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Superfund Program
Proposed Plan | I
PRO^
Salford Quarry Superfund Site,
Operable Unit 1
Lower Salford Township, Pennsylvania August 2012
The United States Environmental Protection Agency Region III (EPA) is issuing this
Proposed Plan to identify its Preferred Alternative for addressing waste, soil and sediment
contamination, known as Operable Unit 1 (OU1), associated with the Salford Quarry Superfund
Site (the Site), in Lower Salford Township, Montgomery County, Pennsylvania. This is the first
planned action at the Site. The proposed remedial action will be a final action for OU1 and will
control the source (quarry waste, soil and sediment) to prevent additional contamination from
migrating to groundwater and surface water (OU2). The final remedial action for OU2, which will
address remaining contamination in groundwater and surface water, will be issued separately. This
Plan includes summaries of other cleanup alternatives evaluated to address contamination at this
Site and provides EPA's rationale for the Preferred Alternatives.
The Preferred Alternatives provide for the
construction of an engineered cell to contain quarry waste,
contaminated soil, and contaminated sediment on-site.
The Preferred Alternatives are based on the findings of the
Remedial Investigation (RI), which was finalized by the
EPA in February 2007, and the Feasibility Study (FS)
dated June 2007.
EPA will consider written and oral comments on
the Preferred Alternatives presented in this Proposed Plan
before the final selection of a remedial alternative for
OU1. Then, EPA, the lead agency, in consultation with
the Pennsylvania Department of Environmental Protection
(PADEP), the support agency, will select a final remedy
for OU1 of the Salford Quarry Superfund Site in a Record
of Decision (ROD).
Salford Quarry Proposed Plan
August 2012
1
Dates to Remember:
August 2, 2012 to
August 31, 2012,
Public Comment Period for
this Proposed Plan.
August 13, 2012
Public Meeting
Lower Salford Township Building
Harleysville, PA, 6:30 pm
AR300084
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PUBLIC PARTICIPATION
This Proposed Plan for the Salford Quarry Superfund Site has been prepared by EPA to
facilitate public participation in the decision-making process regarding remediation of the Site.
EPA issues this proposed plan to fulfill the public notification requirements of Sections
113(k)(2)(B), 117(a), and 121(f)(1)(G) of the Comprehensive Environmental Response,
Compensation and Liability Act of 1980 (CERCLA), as amended, and Section 300.430(f)(2) of the
National Oil and Hazardous Substances Pollution Contingency Plan (NCP). A proposed plan
performs the following:
• Describes the remedial alternatives evaluated and solicits I'm- more information. see ihe
comments on these alternatives AR ai ihe follow mil: locations
• Identifies EPA's Preferred Alternative and explains why
EPA prefers it Indian \ liIIcn Public l.ihrars
• Solicits community involvement in selection of the remedy 'UIK'1 UUk
Id lord P\ ixw
• Refers interested parties to the RI, FS and other Site-related , ^
documents contained in the administrative record file on
which EPA has relied to decide which alternative is
preferred
EPA and PADEP encourage the public to review and
comment on this Proposed Plan for the Salford Quarry
Superfund Site. This Proposed Plan and additional Site
information can be found in the Administrative Record (AR) at
the locations listed to the right. EPA, in consultation with
PADEP, may modify the Preferred Alternative, or select
another alternative based on new information or public
comments.
Interested parties may comment during the public-comment period, which begins on
August 2, 2012 and closes on August 31, 2012. On August 13, 2012, EPA will hold a public
meeting to discuss the remedial alternatives and proposed remedy. It will be held at the Lower
Salford Township Building (379 Main Street) in Harleysville, PA at 6:30 p.m.
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SITE HISTORY
The Site is located at 610 Quarry Road in Lower Salford Township, Montgomery County
Pennsylvania. See Figures 1 and 2. The Site was used from the early 1900s to the 1930s as a shale
quarry. The quarrying activities ceased due to increasing drainage difficulties resulting in water
collecting in the quarry. The Site was a local swimming hole for some time. In the 1950s, the
Ludwig and Son waste disposal business used the unlined site for disposal of industrial,
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commercial, and residential wastes. Some of this waste included fly ash cinders from a coal-fired
power plant.
In 1963, the quarry, as well as a 1.91-acre parcel on the west side of Quarry Road, was
purchased by the American Encaustic Tiling Company, Inc. The company changed its name to the
American Olean Tile Company (AOT) and, in 1969, granted the western parcel to Lower Salford
Township.
According to a general plan of operation for the quarry dated August 11, 1976, AOT
prepared the Site for disposal of process wastes by building an earthen dike parallel with Quarry
Road, approximately 12 feet wide and 10 feet high. The purpose of the dike was to control runoff
that might otherwise affect Quarry Road. AOT used the quarry for disposal of tile waste,
including fired and unfired scrap tile, glaze wash-up sludge (clarifier sludge), and settlement pond
sediment from their Lansdale, Pennsylvania plant. Disposal took place starting at the quarry
driveway off of Quarry Road, and proceeded across the quarry. The waste was dumped from
trucks and the trucks then backed over the waste for compaction.
AOT calculated that it ultimately disposed of 10,550 cubic yards of wastes, covering a
lateral area of approximately 12,000 square feet. Approximately half of the waste is scrap tile, and
the other is washup sludge. The sludge is composed of wash water from various glaze lines and
clay filters that are used in the tile-making process. Boron, in the form of borosilicate, was used in
the glaze. According to AOT, a typical glaze contained approximately 3 to 4 percent borosilicate.
Water contaminated with tetrachloroethene (PCE) and trichloroethene (TCE) was used to
wash equipment at the plant. Consequently, some PCE and TCE may have accumulated in the
clarifier sludge. Lead-containing slurries were also disposed at the Site starting in 1973. In
approximately 1969, two 10,000-gallon steel former waste oil tanks (still containing some waste
oil) were filled with tile slurry and placed in the quarry for disposal.
In October of 1971, AOT applied to the Pennsylvania Department of Environmental
Resources (PADER) for a solid waste disposal permit. In July 1973, PADER requested additional
information about the groundwater and the nature of the scrap tile and sludge that was being
disposed in order to complete the permit application. In response, AOT installed two monitoring
wells MW-01 (presumed to be upgradient) and MW-02 (presumed to be downgradient). See
Figure 3.
In December 1980, PADER notified AOT that it was in violation of Commonwealth law
for failure to have a permit for disposal of solid wastes. This Notice of Violation also requested
that AOT confirm the contents of the two 10,000-gallon steel tanks that were reported to be on
Site. AOT responded that the application for the required permit for disposal of solid wastes was
on file with PADER. However, in 1981 AOT located and sampled the tanks as requested. After
removing some fuel oil from one of the tanks, PADER allowed AOT to backfill the excavated
tanks.
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In May 1982, AOT closed the landfill by grading and capping the waste with
approximately six feet of clay. Topsoil was placed on the cap and seeded. The Site was closed to
the satisfaction of PADER in July 1982, but PADER required post-closure quarterly groundwater
monitoring at wells MW-01 and MW-02 from 1982 until at least 1987. Quarterly monitoring
extended through the 1990's to the present time and is still performed at the Site.
Also in 1982, PADER performed a Preliminary Assessment of the Site. A year later, in
April 1983, NUS Corporation (NUS) performed a Site Inspection for EPA Region III (NUS 1986).
NUS also prepared the Hazard Ranking System Scoring Package for Salford Quarry (HRS 1986),
which it submitted to EPA on January 10, 1986. Based on the HRS score, the Site was proposed
for listing on the National Priorities List (NPL) under CERCLA in January 1987. The NPL listing
was finalized on August 30, 1990. AOT challenged several scoring values, including the toxicity
and persistence of boron at the Site and the lack of data suggesting any release or threatened
release from the Site. On June 19, 1992, the United States Court of Appeals for the District of
Columbia removed Salford Quarry from the NPL, ruling that EPA had acted arbitrarily in
assessing both the toxicity and persistence of boron at the Site. The Site was re-scored to address
the concerns that AOT and the Court had raised with the initial scoring and re-proposed for
inclusion on the NPL on April 1, 1997. The Site remained in proposed status until the listing was
finalized on September 23, 2009.
AOT entered into a Consent Agreement with EPA in March 1988, and agreed to undertake
all actions required for implementation of an RI/FS. AOT retained the consulting services of
Environ Corporation (Environ), which prepared a work plan for the RI/FS in May 1988. At about
the same time, the Agency for Toxic Substances and Disease Registry (ATSDR) issued a report
concluding that the Site posed a potential risk to human health. ATSDR based its conclusion on
the risk to human health posed by possible exposure to hazardous substances via groundwater and
surface water.
In August of 1988, National Gypsum Company (NGC), the parent company of AOT, took
title of the Site, assuming all the obligations of AOT under the Consent Agreement. In October
1990, NGC petitioned the Unites States Bankruptcy Court for relief under Chapter 11 of the
Bankruptcy Code. On May 29, 1991, the United States, on behalf of EPA, filed a Proof of Claim
against NGC alleging NGC's liability under Section 107 of CERCLA, 42 U.S.C. § 9607, for the
release of hazardous substances discovered at the Site. On November 25, 1992, the United States
reached a settlement of EPA's claims against National Gypsum in the bankruptcy litigation. As a
result of this settlement, NGC established the Salford Quarry Custodial Trust, which, among other
things, owns and manages the Site property.
In spring of 1989, Environ performed an interim sampling event to collect data to help plan
the RI/FS. This sampling event included the collection of sediment and surface water from the
West Branch of Skippack Creek and the spring that is located near the Site between Quarry Road
and the Creek, as well as from monitoring wells and residential wells. The final RI/FS work plan
was submitted to EPA in May 1990. RI activities were initiated with the installation of eight new
monitoring wells, which are identified as MW-03 through MW-10 (Figure 3). Also as part of the
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RI/FS, a Natural Resources Inventory and Analysis Report (NRI Report) was prepared by Eastern
States Environmental. The NRI report concluded that existing natural habitats associated with the
Site did not indicate any evidence of significant impact resulting from the existence of the quarry.
In 1991, when sampling by Environ indicated that several residential wells were
contaminated with boron, an Incident Notification Report was filed with EPA's Emergency
Response Section (ERS). ERS confirmed the results and NGC offered to supply the potentially
affected residences with bottled water. By October 1991, 42 residences were eligible for this
water. In December of 1991, ATSDR issued an addendum to the Health Assessment for Salford
Quarry based on the residential well sample results. The revised conclusion was that the Site
posed a threat to human health. The assessment concluded that an alternate water supply should be
provided to the affected homes, and that the homes should be periodically monitored for site-
related contamination. Ultimately, ATSDR recommended that public water be made available to
residents within a specified distance of the Site. In July 1993, EPA began construction of a public
water line for 113 residences in the area of the Salford Quarry Site, which was completed in
January 1995. Bottled water was supplied to affected residents by NGC during the period when
EPA was constructing the waterline. EPA connected affected and potentially affected residences
up to 1.5 miles downgradient (i.e., to the southwest) of the quarry to public water supply to
mitigate immediate threats to human health while EPA evaluated whether additional studies or
cleanup activities would be necessary.
In 1998, ATSDR issued a Public Health Assessment (ATSDR, 1998) for Salford Quarry
that concluded 1) Salford Quarry no longer posed a public health threat to any citizen through
consumption of residential well water due to the installation of a public water line and 2) the spring
contaminated with boron presented a potential health hazard if people collect the water in
containers and use it for drinking. ATSDR recommended the following:
• Characterize the three-dimensional extent of the boron groundwater plume.
• Establish institutional controls and ordinances to prevent the drilling of water
supply wells in the zone of contaminated groundwater.
• Sample the off-site spring. If the spring near the Site is contaminated with boron
above the EPA lifetime health advisory level of 0.6 ppm1 (or 600 micrograms per
liter, |ig/L), consider restricting access to the spring.
SITE CHARACTERISTICS
The Salford Quarry Superfund Site is located at 610 Quarry Road in Lower Salford
Township, Montgomery County, Pennsylvania. Figures 1, 2 and 3 present the Site Location Map,
Zoning Districts and Land Parcel Boundaries Map, and Site Map, respectively. The population of
the township in 2000 was 12,893 (Montgomery County 2005). The quarry property covers
EPA's current lifetime health advisory level is 5 ppm as noted in 6/8/12 Administrative Record correspondence.
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approximately three acres and is bounded on the north, and east sides by residential properties, on
the south side by a residence and farm, and on the west side by quarry Road. The Site includes the
quarry and any areas where contamination from the quarry has come to be located.
Since the quarry was formed on the side of a hill, the quarry resulted in a roughly U-shaped
outline of the quarry walls with the western side of the quarry backfilled to grade. The former
quarry area covers approximately 1.5 acres. Original Site soils were removed by historic
quarrying activities. However, soils surrounding the quarry are mapped as the Lansdale and
Reaville series (PSU 2005). Lansdale soils form in materials weathered from gray or yellowish-
brown sandstone, conglomerate, and shale. Reaville soils form in materials weathered from shale
and siltstone. The depth to bedrock under these soils generally ranges from two to six feet. The
geologic units at the Site are characterized by well-fractured sedimentary rocks that dip gently to
the northwest. The Brunswick and Lockatong Formations underlie the Site. Figure 4 includes
these features as well as known fractures and seeps in and around the Site. In general,
groundwater flow is to the southwest toward the West Branch of Skippack Creek.
Topography in the area around the Site is characterized by moderately broad, gently rolling
hilltops separated by moderately narrow to moderately broad valley bottoms. Elevations within a
'/2-mile radius of the Site range from approximately 200 to 320 feet above mean sea level (amsl),
and the elevation of the quarry cap is approximately 235 feet amsl based on surveyed ground
surface elevations for Site monitoring wells MW-02 and MW-05, which are located on the Site
immediately adjacent to the western side of the quarry.
The most significant surface water body near the Site is the West Branch of Skippack
Creek about 320 feet west of the Site at an elevation of approximately 40 feet below the quarry
cap. The West Branch of the Skippack Creek flows to the south. The source of water for this
branch is two to three miles upstream of the Site, and its confluence with Skippack Creek is
approximately two miles downstream. Skippack Creek eventually flows into Perkiomen Creek, a
tributary of the Schuylkill River. The only other surface water body in the immediate vicinity is a
spring located between the Creek and the Site. Ponded water bodies are also located at points
north of the Site (Figure 3).
The West Branch of Skippack Creek receives the majority of surface water runoff from the
Site. Water drains off the Site to the west via the ramp to the front gate and across Quarry Road.
Water also drains off the Site to the southwest and flows to a culvert near the southern boundary of
the Site that runs to the west under Quarry Road. On the west side of the road, storm water flows
from the culvert down a slope into the dry stream bed with the ponded spring. It appears that some
storm water may drain to the ponded spring and some may drain to the dry stream bed immediately
downgradient of the spring. The dry stream bed reaches to the southwest and intersects with the
West Branch of the Skippack Creek.
The RI Report (CDM, 2007) identified the types, locations and quantities of contaminants
at the Site and evaluated the current and future effects of the contamination on human health and
the environment. The following technical data was obtained during the RI. The RI identified
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inorganic- and organic contaminants in the soil/waste and sediment as the contaminants of
potential concern (COPCs) for OU1.
Landfill Gas
In 2004, a landfill gas survey measured soil vapor at six locations at the surface and 11
locations in the subsurface (Figure 5). Three subsurface gas measurements were collected at the
waste characterization boring locations, and eight were located around the perimeter of the landfill
cap. Organic vapor readings in the surface locations were between 0.0 and 12.4 parts per million
(ppm), with the highest concentration detected in SG03 located near the center of the landfill cap.
No methane gas was detected, and oxygen was measured at normal levels for the surface gas
locations. Organic vapor readings for the subsurface gas locations were between 0 and 22 ppm,
with the highest concentration detected in LG10 located on the western property boundary.
However, the highest organic vapor reading was probably not attributable to Site conditions, as
there were no volatile organic concentrations detected in MW-02, a nearby monitoring well.
Methane was not detected substantially above background levels, and oxygen levels were normal
except at locations LG01 and LG03, where oxygen levels were detected at 7.1 percent and 9.3
percent, respectively. These low concentrations are likely attributed to instrument anomalies due
to soil moisture and not to the actual conditions of the landfill.
Landfill Waste
In 2004, EPA's contractor, CDM, advanced three waste borings (WT01 through WT03) to
characterize the waste; the borings were evenly spaced on the landfill through the clay cap and
waste to the bedrock base of the landfill. See Figure 5. In general, the topsoil and clay cap were
observed to be 6 feet thick (topsoil layer was 0.5 to 1 foot thick). Underlying the cap was a white-
to-light grey tile waste slurry zone, from approximately 6 to 26 feet below ground surface (bgs),
which is in sharp contrast to the mixed municipal waste that extends to the bedrock surface. The
upper limit of the saturated zone was observed at 18.8 feet bgs at waste boring WT01.
Additionally, groundwater was encountered at 18.5 and 18.6 feet bgs at locations WT02 and
WT03, respectively. Therefore, both the tile waste and mixed waste were within the saturated
zone. The tile waste zone generally consisted of moist-to-wet tile slurry containing fragmented or
whole pieces of ceramic floor tiles. The underlying municipal waste zone consisted of a mixture
of moist-to-wet broken glass, plastic, wood chips, nails, and other metals in a moderately silty-
sandy matrix. Auger refusal was encountered between 35.5 and 37.5 feet bgs at the bedrock
surface.
At each boring location, one sample was collected in the industrial tile slurry waste and one
sample was collected in the underlying mixed waste to be analyzed for Target Compound List
(TCL) and Target Analyte List (TAL) parameters, Toxic Characteristic Leaching Procedure
(TCLP) characteristics, total cyanide, total sulfide, boron, lithium, reactivity, ignitability,
corrosivity, pH, and water content. One additional sample was collected at WT03 in the saturated
zone of the tile slurry waste to compare results to the sample collected in the unsaturated zone.
The most common contaminant in the waste was inorganics. Boron is the Site's most
ubiquitous contaminant, although it had the sixth highest concentration among inorganics
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(maximum boron concentration was 3,150 mg/kg at WT02). The highest boron concentration was
detected in the upper tile waste; however, boron was pervasive throughout both the tile and
municipal waste.
Five non-nutrient metals (iron, zinc, lead, aluminum, and copper) were detected at the
Site's highest concentrations. Additionally, cadmium and lead concentrations in tile waste
exceeded federal regulatory limits for hazardous waste in all three sampling locations, as presented
below.
Table 1
Landfill Waste Concentrations of Cadmium and Lead
Contaminant
Hazardous Waste
Regulatory Limit
(ng/L)
Concentration
in WT01 (ng/L)
Concentration
in WT02 (ng/L)
Concentration
in WT03 (jug/L)
Cadmium
1,000
1,100
1,240
2,140
Lead
5,000
107,000
62,300
143,000
The waste samples were analyzed using the TCLP to determine if the waste would be
characterized as hazardous waste based on toxicity. Based on the TCLP analytical results, the
upper tile waste zone was identified as hazardous waste because lead and cadmium concentrations
exceeded the federal TCLP limits. A TCLP limit does not exist for boron. In addition, no TCLP
criteria were exceeded in the deeper municipal waste zone. The hazardous waste regulatory limit
provides information that cadmium and lead concentrations in the waste have the potential to
migrate into groundwater. Specific risks are discussed in the section "Summary of Site Risks."
Although organic contaminants were not significantly pervasive in the waste and
exceedances of screening levels were limited to benzo(a)pyrene, Aroclor-1254, and Aroclor-1260,
the appearance of TCE and TCE degradation products in groundwater, coupled with the presence
of organics in the saturated zone (the water table is within the landfill waste), suggest the presence
of a soil-to-groundwater pathway (i.e., downward migration of contamination in soil and waste to
the underlying aquifer system) at the Site.
Surface and Subsurface Soil
Surface and subsurface soil samples were each collected at five locations situated around
the perimeter of the landfill and at three locations off-site and upgradient from the landfill (Figure
6). Each sample location had a surface soil sample taken from 0-6" below ground surface (bgs)
and a subsurface soil sample taken from 6-24" bgs. The greatest concentrations of inorganic
contaminants (i.e., aluminum at 24,200 mg/kg, chromium at 91.5 mg/kg, copper at 1,820 mg/kg,
iron at 63,600 mg/kg, lead at 1940 mg/kg, mercury at 71.4 mg/kg, and zinc at 2,390 mg/kg) were
found in the subsurface soil located at the west side of the Site in SL-08. Low levels of VOCs, e.g.
PCE, were detected in subsurface soils in all boring locations (SL04 through SL07 with
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concentrations between 3 J |ig/kg and 7 J |ig/kg. At SL-08, PCE, TCE, and cis 1 2 dichloroethene
(cis 1,2 DCE) were 11 J ng/kg, 160 J |ig/kg and 19 J |ig/kg respectively.
Unusual patterns of dead vegetation were first noticed at the base (between cap toe and
Quarry Road) of the disposal area on the Site property in 2004. Site visits since 2004 have
revealed that the area surrounding the spring and dry creek bed continue to be devoid of
vegetation. The water table is near the surface on the western side of the Site and contaminated
water may be within the root zone of many plants. Various contaminants that tend to bind to soil
particles may persist in the soil following an extended drought due to their physical properties.
Therefore, these contaminants would also be available for uptake by plants.
The distribution of maximum detected concentrations in soil and observation of damaged
vegetation suggests that a hot spot exists where the stressed/dead vegetation is observed at the toe
of the landfill near the east side of Quarry Road.
Surface Water and Sediment
In the Fall of 2002, EPA conducted a stream survey to identify possible areas where seeps
or springs may be discharging groundwater into the West Branch of the Skippack Creek. The
survey included visually observing the spring west of the landfill as well as the stream and stream
bank, and measuring temperature and conductivity at 20-foot intervals along the stream
downgradient from the Site. Data were collected from 97 stations along 1,940 feet of stream-
length from the Quarry Road bridge upstream to a point adjacent to MW-06. Figure 7 presents the
2002 stream survey locations along the West Branch of Skippack Creek. During the survey, the
spring was observed to consist of two small pools, each approximately one foot deep, three feet
long, and three feet wide. A dry creek bed leading from the spring to the creek was noted,
although this channel was completely dry on the day of the survey.
Two rounds of surface water and sediment samples were collected at 11 locations along the
West Branch of Skippack Creek and from the spring west of the Site near the Creek (Figure 8).
The first and second rounds of sampling occurred during the Summer 2004 and Fall 2004,
respectively. The samples were analyzed for TCL VOCs, TAL inorganics, boron and lithium. The
sediment samples were also analyzed for total organic carbon, grain size and pH during Summer
2004.
In the surface water samples, the highest concentrations of boron (with a maximum of
70,400 |ig/L in the spring sample) were detected in SW-01, SW-02, SW-03, SW-04, SW-05, and
SW-06, which are located hydraulically downgradient from the quarry, suggesting that the boron is
site-related. See Figure 9. The maximum concentration of selenium (10.4 J |ig/L) was detected at
the spring (SW-01), while the maximum concentration of aluminum (1,560 |ig/L) was detected at
SW02 and for iron 1,028.5 |ig/L at SW-05. The highest concentration of cadmium (0.49 B |ig/L)
was detected at SW-06, although the cadmium concentration is qualified because it was not
detected substantially above concentrations detected in laboratory or field blank samples.
Trichloroethylene was detected at low levels at SW-01 Spring sample (maximum 3.9 |ig/L); Cis
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1,2-Dichloroethene was detected at a maximum concentration of 0.55 ug/L at SWOl. All other
locations were non-detect for VOCs.
In the sediment samples, the highest concentrations of metals in sediment were found at the
spring (SD-01), which is located immediately downgradient of the quarry, and location SD-07,
which is located approximately 160 feet away from the creek. The maximum concentrations of
boron (84.2 mg/kg), manganese (5,230 mg/kg), and thallium (8.9 mg/kg) were detected at
sediment sampling location SD-01. The maximum concentrations of antimony (6.0 J mg/kg),
arsenic (25.9 L mg/kg), copper (41.1 mg/kg), iron (48,800 mg/kg), and nickel (37.4 mg/kg) were
detected at sediment sampling location SD-07. The maximum concentration of lead (38.9 mg/kg)
was detected at SD01. Maximum concentration of cadmium (1.4 mg/kg) was detected at SD-09,
cyanide (0.79 J mg/kg) and vanadium (69.8 mg/kg) were detected at SD-09, which is upstream of
the quarry. In addition, aluminum (20,400 mg/kg) had a maximum concentration at SD-08.
Lithium had a maximum concentration (43.6 mg/kg) at SD01. Low level VOCs were detected in
the sediment samples.
The highest concentration of boron was detected in the spring sediment SD-01 with the
next highest concentration being detected at location SD-07. See Figure 9. Concentrations of
boron in sediment may act as a source to the boron contamination in surface water. Because of its
chemical nature, boron exists as boric acid in the surface water. Boric acid tends to sorb to iron
and aluminum hydroxy compounds, clay minerals, or organic carbon. Therefore, boron could be
adsorbed to the sediment, and remobilize into water when resaturated at the spring.
Groundwater- Site Monitoring Wells
RI data from 1991 to 1993 show contamination extending southwest of the Site (Figure
10). During the 2002/2004 sampling rounds, groundwater samples were collected from ten Site
monitoring wells (MW-01 through MW-10), shown on Figure 11, and analyzed for various site-
related VOCs, SVOCs, pesticides/polychlorinated biphenyls (PCBs), and inorganics.
In general, inorganic concentrations are highest in MW-02 and MW-08, which are both
downgradient from the contaminant source, suggesting migration of site-related contaminants to
these areas. MW-02, which is immediately next to the quarry, showed he highest inorganic
concentrations for: antimony (2.6 |ig/L), arsenic (15.45 K |ig/L above the MCL of 10 ug/L), boron
(329,500 |ig/L), lithium (465 |ig/L), selenium (39.3 J |ig/L), and vanadium (5.75 |ig/L). Maximum
concentration for chromium (15.2 ug/L) was at MW05; iron (20,200 ug/L), at MW07; manganese
(541 ug/L), at MW08; and mercury (3.6 ug/L), at MW07. In addition, consistently high boron
concentrations on the west side of the stream at MW-10 suggest that there is also a flow regime
that is transporting contaminants to the southwest beyond the stream area. Boron is the most
ubiquitous contaminant found in the Site wells. Except for background well MW-06, boron was
detected in all Site monitoring wells.
The wells MW-02, MW-08 and MW-09, located immediately downgradient of the quarry,
showed the highest concentrations of contaminants. The highest concentrations of chloroform
(0.41 |ig/L), DCA (0.235 |ig/L), and VC (9.35 |ig/L) were detected at MW-02; the highest
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concentrations of benzene (0.35 |ig/L), TCE (28 |ig/L) and cis-l,2-DCE (7 |ig/L) were detected at
MW-08; and the highest concentrations of carbon tetrachloride (0.29 |ig/L) and PCE (0.7 |ig/L)
were detected at MW-09. One SVOC, bis(2-ethylhexyl)phthalate (10 |ig/L) was detected at MW-
02.
Groundwater- Area Residential Wells
Groundwater samples were collected from five residential wells in October 2002 (initial
sampling event), 14 residential wells in July/August 2004, and seven additional residential wells in
November 2004, for a total of 25 distinct locations beyond the Site monitoring wells. Three
additional residential wells were sampled in 2010 and a fourth well was sampled in 2011.
Compared to historic levels, the 2002 and 2004 analytical results suggest that the
concentrations of boron and other Site-related contamination in the groundwater have decreased at
locations away from the quarry. (Figure 11) Near the quarry, however, contamination continues to
persist at concentrations similar to levels detected in the early 1990s. Although the waste is a
continuing source, two factors may be influencing the reduction in boron concentrations
downgradient of the source: (1) reduction in groundwater withdrawal from residential wells, and
(2) the installation of the landfill cap in 1982.
In the early 1990s, residential wells in the area were still in use; however, by 1995, 113
homes had been connected to a public water system so that residents were provided with safe
drinking water. As a result, groundwater withdrawal significantly diminished, which, in turn,
reduced migration of Site contaminants downgradient of the quarry.
In addition, PADER oversaw the installation of a landfill cap covering the quarry in 1982.
As a result, the infiltration of surface water (i.e., precipitation) into the landfill has been reduced or
eliminated, reducing contaminants from leaching into the groundwater from stormwater
infiltration. Groundwater continues to be impacted by the water table residing within the landfill
waste. This waste/soil-to-groundwater pathway will continue until the source is addressed. The
Site conceptual model is presented in Figure 13.
SCOPE AND ROLE OF RESPONSE ACTION
This is the first planned action at the Site. The proposed remedial action will be a final
action for OU1. This remedy will control the source (quarry waste, soil and sediment) to prevent
additional contamination from migrating to groundwater and surface water (OU2). The remedial
action for OU2 will address remaining contamination in groundwater, surface water, and vapor
intrusion, if necessary and will be issued separately after the effectiveness of the OU1 remedy
proposed in this Proposed Plan is determined.
Salford Quarry Proposed Plan
August 2012
11
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The proposed actions are intended to address principal threat wastes at the Site. Principal
threat wastes are those source materials considered to be highly toxic or highly mobile that
generally cannot be reliably contained, or would present a significant risk to human health or the
environment should exposure occur.
A source material is a material that
includes or contains hazardous
substances, pollutants or
contaminants that act as a reservoir
for migration of contamination to
groundwater, surface water or air, or
acts as a source for direct exposure.
At this Site, the landfill waste,
soil, and sediment contamination are
considered principal threat wastes.
By addressing this contamination, the
proposed remedy will remove a
source of contamination to ground
and surface water and prevent further
migration of the contamination.
SUMMARY OF SITE RISKS
As part of the RI/FS, a Baseline Human Health Risk Assessment (HHRA) and a Screening
Level Ecological Risk Assessment (SLERA) were conducted to evaluate the potential risks
associated with site contaminants. Given the results of the HHRA and SLERA, it is EPA's current
judgment that the Preferred Alternative identified in this Proposed Plan, or one of the other active
measures considered in this Proposed Plan, is necessary to protect public health or welfare or the
environment from actual or threatened releases of hazardous substances, pollutants, and
contaminants into the environment.
In accordance with EPA guidance, risk-based screening was performed to identify
contaminants of potential concern (COPCs) in soil, waste, sediment, surface water, and
groundwater, which required further evaluation during the human health and ecological risk
assessments to determine which COPCs are COCs, or risk drivers. COCs are determined by taking
COPCs and running a site-specific risk analysis for each COPC and each pathway to indicate areas
of current or potential future risk that exceed EPA's acceptable risk level of 10"4 or exceed an HI
of 1. Table 2 summarizes the site-related COCs identified from both human health and ecological
risk assessments across multiple exposure pathways.
Salford Quarry Proposed Plan
August 2012
12
WHAT IS A "PRINCIPAL THREAT'?
The NCR establishes an expectation that EPA will use treatment to
address the principal threats posed by a site wherever practicable (NCP
Section 300.430(a)(1)(iii)(A)). The "principal threat" concept is applied
to the characterization of "source materials" at a Superfund site, A
source material is material that includes or contains hazardous
substances, pollutants or contaminants that act as a reservoir for
migration of contamination to ground water, surface water or air, or acts
as a source for direct exposure. Contaminated ground water generally
is not considered to be a source material; however, Non-Aqueous Phase
Liquids (NAPLs) in ground water may be viewed as source material.
Principal threat wastes are those source materials considered to be
highly toxic or highly mobile that generally cannot be reliably contained,
or would present a significant risk to human health or the environment
should exposure occur. The decision to treat these wastes is made on a
site-specific basis through a detailed analysis of the alternatives using
the nine remedy selection criteria This analysis provides a basis for
making a statutory finding that the remedy employs treatment as a
principal element.
AR300095
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Table 2
Contaminants of Concern
SLE]
RA *
HK
[RA
Soil
Sediment
Soil
Waste to
Groundwater
Aluminum
\
X
X
Antimony
X
Arsenic
X
Barium
X
Boron
\
X
X
Cadmium
X
X
X
Chromium
\
X
Copper
X
\
X
Cyanide
\
Iron
\
\
X
Lead
X
X
Lithium
X
X
Manganese
X
\
X
Mercury
\
X
Nickel
X
X
Vanadium
\
X
X
Zinc
X
X
X
X - Denotes COC (Contaminant of Concern); For Human health, COCs that contribute the most to the total cancer risks
and hazards are noted on Table 5 and 6 for each media by exposure pathways and exposure routes.
HHRA - Human Health Risk Assessment. For the HHRA, in addition to ingestion and direct contact, the soil COCs
were also identified for soil-to-air pathways. For groundwater, COCs were identified for ingestion of groundwater, skin
contact during bathing and inhalation of contaminants in groundwater during showering. All organics detected in
groundwater were considered for the potential vapors into basement from groundwater exposure route.
SLERA - Screening Level Ecological Risk Assessment
* Contaminants of concern denoted for SLERA were generated from a preliminary screening process. Further
evaluation would be required to refine the current list.
Shaded SLERA COPCs identify primary ecological risk drivers.
Human Health Risks
An HHRA estimates the likelihood of health problems occurring if no cleanup action were
taken at a site. To make these estimates, EPA analyzes the extent of contamination at a site and
considers the routes by which humans could come into contact with these substances under
existing land-use conditions or under potential future use scenarios. The current and/or future land
use assumed for the on- and off- Site receptor populations, and the exposure scenarios evaluated
for each land use in the HHRA are summarized in Tables 3 and 4.
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Table 3 Exposure Scenarios Evaluated for the Onsite Receptor Populations Potentially
Exposed to Inorganic and/or Organic Corn
taminants in Soil and Groundwater at the Site
Land Use
Receptor Population
Exposure Scenarios
Industrial
Current/Future* - Onsite
Maintenance workers
- incidental ingestion of and skin contact with inorganic and
organic contaminated surface soil.
- inhalation of airborne inorganic and organic particulates
and organic vapors from surface soil.
Current/Future - Onsite Visitors
- incidental ingestion of and skin contact with inorganic and
organic contaminated surface soil.
- inhalation of inorganic and organic airborne particulates
and organic vapors from surface soil.
Current/Future - Onsite Trespassers
- incidental ingestion of and skin contact with inorganic and
organic contaminated surface soil.
- inhalation of inorganic and organic airborne particulates
and organic vapors from surface soil.
Future - Onsite Construction
Workers
- incidental ingestion of and skin contact with inorganic and
organic contaminated onsite soil surrounding waste and
waste in the quarry during removal and/or construction
operations.
- inhalation of inorganic and organic airborne particulates
and organic vapors from onsite soil surrounding waste and
waste in the quarry during removal and/or construction
operations.
- skin contact with inorganic and organic and inhalation of
organic contaminated vapors from groundwater located
approximately 15ft to 25ft below ground surface during
removal and/or construction operations.
Current/Future -Onsite Recreational
use of the of the nearby West Branch
of the Skippack Creek
- incidental ingestion of and skin contact with inorganic and
organic contaminated surface water and sediment while
wading and fishing.
- ingestion of inorganic and organic contaminated fish.
Current/Future - Onsite Recreational
use of the Spring located west of the
site and east of the West Branch of
the Skippack Creek.
- incidental ingestion of and skin contact with inorganic and
organic contaminated Spring water and inorganic and
organic sediment while wading.
Residential
Future- Onsite Residential use of the
facility by onsite residents
- incidental ingestion of and skin contact with inorganic and
organic in the soil surrounding the waste and inhalation of
airborne inorganic and organic particulates or organic vapors
from soil.
- ingestion of inorganic and organic contaminated water and
skin contact from bathing with the inorganic and organic
contaminated water and/or exposure to contaminated organic
vapors from showering with the water.
- Groundwater is located 15 ft to 25 ft below ground surface.
There may be a potential exposure for inhalation of volatile
organics that enter basements from the groundwater.
*The risks for the current maintenance worker, trespasser and visitor except for those posed by air (airborne vapors risks are
based on subsurface soil) are based on undisturbed surface soil. Future scenario risks for the maintenance worker are from
combined surface and subsurface soil; the risks for the future construction worker are based on disturbed surface and subsurface
soil (combined) surrounding the waste in the quarry (i.e., soil that surrounds the waste) or from soil in the waste. The risks for
the future resident are based on disturbed surface and subsurface soil (combined) surrounding the waste in the quarry.
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Table 4 Exposure Scenarios Evaluated for the Offsite Receptor Population Potentially
Exposed to Inorganic and/or Organic Contaminants
in Groundwater emanating from the Site
Land Use
Receptor Population
Exposure Scenario(s)
Residential
Current/Future* -Offsite Residents
using Residential Wells Tap Water
- skin contact with inorganic and organic and
inhalation of organic vapors while watering
gardens with contaminated groundwater via
residential wells tap water;
- ingestion of contaminated homegrown
vegetables from residential well tap water
with inorganic and organic used to water
garden.
- skin contact with inorganic and organic and
inhalation of organic vapors while playing
with sprinkler from contaminated residential
well tap water; and,
- incidental ingestion of contaminated
inorganic and organic water, inhalation of
organic vapors, and inorganic and organic
exposure through the skin while swimming in
tap water from the contaminated residential
well tap water used to fill up the swimming
pool.
- Groundwater is located 15 ft to 25 ft below
ground surface. There may be a potential for
current exposure for inhalation of volatile
organics that enter basements from the
groundwater.
Future - Offsite Residents using
Residential Wells Tap Water
- Groundwater is located 15 ft to 25 ft below
ground surface. There may be a potential for
future exposure for inhalation of volatile
organics that enter basements from the
potential migration of onsite contaminated
groundwater.
* Current scenario risks are based on individual residential well data while future scenario risks are based on
potential migration of onsite contaminated groundwater to residential wells. There are no known residents near the
site currently using or expected to use in the future the groundwater for ingestion, bathing or showering.
Separate risk calculations are made for substances in groundwater, soil, sediment, and
surface water that cause cancer (carcinogens) and for those that cause non-carcinogenic health
effects. The level of risk specified by EPA regulation to trigger an action for carcinogenic risks is
lxlO"4 or greater; the benchmark for non-carcinogenic risks is a Hazard Index (HI) of 1.
Carcinogenic and non-carcinogenic risks were estimated for potential human exposure with
affected groundwater, soil, sediment, and surface water at the Site (onsite.) Risks were also
Salford Quarry Proposed Plan
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estimated for offsite residents with existing
residential wells who may use their wells
currently or in the future for non-potable usages.
Risks were also estimated for offsite residents
based on the potential for future contaminated
groundwater to migrate to the offsite residential
area. To understand more about how an HHRA is
conducted, see the following text box entitled
"What is Risk and How is it Calculated?"
All populations and exposure pathways that
were evaluated for the Site (Tables 3 and 4) met
EPA's risk criteria of a cumulative excess cancer
risk of 1 x 10"4 or less and an HI less than 1, except
for those presented in Table 5 and 6 below. Tables
5 and 6 shows only the receptor populations (future
onsite and offsite) that did not meet EPA's risk
criteria by receptor population, primary exposure
pathways, and primary contaminant risk drivers for
groundwater (Table 5) and soil (Table 6).
Groundwater
The future total onsite resident lifetime
cancer risk is 1.1 x 10-3 and is driven by the future
groundwater exposure pathway (see Table 5). The
potential future groundwater lifetime cancer risk is
primarily driven by the potential future exposure to
vinyl chloride and to a lesser extent TCE and
arsenic in groundwater that is used for drinking by
children and adults, bathing by children and
showering by adults) and, by the potential future
resident child and adult exposure to TCE and vinyl
chloride vapors that may seep into the basement
from the contaminated groundwater. These
contaminants have been shown to migrate from
onsite contaminated soils waste to the groundwater
in levels that exceed EPA's acceptable level of risk.
The future total offsite resident lifetime
cancer risk is 1.5 xlO"4 (see Table 5) and is driven
by the future groundwater exposure pathway. The
potential future groundwater offsite resident lifetime
cancer risk is primarily driven by the potential
future exposure to vinyl chloride in groundwater in
Salford Quarry Proposed Plan
August 2012
WHAT IS RISK AND HOW IS IT CALCULATED?
A Superfund human health risk assessment estimates the
baseline risk. This is an estimate of the likelihood of health
problems occurring if no cleanup action were taken at a site.
To estimate the baseline risk at a Superfund site, EPA
undertakes a four-step process:
Step 1
Step 2
Step 3
Step 4
Analyze Contamination
Estimate Exposure
Assess Potential Health Dangers
Characterize Site Risk
In Step 1, EPA looks at the concentrations of contaminants
found at a site as well as past scientific studies on the effects
these contaminants have had on people (or animals, when
human studies are unavailable). Comparisons between site-
specific concentrations and concentrations reported in past
studies help EPA to determine which contaminants are most
likely to pose the greatest threat to human health.
In Step 2, EPA considers the different ways that people
might be exposed to the contaminants identified in Step 1,
the concentrations that people might be exposed to, and the
potential frequency and duration of exposure. Using this
information, EPA calculates a reasonable maximum
exposure (RME) scenario, which portrays the highest level
of human exposure that could reasonably be expected to
In Step 3, EPA uses the information from Step 2 combined
with information on the toxicity of each chemical to assess
potential health risks. EPA considers two types of risk:
cancer risk and non-cancer risk. The likelihood of any kind
of cancer resulting from a Superfund site is generally
expressed as an upper bound probability; for example, a 1 in
10,000 chance. In other words, for every 10,000 people
exposed, one extra cancer may occur as a result of exposure
to site contaminants. An extra cancer case means that one
more person could get cancer than would normally be
expected, given the background cancer rate. For non-cancer
adverse health effects, EPA calculates a hazard index. The
key concept here is that a threshold level (measured usually
as a hazard index of less than 1) exists below which non-
cancer adverse health effects are no longer predicted.
In Step 4, EPA determines whether site risks are great
enough to cause health problems for people at or near the
Superfund site. The results of the three previous steps are
combined, evaluated and summarized. EPA adds up the
potential risks from the individual contaminants and
exposure pathways and calculates a total site risk.
16
AR300099
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Table 5
Summary of Risks for Future Receptor Population Exposures
Exceeding EPA's Risk Criteria* due to Groundwater
Receptor
Population
Cancer
Risk
HI
Primary Exposure
Pathway(s)
Primary
Contaminant Risk
Driver(s)
Future off-site
resident-combined
child/adult
(lifetime*)
1.5 E-04
NA
-ingestion of swimming pool
water;
-Skin exposure through
sprinklers and swimming pool;
-Inhalation of airborne vapors
in swimming pool; and,
-Inhalation of airborne vapors
in the basement.
Vinyl Chloride
Vinyl Chloride
Vinyl Chloride
Vinyl Chloride and
TCE
Future on-site
resident- adult
27
-Ingestion of tap water
Boron, Arsenic, and
TCE
Future on-site
resident- child
82
-Ingestion of tap water; skin
exposure through bathing
Boron, Arsenic, Iron,
Lithium, Manganese,
and TCE.
Future on-site
resident- combined
child/adult
(lifetime)
1.1E-03
NA
Ingestion of tap water; skin
exposure through bathing;
Inhalation of vapors from
showering; and,
Inhalation of vapors in
basement
TCE, Vinyl Chloride
and Arsenic.
TCE
TCE and Vinyl
Chloride
* The receptor populations include soil and groundwater for future onsite residents and groundwater only for future offsite
residents. EPA's Risk Criteria: Cancer Risk- 1E-04-1E-06, HI<1; Lifetime cancer risks are additive for the child and adult
resident; NA- Not Applicable - Non-cancer risks are not additive across receptor populations; Separate child and adult His are
presented for media driving the total non-carcinogenic risk (His) presented in the text. Note that there were no His exceedances for
the future off-site resident child or adult receptor population (HI<1); Therefore, non-cancer risks were not included in this table for
the off-site resident exposure to future groundwater from the Site (see text.)
residential wells tap water used in sprinklers and in swimming pools ; and, primarily driven by
potential future offsite resident lifetime exposure to vinyl chloride and TCE vapors that may seep
into the basement from contaminated groundwater. It should be noted that offsite residential well
water use is not expected, since offsite residents are connected to a public water supply. Seepage
Salford Quarry Proposed Plan
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AR300100
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of vapors from potentially contaminated groundwater that could migrate offsite is the only viable
exposure pathway for offsite residents. This exposure pathway (noted above) meets EPA's
acceptable risk criteria.
Soil
Contaminants, including VOCs and inorganics, found in the waste and the soil surrounding
the waste were evaluated for risk to current and future onsite and off-site residents. The potential
future onsite soil HI (see Table 6) for a future on site resident child that has direct contact (e.g.,
incidental ingestion, skin contact, and inhalation of airborne soil contaminants) with soil
surrounding waste is primarily driven by copper, lead, iron, manganese, mercury, vanadium, zinc
and, to a lesser extent, aluminum, cadmium and chromium.
Table 6
Summary of Risks for Future Receptor Population Exposures
Exceeding EPA's Risk Criteria* due to Soil
Receptor
Population
Cancer
Risk
HI
Media Driving
the Cancer
Risk/Hi
Primary Exposure
Pathway(s)
Primary
Contaminant
Risk
Driver(s)
Future on-site
resident- child
8.9
Soil
-Ingestion of soil surrounding the waste
Aluminum,
Cadmium,
Chromium,
Copper, Iron,
Lead,
Manganese,
Mercury,
Vanadium and
Zinc.
* The receptor populations include soil and groundwater for future onsite residents and groundwater only for future offsite
residents. EPA's Risk Criteria: Cancer Risk- 1E-04-1E-06, HI<1; Lifetime cancer risks are additive for the child and adult
resident; Non-cancer risks are not additive; Separate child and adult His are presented for media driving the total non-carcinogenic
risk (His) presented in the text. Note that there were no HI exceedance for the future on-site resident adult (HI=1) and no cancer
risk exceedance for the future on-site resident-combined child/adult (lifetime cancer risk
-------
EPA also analyzed the soil-to-groundwater pathway to determine if there was a continuing
source of groundwater contamination from the waste. Soil-to-groundwater screening levels were
used to screen for COCs. The maximum concentrations of three metals (boron, cadmium, and
zinc) in quarry waste soil exceeded the human health criteria soil-to-groundwater screening levels
(see Table 7) that are determined to result in groundwater concentrations that pose an unacceptable
risk to receptor populations that drink, bathe and/or use the groundwater for showering.
Table 7
Waste Soil Screening for Groundwater Protection
Range of Concentrations
Site Specific
Range of HI
Contaminant in
Found in Waste Soil
SSLs*
Found in Waste
Waste Soil
(mg/kg)
(mg/kg)
Soil (mg/kg)
Boron
1042-3150
22
47-143
Cadmium
50-117
13
3.8-9
Zinc
22350-29600
6895
3.2-4.3
Soil-to-Groundwater Screening Levels represent HI=1, based on a DAF of 9.85 and back calculated from the April 2006 EPA Region
III RBC Table for tap water.
Exceedances of MCLs for VOCs (TCE and vinyl chloride), bis-2-ethylhexyl phthalate and
arsenic directly beneath the quarry also triggers cleanup of the source material. TCE detected in
wells MW-02 and MW-08 exceeded its MCLs of 5 jj.g/1, and VC detected in wells MW-02 and
MW-08 exceeded its MCL of 2 |ig/l. Bis(2-ethylhexyl)phthalate was detected one time at MW-02
at a concentration of 10 |ig/L, which exceeded the MCL 6 |ig/L. Arsenic, detected at 15.45 K |ig/L
in well MW-02, exceeded the MCL of 10 ug/L.
Human Health Risk Summary
The EPA background study performed for COCs in groundwater and soil conclusively
showed that COC concentrations in both soil and groundwater are higher than background.
Therefore, these COCs cannot be eliminated from future remedial decisions on this basis.
The future total onsite resident non-carcinogenic risk (summed across receptors, pathways
and media) of an HI of 91 for the child resident and HI of 28 for the adult resident exceeds the
threshold at which non-carcinogenic effects can occur and is driven by the future groundwater and
soil exposure pathways. The potential future onsite groundwater His (see Table 5) for the future
child and for the future adult resident are primarily driven by boron in groundwater and to a lesser
extent by TCE, arsenic, iron, lithium, and manganese. The potential future onsite soil HI (see
Table 6) for a future on-site resident child that has direct contact (e.g., incidental ingestion) with
the soil surrounding the waste is primarily driven by copper, iron, lead, manganese, mercury,
vanadium and zinc, and to a lesser extent to aluminum, cadmium and chromium.
Boron, cadmium, and zinc in the source material located in the waste exceeded their
Salford Quarry Proposed Plan
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respective soil-to-groundwater screening levels. Therefore, future groundwater that is used for
drinking (by onsite children and adults); bathing (by onsite children); showering (by onsite adults);
in swimming pools and sprinklers by offsite children and adult); and, that can potentially impact
onsite and offsite residents due to vapor intrusion into indoor air, poses a risk due to the source
material located in the waste that have leached into groundwater and from the source material that
have leached into the soil surrounding the waste and into the groundwater. Soil that is used by
future onsite residence also poses a risk by the ingestion route due to the source material that have
leached into the soil surrounding the waste.
The future total onsite resident lifetime cancer risk of 1.1 x 10-3 (see Table 5), and the
future total offsite resident lifetime cancer risk of 1.5 xlO"4 (see Table 5) are driven by the future
groundwater exposure pathway. There were no cancer risk exceedances for the soil pathway. As
noted above, the groundwater pathway risks are due to the source material located in the waste and
to the source material that have leached into the soil surrounding the waste and into the
groundwater.
It should be noted that the offsite residences downgradient from the quarry are connected to
public drinking water. Therefore, the offsite residences were not assumed to be at risk from
contamination from groundwater used as a potable source. Future risk estimates are provided for
offsite use of residential wells only to inform the offsite residents of their risk if they were to use
their private wells for non-potable usages similar to those assessed in the risk assessment. The
only viable exposure pathway for the offsite resident due to the Site source material in the landfill
is vapor intrusion into the basement of the residences from contaminated groundwater migrating
offsite impacted by the waste and soil surrounding the waste. Currently, the potential for vapor
intrusion into indoor air is low, since the volatile groundwater contamination is limited to directly
beneath the quarry (Figure 12).
Ecological Risks
The primary objective of the SLERA was to characterize the risk to ecological receptors on
and near the Site that may be exposed to contaminants in groundwater, surface water, soil, and
sediment. The SLERA represents Steps 1, 2, and portions of Step 3 of the eight-step process
provided in EPA's "Ecological Risk Assessment Guidance for Superfund: Process for Designing
and Conducting Ecological Risk Assessments'" (USEPA 1997c).
In the SLERA, EPA's contractor, CDM, screened analytical results from the RI against
ecological baseline screening values and developed a list of COPCs. The COPCs are chemicals
whose concentrations exceeded their respective ecological screening value. The selection of
COPCs is used to narrow the focus of the ecological risk assessment. The selection process serves
to identify dominant ecological Site risk and to guide future remediation decisions. The COPCs
were developed during the SLERA. Table 2 above shows the primary ecological risk drivers in the
shaded boxes.
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The Hazard Quotient (HQ) is the ratio of an exposure level by a contaminant (e.g.,
maximum concentration) to a screening value selected for the risk assessment for that substance. If
the exposure level is higher than the screening/toxicity value (HQ > 1) then there is the potential
for risk to the receptor.
The ecological risk assessment concluded that there is a continued potential for Site-related
contaminants to be transported to nearby areas and impact both aquatic and terrestrial habitats.
Also, the SLERA found that animal, avian, and reptile species on Site were at risk due to onsite
soil contamination. Risk based on direct toxicity to ecological receptors was determined based on
exposure to contaminants in soil, sediment, and groundwater, with the majority of the risk due to
inorganic analytes.
Soil
The mean concentrations for all COPCs identified in the surface and subsurface soil, for
which screening values were available, exceeded the average background concentrations.
Moreover, the mean concentrations for mercury (120 times), lead (14 times), copper (11 times),
zinc (5 times), and cadmium (4 times) were all significantly above their average background
concentrations. In addition, the maximum concentration detected for each of these compounds in
subsurface soil was detected at SL08, located directly west of the quarry. The maximum
concentrations for vanadium and manganese identified in the subsurface soil were detected at
SL07, located near SL08, which is also on the west side of the quarry.
No VOCs exceeded ecological screening levels, therefore further VOC analysis was not
undertaken. Ten inorganic analytes (aluminum, chromium, copper, iron, lead, lithium, manganese,
mercury, vanadium, and zinc) exceeded ecological screening levels in surface soil. See Table 8.
Ten inorganic analytes (aluminum, cadmium, chromium, copper, iron, lead, manganese, mercury,
vanadium, and zinc) from the human health screening, as well as boron and lithium exceeded
ecological screening values in subsurface soil. Addressing soil for human health receptors in
subsurface soil will also ensure protection of ecological receptors.
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Table 8 Ecological Risk, Surface Soil
Contaminant
Maximum
Concentration (mg/kg)
Ecological Screening
Level
Surface Soil (mg/kg)
HQ
aluminum*
24,200
1
24,200
chromium
91.5
0.0075
12,200
copper
1,820
15
121
iron
63,600
12
5,300
lead
1,940
16
121
lithium
33
2
16.5
manganese
2,050
330
6.21
mercury
71.4
0.058
1,231
vanadium
49.9
0.5
99.8
zinc
2,390
348.53
6.86
*Since aluminum mobility is pH dependent, it is a COC at locations demonstrating the low pH levels.
Sediment
Thirteen inorganics were identified in the screening-level ecological risk assessment as
COCs: aluminum, antimony, arsenic, barium, boron, cadmium, copper, cyanide, iron, lithium,
manganese, nickel, and vanadium. See Table 9. The mean concentrations for all COPCs
identified in the sediment, for which screening values were available, exceeded the average
background concentrations, except for cadmium. However, it is important to note that all
exceedances were no greater than a factor of two, indicating that mean concentrations were not
greatly elevated above background concentrations. The highest hazard quotient (HQ) was
identified for manganese, calculated from the highest manganese concentration in the sediment
sample collected at the spring (SD01). However, most of the maximum concentrations were
detected at SD07, located in the stream bed directly across from the quarry, likely corresponding to
a point of groundwater discharge.
Since no sediment screening values are available for aluminum, barium, beryllium, boron,
lithium, thallium, and vanadium, background values were calculated using existing upstream data
(SD-09, SD-10, SD-11 and SD-12).
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Table 9 Ecological Risk, Sediment
Contaminant
Maximum
Concentration (mg/kg)
Ecological Screening
Level
Sediment (mg/kg)
HQ
aluminum
23,200
NV
NV
antimony
6
2
3.00
arsenic
25.9
9.8
2.64
barium
505
NV
NV
boron
84.2
NV
NV
cadmium
1.4
0.99
1.41
copper
41.1
31.6
1.30
cyanide
0.79
0.1
7.90
iron
48,800
20,000
2.44
lithium
46.1
NV
NV
manganese
5,230
460
11.37
nickel
37.4
22.7
1.65
vanadium
69.8
NV
NV
NV= no screening value, background values calculated
REMEDIAL ACTION OBJECTIVES
The goal for the final remedy for waste, soil and sediment (OU1) at the Salford Quarry
Site OU1 is to reduce contaminant concentrations to levels that do not present an unacceptable risk
to human health and the environment. Several remedial action objectives (RAOs) have been
identified to mitigate the potential present and/or future risks associated with OU1. These
remedial action objectives are:
• Prevent/minimize human exposure, including ingestion, inhalation, and dermal contact, and
environmental exposure to the quarry waste and related contaminants in the soil.
• Prevent/minimize the migration of contaminants in the waste and soil to the groundwater.
• Prevent/minimize the impacts to the West Branch of Skippack Creek from migration of
contaminants from the soil.
• Prevent/minimize the migration of contaminants in onsite sediment via surface runoff to
adjacent properties and the West Branch of the Skippack Creek; and
• Prevent/minimize exposure to contaminants in soil and sediment by biota.
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In order to address the unacceptable risks posed by conditions at OU1 of the Site and,
thereby, protect human health and the environment, cleanup levels and objectives have been
developed as follows:
For waste and soil, the selected action should address contaminant migration to
surrounding soil, surface water, and groundwater and prevent exposure to waste and soil. Waste
cleanup levels are based on exceedance of site-specific Soil Screening Levels (SSLs). Waste
delineation is an action-specific goal, and waste will be remediated based on visual observation of
contamination. Ultimate disposition of waste will be based on characterization via TCLP as
hazardous or non-hazardous waste.
Table 10 summarizes the cleanup levels for both waste discussed in the previous paragraph
and the soil surrounding the waste. Cleanup goals for the soil surrounding the waste are the more
stringent of site-specific risk-based goals for direct contact (i.e., ingestion, skin contact and
inhalation of airborne contaminants) for the future onsite child and onsite resident. Table 10
presents the more stringent of the cleanup goals for waste and soil surrounding the waste. Post-
excavation confirmation soil sampling, encountering bedrock, undermining Quarry Road, and/or
field observations of stressed vegetation will determine extent of cleanup.
Table 10 Cleanup Levels for Waste and Soil Surrounding the Waste
Contaminant of Concern
Remedial Goal (mg/Kg)
Aluminum
19,021
Boron
22
Cadmium
12
Chromium
111
Copper
1,014
Iron
11,000
Lead
341
Manganese
230
Mercury
8.4
Vanadium
6.3
Zinc
4,565
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For sediment, the selected action should be protective of ecological receptors and minimize
the transport of contamination to the surrounding ground, surface water, and groundwater. There
are no ecological screening values for some COCs. Extent of sediment removal should be based
upon vegetation void, sediment accumulation near the spring, or white residue in the spring water
apparently associated with high contaminant concentrations. This area is an approximately 400
square foot area immediately surrounding SD-07 on Figure 9. Cleanup of sediment to background
concentrations while the source (waste and soil) is addressed will mitigate risk to ecological
receptors. Sediment cleanup levels (presented in Table 11) are the higher of either the SLERA
screening value or the maximum background concentration from the 2002 and 2004 sediment
sampling events at locations SD09, SD10, SD11, and SD12. It is expected that these numbers will
adequately bound the area which is visually void of vegetation near the spring. These numbers
may be refined based upon sampling during design.
Table 11
Cleanup Levels for Sediment
Contaminant of Concern
Remedial Goal (mg/Kg)
Aluminum
15,600
Antimony
3.3
Arsenic
15.1
Barium
231
Boron
9.8
Cadmium
1.5
Copper
35.5
Cyanide
0.79
Iron
35,300
Lithium
31.3
Manganese
2,490
Nickel
32.7
Vanadium
69.8
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Monitoring the sediment and surface water will determine if the cleanup action attenuates
transport of contamination. As part of the Long-Term Monitoring at the Site, groundwater shall be
monitored to assess the effectiveness of the source control.
SUMMARY OF REMEDIAL ALTERNATIVES
The Superfund law and regulations require that the alternative chosen to clean up a
contaminated site meet several criteria. The alternative must protect human health and the
environment and meet the requirements of environmental regulations. Permanent solutions to
contamination problems, which reduce the volume, toxicity, or mobility of the contaminants,
should be developed wherever possible. 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.
The FS identified and evaluated a range of remedial alternatives to protect human health
and the environment from potential risks associated with OU1 of the Site. The alternatives are:
Waste and Soil Alternatives (WS)
WS1 No Action
WS2 Limited Action
WS3 Capping
WS4 Engineered Cell
WS5 Solidification/Stabilization
WS6 Excavation and Offsite Treatment/Disposal
Sediment Alternatives (SD)
SD1 No Action
SD2 Limited Action
SD3 Removal and Onsite Treatment/Disposal
SD4 Removal and Offsite Treatment/Disposal
Section 121 (c) of CERCLA, 42 U.S.C. § 9621(c), requires that the Site be reviewed for
protectiveness every five years if contamination remains at the Site at levels that pose an
unacceptable risk to human health or the environment. EPA will perform five-year reviews if
contamination remains at the Site.
Waste and Soil Alternatives
Alternative WS 1: No Action
Present Worth Cost $ 0
Implementation Time N/A
The no action alternative is required to be considered by the NCP to provide a baseline for
comparison with other alternatives. Under this alternative, no further action would be
implemented and the current status of the waste and soil would remain unchanged. The cap may
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continue to deteriorate resulting in increasing infiltration of water and greater dissolution of
contaminants into the environment. Under Alternative WS1, the existing landfill cap would
continue to minimize water infiltration.
Alternative WS2: Limited Action
Present Worth Cost not calculated since fails threshold criteria
Implementation Time 12 months
For this alternative, repairs to the cap, Institutional Controls (ICs), and additional
engineering controls at the Site would be employed to protect human health. The existing landfill
cap consists of up to six feet of clayey soil based on previous reports and RI borings. While the
cap may not have been adequately maintained since construction in 1982, it has substantially
reduced infiltration of precipitation through the landfill waste to the groundwater when compared
to the infiltration that would have occurred with no cap on the waste material. Repairs to the
existing landfill cap would continue to minimize water infiltration. This alternative does not
address the potential for contaminant migration from waste below the water table to groundwater.
ICs at the Site would restrict contact with contamination through proprietary (e.g.,
easements, covenants) and/or local governmental (e.g., zoning requirements) controls to prevent
redevelopment of the property for use in a manner that would pose an unacceptable risk to
receptors (i.e. for residential use). Engineering controls (fencing, routine inspections) also would
be employed to limit access to the Site. This alternative also includes five-year reviews to ensure
protectiveness for as long as hazardous substances remain on Site posing an unacceptable risk to
human health or the environment.
Alternative WS3: Capping
Present Worth Cost not calculated since fails threshold criteria
Implementation Time 2 months
This alternative includes the construction of a geomembrane cap over areas of the Site
containing contaminated soils that exceed soil cleanup levels. The geomembrane cap would
include a geomembrane barrier layer overlain by protective and vegetative layers and would be
tied into the existing landfill waste cap to promote drainage away from the capped area. The
existing landfill cap over the waste area would continue to minimize water infiltration while the
geomembrane cap would control infiltration of precipitation into other affected areas and limit
direct contact with contaminants by receptors. This alternative does not address the potential for
contaminant migration from waste below the water table to groundwater.
This alternative also includes long-term cap maintenance, property access restrictions, and
institutional controls, such as a restrictive covenant, to control future use of the property. Long-
term cap maintenance would include routine inspection and repair and any auxiliary components
such as surface drainage controls.
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Alternative WS4: Engineered Cell
Present Worth Cost $ 3,327,200
Implementation Time 6 months
This alternative includes excavation and stockpiling of material from the existing cap,
excavation of waste and contaminated soil, construction of a low-permeability engineered cell,
long-term maintenance of engineered cell and drainage system, and institutional controls.
The material comprising the existing cap would be excavated and stockpiled for use during
the construction of the engineered cell. The cap consists of silty clay ranging from 4 to 6 feet thick,
with an estimated average thickness of 4.5 feet, and an estimated volume of 7,167 cubic yards.
Standard heavy construction equipment would be employed for this earthwork activity.
The waste material would be excavated from ground surface to the bottom of the quarry
and temporarily stockpiled. The estimated tile waste volume is 14,513 cubic yards and the
estimated municipal waste volume is 20,815 cubic yards. The total thickness of the landfill
(including the cap) is approximately 30 feet, with half of the waste material located below the
water table where it continues to serve as a source of groundwater contamination. Visible evidence
of waste material would be used to determine when excavation is complete. Also, the bottom of
the quarry is located at the bedrock surface providing a physical barrier for the bottom depth of the
waste.
The contaminated soil would also be excavated and temporarily stockpiled on site. The
assumed contaminated soil volume is 8,956 cubic yards. The estimated volume to be excavated is
20% of the 120,900 square foot site property to a depth of 2 feet. Soil excavation cannot
undermine existing infrastructure, e.g. Quarry Road. Post-excavation soil sampling would verify
that cleanup levels are achieved.
Construction dewatering is required to complete subsurface excavation of the landfilled
waste that extends below the water table. Considering the hydraulic conductivity and specific
capacity of the aquifer, the FS estimated 9,600 gallons of groundwater would be generated per day
based on a conservative estimate of hydraulic conditions at the Site. Excavation below the water
table would occur for an estimated 60 day period during which management of 576,000 gallons of
wastewater would be necessary. Once collected, the wastewater would be treated using temporary
onsite ion exchange units to remove boron contamination and carbon adsorption units to remove
VOCs. The water would be treated to meet the substantive requirements of the National Pollutant
Discharge Elimination System (NPDES) and discharged to the West Branch of Skippack Creek.
This treatment step will reduce the volume of groundwater requiring off-site treatment by 90%
resulting in a more manageable quantity of 57,600 gallons to be transported off-site for treatment.
Surface water run on and run off would be controlled during waste and soil excavation by
installing conventional, temporary storm water/erosion control features, such as berms, ditches,
rock-lined check dams, erosion control blankets, and silt fencing, to minimize storm water run-off
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from work areas and prevent erosion and transport of contaminated soils/sediments to downslope
areas. Dust would be controlled through the use of water or commercial dust suppressants.
A low-permeability engineered cell would be constructed to contain the waste and
contaminated soil. The engineered cell would control leachate production and contaminant
migration by minimizing infiltration of rain water as well as eliminate lateral movement of
groundwater through contaminated waste materials. The cell would also act as a physical barrier,
preventing human exposure to contaminated materials via direct contact.
The landfill excavation area would be backfilled with clean fill to the elevation of the water
table (17,664 cubic yards) and a cell liner would be installed on top of the clean backfill. The
contaminated soil excavation area would be backfilled with clean fill (8,956 cubic yards) to ground
surface. It is estimated that 26,620 cubic yards of clean backfill would be required.
The footprint of the engineered cell is anticipated to be approximately 1 acre. It is
anticipated that the engineered cell would be constructed in general accordance with "Design and
Construction of RCRA/CERCLA Final Covers" (EPA 1991), with low-permeabiliy material above
and below the backfilled waste and contaminated soil. This approach was selected given that the
RI data demonstrated that the tile waste was a RCRA-characteristic hazardous waste because it
failed cadmium and lead TCLP tests. The municipal waste was determined to be non-hazardous
and the contaminated soil has not been tested for TCLP, but it is not expected to be hazardous
waste. The following layers for engineered cell construction have been considered for evaluation
purposes (from top to bottom):
Cap
• 6-inch vegetative layer
• 18-inch protective layer
• geotextile fabric layer
• 12-inch drainage layer
• 20-millimeter (mil) geomembrane barrier layer
• 24-inch low-permeability soil confining layer (
-------
evaluated during the remedial design. Should a leachate collection system be required, a water
treatment system would be needed to treat the leachate prior to discharge to Skippack Creek.
Geomembrane liners are typically installed in parallel sheets, which are seamed together in
accordance with strict quality control requirements (e.g., undergoing liner joint field welding and
meeting soil compaction requirements) to ensure construction of a continuous, low-permeability
barrier. The cell would be constructed with a graded slope to facilitate storm water runoff and
minimize infiltration. A landfill gas control system (e.g., gas vents) would not be required for the
cap, based on the age of the municipal waste materials present.
The process of excavating the waste below the water table, backfilling with clean fill to the
water table, placement of the cell liner, placement of stockpiled waste and contaminated soil, and
construction of the cell cap would raise the top elevation of the landfill area approximately 19 ft
above the current elevation of the cap if placed in the current landfill footprint. Optionally, the cell
could be constructed by grading towards the top elevation of the eastern quarry slope, which is
approximately 30 ft above the current cap elevation, thereby reducing the existing drop off at the
face of the quarry.
Drainage channels would be installed along the edge of the engineered cell to convey run
on/runoff water away from the cell and prevent infiltration. Surface water from these channels
would be directed to existing drainage features that ultimately discharge to the West Branch of
Skippack Creek.
This alternative would include property access restrictions and ICs, such as a township
ordinance or restrictive covenant, to control future use of the property and ensure the integrity of
the remedy.
Alternative WS5: Solidification/Stabilization
Present Worth Cost $ 6,923,200
Implementation Time 6 months
This alternative includes excavation and stockpiling of material from the existing cap,
excavation of waste and contaminated soil, solidification/stabilization of waste and contaminated
soil, long-term maintenance of solidified mass and drainage system and institutional controls.
The excavation and stockpiling of material from the existing cap and excavation of the
waste and contaminated soil would be the same as described under WS4, including dewatering
during excavation. Solidification/stabilization (S/S) is an immobilization technology that EPA
defines as a presumptive remedy for principal threat metals-in-soil waste that is targeted for
treatment. The tile waste, municipal waste, and contaminated soil would be excavated and mixed
with an additive to render it less soluble, mobile, or toxic. The treated material would then be
backfilled into the excavated area. A portion of the treated waste would be placed below the water
table unless treatability tests indicate the contamination in the waste cannot be effectively
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stabilized. If the waste fails the requirements, the treated waste could be placed above the water
table similar to WS4.
After completion of the S/S procedures, confirmatory testing (e.g., SPLP for contaminants,
unconfined compressive strength, and permeability) would be performed to verify that treatment
requirements have been met. Addition of binding agents can increase the volume of treated waste
by up to 30- 50%. Assuming an average volume increase of 40% due to S/S treatment, backfilling
the stabilized waste will raise the elevation above the current landfill cap elevation. Drainage
channels would be installed along the edge of the backfilled landfill area
to convey run on/run off water away from the area. Surface water from these channels would be
directed to existing drainage features that ultimately discharge to the West Branch of Skippack
Creek.
After backfilling the treated material, the vegetative layer and clay layer of the existing cap
would be placed above the solidified mass. This alternative also includes ICs as discussed in WS4.
Alternative WS6: Excavation and Offsite Treatment/Disposal
Present Worth Cost $ 11,356,000
Implementation Time 4 months
This alternative includes excavation and stockpiling material from the existing cap,
excavation of waste and contaminated soil from the Site and offsite treatment/disposal. The
excavation and stockpiling of material from the existing cap and excavation of the waste and
contaminated soil would be the same as described under WS4, including dewatering during
excavation.
Excavated waste and contaminated soil would be stockpiled temporarily onsite and then
loaded into transport trucks and hauled to a licensed offsite disposal facility. The duration assumes
15 loads per day using 20 cubic yard trucks, or 300 cubic yards of waste hauled offsite per day. As
a result, the duration of the transport and offsite disposal activity would require 148 days to
remove a total of 44,284 cubic yards of waste and contaminated soil transported in 2,220
truckloads.
Offsite treatment prior to disposal may be necessary to meet land disposal restrictions
(LDRs) specified under 40 C.F.R. Part 268, which requires treatment of hazardous waste to meet
specified levels for hazardous constituents before disposing of the waste on the land. Because
samples collected from tile waste in 2004 included concentrations of cadmium and lead that were
characteristic for hazardous waste, it is likely that the tile waste (14,513 cubic yards) would require
treatment to meet standards specified in 40 C.F.R. § 268.40 and subsequent disposal at a RCRA
Subtitle C facility. Based on available data, EPA expects that the municipal waste (20,815 cy) and
contaminated soil (8,956 cubic yards) would be characterized and disposed as non-hazardous
waste; however, excavated material would be sampled and analyzed to determine if it should be
managed as a hazardous or non-hazardous waste.
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The excavation area would require 44,284 cubic yards of clean fill to replace the waste and
soil material removed from the site. The existing cap and vegetative layer would be blended with
the clean fill to increase the soil permeability characteristics of the clay material and included as
backfill to achieve the existing grade. Institutional Controls would not be required as the waste
will no longer reside at the Site.
Sediment Alternatives
Alternative SD1: No Action
Present Worth Cost $ 0
Implementation Time N/A
The no action alternative is required to be considered under the NCP to provide a baseline
for comparison with other alternatives. Under this alternative no further action would be
implemented and the current status of the surface water and sediment would remain unchanged.
Section 121 (c) of CERCLA, 42 U.S.C. § 9621(c), would require that the Site be reviewed every
five years because contamination would remain in the surface water and sediment.
Alternative SD2: Limited Action
Present Worth Cost $ 320,000
Implementation Time 30 years
This alternative includes routine surface water and sediment sampling and ICs (local
governmental controls, such as establishing zoning requirements; activity and use restrictions
through the use of proprietary controls, such as easements and covenants; and informational
devices such as notices and advisories) to limit potential exposure to surface water and sediment
near the likely groundwater discharge points at the spring and the West Branch of Skippack Creek.
Alternative SD3: Removal and Onsite Treatment/Disposal
Present Worth Cost $ 75,500
Implementation Time 1 month
This alternative includes the removal of contaminated sediment between the spring and the
bed of the West Branch of Skippack Creek and treatment or disposal back onsite. Extent of
sediment removal is an approximately 400 square foot area immediately surrounding SD-07 on
Figure 9. Area will be based upon vegetation void, sediment accumulation near the spring, or
white residue in the spring water apparently associated with high contaminant concentrations.
This alternative is only possible if Alternative WS4 or WS5 is selected to address waste and soil.
Sediment would be excavated and disposed on-site within an engineered cell (WS4) or treated on-
site via solidification/stabilization (WS5). Sediment excavation would be performed using a
vacuum truck, a small backhoe, or hand tools, all of which could remove the limited amount of
sediment present in the spring and creek bed. Surface water could be collected from the spring and
treated on-site via ion exchange during excavation. The FS estimates the volume of contaminated
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sediment to be 25 cubic yards. The final area of sediment removal will be delineated during
design.
Although the RI indicated that TCE, arsenic and thallium exceeded ambient water quality
criteria for the surface water in several downgradient surface water sample locations, surface water
in the creek would not be removed or treated given the relatively low contaminant levels and
because action taken to address sediment, waste and soil serves to remove the source of surface
water contamination.
Although no contaminated surface water or sediment would remain on site, long-term
monitoring of stream sediments will be required to demonstrate protection of the stream.
Alternative SD4: Removal and Offsite Treatment/Disposal
Present Worth Cost $ 69,600
Implementation Time 1 month
This alternative includes the removal and treatment of contaminated sediments from the
spring and the bed of the West Branch of Skippack Creek. Excavated sediments would be
excavated and treated off-site if necessary to meet LDRs and disposed off-site. EPA anticipates
that the sediment would be characterized and disposed as non-hazardous waste; however,
excavated sediment would be sampled and analyzed to determine proper disposal. Sediment
excavation would be performed using a vacuum truck, a small backhoe, or hand tools, all of which
could remove the limited amount of sediment present in the spring and creek bed. The FS
estimates the volume of contaminated sediment to be 25 cubic yards. Extent of sediment removal
should be based upon vegetation void, sediment accumulation near the spring, or white residue in
the spring water apparently associated with high contaminant concentrations. The final area will
be delineated during design.
Although the RI indicated that TCE, arsenic and thallium exceeded ambient water quality
criteria for the surface water in several downgradient surface water sample locations, surface water
in the creek would not be removed given the relatively low contaminant levels and because action
taken to address sediment, waste and soil would also serve to reduce contamination in the surface
water.
Although no contaminated surface water or sediment would remain on site, long-term
monitoring of stream sediments will be required to demonstrate protection of the stream.
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EVALUATION OF ALTERNATIVES
In this section, the remedial alternatives, summarized above are compared to each other
using the seven criteria set forth in 40 C.F.R. § 300.430(e)(9)(iii). EPA uses these criteria,
summarized in Table 12 below, in the decision-making process. The last two criteria, which are
State and community acceptance, will be evaluated after the public comment period.
This section of the Proposed Plan profiles the relative performance of each alternative
against the evaluation criteria, noting how each compares to the other options under consideration.
A detailed analysis of the alternatives can be found in the FS.
These evaluation criteria relate directly to requirements of Section 121 of CERCLA, 42
U.S.C. § 9621, for determining the overall feasibility and acceptability of a remedy. The nine
criteria fall into three groups described as follows:
Threshold criteria must be satisfied in order for a remedy to be
eligible for selection.
Primary balancing criteria weigh major trade-offs among the
remedial alternatives.
Modifying criteria are the acceptance of the public and the state,
which is considered by EPA after public comment is received on
the Proposed Plan.
Threshold Criteria- Overall protection of human health and the environment
All no action alternatives (WS1, SD1) must be evaluated in accordance with CERCLA and
the NCP to serve as a basis for comparison with the other alternatives. WS1 does not address
potential future leaching of metals into groundwater; although there is no current groundwater use
in the affected area, the contaminants have the potential to migrate to areas where the groundwater
may be used. SD1 will neither decrease the toxicity of contaminants, nor protect public and
ecological health from contamination in sediment. Thus, WS1 and SD1 fail to meet the threshold
criterion of overall protection of human health and the environment.
WS2 (Limited Action) contains no treatment or isolation of contaminated material, so
future release of contaminants is likely to occur. Wastes are presently located below the water
table and migration of contaminants to the groundwater would continue. WS2 is not effective in
controlling the release of contaminants to the environment, and cannot provide protection from
contaminant exposure by workers, residents, or ecological receptors. Thus, this alternative fails to
achieve the threshold criterion and will not be considered further.
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WS3 (Capping) will reduce the
principal exposure routes and, thereby, will
reduce the potential exposure to human and
ecological receptors to contaminants;
however, it does not address the potential for
contaminant migration from waste present
below the water table to the groundwater.
This contamination pathway could lead to
potential short-term and/or long-term exposure
of workers, residents, and ecological
receptors, and thus, this alternative would fail
to meet the threshold criterion. WS3 will not
be retained for further evaluation.
The remaining waste and soil
alternatives (WS4, WS5, and WS6), and
sediment alternatives (SD2, SD3, and SD4)
can each meet the threshold criterion for
Overall Protection of Human Health and the
Environment.
Threshold Criteria -
Compliance with applicable or relevant and
appropriate requirements (ARARs)
The remaining alternatives are
expected to achieve compliance with ARARs
in a reasonable period of time. WS4 and WS5
are expected to comply with RCRA land
disposal restrictions for onsite disposal of
contaminated material. For WS5, the S/S
process would bind contamination into the
waste so that it does not leach into the
groundwater. WS6 will comply with ARARs
related to excavating the waste and soil for
transportation and disposal.
SD2 is not expected to achieve
chemical-specific ARARs because SD2 will
provide some protection to human receptors,
but not ecological receptors. SD3 and SD4
are expected to comply with RCRA land
disposal restrictions for disposal of
contaminated material.
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TABLE 12:
Evaluation Criteria for
Superfund Remedial Alternatives
Threshold Criteria
Overall protection of human health and the
environment - Addresses whether a remedy provides
adequate protection and describes how risks posed
through each pathway are eliminated, reduced, or
controlled through treatment, engineering controls, or
institutional controls.
Compliance with applicable or relevant and
appropriate requirements (ARARs) - Addresses
whether a remedy will meet all of the requirements of
other Federal and State environmental statutes,
regulations, and other requirements that are pertinent to
the Site, and/or justifies a waiver.
Primary Balancing Criteria
Long-term effectiveness and permanence - Addresses
expected residual risk and the ability of a remedy to
maintain reliable protection of human health and the
environment over time, once cleanup goals have been met.
Reduction of toxicity, mobility, or volume through
treatment - Addresses the anticipated performance of the
treatment technologies a remedy may employ.
Short-term effectiveness - Addresses the period of time
needed to achieve protection and any adverse impacts on
human health and the environment that may be posed
during the construction and implementation period, until
cleanup goals are achieved.
Implementabilitv - Addresses the technical and
administrative feasibility of a remedy, including the
availability of materials and services needed to implement
a particular option
Cost - Includes estimated capital and operation and
maintenance costs, compared as present worth costs.
Modifying Criteria
State/Support Agency Acceptance - Indicates whether
the support agency concurs with or has comments on the
Preferred Alternative.
Community Acceptance - Summarizes the public's
general response to the alternatives described in the
Proposed Plan and Remedial Investigation/Feasibility
Study Report. The specific responses to public comments
are addressed in the Responsiveness Summary section of
the Record of Decision.
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Because the No Action Alternatives (WS1 and SD1) and WS2, WS3, and SD2 fail to meet
the threshold criteria, they have been eliminated from further analysis.
Primary Balancing Criteria, Waste and Soil Alternatives-
Long-term effectiveness and permanence
WS4 and WS6 will both achieve high long-term effectiveness and permanence, i.e. will
be able to be maintained over a long period of time. WS5 has an effectiveness that has been
proven at other Superfund sites; however S/S of the COCs identified for this Site depends on
several factors, including finding a suitable binding agent. Moreover, if the binding agent cannot
be mixed with waste uniformly and thoroughly, contamination may not be completely
demobilized. Additionally, the selected reagent must simultaneously reduce the mobility of
multiple inorganic contaminants while not being hindered by the presence of other contaminants.
Contaminants such as oil, grease, phenol, some soluble salts, cyanide and sulfate may inhibit
proper bonding of reagent with waste, reduce the setting of treated material or reduce durability,
strength and leach resistance of the final product. Treatability studies need to be conducted in
order to identify appropriate binding agents and determine the proper formulation for those agents.
Limited data are available on long-term performance of S/S; however, the long-term
environment and conditions to which solidified waste is exposed can affect its stability. For
example, cement-based stabilized wastes are vulnerable to the same physical and chemical
degradation processes as concrete and other cement-based materials (i.e., can potentially degrade
over a period of 50 to 100 years).
Primary Balancing Criteria, Waste and Soil Alternatives-
Reduction of toxicity, mobility, or volume through treatment
If shown to be implementable at the Site in a treatability study, WS5 would reduce
toxicity and mobility, yet increase volume, through treatment. WS4 would not treat the waste, but
prevent direct contact and migration of contaminants. WS6 may involve treatment at the disposal
facility to comply with land disposal restrictions.
Primary Balancing Criteria, Waste and Soil Alternatives-
Short-term effectiveness
WS4 provides the greatest degree of short term effectiveness during construction.
Typical engineering controls will be employed to reduce emissions and runoff from the Site. WS5
will require more precautions than WS4 to protect workers and residents, including protection
from inhalation hazards associated with the use of additives and binding agents as well as the
mixing process. Also, some municipal waste materials may be too large to be treated via S/S and
would require offsite disposal. WS6 provides the least short-term effectiveness since loading and
transportation of the waste and soil may increase potential exposure.
Salford Quarry Proposed Plan
August 2012
36
AR300119
-------
Primary Balancing Criteria, Waste and Soil Alternatives-
Implementability
WS4 and WS6 are readily implementable since they require typical construction
equipment, techniques and personnel. WS6 would require significant quantities of clean backfill
material. Construction equipment, techniques and personnel are equally available for WS5;
however, the treatability study may show that the heterogeneous waste may not be able to be
effectively stabilized.
Primary Balancing Criteria, Sediment Alternatives
SD3 and SD4 are expected to be equally permanent remedies. SD4 is the only option that
may provide a reduction in toxicity or mobility through treatment if the sediment is treated at the
disposal facility. The short-term effectiveness of SD3 is slightly better than SD4, because SD3
poses less of an exposure risk to those implementing the remedy. If WS4 or WS5 are chosen, SD3
provides more ease in implementation than SD4. If WS6 is chosen, SD3 would not be viable
because there would be no on-site disposal location. SD3 and SD4 are both readily
implementable.
Primary Balancing Criteria- Cost
This criterion considers the construction, O&M, and present worth costs associated with
each alternative. The present worth has been calculated based on Federal policy which
recommends assuming a 7% discount rate over a 30-year evaluation period. The costs for the
viable alternatives for waste and soil, sediment and groundwater are presented in Table 13 below.
The majority of the WS4 costs are due to the capital costs associated with excavating the
waste and contaminated soil and constructing the engineered cell. The majority of the WS5 costs
are for excavating and treating the waste and soil. WS6 is the most expensive alternative due to the
capital cost of transporting and disposing a large quantity of waste and contaminated soil offsite.
SD3 costs are for onsite treatment/disposal. SD4 costs are primarily due to the cost of transporting
and disposing contaminated sediment offsite.
Modifying Criteria
The Commonwealth of Pennsylvania is in concurrence with the Preferred Alternative, as
set forth below. The Commonwealth's concurrence should be considered preliminary subject to
consideration of public comments. The Community Acceptance of the Preferred Alternative will
be evaluated after the public comment period ends and public comments are considered.
Substantive comments will be described in the Responsiveness Summary section of the Record of
Decision.
Salford Quarry Proposed Plan
August 2012
37
AR300120
-------
Table 13 Costs (in dollars)
Alternative
Capital
Annual
O&M
Present
Worth
WS4 Engineered Cell *
2,430,700
65,800
3,327,200
WS5
Solidification/Stabilization *
6,018,700
66,500
6,923,200
WS6 Excavation and Offsite
Treatment/ Disposal
11,356,000
—
11,356,000
SD3 Removal and Onsite
Treatment/Disposal
75,500
—
75,000
SD4 Removal and Offsite
T reatment/Disposal
69,600
—
69,000
* costs include groundwater monitoring. Thus, the costs listed are higher than those presented in the FS
PREFERRED ALTERNATIVE
EPA's Preferred Alternative for the Salford Quarry Site, OU1, is a combination of WS4
(Engineered Cell), and SD3 (Removal and Onsite Disposal) to address waste, soil and sediment.
The present worth cost for the total preferred remedy is $3.4 million.
WS4 (Engineered Cell) is chosen because it prevents exposure to Site contaminants by
human and ecological receptors and minimizes the migration of contaminants to groundwater. The
cell would not require an intensive operation and maintenance effort to ensure functional integrity
and is expected to provide long-term effectiveness. Groundwater and surface water monitoring
will be performed to track the impact of the source control. Institutional controls would be
implemented to restrict future Site development and land use to prevent exposure to Site related
contaminants and to protect the remedy. This alternative can also be readily implemented with
lower complexity and a lower cost than WS5 while providing the same level of protectiveness.
SD3 (Removal and Onsite Disposal) is chosen because it prevents contaminated sediment
from being a source of contamination to surface and groundwater by removing the contaminated
sediment and placing it into the engineered cell. This component of the proposed remedy will
provide long-term effectiveness and eliminate the need to monitor the spring and creek bed in
perpetuity. SD3 would also be easier to implement and would result in less exposure to Site
contaminants by construction workers when compared to SD4 (disposal off-site).
Salford Quarry Proposed Plan
August 2012
38
AR300121
-------
Based on the information available in the Administrative Record, EPA believes that the
Preferred Alternative, WS4, and SD3, meets the threshold criteria and provides the best balance
among the other alternatives with respect to the balancing criteria. EPA expects the Preferred
Alternative to satisfy the following statutory requirements of CERCLA Section 121: (1) be
protective of human health and the environment; (2) comply with ARARs; (3) be cost-effective;
(4) and utilize permanent solutions and alternative treatment technologies or resource recovery
technologies to the maximum extent practicable.
The Preferred Alternative does not satisfy the statutory preference for treatment as a
principal element. EPA prefers the engineered cell alternative, which will separate the
contaminants from the environment but will not treat them, because treatment alternatives may not
be implementable, would pose more of a risk of human exposure to contaminants, and are not cost-
effective. Solidification/stabilization of the landfill waste may not be implementable because of
the heterogeneous nature of the waste. Off-site treatment and disposal of landfill waste would
pose more of an exposure risk in implementation than constructing an engineered cell. Off-site
disposal would also be far less cost-effective.
Some of the major ARARs for the Preferred Alternative are as follows:
Chemical-Specific
Pennsylvania Land Recycling and Environmental Remediation Standards Act (Act 2). 35 P.S.
§ 6026.101 et seq.. provides for the promulgation of remediation standards for cleanup of
contaminated sites in the Commonwealth of Pennsylvania. The Act's statewide health standards
for contaminants in soil, set forth at 25 Pa. Code Chpt. 250, Appendix A, Tables 3 and 4, have
been identified as applicable requirements for the soil COCs at the Site. The soil contaminants of
concern are set forth in Table 8. The proposed remedy will be designed to achieve compliance
with these soil cleanup standards.
Action-Specific
Pennsylvania Hazardous Waste Management Regulations. 25 Pa. Code § 264a. 1, which
incorporates federal regulations at 40 C.F.R. § 264. l(j)(2) thru (7), (9) thru (12), establishes
requirements for remediation waste management. 25 Pa. Code § 264a. 1 also incorporates federal
regulations at 40 C.F.R. § 264.554(d), (h), (j), and (k), which establish requirements for the storage
of remediation waste in temporary staging piles; federal regulations at 40 C.F.R. §§ 264.111,
264.114, 264.117, and 264.310(a), which require landfills to be closed in accordance with the
regulations and require owners and operators of such landfills to engage in post-closure care;
federal regulations at 40 C.F.R. §§ 264.301(a) and 264.303(a), which require specific liner systems
for certain landfills. Activities undertaken at the Site will comply with these requirements.
The Pennsylvania Erosion and Sediment Control Regulations. 25 Pa. Code §§ 102.4(b), 102.11,
102.22, set forth measures to limit soil erosion during any earth disturbance activities. Remedial
activities that involve disturbance of the land (cleaning, grading, excavation, etc.) will be
undertaken to comply with these requirements.
Salford Quarry Proposed Plan
August 2012
39
AR300122
-------
The National Pollutant Discharge Elimination System Regulations. 25 Pa. Code §§ 92.31, and the
Pennsylvania Water Quality Standards, 25 Pa. Code §§ 93.1-93.9, set forth requirements in order
to discharge pollutants into waters of the United States. Remedial activities that involve discharge
into the West Branch of the Skippack Creek will be undertaken to comply with these requirements.
The Pennsylvania Stormwater Management Act. 32 P.S. § 680.13, requires the implementation of
measures to control stormwater runoff during construction and remediation activities. Remedial
activities that involve disturbance of the land (cleaning, grading, excavation, etc.) will be
undertaken to comply with these requirements.
Fugitive Emissions Regulations. 25 Pa. Code §§ 123.1, 123.2, establishes standards for the
regulation of particulate matter released during remedial activities. Excavation activities
undertaken at the Site will comply with these requirements.
Location-Specific
Regulations Governing Activities Undertaken in Floodplains are set forth at 40 C.F.R. § 6.302(b)
and Part 6, Appendix A. They require federal agencies to avoid and minimize the destruction of
floodplains. These regulations are relevant and appropriate to the activities that will be undertaken
to excavate and restore the sediment on the Site. Activities undertaken in the floodplains under the
proposed remedy will comply with these regulations.
Regulations Governing Hazardous Waste Facilities Located in Floodplains. which are set forth at
40 C.F.R. § 264.18(b), establish requirements for facilities treating or disposing hazardous waste
within a 100-year flood plain. Actions undertaken under the proposed remedy will comply with
these regulations.
Regulations Governing Fish and Wildlife Protection are set forth at 40 C.F.R. § 6.302(g). These
regulations require federal agencies to take action to protect fish and wildlife when taking action
that could result in the control or structural modification of any natural stream or body of water.
Activities undertaken at the seep or in the stream channel under the proposed remedy will comply
with these requirements.
Regulations Governing Activities Impacting Wetlands are set forth at 40 C.F.R. § 6.302(a) and
Part 6, Appendix A. These regulations require federal agencies to avoid and minimize the
destruction of wetlands. These regulations are relevant and appropriate to the activities that will be
undertaken to excavate and restore sediment on the Site. Additionally, state regulations governing
activities undertaken in wetlands are set forth at 25 Pa. Code § 105.18a. The sediment excavation
activities under the proposed remedy will comply with these state and federal regulations.
To Be Considered (TBC)
Executive Order 11988 - Floodplains Management requires federal agencies to consider the
impacts of federal agency actions to floodplains. The requirements of this Order will be
considered during the design and implementation of the proposed remedy.
Salford Quarry Proposed Plan
August 2012
40
AR300123
-------
Executive Order 11990 - Protection of Wetlands requires federal agencies to take action to
minimize the destruction, loss, or degradation of wetlands in carrying out the agency's
responsibilities. The requirements of this Order will be considered during the design and
implementation of the proposed remedy.
COMMUNITY INVOLVEMENT
EPA relies on public input to assure that the remedy selected for each Superfund site meets
the needs and concerns of the local community.
For further information on the Salford Quarry
Site or to submit comments on the Proposed Plan,
please contact:
Sharon Fang, 3HS21
Remedial Project
Manager
215-814-3018
fang. sharon@epa. gov
Vance Evans, 3HS52
Community Involvement
Coordinator
215-814-5526
evans. vance@epa. gov
To assure that the community's
concerns are being addressed, a public
comment period on this Proposed Plan will
open August 2, 2012 and close on August
31, 2012. During this time, the public is
encouraged to submit comments to the EPA
on this Proposed Plan. A public meeting to
discuss the Proposed Plan will be held on
August 13, 2012 at 6:30 p.m. at the Lower
Salford Township Building (379 Main
Street) in Harleysville, PA. If you have any
questions about the public meeting, contact
Vance Evans or Sharon Fang at the address
or telephone numbers listed. EPA may
modify the Preferred Alternative or develop another alternative based on new information or
public comments. The remedy selected will be documented in a ROD.
Background documents regarding the Salford Quarry Superfund Site, as well as copies of
the Remedial Investigation, Feasibility Study, and this Proposed Plan, are available to the public at
the information repository located at the EPA Region III offices in Philadelphia, Pennsylvania, at
the Indian Valley Public Library in Telford, PA, and online at
http://loggerhead.epa.gov/arweb/public/advanced_search.jsp.
All comments submitted to EPA must be postmarked by August 31, 2012.
U.S. EPA
1650 Arch Street
Philadelphia, PA 19103-2029
Salford Quarry Proposed Plan
August 2012
41
AR300124
-------
File Path: f:\projects\Salfbrd Quarry\GIS\Salfbrd\GIS\salford_ri_2004.apr
Salford Quarry
LEGEND
/V Road Centerlines
yV Railroad Centerlines
Stream Centerlines
~~ Open Water
City Boundaries
Prison Grounds
if! Franconia Township
I I Lower Salford Township
I I Perkiomen Township
l~~1 Skippack Township
I i Towamencin Township
~~ Upper Salford Township
I J Worcester Township
S 1 g I ' s
Salford Quarry
Salford Quarry Figure 1.
Lower Salford Township Site Location Map
CDM Montgomery County, Pennsylvania
AR300125
-------
Hidden Creek
Lower Salford Township
Lower Salford Toymship
township
Site Trustee
Parkside Ridge Associates
Lower Salford Township
File Path: F:\salford quany\gis\salfbrd\gis\salfbrd ri 2006\revised.apr
Notes:
The zoning
districts were revised on June 30, 2004.
LEGEND
Monitoring Well
Road
Dry Creek Bed
Stream
Former Quarry
Parcel Lot
Commercial District
Land Preservation
Overlay District
Mixed-Use District
EZ3
Residential District
— Medium Density
Residential District
Salford Quarry Figure 2.
Lower Salford Township Zoning Districts and Land
CDM Montgomery County, Pennsylvania Parcel Boundaries Map
AR300126
-------
File Path: f:\projects\Salford Quarry\GIS\Salfbrd\GIS\salford_ri_2004.apr
® Monitoring Well
© Piezometer
/\/ Road Edge
/V Dry Creek Bed
/\y Stream
Spring
Pond
Refuse Piles
| | Former Quarry (Capped Area)
| | Unquarried Site Property
MW-10 ^
9
CDM
Salford Quarry Figure 3.
Lower Salford Township Site Map
Montgomery County, Pennsylvania
AR300127
-------
File Path: f:\salford quany\gis\salfbrd\gis\salfbrd_ri_2004.apr
Court
LEGEND
T Seep ,
Contour Interval (ft amsl) /
Stream
Fracture
Road Centerllne
~~ Former Quarry
~~ Unquarried Site Property ^
Lockatong Formation
— ; > / y/y'.
Salford Quarry Figure 4.
. Lower Salford Township Salford Quarry Geology
CDM Montgomery County, Pennsylvania
AR300128
-------
If X
I if
I m SL04
I i-V ¦: ¦: ¦ v ¦: Wvv
ii . . \
I fJ " ¦ SLOK
IJ L,irin /^\ \
I ¦¦ ¦ ¦¦¦ J SG02 X-.->B
I I ¦'¦:? ° LG04
/ /BSL08 / ^ ^ lgwtoT^C1
I// ° / rsi n ffl )
I I n LG09 / LU u l_l SGQfI
1111 1 ¦ "it / r> /
/jLfV ¦¦.¦/ U/ n
I H ¦¦ ¦¦ ¦¦! A*n, _
/ / ° B o X
i i / SG01 LG WT03 U / \ V
/ / / ^ s®05! V
/J/ r^.v?\ —~0-_ p>or\
I 81 / ¦ ¦ ¦ erna \ / *my \
If:':"':'-: :W- H
¦ s ¦ % ¦ s ¦¦¦ "V
/¦: ¦: ¦; ¦; ¦ ; ¦; ¦ ; ¦; .7
I /
1 /
1 /
File Path: f:\salford quany\gis\salfbrd\gis\salfbrd_ri_2004.apr
LEGEND
~ Landfill Gas (LG) Location
o Surface Gas (SG) Location
¦ Soil Sampling (SL) Location
0 Waste Boring (WT) Location
Stream
/ \/ Dry Creek Bed
/\/ Road
]] Spring
H Pond
| | Former Quarry (Capped Area)
| | Unquarried Site Property
7"
Headwall
Site Detail
SL011
600 Feet
Salford Quarry Figure 5.
Lower Salford Township Landfill Gas, Surface/Subsurface
Montgomery County, Pennsylvania Soil Sample, and Waste Characterization
Location Map
AR300129
-------
File Path: f:\salford quany\gis\salfbrd\gis\salfbrd_ri_2004.apr
LEGEND
S Waste Sampling Location
¦ Soil Sampling Location
Stream
A/ Dry Creek Bed
Road Centerline
~~ Spring
Pond
I I Former Quarry
~~ Unquarried Site Property
Note: Field duplicates are indicated by an FD designation.
Boron (ug/kg)
963000
1120000
831000
SL06
WT03
Depth (fbgs)
8-14
20-22
24-36
24-36 FD
Boron (ug/kg)
1850000
2900000
683000
1210000
WT02
Depth (fbgs)
8-12
28-34
Boron (ug/kg)
3150000
1260000
SL08
Depth (fbgs)
0.5-2.0
WT01
Depth (fbgs)
8-18
8-18 FD
30-35
Boron (ug/kg)
21800
Salford Quarry Figure 6.
Lower Salford Township Surface/Subsurface Soil and Waste
CDM Montgomery County, Pennsylvania Sample Map of Boron Concentrations
AR300130
-------
MW-07
MW-08
— Dry Stream Bed
/ MW-09
F:\projects\Salford Quarry\GIS\Salford\GIS\salford_ri_with_dataevalrep_figs.apr
Reference Location 1
MW-03 ®
LEGEND
Monitoring Well
©
Piezometer
Reference Location
~
Stream Survey Location
Section Breaks
1
Stream Segment ID
Pond
A
N
100 200 Feet
Reference Location 2
Salford Quarry Figure 7.
Lower Salford Township 2002 Stream Survey Locations
Montgomery County, Pennsylvania
CDM
AR300131
-------
File Path: f:\salford quany\gis\salfbrd\gis\salfbrd_ri_2004.apr
SD/SW12
XS11
SD/SW11
D/SW10
XS09;
STR01
SD/SW09 o
XS08
XS07
STR02
>/SW08 o
SD/SW07
SD/SW01
XS06
SD/SW06 °
SD/SW05 '
^ STR03
XS05
XS04
SD/SW04
SD/SW03
SD/SW02
STR04
LEGEND
$ Monitoring Well
Stream Gauge (STR)
O Sediment (SD) and Surface Water (SW) Sample Location
x Stream Flow Measurement Cross Section (XS)
/\/ Road Centerline
Stream
Dry Creek Bed
| | Former Quarry
I I Unquarried Site Property
Pond
Note: Well locations provided for reference
Salford Quarry Figure 8.
Lower Salford Township Surface Water/Sediment Sample,
Montgomery County, Pennsylvania Stream Cross Section, and Stream Gauge Location Map
COM
AR300132
-------
SW/SD12 JUL-04 NOV-04
SW 42.5 B 31.4 B
SD 7400 B 7400 J
SW/SD11 JUL-04 NOV-04
SW 38.4 B 32.7 B
SD 7200 B 9800 J
File Path: f:\salford quany\gis\salfbrd\gis\salfbrd_ri_2004.apr
LEGEND
O SW/SD Sampling Location
Road Centerline
Stream
A/ Dry Creek Bed
I I Former Quarry
~~ Unquarried Site Property
SW/SD04
SW
SD
JUL-04
120 L
5500 B
SW/SD02
SW
SD
NOV-04
262
13400 J
JUL-04
127 L
12800 B
1400 Feet
Note: Boron Concentrations for Surface Water = ug/L
Boron Concentrations for Sediment = ug/kg
SW/SD08
SW
SD
JUL-04
110 J
4900 B
NOV-04
52 B
10300 J
SW/SD07
SW
SD
JUL-04
44.5 B
8200 B
NOV-04
151 J
20900
SW/SD01
SW
SD
JUL-04
285000
50300
NOV-04
70400
84200
SW/SD09
NOV-04
50.1 B
8000 J
SW/SD03
SW
SD
JUL-04
86.9 J
8000B
SW/SD05
SW
SW-FD
SD
SD-FD
JUL-04
135 L
137 L
8800 B
8200 B
NOV-04
317
307
11800 J
10100 J
NOV-04
255
11900 J
JUL-04
44.2 B
7200 B
NOV-04
252
7900 J
/
SW/SD06
SW
SD
NOV-04
34.5 B
9800 J
JUL-04
102 J
10300B
SW/SD10
SW
SD
NOV-04
329
16600 J
Salford Quarry Figure 9.
Lower Salford Township Surface Water/Sediment Sample
CDM Montgomery County, Pennsylvania Map of Boron Concentrations
AR300133
J = analyte present. Reported value is estimated; concentration is outside the range for accurate quantitation.
B = not detected substantially above (10x) the level reported in the laboratory or field blanks.
-------
MW-06
110
MW-03
390
RES004 O
155
Parkview Court
MW-07
47000
MW-01
216000
MW-02
229000
MW-04
85900
O RES007
O RES040
410
MW-10
32200
O RES041
307
RES053
6840
RES011
0.230
RES064
4380
RES014
741
RES016
100
O RES017
154
RES081
342
Hideaway Lane
O \reS088O
RES091 \360 c
525 X '
O/ RES095
/ O RES098
O RES101
RES097
325
RES100
1493 O
RES 102
656
RES103
697
CXy O RES104
RES108
392
RES107
461
RES109
RES110
O RES113
RES114
File Path: f:\salford quany\gis\salfbrd\gis\salfbrd_ri_final_2005.apr
N
LEGEND
®
Monitoring Well
o
1991 Sampling Location
o
1993 Sampling Location
N
NPWA Waterline
N
NPWA Waterline (EPA Phase 1)
N
NPWA Waterline (EPA Phase 2)
A/
Road Centerline
A /
Dry Creek Bed
A/
Stream
m
Boron Plume > 7300 ug/L *
wm
Boron Plume > 730 ug/L **
~
Former Quarry
~
Unquarried Site Property
RES022
14
¦
Lockatong Formation
IJL
| Note: The tap water RBC for Boron - 7300 ug/L
RES111O
* Regional Screening Level (RSL), 1-11=1.0 at the time of the Rl.
Current RSL is 3,100 ug/L at Hl=1.0
** RSL Hl=0.1 at the time of the Rl; current RSL is
310 ug/L at Hl=0.1
Salford Quarry
Lower Salford Township
Montgomery County, Pennsylvania
Figure 10.
Plume Map of Boron Concentrations, 1991-1993
AR300134
-------
A,
xO/,
<>.•
v 7300 ug/L
CZ1 Fornior Quarry
~~ Unqua/ried Sito Property
I I Spring
~ Pond
O Loclcatong Formation
Salford Quarry
Lower Salford Township
Montgomery County, Pennsylvania
AR300135
Figure 11.
Plume Map of Boron 2004
* Regional Screening Level (RSL), Hl=1.0 at the time
of the Rl. Current RSL is 3,100 ug/L at Hl=1.0
-------
File Path: f:\salford quany\gis\salfbrd\gis\salfbrd_final_ri_2006.apr
RES001
e/^/omen Cre®
RES004
MW-08
TCE
cis-1,2-DCE
trans-1,2-DCE
1,1-DCE
1,1 -DCA
1,1,1-TCA
VC
Benzene
MW-01
TCE
cis-1,2-DCE
trans-1,2-DCE
1,1-DCA
RES005
MW-02
PCE
TCE
cis-1,2-DCE
trans-1,2-DCE
1,1-DCE
1.1-DCA
1.2-DCA
1,1,1-TCA
VC
Benzene
Heeler Road
RES008
RESWU
RES014. f*ES0ir
RES007
MW-09
TCE 0.42 J
Toluene 1.3
Carbon Tetrachloride 0.29 J
RES019
RES018
LEGEND
~ < RBC (0.026 ug/L)
• 0.026 - 0.60 ug/L
• 0.60 - 5 ug/L
• 5-26 ug/L
• >26 ug/L
A/ Road Centerline
Stream
A/ Dry Creek Bed
~ Former Quarry
~ Unquarried Site Property
~ Open Water
H Pond
Notes:
Selected VOC detections reported.
Bubble scale is based on TCE concentrations only.
RES designations are for residential wells.
A set of residential well samples were also collected
in November 2004. See data table for collection
dates.
Salford Quarry ^
Lower Salford Township VOC Concentrations
Montgomery County, Pennsylvania July/August 2004
AR300136
-------
This model provides a conceptualization of the
movement of groundwater contamination
based on site data and interpretation.
However, since the groundwater occurs in a
fractured bedrock aquifer system,
groundwater flow and contaminant movement
are likely more chaotic than shown and may
differ to some degree.
NW
Landfill.
West Branch
Skippack Creek'
c SE
-Cap
-Tile Slurry Waste
-Mixed Municipal Waste
Unnamed Tributary
Fawn Drive
Hideaway
Lane
SW
LEGEND
Boron
(conce
groundwater plume t
itrations >7,300 ug/l)
Boron
(conceni
groundwater plume t
itrations >730 ug/l)
SCALE
(Approximate)
500 feet
50
feet >
Salford Quarry AR300137 Figure 13.
Lower Salford Township „ , . _
Montgomery County, Pennsylvania Groundwater Conceptual Model
* Regional Screening Level (RSL), Hl=1.0 at the time of the Rl. Current
RSL is 3,100 ug/L at Hl=1.0
** RSL H 1=0.1 at the time of the Rl; current RSL is 310 ug/L at Hl=0.1
------- |