Superfund Program
Proposed Plan
Sharon Steel-Farrell Works Superfund Site- Operable Unit One
Hermitage Township, City of Farrell, PA July, 2006
EPA Announces Cleanup Plan
The U.S. Environmental Protection Agency (EPA) has completed
a Feasibility Study (FS) for Operable Unit One of the Sharon
Steel - Farrell Works Superfund Site (SSFW or Site) located near
Farrell, Pennsylvania (see Figure 1). After the FS, EPA
evaluated and compared several engineering technologies that
could be used to address contamination at the SSFW Site. The
technologies that were determined to be the most appropriate for
cleaning up the slag, dried sludge, and contaminated ground
water at the SSFW Site comprise EPA's Preferred Alternative
and are described in this Proposed Plan. Other technologies that
were evaluated during the FS are also discussed. The terms in
bold italic print are explained in the glossary included in the back of this Proposed Plan.
July 16,2006 to August 14,2006
Public comment period on
alternatives in Proposed Plan.
July 26, 2006 at 6:30 pm
Public meeting at the Stey
Nevant Library
1000 Roemer Boulevard
Farrell, PA 16121
This Proposed Remedial Action Plan
(Proposed Plan) describes remedial
alternatives for mitigating threats posed to
human health and the environment at and
from the Sharon Steel Farrell Works
Superfund Site (Site) located in Farrell,
Pennsylvania. In addition, this Proposed
Plan includes a summary of background
information relating to the Site, describes
the United States Environmental
Protection Agency Region Ill's (EPA's)
preferred remedial alternatives, solicits
public review and comment on all of the
alternatives described in this Proposed
Plan, and provides information on how the
public can be involved in the remedy
selection process.
This Proposed Plan is issued by EPA, the
lead agency for Site activities under the
National Oil and Hazardous Substances
Pollution Contingency Plan (NCP), 40
Figure 1: Site Location Map C.F. R. Part 300, pursuant to the
1
iSKAHttN
Sharon Steel
Farrel Works
w " kv«:
"jjiftsifS
-------
Comprehensive Environmental Response, Compensation, and Liability Act of 1980, as amended
(CERCLA), 42 U.S.C. §§ 9601 to 9675. This Proposed Plan highlights key information from the
Remedial Investigation/Feasibility Study Report (RI/FS) prepared by EPA for the Site. The RI/FS
Report, as well as other documents upon which this Proposed Plan is based, is available for public
inspection in an Administrative Record for the Site. The detailed Administrative Record can be
examined at the following locations:
Stey Nevant Library US EPA Region III
1000 Roemer Blvd. 1650 Arch Street
The Administrative Record File can also be accessed remotely via the internet by going to the
following web site address: http://www.epa.gov/arweb/.
EPA's general information web address for the Sharon Steel - Farrell Works Superfund Site is:
http://www.epa.gov/reg3hwmd/super/sites/PAD0Q1933175/index.htm.
EPA and the Pennsylvania Department of Environmental Protection (PADEP) encourage the public
to review and comment on all of the cleanup options evaluated in this Proposed Plan. EPA is
providing a 30-day public comment period on this Proposed Plan. The public comment period
begins on July 16, 2006 and closes on August 14, 2006. EPA will hold a public meeting to discuss
this Proposed Plan at the Stey Nevant Library located at 1000 Roemer Boulevard in Farrell on July
26, 2006. EPA will summarize and respond to relevant comments received at the public meeting
and to written comments post-marked by midnight on date, in the Responsiveness Summary section
of the ROD, which will document EPA's final selection of a clean-up remedy. Written comments,
postmarked no later than midnight August 14, 2006 should be sent to:
Rashmi Mathur, RPM (3HS22)
U.S. EPA, Region III
1650 Arch Street
Philadelphia, PA 19103
Toll-free: 1-800-553-2509 (x45234)
Although EPA has identified its preferred remedial alternatives, no final decision has been made.
EPA may modify the preferred alternatives, select other response actions, or develop other
alternatives based on comments received during this period. EPA, in consultation with PADEP, will
announce the selection of a remedy for this Site in a Record of Decision.
EPA is issuing this Proposed Plan as part of its public participation responsibilities under Section
300.430(f)(2) of the NCP. This Proposed Plan fulfills the public notification requirements of
CERCLA Sections 113(k)(2)(B), 117(a), and 121(f)(1)(G), 42 U.S.C. §§ 9613(k)(2)(B), 9617(a),
and 9621(f)(1)(G).
Farrell, PA 16121
(724) 983-2714
Philadelphia, PA 19103
(215)814-3157
Site Background
2
-------
BOF
Sludge Area
Northern
Slag Pile
Shenango
River
Dunbar
Asphalt
Floodplain
Dunbar Asphalt
Property
27.1 acres
Southern f. i
Slag Pile
Wetland/
Pond Area
The SSFW Site is comprised of four main areas. 1) The Northern Area: which is approximately
sixty one acres includes those portions of the site which are north of Ohio Street- the Northern Slag
Pile, the Basic Oxygen Furnace (BOF) Sludge Area,
2) Dunbar Asphalt Property: a twenty seven acre
area which includes an eight acre work area under
the asphalt plant operated by the Dunbar Asphalt
Co, 3) a six acre property owned by the William
Brothers, and 4) the Southern Slag Pile:
approximately two hundred and thirty one acres
which includes those areas south of Ohio Street- the
Southern Slag Pile which is currently being mined
by Farrell Slag LLC, and the wetlmds/floodplain
located between the slag piles and the Shenango
River (to the east) and the unnamed tributary (to the
south) (see Figure 2). Farrell Slag LLC operates an
active slag mining operation on the Southern
portion of the Site permitted by Pennsylvania Department of Environmental Protection (PADEP)
and authorized by EPA pursuant to the Prospective Purchasers Agreement (PPA). Farrell Slag will
reduce the volume of contaminated waste slag at the Site by continuing to mine and remove slag
from the Southern Area. Mining is expected to remove over 3 million cubic yards of slag from the
Site, then the slag is beneficially reused to
make road aggregate. Flowever, due to
technical limitations (groundwater
dewatering) and cost/benefit considerations,
Farrell Slag will not remove the last four feet
of slag. This will leave four feet of slag over
the original native soil in the Southern Area.
INSIDE:
Site Background 3
Site Location and History 6
Scope and Role 9
Summaiy of Site Risks 10
Remedial Action Objectives 15
Summaiy of Alternatives 15
Evaluation of Alternatives 21
Summary of the Preferred Alternative 27
Community Participation 28
Glossary 30
The SSFW Site has been separated into the
mi
Northern Area ™
61.4 acres
j Williams
Brothers
Jrell Slag
pting Area
Legend
Operable Units
OU1 - Phase 1j
OU1 - Phase
6bp
MI
Am
II
IE
1 Williams Brothers
W 5.8 acres
s Unnamed
Tributary
re 2: Site Features
j Southern Area
231.2 acres
Figure 3: Operable Units and Land Ownership
-------
over the contaminated soil. The cover will prevent contact with slag, dried sludge, contaminated
slag dust, and contaminated groundwater. The high piles of BOF slag and sludge will be removed
from the banks of the Shenango River and will be used to re-grade the interior portions of the Site.
When regraded, these materials will form open space. The area adjacent to the Shenango River will
be graded to re-create a broad level floodplain. Bio-engineered bank stabilization techniques and
erosion control measures will be designed to stabilize the river bank and prevent further erosion of
contaminated material into the Shenango River and the wetlands area. A passive vegetated
groundwater barrier consisting of poplar trees will be planted between the Northern slag area and
the Shenango River. This vegetated barrier will absorb groundwater from the source areas before it
flows into the Shenango River.
Once the Site has been re-graded, a biosolid material will be worked into the surface material to
create an ideal environment for a high-fertility protective cover over the slag and dried sludge. The
protective biosolid cover will also minimize the ability of water to pass through the slag and sludge.
By reducing the quantity of water passing through the slag and sludge, the migration of
contaminants into the groundwater will also be reduced, and ultimately the discharge of
contaminated groundwater into the Shenango River will be minimized. Remaining groundwater
flow through the site will be intercepted by the passive vegetated groundwater barrier, which will
use poplar trees to absorb groundwater before it is discharged into the Shenango River. The biosolid
cover will also provide a protective barrier between the contaminated slag and sludge and the people
and wildlife that access the Site. This cover will be seeded with native plant species to create a grass
and shrub or tree habitat. Perimeter fencing will be installed around the biosolid cap so that the cap
can be well established. Long-term monitoring of the groundwater, sediment, and surface water in
the Shenango River will be used to demonstrate a decrease in Site-related contaminants discharges
and an increase in water quality in the Shenango River after consolidating contaminated slag and
sludge under the biosolids cover. Certain land use and activity restrictions, known as institutional
controls, will be implemented to prevent unacceptable human health risks and ecological exposure
risks to slag, dried sludge, contaminated dust and contaminated groundwater located at the Site. The
land use restrictions will prohibit damaging the cap and the groundwater use restrictions will
prohibit the use of contaminated groundwater from being used as a drinking water source. The
institutional controls will be implemented through orders or agreements with EPA or through
municipal ordinances (see Figure 4).
4
-------
Bioengineered
Bank Stabilization
*v»sai
Industrial Controls:
- Land Use Restrictions
- Groundwater Use Restrictions
Passive Vegetated
Groundwater Barrier I
Industrial Controls:
- Dust Supression
- Land Use Restrictions
- Groundwater Use Restrictions
Erosion Protection:
- Silt Fence
Legend
^Grading and Biosolid Cover
1 Biosolid Cover - Phase 1
Erosion Protection - Phase 15
Bank Stabilization - Phase 1 ,
| Biosolid Cover - Phase 2
Perimeter Fencing
Perimeter Fence - Phase 1
Perimeter Fence - Phase 2
^Environmental Monitoring
GW Mon itori ng Wfell
© Soil Monitoring Station
© Sed/SW Monitoring Station
>fi Biological Monitoring Station i
Passive GW Barrier
M
Figure 4: Features of Recommended Alternative
In 2000, EPA entered into a Superfund PPA with Farrell Slag LLC because the PPA allows Farrell
Slag to mine and market the slag for beneficial reuse as construction material. Current mining
operation at Farrell Slag LLC is of beneficial reuse because the operation is removing contaminated
slag from the Site. The remedial action will be conducted in two phases that will allow Farrell Slag
to continue mining operations until EPA completes its response actions in the Northern Area of the
Site.
Phase 1 will include the regrading and application of the biosolid cover on the Northern Area; the
bank stabilization along the Shenango River; the erosion protecti on along the wetland/pond habitat,
the implementation of the environmental long-term monitoring program; and the institutional
controls restricting trespassers (fencing) until the biosolid cap is established on the Site, and
groundwater and land use. Phase 1 can be implemented when EPA issues the Final Record of
Decision (ROD) and completes the design and contracting required for construction.
Phase 2 will include the regrading and application of the biosolid cover on the Southern Area. EPA
will coordinate with Farrell Slag regarding the implementation schedule for this area of the Site.
This Proposed Plan summarizes information found in the Remedial Investigation and the Feasibility
Study reports. Both reports are contained in the Administrative Record, along with other
information used to develop the preferred alternative. If more in-depth information is needed, these
documents can be referenced directly. The locations of the Administrative Record for the Site and
5
-------
the address to which you may send comments on this Plan are given at the end of this Proposed Plan.
EPA encourages the public to review these documents in order to gain a more comprehensive
understanding of the Site and the Superfund activities that have been conducted there.
After the public comment period has ended and the comments received during the comment period
have been reviewed and carefully considered, EPA, in consultation with PADEP, will select a final
remedy for Operable Unit One for soil, slag, sludge and groundwater contamination at the SSFW
Site. The final remedy will be described in a Record of Decision (ROD). The public's comments
will be incorporated into a Responsiveness Summary contained in the ROD. Based on new
information and/or public comments received, the remedy selected in the ROD may be different
from the preferred alternative identified in this Proposed Plan. If there is a change from the remedy
proposed in this Proposed Plan to the final remedy, the public will be informed.
This Proposed Plan is being issued as part of EPA's public participation requirements under Section
117(a) of the Comprehensive Environmental Response, Compensation, and Liability Act of1980,
as amended (CERCLA) and Section 300.430(f)(2) of the National Oil and Hazardous Substances
Pollution Contingency Plan (NCP).
Site Location and History
The SSFW Site is approximately 400 acres in size and is located approximately one (1) mile
southwest of the City of Farrell, Mercer County, Pennsylvania (Figure 1). The Site is also located
approximately 400 hundred feet east of the Pennsylvania/Ohio border. Land use in the area is
industrial to the north and east and rural to the west and south.
The S SFW Plant, located across the Shenango River to the northeast of the subj ect site, was founded
in 1900 and began to manufacture a variety of steel products. Throughout the operating history of
the plant, waste and byproducts of the manufacturing process were transported on rail cars across the
Shenango River (via bridge) and side-cast down embankments or piled into large mounds in several
areas adj acent to the Shenango River on the subj ect Site. From 1949 to 1981, waste liquids (acids
and oils) were poured onto the hot slag wastes which were subsequently disposed at the site. This
practice continued until 198 lwhen Sharon Steel was ordered by PADEP to stop disposing the waste
liquids in this manner. Although the disposal of waste liquids stopped in 1981, Sharon Steel
continued to stockpile slag at the site until operations at the plant stopped in 1992. PADEP
conducted several inspections of the waste disposal areas in the 1970's and concluded that Sharon
Steel was responsible for the lack of biological community along at least 11.5 miles of the Shenango
River. In 1992, after Sharon Steel Corporation filed for bankruptcy, the plant shut down and waste
disposal at the Site stopped. Since the Site was no longer in operation, it was evaluated under
CERCLA. In August 1993, samples of groundwater, soil, sediment, and surface water were
collected during an Expanded Site Investigation (ESI) to support the preparation of a Hazard
Ranking System (HRS) score. The HRS score is used to justify placing a site on the National
Priorities List (NPL), a list of the most serious uncontrolled or abandoned hazardous waste sites
requiring long-term clean up actions. The investigation identified metals and organic compounds at
the site. Based on the findings of the ESI, the SSFW Site was recommended for HRS scoring in
1995. The HRS package was completed in February 1998, and the Site scored high enough to
warrant listing on the NPL. On March 6, 1998, the Site was proposed to the NPL. It was formally
added to the NPL on July 28, 1998, making it eligible for Federal cleanup funds.
6
-------
In October 1999, EPA initiated a Remedial Investigation and Feasibility Study (RI/FS) for the Site
to evaluate existing data; collect additional data, as necessary; and assess and consider appropriate
remedial actions. Due to the size and complexity of the Site, the RI was conducted in two phases.
Phase 1 included monitoring well installation, groundwater evaluation, groundwater sampling,
surface water and sediment sampling, slag and sludge sampling, preliminary air/dust dispersion
modeling, and preliminary risk assessments. Phase 1 was completed in early June 2001. Phase 2,
which was completed in early 2004, included additional groundwater sampling, surface and
subsurface soil sampling, residential well sampling, surface water and sediment sampling, biota
sampling (fish, crayfish, amphibians, mammals, and reptiles), slag/sludge sampling in disposal areas,
and final human health and ecological risk assessments. The results of the Phase 1 and 2
investigations are summarized in the Final RI report, dated June 2005. The RI report indicated that
there were unacceptable risks to human health and the environment; therefore, remedial actions
would be required to control, reduce, or eliminate these risks. An FS report was prepared in April
2006 to develop an appropriate range of remedial actions for managing wastes and contaminated
areas on the Site in a manner that will protect human health and the environment and meet
applicable or relevant and appropriate requirements (ARAR).
Site Characteristics and Risks
Geology and Site Drainage
The SSFW Site is located within the glaciated section of the Appalachian Plateaus Physiographic
Province in Mercer County, Pennsylvania. Regional topography consists of hilly uplands and broad
deep valleys cut by the Shenango River. The Shenango River valley contains Quaternary glacial and
alluvial deposits, while the upland areas consist of glacial till. Regionally, glacial deposits are
underlain by Mississippian and Pennsylvanian aged bedrock consisting of shale and sandstone with
some thin beds of limestone, coal, and fireclay. At the Site, the Shenango River has completely
eroded the Pennsylvanian bedrock and as a result, the glacial and alluvial deposits beneath the Site
are directly underlain by Upper Mississipian bedrock of the Pocono Group. The Site is located on
the western floodplain of the Shenango River between the river and the Ohio/Pennsylvania state
boundary.
The slag and sludge wastes are extremely porous and most rainfall infiltrates the wastes and
becomes groundwater. The limited surface runoff from the Northern Area, including the Dunbar
Asphalt Plant, flows overland and eastward into the Shenango River or collects in the sunken
landform within the Northern Area. Drainage from the Northern portion of the Southern area flows
overland in a northward direction into a wetland area bisected by Ohio Street or collects in the
sunken landform within the source area. There is no direct surface connection between this wetland
area and nearby surface water features. Any hydraulic connection to nearby surface waters is
through groundwater. Drainage from the southern portion of the Southern area flows overland in a
southward direction into the emergent wetland/pond area or into the unnamed tributary. Both the
emergent wetland/pond complex and the unnamed tributary ultimately flow into the Shenango River.
Source Areas
Data from onsite soil and groundwater samples, as well as observations made during drilling
operations, were compiled in the RI report to develop an understanding of the nature of the soils,
7
-------
geology, and ground water at the site. This information provides an insight to the nature and extent
of contamination at the site and the direction that contamination may travel. Drilling information at
the site indicates that the waste piles of slag and sludge range in thickness from 5 to over 40 feet.
The BOF Sludge Pile (in the Northern Area) contains the most contamination. 2-
Methylnaphthalene, an organic compound, and several metals (cadmium, chromium, copper, lead,
mercury, silver, sodium, and zinc) were detected at higher concentrations than those found in the
other source areas. Polynuclear aromatic hydrocarbons (PAHs) were detected at significant
concentrations in the northern and southern ends of the BOF Sludge Disposal Area. The Northern
Slag Pile (in the Northern Area) was the least contaminated source/slag area and contained metals,
PAHs, pesticides, and Polychlorinated biphenyls (PCBs). These were the most frequently detected
constituents and were detected in all depth intervals. The Southern Area contained metals, PAHs,
pesticides, and PCBs. The Southern Area also contained notably higher concentrations of most
PAHs, Aroclor-1248, DDT metabolites, and heptachlor epoxide than the other two source/slag areas.
This was particularly true in the central portion of the source area.
Groundwater
Site-related contamination from the Northern and Southern Areas has been detected in groundwater
which flows under the Site. Groundwater occurs under the site in four main aquifers. These four
aquifers include: 1) an uppermost silty sand aquifer, which ranges in thickness from 0 to 30 feet; 2)
an underlying silt and clay low permeability unit, approximately 30 to 70 feet thick; 3) a sand and
gravel aquifer, approximately 70 to 120 feet thick; and 4) an underlying bedrock aquifer. The
lithologies in the first three units are not continuous across the Site.
The two uppermost units contained elevated levels of metals and organic chemicals. Groundwater in
these areas moves towards the east and southeast. Depth to groundwater is approximately three to
five feet below ground surface. At the BOF Sludge and the northern Slag disposal areas,
groundwater flow discharges to the Shenango River. At the Southern Slag disposal area,
groundwater flow discharges to the wetland/pond complex, the unnamed tributary and the Shenango
River. The lower two units indicate groundwater flow towards the north with some discharge to the
Shenango river. The glacial till materials are extensive enough to produce a less permeable layer
above the gravel zone and underlying bedrock. With the exception of barium and thallium,
concentrations of site-related constituents in the gravel and bedrock aquifers are generally consistent
with regional background levels. These observations suggest that there is no downward flow of
contamination into the deeper confined aquifers. Flow in the confined aquifers is generally to the
north and east and does not discharge into the Shenango River. Wells in the confined aquifers
indicated artesian conditions.
Residential Wells
The majority of residences in the surrounding area receive their drinking water from the Shenango
Valley Water Company which has two surface water intakes along the Shenango River at 3.5 miles
upstream and 18 miles downstream of the Site.
Approximately 40 homes within 1 mile of the Site have domestic wells for water use. Well surveys
have revealed that the wells for some of these residents, located west and southwest of the Site, are
screened in the gravel and/or bedrock aquifers. Since ground water flow in the Site gravel and
bedrock aquifers is to the northeast, towards the Shenango River and away from the residential
wells; residential well data indicate these residents have not been impacted by the Site.
8
-------
Additionally, groundwater on Site is contaminated with metals and volatile organic compounds in
the upper two aquifers while the current residents have their drinking water wells in the non-Site
contaminated lower bedrock aquifer.
Wetland Habitats
There is a large (over 80 acre) and ecologically important wetland habitat located in the Southern
Area. This habitat includes emergent wetland areas, a large pond, a small unnamed tributary of
the Shenango River, and associated forested floodplain/wetlands. The habitat supports a variety
of waterfowl, fish, amphibians, and mammals.
The Site is surrounded on three sides by steep slag piles which are directly adjacent to the
wetlands. In addition, there is a small pond with extremely alkaline water (pH 11-12) between
the southern slag pile and the wetland. Some contamination from the waste piles enters the
wetland directly, through erosion of the piles. However, most contamination is carried directly
into the wetland by the discharge of contaminated groundwater from the base of the piles
through the small pond. Given the low contaminant concentrations and the characteristics of the
habitat, the wetland/pond area should be left intact and allowed to recover naturally once the
sources of contamination are eliminated.
The entire wetland/pond area flows through a small channel which connects to the unnamed
tributary of the Shenango River. There are also some places where groundwater from the
Southern Slag pile discharges through seeps directly into the unnamed tributary. The soils,
sediments, and surface waters of the unnamed tributary and its floodplain contain some Site-
related metals and organic compounds.
Shenango River
Site-related contamination from the waste areas has resulted in some contamination of adjacent
floodplain soils located between the site and the Shenango River. While contamination is not
widespread, there are isolated depressions that contain elevated levels of metals and organic
compounds. Shallow groundwater from the waste areas of the site is known to discharge into the
Shenango River and is the most significant source of contamination from the Site. Contamination
related to the site, primarily metals, was detected at elevated levels in sediment and surface water
samples 1 kilometer (km) downstream of the Site.
Scope and Role
This Proposed Plan presents the information necessary to inform the public of the existing
contamination at the Site and risk associated with the exposure to contamination and explain EPA's
proposed clean up alternative. The Proposed Plan also addresses all the remedial activities that are
necessary to remediate the Northern and Southern Areas of the Site (OU-1).
The proposed remedial action primarily addresses exposure to the slag and sludge. The primary
goals of the remedial action are to prevent dust migration and direct contact with contaminated waste
materials, immobilize metals in the soil/waste, decrease migration of contaminates or infiltrate
passing through wastes, and restore wildlife habitat to barren lands by re-grading the site and
covering it with a biosolid material. Although shallow groundwater under the slag areas has elevated
levels of contaminants, there are no current residents using the shallow groundwater for drinking
9
-------
purposes. Potential future use of the Site groundwater will be restricted by institutional controls.
The biosolid cover will immobilize contaminants by reducing the precipitation that can pass through
it into the waste materials, and this in turn, will reduce the concentration of contaminants entering
the ground water and discharging into the Shenango River and the wetland/unnamed tributary.
Ultimately, this remedial action should reduce the overall amount of contamination going into the
Shenango River from the SSFW Site.
Other elements of this cleanup will include the following:
1. Creation of a surface drainage collection system to minimize the amount of surface runoff
passing through surface soils and prevent erosion of surface material into adjacent wetlands
and streams.
2. Re-establishment of a more natural floodplain along the Shenango River and implementation
of bio-engineering techniques to prevent further erosion of the contaminated stream bank.
3. Installation of a passive vegetated groundwater barrier to intercept shallow groundwater in
the source areas before it discharges into the Shenango River.
4. Installation of perimeter fencing to prevent trespassing and unauthorized recreational
activities until the biosolid cover is established.
5. Long-term monitoring to measure decreases in contaminant loads to the wetland/unnamed
tributary habitat, the Shenango River, and its floodplains.
6. Establishment of institutional controls to minimize health exposure risks to regulate future
land use so that the biosolid cap is not damaged and to prohibit shallow contaminated
groundwater from being used for drinking water purposes on Site.
Summary of Site Risks
Risks to human health were determined in a Baseline Human Health Risk Assessment (HHRA).
Risks to the environment were determined in a Baseline Ecological Risk Assessment (ERA). A
Superfund risk assessment estimates the "baseline risk." This is an estimate of the likelihood of
health and environmental problems occurring if no cleanup action were taken at a Site. The HHRA
and ERA are part of the RI report. The HHRA and the ERA indicated that soils, groundwater,
sediment, surface water and fish tissue at, or impacted by, the Site pose an unacceptable level of risk.
It is EPA's current judgment that the preferred alternative identified in the Proposed Plan, or one of
the other active measures considered in the Proposed Plan, is necessary to protect public health or
welfare or the environment from actual or threatened releases of hazardous substances into the
environment.
Human Health
The Human Health Risk Assessment studies the carcinogenic and non-carcinogenic risks to people
exposed to contaminants at the Site. The human health risks for exposure to source material are
shown in Figure 5. A four-step process is used to estimate the baseline human health risk at a
Superfund Site:
10
-------
Exposure
Point/Media
Receptor
Cance
RME
r Risk
CT
Hazarc
RME
Index
CT
Constituents Of Concern
Northern Area
(Northern Slag Pile +
BOF Sludge Area) -
Surface Soil, Dust,
Shallow Subsurface
Soil, Deep
Subsurface Soil
Industrial Worker
2.3E-04
1.6E-05
3E+01
8E+00
Cancer risk due to Cr.
Noncancer hazard due to
Al, Cd, Cr, Fe, Pb, Mn, Tl,
V, Zn. Potential acute
effects due to As, Ba, Ni, V.
(Only Al in surface soil at
BOF Sludge Area can be
attributed to background.)
Construction Worker
1.7E-05
2.1E-06
5E+01
8E+00
Trespasser/Visitor
7.1E-06
1.5E-06
3E+00
9E-01
Adult Resident
5.0E-04
6.0E-05
5E+01
2E+01
Child Resident
3.6E-04
1.1E-04
2E+02
6E+01
Total Adult and Child
8.6E-04
1.7E-04
Southern Area
(Southern Slag Area)
- Surface Soil, Dust,
Shallow Subsurface
Soil, Deep
Subsurface Soil
Industrial Worker
3.6E-05
3.4E-06
4E+01
1E+01
Noncancer hazard due to
Al, Cr, Fe, Mn, Tl, V.
Potential acute effects due
to As, Ba, Ni, V. (Only Al
and As in surface soil/slag
can be attributed to
background.)
Construction Worker
3.6E-06
6.2E-07
7E+01
9E+00
Trespasser/Visitor
4.8E-06
9.1E-07
4E+00
1E+00
Adult Resident
4.5E-05
3.8E-06
8E+01
3E+01
Child Resident
7.5E-05
1.6E-05
2E+02
8E+01
Total Adult and Child
1.2E-04
2.0E-05
Notes:
CT = central tendency
RME = reasonable maximum exposure
Al = aluminum
As = arsenic
Ba = barium
Cd = cadmium
Cr = chromium
Fe = iron
Mn = manganese
Ni = nickel
Pb = lead
Tl = thallium
V = vanadium
Zn = zinc
Figure 5: Risks associated with exposure to source areas. 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 as a substitute
when no human studies are available). Comparisons between site-specific concentrations and
concentrations reported in past studies enable EPA to determine which contaminants are most likely
to pose the greatest threat to human health. Constituents at the various source areas at the SSFW
Site were identified from samples of soil/slag, groundwater, surface water, sediment and fish tissue.
Over 100 constituents (primarily metals but also including volatile organic compounds (VOCs),
semivolatile organic compounds (SVOCs), PAHs, pesticides, PCBs, and dioxins) were detected in
these media however some of these maybe from other upstream sources.
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. The current and potential future land uses play a key role when EPA
determines the exposure scenarios to be evaluated in the Human Health Risk Assessment. The
SSFW Site has historically been used for industrial purposes and is currently zoned for industrial
use. However, since land use and zone can change, a future residential scenario has been considered
and will serve to justify restrictions on land use in the future. The Human Health Risk Assessment
evaluated the pathways which could lead to exposure for people, such as dust inhalation, use or
drinking of well water, wading or swimming in the Shenango River and the wetland ponds, eating
fish or waterfowl, and direct contact with or ingestion of the soil. The possible human receptors
include current and future residents (children and adults), trespassers, recreational users (fishing and
hunting), industrial workers, and construction workers. Using this information, EPA calculates the
11
-------
"reasonable maximum exposure" (RME) scenario, which portrays the highest level of exposure that
could reasonably be expected to occur.
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 NCP, 40 Code of Federal Regulations (CFR) Part 300, establishes a range of
acceptable levels of carcinogenic risk for Superfund sites that range between one in 10,0001 and one
in 1 million additional cancer cases if cleanup action is not taken at a site. In addition to
carcinogenic risk, chemical contaminants that are ingested, inhaled or absorbed through the skin may
present non-carcinogenic risks to different organs of the human body. The non-carcinogenic risks or
toxic effects are expressed as a Hazard Index (HI). EPA considers a HI exceeding one (1) to be an
unacceptable non-carcinogenic risk.
In Step 4, EPA determines whether site risks are great enough to potentially cause health problems
for people at or near a 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.
Summary of Site-Related Human Health Risk
Northern Area
Cancer Risk
Current and future cancer risks associated with exposures to soil and dust at the Northern Area at the
Sharon Steel Farrell Works Site (Northern Slag Pile and BOF Sludge Area) exceed the acceptable
risk range due to potential inhalation of chromium (as Cr+6) in dust (resident and industrial worker).
Chronic Noncancer Hazard
Current and future chronic (long duration) noncancer hazards are a concern due to potential
ingestion and dermal absorption of aluminum in soil and potential inhalation of aluminum in dust
(resident and construction worker), potential ingestion and dermal absorption of cadmium in soil and
potential inhalation of cadmium in dust (child resident only), potential ingestion and dermal
absorption of chromium (as Cr+6) in soil and potential inhalation of chromium (as Cr+6) in dust (child
resident and construction worker), potential ingestion and dermal absorption of iron in soil (child
resident and construction worker), potential ingestion of lead in soil (child resident, adult
nonresident), potential ingestion and dermal absorption of manganese in soil and potential inhalation
of manganese in dust (resident, industrial worker, construction worker, trespasser/visitor), potential
ingestion and dermal absorption of thallium in soil (child resident), potential ingestion and dermal
absorption of vanadium in soil (child resident and construction worker) and potential ingestion and
dermal absorption of zinc in soil (child resident only).
Acute Noncancer Hazard
Current and future acute effects (short term) are a concern due to potential inhalation of arsenic,
1 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 to
from all other causes.
12
-------
barium, nickel, and vanadium in dust (resident, industrial worker, construction worker, and
trespasser/vi si tor).
Background
Aluminum in surface soil at part of the Northern Area (the BOF Sludge Area) is found regionally in
the soils of the area.
Southern Area
Cancer Risk
Current and future potential cancer risks associated with exposures to soil and dust at the Southern
Area at the Sharon Steel Farrell Works Site (Southern Slag Pile) are within the acceptable risk range.
Current and future cancer risks associated with exposures to soil and dust in floodplain soils exceed
the acceptable risk range due to potential ingestion and dermal absorption of benzo(a)pyrene in soil,
and potential inhalation of chromium (as Cr+6) in dust (resident). In addition, current and future
cancer risks associated with exposure to soil and dust in the Ohio Street Wetland exceed the
acceptable risk range due to potential inhalation of chromium (as Cr+6) in dust (resident and
industrial worker).
Chronic Noncancer Hazard
Current and future chronic noncancer hazards at the southern slag pile and floodplain are a concern
due to potential ingestion and dermal absorption of aluminum in soil and potential inhalation of
aluminum in dust (resident, industrial worker, construction worker), potential ingestion and dermal
absorption of chromium (as Cr+6) in soil (resident, industrial worker, construction worker), potential
ingestion and dermal absorption of iron in soil (resident, industrial worker, construction worker),
potential ingestion and dermal absorption of manganese in soil and potential inhalation of
manganese in dust (resident, industrial worker, construction worker, trespasser/visitor), potential
ingestion and dermal absorption of thallium in soil (child resident only at the southern slag pile) and
potential ingestion and dermal absorption of vanadium in soil (resident, industrial worker,
construction worker). Current and future chronic noncancer hazards are also a concern due to
aluminum, chromium and manganese at the Ohio Street Wetland (resident, industrial worker and
construction worker).
Acute Noncancer Hazard
Current and future acute effects are a concern due to potential inhalation of arsenic, barium, nickel
and vanadium in dust (resident, industrial worker, construction worker, and trespasser/visitor).
Background
The presence of aluminum and arsenic in surface soil/slag in the Southern Area can be attributed to
levels found in soils regionally. There are no unacceptable risks to people who may come in contact
with the sediment, or surface water in the wetland/pond habitat.
Lead
Lead is evaluated not by a cancer risk or a non-cancer HI, but by a model that predicts potential
blood-lead levels. Lead in the waste sludge would be associated with potentially unacceptable
blood-lead levels in children, if they accessed the site or the soil was used by residents.
13
-------
Groundwater
Many residents in the area obtain drinking water from private wells screened in the gravel or
bedrock aquifer. Groundwater from the site flows away from these residential wells and towards the
Shenango River; therefore, the Site cannot impact these wells. Sampling of the residential wells has
indicated elevated levels of arsenic, thallium and manganese related to high natural concentrations of
these metals in groundwater in the region. There are no current users of contaminated groundwater
at the Site, and the Shenango River prevents the flow of groundwater to areas east of the river.
Contaminated groundwater from the Site flows directly into the Shenango River or the emergent
wetland/unnamed tributary. Additionally, only the shallow two uppermost aquifers on Site
contained elevated levels of metals and organic chemicals from Site contamination while residential
wells are in the two lowermost non-Site contaminated gravel or bedrock aquifers. The risk
assessment indicated a potential health risk if contaminated groundwater at the Site were to be used
for drinking water or industrial purposes in the future.
Surface Water
The Shenango River supports a variety of wildlife and fish and is used by people for recreational
fishing. There are no unacceptable current risks to people who may come in contact with the
sediment, soil, or surface water of the Shenango River. For people who might eat fish from this
river, unacceptable concentrations of PCBs, dioxins, thallium, and mercury were found in fish tissue.
However, of these only mercury was found to be Site related. Thallium was also found in fish from
the Unnamed Tributary and Slag Pond at unacceptable concentrations that could not be attributed to
background. The risk assessment also indicated a potential health risk if these areas along the
Shenango River were to be used for residential or industrial purposes.
Summary of Site-Related Ecological Risk
The purpose of the ERA was not to assess the risks to individual species; it is designed to assess the
risks to ecological communities. The ERA follows a process similar to that for the HHRA;
however, cancer risks are not considered as these are risks that do not often relate to ecological
community-level effects.
EPA reviews the concentrations of contaminants found at a site as well as past scientific studies on
the effects these contaminants have on plants and animals. Comparisons between site-specific
concentrations and concentrations reported in past scientific studies enable EPA to determine which
contaminants are, most likely, the greatest threats to ecological communities.
Ecological receptors at the site can be exposed to contaminated media by direct exposure (ingestion
of media soil, water or dermal absorption of contaminants) or by ingesting plants and animals that
have absorbed and accumulated contamination. Several of the metals and organic compounds
detected at the site are known to be stored in living organisms. Based on the habitats present on and
near the site, the ERA was designed to consider risks to key elements of the local ecology: plant
communities, soil invertebrate communities, and wildlife species.
Chemical contaminants that are ingested or absorbed through the skin may disrupt growth, behavior,
reproduction, or some other factor that can adversely impact the ecological community. The toxic
effects are expressed as a///for each element of the ecological community. EPA considers an HI
exceeding one (1) to be an unacceptable ecological risk.
14
-------
The source areas are mostly barren slag piles that provide minimal ecological habitat; therefore,
there are no current risks to wildlife.
Remedial Action Objectives
The remedial action objectives (RAOs) describe the goals, or objectives for Site cleanup as set forth
in the Proposed Plan. The RAOs for the site are as follows:
• Prevention of exposure to slag, contaminated soils, and dust
• Prevention of exposure to contaminated groundwater
• Reduction of future migration of chemicals into groundwater
• Reduction of surface runoff of materials into the Shenango River and wetlands
Summary of Alternatives
During the Feasibility Study, various alternatives were evaluated to determine the best cleanup
method to prevent inhalation, dermal contact with waste slag and contaminated soils; prevent/reduce
the migration of contaminated ground water at the Site into the Shenango River; and cleanup
contaminated sediments in the Shenango River, wetland/pond habitat, and the unnamed tributary.
This evaluation was based on the information gathered during the RI. EPA's preferred alternative is
Alternative 4 — Biosolid-Enhanced Cap and Passive Vegetated Groundwater Barrier with
Industrial Controls and Long-Term Monitoring.
Several alternatives evaluated in the FS did not meet the criterion of protecting human health and the
environment; therefore, they are not discussed in detail in this Proposed Plan. These alternatives
were considered, but are not described here because they were not sufficient to achieve all the RAOs
or were not implementable as discussed in the Feasibility Study. Further information can be
obtained from the Administrative Record. These included:
• Alternative 2 - Institutional Controls.
• Alternative 5 - Source Removal, Media Excavation/Extraction, Treatment and Disposal.
Each remaining alternative, except the "no action" alternative, contains some common elements that
were considered in the evaluation process. The common elements include:
• Institutional Controls
o Groundwater restrictions
o Land use restrictions
• Environmental monitoring with objectives determined in a Long Term Monitoring Plan
o Groundwater
o Surface water
o Sediment
15
-------
o Wetland plant community abundance and diversity
• Erosion protection to prevent the erosion of waste slag and sludge into the Shenango River
and the wetland/pond area:
o Streambank stabilization of the west bank of the Shenango River along its frontage
with the SSFW Site.
o Silt fencing will be anchored along the north perimeter of the wetland/pond habitat to
prevent the inflow of eroded material from the adjacent slag piles into the wetland.
The following section is a summary of the most significant cleanup alternatives that were considered
during the Feasibility Study and their associated costs. The number of the alternatives is that which
was used in the Feasibility Study itself.
Alternative 1 - No Action Alternative
Capital Cost: $0
Annual Operation and Maintenance (O&M) Costs: $0
Total O&M Costs: $0
Total Present Worth Cost: $0
Under this alternative, no remedial measures would be implemented at the site to prevent exposure
to the waste slag and sludge, contaminated soil and sediment, or groundwater contamination. The
"no action" alternative is included because the NCP requires that a "no action" alternative be
developed as a baseline for evaluating other remedial alternatives.
This alternative would not reduce human health and ecological risks to acceptable levels and would
not meet ARARs.
Alternative 3a — Industrial Controls, Long-Term Monitoring, and a Geosynthetic Liner/Topsoil
Cap
Capital Cost: $51,267,215
Annual O&M Costs: $68,946
Total O&M Costs: $2,068,3 802
Total Present Worth Cost: $53,335,595
This option uses a H-inch thick polypropylene/clay geosynthetic liner and 12-inch thick topsoil
cover to cover the graded slag/sludge. In addition to covering the contaminated slag/sludge at the
site, this cover would prevent infiltration of precipitation into underlying groundwater and would
significantly reduce the discharge of contaminated groundwater into the Shenango River and the
wetland/pond complex. As a result, this option would require significant area for stormwater
management facilities and point discharges for stormwater from the site into the river, ponds, and
wetlands. Using this cover would eliminate the need for groundwater barriers between the source
areas and the Shenango River and would be among the most effective at attaining groundwater
RAOs.
2
Includes annual costs for environmental monitoring based on quarterly sampling for 30 years.
16
-------
The liner/topsoil cover option will require significant ongoing maintenance and therefore, are
typically only re-vegetated with grass species to allow visual inspection of the cap integrity.
Disadvantages of this cover include the availability of sufficient quantities of topsoil needed for the
large site area.
Alternative 3b — Industrial Controls, Long-Term Monitoring, and a Clay/Topsoil Cap
Capital Cost: $24,084,468
Annual O&M Costs: $68,946
Total O&M Costs: $2,068,380
Total Present Worth Cost: $26,152,848
This option uses a 6-inch thick clay layer and a 12-inch thick topsoil cover to cover the graded
slag/sludge. In addition to covering the contaminated slag/sludge at the site, this cover would
prevent infiltration of precipitation into underlying groundwater and would significantly reduce the
discharge of contaminated groundwater into the Shenango River and the wetland/pond complex. As
a result, this option would require the most area for stormwater management facilities and point
discharges for stormwater from the site into the river, ponds, and wetlands. Using this cover would
eliminate the need for groundwater barriers between the source areas and the Shenango River and
would be among the most effective at attaining groundwater RAOs.
The clay/topsoil cover option will require significant ongoing maintenance and therefore, are
typically only re-vegetated with grass species to allow visual inspection of the cap integrity.
Disadvantages of this cover include the availability of sufficient quantities of clay and topsoil
needed for the large site area.
Alternative 3c - Industrial Controls, Long-Term Monitoring, and a Portland Cement Cap
Total Present Worth Cost: $66,862,599
This option applies Portland cement to the graded mass of slag and sludge to create a cemented crust
of site material that covers the underlying source material. In addition to covering the contaminated
slag/sludge at the site, this cover would prevent infiltration of precipitation into underlying
groundwater and would significantly reduce the discharge of contaminated groundwater into the
Shenango River and the wetland/pond complex. As a result, this option would require the most area
for stormwater management facilities and point discharges for stormwater from the site into the
river, ponds, and wetlands. Using this cover would eliminate the need for groundwater barriers
between the source areas and the Shenango River and would be among the most effective at
attaining groundwater RAOs.
The Portland cement cover option will require minimal ongoing maintenance; however, it would not
be possible to re-vegetate the site in the short or long-term. Under this capping option, the site
would remain a cemented area in the long-term; however, this could provide long-term opportunities
Capital Cost:
Annual O&M Costs:
Total O&M Costs:
$64,844,799
$67,260
$2,017,800
17
-------
for industrial uses.
Alternative 4 — Biosolid-Enhanced Cap and Passive Vegetated Groundwater Barrier with
Industrial Controls and Long-Term Monitoring
Capital Cost: $8,727,200
Annual O&M Costs: $67,260
Total O&M Costs: $2,017,800
Total Present Worth Cost: $10,745,000
This option mixes biosolid material from nearby municipalities into the top 3 to 4 feet the graded
mass of slag and sludge to create an enhanced soil that will cover the underlying source material.
The slag on Site is exempt from being RCRA Hazardous waste through the Bevill Exemption.
Biosolids have been demonstrated to reduce the bioavailability and toxicity of contaminated soils
and have been used successfully at other mine-related sites throughout the United States. In addition
to covering the contaminated slag/sludge at the site, this cover would reduce infiltration of
precipitation into the underlying groundwater, would reduce the loading of contaminants from
contaminated materials into groundwater, and would reduce the discharge of contaminated
groundwater into the Shenango River and the wetland/pond complex. As a result, this option would
require less area for stormwater management facilities and point discharges for stormwater from the
site into the river, ponds, and wetlands.
The biosolid enhanced cover option will require minimal ongoing maintenance, will allow the Site to
be planted with native species, and will facilitate natural re-colonization of native plant species to
create a natural habitat at the site. A benchscale treatability study is currently being conducted to
determine the effectiveness of the biosolid cover on reducing bioavailability and toxicity. Initial
results are promising and appear to demonstrate reduced bioavailability and toxicity; however the
final results are not yet available. The final study is expected to be available in August 2006 and
would be used to determine the optimum blend of biosolid material needed to support the re-
vegetation of the site.
A key benefit of the biosolid enhanced cover is that it allows for the beneficial reuse of a waste
stream generated by municipal waste water treatment plants (biosolid sludge). Municipalities
currently pay a significant amount of money to dispose of their waste sludge; however, some have
begun processing their sludge into a biosolid material that can be sold or given away for agricultural
land amendments to lower their operating costs. Use of a biosolid to create an enhanced cover can
provide cost savings for these municipalities.
Because the groundwater protection afforded by the biosolid enhanced cover is lower than for the
other capping variants, a passive groundwater barrier would be used. This passive vegetated
groundwater barrier would include the planting of two staggered lines of poplar trees between the
source areas and the Shenango River. Poplar trees can draw as much as 30 gallons of groundwater
per day and placing these trees just above the Shenango River will allow the root systems of these
trees to draw some groundwater from the surface aquifers before it is discharges into the Shenango
River. No groundwater protection measures are proposed adjacent to the wetland/pond complex
since this area has no significant groundwater contamination.
18
-------
Alternative 6a — Industrial Controls, Long-Term Monitoring, Geosynthetic Liner/Topsoil Cap,
Hot-Spot Removal and Disposal of Impacted Media, Pump/Treat Impacted Groundwater
Capital Cost: $63,737,282
Annual O&M Costs: $152,445
Total O&M Costs: $4,573,338
Total Present Worth Cost: $68,310,619
This alternative is the same as SWRA 3a except that it adds the pumping and treatment of
contaminated groundwater to address groundwater migration and contamination and the excavation
of hot spots of floodplain soils and suction dredging of sediment in downgradient areas.
Excavation of contaminated floodplain soil hot spots and contaminated sediment hot spots in the
wetland would be accomplished using typical excavation machinery. Areas of significantly high
concentration which drive the ecological risks in this area will be excavated to a depth of two feet,
treated on site to stabilize and demobilize the contaminants, loaded in trucks, and transported to a
nearby municipal landfill for use as cover material. This will require the construction of access
roads to the southeast floodplain.
Dredging of contaminated sediment hot spots in the Shenango River and the wetland ponds would
be accomplished using suction dredging equipment. Areas of significantly high concentration which
drive the ecological risks in this area will be excavated to a depth of two feet, treated on site to
stabilize and demobilize the contaminants, loaded in trucks, and transported to a nearby landfill for
use as cover material.
The groundwater pump and treat system would consist of the installation of extraction wells around
the perimeter of the source areas where groundwater discharges. Due to the site of the site and
direction of groundwater flow, two areas of extraction wells (along the Shenango River and along
the wetland/pond complex) would be required. Contaminated groundwater from these extraction
wells would be pumped from the well into a collection system which would convey contaminated
water to two treatment facilities (one in the north portion of the site and one in the south). Each
treatment facility would consist of a granular activated carbon unit (GAC), to remove organic
contaminants, and an ion exchange unit (IE) to remove metals. The solid waste stream (sludge and
brine) and spent treatment units would be transported off site for disposal and the treated water
would be piped to the Shenango River or the wetland/pond complex and discharged at the surface.
Groundwater treatment demands would be expected to gradually decrease as the groundwater
aquifer is lowered through pumping and the covers prevent further infiltration. A smaller amount of
flow would be expected as groundwater flows through the site from upgradient areas.
Alternative 6b — Industrial Controls, Long-Term Monitoring, Clay/Topsoil Cap, Hot-Spot
Removal and Disposal of Impacted Media, Pump/Treat Impacted Groundwater
Capital Cost: $36,554,535
Annual O&M Costs: $152,445
Total O&M Costs: $4,573,338
Total Present Worth Cost: $41,127,872
19
-------
This alternative is the same as SWRA 6a except that it uses a clay/topsoil cap. The details of the
clay/liner cap are discussed under Alternative 3b.
Alternative 6c — Industrial Controls, Long-Term Monitoring, Portland Cement Cap, Hot-Spot
Removal and Disposal of Impacted Media, Pump/Treat Impacted Groundwater
Capital Cost: $77,134,866
Annual O&M Costs: $150,759
Total O&M Costs: $4,522,758
Total Present Worth Cost: $81,83 7,624
This alternative is the same as SWRA 6a except that it uses a Portland cement cap. The details of
the Portland cement cap are discussed under Alternative 3c.
Alternative 7 — Industrial Controls, Long-Term Monitoring, Biosolid Enhanced Cap,
Groundwater Slurry Wall/Pump & Treatment System, and Sediment Armoring
Capital Cost: $12,127,129
Annual O&M Costs: $145,716
Total O&M Costs: $4,371,487
Total Present Worth Cost: $16,498,607
This alternative is similar to Alternative 4 except that an active groundwater barrier system and
sediment armoring is proposed in place of the passive vegetated groundwater barrier. Because the
groundwater protection afforded by the biosolid enhanced cover is lower than for the other capping
variants, a groundwater barrier is included in this alternative.
The groundwater barrier would consist of 4,500 linear feet of a bentonite slurry wall between the
source areas and the Shenango River to a depth of 15 feet to prevent shallow groundwater from
flowing from the site into the Shenango River. In addition, a pump and treatment system is needed
to remove and treat the contained groundwater before it is discharged to the Shenango River. No
groundwater protection measures are proposed adj acent to the wetland/pond complex since this area
has no significant groundwater contamination. The groundwater pump and treat system would
consist of the installation of extraction wells around the perimeter of the source areas where
groundwater discharges. Due to the site of the site and direction of groundwater flow, one area of
extraction wells would be required along the Shenango River. Contaminated groundwater from
these extraction wells would be pumped from the well into a collection system which would convey
contaminated water to a treatment facility. The treatment facility would consist of a granular
activated carbon unit (GAC), to remove organic contaminants, and an ion exchange unit (IE) to
remove metals. The solid waste stream (sludge and brine) and spent treatment units would be
transported off site for disposal and the treated water would be piped to the Shenango River and
discharged at the surface. Groundwater treatment demands would be expected to gradually decrease
as the groundwater aquifer is lowered through pumping and the biosolid cover reduces future
infiltration.
The sediment armoring would consist of encapsulating sediment hot spots in the Shenango River
20
-------
and the unnamed tributary with an impermeable geosynthetic liner anchored to the stream bottom
and cover with rip rap to prevent future erosion.
Evaluation of Alternatives
In this section, EPA evaluated the alternatives in detail to determine which alternative would be the
most effective in achieving the goals of CERCLA, and in particular, achieving the remedial action
obj ectives established for the Site. EPA uses nine criteria to evaluate cleanup alternatives in order to
select a remedy. Below is a description of each of the nine criteria set forth in the NCP, 40 CFR
§ 300.430(e)(9). These nine criteria can be categorized into three groups: threshold criteria, primary
balancing criteria, and modifying criteria.
Threshold Criteria:
1. Overall Protection of Human Health and the Environment addresses whether a remedy
provides adequate protection to human health and the environment and describes how risks are
eliminated, reduced, or controlled through treatment, engineering controls, or institutional controls.
2. Compliance with ARARs addresses whether a remedy will meet all of the applicable or
relevant and appropriate requirements of environmental statutes, regulations, and/or whether there
are grounds for invoking a waiver.
Primary Balancing Criteria:
3. Long-term Effectiveness refers to the ability of a remedy to maintain reliable protection of
human health and the environment, over time, once cleanup goals are achieved.
4. Reduction of Toxicity, Mobility, or Volume through Treatment addresses the degree to which
alternative treatments will reduce the toxicity, mobility, or volume of the contaminants causing Site-
related risks.
5. Short-term Effectiveness addresses the period of time needed to achieve protection and any
adverse impacts on human health and environment that may be posed during the construction and
implementation period.
6. Implementability addresses the level of technical and administrative difficulty associated
with completing a remedy, including whether materials and services needed to implement a
particular option are readily available.
7. Cost includes estimated capital (startup) costs, as well as operation and maintenance costs,
and are usually combined and presented as the Total Net Present Worth Cost.
Modifying Criteria:
8. State Acceptance indicates whether, based on its review of supporting documents and the
Proposed Plan, the State supports, opposes, or has no comment on the preferred alternative.
21
-------
9. Community Acceptance will be assessed in the ROD following a review of public comments
received on the Proposed Plan and supporting documents included in the Administrative Record.
Overall Protection of Human Health and the Environment
CERCLA requires that the selected remedial action be protective of human health and the
environment. An alternative is protective if current and potential future risks associated with each
exposure pathway at a Site are reduced to acceptable levels. An exposure pathway refers to the way
in which a person or other living organism can come into contact with contaminants.
Alternative 1 does not protect human health or the environment to any greater extent than already
protected; adverse risk from exposure to source material and contaminated media downgradient is
not reduced or eliminated by this option. In fact, exposure and risk could increase over time due to
continued migration of slag/sludge solids with storm water runoff and the percolation of infiltrated
storm water through the source material to groundwater. Also, as stated earlier, Alternatives 2 and 5
considered early in the FS either do not meet this threshold criteria or are not implementable and are
not further evaluated in this Proposed Plan.
Alternatives 3, 4, 6, and 7, all are likely to provide protection of human health and the environment.
The ICs proposed under all of these alternatives will address groundwater usage in the short- and
long-term. Covering the source material prevents onsite exposure to source material, retains the
source material in place to minimize migration (via erosion or dust), and minimizes the percolation
of surface precipitation through the source material to shallow groundwater. The cover/caps for all
these alternatives prevent exposure to source contaminants and address groundwater migration and
erosion of source material into the Shenango River. Ecological risks may remain in downgradient
habitats; however, since these habitats are not visibly impacted, it is believed that source area
controls will allow contaminant levels in these habitats to decrease over time. Alternatives 6 and 7
provide somewhat greater protection to human health and the environment since they will remove
contaminated groundwater from the site and provide for immediate remediation of the most
significantly impacted downgradient media.
Compliance with Applicable or Relevant and Appropriate Requirements (ARARs)
Any cleanup alternative selected by EPA must comply with all applicable or relevant and
appropriate federal and state environmental requirements. Applicable requirements are those
substantive environmental standards, requirements, criteria, or limitations promulgated under
federal or state law that can be legally applied to the remedial action to be implemented at the Site.
Relevant and appropriate requirements, while not being directly applicable, address problems or
situations sufficiently similar to those encountered at the Site that their use is well-suited to the
particular Site. EPA may waive an ARAR under certain conditions; however, EPA is not waiving
any ARARs for this Site. Alternative 1 does not meet the requirements of CERCLA because it
results in unacceptable risks to human health and the environment; therefore, it is not included in the
discussion below. The following are the main ARARs applicable to the Site: Maj or ARARs that may
apply to the groundwater remedies listed in this Proposed Plan include: Federal Maximum
Contaminant Levels (MCLs) and/or Maximum Contaminant Level Goals (MCLGs) for drinking
water established under the Safe Drinking Water Act 42 U.S.C. §§300g-l. To meet the substantive
requirements on surface water discharge on Site the following ARARS may apply: Pennsylvania
22
-------
National Pollutant Discharge Elimination System (NPDES) program requirements; 25 PA Code
Chapters 95.1 - 95.3; Section 402 of the Clean Water Act; and 40 CFR 131 (compliance with
established water quality standards);Storm Water Management Act 32 P.S. §680.13; Erosion and
Sediment Control 25 PA Code 102.4(b)(1), 102.11, 102.22; Pennsylvania Water Quality Standards
25 PA Code Chapters 93.4A, 93.5-93.7 and 93.8a; Pennsylvania Wetland Regulations 25 PA Code
Chapter 105.18a
Long-Term Effectiveness and Permanence
The evaluation of alternatives under this criterion considers the ability of an alternative to maintain
protection of human health and the environment over time, usually measured in one or more
decades. The evaluation takes into account the residual risk remaining from untreated waste at the
conclusion of remedial activities, as well as the adequacy and reliability of containment systems and
institutional controls.
Alternative 1 does not provide any long-term or reliable protection of human health or the
environment. One possible exception is the conditional long-term protection of human
visitors/trespassers by implementing institutional controls at the site; as long as the controls were
enforced in the long-term, they would deter or restrict access to the site.
Alternatives 3, 4, 6, and 7 would all provide partial long-term protection to human health and the
environment through implementation of the capping/covering element, and would provide
conditional long-term protection to human visitors/trespassers through implementation of
institutional controls at the site. The cover systems proposed in these alternatives would all require
some routine monitoring and maintenance to maintain; however, Alternatives 4 and 7 would require
the least maintenance because it would support the rapid establishment of a diverse habitat of native
grasses and shrubs. This habitat, by design, would require very little upkeep and would provide
additional ecological habitat. Alternative 7 would also provide long term effectiveness and
permanence. As long as the institutional controls were enforced in the long-term, and as long as the
cap structure was not breeched, this remedial alternative would prevent or at least restrict exposure
to contaminated source media. This alternative would not address currently impacted media
downgradient of the source material; therefore it would not provide any long-term protection to
human health and the environment downgradient of the site.
The remedial technologies included in Alternatives 6 and 7 to remove contaminated groundwater
from the site; migration of contamination into the Shenango River and risks associated with
groundwater use would be significantly minimized. The long-term effectiveness of the removal and
treatment elements of these remedial alternatives are completely effective over the long-term since
contamination in shallow groundwater under the source material would be eliminated and removed
from the site. The long-term effectiveness at protecting human health and the environment is the
best for these alternatives.
Reduction in Toxicity, Mobility, or Volume through Treatment
This evaluation criterion addresses the statutory preference for selecting remedial actions that
employ treatment technologies that permanently or significantly reduce the toxicity, mobility, or
volume of hazardous substances as their principal element.
Alternative 1 does not reduce the toxicity, mobility, or volume of contamination at the SSFW site.
23
-------
Alternative 3 would reduce the mobility of contaminants because the cover physically blocks the
migration of contaminants in the source material. The volume of contamination discharge in
groundwater would decrease since the covers would prevent infiltration and reduce groundwater
levels under the source material. The toxicity of contaminants materials would be unchanged.
Alternatives 4, 6, and 7 would reduce the toxicity, mobility, and volume of contaminants from the
site. The introduction of groundwater treatment would reduce the volume of contamination in
groundwater due to the covers, the groundwater barriers and the extraction wells. The groundwater
treatment system element of Alternatives 6 and 7 will reduce the toxicity of groundwater at the site.
The use of a biosolid enhanced cap associated with Alternatives 4 and 7 could reduce toxicity of the
source material and groundwater by reducing the bioavailability of contaminants in the covered
source material.
Short-Term Effectiveness
This evaluation criterion addresses the effects of the alternatives during the construction and
implementation phase until remedial action objectives are implemented. The criterion considers
risks to the community and to on-site workers. It also considers available mitigation measures, as
well as the time frame for the attainment of the response objectives.
Alternative 1 is not effective in the short-term because no action is implemented with this option;
however there are also no associated additional adverse impacts. The industrial controls associated
with Alternatives 3, 4, 6, and 7 provide some short-term effectiveness in minimizing human
exposure to source material and groundwater.
Alternatives 3, 4, 6, and 7 are not likely to provide short-term protection to human health or the
environment. The grading associated with all of these alternatives could result in adverse short-term
impacts if not carefully executed and could actually increase potential exposure in the short-term to
contamination during the implementation phase of this remedial alternative. Best management
practices for dust suppression and erosion control should be used to minimize creation of excessive
dust, dispersion, and runoff of contaminants. All of these alternatives would involve the delivery of
a significant amount of material to create the cover, which would create increased human risks due
to increased local traffic. Impacts would be minimized by creating established trucking routes that
minimize the use of small local streets and schedule delivery times to avoid high traffic times
(morning and evening rush hours). Alternatives 4 and 7 would require the least amount of material
to be imported to the Site because the biosolid material is used to supplement the existing waste
slag/sludge to create the cover. The biosolids from local facilities would require transporting
materials the least distance, thus minimizing the affect on traffic.
The work in aquatic habitats (sediment dredging and wetland soil excavation) may also have adverse
short-term impacts to these habitats. In the floodplain and wetlands, excavating contaminated
materials under Alternative 6 would eliminate these habitats in the short-term. These areas would
need to be restored to be compliant with action and location specific-ARARs. Under Alternative 7,
the sediment armoring would result in a temporary loss of benthic invertebrate habitat, which would
be expected to naturally recover over time as the rip rap became a substrate for benthic species and
fish.
Alternative 6 would take the longest to implement due to the amount of work required for its
implementation. Alternative 4 would be the fastest to implement due to the availability of biosolid
24
-------
material and would result in the fastest reductions in off-site contamination.
Implementability
The evaluation of alternatives under this criterion considers the technical and administrative
feasibility of implementing an alternative and the availability of services and materials required
during implementation. Each of the alternatives is implementable, and the services and materials
required for each alternative are available. However, some would be more difficult to implement
than others.
Alternative 1 is most easily implemented since no activities to address remediation of contaminated
media at the site would be initiated. Alternative 4 would be the most easily implemented action
alternative. The availability of biosolid material and the simplicity of the groundwater barrier would
enable this alternative to be implemented with little difficulty. Alternative 7 would be the next most
easily implemented alternative due to the biosolid availability. Alternatives 4 and 7 are technically
feasible and there is an abundance of Class A biosolid material available from local sources to
implement this remedial action. The installation of the groundwater barrier and treatment system
and the sediment armoring are implementable but would take additional time to be installed and
become operational. Alternatives 3 and 6 would be difficult to implement due to the large volume of
topsoil or clay and the difficulty with finding local sources of this volume and transporting it to the
site. The Portland cement variant (c) of these alternatives may be more easily implemented as there
are likely to be adequate sources of this material. Alternative 6 is the most difficult to implement
due to the additional work required for the hot spot excavation, treatment, transportation, and off-site
disposal.
Cost
The Alternative Cost Summary Table (See Figure 6) summarizes the capital, annual O&M, and total
present worth costs for each alternative. The total present worth is based on an O&M time period of
30 years for an engineered cover system and environmental monitoring. For additional details on
the cost estimate breakdown, see the Administrative Record.
Alternative 1 has the lowest cost as there are no actions associated with its implementation.
Alternatives 4 and 7 are the least expensive action alternatives, largely as a result of the availability
and low cost associated with the biosolid enhanced cap. Alternative 4 is less expensive than
Alternative 7 due to the use of passive groundwater controls and the strategy of solely using source
control and LTM to reduce off-site concentrations and risks. Alternatives 3 and 6 are the most
Total Project (Phases 1 and 2
Alternative
No.
Description
Capital
Costs
Annual O&M
Costs
Total O&M
Present Worth
Total Present
Worth
(30 years)
(30 years)
SWRA 1
No action
$ 0
$ 0
$ 0
$ 0
SWRA
3(a)
IC, LTM, and Capping
(Liner/T osoil)
$ 51,267,215
$ 68,946
$ 2,068,380
$ 53,335,595
SWRA
3(b)
IC, LTM, and Capping
(Clay/Tosoil)
$ 24,084,468
$ 68,946
$ 2,068,380
$26,152,848
25
-------
SWRA
3(c)
IC, LTM, and Capping (Portland $ 04 844 7gg
Cement)
$ 67,260
$ 2,017,800
$66,862,599
SWRA 4
IC, LTM, Biosolid Enhanced
Cap, and Passive Vegetated $ 8,727,200
Groundwater Barriers
$ 67,260
$ 2,017,800
$ 10,745,000
SWRA
6(a)
IC, LTM, Capping
(Liner/Topsoil), Hot Spot - 7„ 9ft9
Excavation/Extraction, and GW
Pump and Treat
$ 152,445
$ 4,573,338
$68,310,619
SWRA
6(b)
IC, LTM, Capping (Clay/Topsoil),
Hot Spot Excavation/Extraction, $ 36,554,535
and GW Pump and Treat
$ 152,445
$ 4,573,338
$41,127,872
SWRA
6(c)
IC, LTM, Capping (Portland
Cement), Hot Spot « 77 . QCC
r v /i- a. t- rj ™,, $ 77,314,866
Excavation/Extraction, and GW
Pump and Treat
$ 150,759
$ 4,522,758
$ 81,837,624
SWRA 7
IC, LTM, Biosolid Enhanced
Cap, Groundwater Barrier with ~ .„7 .„q
Pump and Treat System and
Sediment Containment
$ 145,716
$ 4,371,478
$ 16,498,607
Figure 6: Comparison of Costs for Alternatives
Alternative 3 costs are more than twice the costs of Alternative 4 and may not be significantly more
effective. The groundwater treatment systems make SWRA 6 considerably more expensive than
Alternative 3.
Based on the benefit afforded to the other non-modifying selection criteria, Alternative 4 appears to
provide the best cost benefit.
State Acceptance
State acceptance of the preferred alternative will be evaluated after the public comment period ends
and will be described in the ROD.
Community Acceptance
Community acceptance of the preferred alternative will be evaluated after the public comment
period ends and will be described in the ROD.
Summary of the Preferred Alternative - Alternative 4, Total Present Worth= $10,745,000
EPA's preferred alternative for the SSFW Site is Alternative 4 - Biosolid-Enhanced Cap and Passive
Vegetated Groundwater Barrier with Industrial Controls and Long-Term Monitoring. EPA's
preferred alternative includes the following:
• Re-grading and contouring the Site to prevent erosion of slag materials from the Site into
the Shenango River and adjacent habitats and using Class A biosolids to create a protective
cover over the contaminated slag and sludge to prevent contact with the slag and sludge
material, prevent the migration of slag dust from the Site, minimize groundwater
infiltration of metals through the vegetative biosolid cap and reduce the mobility of the
26
-------
metals contamination from the slag and sludge into groundwater by treating the
contaminated slag and sludge with biosolids which binds with the metals, and creating an
open space suitable for wildlife habitat. The slag on Site is exempt from being RCRA
Hazardous Waste through the Bevill Exemption. Additionally, there would be installation
of perimeter fencing and signs to limit trespasser exposure until a biosolid cap is
established on Site.
• Installation of a passive vegetated groundwater barrier to minimize the discharge of
contaminated groundwater from the site into the Shenango River. This would include:
o Planting two staggered lines of poplar trees between the source areas and the
Shenango River. Poplar trees can draw as much as 30 gallons of groundwater per
day. Planting these trees just above the Shenango River will allow the root systems
of these trees to draw some groundwater from the surface aquifers before it
discharges into the Shenango River.
• Implementing erosion protection measures to prevent the erosion of waste slag and sludge
into the Shenango River and the wetland/pond area. This would include:
o Streambank stabilization of the west bank of the Shenango River along its frontage
with the SSFW Site. The bank of the Shenango River would be excavated away to
create a broad and level floodplain at the normal high water elevation. This bank
would be stabilized using a combination of bioengineering techniques including
block placement with willow plantings supplemented by gabion baskets (in high
erosion areas). Streambank stabilization would not be conducted in the Southern
Area since there are no waste piles adjacent to the river and the river bank is well
forested.
• Implementing institutional controls for the Site through orders or agreements with EPA or
by municipal ordinances which would include:
o Prohibition of use of shallow groundwater at the Site for drinking water purposes to
prevent unacceptable exposure to contaminated ground water via ingestion, vapor
inhalation or dermal contact.
o Restriction of certain property uses to prevent activities, such as construction, that
would adversely affect the protective cover or other components of the remedy or
would result in unacceptable exposure risks related to contaminated soil.
• Implementing an environmental monitoring strategy for groundwater, surface water,
sediment and monitoring of planted areas to ensure that there are no adverse impacts on
human health and ecological habitats associated with the Site. Environmental monitoring
measures would be specified in a Long-Term Monitoring Plan.
Overall, based on the currently available information, EPA believes that Alternative 4 would provide
the best balance of tradeoffs among the other alternatives for the following reasons:
27
-------
• It would offer the most cost-effective means to achieve the RAOs established for the site, it
would reduce risks to human health to acceptable levels, and it would meet the ARARs for
the site. While this alternative would leave residual ecological risks, EPA believes that
the source control remedial actions would allow contaminant concentrations in the
impacted habitats to decrease over time.
• It is the most easily implemented alternative available and offers the greatest combination
of short-term benefits with minimal short- and long-term adverse impacts. This alternative
could be implemented faster than the other alternatives, there is sufficient biosolids
material readily available for the cover, and this alternative would allow for the creation of
significant ecological habitat value over an area that currently offers very little. In
addition, this alternative could provide additional recreational opportunities (hunting,
nature watching, and hiking) that are not currently available in this area.
• It would provide the most economical means of treating waste slag and sludge to decrease
its leachability and toxicity.
• It would provide a permanent solution to the problems at the site and would require the
least maintenance to maintain.
EPA's preferred alternative would satisfy the statutory requirements of CERCLA §121(b) by being
protective of human health and the environment; complying with ARARs; being cost-effective;
utilizing permanent solutions and alternative treatment technologies to the maximum extent
practicable; and satisfying the preference for treatment as a principal element. EPA's preferred
alternative could be modified or changed in response to state comments, public comments, or new
information. The total present worth cost of EPA's preferred alternative is $10,745,000.
Community Participation
This Proposed Plan is being distributed to solicit public comment on the appropriate cleanup action
for the Site. EPA relies on public input so that the remedy selected for each Superfund Site
addresses the concerns of the local community. EPA is providing a 30-day public comment period
beginning on July 16, 2006, and ending on August 14, 2006, to encourage public participation in the
selection process. EPA will conduct a public meeting during the comment period in order to
present the Proposed Plan and supporting information, answer questions, and accept both oral and
written comments from the public. The public meeting will be held on July 26, 2006, at the Stey
Nevant Library, 1000 Roemer Boulevard, Farrell, PA 16121 at 6:30 p.m.
EPA will summarize and respond to relevant comments received at the public meeting and to written
comments post-marked by midnight on August 14, 2006, in the Responsiveness Summary section of
the ROD, which will document EPA's final selection of a clean-up remedy. To obtain additional
information relating to this Proposed Plan, please contact either of the following EPA
representatives:
Carrie Deitzel (3HS52) Rashmi Mathur (3HS23)
Community Involvement Coordinator Remedial Project Manager
U.S. EPA - Region III U.S. EPA - Region III
1650 Arch Street 1650 Arch Street
28
-------
Philadelphia, PA 19103 Philadelphia, PA 19103
Phone: 215-814-5525 Phone: 215-814-5234
Toll-free: 1-800-553-2509 (x45525 or x45234)
The detailed Administrative Record can be examined at the following locations:
Stey Nevant Library
1000 Roemer Blvd.
Farrell, PA 16121
(724) 983-2714
US EPA Region III
1650 Arch Street
Philadelphia, PA 19103
(215)814-3157
The Administrative Record File can also be accessed remotely via the internet by going to the
following web site address: http://www.epa.gov/arweb/.
EPA's general information web address for the Sharon Steel - Farrell Works Superfund Site is:
http://www.epa.gov/reg3hwmd/super/sites/PAD0Q1933175/index.htm.
29
-------
Glossary
Administrative Record: EPA's official compilation of documents, data, reports, and other
information that is considered important to the status, and decisions made, relating to a Superfund
Site. The record is placed in the information repository to allow public access to the material.
Air/dust dispersion model: A computer model used to study and predict the transport of air or
transport of dust in the air.
Applicable or Relevant and Appropriate Requirements (ARARs): The federal and state
requirements or criteria that are determined to be legally applicable or relevant for the Site cleanup
work.
Aquifer: A layer of rock or soil that can supply usable quantities of ground water to wells and
springs. Aquifers can be a source of drinking water and provide water for other uses as well.
Artesian conditions: When a confined aquifer contains groundwater that will flow upwards out of a
well without the need for pumping.
Background levels: The concentrations of substances in environmental media (air, water, soil, etc)
that are not related to the Site in question. They may occur naturally or as a result of human
activities other than the Site.
Benchscale treatability study: A small study conducted in a laboratory to test the effectiveness of
a remedial treatment or innovative technology on contaminated site materials.
Bio-engineered bank stabilization techniques: Techniques that are designed (or engineered) to
stabilize or re-build the banks of rivers and streams to prevent erosion. These techniques include
erosion blankets, planting vegetation, and bank reconstruction.
Biosolid: Solid, semi-solid, or liquid materials generated from primary, secondary, or advanced
treatment wastewater or sewage, often used as fertilizer.
Capital costs: The total purchase price.
Carcinogenic: An agent which causes or contributes to the occurrence of cancer.
Class A biosolids: Class A biosolids contain very low levels of pathogens, or agents that cause
disease. To achieve Class A certification, biosolids must undergo heating, composting, digestion or
increased pH that reduces pathogens to low levels.
Code of Federal Regulations (CFR): For example, the citation 40 C.F.R. 260 means Title 40 of
the Code of Federal Regulations, Part 260.
Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA): A
federal law passed in 1980 and amended several times subsequently. The Act created a Trust Fund,
30
-------
known as Superfund, with funds available to investigate and clean up abandoned or uncontrolled
hazardous waste sites.
Confining bed: A hydrogeologic unit of impermeable or distinctly less permeable material
bounding or restricting one or more groundwater aquifers.
Contaminant: Any physical, chemical, biological, or radiological substance or matter that has an
adverse effect on air, water, or soil.
Crushed rock stabilization: The use of gravel and crushed rock to stabilize a bank of a river or
stream.
Depressed biological community: A biological community that shows evidence of being adversely
impacted, altered, or degraded.
Ecological communities: Groups of plant and animal life.
Erosion: A process of group of processes (including weathering, dissolution, abrasion, corrosion,
and transportation) by which loose or consolidated earth materials are dissolved, loosened or worn
away and moved from one place and deposited in another.
Feasibility Study (FS): A report that identifies and evaluates alternatives for addressing the
contamination that presents unacceptable risks at a Superfund site.
Floodplain: An area that borders a body of water (e.g. river) and is subject to flooding.
Gabion baskets: Metal cages filled with rip rap (or rock) which are used for erosion control, to
build dams, or foundations.
Geomembrane/Geosynthetic: These sheet materials are either manmade (e.g., plastic) or manmade
composites (e.g., clays sandwiched in fabric) and are used in the earth ("geo") or soils for filtration,
drainage, protection, separation, reinforcement, sealing and erosion control.
Glaciated: Formed by the process of glaciation or a geological phenomenon in which massive ice
sheets form in the Arctic and Antarctic and advance toward or away from the equator.
Groundwater: The water beneath the earth's surface that flows through the soil and rock openings
and often serves as a source of drinking water.
Hazard Index (HI): A numeric representation of non-cancer risk. A HI exceeding one (1) is
generally considered an unacceptable non-cancer risk.
Hot spots: An isolated area that exhibits high levels of contamination.
High-fertility: Having a high ability to reproduce.
31
-------
Infiltration: The process by which water on the ground surface enters the soil.
Impervious: Eliminating the infiltration of rainwater or natural groundwater recharge.
In-situ: At Superfund sites this generally refers to treatment of contaminated soil in place rather than
removing the soil first.
Institutional Controls: Non-engineered instruments such as administrative and/or legal controls
that minimize the potential for human exposure to contamination by limiting land or resource use.
Long-term monitoring: Monitoring (or sampling) to assess the effectiveness of the remedial
alternative in meeting the cleanup limits and reducing the risk to human health and the environment.
Low-permeability: Having a low ability to allow the passage of a liquid, such as water through
rocks.
Maximum Contaminant Levels (MCLs): Enforceable standards for public drinking water supplies
under the Safe Drinking Water Act. Theses standards apply to specific contaminants which EPA has
determined have an adverse effect on human health above certain levels.
National Oil and Hazardous Substances Pollution Contingency Plan (NCP): The federal
regulations found at 40 C.F.R. Part 300 that provides the organizational structure and procedures for
preparing for and responding to discharges of oil and releases of hazardous substances, pollutants
and contaminants under the Superfund program.
National Priorities List (NPL): EPA's list of the nation's top priority hazardous waste sites that are
eligible to receive federal money for response under CERCLA.
Natural attenuation: The reliance on natural processes (within the context of a carefully controlled
and monitored site cleanup approach) to achieve site-specific remediation objectives within a time
frame that is reasonable compared to that offered by other more active methods. The 'natural
attenuation processes' that are at work in such a remediation approach include a variety of physical,
chemical, or biological processes that, under favorable conditions, act without human intervention to
reduce the mass, toxicity, mobility, volume, or concentration of contaminants in soil or groundwater.
Organic Compound: A carbon-based material.
Passive Vegetated Groundwater Barrier: A barrier placed between a contaminant source area and
a feature to be protected that uses trees or plants to draw groundwater up out of the ground and
minimize the amount of groundwater that passes through.
Pathways: Routes which contaminants may follow as they move by gravity or ground water flow.
In addition, an exposure pathway is the route a contaminant takes in reaching a potential receptor,
such as a person, animal or plant.
Porosity: Degree to which soil, gravel, sediment, or rock is permeated with pores or cavities through
32
-------
which water or air can move.
Present worth costs: The sum of the present values of the annual cash flows minus the initial
investment.
Promulgated: When a law receives final formal approval.
Record of Decision (ROD): A public document that describes the remedial actions selected for a
Superfund Site, why certain remedial actions were chosen as opposed to others, and how much they
will cost. It summarizes the results of the Remedial Investigation and Feasibility Study reports and
the comments received during the comment period for the Proposed Plan.
Remedial Action (RA): The actual construction or implementation phase of a Superfund Clean-up
following a Remedial Design (RD).
Remedial Action Objectives (RAO): The goals of a remedial action.
Remedial Investigation (RI): A study which identifies the nature and extent of contamination at a
Superfund site and forms the basis for the evaluation of environmental and human health risks posed
by the site.
Remedial Investigation/Feasibility Study (RI/FS): A report composed of two scientific studies,
the RI and the FS. The RI is the study to determine the nature and extent of contaminants present at
a Site and the problems caused by their release. The FS is conducted to develop and evaluate
options for the cleanup of a Site.
Resource Conservation and Recovery Act (RCRA): A federal law that established a regulatory
system to track hazardous waste from the time of generation to disposal including requirements for
treating, transporting, storing and disposing of hazardous waste.
Risk Assessment: A human health or ecological evaluation process which provides a framework for
determining the potential health hazards from contamination at a site.
Screened: Slotted to keep out soil particles while allowing water to flow freely. Groundwater well
casings are screened.
Sediment: Soils, sand and minerals washed from land into water.
Seeps: Areas where ground water discharges along the banks into the Creek.
Slag: Soil-like material left as a residue from the smelting of metallic ore. A by-product of the steel
industry.
Sludge: Semi-solid material. A solid by-product of the steel making process. At the SSFW site, the
sludge is a powdery-fine, rust-colored solid.
33
-------
Statutory: Enacted, regulated, or authorized by a law.
Superfund: The common name used for CERCLA.
Topographic depression: A landform that is sunken or depressed below the surrounding area.
34
------- |