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Proposed Plan for DNAPL Cleanup
NSG Former South Plant MGP Superfund Site
Waukegan, Illinois
Community Participation
EPA and Illinois EPA provide information regarding the
North Shore Gas Former South Plant MGP Superfund
site to the community by holding public meetings,
maintaining an Administrative Record for the site, and
publishing announcements in the Lake County News
Sun. Through these means, EPA and Illinois EPA
encourage the public to gain a more comprehensive
understanding of the Superfund activities that have been
conducted at the site. Site information can also be found
at www.epa.gov/region5/cleanup/northshoregassouth.
EPA maintains the site Administrative Record, which
contains the information EPA used to develop the
proposed site remedy, at the following locations:
Waukegan Public Library EPA Region 5
128 N. County Street 77 W. Jackson St.
Waukegan, Illinois 7th Floor Records Center
Hours: 10AM - 6PM Chicago, Illinois
(847) 623-2041 M-F 8AM to 4PM
EPA will be accepting written comments on the South
Plant MGP site Proposed Plan at
www.epa.gov/region5/cleanup/northshoregassouth
during the public comment period, which will run for a
total of thirty (30) days from May 6,2015 to June 5,
2015. Written comments may also be sent to the
following address:
Heriberto Leon
Community Involvement Coordinator
United States Environmental Protection Agency
Mail Code SI-7J
77 W. Jackson Blvd. Chicago, IL 60604
EPA will host an open house at 3:00 pm and hold a
public meeting at 6:00 pm on May 20, 2015 to discuss
all the alternatives and the preferred remedy. Written
and oral comments will be accepted at the meeting. The
meeting will be at:
Bowen Park - Lilac Cottage
1911 North Sheridan
Waukegan, IL 60079
I. INTRODUCTION
The U.S. Environmental Protection Agency
(EPA), in consultation with the Illinois
Environmental Protection Agency (Illinois
EPA), is issuing this Proposed Plan to present
its preferred cleanup alternative for addressing
the pool of undissolved tar-like material,
called "dense, nonaqueous phase liquid
(DNAPL)," that is found beneath the North
Shore Gas (NSG) Company Former South
Plant Manufactured Gas Plant (MGP)
Superfund site in Waukegan, Illinois. EPA
recommends that Alternative D5, Physically
Enhanced DNAPL Recovery, be installed to
address the DNAPL, which is the primary
source of groundwater contamination at the
site.
EPA will explain the rationale for proposing
the preferred alternative in this document, as
well as describing all the alternatives that were
evaluated for DNAPL cleanup. This document
also describes site history, including previous
investigations and response actions performed.
EPA is issuing this Proposed Plan as the lead
oversight agency for the site. Illinois EPA is
providing support. EPA, in consultation with
Illinois EPA, will select a remedy for DNAPL
cleanup after reviewing and considering all
information submitted during a 30-day public
comment period. EPA may modify the
preferred alternative or select another response
action presented in this Proposed Plan based
on new information or public comments.
Therefore, the public is encouraged to review
and comment on all the alternatives presented
in this Proposed Plan.
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EPA is issuing this Proposed Plan as part of its public participation responsibilities under Section
117 of the Comprehensive Environmental Response, Compensation, and Liability Act
(CERCLA) of 1980, as amended, 42 U.S.C Section 9617, commonly known as Superfund, and
Section 300.430 (f)(2) of the National Oil and Hazardous Substances Pollution Contingency Plan
(NCP). This Proposed Plan summarizes information from the site Remedial Investigation (RI)
and Focused Feasibility Study (FFS) reports and other documents that comprise the site
Administrative Record. EPA encourages the public to review the Administrative Record to gain
a more comprehensive understanding of the cleanup and investigative activities that have been
conducted at the site.
II. SITE BACKGROUND
Site Location and Description
The nearly 23-acre NSG Former South Plant MGP Superfund site includes the 1.9-acre former
South Plant MGP parcel located at 2 North Pershing Road and 1 South Pershing Road in
Waukegan (see Figure 1), and several adjacent properties where MGP-derived contaminants
have been found (see Figure 2). The adjacent parcels include:
¦ Waukegan Port District (WPD)-owned property located to the east of the former
MGP parcel on Lake Michigan. The 13.1-acre WPD parcel includes a marina, a
visitor center/administration building, a maintenance building, and asphalt-paved
parking lots.
¦ Akzo Nobel Aerospace Coatings, Inc. (Akzo) parcel located east/southeast of the
former MGP and adjacent to Lake Michigan. The 6.2-acre property consists of
buildings used for manufacturing paints and coatings and asphalt-paved parking lots.
¦ Elgin, Joliet and Eastern (EJ&E) railroad tracks and right-of-way located east and at
the south end of the former MGP property. This parcel is approximately 0.7 acres.
¦ City of Waukegan-owned parcels located southeast of the former MGP site between
the EJ&E, Akzo, and WPD properties. One parcel is a vacated former city street that
abuts a ComEd substation and others include nearby roads and associated right-of-
ways, totaling 0.5 acres.
The Former South Plant MGP property is bounded to the north by a city-owned Metra train
parking lot and to the west by a Union Pacific Railroad train yard. There are no known MGP
residuals on these properties and both are upgradient of the former MGP site based on the
localized groundwater flow direction. South Waukegan Harbor and Lake Michigan are located
approximately 600 feet east of the former MGP property. South Waukegan Harbor was
constructed in the mid-1980s as a marina for recreational boats and has a southern exit to Lake
Michigan. The Waukegan River is located approximately 1,000 feet south of the former MGP
property and flows east past the Akzo property into Lake Michigan.
Site History
MGPs were industrial facilities that were found in every sizable town or city in the U.S. from the
1820s to right after World War II. MGPs heated coal in large industrial ovens to produce
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manufactured gas used for street lighting, heating, and cooking. After the war, natural gas use
replaced manufactured gas use because it was abundant, lower priced, and cleaner burning. Some
MGPs continued to operate after the war, but most ceased operations by the 1960s and were torn
down. Typically, the above-ground structures, such as buildings, tar/oil tanks, and storage sheds,
were demolished and the foundations were backfilled, leaving hardly any visible traces of the
former operations. Below-ground structures such as underground piping and storage tanks, along
with residual contaminants, were often left behind.
Figure 1: NSG Former South Plant Former MGP site location
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Figure 2: NSG South Plant Former MGP site property boundaries
The Waukegan Pipeline Service Company constructed the original South Plant MGP in 1897 and
the Waukegan Gas, Light, and Fuel Company purchased it in 1898. NSG purchased the facility
in 1900 and leased the southern 0.37 acres from the EJ&E Railroad. Aerial surveys and available
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information indicate that this facility was comprised of three gas holders ranging in capacity
from 60,000 to 518,000 cubic feet; an office building with a storage room; a coal shed; boilers;
oil and tar tanks; an engine house; ammonia stills; and a generator house. The South Plant MGP
operated on a full time basis from 1898 to 1927. NSG shut it down in 1927 but later operated it
as a peak production unit during high demand periods between 1935 and 1946 (see Figure 3).
NSG permanently closed the South Plant MGP in 1946 and demolished it in 1951.
Contaminants and Media Affected
The South Plant MGP generated various by-products and wastes, such as coal tar, ammonia,
cyanide, ammonium sulfate, sulfur, wastewater sludges, ash, and tar/oil emulsions. These
materials contain polynuclear aromatic hydrocarbons (PAHs) such as naphthalene and
benzo(a)pyrene; petroleum hydrocarbons such as benzene, toluene, ethylbenzene, and xylene
(BTEX); metals such as arsenic and lead; cyanide; and phenolic compounds. Varying levels of
these contaminants have been found in the site soil, groundwater, and adjacent surface water and
sediment samples.
This Proposed Plan addresses the pool of tar-like free-phase product (the DNAPL) found below
the site. NAPLs are comprised of liquids that do not readily mix with water, such as gasoline or
coal tar, although the compounds may also partially dissolve in water. Chemicals that are denser
than water, such as coal tar, create DNAPLs because they tend to sink to the bottom of the
groundwater column. Products such as gasoline, which is less dense than water, create light
nonaqueous phase liquids (LNAPLs) that float at the top of the water table. The DNAPL found
at the South Plant MGP site is the main source of the groundwater contamination.
Early Environmental Investigations and Response Actions
NSG has conducted contaminant investigations and cleanup activities at the South Plant MGP
site since the early 1990s. Most of these pre-CERCLA cleanup actions were conducted in
accordance with Illinois' voluntary Site Remediation Program (SRP). The investigations focused
on identifying sources of MGP residuals and evaluating soil and groundwater conditions. NSG
dug test pits, took soil borings, and installed groundwater monitoring wells. Groundwater and
soil samples were analyzed for a variety of chemicals of potential concern (COPC). NSG also
worked to delineate the extent of the groundwater contaminant plume and the DNAPL pool.
Environmental Investigations
Illinois EPA conducted a Preliminary Site Inspection in September 1991 and a Screening Site
Inspection (SSI) in November 1991, collecting 11 surface soil samples on the former MGP
property as part of the SSI. Based on the preliminary site inspection and the sampling results,
Illinois EPA recommended that the South Plant MGP site be placed into the EPA
Comprehensive Environmental Response, Compensation, and Liability Information System
(CERCLIS) and that the site be assigned a medium-priority status. The state issued several
reports summarizing these site activities, including:
¦ CERCLA Preliminary Assessment Report, NSG Plant (Illinois EPA, 1991)
¦ CERCLA 1992 Screening Site Inspection, NSG Plant (Illinois EPA, 1992)
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Figure 3 - Aerial view of South Plant MGP, Waukegan, Illinois
1937 Photo
APPROXIMATE MGP
FACILITY BOUNDARY
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Next, in the early 1990s, NSG conducted a preliminary site investigation to determine the
potential environmental impacts of the former MGP contaminants. The preliminary site
investigation showed that chemical compounds associated with past MGP activities may be
present in subsurface soils. NSG conducted a follow-up site investigation in 1999 to compile and
evaluate previously-collected data, evaluate the nature and extent of impacts, and obtain
additional data to assess potential health risks at the MGP property. NSG evaluated most of the
former MGP parcel, excluding the paved portions (Pershing Road and South Harbor Place),
completing eight test trenches and four soil borings (which were converted into temporary
piezometers). Soil samples were analyzed for volatile organic compounds (VOCs), PAHs, and
total organic carbon (TOC). Groundwater samples were analyzed for VOCs, PAHs, metals, and
cyanide. NSG issued several reports summarizing the site investigations, including:
¦ Preliminary Site Investigation South Plant MGP, Waukegan, IL (Barr Engineering,
April 1993)
¦ Site Investigation Report, Former South Plant MGP (Barr Engineering, June 2002)
Most of the soil samples showed contaminant impacts in the upper 3 feet of the soil column.
Impacts from both tar-like and petroleum compounds were suspected to be present in soil and
groundwater, with suspected petroleum-like material found at or near the water table.
Between 2002 and 2006, NGS conducted additional investigations on its MGP property and on
surrounding properties. These investigations were completed for specific objectives, and are
summarized below:
June - Sept. NGS conducted sampling activities to further delineate the lateral and vertical
2002 extent of source material on the MGP property. Analytical results indicated that
soil and groundwater samples had high levels of PAHs and BTEX. Source material
was observed and characterized as tar-saturated soil and DNAPL. (Supplemental
site Investigation Report (Feb. 2003))
July 2003 NSG performed further definition of the extent of suspected source material (based
on visual characterization) at the former MGP property. COPCs in soil above the
water table included BTEX, PAHs, arsenic, and lead. NSG subsequently proposed
to remove the top 3.5 feet of soil across the entire MGP parcel and to remove
source material in some locations to the water table (to about 7 feet below ground
surface (bgs)). (Report to Illinois EPA, November 2003)
June -Aug. NSG took samples to delineate the extent of groundwater impacts on the WPD
2003 property. Three areas on the WPD property exhibited tar-like DNAPL or tar-
saturated soil. These impacts were observed between 6 and 16 feet bgs.
Feb. - NSG advanced soil borings and probes on the Akzo property to characterize soils
March 2004 deeper than 10 feet bgs and found MGP- and petroleum-like odors in most
locations. (Report to Illinois EPA, March 2004)
May 2004 NSG further sampled groundwater under the WPD property, identifying areas
characterized as having tar-like DNAPL or tar-saturated soil on the southeast
corner of the boat parking lot and the northwest corner of the visitor parking lot.
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These impacts were observed between 6 and 22 feet bgs. (Report to Illinois EPA,
July 2005)
May 2005 NSG conducted a ground-penetrating radar survey to determine whether former
MGP structures were beneath Pershing Road and identified potential subsurface
features and anomalies. (Report to Illinois EPA, July 2005)
May - Aug. NSG completed groundwater investigation activities on the MGP and WPD
2005 properties. The objective was to obtain groundwater data for both properties
during a single sampling event. Additional groundwater monitoring wells were
installed, bringing the total to 60 (42 on the MGP and 18 on the WPD properties)
to date. Nine 6-inch diameter DNAPL recovery wells were also installed on the
former MGP and WPD property to the east. WPD property wells installed to the
east are located in the boat parking lot, the maintenance building parking area, and
the Administration building parking lot. (Report to Illinois EPA, August 2007)
Aug. 2005 NSG conducted a DNAPL investigation on the MGP and WPD properties and
installed additional groundwater monitoring wells and took soil samples for
forensic analysis. Results indicated that petroleum hydrocarbons are present, but
the majority of impacts on the WPD property are MGP-related.
Dec. 2005 NSG collected five soil gas samples from a depth of approximately 4.7 to 5 feet
bgs in the vicinity of the WPD maintenance building. Evaluation of the soil gas
results using the Johnson and Ettinger Model (EPA 1991) indicated a low risk
potential for vapor intrusion to indoor air within the WPD maintenance building
(Report to Illinois EPA, June 2006)
Sept. 2006 NSG completed a second round of groundwater sampling to again obtain water
quality data from the MGP and WPD properties during a single sampling event.
Samples were collected from 67 of the now 87 monitoring wells. (Report to
Illinois EPA, September 2007)
Early Response Actions
Between December 2003 and February 2004, NSG excavated soil down to the depth of
groundwater (3.5 to 7 feet bgs) on the former MGP property and disposed of it off-site as part of
a focused remediation effort. Excavation of the top 3.5 feet of soil across the entire property was
completed along with deeper excavation of suspected source material areas in certain areas.
Material removed from excavated areas consisted of fill, soil, suspected source material
(characterized as tar-impacted fill/soil), piping, and debris. After successful removal of suspected
source material, confirmation sampling indicated impacted material above the water table was
removed satisfactorily, except under the Pershing Road right-of-way and along the west property
boundary (see Figure 4). NSG then installed a plastic liner in the excavations and backfilled them
with clean soil. NSG also installed plastic liners along the sidewalls of excavations next to
Pershing Road and along the western property line to help prevent residual contaminants from
moving into the clean imported backfill. NSG disposed of about 19,223 tons of excavated
material as nonhazardous special waste at a nearby licensed landfill. (Report to Illinois EPA,
March 2005)
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Figure 4: Previous Response Action at NSG South Plant Former MGP (Dec. 2003 - February 2004)
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DNAPL Recovery
NSG began DNAPL recovery from 19 vertical extraction wells located on the former MGP and
WPD properties in April 2006 and its DNAPL recovery efforts continue to this day. During
recovery operations, the DNAPL is pumped from the wells into Department of Transportation
(DOT)-approved steel drums, which are then sealed, labeled, manifested, and transported to a
facility in Houston, Texas, where the DNAPL is blended as fuel to be used by local cement kilns.
From April 2006 to May 2007, NSG pumped DNAPL from the wells at approximate 3-week
intervals, moving to six-week intervals from May 2007 to the present. As of January 2015,
approximately 1,370 gallons of DNAPL have been recovered. The DNAPL recovery wells
located in the WPD Administration building parking lot and boat parking lot have accounted for
almost 80 percent of the DNAPL recovered to-date.
Remedial Investigation/Feasibility Study
In July 2007, EPA and NSG entered into an Administrative Order on Consent (AOC) that
required NSG to conduct a Remedial Investigation/Feasibility Study (RI/FS) at both the South
Plant and the North Plant former MGP sites in Waukegan (Docket No. V-W-07-C-877). Integrys
Business Support, LLC (Integrys), which was formed in 2007 with the merger of NSG and other
area utilities, performed the RI/FS under the AOC, with EPA oversight. The RI report was
approved by EPA on January 22, 2014, and the Focused FS (FFS) report to address the DNAPL
was approved by the agency on April 9, 2015. EPA has placed both reports, including
supporting documentation, in the site's Administrative Record.
III. SITE CHARACTERISTICS
Regional Setting
The NSG South Plant MGP site is located in Waukegan, Lake County, Illinois along the western
shore of Lake Michigan (see Figure 1). The population of Waukegan is approximately 89,000,
based on the 2010 U.S. Census Bureau data. The surrounding area is generally flat, with a mean
sea elevation of approximately 597 feet above sea level. The climate in the area is typically
continental, with some modification by Lake Michigan. Average monthly temperatures range
from about 21°F in January to about 73°F in July. The ground surface around the site consists of
grassy vegetation, buildings, and asphalt-paved parking lots and roads. The site is not located
within the 100-year floodplain.
The MGP property is currently zoned as commercial/recreational, while the WPD, Akzo, EJ&E,
and City of Waukegan parcels are zoned general industrial. The city's Lakefront Downtown
Master Plan (July 2003) called for the MGP site area to be developed into mixed-use property
with marina-related services, retail, residential, and open space. This master plan has not been
implemented at this time.
No municipal or private drinking water wells are located at the site or within a one-mile radius of
the site. The City of Waukegan obtains its municipal water supply from Lake Michigan. By
ordinance, water wells in the county are not permitted in areas where a public water supply is
available. In cases where a public water supply is not available, potable water wells may only be
permitted after approval from the county health department.
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Site Geography and Geology
South Waukegan Harbor and Lake Michigan are located approximately 600 feet east of the
South Plant MGP property. The Waukegan River, located approximately 1,000 feet south of the
South Plant MGP, flows east past the Akzo parcel into Lake Michigan and drains a 12 square
mile watershed area. The watershed is highly urbanized, containing only 13% undisturbed land,
and lack of a natural floodplain area has limited expansion of flow in the Waukegan River,
causing erosion to occur in the channel itself. Currently, few storm water detention basins exist
and bank erosion in the area is a direct cause of sedimentation into Lake Michigan. Erosion in
the channel releases urban contaminants that affect the water and sediment quality in the river
and at its mouth. However, it is unlikely the river influences Lake Michigan currents for any
more than the briefest periods during large storm events.
The shallow groundwater in the Waukegan area is generally limited to sand and gravel horizons
in unconsolidated soil and in fractured bedrock aquifers. The unconsolidated materials in the site
area consist primarily of clay with isolated lenses of sand and are not considered productive
aquifers. Recharge to the aquifers is primarily by precipitation and infiltration.
The geology encountered beneath the site is composed of a sand/silty sand layer from the surface
to an average depth of 15 feet underlain by a clay layer.
The following stratigraphic units are found at the site:
¦ Fill - Primarily sand with lesser amounts of gravel, slag, and wood fragments.
Thickness ranges from 2 feet on the west side of the site to 20 feet adjacent to
Waukegan Harbor. In paved areas, the fill includes approximately 3 inches of asphalt
and up to 8 inches of sub-base.
¦ Sand Unit - Primarily natural fine-grained silty sand of alluvial origin. The top of
the sand unit was encountered from 1 to 4 feet bgs, with an average thickness of
approximately 14 feet.
¦ Clay Unit - Primarily very stiff to hard, low plasticity silty clay. Top of clay was
encountered at depths ranging from 14 to 18 feet bgs across the majority of the site
but was present as shallow as 4.5 to 6 feet bgs in the vicinity of the Waukegan River.
The sand unit is the main water-bearing unit at the site. Shallow groundwater is encountered at
about 7 feet below ground surface (bgs) and groundwater contours indicate an easterly flow
toward Lake Michigan. Subsequent groundwater flow measurements beginning in November
2009 continue to indicate this easterly flow direction (see Figure 5).
Cultural and Natural Resource Features
Illinois Department of Conservation's Natural Heritage Database lists no federal or state
threatened and endangered species or pristine natural areas located on the site. The U.S. Fish and
Wildlife Service (FWS) did identify the federally endangered Piping Plover, a migratory bird, as
having a critical habitat approximately V2 miles northeast of the site. The North and South
Harbor marinas, located adjacent and east of the site, are used by recreational boaters during the
boating season from about April 1 to November 1. Beach Park is located adjacent to the North
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Harbor Marina and North Beach Park is located about 0.5 miles northeast of the site along Lake
Michigan.
Figure 5 - Groundwater Flow
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Nature and Extent of DNAPL Contamination
The RI found that DNAPL was a continuing source of contamination to the groundwater and that
two distinct zones of DNAPL impacts were present at the site. The first zone was a 150-ft wide
DNAPL plume that radiates from the north side of the former MGP facility, following a
localized depression in the confining clay layer and extending to the northeast, under South
Harbor Place Drive, into the southwest corner of the WPD parking lot. The second zone of
DNAPL impact radiates to the southeast of the former MGP where the plume is approximately
200 feet wide, underneath the WPD maintenance building and the Akzo facility to a localized
depression in the confining clay layer located west of the WPD Administration Building, where
the plume is approximately 425 feet wide. NSG calculated in the FFS report that the overall areal
extent of the DNAPL plume is 278,600 square feet (roughly 6 acres), with an estimated total
volume of 527,000 gallons of tar-like material (see Figure 6).
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GROUNDWATER ELEVATION CONTOUR
GROUNDWATER FLOW DIRECTION
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Principal Threat Waste
The DNAPL is a continuing source of groundwater contamination at the site and represents a
principal threat waste that needs to be addressed, preferably by treatment, due to its toxicity and
volume.
IV. SCOPE AND ROLE OF THIS ACTION
This Proposed Plan consists of an interim action that only addresses the DNAPL underneath the
site. Once the DNAPL remedial action is completed, EPA will prepare a second Proposed Plan
for a final remedy to address the remaining media of concern (soil, soil vapor, and groundwater)
at the site. EPA's preferred alternative will remove DNAPL from beneath the site and transport it
off site for treatment and disposal, which would satisfy the preference for treatment of principal
threat waste under Superfund policy and law.
V. SUMMARY OF SITE RISKS
EPA approved the RI report on January 22, 2014. As part of the RI report, Integrys conducted a
Baseline Risk Assessment (BLRA), which evaluated the potential for human health and
ecological risks associated with site contaminants. The human health risk assessment (HHRA)
component of the BLRA addressed potential risks to people from contaminated soil and
groundwater in the terrestrial (upland) portion of the site, along with potential exposures to
contaminants in the surface water and sediments at the site (at the marina, beach, and in Lake
Michigan). However, the ecological risk assessment (ERA) only focused on the water bodies
adjacent to the site because EPA determined that the site itself did not contain terrestrial habitat
requiring an ecological risk evaluation.
Chemicals of Concern (COCs)
As stated above, the site DNAPL is a continuing source of contamination to area groundwater.
Primary COCs in the site groundwater contaminant plume include PAHs such as naphthalene
and benzo(a)pyrene; BTEX compounds; and metals such as arsenic and lead.
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Figure 6: Estimated Extent of DNAPL Contamination
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Human Health Risk Assessment
EPA calculates the probability of non-carcinogenic (not cancer-causing) and carcinogenic
(cancer-causing) health effects due to human exposure to site contaminants in human health risk
assessments. For noncarcinogenic chemicals, EPA calculates a hazard quotient (HQ) for each
COC. The HQ is the ratio of the estimated exposure level to a chemical compound over a
specified period of time to a reference dose of the same substance that may cause deleterious
health effects over the same exposure period. EPA recommends that the HQ for exposure to a
COC at a site be limited to 1 or less, which signifies that the exposure level at the site would be
below that which would cause an adverse human health effect. For carcinogenic health risks,
EPA calculates the estimated lifetime cancer risk (ELCR) due to exposure to carcinogenic
chemicals at a site. EPA recommends that site cleanups achieve a target ELCR range of one in
one million (lxlO"6) to one in ten thousand (lxlO"4).
The area around the South Plant MGP site is currently zoned for industrial, commercial, and
recreational uses, with the potential for residential use if the city's master plan is implemented.
Thus, human health risks at the site were assessed for both commercial/industrial (current) and
residential (future) receptors. Each scenario was evaluated against potential exposure pathways,
as summarized in the following table:
Receptor Exposure Pathways
Industrial or commercial worker 111cidcnlal ingestion, dermal contact. \apor
intrusion, iind inhalation of l)\.\IM.-al'lcclcd soil
(as a result of soil disturbance)
Incidental ingestion/dermal contact/inhalation of
DNAPL-affected soils (as a result of soil
disturbance), and groundwater, surface water, and
sediment via dermal contact and inhalation
Incidental ingestion of surface w ater and
sediment/dermal contact with surface water and
sediment potentially impacted by DNAPL
Incidental soil ingestion/dermal contact/inhalation
(including vapor intrusion from DNAPL-impacted
subsurface soil and groundwater)
Construction worker
Recreational \ isitor
Resident (future use)
Human Health Risk Characterization
The DNAPL is primarily a source of contamination in site soil, groundwater, and soil gas rather
than a direct health risk itself; thus, a comprehensive human health risk assessment specific to
DNAPL was not completed. The BLRA did evaluate exposure pathways to DNAPL as part of
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the evaluation of potential health risks due to COCs in soil, groundwater, and soil vapor. A
summary of some of these exposure pathways is included below:
Groundwater: Exposure to groundwater in construction excavations in each area of the site
could potentially be associated with unacceptable risks because DNAPL is present near or below
the water table in one or more wells. However, only construction workers having direct exposure
to groundwater or inhaling vapors in excavations at or below the water table (as shallow as
3-5 feet bgs but typically averaging between 6.5 to 8.5 feet bgs) would be at potential risk. The
potential for exposure of construction workers to groundwater in excavations is likely limited
due to safety considerations other than those related to DNAPL exposure. However, because
exposure to groundwater containing DNAPL or associated vapors is assumed to present
unacceptable risks to construction workers, appropriate steps should be taken to prevent such
exposure.
Surface Soil: There are very few areas of the site where surface soils are both exposed and
where residual DNAPL-like contaminants are present. Most surface soils are either clean soils
that have been imported after remediation was completed or are located below pavement
preventing human exposure. There are some areas on the AKZO property where surface soils are
not under pavement (areas with ornamental trees), but these areas are not near the former MGP
parcel and are not expected to have been impacted by the former MGP activities.
Soil Vapor: The potential vapor intrusion exposure pathway was evaluated using soil vapor
samples taken at depths ranging from 3.5 to 5 feet bgs, with sub-slab samples taken at 1 foot bgs.
Potential impacts were found and are associated with dissolved chemical levels in groundwater
rather than the DNAPL itself.
Conclusions from the HHRA
The following conclusions were made in the HHRA:
• DNAPL is a continuing source of groundwater contamination. The groundwater does not
meet drinking-water standards in any of the areas evaluated, and it should not be used for that
purpose. Estimated risks would exceed the risk management range under a residential tap
water scenario for all areas.
• Because of the presence of DNAPL in one or more wells on each site parcel, construction
worker exposures to subsurface soils, groundwater, and soil vapor on each property should
be assumed to be associated with the potential for unacceptable risks if intrusive construction
activities occur in the future.
• Potential vapor intrusion risks are present (under the residential or industrial scenarios) at the
AKZO and WPD parcels. Health risks for the AKZO area are within the risk management
range for current (industrial) use. For future residential use, ELCRs were within or at the
high end of the risk management range but HQ values were greater than 1. For the WPD
area, risks were at the upper end of the risk management range for current industrial use, and
above the risk management range for future potential residential use.
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Ecological Risk Assessment
The BLRA evaluated the ecological risks at the site and concluded that the upland area does not
support habitat for ecological receptors due to the developed nature of the properties, consistent
with the commercial/industrial zoning of the land. The BLRA also concluded that the nature and
concentration of the COCs detected in surface water and sediment in the marina, Lake Beach,
and open-water environment is not expected to pose an ecological concern. Potential risks
associated with future DNAPL that could potentially discharge into the marina will be addressed
through upland DNAPL management.
Basis for Taking Action
It is EPA's current judgment that the preferred alternative identified in this Proposed Plan is
necessary to protect human health and the environment from actual or threatened releases of
contaminants from this site which may present an imminent and substantial endangerment to
public health or welfare.
VI. REMEDIAL ACTION OBJECTIVE FOR DNAPL
EPA developed the following Remedial Action Objective (RAO) to protect the public and the
environment from potential health risks posed by DNAPL at the site:
¦ Reduce the mass and mobility of recoverable DNAPL to the extent practicable
VII. SUMMARY OF DNAPL REMEDIAL ALTERNATIVES
The DNAPL remedial alternatives evaluated in the FFS are summarized below:
¦ Dl-No Action
¦ D2 - Institutional Controls
¦ D3 - Vertical Engineered Barrier
¦ D4 - Horizontal Well DNAPL Recovery
¦ D5 - Physically-Enhanced DNAPL Recovery
¦ D6 - Chemically-Enhanced DNAPL Recovery
¦ D7 - Thermally-Enhanced Recovery
The Preferred Alternative is Alternative D5 - Physically-Enhanced DNAPL Recovery (see
Figure 7). The Illinois EPA expressed preference for this alternative in its March 31, 2015
comment letter to EPA.
Description of DNAPL Remedial Alternatives
DI - No Action
Under the No Action alternative, EPA would take no further actions to address potential
exposure to the tar-like DNAPL at the site or to address the DNAPL as a continual source of
17
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groundwater and potentially surface water contamination. The No Action alternative is included
in the list of DNAPL alternatives evaluated in the FFS to be consistent with the NCP and it is
used as a baseline for comparisons to the other DNAPL alternatives.
D2 - Institutional Controls
Under Alternative D2, EPA would place institutional controls (ICs) on the site to minimize
exposure to DNAPL. ICs would consist of both administrative and legal controls. Since the
primary mechanism for human exposure to DNAPL would be though consumption of
groundwater contaminated by DNAPL, Alternative D2 would place ICs on the site parcels to
restrict the use of groundwater as a drinking water source until drinking water standards are met.
The ICs would also require worker cautions as well as health and safety planning to protect
potential future construction workers from exposure to DNAPL compounds in the groundwater.
Groundwater ICs would best be a combination of a local ordinance enacted by the Waukegan
City Council creating a restricted groundwater use zone that prohibits the use of DNAPL-
impacted groundwater as a potable water supply and the placement of a Uniform Environmental
Covenant (under 765 ILCS Chapter 22) on the site parcels to provide additional assurances that
the IC will continue to be enforced in the event of property transfer or changes in future land use.
An IC Implementation Plan would be developed to detail groundwater-use restrictions and
document procedures for effectively implementing the ICs. Because no actions would be taken to
reduce the mass or mobility of the DNAPL and site contamination above health-based limits
would be left onsite, EPA would need to conduct a FYR every five years at the site.
D3 - Vertical Engineered Barrier
Under Alternative D3, EPA would install a low-permeability vertical engineered barrier around
the DNAPL plume. Vertical barriers are typically constructed with soil-bentonite ("slurry wall"),
high-density polyethylene (HDPE), or steel sheet piles. The vertical engineered barrier would be
keyed into the underlying confining clay layer a minimum of 3 feet. The confining clay layer
would limit downward migration of DNAPL and the low permeability vertical engineered barrier
would limit the lateral migration of DNAPL. The engineered barrier would contain both the
groundwater and DNAPL, thereby reducing mobility of DNAPL compounds in partial
accordance with the RAO. Because no additional actions would be taken to reduce the mass of
the DNAPL and site contamination above health-based limits would be left onsite, EPA would
need to conduct a FYR every five years at the site.
D4 - Horizontal Well DNAPL Recovery
A network of vertical DNAPL recovery wells is currently being operated at the site. However,
these wells have removed a limited volume of DNAPL since initial operations began in 2006.
Under Alternative D4, a network of horizontal recovery wells would be installed above the clay-
confining layer at site locations that are within and downgradient of accumulated DNAPL.
DNAPL would pass through the horizontal well screen and flow via gravity within the sloped
horizontal well to a collection sump. Then, the DNAPL would be pumped into collection
containers for off-site treatment and disposal.
Compared to the existing vertical DNAPL recovery wells, the horizontal DNPAL recovery wells
will have a significantly greater screened interval within the DNAPL bearing zone and will thus
18
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be much more effective at recovering DNAPL, although it is estimated that DNAPL recovery
would occur over a 30-year period before the mass and mobility is reduced to the extent
practicable.
Three primary horizontal well installation methods were evaluated as part of Alternative D4 -
traditional trench, one-pass trench, and horizontal directional drilling. The preferred method will
be developed during the remedial design phase. Each is briefly described below:
Traditional trench installation would involve an excavator cutting narrow trenches to a depth of
approximately 20 feet bgs in the DNAPL areas, placing the horizontal wells into the excavations,
placing washed stone over the wells to protect the pipe and locally increase hydraulic
conductivity, and then backfilling the excavations with clean soil or fill. This method would
require saw cutting of and removal of pavement along well alignments and the use of trench
boxes or a slurry wall to prevent collapse of the sandy soil during installation. While potentially
implementable at this site, traditional trench installation is better suited for a site with more
cohesive soil, a depth of excavation shallower than groundwater, minimal surface improvements
(e.g., pavement), and minimal subsurface utility crossings.
The one-pass trenching technique uses a specialized trenching machine that simultaneously
removes soil, installs perforated pipe, and places granular backfill into the excavation. The
simultaneous installation avoids the need for trench stabilization. One-pass trenching can achieve
depths up to 30 feet bgs. Similar to the traditional trench method, the one-pass method requires
saw cutting and removal of pavement along the proposed trench alignment. Also similar to the
traditional trench method, the one-pass method typically includes backfilling the trench with
washed stone. While potentially implementable at this site, one-pass trenching is better suited for
sites with minimal surface improvements (e.g., pavement) and minimal subsurface utility
crossings.
Horizontal directional drilling (HDD) is a trenchless horizontal well installation method. The
equipment and procedures are intended to minimize temporary operational disruption, surface
damage, and restoration. Surface impacts are limited to two work areas, one on the entry side and
one on the exit side. Horizontal and vertical control of the HDD drill bit between the entry and
exit side is performed using magnetic steering tools in conjunction with a surface monitoring
system. The locator provides information to the operator to allow real-time path corrections to
follow the planned bore path. Some systems directly transmit the location information to a
display on the drill rig to automatically control the drill path.
Some unique advantages of horizontal drilling include: minimal site preparation and restoration
costs because disturbance is limited to entry and exit points; comparatively easy utility crossings;
and reduced soil management and disposal volumes. Some unique disadvantages include: limited
effectiveness in drilling through stone and cobbles and reliance on the permeability of the
surrounding soil rather than installation of a high permeability granular backfill. Due to the
discrete land disturbance associated with pipe installation using HDD, installation does not allow
backfill around the pipe. Therefore, the pipe will be in direct contact with the subsurface soil and
subject to potential pipe clogging, particularly if installed in soil containing a significant fraction
of fine material. There is also some uncertainty regarding the effectiveness of a horizontal well
system due to possible stratification of subsurface soil; whereas trenching overcomes stratified
soil layers by cutting through the soil profile.
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EPA would still need to conduct a FYR every five years at the site as long as contamination
above health-based limits remain at the site.
D5 - Physically-Enhanced DNAPL Recovery
Under Alternative D5, EPA would physically enhance DNAPL recovery efforts through the use
of simultaneous groundwater extraction and injection. Groundwater injection will locally
increase hydraulic gradients, thereby increasing the rate of DNAPL migration toward recovery
wells. Alternative D5 would involve installation of both injection and extraction wells, as well as
a phase-separation and groundwater treatment facility. It is estimated that DNAPL recovery
would occur over a 7-year period before the mass and mobility is reduced to the extent
practicable.
Physically-enhanced recovery can be performed using a variety of methods and can be
implemented using horizontal or vertical wells. Two primary approaches, separate-phase
extraction and multi-phase extraction, are described below:
Separate-phase extraction would use dedicated DNAPL and dedicated groundwater extraction
pumps in a single vertical well. A low-flow DNAPL recovery pump would be placed at the
bottom of the well in the DNAPL zone and a standard groundwater pump would be installed
above the DNAPL-bearing interval. The groundwater pump would extract a limited volume of
DNAPL, which would be removed by a phase-separation unit. The collected DNAPL would be
sent off site for treatment and disposal and extracted groundwater would be treated on site prior
to re-injection into the ground. Alternatively, extraction could occur in separate but collocated
wells. Separate-phase extraction is most applicable to sites with relatively thick accumulations of
DNAPL, such as at this site.
Multi-phase extraction would use a single pump in each well to simultaneously remove
DNAPL and groundwater. The DNAPL/water mixture would be run through a phase-separator to
collect DNAPL for off-site treatment and disposal and extracted groundwater would be treated
on site prior to re-injection into the ground. Because the DNAPL would be emulsified in the
extracted water, phase separation would be comparatively more challenging and may result in a
higher percentage of water remaining in the separated DNAPL. The increased water content will
make DNAPL treatment more challenging. Multi-phase extraction is most applicable for sites
with relatively thin accumulations of DNAPL, which is not typical at this site.
EPA would need to conduct a FYR every five years at the site as long as contamination above
health-based limits remain at the site.
D6 - Chemically-Enhanced DNAPL Recovery
Under Alternative D6, EPA would enhance DNAPL recovery using injection of chemical
surfactants. The mobilized DNAPL would be recovered using the extraction techniques similar
to those described in Alternative D5. Therefore, implementation of Option D6 will involve
installation of both injection and extraction wells, as well as a phase-separation and groundwater
treatment facility. It is estimated that DNAPL recovery would occur over a 4-year period before
the mass and mobility is reduced to the extent practicable.
Typically, chemically enhanced DNAPL recovery is performed using surfactants and there are
several varieties available for the remediation and oil recovery markets. Surfactant injections are
20
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often amended with electrolytes, polymers, co-solvents, or oxidants to further increase surfactant
effectiveness. Laboratory bench-scale studies are critical to select the proper type and
concentration of surfactant and amendment.
Surfactants are only effective at enhancing the recoverability when in direct contact with
DNAPL. As a result, having an accurate understanding of the DNAPL plume and the subsurface
geology and geochemistry is critical to determining injection zones, well spacing, chemical
volume, and other criteria. Application can be performed using either horizontal or vertical wells
and DNAPL recovery can either be performed in the same well used for chemical injection or in
a separate, downgradient recovery well. Introducing chemicals to the subsurface that may not be
recovered is a concern with this alternative.
EPA would still need to conduct a FYR every five years at the site as long as contamination
above health-based limits remain at the site.
D7 - Thermally-Enhanced Recovery
Under Alternative D7, EPA would increase the temperature of the subsurface to enhance
DNAPL recovery or even to thermally destroy the DNAPL in place. It is estimated that DNAPL
recovery would occur over a 4-year period before the mass and mobility is reduced to the extent
practicable.
Typical thermal treatment technologies include steam-enhanced extraction, electric resistance
heating (ERH), and conductive heating. Each type of thermal treatment technology, as it applies
to recovery of DNAPL, is summarized below:
Steam-enhanced extraction would use steam injected under pressure into the DNAPL zone
through injection wells, which increases the subsurface temperature and causes the DNAPL to
mobilize and be displaced. The DNAPL can then be recovered using multi-phase extraction
wells. The more volatile DNAPL constituents, e.g., BTEX and naphthalene, would also be
volatilized by the increased subsurface temperatures. This method primarily relies on conductive
and convective heat transfer to increase subsurface temperatures. As a result, this technology is
best suited for soil with moderate to high permeability and limited subsurface obstructions, as is
the case for this site. The maximum subsurface temperature is limited by the temperature of the
injected steam (about 100 degrees Celsius).
ERH would use an array of subsurface horizontal or vertical electrodes to apply current through
the soil and groundwater. Soil moisture conducts electrical current and the soil's natural
resistance to the flow of electrical current results in the generation of heat, which causes the
DNAPL to mobilize and be displaced. The DNAPL can then be recovered using multi-phase
extraction wells. The more volatile DNAPL constituents, e.g., BTEX and naphthalene, would
also be volatilized by the increased subsurface temperatures and would need to be collected
separately. Heat distribution from ERH is relatively uniform, even in areas of low permeability
and the maximum temperature of ERH is generally limited to the boiling point of water (about
100 degrees Celsius).
Conductive heating would use heating elements installed in subsurface wells to increase
subsurface temperatures to mobilize and displace the DNAPL. The heat from the elements
radiates through the soil by thermal conduction. The DNAPL is recovered by a multi-phase
extraction system. As with steam-enhanced extraction, the more volatile DNAPL constituents
21
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would be volatilized by the increased subsurface temperatures. Unlike steam-enhanced
extraction, thermal conductive heat transfer occurs relatively uniformly throughout a targeted
treatment zone, even in areas of low permeability, which is often where DNAPL accumulates.
Conductive heating is not limited by the boiling point of water and can achieve temperatures up
to 500 degrees Celsius. As a result, conductive heating is able to thermally degrade volatile
constituents as well as some PAHs. A range of temperatures can be achieved by varying the
power supplied to the conductive heating elements. However, temperatures exceeding the boiling
point of water (about 100 degrees Celsius) are only achievable in the unsaturated soil zone.
EPA would still need to conduct a FYR every five years at the site as long as contamination
above health-based limits remain at the site.
VIII. EVALUATION OF ALTERNATIVES
EPA uses nine criteria to evaluate remedial alternatives in order to select a remedy (see Table 1).
Table 1: The Nine Criteria
EVALl A 1 ION CRSITERIA 1 OR SI PERI I M) REMEDIAL ALTERNATIVES
Threshold Criteria
1.
Overall Protection of Human Health and the Environment determines whether an alternative
eliminates, reduces, or controls threats to the public health and the environment through engineering
controls, treatment, or ICs.
2.
Compliance with Applicable or Relevant and Appropriate Requirements (ARARs) evaluates
whether the alternative meets federal and state environmental statutes, regulations, and other
requirement that pertain to the site, or whether a waiver is justified.
Balancing Criteria
3.
Long-term Effectiveness and Performance considers the ability of an alternative to maintain
protection of human health and the environment over time.
4.
Reduction of Toxicity, Mobility, or Volume of Contaminants through Treatment evaluates an
alternative's use of treatment to reduce the harmful effects of principal contaminants, their ability to
move in the environment, and the amount of contamination present.
5.
Short-term Effectiveness considers the length of time needed to implement an alternative and the
risks the alternative poses to workers, residents, and the environment during implementation.
6.
Implementability considers the technical and administrative feasibility of implementing the
alternative, including factors such as relative availability of goods and services.
7.
Cost includes estimated capital and annual operation and maintenance costs, as well as present worth
cost. Present worth cost is the total of an alternative over time in today's dollar value. Cost estimates
are expected to be accurate within a range of +50% to -30%.
Modifying Criteria
8.
State Acceptance considers whether the State agrees with EPA's analyses and recommendations, as
described in the RI/FS and the Proposed Plan.
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9. Community Acceptance considers whether the local community agrees with EPA's analyses and
preferred alternative. Comments received on the Proposed Plan are an important indicator of
community acceptance.
Comparative analysis of DNAPL Remedial Alternatives
This section of the Proposed Plan evaluates the relative performance of each alternative against
the nine criteria, noting how each compares to the other alternatives under consideration. A more
detailed analysis of the DNAPL alternatives is found in the FFS. Table 2 provides a summary of
the comparison of the DNAPL remedial alternatives.
1. Overall Protection of Human Health and the Environment
Alternative D1 (No Action) would not be protective of human health and the environment as the
DNAPL would remain relatively unabated as a source of groundwater contamination.
Alternative D2 would be protective of human health by using ICs to prevent consumption of
contaminated groundwater at the site, but it would not be protective of potential ecological
receptors in Lake Michigan because no engineering controls would be used to address migration
of DNAPL-contaminated groundwater towards the lake.
Alternative D3 would be protective of human health and the environment because it would
contain the DNAPL in place and prevent further migration of DNAPL-contaminated
groundwater towards the lake.
Alternatives D4, D5, D6, and D7 would be protective of human health and the environment
because DNAPL would be recovered over time and prevent further migration of DNAPL-
contaminated groundwater towards the lake.
2. Compliance with ARARs
There are no ARARs that directly apply to implementation of Alternatives D1 and D2.
However, neither Alternative D1 nor D2 would result in compliance with chemical-specific
groundwater ARARs.
Alternatives D3, D4, D5, D6, and D7 would meet all potential ARARs that would apply to the
various technologies.
3. Long-Term Effectiveness and Permanence
Alternative D1 has no ability to maintain effective protectiveness of human health and the
environment over time.
Alternative D2 would meet the long-term effectiveness and permanence criterion if effective and
enforceable ICs are placed on the site.
Alternative D3 would meet the long-term effectiveness criterion for human health and the
environment. Vertical engineered barriers are a well-established, long-term remedy used to
contain DNAPL at former MGP sites and can provide protection in excess of 30 years.
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Alternatives D4, D5, D6, and D7 would meet the long-term effectiveness and permanence
criterion because a large volume of DNAPL would be permanently removed from the
environment and treated. Permanent removal and treatment provides for greater long-term
protectiveness and permanence than Alternative D3, which is a containment-only remedy.
Further, Alternatives D3, D4, D5, D6, and D7 provide greater long-term protection because these
alternatives are progressively more aggressive in treating DNAPL.
4. Reduction of Toxicity, Mobility, or Volume through Treatment
Alternatives D1 and D2 do not reduce the toxicity, mobility, and volume through treatment of
DNAPL. Alternative D3 only reduced the mobility of DNAPL by containing it in place, but it
provides no treatment to reduce the contaminants' toxicity, mobility, or volume.
Alternatives D4, D5, D6, and D7 will reduce the toxicity, mobility, and volume of DNAPL
through treatment, but to varying degrees. Alternatives D5, D6, and D7 are more aggressive
treatment methods and are expected to remove more DNAPL from the ground in comparison to
Alternative D4.
5. Short-Term Effectiveness
Alternatives D1 and D2 provide no short term risks to workers or the public while being
implemented. It is estimated that at least 6 months will be required to obtain necessary
permissions to place ICs on the site under Alternative D2.
Alternative D3 would present some short-term risks during implementation and operation and
maintenance. It is estimated that 12 months would be required to install the vertical engineered
barrier and groundwater gradient control system, which would immediately limit the off-site
migration of DNAPL. There is a risk that the community could be exposed to a minimal amount
of MGP-residuals during construction via air emissions from exposed contaminated soil, while
workers would need to wear standard protective equipment during remedy construction and
operation and maintenance (O&M). It is expected that the short-term risks would be effectively
managed with health and safety measures.
Alternative D4 would present some short-term risks. It is estimated that 6 months would be
required to install the horizontal recovery well and sump system. It is estimated that DNAPL
recovery would occur over a 30-year period before the mass and mobility is reduced to the extent
practicable. The community could be exposed to a minimal amount of MGP-residuals during
construction via air emissions from exposed contaminated soil or DNAPL, while workers would
need to wear standard protective equipment during remedy construction and O&M. It is
expected that the short-term risks would be effectively managed with health and safety measures.
Alternative D5 would present some short-term risks. It is estimated that 12 months will be
required to install the horizontal recovery wells, groundwater injection and extraction wells,
install the treatment plant and necessary recovery/power lines. It is estimated that DNAPL
recovery would occur over a 7-year period before the mass and mobility is reduced to the extent
practicable. The community could be exposed to a minimal amount of MGP-residuals during
construction via air emissions from exposed contaminated soil or DNAPL, while workers would
need to wear standard protective equipment during remedy construction and O&M. It is
expected that the short-term risks would be effectively managed with health and safety measures.
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Alternative D6 would present some short-term risks. It is estimated that 12 months will be
required to install the horizontal recovery wells, groundwater injection and extraction wells,
install the treatment plant, surfactant injection system, and necessary recovery/power lines. It is
estimated that DNAPL recovery would occur over a 4-year period before the mass and mobility
is reduced to the extent practicable. The community could be exposed to a minimal amount of
MGP-residuals during construction via air emissions from exposed contaminated soil or
DNAPL, while workers would need to wear standard protective equipment during remedy
construction and O&M. It is expected that the short-term risks would be effectively managed
with health and safety measures.
Alternative D7 would present some short-term risks. It is estimated that up to 12 months will be
required to install the thermally-enhanced recovery systems. It is estimated that DNAPL
recovery would occur over a 4-year period before the mass and mobility is reduced to the extent
practicable. The community may be exposed to minimal amounts of contaminants due to an
increased rate of diffusion of contaminants due to increased subsurface temperatures. This risk
will be minimized by not heating underneath occupied buildings and implementing vapor
controls. The community could also be exposed to a minimal amount of MGP-residuals during
construction via air emissions from exposed contaminated soil or DNAPL, while workers would
need to wear standard protective equipment during remedy construction and O&M. It is
expected that the short-term risks would be effectively managed with health and safety measures.
6. Implementability
Alternatives D1 and D2 are implementable. Coordination with the various property owners may
present some administrative challenges for placement of ICs, but they should not be
insurmountable.
Alternative D3 is implementable as vertical barrier walls are easily installed and materials are
readily available. Implementation will be challenging due to extensive utility crossings, working
adjacent to the railroad, and the need to coordinate with property owners.
Alternative D4 would be implementable as recovery trench alignments and HDD construction
methods could be used to minimize or avoid utility and property owner conflicts.
Alternatives D5 and D6 would be implementable, but challenging. Recovery trench alignments
and proposed construction methods could be selected to minimize or avoid utility and property
owner conflicts. However, pump controls, power, and piping will require connection to a
treatment plant proposed to be placed on the MGP parcel. This connection will be completed
through directionally drilled borings under the EJ&E railroad tracks, and trenching through the
Akzo and WPD properties to the wells. Coordination of directional drilling under EJ&E railroad
tracks and trenching through the Akzo and WPD properties are technically implementable, but
could be an administrative challenge.
Alternative D7 would be implementable, but even more challenging than Alternatives D5 and
D6. Thermally-enhanced extraction is technically implementable; however, there are many
implementation challenges. Installation and operation of the thermal system will require careful
coordination and access agreements with Akzo and WPD to allow electrode and recovery
infrastructure to be installed on these properties. Typically, the electrodes need to be located on a
15-20-foot spacing, so there is limited flexibility to accommodate access restrictions within a
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desired treatment zone. The limited flexibility to adjust well locations is particularly relevant to
active roadways, railroads, and industrial buildings.
Table 2: Summary of DNAPL Remedial Options Compared to Superfund Evaluation Criteria
DNAPL Remedial
Options
Dl-No
Action
D2-
ICs
D3-
Vertical
Eng.
Barrier
D4-
Horizontal
Well
DNAPL
Recovery
D5 —
Physically
Enhanced
DNAPL
Recovery
D6
Chemically
Enhanced
DNAPL
Recovery
D7-
Thermally
Enhanced
DNAPL
Recovery
Evaluation Criteria
Threshold Criteria
Protection of Human
Health and
Environment
Does Not
Meet
Meets
Meets
Meets
Meets
Meets
Meets
Compliance with
ARARs
Does not
Meet
Partially
Meets
Partially
Meets
Meets
Meets
Meets
Meets
Balancing Criteria
Long-Term
Effectiveness and
Permanence
Does Not
Meet
Partially
Meets
Meets
Meets
Meets
Meets
Meets
Reduction of
Toxicity, Mobility,
or Volume
Does Not
Meet
Does Not
Meet
Partially
Meets
Meets
Meets
Meets
Meets
Short-Term
Effectiveness
Does Not
Meet
Meets
Meets
Meets
Meets
Meets
Meets
Implementability
N/A
Meets
Meets
Meets
Meets
Meets
Meets
Cost
$50,000
$129,000
$13.4
million
$4.6 million
$10.6 million
$14.3 million
$33.8
million
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7. Cost
The present worth cost of each alternative, using a 7% discount rate, is shown in Table 3.
8. State Acceptance
State acceptance of the preferred alternative will be evaluated after the public comment period
ends. The state did indicate in a comment letter to EPA, dated March 31, 2015, that it preferred
Alternative D5. All comments and EPA's responses to all comments will be available in the
Responsiveness Summary of the ROD.
9. Community Acceptance
Community acceptance of the preferred alternative will be evaluated after the public comment
period ends. Community comments and EPA's responses to all comments will be available in the
Responsiveness Summary of the ROD.
Table 3 - Detailed Costs of Each DNAPL Alternative (using 7% discount rate)
Alternative
Total Capital
Cost ($)
Duration of
Operation
(Years)
Total O&M
Cost, No
Discount
Factor
Total Present
Value Cost of
O&M
Total Present Value
Cost of Alternative
D1 - No Action
$ 0
0
$120,000
$50,000
$50,000
D2 - Institutional
Control
$79,000
30
$120,000
$50,000
$129,000
D3 - Vertical
Engineered
Barrier
$3,684,000
30
$23,000,000
$9,614,000
$13,400,000
D4 - Horizontal
Well DNAPL
Recovery
$1,839,000
31
$7,000,000
$2,808,000
$4,647,000
D5 - Physically-
Enhanced
DNAPL Recovery
$4,446,000
7
$8,000,000
$6,130,000
$10,576,000
D6 - Chemically-
Enhanced
DNAPL Recovery
$8,845,000
4
$6,500,000
$5,490,000
$14,335,000
D7 - Thermally-
Enhanced
DNAPL Recovery
$26,968,000
4
$8,024,000
$6,800,000
$33,768,000
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IX. EPA'S PREFERRED ALTERNATIVE
EPA's preferred alternative is Alternative D5 - Physically Enhanced DNAPL Recovery (see
Figure 7). Under Superfund law, the selected remedy must meet the threshold criteria of Overall
Protection of Human Health and the Environment, and Compliance with ARARs. Alternative D5
will be protective of human health and environment by removing DNAPL mass from the aquifer,
thereby achieving the RAO. Removal of DNAPL from the base of the aquifer will minimize the
potential for DNAPL-contaminated groundwater to migrate to Lake Michigan and the Waukegan
River. Furthermore, DNAPL removal is expected to improve the quality of groundwater and soil
vapor, enabling a suitable remedy to be selected for these media in a final ROD. Removal of
DNAPL will also reduce the risk to potential future construction workers performing excavations
at the site.
Alternative D5 will also comply with location and site-specific ARARs identified in the FFS.
Long-term effectiveness and permanence will be achieved by Alternative D5 by effectively and
aggressively removing the recoverable portion of the DNAPL at a relatively short time period (7
years), which is currently contaminating the groundwater above. Alternative D5 provides for
permanently reducing the volume of DNAPL by sending the recovered portions off site for
destruction, and it is expected to provide for treatment of a significant volume of DNAPL. The
preferred alternative will be implementable because equipment and supplies are readily available
for construction of the remedy. Alternative D5 will be short-term effective because construction
time is of a short duration and workers and the community can be protected through standard
safety measures.
The final two criteria, state acceptance and community acceptance, will be evaluated after the
public comment period for this Proposed Plan.
Estimated Capital Cost: $4,446,000
Estimated Annual O&M Cost: $6,130,000
Estimated Total Present Worth Cost: $10,576,000
Estimated Construction/Implementation Timeframe: 7years
X. COMMUNITY PARTICIPATION
EPA relies on public input so that the remedy selected for each Superfund site meets the needs
and concerns of the local community.
Public Comment Period - To ensure that the community's concerns are being addressed, EPA
will open a public comment period on May 6, 2015 and close it on June 5, 2015. During this time
the public is encouraged to submit comments on the Proposed Plan. A public meeting about
EPA's Preferred Alternative will take place on May 20, 2015 at Bowen Park - Lilac Cottage,
1911 Sheridan, Waukegan, IL.
It is important to note that although EPA has proposed a preferred alternative, the final remedy
has not yet been selected for the site. All comments received will be considered and addressed by
EPA before the final remedy is selected.
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Figure 7
CONCEPTUAL CROSS-SECTION
CONCEPTUAL PROCESS FLOW DIAGRAM
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Detailed information on the material discussed in this document may be found in the site
Administrative Record. These materials include the RI, the FFS and other information used by EPA
in the decision-making process. EPA encourages the public to review the Administrative Record in
order to gain a more comprehensive understanding of the site and the Superfund activities that have
taken place there. Copies of the Administrative Record are available at the following locations:
Written comments, questions about the Proposed Plan, and requests for information can be sent to
either representative below:
Following the conclusion of the public comment period on the Proposed Plan, EPA will prepare a
Responsiveness Summary. The Responsiveness Summary will summarize and respond to
comments on EPA's preferred alternative. EPA will then prepare a formal decision document, the
Record of Decision (ROD), that summarizes the decision process and the alternative selected for the
site. The ROD will include the Responsiveness Summary. Copies of the ROD will be available for
public review in the information repositories listed above.
U.S. EPA-Region 5
Record Center, Room 711
77 West Jackson Boulevard
Chicago, IL 60604
Monday - Friday 8 a.m. to 4 p.m.
Waukegan Public Library
128 N. County Street
Waukegan, Illinois
Hours: 10AM-6PM
(847) 623-2041
Ross del Rosario (SR-6J)
Remedial Project Manager
Region 5 EPA
77 West Jackson Blvd
Chicago, IL 60406
Delrosario.rosauro@epa.gov
Heriberto Leon (SR-5J)
Community Involvement Coordinator
Region 5 EPA
77 West Jackson Blvd
Chicago, IL 60406
Leon.heriberto@epa.gov
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