includes pumping from the perimeter area only to prevent migration of the
contaminant plume. The estimated present worth cost for this remedial action is
$77,300,000, which includes annual O&M costs of $2,397,600 or $2,477,600 (depending on
the ground water discharge option chosen).
PERFORMANCE STANDARDS OR GOALS: Soil action levels for saturated and unsaturated soil
and "principal threat" action levels were developed based on the threat due to
inhalation/ingestion and to ground water using MCLs, RCRA toxicity characteristic levels
(TCLP), and health-based criteria. The target clean-up goal for surface soil is
arsenic 21 mg/kg. The action levels for unsaturated soil include benzene 0.009 mg/kg,
PCE 0.051 mg/kg, TCE 0.017 mg/kg, and arsenic 450 mg/kg. This will reduce the excess
cancer risk level associated with inhalation/ingestion exposure to 10"^. The action
levels for saturated soil include benzene 0.002 mg/kg, PCE 0.012 mg/kg, TCE 0.004 mg/kg,
and arsenic 210 ug/kg based on protection of ground water. Principal threat action
levels include benzene 10 mg/kg, PCE 14 mg/kg, TCE 10 mg/kg, and arsenic 1,000 mg/kg.
Ground water clean-up goals are based on Federal MCLs, proposed MCLs, and a 10-6 excess
cancer risk level and reference dose equal to 1 for noncarcinogens. Chemical-specific
ground water clean-up goals include benzene 0.005 mg/1 (MCL), PCE 0.005 mg/1 (pMCL),
TCE 0.005 mg/1 (MCL), and arsenic 0.05 mg/1. A State ARAR to remediate ground water to
background levels will be waived because of technical impracticability. If the
contingent remedy is employed, an ARAR to comply with SDWA MCLs will also be waived
because of technical impracticability.
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RECORD OF DECISION
OPERABLE UNIT THREE
WHITMOYER LABORATORIES SITE
DECLARATION
SITE NAME AND LOCATION
Whitmoyer Laboratories Site
Lebanon County, Pennsylvania.
This decision document presents the selected remedial action for
the third operable unit of the Whitmoyer Laboratories Site in
Lebanon County, Pennsylvania. This document was developed in
accordance with the Comprehensive Environmental Response,
Compensation and Liability Act of 1980 (CERCLA), as amended by the
Superfund Amendments and Reauthorization Act of 1986 (SARA); and,
to the extent practicable, the National Oil and Hazardous
Substances Pollution Contingency Plan (NCP). This decision is
based on the Administrative Record for this site.
The Pennsylvania Department of Environmental Resources staff have
verbally concurred with the selection of this remedy.
ASSESSMENT OP THE BITE
Pursuant to duly delegated authority, I hereby determine, pursuant
to Section 106 of CERCLA, 42 U.S.C. Section 9606, that actual or
threatened releases of hazardous substances from this site, as
discussed in "Summary of Site Risks," Section VI, if not addressed
by implementing the response action selected in this Record of
Decision, may present an imminent and substantial endangerment to
the public health, welfare, or the environment.
DESCRIPTION OP THE REMEDY
This operable unit (OU) is the third of three operable units for
the site. The first operable unit (OU One) at this site involved
remediation of hazardous concentrated liquids which were abandoned
at the site. The second operable unit (OU Two) involved
remediation of concentrated wastes abandoned in a concrete vault;
concentrated wastes abandoned in two groups of lagoons; outdated
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products and miscellaneous chemicals abandoned in the buildings;
and the buildings and related structures (tanks, process vessels,
etc.) located on the site. This action (OU Three) addresses
contaminated soils and adjacent sediments, and groundwater present
at the site. These media pose some of the principal threats at the
site.
The U.S. Environmental Protection Agency (EPA) has selected, and
the Pennsylvania Department of Environmental Resources staff have
verbally concurred on the selection of the following Remedial
Action for the third operable unit (OU Three) of the Whitmoyer
Laboratories Site. This action addresses the materials making up
the third operable unit by extracting and treating contaminated
groundwater to the extent described herein and the most
contaminated soils/sediments; consolidating and capping less
contaminated soils/sediments; disposing the solid treatment
residuals offsite, such that the materials will not require any
long-term onsite management; and discharging treated groundwater
to either Tulpehocken Creek or the aquifer beneath the site.
The major components of the Selected Remedial Action are as
follows:
* Excavation of all moderately contaminated soils/sediments
from offsite and saturated onsite locations, and all
heavily contaminated onsite and/or offsite soils
[estimated volume « 116,000 cubic yards (CY)].
* Demolition of Buildings 4, 9, 11, and 14.
* Backfilling of the excavated areas with clean fill or
lightly contaminated soil.
* Onsite fixation of the approximately 61,000 CY of heavily
contaminated soils/sediments using an iron-based or other
similar fixation process that provides equivalent
protection.
* Biological treatment of the approximately 5,600 CY of
soils with organic chemical concentrations above the
heavily contaminated soil action levels either prior to
or following the fixation step.
* Consolidation of the moderately contaminated
soils/sediments on site above the groundwater table.
* Capping of the approximately 39,000 CY of moderately
contaminated soils/sediments having contaminant
concentrations above groundwater-based unsaturated soil
cleanup targets with low-permeability materials.
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* Soil capping of all soils/sediments remaining on the
surface following the excavation and consolidation steps
that are not capped with low-permeability materials and
contain greater than 21 mg/kg arsenic; and other
disturbed areas as needed.
* Grading and revegetation of all areas affected by the
soil/sediment remediation.
* Following the soils/sediments remediation, placement of
deed restrictions on areas with remaining contamination.
* Aggressive extraction of all groundwater from the aquifer
beneath the site with concentrations above health-based
levels (e.g.. 50 ug/1 arsenic) until the maximum
groundwater contaminant concentrations are all less than
health-based levels.
* Treatment of the extracted groundwater in an onsite
treatment plant, utilizing physical, chemical and
possibly biological processes.
* Disposal of the treated water by either discharging it
to Tulpehocken Creek, reinjecting it into the aquifer,
or a combination of the two methods.
* Salvaging nonhazardous demolition debris, as feasible.
* Disposal of the following in offsite landfill(s) in
accordance with all applicable regulations: all treated
soils; the groundwater treatment residuals; and the
demolition debris that is not salvaged.
The selected remedy is the last of several phases in the long-term
remediation of this site and will be consistent with previously
selected site remedies.
It may potentially prove technically impracticable to achieve the
health-based groundwater cleanup goals under the selected remedy
for the groundwater. If information emerges from the operation of
the selected remedy system that strongly suggests that it is
technically impracticable to achieve the cleanup goals throughout
the contaainated groundwater plume because of an observed
"leveling-off" of contaminant concentrations, the EPA, in
consultation with the Commonwealth of Pennsylvania, intends to
implement a contingent remedy in those areas where the cleanup
goals will not be met. The contingent remedy is similar to the
selected remedy, with the exception that groundwater would only be
extracted in sufficient quantities to keep the non-attainment area
from growing.
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STATUTORY DETERMINATIONS
Both the selected remedy and the contingency remedy are protective
of human health and the environment, and are cost-effective. EPA
believes that both the selected and contingent remedies will meet
all Federal and State Applicable or Relevant and Appropriate
Requirements with the sole exception of the State action-specific
requirement to remediate groundvater to background concentrations.
Accordingly, I hereby waive the provisions of 25 PA Code, Chapter
75, Part 264 with respect to groundwater backgroud concentrations
due to technical impracticability. Both remedies utilize permanent
solutions and alternative treatment technologies to the maximum
extent practicable and satisfy the statutory preference for
remedies which employ treatment that reduces toxicity, mobility,
or volume as a principal element.
Because both the selected remedy and the contingency remedy for the
third operable unit will result in hazardous substances remaining
onsite above health-based levels, a review under Section 121(c) of
CERCLA, 42 U.S.C. 9621 (c) will be conducted within five years after
the commencement of remedial action to ensure that the remedy
continues to provide adequate protection of human health and the
environment.
Edwin BT'Erickson Date
Regional Administrator
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RECORD OF DECISION
WHITMOYER LABORATORIES SITE
DECISION SUMMARY
I. SITE NAME, LOCATION, AND DESCRIPTION
A. SHE NAME AND LOCATION
The Whitmoyer Laboratories Site (Site) is located on approximately 22 acres in Jackson
Township, Lebanon County, Pennsylvania, about 1 mile southwest of the Borough of Myerstown
(see Figures 1 and 2). The she lies between the Union Canal of Tulpehocken Creek and the
Conrail (Reading) Railroad. Fairlane Avenue forms the site's eastern boundary, while Creamery
Street adjoins the site to the west.
A food storage warehouse is active in Building 18 on the site. Land surrounding the site is
predominantly farmland, with scattered farmhouses. A Sterling Drug factory is located
2,000 feet east of the site, while PJ Valves, a manufacturing plant, is located about 1,500 feet
to the south. A large active limestone quarry, locally referred to as the Calcite Quarry, is
located approximately 1.5 miles west of the site.
B. TOPOGRAPHY. SURFACE WATER. AND DRAINAGE
Topographic relief on the site is moderate, varying in elevation from 493 feet in the southwest
corner to 449 feet rn the northeast corner. The entire site drains to Tulpehocken Creek, with
drainage being roughly perpendicular to the Creek axis. Portions of the site are within the
100-year flood plain of Tulpehocken Creek-Union Canal.
The Union Canal branches from Tulpehocken Creek just west of the site and rejoins the Creek
near the site's eastern boundary. Myerstown is the first downstream community, at a distance
of approximately 3/4th of a mile. Tulpehocken Creek is a tributary to and joins the Schuylkill
River near Reading, Pennsylvania. The Schuylkill River flows into the Delaware River, which
eventually empties into the Atlantic Ocean. Tulpehocken Creek and the Schuylkill River serve
as drinking water supplies and irrigation sources downstream of the site. The headwaters of
the section of Tulpehocken Creek which passes by the site originate approximately 3 miles to
the northwest.
C. GEOLOGY
The Whitmoyer Laboratories Site is located within the Lebanon Valley, part of the Great Valley
portion of the Valley and Ridge Physiographic Province. The valley is a topographic expression
of the underlying, relatively easily eroded carbonate bedrock units. The site is underlain by
carbonate bedrock of the Ontelaunee Formation, the youngest member of the Ordovician Age
Beekmantown Group. A thin mantle of clayey residual soil overlies bedrock in the site vicinity
Depths to bedrock in the site vicinity range from 0-19 feet, based on the Remedial Investigation
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BASE MAP IS A PORTION OF THE USOS RICHLAND.PA QUADRANGLE (75 MINUTE SERIES. I93S,PHOTOREVISEO 1969) CONTOUR INTERVAL 2O'
FIGURE 1
LOCATION MAP
WHITMOYER LABORATORIES SITE. LEBANON COUNTY. PA
IMUS
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SOURCE- GENERAL LAYOUT DRAWING, PREPAREDNESS, PREVENTION B CONTINGENCY PLAN, DEC 22, 1982
QENERAL_ ARRANGEMENT
WHITMOVER LABORATORiES SITE! MYERSTOWN. PA
SCALE M fEET
FIGURE 2
JIMUS
l_l CORPORATON
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(Rl). The depth to bedrock is greatest in the vicinity of Tulpehocken Creek and the Union
Canal.
The Ontelaunee Formation is described in regional literature as a light to dark gray dolomite,
which weathers to a dark grayish brown. The Ontelaunee Formation strikes N60°E to N80°E
predominancy, with an overall dip to the SE of approximately 30°. In the Myerstown area, this
formation is approximately 500 feet thick.
Soils in the area are primarily residual soils derived from weathering of the bedrock surface,
with some alluvium adjacent to Tulpehocken Creek. Based on the Rl, the soils consist
predominantly of silt and clay. A thin veneer of organic-rich topsoil overlies the residual soils
throughout much of the area. Fill material is present in several locations within the site property
boundaries.
D. HYDROGEOLOGY
The carbonate bedrock units underlying the Lebanon Valley form the major aquifer in the area
The various formations present, although differing somewhat in water-yielding capacity, are
considered to form a single, large, heterogeneous, unconfined aquifer. The porosity of the
carbonate aquifer is almost entirely secondary, with fractures enlarged through solution
channeling forming the primary groundwater storage zones and migration pathways.
Groundwater flow directions in the region generally follow topography, then follow stream flow
direction in valley bottoms. In the site area, portions of the groundwater flow both m
northeasterly and southeasterly directions, before generally following the course of the stream
to the east-northeast. Depth to groundwater ranges from 2 to 21 feet below land surface at
the site.
Recharge to groundwater in the carbonate rack units is principally through precipitation
infiltration, with additional recharge due to groundwater migration from adjacent rock units, and
occasional surface water recharge during extended dry periods.
Groundwater beneath the site is classified as a Class 2A aquifer, a current source of drinking
water. The groundwater is used for both potable and industrial water supplies. Approximately
40 residences in the site vicinity have potable water supply wells tapping the aquifer. Twenty
of these residences have been placed on bottled water by EPA due to contamination of their
water supply from the site activities. Large industrial users of groundwater include Sterling
Drug, Inc., Quaker Alloy Casting Co., and P.J. Valves Company.
The Myerstown Water Authority (Authority) provides potable water to the residents of
Myerstown. One of the Authority's reserve wells, No. 8, taps the bedrock aquifer underlying
the site. This well is utilized during periods of high demand. To date, contamination from the
site has not been detected in this well.
An extension to the Myerstown Water Authority's water line has been designed by EPA for
those residents in the vicinity of the site whoses wells have been shown to contain arservc
contamiation. The Whitmoyer Laboratories Private Study Group (WLPSG), a group of frome'
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site owners, have entered into a consent agreement with EPA to provide for the construction
of this extension.
E. CLIMATOLOGY
The Whitmoyer Laboratories Site is located within the southeastern Piedmont Climatologies)
Division of Pennsylvania. Second Mountain, which rises 1,500 feet along the north border, and
South Mountain, which rises 1,000 feet along the southern border, form the Lebanon Valley,
in which the site is located. The Lebanon Valley has a humid continental climate. Due to the
valley's location, weather systems are typically modified before reaching Lebanon County.
Weather extremes are most often the result of unusually strong weather systems.
The average annual precipitation at the site is 42.3 inches. This precipitation is mostly evenly
distributed throughout the year, with slightly less precipitation occurring in the winter. The
average annual snowfall is 27 inches. Evaporation at the site is 36.3 inches; thus, net
precipitation is 6 inches.
In the summer, high temperatures are generally in the mid-80s and the lows near 60°F During
the winter the highs average in the upper 30s and the lows in the 20s. The prevailing wind is
from the northwest in winter and from the west-southwest in summer.
F. POPULATION AND ENVIRONMENTAL RESOURCES
Lebanon County, according to the 1980 census, has a population of 109,829, and is classified
by the Commonwealth of Pennsylvania as a "5th Class" county. The population of Myerstown
in 1984 was 3,270. Populations of 1,296 and 4,683 reside within 1 and 3 miles of the site,
respectively.
Portions of Tulpehocken Creek (Creek) adjacent to the site contain very small open water
wetlands areas consisting of small pockets along the riverine system of the Creek and Union
Canal. Fioodplain forest wetlands exist starting approximately 3.5 miles downstream of the site
The area has some habitat value, with opossum, raccoon, numerous fish, a water snake, and
various songbirds observed during a 1986 EPA site visit.
Tulpehocken Creek has been proposed for inclusion on the Commonwealth of Pennsylvania's
scenic river system, with a "priority 1A status." This designation is for streams which "have
the most urgent need for protection and immediate need for additional study," according to a
Pennsylvania Department of Environmental Resources (PADER) official.
II. SITE HISTORY AND ENFORCEMENT ACTIVITIES
A brief chronology of site history and enforcement activities follows.
1900 Circa -An oil pipeline was constructed across the site.
1934 - Whitmoyer Laboratories, Inc. (WLI) formed.
1957 - WLI begins production of organic arsenicals.
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1964
1971
1977
1978
1982
1984
1985
1986
1987
1988
1989
1990 January
1990 February -
1990 May
1990 June
Rohm & Haas buys WLI. Concentrated wastes placed in a concrete
vault. Groundwater pump-and-treat program initiated. Ocean dumping
of wastes begins.
Groundwater pump-and-treat and ocean dumping program terminated.
Sludges from groundwater treatment consolidated in eastern lagoons.
Beecham Laboratories acquires WU.
Stafford Laboratories, Inc. purchases WLI.
Stafford Laboratories, Inc. files for bankruptcy. Whitmoyer Laboratories Site
proposed for the National Priority List (NPL).
WLI files a RCRA Closure Plan with PADER, and changes its RCRA status from
a Treatment, Storage, or Disposal facility to a generator facility.
Whitmoyer Laboratories Site finalized on the NPL EPA begins providing bottled
water to area residents with contaminated wells.
Stafford Laboratories, Inc. abandons facility, with very little, if any, of the RCRA
Closure Plan implemented. EPA initiates the Remedial Investigation/Feasibility
Study (RI/FS).
EPA initiates an emergency response to remove abandoned drums from the site.
This work continues into the summer of 1990.
EPA selects a remedy for the concentrated liquids operable unit. Abandoned
laboratory wastes are packaged and disposed by EPA. The Whitmoyer
Laboratories Site Rl Report is finalized. Clarence W. Whitmoyer, former president
of WLI, dies. U.S. Department of Justice files claim against estate in Dade
County, Florida.
The concentrated liquids (first) operable unit Remedial Design is
completed.
The Whitmoyer Laboratories Site FS report, which addresses the media
making up the second operable unit, as well as the groundwater
medium, is finalized. Two former site owners, Rohm & Haas and
SmithKline Beecham, propose to EPA a separate remedial alternative for
the vault wastes, lagoon wastes, miscellaneous products/feedstocks.
contaminated soils/sediments, and groundwater.
The concentrated liquids Remedial Action commences.
The FS report which addresses the soils/sediment medium, is finalized
The two former site owners, Rohm & Haas and SmithKline Beecham.
propose to EPA a second, separate unique remedial alternative for the
vault wastes, lagoon wastes, and miscellaneous products/feedstocks
1990 September-
1990 September
1990 December
The concentrated liquids Remedial Action is completed. Two. The two
former site owners, Rohm & Haas and SmithKline Beecham, provide
additional information to EPA on their separate remedial alternatives, and
propose a separate remedial alternative for the site structures.
Rohm and Haas and SmithKline Beecham enter into consent order with
EPA under which they will extend public water services to residents
affected by the Site.
EPA selects a remedy for OU Two.
8
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III. COMMUNITY RELATIONS HISTORY
In accordance with Sections 113 and 117 of CERCLA, 42 U.S.C. Sections 9613 and 9617, EPA
held a public comment period from July 16, 1990 through September 14, 1990 for the third
operable unit Remedial Action described in the Remedial Investigation (Rl) and Feasibility Study
(FS) Reports released in April 1990, and the Soils Feasibility Study Report and Proposed Plan
released in July 1990. The notice of availability of these documents was published in the
Harrisbura Patriot on July 16, 1990 along with notice of the comment period and a public
hearing to be held concerning the third operable unit. The Rl and FS Reports and the Proposed
Plan were made available to the public in the Administrative Record maintained in the EPA
Region III office and at the Myerstown Public Library. A public meeting was held on August
1, 1990 to outline the Preferred Remedial Action and to accept comments from the attendees.
A transcript of the public meeting was maintained in accordance with Section 117(a)(2) of
CERCLA, 42 U.S.C. Section 9617(a)(2). Written and verbal comments were received and are
addressed in the Responsiveness Summary which is attached.
All documents that form the basis for the selection of the remedial decisions contained in this
Record of Decision are included in the Administrative Record for this site and can be reviewed
or referred to for additional information.
IV. SCOPE AND ROLE OF OPERABLE UNIT
As with many Superfund sites, the problems at the Whitmoyer Laboratories Site are complex
As a result, EPA is addressing portions of the site contamination using its emergency response
authorities, whereas other portions are being addressed as a part of the remedial program
A. EMERGENCY RESPONSE ACTIONS
The approximately 800 drums and the laboratory wastes and chemicals and production run
samples abandoned at the site were disposed as an emergency response action. A public
water supply line extension to residences with contaminated wells is currently being designed
and will be constructed as an emergency response action. While the line is being designed.
affected residences are being supplied by EPA with bottled water.
B. OTHER REMEDIAL ACTIONS
EPA has divided the remaining remedial work into three operable units (OUs). These are as
follows:
* OU One: Concentrated liquids abandoned in tanks and process vessels
* OU Two: Vault wastes, lagoon wastes, miscellaneous products/feedstocks.
and site structures
* OU Three: Contaminated soils/sediments and groundwater
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EPA has already selected the cleanup remedy for OUs One and Two. The concentrated liquids
(OU One) pose a principal threat at the site, because of the potential for direct contact;
tank/piping failure with subsequent contamination of Tulpehocken Creek; fire/explosion; and
tank failure from flooding. This action is in the Remedial Action stage. This remediation was
completed in September 1990.
The concentrated wastes abandoned in a concrete vault; concentrated wastes abandoned in
two groups of lagoons; outdated products and miscellaneous chemicals abandoned in the
buildings; and the buildings and related structures (tanks, process vessels, etc.) located on the
site (OU Two materials) also pose some of the principal threats to human health and the
environment from the site, because of the following risks: possible ingestion or direct contact
with the materials; contaminant migration from the materials into the underlying groundwater
that is a source of drinking water for local residents; and contaminant migration to surface
water. A Record of Decision for OU Two was signed by the EPA on December 17, 1990
Major features of this selected remedy include incineration followed by fixation of the high-
organic-content (upper) vault wastes, hazardous miscellaneous products/feedstocks, and
hazardous, combustible site structures; fixation of the low-organic-content (lower) vault wastes
and lagoon wastes; direct landfilling of the nonhazardous miscellaneous products/feedstocks
and site structures; surface cleaning of hazardous, incombustible, impermeable site structures,
and coating and sealing hazardous, incombustible, permeable site structures. The Remedial
Design for OU Two is expected to commence in the near future.
The third OU addressed by this ROD includes contaminated soils and adjacent sediments; and
groundwater. These media also pose some of the principal threats to human health and
environment from the site. The purposes of this response for the soils/sediments are to prevent
current or future exposure to the these materials through treatment and/or containment, and
to reduce the migration of contaminants from the soils/sediments to groundwater and surface
water. The purposes of this response for groundwater are to clean up the contaminated
groundwater to health-based concentration levels if technically practicable, and to prevent
current or future exposure to groundwater exceeding health-based concentration levels. The
remedy for the third OU is currently proposed as the final response action for the site.
V. OPERABLE UNIT CHARACTERISTICS
The site materials to be remediated under OU Three are described as follows:
A. CONTAMINATED SOILS/SEDIMENTS
As discussed in the Whitmoyer Laboratories Site Rl Report, numerous chemicals and hazardous
substances were detected in the contaminated soils/sediments in and around the plant site
In the baseline risk assessment for the soils/sediments, arsenic contamination was determined
to present the greatest risk for the exposure scenarios studied. Other primary soil
contaminants identified include aniline, n-nitrosodiphenylamine, tetrachloroethene (PCE).
trichloroethene (TCE), total-1,2-dichloroethene, benzene, pyrene, benzo(a)pyrene
benzo(b)fluoranthene, and indeno(1,2.3-cd)-pyrene. All of these contaminants are known or
10
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probable carcinogens. Arsenic, PCE. and total-1,2-dichloroethene are also considered to be
systemic toxicants.
Contaminated surface soils at the Whitmoyer Laboratories Site pose an actual or potential threat
of inhalation/ingestion exposure if no remediation occurs. EPA has determined that cleaning
up the contaminated surface soil to a concentration of 21 mg/kg of arsenic will reduce the
excess lifetime cancer risk posed by the surface soils following remediation under the
residential use (soil ingestion/inhalation) scenario to 1 x 1CT6. This 21 mg/kg cleanup target
was established for this site as part of the risk assessment conducted during the RI/FS.
Surface and subsurface soils also pose a threat to groundwater. The threat differs depending
on whether the soils are above or below the groundwater table ("unsaturated" or "saturated",
respectively). EPA has determined that the soils should be remediated to ensure that migration
of soil contaminants to groundwater would not cause groundwater contaminant concentrations
to exceed the groundwater cleanup targets cited below. Groundwater-based cleanup targets
for saturated and unsaturated soils are provided in Table 1.
For the Whitmoyer Laboratories Site, EPA has determined that soils/sediments which contain
at least one contaminant whose leachate concentrations would likely exceed 100 times the
groundwater cleanup targets are the principal threats from the soil/sediment medium. The
corresponding soil concentrations are provided in Table 1. Nearly all of the "principal threat"
(heavily contaminated) soils/sediments contain arsenic in concentrations greater than 1000
mg/kg, the arsenic action level for treatment. Soils with arsenic concentrations greater than this
level will likely exhibit the RCRA characteristic of arsenic toxicity based on a statistical
correlation between total arsenic concentrations in soil and arsenic concentrations in the
resulting leachate. This correlation was developed by EPA using the standard TCLP testing
procedures and is fully described in the Feasibiltiy Study report for this site.
For this ROD, contaminated soils/sediments are defined as the contaminated soils and adjacent
sediments that are contaminated with arsenic and/or organic chemicals above remedial action
levels. The baseline risk assessment indicated that contaminated sediments alone do not
appear to constitute a significant risk to human health and the environment. As a result, the
only sediments addressed by this ROD are those sediments bounded by soils contaminated
above the remedial action levels.
The Rl surface soil data indicating arsenic and organic chemical contamination are presented
on Figs. 3 and 4, respectively. These data demonstrate widespread onsite and offsite arsenic
contamination. Surface organic chemical contamination appears to be limited to onsite soils
The Rl subsurface soil data indicating arsenic and organic chemical contamination in the 2-
foot to 6-foot depth interval are presented on Figs. 5 and 6, respectively. On Figs. 7 and 8.
the Rl subsurface soil data indicating arsenic and organic chemical contamination at depths
greater than 6 feet are presented, respectively. The subsurface soil data indicate that arsenic
and organic chemical contamination are present in subsurface soils onsite. Arsenic
contamination is relatively widespread in offsite subsurface soils, whereas only a limited degree
of subsurface soil organic chemical contamination in offsite areas was noted during the Rl
11
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TABLE 1
REMEDIAL ACTION LEVELS FOR CONTAMINATED SOIL/SEDIMENTS AND GROUNDWATER
WHITMOYER LABORATORIES SITE
LEBANON COUNTY, PENNSYLVANIA
Parameter
Arsenic
Benzene
Trans- 1,2-dichloroethene
Tr ichloroethene
Tet rachloroethene
Pyrene
Benio(a)pyrene
Benzo(b)f luoranthene
N-nitrosodiphenylaaine
Aniline
lndeno(l ,2,3-cdlpyrene
1 , 1 -Diehloroethene
Methylene chloride
4-Chloroaniline
Soil Ingostion-BasedU)
Action Lav* Is (eg/kg)
Residential Use
lBlO-6 BCR(3)
21
14
>1,000<*)
38
8.2
1.6
0.13
0.93
85
73
0.56
-
-
-
Grounduater(2)
Contamination-Based Soil Action Levels (ng/kg)
No Dilution
(Saturated
Soils)
210(8)
0.002
0.037
0.004
0.012
0.033(0.66|(6)
2.1
0.72
0.030(0.66)16)
0.002(0.66)16)
4.2
-
-
-
Underflow
Dilution (Vadose
Zone Soils)
450(8)
0.009
0.16
0.017
0.051
0.140(0.66)(6)
8.9
3.1
0.13(0.66)(6)
0. 009(0. 66)(6)
18
-
-
-
Principal
Threat H)
1.000(8)
10*
200*
10*
14*
3.3
210
72
14*
12"
420
-
-
-
Groundwater (?)
Action Levels
(•9/1)
0.05
0.005
O.l(P)
0.005
O.OOS(P)
-
0.0002(P)
0.0002(P)
-
0.006" (0. 010)1')
0.0004(P)
0.007
0.005**
0.14**
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1
IEMEDIAL ACTION LEVELS FOR CONTAMINATED SOIL/SEDIMENTS AND GROUNDWATER
fHITMOYER LABORATORIES SITE
.EBANON COUNTY, PENNSYLVANIA
•AGE TWO
I) Based on models used in the HI, action levels calculated for commercial use, agricultural use, or
limited construction at the site are higher than the residential use scenario.
21 MCL or 10-« excess cancer risk in GW, converted to soil concentrations using Koc and TOC (=0.65%)
distribution based calculations. Underflow dilution equal to 4.25
3) ECR Excess Cancer Risk
«) Based on leachate concentrations exceeding RCRA toxicity characteristic levels, if available, oc
100 times the 10-6 Excess Cancer Risk level in GW. Action levels indicated by an * were derived
using TCLP methodology. All others are based on equilibrium partitioning using Koc and TOC.
*>) Noncarcinogen, Dose/RfD based (=1).
6) Number shown in parentheses is practical quantitation (detection) limit.
') MCL based standards, unless indicated by a •*. A ** indicates that no MCL or proposed MCL (P) is
available. The value presented is then based on a 1 x 10-* excess cancer risk or a Dose-Rfd ratio
equal to 1.
i> Arsenic levels are based on Rl-measured partitioning data.
-------
LEOEND
r- »
v /
C5J^ iKMimi.
Mt*l«XMU
**>'£• ' yjSZS "H««'» Uf ron W««H
flCURE
SURFACE SOILS - ARSENIC ISOCONCENTRATION CONTOURS
WHITMQYER LABORATORIES SITE. LEBANON CO. PA
• rtn
IMUS
OORMORATOM
-------
LCOENO
•OTf • I MntwC co«loo«> inc rmitmiio ran
«fMUM nimriuiiOM ruoom
f (U. KOCOMCtlltRlTlOX MM.MS Ml *ve« M
KM
MOO
MM.OOO
FICUHC 4
SURFACE SOILS - ORGANIC CONTAMINATION
WHjTMQYER ^ABORATORtES SITE. LEBANON CO. Pft
-------
LEGEND
*<>T<' * CWTOM nwM.ru Mf ran
nutnuto. MB nmunwr
SUBSURFACE SOILS (2 TO 6 FEET) -ARSENIC ISOCONCENTRATION CONTOURS
LAeQRATQQjES SITE. LEBANON CO. PA
tout • fin
IMUS
-------
LEGEND
CONMLMTDll
CKXMItO IMOOH
, Mta (xauoco nan
MMjri
f
-------
lEOENO
MOTE- i i
•.miration MO ctntMTON
I M.L oooOMCf »m«no« wuic$ MC
|««/>«I
SUBSURFACE SOILS (GREATER THAN 6 FEET I -ARSENIC ISOCONCENTRATION CONTOURS
WHITMOYER LABORATORIES SITE. LEBANON CO. Pft
*CMM m HIT
FtQUHE 7
IMUS
-------
LECCNO
f ICMIM i
*%%? "f*1
— •«•
•MUM. U.MTMHOD
I. «*. *oew«c»i«tiuno«. M4.MU Mt
M«.tmmn rtn «iLO*nu< l-«/»«l
; en err-.-—,
1*0
SUBSURFACE SOILS (GREATER THAN 6 FEET) - ORGANIC CONTAMINATION
WHITMOYER LABOHATOTOES SITE. LEBANON CO. PA
FIGURE g
IMUS
-------
The estimated volumes of soils/sediments having at least one contaminant whose concentration
exceeds the remedial action levels are provided in Table 2 for each exposure scenario
described above. An estimated 480,000 CY of soils/sediments present at the site have arsenic
concentrations in excess of the background (1x10*6 excess lifetime cancer risk) concentration
of 21 mg/kg. These soils are located on an estimated 46 acres. Approximately 61,000 CY of
soils/sediments contain at least one contaminant whose concentration is greater than the
principal threat action levels. Of this amount, about 5,600 CY of the principal threat soils
contain contaminants exceeding the organic-based principal threat action levels.
B. GROUNDWATER
During the Rl, numerous contaminants were also detected in the groundwater in and around
the plant site. In the baseline risk assessment for groundwater, arsenic contamination was
determined to present the greatest risk for the exposure scenarios studied. Other primary
groundwater contaminants identified include antimony, cadmium, manganese, aniline, 4-
chloroaniline, PCE, TCE, total-1,2-dichloroethene, 1,1-dichloroethene, methylene chloride, and
benzene. Arsenic, aniline, PCE, TCE, 1,1-dichloroethene, methylene chloride, and benzene
are classified as known or probable carcinogens. Arsenic, antimony, cadmium, manganese,
4-chloroaniline, PCE, total-1,2-dichloroethene, and 1,1-dichloroethene are classified as systemic
toxicants.
Contaminated groundwater at the Whitmoyer Laboratories Site poses an actual or potential
threat to human health and the environment if no remediation occurs. EPA has determined that
contaminant concentrations in groundwater at the Whitmoyer Laboratories Site should be
cleaned to Federal and State drinking water standards, where they are available for the
particular contaminants. These health-based standards reduce the risks posed by the
contaminants to acceptable levels. When there are no Federal or state drinking water
standards, EPA has determined that the excess lifetime cancer risk posed by each contaminant
following remediation should be reduced to 1 x 10^. This cancer risk level would reduce the
probability of contracting cancer as a result of direct exposure to these contaminants in the
groundwater to one additional person in one million, which is an acceptable level. These
cleanup targets were established for this site as part of the risk assessment conducted during
the RI/FS. Using this approach, EPA determined that cleaning up contaminated groundwater
to the concentrations of 50 ug/l arsenic and 10 ug/l aniline will be protective of human health
and the environment. All groundwater containing other contaminant concentrations above nsk-
based levels have arsenic and/or aniline concentrations above the levels cited above (i.e , the
extent of contaminated groundwater is adequately defined by the aniline and arsenic criteria)
The estimated area! extent of contaminated groundwater using the arsenic and aniline criteria
is presented on Figure 9 and totals 215 acres. The depth of contamination was not completely
defined during the Rl; an assumed depth of 500 feet from ground surface was used during the
RI/FS. This assumption results in an estimated volume of contaminated groundwater of
350,000,000 gallons. The estimated average arsenic, aniline and PCE concentrations in this
groundwater are 17 mg/l, 6.4 mg/l, and 0.25 mg/l respectively. The estimated dissolved
quantities of these contaminants are 44,000 Ibs, 20,000 Ibs, and 730 Ibs, respectively. These
quantities reflect only the dissolved portion of the contaminants in the groundwater. Substantial
amounts of the groundwater contaminants may also be adsorbed onto clays found within the
12
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TABLE 2
COMPARISON OP SOIL/SEDIMENT VOLUMES AND QUANTITIES OF
CONTAMINANTS CORRESPONDING TO EACH SOIL REMEDIAL ACTION LEVEL
HHITMOYBR LABORATORIES SITE, LEBANON COUNTY, PENNSYLVANIA
Parameter
olume (Cubic Yards)
real Extent (Acres)
rsenlc Quantity (pounds)
emi -volatile Organics
uantity (pounds)
olatile Organics Quantity
pounds )
Soil Ingest ion-
Based Action Level
Residential Use
480,000
46*
560,000
9,800
78
Groundwater Contamination-Based
Soil Action Levels
No Dilution
(Saturated Soils)
189,000
28
516,000
9,800
78
With Underflow
Dilution (Vadose
Zone Soils)
100,000
15
440,000
4,700
45
Principal Threat
61,000
10
373,000
3,900
8
Area is not adequately defined
:R Excess Cancer Risk
-------
tt€fi>\^
Wi
©
e/-*
OP
or CIIMDIT
AHILIHI CONTkMIHATIO«
CMOUHDWATIR. CASED OH LIMITED
KVAILMLI OPPSITt MTk.
FKMJftC 9
LOCATION OP CONTAMINATED GROUNOWATER
WHITMOYER LABORATORIES SITE. LEBANON COUNTY. PA
IMUS
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bedrock fractures, and organic chemicals such as PCE and aniline could also be present in
the bedrock as nonaqueous phase liquids.
VI. SUMMARY OF SITE RISKS
The objective of this section is to estimate the potential for adverse health or environmental
effects incurred by human or ecological receptors exposed to the materials making up the OU
Three under the exposure scenarios established in the Rl Report for the Whitmoyer Laboratories
Site. This section characterizes the potential noncarcinogenic, carcinogenic, and environmental
risks associated with OU Three. EPA guidelines for the use of dose-additive models are used
to combine the risks for individual chemicals to estimate cumulative risks for the mixtures found
onsite, assuming the toxicological endpoints are the same. This section summarizes the risk
assessment presented in the Whitmoyer Laboratories Site Rl Report, which was finalized in
November 1989.
A. HUMAN HEALTH RISKS
For human health risks, both carcinogenic risk and the potential for noncarcinogenic effects are
presented. Carcinogenic risk is evaluated by determining the excess lifetime cancer risks
(ELCRs) for actual or potentially exposed individuals. ELCRs are determined by multiplying the
contaminant exposure dose with the cancer potency factor (cancer slope factor). These risks
are probabilities that are generally expressed in scientific notation (e.g.. 1 x 1CT6). An ELCR
of 1 x 1CT6 indicates that, as a plausible upper bound, an individual has a one-in-one million
chance of developing cancer as a result of site-related exposure to a carcinogen over a 70-
year lifetime under the specific exposure conditions at a site.
Cancer potency factors (CPFs) have been developed by EPA's Carcinogen Risk Assessment
Verification Endeavor workgroup for estimating lifetime cancer risks associated with exposure
to potentially carcinogenic chemicals. CPFs, which are expressed in units of (mg/kg-day)'7. are
multiplied by the estimated intake of a potential carcinogen, in mg/kg-day, to provide an upper
bound estimate of the ELCR associated with exposure at that intake level. The term "upper
bound" reflects the conservative estimate of the risks calculated from the CPF. Use of this
approach makes underestimation of the actual cancer risk highly unlikely. Cancer potency
factors are derived from the results of human epidemiological studies or chronic animal
bioassays to which animal-to-human extrapolation and uncertainty factors have been applied
Potential concern for noncarcinogenic effects of a single contaminant in a single medium is
expressed as the hazard quotient (HQ) [or the ratio of estimated intake derived from the
contaminant concentration in a given medium to the contaminant's reference dose (RfD)). The
HQ is also referred to as the Dose/RfO ratio. By adding the HQs for all contaminants within
a medium or across all media to which a given population may reasonably be exposed, the
Hazard Index (HI) can be generated. The HI provides a useful reference point for gauging the
potential significance of multiple contaminant exposures within a single medium or across
media.
Reference doses (RfDs) have been developed by EPA for indicating the potential for adverse
health effects from exposure to chemicals exhibiting noncarcinogenic effects. RfDs, which are
13
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expressed in units of mg/kg-day, are estimates of acceptable lifetime daily exposure levels for
humans, including sensitive individuals. Estimated intakes of chemicals from environmental
media (e.g. the amount of a chemical ingested from contaminated drinking water) can be
compared to the RfD. RfDs are derived from human epidemiologicat studies or animal studies
to which uncertainty factors have been applied (e.g.. to account for the use of animal data to
predict effects in humans). These uncertainty factors help ensure that the RfDs will not
underestimate the potential for adverse noncarcinogenic health effects to occur.
The following risk summary is presented by medium for the OU Three media.
1. Soils/Sediments
The contaminant concentrations and exposure pathways for the contaminated soils sediments
are briefly described above in Section V.A. above. The major exposure pathways include
accidental ingestion/inhalation by future site residents, present or future site workers, or farmers
cultivating or pasturing animals on fields adjacent to the site presently or in the future;
consumption of crops/beef grown on/pastured on fields adjacent to the site presently or in the
future; and present or future consumption of groundwater contaminated by soil/sediment
leachate.
A conservative accidental ingestion/inhalation exposure scenario for residential use of the site
was developed. Key assumptions include that children and adults would ingest 200 mg/day
and 100 mg/day of soil, respectively. Based on this scenario, an HQ of 470 and an ELCR of
1.1 x 10° was calculated for a reasonable worst-case exposure to the arsenic in soils from the
drum burial area of the site. Thus, under the conditions of the risk assessment, adverse
noncarcinogenic health effects are possible (since the HQ is greater than 1), and the
carcinogenic risk is greater than the CERCLA acceptable ELCR of between 1 x 1 Cr4 and 1 x
10'6.
Similarly, a conservative accidental ingestion/inhalation exposure scenario was developed for
commercial/industrial use of the site. Key assumptions of this scenario include that adults
would ingest 100 mg/day of soil for 165 days/year and a 40-year working lifetime. Based on
this scenario, an HQ of 18.2 and an ELCR of 1.87 x 1CT2 was calculated for a reasonable worst-
case exposure to soils from the drum burial area of the site. Thus, adverse noncarcinogenic
health effects are possible and there is a significant excess lifetime cancer risk under the
conditions of the risk assessment.
Farm workers tilling fields containing contaminated surface soils adjacent to the site can
potentially inhale soil particulates. A conservative inhalation model for this exposure was
developed in the baseline risk assessment. Key assumptions of this model include that the
workers would inhale 1.3 cubic meters per hour of particulate-laden air for 12 hours/day and
10 days/year of a 40-year working lifetime. Based on this scenario, an ELCR of 3.0 x 1CT2 was
calculated for an exposure to average soil arsenic concentrations in soils from the Grumbine
field immediately north of the Whitmoyer Laboratories property. Thus, there is a significant
excess lifetime cancer risk under the conditions of the risk assessment.
14
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Consumption of vegetables grown on contaminated soils and consumption of beef or dairy
products raised on/produced on contaminated pastureland also pose potential risk to human
health. These exposures were also modeled in the baseline risk assessment. Key assumptions
for the vegetable consumption scenario include a soil-vegetable partition coefficient
(contaminant concentration in plant/contaminant concentration in soil) of 0.2, a 50 gram/day
consumption rate, and a 70 kilogram (kg) receptor body weight. Key assumptions for the
scenario involving consumption of beef or dairy products produced from animals pastured on
contaminated fields include a soil-vegetation partition coefficient of 0.2, a product-vegetation
partition coefficient (contaminant concentration in milk or beef/contaminant concentration in soil)
of 0.01 for beef and 0.001 for dairy products, and a 70 kg receptor body weight. Based on
these scenarios, an HQ of 13.8 and an ELCR of 2.1 x 1CT2 was calculated for vegetable
consumption; an ELCR of 1.9 x 10^ was calculated for beef consumption; and an ELCR of 7
x 10~5 was calculated for milk consumption for products produced on soils from the Grumbine
field having average soil arsenic concentrations. Thus, adverse noncarcinogenic health effects
are possible and there is a significant excess lifetime cancer risk under the conditions of the
risk assessment.
Precipitation that has contacted contaminated soils could run off and potentially contaminate
surface water. The surface-water pathway was not quantitatively analyzed in the baseline risk
assessment.
Contaminated soils are contributing to the groundwater contamination at the Whitmoyer
Laboratories Site and would continue to contaminate groundwater in the future if left
unremediated. The groundwater pathway is further discussed below.
2. Groundwater
As identified in the Rl and described briefly in Section V.B, the groundwater at the site and
downgradient of the site is highly contaminated. Peak concentrations of arsenic and orgamcs
(eg., tetrachloroethene) measured in the groundwater exceed Safe Drinking Water Act (SDWA)
Maximum Contaminant Levels (MCLs) of 50 ug/l arsenic and 5 ug/1 tetrachloroethene
(proposed) by a factor of about 3,000. ELCRs and His for the onsite/near-site groundwater
(residential use-reasonable worst case scenario) approach unity and exceed 6000, respectively
This scenario assumes residential use of the site and consumption of the most contaminated
groundwater at a rate of 2 liters/day for 70 years by a 70-kg adult. The risk data indicate
potential adverse carcinogenic and noncarcinogenic effects under this exposure scenario
B. ENVIRONMENTAL RISKS
Based on the aquatic biota survey and fish tissue sampling conducted during the Rl. no
evidence of impacts on the ecosystem from the site was observed. Fish tissue arsenic
concentrations were below 2 mg/kg, the method detection limit. Sensitive benthic species. e.g..
stoneflies and mayflies, were found in downstream waters of Tulpehocken Creek. (There are
no endangered species or natural resources of special concern in the vicinity of the site)
Thus, contamination from the materials making up OU Three do not appear to be impacting
the ecosystem currently. As heavily contaminated groundwater continues to migrate otfsile over
15
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time, contaminant contribution to surface water and sediment could potentially affect the
ecosystem in the future if no remediation occurs.
In summary, actual or threatened releases of hazardous substances from the materials making
up OU Three, if not addressed by implementing the response in this ROD, may present an
imminent and substantial endangerment to public health, welfare, or the environment.
VII. DESCRIPTION AND COMPARISON OF ALTERNATIVES
Based on the Rl risk assessment for the OU Three materials, EPA developed the following
remedial action objectives to protect human health and the environment:
1. Prevent human exposure (dermal contact, ingestion, inhalation) to soils/sediments
having contaminants in concentrations greater than carcinogenic (ELCR greater
than 1 x 10"6) and noncarcinogenic (Hazard Index greater than 1) risk-based
levels.
2. Prevent human exposure (dermal contact, ingestion, inhalation) to groundwater
having contaminants in concentrations greater than MCLs (e.g.. 50 ug/l arsenic
and 5 ug/l PCE), where available, or, if MCLs are not available, carcinogenic
(ELCR greater than 1 x 1CT6) and noncarcinogenic (Hazard Index greater than
1) risk-based levels.
3. Prevent migration (via leaching) of contaminants in soils/sediments that would
result in groundwater contamination in excess of MCLs (e.g.. 50 ug/l arsenic
and 5 ug/l PCE), where available, or carcinogenic/noncarcinogenic risk-based
cleanup levels (ELCR greater than 1 x lO^/Hazard Index greater than 1).
4. Prevent migration of contaminants in soils/sediments (via runoff, flooding, erosion)
or groundwater (via groundwater discharge) that would result in surface-water
contamination in excess of the more stringent of the Pennsylvania Water Quality
Standards (e.g.. 50 ug/l arsenic) or Federal Ambient Water Quality Criteria, where
available; or carcinogenic/noncarcinogenic risk-based cleanup levels.
5. Restore groundwater contaminant concentrations to the MCLs (e.g.. 50 ug i
arsenic), where available, or carcinogenic/noncarcinogenic risk-based cleanup
levels (ELCR greater than 1 x 1CT6/Hazard Index greater than 1) as soon as is
technically practicable.
6. Comply with chemical-specific, location-specific, and action-specific applicable
or relevant and appropriate regulations (ARARs), including MCLs and RCRA lane
disposal restrictions.
Based on data available in the Rl and FS Reports, the following OU Three materials will need
to be remediated to achieve the remedial action objectives:
16
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* Contaminated Soils/Sediments - Estimated volume is 480,000 cubic yards.
* Contaminated Groundwater - Estimated volume is 350,000,000 gallons
The Superfund process requires that the alternative chosen to clean up a hazardous waste site
meet several criteria. The alternative must protect human health and the environment, be cost-
effective, and meet the requirements of environmental regulations. Permanent solutions to
contamination problems should be developed wherever possible. These solutions should
reduce the volume, toxicity, or mobility of the contaminants. Emphasis is also placed on
treating the wastes at the site, whenever this is possible, and on applying innovative
technologies to clean up the contaminants.
EPA studied a variety of technologies to see if they were applicable for use on the
contaminated soils/sediments and groundwater. The technologies determined to be most
applicable to these materials were developed into remedial alternatives. Because of the
different nature of each of these media, separate remedial alternatives for each medium were
developed. These individual alternatives are presented and discussed below. The remedial
alternatives developed by the former site owners and presented to the EPA are also described
and discussed.
A. SUMMARY OF ALTERNATIVES - SOILS/SEDIMENTS
Alternatives 1 through 8 for the contaminated soils/sediments are numbered to correspond with
the numbers in the soils FS report (7/90). Alternative 9 is the alternative presented by the
former site owners. The alternatives are the following:
Alternative 1: No Action
Alternative 2: Soil Capping
Alternative 3: Consolidation/Clay Capping
Alternative 4: Bulk Excavation/Offsite Landfill
Alternative 5: Bulk Excavation/Fixation/Offsite Landfill
Alternative 6: Bulk Excavation/Biological Treatment, Fixation/Offsite Landfill
Alternative 7: Bulk Excavation/Incineration, Fixation/Offsite Landfill
Alternative 8: In-situ Vitrification
Alternative 9: Soil Flushing
1. Alternative 1: NO ACTION
The Superfund Program requires that the "no action" alternative be evaluated at every site to
establish a baseline for comparison with the other alternatives. Under this alternative, EPA
would take no actions other than performing reviews every 5 years. Under this alternative, there
would be no deed restrictions or any other institutional controls. Alternative 1 would not
comply with the groundwater relevant and appropriate Safe Drinking Water Act (SDWA)
Maximum Contaminant Level (MCL) of 50 ug/l arsenic, and possibly not with the pertinent
relevant and appropriate MCLs for organic chemicals. Alternative 1 would also not comply with
the CERCLA preference for a remedy that employs treatment to reduce toxicity, mobility, of
volume as a principal element. While no capital costs would be incurred under this alternative
17
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annual operation & maintenance (O&M) costs are estimated to be $3,600. This alternative has
a present-worth cost of $56,000. and can be implemented immediately.
2. Alternative 2: SOIL CAPPING
Under Alternative 2, the entire area of surface soil contamination (arsenic concentration greater
than 21 mg/kg) (40 acres) would be left in place and capped with 1.5 feet of clean soil and 6
inches of topsoil. Erosion control measures (e.g.. riprap) would be applied to the stream
channel. These measures would require maintenance indefinitely. Deed restrictions would be
placed on areas where contaminated soils/sediments remain following remediation; and long-
term groundwater monitoring in compliance with the relevant and appropriate requirements of
40 CFR 264.117 and 5-year reviews would be conducted. Alternative 2 would not comply with
the SDWA MCL for arsenic, and possibly not with the pertinent MCLs for organic chemicals
Alternative 2 would also not comply with the CERCLA preference for a remedy that employs
treatment to reduce toxicity, mobility, or volume as a principal element. The estimated capital
cost of this alternative is $4,440,000. Annual O&M costs are estimated to be $7,600. The
estimated present-worth cost of this alternative is $4,450,000. The estimated time to Implement
this alternative is approximately 2 years.
3. Alternative 3: IMPERMEABLE CAPPING
Under Alternative 3, Buildings 4, 9, 11, and 14 would be demolished and the pipeline/pump
station would be temporarily abandoned or relocated to facilitate the excavation of
contaminated soils/sediments. The demolition debris would either be landfilled offsite m
compliance with all applicable regulations or salvaged. Saturated soils/sediments with
contaminant concentrations exceeding the groundwater-based soil action levels for saturated
soils and unsaturated soils with contaminant concentrations exceeding the groundwater-based
soil action levels for unsaturated soils would be consolidated in the vadose zone onsite The
excavation areas would be backfilled with clean fill or lightly contaminated soil. During
excavation of the saturated soils and stream sediments, the groundwater table would be
lowered by groundwater pumping, and Tulpehocken Creek/Union Canal would be temporarily
relocated. The extracted contaminated groundwater would be treated in the groundwater
pump-and-treat system, if present, or in a temporary treatment system. The extracted
uncontaminated groundwater would be directly discharged to the creek. The final stream
channel would be located in a similar position and with similar dimensions as the current
channel. Erosion control measures would be implemented during the stream relocation
process. The onsite canal lock would be archived during remediation and would be reinstalled
at the completion of activities.
Following consolidation of the excavated soils/sediments, the approximately 100.000 CY of soils
with contaminant concentrations above the groundwater-based unsaturated soil action levels
would be impermeably capped (e.g.. with clay). The cap would be designed to meet the
relevant and appropriate RCRA landfill closure requirements in 40 CFR 264.310, which, among
other things, specify that the permeability of the cap must be less than or equal to the
permeability of the natural underlying materials at the site. All surface soils that are not
impermeably capped and contain greater than 21 mg/kg arsenic would be capped with soil
All affected areas would be graded and revegetated.
18
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Following implementation of Alternative 3, deed restrictions would be placed on areas where
contaminated soils/sediments remain. Consistent with the relevant and appropriate
requirements of 40 CFR 264.117, long-term O&M would be conducted to monitor the
groundwater around the consolidated wastes and to ensure the integrity of the cap, and 5-
year reviews would be conducted. Alternative 3 should comply with all applicable or relevant
and appropriate requirements (ARARs).
Alternative 3 would not comply with the CERCLA preference for a remedy that employs
treatment to reduce toxicrty, mobility, or volume as a principal element. The estimated capital
cost of this alternative is $8,400,000. Annual O&M costs are estimated to be $7,600. The
estimated present-worth cost of this alternative is $8,300,000. The estimated time to implement
this alternative is approximately 2 years.
4. Alternative 4: BULK EXCAVATION/LANDFILL
Under Alternative 4, some or all of the contaminated soils would be excavated and disposed
offsite. The approximately 61,000 CY of soils/sediments with contaminant concentrations
exceeding the "principal threat' action levels (see Table 1) would be disposed in an offsite
landfill in accordance with all applicable regulations. Since nearly all of these soils exhibit the
toxicity characteristic for arsenic, they would be disposed in a hazardous waste landfill. The
approximately 39,000 CY of soils/sediments which contain contaminant concentrations less than
the "principal threat" action levels but greater than the groundwater-based unsaturated soil
action levels (see Table 1) would either be disposed offsite in an intermediate landfill (Options
A or B) or be consolidated in an onsite vadose zone and covered by an impermeable cap
(Option C). The impermeable cap would be designed to meet the relevant and appropriate
requirements of RCRA landfill closure in 40 CFR 264.310. The balance of the contaminated
soils would either be taken offsite to a less secure, nonhazardous landfill (Option A) or remain
onsite. If these soils are left onsite (Options B and C), saturated soils with contaminant
concentrations exceeding the groundwater-based saturated soil action levels (see Table 1)
would be relocated to the vadose zone onsite. Following this consolidation, surface soils with
arsenic concentrations greater than 21 mg/kg arsenic but with contaminant concentrations less
than the groundwater-based unsaturated soil action levels would be covered by a soil cap
Other activities required to implement this alternative include demolition of Buildings 4, 8, 9,11
and 14 and temporary abandonment or relocation of the pipeline/pump station. The demolition
debris would either be landfilled in an offsite landfill in accordance with all applicable
regulations or salvaged. During excavation of the saturated soils and stream sediments, the
groundwater table would be lowered by groundwater pumping, and Tulpehocken Creek/Union
Canal would be temporarily relocated. The extracted contaminated groundwater would be
treated in the groundwater pump-and-treat system, if present, or in a temporary treatment
system. The extracted uncontaminated groundwater would be directly discharged to the creek
The final stream channel would be located in a similar position and with similar dimensions
as the current channel. Erosion control measures would be implemented during the stream
relocation process. The onsite canal lock would be archived during remediation and would be
reinstalled at the completion of activities. The excavated areas would be backfilled with clean
fill, covered with soil, graded, and revegetated.
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Option A would comply with RCRA landfill clean closure requirements, 40 CFR Part 264.
Subpart N. Therefore, deed restrictions would not be required for this option. For Options B
and C, deed restrictions would be used to control access to the contaminated soils remaining
at the site. Since contaminants remain onsite under Options B and C, 5-year reviews would
be conducted. Long-term groundwater monitoring in compliance with the relevant and
appropriate requirements of 40 CFR 264.117 would also be conducted following implementation
of Option C, since materials which pose a potential threat to groundwater would remain on site.
None of the Alternative 4 options would comply with RCRA land disposal restrictions (LDRs, 40
CFR Part 268). These restrictions require RCRA hazardous wastes, such as the soils/sediments
exhibiting the arsenic toxicity characteristic, to be treated prior to placement in a landfill. These
restrictions apply to the soils/sediments after May 8, 1992. Since it would be impossible to
landfill the hazardous soils/sediments prior to this date (because of the time required for stream
and pipeline relocation), this ARAR would not be met. Alternative 4 complies with all other
ARARs.
Alternative 4 would not comply with the CERCLA preference for a remedy that employs
treatment to reduce toxicity, mobility, or volume as a principal element. The estimated capital,
annual O & M, and net present-worth costs associated with this alternative are $82,000,000.
34,000/year, and $80,000,000, respectively, for Option A; $40,000,000, $7,600/year, and
$39.000,000, respectively, for Option B; and $34,000,000, $7,600/year, and $33,000.000.
respectively, for Option C. The estimated time to implement this alternative is approximately
2 years.
5. Alternative 5: BULK EXCAVATION/FIXATION/OFFSITE LANDFILL
Under Alternative 5, all saturated soils/sediments with contaminant concentrations exceeding
the groundwater-based action levels for saturated soils would be excavated, as would all of
those unsaturated soils with contaminant concentrations exceeding the "principal threat" action
levels (see Table 1). Additionally, the unsaturated soils/sediments with contaminant
concentrations exceeding the groundwater-based action levels for unsaturated soils but less
than the "principal threat" action levels would be consolidated in the vadose zone onsite To
facilitate the excavation of these approximately 116,000 CY of contaminated soils/sediments
Buildings 4, 9, 11, and 14 would be demolished and the pipeline/pump station would be
temporarily abandoned or relocated. The demolition debris would either be landfilled off site in
compliance with all applicable regulations or salvaged. The excavation areas would be
backfilled with clean fill or lightly contaminated soil. During excavation of the saturated soils
and stream sediments, the groundwater table would be lowered by groundwater pumping, and
Tulpehocken Creek/Union Canal would be temporarily relocated. The extracted contaminated
groundwater would be treated in the groundwater pump-and-treat system, if present, or m a
temporary treatment system. The extracted uncontaminated groundwater would be directly
discharged to the creek. The final stream channel would be located in a similar position and
with similar dimensions as the current channel. Erosion control measures would be
implemented during the stream relocation process. The onsite canal lock would be archived
during remediation and would be reinstalled at the completion of activities.
20
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The approximately 61,000 CY ol 'principal threat' soils/sediments would be treated using iron-
based fixation or a similar process. The approximately 5,600 CY of "principal threat"
soils/sediments with organic chemical concentrations above the "principal threat" organic
chemical soil action levels would also be fixated with activated carbon. Following treatment,
the arsenic mobility of the treated wastes would be reduced by at least 90%. The fixation
would occur onsite in accordance with RCRA standards for miscellaneous treatment units (40
CFR Part 264, Subpart X). The fixation unit would be mobilized, operated, and closed
according to the requirements of 40 CFR 264.600, et sea. The specific operating parameters
for the fixation process would be determined in the Remedial Design phase through engineering
design and analysis and the competitive bidding process. Because most of the "principal
threat" soils/sediments exhibit the RCRA characteristic of arsenic toxicity and Alternative 5
constitutes treatment, RCRA Subtitle C is applicable. The RCRA land disposal restriction
treatment standard for these wastes is 5.0 mg/l arsenic, as measured by the EP Toxicity Test
or TCLP. (A national capacity extension for these wastes is in effect until May 8, 1992.) The
fixation process should achieve this treatment standard. The treated soils/sediments should
no longer be RCRA characteristic wastes as the fixation process would prevent these materials
from exceeding the TCLP limit for arsenic; they would be considered residual wastes under
Pennsylvania law (25 PA Code, Chapter 75). All treated soils would be landfiiled off site in an
intermediate (residual waste) landfill. Offsite landfill disposal would comply with all ARARs.
The approximately 39,000 CY of soils/sediments site with contaminant concentrations less than
the "principal threat1 action levels but above the groundwater-based unsaturated soil action
levels would be consolidated onsite in the vadose zone and capped with impermeable material
The cap would be designed to meet the relevant and appropriate requirements of RCRA landfill
closure in 40 CFR 264.310. The remaining approximately 16,000 CY of excavated
soils/sediments with contaminant concentrations less than the groundwater-based unsaturated
soil action levels would be placed onsite in the vadose zone. All soils remaining on the surface
after the impermeable cap is placed and which contain greater than 21 mg/kg arsenic.but less
than the groundwater based unsaturated soil action levels, would be capped with soil. All
affected areas would be graded and revegetated. Following implementation of Alternative 5,
deed restrictions would be placed on areas where contaminated soils/sediments remain. Since
contaminants remain onsite under Alternative 5, 5-year reviews would be conducted. Long-
term groundwater monitoring in compliance with the relevant and appropriate requirements of
40 CFR 264.117 would also be conducted following implementation of Alternative 5, since
materials which pose a potential threat to groundwater would remain on site.
Alternative 5 would comply with the CERCLA preference for a remedy that employs treatment
to reduce toxicity, mobility, or volume as a principal element. The estimated capital cost of this
alternative is $28,000,000. Annual O&M costs are estimated to be $7,600. The estimated
present-worth cost of this alternative is $27,000,000. The estimated time to implement this
alternative is approximately 3 years.
6. Alternative 6: BULK EXCAVATION/BIOLOGICAL TREATMENT, FKATION/OFFSITE LANDFILL
Under Alternative 6, all saturated soils/sediments with contaminant concentrations exceeding
the gvoundwater-based action levels for saturated soils would be excavated, as would all of
21
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those unsaturated soils with contaminant concentrations exceeding the "principal threat" action
levels (see Table 1). Additionally, the unsaturated soils/sediments with contaminant
concentrations exceeding the groundwater-based action levels for unsaturated soils but less
than the "principal threat" action levels would be consolidated in the vadose zone onsite. To
facilitate the excavation of these approximately 116,000 CY of contaminated soils/sediments,
Buildings 4, 9, 11, and 14 would be demolished and the pipeline/pump station would be
temporarily abandoned or relocated. The demolition debris would either be landfilled offsite in
compliance with all applicable regulations or salvaged. The excavation areas would be
backfilled with clean fill or lightly contaminated soil. During excavation of the saturated soils
and stream sediments, the groundwater table would be lowered by groundwater pumping, and
Tulpehocken Creek/Union Canal would be temporarily relocated. The extracted contaminated
groundwater would be treated in the groundwater pump-and-treat system, if present, or in a
temporary treatment system. The extracted uncontaminated groundwater would be directly
discharged to the creek. The final stream channel would be located in a similar position and
with similar dimensions as the current channel. Erosion control measures would be
implemented during the stream relocation process. The onsite canal lock woufd be archived
during remediation and would be reinstalled at the completion of activities.
The approximately 61,000 CY of "principal threat" soils/sediments woulo be treated using iron-
based fixation or a similar process. The approximately 5,600 CY of "principal threat"
soils/sediments with organic chemical concentrations above the "principal threat" organic
chemical soil action levels would also be biologically treated, either before or after the fixation
step. Following treatment, the arsenic mobility of the treated wastes would be reduced by at
least 90%, and an estimated 50 to 100 percent of the organics would be destroyed. The
fixation and biological treatment would occur onsite in accordance with RCRA standards for
miscellaneous treatment units (40 CFR Part 264, Subpart X). The fixation and biological
treatment units would be mobilized, operated, and closed according to the requirements of 40
CFR 264.600, et sea. The specific operating parameters for the fixation process would be
determined in the Remedial Design phase through engineering design and analysts and the
competitive bidding process. A treatabitity study would be conducted prior to full-scale
irrr ementation to validate the biological treatment. The specific operating parameters for the
biological treatment process would be determined in the Remedial Design phase through the
treatability study, engineering design and analysis, and the competitive bidding process
Because most of the "principal threat" soils/sediments exhibit the RCRA characteristic of arsenic
toxicity and Alternative 6 constitutes treatment, RCRA Subtitle C is applicable. The RCRA land
disposal restriction treatment standard for these wastes is 5.0 mg/l arsenic, as measured by the
EP Toxicity Test or TCLP. (A national capacity extension for these wastes is in effect until
May 8,1992.) The fixation/biological treatment process should achieve this treatment standard
The treated soils/sediments should no longer be RCRA characteristic wastes as the fixation
process would prevent these materials from exceeding the TCLP limit for arsenic; they would
be considered residual wastes under Pennsylvania law (25 PA Code, Chapter 75). All treated
soils would be landfilled off site in an intermediate (residual waste) landfill. Offsite landfill
disposal would comply with all ARARs.
22
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The approximately 39,000 CY of soils/sediments site with contaminant concentrations less than
the "principal threat" action levels but above the groundwater-based unsaturated soil action
levels would be consolidated onsite in the vadose zone and capped with impermeable material.
The cap would be designed to meet the relevant and appropriate requirements of RCRA landfill
closure in 40 CFR 264.310.
The remaining approximately 16,000 CY of excavated soils/sediments with contaminant
concentrations less than the groundwater-based unsaturated soil action levels would also be
placed onsite in the vadose zone. After the impermeable capping step is completed, all soils
remaining on the surface which contain greater than 21 mg/kg arsenic would be capped with
soil. All affected areas would be graded and revegetated. Following implementation of
Alternative 6, deed restrictions would be placed on areas where contaminated soils/sediments
remain. Since contaminants remain onsite under Alternative 6, 5-year reviews would be
conducted. Long-term groundwater monitoring in compliance with the relevant and appropriate
requirements of 40 CFR 264.117 would also be conducted following implementation of
Alternative 6, since materials which pose a potential threat to groundwater would remain on
site.
Alternative 6 would comply with the CERCLA preference for a remedy that employs treatment
to reduce toxicity, mobility, or volume as a principal element. The estimated capital cost of this
alternative is $28.000,000. Annual O&M costs are estimated to be $7,600. The estimated
present-worth cost of this alternative is $25,000,000. The estimated time to implement this
alternative is approximately 5 years.
7. Alternative 7: BULK EXCAVATION/INCINERATION, FIXATION/OFFSITE LANDFILL
Under Alternative 7, all saturated soils/sediments with contaminant concentrations exceeding
the groundwater-based action levels for saturated soils would be excavated, as would all
unsaturated soils with contaminant concentrations exceeding the "principal threat" action levels
(see Table 1). Additionally, the unsaturated soils/sediments with contaminant concentrations
exceeding the groundwater-based action levels for unsaturated soils but less than the "principal
threat" action levels would be consolidated in the vadose zone onsite. To facilitate the
excavation of these approximately 116,000 CY of contaminated soils/sediments, Buildings 4.
9, 11, and 14 would be demolished and the pipeline/pump station would be temporarily
abandoned or relocated. The demolition debris would either be landfilled offsite in compliance
with all applicable regulations or salvaged. The excavation areas would be backfilled with clean
fill or lightly contaminated soil. During excavation of the saturated soils and stream sediments,
the groundwater table would be lowered by groundwater pumping, and Tulpehocken
Creek/Union Canal would be temporarily relocated. The extracted contaminated groundwater
would be treated in the groundwater pump-and-treat system, if present, or in a temporary
treatment system. The extracted uncontaminated groundwater would be directly discharged
to the creek. The final stream channel would be located in a similar position and with similar
dimensions as the current channel. Erosion control measures would be implemented during
the stream relocation process. The onsite canal lock would be archived during remediation and
would be reinstalled at the completion of activities.
23
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The approximately 61,000 CY of "principal threat' soils/sediments would be treated using iron-
based fixation or a similar process. The approximately 5,600 CY of "principal threat"
soils/sediments with organic chemical concentrations above the "principal threat" organic
chemical soii action levels would first be thermally treated, followed by fixation with cement,
iron, or similar reagents. Following treatment, the arsenic mobility of the treated wastes would
be reduced by greater than 90%, and nearly all of the organic contaminants would be
destroyed. The fixation treatment would occur onsite in a mobile unit, in accordance with
RCRA standards for miscellaneous treatment units (40 CFR Part 264, Subpart X). The fixation
unit would be mobilized, operated, and closed according to the requirements of 40 CFR
264.600, et sea. These requirements are applicable to the soils/sediments to be fixated,
because treatment and disposal of hazardous waste (arsenic characteristic wastes) are
occurring. The specific operating parameters for the fixation process would be determined in
the Remedial Design phase through engineering design and analysis and the competitive
bidding process. The thermal treatment would occur onsite in a mobile unit, in accordance
with RCRA 40 CFR Part 264, Subpart 0 standards. The specific type of incineration process
(e.g.. rotary kiln) would be determined in the Remedial Design phase through engineering
design and analysis and the competitive bidding process. The incineration unit would be
mobilized, operated, and closed according to the requirements of RCRA Part 264 Subpart 0,
40 CFR 264.340 et sea. These requirements are applicable to the soils/sediments to be
incinerated, because treatment and disposal of hazardous waste (arsenic characteristic wastes)
are occurring. Specific operating practices necessary to meet the performance objectives,
including a 99.99 percent destruction and removal efficiency (DRE) of stack emissions as
required by Subpart O of RCRA, would be determined through a trial burn at the site after the
installation of the incineration unit. Specialized air pollution control equipment would be applied
during the incineration step to capture contaminants in the exhaust air and thus ensure
compliance with the relevant and appropriate NAAQS (40 CFR Part 50) and National Emissions
Standards for Hazardous Air Pollutants (NESHAPS) (40 CFR Part 61, Subpart N). A pilot-
scale study would be conducted prior to full-scale implementation to adequately evaluate
arsenic removal versus size and .cost for the air pollution control equipment. The specific
operating parameters for the thermal treatment process would be determined in the Remedial
Design phase through the pilot-scale study, engineering design and analysis, and the
competitive bidding process.
Because most of the "principal threat' soils/sediments exhibit the RCRA characteristic of arsenic
toxicity and Alternative 7 constitutes treatment, RCRA Subtitle C is applicable. The RCRA land
disposal restriction treatment standard for these wastes is 5.0 mg/l arsenic, as measured by the
EP Toxicity Test or TCLP. (A national capacity extension for these wastes is in effect until
May 8, 1992.) The incineration/fixation treatment process should achieve this treatment
standard. The treated soils/sediments should no longer be RCRA characteristic wastes as the
fixation process would prevent these materials from exceeding the TCLP limit for arsenic; they
would be considered residual wastes under Pennsylvania law (25 PA Code, Chapter 75) All
treated soils would be landfilled off site in an intermediate (residual waste) landfill. Offsite
landfill disposal would comply with all ARARs.
-------
The approximately 39,000 CY of soils/sediments site with contaminant concentrations less than
the "principal threat" action levels but above the groundwater-based unsaturated soil action
levels would be consolidated onsite in the vadose zone and capped with impermeable material
The cap would be designed to meet the relevant and appropriate requirements of RCRA landfill
Closure in 40 CFR 264.310.
The remaining approximately 16,000 CY of excavated soils/sediments with contaminant
concentrations less than the groundwater-based unsaturated soil action levels would also be
placed onsite in the vadose zone. After the impermeable capping step is completed, all soils
remaining on the surface which contain greater than 21 mg/kg arsenic would be capped with
soil. All affected areas would be graded and revegetated. Following implementation of
Alternative 7, deed restrictions would be placed on areas where contaminated soils/sediments
remain. Since contaminants remain onsite under Alternative 7, 5-year reviews would be
conducted. Long-term groundwater monitoring in compliance with the relevant and appropriate
requirements of 40 CFR 264.117 would also be conducted following implementation of
Alternative 7, since materials which pose a potential threat to groundwater would remain on
site.
Alternative 7 would comply with the CERCLA preference for a remedy that employs treatment
to reduce toxicity, mobility, or volume as a principal element. The estimated capital cost of this
alternative is $33,000,000. Annual O&M costs are estimated to be $7,600. The estimated
present-worth cost of this alternative is $32,000,000. The estimated time to implement this
alternative is approximately 3 years.
8. Alternative 8: IN-SITU VITRIFICATION
Under Alternative 8, all saturated soils/sediments with contaminant concentrations exceeding
the groundwater-based action levels for saturated soils would be excavated. Additionally, the
unsaturated soils with contaminant concentrations exceeding the groundwater-based action
levels for unsaturated soils would be consolidated in the vadose zone onsite. To facilitate the
excavation/consolidation of these approximately 116,000 CY of contaminated soils/sediments
Buildings 4, 9. 11, and 14 would be demolished and the pipeline/pump station would be
temporarily abandoned or relocated. The demolition debris would either be landfilled offsite in
compliance with all applicable regulations or salvaged. The excavation areas would be
backfilled with clean fill or lightly contaminated soil. During excavation of the saturated soils
and stream sediments, the groundwater table would be lowered by groundwater pumping, anc
Tulpehocken Creek/Union Canal would be temporarily relocated. The extracted contaminated
groundwater would be treated in the groundwater pump-and-treat system, if present, or m a
temporary treatment system. The extracted uncontaminated groundwater would be directly
discharged to the creek. The final stream channel would be located in a similar position and
with similar dimensions as the current channel. Erosion control measures would be
implemented during the stream relocation process. The onsite canal lock would be archivec
during remediation and would be reinstalled at the completion of activities.
The approximately 61,000 CY of "principal threat" soils/sediments would be consolidated on site
These soils/sediments would then be heated in place using electricity passing throug-
electrodes until the mixture formed a pool of molten glass. Nearly all of the organ -
25
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contaminants would be destroyed during heating, while the metal contaminants would become
trapped in the glass during the subsequent cooling step. The arsenic mobility of the treated
soils/sediments might be reduced by approximately 90%. The vitrification would be conducted
with a mobile unit in accordance with RCRA standards for miscellaneous treatment units (40
CFR Part 264, Subpart X). These standards have been determined to be relevant and
appropriate to the vitrification step because placement is not occurring. The vitrification unit
would be mobilized, operated, and closed according to the requirements of 40 CFR 264 600,
et sea. A treatability study would be conducted prior to full-scale implementation to validate
the proposed treatment. The specific operating parameters of the vitrification unit would be
determined in the Remedial Design phase through the treatability study, engineering design and
analysis, and the competitive bidding process. Specialized air pollution control equipment
would be applied during the vitrification step to capture contaminants in the exhaust air and
thus ensure compliance with the relevant and appropriate NAAQS (40 CFR Part 50) and
NESHAPS (40 CFR Part 61, Subpart N). Residuals from the air pollution control system would
be vitrified in subsequent batches. Once the vitrification step is completed, gravel would be
placed around the vitrified material to direct infiltration and groundwater around it. The gravel
would be covered by a soil cap.
The approximately 39,000 CY of soils/sediments site with contaminant concentrations less than
the "principal threat" action levels but above the groundwater-based unsaturated soil action
levels would be consolidated onsite in the vadose zone and capped with impermeable material
The cap would be designed to meet the relevant and appropriate requirements of RCRA landfill
closure in 40 CFR 264.310.
The remaining approximately 16,000 CY of excavated soils/sediments with contaminant
concentrations less than the groundwater-based unsaturated soil action levels would also be
placed onsite in the vadose zone. After the impermeable capping and vitrified materials capping
steps are completed, all soils remaining on the surface which contain greater than 21 mg/kg
arsenic would be capped with soil. All affected areas would be graded and revegetated
Following implementation of Alternative 8, deed restrictions would be placed on areas where
contaminated soils/sediments remain. Since contaminants remain onsite under Alternative 8
5-year reviews would be conducted. Long-term groundwater monitoring in compliance with the
relevant and appropriate requirements of 40 CFR 264.117 would also be conducted following
implementation of Alternative 8, since materials which pose a potential threat to groundwater
would remain on site.
Alternative 8 would comply with the CERCLA preference for a remedy that employs treatment
to reduce toxicity, mobility, or volume as a principal element. The estimated capital cost of this
alternative is $45,000,000. Annual O&M costs are estimated to be $7,600. The estimatec
present-worth cost of this alternative is $44,000,000. The estimated time to implement tr.s
alternative is approximately 3 years.
Alternative 9: SOIL FLUSHING
[Note: The WLPSG submitted an initial soil washing (flushing) proposal to EPA in Februa^/
1990. The former owners submitted supplemental information describing the former owners
soil flushing proposal in more detail to EPA on September 14, 1990. This alternative
26
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description, as well as the rest of this Record of Decision, incorporate the new supplemental
information.]
Under the former owners' proposal (Alternative 9), a 3-year in situ pilot-scale soil flushing
demonstration program (treatability study) would be conducted. In one place in the former
owners' proposal, it is stated that the objective of the pilot program is to determine if arsenic
can be leached from the soil in place over an extended period of time, as well as to provide
an initial evaluation of sediment flushing. In another place it is stated that the objective is to
determine whether arsenic will leach from the soils at levels above the threshold for
groundwater impact. Leachate from the soil flushing test will in theory be captured by the
pumping network installed by the former owners as part of their groundwater remedial
alternative.
Once the 3-year study results are obtained, they would be studied to determine if the leachate
concentration is above the threshold for groundwater impact. This threshold is defined as not
exceeding SDWA MCLs at the point of exposure. A realistic exposure point is more than 500
feet from the site boundary, according to the former owners. If soil leachate concentrations are
above the former owner-defined threshold, soils and sediment flushing would be expanded
If the leachate concentrations are below the former owner groundwater impact threshold.
surface soils that exceed action levels protective of human health would be capped
Institutional controls would be applied to the entire site plus off-site areas that are capped
and/or treated with soil flushing.
To conduct the pilot-scale study, a percolation/leaching field would be installed in a 20-foot by
20-foot, moderately contaminated area. A wall would be constructed around the perimeter of
the leaching area to control the lateral migration of washing solution. Horizontal dram pipes
would be installed under the soils to be leached to collect the leaching fluid. Leachate
produced during the study would be treated in the groundwater pump-and-treat system
Additional soil and sediment washing testing would be conducted in a mobile laboratory on
site.
Alternative 9 would not comply with the groundwater relevant and appropriate requirement of
50 ug/l arsenic for the entire groundwater plume area of attainment, and possibly not with the
pertinent relevant and appropriate MCLs for organic chemicals. This noncompliance occurs
because a remedial objective is to not exceed MCLs at a realistic exposure point. (A realistic
exposure point is more than 500 feet from the site boundary, according to the former owners )
The groundwater plume closer to the site would be allowed to exceed MCLs at the completion
of the remediation. Additionally, since only a small area of soil contamination would be
addressed during the 3-year pilot program, the remaining area of soil contamination would
continue to leach contaminants to the groundwater and cause MCLs to be exceeded during
this period.
The former owners estimate the total cost of their demonstration program, including two years
of O&M, at $1,400,000. The former owners estimate that the present worth cost of the soil
maximum expansion, including 27 years of O&M, at $7,300,000. This figure includes costs for
soil capping and institutional controls. Thus the total cost of Alternative 9 for maximum
expansion is $8,700,000. The maximum expansion would encompass an estimated 156 acres
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10. COMPARATIVE ANALYSIS OF ALTERNATIVES - SOILS/SEDIMENTS
The nine soil/sediment remedial action alternatives described above and the selected remedy
were evaluated under the nine evaluation criteria in the NCP 40 CFR 300.430(e)(9) as set forth
in "Guidance for Conducting Remedial Investigations and Feasibility Studies Under CERCLA"
(EPA, October 1988), EPA Directive 9355.3-02 "Draft Guidance on Preparing Superfund Decision
Documents: The Proposed Plan and Record of Decision," and "Guidance on Preparing
Superfund Decision Documents: The Proposed Plan, The Record of Decision, Explanation of
Significant Differences, and the Record of Decision Amendment" (EPA/540/6-89/007, July 1989
Interim Final). These nine criteria can be further categorized into three groups: threshold
criteria, primary balancing criteria, and modifying criteria, as follows:
Threshold Criteria
* Overall protection of human health and the environment
* Compliance with applicable or relevant and appropriate requirements (ARARs)
Primary Balancing Criteria
Long-term effectiveness
Reduction of toxicity, mobility or volume through treatment
Short-term effectiveness
Implementability
Cost
Modifying Criteria
* Community Acceptance
* State Acceptance
These evaluation criteria, which measure the overall feasibility and acceptability of the remedy.
relate directly to requirements in Section 121 of CERCLA, 42 U.S.C. Section 9621. 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 alternatives. State and community
acceptance are modifying criteria formally taken into account after public comment is received
on the Proposed Plan. The evaluations are as follows:
Overall Protection. Alternatives 3, 4, 5, 6, 7, and 8 would provide adequate protection of
human health and the environment by eliminating, reducing, or controlling risk through
treatment, engineering controls, or institutional controls. Alternatives 5, 6, and 7 would treat
the most heavily contaminated ("principal threat") soils/sediments and dispose these treated
materials off site. Moderately contaminated soils/sediments would be consolidated on site The
contaminated soils/sediments remaining at the site would be capped to reduce the risks
associated with direct contact and minimize the migration of contamination to the groundwater
28
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Alternatives 5, 6, 7, and 8 would be more protective than the other alternatives, since the
heavily contaminated soils would be treated to reduce toxicity. mobility, or volume. Alternative
5 would be less protective than Alternatives 6, 7. and 8, since the organic chemicals in the
soils/sediments would be fixated rather than destroyed. There are risks associated with arsenic
volatilization during the incineration or vitrification steps of Alternatives 7 and 8; these risks
would be managed through the use of specialized air pollution control equipment. Alternative
3 would be less protective of human health and the environment than Alternatives 5, 6. 7, and
8, because the heavily contaminated wastes would remain untreated and there is the potential
of containment system failure from sinkhole formation, erosion, or other causes. Containment
system failure could result in a substantial release of contaminants to groundwater.
Alternative 2 would not be protective of human health and the environment, as precipitation
infiltration would continue to cause substantial groundwater contamination.
Alternative 9 would be less protective of human health or the environment than Alternatives 5,
6, 7, and 8. Under Alternative 9, either no remediation other than soil capping and institutional
controls would occur, or soil flushing would be implemented on the most contaminated soils
If only soil capping/institutional controls occur, the alternative would essentially be the
equivalent of Alternative 2, and would not be protective of human health and the environment
If the maximum soil flushing expansion occurs, there is a significant risk that some of the
leaching solution would escape the well capture network (because of the site's complex
hydrogeology) and contaminate downgradient groundwater. If soil flushing is implemented, the
flushing duration can not be specified, because the former owners did not specify a
soil/sediment cleanup level. Rather, they specified that soils/sediments would be treated until
the effect of leachate on groundwater would not exceed MCLs at the point of exposure (A
realistic exposure point is more than 500 feet from the site boundary, according to the former
owners.) Using the former owners' calculations, it would take 10,000 to 24,000 years for the
maximum soil flushing option for soils to be cleaned up to a point where their leachate
concentration would meet MCLs. (See the discussion in the attached Responsiveness
Summary.) Thus, the soil flushing treatment duration would likely be very lengthy. During
this period, the groundwater capture network would have to be operated to protect current or
potential future downgradient groundwater users.
Under the former owners' proposal, soils/sediments would not be remediated to a point where
contaminant concentrations in the entire aquifer would be at or below the groundwater cleanup
levels presented in Section V above. Rather, they would only be remediated until a point where
groundwater woula meet MCLs at a point at least 500 feet beyond the site boundary. In the
absence of MCLs, the former owners advocate the use of a 1 x 10"4 excess lifetime cancer risk-
based cleanup level for carcinogens and a Hazard Quotient of 1 for non-carcinogens. EPA has
determined that, in the absence of MCLs, a 1 x 1CT6 excess lifetime cancer risk-based standard
is appropriate for groundwater. Given the site-specific conditions, EPA has determined that
reducing groundwater contaminant concentrations at the Whitmoyer Laboratories Site to only
a 1 x 10""* excess lifetime cancer risk-based level in the absence of MCLs is not protective of
human health. Additionally, EPA has determined that contaminant concentrations should be
reduced below MCLs (where they exist for the contaminants) in the entire aquifer, and not just
for portions of the aquifer at a significant distance downgradient of the site.
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Under Alternative 9, only minimal actions would occur during the 3-year pilot-scale program.
During these 3 years, groundwater contamination would continue to occur and the potential for
surface runoff and inhalation/ingestion would continue to exist.
The "no action" alternative is not protective of human health and the environment; therefore, it
is not considered further in this analysis as an option for the soils/sediments.
Compliance with ARARs. Alternatives 3, 5, 6, 7, and 8 would meet their respective ARARs.
Alternative 6 would comply with the applicable LDRs for arsenic characteristic wastes, the
applicable RCRA miscellaneous treatment unit standards, and the relevant and appropriate
RCRA closure and groundwater monitoring requirements. Also, the relevant and appropriate
SDWA groundwater quality standards would be met.
Alternative 4 would not be expected to comply with the LDR standards for arsenic characteristic
wastes, since the heavily contaminated soils would not be completely landfilled by May 8,
1992. There is a RCRA land disposal restriction capacity extension until this date - see 55 PR
22520. Thus, an ARAR waiver would be required to implement Alternative 4. Alternative 2 would
not comply with the relevant and appropriate groundwater quality standards. Alternative 9
would also not comply with the relevant and appropriate groundwater quality standards,
because the soils/sediments would not be cleaned up to a point where they would no longer
cause the entire aquifer (area of attainment) to meet these standards. Rather, under Alternative
9 soils/sediments would only be cleaned up to a point where groundwater would meet these
standards at a point of exposure a minimum of 500 feet downgradient of the site. Alternatives
2, 3, and 4 would not conform with the CERCLA preference for treatment.
Long-term Effectiveness and Permanence. Alternative 6 would reduce the hazards posed
-by the soils/sediments by fixating the arsenic in the most heavily contaminated materials and
biologically treating the soils/sediments most heavily contaminated with organic chemicals The
long-term risk of exposure to the treated soils/sediments would be reduced by placing these
materials in an offsite landfill. Potential future exposure to the less contaminated materials would
be addressed by the following engineering and institutional controls: removing soils/sediments
that can contaminate groundwater from the saturated zone and offsite locations; consolidating
the excavated materials; capping the soils which present the potential for exposure in the
future; and placing deed restrictions on capped areas.
Alternatives 7 and 8 would be slightly more protective than the Alternative 6, in that a slightly
higher percentage of the organic contamination in the "principal threat1 soils/sediments would
be destroyed. On the other hand, Alternative 8 would be less protective than the Alternatives
5, 6, and 7 since the treated wastes would not be contained in a landfill. Alternative 5 would
be less effective than Alternatives 6, 7, and 8 since the organic contaminants in the most
heavily contaminated soils would be immobilized rather than destroyed.
Alternatives 5, 6, 7, and 8 would be less protective of human health and the environment than
Options A (clean closure) and B of Alternative 4, because the approximately 39,000 CY of
soils/sediments which contain contaminant concentrations less than the "principal threat" action
levels but greater than the groundwater-based unsaturated soil action levels would remain on
site, and there is the potential for the containment (capping) system to fail from sinkhole
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formation, erosion, or other causes. The onstte containment system would require long-term
maintenance, and portions of it might need to be replaced in the future. (A groundwater
monitoring system would be placed around the capped areas to assess the effectiveness of
the remedy.) If deed restrictions are not effective, direct exposure to the wastes in the future
could result from construction activities.
Alternatives 5, 6, and 7 would be more effective in the long-term than Alternatives 2 and 3,
since the most heavily contaminated ("principal threat") soils/sediments would be both treated
and landfilled off site. Alternatives 5, 6, 7, and 8 would be more permanent than Alternative 4,
since the heavily contaminated soils would be treated prior to offsite disposal.
Alternative 9 would be less effective in the long term than Alternatives 5, 6, 7, and 8. Under
Alternative 9, either no remediation other than soil capping and institutional controls would
occur, or soil flushing would be imptemented on the most contaminated soils. If only soil
capping/institutional controls occur, the alternative would essentially be the equivalent of
Alternative 2, and would not be effective in the long-term. If the maximum soil flushing
expansion occurs, an undefined quantity of soils would be treated to reduce their contaminant
concentration. This quantity could potentially exceed the quantity to be treated under
Alternatives 5, 6, 7, and 6. For the soils to be treated under Alternative 9, treatment would only
occur until a point where leachate concentrations would not cause groundwater to exceed
MCLs at an unspecified point at least 500 feet beyond the site boundary. In the absence of
MCLs, the former owners advocate the use of a 1 x 1(H excess lifetime cancer risk-based
cleanup level for carcinogens and a Hazard Quotient of 1 for non-carcinogens. EPA has
determined that, in the absence of MCLs, a 1 x 1CT6 excess lifetime cancer risk-based standard
is appropriate for groundwater. Given the site-specific conditions, EPA has determined that
cleaning up groundwater at the Whitmoyer Laboratories Site to a 1 x 1CT4 excess lifetime
cancer risk-based level, in the absence of MCLs, is not protective of human health
Additionally, EPA has determined that contaminant concentrations should be reduced below
MCLs (where they exist for the contaminants) in the entire aquifer, and not just for portions of
the aquifer at a significant distance downgradient of the site. Thus, residual risks would be
higher under Alternative 9 than under Alternatives 5. 6, 7, and 8.
If the maximum soil flushing expansion occurs, there is a significant risk that some of the
leaching solution escaping the well capture network (because of the site's complex
hydrogeology) and contaminating downgradient groundwater. If soil flushing is implemented.
the flushing duration can not be specified, because the former owners did not specify a
soil/sediment cleanup level. Rather, they specified that soils/sediments would be treated until
the effect of leachate on groundwater would not exceed MCLs at the point of exposure (A
realistic exposure point is more than 500 feet from the site boundary according to the former
owners.) Using the former owner calculations, it would take 10,000 to 24,000 years for the
maximum soil flushing option for soils to be cleaned up to a point where their leachate
concentration would meet MCLs. (See the discussion in the attached Responsiveness
Summary.) Thus, the soil flushing treatment duration would likely be very lengthy. During this
period, the groundwater capture network would have to be operated to protect current or
potential future downgradient groundwater users.
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Reduction of Toxictty, Mobility, or Volume of the Contaminants Through Treatment.
Alternatives 5, 6, 7, and 8 would treat the heavily contaminated soils to reduce toxicity, mobility,
or volume. Alternative 6 would reduce the mobility of the arsenic in the wastes by fixation with
iron, and would reduce the toxicity of the soils/sediment heavily contaminated with organics by
(biologically treating (destroying) these contaminants. Alternatives 7 and 8 would eliminate the
toxicity of the organic contaminants in the wastes by thermal destruction, and would reduce
the mobility of arsenic by fixation for Alternative 7 and encapsulation in a glass matrix for
Alternative 8. Alternative 5 would reduce the contaminant mobility by fixation with iron and
activated carbon.
It is uncertain what quantity of soils/sediments would be treated under Alternative 9. If no full-
scale flushing is implemented, only a minor reduction of contaminant mobility and toxicity would
be realized during the 3-year treatability study. If the maximum expansion is implemented, the
soils would only be treated until a point where leachate concentrations would not cause
groundwater to exceed MCLs at an unspecified point at least 500 feet beyond the site
boundary. Some additional reduction in mobility would result from the capture and treatment
of contaminants. However, the mobility of the contaminants in the treated soils/sediments
would remain higher under Alternative 9 than under Alternatives 5, 6, 7, and 8.
No reduction in toxicity, mobility, or volume is realized for Alternatives 2, 3, and 4. Disposal
without treatment is the least preferred option under CERCLA.
Short-term Effectiveness. Under Alternatives 5 and 6, there would be a minimal increase in
short-term worker exposure risk during the excavation, treatment, and capping steps. The
community would also have a minimal short-term exposure risk from fugitive dust, erosion and
runoff, and transport of the treated wastes off site. These risks would be minimized by safe
operating practices. Similarly, Alternatives 2, 3, and 4 would only pose minimal short-term risks
There is a potential risk associated with arsenic volatilization under Alternatives 7 and 8 This
risk would be reduced to acceptable levels by the use of specialized air pollution control
equipment.
All of the alternatives except Alternatives 2 and 9 include a temporary stream relocation
program. The Tulpehocken Creek ecosystem would be moderately impacted during this
program. These effects would be minimized by employing sound ecological practices.
Alternative 6 would be implemented within an estimated 5 years from the remedy selection date
This timeframe is necessary for efficient biological treatment of the soils/sediments heavily
contaminated with organic chemicals. All other alternatives, with the exception of Alternative
9. would require much shorter timeframes (2 to 3 years).
Full-scale treatment under Alternative 9 would not commence for a minimum of 3 years. During
this time groundwater contamination would continue and the potential for surface runoff
contamination and direct contact exposure would remain. The timeframe for completion of
Alternative 9 depends on whether or not full-scale flushing is implemented, and the target
cleanup level of the flushing effort if implemented. If no full-scale flushing is implemented (only
soil capping and placement of institutional controls occurs), the remediation could be
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completed 2 to 3 years after completion of the soil flushing demonstration program. If soil
flushing is implemented, the flushing duration can not be specified, because the former owners
did not specify a soil/sediment cleanup level. Rather, they specified that soils/sediments would
be treated until the effect of leachate on groundwater would not exceed MCLs at the point of
exposure. (A realistic exposure point is more than 500 feet from the site boundary, according
to the former owners.) Using the former owner calculations, it would take 10,000 to 24,000
years for the maximum soil flushing option for soils to be cleaned up to a point where their
leachate concentration would meet MCLs. (See the discussion in the attached Responsiveness
Summary.) Thus, the soil flushing treatment duration would likely be very lengthy.
If the maximum soil flushing expansion occurs, there is a significant risk that some of the
leaching solution escaping the well capture network (because of the site's complex
hydrogeology) and contaminating downgradient groundwater during implementation. During
soil flushing, the groundwater capture network would have to be operated to protect current
or potential future downgradient groundwater users.
ImplementabilMy. The various alternatives have few associated administrative difficulties that
coutd delay implementation. Permits would be required for the offsite disposal of the treated
materials (Alternatives 5, 6, 7, and 9) or untreated wastes (Alternative 4). The iron fixation
process utilized by Alternatives 5 and 6 and the soil flushing program of Alternative 9 are
relatively unproven on a large scale. However, remediation equipment and specialists are
readily available. Biological treatment of soils heavily contaminated with arsenic is also
relatively unproven. These processes have been proven on a small scale basis. The iron
fixation treatability study conducted during the RI/FS indicated that the iron fixation step
immobilized the soluble arsenic in the soils and allowed biological processes to occur. Bench-
scale optimization studies would be required prior to implementation of Alternatives 5, 6, and
7 to optimize reagent dosages and operating conditions. A 3-year pilot-scale treatability study
would be required prior to implementation of Alternative 9. For Alternatives 7, and 8, treatment
equipment and skilled workers would be available but limited. For Alternative 4, hazardous
waste disposal facilities are available but limited. The technology, equipment, and specialists
required to implement Alternatives 2, 3, 4, 5, 6, and 9 would be readily available. For all of the
alternatives, monitoring of air and water during implementation would be required. For
Alternatives 5 through 9. monitoring of the treated wastes would also be required. Process
monitoring would be especially important for Alternative 9, since heavily contaminated leaching
solution could escape the containment system and contaminate groundwater. Long-term
groundwater monitoring would be required for all of the alternatives except Option A of
Alternative 4, to establish the continued viability of the alternative.
Cost. The lowest-cost alternative is Alternative 2 at $4,450,000. The highest cost alternative
is Alternative 4A, at $80,000,000. The other FS alternative costs are presented in the alternative
description sections.
State Acceptance. The Commonwealth of Pennsylvania supports the selection of Alternative
6.
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Community Accepter A public meeting on the Proposed Plan was held August 1 in
Lebanon County, Penr .vania. Comments received from the public during the comment
period are referenced in the Responsiveness Summary attached to this Record of Decision.
B. SUMMARY OF ALTERNATIVES - GflOUNDWATER
Alternatives 1 through 4 for the groundwater are numbered to correspond with the numbers in
the first FS report (2/90). Alternative 5 is the alternative presented by the former site owners.
The alternatives are the following:
* Alternative 1: No Action
* Alternative 2: Plume Containment
* Alternative 3: Extraction (As > 1,000 ug/l)/ Physical. Chemical, (and Biological)
Treatment/Discharge
* Alternative 4: Extraction of All Contaminated Groundwater/Physical, Chemical, (and
Biological) Treatment/Discharge
* Alternative 5: Phased Approach
1. Alternative 1: NO ACTION
Under the Superfund program, the "no action" alternative is required to be evaluated at every
site to establish a baseline for comparison with the other alternatives. For this alternative, EPA
would take no actions other than monitoring groundwater annually and performing reviews
every 5 years. Alternative 1 would not comply with the relevant and appropriate groundwater
quality ARARs ( §£., the SDWA MCL of 50 ug/l arsenic and the state hazardous waste
regulation requirement of cleaning up groundwater to background concentrations). While no
capital costs would be incurred under this alternative, annual operation & maintenance (O&M)
costs are estimated to be $13,400. This alternative has a present-worth cost of $200,000, and
can be implemented immediately.
2. Alternative 2: PLUME CONTAINMENT
Under Alternative 2, a network of groundwater collection wells would be established near the
perimeter of the contaminated groundwater plume. These wells would be operated to only
remove enough groundwater from the aquifer to keep the contaminant plume from growing
Fracturing methods (e.g.. hydrofracturing or blasting) could be used to enhance the
groundwater removal system. An estimated 150 gallons per minute (GPM) of groundwater
would be removed.
The extracted groundwater would be treated in an onstte treatment plant constructed and
operated in compliance with 40 CFR 264.600 et sea. The treatment plant would utilize physical,
chemical and possibly biological processes. Bench-scale studies would be conducted prior
to full-scale design, to optimize the treatment process and determine if biological treatment
would be appropriate. An extensive aquifer testing program would also be required prior to
design of the treatment plant. The treated water would either be discharged to Tulpehocken
Creek (creek discharge option), reinjected into the aquifer (reinjection option), or disposed
using a combination of the two methods. Treated water disposal would comply with all ARARs
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[££., Pennsylvania water quality standards (25 PA Code, Chapter 93) and Pennsylvania
wastewater discharge standards (25 PA Code, Chapter 92)]. Treatment plant residuals would
be considered residual wastes under Pennsylvania law (25 PA Code, Chapter 75). These
residuals would be landfilled offsite in an intermediate (residual waste) landfill. Offsite landfill
disposal would comply with all disposal ARARs. If the treatment plant includes an air stripping
unit, this unit would be operated to comply with the relevant and appropriate NAAQS (40 CFR
Part 50) for ozone.
As no attempt to actively clean up the aquifer would be made under Alternative 2, the relevant
and appropriate requirements of the SDWA MCLs (40 CFR Part 141) and the state hazardous
waste regulations requirement (25 PA Code, Chapter 75, Part 264) of cleaning up the entire
aquifer to background concentrations would not be met. Thus, ARAR waivers would be
required to implement this alternative. Compliance with the state regulation is technically
impracticable. Groundwater monitoring would be conducted during the remediation period in
compliance with 40 CFR 264.101. Residences with potentially affected potable water supply
wells would be included in the monitoring program to ensure contaminated groundwater has
not bypassed the containment system to pose an exposure threat. Deed restrictions would be
placed on the contaminated aquifer to restrict its use.
Alternative 2 would comply with the CERCLA preference for a remedy that employs treatment
to reduce toxicity, mobility, or volume as a principal element. The estimated capital costs of
this alternative are $6,000,000 for the creek discharge option and $7,720,000 for the rejection
option. Annual O&M costs are estimated to be $1,000,000 for the creek discharge option and
$1,040,000 for the reinjection option. The estimated present-worth costs of this alternative are
$21,400,000 and $23,600,000 for the creek discharge and reinjection options, respectively The
estimated time to implement this alternative is approximately 2.5 years.
3. Alternative 3: EXTRACTION (As > 1,000 ug/l)/PHYSICAL, CHEMICAL, (AND BIOLOGICAL)
TREATMENT/DISCHARGE
A network of groundwater collection wells would be established throughout the most
contaminated part of the contaminated groundwater plume. These wells would be operated
to remove groundwater from the portion(s) of the aquifer with arsenic concentrations of 1.000
ug/l or greater (i.e., the most contaminated groundwater). These portion(s) of the contaminated
aquifer contain approximately 98% of the contaminant mass. Fracturing methods (e q
hydrofracturing or blasting) could be used to enhance the groundwater removal system An
estimated 300 gallons per minute (GPM) of groundwater would be removed.
The extracted groundwater would be treated in an onsite treatment plant constructed and
operated in compliance with 40 CFR 264.600 et sea. The treatment plant would utilize physical
chemical and possibly biological processes. Bench-scale studies would be conducted prior
to full-scale design, to optimize the treatment process and determine if biological treatment
would be appropriate. An extensive aquifer testing program would also be required prior to
design of the treatment plant. The treated water would either be discharged to Tulpehocken
Creek (creek discharge option), reinjected into the aquifer (reinjection option), or disposed
using a combination of the two methods. Treated water disposal would comply with all ARARs
tea.. Pennsylvania water quality standards (25 PA Code, Chapter 93) and Pennsylvania
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wastewater discharge standards (25 PA Code. Chapter 92)]. Treatment plant residuals would
be considered residual wastes under Pennsylvania law (25 PA Code, Chapter 75). These
residuals would be landfilled off site in an intermediate (residual waste) landfill. Offsite landfill
disposal would comply with all disposal ARARs. If the treatment plant includes an air stripping
unit, this unit would be operated to comply with the relevant and appropriate NAAQS (40 CFR
Part 50) for ozone.
As no attempt to actively clean up the portion of the aquifer with arsenic concentrations less
than 1,000 ug/l would be made under Alternative 3, the relevant and appropriate requirements
of the SDWA MCLs (40 CFR Part 141) (Table 1) and the state hazardous waste regulations (25
PA Code, Chapter 75, Part 264) would not be met. Thus, ARAR waivers would be required to
implement this alternative. Groundwater monitoring would be conducted during the remediation
period in compliance with 40 CFR 264.101. Deed restrictions would be placed on the
contaminated aquifer to restrict its use.
Alternative 3 would comply with the CERCLA preference for a remedy that employs treatment
to reduce toxicity, mobility, or volume as a principal element. The estimated capital costs of
this alternative are $12,900,000 for the creek discharge option and $16,000,000 for the
reinjection option. Annual O&M costs are estimated to be $2,020,000 for the creek discharge
option and $2,070,000 for the reinjection option. The estimated present-worth costs of this
alternative are $43,800,000 and $47,600,000 for the creek discharge and reinjection options.
respectively. The estimated time to implement this alternative is approximately 2.5 years
4. Alternative 4: EXTRACTION OF ALL CONTAMINATED GROUNDWATER/PHYSICAL
CHEMICAL, (AND BIOLOGICAL) TREATMENT/DISCHARGE
The goal of Alternative 4 is to return the entire contaminated aquifer to its beneficial use as
soon as is practicable. To accomplish this, a network of groundwater collection wells would
be established throughout the contaminated groundwater plume. These wells would be
operated to remove essentially all groundwater from the aquifer with concentrations above the
remedial action levels (e.g.. 50 ug/l arsenic). Fracturing methods (e.g.. hydrofractunng or
blasting) could be used to enhance the groundwater removal system. An estimated 600
gallons per minute (GPM) of groundwater would be removed; however, the size of the treatment
system and associated pumping and piping systems will be determined duing the Remedial
Design Phase of project implementation. Although the Feasibility Study and Proposed Plan
specified certain pumping and treatment rates, optimization of the chosen system during design
will ensure that the minimum required pumping and treatment rates will be utilized for the
Remedial Action. Accordingly, capital and operation and maintenance costs will also be
minimized.
The extracted groundwater would be treated in an onsite treatment plant constructed anc
operated in compliance with 40 CFR 264 et seq. The treatment plant would utilize physical
chemical and possibly biological processes. Bench-scale studies would be conducted pncr
to full-scale design, to optimize the treatment process and determine if biological treatment
would be appropriate. An extensive aquifer testing program would also be required prior :c
design of the treatment plant. The treated water would either be discharged to Tulpehocker
Creek (creek discharge option), reinjected into the aquifer (reinjection option), or disposer
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using a combination of the two methods. Treated water disposal would comply with all ARARs
[e.g.. Pennsylvania water quality standards (25 PA Code, Chapter 93) and Pennsylvania
wastewater discharge standards (25 PA Code. Chapter 92)]. Treatment plant residuals would
be considered residual wastes under Pennsylvania law (25 PA Code, Chapter 75). These
residuals would be landfilled off site in an intermediate (residual waste) landfill. Offsite landfill
disposal would comply with all disposal ARARs. If the treatment plant includes an air stripping
unit, this unit would be operated to comply with the relevant and appropriate NAAQS (40 CFR
Part 50) for ozone.
Alternative 4 would comply with all ARARs, including the relevant and appropriate MCLs (40
CFR Part 141), with the sole exception of the relevant and appropriate state hazardous waste
regulation requirement (25 PA Code, Chapter 75, Part 264) of cleaning up the entire aquifer to
background concentrations. Compliance with this regulation is technically impracticable A
waiver for this ARAR would be required to implement Alternative 4. Deed restrictions would be
placed on the contaminated aquifer to restrict its use.
Alternative 4 would comply with the CERCLA preference for a remedy that employs treatment
to reduce toxicity, mobility, or volume as a principal element. The estimated capital costs of
this alternative are $15,600,000 for the creek discharge option and $19,800,000 for the
reinjection option. Annual O&M costs are estimated to be $2,390,000 for the creek discharge
option and $2,470,000 for the reinjection option. The estimated present-worth costs of this
alternative are $52,300,000 and $57,700,000 for the creek discharge and reinjection options.
respectively. The estimated time to implement this alternative is approximately 2.5 years.
Alternative 5: PHASED APPROACH
[Note: the former owners submitted an initial groundwater proposal to EPA in February 1990
The former owners submitted supplemental information describing the former owners
groundwater proposal in more detail to EPA on September 14, 1990. This alternative
description, as well as the rest of this Record of Decision, incorporates the new supplemental
information.]
Under the former owner's proposal (Alternative 5), a 3-year large-scale pilot program would be
implemented. During the 3-year period, the pumping system and treatment facility would be
initially operated. According to the former owners, the objectives of the pilot program include
providing all the necessary data to select and design a final groundwater remedy;
In the first year of the 3-year program, an onsite groundwater recovery well network and
groundwater treatment system would be designed, installed, and tested. The recovery well and
treatment system would be operated during the second and third years of the program Also.
during the second year, offsite monitoring wells would be installed and tested. In the third year
these wells would be monitored.
The ecovery well and treatment system would be operated at approximately 120 gpm The
system operation would only pump and treat the most contaminated groundwater. The
extracted groundwater would be physically and chemically treated to remove contaminants
Portions of the groundwater would be reinjected into the aquifer or used for soil flushing, while
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the remainder would be discharged to Tulpehocken Creek. Up to 40 wells would be installed
to establish the otfsite monitoring well system.
Other than monitoring, offsite groundwater would be unaddressed; the contaminant plume
would continue to grow during the 3-year period. The relevant and appropriate groundwater
quality ARARs [MCLs (40 CFR Part 141)] (Table 1), and the state hazardous waste regulation
requirement (25 PA Code, Chapter 75, Part 264) of cleaning up the entire aquifer to
background concentrations would not be met during the pilot program. Thus, ARAR waivers
would be required to implement this alternative. Deed restrictions would be placed on the
contaminated aquifer to restrict its use during the pilot program.
Once the 3-year pilot program is completed, the final groundwater remedy would be selected
and the long-term (Phase II) groundwater remediation program implemented. According to the
former owners, the objectives of the long-term program are to provide for removal and
treatment of arsenic and other contaminants from groundwater that has become contaminated;
to protect human health by preventing exposure to groundwater above MCLs; to serve as a
collector system for soil flushing leachate; and to provide a source of water for the soil flushing
program. Specific groundwater remediation objectives (e.g, restore contaminant concentrations
in the entire area of attainment to MCLs or 1 x 1CT6 excess lifetime cancer risk-based levels)
were not specified by the former owners.
The former owners anticipate that the Phase II program would be an expansion of the Phase
I program, with a more extensive network of pumping wells. A long-term groundwater pumping
rate of 300 to 400 gallons per minute is expected, with the actual rate determined based upon
Phase I data. The system would pump and treat groundwater only from the most highly
contaminated (undefined) part of the plume. It is unclear how long the long-term pump-and-
treat system would operate. In one place the former owners stated the system would operate
up to 27 years. In another place they stated it would be operated until groundwater
remediation goals were achieved.
If groundwater is extracted from only the most contaminated portion of the plume (and is not
extracted from the entire contaminant plume), Alternative 5 would not comply with the
groundwater relevant and appropriate requirement of 50 ug/l arsenic for the entire groundwater
plume area of attainment, and possibly not with the pertinent relevant and appropriate MCLs
for organic chemicals. The portion of the aquifer unaddressed by the extraction system that
contained contaminant concentrations in excess of MCLs would be expected to grow over time
The former owners estimate the total cost of their pilot-scale program, including two years of
O&M, at $5,500,000. The former owners estimate that the present worth cost of the long-term
groundwater pump-and-treat program, including 27 years of O&M, at $34,000,000. Thus the
former owners' estimated total cost of Alternative 5 is $39,500,000.
6. COMPARATIVE ANALYSIS OF ALTERNATIVES - GROUNDWATER
The five groundwater remedial action alternatives described above were evaluated using the
nine criteria in the NCP. The evaluations are as follows:
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Overall Protection. Alternative 4 would provide adequate protection of human health and the
environment by collecting and treating the entire contaminated groundwater plume, although
the remediation time may well exceed 30 years. Alternative 2 would be less protective, since
it is heavily dependent on deed restrictions and monitoring to prevent exposure. Under
Alternative 2. offsite groundwater quality would deteriorate in the near-term. If the plume
containment (capture) system is incomplete, increasing amounts of contaminants would escape
the containment system over time.
Alternatives 3 and 5 would be less protective than Alternative 4, since not all of the
contaminated groundwater would be extracted. The groundwater contaminant plume would be
allowed to grow over time. Unlike Alternative 2, Alternatives .3 and 5 would remove the most
heavily contaminated groundwater from the aquifer. However, Alternative 2 would keep the
contaminant plume from growing.
Since the remedial action objectives (cleanup levels) under Alternative 5 were not specified, they
can not be compared with those for Alternatives 2-4. For groundwater-based soil cleanup
levels, the former owners advocate the use of a 1 x 1CT4 excess lifetime cancer risk-based
cleanup level for carcinogens and a Hazard Quotient of 1 for non-carcinogens in the absence
of MCLs. EPA has determined that, in the absence of MCLs, a 1 x 1CT6 excess lifetime cancer
risk-based standard is appropriate for groundwater. Given the site-specific conditions, EPA has
determined that cleaning up groundwater at the Whitmoyer Laboratories Site to a 1 x 10~4
excess lifetime cancer risk-based standard is not protective of human health.
The "no action" alternative is not protective of human health and the environment; therefore, it
is not considered further in this analysis as an option foMhe groundwater.
Regulatory Compliance. Alternative 4 would meet all' of its applicable and relevant and
appropriate requirements, including the relevant and appropriate SDWA MCLs (40 CPR Part
141) (Table 1), with the sole exception of the state relevant and appropriate requirement of
cleaning up to background (25 PA Code, Chapter 75, Part 264). Since compliance with this
ARAR is technically impracticable, an ARAR waiver is justified. Under Alternatives 2 and 5, the
entire contaminated groundwater plume would not comply with the relevant and appropriate
SDWA MCLs, as well as the state requirement of cleaning up to background. Under Alternative
3, the unremediated portion of the contaminated groundwater plume containing less than 1.000
ug/l would not comply with the relevant and appropriate SDWA MCLs, and the entire plume
would not comply with the state background requirement. Thus, a waiver o1 the SDWA MCL
ARAR would be required to implement all of the alternatives except Alternative 4; and a waiver
of the state background requirement would be required for all of the alternatives. A waiver of
the state background requirement is justifiable because of technical impracticability. AM of the
alternatives would conform with the CERCLA preference for treatment.
Long-term Effectiveness and Permanence. If Alternative 4 proved to be technically
practicable, risks from the groundwater would be virtually eliminated, although the remediation
timeframe may exceed 30 years. Proper disposal of treatment residuals would prevent ft -e
risks. Alternative 2 would be less effective in the same timeframe as Alternative 4, as much
less contamination would be removed from the aquifer, and contamination would continue to
39
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migrate off site and deteriorate offsite groundwater quality. Continued expansion of the
groundwater plume would be controlled by the groundwater extraction system. Under
Alternative 3, migration of the most contaminated portion of the groundwater plume would be
controlled by the extraction system. This portion would be actively remediated. However, the
less contaminated portion of the plume would be allowed to expand over time and pose future
hearth risks.
Since a final remedy would not be selected at this time under Alternative 5, the long-term
effectiveness of this alternative can not be completely discussed. The pilot-scale program
making up Alternative 5 is intended to evaluate the potential for both active remediation and
containment of the contaminated groundwater. The former owners propose to only pump and
treat groundwater from the most contaminated portion of the groundwater plume. Apparently
the less contaminated portion of the plume would be allowed to expand over time and continue
to pose future health risks.
Reduction of Toxicrty, Mobility, or Volume of the Contaminants Through Treatment.
Alternative 4 would reduce the toxicity, mobility, and volume of the contamination present in the
groundwater. The contaminant mobility would be reduced by the collection system and
treatment of the extracted contaminants to destroy the organic contaminants and immobilize
the arsenic in a relatively insoluble chemical precipitate. Contaminant toxicity would be reduced
by organic destruction. The volume of contaminated groundwater would be significantly
reduced over time.
Under Alternative 2, contaminant mobility would be reduced somewhat by the containment
system and the treatment of the extracted contaminants. However, the extraction system would
be less aggressive than the Alternative 4 system, and significantly less quantities of
contaminants would be removed for treatment in equivalent timeframes. Contaminant toxicity
would be reduced somewhat by the organic destruction. There would be no reduction in
contaminated groundwater volume, since active remediation of the groundwater plume would
not be attempted.
Under Alternative 3, approximately 50% of the groundwater plume containing approximately 98%
of the groundwater contaminants would be actively remediated. However, the volume of
contaminated groundwater would increase over time as the unaddressed groundwater plume
expands.
The former owners do not specify what portion of the contaminated aquifer would be actively
remediated under their program (Alternative 5). An estimated 300 to 400 gallons per minute
would be withdrawn, significantly less than the estimated 600 gallons per minute under
Alternative 4. The former owners also stated that only the most highly contaminated pan ol
the plume would be pumped and treated. Apparently the less contaminated part of the plume
would be unaddressed by the pump-and-treat program. If this is the case, the volume of
contaminated groundwater would increase over time as the unaddressed plume expands
Short-term Effectiveness. Alternative 4 would have a high degree of short-term effectiveness
Complete remediation of the groundwater may take more than 30 years, however. Alternative
2 would be less effective in the short-term, as contaminant concentrations in the offsite
40
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groundwater would be allowed to increase over time. If the plume capture system is
incomplete (which is a significant possibility considering the complex hydrogeologic setting of
the site), increasing amounts of contaminants would escape the containment system over time.
Discharge of groundwater contaminants to surface water could also increase over time. The
remediation timeframe would be significantly longer than for Alternative 4.
Because Alternatives 3 and 5 allow the contaminant plume to increase over time, these
alternatives are less reliable than Alternative 4. The remediation timeframe for Alternative 3 is
comparable to the Alternative 4 timeframe and less than the timeframe for Alternative 2.
Because Alternative 5 does not specify the final groundwater remedy, its remediation timeframe
can not be discussed.
Impfementabillty. There is a concern whether achieving the groundwater cleanup goals is
technically feasible. The proposed groundwater treatment technologies for all of the alternatives
are highly reliable. The various alternatives have few associated administrative difficulties that
could delay implementation. Permits would be required for the offsite disposal of the treatment
residuals. The equipment, specialists, and treatment/disposal facilities necessary to implement
the alternatives are readily available. Bench-scale treatment optimization studies would be
required prior to implementation of all of the alternatives to optimize reagent dosages and
operating conditions. Additionally, an aquifer testing program would be required for all of the
alternatives to permit more accurate estimation of the required treatment plant capacity. For
all of the alternatives, monitoring of air, groundwater, surface water, and the treatment residuals
during implementation would be required. Groundwater monitoring would be especially
important for the plume containment option (Alternative 2), since heavily groundwater could
escape the containment system and further contaminate groundwater.
Cost. The estimated present-worth costs of Alternative 4 for the groundwater are $52,300,000
and $57,700,000 for the creek discharge and reinjection options, respectively. Alternative 4 is
the highest cost alternative. The lowest-cost alternative is Alternative 2 at $21,400,000 (creek
discharge option). The other alternative costs are presented in the alternative description
sections.
State Acceptance. The Commonwealth of Pennsylvania supports the selection of Alternative
4, with the contingent remedy of Alternative 2.
Community Acceptance. A public meeting on the Proposed Plan was held August 1 in
Lebanon County, Pennsylvania. Comments received from the public during the comment
period are referenced in the Responsiveness Summary attached to this Record of Decision
VIII. THE SELECTED REMEDY
Based upon consideration of information available for Operable Unit Three of the Whitmoyer
Laboratories Site, including the documents available in the Administrative Record, an evaluation
of the risks currently posed by the site, the requirements of CERCLA, the detailed evaluation
of alternatives, and community input; both EPA has selected the following alternatives as the
remedy to be implemented for the operable unit.
41
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A. SOILS/SEDIMENTTS
Alternative 6 - Iron-based fixation of the "principal threat" soils/sediments; biological treatment
of the soils/sediments which contain organic chemicals in concentrations greater than the
"principal threat" organic action levels; onsrte consolidation of the soils which pose a threat to
groundwater but contain contaminant concentrations less than the "principal threat" action
levels, followed by capping with impermeable materials; and soil capping of the lightly
contaminated surface soils. The "principal threat1 soils/sediments would be treated to comply
with RCRA land disposal restrictions; to reduce the arsenic mobility, as measured by the TCLP,
by at least 90%; and to reduce the organic contaminant concentrations to the "principal threat"
soil action levels (biologically treated soils only), prior to being landfilled at an offsite disposal
facility.
B. GROUNDWATER
Alternative 4 - Extraction of all contaminated groundwater, followed by physical, chemical and
possibly biological treatment and discharge of the treated water to reinjection wells and/or
Tuipehocken Creek. Based on current information, this alternative appears to provide the best
balance of trade-offs among the groundwater alternatives with respect to nine criteria that EPA
uses to evaluate alternatives.
There is a moderate degree of uncertainty over whether the selected remedy will be able to
meet the groundwater health-based cleanup levels identified by the EPA. It may potentially
prove technically impracticable to achieve the health-based groundwater cleanup goals under
the selected remedy for the groundwater. It will be difficult to predict the ultimate
concentrations to which contaminants in the groundwater may be reduced until the Alternative
4 extraction system has been operating for some period of time. If information emerges from
the operation of the Alternative 4 extraction system that strongly suggests that it is technically
impracticable to achieve the cleanup goals throughout the contaminated groundwater plume
because of an observed "leveling-off" of contaminant concentrations, the EPA, in consultation
with the Commonwealth of Pennsylvania, intends to select the contingent remedy of Alternative
2 in those areas where the cleanup goals will not be met. Alternative 2 would involve extracting
groundwater from the perimeter of the targeted groundwater plume only in sufficient quantities
to keep the plume from spreading. In other words, active remediation would not be attempted
The estimated present-value cost of this selected remedy is $77,300,000; as follows:
Medium Present-value Cost
Soils/Sediments $25,000,000
Groundwater $52.300.000
TOTAL COST $77,300,000
42
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The major components of the selected remedial action are as follows:
* Excavation of all moderately contaminated soils/sediments from offsite and saturated
onsite locations, and all heavily contaminated soils [estimated volume = 116,000
cubic yards (CY)].
* Demolition of Buildings 4, 9, 11. and 14.
* Backfilling of the excavated areas with clean fill or lightly contaminated soil.
* Onsite fixation of the approximately 61,000 CY of heavily contaminated
soils/sediments using an iron-based or other similar fixation process that provides
equivalent protection.
* Biological treatment of the approximately 5,600 CY of soils with organic chemical
concentrations above the heavily contaminated soil action levels either prior to or
following the fixation step.
* Consolidation of the moderately contaminated soils/sediments on site above the
groundwater table.
* Capping of the approximately 39,000 CY of moderately contaminated soils/sediments
having contaminant concentrations above groundwater-based unsaturated soil
cleanup targets with low-permeability materials.
* Soil capping of all soils/sediments remaining on the surface following the excavation
and consolidation steps that are not capped with low-permeability materials and
contain greater than 21 mg/kg arsenic; and other disturbed areas as needed.
* Grading and revegetation of all areas affected by the soil/sediment remediation
* Following the soils/sediments remediation, placement of deed restrictions on areas
with remaining contamination.
* Aggressive extraction of all groundwater from the aquifer beneath the site with
concentrations above health-based levels (e.g.. 50 ug/l arsenic) until the maxtmum
groundwater contaminant concentrations are alf less than health-based levels.
* Treatment of the extracted groundwater in an onsite treatment plant, utilizing
physical, chemical and possibly biological processes. The size of the treatment
system and associated pumping and piping systems will be determined during the
Remedial Design Phase of project implementation. Although the Feasibility Study
and Proposed Plan specified certain pumping and treatment rates, optimization of
the chosen system during design will ensure that the minimum required pumping
and treatment rates will be utilized for the Remedial Action. Accordingly, capital and
operation and maintenance costs will also be minimized.
43
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* Disposal of the treated water by either discharging it to Tulpehocken Creek,
reinjecting ft into the aquifer, or a combination of the two methods.
* Salvaging nonhazardous demolition debris, as feasible.
* Disposal of the following in off site landfill (s) in accordance with all applicable
regulations: the treated soils; the groundwater treatment residuals; and the
demolition debris that is not salvaged.
The selected remedy is the last of several phases in the long-term remediation of this site and
will be consistent with previously selected site remedies.
The contingent remedy is similar to the selected remedy, with the exception that groundwater
would only be extracted from the perimeter of the non-attainment area in sufficient quantities
to keep this area from growing. Additionally, contact with contaminated groundwater would be
restricted through the use of deed restrictions and an extensive groundwater monitoring
program.
These actions will significantly reduce or eliminate the actual and potential threats to human
health and the environment posed by the OU Three materials, and are consistent with EPA's
strategy for remediation of the site.
IX. STATUTORY DETERMINATIONS
Under its legal authorities, EPA's primary responsibility at Superfund sites is to undertake
remedial actions that are protective of human health and the environment. In addition, Section
121 of CERCLA establishes several other statutory requirements and preferences. These
specify that when complete, the selected remedial action (and the contingent remedial action)
for this site must comply with applicable or relevant and appropriate environmental standards
established under Federal and State environmental laws unless a statutory waiver is granted
The selected remedy and contingent remedy also must be cost-effective and utilize treatment
technologies or resource recovery technologies to the maximum extent practicable. Finally, the
statute includes a preference for remedies that permanently and significantly reduce the volume,
toxicity, or mobility of hazardous wastes. The following sections discuss how the selected
remedy and contingent remedy for this site meet these statutory requirements.
A. PROTECTION OF HUMAN HEALTH AND THE ENVIRONMENT
Based on the risk assessment developed for OU Three materials, actual or potential exposure
pathways include groundwater consumption, dermal contact, accidental ingestion, and
inhalation. The selected remedy addresses these risks (protects human health and the
environment) by reducing the mobility of the arsenic in the heavily contaminated soils using an
iron-based or other similar fixation process; destroying the organic contamination in the
soils/sediments that are heavily contaminated with organic chemicals by biological treatment,
consolidating and impermeably capping untreated soils which pose a threat to groundwater,
soil capping surface soils which pose only a direct contact threat; salvaging nonhazardous
demolition debris, as feasible; aggressively collecting and treating all contaminated groundwater
44
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(i.e., restoring the contaminated aquifer); and disposal of the treated soils/sediments, the
groundwater treatment residuals, and the untreated (nonhazardous) demolition debris that is
not salvaged in offsite landfill(s) to further reduce contaminant mobility and access to these
materials.
The selected remedy will not pose any unacceptable short-term risks or cross-media impacts
to the site, the workers, or the community. There will be some long-term risks associated with
leaving moderately and lightly contaminated soils/sediments at the site. However, these
materials wilt be capped, and access to these materials will be restricted by placing deed
restrictions on areas where they are present following the remediation. Since metals cannot be
destroyed, there will be some long-term risk associated with the heavy metal (primarily arsenic)
content of the heavily contaminated soils/sediments. However, these soils/sediments will be
treated prior to disposal to reduce the mobility of the heavy metals, and the treated
soils/sediments will be placed into an offsite landfill for proper long-term management.
The contingent remedy addresses the risks posed by the contaminated soils/sediments in the
same manner as the selected remedy. However, for the groundwater medium, active
restoration of the aquifer would not occur; only measures intended to keep the contaminant
plume from expanding would occur. The contingent remedy would protect human health and
the environment by halting plume expansion and restricting contact with contaminated
groundwater through the use of deed restrictions and groundwater monitoring.
B. ATTAINMENT OF APPLICABLE OR RELEVANT AND APPROPRIATE REQUIREMENTS
The selected remedy will attain all applicable or relevant and appropriate requirements for the
site, the OU Three materials, and the actions that will be implemented, with the exception of
the state action-specific requirement to remediate groundwater to background concentrations
(25 PA Code, Chapter 75, Part 264). This ARAR would be waived because of technical
impracticability. The contingent remedy for groundwater would also not comply with the
relevant and appropriate SDWA MCL chemical-specific ARAR. This ARAR would be waived
because of technical impracticability if the contingent remedy is elected by the EPA in the
future. The other major ARARs include the following:
* Action-Specific ARARs - Soil/sediment excavation activities will be in accordance with
Pennsylvania requirements for erosion control (25 PA Code, Chapter 102), and 4G
CFR 264.31. Remedial activities will be conducted in compliance with the Fish and
Wildlife Coordination Act (16 USC 661). The fixation, biological treatment, anc
groundwater treatment plants will be designed and operated in accordance wnh
RCRA Subtitle C miscellaneous treatment unit standards (40 CFR Part 264, Subpan
X). The treated soils/sediments and groundwater treatment residuals will be
monitored to ensure compliance with RCRA Subtitle C land disposal restrictions (40
CFR Part 268) (i.e., to ensure that the treated soils/sediments and groundwater
treatment residuals are nonhazardous), prior to disposal at an approved offsite
facility. Groundwater treatment will employ air monitoring as appropriate to ensjre
compliance with 55 FR No. 120, June 21, 1990 (page 25454). Capping cf
moderately contaminated soils/sediments onsite would be conducted to meet the
relevant and appropriate requirements of RCRA landfill closure in 40 CFR 264 3iC
45
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Materials transported offsite will meet the CERCLA otfsite disposal policy and comply
with Federal transportation regulations (40 CFR Parts 262 and 263; 49 CFR Parts
107 and 171-179) and Pennsylvania regulations (25 PA Code, Chapter 263) for
material transport. During contaminated soils/sediment removal and treatment, air
monitoring will be performed to ensure that any air emissions comply with Clean
Air Act (40 CFR Parts 50 and 61) and Pennsylvania air quality regulations (25 PA
Code, Chapters 123,127, and 131). OSHA requirements (29 CFR Parts 1904, 1910.
and 1926) will be met for workers engaged in remedial activities. The offsite
landfill accepting the treated soils/sediments, unsalvaged demolition waste, and
groundwater treatment residuals will comply with RCRA Subtitle D and state
industrial (solid) waste management regulations. Treated groundwater disposal will
comply with all ARARs fe.g.. Pennsylvania water quality standards (25 PA Code,
Chapter 93) and Pennsylvania wastewater discharge standards (25 PA Code,
Chapter 92)]. Long-term groundwater monitoring in compliance with 40 CFR
264.117 will also be conducted following implementation of the selected remedy.
Chemical-Specific ARARs - RCRA Subtitle C and Commonwealth of Pennsylvania
requirements for identification of characteristic hazardous wastes (40 CFR Part 261
and 25 PA Code, Chapter 261, respectively) will be complied with during the
remediation of OU Three materials. Groundwater will be remediate to the Maximum
Contaminant Levels specified in the Safe Drinking Water Act (40 CFR Part 141) if
technically practicable. Air emissions during remedial activities will be monitored
for compliance with Clean Air Act (40 CFR Parts 50 and 61) and Pennsylvania air
quality regulations (25 PA Code, Chapters 123,127, and 131). Clean Water Act (40
CFR Part 122) and Pennsylvania (25 PA Code, Chapter 92) direct discharge
standards would be met by the groundwater remediation.
Location-Specific ARARs - Remediation of the contaminated soils/sediments will be
conducted in accordance with the Federal Floodplains Management and Executive
Order (E.O. 11988).
Other Criteria, Advisories, or Guidance to be Considered- In determining acceptable
soil/sediment and groundwater remedial action levels EPA used advisory levels and
guidelines that are "to-be-considered" for the remedial actions. These are-
EPA-established reference doses for contaminants posing noncarcmogemc
threats to human health
EPA-established carcinogenic potency factor for contaminants posing
carcinogenic threats to human health
Proposed primary drinking water standards under the Safe Drinking Water
Act for tetrachtoroethene, benzo(a)pyrene, indeno(1,2,3-cd)pyrene, and
benzo(b)1luoranthene
The selected remedy will also comply with the Commonwealth of Pennsylvania
guidance document "Hazardous Waste and Petroleum Products Contamination
Cleanup Projects" which requires Best Available Technology for air strippers ana
other equipment designed to remove volatile organic chemicals from water
46
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The selected remedy satisfies the CERCLA preference for remedies that incorporate
treatment as a principal component.
C. COST-EFFECTIVENESS
The estimated present worth cost of the selected remedy for OU Three is $77,300,000. EPA
and the Commonwealth of Pennsylvania believe the selected remedy is cost-effective in
mitigating the risks posed by the OU Three materials in a reasonable period of time (an
estimated 5 years for the soils/sediments) and meets all other requirements of CERCLA.
Because groundwater concentrations in the entire area of attainment will be restored to health-
based levels if technically practicable, the majority of organic contaminants present in the OU
Three materials will be destroyed, the metal contaminants in the groundwater and "principal
threat" soils/sediments will be treated to reduce mobility, and the treated nonhazardous wastes
and demolition debris will be disposed in an appropriate landfill (or salvaged, as appropriate),
the selected remedy affords a high degree of long-term effectiveness and permanence.
Although the no-action alternative, the soil capping alternative (Alternative 2), and the
impermeable capping alternative (Alternative 3) can be implemented at lower costs than the
selected soil/sediment remedy, these alternatives do not provide for permanent treatment and
are not as effective in protecting human health and the environment. In addition, these
alternatives do not meet ARARs. Although the soil flushing program (Alternative 9) can be
implemented at lower costs than the selected soil/sediment remedy, this alternative is not as
effective in protecting human health and the environment. In addition, the alternatives does not
meet ARARs.
The no-action alternative, the plume containment alternative (Alternative 2), the extraction and
treatment of the most contaminated groundwater alternative (Alternative 3), and the phased
approach (Alternative 5) can be implemented at lower costs than the selected groundwater
remedy. However, these alternatives are less protective of human health and the environment.
do not meet the MCL ARAR or currently justify a waiver, and do not attempt to restore the
contaminated aquifer to its beneficial uses as soon as may be technically practicable. The
contingent groundwater remedy is less expensive than Alternatives 3 and 5, yet more expensive
than the no-action alternative. However, the no-action alternative is not protective of human
health and the environment and does not meet ARARs or justify a waiver. (If the criterion for
election of the contingent remedy is met, a waiver of the MCL ARAR would be justified)
D. PREFERENCE FOR TREATMENT AS A PRINCIPAL ELEMENT
By treating all of the OU Three soils/sediments that pose the principal threats to human health
and the environment and all contaminated groundwater, the selected remedy addresses the
principal threats posed by the OU Three materials through the use of treatment technologies
Therefore, the statutory preference for remedies that employ treatment as a principal element
is satisfied.
E. UTILIZATION OF PERMANENT SOLUTIONS AND ALTERNATIVE TREATMENT (OR
RESOURCE RECOVERY TECHNOLOGIES) TO THE MAXIMUM EXTENT PRACTICABLE
47
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EPA has determined that the selected remedial action represents the maximum extent to which
permanent solutions and treatment technologies can be utilized while providing the best
balance among the other evaluation criteria. Of the alternatives that are protective of human
health and the environment and meet ARARs. EPA has determined that the selected remedy
provides the best balance of trade-offs in terms of long-term effectiveness and permanence;
implementability; short-term effectiveness; reduction in toxicity, mobility, or volume through
treatment; state and community acceptance; and the CERCLA preference for treatment of the
soils/sediments and groundwater.
The selected remedy and contingent remedy addresses the principal threats posed by the OU
Three materials. The remedy is protective of human health and the environment, meets ARARs
or a waiver is justified, incorporates treatment as a principal element, and is cost-effective. The
major tradeoffs that provide the basis for the selection decision are long-term effectiveness and
permanence; reduction of toxicity, mobility or volume through treatment; short-term
effectiveness; and cost.
Of the soil/sediment alternatives which are protective of human health and the environment and
meet ARARs. Alternative 5 is less effective in the long-term and more expensive to implement
than the selected remedy. While Alternative 3 is less expensive than the selected remedy,
contaminant toxicity, mobility, or volume is not reduced through treatment. Although
Alternatives 4A and 4B are more effective in the long term than the selected remedy, these
alternatives are more expensive to fmplement and contaminant toxicity, mobility, or volume is
not reduced through treatment. Alternative 4C is less effective in the long term and more
expensive to implement than the selected remedy, and contaminant toxicity, mobility, or volume
is not reduced through treatment There is less short-term risk associated with the selected
remedy than for Alternative 7 (thermal treatment) and Alternative 8 (vitrification). These
alternatives are also significantly more expensive than the selected remedy, although they would
be slightly more effective. The soil flushing program (Alternative 9) can also be implemented
at a tower cost than the selected soil/sediment remedy. However, it appears likely that the
proposed soil flushing program would be impracticably lengthy. In-situ soil washing, as
proposed for the former owners, would also have the added disadvantages o1 possible loss
of the leaching fluid to the complex groundwater system. During the 3 years that a soils
remedy decision would be delayed, groundwater contamination would continue and the
potential for surface runoff contamination and direct contact with contaminated soils would
continue to exist. Alternative 9 would also not comply with the groundwater MCL ARAR
Based on the above evaluations, the selected remedy was determined to be the most
appropriate remedy for the soil/sediment medium of Operable Unit Three at the Whitmoyer
Laboratories Site.
The selected remedy for groundwater is the most protective of the groundwater alternatives
and is the only alternative which complies with the MCL ARAR. (This ARAR would be waived
because of technical impracticability if the contingent remedy is elected by the EPA in the
future.) Of the groundwater alternatives, the selected remedy attempts to restore me
contaminated aquifer to its beneficial uses as soon as may be technically practicable
Therefore, it would be the most effective alternative in the short term. Under Alternative 2
offsite groundwater contaminant concentrations would increase in the short-term For
48
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Alternatives 3 and 5, the contaminant plume would continue to grow in the short term. If the
selected remedy proves to be technically practicable, it would also be the most effective
alternative in the long-term. Alternative 2 would be less effective in the same timeframe as the
selected remedy, as much less contamination would be removed from the aquifer, and
contamination would continue to migrate off site and deteriorate offsite groundwater quality.
Under Alternative 3, the less contaminated portion of the plume would be allowed to expand
over time and pose future health risks. The former owners stated that only the most highly
contaminated part of the plume would be pumped and treated under Alternative 5. Apparently
the less contaminated part of the plume would be unaddressed by the pump-and-treat program.
If this is the case, the unaddressed plume of contaminated groundwater would continue to
expand over time and pose future health risks. Under Alternative 5, the groundwater remedy
decision would be delayed for 3 years, while a decision on whether to actively remediate or
contain groundwater is being made. During the 3-year pilot program, the plume will be
permitted to spread and pose future health risks. Thus, this alternative is not effective in the
short-term. Since a final remedy would not be selected at this time under Alternative 5, the
long-term effectiveness of this alternative is unclear. Sufficient information exists to evaluate the
groundwater alternatives options at this time. The remedial decision maintains the flexibility of
selecting a plume containment remedy in the future if cleaning up the aquifer to health-based
levels proves technically impracticable. Based on the above evaluations, the selected remedy
was determined to be the most appropriate remedy for the groundwater medium of Operable
Unit Three at the Whitmoyer Laboratories Site. If cleaning up the aquifer to health-based levels
proves technically impracticable, a provision for election of a contingency remedy (and the
waiver of the MCL ARAR) is made.
X. EXPLANATION OF SIGNIFICANT CHANGES
The Proposed Plan for Operable Unit Three at the Whitmoyer Laboratories Site was released
for comment in July 1990. The Proposed Plan identified EPA's preferred alternative. EPA
reviewed all of the comments submitted during the public comment period. Upon review of
these comments, it was determined that no significant changes to the remedy, as it was
originally identified in the Proposed Plan, were necessary.
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Appendix A
APPLICABLE OR RELEVANT AND APPROPRIATE REQUIREMENTS
OPERABLE UNIT THREE
WHITMOYBR LABORATORIES SITE
Standard, Requirement,
Criterion or Limitation,
Chemical-Specific ARAKa
RCM Hazardous Waste
Identification
Haiardoua Watte Identification
Safe Drinking Water Act (SDMA)
Maximum Contaminant Levels
(NCLs)
Clean Air Act (CAR) Air
Emissions
CAA Air Emissions
Air Quality Regulations
Clean Water Act Discharge
Standards
Direct Discharge Standards
Water Quality Standards
Location-Specific ARARs
Federal Floodplairn Management
Citation
40 CFR Part 261
Description
RCRA regulations for hazardous
waste identification
Discueaioa
Soil/sediment and
groundwater media
25 PA Code, Chapter 261 Pennsylvania regulations for Soil/sediment and
hazardous waste identification groundwater media
40 CFR Part 141
40 CFR Part 50
40 CFR Part 61
25 PA Code, Chapters
123, 127 and 131
40 CFR Part 122
25 PA Code, Chapter 92
25 PA Code, Chapter 93
Executive Order 119BB
SDWA primary and secondary
drinking water standards
Rational Ambient Air Quality
Standards
National Emissions Standards
for Hazardous Air Pollutants
Pennsylvania air quality
regulations
Clean Water Act standards for
direct discharges
Pennsylvania direct discharge
standards
Pennsylvania water quality
standards
Soil/sediment and
groundwatec media
Soil/sediment and
groundwater media
Soil/sediment inciner-
ation and vitrifi-
cation options only
Soil/sediment and
groundwater media
Soil/sediment and
groundwater media
Soil/sediment and
groundwater media
Soil/sediment and
groundwater media
Federal floodplains management Soil/sediment medium
regulations only
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Appendix A
APPLICABLE OR RELEVANT AND APPROPRIATE REQUIREMENTS
OPERABLE UNIT THREE
HHITMOYER LABORATORIES SITE
Page Two
Standard, Requirement,
Criterion or Limitation
action-Specific AKARa
RCRA Incineration
RCRA Niacellaneoua Treatment
U.S. Department of
Transportation (DOT) Haste
Transportation
RCRA Hazardous Haste
Transportation
Haste Transportation
Occupational Safety and Health
Administration (OSIIA) Asbestos
Management
OSHA Horker Protection
Citation
40 CFR Part 264
Subpart O
40 CPR Part 264,
Subpart X
49 CFR Parts 107 and
171-179
40 CFR Parts 262 and
263
Description
RCRA regulations Cor hazardous
vaste incinerators
RCRA regulations for
miscellaneous treatment units
DOT regulations for Haste
transport
RCRA regulations for the
transport of hazardous waste
25 PA Code, Chapter 263 Pennsylvania regulations Cor
waste transportation
29 CFR Part 1926
29 CFR Parts 1904,
1910, and 1926
RCRA Land Disposal Restrictions 40 CFR Part 268
RCRA Hazardous Waste Landfill
40 CFR Part 264,
Subpart N
OSHA regulations for asbestos
removal
OSHA regulations for the
protection of workers
RCRA restrictions on the land
disposal of hazardous waste
RCRA requirements for solid
waste landfills
Discussion
Soil/sediment
incineration option
only
Soil/sediment
fiMation,biotreatment,
and vitriCication
options, and ground-
water treatment
Soil/sediment and
groundwater media
Soil/sediment and
groundwater media
Soil/sediment and
groundwater media
Soil/sediment medium
only
Soil/sediment and
groundwater media
Soil/sediment and
groundwater media
Soil/sediment and
groundwater media
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Appendix A
APPLICABLE OR RELEVANT AND APPROPRIATE REQUIREMENTS
OPERABLE UNIT THREE
WHITMOYER LABORATORIES SITE
Page Three
Standard, Requirement,
Criterion or Limitation
Hction-Specific ABARs Icont*d)
RCRA Gioundwater Monitoring
RCRA Solid Haste Landfill
Solid Naste Nanagenent
Erosion Control
RCRA Landfill Closure and
Post-Closure
Fish and Wildlife Coordination
Act
Citation
40 CPR Part 264
RCRA Subtitle D
25 PA Code, Chapter 75
25 PA Code, Chapter 102
40 CFR Part 264
16 USC 661
Description
RCRA groundwater Monitoring
requirenents
RCRA requirements for solid
waste landfills
Criteria Cor siting and
operating landfills
Erosion control limits on
excavation activities
RCRA regulations Cor landfill
closure and post-closure
Governs modifications to
bodies of water
Discussion
Soil/sediment and
groundwater media
Soil/sediment and
groundwater media
Soil/sediment and
groundwater media
Soil/sediment medium
only
Soil/sediment medium
only
Soil/sediment medium
only
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RESPONSIVENESS SUMMARY
OPERABLE UNIT THREE
WHITMOYER LABORATORIES SITE
JACKSON TOWNSHIP, LEBANON COUNTY, PENNSYLVANIA
From July 16, 1990 through December 3. 1990, the U.S. Environmental Protection Agency
(EPA) held a public comment period on the Proposed Plan and the Remedial
Investigation/Feasibility Study (RI/FS) for Operable Unit Three of the Whitmoyer Laboratories
Site in Lebanon County, Pennsylvania. This responsiveness summary summarizes comments
on the Proposed Plan and RI/FS pertinent to Operable Unit Three that were expressed by local
officials, state officials, and other interested parties; and provides EPA responses to the
comments.
This responsiveness summary is divided into the following sections:
* Overview
* Background on Community Involvement
* Summary of Comments Received during Public Comment Period and Agency
Responses
* Remaining Concerns
A. OVERVIEW
At the time of the public comment period, EPA had already endorsed a preferred alternative for
Operable Unit Three of the Whitmoyer Laboratories Site. EPA's recommended alternative
addressed contaminated soils/sediments and groundwater at the site. The preferred alternative
specified in the Record of Decision (ROD) for Operable Unit Three involves:
* Excavation of all moderately contaminated soils/sediments from offsite and
saturated onsite locations, and all heavily contaminated soils [estimated volume
= 116,000 cubic yards (CY)].
* Demolition of Buildings 4, 9, 11, and 14.
* Backfilling of the excavated areas with clean fill or lightly contaminated soil
* Onsite fixation of the approximately 61,000 CY of heavily contaminated
soils/sediments using an iron-based or other similar fixation process that provides
equivalent protection.
* Biological treatment of the approximately 5,600 CY of soils with organic chemical
concentrations above the heavily contaminated soil action levels either prior to
or following the fixation step.
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* Consolidation of the moderately contaminated soils/sediments on site above the
groundwater table.
* Capping of the approximately 39,000 CY of moderately contaminated
soils/sediments having contaminant concentrations above groundwater-based
unsaturated soil cleanup targets with low-permeability materials.
* Soil capping of all soils/sediments remaining on the surface following the
excavation and consolidation steps that are not capped with low-permeability
materials and contain greater than 21 mg/kg arsenic; and other disturbed areas
as needed.
* Grading and revegetation of all areas affected by the soil/sediment remediation.
* Following the soils/sediments remediation, use of institutional controls for areas
with remaining contamination.
* Aggressive extraction of all groundwater from the aquifer beneath the site with
concentrations above health-based levels (e.g., 50 ug/l arsenic) until the
maximum groundwater contaminant concentrations are all less than health-
based levels.
* Treatment of the extracted groundwater in an onsite treatment plant, utilizing
physical, chemical and possibly biological processes.
* Disposal of the treated water by either discharging it to Tulpehocken Creek,
reinjecting it into the aquifer, or a combination of the two methods.
* Salvaging nonhazardous demolition debris, as feasible.
* Disposal of the following in offsite landfill(s) in accordance with all applicable
regulations: the treated soils; the groundwater treatment residuals; and the
demolition debris that is not salvaged.
It may potentially prove technically impracticable to achieve the health-based groundwater
cleanup goals under the selected remedy for the groundwater. If information emerges from the
operation of the selected remedy system that strongly suggests that it is technically
impracticable to achieve the cleanup goals throughout the contaminated groundwater plume
because of an observed "leveling-off" of contaminant concentrations, the EPA, in consultation
with the Commonwealth of Pennsylvania, intends to implement a contingent remedy in those
areas where the cleanup goals will not be met. The contingent remedy is similar to the
selected remedy, with the exception that groundwater would only be extracted from the
perimeter of the non-attainment area in sufficient quantities to keep this area from growing
Judging from the comments received during the public comment period, the Pennsylvania
Department of Environmental Resources (DER) strongly supports the preferred alternative. The
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Jackson Township Board of Supervisors does not support the preferred alternative The
present owner of a property that contains some of the contaminated soils/sediments (Buckeye
Pipe Line Company) questions EPA's recommendation of excavating, treating, and disposing
off site the most contaminated soils/sediments and managing the less contaminated
soils/sediments through engineering controls. They also question the prudence and cost-
effectiveness of an aggressive aquifer restoration program. Rather, they support the
implementation of a soil flushing alternative for the contaminated soils/sediments, and a plume
containment remedy for the contaminated groundwater. The former site owners, Rohm & Haas
and SmithKline Beecham, support the alternatives of pumping and treating only the most
contaminated groundwater and flushing contaminants from the contaminated soils/sediments
using treated groundwater. Under the soil flushing alternative, contaminants mobilized during
the flushing would be captured in the groundwater extraction system. These issues are
discussed in Section C below.
B. BACKGROUND ON COMMUNITY INVOLVEMENT
There has been consistent community interest in the Whitmoyer site since its proposal for listing
in 1984, Public meetings have attracted approximately 50 local residents as well as most major
local media. In spite of this interest, however, there have been no attempts to organize any
formal special interest groups to address the Site or apply for a Technical Assistance Grant
With respect to Operable Unit Three, there has been little community interest in the remedy
proposed by EPA for this Operable Unit. Local officials, however, have expressed concern over
EPA's proposed plan for Operable Unit Three, though much of their concern was focused on
Operable Unit Two.
C. SUMMARY OF COMMENTS RECEIVED DURING PUBUC COMMENT PERIOD AND
AGENCY RESPONSES
Comments raised during the public comment period for Operable Unit Three of the Whitmoyer
Laboratories Site are summarized below. EPA responses to the comments are provided The
comments are categorized by relevant topics.
Impact on Surrounding Community
1. The former Whitmoyer Laboratories, Inc. owners commented that the preferred alternative
for remediating soils/sediments would extremely disrupt the community through the
excavation, movement, and placement of 313,500 cubic yards (CY) of material and
transport of over 35,000 truck loads through the community.
EPA Response: Using the FS estimates, approximately 197,000 CY of materials (130.00C
CY of clean soil, 48,000 CY of fill, 12,500 CY of clay, and 6,000 CY of ferric sulfate/iime
would be brought to the site, and 70,000 CY of materials (68,000 CY of treated soils arc
1700 CY of demolition debris) would be transported from the site. These quantities to;a>
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to 267,000 CY. Most of these shipments would likely occur in 15 or 20-CY trucks.
Using 15-CY trucks, approximately 17,800 truck loads would be required to move this
total quantity of material. Assuming a 12-hour workday, 250 workdays per year, and a
3-year remediation, this quantity equates to approximately 2 truck trips per hour. Given
the cleanup effort required, EPA does not consider this additional traffic to be extremely
disruptive. (Note: there is significant current truck traffic associated with the
warehousing operation on site).
2. The former owners commented that EPA did not assess the risks associated with
implementation of the soil/sediment remedial alternative, including inhalation of fugitive
dusts, dermal contact with arsenic laden dust, the increased likelihood of traffic
accidents on area roads, and erosion of soils during remediation.
EPA Response: EPA disagrees. EPA has evaluated the long- and short-term risks from
implementation of the preferred soil/sediment alternative. These risks were determined
to be acceptable and will be further evaluated during the Remedial Design phase of
project implementation. For example, fugitive dust emissions during demolition and
excavation are expected to be minor, and appropriate monitoring or ambient air
conditions will be conducted during the Remedial Action to ensure the acceptability of
any emissions. If necessary, air pollution control measures, such as wetting these
materials, will be implemented to minimize fugitive dust releases. A pathway for dermal
contact with arsenic laden dust does not exist at the Site. With respect to risks from
transportation accidents, the selected remedy is equal to any other alternative meeting
the threshold criteria for protection of human health and the environment. Finally, the
selected remedy will be implemented in accordance with Pennsylvania erosion control
requirements and all appropriate ARARs.
3 The former owners commented that, under EPA's preferred groundwater alternative, the
groundwater withdrawal may result in the drying up or lowering of production rates of
agricultural, livestock, industrial and commercial wells in the area.
EPA Response: EPA disagrees. It is unlikely that local wells will be affected by the
proposed groundwater withdrawal program to any great extent. The proposed Remedial
Action will be designed so as not to significantly lower the water table in the
surrounding area. To ensure such a system will work properly, local conditions will be
carefully monitored during the implementation phase of the project and appropriate
adjustments made during the Remedial Action to mitigate any such effects.
4. The former owners commented that, under EPA's preferred soil/sediment alternative the
Tulpehocken Creek ecosystem would unnecessarily be destroyed, and the historic locks
and potentially significant archaeological areas in the northeast corner of the site wouic
be threatened unnecessarily.
EPA Response: Unfortunately, it is necessary to disrupt (but not destroy) a smai!
portion of the Tulpehocken Creek ecosystem to carry out the soil/sediment remediation
Mitigative measures as described in the ROD will be implemented to minimize the
temporary ecosystem damage. During the remediation, the historic locks will ce
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carefully dismantled and archived. Following completion of the soil/sediment excavation,
the locks will be restored as a part of the Tulpehocken Creek/Union Canal restoration
program.
5. The former owners commented that the implementation of the preferred alternatives for
Operable Units Two and Three would result in a massive engineering project which
would indirectly disrupt the community.
EPA Response: EPA does not believe the selected remedies for Operable Units Two and
Three will significantly disrupt the community. (See the responses to Comments 1 and
2.) While the construction of several treatment plants on site will be significant,
construction management practices would be used to efficiently schedule the work and
minimize community disruption. For example, site structure demolition could occur prior
to initiation of the soil/sediment excavation program. Remediation of Operable Unit One
(the concentrated liquids) has been scheduled for completion prior to other site remedial
activities, and has already been completed with minimal community disruption.
Appropriateness of Preferred Soil/Sediment Alternative
6. The former owners commented that the 21 mg/kg arsenic surface soil/direct contact
action level is overly conservative, because it is based on unrealistic exposure scenarios
and the unjustified use of the overly conservative 10** excess lifetime cancer risk
cleanup level. They commented that a surface soil action level of 200 mg/kg arsenic
would be more appropriate.
EPA Response: EPA believes the 21 mg/kg arsenic surface soil/direct contact action
level is based on a reasonable maximum residential use exposure scenario given the
existing and historical residential development patterns in the site vicinity. Also, EPA
believes that use of the 1 x 10"6 excess lifetime cancer risk cleanup level is appropriate
and justified as described in the NCP and in EPA guidance on risk assessment
7. The former owners commented that the groundwater dilution factor of 4.25 used to
derive groundwater-based unsaturated soil cleanup levels is in error, and a factor of 5 1
is more appropriate.
EPA Response: The former owners base their conclusion on two assumptions that differ
from the EPA assumptions. First, the former owners assert that percolating rainwater
should be assumed to mix with the entire groundwater underflow beneath the site EPA
on the other hand, believes that only mixing with shallow groundwater should be
considered. EPA believes its assumption of infiltration mixing with only shallow
groundwater is more representative of site conditions based on the data collected during
the Remedial Investigation and described in the Rl and FS reports for the site. Second
the former owners suggest that the infiltration through the lagoon area should not be
considered, because there will be no contaminated soils present there following lagoon
waste removal. As presented in the soils FS report (Figure 4-3), the lagoon area will
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likely be utilized for soil/sediment consolidation under the preferred alternative.
Therefore, EPA believes it is appropriate to include the estimated infiltration rate for the
lagoon area in the dilution calculation.
8. The former owners commented that no groundwater dilution factor was used to derive
groundwater-based saturated soil cleanup levels, and that the use of a factor of 5.07 is
more appropriate than none at all.
EPA Response: The former owners base their proposed dilution factor on the
assumption that saturated soil leachate should be assumed to mix with the entire
groundwater underflow beneath the site. EPA, on the other hand, believes that
assumption of any mixing dilution is inappropriate for saturated soils. Saturated soils
at the Whitmoyer Laboratories primarily consists of alluvial materials, including significant
quantities of sands and gravels. It is conceivable that water supply weits could be
directly completed in the saturated soils. Therefore, since it is possible for receptors
to directly ingest saturated soil leachate, EPA believes it is more appropriate to not
consider any potential dilution effects.
9. The former owners commented that saturated zone attenuation factors should be applied
when calculating groundwater-based cleanup levels, since site data indicate significant
attenuation of contaminant concentration levels at increasing distances from the site
EPA Response: The former owner argument is based on the presumption that the
remedial action levels should be achieved 500 feet downgradient of the site, and that
significant attenuation should occur over this distance. This argument is in direct conflict
with EPA policy. EPA policy states that cleanup levels should be achieved for the entire
groundwater plume (area of attainment), and not only at some point downgradient from
the site. The approach proposed by the former owners would only be acceptable if the
use of Alternate Control Limits (ACLs) were justified. Adoption of ACLs is not warranted
for the Whitmoyer Laboratories Site, based on site conditions ("Guidance for Remedial
Actions for Contaminated Ground Water at Superfund Sites", OSWER Directive 9283 1 -
2, December 1988). Therefore, use of attenuation factors as proposed by the former
owners is inappropriate.
10. The former owners commented that unsaturated zone attenuation factors should also
be applied when calculating groundwater-based unsaturated soil cleanup levels, since
site data indicate significant attenuation of contaminants with depth.
EPA Response: To properly implement the former owner proposal, accurate vadose
zone attenuation levels would have to be derived (sufficient information does not now
exist), and cleanup levels would have to be derived for each interval (e.g., foot) the soil
lies above the water table or bedrock. In other words, a higher attenuation factor would
be appropriate for soils present 8 feet above the water table/bedrock than soils only i
foot above this level. Implementation of such a system would be unworkable The
groundwater-based soil action levels derived in the soils FS report are based on
partitioning using either site-specific partitioning data or estimated partition coefficients
based on the organic carbon content of site soils (the K^-f^ model, as presented m
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"The Soil Chemistry of Hazardous Materials", Oragun, J., 1988). These partition
coefficients take into account contaminant sorption, which is believed to be the primary
reason for the observed decreased arsenic concentrations at depth noted by the former
owners. EPA believes the methodology used to derive the groundwater-based
unsaturated soil action levels is appropriately conservative for the protection of human
health.
11. The former owners commented that using the Organic Leaching Model (OLM) instead
of the KoC-foc model would have resulted in more plausible groundwater-based
soil/sediment cleanup levels.
EPA Response: EPA believes the KoC-foc model is more representative of site-specific
conditions, since it incorporates the important variable of the total organic content (TOO)
of the site soils. Typically, the extent of organic chemical sorption directly correlates
with the TOO content of soils (Dragun, 1988). The OLM model is generally only used
when site-specific soil TOC data are not available and does not incorporate the use of
TOC.
12. The former owners commented that the main groundwater-based soil/sediment concern
at the site is not the possibility that groundwater will be contaminated by water
percolating through contaminated soil, but rather the opposite mechanism of soils
becoming contaminated by groundwater during periodic high groundwater levels The
site data suggest that contamination of the groundwater from soils containing arsenic
is not a contaminant source or pathway of concern.
EPA Response: EPA strongly disagrees with the former owners. The soils are one of
the primary sources (if not the primary source) of continuing groundwater contamination
During the RI/FS, soil/sediment leachate concentrations of 26,800 ug/l arsenic, over 500
times the groundwater cleanup level of 50 ug/l, were measured. Percolating rainwater
with similar concentrations will continue to contaminate groundwater if no action or
ineffective action is taken. If the soil (vault, lagoon, miscellaneous products/feedstocks.
and site structures) remediation(s) do not take place, the continuing releases to
groundwater from these media will substantially lengthen the time required for
groundwater remediation (if not render it technically impracticable).
13. The former owners commented that remediation of sediments is unjustified.
EPA Response: EPA disagrees. Remediation of a portion of the sediments is justified
as it is impracticable to leave existing sediments adjacent to soils to be excavated m
place during the preferred alternative soil excavation program. Therefore, these adjacent
sediments will be excavated at the same time as the soils and managed in accordance
with their contaminant levels. However, EPA will not be remediating sediments
downstream of the soil excavation area.
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14. The former owners commented that the sediment exposure scenario presented in the
soils FS report is unrealistic, and that the scenario presented in the Rl report is more
appropriate.
EPA Response: EPA agrees that the scenario presented in the Rl report is appropriate
for evaluating exposures to the in-place sediments, but not for evaluating excavated
sediments. The exposure scenario presented in the FS report refers to potential
exposure to the sediments once they are excavated and managed (e.g., consolidated
on site), and not to in-place exposure. Since we are dealing with excavated sedimants,
the FS scenario is appropriate.
15. The former owners commented that the setting of independent action levels for heavily
contaminated soils makes no sense.
EPA Response: EPA disagrees. The National Contingency Plan (NCP) requires the
identification of the principal threats posed by Superfund sites. In this case, EPA has
determined that those soils with at least one contaminant having a concentration above
the heavily contaminated ("principal threat") soil action levels pose one of the principal
threats at the site. EPA expects to use treatment to address principal threats posed by
a site, wherever practicable, and to use engineering controls, such as containment, for
waste that poses a relatively low long-term threat or where treatment is impracticable
(40 CFR 300.430). EPA developed its soil/sediment remedial alternatives in accordance
with these requirements.
16. The former owners commented that EPA applied a totally arbitrary and scientifically
insupportable uncertainty factor of 2.1 to derive a heavily contaminated soil action level
of 1000 mg/kg for arsenic.
EPA Response: EPA disagrees. EPA evaluated using either a total arsenic content action
level or Toxicity Characteristic Leachate Procedure (TCLP) extract arsenic content action
level for soils contaminated with arsenic. Because of the high cost of each TCLP
analysis, it was decided to base the principal threat action level on a total arsenic basis
rather than a teachable arsenic basis, using a statistical correlation between total arsenic
concentrations found in the soil and the concentrations of arsenic found in the leachate
based on the TCLP testing procedure. Given the variability in the soils TCLP data a
"safety factor" approach was developed, with the goal of no more than 10% false
negative. (The 10% chance of a false negative was chosen using engineering
judgement.) This approach is consistent with RCRA (40 CFR 261) requirements lor
hazardous waste determinations. Using the statistical approach, a safety factor of 2 i
is necessary to achieve the goal of no more than 10% false negatives. It was not
deemed appropriate to apply a safety factor to the regression curve developed to
estimate which soil arsenic concentrations corresponded with leachate concentration at
the arsenic MCL, because the cost of a false negative (i.e., a groundwater concentration
of 55 ug/l arsenic in a portion of the aquifer) is not substantial.
17. The former owners commented that EPA's preferred alternative of treating arsenic
contaminated soils by iron fixation will not work, as the apparent success noted in soils
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fixation treatability study is a product of the testing procedure and not the treatment
itself. Water is necessary for the desired reaction to take place. EPA's proposed
treatment would occur in dry or slightly moist conditions.
EPA Response: EPA agrees that water is necessary to complete the desired reaction.
Water was added during the treatability study, and a liquid phase reaction was allowed
to occur. The selected remedy does not preclude adding water to the soil/fixative
mixture if desired. The decision on whether or not to add water to the mixture will be
made during the remedial design phase.
EPA currently believes that adding water during treatment is not essential. One must
look at the big picture. Once the soils/sediments are treated, they will be placed in a
landfill. If the soil/fixative mixture is not wetted and the landfill cap is effective, the
treated material will never be wetted and contaminants will not be removed by
percolating water. If the cap is not completely effective and the treated soils/sediments
become wetted, the desired reaction will occur and the arsenic present in the materials
will be immobilized. In either case, significant arsenic releases should not occur.
18. The former owners commented that no meaningful evaluation of the effectiveness of the
remedial alternatives has been performed, since the chemical characteristics of arsenic
relevant to the site and the soil properties governing arsenic behavior were not
completely characterized. There is no scientific basis to conclude the soil remedy
selected by EPA will be effective.
EPA Response: EPA disagrees. Sufficient information exists to support the selection
of a soils/sediment remedy. The remedy selection process followed by EPA tor the
heavily arsenic-contaminated soils/sediments is typical of the Superfund remedy selection
process. Treatability testing indicated that the selected iron fixation remedy will be
capable of achieving the remedial objectives (e.g., complying with the RCRA LDRs) on
a worst-case sample. The iron fixation bench-scale study was conducted in accordance
with EPA protocols. The treatability study data were validated using standard EPA data
validation procedures. Successful fixation of arsenic compounds with iron has also been
reported by other researchers. (See, for example, the American NUKEM data presented
in the discussion of the RCRA "third-third" land disposal restrictions promulgation notice )
Further optimization of the treatment process will occur during the remedial design
phase of the project.
The missing information cited by the former owners (e.g., the effects of calcium content,
soil iron oxide content, soil surface area, and soil phosphorus content on arsenic
behavior in soil) would be extremely difficult and expensive to collect. Review of
available data show it is extremely unlikely that collection of this information would result
in the discovery of a more viable (cost-effective) treatment for the soil arsenic
contamination.
19. The former owners expressed concern that the iron fixation technology may fail over
long time periods.
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EPA Response: EPA disagrees. The RI/FS treatability data indicate that small quantities
of arsenic may be released from the iron-fixated wastes over extended periods upon
exposure to the atmosphere. However, this possibility will be precluded by placement
of the treated waste in a capped and lined offsite landfill.
20. The former owners commented that the six fixating agents tested by EPA in their soil
fixation study do not represent all of the agents available for commercial use, and to that
extent the study was incomplete.
EPA Response: EPA disagrees as to the ineffectiveness of the fixation process. The soils
fixation study was phased to allow the efficient evaluation of candidate fixating agents.
When promising results were achieved with the low-cost iron fixative during the first
phase, second phase work concentrated on the validation of this agent. No other
potentially effective fixatives with costs comparable to the iron fixative were identified by
EPA during the screening of candidate fixatives. If others were identified, they would
have been tested during the study.
21. The former owners commented that relatively high dissolved salt concentrations may be
generated during the fixation process. These salt concentrations can enhance metals
mobility in the environment and therefore may defeat the whole purpose of the fixation
process.
EPA Response: EPA disagrees as to the ineffectiveness of the fixation process. The
fixated wastes were demonstrated to be stable in the soils fixation study in the presence
of three lixiviants: TCLP extraction fluid (acetic acid), distilled water, and background
groundwater. The stability of the treated materials will be further enhanced by their
placement in a capped and lined landfill.
22. The former owners commented that actual operation of the iron fixation plant would be
a technical nightmare, since iron fixation treatment on this kind of scale is unproven
For example, crushing and grinding of the excavated soils/sediments will result in
considerable noise and dust.
EPA Response: While EPA agrees that iron fixation treatment is innovative and has not
been conducted on the scale as outlined in the selected remedy, plant operation will
not be a technical nightmare. The preliminarily designed treatment plant identified in the
soils FS report included the use of screens, conveyors, pug mills, chemical silos, and
standard air pollution control equipment. These pieces of equipment are routinely
utilized by industry; their use would not be a technical nightmare. It is uncertain whether
crushing and grinding will be required as a part of the plant flowsheet. This will be
determined during the final design. However, because very little of the soils and
sediments will require crushing, considerable noise will not be generated and
engineering measures (e.g., wetting the crusher feed if necessary) will minimize dust
generation.
23. The former owners commented that the EPA proposal of placing the treated wastes m
an intermediate landfill will not be implementable. since it is unlikely that any
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intermediate landfill will accept the treated material because of concerns about the
efficacy of the treatment. If EPA is unable to identify an intermediate landfill to accept
the treated material and the material must instead be sent to a hazardous waste landfill,
the cost of the preferred alternative will increase by up to $15 million.
EPA Response: EPA disagrees. EPA believes the iron treatment will work and the treated
material will be accepted at intermediate landfills based on EPA contacts with such
landfills during the RI/FS process.
24. The former owners commented that EPA should not select bioremediation as the
treatment technology for soils heavily contaminated with organic chemicals, since it is
not certain that the treatment will work.
EPA Response: Bioremediation treatment is an innovative technology; it is not certain
that it will work on the Whitmoyer Laboratories soils/sediments. The majority of the
primary organic contaminants (e.g., aniline and polycyclic aromatic hydrocarbons) have
been effectively biodegraded in numerous other site applications. It is possible, as
explained in the Feasibility Study, that fixating the soils with iron prior to initiation of the
biotreatment will reduce any arsenic inhibitory effects presented by the soils/sediments
The viability of bioremediation will be confirmed during bench-scale optimization studies
to be conducted during the remedial design for the contaminated soils/sediments.
If biodegradation is successful, its implementation will be protective of human health and
the environment; will comply with applicable or relevant and appropriate regulations
(ARARs) (e.g., RCRA land disposal restrictions); will be effective in the long-term and
permanent; will involve treatment of the principal threats posed by this operable unit;
will reduce toxicity, mobility, or volume through treatment; will comply with the CERCLA
preference for treatment; will be more cost-effective than other organic chemical
treatment options (e.g., vitrification, incineration, and fixation with activated carbon); and
will not present the incremental risks to human health and the environment posed by
arsenic emissions during the thermal treatment (vitrification and incineration) options
(These risks were determined to be acceptable.) The NCP requires EPA to consider
using innovative technology when such technology offers the potential for comparable
or superior treatment performance or implementability, fewer or lesser adverse impacts
than other approaches, or lower costs for similar levels of performance than
demonstrated technologies. The NCP further requires EPA to use alternative treatment
(i.e., innovative) technologies to the maximum extent practicable (40 CFR 300.430). The
selection of the biotreatment for the heavily organic contaminated soils/sediments is in
accordance with these requirements.
25. The former owners commented that EPA did not explain where and how the soils to be
biologically treated would be stored during the estimated 5 years the bioremediation
process will take. They suggested that storage would not meet state ARARs.
EPA Response: EPA disagrees. EPA believes that based on data as set forth in the
Feasibility Study, the soil/sediment excavation program will not be completed until nearly
three years after its initiation. Thus, it is unlikely substantial quantities of soils/sediments
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would be stored for 4.5 years prior to treatment initiation. Excavated soils/sediments
awaiting biotreatment would be stored (if necessary) in an environmentally acceptable
manner, in compliance with state and'federal ARARs.
26. The former owners commented that leachate generated during the biological treatment
may contain chemical concentrations in excess of secondary drinking water standards,
and that there is the potential for ground water pollution if a liner failure occurs during
landfarming.
EPA Response: The biological treatment system will be designed to meet ARARs and
to prevent groundwater pollution from the biotreatment operations. It is possible that
the remedial design will consist of biological treatment in a bioslurry reactor vessel. In
this case, liner failure would not be possible. However, a monitoring system will be
designed and installed for detection of any such failures and should a failure be
detected, appropriate measures for remediation will be taken.
27. The former owners commented that significant quantities of volatile organic chemicals
would volatilize during soil/sediment storage and the biological treatment process. This
volatilization would raise significant air pollution problems.
EPA Response: EPA disagrees. All of the heavily contaminated ("principal threat')
soils/sediments spread across the site contain an estimated total of only 8 pounds
(approximately one gallon) of volatile organic chemicals. This figure includes those
soils/sediments that will be and will not not be biologically treated. Because of these
small quantities, no adverse effects on human health and the environment would be
expected. Nonetheless, air pollution controls, if required, will be specified during the
remedial design phase of the project.
28 The former owners commented that the estimated duration of the selected soil/sediment
remedy is uncertain. In the Proposed Plan, a duration of 5 years is presented, whereas,
in Appendix E of the FS, a 9-year duration is estimated.
EPA Response: EPA estimates the remediation will last 5 years, once it is initiated. The
9-year figure presented in the soils FS appendix is an error. This figure should be 3
years. The difference in durations represent time required for bench-scale testing and
construction, as well as the time for additional lifts if a multiple lift system is specified
during the remedial design phase.
29 The former owners commented that the limited availability of equipment and resources
for performing bioremediation projects will result in delays for the proposed treatment
of the contaminated soils/sediments.
EPA Response: EPA disagrees. As discussed in the Feasibility Study Report, equipment
and resources are readily available to conduct the proposed Remedial Action While
minor delays are possible, these will not have a significant effect on overall remediation
of the site.
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30. The former owners commented that EPA should not have rejected soil flushing as a
remedial technology, but rather should select this technology as the soil/sediment
remedy. The present owner of a property that contains some of the contaminated
soils/sediments (Buckeye Pipe Line Company) also stated that in situ leaching (i.e soil
flushing) may be a better alternative. The former owners stated that the soil flushing
remedy will be completed well before groundwater cleanup levels are achieved.
EPA Response: EPA gave serious consideration to the soil flushing alternative proposed
by the former owners. While this alternative is purportedly less costly than the selected
remedy (according to the former owners' cost estimate), EPA believes that the selected
remedy is cost-effective in mitigating the risks posed by the contaminated
soils/sediments in a reasonable period of time (an estimated 5 years) and meets all
other requirements of CERCLA. Because the majority of organic contaminants present
in the heavily contaminated soils/sediments will be destroyed, the metal contaminants
in these materials treated to reduce mobility, the treated material disposed in an
intermediate landfill; and the less contaminated soils/sediments will be managed using
a combination of engineering and institutional controls, the selected remedy affords a
high degree of long-term effectiveness and permanence.
Under the soil flushing system, there is the danger of mobilized contaminants in the
flushate to escaping the well capture network and substantially further degrading
downgradient groundwater, considering the karst setting and complex hydrogeology
present at the site. Using the former owners' calculations, it will take 96,000 years for
percolating rainwater to wash out arsenic contamination from the soils to the cleanup
level of 50 ug/l, given the assumption that one-half of a pore volume is exchanged per
year. The former owners estimate that 5 pore volume exchanges per year would occur
during soil flushing. Given this assumption, the cleanup would occur ten times as fast
as for no action; and the leachate from the most contaminated soil would reach the
cleanup level of 50- ug/l arsenic in 10,000 years. This duration is obviously beyond the
realm of practicability. (EPA estimates that only 2 pore volumes per year could be
transmitted by the aquifer. If this is the case, the cleanup duration would last an
estimated 24,000 years.)
In comparison, the soil/sediment remediation could be completed in an estimated 5
years. The duration required for groundwater cleanup is uncertain. However
extrapolating the contaminant reduction rates achieved during the 7-year pump-and
treat program, the aquifer could be cleaned up to the arsenic standard of 50 ug/l m 13
years. (During the pump-and-treat program, aquifer arsenic concentrations were reducec
by one order of magnitude roughly every 3.7 years.)
31 The former owners commented that EPA's calculations indicated it would take about
100,000 years for the leachate concentrations of the most contaminated soils to reac*
50 ug/l, whereas the former owners calculations showed it would take about 96 000
years. This apparent discrepancy shows the sloppiness in the soils FS report
EPA Response: EPA disagrees. For all intents and purposes, these numbers are tre
same.
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32. The former owners commented that up to 67% of the arsenic was removed from site
soils in one pass during the soil washing treatability study, and implied that an ongoing
soil flushing involving continuous washing over a long period of time would achieve
greater removals in a reasonable timeframe.
EPA Response: The soil washing data using aggressive leaching solutions is not
comparable with the former owners' proposed program that uses plain water as a
lixiviant. Using the former owners' own calculations, it will take between 10,000 years
and 2- ,000 years to achieve the soil/sediment remedial action objectives. (See the
response to Comment 30 and Figure 1 of "Comments on the Proposed Plan for Soils.
Sediments and Ground Water at the Whitmoyer Laboratories Site," GeoTrans, Inc,
September 1990).
Appropriateness of Preferred Groundwater Alternative
33. The former owners commented that selection of EPA's preferred groundwater alternative,
aggressive pumping-and-treating (Alternative 4), is not warranted, since the groundwater
remediation will likely require 35,000 years and the groundwater plume is only growing
at a rate of one foot per year. Even if the estimated cleanup duration of 160 years
presented in the FS report (February 1990) is accurate, EPA's preferred groundwater
alternative should be considered technically infeasible. When the contingent remedy of
plume containment is inevitably selected, the 600 gallon per minute (GPM) groundwater
treatment plant will be grossly underutilized.
The present owner of a property that contains some of the contaminated soils/sediments
(Buckeye Pipe Line Company) commented that EPA's preferred alternative includes more
wells than is necessary for protection of public health and the environment. A less
costly alternative for groundwater that would afford similar protection could involve
Alternative 2 plus a set of wells to intercept groundwater containing greater than 1.000
ug/l arsenic.
EPA Response: The former owner calculations of the 35,000-year groundwater
remediation duration and the groundwater plume rate of growth are based on the
conceptual model that all of the groundwater fractures are completely filled with soils
exhibiting the same partitioning behavior observed during the bench-scale testing of site
soils. A similar approach was presented in the groundwater FS report (February 1990)
Based on the new partitioning data, EPA does not agree with this approach if the
fractures were completely filled with soils having a similar partitioning behavior
contaminant concentrations measured in offsite wells and springs (e.g., the Wagner
residential well and the PJ Valves Co. well) in 1967 could not be explained Since
arsenic was reportedly first used at the site in 1957, it would have been impossible for
the observed contamination to travel to the offsite observation points in only 10 years
given the soil partitioning characteristics. Therefore, EPA believes that the conceptual
model of the bedrock fractures being only partially filled with soils is more accurate ci
existing site conditions. This model is supported by observations made during the
drilling programs conducted by both Rohm & Haas and EPA. During both programs
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it was noted that some fractures were filled with soils while others were "clean" This
groundwater conceptual model was calibrated using site data, most notably the
groundwater concentrations noted in offsite wells in 1967, the assumed 10-year travel
time, and estimated groundwater flow rates. Using these data, a "bulk Kg" (partition
coefficient) of 5 is estimated for the aquifer. (Standard Calculation Sheet Re:
Groundwater Modelling Calibration (reruns) 12/15/90). (This logic was similarly utilized
for the assumption that the soils had a Kg of 5 in the modeling presented in the FS
report.) The actual bulk Kg for the aquifer may be significantly less than 5, as the
offsite contaminated wells and springs may have been significantly contaminated prior
to 1967. A Kg lower than 5 would produce a predicted cleanup time frame lower than
160 years. Given this conclusion, EPA still believes the modeling presented in the
groundwater FS report is a reasonable rough estimate.
The former owners pointed out that the change in arsenic Kg value with concentration
explains how the groundwater became contaminated in a short period of time, but the
groundwater plume will now only grow at a rate of one foot per year. However, much
of the plume growth in the 1960's occurred while arsenic concentrations (at the plume
perimeter) were approximately 1 mg/l or less. At these concentrations plume growth
under the former owner model should have been very slow, and contamination should
not have reached outlying wells such as the Wagner well and the PJ Valves well. Thus,
the former owner model does not appear to accurately represent site conditions
Further support to the refined EPA model is provided by reviewing the historic data of
the onsite wells (e.g., well 7) and offsite well 16B. Arsenic concentrations measured in
well 16B historically have been approximately one-half the concentration measured m
well 7, despite the fact that well 16B is located approximately 600 feet east of well 7
This relatively small reduction would not have been observed if bedrock fractures were
completely filled with soil.
EPA also reviewed the data from the groundwater pump-and-treat program conducted
by Rohm & Haas. During the period 1965-1969 when only wells 1-7 were in service.
the arsenic concentration in the extracted groundwater was reduced from 1160 mg/l to
150 mg/l. (Overall the reduction in concentration was from 8500 mg/l at day 10 to 150
mg/l at day 1290.) These data indicate that the arsenic concentration was decreasing
by one order of magnitude every 1350 days (3.7 years). Using this rate, the
groundwater concentration could be reduced from 212 mg/l to 0.05 mg/l (the
groundwater arsenic cleanup level) in 13 years. The reduction in arsenic concentration
during the pump-and-treat program occurred despite the fact that infiltration through
contaminated soils/sediments and the groundwater treatment system itself continued to
add arsenic contamination to the groundwater. If the contaminant contribution sources
of the soils/sediments (as well as the vault and lagoon wastes, miscellaneous
products/feedstocks, and site structures) are eliminated as planned by EPA, groundwater
cleanup rates would be expected to be faster than they would otherwise be.
EPA does not expect all contaminated groundwater will be remediated below the
cleanup levels in 13 years. Some "tailing effect" is expected. However, given me
existing database, EPA believes there is a good possibility that the contaminated aquifer
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could be restored to its beneficial uses in a reasonable timeframe, and is using this
justification for its selection of Alternative 4 as the groundwater remedy. EPA recognizes
there is uncertainty regarding the duration of the groundwater cleanup, but does not feel
that writing off the aquifer and implementing a containment system, as proposed by
the former owners and Buckeye Pipeline Company (The Application of EPA's Pump and
Treat Memorandum and the NCP to the Whitmoyer Laboratories Superfund Site",
Whitmoyer Laboratories Private Study Group, June 1990) is warranted at this time EPA
also believes there is sufficient evidence to support the selection of an aggressive pump-
and-treat program, as specified in Alternative 4, at this time. Even if this program is not
completely successful and the contingent remedy of plume containment must be
implemented for portions of the aquifer, much of the aquifer should be restored to its
beneficial uses during the aggressive program, and substantial quantities of
contamination will be removed from the aquifer.
The size of the treatment system and associated pumping and piping systems will be
determined during the Remedial design phase of project implementation. Although the
Feasibility Study and Proposed Plan specified certain pumping and treatment rates,
optimization of the chosen system during design will ensure that the minimum required
pumping and treatment rates will be utilized for the Remedial Action. Accordingly.
capital and operation and maintenance costs will also be minimized.
34. The former owners commented that after the first year of the prior pumping,
concentrations of arsenic did not decrease in any discernable manner.
EPA Response: The data cited in the response to Comment 33 above directly conflict
with this conclusion.
35. The former owners commented that their proposal of the 3-year pilot program, which
starts by treating the most contaminated areas first, should be selected by EPA, because
it is consistent with EPA guidance on initiating an early response action and using a
staged approach at sites where available data do not clearly define the parameters
necessary to optimize system design.
EPA Response: EPA's guidance on early response actions refer to the implementation
of a response action to prevent the contaminant plume from spreading while the
investigation to select the remediation system progresses. The former owners approach
does not prevent the contaminant plume from spreading. The time for implementing an
early response action at the Whitmoyer Site was in 1986, when EPA's negotiations with
the former owners began, and has now past. Sufficient information now exists to select
the remediation system. While the database necessary to finish the remedial design of
the groundwater extraction and treatment systems is not complete, the required
information will be collected during the remedial design phase. EPA sees no justification
for delaying selection of the ultimate remedy for groundwater.
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36. The former owners commented that there are not sufficient data to support the selection
of a groundwater remedy. Data gaps include the valence of arsenic at the site; the
composition and relative amounts of inorganic and organic arsenic compounds in
groundwater; the leaching or adsorption characteristic characteristics of the soil.
bedrock, and fissure fillings; the impact of pumping on groundwater elevations and flow
directions; and groundwater/surface-water relationships.
EPA Response: EPA agrees that more information on several of these items will need
to be collected during the remedial design phase of the groundwater remediation.
However, EPA believes there is sufficient information available at this point to support
the selection of a groundwater remedy.
37. The former owners commented that the Rl failed to adequately determine the extent of
groundwater contamination below 150 feet in depth, and that the assumption that
groundwater is contaminated to a depth of 500 feet may lead to an overestimation of
the extent of contamination.
EPA Response: EPA installed nine new wells to a depth below 150 feet during the Rl
Samples from the deepest installed well (107C), at a depth of 385 feet, were significantly
contaminated with arsenic and aniline. Existing well 4, at a depth of +335 feet, has also
been historically demonstrated to be substantially contaminated. This well was used for
the injection of contaminated water. Given these data, it is reasonable engineering
judgement to estimate that the aquifer is contaminated to a depth of 500 feet Cost
constraints limited the placement of deep wells during the Rl program. Further
placement of wells that define the extent of groundwater contamination at depth will
likely occur during the remedial design phase of the groundwater remediation.
38. The former owners commented that, under Alternative 3, the volume of contaminated
groundwater will decrease over time.
EPA Response: EPA disagrees. If no action is taken on the portion of the plume
containing between 50 ug/l and 1,000 ug/l arsenic, this plume will grow over time, at a
rate significantly greater than the one foot per year averred by the former owners (See
the response to Comment 33.)
39. The former owners commented that there is virtually no support for the assumed
southern (or second) lobe of groundwater contamination.
EPA Response: EPA disagrees. There are several contaminated wells that demonstrate
the southern lobe of groundwater contamination, including the Wagner residential wen
(RW0003), the PJ Valves Co. wells (RW0007), the G. Hamish well, and the High well
These last two wells were not sampled during the Rl, since valid data from these wells
were available from prior EPA and DER sampling efforts.
40. The former owners commented that lowering the water table beyond the area affected
by the previous pumping program, as envisioned under EPA's preferred groundwater
alternative, might trigger the formation of sinkholes.
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EPA Response: No sinkhole formation was noted during the 7-year groundwater pump-
and-treat program conducted by Rohm & Haas. Bedrock cavities were only infrequently
encountered during the Rl drilling program. As the former owners pointed out,
catastrophic collapse of the rock mass because of failure of rock voids is uncommon
in the Whitmoyer Laboratories Site region. Rather most of the sinkholes that do form
are relatively small ("Whitmoyer Laboratories Site - Background Information - Proposed
Phase I Remediation," Whitmoyer Laboratories Private Study Group, March 1990) and
(Telephone conversation between Bill Kochanov and John Trepanowski, 9/21/90). Given
these considerations, it is unlikely that catastrophic sinkholes would form from operation
of the aggressive groundwater extraction system. Because of the rural agricultural site
setting, even if sinkholes would form from groundwater extraction, the probability of
significant economic damage resulting from their formation is low.
41. The former owners implied that their proposed program would avoid overpumping which
would dewater portions of the aquifer that are highly contaminated, but which would also
leave arsenic bound to fracture fillings that could recontaminate groundwater; whereas
EPA's preferred alternative would realize these results.
EPA Response: The preferred alternative groundwater withdrawal system would be
flexibly designed. To reach the contamination reduction objective at least two
approaches could be used to protect the water table in the area.either alone or in
combination with each other. Continual monitoring of water levels both on and off the
Site property would allow feedback of aquifer conditions during remediation. The
system would be designed with pumps that could be turned on or off depending upon
groundwater conditions to protect the adjacent wells and surrounding groundwater
Additionally, a groundwater re-injection program could be operated in the Site area to
maintain the level of the surrounding water table.
42. The former owners question the efficacy of the groundwater treatment system presented
in the FS report. The present owner of a property that contains some of the
contaminated soils/sediments (Buckeye Pipe Line Company) commented that the
groundwater treatment system presented in the FS report is unnecessarily costly
EPA Response: The exact groundwater treatment method is not specified in the selected
remedy. The specific treatment method to be utilized will be engineered during the
remedial design phase. The preliminary design presented in the FS was only provided
as an example of a potentially viable treatment system and for cost estimation purposes
If the system presented by the former owners or the modifications suggested by
Buckeye are determined to represent the optimal treatment system, they will be
incorporated into the final design.
43. The former owners argue that groundwater cleanup standards based on 1CT6 excess
lifetime cancer risks are too stringent, since the groundwater is not now used for
drinking water, and there is no reasonable expectation that groundwater in the area will
be a future drinking water source.
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EPA Response: The aquifer beneath the site is a current source of drinking water for
many nearby residents who are not connected to the Myerstown public water supply.
Additionally, the Myerstown public water supply system has one well (#8) located in the
aquifer. EPA classifies the aquifer as a Class 2 aquifer (current and potential sources
of drinking water and waters having other beneficial uses).
44. The former owners claimed that EPA mischaracterized their groundwater proposal
(Alternative 5) in the Proposed Plan for Operable Unit 3 by stating that their program
would be operated to contain (and not actively remediate) onsite groundwater.
EPA Response: Epa's characterization comes directly from the former owners' June 1990
submittal ("The Application of EPA's Pump and Treat Memorandum and the NCP to the
Whitmoyer Laboratories Superfund Site", Whrtmoyer Laboratories Private Study Group,
June 1990):
"the ground water on-site would be contained by the WLPSG's
proposed pump and treat system."
45. The former owners commented that different investigative techniques should have been
used during the Remedial Investigation (Rl), including more comprehensive and frequent
groundwater elevation surveys; pumping/injection tests at higher rates and longer in
duration; coring, downhole geophysics, and packer testing; and surface geophysics.
EPA Response: There are several alternate investigatory approaches that can be utilized
during an Rl. EPA focussed its Rl by having an extensive screening program, including
an extended review of historical documents, interviews with former employees, a review
of historical air photos, a fracture trace analysis, and an evaluation of existing wells for
Rl usability. Based on the extensive database developed from the review of historical
documents and interviews with former employees and given the practical Rl cost and
time constraints, completion of the work suggested by the former owners during the Rl
was evaluated and eliminated as a cost-reduction step. EPA believes that adequate
investigation of site conditions for decision making purposes with respect to selecting
a remedy and commencing Remedial Action have been completed. Much of this work
(e.g., additional groundwater elevation surveys and more extensive aquifer testing) will
be conducted during the remedial design phase of the groundwater remediation.
46. The former owners commented that the descriptions of the aquifer hydraulic
characteristics in the Rl and PS reports are inconsistent.
EPA Response: The differences in aquifer hydraulic characteristics presented in the Rl
and FS reports result from the use of two different approaches in estimating these
characteristics. These approaches differ because the process used in the evaluation
of site conditions is an evolving one which is continually refined and updated as data
are continually analyzed. EPA believes the approach used in the FS report is more
appropriate for the preliminary design of the groundwater extraction systems presented
as a part of each groundwater alternative and followed logically from continuing data
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analysis in the Rl. The Rl approach was utilized to calculate an alternative extraction
rate for the FS sensitivity analysis.
47. The former owners commented that the Rl data do not support the EPA assertion that
the aquifer underlying the site is a single large heterogeneous unconfined aquifer.
EPA Response: The Rl data indicate that the fractured limestone aquifer is
heterogeneous and anisotropic. There is no evidence of a low permeability confining
layer that could be considered a boundary between two or more separate aquifers.
Both the presence of contamination at all levels within the formation underlying the site
and the similar hydraulic heads for wells open over different depth intervals at a given
location support the description of the fractured limestone as a single aquifer. The
response to pumping discrete, highly transmissive zones within an otherwise less
transmissive aquifer would be expected to be similar to what was observed at the site.
and does not indicate the presence of hydraulic barriers between fractures encountered
at different depths. Horizontal hydraulic conductivities of 1-2 orders of magnitude higher
than vertical hydraulic conductivities are not uncommon. This difference does not
indicate the existence of separate aquifers, however. The FS description of the aquifer
as a single, heterogeneous, highly anisotropic aquifer best describes the conditions at
the site.
48. The former owners commented that, with the deep well drilling technique used, drilling
fluids and cross-contamination from upper portions ~of the aquifer may have migrated
downward via the wells, affecting water quality analyses.
EPA Response: EPA disagrees. The well completion technique used is a standard
operating procedure for site investigations. Grout seals were allowed to cure overnight
before drilling proceeded. When drilling resumed, removed cuttings were dry, indicating
waters from upper portion of the aquifer were not migrating down the borehole.
49 The present owner of a property that contains some of the contaminated
soils/sediments (Buckeye Pipe Line Company) commented that EPA has not presented
adequate justification for the proposed remediation of the Buckeye property. The
Buckeye property is not the primary source of the groundwater contamination at the
site. The proposed remediation will impact Buckeye operations.
EPA Response: Remediation of the contaminated soils (and lagoon wastes) on the
Buckeye property is necessary to achieve the remedial action objectives for the site
which include the elimination of a serious threat to groundwater from contaminated
materials on the site. EPA believes their selected remedy, which will likely impact
pipeline operations, is the best overall approach for addressing site contamination
Risk Assessment
50. The former owners commented that the exposure assumptions presented in the
baseline risk assessment (found in the Rl report) did not use reasonable maximum
exposure (RME) values. Instead average and worst-case assumption values were used
20
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despite EPA guidance documents available at the time which specifically instructed that
the use of average and worst-case assumptions are not appropriate. In using a worst-
case scenario, EPA overestimated the risks posed by the Whitmoyer site.
EPA Response: The Whitmoyer Rl was dratted and finalized in the summer and fall of
1989, respectively. The guidance document referred to in the comments, "Risk
Assessment Guidance for Superfund, Volume I. Human Health Evaluation Manual' (EPA,
December 1989) is dated December 1989. This document was generally not available
to the public until February/March 1990. Consequently, the Whitmoyer Rl and
groundwater FS reports were written before the December 1989 guidance document
was available. The RI/FS was conducted per the guidance available at that time.
In reality, the evaluation of the RME versus worst-case or average exposures has
marginal impact on the risk analysis results. The evaluation of the average and
maximum exposures provide a range of possible risk analysis estimates. The RME is
an estimate that is within the range of possible exposures. The guidance document
cited by the former owners states as follows:
In the past, exposures generally were estimated for an average
and an upper-bound exposure case, instead of a single exposure
case (for both current and future land use) as recommended here.
The advantage of the two case approach is that the resulting
ranoe of exposures provides some measure of the uncertainty
surrounding these estimates. The disadvantage of this approach
is that the upper-bound estimate of exposure may be above the
range of possible exposures, whereas the average estimate is
lower than exposures potentially experienced by much of the
population. The intent of the RME is to estimate a conservative
exposure case (i.e., well above the average case) that is still within
the range of possible exposures. Uncertainty is still evaluated
under this approach. However, instead of combining many
sources of uncertainty into average and upper-bound exposure
estimates, the variation in individual exposure variables is used to
evaluate uncertainty. In this way, the variables contributing most
to the uncertainty in the exposure estimate are more easily
identified.
It serves no real purpose to recalculate risk using the RME (i.e., a 95 percent upper
confidence limit on the arithmetic mean) because an evaluation of exposures to the
average contaminant concentrations in the groundwater and soils at Whitmoyer (which
predict lower risks than the RME methodology) yields unacceptable risks (i.e., a health
index greater than 1 and excess lifetime cancer risks in excess of the 1 x KT4 -1 x icr
6 acceptable risk range).
In summary, the Whitmoyer Rl risk assessment was conducted per the guidance
available at the time. The Rl analysis conservatively provides a range of risks potentially
incurred by receptors who may contact site contaminants. (Current and future exposure
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scenarios were considered.) The risks for average contaminant concentration
exposures, which are less than RME risks, are unacceptably high. Also, the failure to
calculate RME risks in no way impacted the development of the cleanup standards for
the Whitmoyer Laboratories Site (see the response to comment 53 below).
51. The former owners commented that many of the elements common to risk assessments
(hazard identification, dose-response assessment, exposure assessment, and risk
characterization) appear to be missing in the documents on which the Proposed Plan
is based.
EPA Response: EPA disagrees. The risk assessment for the Whitmoyer Laboratories Site
clearly contains all of the cited elements. The baseline risk assessment presented in
the Rl report was outlined and composed using these elements.
52. The former owners commented that there is no discussion of the uncertainties
associated with the exposure assumptions or values presented in the exposure
assessment and risk assessment.
EPA Response: EPA disagrees. Uncertainties in the exposure assessment and risk
assessment are discussed in several sections of the Whitmoyer Rl report (e.g., pages
6-46, 6-49, 6-52, 6-53. 6-54, 6-94, and 6-95).
53. The former owners commented that, because risks for all media via all pathways have
been estimated without incorporating reasonable activity patterns or data, the results of
the combined assumptions exaggerate the potential risk.
EPA Response: The exposure scenarios established for the Whitmoyer Site were based
upon EPA guidance available at the time and upon the current and potential future use
of the Whitmoyer site. Although site-specific population-activity-pattern data were not
collected, the assumptions made were reasonable for the stable rural community in the
vicinity of the site. Therefore, EPA does not believe the risks are exaggerated by the
assumptions made. (Also see the responses to comments 55 and 56).
54 The former owners commented that ingested arsenic should be treated as a non-
carcinogen and not as a carcinogen. They stated that EPA treated ingested arsenic as
a non-carcinogen in their proposed RCRA corrective action rule, citing a personal
communication with Ms. S. Griffin of EPA.
EPA Response: EPA believes treating ingested arsenic as a carcinogen is justified. All
current EPA guidance, including the EPA Integrated Risk Information System (IRIS) and
the Health Effects Assessment tables, classify ingested arsenic as a carcinogen. Ms
Griffin of EPA denies making the statement attributed to her by the former owners.
55. The former owners commented that the Whitmoyer risk assessment does not
incorporate the arsenic inhalation absorption factor of 0.3, as presented in the most
recent IRIS listing.
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EPA Response: EPA agrees with the former owners. The most recent IRIS information
indicates that a 30 percent absorption factor is appropriate. However, the adjustment
of the risk analysis results to reflect this new absorption factor would not alter the
conclusion that contaminant concentrations (most notably arsenic) in the environmental
media (e.g., groundwater, soils) at the Whitmoyer Laboratories Site present a potential
human health threat under one or more of the exposure scenarios evaluated because
this revised calculations would still indicate unacceptable human health risks.
Additionally, the soil/sediment and groundwater cleanup levels are based on the
ingestion route of exposure (and drinking water standards),not inhalation. Thus, the
recent change in the absorption factor does not affect the cleanup levels set for the
soils/sediments and groundwater at the Whitmoyer Laboratories Site.
56. The former owners commented that some of the EPA exposure duration estimates are
overestimated and do not represent reasonable durations. For example, for substances
EPA considers carcinogenic, the exposure duration should be only 30 years as the
potential residence time near the site, not the 70 years used in the soils FS report
EPA Response: The 30-year exposure duration is the national upper-bound time (90th
percentile) at one residence suggested by the new December 1989 EPA risk
assessment guidance. By all appearances, the community in the vicinity of the
Whitmoyer site is a stable, rural community. (One example of this is that few residences
with contaminated potable water supply wells have changed ownership during the last
26 years). Consequently, a 70-year exposure timeframe is certainly possible for this
area, and was adopted based on professional judgement. Given the contaminant
concentrations detected in the environmental media at Whitmoyer, the 30-year versus
70-year timeframe argument does not alter the conclusion that the contaminant
concentrations at Whitmoyer present a potential human health hazard because the risk
assessment would predict unacceptable human health risks using either timeframe
57. The former owners commented that the failure to collect arsenic speciation data during
the Rl made the risk assessment of limited value. The risk assessment assumption that
all arsenic detected is inorganic arsenic may lead to a substantial overestimation of risk
EPA Response: During RI/FS scoping, the former owners commented that all analyses
for valences of arsenic (speciation) should be eliminated. (Technical Assessment of
the Need for Immediate Removal of Vault/Lagoon Contents at Whitmoyer Laboratories
Site*, January 1987). This comment was incorporated into the Rl.
In general, organic arsenic compounds are less toxic than inorganic forms of arsenic
There are exceptions to this rule, however. Presently, there are inadequate toxicology
data to determine the carcinogenic potential for organic arsenic compounds.
Assuming that a substantial percentage of the arsenic contamination detected during
the Rl is organic arsenic, the risk analysis based on the assumption that all arsenic
present at the site is inorganic may have overestimated the noncarcinogenic ana
carcinogenic risks calculated for the site. For example, assuming that the percentage
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of organic arsenic is 50 percent and assuming that organic arsenic is one-tenth as
potent a carcinogen as inorganic arsenic, the predicted excess lifetime cancer risk
would be approximately one-half the risk assuming 100 percent inorganic arsenic.
However, given the very high arsenic concentrations measured at Whttmoyer. the
assumption that organic arsenic is prominent at the site does little to alter the overall
conclusion that the Operable Unit 3 materials present substantial noncarcinogenic and
carcinogenic risks, and require remediation. The assumption of 100 percent inorganic
arsenic adds a measure of conservatism to the risk assessment.
58. The former owners commented that the Rl surface soil sampling strategy biased the risk
estimates, because sampling concentrated on target locations suspected of containing
high contaminant concentrations, rather than using a grid or random sampling plan
EPA Response: The sampling strategy used at the Whrtmoyer Laboratories site is typical
of that used to investigate uncontrolled hazardous waste sites such as Superfund sites
In addition to samples collected to confirm or deny the potential presence of various
source areas throughout the site, samples were also collected away from potential
source areas to address data gaps. It should be noted that in the "occurrence and
distribution of contaminants in soils" and risk assessment presentations in the Rl report.
EPA did not assume that chemical constituents are present continuously throughout the
site at "hot spot" concentrations, as maintained by the former owners. The entire site
was divided into five distinct areas based upon contaminant concentrations detected
and source areas. Consequently, EPA did recognize that chemical concentrations do
vary across the site and did not bias its risk assessment as asserted by the former
owners.
59. The former owners commented that EPA's sampling strategy may have resulted in the
inaccurate classification of large areas of the site as contaminated, when they do not
pose a threat to human health and the environment.
EPA Response: EPA believes that the site has been reasonably classified given the
existing data base. The areas of the site to be remediated will be more accurately
delineated during the remedial design and remedial action phases of the project The
action levels presented in the ROD will be used to differentiate soils/sediments that
require remediation from soils/sediments that do not.
60. The former owners implied in their comments that the NCR requires EPA to minimize
potential risks at Superfund sites.
EPA Response: The NCP does not require EPA to minimize potential risks. The NCP
requires EPA to select a remedy which is protective of human health and the
environment [i.e., reduces the risks (current or future, actual or potential) to a~
acceptable level, for example the 1 x 10~6 excess cancer risk level]. EPA's selectee
remedy meets all the requirements established in the NCP.
61. The former owners commented that the use of a 1 x 10r6 excess cancer risk level at :^e
Whrtmoyer Laboratories Site is not scientifically justified, Furthermore, its use s
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inconsistent with EPA having adopted 10~* risk goals at other Superfund sites and in
other regulatory programs. Also, the Whitmoyer arsenic cleanup levels are inconsistent
with the arsenic cleanup levels proposed in the proposed RCRA corrective action
regulations.
EPA Response: In the Superfund program, EPA establishes acceptable risk levels and
cleanup goals on a site-specific basis. Consequently it is anticipated that cleanup goals
will vary based on site-specific conditions, the nature of the environmental problem
under consideration, and the lexicological information available to the risk assessor
The EPA has taken into account site-specific conditions at the Whitmoyer Laboratories
Site (e.g., the residential and agricultural use of adjoining properties), and has decided
that the 1 x 1CT6 excess cancer risk level goal is appropriate for the Whitmoyer
Laboratories Site. (See also Attachment 1.)
It should be noted that the proposed RCRA corrective action regulations are proposed
only and not promulgated, and are subject to substantial change.
62. The former owners commented that the groundwater-based soil action (cleanup) levels
and groundwater action levels for the Whitmoyer Laboratories Site should be changed
to reflect the recently published proposed drinking water standards for benzo(a)pyrene,
indeno(1,2,3-cd)pyrene, and benzo(b)fluoranthene.
EPA Response: EPA agrees. The cleanup levels have been adjusted in the ROD to
reflect these new values.
D. REMAINING CONCERNS
An issue that EPA was unable to address during remedial planning activities was how much
of the cleanup will be paid by potentially responsible parties. EPA was unable to address this
since negotiations are still unresolved. EPA will inform the community if the negotiations are
successfully concluded.
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