PB95-964012
EPA/ROD/R04-95/221
April 1995
EPA Superfund
Record of Decision:
Koppers Co., Inc. (Charleston Plant)
(O.U. 1), Charleston, SC
3/29/1995
-------
INTERIM ACTION
RECORD OF DECISION
-\.\~EO srJf~
v~ ~~
i ~ T,
~ -- z
-SuJ
:XJ (!J
~ OC(
~ a
;.a,~ v~
AIL PRO~€
for the
Koppers Co., Inc. (Charleston Plant) NPL Site-
Charleston, Charleston County, South Carolina
March 1995
-------
RECORD OF DECISION DECLARATION
SITE NAME AND LOCATION
Koppers Co., Inc. (Charleston Plant) NPL Site
Charleston County, Charleston, South Carolina
STATEMENT AND BASIS OF PURPOSE
This decision document presents the selected Interim
Remedial Action for the Koppers Co., Inc. (Charleston Plant) NPL
Site in Charleston, South Carolina, which was chosen in
accordance with the Comprehensive Environmental Response,
Compensation, and Liability Act of 1980 (CERCLA), as amended by
the Superfund Amendments and Reauthorization Act of 1986 (SARA),
and to the extent practicable, the National Oil and Hazardous
Substances Contingency Plan (NCP). This decision is based on the
Administrative Record for this site.
The State of South Carolina concurs with the selected
Interim Remedial Action.
ASSESSMENT OF THE SITE
Actual or threatened releases of hazardous substances from
this site, if not addressed by implementing the response action
selected in this Interim Action ROD, may present imminent and
substantial endangerment to public health, welfare or the
environment.
DESCRIPTION OF THE INTERIM REMEDY
The interim remedy is designed to address the principal
threat posed by the site in the short-term while a final long-
term remedial solution for the site is being developed. The
primary objective of the interim action is to mitigate off-site
migration of nonaqueous phase liquid (NAPL) from the Former
Treatment Area to the eastern end of the Milford Street Drainage
Ditch and to mitigate a current/future potential risk to human
health posed by exposure to sediments and surface waters of the
Milford Street and Hagood Avenue Drainage Ditches. The interim
action remedy will be consistent with, and an integral component
of, the final site-wide remedy.
The major components of the selected interim remedy include:
.
An interceptor trench and sump to eliminate off-site
migration of NAPL to the eastern end of the Milford Street
Drainage Ditch;
.
Collection and treatment of recovered groundwater/NAPL and
discharge to a selected discharge point;
-------
,-
.
Permanent reconstruction of the Milford Street Drainage
Ditch to eliminate exposure to sediment and to mitigate
potential NAPL migration;
.
Inspection of the subsurface drainage system which connects
the Milford Street and Hagood Avenue drainage systems,
followed by necessary repairs to mitigate the existing
drainage system as a conduit for potential migration of
constituents and NAPL to the Hagood Avenue Drainage System;
Permanent reconstruction of the Hagood Avenue Drainage Ditch
to eliminate exposure to sediment; and
.
.
Extraction well technology to mitigate off-site migration of
NAPL in the intermediate water-bearing unit underlying the
Former Treatment Area.
STATUTORY DETERMINATIONS
This interim action is protective of human health and the
environment, complies with Federal and State applicable or
relevant and appropriate requirements for this limited-scope
action, and is cost-effective. Although this interim action is
not intended to fully address the statutory mandate for
permanence and treatment to the maximum extent-practicable, this
interim action does utilize treatment and thus is in furtherance
of that statutory mandate. Because this action does not
constitute the final remedy for the site, the statutory
preference for remedies that employ treatment that reduces
toxicity, mobility, or volume as a principal element, although
partially addressed in this remedy, will be addressed by the
final response action. Subsequent actions are planned to fully
address the threats posed by the conditions at this site.
Because this remedy will result in hazardous substances remaining
on-site above health-based levels, a review will be conducted to
ensure that the remedy continues to provide adequate protection
of human health and the environment within five years after'
commencement of the remedial action. Because this is an interim
action ROD, review of this site and of this remedy will be
ongoing as EPA continues to develop final remedial alternatives.
~~~~-
~~ ~ C\~
Richard D. Green, Associate Director
Office of Superfund and Emergency Response
Waste Management Division
EPA-Region IV
DATE
-------
SECTION
1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0
9.0
10.0
TABLE OF CONTENTS
PAGE
Site Name, Location, and Description.......................1
Site
2.1
2.2
2.3
History and Enforcement Activities....................1
Wood-Treating Operations........ . . . . . . . . . . . . . . . . . . . . . .1
Subsequent Site Operations............................ 6
Previous Removal Actions and Investigations...........7
Highlights of Community Participation......................8
Scope and Role of the Interim Action Within Site Strategy..9
Summary of Site Characteristics............................9
5.1 Geology and Hydrogeology.......... . . . . . . . . . . . . . . . . . . .10
5.2 Occurrence and Characteristics of NAPL...............16
Summary of Site Risks.................. . . . . . . . . . . . . . . . . . . .19
Description of Alternatives............ .... .... ...... .... .21
Summary of Comparative Analysis of Alternatives...........23
The Selected Remedy................... . . . . . . . . . . . . . . . . . . . .26
9.1 Performance Standard 1: Eliminate Off-Site Migration of
NAPL to the Eastern End of Milford Street Drainage
D itch. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 6
9.2 Performance Standard 2: Mitigate the Drainage System as
a Conduit for Potential NAPL and Constituent Migration
to the Hagood Avenue Drainage System.................31
9.3 Performance Standard 3: Eliminate Potential Exposure to
Sediments of the Hagood Avenue Drainage Ditch........32
9.4 Performance Standard 4: Mitigate Off-Site Migration of
NAPL in the Intermediate Water-Bearing Unit Underlying
the Former Trea tmen t Area.... . . . . . . . . . . . . . . . . . . . . . . . . 33
Statutory Determinations,........... ... .... .............. .33
10.1 Protection of Human Health and the Environment.......33
10.2 Compliance with ARARs............. .... .......... .....34,
10.3 Cost Effectiveness.................................. .34
10.4 Utilization of Permanent Solutions and Alternative
Treatment Technologies to the Maximum Extent
Practicable. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ... . . . . . .34
10.5 Preference for Treatment as a Principal Element......34
Appendix A:
State of South Carolina Interim Action Concurrence
Letter
Appendix B:
Responsiveness Summary
. Attachment 1: Verbatim Transcript of January
26, 1995 Public Meeting
Attachment 2: Written Comments Received
During Formal Public Comment Period
.
Appendix C:
Superfund Remedial Investigation Findings and
Proposed Interim Remedial Action Fact Sheet,
January 1995
-------
LIST OF FIGURES/TABLES
FIGURE OR TABLE/TITLE
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6
Figure 7
Figure 8
Figure 9
PAGE
Site Area
Map. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Si te Base Map. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3
Site Base Map (Areas of Interest) .....................5
North-South Geologic Cross-Section A-A' ..............11
North-South Geologic Cross-Section B-B' ..............12
East-West Geologic Cross-Section C-C' ................13
Water Table Map of Shallow and Intermediate Wells....14
Piezometric Map of Deep Wells... . . . . . . . . . . . . . . . . . . . . .15
Interim Remedial Action Area Map.....................17
Figure 10 Proposed Interim Remedial Action Site Plan...........27
Figure 11 North-South Cross Section....... .....................28
Table 1
Figure 12 East-West Cross Section..............................29
Table 2
Lifetime Carcinogenic and Non-Carcinogenic Risks for
Exposure Scenarios Applicable to Interim Remedial
Ac t i on. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Surface Sediment Cleanup Goals Protective of Human
Heal th. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
-------
Final Interim Action ROD
March 1995
Page 1
1.0
SITE NAME, LOCATION, AND DESCRIPTION
The Koppers Co., Inc. (Charleston Plant) Superfund site
(hereinafter referred to as "the site") is located in the
Charleston Heights section , of Charleston, SC and lies to the
north of downtown Charleston on the west side of the peninsula
formed by the Ashley and Cooper Rivers. The general location of
the site is depicted in Figure 1. The site is approximately 102
acres in size and consists of a number of parcels of property
that currently contain a variety of commercial operations. The
present use of the area surrounding the site to the north, south,
and east consists of a mixture of industrial, commercial and
residential properties. The Ashley River borders the site to the
west. The total resident, student, and worker population within
a 4-mile radius of the site is approximately 150,000.
The specific boundaries of the site are illustrated on
Figure 2. The parcel of property bound to the north by Milford
Street, to the south by Braswell Street, to the east by
Interstate 26, and to the west by the Ashley River represents an
approximate 45 acre parcel. This 45 acre parcel was previously
owned by the Koppers Company from 1940 to 1978 and was used
during their wood-treating operations. In 1988, BNS
Acquisitions, Inc. acquired the outstanding common stock of
Koppers Co., Inc. In 1989, BNS Acquisitions merged into Koppers
Company, Inc., with ,Koppers Company, Inc. being the surviving
corporation. The company underwent a name change to Beazer
Materials and Services, Inc. and in 1990, that name was changed
to Beazer East, Inc. (Beazer).
The remaining portion of the site, which comprises
approximately 57 acres located south and adjacent to the former
Koppers property, was never owned by Koppers. These 57 acres
were part of a larger tract of land (the entire area south of
Braswell Street) owned by the Ashepoo Phosphate Works, which
operated a phosphate plant there beginning around the turn of the
century. The property was used for phosphate and fertilizer
operations by a series of owners until 1978. In 1984, a fish
kill occurred in the Ashley River after a barge canal was dredged
on the property and sediments released to the river. EPA
incorporated these 57 acres into the site boundaries to determine
the environmental impact that the dredging operations had on the
Ashley River and surrounding environment.
2.0
SITE HISTORY AND ENFORCEMENT ACTIVITIES
2.1
Wood-Treating Operations
Wood-treating operations at the site began in the early
1900's, when a wood-treating facility was built in the eastern
portion of the site. Koppers acquired the property (north of
Braswell Street, south of Milford Street, and adjacent to the
Ashley River) in 1940 and continued to operate it as a wood-
treating facility until 1977 when wood-treating operations
ceased. In 1978, the property was sold to Braswell Shipyards,
Inc. (now known as Braswell Services Group, Inc.) which
-------
-------- ---
RGURE 1
SITE AREA MAP
Koppers Co., Inc. (Charluton Plant) Site
Source: Bauer East, Inc., Pittsburgh, PA
-------
OB457.3A
\
I
I
\
\
j
I
SOURCE: BEAZER EAST, INC. PITTSBURG, P A 1995
...
I
j &IIDD
41 TAX MAP , ... OCHIO
12 TAXMAP'~
D H91t
I:ZJ PIIOP!InY POIIIIOLY o.a BY ICOPPUIS Cl'Jtl'NfY
CIIIQI
028
700 0 700 1400
t::3 I I I ~
SCALE IN FEET
...
...
... ...
... ... ...
01.5
AGURE 2
SITE BASE MAP
FORMER KOPPERS SITE
CHARLESTON, SC
-------
Final Interim Action ROD
March 1995
Page 4
subdivided the property into a number of parcels and sold all but
two. Braswell Shipyards later re-acquired one of the parcels
and, since 1978, has operated a military ship cleaning, repair,
and refurbishing business on two parcels in the northwest corner
of the site. In 1994, Beazer acquired the three parcels from
Braswell Shipyards, Inc.
Koppers' wood-treating operations consisted primarily of
treating raw lumber and utility poles with creosote. For short
periods of time, pentachlorophenol (penta) and copper chromium
arsenate (CCA) were also used as preservatives in the wood-
treating process. The plant processed poles for utilities such
as the power company and the telephone company, foundation
pilings for construction of buildings, docks and wharfs, and
railroad ties, cross ties, switch ties, bridge timbers, and other
railroad materials. The volume of wood treated at the site was
approximately 200,000 cubic feet per month.
The majority of wood-treating operations were conducted in
the eastern portion of the site, now identified as the former
Treatment Area (See Figure 3). In the Former Treatment Area,
Koppers maintained numerous above-ground storage tanks for the
storage of wood-preservatives. The tank farm area in the
northeastern corner of the Former Treatment Area contained six
above-ground storage tanks ranging in size from 50,000 to 650,000
gallons. Koppers also maintained six above-ground working tanks,
four of which were on an elevated platform, located east of the
treatment building. When penta and CCA were in use, separate
working tahks contained these preservatives. When needed, the
creosote was pumped through a pipeline from the storage tanks in
the tank farm to the working tanks. The wood-preservatives were
then cycled between the working tanks and the treatment cylinders
during the treatment process.
Once the virgin lumber was sized, seasoned, or otherwise
made ready for treatment, it was pressure treated in one of four
pressure treating cylinders. One pressure treating cylinder was
dedicated to treating with both penta and CCA, and the remaining
three were used exclusively for creosote. All treating cylinders
were cylindrical vessels 133 feet long and 8 feet in diameter
with a door at one end. Generally, the wood was loaded onto tram
cars which were pushed into the cylinders. The cylinder was
sealed, a vacuum was applied to remove most of the air from the
cylinder and wood cells, and the wood was impregnated with the
wood-preservative. At the end of the treatment process, the
excess wood-preservative was pumped from the cylinder to the
working tanks for re-use. . A final vacuum was then placed on the
treatment cylinder and any additional wood-preservative drawn out
of the wood. The cylinder door was then opened and the trams,
loaded with treated wood, were pulled from the cylinder onto the
drip tracks.
The Drip Track Area (Figure 3) extended from the Treatment
Area in the eastern portion of the site to approximately two
thirds of the way to the Ashley River and parallel to the
southern Koppers property boundary. The drip tracks were
elevated above the rest of the site by 5 to 6 feet. These tracks
-------
~
~
!
<
co
UJ
on
~
~ SOURCE: BEAZER EAST, INC., PITTSBURGH, PA., 1995
--:--...
-f\ -
\.) ~
+
- J
. -
\ ,
- -
- i
(
~-too 0 600 1200
- / I I I I
/
+ +- - +-
.' c,... SCALE IN FEET
1" = 600'-0"
FIGURE 3
511£ BASE MAP
fORMER KOPPERS Sl1E
CHARLESTON,SC
L
-------
. -
Final Interim Action ROD
March 1995
Page 6
were constructed at this elevation when the facility was built to
facilitate manual movement of treated wood during off loading to
a vehicle for transport from the site. Treated wood was either
shipped directly to the customer or stored on-site.
During the treatment process, wastewater was generated when
steam was used to remove moisture from the wood and from the
boiler system. The wastewater from the treatment process
contained oils, creosote, and other solids. The wastewater was
recovered in a sump pit located adjacent to the treatment
cylinders and pumped to a series of six Separation Tanks located
near the Treatment Area just south of Braswell Street. Creosote,
which has a density greater than water, would settle to the
bottom of the sump pit and Separation Tanks. This creosote was
recovered, pumped to a dehydrator to remove excess moisture, and
then to the working tanks for re-use. Water from the Separation
Tanks was discharged to a ditch, now known as the South Braswell
Street Drainage Ditch, which flowed eastward to the Ashley River.
On occasion, the volume of the Separation Tanks was not
sufficient to handle all the material coming from the sump pit
and creosote would overflow into the South Braswell Street
Drainage Ditch. Historical aerial photographs and sampling
conducted during the RI indicate that creosote constituents were
transported with wastewater and surface water run-off along the
South Braswell Street Drainage Ditch into the Old Impoundment
Area (Figure 3). After the mid 1960's, wastewater from the
Separation Tanks was discharged to the publicly owned treatment
works (POTW).
Residues that settled to the bottom of the treatment cylinders
were removed periodically when accumulations interfered with the
treatment processes. Most of the material removed was sand and
bark which were coated with creosote. The creosote residue was
transported by rail and deposited in the northwestern corner of
the site in an area now referred to as the Creosote Treating
Cylinder Residue Area (Figure 3). This practice was discontinued
in the mid 1960's when residue materials were hauled off-site by
a private waste hauler. In addition, a four-acre tract of land
in the northwest corner of the former Ashepoo Phosphate Works
property (south of Braswell Street) was leased by Koppers from
1953 to 1968 for the stated purpose of depositing sawdust, bark,
and other wood waste materials resulting from stripping
operations.
2.2
Subsequent Site Operations
Subsequent to Koppers' operations, the Former Treatment Area
was used by several industries leasing the properties. The
creosote storage tanks in the Tank Farm Area were used by Fed-
Serv Industries in the early 1980's to store waste oil. From
1978-1982, Pepper Industries utilized the working tanks to store
ship bilge and tank wastes.
As discussed above, Braswell Shipyards has operated a
commercial and military ship cleaning, repair, and refurbishing
business on the northwest corner of the site since 1978. In
operating this shipyard, Braswell has been required to pump
-------
Final Interim Action ROD
March 1995
Page 7
bilges and to handle solvents and paint. Braswell operations
also include ship paint removal using "Black Beauty" or "Black
Diamond" carbon blasting. The parcel of property just south of
Braswell Shipyards is used by Parker Marine, Inc. for
prefabrication of marine structures.
The 57 acre parcel south and adjacent to the former Koppers
property was used by a series of owners to produce fertilizers
and phosphates from around the turn of the century to 1978. In
November 1984, after obtaining a permit from the U.S. Army Corps
of Engineers, Southern Dredging dredged a barge canal
approximately 1000 feet inward from the Ashley River (Figure 3) .
Slurry material from the canal dredging was pumped approximately
700 feet east of the barge canal and deposited in a bermed spoils
area. Water was allowed to flow over a culvert into the South
Tidal Marsh while solids settled out and were deposited in the
bermed spoils area. As a result of this dredging operation,
South Carolina regulatory personnel responded to the presence of
exposed creosoted poles, highly turbid water and an oily sheen on
the Ashley River adjacent to the canal. Approximately 100 dead
fish were observed in the Ashley River within ~ mile downstream
of the canal. It is believed that this barge canal was dredged
in the area formerly leased by Koppers for the disposal of wood
waste materials resulting from their stripping operations.
2.3
Previous Removal Actions and Investigations
The first area to be investigated on-site was the Pepper
Industries facility which utilized the former working tanks and
wood treatment building. After Pepper Industries abandoned the
property in November 1982, Braswell Shipyards notified the South
Carolina Department of Health and Environmental Control (SCDHEC)
that the tanks were leaking their contents. Sampling and
analysis indicated that the tanks contained various oils,
contaminated water, and oily sludges. Under an Administrative
Order Qn Consent (AOC) issued by SCDHEC in August 1983, Pepper
Industries began a cleanup operation in the working tank area,.
but later declared bankruptcy and ceased all cleanup activities.
Braswell Shipyards performed a cleanup operation of the Pepper
Industries property in January 1987, during which they removed
all the tanks and containers on the property and arranged for
proper disposal of the wastes. Koppers financed half the expense
of this cleanup operation.
Historical investigations conducted from 1983-1985 by SCDHEC
and EPA-Region IV revealed numerous releases of waste oil from
the storage tanks in the Tank Farm Area leased by Fed Serv
Industries. Under an AOC issued by EPA in March 1985, Fed Serv,
Koppers and a suite of other entities initiated emergency
response actions at the former Tank Farm Area. The activities
conducted at this time included proper disposal of material in
the tanks, dismantling of the tanks, and excavation and disposal
of soils.
As a follow-up to Site Inspections conducted by EPA and
SCDHEC regarding activities conducted by Pepper Industries, Fed
Serv, and Southern Dredging, EPA initiated a Site Inspection in
-------
'!-
Final Interim Action ROD
March 1995
Page 8
1988 on the former Koppers Wood Treating Plant to gather the
necessary information required to prepare the Hazard Ranking
System (HRS) package. Based upon the results of this
investigation, the Koppers Co., Inc. (Charleston Plant) Site
,received a HRS score of 50 d~e to the release of wood-treating
constituents via the surface water pathway. The site was
proposed for inclusion on the National priorities List (NPL) in
February 1992 and became Final in December 1994.
In January 1993, Beazer entered into an AOC with EPA for the
performance of a Remedial Investigation/Feasibility Study (RI/FS)
at the site. Beazer retained ENSR Consulting & Engineering
(ENSR) of Acton, MA to conduct the work required to complete the
RI/FS process. EPA and SCDHEC provided oversight of all work
conducted during the RI/FS. The RI Report and Technical
Memorandum for Interim Remedial Measures were prepared by ENSR
and accepted as Final by EPA in January 1995., The data presented
in these reports, which is summarized in this Interim Remedial
Action Record of Decision (ROD), provides the rationale for
proceeding with interim action in the Former Treatment Area of
the site.
3.0
HIGHLIGHTS OF COMMUNITY PARTICIPATION
In late April 1993, EPA conducted community interviews to
determine the public's concerns related to the Koppers site. In
May 1993, EPA issued a fact sheet to local citizens and public
officials announcing the initiation of RI/FS activities at the
site. Concurrent with the release of this fact sheet, the Final
RI/FS Work Plan documents were submitted for public review to the
information repositories located at EPA's office in Atlanta, GA
and the Charleston County Main Library in Charleston, SC. On May
25, 1993, EPA held an RI Kick-Off Public Meeting at the
Charleston Public Works Building in Charleston, SC to provide a
description of the Superfund process, the work to be performed,
and to answer any questions regarding the site. .
In January 1995, EPA released a summary publication titled,
"Superfund Remedial Investigation Findings and Proposed Interim
Remedial Action Fact Sheet" to local citizens and public
officials. This fact sheet is attached to this document as
Appendix C. The stated purpose of this fact sheet was to provide
the reader with a description of the site and a brief history,
summarize the findings of the RI and the human health Baseline
Risk Assessment, and outline EPA's proposed approach for Interim
Remedial Action at the site. The Final RI Report, Final Human
Health Baseline Risk Assessment (BRA), Technical Memorandum for
Interim Remedial Measures and other site related documents were
assembled in an Administrative Record (AR) and submitted to the
information repositories above for public review and information
concurrent with the release of the fact sheet.
A notice to area citizens regarding the availability of the
site AR, EPA's proposed approach for interim remedial measures,
and initiation of the 30-day public comment period was published
in Charleston's daily newspaper, The Post and Courier, on January
-------
Final Interim Action ROD
March 1995
Page 9
19, 1995. A formal public comment period was held from January
20 through February 21, 1995. EPA held a public meeting on
January 26, 1995 at the Charleston Public Works Building to
present the results of the RI, BRA, and rationale behind the
proposed interim remedial action. This meeting was attended by
approximately 50 people.
A response to comments received during the January 26, 1995
meeting and 30-day public comment period is included in the
Responsiveness Summary, which is attached to this Interim Action
ROD as Appendix B. This decision document presents the selected
Interim Remedial Action for the Koppers Co., Inc. (Charleston
Plant) NPL site, chosen in accordance with CERCLA, amended by
SARA, and in accordance with the National Contingency Plan. The
decision for this site is based on the materials in the AR and
comments received during the public comment period.
4.0
SCOPE AND ROLE OF THE INTERIM ACTION WITHIN SITE STRATEGY
The primary objective of the interim action is to mitigate
off-site migration of nonaqueous phase liquid (NAPL) from the
Former Treatment Area to the eastern end of the Milford Street
Drainage Ditch in order to expedite remediation of a potential
risk to human health and the environment. The means by which
this objective will be accomplished are divided into four
fundamental steps and are described in detail in Section 9.0 -
The Selected Remedy of this decision document.
The interim action is designed to address the principal
threat posed by the site in the short-term while a final long-
term remedial solution for the site is being developed.
Following completion of the site-wide Feasibility Study, EPA will
issue a Proposed Plan for a final remedial action at this site.
The final remedy will address unacceptable risk levels posed to
human health and the environment by other media
(surface/subsurface soil, sediment, surface water) in addition to
groundwater. The interim action will provide valuable
operational data to optimize site-wide remediation of the NAPL
and groundwater. To the extent possible, the Interim Action is
designed to be compatible with the final remediation plans for
this site. Under the current schedule, the Final ROD for this
site is expected to be issued by early 1996.
5.0
SUMMARY OF SITE CHARACTERISTICS
This interim action is concerned with mitigation of off-site
migration of NAPL from the Former Treatment Area. Therefore,
this section provides a summary of those site characteristics
most related to this general area of the site. The reader is
referred to the Final RI Report and Technical Memorandum for
Interim Remedial Measures for a more detailed, comprehensive
description of site characteristics and contamination present.
-------
L
Final Interim Action ROD
March 1995
Page 10
5.1
Geology and Hydrogeology
Boring logs from the RI and past investigations have been
used to develop an understanding of the stratigraphy and
hydrogeology underlying the Former Treatment Area. Three cross-
sections on Figures 4, 5, and 6 illustrate the subsurface
stratigraphy of the Former Treatment Area. Please refer to
Figure 9 in Section 5.2 for applicable boring and monitoring well
locations in the Former Treatment Area of the site.
The eastern north-south cross section (transect A-A' on
Figure 4) best illustrates the first three lithologic' units. the
first unit observed in a tan-gray silty sand extending to depths
of 11 to 16 feet below grade. Grain size analyses indicate that
this unit, hereinafter referred to as the shallow-water bearing
zone, is made up of 0.0 to 14.6 percent gravel, 81.4 to 95.4
percent sand, and 4.0 to 4.6 percent silt/clay. Beneath the
shallow-water bearing zone is a 5 to 13 foot thick sand and clay
unit referred to as the shallow clay zone. Based on boring logs,
this zone is believed to extend north at least as far as CCW MW-
5S and south to MW-20D. The third lithologic unit, called the
intermediate water-bearing zone, is a gray sand and silt unit.
Grain size analysis of this unit indicates that it is made up of
5.5 percent gravel, 90.5 percent sand and 4.0 percent silt/clay.
I
I
I .
The fourth lithologic unit encountered is a gray clay to
gray sand and clay located beneath the intermediate water-bearing
zone. The top of this intermediate clay zone is located about 33
to 38 feet below grade and the unit ranges in thickness from 3 to
9 feet. The intermediate clay zone extends beneath the entire
Former Treatment Area. The fifth lithologic unit, the deep
water-bearing zone, is a gray-green sand and silt 5 to 14 feet
thick. The Cooper Marl is the sixth unit encountered and is
located approximately 56 to 58 feet below grade in the Former
Treatment Area. The Cooper Marl formation is reportedly 260 feet
thick in. the study area.
The east-west cross section (Figure 6) illustrates that the
shallow clay zone pinches out somewhere between SB-99 and CPW W-
lI. As a result, the shallow and intermediate water-bearing
zones are one unit in the western portion of the Former Treatment
Area. The western north-south cross section (transect B-B' on
Figure 5) shows that the shallow/intermediate water-bearing unit
reaches depths of 32 to 38 feet below grade and extends south to
MW-09I and north to CPW W-5D.
Due to the discontinuity of the shallow clay zone, the
shallow and intermediate water-bearing zones are considered to be
on interconnected unit. The water table in this zone is located
between 2.5 and 7.5 feet below grade. Groundwater in the
shallow/intermediate zone flows to the north with a gradient of
approximately 0.006 (See Figure 7). A pumping test performed on
PW-01S indicates that this zone has a transmissivity of
approximately 0.0834 ft2/min and a hydraulic conductivity of
0.0076 ft/min (3.9 x 10-3 em/see) resulting in a predicted
groundwater flow velocity of approximately 80 ft/yr to the north.
A flexible wall permeameter test indicates that the shallow clay
-------
,........
~
C)
z
"'-"
~
w
W
LL
z -10
z
o
~
«
~ -20
-.J
w
-30
-- - - -.
EASTERN SECTION
SOUTH NORTH
A A'
2
(I)
N
.-
I
~
FlLL--.::: 2
SAND:"'--..
" SILT
10
o
... ..... .....
1,920
1,870
.. .... .... ..,...
... ..... .... .........
GRAY CLAY-:..;.':::'. ::::. ::::::::::::::
"SILT :.:-:-:.:::-:-:-:-:-:-:. 'GRAY' SAND-:
.:-:-:-:-:-:-:-:-:.:-:-:-: :-:-:" CLAY:-:-:
............. ........ .....
................... -.......
............ .............
....................... ,_..
...................~-
.......... .
;.;..-.;..;.
GRAY-GREEN
SAND" SILT
GRAY SAND
-40
J£IDIl
j WELL BORING AI«) SCREEN LOCA11ON
~ NAPL SA1URATED SOILS
[ S1I8NGERS ~ NAPL .. SOIlS
NA NOT AVAII..ABl£
. VALUE CALCULATED BASED ON
ONE-HALf ~ DE1EC11ON LIlT
V WAtER TABlL FOR SHALLOW/
1N1ERMEDIATE WATER BEARING
UNIT AS MEASURED 3/8/84
t.:-:-:.:-:-:.I LOW PERUEABlUTY ZONES
13 U20 PHASE I SAMPl.MG
.fJ 1,870 PHASE U SAaFUNG
roTA!. PAH CONCENTRA'TION ..
GROUNDWAtER (uglL)
20
10
o
,........
o
>
C).
Z
"'-"
~
W
W
LL
-10 z
z
o
~
«
-20 >
w
-.J
W
-30
-40
9
VER 11 CAL
EXAGGERA 11 ON
20:1
o 180
SCALE IN FEET
~
:t
...
~ SOURCE: BEAlER EAST. INC. PITTSBURG. P A 1995
:>
AGURE 4
NORTH-SOUTH
GEOLOGIC CROSS-SECl1ON A-A'
FORMER KOPPERS SITE
CHARLESTON. SC
-------
WESTERN SECTION
SOUTH
B
NORTH
B.
o
10
3b
~
&
~
~
~
&
8 ~
I ~ ~
lRo 0.
iii: (,)
iD
3b
~
&
Oi
3b
~
&
2
20
..~.._..
. SL..
10
10
o
BROWN.-GRA Y
SAND, SOME SILT
21,160
26,080
o
,,-...
Q
>
C).
Z
'-""
,,-...
~
(!)
Z
'-""
as.
as.
NA
NA
t:i -10
LaJ
lL.
Z
z
0-20
t-.
<
>
LaJ
-.J
LaJ
-30
-10~
w
u..
z
-205
F
<
>
W
-.J
w
-30
27,360
25,540
GRAY SAND
ac SILT
..::::::::::::::::::::::::::::::::::::..,
:':" " :::::.::::::: :.:.:.:.:.:-:::::::::::::::::::::::::::::::::::~~X:::::::::::::::::::::::::::::::7:.~>-
GRAY SAN . :::::::: ':::::::::::::::::::::::.Q.AY.::::::::::::::::::::::::::::::::::::.. ""
o!c SILT:.'::.'::.':::..::.. :::::.': :::::::.'.':::::::::::::..::::.':.'::.'::::::::::::::.':.'::.':::::::. ':::.
.:.:-:.:-:.:.:.:.:-:.:.:.:.:.:.:-:.:.:-:.:-:.:.:-:.:.:.:.:.:-:-:.:.:.:-:-:.:.:.:.:.:.:-:.:-:.:.:.:.:.:.:.:.:.:.:-:.:.:.:-:.:.:.:.:.:.:-:.:-:-:.:-:.:-:.:-:.:.:.'Ctt'AY'. :-:.:-:.:
:-:.:.:-:.:-:-:.:-:.:-:.:.:-:.:.:.:-:-:.:.:.:-:-:.:.:-:.:.:-:.:.:-:.:.:-:.:.:.:.:.:.:.:.:.:.:.:.:.:.:-:.:.:.:.:.:.:.:-:.:.:-:-:':-:':.:':.:':.:':':':':.:':':-:'~"!::.:':':-:'.
.""""">""""""""""""""""""""""""""""""""""""" ".0.
... w- .-.-.- - - -.-.-- - - _.--.......-:<-:.~.~-:~:-:-:-~~:~.~-:~.:.>~-::::: :::::.
"""""""""""""""""" "0...
"""""""""""""""""" "'"
""'-"""""" "'-""""""" """
"""""""""""""""""" ....,
:.:-:':-:-:-:-:':-:':-:-:-:.:-:-:-.l~.~.~~':-:-:-:':-:-:':':-:
::::::::::::::::.SAND o!c ClAY:::: :::::.
""""""""""',..,. ........,. "'"
""""""""""""'" ...,..... "'."
"".........................,...... "'"
..........,................ ........, ....
"""""""""""""""""" ....
---------
GRAY
SAND
-40
-40
NA
NA
- - - ---.~.~.~ :-:"":'.~.~.~.~.'~'.'.'.'.'.'.'.'.'. '.'.'.'.'.'
.""""""""""""""""""""""""""" ......
.:-:.:-:.:-:-:-:.:.:.:.:-:.:.:.:-:.:-:.:.:-:.:-:-:.:-:-:.:-:-:-:.:-:.:.:':-:~QQP.E;~. .~~:-: .:-:.:.:-:.
""'...............................,...... ........... ......
"""""""""""""""""""""""""'" "'"
-50
-50
JaiDIl
j lIEU.. BORING AND SCREEN LOCA lION
~ NAPL SA1URATED SOILS
[ STRINGERS OF NAPt. IN SOILS
10
NA NOT AVAILA8LE
. VALUE CALCUlATED BASEl) ON
0NE-HAlF OF DElEC110N LAlIT
V WAlER TABLE FOR SHALLOW/
1N1ERMEDIAlE WAlER BEARING
UNT AS WEASURED 3/a/M
t.:.:.:.:.:.:.1 LOW P£RMEA8IUTY ZONES
VERTICAL
EXAGGERA TlON
20: 1
o 200
SCALE IN FEET
~U20PHASEISAMPUNG
1'1,870PHASE . SAMPUNC
TOTAL PAH CONCENTRATION IN
CROUNDWAlER (ugJL)
FIGURE 5
NORTH-SOUTH
GEOlOGIC CROSS-SECTION 8-8'
FORMER KOPPERS SITE
CHARLESTON, SC
<
I/)
"
~ SOURCE: 8EAZER EAST, INC. PITTSBURG. P A 1995
a
L
---
-------
2
10
""'"
~
C>
Z
~
o
ti -10
w
I.L..
Z
z
o -20
F=
~
W
-J
W
-30
-40
-50
EAST
C'
i5 20
~
=-
10
BRO'Mf-GRAY
SAND. $OWE
SIlT
--
WEST
C
F:
~
a
es
~
ib
8 0.
- GI
I I
51 51
--
. .51- . .
ORANCE BROWN
SAND 51. T
SAND
82-
NA
""""...,...... ...
"""""""'" ....
"""""-" ...
GRAY SAND.
SOME SILT
85e
85e
OLIVE-GRAY
SAND. SOME
SILT
~~GR~;:777:7::::::7::IT0~~¥t)}\r~ :E:.~4+~?~/-:.: sc:.l ~.
. .:-:-:.:. : .:. :-: <:LAY.:-: -:.:.:-: .:-:.:.:.: .:-:-:.:-: -:.:.:-: .:. :-:.:.: .:. :-:-:.:. :.:. :-:-:.:-:- :-:. :.:.:.:- :-:-:.:.: .:-:-: -:. .. :.:-: .:-:-:.: .:.: .:-:-:-:.:.:-: -:.: -:-:.
. '-":~:";'; '~'':..:.::':'".:';''';'.-';':'.~:;':''~':':'':':':'.::,,:,,:''''''' ......... '~''':':''.~.:':
GRAY-GREEN
85e SAND
85e
GRAY-GREEN
SAND . SILT
.------------------
"""""""""""""""""""......,.........""""""""""""""'"
.. ..................,..,...........-,..................,""""""""""""'"
:':':.':':~~..~~.':-:':-:-:-:-:':':':':':-:':-:':':':-:-:':':':-:-:-:.:.:.:-:.:-:.:.:.:-:.:.:.:-:-:.:.:.:-:.:-:.:.:.:-:.:-:.:-:-:.:.:-:-:.:.:-:
.. """""""""""""""""'-'-"""""""",...........................
.. -"""""""""""""""""""""""""'"""""""""""."""
""""..'.'.""""""""""""""""""".'"""""""'.""""""'"
WDD
j E.1. BORING N«> SCREEN LOCA 1ION HI.
~ NAPl SA 1\JRA1ED SOI.S
~ STRINCERS Of NAP\. IN SOLS
11
NOT AVNUaS.
VALUE CALCULA1tD IIASm ON
ONE-HALF OF DE1EC1ION LMT
V WATER TABLE fOR SHAlLOWI
IN1ERMEDIATE WATUt BEARING
tHT AS WEASUR£I) J/i~
[':':':':':':'1 LOW PERWEABlUTY ZONES
o
-10 ~
W
~
z
-20 ~
F
<
>
W
-J
W
-30
-40
-50
""'"
~
C>
Z
~
VERTICAL
EXAGGERA TlON
20:1
~ 1.t20 PHASE I SMtPUNC
] 1.870 PHASE . SMFUNG
TOTAL PAM CONCEN1RA1ION IN
GROUNDWATER (1191\.)
o 220
SCALE IN FEET
FIGURE 6
EAST -Yt£ST
GEOLOGIC CROSS-SECTION C-C'
FORMER KOPPERS SITE
CHARLESTON. SC
)
; SOURCE: BEAZER EAST. INC. PITTSBURG. P A 1995
)
:..
-------
~
.
i
+
- -
- /
~
,
o
I
ISO
I
- ;
+ - / /'
--.::- '\./
L.. - --' - -...,
SCAU: IN FEET
/
I
-
-.J
,..--
800
I
o
800
1200
I
-
.& -... -. ---- 8IU.
l:J. --'--CI.
. - ----...
o ......--=--
c( -~"'-1DJ\18
:::: --3.0="T4a~-'=)-
II) .&3.58-.1D1£WI..--_~
~ SOURCE: BEAZER EAST, INC. PITTSBURG. PA 1995
r-. --
. <.... .
.' .--, --
. , .
i - '=) -
1+ -' . +
. Ilr ,..
-
/
r
+-
- .4-'
+
SCALL IN FEET
t.
--
. ........ UICA-
----OO1lll-1D-
CiIMuM ITA. ftMC ....... .....
~===-~=.... -1D---'
1nE-.--
~..=-:. =:"...: ~....~:=
FIGURE 7
WATER TABLE MAP OF
SHALLOW AND INTERMEDIATE WELL
MARCH 9. 1994
FORMER KOPPERS SITE
CHARLESTON, SC
-------
I--~-
I
.
~
"
I
f <....~ --
! "'-., ---
J . \ -\ .
. ) + ..-J n' +
,,""". / \-
r-'j
./
+-
100
I
+.
LIIIIII
. -... "'_"-'--IOIL
A --.--......
. - -.---....
o ...,. --.:T --
< ---",--na.
CO --3 O"1IJI~---'"
,... . .......) - ano- -)
It) .3.58 -- ..- II.WL DLVA- <-J
~ SOURCE: BEAZER EAST, INC. PITTSBURG, PA 1995
o
....
. ---...wI 1JICa'"
_AI. -- 001111- 10--'
~ ITA. PUIIIE CZII:II8A. .......
~....... ..... ...-.aD 11)--'
--...--
811--.--
~..:=:. ="~ ~ru--=':
--
.. ."..
~
.. --.
........
o
I
150
I
SCALI II FET
o
100
12110
I
+
SCALI II FET
FIGURE 8
PIEZOMETRIC MAP OF DEEP WELLS
MARCH 9, 1994
FORMER KOPPERS SITE
CHARLESTON, SC
-------
. -
I
,
Final Interim Action ROD
March 1995
Page 16
zone has a vertical permeability of 5.9 X 10-8 ft/min (or 3.0 X
10-8 cm/sec) .
The deep water-bearing zone is considered separate from the
shallow/intermediate water-bearing zones because it is
consistently separated from the overlying units by the
intermediate clay zone, and because it has a different
groundwater flow direction and chemistry. The piezometric
surface of the deep water-bearing zone is found between 8.3 and
10.7 feet below grade, and a downward gradient exists between the
shallow/intermediate and the deep water-bearing zones.
Groundwater in the deep zone flows to the southwest with a
gradient of 0.017 (See Figure 8). Slug tests indicate that the
deep water-bearing zone has a hydraulic conductivity of 0.0024
ft/min (1.2 x 10~ cm/sec), resulting in a predicted groundwater
flow velocity of approximately 72 ft/yr to the west. A flexible
wall permeameter test indicates that the intermediate clay has a
vertical permeability of 2.6 x 10~ ft/min (1.3 x 10~ cm/sec).
5.2
Occurrence and Characteristics of NAPL
The subsurface of the Former Treatment Area contains
potentially recoverable quantities of NAPL and is considered a
definite source area of constituents detected in the sediments
and surface waters of the Milford Street Drainage Ditch, the
Hagood Avenue Drainage Ditch and the headwaters of the North
Tidal Marsh. Although it appears that creosote is the primary
component of the NAPL, other releases associated with subsequent
operations may have contributed to this problem by altering the
composition and/or physical properties of the creosote. Figure 9
provides an illustration of the horizontal extent of NAPL and the
approximate extent of dissolved constituents as determined from
monitoring wells and boring logs.
Review of boring logs and drainage ditch transect logs has
provided information on the probable vertical location of NAPL in
the subsurface of the Former Treatment Area. NAPL includes both
light nonaqueous phase liquids (LNAPL) and dense nonaqueous phase
liquids (DNAPL). Three primary issues relating to NAPL
occurrence in the Former Treatment Area have been considered: 1)
the location of NAPL in relation to the discontinuous shallow
clay zone; 2) the pathway for NAPL migration to the Milford
Street Drainage Ditch and; 3) the potential for NAPL migration
through a subsurface storm drain to the Hagood Avenue Drainage
Ditch and headwaters of the North Tidal Marsh. These issues are
discussed further below and the methodology by which they will be
addressed form the basis of EPA's Interim Remedial Action.
The location of NAPL in relation to the shallow clay zone is
most easily observed on the three cross sections (Figures 4, 5,
and 6). A cross hatched and solid black pattern were added to
the left side of each boring to indicate where stringers of NAPL
and NAPL, respectively, were observed in the borings.
Furthermore, the total polynuclear aromatic hydrocarbon (PAH)
concentrations in groundwater are listed next to each well
screen.
-------
'---.
\ .~,. .~
\~~--"-
. ~
1tr-'81
..\ '" DISCH£:.
'. '" jI
. \\ \\ \ DI I /
~ ~ :: \ /
~~ ',' ~ \. /
~~ \ \ \
~ LJ 2-
--"
ale "-&7
..--- \
\./
.~
, ~ \
r 'jO
DENSE TREES
\ ~
tI
\
\
\~ '1
\/\
r
nl
I
f
,
-------
Final Interim Action ROD
March 1995
Page-1S
The eastern north-south cross section of the Former
Treatment Area (Figure 4) indicates that the NAPL is restricted
to the shallow-water bearing zone, above the shallow clay zone.
The total PAR concentrations are relatively high in shallow wells
MW-12S and CCW MW-5S, where NAPL was observed near the well
screen, and relatively low in intermediate well MW-22I, where
NAPL was not observed near the well screen. The total PAR
concentration in MW-11I is relatively elevated, possibly because
it is near the edge of the shallow clay unit (Figure 6). The
boring logs and groundwater data, therefore, indicate that in the
eastern portion of the ,Former Treatment Area, NAPL is limited to
the shallow water-bearing zone.
In the western portion of the Former Treatment Area where
there is no shallow clay zone (Figure 5), NAPL is observed at
various depths in the shallow/intermediate water-bearing zones.
Borings MW-09I and MW-10I clearly illustrate that NAPL tends to
pool wherever a coarse-grained lens overlies a fine-grained lens.
Moreover, groundwater PAR concentrations were relatively high in
the shallow/intermediate wells observed to contain NAPL, and
relatively low elsewhere.
The east-west cross section (Figure 6) gives an overall
picture of the NAPL being restricted to the shallow water-bearing
unit in the eastern portion of the Former Treatment Area. At the
point where the shallow clay zone ends, NAPL can migrate into the
-intermediate water-bearing zone. The concentrations of PARs in
groundwater indicate that NAPL may be present beneath the western
edge of the shallow clay unit (MW-11I), but it is not present
further east beneath the shallow clay zone, nor does NAPL appear
to be present in the deep water-bearing zone anywhere in the
Former Treatment Area.
The second issue related to NAPL occurrence regards the
pathway of NAPL migration to the surface drainage ditch located
just north of Milford Street (the Milford Street Drainage Ditch) .
Survey information and water level measurements indicate that the
eastern portion of the Milford Street Drainage Ditch intersects
the water table. This is illustrated on north-south cross
section A-A' (Figure 4). Boring logs and drainage ditch transect
logs suggest that soils located within the water table
fluctuation zone are stained with NAPL. This observation,
combined with the absence of any continuous NAPL saturated lens
in the unsaturated zone between the property boundary and the
drainage ditch, suggests that NAPL is migrating along the water
table to the drainage ditch.
The last issue considered was the transport mechanism for
NAPL to reach the Hagood Avenue Drainage Ditch located
approximately 1,000 feet north of the Former Treatment Area.
NAPL has been observed in the Hagood Avenue Drainage Ditch which
feeds into the North Tidal Marsh. The headwaters of the North
Tidal Marsh contain surface water and sediment which exceed
screening level ecological benchmarks for PARs, among other
constituents. Information on the storm drain system in the area
indicates that water in the eastern end of the Milford Street
Drainage Ditch enters a culvert at the east end of Milford
-------
i-
I
I
Final Interim Action ROD
March 1995
Page 19
Street. This culvert is connected to a subsurface storm drain
line that runs approximately parallel to 1-26 then connects with
the Hagood Avenue Drainage Ditch. Therefore, NAPL and other
site-related constituents are transported off-site from the
source area (i.e. the Former Treatment Area) through this
drainage system and ultimately into the Hagood Avenue Drainage
Ditch and North Tidal Marsh system.
6.0
SUMMARY OF SITE RISKS
CERCLA directs EPA to protect human health and the
environment from current and potential future exposures to
hazardous substances at the site. The Human Health Baseline Risk
Assessment has been completed for the site and is included in the
AR located at the information repositories. This section will
focus only on the human health risks addressed by EPA's Interim
Remedial Action. Preparation of the Baseline Ecological Risk
Assessment is currently underway, and therefore, risks posed by
the site to ecological receptors will not be addressed in the
Interim Remedial Action ROD.
The exposure scenarios applicable to this interim action
include the future on-site worker and current off-site resident.
Applicable exposure pathways for the above scenarios include
incidental ingestiop and dermal contact with the surface waters
and sediments of the Milford Street and Hagood Avenue Drainage
Ditches. Incidental ingestion and dermal contact with surface
soils were evaluated for the future on-site worker and current
off-site resident during the Baseline Risk Assessment. However,
this exposure pathway is not applicable to the interim action and
quantitative risk information relating to exposure to surface
soils will not be presented in this section.
EPA employed a reasonable maximum exposure (RME) approach' to
estimate the potential exposures and associated risks at the
site. The RME is the highest exposure that is reasonably'
expected to occur at the site and is intended to estimate a
conservative exposure case that is still within the range of
possible exposures. The risks posed by potential exposure to
contaminants in the surface waters and sediments in the Milford
Street and Hagood Avenue Drainage Ditch were quantified by
combining the contaminant exposure point concentrations and
assumptions regarding exposure frequency, duration and magnitude
with contaminant-specific toxicity values. Carcinogenic and non-
carcinogenic risks were then calculated for the exposure pathways
and scenarios above.
The carcinogenic risk range EPA has set for Superfund
cleanups to be protective of human health is 1 x 104 to 1 x 10~.
For example, a cancer risk of 1 x 10~ indicates that an
individual has a 1 in 1,000,000 (or 1 in 10,000 for 1 x 104)
incremental chance of developing cancer as a result of site-
related exposure to a carcinogen over a 70 year lifetime under
the specific exposure conditions assumed in the Baseline Risk
Assessment. EPA generally uses the benchmark risk level of 1 x
104 for the cumulative risk to a single receptor to trigger
-------
Final Interim Action ROD
March 1995
Page 20
action for contaminated media. Noncancer exposure estimates were
. developed using EPA reference doses to calculate a Hazard Index
(HI). A HI greater than 1 indicates that contaminants are
present at concentrations that could produce harmful effects.
It was assumed that the future on-site worker would be
exposed to surface waters and sediments of the Milford Street
Drainage Ditch 24 days/year (exposure frequency) for a 25 year
duration. Moreover, is was assumed that the current off-site
resident would be exposed to surface waters and sediments of the
Hagood Avenue Drainage Ditch 24 days/year, with an exposure
duration of 6 years for the child and 24 years for the adult.
Exposure assumptions for other pertinent parameters such as body
weight, ingestion rate, and parts of body exposed can be found in
the Baseline Risk Assessment.
The resultant carcinogenic and non-carcinogenic risks for
the future on-site worker and current off-site resident are
presented in Table 1 below. Exposure to surface waters and
sediments of the Milford Street and Hagood Avenue Drainage
Ditches resulted in unacceptable carcinogenic risks under both
exposure scenarios. The carcinogenic risks for the future on-
site worker and current off-site resident are 7 x 10-3 and 1 x 10.
I, respectively. Furthermore, child exposure to surface waters
and sediments of the Hagood Avenue Drainage Ditch resulted in an
unacceptable non-cancer HI of 10,000. As indicated on Table 1,
the high risks for both scenarios are driven primarily by dermal
contact with surface waters of the Milford Street and Hagood
Avenue Drainag~ Ditches. The primary contaminants of concern
(COCs) are constituents related to wood-treating operations and
PARs associated with the presence of NAPL in these drainage
ditches as described in Section 5.2 above.
EPA is proceeding with Interim Remedial Action at this site
to mitigate off-site migration of NAPL and to achieve significant
risk reduction quickly while a final remedial solution for the
site is being developed. The interim action will consist of
source control in the Former Treatment Area combined with
reconstruction of the Milford Street and Hagood Avenue Drainage
Ditches to mitigate the risks associated with exposures to
sediments and surface waters of these ditches. Furthermore, the
goal of the interim action is to reduce COC concentrations in the
surface water of the Hagood Avenue Drainage Ditch to adequately
protective levels, thereby mitigating adverse impacts associated
with discharge to the headwaters of the North Tidal Marsh.
-------
Final Interim Action ROD
March 1995
Page 21
TABLE 1
LIFETIME CARCINOGENIC AND NON-CARCINOGENIC RISKS
FOR EXPOSURE SCENARIOS APPLICABLE TO INTERIM REMEDIAL ACTION
Exposure Pathway Future On-Site Worker Current Off-Site Resident
{Milford St. Drainage (Hagood Avenue Drainage
Ditch) Di tch)
Cancer Risk Hazard Cancer Hazard Index
Index Risk
SURFACE WATER
. Incidental Not Not 1 X 10-4 0.06 (adult)
Ingestion Evaluated Evaluated 9.0 (child)
. Dermal 7 X 10-3
Contact 0.2 1 X 10-1 0.4 (adult)
10,000 (child)
SEDIMENT
. Incidental 2 X 10.s 0.2 6 X 10-s 0.3 (adult)
Ingestion 1.0 (child)
. Dermal
Contact 9 X 10-6 0.08 1 X 10.s 0.1 (adult)
0.1 (child)
TOTAL CANCER 7 X 10-3 0.5 1 x 10-1 0.9 (adult)
RISK/HI 10,000 (child)
7.0
DESCRIPTION OF ALTERNATIVES
EPA considered two alternatives before proposing the Interim
Remedial Action. The alternatives are briefly summarized below.
No-Action: CERCLA requires EPA to consider a "no-action"
alternative at every. site for which a remedial action is
proposed, to serve as a baseline for comparison with other
alternatives. Under the No-Action alternative, EPA would take no
further action at this time to mitigate off-site migration of.
NAPL and to protect human health and the environment in the
short-term. However, these remedial action objectives, among
others, would be satisfied in the Final ROD for the site. There
are no costs associated with the No-Action alternative.
Interim Remedial Action: The Interim Remedial Action alternative
was developed to protect human health and the environment in the
short-term while a final long-term remedial solution for the site
is being developed. The Interim Remedial Action will be
consistent with, and an integral component of, the Final remedy
for the former Treatment Area and the entire site. The Interim
Remedial Action was developed to satisfy a remedial action
objective identified in the Final RI Report which stated, "Remove
or otherwise control the discharge of NAPL from the Former
Treatment Area to the eastern end of the Milford Street Drainage
Di tch and by doing so remove or otherwise control the discharge
of NAPL and other dominant transport mechanisms to the Hagood
Avenue Drainage Di tch and the North Tidal Marsh.". Moreover,
permanent reconstruction of the Milford Street and Hagood Avenue
Drainage Ditches conducted during the Interim Remedial Action
-------
Final Interim Action ROD
March 1995
Page 22
will protect human health by mitigating exposure to sediments and
surface waters of these ditches.
The conceptual approach and performance standards of the
.Interim Remedial Action are described in Section 9.0 of this ROD.
A detailed design effort, consistent with this conceptual
approach, will be conducted to support procurement of
construction contractors necessary for implementation of the
interim remedy. In general, the interim action is a four-step
approach designed to meet the following objectives:
Shallow Water-Bearing Unit
Step 1A - Objective: Eliminate future off-site migration of NAPL
to the Milford Street Drainage Ditch.
Approach: An interceptor trench will be installed at the
location of the storm water drainage ditch on Milford Street.
Groundwater and NAPL will be pumped from this trench to
hydraulically control groundwater and NAPL migration. As part of
this installation, the storm water drainage ditch will be
permanently reconstructed, thereby eliminating potential human
exposure to sediments and surface waters of the Milford Street
Drainage Ditch. Groundwater monitoring wells will be installed
to evaluate the induced capture zone of the trench. Groundwater
and NAPL recovered from the trench will be pumped to a water
treatment plant located at 1961 Milford Street. The water
treatment plant will be designed, installed and operated to meet
all appropriate regulatory effluent standards of the chosen
discharge option. Treated groundwater will be discharged to
either: 1) the North Charleston Sewer District (NCSD); 2) the
Ashley River via an appropriate National Pollution Discharge
Elimination System (NPDES) permit; or 3) another EPA/SCDHEC
approved discharge option. The North Charleston Sewer District
is the preferred discharge point for treated groundwater, however'
flexibility must be preserved in the event that final approval
from NCSD cannot be obtained. '
Step 1B - Objective: Mitigate the drainage system as a conduit
for potential NAPL migration to the Hagood Avenue Drainage Ditch.
Approach: An inspection survey will be conducted on the
subsurface drain pipe that connects the Milford Street and Hagood
Avenue Drainage Ditches. Measures will be implemented to clean
and/or repair this drain pipe as necessary, to mitigate its
potential to act as a conduit, or preferential flow path, for
NAPL migration to the Hagood Avenue Drainage Ditch.
Step 1C - Objective: Eliminate potential exposure to
constituents in sediments of the Hagood Avenue Drainage Ditch.
Approach: The Hagood Avenue Drainage Ditch will be permanently
reconstructed to prevent future migration of NAPL and to
eliminate potential human exposure to surface waters and
sediments of this drainage ditch. The method of reconstruction
will be determined by experience gained from reconstruction of
the Milford Street Drainage Ditch.
-------
Final Interim Action ROD
March 1995
Page 23
Intermediate Water-Bearing Unit
Step 2 - Objective: Mitigate off-site migration of NAPL in the
intermediate water-bearing unit underlying the Former Treatment
Area~
Approach: Conventional groundwater recovery technology or
innovative/experimental well technology will be utilized to
hydraulically contain NAPL in the intermediate water-bearing
underlying the Former Treatment Area. This well(s} will be
installed south of Milford Street and in an area where the
shallow clay unit is not present.
unit
A cost estimate, expressed in 1994 dollars, for the Interim
Remedial Action was developed based upon conceptual engineering
and design. The capital costs for the interim action, which
includes the direct (construction) and indirect costs (non-
construction) incurred in the first year, are estimated at
$1,350,000. Yearly Operation and Maintenance (O&M) costs are
estimated at $138,000. The total present worth cost for the
interim action was estimated at $3,060,000. The total present
worth cost represents a sum of money invested in the base year at
an assumed interest rate of 7%, and if disbursed as needed, would
be sufficient to cover all costs of the interim action over its
planned life.
8.0
SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES
EPA conducts a comparative analysis to evaluate the relative
performance of each alternative in relation to nine criteria.
The purpose is to identify and clearly understand the advantages
and disadvantages of the two alternatives considered in the above
Section 7.0. This evaluation is more limited in scope and depth
than would be the case if the interim action was to be the final
remedy for this site. The comparative analysis utilizing the
nine evaluation criteria is presented below.
1. Overall Protection of Human Health and the Environment
addresses the degree to which an alternative provides adequate
protection of human health and the environment and describes how
risks posed through exposure pathways are eliminated, reduced, or
controlled through treatment, engineering controls, and/or
institutional controls.
.
The No-Action Alternative would no~ provide adequate
protection of human health and the environment in the short-
term while a final long-term remedial solution is being
developed. As documented in Section 6.0, potential human
health risks do exist from exposure to sediments and surface
waters of the Milford Street and Hagood Avenue Drainage
Ditches.
.
The Interim Remedial Action will protect human health and
the environment in the short-term while a final long-term
remedial solution is being developed. The Interim Remedial
Action shall mitigate off-site NAPL migration and eliminate
-------
Final Interim Action ROD
March 1995
Page 24
potential human health risks by permanently reconstructing
the Milford Street and Hagood Avenue Drainage Ditches.
2. Compliance with Applicable or Relevant and Appropriate
Requirements (ARARs) addresses whether or not an alternative
complies with all legally applicable or relevant and appropriate
state and federal requirements, standards, criteria and
limitations which are collectively referred to as "ARARs".
.
Interim remedial actions, followed by a final ARAR-compliant
ROD, must attain ARARs only if they are within the scope of
that action. For example, the primary goal of this Interim
Remedial Action is to mitigate off-site migration of NAPL in
the Former Treatment Area. Therefore, groundwater quality
standards such as Maximum Contaminant Levels (MCLs) are not
ARARs since the objective of the action is containment, not
cleanup. However, requirements related to discharge of the
treated groundwater are ARARs and will be met by this
interim action. Furthermore, solid materials generated by
the reconstruction and remediation of the Milford
Street/Hagood Avenue Drainage Ditches and any necessary
repair to the subsurface drain pipe between Milford Street
and Hagood Avenue shall be handled and disposed of in
accordance with ARARs.
3. Long-Ter.m Effectiveness and Permanence refers to the
residual risk and the ability of a remedy to maintain reliable
protection of human health and the environment over time.
The long-term effectiveness of the interim action cannot be
evaluated at this point. However, the interim action will
provide valuable operational data to optimize site-wide
remediation of NAPL/groundwater. The long-term
effectiveness and permanence of the Interim Remedial Action
will be evaluated, considered, and modified as necessary
during the Final ROD for this site.
4. Reduction of Toxicity, Mobility, or Volume addresses the
statutory preference for selecting remedial actions that employ
treatment technologies that permanently and significantly reduce
toxicity, mobility, or volume of the hazardous substances as
their principal element.
.
Installation of the interceptor trench, sump pump and
intermediate water-bearing zone recovery well will reduce
the mobility of NAPL and contaminated groundwater underlying
the Former Treatment Area. Moreover, treatment of the
NAPL/groundwater in the water treatment plant will reduce
the toxicity and volume of NAPL/groundwater.
5. Short-Ter.m Effectiveness refers to the period of time needed
to complete the remedy and any adverse impacts on human health
and the environment that may be posed during construction and
implementation of the remedy.
.
.
No adverse short-term impacts are expected to result from
this interim action. Site work will adhere to a site-
-------
Final Interim Action ROD
March 1995
Page 25
specific Health and Safety Plan to reduce any potential
short-term risks to workers, nearby property owners, and
residents.
6. Implementability refers to the technical and administrative
feasibility of implementing an alternative, including the
availability of various services and materials required for its
implementation.
.
The required construction technology for implementation of
the Interim Remedial Action is proven .and the necessary
materials/services are readily available. The
administrative requirements for implementation are
manageable. Special attention must be devoted to nearby
businesses and property owners to minimize disruptions to
their operations during construction of the interim remedy.
7. Cost consists of the capital (up front) costs of
implementing an alternative, plus the costs to operate and
maintain the alternative in the long-term. Under this criterion,
the cost-effectiveness of each alternative is evaluated and
compared to other alternatives under consideration.
.
The total estimated capital cost of the Interim Remedial
Action is $1,350,000 with annual O&M costs of $138,000. The
total present worth cost of the Interim Remedial Action is
$3,060,000. The interim action provides a high degree of
cost-effectiveness given that: 1) remedial activities
implem~nted under this Interim ROD would be required under
the Final ROD for the site; and 2) data gathered and lessons
learned during implementation of the interim action will
optimize the site-wide remediation strategy.
8. State Acceptance addresses whether the South Carolina
Department of Health and Environmental Control (SCDHEC) concurs
with, opposes, or has comments on the alternative selected by
EPA.
.
SCDHEC has participated actively during the RI process at
the site and concurs with EPA's Interim Remedial Action.
The State concurrence letter is attached to this document as
Appendix A.
9. Community Acceptance addresses whether the public agrees
with EPA's Interim Remedial Action.
.
A public meeting was held on January 26, 1995, to present
the results of the RI, the human health Baseline Risk
Assessment and the proposed approach and rationale for
Interim Remedial Action at the site. Comments received at
the meeting were generally supportive of the interim action.
A response to comments received, and a verbatim transcript
of the meeting is attached to this document as Appendix B.
-------
I~
I
I
Final Interim Action ROD
March 1995
Page 26
9.0
THE SELECTED REMEDY
Based upon the requirements of CERCLA, the NCP,
consideration of the alternatives, and public and State comments
received, EPA has decided to proceed with Interim Remedial Action
at the site. Generally, the stated purpose of this Interim
Remedial Action is three-fold: 1) Mitigate off-site migration of
NAPL from the Former Treatment Area to the eastern end of the
Milford Street Drainage Ditch; 2) Expedite remediation of a
potential human health risk due to exposure to sediments and
surface waters of the Milford Street and Hagood Avenue Drainage
Ditches; and 3) Provide operational and implementation data
needed to optimize a cost-effective site-wide remediation.
This interim action is consistent with EPA's guidance
regarding groundwater remediation at sites with NAPL .
contamination. This guidance document titled, "Guidance for
Evaluating the Technical Impracticability of Groundwater
Restoration, OSWER Directive 9234.2-25, September 1993", promotes
the use of a phased approach to groundwater remediation at sites
with NAPL contamination such as creosote. Interim actions are
encouraged at NAPL sites to remove and/or control the source area
(i.e. NAPL zone) and to control plume migration. This Interim
Remedial Action shall be properly designed, constructed, operated
and monitored to remove and/or control the NAPL source area
underlying the Former Treatment Area and contain the aqueous
contaminant plume. The interim action will not only reduce risks
posed by human exposure to the sediments and surface waters of
the Milford Street and Hagood Avenue Drainage Ditches, but will
also provide useful information in evaluating the restoration
potential of the site during the Final ROD.
As delineated in Section 7.0, the Interim Remedial Action
consists of 4 incremental steps designed to satisfy distinct
objectives. This section presents the Performance Standards for
each incremental step of the interim remedy and delineates the
ARARs that must be met for each step. A detailed design shall be
conducted to fully describe how the Performance Standards and
ARARs listed below will be met during implementation of the
Interim Remedial Action. The implementation sequence of the
interim action shall occur in the order presented below.
9.1
Performance Standard 1: Eliminate Off-Site Migration of
NAPL to the Eastern End of the Milford Street Drainage Ditch
The conceptual layout of the Interim. Remedial Action is
illustrated in Figure 10. In order to achieve the above
Performance Standard, an interceptor trench will be installed in
close proximity to the current location of the Milford Street
Drainage Ditch. The trench will be installed to the shallow clay
unit to a depth of approximately 15 feet below the ground
surface. The cross-sections on Figures 11 and 12 provide a
general schematic of the interceptor trench. The interceptor
trench will consist of a continuous trench approximately 350 feet
in length filled with highly permeable backfill. The trench will
be constructed with a machine capable of digging, installing
perforated drainage pipe and backfilling in one continuous pass.
-------
-- ---
- , '''. \ I ... ' ' \ I SC' J;::-' \.'. ./
..._'~. ----'" \ 't Iy-'.~ \, '\ ":' DI nl.- /: \
~ \ :;,"'--~--~. \. ,~I
. \ ':----- ---r-' 'i \ ~"j ,
\ \. ' /i
t \ \~J
/ \ ~) ~ '\ \ /'. \
,. ...~ 1(. " / /-
I ~ --4l" \ . DI .// SICN~
. \ ~.--==:::::- ----- \ \ . '. . \. ~// ~
C. ~ \ 1\ , V I
""'\ n \ . +
. \ . .~ \
~ \ \ ~ \~
~ R~I LINE
o B SURVE
ND LEANED
\
\
\
g\ ~.
I() '--.../" \
"T .
:g SOURCE: SE:AZER EAST
<$
~\ /"
\~------
l
I I
I
,...-.\
V
~
~ .
r 11°
~
\
,\)../
\~ PROPOSED
'TREATMENT
PLANT
I I
J 1m
n ! \
ff / \
DENSE TREES
PROPOSED IRM SITE PLAN
FORMER KOPPERS SITE
CHARLESTON. SC
-------
084570A
SOUTH
S
2
...-.
~
"
z
'-" 1 0
~
w
w
u..
Z
z
o
F 0
<{
>
w
-'
w
-10
""0
1::1....
~o
(/)~
0.:
Q::z
0-
~.:
-II::
~o
GRAY SAND
SOME SILT
INTERCEPTOR
TRENCH
..
GROUNDWATER GRAVEL
flOW BACKFILL
~:<~~~NAGE.... ....
.. ..........
.................... ............
............................................... .
.....""""" .
.................... .
........ .
:.: -:':-:-::-. -:.:-:-: -:':-:-:':':-:-..:-:-. :-: -:-: '9RA~ :$~~D:-:-:-:-:-:-:':-:-:-:
-''''''''.:..:.: ~.................. ...............&. CLAX'"""""""""""
.............. .
............. .
NORTH
st
20
...-.
~
"
z
10 '-".
~
w
w
u..
Z
z
o
o F
<{
>
w
-'
w
-10
SOURCE: BEAZER EAST, INC., PITTSBURGH, PA., 1995
NOT TO SCALE
RGURE 11
NORlH-SOUlH CROSS SECl10N
FORMER KOPPERS SllE
CHARLESTON. SC
-------
084571A
WEST
A
2
RECOVERY OR
UVB WELL
r--.. 10
o
>
0
Z
'--"
.....
W
W
l.L. 0
Z SAND
Z
0
.....
«
>
w-10
.....J
w
CLEAN OUT ~~~PTOR
MilfORD STREET
DRAINAGE DITCH
EAST
A'
20
,.....,............... .
SURF ACE WATER
SEAL
. . .
:0 .. .'. :~..;.~.: ... .....> . ...... .". .:- ...: . ..
:. . . ~.. .. ~RA.~L BAC~FI~L. :. . "a ....
. ..: ~ .'.. . .. . '!
,'4 ""..:...:: ,4', :.," "'..:'~
.~ .~.: ~....:' '.~4' . .'
.. .. JJ'" . ..'. . :... ..
"... : ." ..
.. '," ','" .....
. ..
\:.-:-:..:. :-::.:: :-::-::.:.:-:-:.:~.~~.-:-:-::. .:-: :-:.:-:-:-
,..~.:.: :.:.:.:-:.:.:.:.:.:.:...:.:.~ANQ.:.:.:-:.. ... .:.:.:.:.:
-.;.: . . . . . . . . . & CLAY. . .. ......
DRAINAGE . . . . . . . . . . . . . . .. .......
PIPE
GRAY SAND
c!c SILT
. . . . . . . . . . . . . . .
"""""""""" .
--.~.-:--:-.'..'.'.'..'.'.'.'.'.'.'.'.'.'.'.'.'.'.'.'.'.'.'.',',',',',',',',',','
~ .~'.~'.~.~.:: [[[
1 0 r--..
o
>
<-'
Z
'--"
o
z
o
.....
«
>
-10w
.....J
w
-20
SOURCE: BEAZER EAST, INC., PITTSBURGH, PA., 1995
NOTE: LOCATION OF INTERMEDIATE WELL IS SHOWN FOR ILLUSTRATION PURPOSES ONLY.
:::::::::::::::::::.::::: ::: -:::::::::::::::.::::::::::::::: .~~~\,I't~. ::::::-::::::::::::::-:-::::::::::::::::::::::::::
................................. ................................
.......................... ............,..........................
......................................... .
"",""""""""""""""""""""""""""""" .
-------------
J-
W
W
-------
Final Interim Action ROD
March 1995
Page 30
The drain pipe will be sloped such that all groundwater will flow
by gravity into a sump pump at one end of the trench. This
conceptual layout may be modified in the detailed design phase so
long as Performance Standard 1 is achieved.
Groundwater and NAPL will be pumped from the interceptor
trench/sump to hydraulically control NAPL/groundwater migration
in the shallow water-bearing unit. A monitoring network and
sampling strategy shall be implemented to evaluate the induced
capture zone of the trench and to verify that NAPL source control
in this area has been achieved. Groundwater and NAPL recovered
from the trench will be conveyed to a water treatment plant
located at 1961 Milford Street. The water treatment plant shall
be designed, constructed, operated, and maintained to meet the
ARARs of the selected discharge option. Effluent from the water
treatment plant will be discharged to either: 1) the North
Charleston Sewer District's (NCSD) publicly owned treatment works
(POTW); 2) the Ashley River via an appropriate NPDES permit; or
3) another EPA/SCDHEC approved discharge option. The preferred
discharge point of treated effluent is the NCSD POTW, however
final approval has not yet been received. Therefore, flexibility
must be preserved regarding the type of treatment necessary to
achieve the required discharge limits of the selected discharge
point. The treatment technology employed to meet the required
discharge limits shall be specified in the detailed design
document.
As discussed in Section 6.0, surface water and sediments in
the Milford Street Drainage Ditch are found at concentrations
greater than those deemed adequately protective of human health.
A range of surface sediment cleanup goals for the constituents of
concern based on protection of the future on-site worker are
listed in Table 2. Permanent reconstruction of the Milford
Street Drainage Ditch shall be conducted to remove contaminated
soils on the bottom and sidewalls of the ditch and eliminate the
NAPL migration pathway. Therefore, permanent reconstruction
shall attain the sediment cleanup goals listed in Table 2 and
eliminate potential human health risks associated with exposure
to sediments and surface waters of the Milford Street Drainage
Ditch.
Vertical excavation limits during permanent reconstruction
of the Milford Street Drainage Ditch shall be the observed water
table. Limits to horizontal excavation shall be instituted when
visually impacted material in the vadose zone has been removed,
or upon encroachment to subsurface utilities and/or road-side.
Where technically practicable, subsurface soils in the vadose
zone in the immediate area of the trench shall be excavated to
achieve the subsurface soil cleanup goals identified to be
protective of the Future Utility Worker in the Final Human Health
Baseline Risk Assessment. Prior to the placement of a permanent
structure on the Milford Street Drainage Ditch, excavation
confirmation sampling and analysis shall be conducted to document
residual contaminant concentrations in the vadose zone, if any.
-------
Final Interim Action ROD
March 1995
Page 31
TABLE 2
SURFACE SEDIMENT CLEANUP GOALS PROTECTIVE OF HUMAN HEALTH
.
Constituent Protective Carcinogenic Risk Range Interim
Sediment'Concentration (mg/kg) Soil
10-6 10-.1 104 Cleanup
Level
HAGOOD AVENUE DRAINAGE DITCH - CURRENT OFF-SITE RESIDENT
Arsenic 7.7 77 770
B(a)P-TE 1.6 16 160
Dioxin TEQ 0.0001 0.001 0.01
Lead 5001
MILFORD STREET DRAINAGE DITCH - FUTURE ON-SITE WORKER
Arsenic 30.3 303 3030
B(a)P-TE 5.2 52 520
Dieldrin 2.39 23.9 239
Dioxin TEQ 0.0004 0.004 0.04
Lead 5001
1 - Represents EPAinterim soil cleanup level of residential soil. Source:
SPA's Final Baseline Risk Assessment, 1994
All soil removed during installation of the interceptor
trench and reconstruction of the Milford Street Drainage Ditch
shall by handled, treated, and/or disposed of in full accordance
with all ARARs including, but not limited to, requirements
related to its characteristics (40 CPR 261.2 - Subpart C) and/or
class listing (40 CFR 261.3 - Subpart D). Furthermore, all
construction activities shall be conducted in a manner which
provides adequate short-term protection and minimizes disruptions
to businesses that utilize Milford Street for access.
9.2
Performance Standard 2: Mitigate the Drainage System as a
Conduit for Potential NAPL and Constituent Migration to the
Hagood Avenue Drainage System
The subsurface storm drain which connects the Milford Street
and Hagood Avenue drainage systems shall be cleaned, inspected,
and repaired as necessary to prevent NAPL and/or constituent
migration. The origins of all pipes in this section shall be
determined. Existing storm sewer routing details shall be
confirmed through an inspection of surface features, observations
of visible inflows and outflows, and visual inspection from any
manholes.
Following this preparatory work, this section of storm drain
shall be cleaned. Immediately after cleaning, the storm drain
system shall be visually inspected for leaks with a camera. The
camera view shall be monitored from the surface and recorded on a
-------
Final Interim Action ROD
March 1995
Page 32
video cassette. Locations of features observed with the camera
. should be recorded relative to a reference feature, such as a
manhole or catch basin. .The recorded camera survey, inspector
notes, photographs of the manholes and catch basins, and a sewer
map showing the inspection findings shall be submitted to EPA and
SCDHEC in a letter report. This report shall include
recommendations for repairs and future action, if any, based upon
the inspection findings.
EPA and SCDHEC shall have an opportunity to review and
comment on the repair recommendation report.. Following mutual
agreement on future course of action, the storm sewer pipe{s)
shall be repaired as necessary.
9.3
Performance Standard 3: El~inate Potential Exposure to
Sediments of the Hagood Avenue Drainage Ditch
Permanent reconstruction of the Hagood Avenue Drainage Ditch
shall be conducted to meet the above Performance Standard 3. As
discussed in Section 6.0, surface water and sediments in the
Hagood Avenue Drainage Ditch are found at concentrations greater
than those deemed adequately protective of human health. A range
of surface sediment cleanup goals for the constituents of concern
based on protection of the current off-site resident are listed
in Table 2. Permanent reconstruction of the Hagood Avenue
Drainage Ditch shall be conducted to remove contaminated soils on
the bottom and sidewalls of the ditch. Therefore, permanent
reconstruction shall attain the sediment cleanup goals listed in
Table 2 and eliminate the potential human health risks associated
with exposure to sediments and surface waters of the Hagood
Avenue Drainage Ditch.
Vertical excavation limits during permanent reconstruction
of the Hagood Avenue Drainage Ditch shall be the observed water
table. Limits to horizontal excavation shall be instituted when
visually impacted material in the vadose zone has been removed,
or upon encroachment to subsurface utilities and/or road-side.
Where technically practicable, subsurface soils in the vadose
zone in the immediate area of the trench shall be excavated to
achieve the subsurface soil cleanup goals identified to be
protective of the Future Utility Worker in the Final Human Health
Baseline Risk Assessment. Prior to the placement of a permanent
structure on the Hagood Avenue Drainage Ditch, excavation
confirmation sampling and analysis shall be conducted to document
residual contaminant concentrations in the vadose zone, if any.
An additional goal of Performance Standard 3 is to reduce
constituent concentrations in the surface water of the Hagood
Avenue Drainage Ditch to adequately protective levels, thereby
mitigating adverse impacts associated with discharge to the
headwaters of the North Tidal Marsh. This issue, together with
mitigating other dominant transport mechanisms, is important
considering the potential for future remediation efforts in the
headwaters of the North Tidal Marsh. A monitoring program shall
be developed and implemented to evaluate the effectiveness of the
Interim Remedial Action in mitigating constituent transport
mechanisms to the headwaters of the North Tidal Marsh.
-------
Final Interim Action ROD
March 1995
Page 33
All soil removed during permanent reconstruction of the
Hagood Avenue Drainage Ditch shall be handled, treated, and/or
disposed of in full accordance with all ARARs including, but not
limited to, requirements related to its characteristics (40 CFR
261.2 - Subpart C) and/or class listing (40 CFR 261.3 - Subpart
D). Furthermore, all construction activities shall be conducted
in a manner which provides adequate short-term protection and
minimizes disruptions to businesses and residents that utilize
Hagood Avenue for access.
9.4
Perfor.mance Standard 4: Mitigate Off-Site Migration of NAPL
in the Inter.mediate Water-Bearing Unit Underlying the For.mer
Treatment Area
Groundwater recovery technology will be utilized to
hydraulically contain the groundwater and NAPL in the
intermediate water-bearing zone beneath the Former Treatment
Area. The recovery technology employed may consist of
conventional groundwater extraction well(s) and/or innovative
well technology. The location for the recovery well(s) will be
selected after evaluation of the NAPL distribution and operation
of the interceptor trench. This well will likely be located
south of Milford. Street where the shallow clay unit pinches out.
A monitoring program shall be implemented to collect
detailed information 'regarding aquifer response to operation of
the above extraction well(s). The data and information gathered
while working to meet the requirements of this Performance
Standard shall play an integral role in determining the optimal
method to attain hydraulic source control in the intermediate
water-bearing zone beneath the Former Treatment Area. This
information will be evaluated and considered by EPA during
development of the site-wide remedy in the Final ROD for the
site.
. A. detailed design report shall be prepared which fully
delineates how the above Performance Standards and ARARs will .be
met during implementation of the Interim Remedial Action. This
report will serve as the foundation from which construction bids
will be solicited from qualified contractors. This report shall
be submitted to EPA and SCDHEC for review, comment and approval
prior to initiating the bid process for construction of the
Interim Remedial Action. Construction on the interceptor trench
is tentatively scheduled to begin in late 1995. The estimated
total capital cost of the Interim Remedial Action is $1,350,000
with annual O&M costs of $138,OOO/year. The total present worth
for the interim action is estimated at $3,060,000.
10.0 STATUTORY DETERMINATIONS
This section of the Interim Action ROD describes how EPA's
Interim Remedial Action meets the statutory requirements as
delineated in Section 121 of CERCLA.
10.1 Protection of Human Health and the Environment
EPA's Interim Remedial Action will reduce the current/future
-------
Final Interim Action ROD
March 1995
Page 34
potential human health risks associated with dermal contact and
incidental ingestion of sediments and surface waters of the
Milford Street and Hagood Avenue Drainage Ditches. This will be
accomplished by installation of an interceptor trench for NAPL
. source control on the Milford Street Drainage Ditch combined with
permanent reconstruction of the Milford Street and Hagood Avenue
Drainage Ditches. The interim remedy is consistent with EPA
guidance regarding remediation of sites with NAPL contamination
by utilizing an early action and a phased approach to reduce the
primary risks and gain source control. Therefore, the Interim
Remedial Action is adequately protective of human health and the
environment.
10.2 Compliance with ARARs
The Interim Remedial Action will meet all ARARs discussed in
Section 9.0 of this document. Primarily, these ARARs relate to
soil excavation and management during remedy implementation and
effluent discharge limits of the selected discharge option.
Compliance with all ARARs which may apply to site-wide
remediation will be addressed in the final ROD for the site.
10.3 Cost Effectiveness
EPA believes the interim action will substantially reduce
the risks posed to human health and the environment at an
estimated present worth cost of $3,060,000. The interim action
is cost effective in that it mitigates further NAPL/groundwater
migration while a final long-term solution is being developed.
Moreover, data gathered during the interim action will assist in
developing optimal and cost-effective strategies for the final
remedial action at this site.
10.4 Utilization of Permanent Solutions and Alternative Treatment
Technologies to the Maximum Extent Practicable
Although this remedy is not the final action for the site,
it does represent the maximum extent to which permanent solutions
and treatment can be practicably applied to the site.
Reconstruction of the Milford Street and Hagood Avenue Drainage
Ditches shall be permanent so as to alleviate the need to re-
visit these areas during the final remedial action. The water
treatment portion of the interim action will permanently reduce
influent contaminant concentrations to appropriate standards and
will be designed accordingly to accommodate site-wide remediation
plans. Furthermore, the use of innovative technology to
hydraulically control off-site migration of NAPL in the
intermediate water-bearing zone will be evaluated during the
fourth step of the interim action.
10.5 Preference for Treatment as a Principal Element
Although this remedy is not the final action for the site,
the Interim Remedial Action will fulfill the preference for.
treatment as a principal element, through extraction and
treatment of recovered groundwater and NAPL.
-------
Appendix A
State of South Carolina
Interim Action Concurrence letter
-------
MAR-29-1995
1219:35 FROM
TO
91412J43471681
P.02
DHEC
CommI88IoII8r: Douglas Eo Bryant
BoIInf: Richard e. Jatlbour, ODS. C/1airman
Robert J. Stripling. Jr. 'rICe Chairman
~ra J. MoIanCS8r. S8c:ttlal')
JOhn H. Buniaa
William M. Hull. Jr. MD
Roger Leeks. Jr.
BurrMlt R t.4aybIn1c. III
Deewtrnent of NeaIth and 8Iwf_ta' Control
2600 Bull Street. Columbia, SC 29201
Promoting HUItIl. Protecting fit. I!nWfOttment
March 28, 1994
John H. Hankinson, Jr.
Reqional Administrator
U.s. EPA, Region IV
345 Courtland S~ree~
Atlanta, GA 30365
RE:
Koppers Site - Interim Action Record ot Decision
Dear Mr. Hankinson:
The Departmant has reviewed the Interim Action Record of Decision
(ROD) dated March 27, 1995 tor the Koppers Co, Inc. (Charleston
Plant) NPL site and concurs with the ROD. In concurring wi~h ~his
ROD, the South Carolina Department of Health and Environmental
Control (SCDHIC) does not waive any riqht or authority it may have
under federal or state law. SCOHEC reserves any right and authority
it may have to require corrective action in accordance with the
South Carolina Hazardous Waste Management Act and the South
Carolina POllution Control Act. These righ~s include, but are not
limited to, the right to ensure that all necessary permits are
obtained, all clean-up goals and criteria are met, and to take a
separate action in the event clean-up goals and criteria are not
met. Nothing in the concurrence shall preclude SCDHEC from
exercising any administrative, legal and equitable remedies
available to require additional response actions in the event that:
(l)(a) previously unknown or undetected conditions arise at the
site, or (D) SCDHEC receives additional information not previously
available concerning the premises upon which SCDBEC relied in
concurring with the selected remedial alterna.tive; and (2) the
implementation of the remedial alternative selected in the ROD is
no longer protective of public health and the environment.
The State conc:urs wi th the selected interim action of: 1)
Installa~ion of an interceptor trench and sump to eliminate off-
site migration of NAPL to the eastern end of the Milford street
drainage ditch; 2) Collection and treatment of recovered
qroundwater INAPL and discharge to approved discharge point; 3)
Permanent reconstruction of the Milford $treet drainage di~ch to
eliminate exposure and migration of contamination; 4) Inspection
and repair of the existing drainage system; 5) Permanent
reconstruction of the Hagood Avenue drainage ditch to eliminate
eXposure to contamination; and 6) Extraction and treatment of
qrounawater/NAPL from the intermediate water-bearing unit
underlying the Former Treatment Area.
.ft.
-------
MAR-29-1995 09:36 FROM
TO
914043471681
P.03
Page 2
Mr. John H. Hankinson,
Koppers Site - Interim
March 28, 1995
Jr. -
Action ROD
state concurrence on this interim action remedial alternative is
based on the alternative meeting all applicable clean-up criteria.
Concurrence of the Interim Action ROD..does not constitute
concurrence of ~he Second Quarter 1996 Site-wide ROD.
Sincerely,
;( ~-- ~_.~
-
R. Lewis Shaw, P.E.
Deputy Commissioner
Environmental Quality Control
co:
Hartsill Truesdale
Keith Lindler
Gary stewart
Richard Hayne.
Billy Britton
Wayne Fanning, Trident EQC
-------
Appendix B
Responsiveness Summary
-------
Responsiveness Summary
Final Interim Action ROD
page 1
1.0
INTRODUCTION
The Responsiveness Summary provides a written summary of
significant comments, criticisms, and new relevant information
that was submitted to EPA during the formal public comment
period. The Responsiveness Summary is an integral component of
the Interim Action Record of Decision and represents the final
step in selection of the interim remedy for the Koppers Co., Inc.
(Charleston Plant) Site. This document allows EPA to reassess
its initial determination that the Interim Remedial Action
provides the best balance of trade-offs by factoring in any new
information or points of view expressed by the community and
local officials during the public comment period. These comments
may prompt EPA to modify aspects of the preferred alternative or
decide that another alternative provides a more appropriate
balance.
A brief background on community involvement at the Koppers
site in Charleston is provided in Section 1.1. A summary of oral
comments received during the January 26, 1995 public meeting in
Charleston, South Carolina is presented in Section 1.2. Written
comments received from the public during the formal comment
period are summarized in Section 1.3. Section 2.0 of the
Responsiveness Summary provides EPA's response and concluding
remarks to all public comments received on the EPA's Interim
Remedial Action and supporting documentation.
1.1
BACKGROUND OF COMMUNITY INVOLVEMENT
EPA's efforts to inform the local citizens and public
officials of current activities and the highlights of community
participation in the Superfund process at the site were presented
in Section 3.0 of the ROD. In late April 1993, EPA conducted
community interviews to determine the public's concerns related
to the Koppers site. Up to that point, residents near the site
knew little or nothing of the former Koppers operation. In fact,
two environmental issues not related to the Koppers site seemed
to be of most concern to the citizens interviewed by EPA. These
issues centered around the construction of an aquarium on the
Cooper River side of the peninsula near a former coal
gasification plant and the June 1991 explosion at the Albright
Wilson Chemical Plant which is approximately 1 mile from the
site.
The former Koppers site and adjacent property has been
subdivided into numerous parcels on which active businesses are
located. Owners of these parcels have expressed concern about
depressed property values and what might happen to their business
operations when cleanup activities begin. In fact, several
property owners on and near the site have taken or are taking
legal action against Beazer East Inc. for recovery of damages
incurred as a result of contamination on-site. Beazer East has
obtained access agreements from all property owners necessary to
fulfill the objectives of the RI. EPA has assisted in this
endeavor, and has remained in frequent contact with specific
property owners to ensure that certain requests/concerns are
adequately addressed.
-------
Responsiveness Summary
Final Interim Action ROD
page 2
EPA has made a concerted effort to ensure that the residents
of local communities, primarily the Rosemont and Four-Mile
Hibernian communities, stay abreast of current activities at the
site and findings of the RI. A special meeting was conducted
with residents of these community associations on the night of
January 25, 1995, prior to the formal public meeting required by
law on January 26. EPA and SCDHEC officials met with these
individuals to present the findings of the RI, a summary of the
risks posed by exposure to sediment/surface water of the Hagood
Avenue Drainage Ditch, and EPA's proposed approach to interim
action at the site.
The representatives from the Rosemont and Four-Mile
Hibernian communities expressed some concern over the estimated
potential risks posed by contact with sediment/surface water of
the Hagood Avenue Drainage Ditch, but stated they did not believe
children or adults came in frequent contact with this drainage
ditch. However, a request was made to post warning signs along
this drainage ditch and portions of the North Tidal Marsh to
mitigate possible exposure in the short-term, prior to
implementation of the interim action. This request is currently
under evaluation by EPA and SCDHEC. Some concern was also
expressed regarding the potential for site-related contamination
to be transported into neighborhood yards which backup to the
North Tidal Marsh during abnormally high flood tides. Otherwise,
the local community group was generally supportive of EPA's
proposed interim action and were pleased that something was being
done to rectify environmental problems in the area. Furthermore,
the Four-Mile Hibernian Community has formally expressed an
interest in applying for a Technical Assistance Grant to
facilitate their understanding of the future work conducted at
the Koppers site.
EPA also held an informal meeting with representatives of
the City of Charleston's Commissioner of Public Works (CPW) on
the morning of January 26, 1995. CPWowns and operates a
maintenance facility just north of Milford Street. Throughout
the RI process, EPA has maintained a dialogue with CPW because
NAPL migrating from the Former Treatment Area has been noted in
the subsurface underlying their property. Representatives of CPW
were supportive of EPA's proposed interim action, but requested
that proper steps be taken to assure access to their facility is
maintained during construction of the interceptor trench.
Discussions also focused on the effects that the capture zone
induced by the interceptor trench would have on the plume of
gasoline constituents migrating from the former location of
underground fuel storage tanks on the CPW property.
1.2
SUMMARY OF PUBLIC COMMENTS RECEIVED AT JANUARY 26, 1995
PUBLIC MEETING
In January 1995, EPA released a summary fact sheet titled,
"Superfund Remedial Investigation Findings and Proposed Interim
Remedial Action", to local citizens and public officials on the
Koppers site mailing list. This fact sheet described EPA's
proposal for proceeding with interim action at the Koppers site
-------
Responsiveness Summary
Final Interim Action ROD
page 3
and rationale supporting this action. In addition,
sheet announced the initiation of the formal 30-day
comment period from January 20 through February 21,
date, time and place of the public meeting.
this fact
public
1995 and the
On January 26, 1995, EPA held a public meeting at the
Charleston Public Works Building in Charleston, South Carolina to
present the results of the RI, the human health Baseline Risk
Assessment, and the proposed approach to Interim Remedial Action
at the site. The meeting was attended by approximately 50
people. Pursuant to the requirements of Section 117 of CERCLA, a
verbatim transcript of this meeting was kept. This transcript is
included as Attachment 1 to this Responsiveness Summary.
While not explicitly stated, the attendees at the meeting
seemed generally supportive of EPA's Interim Remedial Action to
mitigate off-site migration of NAPL and to reduce human health
risks associated with exposure to sediments and surface waters of
the Milford Street and Hagood Avenue Drainage Ditches. No major
opposition to EPA's proposal was implied or otherwise stated.
The remaining text under this section provides a general summary
of the nature of comments/questions received during the question
and answer period of the public meeting, followed by EPA's
paraphrased response.
Comment/Question: What about the human health aspect of the
cleanup? Is there going to be a study of the people that live
along the North Tidal Marsh or a health assessment?
EPA Response: It was explained that the human health risk
assessment has been completed. The potential risks associated
with exposure to sediments/surface waters of the Hagood Avenue
Drainage Ditch provided the justification to proceed with early
action in this area. It was further explained that the Agency
for Toxic Substances and Disease Registry has been consulted
regarding short-term risks associated with exposure and has
concluded that concentrations of contaminants are not.present in
the drainage ditch at levels that present a human health threat
in the short-term (while a final solution is being developed) .
Based upon the information available to date, a person-to-person
health assessment will not be conducted.
Comment/Question: The communities in the neck area of
Charleston, particularly the Rosemont community, seem to have a
high frequency of cancer cases. The community needs to be more
enlightened on what's really going on beneath the surface because
they don't know what they're being exposed to.
EPA Response: EPA believes community outreach is important,
which is why a special meeting was held with Rosemont last night
to inform those people who may potentially exposed to surface
water/sediment in the Hagood Avenue Drainage Ditch.
Comment/Question: What is the benchmark (ecological screening
criteria) for PAHs in sediment?
-------
Responsiveness Summary
Final Interim Action ROD
page 4
EPA Response: There are two benchmarks of relevance, the ER-L
(Environmental Effects Range Low) and the ER-M (Environmental
Effects Range Median). I can't recall these numbers off the top
of my head, but would. be happy to get them for you immediately
after the meeting.
Comment/Question: Are the levels of PARs and other contaminants
present at Koppers similar to those found at the aquarium site,
and if so, why have the investigative strategies been treated
differently.
EPA Response: Yes, the levels of PARs and other contaminants
present at both sites are similar. The Calhoun Park site
investigation has been challenging given the fact that the City
of Charleston is proposing to build an aquarium adjacent to a
parcel of land that was formerly used for coal gasification.
However, remediation strategies at sites can vary so long as the
end result is adequate protection of human health and the
environment. Since this question is unrelated to the Koppers
site, I would be happy to discuss this with you following the
meeting.
Comment/Question: What will happen to the soil/sediment
excavated during drainage ditch excavation?
EPA Response: The details are still being worked out, but the
material will either be stockpiled for later treatment or
disposed of off-site appropriately.
Comment/Question: will the EPA proposed cleanup option permit
use of the property by active businesses surrounding the Former
Treatment Area during and after construction?
EPA Response: Disruptions to neighboring businesses will be
minimized to the maximum extent possible during and after
construction. This will require cooperation by all parties
involved, but will be manageable.
1..3
SUMMARY OF WRITTEN COMMENTS RECEIVED DURING FORMAL COMMENT
PERIOD
During the 3D-day formal comment period, written comments
were received from Beazer East, Inc. and the South Carolina
Department of Health and Environmental Control (SCDHEC). These
written comments are attached to this Responsiveness Summary as
Attachment 2. As such, these comments will become part of the
Administrative Record for this site. .
In a letter dated February 7, 1995, Mr. Richard Haynes
transmitted comments from SCDHEC. The comments in this letter
focused on the RI Report and provided several' reasons supporting
SCDHEC's disapproval of the RI Report. The issue of most
significance related to a statement made in the Executive Summary
of the RI Report which stated that because of the salinity of
groundwater in MW-13S, the groundwater in this area will not
require remediation. This statement was apparently made due to a
-------
Responsiveness Summary
Final Interim Action ROD
page 5
misunderstanding of South Carolina Water Classifications and
Standards regarding classification of groundwater where
concentrations of total dissolved solids (TDS) exceed 10,000
parts per million (ppm).
The groundwater collected from MW-13S, which is located
south of the barge canal and approximately 300 feet from the
Ashley River, had a salinity value within the range for sea
water. According to the above standards, all groundwaters of the
state are classified as Class GB until reclassified through
proper administrative procedures. Therefore, the quality
standards for Class GB groundwaters set forth in the State
Primary Drinking Water Regulations, R.61-58.5 must be enforced.
However, Beazer East can petition SCDHEC to reclassify
groundwater in the portion of the site where the concentration of
TDS exceeds 10,000 ppm. In response to this SCDHEC comment, the
subject statement in the RI Report will be revised and the
appropriate administrative procedures to reclassify groundwater
in applicable portions of the site will be explored.
In a letter dated February 20, 1995, Ms. Shannon Craig
transmitted comments from Beazer. The comments in this letter
focused on the Interim Remedial Action and the Human Health
Baseline Risk Assessment prepared by EPA. Beazer also recognizes
the importance of NAPL source control in the Former Treatment
Area and the need to reduce potential risks in the short-term
posed by exposure to sediment/surface water in the Milford Street
and Hagood Avenue Drainage Ditches. EPA acknowledges that this
interim action is likely to be an important part of the final
remedy for the Former Treatment Area. Beazer states that the
North Charleston Sewer District is the preferred option for
discharge of treated groundwater, but requests flexibility to
pursue other options should final approval not be granted. This
flexibility has been incorporated into the Interim Action ROD.
In the aforementioned letter, Beazer discussed a wide range
of uncertainties in the toxicity and exposure values used 'in the
Baseline Risk Assessment. Most of these uncertainties are well
recognized as relevant to the current status of the science of
risk assessment. Beazer has concluded that the assumptions and
values used in the risk assessment, when considering the
uncertainties, generally over-estimate the risk posed, perhaps to
a large degree. Much of the claimed over-estimation is discussed
relative to differences in the Reasonable Maximum Exposure (RME)
values used and typical (or average) values for the exposure
parameters.
The use of RME is consistent with CERCLA regulations and
represents EPA's intention to be protective of individuals
exposed at the "high end" of the risk curve. Therefore, EPA
makes no claim that its risk assessment methodology produces
actual risk values. On the contrary, the risk values in the
Baseline Risk Assessment are intended to be values that the
Agency believes, with a high degree of confidence, do not under-
estimate the risk. The appropriateness of the degree of
conservatism reflected in the Agency's risk assessment
methodology and the values chosen specifically for the Baseline
-------
Responsiveness Summary
Final Interim Action ROD
page 6
Risk Assessment for this site are likely to remain as an area of
different opinions by the stakeholders.
2.0
CONCLUSION
Community and State of South Carolina acceptance are
modifying criteria that are considered in the remedy selection
process. EPA has given serious consideration to all comments
received, written and oral, during the 30-day public comment
period, and has consulted with the State of South Carolina. The
State of South Carolina concurs with EPA's Interim Remedial
Action and no community opposition was noted. Based upon these
considerations, EPA has determined that the Interim Remedial
Action provides the best balance between all remedy selection
criteria and selects this interim action remedy. A subsequent
Final ROD is planned to fully address the threats posed by this
site.
~
-------
Attachment 1
Verbatim Transcript
January 26, 1995 Public Meeting
-------
1
2
3
4
5
6
7
8
9
REGION IV
10
11
PUBLIC INFORMATION MEETING
12
13
FOR THE KOPPERS COMPANY CHARLESTON PLANT
14
15
SUPERFUND SITE
16
17
JANUARY 26, 1995 - 7:00 PM
18
19
CHARLESTON PUBLIC WORKS BUILDING
20
21
CHARLESTON, SC
22
23
24
. 25
A. WILLIAM ROBERTS, JR., & ASSOCIATES
1
-------
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
2
1
MS. PEURIFOY:
Good evening.
My name is
2
I'm with the Environmental
Cynthia Peurifoy.
3
Protection Agency out of Atlanta, Georgia.
I would
4
like to welcome you here tonight for our proposed
5
plan meeting for proposed interim action on the
6
Koppers Company, Charleston.Plant Superfund Site.
7
I'd like to introduce some people to you tonight that
8
are here.
9
First of all, this is Craig Zeller.
He
.is the remedial project manager for the site for
EPA.
We also have Mr. Jan Rogers who is our section
chief for the South Carolina section of the remedial
program, and we have Kevin Koporec who is here.
He
is an expert on risk assessments for EPA, so he can
answer all of your questions.
For the South Carolina
Department of Health and Environmental Control we
have Mr. Gary Stewart, Mr. Billy Britton,
Mr. Richard Haynes and also Mr. Wayne Fanning.
I want to go over some things with you
tonight.
First of all, I'd like to talk to you about
the technical assistance grant program which is a
grant of $50,000 that can be given to affected
communities to hire technical advisors.
This advisor
can review site-related documents, meet with the
groups to explain and communicate concerns and
A. WILLIAM ROBERTS, JR., & ASSOCIATES
-------
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
3
1
comments to the EPA, potentially irresponsible
2
parties, et cetera.
3
The recipient of the grant must
4
contribute 20 percent, but it can be made through
5
cash, donated supplies, volunteer services or other
6
There must be a plan prepared for this grant
means.
7
as far as how you're going to use the funds and you
8
I
can also hire someone to handle your administrative.
9
tasks related to the grant.
Tag funds may not be
used to develop new information nor sampling nor
underwrite legal actions.
Groups must be nonprofit
and must be incorporated and must live near the
site.
I have some information over on the table
about the technical assistance grants program and I
can help you in any way you like.
We are in a public comment period right
now in the proposed interim action, which is until
February 21st.
It can be extended for an additional
30 days upon request.
We have a site information
repository established at the Charleston County main
library.
The documents are available at the public
document area.
I went there today; they're there.
There is a lot of stuff there to look at there, and
I'd encourage you to get out and take a look at it.
We also have an 800 number which you can
A. WILLIAM ROBERTS, JR., & ASSOCIATES
-------
10
1 1
12
13
14
15
16
17
18
19
20
21
22
23
24
25
4
1
call us at for updates, information, comments,
2
whatever.
It's 1-800-435-9233.
3
A little bit about tonight's meeting.
As
4
you know, we have a court reporter here.
It's very
5
important that we get all of your questions and
6
comments, so I'd like to encourage you to identify
7
yourself when you have a question or comment. state
your name and make sure that she can hear you. The-
comments that we get tonight will be put into a
8
9
document that's called a responsiveness summary which
will be a part of the record of decision for this
action.
I'd like to now turn it over to
Mr. Zeller.
MR. ZELLER:
Thanks.
LikelCynthia said,
my name is Craig Zeller.
I am the project manager
with EPA in Region 4, Atlanta," and I have been
assigned here with the task to try explain about five
volumes of information that represent about this much
(indicating) in linear. feet in hopefully about 45
minutes.
My hope and my goal here is at the end of
this discussion .that you all have a sound
understanding of what we have found out here.
It is
a rather large site, rather interesting site, and if
you at any time have any questions -- government
A. WILLIAM ROBERTS, JR., & ASSOCIATES
-------
10
11
12
13
15
16
17
18
19
20
21
22
23
24
25
5
1
bureaucrats like to talk in acronyms and all kinds of
2
slang terms associated with environmental science
3
stuff -- so if you don't understand something I'm
4
saying, please stop me and I'll try to explain it.
5
Like I said, I'm going to try to go
6
through these first five items here talking about the
7
former Koppers site and what they did out there for a
8
9
good 50 years or so, talk about the findings of th~.
remedial investigation which was conducted to find
the nature and extent of contamination at the site,
go into a baseline risk assessment summary which
we'll try to summarize with respect to what we found
as far as concentrations and what that means to the
14
human health and potential risk posed and what we
. really want to.talk about tonight is EPA and.the
company responsible out here is going forward with
the proposed interim action.
What I can explain is this is one piece
of the puzzle.
It's a short~term remedy that we want
to get implemented now while a final long-term
correction or remedy is under way.
That's what we
want to talk about today and that's what the 30-day
comment period is all about.
After that I'm going to kind of give you
a good idea on the future schedule and the objectives
A. WILLIAM ROBERTS, JR., & ASSOCIATES
-------
10
11
12
13
14
15
16
17
18
19
20
21 .
22
23
24
25
6
1
for the remedial action that we've established.
When
2
I get done talking, I want to give Sharon Craig who
3
is with Beazer East, Inc. -- they are the company
4
that is taking over Koppers and the liability of the
5
Koppers Company and they have been cooperating with
6
EPA and the state in conducting this investigation so
7
far -- so I wanted to give her an opportunity to
8
address the crowd.
At that time we'll sit down an~
9
then it's your turn to ask some questions and
hopefully we can provide very good answers.
What is the Koppers site?
The Koppers
site is or was approximately a 45-acre parcel.
They
treated wood on this parcel that is bound to the east
by Interstate 26, to the north by Milford Street, to
the south by Braswell Street and to the west by the
Ashley River.
That approximate pie shape there
represents about 45 acres.
From the period of 1940 to 1978 Koppers
in their name operated a wood-treating plant there.
They primarily treated wood with creosote which
consists of a wide range of compounds we call
polynuclear aromatic hydrocarbons, but they also
treated wood using chromium copper arsenate, which we
call CCA, and pentachlorophenol.
In general, the
wood-treating process I guess could .be described as
A. WILLIAM ROBERTS, JR., & ASSOCIATES
-------
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
7
1
bringing virgin wood in; pine, timbers, railroad
2
ties, whatever it may be, they were brought in and
3
stored on-site.
Normally the virgin wood was stored
4
generally in the central portion of the site.
It was
5
brought in by rail for a while, but when the trucks
6
got moving along, they were also brought in on semis
7
as well.
8
The majority of all the treatment
9
activity took place in. this area we're calling the
former treatment area.
In the former treatment area
there were several aboveground storage tanks, upwards
of 12 storage tanks, that held the raw creosote.
Raw creosote was pumped from the storage
tanks that were in this area to a set of working
tanks.
From the working tanks, the creosote was
pumped into pressure cylinders or vessels.
These
vessels were rather large in nature.
They were 130
They had a big
feet long and about eight feet high.
door on them.
They would rail in the wood, shut the
door, screw it real tight like a big safe, pressure
it, suck out all of the water out of the wood and
then impregnate it with the wood preservative of
cpoice.
As I men~ioned, primarily that was creosote
but on occasion for a short period of time they did
use the other two, CCA and pentachlorophenol.
A. WILLIAM ROBERTS, JR., & ASSOCIATES
-------
10
11
12
13
14
I 15
16
17
18
19
20
21
22
23
24
25
8
1
ABother brief desc~iption of the process
2
following tre~tment in this general area of the
3
former treatment area, treated wood would then be
4
rolled out of here on the drip-track area where it
5
was allowed to drip or dry and then it would be
6
stockpiled on-site for shipment to the ultimate
7
user.
8
Treated wood was used by the railroad _.
9
industry for rai~roadties.
It was used by the
building industry for foundation pilings, all kinds
of construction materials such as that.
Some other
interesting features here:
Following treatment in
the treatment area, there were some attempts to
recycle the. material.
Material that was recovered
from the treatment cy~inders themselves wer~
recovered in the sump pump and pumped back to the
working. tanks.
Wastewater -- there was a lot of water
that was genexated in this process -- was collected
and pumped aCXQSS the street to this little
separation ta~k area.
There was a series of six
separation ta~ks where the water was collected
there.
It was put into a dehydrator.
Basically they
tried to boil the water off and collect any creosote
that was left.
A. WJLLIAM ROBERTS, JR., & ASSOCIATES
-------
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
9
1
On occasion these tanks would overflow
2
and run down to Braswell, what we now call the south
3
Braswell street drainage ditch.
This thing was lined
4
with wood plumes and this creosote in the water and
5
all the residuals from these tanks would run down
6
this ditch and sometimes overflow, we believe from a
7
review of the historical area photographs we found,
8
generally in the old impoundment. area and then
9
subsequently out into .the south marsh and there is
some information to support that it may have been
diverted for a while over into the central drainage
ditch and then subsequently out into the Ashley
River.
For a while through the main part of the
operations up to the mid '60s, residual creosote from
the cylinders was taken over here and buried in the
western area of the site that's now currently owned
by Braswell Shipyards~
We call this place the
creosote treating cylinder residue area.
Some other
interesting facts of this site was that in 1984 under
a permit with the u.s. Army Corps of Engineers,
Southern Dredging came in and dredged the barge canal
through this area of the site.
This was just done in
November of 1984.
Well, this dredging activity
exposed numerous creosoted poles and highly turbid
A. WILLIAM ROBERTS, JR., & ASSOCIATES
-------
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
10
1
water and released a lot of sediments which was
2
purportedly documented to have resulted in a fish
3
kill.
A South Carolina regulatory group responded to
4
a reported fish kill in that area and collected
5
approximately 100 dead fish.
6
Again under a permit, with this dredging
7
permit, all the spoils from this area were pumped
8
approximately 700 feet deep to the spoils area.
This
9
is a very primitive fed sedimentation basin.
Berms
were pushed up to be about three or four feet high,
water was pumped in there, the sediment had fallen to
the bottom then water was skimmed off the top and
drained here into south tidal marsh.
That's kind of
a brief. history.
We have split this site up, but if
you look at this whole site that is outlin~d here, as
I mentioned, the pie-shaped wedge that sits right
through here is about 45 acres.
When this site became proposed to the
National Priorities List, which is EPA's list of the
most serious abandoned hazardous waste sites in the
U.S., when it was proposed, we expanded the site
boundaries to include this area right here which is
approximately 57 acres.
Our sole purpose for doing
that was to investigate the potential damage or
impacts that this barge dredging incident could have
A. WILLIAM ROBERTS, JR., & ASSOCIATES
-------
,
10
11
12
13
14
I 15
16
17
18
19
20
21
22
23
24
25
11
1
had on that property.
So when you look at the whole
2
kit and caboodle, you're looking at about 102 acres,
3
so it's a rather large Superfund site in the whole
4
grand scheme of things.
5
We've split this thing up into general
6
areas of focus that throughout this presentation I'll
7
keep referring to you.
Starting from the north, we
8
call this the Hagood Avenue drainage ditch; as I
9
mentioned, the former ,treatment area; the North
Milford Street drainage ditch; the drip-track area;
the old impoundment; the spoils area.
This is the
south tidal marsh, the north tidal marsh up there;
the Ashley River, central drainage ditch, creosote
residual; those are some of the areas that you want
to keep looking at. '
Moving on, how did we get here?
As I
mentioned, this Superfund site was proposed for
inclusion on the National Priorities List, EPA's
quote, unquote, Superfund list, in February of '92.
It was finalized just this December.
It became final
on the NPL in December of '94.
We felt pretty
strongly about that proposed listing and that's why
we started the work in January of 1993.
In January
of 1993 EPA and the responsible party for this site
entered into an agreement.
We call it an
A. WILLIAM ROBERTS, JR., & ASSOCIATES
-------
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
12
1
Administrative Order on Consent.
As far as the
2
agreement, Beazer, Inc. agreed to fully conduct the
3
remedial investigation and feasibility study phase of
4
this project.
5
In essence what this means is that the
6
objective of the RI.is to go and find the nature and
7
status of this contamination.
The feasibility study,
8
which we're currently entering -- they're ending the
9
RI phase right now, that's why I'm here today
summarizing the results and we're jumping into the
feasibility study which is an engineering study
designed to look at feasible alternatives that are
cost effective and result in a degree of risk
reduction.
This Rlprocess started approximately two
years ago.
In June through August of '93 we
conducted the Phase I field program which was the
actual recovery well and the whole nine yards were
installed.
We conducted a Phase II program in
February and May of last year.
That was based on
results of the phase I and provided more focused
study as opposed to a si te-wide study - It's a .
102-acre facility -- and then started focusing on
areas that we call areas of concern.
There was some supplemental fieldwork
A. WILLIAM ROBERTS, JR., & ASSOCIATES
-------
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
13
1
that was done out there this past September.
The
2
supplemental investigation was conducted to support
3
the development and conceptual value and the proposed
4
hearing on remedial action that we'll get into here
5
briefly.
6
But as a result of all these field
7
programs that were conducted, you can see we
8
collected a lot of samples which resulted in a lot-of
9
data which I'm trying .to summarize to you today in a
very comprehensive yet understandable manner.
Through this investigation we collected surface soil
samples from 145 locations across the site and
subsurface soil samples which were taken from about 6
inches below land surface to the water table which on
average extends to about four feet below land surface
across the site.
We collected 215 samples in the
subsurface areas.
The geologic groundwater
investigation included collection of 91 samples from
what we call piezometers, 11 drive-point wells and 29
conventional wells.
A piezometer is basically a tube
stuck in the ground; it's designed to measure water,
water level, how deep is the water.
It gives you an
idea on where water may be flowing.
Drive-point
wells are nothing but a real quick and dirty
A. WILLIAM ROBERTS, JR., & ASSOCIATES
-------
10 .
11
12
13
14
115
16
17
18
19
20
21
22
23
24
25
14
1
conventional monitoring well.
Now a conventional
2
monitoring takes a lot of time, takes a lot of money
3
to install but it does give you highly reliable
4
groundwater data.
5
We collected surface water at 60
6
locations across the site, in the Ashley River, the
7
north tidal marsh and the south tidal marsh, across
8
all the drainage ditches on-site all encompassed. _.
9
Sediment was collected to depths up to three feet at
90 locations and there was also a fairly extensive
ecological study that attempted to evaluate what
types of effects the contamination present would have
on the ecological-receptors of this area.
That
consisted of an eight week caged oyster study where
we actually took clean, fresh oysters, set them out
in locations or areas that we were interested in and
set them out there for a good month and picked them
up afterwards and analyzed the muscle tissue.
Oysters being filter feeders, we wanted to see if
they had sucked in and blown out stuff and collected
that stuff over a period of time.
We also sampled indigenous mussels that
were inhabiting the local marshlands.
We did some
sediment toxicity testing with two test PCs, which
basically consisted of collecting sediments in
A. WILLIAM ROBERTS, JR., & ASSOCIATES
-------
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
15
1
various portions across the site, subjecting it to a
2
ten-day toxicity test to see if these animals
3 .
survived or if they died, and I'll go into the
4
results of that study.
5
Real briefly to summarize the results of
6
the RI report, first let's look at surface water
7
features.
They're.very important on this property
8
just due to the fact that groundwater is only 4 fe~t
9
below land surface. Let's start in the north portion
quickly.
This is the former treatment area. There
is a Milford street ditch that runs -- we call this
the eastern portion of the ditch -- it runs easterly
at this point in time where it connects into a
subsurface drain pipe that runs essentially parallel
to 126.
The subsurface pipe carries water. from the
site into this Hagood Avenue ditch and then water and
constituents from the site are subsequently
transported in the Hagood Avenue ditch.
There's kind of a divide here in the
Milford street ditch.
The western end of this then.
flows towards the Ashley River; however, the
constituents that we're worrLed about at this point
in time appear not to have affected this ditch as
much as this area.
Another ditch that I mentioned, the South
A. WILLIAM ROBERTS, JR., & ASSOCIATES
-------
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
16
1
Braswell ditch, this ditch carries run-off from the
2
Currently it runs down
eastern portion of the site.
3
through here, is run under a subsurface culvert under
4
Braswell street and then it's channeled out through
5
the barge canal and subsequently to the Ashley
6
River. - It's a big concern for us.
The central
7
drainage ditch still has water in it and carries
8
run-9ff from the site, about the western third, in~o
9
the Ashley River.
Then there's another surface water
ditch here that's not marked, but it is-important,
that comes along the southern portion of the
property.
This is Monrovia Cemetery.
It comes
through here and discharges into the south tidal
marsh.
So those are the surface features that we're
most worried about.
It's got some physical
characteristics and I'll get into the chemicals
later.
This is the ground water flow direction
in the shallow intermediate aquifer.
There are three
water-bearing units in the subsurface of the site.
To simplify matters, there's a shallow water-bearing
unit that is encountered about four feet below land
surface.
It extends approximately about 15 feet
below land surface in this area of the site.
The shallow clay layer then pinches it
A. WILLIAM ROBERTS, JR., & ASSOCIATES
-------
'10
11
12
13
14
1.5
16
17
18
19
20
21
,22
23
24
25
17
1
out in this area of the site.
In this area it's not
2
present.
Groundwater; then it's separated by the
3
intermediate zone, then there's an intermediate clay
4
,that's approximately 35 feet below land surface.
5
Below that there is a deep water-bearing unit and
6
it's approximately ten to 15 feet thick in some areas
7
and it sits above the Cooper formation.
The Cooper
8
formation is a very interesting geological 'feature-uf
9
this area.
On average it's encountered about 55 feet
below land surface in this area.
It's an enormous
clay layer that's reportedly 260 feet thick in this
area.
We would not expect contaminants to go below
tha t. .
It's an enormous clay layer, and it's been
very efficient at holding things where they are.
The shallow or intermediate water-bearing
zone or the aquifer and the groundwater in this
northeastern area, the groundwater is flowing in this
direction.
These numbers here are actually water
levels and as, you can simplify things, water flows
downhill and this would be the so-called groundwater
mound in this area.
And as you can see, it flows 10,
11, 12.
This iS,just a map that we've generated
based on water level measurements in the 29 wells
being put in.
The groundwater in this shallow unit
A. WILLIAM ROBERTS, JR., & ASSOCIATES
-------
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
18
1
flows this way, but there appears to be a divide in
2
the site around this vicinity and then water on the
3
. western two-thirds of this site then flows westward
4
towards the Ashley River.
5
Real briefly about the groundwater
6
quality in this area, we've characterized what we
7
would call two distinct source areas.
Source areas
8
are areas where we can actually find black
9
creosote-type product.
Now; the source areas that
we've defined are the former treatment area, which is
no surprise due to the fact that the majority of all
the treatment took place in this area.
The wells that were installed in this
area have been largely impacted.
There are
detectab~e quantities of black liquid type material
or oil.
Oil is heavier than water, so it is sinking
down until it finds a clay lens or something that
won't allow it to pass through.
Another area that we've defined as a
source area here is the former impoundment area.
We
have also detected nonaqueous phase liquids or oil
down about 35 feet below land surface in this area as
well.
Those are the two source areas.
The two areas of groundwater that we're
concerned with in the shallow intermediate zones are
A. WILLIAM ROBERTS, JR., & ASSOCIATES
-------
19
1
the former treatment area an4 the impoundment area.
2
Now, the deep water-bearing zone is
3
separated, as I mentioned, by that intermediate clay
4
lens, and it seems to be separate altogether.
The
5
intermediate clay layer appears to have separated
6
these two aquifers very well because we've measured
7
completely different groundwater chemistries and just
8
This deeper aquifer that sits _.
by flow direction.
9
right above the Cooper is flowing straight to the.
o
Ashley River and for the most part, this deep aquifer'
1
has been relatively unaffected by previous site
2
activities.
3
I want to talk about the surface and
4
subsurface soil concentrations that we found.
5
According to baseline risk assessments, . there were
6
five chemicals of concern that pose potential risk to
7
human health in the environment at this point in
8
time.
These were creosote compounds.
And the way
9
EPA looks at creosote compounds, we summarize these
:0
things into what we call benzo (a) pyrene toxicity
:1
equivalents.
All we've done is look at the
:2
compounds.
The family compounds' that make creosote
:3
are called poly aromatic hydrocarbons.
There are 17
:4
compounds primarily that make up creosote.
Seven of
:5
those compounds are potential carcinogens to humans,
A. WILLIAM ROBERTS, JR., & ASSOCIATES
-------
10
11
12
13
14
115
16
17
18
19
20
21
22
23
24
25
20
1
so all this BAP, benzo (a) pyrene, toxicity
2
equivalent is looking at the seven carcinogenic PAHs
3
and it translates it into one concentration.
So it's
4
a nice summary parameter that we can use to present
5
the results to people that care about this kind of
6
stuff.
7
But back to the point, there was five
8
chemicals or five constituents that were present i~
9
enough concentration that caused us concern.
Those
were the benzo (a) pyrenes, chromium, lead, arsenic,
dioxin and pentachlorophenol.
This one here shows
the concentrations of benzo (a) pyrene.
What I've
tried to do is I've come in here with my red pen and
tried to show you -- in the surface soil now, in the
. top six inches .of soil -- trying to show you what
we're going to classify as a hot spot.
Red equals
hot.
So as you can see, we've got some high
concentrations, again, no surprise here, in the
former treatment area, in the drip-track area, in
that little isolated portion, near the old
impoundment area, up on the Braswell portion of the
property and then interestingly enough along this
south road that was never really owned by Koppers and
never really received creosote-type compounds.
I'll
A. WILLIAM ROBERTS, JR., & ASSOCIATES
-------
10
11
12
13
14
15
16
17
18
19
20
21
22 .
23
24
25
21
1
get into that in a little bit.
2
That was benzo (a) pyrene in the surface
3
soil.
This was pentachlorophenol, which I mentioned
4
was a wood preservative of choice for a while used
5
for an unknown period of time.
As you can see,
6
pentachlorophenol is detected right where the former
7
Our highest concentrations were
penta tank was at.
8
9
really only detected at that point.
We had a sma11"
trace in here, but the highest concentrations were
consequently right where the former treatment tank
was at.
Now, as a result of penta, there is a
contaminant that is a potential carcinogen to humans;
it's. called dioxin, which is this map.
The dioxin is
found as a trace constituent of, technical grade
pentachlorophenol.
When it's sold, it has it in it.
Now, we also found dioxin above health base standards
right where we found the pentachlorophenol, so we
have a good handle on that.
That's in the surface
soil again.
This is the concentrations of arsenic in
the soil where we were originally looking for arsenic
on this site because Beazer told us that they used a
wood preservative called CCA, chromium copper
arsenate.
.
Well, interestingly enough' the highest
A. WILLIAM ROBERTS, JR., & ASSOCIATES
-------
1-
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
22
1
levels of arsenic we detected were down here along
2
this south road just south of the barge canal.
This
3
is what we're going to call the hot spots for
4
There were concentrations detected out
arsenic.
5
there above human health standards.
We will address
6
those, but the interesting portion is that the
7
highest concentration appeared to be in areas that
8
Beazer never used, but we think we know where t~at~s
9
coming from.
Also, the lead concentrations look very
similar.
We didn't expect lead to be a contaminant
that would have been associated with wood
preservatives, but we analyzed for it anyhow.
Again,
we found lead down here on this barge canal road.
Down here are the hot spots with the letter on that
road where also the arsenic is.
That was the surface
soil.
I want to get into subsurface soil across
the site and these look very similar in nature.
This
is subsurface for benzo (a) pyrene.
Again, your hot
spots are in the same general areas that the surface
were,
the former treatment area, up here where the
storage tanks were at, through the drip tracks, the
impoundment and then some isolated areas here.
You
can see this is where we thought the creosote
A. WILLIAM ROBERTS, JR., & ASSOCIATES
-------
10
11
12
13
14
151
16
17
18
19
20
21
22
23
24 .
25
23
1
residual area. was at, and we feel that we've seen
2
some evidence that that was the case there, benzo (a)
3
pyrene creosote compounds.
4
This is arsenic again in the subsurface
5
and, very similar to the surface, you can see the
6
highest concentrations of arsenic again are down here
7
on the road.
There are some levels of arsenic above.
8
human health standards in this former treatment ar~~,
9
but again, the area of highest concern is down here
on the south barge canal.
This is lead and you will see a similar
pattern developing.
Again, the highest levels of
lead, which would not be attributed to wood-treating
operations, are down there on the South Braswell
Road.
And. then dioxin,' again, was detected above the
human health base standards in the area where the
former treatment deck was at.
That's the surface soil.
That gives you
a good idea of those concentrations.
What's going to
happen now?
All the isoplatlines you saw in there
are above human health standards, so we're entering
into an engineering phase now where we're going to
look at stopping those exposure pathways by numerous
options.
We're going to evaluate capping that
material; excavating that material and replacing it
A. WILLIAM ROBERTS, JR., & ASSOCIATES
-------
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
24
1
with clean fill; excavating that material and
2
possibly treating it; that type of thing.
3
We will excavate that material -- we will
4
treat that material to come in compliance with EPA's
5
acceptable risk range.
How much we actually clean is
6
still to be debated based on some costs and risk
7
analysis.
It will be within EPA's risk range.
It is
8
a matter of how much we take out, and I can get in~b
9
that later.
This is, very quickly, the sediment
results that are very interesting.
This was
arsenic.
There were numerous contaminants above the
ecological screening level benchmarks that we've used
at this phase.
We are in the process right now of
developing formal ecological cleanup numbers. We
have these for human health numbers and those are
what I just showed you.
We're going through an
ecological risk assessment that will give us cleanup
goals for surface waters and sediments and possibly
groundwater of this area. .
Now, we have a good number of
contaminants that have exceeded these screening level
benchmarks.
All they tell you: is that this
contaminant is at a concentration that may be a
problem to you.
I have picked out a few of these as
A. WILLIAM ROBERTS, JR., & ASSOCIATES
-------
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
~5
25
1
indicators because these patterns are very similar as
2
they were in the surface and subsurface soil.
But
3
what these dots mean, the bigger the dot, the higher
4
it is over our ecological benchmark.
5
These circles right here that are clear
6
would be right in that fringe area.
We're not as
7
concerned about these sediment samples.
What we are
8
concerned about are these, where these pop up.
Ana.
9
what we see -- and this is concentrations of arsenic
that pop up.
This is concentrations of arsenic and
sediment.
Again, we expected to find some arsenic
here on-site.
Each one of these tiers is a different
level in the sediment, so this would be 0 to 6
inches.
This was 6 inches to 12 inches.
This was
one foot to two foot, and this was two foot to. three
foot, so as you can see for that particular sample,
concentrations are getting higher as you progress
deeper.
Now, this is arsenic.
This was actually
a very big surprise to us.
We didn't really expect
to find this.
Well, it turns out that arsenic and
lead, which I'll show you next, can be traced back to
former fertilizer/phosphate manufacturers.
They were
a direct component of that process.
Well,
coincidentally enough there were former fertilizer
A. WILLIAM ROBERTS, JR., & ASSOCIATES
-------
10
11
12
13
14
15,
16
17
18
19
20
21
22
23
24
25
26
1
plants located historically to the north and to the
2
There was a former fertilizer plant that was
south.
3
located down in this area and also up in this area
4
where you're seeing the high levels of arsenic.
5
This is lead, very similar distribution
6
Again, this area in the south marsh,
for lead.
7
you're seeing high lead concentrations, hiqh lead
8
concentrations here where another former fertilizer
9
plant was and then we also we have some lead
concentrations in the headwaters of this north
marsh.
The total PAHs or creosote compounds are
kind of what we expected to see.
We found elevated
concentrations of creosote-type compounds in the
headwaters of this north marsh.
These are actually
carried from the site to this area.
Our estimates
are about the first 800 to 1,000 feet of the
headwaters of that north marsh have been impacted by
creosote-type compounds.
As you can see here in the Ashley River,
the shoreline of the Ashley River and this adjacent
stretch of the Ashley River, approximately 1,500 feet
of the Ashley River riverfront has been impacted by
creosote-type constituents in the sediments.
They
are present at depths to three feet in that
A. WILLIAM ROBERTS, JR., & ASSOCIATES
-------
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
27
1
sediment.
We have not attempted at this point in
2
time to define the vertical extent of that
3
contamination, but we intend to do that here in the
4
next few months.
We're going to go back out in the
5
field and possibly do some lab recording out there.
6
Also there's some PAH compounds detected
7
in the barge canal as we'd expect and also some PAH
8
compounds detected near the dredge spoils area and-.
9
the berm spoils area where that stuff would have come
off during that incident.
This shows a little schematic on the
ecological assessment that we did and whether or not
these sediments were toxic to the test organisms that
we looked at or the test species.
The N means it was'
nontoxic or no significant toxicity was
demonstrated.
The left alphabetic number here was
one test species and the right was another, so where
you have down here a pair of Ts, that means that that
sediment from the south, from the headwaters of the
south tidal marsh was toxic to both organisms that we
looked at.
other toxicity that was observed was also
here in the headwaters of the north marsh.
It
demonstrated toxicity for one of the organisms we
looked at.
We had toxicity demonstrated in the
A. WILLIAM ROBERTS, JR., & ASSOCIATES
-------
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
28
1
sediments of the Ashley River adjacent to the site,
2
and we also had toxicity to the ecological receptors
3
here in the south tidal marsh.
4
Like I said, we are in the process of
5
developing cleanup goals for sediment and those will
6
be incorporated into the feasibility.
7
But what does all this mean, Craig?
8
9
These are all levels and you've got some nice red -.
figures for us, but w~at does all this mean?
We're
trying to get a handle on it ourselves in the
baseline risk assessment summary and we looked at
potential exposure pathways for humans on the site.
The exposure pathways that we evaluated were
incidental ingestion and dermal contact with
, surface/subsurface soils on-site.
We looked .at
groundwater ingestion as a potential possibility just
in case there was a future on-site resident that may
locate on our site.
Case in point, that all the
water in the area for potable use is supplied by the
city.
Everybody in this area is on city water.
We did conduct some recovery well
surveys.
We looked at all available records and we
did conduct some surveys there; exposure pathways
incomplete.
We also looked at incidental ingestion
A. WILLIAM ROBERTS, JR., & ASSOCIATES
-------
10
11
12
13
14
15.
16
17
18
19
20
21
22
23
24
25
29
1
and dermal contact with the surface water while
2
wading in the river, while possibly coming in contact
3 .
with surface water in the ditches on the site, and we
4
also looked at possible ingestion of fish or
5
shellfish in the area, and last but not least, we
6
also looked at incidental ingestion and dermal
7
contact with the sediments.
8
Carcinogenic risks, we looked at specs-'
9
from exposure to soil .and subsurface soils and all
these are exposure pathways that we looked at. two
ways; carcinogenic risk and noncarcinogenic risk.
EPA classified carcinogenic risks under
class A, B1, B2, C, D or E.
A means that it is a
known human carcinogen.
Class E would be it's not
classified.
There's no evidence of carcinogenics to
humans.
Most of the constituents, the ones that we
looked at -- the creosote constituent, lead, and
those -- are classified' as B2 carcinogens, which is
it's a probable human carcinogen based on sufficient
studies conducted on animals.
It's insufficient
based on human tests.
Now, this is where it gets confusing and
sometimes I get lost here.
EPA has defined its
protected risk range, as you will hear people talk
about as one times the ten to minus four or one times.
A. WILLIAM ROBERTS, JR., & ASSOCIATES
-------
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
30
1
ten to minus six.
If the risk is calculated to fall
2
within that range, it's acceptable.
If it falls
3
outside of ten to the'minus six, it's acceptable and
4
also if it falls in between there.
5
Now, this is an incremental chance.
What
6
this means is that if you, under the exposure
7
pathways that were evaluated, if your risk falls
8
I
outside of that range -- let me explain it this way'.
9
One in 10,000 or one in one million.
Now your
exposures to this contaminant on-site result in a one
in one hundredth chance of dying by exposures of this
contaminant present on-site.
That is unacceptable to
EPA, and the EPA Commission has to do something about
that; but that's defined as an incremental chance.
Everybody in this room, by living on
God's green Earth, your chances of developing cancer
are .3, so if you were exposed to soils on this site
and your incremental chance went up to one in one
hundred or .01.
Your chance now of developing cancer
in relation to the site exposure has gone to .31.
We also looked at non-carcinogenic risks,
which we looked at exposure estimates, referenced
those, and those are calculated to be hazardous.
If
you have an HI greater than one after you sum this
all up, we conclude that that could cause adverse
A. WILLIAM ROBERTS, JR., & ASSOCIATES
-------
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
31
1
health effects.
2
Let me try to tell you what this all
3
Under the exposure pathways, either of
means here.
4
the scenarios that we looked at, on top here we
5
hypothetically developed exposure scenarios for a
6
current on-site worker, a future on-site worker, a
7
future utility worker and a current off-site
8
resident.
We looked at the potential exposure
9
pathways that this person may be exposed to.
We
looked at the exposure to surface -soils, subsurface
soils, surface water and sediment.
Now what we did, then, is you make
assumptions on the frequency that this person may be
exposed and the duration that this person may be
exposed.
These are all thrown into a ve~y
complicated mathematical formula and at the bottom
you get the numbers that are down here.
Now, the
shaded numbers that I have shaded here are
unacceptable risks as defined by EPA.
EPA has
mandated in the law to do something about that.
Let
me go through this.
The current on-site worker, for instance,
we assume that in the eastern portion of the site
this current on-site worker would be exposed to
surface soil samples 25 days a year.
And then in the
A. WILLIAM ROBERTS, JR., & ASSOCIATES
-------
j
. , 1
2
3
4
5
6
7
8
9
10
11
12
13
14
1,5
16
17
18
19
20
21
22
23
24
25
32
middle or the western portion of that site, we'd
assume that he would be exposed to this stuff 250
days a year.
The difference here being that the
eastern portion of the site now is heavily paved,
whereas the middle and the western portion of that
site are primarily unpaved; so we tried to reduce the
exposure frequency.
,
This person was assumed to be a duratien
of exposure of 15 yea~s and this person would also be
assumed to be exposed to the surface water two days a
year for 15 years and also sediment.
Those numbers
are all calculated.
We calculated unacceptable risk
for the current on-site worker to be five times ten
to the minus four or out of EPA's risk range.
The
accepted risk range would be one times ten to the
minus four.
We also calculated an unacceptable
noncancer HI of two.
Anything under one we expect to
be okay.
That's the least extreme.
Now, going to
the worst scenario that we've seen or the highest
risk that we've calculated for this site, where the
so-called current off-site resident or the person
that's not necessarily living on-site now but may
occasionally trespass on the site or may be
occasionally exposed to site-related constituents.
A. WILLIAM ROBERTS, JR., & ASSOCIATES
-------
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
33
1
What we looked at was the adult and child
2
exposure scenarios, exposure to surface soil on-site
3
for the adult possibly wandering across the site and
4
coming into contact there and primarily the surface
5
water/sediment pathways.
Now, what we calculated
6
there was one times ten to the minus one risk range.
7
That's well outside of EPA's risk range that says,
8
.
EPA, you must do something about that.
9
Also, we calculated fairly high hazard
indexes for -- greater than one up to 10,000 -- for
the child that was playing in the Hagood Avenue ditch
over a period of six years and was coming in contact
with that stuff for 24 days a year.
So we looked at
those risks and we said, these are something that we
have enough data on the table now that we should do
something about this.
And this is really the topic
of where we're at now.
This gets into the proposed
interim action.
This is what EPA has proposed to do in
the short term.
What we want to do here now is we
want to reduce the potential for short-term human
health risks in that northeastern area associated
with the dermal contact/incidental ingestion of
surface waters and sediments in that Hagood Avenue
ditch and the Milford Street ditch, while a final
A. WILLIAM ROBERTS, JR., & ASSOCIATES
-------
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
34
1
long-term remedial solution for the site is being
2
developed.
3
We have enough information now that we
4
feel that we can go ahead with this piece of the
5
remedy.
This is one piece of the remedy, that is not
6
the final remedy.
The final one will come likely in
7
the next year.
8
But what we want to do here, and I'll ~o
9
through these four steps~
These four steps are. in
that fact sheet that some of you mayor may not have,
but step 1A is what we're calling eliminate the
future migration of NAPL, nonaqueous phase liquid,
creosote, oil, whatever you want to call it, to the
Milford street drainage ditch.
As I mentioned, creosote is traveling
along that Milford street drainage ditch and it's
being carried along that subsurface culvert in the
subsurface drainage pipe that runs between Milford
and Hagood and then is transported to the Hagood
Avenue ditch.
The way we want to do that is
construct an interceptor trench, reconstruct the
ditch and treat the collected water.
step two would
be mitigate the drainage system as a conduit for
potential migration to the Hagood Avenue ditch.
What
I'm referring to is that subsurface drain pipe that
A. WILLIAM ROBERTS, JR., & .ASSOCIATES
-------
10
11
12
13
14
.15
16
17
18
19
20
21
22
23
24
25
35
1
runs between Milford and Hagood.
We're going to go
2
in there and inspect that ditch, inspect that pipe,
3
see if there are any leaks, see if there's any
4
product in that pipe and repair that as necessary.
5
Now, that repair is yet to be determined
6
but the two extremes would be doing nothing if we see
7
no leaks or that we see so many leaks that it may
8
make sense just to pull the thing out and reconstruct
9
it altogether.
There'.s no .way for us to know that
now and we will determine that on the official
inspection.
step 1C then would be eliminate the
potential exposure to the sediments that are
currently in that Hagood Avenue ditch.
And the way
we're going to do that is we're going to reconstruct
that ditch.
We're going to go in there and we're
going to pullout those contaminated sediments,
remediate them to health base levels and reconstruct
that ditch so that we don't have that. problem
anymore.
Then step two, finally, we're going to go
back. to the former treatment area and then look at
mitigating the off-site migration in the intermediate
zone, and we'll do that by a recovery well.
Let me
mention here that the cost right now on estimates are
A. WILLIAM ROBERTS, JR., & ASSOCIATES
-------
11
12
13
14
15
16
17
18
19
20
21
22
23
24
.25
36
1
an upfront cost of $1.35 million, total operation and
2
maintenance cost, annual cost of $138,000 a year for
3
. a total present worth value of just over $3 million.
4
Let's look at what I just talked about,
5
and I'll go through those steps one more time so you
6
get a good idea of what we're talking about here.
7
As I mentioned,
This is the former treatment area.
8
9
the NAPL is in this area, subsurface here.
A larg~.
majority of it is concentrated about 15 feet below
10
land surface and it's moving in this direction. So
what we propose to do is put an interceptor trench
approximately 350 feet in length, it will be about
one and a half feet wide.
What we intend to do is
with a machine come in in one continuous path,
excavate thisl trench down about 1.5 feet .below land
surface and install a drain pipe at the bottom of
that drainage ditch, on top of that shallow clay
layer, and then backfill it with a pervious gravel so
that it will create a preferential flow path so that
.we're going to recover all that groundwater and free
product in this interceptor trench in the sump pump.
The sump pump will be located at one end.
Right now
for illustration purposes it's right here.
This sump pump, then, at a rate of five
gallons per minute, will recover material from this
A. WILLIAM ROBERTS, JR., & ASSOCIATES
-------
10
11
12
13
14
l5
16
17
18
19
20
21
22
23
24
25
37
1
area, pump it back to a warehouse that's currently
2
located at 1961 Milford street, it sits right down
3
there, and that water will be treated in accordance
4
with all regulatory discharge requirements and right
5
now we're working on negotiations with the North
6
Charleston Sewer District to discharge that to them.
7
So that will be in full accordance with the North
8
,
Charleston Sewer District and will be to all
9
applicable standards. .
So what we're trying to do, as you can
see, is right now via subsurface borings we have
delineated where this black creosote is in the
subsurface and we estimate it to about 150 feet north
of Milford Street.
So what we're trying to do here
is induce a capture zone to reverse the gradient .on
that stuff and pull that stuff back and stop it right
there.
We also have a dissolved constituent that
is a little bit further out there.
To give you an
idea real quickly on the subsurface there for those
who are interested, here is a subsurface
cross-section that extends down.
In the inset down
there you'll see cross-section AA is the
easternmost.
Now, the interesting thing about that is
A. WILLIAM ROBERTS, JR., & ASSOCIATES
-------
10
11
12
13
14
.15
16
17
18
19
20
21
22
23
24
25
38
1
that here in the eastern section you can see the
2
Now, via all the borings we
shallow clay is present.
3
put in, coming down here, these little black sections
4
here were where we have actually observed creosote
5
and NAPL in the subsurface.
6
Here in the western section you can see
7
that we don't have that shallow clay.
The shallow
8
clay is gone.
We do have the intermediate clay ana.
9
some of the wells we put in that area, these wells
are actually located in the former treatment area and
we do have stringers and visible NAPL in some of
those areas.
Let me show you another cross-section.
This runs parallel to Milford street.
This is a
really good illustration of what we're going to do.
You can see here the shallow clay layer benches out.
Here it is.
We're proposing to install that trench
on top of this shallow clay.
You can see that we
have some NAPL in here and we also have some NAPL
that's rolling over that and also sticking in this
one well here.
As you progress in this direction, we
don't have NAPL that far over.
Here is a cross-section that's running
north and south through that area, and over here on
the left this is where the groundwater flow will be
A. WILLIAM ROBERTS, JR., & ASSOCIATES
-------
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
39
1
coming in.
We're going to want that groundwater flow
2
to run into this interceptor trench and the gravel
backfill and percolate down in this drainage pipe
3
4
where we're going to collect it.
On top of this
5
you'll see that's where the Milford drainage ditch is
6
going to be and we're going to put a new drain pipe
7
on top of that.
Likely it will be a precast concrete
8
drain that's going to be raised above the water
9
table, hopefully, so that we stop all transport
mechanisms.
So what we're doing here is very simple.
Let's stop the source; let's stop the source and head
it off at the path so to speak.
Then after we stop
the source effectively, which is step 1A, let's go in
and rectify the problem that the source has caused
over the past years and that is to mitigate the
potential pathways along that subsurface drain pipe
and let's go get those sediments in the Hagood Avenue
ditch that have been impacted by this past transport
mechanism.
What we want to do on step 2 then is to
come in and where we have a potential for NAPL to
migrate in this intermediate water~bearing zone we
want to come with a recovery well, screen in that
intermediate zone and recover all the impacted water
A. WILLIAM ROBERTS, JR., & ASSOCIATES
-------
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
40
1
that's in that area so that's kind of the fourth step
2
of four.
3
As you can see here, here is a good cut
4
of what this interceptor trench is going to look
5
like.
You can see the gravel backfill, the Milford
6
street ditch on top of it and then the perforated
7
drain pipe where the stuff will collect, actually
8
infiltrate down there and collect in there -and it -.
9
will be directed to the sump pump and be pumped up to
the building and be treated at that time and be
discharged into the North Charleston Sewer District.
That's in general what we're proposing to
do and let me just keep on rolling here.
I'll finish
here in a few minutes and you can ask us all the
questions you want.
What we're going~to do is reduce
the human health exposures to surface and subsurface
soils to levels being protective by EPA.
We're also
going to reduce the potential human health risk posed
by contact with the sediments that are in those
ditches.
This is all the stuff we're doing pow in
the feasibility study.
We're going to remove and control the
discharge of free product to that Milford Street
ditch, and the way we're going to do that is the
subject of our proposed interim action which I just
A. WILLIAM ROBERTS, JR., & ASSOCIATES
-------
10
11
12
13
14
15
16
17 .
18
19
20
21
22
23
24
25
41
1
presented to you.
We also want to remove or
2
otherwise control NAPL that would be below the water
3.
table north of the former treatment area, material
4
that may be north of Milford street, we also want to
5
try and reverse that gradient and pull it back and
6
stop any more further migration of that material.
7
We want to address the dissolved. phase
8
contaminants that appears to be emanating from the-.
9
source area in the northeastern area.
We want to
control the source area that's in the impoundment
area.
As. I mentioned, we have another distinct
source here, the old impoundment area where NAPL is
detected a good 30 feet below the land surface
there.
Our concern there would be NAPL could
potentially be transported to the Ashley River and/or
the barge canal; so, again, we want to head that off
at the path as well.
We want to mitigate the surface water and
sediment transport mechanisms that are currently
9ngoing that have apparently impacted that south
tidal marsh, and we also want to satisfy the
ecological remedial action objective that is
currently being developed right now.
Where does this lead us?
We're going to
head back out in the field approximately in March.
A. WILLIAM ROBERTS, JR., & ASSOCIATES
-------
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
42
1
The objective of this fieldwork will be basically
2
twofold, but the primary purpose of this is we're
3
going to head back out in the south tidal marsh and
4
see if we can't find the source of this lead and
5
arsenic that we've detected in the sediment and
6
We believe that
surface waters of that area.
7
material is coming from land and property formerly
owned by the fertilizer/phosphate companies there.-'
8
That's not confirmed yet, but that's our suspicion
based on an understanding of that historical area and
photographs, the samples that we've collected and a
general understanding of that fertilizer/phosphate
product.
We will determine or attempt to determine
what the source areas are during that
classification.
As I mentioned, we're also tossing
around the idea of going back out in the Ashley River
and doing some deep coring in the Ashley to see if we
can't find the extent of contamination in that area,
the volume that we're potentially looking at to
remediate.
As I .mentioned, the proposed plan public
comment period on the proposed interim remedy that
we're planning to go ahead with runs to the 21st of
February.
I would be very interested in hearing any
A. WILLIAM ROBERTS, JR., & ASSOCIATES
-------
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
43
1
written or oral comments that you all may have.
You
2
can express them here tonight to me, you can write to
3
me, you can call me, whatever is most convenient to
4
you; but I am interested in what you have to say
5
about that.
6
Following that formal comment period
7
we're going to respond to all comments received in
8
response to this summary and wrap up the formal
9
decision in what we call a Record of Decision.
'We're
hoping to be done with that by March of 1995.
We
will continue detailed design on that remedy, and we
hope to start construction on that thing by late
fall, early winter, 1995.
That's a fairly aggressive schedule, but
if we can get cooperation by all parties, there's no
reason we shouldn't.
We've had that all the way
through this proce~s, and we think, weather
permitting, of course, that we can get out there and
do that.
As I mentioned, the ecological risk
assessment is ongoing.
The idea of that whole
assessment is to develop cleanup goals for the
sediments and the surface waters and potentially
groundwater that can be protective of ecological
receptors in the area.
The results of that will be
A. WILLIAM ROBERTS, JR., & ASSOCIATES
-------
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
44
1
incorporated into the feasibility study and then we
will evaluate the volume of material that we have to
2
3
deal with at that time.
4
I hope to be back here in approximately a
5
We hope to wrap up that feasibility study late
year.
6
summer, early fall this year, and I hope to be back
7
here, like I said, in about a year with a big
8
I think it's key to understand that what -.
remedy.
9
we're proposing now is just one part of the puzzle.
It's not the entire solution, but we think we have
enough data at this point in time to go ahead with
this remedy that would address the highest risks that
we've detected at the site and we've calculated for
this site.
The big picture then, as I mentioned,
will focus on the north and south marsh, the drainage
ditches, the on-site surface and subsurface soils,
the Ashley River, the barge canal.
In general,
that's what the big picture will entail -- and also
Sburce control of the impound.
Let me sit down here and at this point
I'll turn it over to Sharon Craig real quickly if she
has anything she wants to say, and then we'll stay
around and answer questions for as long as you all
have questions.
A. WILLIAM ROBERTS, JR., & ASSOCIATES
-------
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
45
1
MS. CRAIG:
Craig has done such a good
2
job there really isn't too much for me to add but to
3
introduce myself to you again.
I was here back in
4
the end of May 1993, and I have the opportunity to be
5
here with you today and I hope to be here with you
6
when we come back in about a year.
7
This has been a very productive, busy
8
time for the EPA, the state, the trustees and.
9
I'd like to int'roduce my project manager,
Beazer.
engineering consultant, Doug SimmonS, if you want to
stand up.
A lot of the productivity, I think, is as
a result of his hard work.
We've all worked very
hard trying to reach common goals and that's been to
finish the remedial investigation in a reasonable
period of time so that we know what. the extent of the
constituents are so that we can move forward with the
engineering studies, the feasibility studies so that
we can really do what we want to do which is
remediate the site.
Beazer is totally in favor of the interim
measures; in fact, we're working with the state and
the EPA to make sure that happens as quickly as
possible.
I just want you to know that I intend to
be here for quite a while as the corporate
representative for Beazer.
If you have any questions
A. WILLIAM ROBERTS, JR., & ASSOCIATES
-------
1 -
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
46
1
for me directly, you can reach me in Pittsburgh at a
2
telephone number I'll give you, if you want to write
3
that down, or you can contact EPA, and Craig Zeller
4
will put you in touch with me.
My telephone number
5
is (412) 227-2684.
I'm busy, but I will try to get
6
back to you if you call me.
I will be happy to come
7
back to Charleston and meet with any of you, if you
8
I
so desire, to answer questions.
9
I can come. with the EPA.
That's what my
job is, so I'll be here.
Thank you.
MR. ZELLER:
You might want to mention
how Beazer became --
MS. CRAIG:
Koppers Company, Inc. that
had been the former owners of this site and treated
wood here sold the site in 1978.
In 1988 there was a
takeover by a British firm headed by Brian Beazer,
hence our new name.
We're the old Koppers Company
and all of the different industries that were owned
by Koppers were sold off except for the aggregate
which was what Mr. Beazer really wanted and ~he
liabilities and that's where I come in.
I'm one of five program managers.
I've
been with Koppers, Keystone and now Beazer for ten
years.
My father worked for the company, and I hope
to be with the company until I retire; maybe here in
A. WILLIAM ROBERTS, JR., & ASSOCIATES
-------
10
11
12
13
14
15
16
17
18
19
20.
21
22
23
24
25
47
1
Charleston, I don't know.
I like
It's a nice area.
2
the people.
I like everyone I've met.
It's been
3
productive, hard work, but I'm really looking forward
4
to moving forward on this site and seeing that we can
5
get this remediated as quickly, as painlessly but as
6
fast as we can.
Thank you very much.
7
MR. ZELLER:
Well, that kind of ends the
8
formal presentation, but if we did something too fast
9
or didn't adequately summarize it, or maybe you're
more confused than you ever thought you could be, I'm
here to straighten you out; so if you have any
questions, please ask them now.
MEMBER OF AUDIENCE:
You told us about
the cleanup site and what you're planning on doing in
the ecological area.
What about the human aspect of
it all?
Is there going to be study of the people
that live along this marsh or a health assessment of
them or what?
MR. ZELLER:
Well, we've completed the
health assessment portion of it as far as trying to
quantify what the potential risks would be based on
the exposure and duration that we talked about.
As
far as a person-by-person study, no, that's not part
of the plan at this point in time.
But we do plan on
cleaning up those sediments in the Hagood Avenue
A. WILLIAM ROBERTS, JR., & ASSOCIATES
-------
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
48
1
marsh to at least human health base standards and if
2
the ecological standards come out to be lower or more
3
. stringent, we may even go to those, particularly in
4
the ecological areas like in the marsh area itself.
5
But those areas will be cleaned up to levels deemed
6
adequately protective of human health.
That's our
7
mission.
That's what the law says we have to do.
8
MEMBER OF AUDIENCE:
Just pursuing th~s
9
question a little further, do you know if there are
any other agencies that have an interest in doing
what she suggested in terms of an actual health
assessment?
MR. ZELLER:
When we first learned about
those risks, then we were concerned about them, of
course, as we,always are when we see risks that high
or elevated in the acceptable range, so we consulted
with a liaison agency we have called the Agency for
Toxic Substances & Disease Registry, ATSDR, it's a
mouthful.
But what we were concerned about the
risks that we looked at is long-term risks.
We were
looking at exposure durations of six to 24 years to
the surface soil and sediments.
What we were worried
about is in the next year while we start our
construction and as we get under way with our
A. WILLIAM ROBERTS, JR., & ASSOCIATES
-------
10
11
12
13
14
1-5
16
17
18
19
20
21
22
23
24
25
49
1
four-step process that we're proposing, is there a
2
short-term --less than a year -- is there a short
3
term carcinogenic risk or a non-carcinogenic risk,
4
and they came back to me.
They actually looked at
5
maximum concentrations detected in those waters, not
6
a statistical average, they actually took the max,
7
and their response.to me was that there is no concern
8
for the short term for the people in that area.
9
MEMBER OF .AUDIENCE:
Given that they've
been exposed to that for -- I mean the place closed
nearly 24 -- I mean two years ago, there's a
long-term exposure which your study identifies.
MR. ZELLER:
Right.
We spoke with the
Rosemont group last night about this issue and things
we may do to stop exposures if they are happening.
There's been some discussion about posting that area
in the interim as far as please don't -- the question
we need to answer is are there people wading in those
ditches?
Are there people walking in those ditches
..
and being exposed to that material there, 'w~ether it
be surface water or sediment?
And EPA, if we're
going to err, we're going to err on the conservative
side which is why we make an exposure assumption.
The last thing we want to do is
underestimate the risks because that's an error that
A. WILLIAM ROBERTS, JR., & ASSOCIATES
-------
. 9
10
11
12
13
14
. .15
16
17
18
19
20
21
22
23
24
25
50
1
we really can't afford to make.
So what we've tried
2
to do is make some fairly conservative exposure
3
assumptions, that is, exposure assumptions were 24
4
days a year for a six-year period.
So you have to
5
ask yourself, does that actually happen?
We want to
6
be conservative, again, and based on the exposure
7
assumptions, we're going to try remediation of that
8
area and that's the way our program works.
Now, has there been a long-term exposure
up there at that plant?
Granted, it had been in
operation for a good 50 years.
That's hard for us to
answer.
I know in other sites where there has been a
big concern on that, where there's a widespread
concern about, say, lead blood levels, I've known of
those types of programs that are established where
you can come in and people can get their levels
monitored and stuff.
The thing that's hard to characterize is
that cancer, as I mentioned, the baseline risk of
'developing cancer by living on God's green Earth is
.30.
What we're calculating is an unacceptable
incremental risk, but how do you classify that?
If
your baseline risk is .30 living on God's green Earth
and then we're calculating incremental risks of, say,
.05, where4s the cause and effect?
It's hard to
A. WILLIAM ROBERTS, JR., & ASSOCIATES
-------
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
51
1
I don't know.
It could be that this gentleman
say.
2
smokes a pack of cigarettes a day.
It's
Who knows?
3
hard to predict people and we're trying to work
4
within the law as defined and stay within the EPA's
5
acceptable risk range area.
6
I have a statement.
MEMBER OF AUDIENCE:
7
I'm from the four mile area adjacent to the Rosemont
8
I stated last night in a meeting with the
community.
9
EPA that where that ditch is located, the house that
sits on the ditch, there's a young guy that died
there at a young age with cancer.
I know that you
can't blame chemicals for cancer just because of the
fact that it's in your backyard.
The first thing
you'~e going to not blame is the chemicals because
nobody is going to accept the responsibility.
This
is what we get from the EPA and actually society as a
whole.
It's just how they're geared up to believe
things.
It seems to me that if there's a chemical
in a ditch next to a house that is known to cause
cancer and someone in that house dies from cancer,
the first thing you should look at is that chemical,
not the last thing you look at is that chemical; but
this is what the Rosemont community is facing.
You
mentioned five different chemicals.
Has anyone
A. WILLIAM ROBERTS, JR., & ASSOCIATES
-------
10-
11
12
13
14
1-5
16
17
18
19
20
21
22
23
24
25
52
1
actually told the community what they've been exposed
to or what they may have been exposed to so they'll
2
3
know what to look for to know if they do have a
4
problem?
5
Our Congressmen, when they
MR. ZELLER:
6
wrote this law, that was what they envisioned of the
7
program.
8
Well, the Rosell\ont.
MEMBER OF AUDIENCE:
9
area, I'll speak on record for this, I've lived in
that area most all my life, for some 20 plus years
and the people there experience cancer-related deaths
all the time.
It's about the norm, like everybody
knows somebody who has either died in their family
from some type of cancer or a neighbor that has; so
to actually rule out affective -- like you say
chemicals haven't caused near one of those deaths, I
think it would be ludicrous, but you know, I'm not a
scientist.
I think that the community needs to be-
more enlightened on what's really going on beneath
the surface because they don't know that they're
being exposed to, chemicals right outside of the
ditch.
There's people walking on the grass where
that ditch is.
I don't say people go into the ditch,
but people walk daily where that ditch is because
it's right near a group of homes.
A. WILLIAM ROBERTS, JR., & ASSOCIATES
-------
10
11
12 '
13
14
15
16
17
18
19
20
21
22
23
24
25
53
1
MR. ZELLER:
The outreach efforts, that's
2
why we scheduled the meeting last night, to try and
3
reach them.
That's 'why we had a special info meeting
4
last night to try to reach those individuals who we
5
thought needed to be informed of these findings.
6
We're not trying to hide these findings by any means,
7
that's why we scheduled that meeting last night.
We
8
tried to address your concerns regarding surface
9
The primary pathway and the pathway that is
water.
the dominant pathway there is through that surface
water ditch.
Now, unless people are coming in
contact with the surface water and the sediments in
that ditch, you literally almost have to get in
there. We did talk last night about the potential
for high waters,and could that disperse contaminants
and what have you. We've looked at the primary
transport pathway.
We do have sediments that show a direct
nice little demarcation through that ditch and about
: to the 800,000 feet mark to that north tidal marsh.
We may breathe that.
Now, we're not worried about
airborne transport.
The pathway of concern according
to our risk assessment and that I firmly believe from
the results is that you are at risk if you have
dermal contact with that surface water.
A. WILLIAM ROBERTS, JR., & ASSOCIATES
-------
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
54
1
MEMBER OF AUDIENCE:
Isn't it hard to
2
believe that a little kid living next to a ditch with
3
a chemical in it wouldn't actually come in contact
4
with that chemical without anyone knowing?
5
Yes, we were all kids at one
MR. ZELLER:
6
We've all played in ditches.
We assumed that
time.
7
a child age one through six would play in that ditch
8
24 days a year, basic living.
9
MEMBER OF AUDIENCE:
The tests that you
did, were those samples taken from that ditch, the
shellfish, were those taken from the ditch?
MR. ZELLER:
The toxicity tests?
MEMBER OF AUDIENCE:
Yes.
MR. ZELLER:
The toxicity testing was
done more in the headwaters.
I'll show 'you.
MEMBER OF AUDIENCE:
Because that portion
of the property there, the residents crab, they catch
shrimp along that stretch of marsh because it borders
their property and this is something they've been
doing for years, you know, decades.
MR. ZELLER:
The toxic sediments that we
determined for the one test was up in this area, so
in the ditch that you're talking about -- this is
Rosemont -- and the ditch that is really a surface
ditch at this point is generally in this area.
We
A. WILLIAM ROBERTS, JR., & ASSOCIATES
-------
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
55
1
have samples.
As you can see, we had six and we had
2
a good six or seven samples in that area.
We've got
3
it covered pretty well.
We feel like we've got a
4
good handle on what's happening.
I believe there is
5
a shellfish advisory for that entire area.
That I
6
can follow up on with the state, people I work with;
7
so I can find out what that is.
8
We mentioned that yesterday, as far as-.
9
talking about posting .that and making that known.
The key issue is realizing what the exposure pathway
is.
Once you know that, let's stop it.
Let's inform
the citizens that you don't want to be doing this and
that's what you need to do to stop it.
You can tell
people that smoke cigarettes the surgeon general
warns that cigarettes could be bad for your health,
but a lot of people still do, but at least that
warning is there.
Now, that's what we want to do.
We told you that we would seriously
evaluate that.
I know that my colleagues at the
state of South Carolina are dealing with the~~
impossible right now, so --
MEMBER OF AUDIENCE:
You talked about the
screening criteria.
What is the benchmark for
acceptable levels for PAHs?
MR. ZELLER:
Well, there's two levels.
A. WILLIAM ROBERTS, JR., & ASSOCIATES
. .
-------
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
56
1
We call them environment effects range low and
2
environment effects range medium -- feel free to jump
3
in here if I'm misspeaking, Beazer people.
The way
4
they were developed, there were all kinds of studies
5
done and Dr. X, College of Charleston, will look at
6
this one species or test organism and then he or she
7
would subject this test organism to these differing
8
levels of the same conta~inant but of varying
9
degrees.
What the 50 range means is that that's the
median so at that concentration, 50 percent of the
population died, that's the median; is that right?
MEMBER OF AUDIENCE:
That's what an LT 50
is.
The ERM range is of all of the studies that were
done, 50 percent of those studies indicated toxicity
at that level.
The ERL is the 10 percent.
MR. ZELLER:
To answer the question, what
is the ERM for PAHs?
MEMBER OF AUDIENCE:
I don't know off the
top of my head.
MR. ZELLER:
I could get that for you.
MEMBER OF AUDIENCE:
And I think 44,000.
MEMBER OF AUDIENCE:
Was the average
level of contaminant found of PAHs found?
It's
usually expressed in milligrams per kilograms.
MR. ZELLER:
Yes.
A. WILLIAM ROBERTS, JR., & ASSOCIATES
-------
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
57
1
So what was the
MEMBER OF AUDIENCE:
2
level you found, if you can give me that; if not,
3
what was the worst case scenario and what was the hot
4
spot?
5
Well, the highest
MR. ZELLER:
6
concentrations we found were in the river actually
7
right adjacent to the site, and I can't, quote, pull
8
the number off, but at the end of this meeting I'l~
9
show you the actual concentrations, no problem, I've
got them right there on the map.
MEMBER OF AUDIENCE:
Well, that seems to
be -- you said the five elements that you found, the
worst contaminant that you found --
MR. ZELLER:
Well, PARs, just because of
the creosote~ yes, there was a lot of PAHs in the
sediment; for instance, in the south tidal marsh,
that number I do recall, I think it was 41,400 parts
per million or milligrams per kilogram of lead in
that sediment.
That's a lot of lead in that and the
way the common conversion is, that is 10,000 EPM is 1
percent, so that's 4.1 percent.
MEMBER OF AUDIENCE:
.1 don't know that
you're the person to ask this question to, but one of
the things .that's going on in Charleston is that the
Charleston Koppers site which is a proposed aquarium
A. WILLIAM ROBERTS, JR., & ASSOCIATES
-------
10
11
12
13
14
.15
16
17
18
19
20
21
22
23
24
25
58
1
is very similar to this site in that there was
2
creosote contaminant or PCPs and I just wondered if
3
someone from the EPA or DHEC can tell us why EPA took
4
that off their hazard ranking of priorities list when
5
in fact it appears that there's significant work to
6
be asked of Beazer to do on this site.
7
Well, Jeff could talk about
MR. ZELLER:
8
I
that, my supervisor, Jeff.
That project is also
9
under a colleague of~ine that works on that.
I
don't know if that actually is a true story, that
it's been taken off the NPL.
Or was it ever --
MR. ROGERS:
The aquarium site never was
on the list.
MEMBER OF AUDIENCE:
Was it not being
considered?
MR. ROGERS:
It was only looked at
because there was a consideration that it was
contaminated from past operations at the aquarium
site unrelated to coal gasification and those
activities did not result in enough contamination
that it would have ever ranked as an NPL site.
It
dates back to the Navy's operation or utilization of
the property during World War II and some other
things; so it was like any other site that's
identified in the country that may have
A. WILLIAM ROBERTS, JR., & ASSOCIATES
-------
10
11
12
13
14
15
16
17
18
19
59
1
contamination.
It's evaluated and at least
2
preliminarily scored to see if it has merit for
3 -
putting it on the National Priority List.
4
The thing going on over there is you do
5
have an NPL site right across the street, Calhoun
6
Park, and the contamination from that site has gone
7
over and affected those areas to some extent, mostly
8
in the subsurface groundwater, but certainly via some
9
surface migration pathways out into the shallow
intertidal sediments along the waterfront.
So what
you've got is an activity trying to deal with the NPL
site mostly concentrated as a problem over at the
Calhoun Park area with some migration over under the
aquarium property and what's going on is there's no
contamination per see
The site in and of itself
wouldn't rank.
The site doesn't become an NPL site;
the site becomes an area of contamination related to
an NPL site.
MEMBER OF AUDIENCE:
But isn't that why
20 .- ~ you added this 57 extra acres to the 42 because it
21
22
23
24
25
was adjacent and there was --
MR. ROGERS:
That technically is not part
of that official NPL site.
That's being brought in
because of commingling and contribution and any
number of other things going on as we went out there
A. WILLIAM ROBERTS, JR., & ASSOCIATES
-------
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
60
1
and looked, traced the creosote.
2
MEMBER OF AUDIENCE:
It sounded similar,
3
the migration.
4
Yes, but this property isn't
MR. ROGERS:
5
part of the NPL site either.
It's being
6
Under the NPL process, we rank a
incorporated.
7
We don't change the dimensions or
site.
8
What we do is go out afid
configuration of the site.
9
start identifying are~s of contamination related to
the operation that caused it to be a site, and we
will deal with cleanup within the area of
contamination, but it doesn't necessarily make the
other property. an NPL site.
MEMBER OF AUDIENCE:
I know that there
was a study from DHEC that they found 13,000
milligrams per kilogram of PAHs on the aquarium site
itself.
Now, whether or not that migrated, I'm not a
scientist.
MR. ROGERS:
I don't remember the
numbers.
Those pretty much are all attributable to
coming from across the street.
MEMBER OF AUDIENCE:
But I guess my
question, is there, wherever they came from --
MR. ROGERS:
And they'll be cleaned up in
relation to the Calhoun Park site.
The controversy
A. WILLIAM ROBERTS, JR., & ASSOCIATES
-------
10
1 1
12
13
14
15
16
17
18
19
20
21
22
23
24
25
61
1
right now is is it safe to build an aquarium on an
2
area that's contaminated.
Well, the nature of the
3
contamination and where it is suggests that it both
4
can exist while -- well, the aquarium can exist while
5
the cleanup is going on related to the migration and
6
the contamination over there.
7
But, again,
MEMBER OF AUDIENCE:
8
.
unfortunately we've never had this discussion about.
9
the aquarium site, so .when you're talking about
dermal contact, are you talking about people going in
and actually constructing an aquarium and the PAHs
are there?
That would be certainly my concern as a
citizen, trying to protect them from that, when in
fact that's one of the risks that you've listed.
MR. ZELLER:
Yes, that's.definitely a
risk that we evaluate.
I'm not familiar with that
risk assessment -~
MEMBER OF AUDIENCE:
Yeah, and that's
probably not fair to do but --
MR. ROGERS:
We can talk about it after
the main meeting here.
We've looked at the nature of
that construction and the fact -- and certainly the
city has looked at it more than we have -- to make
sure that in fact there would not be an undue risk
created by building it and causing any kind of
A. WILLIAM ROBERTS, JR., & ASSOCIATES
-------
1-
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
62
1
worsening of the problem and also in the process of
2
building it causing any undue exposure to the workers
3
- as it's constructed.
4
Well, I think
MEMBER OF AUDIENCE:
5
because they're putting up the sand block, is that
6
something that you envision?
7
That's very possible.
We're
MR. ZELLER:
8
9
looking at similar concentrations on the order of _.
magnitude of what you just mentioned, and they're all
similar contaminants and that's what it possibly
could be /
The big problem that comes is right now
we've been looking at elevated concentrations down to
three feet.
How deep do you have to go?
I will tell
you that if we have to go for instance 15 feet and
we've got 1,800 feet of riverfront and we dredge all
the way to the channel and you get four million cubic
yards of material and you want to treat it and your
cost is $500 million, chances are we won't spend $500
million.
We will give that to President Clinton to
:reduce the deficit but that's the type of valued
engineering that goes into this thing.
So some
possibilities exist that we may combine some response
action where we may go in and excavate three feet and
then come back over with large enough grain sizes
that aren't going to be carried away in the Ashley
A. WILLIAM ROBERTS, JR., & ASSOCIATES
-------
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
63
1
River.
2
Those are all options that will be
evaluated and the options really range from doing
nothing to doing the extraordinary which I just
described, which is dredging the entire area, not
3
4
5
6
just the contaminated material, but there are an
7
established set of criteria.
Two of them are
8
community acceptance, does the community want this-.
9
done, and state acceptance, does DHEC like this.
The
other seven are really related to costs, can it be
done, is the technology proven, does it apply to an
I
EPA regulation and other federal regulations.
There's seven of them, but I can't cite them off the
top ~f my head.
They're there, and it's a fairly
detailed process,and that's what we're ,going into
now, a feasibility detail stage and that's very
similar to what we're going to do with the soils.
We've established this protective risk
range that bracket these numbers.
Now we're going to
go in and look at ways that we can cost effectively
reduce that potential to human health risk, cost
effective as well as can we do it.
The two big issues are risk -- the one
big issue is risk reduction.
The way the Superfund
program is heading now is are you getting a large
A. WILLIAM ROBERTS, JR., & ASSOCIATES
-------
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
64
1
degree of risk reduction for the money spent.
That's
2
where we're trying to go at.
We want to get a big
3
bang for our bucks so to speak.
Those will be
4
evaluated in detail.
5
MEMBER OF AUDIENCE:
I have another
6
question.
7
Okay.
MR. ZELLER:
8
I know you said. -
MEMBER OF AUDIENCE:
9
you're going to clean up the Hagood street ditch and
last night we talked about a fence and it seemed like
that was not the thing to do, but while you're
excavating the stuff out of this ditch, this pile,
mound or something, what would happen to the soil and
sediment during the time you're working?
MR. ZELLER:
During the .time we're
working?
MEMBER OF AUDIENCE:
Yes.
MR. ZELLER:
We have to work out those
details.
The soil, we're going to either stockpile
it or treat it later or take it off site. :
MEMBER OF AUDIENCE:
That's what I was
saying.
MR. ZELLER:
If we stockpile it, we will
secure that.
We have talked about
We'll cover that.
potential locations for this thing, but I know where .0
A. WILLIAM ROBERTS, JR., & ASSOCIATES
-------
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
65
1
you're going to and we don't want to create an
2
attractive nuisance for people to come in and say,
3
wow, isn't this nice, and there's areas that we can
4
take that to stockpile and make sure it's secure; but
5
that's the type of stuff that we will evaluate in
6
this detailed design because we had a meeting today
7
with the City of Charleston and they said, hey, this
8
is real close, right across the street from our
9
You're talking about putting
maintenance garage.
this interceptor trench here, but we've got trucks
coming in and out of there all day.
You're going to
have to work with us here.
Well, we will.
Those are all concerns and issues that
we'll have to deal with during that time, during the
detail design, but those are the things and that's
why it's nice to come here and hear the concerns the
community has so that we can. effectively address
those in the upcoming months so that when we get out
there, hopefully we've done our homework and
everything goes real smoothly.
MEMBER OF AUDIENCE:
While the cleanup is
going on, or the assessment and the cleanup you
proposed, will that permit use of the site or the
surrounding sites and areas?
MR. ZELLER:
We have to work with
A. WILLIAM ROBERTS, JR., & ASSOCIATES
-------
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
66
1
existing property owners.
2
So use will
MEMBER OF AUDIENCE:
3
continue?
4
To the maximum extent
MR. ZELLER:
5
There may be -- it's tricky.
It's
possible, yes.
6
going to be tricky, but we can manage it,
7
definitely.
There's a lot of business in that area,
8
as you know.
It will be tricky, and it's going to-.
9
take some cooperation and patience by all parties
involved, but I'm sure we can get through that no
problem.
I
Anybody else?
Okay.
Well, I really do
appreciate your time.
I hope everyone has a handle
on what's going on.
We'll be here for a while.
If
you want to t,alk ~ne on one, no problem..
(The meeting was concluded at 8:30 PM.)
A. WILLIAM ROBERTS, JR., & ASSOCIATES
-------
Attachment 2
Written Comm~nts Received During
30-Day Formal Comment Period
-------
DHEC
c-nIaIon8r. Douglas E. Btyant
Department of Health and Environmental Control
2600 Bull Street. Columbia, SC 29201
Board: Richard E. Jabbour, DDS, Chairman
Robert J. Sb1pllng, Jr. Vic:e ChaIrman
Sandra J. Molander, Secretary
John H. Burriss
William M. Hull, Jr. MD
Roger L8ek8, Jr.
Bumet R Maybenk, III
Promoting Health, ProfeCtlng the Environment
February 7, 1995
Craig Zeller
Remedial Project Manager
U.S. EPA, Region IV
345 Courtland Street
Atlanta, GA 30365
RE:
Final R1 Report for the Koppers Site
Dear Mr. Zeller:
The Final R1 Report has been reviewed as requested. I am of the understanding that the RI Report
has been approved by the EPA as being final and is in the depository. Therefore, the State offers
these comments to be included in the Administrative Record for this site. Attached are additional
comments from our Hydrogeologist. Billy Britton. for this site.
The majority of our comments in my December 14, 1994 letter to you on the revised RI Report
have not been addressed. Overall, the RI Report does a good job of presenting the massive
amount of data and conclusions. The conclusion and recommendations section is a major
improvement and for the most part we are in agreement with those conclusions and
recommendations. However. we feel that there are significant areas that have not been resolved to
our satisfaction.
One main problem that the State has with the RI Report is the fact that the "Dead Zone" in the
South Marsh is not discussed in detail in the final report. This comment has been presented to the
EP A from both Billy Britton and myself of DHEC and Jane Settle of DNR on the draft RI, revised
RI, and no..\' the fina! RI Reports. The dead zonc is not speci!'icaliy melitiond in the RI Report,
which only presents the data from this area and does not describe it in detail. This area is of major
ecological concern to both DHEC and DNR. Therefore, we feel that the dead zone should be
discussed and a hypothesis presented for its occurrence in the RI Report.
Another area of concern. commented on by both Billy Britton and myself, is the test pit
excavations done in the former Koppers Treatment Area. The text states that a black liquid was
not discovered' in these pits. I agree that initially these pits did not reveal the creosote or black
liquid when first excavated. However. these pits were left open for a period of time and the
creosote liquid did leach into the pits at a slow rat~. This condition was observed by DHEC and
EP A personnel on site. Th~ text as currently written is misleading and should be changed to reflect.
the actual conditions.
--
'"" '~cycled pap~'
-------
Page 2
Mr. Craig Zeller
Final RI for Koppers
February 7, 1995
I have requested in previous comments that a figure showing a "blow-up" view of the Braswell
Street drainage ditch in the area of the Old Impoundment be included in the RI Report. The figure
should show where the orginal ditch was discovered in the RI, the current ditch, old
impoundment, and where aerial photographs show connection to the impoundment. This figure
would be helpful to the reader to get an understanding of the drainage pathway past and present.
A few other minor comments of mine were not addressed in addition to the one mentioned
previously. Therefore based on these comments and the attached comments, the State does not
approve of the RI Report. If you have any questions, please call me at (803) 896-4070.
z-----
cc:
Billy Britton
Gary Stewart
-------
DlfEC
CommIuIoner. Douglas E. Bryant
Depanment 01 Health and Environmental Control
2600 Bull Street. Columbia, SC 29201
Board: Richard E. Jabbour. DDS. Chairman
Robert J. Stripling. Jr., Vice Chairman
Sandra J. Molander. Secretary
John H. Burriss
William M. Hull. Jr. MD
Roger Leaks. Jr.
Burnet R. Maybank. III
Promoting Health. Protecting the Environment
MEMORANDUM
TO:
Richard Haynes, Engineer
Site Engineering Section
Division of Site Engineering and Screening
Bureau of Solid and Hazardous Waste Management
FROM:
Billy Britton, Hydrologist 11-0
Superfund Section
Division of Hydrogeology
Bureau of Solid and Hazardous Waste Management
DATE:
February 6, 1995
RE:
Final Remedial Investigation Report
Koppers-Charfeston NPL Site
SCD 980 310 239
Charleston County
The referenced document was reviewed by the Division of Hydrogeology (Division), as
requested. As a result of this review, it is apparent that the Potentially Responsible Party failed
to address eight of the twelve comments included in the memorandum from Britton to Haynes
dated December 14, 1994 regarding the Revised Remedial Investigation report. The writer is
not satisfied with the report as currently written, and, as a result, will reiterate each comment
that haS not been addressed for the Administrative Record that will be kept on this site. The
Division's comments are provided below. One additional comment (comment #9) is also
included in this memorandum.
1)
The third paragraph on page 2-7 discusses the test pits excavated in the vicinity of the
aeration reservoir in the former Koppers Treatment Area during Phase II of the remedial
investigation (RI). In the discussion, the text states that test pits TP-07 A through TP-
07G were excavated in an effort to located a black liquid encountered during a previous
response action undertaken in 1985. The text notes that no black liquid was encountered
in test pit TP-07 A, but it fails to note that a black liquid with the odor of creosote was
encountered in test pits TP-07C through TP-07G. Revise the text to reflect that the black
liquid was encountered in the vicinity of the aeration reservoir. This comment has been
made on each of the three versions of this document.
2)
Section 2.3.4 on page 2.8 discusses the investigation of an underground concrete
Sf'9j()()94. ~
o f"cycl"d PlIPt!f
-------
Richard Haynes
February 6, 1995
Page 2
structure located adjacent to the former Koppers Treatment Area. The structure was
determined to contain from three inches to four feet of non-aqueous phase liquid
(NAPL). This structure contains NAPL and should be included in the discussions of
NAPL sources that take place later in this document. This comment has been made on
each of the three versions of this documem.
3)
Figures 3-16, 3-17, 3-20, 3-21, 3-22, and 3-23 plot the drawdown produced in the
observation wells over the duration of the pumping test conducted during Phase II of the
RI. In each of these time versus drawdown plots a boundary effect is apparent. What
is this boundary effect attributed to? The Rl Report did not include any explanation of
boundary effects. This comment was made previously on the Revised RI Report.
4)
Section 4.12.1 fails to mention that volatile organic compounds (VOCs) were detected
in and north of the Former Treatment Area at concentrations above SDW A MCLs. This
oversight should be corrected. This comment was made previously on the Revised RI
Report. .
5)
Section 4.12.3 describes the results of the RI in the Drip Track Area. However, the
results from samples collected from the eastern portion of the Drip Track Area, are not
discussed in Section 4.12.3. Instead, the eastern portion of the Drip Track Area is
included in Section 4.12.1 which discusses the Former Treatment Area. The eastern
portion of the Drip Track Area should be discussed in Section 4.12.3. It is more
appropriate. This comment was made previously on the Revised RI Report.
6)
Figures depicting total VOCs and total semi-volatile organic compound.s (SVOCs) would
be useful in addition to the figures currently presented in Section 4. This comment was
made previously on the Revised Rl Report.
7)
Section 5.2.2.3 on Page 5-11 states that it is unlikely that there are large amounts of
creosote migrating through the subsurface because creosote is only slightly denser than
water and has a moderate interfacial tension, the geology of the site is heterogeneous,
and there is a lack of significant accumulations of creosote. The Division disagrees with
this statement for the following reason. Large amounts of creosote have already
migrated onto two properties located north of Milford Street, and there is no evidence
to support the conclusion that the creosote has stopped migrating. This comment was
made previously on the Revised RI Report.
8)
The area of dead vegetation located in the South Marsh is discussed very little in the
report and no hypothesis is proposed to explain its occurrence. This area should be
discussed further in Section 4. An adequate discussion of this area should include a
suspected cause and a probable source for the dead vegetation. .
SF9$()()96. WEB
-------
Richard Haynes
February 6, 1995
Page 3
9)
The discussion located at the top of page ES-lO states that because of the salinity of the
groundwater in the vicinity of the land between the south tidal marsh and the barge canal
groundwater in this area will not require remediation. The writer wishes to clear up any
misunderstandings which may have occurred regarding the classification of groundwater
in the south tidal marsh or, for that matter, any portion of the site where concentrations
of total dissolved solids exceed 10,000 parts per million. As stated in Regulation 61-68,
Water Classifications and Standards, all groundwaters of the stat~ are classified as Class
GB untii reclassified through proper administrative procedures. Therefore, the quality
standards for Class GB ground waters set forth in the State Primary Drinking Water
Regulations, R.61-58.5 must be enforced. However, the Potentially Responsible Party
can petition the Department to reclassify groundwater in the portion of the site where the
concentration of total dissolved solids exceeds 10,000 parts per million. The writer will
make every effort to provide assistance in this matter.
smOO96. ~B
-------
---
BEAZER EAST, INC., 436 SEVENTH A VENUE, PITTSBURGH, PA 15219
VIA FEDERAL EXPRESS
20 February 1995
Mr. Craig Zeller
Remedial Project Manager
U. S. Environmental Protection Agency - Region IV
345 Courtland Street, NE
Atlanta, GA 30365
Dear Mr. Zeller:
Beazer East, Inc. (Beazer) appreciates the opportunity to comment on the Interim Remedial
Action approach and the Human Health Baseline Risk Assessment (BRA) for the Kopper Co.,
Inc. (Charleston Plant) Site. .
Interim Remedial Action
As a primary participant in developing the Interim Remedial Action approach, Beazer East Inc.
(Beazer) fully endorses and supports the proposed work. The Interim Remedial Action is a
significant step towards final clean-up of the site. Beazer believes that the Fact Sheet accurately
reflects the site conditions and general aspects of the Interim Remedial Action. However, some
issues bear further clarification and emphasis. .
The Interim Remedial Action is anticipated to be consistent with, and a major part of, the final
remedy for the former treatment area. The need to provide permanent remedies was a
fundamental consideration when developing the Interim Remedial Action. Reconstruction and
lining of the Milford Street and Hagood A venue ditches will permanently eliminate the potential
for contact with constituents of concern in the ditches. The proposed interceptor trench will
provide positive control of groundwater and nonaqueous phase liquids as well as providing
removal and treatment of nonaqueous phase liquids and dissolved phase constituents in
groundwater. Beazer requests that the Environmental Protection Agency, Region I (EP A) and
the South Carolina Department of Health & Environmental Control (SCHDEC) acknowledge that
this Interim Remedial Action is likely to be an important part of the final remedy for the former
treatment area.
-------
Mr. Craig Zeller
20 February 1995
Page 2
The Fact Sheet accurately reflects the goals and conceptual design of the Interim Remedial
Action. The need for minor changes in the design may become necessary during the detailed
design work. The North Charleston Sewer District is stated as the discharge point for treated
groundwater in the fact sheet. While this is the preferred option at this time and Beazer is
actively pursuing this option, final approval has not yet been received. Beazer requests the
flexibility to propose other appropriate discharge options. Other minor design changes may also
be proposed. For example, the location of the collection sump for the interceptor trench may
be moved from the east end of the trench to the west end of the trench. This change is being
considered to reduce the length of transfer lines required to convey water to the treatment plant.
None of the design changes under consideration fundamentally change the goals or expected
performance of the Interim Remedial Action. Design documents for the Interim Remedial
Action will be submitted for regulatory review.
In order to implement the Interim Remedial Action as quickly as possible, assistance from EPA
and SCDHEC in streamlining the design review and permitting processes is requested. Beazer
looks forward to working with the EP A and SCDHEC on implementation of this important
project.
Human Health Baseline Risk Assessment
Beazer has reviewed the Human Health Baseline Risk Assessment (BRA) for the Koppers
Company, Inc. (Charleston Plant). Beazer is concerned about the limited discussion of the
potential risks presented in the BRA. As pointed out in a revised Uncertainty and Limitations
Section (attached to. this letter) that includes a semi-quantitative analysis of the uncertainty
surrounding the estimates of potential risks shown in the BRA, potential risks to typical workers
and typical offsite residents will be substantially lower than those for the reasonable maximum
exposures (RME) shown in the BRA. One reason for this overestimation is that the RME
assumptions are designed to significantly overestimate potential risk and are thus not intended
to be representative of the potential risks of typical people. Another reason is that exposure
pathways, such as potable use of shallow groundwater, were included in the BRA, even though
they never occur.
Beazer believes a thorough discussion of potential exposures of the typical worker and offsite
resident is critically important in helping the public put into perspective the RME risks estimated
in the BRA. Beazer is very concerned that the BRA does not provide an accurate and
representative description of potential typical risks at this site, and how they differ from the
RME exposures presented in the document.
-------
1-
Mr. Craig Zeller
20 February 1995
Page 3
Beazer appreciates the opportunity to submit these comments in the IRM and the BRA and is
willing to discuss our findings with you at your convenience.
Very truly yours,
0~/{' 7f-vD
Shannon K. Craig
Program Manager - Environmental Group
SKC/avb
Attachment
cc:
Paul D. Anderson ( with enclosures)
Donald C. Bluedorn II, Esquire (with enclosures)
Billie S. Flaherty, Esquire (with enclosures)
John E. Frey, Esquire (with enclosures)
Douglas E. Simmons (with enclosures)
Robert E. Stepp, Esquire (with enclosures)
Elizabeth H. Warner, Esquire (with enclosures)
-------
7.0 Uncertainties and Limitations
7. ,
Introduction
One of the principal objectives of the uncertainty analysis is to discuss the assumptions and
procedures that introduce the greatest amount of uncertainty into the results of the baseline
risk assessment (BRA). Another principal objective is to assess, quantitatively if possible, the
contribution of these assumptions and procedures to the overestimation or underestimation of
potential risk.
The uncertainty surrounding the estimates of potential risk at this site can be viewed as arising
from four general areas. These parallel the four steps of the risk assessment process and are
discussed below:
.
Data evaluation;
Selection of exposure pathways and input parameters;
Derivation and selection of toxicity parameters; and,
Procedures used to estimate potential risk.
.
.
.
The uncertainty analysis presented in the this section is primarily qualitative although for
several of the key potential receptors (current on-site worker, trespasser, current utility
worker and current off-site resident) a semi-quantitative analysis of the uncertainty
surrounding their potential exposure is presented.
7.2 Data Evaluation
The purpose of data evaluation is to determine which constituents, if any, are present at the site
at concentrations requiring further investigation. Uncertainty with respect to data evaluation
can arise from many sources, such as the quality of the data used to characterize the site, the
process used to select data to use in the risk assessment, and the statistical treatment of data.
Typically, the data evaluation process includes data gathered during site-wide sampling of all
environmental media at a site.
At the former Koppers site, surface and subsurface soil, sediment, surface water, and
groundwater were analyzed in two phases of sampling. Phase I data for all constituents and
Phase II dioxin data were used as the basis of the baseline risk assessment.
The sampling plan was designed to provide sufficient samples in all media to result in a high
level of confidence in the representativeness of the data set. Given the number of samples in the
data set for all media and the spatial distribution of the samples taken, it is likely that most, if
not all, constituents present in environmental media at the site were detected during sampling.
However, despite extensive sampling and analysis, it is possible, although not likely, that. .
constituents present at the site were not detected in analyses. This possibility introduces some
uncertainty into the BRA. For a constituent to be present but not de~ected at the site, at least one
of two conditions would need to be true. Either the constituent would need to be present in so few
1
-------
locations that the extensive sampling conducted at the site missed these locations, or the
constituent would need to be present at a concentration too low to be detected. If either (or both)
of these two conditions were true, the constituent would likely not fulfill the frequency of
detection or concentration criteria used to select constituents of potential concern in the
baseline nsk assessment.
7.2.7 COPC Selection Process
The screening process used to select COPCS to evaluate in the BRA was intended to include all
constituents with concentrations high enough to be of concern for the protection of public health.
Given that the screening procedure compared the maximum constituent concentration to
screening criteria, it is unlikely constituents posing a potential public health concern have been
excluded from the BRA. Quite the opposite is likely to be the case: many of the constituents
included in the BRA are not likely to pose a potential concern to public health. The results of the
BRA demonstrate that the screening procedure used was sufficiently conservative,so that
potential sources of public health threats were not overlooked.
7.2.2 Estimation of Exposure Point Concentrations
The primary sources of uncertainty associated with estimating exposure point concentrations
(EPCs) involve the biased nature of some of the sampling conducted at the site and the statistical
techniques used to summarize the data.
The sampling bias arises because sampling at the site was not conducted in a random fashion.
Rather, more samples were taken from areas where, a priori, higher constituent concentrations
were expected to occur. This often leads to overestimates of actual EPCs and overestimation of
potential exposures and risks. To account for this bias in soil sampling, the BRA employed a
"nearest neighbor" approach, in which weighted average concentrations were used to calculate
EPCs in soil. The weighting procedure treats all locations equally, whether the location is
represented by one sample or several. This procedure reduces some of the potential to
overestimate EPCs due to the biased sampling conducted at the site.
The second important source of uncertainty involves the statistical methods used to estimate
EPCs and the assumptions inherent in these statistical methods. Generally, an upper bound
estimate of the mean concentration is used to represent the EPC instead of the measured mean
concentration. This is done to account for the possibility that the true mean is higher than the
measured mean because unsampled areas of the site may have higher constituent concentrations.
Ninety-five percent upper confidence limit (UCL) concentrations were calculated in the
baseline risk assessment using the H-statistic. Exposure point concentrations were assumed to
equal the 95% UCL, or the maximum detected concentration in cases where the calculated UCL
exceeded the maximum.
The UCL calculation assumes constituent concentrations are randomly distributed, that we have
no knowledge about the causes of their distribution, and that there is a 95% chance that the
actual mean concentration is lower than the calculated UCL concentration. The assumption that
concentrations are randomly distributed means that it is possible uoncentrations higher than
those previously found may exist on the site. Moreover, because the H-statistic assumes a
2
-------
lognormal distribution, the higher concentrations could be substantially greater than those
detected to date. Given the available knowledge about the historical operations at the site, about
the sources of constituents detected at the site, and about the distribution of constituents at the
site confirmed by the Phase I and II data, these assumptions are likely false.
An example of this is provided by UCL concentrations calculated using the H-statistic which
exceed the maximum detected concentration by a substantial margin and are, for some
constituents, predicted to be greater than one part per part. These anomalous results likely
occur because the statistical technique assumes much higher concentrations than those detected
could exist when they actually do not. In most cases, the locations with highest concentrations
were identified and detected during sampling, based on information about the sources of
constituents at the site. Given that distributions of constituents at the site are well
characterized by site investigation data, it may be more appropriate to use alternative
procedures to estimate EPCs, such as further subdivision of the site into areas of roughly
similar concentrations or use of a weighted mean concentration to calculate EPCs.
Because the assumptions upon which the procedures used in the BRA to calculate EPCs do not
hold at this site, the calculated EPCs represent concentrations that are greater than 95% UCLs.
In other words, the chance that the actual mean is less than the EPC is greater than 95 percent.
Consequently, potential exposures and risks at this site, if any, are likely to be overestimated
by the EPCs used in the BRA.
7.2.3 Uncertainty Associated with Dioxin EPC
The treatment of dioxin data at this site introduces an additional measure of uncertainty into the
BRA. For constituents other than dioxin, samples were taken from all relevant environmental
media from all portions of the site. Because dioxin sampling is costly, however, dioxin samples
were taken primarily from areas in which dioxin was anticipated to occur. Such areas were
identified based on knowledge of historical industrial activities at the site. In particular, the
areas where pentachlorophenol had been used or stored. When the biased dioxin data is evaluated
using the same approach as for other constituents, the resulting EPC is biased upwards, in
comparison to other constituents, because sampling was not conducted in a random manner and
few samples were available from locations where dioxin was not expected to be found.
As a result of the statistical procedures employed in the baseline risk assessment, the EPC used
to represent dioxin in surface soil from Zone A is the maximum detected concentration (20
ug/kg) obtained from a location expected to have an elevated dioxin concentration. Locations
having lower concentrations of dioxin are not accounted for resulting in an overestimate of the
actual concentration of dioxin in Zone A surface soil. This in turn leads to an overestimate of
receptors' potential exposures and subsequent potential risk, if any, provided that receptors do
not preferentially contact the small portion of Zone A assumed to have this maximum
concentration. Available information about the site indicates that current workers in Zone A
have little, if any, contact with surface soil. Moreover, no evidence exists suggesting current
workers in this zone would preferentially contact soil from this particular portion of Zone A.
In order to develop a more realistic concentration in Zone A, a weighted average dioxin
3
-------
1-
concentration in Zone A surface soil was derived based on several factors, including actual
detected levels of dioxin, the magnitude of detected concentrations of pentachlorophenol and their
proximity to detected dioxin concentrations, and historical information about the site. As stated
above, it was anticipated that elevated concentrations of dioxin may be present in locations
where pentachlorophenol was formerly used.
Based on this information, Zone A was divided into three concentric rings. The innermost ring
represents locations where pentachlorophenol and, therefore, dioxin, concentrations were
expected to be highest, given available knowledge about historical operations at the site. This
ring includes the locations where the maximum concentrations for both dioxin (20 ug/kg) and
pentachlorophenol (460,000 ug/kg) were detected. The maximum detected dioxin
concentration was used to represent the innermost ring. The middle ring represents areas
where pentachlorophenol and dioxin were detected at intermediate concentrations. Dioxin was
detected in this ring at concentrations of 6, 7.5, and 8 ug/kg (duplicates were averaged at one
location). The middle ring also includes pentachlorophenol concentrations ranging from 4,700
to 12,000 ug/kg. As a conservative measure, a concentration of 8 ug/kg was selected to
represent the middle ring. The outermost ring represents areas where dioxin concentrations
were expected to be equal to the lowest concentration detected on-site. Dioxin was detected in
one sample in the outermost ring at 0.7 ug/kg. At locations other than Zone A, dioxin was
detected at concentrations of 0.8 ug/kg (Zone C) and 0.004 ug/kg (off-site). A qmservative
estimate of concentration of 1 ug/kg was used to represent the outermost ring in Zone A.
The concentration of dioxin in Zone A surface soil was determined by combining the
representative concentrations from each of the three rings within the zone on an area weighted
basis. The innermost ring, with the highest dioxin concentrations, was assumed to comprise 5%
of the area within Zone A, the middle ring, with intermediate dioxin concentrations, comprised
20% of Zone A, and the outer ring, with the lowest dioxin concentrations, comprised 75% of
Zone A. Making these assumptions, the resulting Zone A surface soil dioxin concentration was
estimated to be 3.35 ug/kg. This concentration is 6-fold lower than the EPC of 20 ug/kg, equal
to the maximum detected concentration, used in the BRA to represent the entire zone. This
suggest that potential exposures and risks, if any, associated with receptors contacting dioxin in
Zone A surface soils may be about six times lower than estimated by the BRA, because of how the
dioxin EPC was calculated.
7.3
Exposure Pathways and Input Parameters
The BRA employed several exposure scenarios including those associated with the site as it is at
present and several future scenarios. The future scenarios included the site remaining
industrial/commercial, having a hypothetical marina developed on the site, and being developed
for residential use. Within each of these scenarios, several pathways were investigated
generally including ingestion of and dermal contact with soils, sediments and surface waters.
Some of the scenarios included consumption of fish from the Ashley River and consumption of
groundwater.
4
-------
7.3.7 Selection of Exposure Scenarios and Pathways
A comprehensive conceptual model of the site was developed in the BRA. This identified the
possible current and future exposure scenarios and the primary exposure pathways within each
scenario. The BRA estimated potential risks associated with these scenarios even though several
of them (future residential development and future marina development) are very unlikely to
ever happen at this site given current and predicted land use. Similarly, consumption of
groundwater is also almost certain to never occur at this site given the quality of the
groundwater and the availability of a public water supply. To the extent the potential risk
associated with these unlikely hypothetical future scenarios and pathways were estimated using
default assumptions, the potential risks associated with the site have been overestimated.
Default assumptions were also employed by the BRA to estimate potential risks to future on-site
commercial and utility workers. The default assumptions are designed to overestimate potential
risk. Site-specific information about current workers indicates that their potential exposures
are substantially lower than would be predicted by standard default assumptions. To the extent
future on-site and utility workers are similar to current on-site and utility workers, their
potential exposures and risks, if any, have been overestimated by the default assumptions
employed in the BRA.
7.3.2 Selection of Exposure Parameters
The assumptions used to estimate the potential exposure to COPC can be surrounded by a great
deal of uncertainty either because limited information about a particular exposure parameter is
available or the parameter varies between people. Typically when limited information is
available, a conservative (Le. health protective) estimate of the parameter is employed. This
leads to an overestimate of potential exposure, and ultimately of potential risk. This may be
appropriate, however, to assure risk managers charged with protecting the public's health that
actual risks are not underestimated. One consequence of making conservative assumptions is
that the potential exposure of a typical person can be overestimated and that the estimates of
potential exposure presented in a risk assessment are not representative of a typical person.
In many cases it is possible to develop at least a semi-quantitative estimate of the degree to
which a typical person's potential exposure is overestimated. The selection of an upper bound
for an exposure parameter implies that sufficient information is available to determine what
values of the parameter overestimate exposure, what values underestimate exposure and what
values represent typical exposures. This range of values can be based upon professional
judgement, site-specific information, or generic information collected from the literature.
For this site, the degree to which the potential exposure of typical individuals is overestimated
by the BRA is evaluated for four current receptors: on-site worker; utility worker;
trespasser; and, off-site resident child. The evaluation is performed by estimating the
difference between the value used in the risk assessment and the value assumed to represent a
typical receptor for each ,of the exposure parameters that determines potential exposure.
Tables 7-1 to 7-4 present a summary of the following: range; typical value; value used in the
risk assessment; basis for the selection of the risk assessment value; and the difference between
the values, for each parameter used to estimate potential exposure. The typical value
5
-------
represents either the average of data used to define a particular parameter (for example, in
estimating COPC concentration, or soil ingestion rate) or a value that is assumed to represent a
typical receptor (for example, the exposure frequency, or the amount of skin exposed to
sediment, water or soil).
By comparing the typical value to the value used in the risk assessment, the difference between
the two can be determined, as can the degree to which a particular parameter contributes to
either an over- or underestimate of potential exposure. Thus, for the on-site worker, the soil
ingestion rate used in the risk assessment overestimates soil ingestion of a typical worker by
about '.25-fold (Table 7-'). Combining the differences of all the parameters for a particular
receptor leads to an estimate of the degree to which the receptor's potential exposure is over-
or underestimated by the assumptions used in the risk assessment. For the on-site worker in
Zone A, the potential exposure to dioxin via soil ingestion to a typical worker is about 275 times
lower than estimated in the BRA and potential dermal exposures are about 865 times lower than
estimated in the BRA (Table 7-') suggesting that the typical risks to on-site workers are
likely to be less than one in one million. Parallel comparisons for cPAH, arsenic and
pentachlorophenol indicate that a typical current worker's potential risks from these COPC in
Zone A surface soil are also several hundred fold lower than estimated in the BRA (Table 7-')
and likely to be less than one in one million.
When potential exposure of other current receptors (utility worker and trespasser) to COPC in
surface soils using "typical" constituent concentrations and exposure parameters, the findings
are similar to those discussed above. The potential exposures, and therefore also the potential
risks, are likely to be several hundred fold lower than estimated in the BRA and are likely to be
less than one in one million for most CO PC (Tables 7-2 and 7-3).
The results of such comparisons for potential surface water and sediment exposures also
indicate that the typical receptor is likely to have substantially smaller exposures to COPC than
estimated in the BRA. (The magnitude will depend upon the mean sediment and
surface water concentrations provided by Black and Veatch. Until those are
available it is not possible to determine whether the potential risks from COPC
in sediment and surface water to the typical receptor just a little or
substantially lower than the RME estimates in shown in the BRA.)
While the risk assessment overestimates the potential risk to the typical or average receptor, it
is important to point out that potential risk is determined by an individual's specific behaviors
and characteristics. As shown in Tables 7-' through 7-5, behaviors which lead to greater
potential exposure than estimated in the risk assessment are possible. This makes it possible
that some receptors may have potential exposures greater than those estimated in the risk
assessment. This will only occur if all of the characteristics of the receptor lead to exposures
that are equal to, or greater than, those used in the risk assessment. While theoretically
possible, this is unlikely to occur. In general, the exposure assumptions lead to an overestimate
of potential risk.
(Note the differences between typical and RME receptor' exposure assume the
site-specifc information developed (on worker exposure frequency and duration
and dioxin concentration in Zone A soils) by Beazer and provided to EPA will be
6
-------
employed in the BRA. If not, then the magnitude of overestimation will be
larger than indicated by the discussion above.)
7.3..3 Definition of Exposure Zones
In order to estimate a receptor's potential exposure at a site, it is necessary to determine the
geographical location where the receptor is assumed to be exposed. Once the area of interest has
been defined, the appropriate data can be selected and the exposure point concentration can be
calculated. Ideally, areas of exposure should be defined based on actual exposures or known
behaviors of receptors at the site. Often, however, this information is unavailable. Lacking
absolute knowledge about the activities that occur at the site or about behaviors of receptors at
or near the site, it is necessary to make some assumptions. Such assumptions add to the
uncertainty in the baseline risk assessment.
At the former Koppers site, knowledge about the historical activities that occurred at the site
was used to define the exposure areas evaluated in the baseline risk assessment. Potential
exposure to soil was evaluated in three on-site zones, corresponding to former industrial
activities at the site. Zone A represents the portion of the site where wood treating operations
took place, Zone B represents the portion of the site where raw wood was stored prior to being
treated, and Zone C represents the portion of the site where treated wood was stored prior to
shipping. Using available information about historical activities at the site to evaluate potential
exposure to soil (particularly in Zones A and B) reduces some of the uncertainty associated with
breaking up the site into exp.osure areas. Zone C, however, is a very large area and encompasses
not only portions of the site formerly used for treated wood storage but also for industrial
activities unrelated to Koppers or woodtreating. Because of the size of Zone C and the variety of
current and historical industrial operations that have occurred there, the potential for
exposure to soil is not consistent among portions within Zone C. The variability in both
constituent concentrations and the potential for exposure in Zone C, in comparison to Zones A
and B, results in additional uncertainty relating to the exposures and risks estimated for this
zone.
Surface water and sediment were evaluated at the site in Zones A, B, C, and D. Zone A comprises
the ditch along Hagood Avenue north of the site, Zone B includes on-site surface water' and
sediment locations not including portions proximal to the Ashley River, Zone C comprises on-
site surface water and sediment locations proximal to the Ashley River, and Zone D includes
surface water and sediment locations in the Ashley River. Zones Band C are very large areas,
each encompassing several distinct areas of surface water and sediment. For example, Zone C
includes surface water locations on-site as well as in the marsh areas north and south of the
site. As described above for soil zones, it is likely such large zones include widely diverse
constituent concentrations and potentials for exposure. This approach introduces some
uncertainty into the risk assessment.
7.4 Toxicity Assessment
The BRA evaluated both noncarcinogenic (assumed to have a threshold) and carcinogenic
7
-------
(assumed to be without a threshold) health effects. EPA has derived reference doses (RIDs) for
the evaluation of potential noncarcinogenic effects and cancer slope factors (CSFs) for the
evaluation of potential carcinogenic effects. Two of the most important sources of uncertainty in
dose-response assessment include animal-to-human extrapolation and high-to-Iow dose
extrapolation.
7.4.1 Animal-to-Human Extrapolation
Ideally, human data sets would be used to derive dose-response factors used in the BRA,
however, such data sets are often unavailable. For many constituents, animal studies provide
the only reliable information on which to base an estimate of adverse health effects.
Extrapolating animal data to humans introduces a great deal of uncertainty into the risk
assessment. This uncertainty can be reduced if the fate of and mechanism by which a constituent
causes adverse effects is known in both animals and humans. When the fate and mechanism are
unknown, uncertainty increases. To account for this uncertainty, conservative assumptions are
made and uncertainty factors are incorporated in deriving noncarcinogenic dose-response
factors. Uncertainty factors are used to account for uncertainty in extrapolating both from
animals to humans and from the subchronic exposures often used in laboratory experiments to
chronic exposures, and to protect sensitive members of the population. The effect of these
assumptions is that overestimation of potential health effects in humans is far mpre likely than
underestimation.
Lacking knowledge about a constituent's fate in humans, it is possible that an effect not revealed
in an animal experiment will manifest itself in humans. In this case, the dose-response factor
can underestimate potential health effects in humans. On the other hand, effects observed in
animal experiments may not be observed in humans, resulting in an overestimate of the
potential health effects in humans.
7.4.2 High-to-Low Dose Extrapolation
The concentration of constituents to which people are potentially exposed at CERCLA sites is
usually much lower than the levels used in the studies from which dose-response relationships
are developed. Estimating potential health effects at such sites, therefore, requires the use of
models that allow extrapolation of health effects from high experimental to low environmental
doses. These models contain assumptions that may introduce a large amount of uncertainty.
For instance, the EPA CSFs are derived using the upper 95% confidence limit of the slope
predicted by the linearized multistage model. EPA recognizes that this method produces
conservative risk estimates and that other mathematical models exist. Several dose-response
models are available for low-dose extrapolation. These include the probit, the multi-hit, the
logit, and the multistage models. These models are generally statistical in character and have
little biological basis. Int he Guidelines for Carcinogen Risk Assessment, EPA states:
No single mathematical procedure is recognized as the most appropriate for low-dose
extrapolation in carcinogenesis. When relevant biological evidence on mechanism of
action exists (e.g. pharmacokinetics or target organ dose), the models or procedures
employed would be consistent with the evidence. When data and information are limited,
8
-------
however, and when much uncertainty exists regarding the mechanism of carcinogenic
action, models or procedures that incorporate low-dose linearity are preferred when
compatible with the limited information.
EPA policy is to use the linearized multistage model unless there is adequate scientific
justification for using another model. Many countries and some U.S scientists have determined
that such justification exists for dioxin.
EPA emphasizes in the guidelines that the upper-bound estimate generated by the linearized
multistage model leads to a plausible upper limit to the risk that is consistent with some
proposed mechanisms of carcinogenesis. Such an estimate, however, does not give a realistic
prediction of the risk. The true risk is unknown and may be as low as zero.
7.5
Risk Characterization
In the risk characterization, the estimated potential exposures are combined with the assumed
dose-response information to estimate the potential for adverse human health effects to occur.
Two important sources of uncertainty associated with this step of the risk assessment process
are potential exposure to multiple constituents and the combination of upper~bound exposure
and toxicity estimates.
7.5.7 Exposure to Multiple Constituents
Each complete exposure pathway has associated with it, potential risks from several
constituents. USEPA guidance requires that each receptor's total potential carcinogenic risk be
estimated by combining the potential risk from each constituent and pathway of interest for that
receptor unless there is reason to believe the constituents interact synergistically or
antagonistically. For virtually all combinations of constituents, little or no evidence of
interaction is available. Therefore, it is not clear whether the assumption of additivity leads to
an over- or underestimate of potential risk.
For noncarcinogens, USEPA recommends summing hazard indices only for those constituents
with similar toxic endpoints. The toxic endpoint is defined as the most sensitive
noncarcinogenic health effect used to derive the dose-response value. As a screening step in this
baseline risk assessment, all hazard indices for a receptor have been summed, regardless of the
toxic endpoint of the constituents. This approach will overestimate" potential risk for some
groups of constituents, because mechanisms of action and toxic endpoints in the human body may
differ for certain constituents. If the sum of all hazard indices for a receptor is less than one, it
is not necessary to perform a toxic endpoint-specific analysis. If, however, the total hazard
index for a receptor exceeds one, such an analysis should be conducted. As shown in Table 5-3,
hazard indices for several receptors exceed one. In many cases, the hazard indices for the
individual COPC themselves exceed one. In other cases, however, a toxic endpoint-specific
analysis would reduce some of the uncertainty associated with the estimated noncarcinogenic
risks.
7.5.2 Combination of Several Upper-Bound Assumption's
9
-------
Generally, the goal of a baseline risk assessment is to estimate the potential risk associated with
Reasonable Maximum Exposures. USEPA guidance describes Reasonable Maximum Exposures as
lying between the 90th and 99th percentiles of the distribution of potential risk. Many of the
assumptions used in the BRA, by themselves, describe behaviors or characteristics that would
. lead to conservative but not unreasonable estimates of potential risk, and would likely fall
within the range USEPA has defined as representing Reasonable Maximum Exposures. When
several conservative assumptions are combined, however, the result in many cases is an
estimate of potential risk that falls above the range of risk defined as Reasonable Maximum
Exposure. This is likely the case for many of the receptors evaluated in the BRA.
This is best illustrated by a simple example. Assume potential risk depends on three variables
(soil ingestion rate, constituent concentration in soil, and constituent CSF). The mean, upper
95% bound, and maximum values are available for each variable. Multiplying the three
maximum values results in a bounding estimate of risk that clearly lies outside EPA's range of
Reasonable Maximum Exposures. Consider the effect, however, of multiplying the upper 95%
bound values. This assumes the 5% of the people most sensitive to the potential carcinogenic
effects of the constituent will also ingest soil at a rate exceeding the rate for 95% of the
population, and that all the soil these people eat will have a constituent concentration that we
are 95% confident exceeds the average concentration on-site. The consequence of these
assumptions is that the estimated potential risk is representative of 0.0125% of ~he population
(0.05 x 0.05 x 0.05 = 0.000125 x 100 = 0.0125%). Put another way, these assumptions
overestimate risks for 9,999 out of 10,000 people, or 99.99% of the population. The
conservative nature of the potential risks estimated by the superfund risk assessment process
is not generally recognized. In reality, the estimates are more conservative than outlined
above, because many more than" three upper 95% assumptions are used to estimate potential
risks from each exposure pathway presented in the baseline risk assessment.
Because the BRA employed upper 95% bounds and maxima for most exposure and toxicity
assumptions it is likely to overestimate the potential of a typical member of the potentially
exposed populations by 1 OO-fold or more. This does not mean that no one can have a potential
risk greater than estimated by the BRA. It does suggest, however, that there is little chance that
potential risks have been underestimated, and that the potential risks for most people have been.
overestimated. "
10
-------
TABLE 7-1
Current On-Site Worker
Difference
RME between RME
Typical Value and Typical
Parameter Ranae Value Used Rationale for RME Value Used Values
Surface Soil Exposure Pathway
Concentration in Surface Soil (mg/kg)
Zone A Pentachlorophenol 0.18 - 167 Z4.4 167 Maximum grid concentration. 6.8
Zone A CPAH 44.3 16.4 44.3 Maximum grid concentration. Z.7
Zone A Dioxin 0.0007-0.0Z 0.00335 O.OZ Maximum grid concentration. 6
Zone A Arsenic 3.4 - 15Z 3Z.3 15Z Maximum grid concentration. 4.7
Soil Ingestion Rate (mg/d) 1.8-437.1 40 50 Recommended by USEPA (1991) 1.25
Soil Adherence (mg/cmZ) O.Z - 1 0.6 1 Range is from USEPA (199Z). Value used 1.67
is recommended "upper limit".
Skin Exposed (cmUd) 0 - 10,000 1000 Z300 Professional judgement 2.3
Exposure Frequency (dayslyear) 0 - Z50 < 1 . Z5. Upper bound based on site-specific data. 25
Exposure Duration (years) 0 - 15 10. 15. Upper bound based on site-specific data. 1.5
Body Weight (kg) 44 - 107 68.7 70 Recommended by USEPA (1989). 0.98
Surface Water Exposure Pathway
Concentration in Water (mg/l)
Zones B/C CPAH 0.196 0.196 95% UCL concentration.
Zones B/C Arsenic 0.002 - Z.6 0.112 95% UCL concentration.
Zones B/C Pentachlorophenol 0.003 - 0.13 0.018 95% UCL concentration.
Skin Exposed (cmZ) 0 - 10,000 1000 2300 Professional judgement 2.3
Exposure Time (hr/d) 0-8 < 0.5 2.6 Natl average time spent swimming while 5.2
on vacation.
Exposure Frequency (days/year) 0 - 50 < 1 . 2. Upper bound based on site-specific data. 2
Exposure Duration (years) 0 - 15 10. 15. Upper bound based on site-specific data. 1.5
Body Weight (kg) 44 - 107 68.7 70 Recommended by USEPA (1989). 0.98
Sediment Exposure Pathway
Concentration in Sediment (mg/kg)
Zone B/C Arsenic 3.1 - 604 84.Z 95% ua. concentration.
Zone B/C Carbazole 0.073 - 130 84.3 95% UCL concentration.
Zone B/C CPAH 72.9 72.9 95% UCL concentration.
Zone B/CPentachlorophenol 0.48 - 47 47 Maximum detected concentration.
Zone B/C Dieldrin 0.006 - 4.5 4.5 Maximum detected concentration.
Sediment Ingestion Rate (mg/d) 1.8-437.1 40 100 Recommended by USEPA (1991) for soil. Z.5
Sediment Adherence (mg/anZ) O.Z - 1 0.6 0.6 Range is from USEPA (1992). Value 1
chosen using professional judgement.
Skin Exposed (cmUd) 0 - 10,000 1000 2300 Professional judgement. 2.3
Exposure Frequency (days/year) 0 - 50 < 1 . 2. Upper bound based on site-specific data. 2
Exposure Duration (years) 0 - 15 10 * 15* Upper bound based on site-specific data. 1.5
Body WeiQht (kQ) 44 - 1 07 68.7 70 Recommended bv USEPA (1989). 0.98
. Assumes baseline risk assessment incorporates recommended site-specific exposure parameters.
Current OSW Uncertainty
Page 1
11122194
-------
TABLE 7-2
Current Utility Worker
Difference
RME between RME
Typical Value and Typical
Parameter Ranoe Value Used Rationale for RME Value Used Values
Surface Soil Exposure Pathway
Concentration in Surface Soil (mg/kg)
Zone A Pentachlorophenol 0.18 - 1 67 24.4 152 Maximum grid concentration. 6.8
Zone A CPAH 44.3 16.4 44.3 Maximum grid concentration. 2.7
Zone A Dioxin 0.0007-0.02 0.00335 0.02 Maximum grid concentration. 6
Zone A Arsenic 3.4 - 1 S2 32.3 152 Maximum grid concentration. 4.7
Soil Ingestion Rate (mg/d) 1.8 - 437.1 40 50 Recommended by USEPA (1991) 1.25
Soil Adherence (mg/cm2) 0.2 - 1 0.6 1 Range is from USEPA (1992). Value used 1.67
is recommended "upper limit".
Skin Exposed (cm2ld) 0 - 10,000 1000 2300 Professional judgement 2.3
Exposure Frequency (days/year) 0 - 10 < 1 * 1 * Upper bound based on site-specific data. S
Exposure Duration (years) 0 - 2S 10 * 25 * Upper bound based on site-specific data. 2.S
Body Weight (kg) 44 - 107 68.7 70 Recommended by USEPA (1989). 0.98
Subsurface Soil Exposure Pathway
Concentration in Subs. Soil (mg/kg)
Zone A Pentachlorophenol 0.084 - 210 47 210 Maximum grid concentration. 4.5
Zone A CPAH 172 61 172 Maximum grid concentration. 2.8
Zone A Dioxin 2E-6 - 0.027 0.0022 0.027 Maximum grid concentration. 12.3
Zone A Arsenic 0.63 - 734 91.7 734 Maximum grid concentration. 8
Soil Ingestion Rate (mg/d) 1.8 - 437.1 40 50 Recommended by USEPA (1991) 1.25
Soil Adherence (mg/cm2) 0.2 - 1 0.6 1 Range is from USEPA (1992). Value used 1.67
is recommended "upper limit".
Skin Exposed (cm2ld) 0 - 10,000 1000 2300 Professional judgement 2.3
Exposure Frequency (days/year) 0 - 10 < 1 * 1 * Upper bound based on site-specific data. 5
Exposure Duration (years) 0 - 25 10* 25 * Upper bound based on site-specific data. 2.5
Body Weight (kg) 44 - 107 68.7 70 Recommended by USEPA (1989). 0.98
* Assumes baseline risk assessment incorporates recommended site-specific exposure parameters.
Current UW Uncertainty
Page 1
11/22194
-------
TABLE 7-3
Current Trespasser
Difference
RME between RME
Typical Value and Typical
, Parameter RanQe Value Used Rationale for RME Value Used Values
!
! Surface Soil Exposure Pathway
Concentration in Surface Soil (mg/kg)
Zone A Pentachlorophenol 0.18-167 24.4 167 Maximum grid concentration. 6.8
Zone A CPAH 44.3 16.4 44.3 Maximum grid concentration. 2.7
Zone A Dioxin 0.0007-0.02 0.00335 0.02 Maximum grid concentration. 6
Zone A Arsenic 3.4 - 1 52 32.3 152 Maximum grid concentration. 4.7
Soil Ingestion Rate (mg/d) 1.8 - 437.1 40 100 Recommended by USEPA (1991) 2.5
Soil Adherence (mg/cm2) 0.2 - 1 0.6 1 Range is from USEPA (1992). Value used 1.67
is recommended "upper limit".
Skin Exposed (cm2/d) 0 - 10,000 1000 2300 Professional judgement 2.3
Exposure Frequency (dayslyear) 0 - 52 6 24 Professional judgement 4
Exposure Duration (years) 5.0 - 70 5 24 Professional judgement. 4.8
Body Weight (kg) 44 - 107 68.7 70 Recommended by USEPA (1989). 0.98
Surface Water Exposure Pathway
Concentration in Water (mg/L)
Zones BIC CPAH 0.196 0.196 95% UCL concentration.
Zones B/C Arsenic 0.002 - 2.6 0.112 95% UCL concentration.
Zones BIC Pentachlorophenol 0.003 - 0.13 0.018 95% UCL concentration.
Skin Exposed (cm2) 0-10,000 2000 6380 Professional judgement 3.19
Exposure Time (hr/d) 0-8 0.5 2.6 National average time spent swimming 5.2
while on vacation.
Water Ingestion Rate (Uhr) 0 - 0.01 < 0.01 0.01 Professional judgement 2
Exposure Frequency (days/year) 0 - 52 2 24 Professional judgement. 12
Exposure Duration (years) 5.0 - 70 5 24 Professional judgement. 4.8
Body Weight (kg) 44 - 107 68.7 70 Recommended by USEPA (1989). 0.98
Sediment Exposure Pathway
Concentration in Sediment (mg/kg)
Zone BIC Arsenic 3.1 - 604 84.2 95% UCL concentration.
Zone BIC Carbazole 0.073 - 130 84.3 95% UCL concentration.
Zone BIC CPAH 72.9 72.9 95% UCL concentration.
Zone BIC Pentachlorophenol 0.48 - 47 47 Maximum detected concentration.
Zone BIC Dieldrin 0.006 - 4.5 4.5 Maximum detected concentration.
, Sediment Ingestion Rate (mg/d) 1.8 - 437.1 40 100 Recommended by USEPA (1991) for soil. 2.5
Sediment Adherence (mg/cm2) 0.2 - 1 0.6 0.6 Range is from USEPA (1992). Value 1
chosen using professional judgement.
Skin Exposed (crn2/d) 0 - 10,000 1000 3100 Professional judgement. 3.1
, Exposure Frequency (days/year) 0 - 52 2 24 Upper bound based on site-spedfic data. 12
! Exposure Duration (years) 5.0 - 70 5 24 Upper bound based on site-spedfic data. 4.8
Bodv Weiaht (ka) 44 - 107 68.7 70 Recommended by USEPA (989). . 0.98
Current Tres Uncertainty
Page 1
11/22/94
-------
TABLE 7-4
Current Off-site Resident Child
Difference
between RME
Typical RME Value and Typical
Parameter Rance Value Used Rationale for RME Value Used Value
Sediment Exposure Pathway
Concentration in Sediment (mg/kg)
Zone A CPAH 25.2 25.5 Maximum detected concentration.
Zone A Dioxin 0.001 0.001 Maximum detected concentration.
Sediment Ingestion Rate (mg/d) 3. 1854 86 200 Recommended by USEPA (1991 b) for soil. 2.33
Sediment Adherence (mg/cm2) 0.2 - 1 0.6 0.6 Range is from USEPA (1992) for soil. Value 1
chosen using professional judgement.
Skin Exposed (cm2/d) 0 . 7300 1000 1870 Professional judgement 1.87
Exposure Frequency (days/year) 0 - 52 < 1 24 Professional judgement. 24
Exposure Duration (years) 0-6 6 6 Professional judgement. 1
Body Weight (kg) 7.0 - 20 12.9 15 Recommended by USEPA (1989) for ages 0.86
1-4.
Surface Water Exposure Pathway
Concentration in Water (mg/L)
Zone A CPAH 0.252 0.252 Maximum detected concentration.
Zone A Dioxin 8.5E-05 8.5E-05 Maximum detected concentration.
Skin Exposed (cm2) 0 - 7300 2000 3735 Professional judgement 1.87
Exposure Time (hr/d) 0-8 0.5 2.6 National average time spent swimming 5.2
while on vacation.
Water Ingestion Rate (Uhr) 0 - 0.01 < 0.01 0.01 Recommended by USEPA (1989). 2
Exposure Frequency (days/year) 0 - 52 6 24 Professional judgement 4
Exposure Duration (years) 0-6 6 6 Professional judgement. 1
Body Weight (kg) 7.0 - 20 12.9 15 Recommended by USEPA (1989) for ages 0.86
1-4.
Current OSR Uncertainty
Page 1
11/22/94
-------
KOPPERS SUPERFUND SITE MAll.ING LIST COUPON
'i
t.~
! ;
t
j
If you have had a change of address and would like to continue to receive site
related information or would like for EPA to add your name and address to the
mailing list for the Koppers Superfund Site, please complete this self.addressed
form. If you t.- -;e any questions regarding this mailing list, please call Cynthia
Peurifoy at 1.800.435. 9233.
NAME:
Beazer East, Inc. (Ms. Shannon Craig)
ADDRESS:
436 Seventh Avenue
Pittsburgh, PA
15219
TELEPHONE: (412) 22,-2684
THIS SPACE TO WRITE YOUR COMMENTS
Your input on the Proposed Interim Remedial Action for the Koppers Co.. Inc. (Charleston Plant)
Superfund Site is important in helping EPA select an interim remedyfor the site. You may use the space
below to write your comments, thenfold and mail. A response to your comment will be included in the
Responsiveness Summary.
P1Pn~P ~PP the attached comments.
-------
Appendix C
Superfund Remedial Investigation Findings
and Proposed Interim Remedial Action Fact Sheet
January 1995
-------
ft
.
SUPERFUND REMEDIAL INVESTIGATION
FINDINGS AND PROPOSED INTERIM
REMEDIAL ACTION FACT SHEET
Koppers Co., Inc. (Charleston Plant) Site
Charleston, Charleston County, South Carolina
U. S. Environmental Protection Agency, Region IV, Atlanta, GA
January. 1995
. Terms specific to the Superfund process (in bold print) are
defmed in a glossary at the end of this publication.
INTRODUCfION
This fact sheet is one in a series developed by the Region
IV Office of the United States Environmental Protection
Agency (EP A) to inform citizens and local officials of
cUlTent activities at the Koppers Co., Inc: (Charleston Plant)
Superfund Site in Charleston, South Carolina. In a similar
fact sheet dated May 1993, EPA briefly summarized the
Superfund process, the site background and history, and the
work pI armed for the Remedial Investigation (RI). This
fact sheet will provide the reader with a description of the
site and a brief history, summarize the f'mdings of the RI
and the human health Baseline Risk Assessment, and
outline BPA's proposed approach for Interim Remedial
Action at the Koppers Co., Inc. site.
BPA is issuing this fact sheet as part of its public
participation responsibilities under Section 117(a) of the
Comprehensive Environmental Response, Compensation
and Liability Act (CERCLA, more commonly known as
Superfund). This fact sheet summarizes infonnation that
can be found in greater detail in the Final Remedial
Investigation Report, the Final Human Health Baseline Risk
Assessment, and Final Technical Memorandum for Interim
Remedial Measures contained in the Administrative
Record located at the established information repositories.
The reader is referred to the infonnation repositories listed
at the end of this publication for a more detailed account of
this subject matter.
SITE DESCRIPTION AND mSTORY
The Koppers site is located in the Charleston Heights
section of Charleston, SC and lies to the north of downtown
Charleston on the west side of the peninsula formed by the
Ashley and Cooper Rivers. The general location of the site
is depicted on Figure 1 located at the end of this
publication. The site is approximately 102 acres in size and
consists of a number of parcels of property that cUlTently
contain a variety of commercial operations. The present
use of the area surrounding the site to the north, south, and
east consists of a mixture of industrial, commercial and
residential properties. The Ashley River borders the site to
the west. The total resident, student, and worker population
within a 4-mile radius of the site is approximately 150,000.
The specific boundaries of the site are illustrated on Figure
2. The parcel of property bound to the north by Milford
Street, to the south by Braswell Street, to the east by
Interstate 26, and to the west by the Ashley River
represents an approximate 45 acre parcel. This 45 acre
parcel was previously owned by the Kop~rs Company
. from 1940 to 1978 and was used during their wood-treating
operations. The plant treated poles. for use by utilities,
foundation pilings for the construction of buildings, docks,
wharfs, railroad ties, and other railroad construction
materials. The majority of wood-treating operations were
conducted in the eastern portion of the site, now identified
as the fonner Treatment Area (Figure 2).
Proposed Interim Remedial Action
Public Comment Period:
January 20 - February 21, 1995
Public Meeting
Date: January 26, 1995
Time: 7:00 PM
Place: Charleston Public Works Building
103 Sl Philip Street
Charleston, SC
-------
In the former Treatment Area, Koppers maintained several
above ground storage tanks in the Tank Farm Area and
Working Tank Area for the storage of wood-preservatives.
Wood-preservatives were pumped from the Working Tanks
into cylindrical pressure treating vessels. In the treatment
vesseis, moisture was removed from the virgin wood under
a vacuum and impregnated with the wood preservatives.
Creosote was the primary preservative used over the life of
the plant. Pentachlorophenol (penta) and Copper Chromium
Arsenate (CCA) were also used to a lesser degree.
Following pressure treatment, excess creosote was
recovered from the cylinders and stored in the Working
Tanks for reuse. Wastewater from the treatment process
which contained oils, creosote and other solids was
collected in a sump pit and pumped to the Separation
Tanks. Creosote was recovered in the Separation Tanks via
a dehydrator and pumped to the Working Tanks for use.
Trams loaded with treated wood were then pulled to the
Drip-Track Area and stored on the 45-acre parcel until it
was shipped off-site for sale.
The practice of treating wood at the Koppers site resulted
in numerous discharges to the environment. Wastewater
from the Separation Tanks flowed eastward toward the
Ashley River into a ditch, now known as the South
Braswell Street Drainage Ditch. Historical aerial
photographs and sampling conducted during the RI indicate
that creosote constituents were transported with wastewater
and surface water run-off along the South Braswell Street
Drainage Ditch into the Old Impoundment Area (See Figure
2). Residues from the creosote treatment cylinders were
filled in the northwest portion of the 45-acre parcel
(Treatment Cylinder Residue Area) until the mid-1960's.
Koppers also entered into a five year agreement in 1953 to
lease a four acre tract of land south of Braswell Street near
the present day Barge Canal for the pwpose of depositing
saw dust, bark, and other wood waste materials resulting
from stripping operations.
The remaining portion of the site, which comprises
approximately 57 acres located south and adjacent to the
former Koppers property, was never owned by Koppers.
These 57 acres were part of a larger tract of land (the entire
area south of Braswell Street) owned by the Ashepoo
Phosphate Works, which operated a phosphate plant there
beginning around the turn of the century. The property was
used for phosphate and fertilizer operations by a series of
owners until 1978. In November 1984, Southern Dredging
dredged a barge canal approximately 1000 feet inward from
the Ashley River on this property just south of Braswell
Street. Material from the canal dredging was piled
approximately 700 feet east of the barge canal in a bermed
spoils area. As a result of this dredging operation, South
Carolina regulatory personnel responded to the presence of
exposed creosoted poles, highly turbid water and an oily
sheen on the Ashley River adjacent to the canal.
Approximately 100 dead fish were observed in the Ashley
River within 'A mile downstream of the canal. EP A
incorporated these 57 acres into the site boundaries to
determine the environmental impact that the dredging
operations had on the Ashley River and surrounding
environment.
Subsequent to Koppers' operations on-site, the former
Treatment Area was used by several industries. The former
creosote storage tanks were used by FedServ Industries to
store waste oil. Historical investigations conducted from
1983-1985 by the South Carolina Department of Health and
Environmental .Control (SCDHEC) and EPA revealed
spilled waste oil on the ground immediately surrounding the
six storage tanks. In 1985, cleanup and remedial activities
were undertaken. These activities included disposal of
materials in the tanks, dismantling of the tanks and
excavation and disposal of contaminated soil. From 1978
to 1982, Pepper Industries used the former Working Tanks
to store ship bilge and tank wastes. These tanks were
dismantled in 1987. In 1988, EPA conducted a Site
Inspection to gather the necessary information required to
prepare the Hazard Ranking System (HRS) package.
Based upon the results of this investigation, the Koppers
Co., Inc. (Charleston Plant) Site was proposed for inclusion
on the National Priorities List (NPL) in February 1992.
The site became Final on the NPL in December 1994.
REMEDIAL INVESTIGATION SUMMARY
In January 1993, Beazer East, Inc. (formerly Koppers Co.,
Inc.) entered into an Administrative Order on Consent
(AOC) with EPA for the performance of a Remedial
Investigation/Feasibility Study (RIIFS). Beazer East, Inc.
retained ENSR Consulting & Engineering of Acton, MA to
conduct the work required to complete the Rl/FS process.
EPA and SCDHEC provided oversight of all work
conducted during the Rl/FS.
The overall objective of the RI was to fully deime the
nature and extent of contamination present on-site. This
objective was accomplished by the implementation of an
extensive two-phase field program. Phase I field work was
conducted from June-August 1993. The Phase n field
program was based upon the results of Phase I and was
conducted from February-May 1994. Furthermore, a
supplemental field investigation was conducted in
September 1994 in the former Treatment Area tb support
the conceptual design of the proposed Interim Remedial
Action discussed below.
Environmental samples were collected and submitted for
chemical analyses from the following media of concern:
surface soil, subsurface soil, geologic/groundwater, surface
2
-------
water, sediment, and ecological receptors. Surface soil
samples were collected from a total of 145 locations across
the site. A total of 215 subsurface soil samples were
collected via borings and test pit excavations from the zone
extending immediately above the water table to
approximately 60 feet below land surface (BLS). The
geologic/groundwater investigation consisted of 91
groundwater samples collected from 7 piezometers, 11
drive-point wells, and 29 conventional groundwater
monitoring wells. Surface water samples were collected
from 60 locations in the Ashley River, adjacent tidal
marshes, the Barge Canal, and drainage ditches on- and off-
site. Sediment samples were collected from 90 locations in
the same areas of interest as surface water. The ecological
receptor investigation included an 8-week caged oyster.
study at 10 locations in the Ashley River, adjacent tidal
marshes and Barge Canal; sampling and analysis of
indigenous mussel populations at 4 locations; and sediment
toxicity testing from 8 locations.
The discussion below provides the reader with a brief,
qualitative summary of the physical characteristics of the
site and the nature and extent of contamination as
determined from the RI field program described above.
The reader is encouraged to visit the information
repositories or attend the upcmriing EP A meeting on
January 26, 1995 for a more detailed, quantitative account
of this subject matter.
The site geology is composed of a series of water-
bearing units and clay-<:onfming units as follows:
1) a layer of fill, 2) a shallow water-bearing unit,
3) a shallow clay unit, 4) an intermediate water-
bearing unit, 5) an intermediate clay unit, 6) a
deep-water bearing unit, and 7) the Cooper Marl
clay formation, encountered at depths ranging from
55 to 67 feet below land surface (BLS).
The shallow clay is found intermittently across the
site. In the western portion of the site, the
intermediate water-bearing unit is absent and the
shallow and intermediate clay units are contiguous.
The shallow and intermediate water-bearing units
act as one hydrologic unit which generally flows to
the nearest surface water body. A groundwater
divide is present near the central portion of the site.
Groundwater east of this divide, underlying the
former Treatment Area, flows north toward the
North Tidal Marsh. Groundwater west of this
divide flows toward the Ashley River. Predicted
groundwater flow velocity is approximately 80 ft/yr
to the north and 67 ft/yr to the west.
3
.
Groundwater flow in the deep water-bearing unit is
west toward the Ashley River at a predicted
velocity of approximately 72 ft/yr.
Within a 1 mile radius of the site, groundwater in
water-bearing units above the Cooper Marl is not
used for residential or industrial supply. Industrial
wells within a 3-mile radius are open to formations
beneath the Cooper Marl. The Cooper Marl clay
confming unit is reportedly 260 feet thick in the
study area.
.
Polynuclear Aromatic Hydrocarbons. or PAHs
(Please see definition for creosote in glossary),
pentachlorophenol, dioxin, arsenic and lead ar~
present in surface/subsurface soil on-site at
concentrations greater than those deemed to be
adequately protective of human health.
.
The highest concentrations of P AHs in
surface/subsurface soil were found in two definite
source areas, the former Treatment Area and
Impoundment Area. A third possible source area
was identified near the Creosote Residual Area.
.
Distribution of pentachlorophenol and dioxin in
surface/subsurface soil is limited to the area which
formerly contained the penta storage tank in the
Treatment Area.
The highest levels of lead and arsenic in
surface/subsurface soil detected during the RI were
found to the south of the 45 acre parcel in areas
not associated with wood treating operations.
Specifically, these areas include the road just south
of the Barge Canal and property formerly owned
by fertilizer/phosphate companies. These historical
operations may be the source of elevated levels of
lead and arsenic detected .
The subsurface of the former Treatment Area
contains potentially recoverable quantities of Non-
aqueous pbase liquid (NAPL) and is considered
a definite source area of constituents detected in .
sediments and surface waters of the headwaters of
the North Tidal Marsh. Creosote is the primary
component of the NAPL, but other releases
associated with subsequent operations may have
contributed to this problem.
NAPL has been observed in the Hagood Avenue
Drainage Ditch which feeds the North Tidal Marsh.
NAPL is introduced into this system via discharge
from the source area into the eastern end of the
Milford Street Drainage Ditch. NAPL is then
-------
transported via a subsurface culvert which runs
approximately parallel to 1-26 then empties into the
Hagood A venue Drainage Ditch.
.
The Impoundment Area is a defInite source area
with potentially recoverable quantities of NAPL.
NAPL has been observed in the South Braswell
. Street Drainage Ditch which discharges to tpe
Barge Canal.
.
NAPL has been observed in Ashley River
sediments north of the Braswell Shipyard dock.
Possible sources include the Creosote Residual
Area, historical discharges via the Central Drainage
Ditch, and tidal transport from the Barge Canal.
Sediments of the Hagood A venue. Milford Street,
South Braswell Street, and Central Drainage
Ditches exceed levels deemed protective of human
health. Primary constituents of concern include
arsenic, PARs, and lead.
.
The headwaters of the North Tidal Marsh contain
surface water and sediment which exceed screening
level ecological benchmarks. Primary constituents
of concern include PARs, lead, arsenic, copper.
mercury, zinc, and several pesticides. Sediments
collected from this area demonstrated significant
toxicity for one of two test species evaluated.
.
Sediments collected to a depth of 3 feet in the
Ashley River approximately 900 feet upstream and
downstream of the Central Drainage Ditch contain
concentrations of PARs which exceed screening
level ecological benchmarks. Sediments collected
in the Ashley River near the Barge Canal
demonstrated signifIcant toxicity for both test
species evaluated.
The marsh area north of Braswell Shipyard and
adjacent to the Ashley River contains
concentrations of sediment which exceed ecological
benchmarks. Primary constituents of concern
include PARs, arsenic, lead. and copper.
Sediments collected to a depth of 3 feet in the
Barge Canal exceed screening level ecological .
benchmarks for P AHs.
Sediments in the headwaters of the South Tidal
Marsh contain concentrations which exceed
screening level ecological benchmarks. The
highest sediment concentrations of lead and arsenic
detected during the RI were found in the
headwaters of this marsh. Historical
ferti1izer/phosphate operations are the likely source
of these primary constituents of concern. Other
inorganic constituents and P AHs were present in
this area at concentrations exceeding ecological
benchmarks. Sediments from 3 locations in this
area demonstrated significant toxicity for both test
species evaluated.
HUMAN HEALTH BASELINE RISK ASSESSMENT
SUMMARY
CERCLA directs EP A to protect human health and the
environment for current and potential future exposure to
hazardous substances at the site. A human health Baseline
Risk Assessment was conducted to evaluate the potential
current and future human health impacts associated with
exposure to constituents detected at the site. An Ecological
Risk Assessment is currently underway that will evaluate
whether site constituents pose potential current/future
exposure impacts to sensitive ecological receptors.
The human exposure pathways, which were evaluated
included: 1) incidental ingestion and dermal contact with
surface/subsurface soils; 2) groundwater ingestion and
inhalation; 3) incidental ingestion and dermal contact with
surface water including consumption of fish caught from
neighboring surface waters; and 4) incidental ingestion and
dermal contact with sediment Current and future exposure
scenarios that were evaluated included: 1) current/future on-
site worker; 2) current/future on-site utility worker; 3)
current off-site resident who trespasses on-site; 4) future on-
site resident; and 5) future marina worker. Future land-use
plans developed by the City of Charleston recommend
heavy industrial uses for the area of the site, which has
historically been the area's use.
EP A evaluated constituents detected on-site according to
their potential to produce either cancer and/or non-cancer
health effects. The carcinogenic risk range EP A has set for
Superfund cleanups to be protective of human health is 1 x
1 Q4 to 1 X 10-6. For example, a cancer risk of 1 x 1 cr
indicates that an individual has a 1 in 1.000,000 (or 1 in
10,000 for 1 x lQ4) incremental chance of developing
cancer as a result of site-related exposure to a carcinogen
over a 70 year lifetime under the specifIc exposure
conditions at the Site. EP A generally uses the cumulative
benchmark risk level of 1 x lQ4 for all exposures relating
to a particular medium to trigger action for that medium.'
Noncancer exposure estimates were developed using EP A
reference doses to calculate a Hazard Index (HI). A III
greater than 1 indicates that constituents are present at
concentrations that could produce harmful effects.
Exposures associated with the pathways described above
resulted in unacceptable carcinogenic and non-carcinogenic
4
-------
risks. Carcinogenic risks for the current on-site worker
(including utility worker) ranged from 5 x lQ-4 to 2 x lO-6.
Non-cancer In's for the current on-site worker ranged from
0.001 to a maximum of 2 for the current on-site worker
exposed to surface soils in the former Treatment Area.
Carcinogenic risks for the future on-site worker (including
utility worker) ranged from 8 x lO.3 to 3 X lO.5. Non-
cancer In's for the future on-site worker ranged from 0.03
to a maximum of 20 for the future worker exposed to
surface soils in the former Treatment Area. Carcinogenic
risks for the current off-site resident were calculated to be
1 X 10-1. Non-cancer ill's for the adult off-site resident
were lO, while the In for the off-site child resident was
1,000. The high risks for the current off-site resident
scenarios were driven by dermal contact exposure with
drainage ditch surface waters, specifically the Hagood
A venue Drainage Ditch located to the north of the site.
The exposure frequency for the current off-site resident was
24 days/year with an exposure duration of 6 years for the
child and 24 years for the adult.
PROPOSED INTERIM REMEDIAL ACTION
EP A is proposing an Interim Remedial Action (IRA) to
protect human health and the environment in the short-term,
while a fmal long-term remedial solution for the site is
being developed. The objective of EP A's proposed IRA is
to remove or otherwise control the discharge of NAPL from
the former Treatment Area to the eastern end of the Milford
Street Drainage Ditch. The proposed action will also
mitigate the discharge of NAPL and other dominant
transport mechanisms to the Hagood Avenue Drainage
Ditch and North Tidal Marsh.
Figure 3 provides an illustration of the former Treatment
Area and conceptual layout of the proposed IRA. Vertical
cross-sections provided in Figures 4 and 5 illustrate the
subsurface stratigraphy of the former Treatment Area. The
subsurface in this area can be described as follows:
.
A shallow water-bearing unit extends to depths of
11-16 feet BLS. The water table in this area was
encountered between 2 and 7.5 feet BLS.
.
A shallow clay unit ranging in thickness from 5 to
13 feet underlies the shallow water-bearing zone.
As shown on Figure 5, this shallow clay unit
pinches out in the western portion of the former
Treatment Area.
An intermediate water-bearing unit extends to
depths of 32-38 feet BLS. Due to the discontinuity
of the shallow clay unit, the shallow and
intermediate water-bearing zones are considered
one unit in the western portion of this area.
.
.
An intermediate clay unit ranging in thickness from
3 to 9 feet underlies the intermediate water-bearing
zone. The intermediate clay unit extends beneath
the entire former Treatment Area.
A deep water-bearing zone is present in this area,
but is considered separate from the
shallow/intermediate water-bearing zone due to
different groundwater flow directions and
chemistry. Wells installed into the deep water-
bearing zone in this area did not indicate the
presence of site-related constituents. .
Data collected during the RI field program confirmed the
presence of a NAPL piume approximately 150 feet north of
the Milford Street Drainage Ditch. In the eastern portion of
the former Treatment Area, NAPL is restricted to the
shallow water-bearing zone, above the shallow clay unit.
At the point where the shallow clay unit ends, NAPL can
migrate into the intermediate water-bearing zone. The
concentrations in monitoring wells in this area suggest
NAPL may be present beneath the western edge of the
shallow clay unit.
EPA and SCDHEC are proposing to proceed with interim
action in the former Treatment Area in order to reduce
potential human health risks associated with dermal contact
with surface waters and sediments of the Hagood Avenue
and Milford Street Drainage Ditches. The proposed .
conceptual approach for the IRA is outlined below:
Shallow Water-Bearing Unit
SteD IA - Objective: Eliminate future off-site migration of
NAPL to the Milford Street Drainage Ditch.
Proposed Approach: An interceptor trench will be installed
at the location of the storm water drainage ditch on Milford
Street. Groundwater and NAPL will be pumped from this
trench to hydraulically control groundwater and NAPL
migration. As part of this installation, the storm water
drainage ditch will be reconstructed to: I) elevate the
bottom above the static (prior to pumping) water table and;
2) remove sediments and reconstruct the ditch side walls
and bottom, to mitigate residual NAPL from entering the
drainage ditch. Groundwater monitoring wells will be
installed to evaluate the induced capture zone of the trench.
Groundwater and NAPL recovered from the trench will be
pumped to a water treatment plant located at 1961 Milford
Street. The water treatment plant will be designed and
installed to meet all appropriate regulatory discharge
standards prior to discharge to the North Charleston Sewer
District.
5
-------
Step IB - Objective: Mitigate the drainage system as a
conduit for potential NAPL migration to the Hagood
A venue Drainage Ditch.
Proposed Approach: An inspection survey will be
conducted on the subsurface drain pipe that connects the
Milford Street and Hagood Avenue Drainage Ditches.
Measures will be implemented to clean and/or repair this
drain pipe as necessary.
Step lC - Objective: Eliminate potential exposure to
constituents in sediments of the Hagood A venue Drainage
Ditch.
Proposed Approach: The Hagood Avenue Drainage Ditch
will be remediated/reconstructed to prevent future migration
of NAPL. The method of reconstruction will be determined
by experience gained from reconstruction of the Milford
Street Drainage Ditch. Methods may include removal of
sediments, raising the bottom of the ditch above the water'
table and/or installing liners.
Intermediate Water-Bearinl! Unit
Step 2 - Objective: Mitigate off-site migration of NAPL in
the intermediate water-bearing unit underlying the former
Treatment Area. .
Proposed Approach: A groundwater recovery well screened
within the intermediate water-bearing unit will be used to
hydraulically contain NAPL. As shown on Figure 3, this
well will be installed south of Milford Street and in an area
where the shallow clay unit is not present.
Implementation of the IRA is proposed as a component of
the Final site-wide remediation. This interim action will be
followed by a Final Record of Decision (ROD) that will
provide long-term protection of human health and the
environment, fully address the principal threats posed by the
site, and address the statutory preference for treatment that
reduces the toxicity, mobility, or volume of wastes. By
implementing the interim action in a step wise approach, an
evaluation of each step can be completed to provide an
opportunity to incOlporate the results into subsequent steps
of the interim action and in the Final site-wide remediation.
Following completion of the public comment period, EP A
will prepare an Interim Remedial Action ROD and will
respond to all public comments received on the proposed
approach in a Responsiveness Summary. The IRA ROD is
scheduled for completion by March 1995. Construction of
the IRA treatment system is scheduled to begin by late
1995. The estimated total capital cost for the IRA is
$1,350,000. Annual operation and maintenance (O&M)
costs are estimated at $138,OOO/year. Total present worth
for the IRA, which accounts for a series of yearly O&M
expenditures by using an appropriate discount factor, is
$3,060,000.
FUTURE ACTIVITIES
Additional field work is necessary to determine the source
of elevated concentrations of inorganics, specifically lead
and arsenic, detected in sediments of the headwaters of the
South Tidal Marsh. Based upon a review of historical
aerial photographs, elevated concentrations of lead and
arsenic in surface/subsurface soil samples collected from
property formerly owned by the former fertilizer/phosphate
companies to the south, and a general understanding of the
fertilizer/phosphate manufacturing processes, EP A believes
that the parcels of property formerly owned by these
companies may by the source of lead and arsenic currently
present in the South Tidal Marsh. The scope of this field
work is currently in the planning stages and is expected to
begin in early March 1995.
An Ecological Risk Assessment has been initiated to
determine whether site-related constituents pose potential
hazards to populations of ecological receptors inhabiting or
frequenting the wetlands of the site and/or the reach of the
Ashley River adjacent to the site. This ecological risk
assessment will provide a basis to determine
environmentally protective sediment, surface water and
groundwater cleanup levels for those constituents found to
pose potential hazards to populations of ecological receptors
inhabiting the wetlands of the site and/or the adjacent reach
of the Ashley River. Appropriate sediment, surface water
and groundwater cleanup goals will be incOlporated into
Remedial Action Objectives for .protection of the
environment. Recommended Remedial Action Objectives
addressing ecological risk will be delineated and addressed
in the Feasibility Study to be completed by Summer 1995.
A Feasibility Study has been initiated to identify, develop
and evaluate remedial alternatives to satisfy the following
objectives:
.
Reduce potential human health risks from exposure
to surface and subsurface soils to levels deemed
adequately protective by EPA. This objective may
be achieved by one or a combination of general
response actions consisting of containment,
capping, removal, disposal, institutional controls,
and/or treatment of soils with unacceptable levels
of constituents.
.
Reduce potential human health risks from exposure
to sediments to levels deemed to be adequately
protective by EPA. This objective will be achieved
by one or a combination of general response
6
-------
actions consisting of containment, capping,
removal, disposal, and/or treatment of sediments
with unacceptable levels of constituents.
.
Remove or otherwise control the discharge of
NAPL from the former Treabnent Area to the
eastern end of the Milford Street Drainage Ditch
and by doing so remove or otherwise control the
discharge of NAPL and other dominant transport
mechanisms to the Hagood A venue Drainage Ditch
and the North Tidal Marsh. The means by which
this will be accomplished are the subject of EPA's
proposed Interim Remedial Action.
.
Remove or otherwise control NAPL present below
the water table off-site and to the north of the
former Treabnent Area.
Mitigate the further migration of dissolved-phase
constituents from the NAPL source area in the
former Treabnent Area.
Remove or otherwise control the discharge of
NAPL and other dominant transport mechanisms
from the Old Impoundment Area to the South
Braswell Drainage Ditch, Barge Canal and
surrounding area.
Mitigate the surface water and sediment transport
mechanisms which have adversely impacted the
headwaters of the South Tidal Marsh.
issue its preferred remedial alternative, or Proposed Plan,
for public review and comment The fmal remedy for the
Koppers Co., Inc. (Charleston Plant) Site, as presented in
the ROD, is expected by the end of 1995.
OPPORTUNITY FOR COMMUNITY INVOLVEMENT
Concurrent with the release of this fact sheet, EP A has
initiated a 3O-day public comment period from January 20,
1995 to February 21, 1995 for submission of written and
oral comments on the proposed Interim Remedial Action
and all supporting documentation located in the information
repositories listed below. All comments, written and oral,
should be directed to Craig Zeller, EPA Remedial Project
Manager for the Koppers Site, at the address and telephone
number below. Upon timely request, EPA will extend the
public comment period by 30 additional days.
EPA will hold a public meeting at 7:00 PM on January 26,
1995 to present the information contained in the RI Report,
Human Health Baseline Risk Assessment and proposed
conceptual approach for Interim Remedial Action in the
former Treatment Area. The meeting will be held at the
Charleston Public Works Building located at 103 SL Philip
Street, Charleston, South Carolina. Representatives from
EP A, SCDHEC and Beazer East, Inc. will be available to
answer any questions the public may have regarding the
information available and future activities planned for the
site. EP A will also accommodate requests for informal
meetings during the public comment period, to further
explain the fmdings of the RI and the proposed Interim
Remedial Action. Individuals interested in arranging
briefmgs should contact EPA's Community Relations
Coordinator for the site.
The Feasibility Study is scheduled to be completed and
released to the public by Summer 1995. Concurrent with
the release of the Feasibility Study document, EPA will
FOR MORE INFORMATION CONTACT:
Craig Zeller
Remedial Project Manager
Cynthia Peurifoy
Community Relations Coordinator
U.S. Environmental Protection Agency - Region IV
345 Courtland Street, NE., Atlanta, GA 30365
(404)347-7791 or 1-800-435-9233
......................
Richard Haynes, P.E.
SC Department of Health & Environmental Control
2600 Bull Street, Columbia, SC 29201
(803 )896-4070
ADMINISTRATIVE RECORD AND INFORMATION REPOSITORIES
Charleston County Main Library
404 King Street
Charleston, SC 29402
(803)723-1645
U.S EPA Region IV Records Center
345 Courtland Street, NE
Atlanta, GA 30365
(404)347-0506
7
-------
GLOSSARY
Administrative Record - A me which contains all information used by EP A to make its decision on the selection of a response
action under CERCLA. This me is required to be available for public review and a copy is to be established at or near the site,
usually at the information repository. A duplicate file is maintained in a central location such as a regional EPA and/or state
office
Dasenne Risk Assessment - An assessment which provides an evaluation of the potential risk to human health and the
environment in the absence of remedial action.
Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) - A federal law passed in 1980 and
modified in 1986 by the Superfund Amendments and Reauthorization Act (SARA). The Act created a trust fund, known as
Superfund to investigate and clean up abandoned or uncontrolled hazardous waste sites.
Creosote - is an oily, translucent, brown to black liquid willi a sharp smoky or tarry odor. It is a very complex mixture of
organic compounds, is practically insoluble, and denser than water. Creosote is primarily comprised of a family of chemicals
known as Polynuclear Aromatic Hydrocarbons (PARs). Of the 17 PARs of which creosote is composed, 7 are potentially
carcinogenic to humans.
Dioxin - is found as a trace constituent in technical grade pentachlorophenol and is classified as a probable human carcinogen.
Hazard Ranking System (HRS) - A scoring system used by EPA to evaluate relative risks to public health and the
environment A score is calculated based on actual or potential release of hazardous substances through all media present (i.e.
the air, soils, surface water, sediments, groundwater). If a site scores above 28.5, the site is proposed for inclusion on the
National Priorities List
Information Repository - Materials on Superfund and a specific site located conveniently for local residents.
National Priorities List (NPL) - EPA's list of uncontrolled or abandoned hazardous waste sites eligible for long-term clean
up under the Superfund Remedial Program.
Non-Aqueous Phase Liquid (NAPL) - F1uids such as chlorinated solvents, creosote, coal tar wastes and pesticides which do
not mix with water. NAPLs are generally classified as LNAPL (lighter that water) or DNAPL (density greater than water).
As a result of widespread production, transportation, use and disposal of hazardous NAPLs, particularly since 1940, there are
numerous NAPL contamination sites in the United States.
RemediallnvestigationIFeasibility Study (RIfFS) - Two distinct but related studies. normally conducted together, intended
to defme the nature and extent of contamination at a site and to evaluate appropriate site-specific remedies. .
Record of Decision (ROD) - A public document that explains which clean up alternative will be used at a National Priorities
List site and the reasons for choosing the cleanup alternative over other possibilities.
8
-------
AGURE 1
SITE AREA MAP
Koppers Co.. Inc. (Charleston Plant) Site
9
Source: Beazer East, Inc.. Pittsburgh, PA
-------
-~~
~
.
~
!
I
+
at':"" -
+.
./
. "+-"
o 600
I I
SCALE IN FEET
1" = 600'-0"
1200
I
r-:j
<
II)
CO
It)
..,.
~ SOURCE: BEAZER EAST, INC., PITTSBURGH, PA., 1995
RGURE 2
Sl1E BASE MAP
KOPPERS CO.. INC.
(CHARLESTON PLAN1) SITE
10
-------
084569A
~
,
-,---,
APPROXIMATE LOCAl1ON OF~ ~-'
DISSOLVED PlUME ",
..",.-'
--
------
\ -'---
. \ ,-
/
,
,
\
\
\
\
\
\
\
\
-
-
~~
r- - ,It.----/\
r- 2 6.-j
\
I
I
fi
,/
if
I,
I.r)
"
/1
o 80
I I
SCALE IN FEET
1" = 80'-0"
160 FIGURE 3
I INlERlM REMEDiAl ACl10N BASEMAP
KOPPERS CO.. INC.
(CHARLESTON PLANT) SITE
-------
084570A
SOUTH
B
2
,......
~
C)
z
.......... 10
.....
w
~
- Z
tV
Z
0
F 0
~
W
-1
W
-10
~~
~Q
(I)'
o~
«~
0%
~;c
-«
:10
GRAY SAND
SOME SILT
..
GROUNDWA TER
flOW
SURF' ACE WATER
SEAL
INTERCEPTOR
1RENCH
GRAVEL
BACKF'lLL
DRAINAGE
PIPE
LLD~t:~<
................ .
'...........,. .
. '.',',',',',',',',',',',',',',',',','.',',','.',',','.',"
................,......... .
SOURCE: BEAZER EAST, INC., PITTSBURGH, PA., 1995
NOT TO SCALE
NORTH
B'
20
,......
~
C)
z
10 ..........
.....
w
W
LL
Z
Z
o
o F
~
~
w
-10
AGURE 4
NORTH-SOUTH CROSS SECl10N
KOPPERS CO., INC.
(CHARLESTON PLANT) SllE
-------
084571 A
2
WEST
A
RECOVERY OR
UVB WEll
,-... 10
c
>
"
Z
......"
t-
W
W
LL 0
- z
U) SAND
Z
0
F
<{
>
w-10
...J
w
ClEANOUT INTERCEPTOR
TRENCH
MILFORD STREET
DRAINAGE DITCH
EAST
A'
20
SURFACE WATER
SEAl
1 0 ,-...
C
>
"
Z
......"
J-
W
W
LL
Z
Z
o
F
<{
-10Gj
....J
w
o
_.~. ~... . [[[ - 20
>7zZ2+~v$-y
'.'.~.:~.:~:.~:.~[[[
SOURCE: BEAZER EAST, INC.:-PlTrsBURGH, PA:1995 - .
NOTE: lOCA l10N Of INTERMEDIATE WELl IS SHOWN FOR ILlUSTRA l10N PURPOSES ONLY.
-20
\(L....................<~ .... ..........
....... . . . .. . . ..at CLAY' . .. .
-------
1-
KOPPERS SUPERFUND SITE MAILING LIST COUPON
If you have had a change of address and would like to continue to receive site
related information or would like for EP A to add your name and address to the
mailing list for the Koppers Superfund Site, please complete this self-addressed
form. . If you have any questions regarding this mailing list, please call Cynthia
Peurifoy at 1-800-435- 9233.
NAME:
ADDRESS:
TELEPHONE: (
)
USE THIS SPACE TO WRITE YOUR COMMENTS
Your input on the Proposed Interim Remedial Action for the Koppers Co.. Inc. (Charleston Plant]
Super:fund Site is important in helping EPA select an interim remedyfor the site. You may use the space
below to write your comments. thenfold and mail. A response to your comment will be included in the
Responsiveness Summary.
14
,
,
j
-------
~
\1,;
KOPPERS CO., INC. (CHARLESTON PLANT) t;;UPERFUND SITE
PROPOSED INTERIM REMEDIAL ACTION PUBLIC COMMENT SHEET
---.....------------.-.-----------------------------.-------------.-.----.-..-.-.------.--.-.-------
---..---.----------------------------.-------------.-..-----.-----------------.-.-------------------
Fold on dashed lines, staple, stamp and mail
Name
Address
City
~acc
Stamp
Here
State _Zip -
Cynthia Peurlfoy, Community Relations Coordinator
North Superfund Remedial BrancbIWaste Division
U. S. EPA, Region 4
345 Courtland Street, NE
Atlanta, GA 30365
------- |