Superfund Record of Decision Townsend Saw Chain Co. Pontiac SC


                                    EPA/ROD/R04-97/019
                                    1997
EPA Superfund
     Record of Decision:
     TOWNSEND SAW CHAIN CO.
     EPA ID: SCD980558050
     OU01
     PONTIAC, SC
     12/19/1996

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                          RECORD OF DECISION

                    REMEDIAL ALTERNATIVE SELECTION


                    TOWNSEND SAW CHAIN COMPANY SITE

                       PONTIAC, RICHLAND COUNTY
                            SOUTH CAROLINA
                    U.S. ENVIRONMENTAL PROTECTION AGENCY
                                 REGION IV
                              ATLANTA, GEORGIA

                               DECEMBER 1996

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                          DECLARATION  FOR  THE RECORD OF  DECISION

SITE  NAME AND LOCATION

Townsend Saw Chain Company Site,
Pontiac, Richland County, South Carolina.

STATEMENT OF BASIS  AND PURPOSE

This decision document presents the selected remedial alternative  for the Townsend Saw Chain Company
Site,  Pontiac, Richland County, South Carolina,  which was chosen in accordance with the Comprehensive
Environmental Response, Compensation and Liability Act of 1980 (CERCIA),  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 file
for this Site.  The State of South Carolina concurs with the selected remedy.

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 Record of Decision (ROD), may present an imminent and substantial
endangerment to public health, welfare,  or the environment.

DESCRIPTION OF THE  REMEDY

This remedial action is the final action (remedy)  for this Site.   It addresses the principal threat  posed
by the Site,  which is  contaminated groundwater.   It also addresses contamination in other media.  The
selected alternative utilizes an innovative treatment technology referred to herein as "in-situ  chemical
treatment," to immobilize chromium by chemically altering it to its less-toxic trivalent state,  reducing
both the toxicity and volume of the affected groundwater.   Additionally,  continued operation of  the
Interim Action pump-and-treat system during treatment will also lessen the mobility and volume of
contaminated groundwater, although in a slower manner.  Therefore, this remedy meets the statutory
preference for remedial alternatives which reduce the toxicity, mobility or volume of contaminated media.

The components of the  selected remedy include:

    SOIL TREATMENT (Source Control)
      - Excavation and removal of uppermost highly-contaminated soils
      - Treatment of surficial soils through in-situ chemical treatment

    GROUNDWATER REMEDIATION
      - In-situ chemical treatment of groundwater
      - Continued operation of the Interim Action Pump and Treat System (IAPTS)
      - Sediment removal action at the Seep (Offsite Area)

    SITE MONITORING
      - Continued guarterly sampling/analysis of Site groundwater
      - Additional guarterly sampling of surface water in the unnamed offsite tributary
      - Periodic sampling of treated Site soils

STATUTORY DETERMINATIONS

The selected remedy is protective of human health and the environment,  complies with Federal and State
reguirements that are  legally applicable or relevant and appropriate to the remedial action,  and is
cost-effective.  This  remedy utilizes permanent solutions and alternative/treatment technology to the
maximum extent practicable,  and satisfies the statutory preference for remedies that employ treatment
that reduces toxicity, mobility or volume as a principal element.

Because this remedy will result in groundwater containing hazardous substances remaining onsite  above
health-based levels until the remediation levels are attained, a review will be conducted within five
years after commencement of the remedial action,  to ensure that the remedy continues to provide  adeguate
protection of human health and the environment.

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                               RECORD OF DECISION
                        TOWNSEND SAW CHAIN COMPANY SITE

                              TABLE OF CONTENTS             iv

TABLE OF CONTENTS	 iv

LIST OF FIGURES AND TABLES 	 vi

1. 0 INTRODUCTION	  1

2 . 0 SITE LOCATION AND DESCRIPTION	  3
    2 .1  Site Description	  3
    2.2 Site Topography, Drainage and Climate	  6
    2 . 3 Surface Water and Wetlands	  6
    2 . 4 Geologic and Hydrogeologic Setting	  7
    2.5 Site-Specific Geology and Hydrogeology	  7
    2 . 6 Demography and Land Use	  8

3 . 0 SITE HISTORY AND ENFORCEMENT ACTIVITIES	  9
    3.1 Site Operations	  9
    3.2 Enforcement, Investigation and Remediation	 11

4 . 0 HIGHLIGHTS OF COMMUNITY PARTICIPATION	 14

5.0 SCOPE AND ROLE OF RESPONSE ACTION WITHIN SITE STRATEGY. 16

6. 0 SUMMARY OF SITE CHARACTERISTICS	  17
    6.1 Sources of Contamination	  17
    6.2 Nature and Extent of Contamination	  18
        6.2.1 Groundwater	  18
        6.2.2 Soil	  36
        6.2.3 Surface Water	  36
        6.2.4 Sediment	  41
    6.3 Contaminant Migration	  41

7. 0 SUMMARY OF SITE RISKS	 44
    7.1 Chemicals of Potential Concern	 45
    7.2 Exposure Assessment	 46
    7. 3 Toxicity Assessment	 47
    7.4 Human Health Risk Characterization	 50
    7. 5 Ecological Risk Assessment	 53

8 . 0 DESCRIPTION OF REMEDIAL ALTERNATIVES	 54
    8.1 Remedial Action Objectives (RAOs)	 54
    8 . 2 Remediation Levels	 55
    8.3 Source Control  (Soil)  Remedial Alternatives	 57
         8.3.1 Alternative SI:   No Action 	 57
         8.3.2 Alternative S2:   RCRA Cap 	 58
         8.3.3 Alternative S3:   Solidification/
               Stabilization 	 58
        8.3.4 Alternative S4:   Insitu Chemical Treatment  .. 59
        8.3.5 Alternative S5:   Excavation,  Offsite Disposal 61
        8 . 4 Groundwater Remedial Alternatives	 62
            8.4.1 Alternative GW1:  No Action	 62
            8.4.2 Alternative GW2:  Groundwater Use
                   Restrictions and Monitoring	 63
            8.4.3 Alternative GW3A:  Groundwater Extraction,
                   Treatment,  Sprayfield Discharge	 63
            8.4.4 Alternative GW3B:  Groundwater Extraction,
                   Treatment,  Treatment Works Discharge	 64
            8.4.5 Alternative GW4:  Insitu Chemical Treatment  .. 65

  9.0  SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES	 67

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10 . 0 THE SELECTED REMEDY	 73
        10 .1  Description of the Remedy Components	 73
              10.1.1  Source Control (Soil Remediation)	 74
              10.1.2  Groundwater Remediation	 74
              10.1.3  Site Monitoring	 75
       10.2    Applicable or Relevant & Appropriate Requirements.76
              10.2.1  Applicable Requirements	 76
             10.2.2  Relevant and Appropriate Requirements	 77
              10.2.3. "To Be Considered"  (TBC)  Criteria	 79
              10.2.4  Other Requirements	 81
       10 . 3   Performance Standards	 81
       10 . 4   Variations from the Proposed Plan	 81
11.0  STATUTORY DETERMINATIONS.
                                                                 82
APPENDICES
      APPENDIX A: RESPONSIVENESS SUMMARY
      APPENDIX B: STATE OF SOUTH CAROLINA CONCURRENCE LETTER
FIGURE
                                                              PAGE
   1     Site Location Map	  2
          Site Area Map	  4
   3      Site Layout Map	  5
   4      Adj acent and Nearby Properties	 10
   5      Monitor Well Locations	 33
   6      March 1996 Groundwater Contaminant Plume	 34
   7      Wastewater Ponds Area Soil Sample Locations	 38
   8      Wastewater Ponds Area Hex Chromium Distribution	 39
   9      Surface Water and Sediment Sample Locations	 42

TABLE                                                        PAGE

  1       RI Groundwater Sampling Results (Inorganics)	 19
  2       RI Groundwater Sampling Results (Organics)	 27
  3       March 1996 Groundwater Sampling Results	 35
  4       Wastewater Ponds Area Soil Sample Results	 37
  5       Surface Water Sample Results	 40
  6       Sediment Sample Results	 43
  7       Summary of Exposure Parameters	 48
  8       COG Exposure Point Concentrations and
          Toxicity Values	 49
  9       Summary of Total Site Risks	 51
  10      Site Remediation Levels	 56
  11      Remedial Alternatives	 67

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RECORD OF DECISION
TOWNSEND SAW CHAIN COMPANY SITE
Pontiac, Richland County, South Carolina
December 1996
1.0 INTRODUCTION
The Townsend Saw Chain Site is a small manufacturing facility located approximately 10 miles
east-northeast of Columbia, South Carolina (Figure 1). The facility is active and is presently owned
by Deere and Company (John Deere). It was formerly owned and managed by the Homelite Division of
Textron, Inc., located in Charlotte, North Carolina. In use since 1964, the facility has been used since
1972 for the manufacture of the saw chain, bar, and other components of chain saws. Prior to 1972,
between 1964 and 1971, Dictaphone Corporation manufactured specialized recording eguipment at the
facility.

Between 1966 and 1981, under both Dictaphone and Townsend Saw Chain Company (later Homelite Division of
Textron) ownership, waste rinsewaters produced during metals-plating and other processes were disposed of
by direct discharge to the ground surface in the low lying "waste pond" areas adjacent to the facility on
the north side. These discharges caused contamination of Site groundwater. The main Site contaminant is
hexavalent chromium.

The South Carolina Department of Health and Environmental Control (SCDHEC) has overseen environmental
investigations and ongoing remediation of groundwater at the Site since 1982. The Site was evaluated by
EPA for possible inclusion on the National Priorities List, using the Hazard Ranking System (HRS), in
1987. Because of the potential threat to groundwater and the large number of people in the surrounding
area served by water wells, the Site was assigned an HRS score of 35.94, and was proposed for listing on
the NPL in June 1988. The Site was listed on the NPL in February 1990. Potentially Responsible Parties
(PRPs) named at this Site are Textron, Inc. and Dictaphone Corporation (later Pitney Bowes).

In August 1991, Homelite Textron, Inc. ("Textron") signed an Administrative Order on Consent to perform a
Remedial Investigation/Feasibility Study (RI/FS) at the Townsend Site. RI field work began in May 1992
and continued, in two phases, through December 1993. In late 1993, groundwater data appeared to indicate
that the areal extent of chromium-contaminated groundwater in the surficial aguifer was greater than
previously believed. Because data indicated (1) that nearby potable water wells could be impacted at
unacceptable levels unless measures were taken to intercept and/or control the offsite movement of the
contaminant plume, and (2) that a potential for harmful ecological effects existed in and along the
unnamed offsite tributary and Spears Creek, EPA issued an Interim Record of Decision in December 1993.
Textron voluntarily agreed to perform-this Interim Remedial Action, which was described in EPA's
Unilateral Administrative Order (UAO) of May 4, 1994. The interim action consisted of the following:

a) a short, focused hydrogeologic study to define contamination extent;
b) design of an offsite pump-and-treat system to intercept the migrating groundwater and direct it to
onsite water treatment eguipment, followed by appropriate disposal; and
c) construction and operation of the system. A five-well pump-and treat system was constructed between
June and December 1995 and began operations in December 1995.

This Record of Decision documents the selection of the final remedial action (remedy) for this Site. It
addresses contamination of groundwater, surface water, soil and sediment at the Site. The principal
threat posed by the Site is exposure to contaminated groundwater. This future potential risk to human
health will be reduced or eliminated by the proposed remedy described in this Record of Decision.

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joins a 7-foot metal mesh fence which encloses the property to the north, west and south. Across SC Road
53 to the northeast is a large single parcel of land (approximately 350 acres) onto which contaminated
groundwater has migrated (the ("offsite areas"). Throughout this document, the terms onsite and offsite
are used to denote locations within the facility property ("onsite") and those across SC Road 53
generally in the northeast direction ("offsite").

During the RI, the five areas shown on Figure 3 were investigated, in addition to the offsite unnamed
tributary of Spears Creek. The tributary is fed by a small seep or spring located approximately
560 feet north of the property boundary along SC Road 53.

2 .2 Site Topography, Drainage and Climate

The Site lies within the Upper Coastal Plain physiographic province. Topographically, the region is
characterized by flat or gently rolling terrain dissected by densely vegetated streams and creeks. Soils
in the area consist predominantly of guartz sand, resulting in high soil permeability and rapid
infiltration of rainwater into the underlying geologic units. There is little or no surface runoff
during or after rainfall.

The Site property is generally flat; elevations onsite range from 350 to 375 feet above mean sea level.
The whitish, sandy surface soils are generally poor, containing little organic matter. Trees and
vegetative cover generally consists of scrub oak and short loblolly pines, with little underbrush, except
near surface water, which supports more diverse flora. The spray field area south of the plant is
covered by perennial grasses.

The nearest significant drainage is the above-mentioned spring, which feeds an unnamed tributary of
Spears Creek. The tributary flows northeastward to its confluence with Spears Creek. To the south along
Interstate 20 there is a drainage ditch which only intermittently carries water. There appears to be no
direct (surface) drainage of any portion of the Site to any drainage features.

The climate of Richland County is generally mild, with hot humid summers and short winters. The major
influences on climate are the Atlantic Ocean, which provides humidity, and the Blue Ridge mountains north
and northwest of the county, which impede the eastward movement of cold air masses. Average mid-afternoon
humidity is about 55 percent. Precipitation, averaging close to 46 inches annually, is evenly
distributed throughout the year. Based on Columbia Airport data (located 20 miles distant), prevailing
wind direction is from the west to west-southwest. However, measurements from an onsite weather
monitoring station operated between November 1992 and October 1993 indicate that wind from the
south-southeast predominates at the Site. A high percentage of sunshine (60% winter, 65% summer),
combined with the highly porous sandy soils, generate high infiltration and evapotranspiration rates
which greatly reduce surface runoff.

2 . 3 Surface Water and Wetlands

As noted above, the nearest surface water is the unnamed tributary to Spears Creek (Figure 2). There
appears to be no surface water drainage from the plant property to the tributary. The absence of direct
overland drainage of water to the tributary and measurements of the water table indicate that it is fed
almost entirely by groundwater flow. A narrow band of wet, marshy, heavily-vegetated soil forms the
banks of the unnamed tributary, from its origin some 560 feet northeast of the facility property line to
its confluence with Spears Creek, which is approximately 2,700 feet northeast of the property boundary
along SC Road 53. A broad wetlands area along Spears Creek, approximately 800 feet in width and centered
on Spears Creek, is classified as Palustrine Forested Wetland by the U.S. Fish and Wildlife Service (U.S.
Department of Interior). Southwest of the Site, a tributary of Colonel's Creek is present about 1700
feet from the property line, but no overland flow to this tributary is evident.

2.4 Geologic and Hydrogeologic Setting

The Upper Coastal Plain province is underlain by a seaward-dipping wedge of unconsolidated sediments
overlying crystalline bedrock. The sandy surface soils (the Lakeland and Kershaw soil series) were
formed from Tertiary marine and eolian (wind-deposited) sands. These soils are typically gray to white
and give the surrounding White Sand Hills region its name.

Underlying these soils is the upper Cretaceous Middendorf Formation (previously designated the Tuscaloosa
Formation). The Middendorf consists of sands and kaolinitic clays representing fluvial and deltaic
geologic environments. Subsurface structures present in these sediments include stream channels, overbank
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deposits, channel scours and fills, and floodplain deposits. Locally, such structures may control
groundwater flow patterns. The formation is approximately 200 feet thick in the area of the Site.

Sand strata within the Middendorf are productive aquifers, and the formation serves as a major aquifer in
South Carolina. Yields of 10 to 25 gallons per minute (gpm) from wells screened at depths of 50-100
feet, and up to several hundred gpm from those screened from 150-200 feet, are obtained in the Fort
Jackson area. Groundwater in both the surficial Tertiary deposits and the Middendorf formation is
classified by EPA as Class IIA and by South Carolina as Class GB.

2.5 Site-Specific Geology and Hydrogeology

Boring logs from the Remedial Investigation and from past investigations have been used to develop an
understanding of Site geology. Based on stratigraphic and hydrogeologic characteristics, sediments
underlying the Site can be divided into three units:

Unit I is exposed at the surface and consists of interbedded and alternating layers of sand, silty
or clayey sand, and silt or clay lenses. These various strata are apparently hydraulically connected.
Groundwater occurrence and movement in Unit I is controlled by the types of sediment strata present, and
their configuration. Perched water zones occur within the upper part of Unit I; for example, water level
data from well MW-25 indicate that this well is screened in a perched water zone.

Detailed cross sections based on the numerous RI well borings (see RI Report) indicated the presence
of three sand layers or "lobes." Most Site wells are in the upper and middle sand lobes.

Unit II is a low-permeability confining unit consisting of hard, dry, kaolinitic silty clays or
clayey silt. Unit II appears to be laterally continuous on the Site property. Subsurface borings to
date have not resulted in the identification of any locations where Unit II is absent; however, in the
off site areas it occurs deeper (approximately 75 feet below ground surface) than onsite.

Unit III consists of slightly silty, fine- to medium-grained sand. Because only a few Site well
borings have penetrated into Unit III, its hydrogeologic and stratigraphic characteristics are not as
well known.

The lower portion of unit I, and all of units II and III, are part of the Middendorf Formation. It is
important to note that the simple, general outline of units I-III given above is not meant to infer that
simple patterns of groundwater flow and occurrence are present. Viewed as a whole, the subsurface
arrangement of various sediment lenses and layers, having different grain sizes and hydrologic
properties, creates a complex geometry and greatly complicates attempts to determine contaminant
distribution or to model groundwater flow patterns.

2.6 Demography and Land Use

Census data (1990) indicate that 10,220 people reside within a three-mile radius of the Site. However,
the great majority of this population resides west of the Site closer to Columbia. Site reconnaissance
indicates that only a few homes or businesses are present within ^> mile of the Site. Pontiac Elementary
School is located some 300 feet north of the Site property line on SC Road 53. The nearest homes and
businesses are located across 1-20 to the southeast, along Spears Creek Church Road, 1,200 feet from the
plant building. These 8 homes and businesses have private water wells serving 61 people. These are the
only wells within a ^> mile radius; none are hydraulically downgradient of the Site. The nearest private
water wells which are in the direction of groundwater movement are 23 wells which belong to homeowners
whose properties surround Woodcreek Lake. The nearest of these is 5,400 feet northeast of the property
boundary. The nearest community water well is located 5600 feet east of the Site (south of 1-20) . All
of these distances are approximate.

Figure 4 illustrates the ownership and land use of nearby properties. The site (facility) property is
zoned "light industrial." The present Site owner, as well as the county planning authority, foresee
continued use of the Site for industrial purposes. Although not shown on the figure, along SC Road 53 in
the offsite area there is a strip of property zoned "commercial." Behind this strip, a housing
development is planned which will involve most of the offsite parcel of land. However, homesites are not
planned in areas along the tributary or near the area of contaminated groundwater. While many areas
nearby remain zoned "rural," Richland County expects the northeastern portion of the county to experience
significant growth through 2005.
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3.0 SITE HISTORY

3.1 Site Operations

In 1964, Dictaphone Corporation purchased an approximately 100-acre parcel of land, which eventually
became the Site, and constructed a small manufacturing facility to be used primarily for the assembly of
certain models of the company's line of office recording eguipment. Details of the operations used are
unavailable, but two permits issued by the State of South Carolina indicate that wastewaters generated
onsite contained low levels of zinc, cyanide, chromium (chromate ion) and residues from acid and alkali
cleaning. Operations on site were permitted for the period between June 1966 and June 1971.

Townsend Saw Chain Company purchased the Site in June of 1971. Their operations onsite began in July
1972. From that time to the present, the main operation of the facility has been the manufacture and
assembly of saw chains for chain saws. Processes which comprise this overall operation include metal
punch-pressing, metal plating (chromium) , heat treatment (heat guench bath), a rust-preventative bath,
and metal parts cleaning and finishing. Wastewaters produced by these processes contained chromium,
cadmium, cyanide, nitrite and nitrate salts, and several volatile organic compounds (VOCs).

Between 1966 and 1981, under both Dictaphone and Townsend Saw Chain Company (later Textron), waste
rinsewaters produced during the metals-plating and other processes described above, were disposed of by
direct discharge to the ground surface in the low-lying "waste pond" areas adjacent to the facility on
the north side. These discharges, which occurred over a period of approximately 15 years, are the origin
of the onsite groundwater contamination.

In 1982, after SCDHEC investigated the site, Textron was cited by the State for violations of the
established wastewater treatment rules. Investigations since 1982 have confirmed the presence of
chromium, other metals, nitrate, and VOCs, in both onsite and offsite groundwater, at levels above the
Federal Safe Drinking Water Act of 1974 (SDWA) Maximum Contaminant Levels (MCLs).

3.2 Enforcement, Investigation and Remediation

Since 1982, SCDHEC has continued to oversee Textron's remediation program for groundwater. In 1982, as
reguired by a Consent Order, a groundwater treatment system was installed, consisting of five extraction
(pumping) wells, chemical treatment tanks, and a spray or irrigation field for disposal of the treated
water. Two pumping wells were located within the former wastewater ponds area with the remaining three
wells positioned in a line along SC Road 53. This system operated until 1995. After treatment to the
then-applicable South Carolina groundwater guality standard for chromium (0.050 mg/1) , groundwater was
then discharged to a spray field. Performance of the system and conditions at the spray field have
been monitored by SCDHEC under an industrial wastewater permit.

Between 1985 and 1988, SCDHEC and EPA took the necessary steps to list the Site on the National
Priorities List (NPL), which places it in the Superfund program. A 1985 Preliminary Assessment/Site
Inspection (PA/SI) by SCDHEC revealed elevated or above -background concentrations of chromium, lead,
cadmium, arsenic, cyanide, nickel, and four VOCs in groundwater at the site. Chromium, lead, cadmium and
arsenic were present at elevated levels in sediments within the waste pond area, and a stream water
sample taken just across Spears Creek Church Road north of the site contained chromium and four VOCs.
Based on these results, the Site was then ranked by EPA in 1987 using the Hazard Ranking System (HRS),
which evaluates the potential for public exposure to site contamination. Because of the potential for
migration of groundwater contaminants offsite, and the large number of people in the surrounding area
served by water wells, the Site was assigned an HRS score of 35.94 and was proposed for listing on the
NPL in June 1988. The Site was finalized on the NPL in February 1990.

In 1987, SCDHEC identified problems in the 1982 pump-and-treat system's design and performance. To
address those deficiencies, a 1988 modification to the 1982 Court Order directed Textron to further
investigate and define the extent of groundwater contamination, and to investigate Site hydrogeology as
necessary to modify the system's design. A report with design revisions was submitted to SCDHEC in 1990,
and following SCDHEC review, again in December 1991. A final permit to construct the system was issued
in December 1993.

In October 1991, EPA and Homelite signed an Administrative Order on Consent under which Textron agreed to
conduct an RI/FS at the Site. Dictaphone Corporation was named as a Potentially Responsible Party (PRP)
by EPA when the Agency notified both Textron and Dictaphone (Pitney-Bowes) that an RI/FS was reguired
under CERCLA. Textron has voluntarily undertaken all Superfund investigation and remediation activities
to date.
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Textron retained Aquaterra Environmental Consultants, Inc. to perform the RI. RI field work began in
early May 1992. The initial effort (referred to as "Phase V, in the Administrative Record) was followed
by further investigation of Site groundwater and soils ("Phase II"). Combined Phase I and II activities
included the installation and addition of 15 new monitoring wells to the previous monitoring well
network. In total, RI sampling included collection and laboratory analysis of approximately 200 samples
of surface and subsurface soils, groundwater, stream (surface) water, sediment, and air. Between January
and July 1993, at the end of Phase II work, three rounds of offsite shallow groundwater sampling were
performed. These 49 off site groundwater samples suggested that the plume of contaminated groundwater
was moving offsite, continuing to enlarge, and potentially threatening downgradient private water wells.

After discussions with SCDHEC and Textron in July 1993, EPA decided to move forward with an Interim
Remedial Action at the Site. A public meeting was held in late August 1993, at Pontiac Elementary
School, to discuss the proposed Interim Action and solicit public comment. An Interim Record of Decision
(ROD) requiring Textron to take actions to prevent the continued offsite northeastward migration of
contaminated groundwater was issued by EPA in December 1993. EPA then issued a Unilateral Administrative
Order for implementing the Interim Remedial Action (the "Interim Action") to Textron in May 1994.
Textron voluntarily agreed to do all of the work outlined in the UAO requirements.

During the summer of 1994 Textron retained SECOR International, Inc., to perform the environmental
activities comprising the Interim Action. The first step of the work involved a focused hydrogeologic
study in the area northeast of Spears Creek Church Road (the offsite area). After SECOR's work plans for
the hydrogeologic study and the Interim Remedial Action were approved by EPA, field work began in August
1994 and was completed in November 1994. A report ("Results of the Offsite Hydrogeologic Study")
summarizing the study findings, and serving as a general basis for planning the offsite "Interim Action
pump-and-treat system" (or "IAPTS"), was submitted to EPA in January 1995.

Between June and December 1995, the Interim Action pump-and-treat system was constructed and new
treatment equipment installed in the wastewater treatment system. The system consists of the three
previously-used recovery wells located along SC Road 53, and two new recovery wells located in the
offsite area. Groundwater from these wells is pumped to a treatment facility at the plant, and treated
in electrochemical precipitation cells. The material precipitated within the treatment cells during
treatment is a potentially hazardous sludge, and is therefore handled and disposed of offsite in
accordance with EPA and State regulations for handling hazardous wastes. Treated groundwater is then
discharged to an onsite SCDHEC-permitted sprayfield. Captured groundwater is not treated for VOCs or
nitrate, based on weighted-average calculations (presented in the Interim Remedial Action design) which
documented below-MCL concentrations of these contaminants in the system-collected (influent) water. Full
operations of the groundwater pump-and-treat system began in December 1995. As a result of EPA-SCDHEC
coordination, this system fulfills both the 1993 State permit and EPA's 1994 Unilateral Administrative
Order. Data collected to date indicate that the system is capturing affected groundwater in the off site
area. The system does not treat any plant process wastewater as the previous system did, since the plant
converted in 1995 to a 100% water-reuse system that generates dewatered sludge but no wastewater.

In October 1995 EPA approved the final Remedial Investigation Report prepared by Aquaterra. During late
1994 and early 1995, SECOR completed work on a number of feasibility issues described in the FS,
including (1) conducting a pilot-scale demonstration study of in-situ chromium reduction, (2)
determination of a leaching-based remediation (cleanup) level, (3) further sampling of sediment at the
seep and nearby locations, and (4) completing an Addendum to the Baseline Risk Assessment, which was
originally completed in 1993 by an EPA contractor. These issues and results are discussed in the FS,
which was approved by EPA in September 1996.

4.0 HIGHLIGHTS OF COMMUNITY PARTICIPATION

Since the September 1991 announcement of the signing of an Administrative Order on Consent to initiate an
RI/FS at the Site, EPA has maintained periodic contact with area residents through the use of fact
sheets, public notices, meetings, correspondence, and telephone contact. The mailing list for the Site
includes more than 600 individuals and households.

In April 1992, at the time of the completion of the RI work plans, EPA established an information
repository at the closest public library, which is the Richland County Northeast Branch Library in
eastern portion of the city of Columbia. Materials placed at the repository at that time included
background information on Superfund and on the Site. In December 1992 the Administrative Record (AR) for
the Townsend Saw Chain Site was established. Upon EPA approval, the RI/FS work plans were then added to
the AR.

An RI "kickoff" public meeting was held by EPA at Pontiac Elementary School on April 22, 1992.
Approximately 70 persons attended this meeting. Public questions and concerns centered around the
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proximity of the Site to Pontiac Elementary School, and the long period of groundwater cleanup that had
been ongoing without completion of the cleanup effort. EPA staff explained the lack of any health
threats to school children based on then-current knowledge of the Site, and that the RI work included
verifying the absence of any such threats. EPA and SCDHEC officials also explained the specific details
of Homelite-Textron's groundwater remediation activities, and EPA's plans and objectives concerning
groundwater contamination.

During the summer of 1993, after completion of RI Phase II field work, EPA determined that an Interim
Remedial Action to address offsite groundwater contamination was warranted in view of inconclusive data
concerning the full downgradient, offsite extent of Site-affected groundwater, and the likelihood of
continuing off site migration of contaminated groundwater. On August 18, 1993, a focused Feasibility
Study document entitled "Technical Memorandum on Interim Remedial Action, which described the proposed
action, was placed at the information repository. EPA prepared an August 1993 Proposed Plan Fact Sheet
to publicly propose the Interim Remedial Action and to solicit public comments. The fact sheet also
announced the opening of a 30-day public comment period on August 20, 1993. A notice to area citizens
announcing the August 31, 1993, Proposed Plan public meeting and the public comment period was published
in Columbia's daily newspaper, The State, on August 20, 1993.

An Interim Action Proposed Plan public meeting was held to present the Interim Remedial Action Proposed
Plan to the public on August 31, 1993, at Pontiac Elementary School. Approximately 70 persons attended
the meeting. EPA officials explained that the Interim Action consisted of a hydrogeologic study in the
offsite area to define the extent of contamination, followed by expedited design and construction of an
extraction and treatment system to capture and treat the affected groundwater and prevent continued
offsite movement. As detailed in the Responsiveness Summary of the December 1993 Interim Record of
Decision, the public expressed a great deal of interest in the Interim Remedial Action. Most guestions
concerned EPA's planned precautionary sampling of four private water wells at the southwest end of
Woodcreek Lake. In response to these concerns, water wells belonging to a group of residents belonging
to the homeowners, group were sampled in September 1993 and again in July 1994 in joint EPA-SCDHEC
efforts. Also as a precaution, Textron sampled 7 private wells located along the south side of
Interstate Highway 20 although not in the known direction of groundwater movement. Sample results from
the 1-20 and Woodcreek Lake wells have indicated, in all cases, non-detects or far below the MCLs for
inorganics (such as chromium) and VOCs.

A notice publicizing the issuance of the Interim Record of Decision was published in The State in May of
1994. Throughout 1994 and 1995, EPA maintained ongoing contact with the local homeowners' group (at
Woodcreek Lake), as well as the business partnership which owns all of the affected offsite property.
"Update Letters" were sent to the president of the homeowners, group in December 1993, September 1994,
and September 1995, describing progress and activities at the Site. In October 1994 and again in October
1995, in response to reguests for assistance from the partnership in dealing with lending institutions,
EPA provided letters to the partnership clarifying the Site's status and describing the ongoing work
under both the RI/FS and the Interim Remedial Action.

As announced in an April 1995 fact sheet, EPA held a public meeting on April 27, 1995, to update local
residents and the public concerning the results of the offsite hydrogeology work and plans for the
offsite pump-and-treat system. Attendance at this meeting was very light and no significant concerns
were expressed.

In July 1996, prior to finalizing the FS, EPA issued a fact sheet describing the technologies and
remedial alternatives for final cleanup of the Site. The fact sheet also reguested public input on the
alternatives and initial evaluation of them. After finalization of the FS, a Proposed Plan Fact Sheet
was issued in early September 1996 describing EPA's selected remedy and announcing a September 17, 1996
public meeting. Attendance at this meeting was very small and no concerns about the proposed action
were expressed.

5.0 SCOPE AND ROLE OF THE REMEDIAL ACTION WITHIN SITE STRATEGY

The scope of this remedial action, which is described more fully in section 10 of this ROD, includes (1)
source control, to prevent leaching of chromium to groundwater, (2) remediation of groundwater, (3)
remediation of surface water, and (4) remedial action to address sediment contamination.

This remedial action is the final action (remedy) for this Site. It addresses the principal threat posed
by the Site, which is contamination of groundwater. It also addresses contamination in other media. The
selected alternative utilizes an innovative treatment technology referred to herein as "in-situ chemical
treatment", to immobilize chromium by changing it to its less-toxic trivalent state. This removes the
toxicity of the chromium, and reduces the volume of the affected groundwater. Additionally, through
continued operation of the Interim Action pump-and-treat system, which is part of this remedy, the
-------
mobility and volume of contaminated groundwater will be reduced. Therefore, this remedy meets the
statutory preference for remedial alternatives which reduce the toxicity, mobility or volume of
contamination.

6.0 SUMMARY OF SITE CHARACTERISTICS

6.1 Sources of Contamination

Contamination of soil, groundwater, surface water and sediment occurred as a result of past wastewater
disposal operations at the Site. Investigation of potential air contamination during the RI indicated
that air emissions are not of concern at the Site. No other sources of contamination were identified
during the RI/FS or the Interim Remedial Action. Section 6.2 below details the nature and extent of
onsite and offsite contamination.

Hexavalent and trivalent chromium is present in former wastewater ponds area soils just north of the
plant building (refer to Figure 4). The former wastewater ponds area forms a low-lying, hourglass-shaped
basin into which process wastewaters were discharged between 1966 and 1981. In addition to contaminating
surface and subsurface soil, these wastewaters were the source of Site groundwater contamination.

During excavation work for the new groundwater treatment eguipment building early in the RI, an abandoned
4-inch clay tile pipeline was uncovered near the northwest corner of the building, which had apparently
been used to convey wastewater to the low-lying area. Resultant soil contamination by several metals was
present at one small area along the former location of this wastewater pipeline.

Just north of the building, a drainage pipe and associated ditch continuing about 75 feet beyond it, was
also located early in the RI, which apparently carried water from floor drains of some of the interior
shop areas and possibly process wastewaters. Soil in a small area around this ditch contained elevated
levels of metals. The distribution of nitrates in groundwater indicates a likely origin in wastewaters
discharged to the ground in this area.

Offsite groundwater contamination reflects the migration of Site contaminated groundwater, toward
hydraulically downgradient, topographically lower areas northeast of the Site. No other Site related
sources of groundwater contamination have been identified to date in the offsite areas, although the
possibility cannot be ruled out. The chromium distribution strongly indicates that it migrated from the
former wastewater ponds, northeastward across SC Road 53. VOC detections at MW-1 and MW-3 suggest that
their origin is at least partially from the former septic tank located beside the main parking lot (east
end of building).

Surface water and sediment in the unnamed offsite tributary to Spears Creek exhibit contamination
transported by Site-originated chromium-bearing groundwater.

6.2 Nature and Extent of Contamination

Environmental contamination at the Site can be summarized as follows:

• Groundwater onsite and in a portion of the offsite area exhibits greatly elevated concentrations
of chromium and sporadic, inconsistent detections of VOCs;
• Surface soil in two small "hotspots" on the plant property contained chromium, cadmium, lead and
cyanide at elevated levels;
• Surface soil in the former wastewater ponds area contains elevated levels of hexavalent and
trivalent chromium;
• Surface water in the unnamed offsite tributary contains above background levels of chromium;and,
• Sediment in the unnamed offsite tributary contains elevated levels of chromium.

6.2.1 Groundwater

The RI verified that Unit I groundwater onsite and in the offsite area is impacted primarily by elevated
concentrations of hexavalent chromium. Detected concentrations ranged up to 3.11 mg/1 total chromium.
Table 1 details RI sampling results for inorganic contaminants (metals), with the wells grouped by
geologic unit. VOCs were also detected at a number of wells, at individual VOC concentrations ranging
from the detection limit (1.0 micrograms per liter, or ug/1) to 110 ug/1. The primary VOC contaminants
are trichloroethylene and tetrachloroethylene; other detections of related daughter compounds were
generally less than 20 ug/1. There were detections of acetone and propanol; the absence of these in
later post-RI sampling (1994-1996) suggests they represented laboratory contamination. Organic
contaminant concentrations from the RI are presented in Table 2. The locations of the RI monitor wells
are shown in Figure 5.
-------
During the Interim Remedial Action field work (the "Offsite Hydrogeologic Study"), a geochemical
comparison was performed which indicated that almost all chromium in the aguifer occurs in the hexavalent
form. More recent sampling events continue to show a chromium groundwater contaminant plume as shown in
Figure 6, with recurring but inconsistent detections of trace VOCs. Table 3 lists the March (first
guarter) 1996 analytical results from the guarterly IAPTS sampling event, upon which Figure 6 was based.

As presented in the FS, the volume of chromium-impacted groundwater is estimated to be approximately
26,200,000 gallons. The volume of nitrate-impacted groundwater is much smaller, estimated at
approximately 7,400,000 gallons. VOC detections occur sporadically and generally within the chromium
plume area; because there is no coherent plume, the VOC-impacted volume cannot be reliably estimated.

6.2.2 Soil

The RI generated a very large amount of tabulated data concerning Site soils. In order to focus on
necessary Site remediation, all of the RI data collected will not be repeated here.

In developing the RI work plan in 1992, five possible areas of soil contamination came to light (Figure
3). The amounts of contamination detected in soils at (1) the sprayfield, and (2) the septic tanks and
associated leachfields, were not significant, and since there is no significance for remediation, the
data are not repeated here. It should be noted that, based on wastewater and wastewater sludge
analytical results, Textron had the solid material in both septic tanks removed in 1993.

RI data showed significant soil contamination of lead, chromium, cadmium, and cyanide affecting two small
"hotspot" areas near two former point sources: (1) the "drainage ditch/pipe area," and (2) the
"four-inch wastewater pipe" area (Figure 3). The soil surrounding the latter area was excavated, tested
and disposed of in accordance with RCRA reguirements, during construction of a new treatment eguipment
building in 1993 (in accordance with the State wastewater permit). The drainage ditch area soils have
been excavated and removed as part of the Interim Remedial Action and are also not further considered
here.

Soil in the former wastewater ponds area was investigated in 1994 and early 1995 in post-RI and Interim
Remedial Action activities. Extensive sampling (Table 4) at the locations shown on Figure 7 indicated
that small pockets of hexavalent chromium-bearing surface soils remain in this area. A maximum value of
279 mg/kg was detected in one sample although most contained much less. Figure 8 illustrates the
distribution of hexavalent chromium in surface soils in the former wastewater ponds area.

6.2.3 Surface Water

Table 5 summarizes surface water data collected at the offsite tributary from the State permit sampling
(seep location), RI (1992/1993), and post-RI (1994/1995) activities. In the RI samples, concentrations
of contaminants other than chromium were not significant for risk or remediation purposes and thus are
not repeated here. Total chromium sample results from the seep prior to the RI (1982 to May 1992)
generally ranged from below a 0.010 mg/1 detection limit, up to 0.350 mg/1. Sample locations for these
samples are shown in Figure 9.

6.2.4 Sediment

Table 6 summarizes the sediment data collected from stations along the offsite tributary for the same
phases of Site work as described immediately above. Sample locations match those presented in Figure 9
for surface water. In similar fashion to the surface water samples, concentrations of contaminants other
than chromium in RI sediment samples were not significant for risk or remediation purposes and are not
repeated here. In samples from the locations close to the seep (i.e. the 1994/1995 samples with the "SD"
prefix), total chromium concentrations ranged from 2.63 mg/kg and 6.75 mg/kg deeper in the sediment (12
to 14, and 30 inches, respectively, below the sediment-water interface), to 1,643.75 mg/kg between 0 and
2 inches below the sediment-water interface. Total chromium at the downstream locations (SED 1 through
SED 7) ranged from 10.8 mg/kg (SED 1, 5/92) to 523 mg/kg (SED 2, 5/92); however, excluding the 523 mg/kg
value and one other detection at SED 7 (103 mg/kg, 101 mg/kg in the duplicate), the remaining eight
downstream samples were all below 50 mg/kg. Maximum total chromium levels recorded from the seep (SED 4)
and from approximately 50 feet uphill of it (SED 5) were 899 mg/kg and 630 mg/kg. Comparison of the
sediment characteristics versus chromium content of the RI samples suggested that the distribution of
chromium in stream sediment is closely associated with the presence of clays and organic matter, and is
therefore likely to be extremely variable along the tributary streambed. Analysis for hexavalent
chromium has been performed less freguently; detections occurred in seep bank samples (Seep 1, 3, 4) at
7, 10 and 1 mg/kg respectively, but none was detected at the far downstream locations SED 6 and SED 7.
Seep area sediment ("SD" prefix) contained between 0.45 and 1.62 mg/kg hexavalent chromium.
-------
TABLE 1
RI GROUNDWATER SAMPLING RESULTS (Inorganics)

(TAL - Total Inorganics Results for Unit I Monitoring Wells) .
Parameter

MW-2
06/11/92
1120
12 U
1 U
151
1 U
1 U
2630
5 U
2 U
4 U
675
17.4
2960
28.6
0.2 U
.7 U
2920 B
1 U
3 U
1500
1 U
3.4 B
62.8
10 U
18
0.02 U

MW-3
06/11/92
12100
12 U
1.8 B
46.1
1 U
1 U
612
19.3
2 U
5 B
6320
6.2
686
23.3
0.2 U
8.1 B
756 B
1 U
3 U
1840
1 U
21.9
42
10 U
0.7
0.02 U

MW-4A
06/09/92
139
12 U
10 U
18.8
1 U
1 U
564
1160
4.2 B
4.1 B
227
1.2 B
451
4.5
0.2 U
5.1 B
1620 B
3.2 U
3 U
77400
1 U
2 U
52.6
24.9
10.2
0.02 U

MW-4A (Dup)
06/09/92
124
12 U
10 U
18.9
1 U
1 U
616
1180
4.5 B
2.4 B
165
1.3 B
429
3.7
0.2 U
7 B
1640 B
3.2
3 U
78300
1 U
2 U
67.8
35.2
10.2
0.02 U

MW-4B
06/11/92
173
12 U
1.7 B
18.6
1 U
1 U
1800
658
4.5 B
4 U
221
5.3
444
6.2
0.2 U
7 U
206 B
3.4
3 U
65100
1 U
2 U
47.2
10 U
5.6
0.02 U
NA
NA
MW-5
06/10/92
438
12 U
1 U
6.9
1 U
1 U
1510
5 U
2 U
4 U
246
1.3 B
133
2.6 B
0.2 U
7 U
313 B
1 U
3 U
729 B
1 U
2 U
39.9
10 U
0.62
0.02 U

MW-7
06/08/92
605
12 U
1 U
7.1
1 U
1 U
360
100
2 U
4 B
442
4.5
135
4.1
0.2 U
4.9 B
237 B
1.5 B
3 U
17600
1 U
2 U
38.5
10 U
1.5
0.02 U
NA

MW-7 (Dup)
06/08/92
1280
12 U
1 U
7.8
1 U
1 U
274
101
2 U
5.7 B
462
2.8
155
3.7
0.2 U
4 U
271 B
1.5 B
3 U
17100
1 U
2.8 B
29.2
10 U
1.7
0.02 U
NA

MW-8
06/11/92
2820
12 U
1 U
70.4
1 U
9
8830
5 U
4.5 B
4 U
1920
4.4
1480
59.7
0.2 U
7 U
6880
1 U
3 U
18500
1 U
8.3
60
10 U
14.1
0.02 U
1.3

MW-9
06/10/92
26200
12 U
1 U
94.2
1 U
2.3 B
6150
82.9
4.1 B
26.2
57000
21.2
1910
213
0.24
19.1 B
3580 B
1 U
3 U
4960
1 U
209
95.4
10 U
1.8
0.02 U
NA

MW-10A
06/11/92
12400
12
2.4
20.4
1 U
1 U
772
541
9.4
8.8
9790
6.7
293
16.8
0.4
9.1
497
4.6
3 U

U
B

B
B

125000
1 U
46.1
96.9
77.1
15.1
0.04
NA

Result units are Ig/L except for nitrate/nitrite, Kjeldahl nitrogen, and sulfate which are mg/L.
U - The analyte was analyzed for but not detected at or above the IDL
B - The reported value is less than the Contract Reguired Detection Limit (CRDL).
but greater than or egual to the Instrument Detection Limit (IDL).
NA - Compound not analyzed
-------
TABIiE 1 (cont'd)
RI GROUNDWATER SAMPLING RESULTS (Inorganics)

Parameter MW-10A MW-11 MW-12 MW-13 MW-14 MW-16 MW-19
10/08/92 06/08/92 06/08/92 06/08/92 06/10/92 06/09/92 06/15/92
Aluminum
Antimony
Arsenic
Barium
Beryllium
Cadmium
Calcium
Chromium
Cobalt
Copper
Iron
Lead
Magnesium
Manganese
Mercury
Nickel
Potassium
Selenium
Silver
Sodium
Thallium
Vanadium
Zinc
Cyanide
Nitrate
Nitrite
Kj eldahl
Chromium,
Sulfate
13600
12 U
1 U
18.3
1 U
1 U
1580
459
10.9
11.1
12300
8
321
18.5
0.2 U
7 U
561 B
6
3 U
127000
1 U
57.2
29.4
91.9
8.6
0.03
NA
hex NA

15600
12 U
1 U
20.2
1 U
2.5 B
15800
13
8.2
2 U
3000
7.1
11200
182
0.2
5.4
91000
39
1 U
452000
1 U
13.1
209
10.1
7.4
0.02 U
NA
NA

10800
12 U
1 U
156
1 U
1 U
44200
33
5.1
13.2
8740
10
5080
230
U 0.2 U
B 12.9 B
136000
10 U
3 U
20000
1 U
47 4
136 47
10 U
2.3 2
0.02 U 0.
NA
NA

1770
12 U
1 U
23.2
1 U
1 U
2630
6.5
2
4.6
1890
11.9
544
67.9
0.2
4

2.1
3 U
14500
1 U
.4 B
.1
10 U
.2
02 U
NA
NA

42700
12 U
1 U
62.7
1 U
1 U
1100
63.1
U 2.5 B
B 17.6
22300
8.2
749
40.5
U 1.3
U 21.3 B
850 B 3930
B 1 U
3 U
12200
1 U
94.6
81.4
10 U
0.85
0.02 U
NA
NA

924
12 U
1 U
8.9
1 U
1 U
329
5 U
2 U
4.1 B
447
10.8
202
3.2
0.2 U
4 U
231 B
1.5 B
3 U
7950
1 U
3 B
36.3
10 U
1.4
0.02 U
NA
NA

3250
12 U
1 U
9.6
1 U
1 U
376
5 U
2 U
4 U
1200
2.9
135
4.7
0.24
7 U
219 B
1 U
3 U
3920
1 U
8.7
35
10 U
0.86
0.02 U
NA

Result units are Ig/L except for nitrate/nitrite, Kjeldahl nitrogen, and sulfate which are mg/L.
U - The analyte was analyzed for but not detected at or above the IDL.
B - The reported value is less than the Contract Reguired Detection Limit (CRDL),
but greater than or egual to the Instrument Detection Limit (IDL).
NA - Compound not analyzed
-------
TABIiE 1 (cont'd)
RI GROUNDWATER SAMPLING RESULTS (Inorganics)
Parameter
Aluminum
Antimony
Arsenic
Barium
Beryllium
Cadmium
Calcium
Chromium
Cobalt
Copper
Iron
Lead
Magnesium
Manganese
Mercury
Nickel
Potassium
Selenium
Silver
Sodium
Thallium
Vanadium
Zinc
Cyanide
Nitrate
Nitrite
Kj eldahl
Chromium,
Sulfate
MW-21 MW-22
06/09/92 06/09/92
4550
12 U
1 U
38.1
1 U
1 U
333
2740
7
8.7 B
3490
8.7
425
6
0.2 U
30.7 B
551 B
1.3 B
3 U
224000
1 U
18.6
105
156
6.5
0.02 U
NA
hex NA

1930
12
10
26.3
1
1

U
U

U
U
8480
5
2
2.3
858
4.8
129000
78.6
0.2
4
2780
15
3
199000
1
7.7
87.6
10
3.6
0.02
NA
NA

U
U
B

U
U
B
B
U

MW-25
06/10/92
20400
12 U
10 U
244
1 U
1 U
486
1390
15.7
21.3
21300
8.7
1240
28.6
2.4
72.5
1290 B
1.3 B
3 U
289000
1 U
70.4
146
418
11.9
0.16
4.6
NA

MW-28
06/10/92
3050
12
1
6.6
1
1
605
112
2
4
2740
3.5
93.9
5.9
0.2
7
226
1
3
11400
1 U
9.5
59
10
0.96
0.02
NA
NA

U
U

U
U
B
U
U

MW-30
06/10/92
2900
12
1
9.9
1
1
900
22.4
2
4
1960
3
237
5.1
0.
7
362
1
3
16900
1
12.
52
10
2.
0.
NA
NA

U
U

22
U
B
B
U

U
9

U
4
02 U

06/09/92
905
12
10
17.5
1
1
381
3110
3.4
5.8
3680
8.8
248
6.2
0.
8.3
2920
6.4
3
90700
1
7.6
85.4
19.6
13.9
0.02
NA
50

U
U

B
B

42
B
B

MW-33A
08/18/92
526
12
10
15.5
1
1
517
2680
5.6
5.2
1330
4.5
218
6.4
0.
7
2510
4.6
3
84700
1
4.8
97.8
10
15.7
0.2
NA
NA

U
U

67
U
B

U
B

Result units are Ig/L except for nitrate/nitrite, Kjeldahl nitrogen, and sulfate which are mg/L.
U - The analyte was analyzed for but not detected at or above the IDL.
B - The reported value is less than the Contract Reguired Detection Limit (CRDL).
but greater than or egual to the Instrument Detection Limit (IDL).
NA - Compound not analyzed
-------
TABIiE 1 (cont'd)
RI GROUNDWATER SAMPLING RESULTS (Inorganics)
Parameter
MW-34A
MW-35A
10/07/92 06/15/92
Aluminum
Antimony
Arsenic
Barium
Beryllium
Cadmium
Calcium
Chromium
Cobalt
Copper
Iron
Lead
Magnesium
Manganese
Mercury
Nickel
Potassium
Selenium
Silver
Sodium
Thallium
Vanadium
Zinc
Cyanide
Nitrate
Nitrite
Kj eldahl
Chromium, hex
Sulfate
13600
12 U
1.5 B
27.8
1 U
1 U
461
472
2.4 B
8 B
10500
7.7
331
33.4
0.46
7 U
566 B
1.3 B
3 U
36600
1 U
36.7
33.5
10 U
4.7
0.02 U
NA
NA

1070
12 U
1 U
25.4
1 U
1 U
991
2000
2.8 B
4 U
421
1 U
498
6.8
0.2 U
7 U
2760 B
1 U
3 U
30600
1 U
2.4 B
95.7
10 U
8.7
0.02 U
NA
NA

10/07/92
832
12 U
1 U
25.7
1 U
1 U
547
2030
5.1
4 U
714
1.9 B
516
7.3
1.6
7 U
2830 B
1 U
3 U
33800
1 U
3.4 B
26.4
10 U
9.5
0.02
NA
NA

MW-35B
06/16/92
48100
12.6 B
2.2 B
84.7
1.7
1 U
7270
425
3.8 B
30.8
27500
8.6
3180
133
0.24
18.6 B
2720 B
1 U
3 U
35700
1 U
179
115
10 U
7.5
0.02

NA
NA
08/04/92
17100
12 U
1 U
108
1 U
1 U
6950
723
6.2
31.2
27300
18
3180
120
0.26
8.7 B
3030 B
1 U
3 U
32400
1 U
280
112
NA
NA
NA

NA
NA
10/07/92
4880
12 U
1 U
47.5
1 U
1 U
2630
711
5.2
16.4
6940
6.6
1340
33
0.23
7 U
1620 B
1 U
3 U
32800
1 U
75.4
25.1
11.7
8.1
0.02 U

NA
NA
MW-36
10/08/92
11000

3.1
22.6
1 U
1 U
715
16.6
2.2 B
9.9
7970
13.8
475
27.1
0.2 U
7 U
340 B
1 U
3 U
2960
1 U
16.4
42.7
10 U
1.1
0.04
NA
NA

Aluminum
Antimony
Arsenic
Barium
Beryllium
Cadmium
Calcium
Chromium
Cobalt
Copper
Iron
Lead
Magnesium
Manganese
Mercury
Nickel
Potassium
Selenium
Silver
Sodium
Thallium
Vanadium
Zinc
Cyanide
Nitrate
Nitrite
Kj eldahl
Chromium,
Sulfate
MW-37
06/16/92
89500
12.2 B
6.3
178
2.6
1 U
20600
148
12.8
125
65100
34.6
6270
906
0.31
65.4
3110 B
10 U
3 U
25900
1 U
366
199
10 U
0.84
0.02 U
NA
hex NA

08/04/92
57000
12 U
3.4
127
2.2
1 U
13700
98.8
9.3
106
45400
18
4450
533
0.27
39.8
2360 B
1 U
3 U
17500
1 U
257
174
NA
NA
NA
NA
NA

10/08/92
19100
12 U
2.3 B
50.5
1 U
1 U
6510
29.4
3.6 B
54
14500
12.2
1570
155
0.2 U
20.8 B
1050 B
1 U
3 U
7650
1 U
80.2
66.2
10 U
1.4
0.05
NA
NA

MW-38
06/16/92
108000
19.8 B
18 B
232
7.2
1 U
46400
358
11.4
156
59200
79.5
14800
741
0.93
56.8
5380
10 U
3 U
101000
1 U
265
282
14.9
7.6
0.03
NA
NA

08/04/92
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
0.38
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA

10/08/92
24300
12 U
1.4 B
83.5
1 U
1 U
9240
806
7.1
41.3
14200
19.1
3100
197
0.2 U
10.6 B
1810 B
1 U
3 U
68700
1 U
76.6
78.6
12.9
1.9
0.02 U
NA
NA

MW-39A
09/07/93
4910
35 U
2 B
15.9
1 U
3 U
1990
11
4 U
9.6
2720
4.4
230
6.3
0.21 B
8 U
517 B
2 U
3 U
1790
9.4
8.9
11.7
4 B
0.13
0.02 U
NA
0.01 U
1 U
Result units are in Ig/L except for nitrate/nitrite, Kjeldahl nitrogen, and sulfate which are mg/L.
U - The analyte was analyzed for but not detected at or above the IDL.
B - The reported value is less than the Contract Reguired Detection Limit (CRDL),
but greater than or egual to the Instrument Detection Limit (IDL).
NA - Compound not analyzed
-------
TABIiE 1 (cont'd)
RI GROUNDWATER SAMPLING RESULTS (Inorganics)
Parameter

Aluminum
Antimony
Arsenic
Barium
Beryllium
Cadmium
Calcium
Chromium
Cobalt
Copper
Iron
Lead
Magnesium
Manganese
Mercury
Nickel
Potassium
Selenium
Silver
Sodium
Thallium
Vanadium
Zinc
Cyanide
Nitrate
Nitrite
Kj eldahl
Chromium, hex
Sulfate
MW - 40A
09/08/93
287
35 U
2 U
5.2
1 U
3 U
213
4 U
4 U
3 U
62.5
1.3 B
89.4 B
2.2 B
0.2 U
8 U
355 B
2 U
3 U
1400
2 U
2 U
4.8
3.5 B
0.08
0.01 U
NA
0.01 U
1 U
MW - 41A
09/09/93
81100
35 U
24.8
139
3
3 U
26000
161
4 U
34.7
62300
60.8
5570
438
0.66
43.3
2240 B
2 U
3 U
14600
4.4
157
203
2 B
2.5
0.05
NA
0.03
56
MW - 41B
09/08/93
46500
35
12.4
115
2.5
3
13000
314
5.9
45.1
53000
32.8
2580
226
0.62
114
2660
2
3
24300
7.2
356
159
3.5
0.48
0.02

0.01
7.2
MW -
08/26/93
10600
20 U
5 U
150
6
5 U
43100
30
20 U
31
5600
8
10700
290
0.2 U
20 U
4600
2 U
10 U
151000
5 U
29
390
10 U
1.8
0.04
NA
NA
NA
42A
09/10/93
31000
35 U
2 U
131
1.7
3 U
21700
57
4 U
36
28000
1 U
5690
551
0.27
26.4 B
2510 B
2 U
3 U
55300
2 U
31.8
183
3 B
0.79
0.2
NA
0.02
50
MW - 42B
09/08/93
5810
35 U
3.6
41.7
1 U
3 U
6720
14.4
4 U
11.9
3370
9.9
1240
62.1
0.26
8 U
794 B
2 U
3 U
13300
2.6 B
19.6
28.3
3 B
0.5
0.04

0.01 U
14
Result units are in Ig/L except For nitrate/nitrite. Kjeldahl nitrogen, and sulfate which are mg/L.
U - The analyte was analyzed for but not detected at or above the IDL.
B - The reported value is less than the Contract Reguired Detection Limit (CRDL).
but greater than or egual to the Instrument Detection Limit (IDL).
NA - Compound not analyzed
-------
TABIiE 1 (cont,d)
RI GROUNDWATER SAMPLING RESULTS (Inorganics)

(TAL - Total Inorganics Results for Unit I Lower Sand Lobe Monitoring Wells).

Parameter MW - 4B (4A) MW - 35B (old 35D) MW - 41B MW - 42B
6/11/92 6/16/92 8/4/92 10/7/92 9/8/93 9/8/93
Aluminum
Antimony
Arsenic
Barium
Beryllium
Cadmium
Calcium
Chromium
Cobalt
Copper
Iron
Lead
Magnesium
Manganese
Mercury
Nickel
Potassium
Selenium
Silver
Sodium
Thallium
Vanadium
Zinc
Cyanide
Nitrate
Nitrite
Chromium +6
Sulfate
173
12
1.7
18.6
1
1
1800
658
4.5
4
221
5.3
444
6.2
0.2
7
206
3.4
3
65100
1
2
47.2
10
5.6
0.02
NA
NA

U
B

U
U

B
U

U
U
B

U
U

48100
12.6 B
2.2 B
84.7
1.7
1 U
7270
425
3.8 B
30.8
27500
8.6
3180
133
0.24
18.6 B
2720 B
1 U
3 U
35700
1 U
179
115
10 U
7.5
0.02
NA
NA
17100
12 U
1 U
108
1 U
1 U
6950
723
6.2
31.2
27300
18
3180
120
0.26
8.7 B
3030 B
1 U
3 U
32400
1 U
280
112
NA
NA
NA
NA
NA
4880
12 U
1 U
47.5
1 U
1 U
2630
711
5.2
16.4
6940
6.6
1340
33
0.23
7 U
1620 B
1 U
3 U
32800
1 U
75.4
25.1
11.7
8.1
0.02 U
NA
NA
46500
35 U
12.4
115
2.5
3 U
13000
314
5.9
45.1
53000
32.8
2580
226
0.62
114
2660 B
2 U
3 U
24300
7.2
356
159
3.5 B
0.48
0.02
0.01 U
7.2
5810
36
3.6
41.7
1
3
6720
14.4
4
11.9
3370
9.9
1240
62.1
0.26
8
794
2
3
13300
2.6
19.6
28.3
3
0.5
0.04
0.01
14

U
U

U
B
U
U

Result units are in ug/L except for nitrate/nitrite/sulfate which are mg/L.
N-4 - Compound not analyzed
U - The analyte was analyzed for but not detected at or above the IDL.
B - The reported value is less than the Contract Reguired Detection Limit (CRDL)
but greater than or egual to the Instrument Detection Limit (IDL).
-------
TABLE 2
GROUNDWATER SAMPLING RESULTS (Organics)
(Volatile Organic Compounds, Unit I Shallow Monitoring Wells.)
MW-1 MW-2 MW-3 MW-4A MW-4A MW-5 MW-6
Target Compound List 6/11/92 6/11/92 6/11/92 6/9/92 6/9/92 6/10/92 6/10/92
DUP

Acetone 5U 5U 5U 5U 5U 5U 5U
Benzene 1U 1U 1U 1U 1U 1U 1U
Bromodichloromethane 1 U 1U 1U 1U 1U 1U 1U
2-Butanone 5U 5U 5U 5U 5U 5U 5U
Carbon Tetrachloride 1 U 1U 1U 1U 1U 1U 1U
Chloroform 2 1J 0.6J 2B 2B 1U 1U
Chloromethane 1 J 1 U 1U 1U 1U 1U 1U
1,1-Dichloroethane 5 5 1U3 3 1U 1U
1,1-Dichloroethene 8 9 1 U 16 15 1U 1U
cis-l,2-Dichloroethene 5 6 1U2 1J 1U 1U
Ethylbenzene 1 U 1U 1U 1U 1U 1U 1U
2-Hexanone 5U 5U 5U 5U 5U 5U 5U
Methyl ene Chloride 2J 2J 0.8J 2U 2U 2U 2U
Tetrachloroethene 18 17 0.5J 8 7U 1U 1U
Toluene 0.9J 0.3J 0.2J 0.6JB 0.4JB 1U 1U
1,1,1-Trichloroethane 4 4 1U9 8 1U 1U
Trichloroethene 85 59 1 J 21 19 1 U 1 U
Xylenes (total) 1U 1U 1U 1U 1U 1U 1U
Decane 0.7 J
Benzene B Value 1 U 1U 1U 1U 1U 1U 1U
Chloroform B Value 1U 1U 1U 0.5J 0.5J 1U 1U
Toluene B Value 1 U 1U 1U 0.8J 0.8J 1U 1U

Result units are in Ig/L
J - Estimated concentration of analyte which is present but at a concentration less than the stated
detection limit.
B - Allowable analyte present in the sample's associated Method Blank and/or Instrument Blank.
U - Compound was analyzed but not detected.
-------
TABIiE 2 (cont'd)
GROUNDWATER SAMPLING RESULTS (Organics)

MW-7 MW-7 MW-8 MW-9 MW-10A MW-11 MW-12
Target Compound List 6/8/92 6/8/92 6/11/92 6/10/92 6/11/92 6/8/92 6/8/92
DUP

Acetone 5U 5U 5U 5U 5U 5U 5U
Benzene 1U 1U 1U 1U 1U 1U 1U
Bromodichloromethane 1U 1U 1U 1U 1U 1U 1U
2-Butanone 5U 5U 5U 5U 5U 5U 5U
Carbon Tetrachloride 1U 1U 1U 1U 1U 1U 1U
Chloroform 3B 3B 5 1U 2 0.7JB 1U
Chloromethane 1U 0.7J 1U 1U 1U 3 1U
1,1-Dichloroethane 1U 1U 1U 1U 0.8J 1U 1U
1,1-Dichloroethene 0.6J0.6J 2 2 2 1U 1U
cis-l,2-Dichloroethene 1U 1U 3 1U 1U 1U 1U
Ethylbenzene 1U 0.2 J 1U 1U 1U 1U 1U
2-Hexanone 5U 5U 5U 5U 5U 5U 5U
Methylene Chloride 3 3 11 2U 5 2U 2U
1,1,2,2-Tetrachloroethane 1U 1U 1U 1U 1U 1U 1U
Tetrachloroethene 1U 1U 14 19 0.6J 1U 1U
Toluene 3 3 6 1U 2 1U 1U
1,1,1-Trichloroethane 3 4 1J 3 2 0.8J 1U
Trichloroethene 1U 1U 72 1 2 0.8J 1U 1U
Xylenes (total) 1U 1U 1U 1U 1U 1U 1U
Unknown Alkane 4 JB 5 JB
Decane 5 J
Unknown 3 J
Benzene B Value 1U 1U 1U 1U 1U 1U 1U
Chloroform B Value 0.1J 0.1J 1U 1U 1U 0.1J 0.1J
Toluene B Value 1U 1U 1U 1U 1U 1U 1U

Result units are in ug/L.
J - Estimated concentration of analyte which is present but at a concentration less than the stated
detection limit.
B - Allowable analyte present in the sample's associated Method Blank and/or Instrument Blank.
U - Compound was analyzed but not detected.
-------
TABLE 2 (cont'd)
GROUNDlflATER SAMPLING RESULTS (Organics)
Target Compound List

Acetone
Benzene
Bromodichloromethane
2-Butanone
Carbon Tetrachloride
Chloroform
Chioromethane
1,1-Dichloroethane
1,1-Dichloroethene
cis-1, 2-Dichloroethene
Ethylbenzene
2-Hexanone
Methylene Chloride
Tetrachloroethene
Toluene
1,1,1-Trichloroethane
Trichloroethene
Xylenes (total)
Unknown
Unknown
Unknown
Unknown Alkane
Decane
Benzene B Value
Chloroform B Value
Toluene B Value

Result units are in ug/L.
J - Estimated concentration of analyte which is present but at a concentration less than the stated
detection limit.
B - Allowable analyte present in the sample's associated Method Blank and/or Instrument Blank.
U - Compound was analyzed but not detected.
MW-13
6/8/92
5 U
1 U
1 U
5 U
0.7 J
6 B
1 U
1 U
1 U
1 U
0.4 J
5 U
10
1 U
7
1 U
1 U
1 U
0.7 J
0.6 J
3 J
7 JB
4 J
1 U
0.1 J
1 U
MW-14
6/10/92
5
1
1
5
1
2
1
1
1
1
1
5
2
1
2
1
1
1

1
1
1
U
U
U
U
U

U
U
U
U
U
U
J
U

U
U
U

U
U
U
MW-16
6/9/92
5
1
1
5
1
1
1
1
1
1
1
5
2
1
1
1
1
1

1
0.5
0.8
U
U
U
U
U
U
U
U
U
U
U
U
U
P
U
U
U
U

U
J
J
MW-19
MW-21
6/15/92 6/9/92
5 U
1 U
1 U
5 U
1 U
1 U
1 U
1 U
1 U
1 U
1 U
5 U
2 U
1 U
0.6
1 U
1 U
1 U
0.5

1 U
1 U
1 U
5
1
1
5
1
0.8
1
1
1
1
1
5
2
1
J 0.
1
1
1
J 5
2

1
0.5
0.8
U
U
U
U
U
JB
U
U
U
U
U
U
J
U
7 JB
U
U
U
J
J

U
J
J
5
1
1
5
1
0.3
1
1
1
1
1
5
2
1
1
1
1
1
3

1
0.5
0.8
MW-22
6/9/92
U
U
U
U
U
JB
U
U
U
U
U
U
U
U
U
U
U
U
J

U
J
J
5
1
1
5
1
1
1
1
4
1
1
5
2
0,
1
MW-25
6/10/92
U
U
U
U
U
J
U
U

U
U
U
J
.6 U
U
14
1
1
1

1
1
1
J
U
J

U
U
U
-------
TABIiE 2 (cont'd)
GROUNDWATER SAMPLING RESULTS (Organics)

MW-28 MW-30 MW-33A MW-33A MW-35A MW-37 MW-38
Target Compound List 6/10/92 6/10/92 6/9/92 8/18/92 6/15/92 6/16/92 6/16/92

Acetone 5U 5U 5U 10 U 5U 17 5U
Benzene 1U 1U 1U 1U 1U 1U 1U
Bromodichloromethane 1U 1U 1U 10 U 1U 1U 2
2-Butanone 5U 5U 5U 5U 5U 5U 5U
Carbon Tetrachloride 1U 1U 1U 1U 1U 1U 1U
Chloroform 1U 1U 3B 2J 0.9J 9 15
Chloromethane 1J 1J 1U 10 U 1U 0.7J 1U
1,1-Dichloroethane 1U 1U 14 12 1U 1U 1U
1,1-Dichloroethene 1U 1 U 18 15 4 1U 1U
cis-l,2-Dichloroethene 1U 1U 3 10 U 1J 1U 1U
Ethylbenzene 1U 1U 1U 10 U 1U 0.3J 1U
2-Hexanone 5U 5U 5U 5U 5U 5U 5U
Methylene Chloride 2U 2U0.3J 10 U 4 6 3
Tetrachloroethene 1U 1 U 17 14 3 1U 1U
Toluene 1U 0.6J 1U 10 U 0.4J 5 3
1,1,1-Trichloroethane 1U lull 9J 6 1U 1U
Trichloroethene 1U 1U 35 25 11 0.1J 1U
Xylenes (total) 1U 1U 1U 1U 1U 1U 1U
Benzene B Value 1U 1U 1U 1U 1U 1U 1U
Chloroform B Value 1U 1U 0.5J 1U 1U 1U 1U
Toluene B Value 1U 1U 0.8J 1U 1U 1U 1U

Result units are in ug/L.
J - Estimated concentration of analyte which is present but at a concentration less than the stated
detection limit.
B - Allowable analyte present in the sample's associated Method Blank and/or Instrument Blank
U - Compound was analyzed but not defected.
-------
TABIiE 2 (cont'd)
GROUNDWATER SAMPLING RESULTS (Organics)

MW-39A MW-40A MW-41A MW-42A
Target Compound List 9/7/93 9/8/93 9/9/93 9/9/93

Acetone 5 U 140 540 5 U
Benzene 1 U IB 3B 3B
Bromodichloromethane 1 U 1 U 1 U 2
Bromoform 1U 1 U 1U 1U
2-Butanone 4 J 5 U 7 5 U
Carbon Tetrachloride 1U 1U 1U 1U
Chloroform 1 U 1 U 2 15
Chloromethane 1U 1 U 1U 1U
1,1-Dichloroethane 1U 1U 1U 1U
1,1-Dichloroethene 1U 1U 1U 1U
cis-l,2-Dichloroethene 1U 1U 1U 1U
Ethylbenzene 1U 1U 1U 1U
Methylene Chloride 2U 2U 2U 2U
2-Hexanone 5U 5U 2J 5U
Styrene 1U 1U 0.6J 0.5J
Tetrachloroethene 80 78 32 5 U
Toluene 1 U 1 U 1 1
1,1,1-Trichloroethane 1U 1U 1U 1U
Trichloroethene 2 2 0.8 J 1 U
Xylenes (total) 1 1 0.3 J 1 U
2-Propanol NI NI 91 J NI
Benzene B Value 1 U 2 3 3
Chloroform B Value 1U 1 U 1U 1U
Toluene B Value 1U 1U 1U 1U

Result units are in ug/L.
J - Estimated concentration of analyte which is present but at a concentration less than the stated
detection limit.
B - Allowable analyte present in the sample's associated Method Blank and/or Instrument Blank.
U - Compound was analyzed but not detected.
-------
TABIiE 2 (cont,d)
GROUNDWATER SAMPLING RESULTS (Organics)

(Volatile Organic Results for Unit I Lower Sand Lobe Ground Water Monitoring Wells)

MW-4B MW-35B MW-41B MW-42B
Target Compound List 6/11/92 6/16/92 9/8/93 9/8/93

Acetone 5 U 5 U 230 5 U
Benzene 1U 1U 2B 2B
Bromodichloromethane 1 U 2 1 U 1 U
2-Butanone 5U 5U 3J 5U
Chloroform 2 13 8 3
Chloromethane 1J 1U 1U 1U
1,1-Dichloroethene 0.4J 3 1U 1U
cis-l,2-Dichloroethene 1 U 2 1 U 1 U
Methylene Chloride 3 6 2 U 2 U
Tetrachloroethene 1 U 3 110 52
Toluene 3 6 0.9 J 1 U
1,1,1-Trichloroethane 1U 1J 1U 1U
Trichloroethene 1 U 16 3 1 U
Xylenes (total) 1U 1U 2 0.7J
Tentatively identified Compounds
Decane NI 7 J 84 J NI

Result units are in ug/L.
J - Estimated concentration of analyte which is present but at a concentration less than the stated
detection limit.
B - Benzene at 2J NI - None Identified
U - Compound was analyzed but not detected.
NA - Compound Not Analyzed.

-------
TABIiE 3
MARCH 1996 GROUNDWATER SAMPLING RESULTS
Well
Chromium TOTAL
(mg/1)
MW-1
MW-6
MW-10
MW-11
MW-1 2
MW-1 3
MW-1 4
MW-22
MW-28
MW-33
MW-35A
MW-38
MW-43
MW-44
MW-53
MW-54
EW-6
EW-7
EW-8
EW-12
EW-13
SEEP
<0
0.
0.
0.
0.
<0
0.
<0
0.
2.
0.
0.
0.
0.
0.
<0.
0.
0.
4.
0.
0.
0.
.010
0188
310
00936
0053
.010
0155
.010
0466
250
498
513
014
0237
139
010 MX
826
155
260
880
043
187
Chromium HEXV
(mg/1)
<0
0.
0.

0.
<0
<0
0.
1.
0.
0.
0.

0.
0.
1

3
1
0
0
.010
016
326
NA
NA
012 MX
.010
.010
042
78
516
474
012
NA
080
032 MX
.07
NA
.88
.15
.031
.190
Nitrate
(mg/1)
9
0
3
1
1
0
1
1
0
8
5
0
0
0
3
2
2

4
5
2
1
.29
.123
.81
.51
.61
.366
.61
.63
.268
.56
.15
.716
.365
.623
.01
.60
.09
NA
.58
.89
.05
.91
Total VOC
(mg/1)
0
0
0

0
0
0
0
0
0
0
0

.
.

.
.
.
.
.
.
.
.
2
0483
0021
0022 LC
BQL
0046 MX
0025
0027
0017
003
0426
0149
021
.4
BQL

0
0

0
0
0

0
.0527
.0491
BQL
.0257
.0226
.0501
BQL
.0055
NOTES
NA = Not analyzed for in this sample.
LC = Common laboratory contaminant BQL = Below guantitation limit, QL = 0.001 mg/1.
MX = This result is from the higher of two samples (duplicate).
-------
TABIiE 4
WASTEWATER PONDS AREA SOIL SAMPLE RESULTS
Sample ID
Date
Sample Depth (feet)
Total Chromium
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
9/22/94
9/22/94
9/22/94
9/22/94
9/22/94
9/22/94
9/22/94
9/22/94
9/22/94
9/22/94
9/22/94
9/22/94
9/22/94
9/22/94
9/22/94
9/22/94
9/22/94
9/22/94
9/22/94
9/22/94
9/22/94
9/22/94
9/22/94
9/22/94
9/23/94
9/23/94
9/23/94
9/23/94
9/23/94
9/23/94
9/23/94
9/23/94
9/23/94
9/23/94
0,
1,
1,
0,
0,
1,
0,
0,
0,
1,
1,
1,
1,
1,
1,
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
.5
.0
.0
.5
.5
.0
.5
.5
.5
.0
.0
.0
.0
.0
.0
.5
.3
.3
.3
.3
.3
.3
.3
.3
.3
.3
.3
.3
.3
.3
.3
.2
.2
.2
Units = mg/kg

67
153
67
626
389
346
13
13
422
508
787
658
174
4215
260
99
77
583
570
171
1237
1064
124
1111
30832
16477
19676
Hexavalent Chromium

0.44
0.52
0.42
4.69
12.18
4.52
14.43
19.26
10.02
2.94
4.19
4.52
0.44
0.44
0.94
15.01
34.37
61.02
31.87
18.76
91.83
13.01
14.18
5.19
4.69
Not Analyzed
Not Analyzed
Not Analyzed
Not Analyzed
Not Analyzed
Not Analyzed
1.30
209.00
279.00
-------
TABIiE 5
SURFACE TSATER SAMPIiE RESULTS
Concentration
Sample Date Sample Location Source (Ig/L) Sample Date

Chromium, Total
Sample Location Source

Chromium, Total
12/9/82
2/7/83
3/21/83
7/19/83
10/6/83
1/17/84
4/9/84
7/12/84
10/10/84
4/12/85
10/15/85
1/26/86
4/24/86
11/4/86
3/27/87
6/10/87
5/18/88
11/15/88
2/3/89
5/15/89
8/29/89
5/2/90
8/2/90
6/7/91
5/18/92

Seep Location
Seep Location
Seep Location
Seep Location
Seep Location
Seep Location
Seep Location
Seep Location
Seep Location
Seep Location
Seep Location
Seep Location
Seep Location
Seep Location
Seep Location
Seep Location
Seep Location
Seep Location
Seep Location
Seep Location
Seep Location
Seep Location
Seep Location
Seep Location
SW-1
SW-2
SW-3
(1)
(1)
(1)
(1)
(1)
(1)
(1)
(1)
(1)
(1)
(1)
(1)
(1)
(1)
(1)
(1)
(1)
(1)
(1)
(1)
(1)
(1)
(1)
(1)
(2)
(2)
(2)
120
140
140
80
120
80
100
110
140
10 U
10 U
10 U
10 U
10
120
130
350
250
220
250
220
240
240
190
70.7
115
166
NOTES
U = Data gualifier: U = below guantitation limit (BQL)
(1) = SCDHEC permit-reguired guarterly sampling
(2) = RI surface water sampling events (RI Report,
Aguaterra Env. Consultants, 1995)
5/18/92

9/29/92

11/18/92
12/30/92

6/17/93
9/14/93
9/22/94

1/15/95

9/22/94

11/9/95

SW-4 (seep)
SW-4 Duplicate
SW-1
SW-2
SW-3
SW-4 (seep)
SW-4 (seep)
SW-7
SW-7
SW-7
SW-7 Duplicate
SW-4 (seep)
SW-4 (seep)
T-H-SW-2
T-H-SW-3
T-H-SW-4
Seep Location
Chromium, Hexavalent
T-H-SW-1 (seep)
T-H-SW-2
T-H-SW-3
T-H-SW-4
SWO-95 (seep)
SW15-95
SW30-95
SW45-95
SW60-95
(2)
(2)
(2)
(2)
(2)
(2)
(2)
(2)
(2)
(2)
(2)
(2)
(2)
(3)
(3)
(3)
(1)

(3)
(3)
(3)
(3)
(4)
(4)
(4)
(4)
(4)
(3) = SECOR 1994 post-RI surface water and
sediment sampling
(4) = SECOR 1995 post-RI surface water and
sediment sampling
Concentration
(Ig/L)
35.7
39.6
63.9
103
164
47.5
50 U
40
55.0
58.8
40
50
50
49
10 U
10 U
130

10 U
10 U
10 U
10 U
100 U
100 U
100 U
400
300
-------
6. 3 Contaminant Migration

Site contaminants in soil (section 6.2.2), which are predominantly metals, are generally immobile once
transferred to soil, and thus have remained near their source. Leachability work performed as part of
the FS demonstrated, however, that low-level hexavalent chromium remaining in surface soils is likely
leaching to groundwater at levels that would cause exceedance of the MCL. It is assumed that the same
basic mechanism has been operating since 1964-1981 time period. As noted in section 6.1 above, surface
water in the offsite tributary has become contaminated through its main origin as groundwater discharge
at the seep. Sediment likewise has become contaminated via groundwater discharge and conseguent transfer
of contaminants to the sediment. There is no evidence that direct surface water migration from the site
(stream or overland flow) has occurred.

Groundwater contamination has migrated from its source in the former wastewater ponds area, to
groundwater, surface water and sediment in the offsite area. This migration is believed to have resulted
from dissolution and simple groundwater-flow transport. In the RI, probable average linear velocities
(flowrates, V) were calculated based on a measured hydraulic gradient and a measured set of hydraulic
conductivity (K) values, as follows:

Unit I upper sand V = 7.6 ft/year
Unit I middle sand V = 635 ft/year
Unit I lower sand V = 197 ft/year

Comparison of these estimates with the groundwater contamination extent (Figure 6) indicates that offsite
movement of Site contaminants has been retarded to a significant degree by various physical and chemical
factors.

7.0 SUMMARY OF SITE RISKS

Actual or threatened releases of hazardous substances from this site could, if not addressed by the
response action selected in this Record of Decision, present an imminent and substantial endangerment to
public health and the environment. Potential risks to human health posed by the Site were guantified in
a Baseline Risk Assessment (BRA) completed in late 1993, as part of the RI/FS. The BRA evaluated all
risks caused by contamination detected in Site soils, groundwater, surface water and sediment.

After the RI, as part of the FS work during 1995, an Addendum to the Baseline Risk Assessment was
prepared to revise the BRA conclusions regarding contaminated soils (only). The original BRA assumed a
residential future use scenario. However, in accordance with recent guidance, EPA reevaluated likely
future land usage and concluded that continued industrial use of the Site property is the most reasonable
assumption. Use of an industrial land use scenario altered the assumptions concerning exposure freguency
and duration, thus altering the calculated risk levels. The major effect of this revision ("Addendum to
the BRA," Appendix B of the FS) was the determination that no unacceptable current or future risks are
presented by Site soils, assuming continued industrial Site use.

Overall human health risks presented by this site may be gualitatively summarized as follows:

• Under the current land use, there are no unacceptable human health risks presented by the Site
via any medium.

• Under the assumed future land use scenario, which is residential and commercial in the offsite
area and continued industrial use of the Site, excess human health risks are presented via
ingestion of contaminated groundwater.

The following sections summarize the major sections of the risk assessment process. Unless indicated
otherwise, conclusions are based directly on the BRA (1993). Additionally, section 7.5 addresses
potential ecological risks.
-------
TABIiE 6
SEDIMENT SAMPIiE RESULTS
Sample Date Sample Location Source

Chromium, Total
Depth
(inches)
Concentration
(mg/kg)
5/18/92

9/29/92

12/30/92

9/22/94

11/8/95

U = Data
SURFACE = 0
Sed 1
Sed 2
Sed 3
Sed 4
Sed 4
Sed 5
Sed 1
Sed 2
Sed 3
Sed 4
Sed 5
Sed 6A
Sed 7A
Sed 7A Duplicate
Sed 7B
Sed 6B
T-H-SD-1
T-H-SD-2
T-H-SD-3
T-H-SD-4
Seep 1
Seep 2
Seep 3
Seep 4
SDO-95
SDO-95
SD15-95
SD15-95
[1]
[1]
[1]
[1]
[1]
[1]
[1]
[1]
[1]
[1]
[1]
[1]
[1]
[1]
[1]
[1]
[2]
[2]
[2]
[2]
[3]
[3]
[3]
[3]
[4]
[4]
[4]
[4]
qualifier; u = below guantitation
Surface (a)
Surface
Surface
Surface
Surface
Surface
Surface
Surface
Surface
Surface
Surface
Surface
Surface
Surface
Surface
Surface
Surface
Surface
Surface
Surface
0-6
0-12
12-18
NA
0-2
6-8
2-4
12-14
limit (BQL)
10.8
523
49.4
162
172
32.8
17.1
24.8
38.2
91.1
899
15
103
101
13.4
3.8
630
35
2.2
1-U
47
255
116
8.0
552.3
7.89
170.95
13.15
(3) = SECt
to 6 inches below sed/water interface samj
[1] = RI sediment sampling events
[2] = SECOR
1994 sediment sampling

(4) = SECt
samj
Sample Date
11/8/95
11/8/95
11/8/95

Sample Location

Source
Depth
(inches)
Chromium, Total
SD30-95
SD30-95
SD45-95
SD45-95
SD52.5-95
SD60-95
SD60-95

Sed 6A
Sed 6B
Sed 7A
Sed 7A Duplicate
Sed 7B
Seep 3
Seep 4
Seep 1
SDO-95
SDO-95
SD2.5-95
SD15-95
SD15-95
SD30-95
SD30-95
SD45-95
SD45-95
SD52.5-95
SD60-95
SD60-95
[4]
[4]
[4]
[4]
[4]
[4]
[4]
Chromium,
[1]
[1]
[1]
[1]
[1]
[2]
[2]
[2]
[4]
[4]
[4]
[4]
[4]
[4]
[4]
[4]
[4]
[4]
[4]
[4]
0-2
12-14
0-2
10-12
30
12
18
Hexavalent
Surface (a)
Surface
Surface
Surface
Surface
12-18
NA
0-6
0-2
6-8
18
2-4
12-14
0-2
12-14
0-2
10-12
24
12
18
.994 post-RI sediment
sampling (bank of seep)
SECOR 1995 post-RI sediment
sampling (seep area)
Concentration
(mg/kg)
1643.75
263
407.65
18.41
6.75
94.68
72.325

0.02 U
0.02 U
0.02 U
0.02 U
0.02 U
10
1
7
0.6
0.75
1.62
0.63
0.66
0.51
0.48
0.45
0.51
0.78
0.645
0.69
-------
7.1 Chemicals of Concern (COCs)

COCs originate in the BRA from "chemicals of potential concern" (COPCs) , which comprise all of the
chemicals occurring at the Site which could pose risks. All of the detected chemicals are compared to
naturally-occurring background and essential nutrient concentrations, and screened for infrequent
detection and common laboratory contaminants. A concentration- toxicity screening is then conducted,
which removes those chemicals which do not have the potential to contribute significantly to risk. As
detailed in the BRA, some 25 chemicals were considered chemicals of potential concern and were used in
calculating health risks.

As a result of the risk calculation process, as described briefly in the following sections, a group of
chemicals were identified, each of which contributes significant risk (noncarcinogenic risk (HI) 0.1 and
carcinogenic risk > 10 -6) . These chemicals are referred to as the Site "chemicals of concern" (COCs)
in the BRA and the Addendum.

From the original COG list (those appearing in Tables 8-6 through 8-17 of the BRA), all COCs in soils
have been deleted based on the BRA Addendum as described above. No surface water COCs were identified in
the BRA. During review of the draft FS, three groundwater COCs and one sediment COG were deleted by EPA:
two VOCs, bromodichloromethane and chloroform ("Trihalomethanes") from groundwater, arsenic from
groundwater, and arsenic from sediment. Neither of the two VOCs has exceeded 0.015 mg/1; the MCL for the
Trihalomethanes group is 0.100 mg/1 (total), which has never been approached in sample data. Arsenic
concentrations in groundwater have ranged from 0.001 to 0.0031 mg/1, significantly below the MCL
(0.05 mg/1). The inclusion of arsenic as the lone sediment COG was based entirely on a single detection
that has been judged spurious. Finally, due to a revision in the reference dose for manganese, the
corrected manganese groundwater remediation level would be above recorded maximum values in Site
groundwater. These COG deletions are documented in the Site Administrative Record.

As a result of these changes, all of the nine remaining Site COCs occur in the groundwater medium:

chromium lead 1,1-dichloroethylene
cadmium nitrate tetrachloroethylene
cyanide vanadium trichloroethylene

7.2 Exposure Assessment

Exposure assessment consists of identifying the specific population groups that could be affected by the
Site, and evaluating the exposure pathways by which these people could be exposed to contaminants. Based
on the original BRA and subsequent work, the potential exposure pathways can be summarized as follows;

• Currently, the Site is used for industrial purposes. There are no private water wells onsite or
within the offsite areas which have Site- contaminated groundwater. Based on evaluation of the
"Site worker" exposure scenario detailed in the BRA Addendum (soil ingestion, dermal contact)
and the absence of any other current-use COCs, there are no viable exposure pathways onsite or
offsite at present.

• Under a future land use scenario which includes residential development in the offsite area,
unacceptable risk to residents could result from 1. ingestion of contaminated groundwater, or
2. inhalation of such groundwater during showering.

In order to quantify the exposure associated with each pathway, various standard assumptions are made for
key variables in the exposure calculations (BRA and the Addendum). These variables include the
contaminant level in the medium, usually referred to as the exposure point concentration; and the amount
of the chemical taken into the body, or chronic daily intake, which must be calculated using a number of
assumptions. To evaluate a Reasonable Maximum Exposure (RME) scenario, each of the variables was
selected with the goal of producing the maximum exposure that could reasonably be expected to occur.

Table 7 lists and defines the assumptions used to calculate the daily intake of each COG. Table 8
presents the exposure point concentrations calculated for each of the COCs (as well as the toxicity
values discussed in the following section). For each contaminant, the exposure point concentration
represents the upper 95 percent confidence limit of the arithmetic mean of all sampling data (qualified
as described in Section 7.1 above).
-------
7.3 Toxicity Assessment

As part of the risk assessment, the toxic effects of Site contaminants were investigated and evaluated.
Such effects may be carcinogenic, causing excess cancer risk, or noncarcinogenic in nature. In order to
calculate risk, the variables described below are used.

The reference dose (RfD) , used in estimating noncarcinogenic risk, is an estimate of the daily dose of a
substance to which a person may be exposed without appreciable risk of health effects. It is expressed
as mg/kg/day. RfDs are based on human epidemiological studies or animal studies, and have built-in
uncertainty factors that prevent underestimation of potential adverse effects. To estimate carcinogenic
risk, a slope factor is used to estimate the upper bound excess cancer risk posed by a lifetime of
exposure to carcinogens. The slope factor is an estimate of the dose-response curve at very low doses,
and is extrapolated from dose-response data at high doses.

Table 8 presents the toxicity values used to calculate Site risks. Carcinogenic contaminants are
classified in the "WOE" column of the table according to EPA's weight-of-evidence system. This
classification scheme is summarized below:

Group A: Known human carcinogen.

Group Bl: Probable human carcinogen, based on limited human epidemiological evidence.

Group B2: Probable human carcinogen, based on inadeguate human epidemiological evidence but sufficient
evidence of carcinogenicity in animals.

Group C: Possible human carcinogen, limited evidence of carcinogenicity in animals.

Group D: Not classifiable due to insufficient data.

Group E: Not a human carcinogen, based on adeguate animal studies and/or human epidemiological evidence.

7.4 Human Health Risk Characterization

The final step of the Baseline Risk Assessment is the generation of numerical estimates of risk. In the
BRA and the Addendum, this was accomplished by integrating the exposure and toxicity information
described above. Table 9 summarizes the total hazard guotient (noncarcinogenic risk) and total cancer
risk, respectively, associated with the Site.

To estimate noncarcinogenic risk, hazard guotients (HQs) are calculated for each contaminant in each
exposure pathway. The HQ is the ratio of the daily intake divided by the RfD. An HQ value egual or
close to unity (1) indicates the potential for adverse effects. For each pathway, the individual
contaminant Hgs are added together to give a total hazard index, or HI. Under a reasonable maximum
exposure scenario, a person could be exposed to more than one pathway (for example, if groundwater were
used for potable water, both ingestion of groundwater COCs, and inhalation of COCs while showering).
Therefore, the total HI for each population is a summation of the constituent exposure pathways.
Carcinogenic risk estimates are generated in similar fashion for exposure pathways and populations.

Based on the National Oil and Hazardous Substances Contingency Plan, or NCP, EPA uses a benchmark of
Hazard Index (HI) = 1.0 to identify unacceptable noncarcinogenic risks (HI > 1) which reguire remedial
action. For Sites where hazardous substances cause excess risk of cancer, a risk level greater than one
in ten thousand, or 1 X 10 -4 (i.e. one excess cancer death in 10,000 persons) is unacceptable and
reguires EPA to take remedial action, while for situations with risk levels between 1 X 10 -6 (one in one
million) and 1 X 10 -4 EPA may reguire action. An excess risk of less than 1 x 10 -6 is considered
sufficiently protective of human health and the environment.

There are no human health risks under present use conditions. Under the future use (residential)
scenario, excess carcinogenic risk to future water well users in the offsite area is estimated to be 4 x
10 -5 for adult resident and 2.5 x 10 -5 for child resident. The risk is due entirely to potential
ingestion of, and exposure via showering to, shallow groundwater. Noncarcinogenic risk is presented
under a future use scenario and is estimated at HI = 45.8 for the adult resident and 108.6 for the child
resident. As above, excess risk is due entirely to potential ingestion of, and exposure via showering
to, shallow groundwater.
-------
TABIiE 7
SUMMARY OF EXPOSURE PARAMETERS
Pathway: Ingestion of groundwater, future land use scenario
(residential)

Exposure Parameter: IR EF ED BW AT n AT c
(see KEY below)

Population:

Future adult residents 2.0 350 24 70 8,760 25,550
Future child residents 1.0 350 6 15 2,190 25,550

Exposure Intake Formula:

EPC X IR X EF X ED
BW x (AT n or AT c)

KEY

References for all variables are detailed in the Baseline Risk Assessment.

EPC= Exposure Point Concentration

IR = Ingestion rate of groundwater (liters/day).

EF = Exposure frequency (days or events/yr). 350: daily ingestion minus 2 wks annual vacation.

ED = Exposure duration (years). Adult- 24 years, child- 6 years.

BW = Body weight (kg). Standard values are 70 kg (adult average), 15 kg (children 1-6
yrs, 50th percentile.
AT n = Averaging Time (noncarcinogenic). 8,760 days for the adult (24 years x 365 days),
2,190 days for a child (6 years x 365 days).

AT n = Averaging Time (carcinogenic). 25,550 days for the adult (70 years x 365 days),
also 25,550 days for a child (70 years x 365 days).
-------
TABIiE 8
COC EXPOSURE POINT CONCENTRATIONS
AND TOXICITY VALUES
Chemical E.P. Cone.
(mg/1)
of Concern Medium =
Oral 1
Groundwater
imium 2 .
dum 0 .
tide 0 .
[ 0.
fanese 0.
•ate 10
.dium 0 .
dichloroethylene 0.
•achloroethylene 0.
ihloroethylene 0.
74
001
0242
0111
1048
.83
1096
00525
00709
03359
5.00E-3
5.00E-4
2.20E-2
NA
2.3E-2
1.6E+00
7.00E-3
9.00E-3
NA
6.00E-3
Reference Dose
(mg/kq/day)
Inhal- Dermal 3
ation 2
NA
NA
NA
NA
1.43E-5
NA
NA
NA
NA
NA

1
1
4

.OOE-3
.OOE-4
.40E-3
NA
1
3
1
7
.84E-2
.20E-1
.40E-3
.20E-3
NA
4
.80E-3
Cancer Slope Factor
(mg/kg/day) -1
Oral 4 Inhal- Dermal 6
ation 5
NA 4.20E+1 NA
NA 6.30E+0 NA
NA NA NA
NA NA NA
NA
NA
NA
6.0E-1 1.75E-1 7.50E-1
5.2E-2 2.0E-3 6.5E-2
1.1E-2 6. OOE-3 1.38E-2
Cancer
WOE

A
Bl

C
B2

Lead

Mang.

Nitr.

Vana<

I,!-'

Tetr.

Trie!

NOTES

1. Oral reference doses are taken from IRIS except as follows; vanadium dose is from HEAST, trichloroethylene
dose was obtained from NCEA Superfund Technical Support Center.
2. Manganese inhalation reference dose was taken from IRIS.
3. All dermal reference doses assume a 20% absorption efficiency of the oral reference dose, except as
follows: 1,1-dichloroethylene and trichloroethylene reference doses assume an 80% efficiency of the oral
reference dose.
4. Oral slope factors are from IRIS, except for tetrachloroethylene and trichloroethylene, which were
obtained from the NCEA Superfund Technical Support Center.
5. Inhalation slope factors are from IRIS, except for tetrachloroethylene and trichloroethylene, which was
obtained from the NCEA Superfund Technical Support Center.
6. Dermal slope factors for the three COCs which have them assume an 80% absorption efficiency of the oral
slope factor.
7. WOE = weight of evidence used to classify carcinogenic substances (see text).
-------
TABIiE 9
SUMMARY OF TOTAL SITE RISKS
E.P. Cone.
(mg/1)
medium =
Groundwater
2.74
0.001
0.0242
0.0111
10.83
0.1096
0.00525
0.00709
0.03359
Future Use
Scenario
Noncarcinogenic
Risk
Oral Inha^
atioi
14.8 NA
NA NA
29.7 NA
NA NA
0.183 NA
0.423 NA
NA NA
NA NA
0.151 NA
Noncarcinogenic
Future Use Scenario:
Adult Resident
Groundwater Exposures

Chromium

Cadmium

Cyanide

Lead

Nitrate

Vanadium

1,1-dichloroethylene

Tetrachloroethylene

Trichloroethylene

TOTAL SITE RISKS (2)

Adult Resident:

NOTES

1. For 1.1-dichloroethylene, which contributes risk via inhalation during showering, the air concentration utilized
was 0.13436 mg/m 3.
2. The totals for both carcinogenic and noncarcinogenic risks differ from those presented in Table 8-1 of the
Baseline Risk Assessment (Dynamac 1993) due to the deletion of arsenic, chloroform and bromodichloromethane as
COCs. Refer to pages 45-46 of this ROD.
Cancer
Hazard Risk
Index Oral Inhal-
ation
14.8 NA NA
NA NA
29.7 NA NA
NA NA
0.183 NA NA
0.423 NA NA
2.96E-5 3.6E-6
3.47E-6 NA
0.151 3.47E-6 NA

Cancer
Risk

-
-
-
-
-
3.32E-
3.47E-
3.47E-
45.25
Carcinogenic Risk
4.0E-5
-------
TABIiE 9 (continued)
SUMMARY OF TOTAL SITE RISK
Chemical
of Concern
Future Use Scenario:
Child Resident
Groundwater Exposures

Chromium
Cadmium
Cyanide
Lead
Nitrate
Vanadium
1,1-dichloroethylene
Tetrachloroethylene
Trichloroethylene

TOTAL SITE RISKS (2)
E.P. Cone. 1 Noncarcinogenic
(mg/1) Risk

medium = Oral Inhal-
Groundwater ation Dermal
2.74
0.001
0.0242
0.0111
10.83
0.1096
0.00525
0.00709
0.03359
35.1
0.128
70.4
NA
0.433
1.00
NA
NA
0.358
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Hazard
Index
35.1

70.4

0.433
1.00

0.358

1
1
2

Oral

NA
NA
NA
NA
NA
NA
.70E-5
.99E-6
.OOE-6
Cancer
Risk
Inhal-
ation
NA
NA
NA
NA
NA
NA
4.04E-6
NA
NA
Dermal
NA
NA
NA
NA
NA
NA
NA
NA
NA
Cancer

Risk(l)
2.10E-5
1.99E-6
2.OOE-6
Child Resident
Future Use
Scenario
Noncarcinogenic Risk
107.29
Carcinogenic Risk
2.50E-5
NOTES
1. For 1,1-dichloroethylene, which contributes risk via inhalation during showering, the air concentration utilized was 0.13436 mg/m 3.

2. The totals for both carcinogenic and noncarcinogenic risks differ from those presented in Table 8-1 of the Baseline Risk
Assessment (Dynamac 1993) due to the deletion of arsenic, chloroform and bromodichloromethane as COCs. Refer to pages 45-46
of this ROD.
-------
It should be noted that there is some degree of uncertainty associated with the calculated numerical
estimates of human health risks generated in the Baseline Risk Assessment and the Addendum. This is due
to the considerable number of assumptions required to calculate risks, and in the specific selections
made for each variable from a range of possibilities.

7.5 Environmental (Ecological) Risks

The 1993 BRA recommended further investigation of Site ecological communities and the potential for
toxicity to stream biota. Toward this end, field work for an Ecological Assessment (EA) was carried
out in late 1993 and a final EA Report completed in May 1994. The EA included both a field assessment
(Rapid Bioassessment Protocol II) and laboratory toxicity studies.

Concerning surface water, the EA concluded that there was evidence of observable toxicity to test
organisms in water containing 0.049 mg/1 total chromium. Based on this, a "no observable effects" level
(NOEL) was estimated at 0.024 mg/1. Concerning sediment, toxicity was not demonstrated or resolved due
to problems related to natural background effects.

Total chromium levels in seep sediment ranged up to 630 mg/kg and 899 mg/kg, 8 to 11 times the relevant
EPA Region IV Sediment Screening Value of 81 mg/kg, which is based on National Atmospheric and Oceanic
Administration (NOAA) sediment screening criteria. The NOAA "Effects Range Low" (ER-L) value, 81 mg/kg,
represents the lower end (lowest 10%) cutoff value within a range of total chromium levels shown to have
caused toxicity in a large group of studies nationwide, with each number from one study. Based on (1)
the documented total chromium levels in seep sediment, (2) the NOAA sediment criteria, (3) the
exacerbating effect of the very low mineral content of tributary water, and (4) consultation with the US
Fish and Wildlife Service regarding their experience at other chromium sites, EPA believes that offsite
sediment is capable of causing ecological harm in the offsite area if left unaddressed.

No state- or federally- designated endangered or threatened species are known to exist on the facility
property. This is also true for the offsite area, although active nesting sites of the endangered
Red-cockaded Woodpecker are located approximately one to two miles south of the Site at Fort Jackson.

8.0 DESCRIPTION OF REMEDIAL ALTERNATIVES

Remedial alternatives for addressing Site contamination were developed in the FS. As an initial step,
the general objectives to be attained by the selected remedy (Remedial Action Objectives, RAOs) were
determined and are presented in section 8.1 below. Working from these RAOs, which are general in nature,
the FS considered health-based criteria from the risk assessment work, as well as all of the applicable
or relevant and appropriate requirements (ARARs), in order to develop appropriate remediation levels
(RLs) for Site contaminants. Site RLs are presented in section 8.2 below.

Although RAOs were developed for soil, groundwater and surface water, separate remedial alternatives such
as those described in sections 8.3 and 8.4 were not developed to specifically address surface water and
sediment. However, surface water and sediment will be addressed as part of any of the groundwater
alternatives:

Surface water: Since the source of tributary water is predominantly groundwater, the applicable surface
water RL will be accomplished through remediation of groundwater. Sediment (see section 7.5): EPA has
determined that a small-scale removal of sediment in the seep area would remove any actual or potential
ecological threats from contaminated sediment, and would constitute a sufficient and cost-effective
action in comparison to further ecological or toxicity studies. Thus, while no sediment remediation
level has been established, contaminated sediment will be addressed by performance of this excavation and
removal action as described in the FS. The area to be addressed is a small elongate basin just
downstream of the actual seep (surrounding the "SD" sample locations in Figure 9). The action will
remove the uppermost layer of highly-impacted chromium -bearing sediment and is expected to include
approximately 30 - 85 cubic yards of material. It will be performed after the effectiveness of the
groundwater remedy is demonstrated, so that newly-exposed sediment is not re-contaminated following the
action.

8.1 Remedial Action objectives (RAOs)

The following Site-specific RAOS were established in the FS:

Soil:

• Prevent the leaching of contamination into groundwater, which can contribute to human health
risk via groundwater;
-------
Groundwater:
• Prevent exposure to chemicals of concern in groundwater which pose an unacceptable human health
risk

• Reduce concentrations of chemicals of concern, thereby restoring potential use of the aguifer as
a potable water source; and

• Prevent or reduce the continued discharge of contaminated groundwater to surface water, such
that surface water guality standards are not exceeded.
Surface Water:
• Reduce contamination to levels which a) cannot pose ecological risk to tributary flora and
fauna, and b) are incapable of re-Contaminating tributary sediment.

Sediment:

• Prevent exposure of the tributary ecosystem to chemicals of concern, and/or reduce the
concentrations of chemicals of concern such that no unacceptable ecological risks are
presented.

8.2 Remediation Levels

In order to establish site-specific remediation levels (RLs) , the following were considered in the FS:

1. Health-based criteria (suggested RLs) from the BRA and the BRA Addendum;

2. ARARs which pertain to the Site location, specific Site contaminants, or specific types of remedial
actions; and

3. EPA guidance concerning calculation of permissible site specific surface water concentrations
protective of ambient surface water guality.

RLs for the site are presented in Table 10. The RL for surface soils was determined (FS Appendix D)
based on leachability testing of field samples, which identified a hexavalent chromium level at or below
which leaching to groundwater at a level capable of impacting groundwater above the MCL does not occur.
This RL is based only on the reguirement to protect groundwater, as there is no unacceptable current or
future risk presented by Site soils. All of the groundwater RLs are based on their respective MCLs except
for vanadium, which is based on the BRA (BRA chapter 8). As noted previously, there are no separate RLS
for sediment, although sediment will be addressed as part of the groundwater remedial alternative once
selected (see 8.0 above). Finally, a chromium surface water RL, based on the Federal and State ambient
water guality criterion (AWQC) , was developed by SCDHEC in December 1996. The AWQC is considered a
relevant and appropriate ARAR by the State of South Carolina for surface water guality.

8.3 Source Control (Soil) Remedial Alternatives

All costs in this section and in section 8.4 below are estimates and should be considered approximate
(+/- 30%). They are intended primarily for comparison among alternatives. In accordance with EPA
guidance, a discount factor of 7% was used in calculating net present worth cost. Certain of the soil
and groundwater alternatives include preparing CERCLA-reguired Five-Year Reviews, which are remedy status
reports necessary for a selected remedial alternative in which hazardous substances will remain on a site
longer than 5 years.
-------
Medium 1

Surface Soil (2)

Surface Water

Groundwater (4)
NOTES

(1)

(2)

(3)
TABIiE 10
SITE REMEDIATION IiEVELS

Chemical

Chromium +6 (hexavalent)

Chromium (3)

Chromium (total)

Cadmium

Cyanide

Lead

Nitrate

Vanadium (6)

1,1-dichloroethylene

Trichloroethylene

Tetrachloroethylene
Remediation Level

16 mg/kg

0.040 mg/1

0.100 mg/1

0.005 mg/1

0.200 mg/1

0.015 mg/1

10.0 mg/1

0.110 mg/1

0.007 mg/1

0.005 mg/1

0.005 mg/1
(4)

(5)
(6)
Although not listed here, sediment is affected by site-related contamination and is
addressed by the selected remedy described in this Record of Decision. See section 8.0.
Remediation level (RL) is for the protection of groundwater from leaching. This RL was
determined from leaching tests using Site soils and a target groundwater level of 0.100
mg/1, the State and Federal maximum Contaminant Level (MCL) for chromium.
Measured as hexavalent or total chromium. The RL in based on the State and Federal
chronic ambient water guality criterion (AWQC) for chromium. It is intended for the
protection of the ecosystem in and along the offsite tributary; there is no human health
threat associated with chromium in surface water. The RL is based upon the AWQC, which
South Carolina considers to be a relevant and appropriate criterion for protecting
surface water guality in the offsite tributary and surface waters statewide.
All groundwater RLs are State and Federal Maximum Contaminant Levels (MCLs) under
the Safe Drinking water Act (1974), except as indicated in footnotes (5) and (6) below:
EPA Action Level.
Baseline Risk Assessment, Townsend Saw Chain Site (Dynamac 1993).
-------
ATTACHMENT A

Proposed Plan for Townsend Saw Chain Superfund Site
-------
8.3.1 Alternative SI: No Action

Under CERCLA, consideration of cleanup alternatives must always include a "no action" option, to serve as
a baseline for comparison to the other alternatives. In theory, under this alternative, no activities
would be undertaken nor any funds expended to address Site soil contamination. The practical effect of
taking no action would be to allow continued leaching of chromium to groundwater to occur; surface soils
in the former waste ponds area are believed to be a continuing source of chromium contamination to the
underlying groundwater. Such leaching may well be lengthening the current groundwater cleanup process
(extraction and treatment) by transporting chromium back into the groundwater. Under the likely future
land use scenario of continued industrial use of the Site property, surface soil poses no human health
risks to Site workers or trespassers.

The only cost associated with this alternative is for Five-Year Reviews, assuming that some of the
contaminated surface soils remaining onsite will be shown (by test) to constitute hazardous waste.
("Hazardous wastes" are defined by the Resource Conservation and Recovery Act (RCRA), which governs
handling and disposal of hazardous wastes and regulates facilities which generate and/or store such
materials.) At a cost of $15,000 each and assuming six reviews over a 30-year period, the total cost is
approximately $34,000.

8.3.2 Alternative S2: RCRA Cap

Under this alternative, chromium-bearing surface soils would be left in place, the area graded, and then
capped with an impermeable material. The intent of this action is to inhibit the infiltration of surface
water into and through the impacted area. Such a cap would be constructed in accordance with the
reguirements of RCRA. A cap would protect the impacted soils from surface water infiltration through the
use of a low hydraulic conductivity layer (geomembrane or soil) , a drainage layer and a stabilizing
soil/vegetation layer over the affected areas.

Construction of a RCRA-type soil and geomembrane cap would likely reguire up to six months, and
maintenance of the covered area would be expected to occur over the lifetime of the cap (typically 30
years) . Typical maintenance would include periodic inspections to locate and repair any damage to the
cap which could be caused by settling or erosion. The location, toxicity and volume of affected soils
would remain the same after capping activities. A properly engineered cap would be expected to reduce
transport and dispersion of contaminants in the affected soils, including the leaching of chromium to
groundwater.

In general, capping is technically feasible for containing the affected area of soil. Short-term
exposures of construction workers to chromium-bearing soils are manageable, primarily through the use
of water to maintain dust control during excavation activities. Eguipment for installing a cap would
likely be readily available; similarly, the needed approvals and permits can likely be readily obtained.

The costs for implementing Alternative S2 are $506,000 in capital costs, and $40,000 in annual operations
and maintenance (O&M) costs (includes Five Year Reviews), for a total net present worth cost of $546,000.

8.3.3 Alternative S3: Solidification/Stabilization

Alternative S3 involves the treatment of impacted soil by stabilization or solidification technigues.
These are additives or processes which physically or chemically immobilize contaminants in soils.
Stabilization agents such as Portland cement and sodium silicate are commonly utilized for the treatment
of heavy metal impacted soils. This system maximizes the containment of inorganic chemicals of concern
within the treatment area, by thoroughly immobilizing them within a hardened resistant mass, or
"monolith."

Implementation would involve adding aluminosilicate materials and cement with water to the soils. The
soils and binders would be thoroughly mixed with machines typically used for concrete mixing, or they
could be mixed in place with backhoe eguipment. After mixing is complete, the soils would be backfilled
into the original excavation and allowed to cure and harden. The hardened soil matrix would then be
covered with one foot of native soil, graded to provide adeguate drainage, and a vegetative stand would
then be established. Beforehand, a pilot treatability study might be reguired to confirm that this
alternative can meet the remediation levels.

Stabilization/solidification would likely be completed in less than one year. Performance of the process
in resisting leaching or natural degradation will depend on proper operation of eguipment, particularly
during mixing, and on accurate characterization of physical soil conditions.
-------
Stabilization/solidification may require excavation of affected soils before treatment, although the
treatment itself can in theory be performed in-situ. Dust control measures would be needed if excavation
is required. Short-term community and worker exposures could occur from particulate emissions from the
pretreatment screening, crushing and mixing processes. If stabilization/solidification is conducted in-
situ, however, short term exposure of nearby community and onsite workers to the potential contaminants
would not be expected. After treatment, hexavalent chromium in the soil will have undergone a
significant reduction in its mobility and hence its toxicity. Operations would not be expected to
adversely affect the environment in the Site vicinity.

Stabilization/solidification is expected to be technically and administratively feasible, based on the
effectiveness of this technology at similar sites. Equipment for implementing
stabilization/solidification would likely be readily available.

The costs for implementing this alternative include $722,000 in capital costs. Because treated wastes
would remain onsite, Five Year Reviews would be required, although typical Five Year Review requirements
and costs would essentially be covered within the currently-ongoing groundwater monitoring. With the
inclusion of $88,000 in annual, repeating operations and O&M costs, the total net present worth cost is
$810,000.

8.3.4 Alternative S4: In-situ Chemical Treatment

In-situ chemical treatment, and specifically, in-situ chromium reduction, is a new, "innovative"
technology in which a liquid solution containing a reducing agent is placed on, and percolated into,
chromium-bearing soils. Upon contact with the reducing agent, hexavalent chromium in the soils are
reduced to an insoluble, non-toxic, more stable chemical state. The treatment may be accomplished
in-situ, that is, with no excavation required; reagent may be simply percolated into the soil. This
technology is particularly applicable to sites with shallow soil impacts (< 2 feet deep) such as the
Townsend Saw Chain Site. In-situ chromium reduction is classified by EPA as an "emerging" technology,
which means that it has been employed at a limited number of sites and therefore, extensive operational
data are not available at present.

To implement in-situ chemical treatment, first, surficial soils and sludges (up to 6 inches) within the
former wastewater ponds area would be removed and disposed of offsite. This will remove the most highly
affected soils and break up the crusty top layer, improving contact of the treatment solution with the
chromium-impacted material. Introduction of the solution may be accomplished by any number of means,
including injection or use of surface application equipment, such as that in use at the onsite
sprayfields. The treatment solution percolates through impacted soils and reduces the hexavalent
chromium. Soil sampling would be undertaken to verify the effectiveness and permanence of the
reduction/immobilization effects. Targeted or repeated applications may be required to achieve the
remediation levels.

Pilot-scale treatability testing was conducted at the Site during late April - early May 1995, as
reported in the treatability study report entitled "Demonstration Study: In-situ Chromium Reduction in
Soil and Groundwater, Homelite - Textron." The EPA National Risk Management Research Laboratory in
Cincinnati, Ohio assisted in EPA's review of this work. The Demonstration Study was not intended to
determine all of the delivery methodologies, operating parameters, and testing programs needed for
full-scale implementation, but rather to demonstrate the basic chemical effect in onsite field trials.
Reduction of hexavalent chromium concentrations was demonstrated in both soil and groundwater.

In-situ chemical treatment activities would be expected to occur over a period of approximately two
years. Reduction of hexavalent chromium to concentrations below levels of concern is likely to occur
rapidly. Additional treatability work will likely be needed to determine design parameters before
full-scale remediation. If needed, installation of in-situ chemical injection equipment should be
implementable at the Site without major technical or administrative difficulties. Dust control measures
and personal protective equipment would be required during the first stage of remedial activities,
excavation of the top 6 inches of soil, to prevent short-term exposures of the community and Site workers
to contaminants. No significant difficulties in obtaining qualified personnel, appropriate materials, or
regulatory permits are anticipated for conducting chemical treatment activities.

Alternative S4 would involve $769,000 in capital cost outlays. Assuming treatment is successful, Five
Year Reviews would not be necessary, although the requirements and costs would be covered in any case
within the currently-ongoing groundwater monitoring. Approximately $88,000 in annual O&M costs are
anticipated, for a total net present worth cost of $857,000.
-------
8.3.5 Alternative S5: Excavation and Offsite Disposal

This alternative would involve excavating the impacted soils at the Site, and disposing of the soils
offsite at a RCRA - permitted hazardous waste landfill. It may be possible to dispose of the soil at a
RCRA solid waste landfill, which would be less expensive than disposal in a hazardous waste landfill.
The final destination of the impacted soil would be decided during remedial design, depending on the
results of soil sampling. For cost estimating purposes, it will be assumed that the soil will be
disposed of at a hazardous waste landfill.

The areal extent of the soils having hexavalent chromium concentrations greater than the remediation
level of 16 mg/kg is 35,000 sguare feet, with an average depth of two feet. This calculates to
approximately 2,600 cubic yards of soils which have been affected by hexavalent chromium, located
primarily in the former wastewater ponds. No particular technical difficulties are anticipated with
excavation, although a water source would be reguired for dust control during the handling of soils. Air
monitoring of particulates may be reguired during excavation activities, due to the elevated
concentrations of hexavalent chromium in certain areas of surface soil. Permits are expected to be
reguired by local, state and federal agencies for the transportation of affected soil from the Site to a
hazardous waste treatment/disposal facility.

After excavation, clean native fill material would be placed in the excavation, and compacted as needed.
The entire excavation location would then be graded to provide proper drainage and a natural vegetation
stand would be established to reduce erosion. Offsite disposal activities would be completed within one
to two months. It is anticipated that no O&M costs would be incurred after carrying out this
alternative. Remedial objectives would be met by this alternative.

Excavation and offsite disposal costs will include $1,365,000 in capital costs, and since the affected
soils would no longer be onsite, no Five Year Reviews and no annual O&M costs, for a total net present
worth cost of $1,365,000.

8.4 Groundwater Remedial Alternatives

Each groundwater alternative described in this section, other than the no action alternative, includes
the following components, as described in the Proposed Plan. The no action alternative does not
include items 3 and 4 below.

1. Continued operation of the Interim Action pump-and-treat system (IAPTS);

2. Continued guarterly monitoring of selected wells on- and off site, in order to properly monitor the
effectiveness of the selected groundwater alternative (as is presently done for the IAPTS);

3. Regular (periodic) sampling of off site tributary surface water at one midpoint station and one
downstream station (both upstream of Spears Creek), in addition to the ongoing guarterly sampling of
the seep/spring area; and finally,

4. Performing a small-scale sediment removal in the offsite seep area (estimated 30-85 cubic yards).
This action will be conducted after the effectiveness of the IAPTS in capturing the affected
groundwater has been demonstrated, in order to prevent re-contamination of the sediment by
chromium-bearing surface water (see 8.0 above)

8.4.1 Alternative GW1: No Action

As with the soil no action alternative, under this alternative, no activities would be undertaken nor any
funds expended to address Site groundwater contamination. However, the IAPTS, constructed in 1995, is
currently operating and is expected to play a role in the Site remedy. Therefore, for comparison
purposes, this alternative will consist of continued operation of the IAPTS only.

The costs for constructing, operating and maintaining the IAPTS, which includes the associated analytical
and reporting reguirements, are $2,058,000 in capital costs and $1,992,000 in annual O&M costs (30
years). Because of the ongoing groundwater monitoring and reporting, Five Year Reviews would be covered
in routine ongoing reporting, and costs would be minimal to none. The total net present worth cost is
thus $4,050,000.

8.4.2 Alternative GW2: Groundwater Use Restrictions and Monitoring

Under this alternative, institutional controls would be implemented to restrict the use of contaminated
groundwater. State-imposed deed restrictions would be used to prevent certain future uses of the
-------
aquifer, such as for potable and industrial water supplies, irrigation, and washing. Permit restrictions
would require the State of South Carolina to restrict all well drilling permits issued for new wells on
properties that may draw water from the impacted groundwater plume. These restrictions may be written
into the property deeds to inform future property owners about the possibility of impacted groundwater
beneath their property.

Ongoing groundwater assessments would be performed to address impacts to groundwater quality downgradient
of the Site and future land use considerations. This would require periodic groundwater sampling to
monitor the movement of the groundwater plume as well as water quality within it.

Although this alternative would prevent human exposure to contaminants, it could require a very long
treatment period to meet the Site objectives of 1) reducing contaminant concentrations in surface water
to ecologically-sound conditions, or 2) restoring groundwater to its beneficial use as a potable water
source. Natural reductions of contaminant levels in groundwater may occur, but the time period involved
would likely be very long.

Costs for implementing use restrictions and monitoring only are $2,086,000 in capital costs and
$1,992,000 in long-term O&M costs. Five Year Reviews are not included for the same reasons described
above under Alternative GW1. Total net present worth cost is $4,078,000.

8.4.3 Alternative GW3A: Groundwater Extraction, Treatment, Sprayfield Discharge

Alternative GW3A consists of installing additional extraction wells throughout the Site, to increase the
quantity of impacted groundwater removed, and treatment of this larger quantity of groundwater. This
would essentially represent an expansion of the existing IAPTS.

Installation of an extraction, treatment and discharge system is expected to require several months.
Operation and maintenance of the system is expected to occur over the lifetime of the system (for
cost-estimating purposes, thirty years) . For treatment, a chemical reduction process would be used as is
currently being used for the IAPTS. The treated water would be discharged to the currently-permitted
sprayfield. Appropriate equipment is available for the activities needed under this alternative.
Installation of the required process equipment would be expected to be completed at the Site without
major technical or administrative difficulties, based on recent experience with IAPTS construction and
installation. No significant difficulties in obtaining permits or approvals are anticipated for
conducting expanded pump-and-treat activities.

Groundwater extraction and treatment is a reliable and proven technology. An advantage of this system is
that it would be an expansion of the existing IAPTS, and ongoing operations and maintenance and
groundwater monitoring programs could merely be expanded. When operating properly, a pump-and-treat
system (whether the IAPTS or an expanded system as envisioned here) can meet the remedial levels for both
hexavalent chromium and the other groundwater COCs. However, pump-and-treat remediation is affected
by a variety of subsurface geochemical processes which often lengthen the time necessary to bring
contaminant concentrations down to standards. EPA has documented that, over time, contaminant
concentrations level off above remediation targets (usually the MCL), requiring inordinate amounts of
time to achieve any further minor reductions.

This alternative assumes that five new pumping wells would be needed. Pumping of these wells would
capture dissolved contaminants and create a hydraulic barrier to control contaminant migration.
Groundwater modeling would be conducted during remedial design to determine the actual locations and
pumping rates of the wells. An extraction rate of 30 gpm was assumed for cost estimating purposes, based
on preliminary modeling conducted for the IAPTS. A thirty-year operation duration was assumed due to the
relatively slow attainment of the MCLs as described above.

Alternative GW3A will involve $4,028,000 in capital costs and $2,655,000 in annual O&M costs. Five Year
Reviews are not included for the same reasons described above under Alternative GW1. The total net
present worth cost is thus $6,683,000.

8.4.4 Alternative GW3B: Groundwater Extraction, Treatment, POTW Discharge

Alternative GW3B is identical to Alternative GW3A, except that the treated groundwater would be
discharged to a local publicly-owned treatment works (POTW), rather than being discharged to the onsite
sprayfield. Depending on the Industrial Pretreatment standards required by the POTW, it is possible that
some or all of the treatment steps of the current treatment process may no longer be necessary.
Additional costs would be incurred, in the form of fees, to discharge to a POTW. The treatment system's
effluent would be monitored to assure compliance with the Industrial Pretreatment standards and any other
requirements established by SCDHEC.
-------
Costs for this alternative include a capital cost of $4,051,000 plus $2,762,000 O&M costs, for a total
cost of $6,813,000.

8.4.5 Alternative GW4: In-situ Chemical Treatment

As described earlier under Alternative S4, In-situ Chemical Treatment is a new, innovative technology
which uses liquid solutions containing a reducing agent. To remediate groundwater, the solutions are
delivered into the saturated zone (into the aguifer) to allow and foster contact between contaminated
groundwater and the reductant solution. Upon contact, the hexavalent chromium in the affected
groundwater is reduced, and precipitates, forming an inert, insoluble, non-toxic mineral containing
chromium in its more stable (trivalent) chemical state.

In-situ chemical treatment activities are expected to occur over a period of approximately one to two
years. Reduction of hexavalent chromium to a concentration below the remediation level is expected to
occur rapidly; however, a phased approach to remediation would likely be undertaken. In conjunction with
the existing IAPTS, this alternative would provide a contained "treatment area" for groundwater, within
which evaluation of the reduction/immobilization effects can be evaluated. In-situ chemical treatment
performance would depend in large measure on maintaining peak operating conditions and careful
maintenance of the delivery systems used to place the reductant solutions into contact with groundwater.
Specially-targeted or repeated applications may be required to achieve the chromium remediation level.
Even with a phased approach, in-situ chemical treatment is expected to be conducted over a short time
(one to two years) , with minimal maintenance of treatment equipment required. Regular monitoring of
the affected groundwater would be required throughout the remediation process.

Chemical treatment is a commonly-used technology ex-situ (i.e. in treatment vessels) for treating
groundwater affected by heavy metals, and is the technology currently in use at the Site. As an in-situ
treatment, however, there is very little operational record from environmental sites upon which to
conclude that the treatment will, without uncertainty, based on similar sites, perform exactly as
intended. However, this is also true for a number of other innovative technologies in use at EPA sites.

There are no obvious technical problems which would preclude use of the treatment. The reducing
solutions used will likely contain small amounts of sulfate; however, Site groundwater data show that it
already contains sulfate, suggesting that the addition of more sulfate via the injected solutions should
not significantly affect the natural groundwater composition. The quantities of chemicals likely to be
used in the solutions are minimal and unlikely to pose problems in gaining the needed permits for
injection via wells. Appropriate equipment is expected to be available as needed, and installation of it
is unlikely to pose any difficulties. Equipment options may include, alone or in combination, use of the
current sprayfield equipment, multiple well points, or other simple technologies capable of delivering
the solutions to the affected groundwater.

Pilot-scale treatability testing was conducted at the Site during late April - early May 1995
("Demonstration Study: In-situ Chromium Reduction in Soil and Groundwater, Homelite - Textron"). As
noted under Alternative S4, the Demonstration Study showed that the basic chemical effect, reduction of
hexavalent chromium concentrations in groundwater, was demonstrated. Additional treatability work would
be needed to determine design parameters before full-scale remediation.

During the treatment period, while the IAPTS is operational, remediation levels for all of the chemicals
of concern would be pursued. However, under this Alternative, if hexavalent chromium levels throughout
the plume are successfully and substantially reduced to levels below the groundwater remediation level
(0.1 mg/1), the need for continued groundwater extraction and/or groundwater treatment to address the
other groundwater CoCs would need to be considered separately, depending on the concentrations still
present in the aquifer. This could require EPA to modify the Site remedy in order to 1) consider the
need for, and effectiveness of, continued pumping, and 2) consider other options, such as reduced or
targeted pumping, dispersion modeling and/or modeling of other natural degradation processes, and/or use
of any new or innovative technologies as may become available.

The cost estimates assume that the IAPTS operates for a total of five years, and that successful
treatment eliminates the need for Five Year Reviews. Capital costs for In-situ Chemical Treatment
total $2,624,000, which includes approximately $1.4 million for construction of the IAPTS; and O&M costs
of $658,000, for a grand total cost of $3,282,000.
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9.0 SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES

As set forth in the NCP, 40 CFR 300.430(e)(9), EPA uses nine criteria to evaluate the remedial
alternatives which could be employed for a given Site. These criteria are described below. To be
selected by EPA, an alternative must meet the first two "threshold" criteria, overall protection of human
health and the environment, and compliance with ARARs. Criteria 3 through 7 are used to identify
differences and advantages among those alternatives which meet the threshold criteria. Finally, the
preferred alternative is then further evaluated against the final two criteria, State acceptance and
community acceptance.

An evaluation of the proposed remedial alternatives in relation to each of the nine criteria is presented
below. A description of each criterion is followed by the site-specific analysis, indicated by the " 6 "
symbol. For ease of reference in reviewing the alternatives, Table 11 below presents a summary of the
remedial alternatives and associated costs. As noted at section 8.3, costs are estimates and are
intended for comparison purposes.
TABIiE 11
REMEDIAL ALTERNATIVES

Medium Alt. Title Cost
Soil SI No Action $34,000
S2 RCRA Cap $546,000
S3 Solidification/ $810,000
Stabilization
S4 In-situ Chemical Treatment $857,000
S5 Excavation and Offsite Disposal $1,365,000
Groundwater GW1 No Action $4,050,000
GW2 Groundwater Use Restrictions and $4,078,000
Monitoring
GW3A Groundwater Extraction, Treatment, $6,683,000
and Sprayfield Discharge
GW3B Groundwater Extraction, Treatment, $6,813,000
and Sprayfield Discharge

GW4 In-situ Chemical Treatment $3,282,000
1. Overall Protection of Human Health and the Environment addresses the degree to which an alternative
meets the reguirement that it be protective of human health and the environment. This includes an
assessment of how public health and environmental risks are properly eliminated, reduced or controlled
through treatment, engineering controls, or controls placed on the property to restrict access and
(future) development.

• The no action alternatives for both soil and groundwater would not be as protective of human
health and the environment as would the other choices available for selection. Although the
groundwater no action alternative would include continued operation of the Interim Action
Pump-and-Treat System, no action would be undertaken to address offsite tributary sediment or
monitor its downstream water guality (currently only the seep is sampled). Also, under the soil
no action, leaching of chromium to groundwater that is probably occurring now would be allowed
to continue, thus continuing to impact groundwater and working against the current groundwater
pump-and-treat effort.

• Most of the other alternatives would likely be protective of human health and the environment.
However, excavation and offsite disposal of soil (S5) may simply transfer the disposal problem
to the community where the landfill is located, and thus may not be protective of human health
due to the possibility of release even at a regulated landfill facility. All of the groundwater
alternatives other than no action would be generally protective of human health and the
environment, although the in-situ treatment (GW4) would achieve protectiveness in a shorter time
period than would those relying on the ongoing pump-and-treat effort (GW2) or even expanded
pump-and-treat (GW3A and 3B).

2. Compliance with Applicable or Relevant and Appropriate Requirements (ARARs) addresses whether or not
an alternative complies with all state and federal environmental and public health laws and
reguirements that apply, or are relevant and appropriate, to the conditions and cleanup options at a
specific site. If an ARAR cannot be met, the analysis of the alternative must provide the grounds
for invoking a statutory waiver.
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• The soil and groundwater no action alternatives do not meet ARARs. The soil no action
alternative fails to address leaching, allowing contaminated soil to continue to impact
groundwater at levels exceeding the MCLs. Due to the groundwater to-surface water discharge
that is occurring, neither the groundwater no action alternative nor the use restrictions and
monitoring option (52) meets State and Federal ARARs regarding protection of ambient water
guality in State surface waters, nor does it address potential ecological impacts to sediment
originating from chromium-bearing stream water.

• Most of the other alternatives for soil and groundwater would generally meet the ARARs that
would apply to the specific actions, locations, and chemicals present at this Site. However,
for some alternatives, meeting ARARs may prove more difficult than others. Among the soil
alternatives, for example, a RCRA cap (S2) reguires consistent and regular maintenance that can
be troublesome, and problems of this kind can cause failure to meet RCRA reguirements.
Excavation and offsite disposal (S5) could easily meet ARARs onsite, but could also introduce
RCRA compliance problems at the landfill facility utilized for disposal.

3. Long-Term Effectiveness and Permanence refers to the ability of an alternative to maintain reliable
protection of human health and the environment over time once the cleanup levels have been met.
Since the no action alternatives do not meet the threshold criteria above (are not protective and do
not meet ARARs), they are not considered further below.

• Among the soil alternatives other than the no action, the treatment or excavation alternatives
(S3, S4 and S5) are rated highly. However, verifying the permanence and long-term effectiveness
of solidification/stabilization (S3) reguires long term monitoring, essentially forever; and
there can be problems if the physical processes used to mix the affected soils and the
binding/reacting agents produce a monolith that is not fully homogenous, creating "less-cured"
or "less-stable" areas of the monolith that can leach. Excavation and disposal (S5) could be
considered permanent and effective at the Site, but could pose problems over the long-term at
the chosen landfill facility. Concerning in-situ chemical treatment (S4), soil leachability
testing performed in 1995 for the FS indicated that, once chromium is converted by treatment to
the trivalent form (Cr3+), it will not be re-mobilized by contact with precipitation percolating
downward to the water table.

• Long-term effectiveness and permanence of use restrictions and monitoring (GW2), as well as the
groundwater no action alternative, must be considered somewhat guestionable in view of EPA and
industry long-term experience with pump-and-treat remedies, which indicates that the performance
of pump-and-treat systems often drops off substantially over time, while contaminant levels
still remain above standards. This same problem (decreasing effectiveness over time) may impact
Alternatives GW3A and GW3B, each of which comprises an expansion of the current pump-and-treat
arrangement. While the long-term effectiveness and permanence of in-situ chemical treatment
(GW4) would have to be verified, onsite treatability work (as reported in the FS) supports the
probability that the treatment of groundwater, once completed, will be permanent.

4. Reduction of Toxicity, Mobility, and 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 substance as their principal element.

• A properly constructed RCRA Cap (S2) would achieve a reduction of the mobility of soil-borne
hexavalent chromium, but no reduction of its current volume or toxicity. In contrast,
Alternatives S3, S4 and S5 achieve reductions in two or more of these characteristics. For S5
(excavation/offsite disposal), however, toxicity and mobility reduction assumes that some
treatment would be undertaken at a disposal facility; no actual volume reduction would occur,
although onsite there would be no volume remaining, since the soil would have been removed.
Solidification/stabilization (S3) would be expected to reduce the toxicity and mobility of
contamination, but not its volume, which would essentially egual the volume of the
treatment-created monolith. Although still considered an "emerging" technology by EPA, in-situ
chemical treatment (S4) has the potential to reduce the toxicity, mobility, and volume of the
chromium-impacted soils.

• The use restrictions and monitoring alternative (GW2) and both of the expanded pump-and-treat
alternatives (GW3A, GW3B) include continued pump-and-treat for groundwater. These alternatives
will achieve reduction of the volume of contamination, but very slowly and only over a long
period of time, as the affected groundwater is captured by the system. No reduction in chemical
toxicity of the groundwater not yet captured is achieved, although physical mobility is reduced
through the system's five pumping wells, which create a hydraulic barrier (a capture zone) that
effectively prevents offsite escape of affected groundwater. In contrast, in-situ chemical
treatment (GW4) has the potential to reduce the toxicity of chromium-bearing groundwater by
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causing precipitation of the chromium onto subsurface soil particles, thus removing it from
groundwater. This removes contaminant mobility and volume as well. The potential for a
permanent and total removal of chromium from groundwater sets Alternative GW4 apart from the
others.

5. Short-Term Effectiveness addresses the impacts of an alternative on human health and the environment
during the construction and implementation phase, until remedial action objectives have been met.

• All of the soil and groundwater alternatives are rated generally even on this criterion, and no
significant negative impacts are expected.

6. Implementability refers to the technical and administrative feasibility of implementing an
alternative, including the availability of the various services and materials required for its
implementation.

• All of the soil and groundwater alternatives should be easily implementable, in that the
materials and services needed to design and construct each one are readily available.
Differences among the alternatives are not significant.

7. Cost refers to the capital (primarily construction and purchase) costs for implementing an
alternative, plus the costs to operate and maintain the alternative over the long term. Under this
criterion, the cost-effectiveness of the alternative can be evaluated (see Table 11).

• Total present-worth cost of the soil alternatives, excluding no action, are generally in the
same order of magnitude except for excavation and disposal (SS). Alternative S4, otherwise
comparable to solidification/stabilization (S3), is more cost effective in that it does not
create a "treatment cell" requiring long-term monitoring; successfully-treated soil would
require almost no monitoring over the long term.

• Cost differences among the groundwater alternatives reflect the three general approaches
described: continued IAPTS operation for as long as 30 years for about $4 million (GW1 and
GW2), expand/larger IAPTS for up to 30 years for about $6.7 to 6.8 million (GW3A and 3B) , or
treat the groundwater (in-situ chemical treatment) over five years for about $3.3 million.
Alternative GW4 involves incurring more costs over the short term, but eliminates O&M costs that
otherwise would be incurred during later years of operation.

8. State Acceptance addresses whether, based on its review of the RI, FS, and Proposed Plan, the State
concurs with, opposes, or has no comments on the alternative proposed by EPA as the selected
alternative (or "remedy").

• The State of South Carolina concurs with this selected alternative. The State's letter of
concurrence is attached to this ROD as Appendix B.

9. Community Acceptance addresses whether the public agrees with EPA's selection of the alternative.
Written or oral public comments, as well as informal feedback from the Proposed Plan Public Meeting
or from discussions with residents, citizens or officials, are all considered in judging community
acceptance.

• A public meeting was held on September 17, 1996, to present the Proposed Plan for Remedial
Action at the Site to the community. The meeting was announced in an advertisement in the
Columbia, South Carolina, daily newspaper, and also in a fact sheet mailed to some 600
residents, interested local officials, and others. Comments at the meeting were generally
supportive of the proposed action. Although very few persons attended the meeting, EPA believes
there remains strong local interest and concern from residents living near the Site and
particularly around Woodcreek Lake. Extension of the public comment period was not requested.

10.0 THE SELECTED REMEDY

Based upon consideration of the requirements of CERCLA, the NCP, detailed analysis of the remedial
alternatives, and public and state comments, EPA has selected soil Alternative S4, In-situ Chemical
Treatment, and groundwater Alternative GW4, In-situ Chemical Treatment, for remediation of this Site.
Upon completion of this remedy, the risks associated with the Site are projected to be below EPA's
acceptable risk range of 1 X 10 -4 to 1 X 10 -6 for carcinogens and below a hazard quotient of 1 for
noncarcinogens. These levels are considered protective of human health and the environment. The
estimated present worth cost of the remedy, which includes $3,393,000 in capital costs and $746,000 in
O&M/monitoring, totals $4,139,000.
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10.1 Description of the Selected Remedy

The remedy consists of a source control (soil remediation) component, a groundwater remediation
component, a site monitoring program, and performance of the seep-area sediment removal. The sediment
action is considered part of the groundwater remediation component. A remedial design will be reguired
to plan and design the remedial action selected by this ROD.

The basic in-situ chemical treatment process to be employed for both soils and groundwater is described
generally in sections 8.3.4 and 8.4.5. Because in-situ chemical treatment, and specifically, in-situ
chromium reduction, has been used at relatively few sites, the specific seguence of activities that will
be performed cannot be presented in detail here, but rather, will have to be determined during a remedial
design (RD) phase of work. In addition to the standard Superfund RD elements, which will be modified as
appropriate for the nature and scope of this work, the RD will include, at a minimum, the following
elements:

a. A plan for removal of the most-contaminated surficial soils and sludges (up to 6 inches depth)
within the former wastewater ponds area, and their disposal offsite;
b. A plan for testing and evaluating the various delivery methodologies and/or strategies which could
be used to place
treatment solutions into contact with soil and groundwater;
c. A strategy for verifying the effectiveness and non reversibility of the chemical treatment process;
and,
d. Utilization of multiple, phased actions in order to maximize the ability to modify and improve the
treatment's effectiveness, as the process is implemented across the Site.

In accordance with the NCP, any modification to the selected remedy described in this ROD would be
accomplished by EPA through a formal ROD modification process, such as an Explanation of Significant
Differences or a ROD Amendment; and any such modification will take into account state and public
comments.

10.1.1 Source Control (Soil Remediation)

After the most-impacted surficial soils and sludges currently located within the former wastewater ponds
area are removed, in-situ chemical treatment of the affected soils will be completed, in a phased
approach to be detailed in the Remedial Design. For both soil and groundwater, the RD will be oriented
towards treatability issues such as those described immediately above, rather than the "construction
design" issues more common in CERCLA remedies. Anticipated treatability issues specific to soil
remediation include verifying the non-remobilization of hexavalent chromium under ambient surface-soil
conditions.

Available information suggests that treatment activities will reguire approximately one year, although
this will have to be determined in the RD. Periodic soil sampling will be conducted for five years, to
confirm the success of treatment. The remediation level applicable to surface soils, determined in the
FS to be protective of groundwater against leaching, is 16 mg/kg hexavalent chromium (Table 10).

10.1.2 Groundwater Remediation

This component of the remedy includes a) in-situ chemical treatment of groundwater, and b) continued
operation of the IAPTS to capture and treat affected groundwater, and c) performance of the seep-area
sediment removal.

In-situ Chemical Treatment and IAPTS Operation

As described above, an RD will be prepared to plan the specific activities by which in-situ chemical
treatment of chromium-impacted groundwater (and soil) will occur. Anticipated treatability issues
specific to groundwater remediation include evaluating the various delivery methodologies that could be
used to place reductant solutions into the aguifer to foster contact between contaminated groundwater and
the solution.

In-situ chemical treatment activities are expected to reguire a period of approximately one to two years,
and to achieve rapid reduction of hexavalent chromium to levels below the remediation level for chromium.
During this period, the IAPTS will remain operational, and gradual capture of both chromium and the other
groundwater COCs will continue. IAPTS operation will maintain a hydraulically-controlled "treatment
area" within which reduction/immobilization effects can be evaluated. Regular monitoring of the affected
groundwater will be continued throughout the remediation process.
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Successful in-situ chemical treatment should bring chromium groundwater concentrations throughout the
plume to levels below the remediation level (0.1 mg/1 total chromium). Once this is confirmed, EPA will
then reevaluate the need for continued groundwater extraction and treatment to address only the other
groundwater COCs, depending on the concentrations which are still present in the aguifer at that time.
This reevaluation will allow EPA to consider the need for continued pumping, as well as to consider other
options, including:

• reduced or targeted pumping,
• pulse pumping at one or more wells,
• installation of additional or replacement wells,
• targeted use of any new or innovative technologies as may become available,
• modeling or evaluation of natural attenuation processes, or others.

Seep Area Sediment Removal

As described in the FS (Appendix G), a small-scale removal action will be conducted to remove the
uppermost layer of sediment in a small area surrounding the seep which contains significantly elevated
levels of chromium. In a simple and direct manner, this action will permanently eliminate any potential
harm or effects to tributary plants and animals. The estimated volume of affected sediment is between 30
and 85 cubic yards. The action will be undertaken during the remedial action, but after EPA is satisfied
that the area of effective hydraulic groundwater capture imposed by the IAPTS is sufficient to prevent
sediment re-contamination from chromium-bearing stream water once the sediment action is completed.

10.1.3 Site Monitoring

A Site Monitoring Plan will be developed during the remedial design phase. As a minimum, site monitoring
will include the guarterly groundwater sampling presently conducted in accordance with both the IAPTS
(1994 Unilateral Administrative Order) and the current SCDHEC (state) industrial wastewater permit. The
present sampling scheme consists of sampling and analysis from fifteen monitor wells, two extraction
wells, and a surface water sample at the spring/seep which feeds the unnamed offsite tributary. To the
current program will be added the following:

• In order to evaluate and monitor surface water guality, surface water samples will be collected
and analyzed for chromium, from a minimum of one (1) "midpoint" station on the tributary, and
one (1) downstream station at some distance down the unnamed tributary (both upstream of Spears
Creek).

10.2 Applicable or Relevant and Appropriate Requirements (ARARs)

This section presents the ARARs which will govern implementation of the selected remedy.

10.2.1 Applicable Requirements

The following general processes and technologies are those expected by EPA to be used in implementing the
remedy. Each is followed by the ARARs associated with its use. It is possible that development of new,
unforeseen information about the Site during the design phase may cause modifications or additions to the
listed ARARs.

Sludge generation from exsitu (current process) chromium reduction: The present remediation process
includes treatment of impacted groundwater in electrochemical precipitation cells, which remove inorganic
contaminants (metals, predominantly chromium) from the groundwater. The precipitation of metals
generates a solid hazardous-waste sludge. This treatment process shall comply with all applicable
portions of the following federal and State of South Carolina regulations:

40 CFR Parts 261, 262 (Subparts A-D), 263, and 268, promulgated under the authority of the Resource
Conservation and Recovery Act.

These regulations govern the identification, transportation, manifestation, and land disposal
restriction reguirements of hazardous wastes. In this case, the regulations would be applicable to
the sludges which will be produced as a result of chemical treatment of groundwater pumped for
treatment from the IAPTS. Sludge from the presently-used physical/chemical removal process
probably constitutes hazardous waste based on its characteristics.

SC Reg. 61-79.124, .261, .262, .263 and .268, South Carolina Hazardous Waste Management Regulations,
promulgated pursuant to the Hazardous Waste Management Act, SC Code of Laws, 1976, as amended.
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Establishes criteria for identifying and handling hazardous wastes, as well as land disposal
restrictions. These regulations are also applicable in exactly the same manner as described above
for the federal hazardous waste regulations.

49 CPR Part 107, 171-179, promulgated under the authority of the Hazardous Materials Transportation Act.

Regulates the labeling, packaging, placarding, and transport of hazardous materials offsite. These
regulations are applicable in the event hazardous wastes (sludges from treatment) are transported
off-site for treatment or disposal.

Construction and use of monitoring or extraction wells: The ARAR listed below is applicable to all
groundwater remediation activities undertaken pursuant to this remedial action which involve monitoring
or extraction wells.

SC Reg. 61-71, South Carolina Well Standards and Regulations, promulgated under the Safe Drinking Water
Act, SC Code of Laws, 1976, as amended.

SC Reg. 61-71 establishes standards for well construction, location and abandonment activities
conducted as part of investigation or cleanup operations, at all environmental or hazardous waste
sites in the State of South Carolina.

10.2.2 Relevant and Appropriate Requirements

The following regulations are considered relevant and appropriate criteria governing groundwater
remediation by the method indicated.

Groundwater treatment through both in-situ chemical treatment and operation of a pump-and-treat system:

40 CPR Parts 141-143, National Primary and Secondary Drinking Water Standards, promulgated under the
authority of the Clean Water Act.

These regulations establish acceptable maximum levels of numerous substances in public drinking
water supplies, whether publicly owned or from other sources such as groundwater. Maximum
Contaminant Levels (MCLs) and Maximum Contaminant Level Goals (MCLGs) are specifically identified
in the NCP as remedial action objectives for ground waters that are current or potential sources of
drinking water supply (NCP 40 CFR ° 300.430 (a)(1)(ii)(F). Therefore, MCLs and MCLGs are relevant
and appropriate as criteria for groundwater remediation at this Site.

SC Reg. 61-58, South Carolina Primary Drinking Water Regulations, promulgated pursuant to the Safe
Drinking Water Act, SC Code of Laws, 1976, as amended.

These regulations are similar to the federal regulations described above, and are relevant and
appropriate as remediation criteria for the same reasons set forth above.

SC Reg. 61-68, South Carolina Water Classifications and Standards, promulgated pursuant to the Pollution
Control Act, SC Code of Laws, 1976, as amended.

This regulation establishes classifications for water use. Additionally, the Ambient Water Quality
Criteria (AWQCs) established in 40 CFR Part 131 are incorporated into SC Reg. 61-68 as numerical
standards for protecting ambient water guality in state surface waters. For this reason, EPA
designates this regulation as "relevant and appropriate" to surface water remediation at this site.
SC Reg. 61-68 is also applicable to discharge of treated waters from the groundwater treatment
system, to any surface water body.

Treatment of groundwater through the in-situ chemical treatment process:

40 CFR Parts 144 and 146, National Underground Injection Control (UIC) Program, promulgated under the
authority of the Clean Water Act; and,

SC Reg. 61-87, South Carolina UIC Regulations, promulgated pursuant to the SC Pollution Control Act, SC
Code of Laws, 1976, as amended.
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The UIC regulations outline specific requirements for injecting liquids or liquid wastes into the
saturated subsurface environment, and outline a number of specific prohibitions on such actions.
Since in-situ chemical treatment will likely require that reductant-bearing solutions be injected
or otherwise placed into the subsurface, and because the solutions could impact natural
groundwaters, these regulations are considered relevant and appropriate.

10.2.3 "To Be Considered" (TBC) Criteria

The following references and regulations are designated "To Be Considered" during the design and
implementation of the selected remedy:

Groundwater remediation:

Guidelines for Ground Water Use and Classification, EPA Ground Water Protection Strategy, U.S. EPA, 1986.

This document outlines EPA's policy of considering a site's groundwater classification in
evaluating possible remedial response actions. Groundwater at the Site is classified by EPA as
Class IIA, and by South Carolina as Class GB, indicating its potential use as a source of drinking
water.

Surface water remediation via groundwater pump-and-treat (source reduction) or by in-situ chemical
treatment:

National Oceanic and Atmospheric Administration (NOAA) ER-L/ER-M Values, 1994, and EPA Region IV, Waste
Management Division, Sediment Screening Values for Hazardous Waste Sites (2/16/94).

These guidelines were developed as screening criteria for sediment contamination in surface water
bodies, and are based on toxicity to aquatic life. During the RI, exceedance of these criteria was
among the factors which lead to initiation of the 1993/1994 Ecological Assessment. Although the
ER-L and ER-M values (upon which the Region IV numbers are based) were not themselves intended to
serve as remediation levels, they should be considered when determining an appropriate sediment
remediation goal, or when judging any potential improvements in surface water quality in the
offsite tributary.

40 CFR Part 131, Ambient Water Quality Criteria (AWQC) (CWA ° 304), promulgated under the authority of
the Clean Water Act.

These regulations set numerical criteria for ambient water quality based on toxicity to aquatic
organisms and human health. The AWQCs were established to serve as "flags" indicating when
site-specific ecological investigation (such as toxicity testing) is warranted. The AWQC for
chromium was established in 1984. In similar fashion to the NOAA and EPA Region IV values cited
above, these regulations should be considered when evaluating the impacts of groundwater pumping on
the surface water quality in the offsite tributary. As noted above, State regulation 61-68
utilizes the AWQCs established in this Federal regulation as criteria for protecting surface water
quality in the offsite tributary and all State waters.

Discharge of treated groundwater to a surface water body: In the event that this discharge option is
accepted by EPA and SCDHEC as the best option for disposal of treated groundwater, based upon a request
from the PRP to alter the present sprayfield discharge arrangement, then the following to-be-considered
ARAR would become applicable.

40 CFR Part 122, 125, 129, 133 and 136, CWA Discharge Limitations (CWA ° 301), promulgated under the
authority of the Clean Water Act.

Applicable to any point-source discharges of wastewaters to waters of the United States. At this
Site, it is applicable to discharge of treated waters from the groundwater treatment system, to any
surface water body.

SC Reg. 61-68, South Carolina Water Classifications and Standards, promulgated pursuant to the Pollution
Control Act, SC Code of Laws, 1976, as amended.

These regulations establish classifications for water use, and set numerical standards for
protecting state waters. SC Reg. 61-68 is also applicable to discharge of treated waters from the
groundwater treatment system, to any surface water body.
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Discharge of the treated groundwater to a Publicly Owned Treatment Works (POTW): In the event that this
discharge option is accepted by EPA and SCDHEC as the best option for disposal of treated groundwater,
based upon a reguest from the PRP to alter the present sprayfield discharge arrangement, then discharge
of treated water will be accomplished in compliance with the following ARAR:

40 CFR ° 403.5, CWA Pretreatment Standards (CWA ° 307), promulgated under the authority of the Clean
Water Act.

Regulates discharges of water to POTWs. This regulation would be applicable to discharge of
treated waters from the groundwater treatment system to a local POTW.

SC Reg. 61-68, South Carolina Water Classifications and Standards, as cited above.

These regulations establish classifications for water use, and set numerical standards for
protecting ambient water guality in state waters. SC Reg.61-68 is also applicable to discharge of
treated waters from the groundwater treatment system to a local POTW.

10.2.4 Other requirements

Remedial design often includes the discovery and use of unforeseeable but necessary reguirements.
Therefore, during design of the selected remedy, EPA may elect to designate further ARARs which apply, or
are relevant and appropriate, to the remediation of soil, sediment, groundwater, or surface water at this
Site. This would be done through a formal ROD modification process such as an Explanation of Significant
Differences (BSD) or a ROD Amendment.

10.3 Performance Standards

The standards defined in this section comprise the performance standards defining successful
implementation of this remedy:

A. The RLs listed in Table 10 on page 56 of this ROD are performance standards.

B. Treated groundwater generated by continued operation of the IAPTS shall meet the applicable State of
South Carolina permit reguirements, which are performance standards for purposes of this remedy
also.

C. As a performance standard, groundwater remediation performed under this remedy shall prevent or
control the offsite migration of all groundwater containing, the Site COCs at levels above their
respective RLS, until such time as the groundwater guality meets the RLs as listed in Table 10.

It is expected that the remedial design process will lead to the establishment of more process-specific
performance standards for the in-situ chemical treatment process. In combination with the general
performance standards listed above, these process-specific performance standards will allow EPA and
SCDHEC to better judge the extent and degree of success accomplished by in-situ treatment and the remedy
as a whole.

10.4 Variations from the Proposed Plan

During preparation of this ROD, certain discrepancies between the Proposed Plan (September 1996) , the FS
Fact Sheet (July 1996), and this document became apparent. None of these are significant to the overall
scope and content of the selected remedy.

1. The FS contemplated the use of a remediation level eguivalent to the Federal chronic AWQC for
hexavalent chromium, 0.011 mg/1, based upon South Carolina Regulation 61-68, which uses the Federal
AWQCs as criteria for protecting ambient water guality. In December 1996, at EPA's reguest, SCDHEC
calculated a new acceptable surface water standard for the offsite tributary that is consistent with
SC Regulation 61-68, which is 0.040 mg/1. The surface water RL is discussed further in the
Responsiveness Summary to this ROD (Appendix A).

2. Concerning Site monitoring, since the time of the Proposed Plan, EPA has decided that periodic
sampling of surface water from a midpoint station, as well as from a downstream station, is
reguired. The Proposed Plan calls only for a sample from one downstream sample point on the unnamed
tributary.

3. The Proposed Plan fact sheet has the MCL for cadmium listed as 100 ug/1, which should read 5 ug/1.
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4. The risk levels presented in Table 9 are slightly different from those shown on page 5 of the
Proposed Plan due to a mathematics error.

11.0 STATUTORY DETERMINATIONS

EPA and the State of South Carolina believe that the selected remedy achieves the best possible balance
of trade-offs in terms of long-term effectiveness and permanence, reduction of toxicity/mobility/volume,
short-term effectiveness, implementability, and cost. The selected alternative is superior to the other
alternatives in reducing toxicity/mobility/volume; is as easily or more easily implementable; and is the
most cost-effective choice.

In addition to these considerations, section 121(b)(1) of CERCLA, 42 U.S.C. ° 9621(b)(1), requires that a
selected remedy must protect human health and the environment; meet ARARs (unless waived); be
cost-effective; use permanent solutions, and alternative treatment technologies or resource recovery
technologies to the maximum extent practicable; and finally, wherever feasible, employ treatment to
reduce the toxicity, mobility or volume of the contaminants. The selected remedy for this Site meets all
of these statutory requirements, as described below.

Protection of human health and the environment: The remedy will reduce and eventually remove future
human health risks from ingestion of contaminated groundwater. This will be accomplished through
implementation of an in-situ chemical treatment program for Site soils and groundwater, and continued
operation of the existing groundwater pump-and-treat system (the IAPTS). Upon completion of this remedy,
the risks associated with the Site are projected to be below EPA's acceptable risk range of 1 X 10 -4 to
1 X 10 -6 for carcinogens and below a hazard quotient of 1 for noncarcinogens.

During the in-situ treatment period, operation of the IAPTS will prevent the offsite migration of
contaminated groundwater which otherwise could migrate offsite toward private water wells. Additionally,
reduction of the amount of groundwater-borne chromium entering the tributary, and completion of the
sediment removal action, should positively impact tributary ecology.

Compliance with ARARs: The selected remedy will meet all of the State and Federal ARARs listed in
Section 10.2. of this ROD. No waivers of Federal or State requirements are anticipated at present.

Cost effectiveness: The remedy is cost effective in that it is expected to achieve permanent chemical
alteration and detoxification of the treated groundwater and soil, thereby eliminating long-term O&M
costs expected under other alternatives.

Utilization of permanent solutions, and alternative treatment technologies or resource recovery
technologies to the maximum extent practicable: The selected remedy represents the maximum extent to
which permanent solutions and treatment can practicably be used for this action. It employs an
innovative technology, in-situ chemical treatment, to permanently reduce contaminant concentrations in
both soil and groundwater. The remedy has the potential to achieve permanent reductions of groundwater
toxicity, mobility and volume in a reasonable period of time (5 years or less). The remedy soil
component, also utilizing in-situ chemical treatment, accomplishes permanent treatment rather than
creating a treatment cell or generating large quantities of material requiring landfill disposal.

Preference for treatment as a principal remedy element: The selected remedy employs direct treatment of
contaminated soil and groundwater as the principal element of the action. Continued operation of the
existing groundwater pump-and-treat system will also contribute toward fulfilling the preference for
treatment as a principal element, though at a slower pace, through extraction and treatment of
contaminated groundwater.
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RESPONSIVENESS SUMMARY
TOWNSEND SAW CHAIN COMPANY SITE
1. Overview
The U. S. Environmental Protection Agency (EPA) held a public comment period from September 6, 1996 to
October 7, 1996, for interested parties to comment on the Remedial Investigation/Feasibility Study
(RI/FS) results and the Proposed Plan for Remedial Action at the Townsend Saw Chain Company Site in
Pontiac, Richland County, South Carolina. During this period there were no reguests to extend the
comment period for an additional 30 days.

EPA and the South Carolina Department of Health and Environmental Control (SCDHEC) hosted a public
meeting at 7:30 p.m. on September 17, 1996, at Pontiac Elementary School in Pontiac, South Carolina at
which the results of the RI/FS, the current status of pump-and-treat operations under the Interim
Remedial Action, and the Proposed Plan for the final Remedial Action were presented. Both at this
meeting and in the Fact Sheet which preceded it, local citizens were told that the major purpose of the
meeting was to receive comments and guestions from the public.

EPA proposed a selected remedy comprising the following components:

• SOIL TREATMENT (Source Control): Alternative S4
In-situ Chemical Treatment of surficial soils

• GROUNDWATER REMEDIATION: Alternative GW4
In-situ chemical treatment of groundwater
Continued operation of the Interim Action Pump and Treat System (IAPTS)
Sediment removal action at the Seep (Offsite Area)

SITE MONITORING
Continued guarterly sampling/analysis of Site groundwater
Additional guarterly sampling of surface water in the unnamed offsite tributary
Periodic sampling of treated Site soils

EPA's "Proposed Plan Fact Sheet" was mailed to an estimated 600 individuals on the Site mailing list.
Attendance at the Proposed Plan Public Meeting was very light. Based on the submission of only one set
of written comments during the public comment period, and the absence of comments at the meeting, EPA
believes the residents and local officials in the Pontiac, South Carolina area support the actions
proposed by EPA and SCDHEC.

This Responsiveness Summary provides a summary of citizens' comments and concerns identified and received
at the September 17, 1996 public meeting and during the public comment period, and EPA's response to
those comments and concerns. The following sections and attachments are included herein:

• Background of Community Involvement

• Summary of Comments Received During the Public Comment Period and EPA' s Responses

• Attachment A: Proposed Plan for Townsend Saw Chain Company Superfund Site

• Attachment B: Public Notice of Public Comment Period

• Attachment C: Letter (Public Comment) Concerning the Proposed Plan

• Attachment D: Proposed Plan Public Meeting Sign In Sheets

• Attachment E: Official Transcript of the Proposed Plan Public Meeting

2. Background of Community Involvement

EPA's community relations program for the Site began in December of 1991, when EPA conducted community
interviews with local residents and officials in order to develop a community relations plan for the
Site. At that time, the main concerns expressed by residents living in areas near the Site were as
follows: (1) the possibility of health threats to children attending Pontiac Elementary School, which is
located approximately 500 feet northwest of the Site; and (2), concerns from persons living near,
particularly east of, the Site. Many residents were surprised to learn that a final overall cleanup was
not, in fact, already underway, and asked why the cleanup is taking so long.
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EPA personnel conducting the interviews, including the Remedial Project Manager (RPM) and the Community
Relations Coordinator (CRC) , explained the current status of Site work at that time, why the Site was to
be investigated under Superfund, and what would occur once field work began.

An RI "kickoff" public meeting was held by EPA at Pontiac Elementary School on April 22, 1992.
Approximately 70 persons attended this meeting. Public guestions and concerns centered around the
proximity of the Site to Pontiac Elementary School, and the long period of groundwater cleanup that had
been ongoing without completion of the cleanup effort. EPA staff explained the lack of any health
threats to school children based on then current knowledge of the Site, and that the RI work included
verifying the absence of any such threats. EPA and SCDHEC officials also explained the specific details
of Homelite Textron's groundwater remediation activities, and EPA's plans and objectives concerning
groundwater contamination.

During the summer of 1993, after completion of RI Phase II field work, EPA and SCDHEC determined that an
Interim Remedial Action to address offsite groundwater contamination was warranted in view of
inconclusive data concerning the full downgradient, offsite extent of Site-affected groundwater, and the
likelihood of continuing offsite migration of contaminated groundwater. EPA prepared an August 1993
Proposed Plan Fact Sheet to publicly propose the Interim Remedial Action and to solicit public comments.
The fact sheet also announced the opening of a 30-day public comment period on August 20, 1993. A notice
to area citizens announcing the August 31, 1993, Proposed Plan public meeting and the upcoming public
comment period was published in Columbia's daily newspaper, The State, on August 20, 1993.

An Interim Action Proposed Plan public meeting was held on August 31, 1993, at Pontiac Elementary School.
Approximately 70 persons attended the meeting. EPA officials explained that the Interim Action consisted
of a hydrogeologic study in the offsite area to define the extent of contamination, followed by expedited
design and construction of an extraction and treatment system to capture and treat the affected
groundwater and prevent continued offsite movement. As detailed in the Responsiveness Summary of the
December 1993 Interim Record of Decision, the public expressed a great deal of interest in the Interim
Remedial Action. Most guestions concerned EPA's planned precautionary sampling of four private water
wells at the southwest end of woodcreek Lake. In response to these concerns, water wells belonging to a
group of residents belonging to the homeowners, group were sampled in September 1993 and again in July
1994 in joint EPA-SCDHEC efforts. Also as a precaution, Textron sampled 7 private wells located along
the south side of Interstate Highway 20 although not in the known direction of groundwater movement.
Sample results from the 1-20 and Woodcreek Lake wells have indicated, in all cases, non-detects or far
below levels of concern for inorganic contaminants (such as chromium) and volatile organic compounds
(VOCs).

A notice publicizing the issuance of the Interim Record of Decision was published in The State in May
1994. Throughout 1994 and 1995, EPA maintained ongoing contact with the local homeowners' group (at
Woodcreek Lake) , as well as the business partnership which owns all of the affected offsite property.

Following issuance of a fact sheet, EPA held a public meeting on April 27, 1995, to update local
residents and the public concerning the results of the offsite hydrogeology work and plans for the
offsite pump-and-treat system. Attendance at this meeting was very light and no significant concerns
were expressed.

In summary, since late 1994, public attention concerning the site has been very limited. The Site has
received only infreguent coverage in the one major newspaper published in the area. There have been
occasional reguests to be added to the Site mailing list, which has been expanded and now includes some
600 persons and businesses.

3. Summary of Comments Received During the Public Comment Period and Agency Responses

The Public Comment Period opened on September 6, 1996, and was closed on October 7, 1996. The Public
Notice which was published in the area's local paper, The State, can be found at Attachment B.

As noted above, on September 17, 1996, EPA held a public meeting to present the Proposed Plan for the
Site to the community and to receive comments. No comments by the public were expressed at this meeting,
which was very lightly attended.
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One letter was received during the public comment period, from SECOR International, the consultant for
the Potentially Responsible Party (PRP). The letter (Attachment C) concerns one specific technical
question, as discussed below.

Comprehensive Response to Specific Legal or Technical Question

The letter received during the comment period (Attachment C) concerns EPA's selection of a surface water
remediation level (RL) for the Site, based on the Feasibility Study.

The main point expressed in the PRP consultants' letter is that the FS surface water remediation level
(referred to as "remediation goal in the FS), 0.011 milligrams per liter (mg/1) total chromium, is overly
conservative, in view of the following:

• The RL is not based on site-specific data but rather on the Ambient Water Quality Criterion
(AWQC) for hexavalent chromium, and ignores site-specific Ecological Assessment results;

• The AWQC of 0.011 mg/1) is intended to account for the effects of hexavalent chromium only;

• The much-less-toxic trivalent form of chromium is expected to predominate in the tributary, and
sufficient organic matter is present to reduce the hexavalent chromium to the trivalent state;

• No adverse effects were noted to the test species in the EA until a concentration of 0.049 mg/1
chromium, more than 4 times the RL, was present; and finally,

• The AWQCs have not been revised since 1985 and thus do not incorporate any more recent
scientific findings concerning freshwater toxicity.

The letter suggests that a final surface water remediation level be identified later, after groundwater
remediation activities have taken place, and notes that the two environmental consulting firms that
performed the EA "recommended performing no active remediation of the surface water and sediment in the
offsite tributary, as the impacts are only slight to moderate and the treatment of the onsite
groundwater...will likely result in the mitigation of the chromium in the offsite tributary."

RESPONSE: EPA agrees that, when feasible and when done in compliance with applicable or relevant and
appropriate requirements (ARARs), data from site-specific studies should be used to establish remediation
or cleanup standards to be met by the selected alternative. For this reason, the issue was revisited
during preparation of the Record of Decision (ROD).

To establish a cleanup standard for surface water, in addition to the toxicity data from the Ecological
Assessment, EPA must consider State and Federal ARARs for surface water. As described in section 10.2 of
the Record of Decision, EPA and SCDHEC do not use the Federal AWQCs in the same manner: SCDHEC uses the
AWQCs as numerical criteria in all State surface waters. In accordance with the NCP, EPA must consider
State ARARs in determining cleanup standards, whether such ARARs are more, or less, stringent than those
promulgated by EPA. In consultations with EPA concerning its concurrence with the proposed remedy,
SCDHEC indicated that an acceptable surface water standard must be based upon the AWQC in order to
maintain intra-state consistency and legal integrity within their statewide water protection program.

At the request of EPA, SCDHEC investigated potential cleanup criteria based upon the AWQC, and calculated
that a level of 0.040 mg/1 chromium (measured as hexavalent or total) would be protective of aquatic
flora and fauna in the offsite tributary. This calculation was performed in a similar manner as would be
done for a permit under the National Pollution Discharge Elimination System (NPDES). In accordance with
the Prothro Amendment to the Clean Water Act, the calculation accounts for the presence of dissolved
solids in the stream water and utilizes the Suspended Solids Partitioning Method. The calculation by
SCDHEC is as follows:

Ct=Cdx (1+Kdx TSS x 10 -6)

where Ct = Total instream chromium concentration after mixing
Cd = Criteria x measured percent dissolved considered most relevant
in fresh water (0.011 x 0.95 = 0.01 mg/1)
TSS= Total suspended solids (total instream solids after mixing) 10 mg/1
Kd = Chromium partition coefficient = 3 x 10 -5 I/kg

C t = 0.01 (1 + 3 x 10 -5 x 10 x 10 -6)
= 0.01 (1 + 3)
= 0.040 mg/1 or 40 ug/1
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EPA is selecting this value as the remediation level (RL) for surface water for the following reasons.
First, it is close to, but still slightly below, the lowest adverse effects level (LOEL) determined in
the Ecological Assessment, 0.049 mg/1. This represents a comparison with, and usage of, site-specific
data. The 0.040 mg/1 RL is also consistent with the methods by which other surface water discharge
reguirements throughout the State of South Carolina are determined, and meets the State ARAR for ambient
surface water guality. (This latter point, consistency, is appropriate because the continuing
contaminated groundwater discharge to surface water can reasonably be considered an ongoing discharge).
Finally, the RL is not eguivalent to the hexavalent chromium AWQC itself, which accords with the fact
that the AWQCs were not originally intended by EPA to serve as cleanup criteria.

Concerning other points raised in the letter, EPA acknowledges that the surface water RL may need to be
reevaluated in light of new information during remedial design or remedial action. We do not agree that
it is appropriate to wait until the groundwater remedial action is underway or complete to determine a
surface water RL. As described in the ROD, both the near-future in-situ chemical treatment, and the
presently ongoing operation of the groundwater pump-and-treat system, are intended to impact surface
water and reduce chromium concentrations. EPA does not agree that no active remediation of the surface
water and sediment in the offsite tributary take place; we have, however, acknowledged the difficulty in
determining a well-supported sediment remediation level, and based on discussion with all parties, have
selected a limited sediment action appropriate to the scale of the problem. At the time the "no active
remediation" recommendation was made, the full range of chromium concentrations present in the seep-area
sediment was not known (up to 1,647 mg/1 total chromium in sediment samples). Finally, EPA agrees that
operation of the groundwater pump-and-treat system will likely improve surface water, and is reguiring
this as part of the selected remedy.
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INTRODUCTION

The United States Environmental Protection Agency (EPA) , Region IV, has prepared this fact sheet to
propose a final cleanup plan to address environmental contamination at the Townsend Saw Chain Company
Superfund Site ("the Site"), in Pontiac, South Carolina. EPA is the lead Agency for remedial activities
at the Site, and, in cooperation with the South Carolina Department of Health and Environmental Control
(SCDHEQ, is overseeing environmental investigation and cleanup of the Site. Presently, the Site poses no
risks to workers or residents living nearby. However, in the event groundwater was used as a potable
water supply in the future, there could be risks posed through consumption of groundwater from wells
located within the affected area.

The selection of a cleanup plan to address this Site represents a preliminary decision by EPA, subject
to a public comment period. SCDHEC has informally concurred with EPA's selection. However, a final
decision will be made by EPA only after all public comments have been reviewed and considered.

As outlined in section 117(a) of the Comprehensive Environmental Response, Compensation and Liability Act
of 1980 (CERCLA, known as "Superfund"), as amended by the Superfund Amendments and Reauthorization Act of
1986, EPA encourages public participation by providing an opportunity for the public to comment on the
proposed remedial actions. As a result of such comments, EPA may modify or change its preferred
alternative before issuing a Record of Decision for the Site. Further information concerning
opportunities for public participation can be found on page 14.

Recent activities at the Site have included the completion of a Feasibility Study (FS) for the Site. The
FS is a report in which all of the cleanup technologies and cleanup plans which could be used to address
Site contamination, are evaluated and compared, in order to support EPA's selection of the best plan for
the Site ("the remedy") . The purpose of this fact sheet is to present EPA's preferred remedy for the
Site, and request public review and comment on the planned course of action (known as "the Proposed
Plan"). Your questions and comments should be directed to the EPA and SCDHEC staff working on this
Site, who are listed on page 14 of this fact sheet. The location of the information repository, which
contains the Remedial Investigation (RI) Report and other reports, correspondence and documents
concerning the Site, is also listed on page 14.

PUBLIC MEETING
Proposed Plan for Final Cleanup
of the Townsend Saw Chain Superfund Site
Tuesday, September 17, 1996 - 7:30 p.m.
PONTIAC ELEMENTARY SCHOOL
500 Spears Creek Church Road, Pontiac, South Carolina

THIS PROPOSED PLAN:

1. Presents a summary of Site background and the nature and extent of Site contamination;
2. Describes EPA's evaluation of available alternatives for Site cleanup, and provides a summary
analysis explaining why EPA is proposing its preferred alternative; and
3. Requests public review and comment on this course of action, including how to get more
information and where to send your comments.

This fact sheet is also intended to supplement the recently issued "Feasibility Study Fact Sheet,
Townsend Saw Chain Superfund Site" (July 1996) . Please refer to that document, or to the FS document
itself (page 14), for a more detailed presentation of the other remedial alternatives not selected by EPA
for use at the Site.

Scope and Role of This Action: The action EPA is proposing in this Proposed Plan will address all of the
principal environmental risks associated with the Site. These are (1) potential long-term human health
risk in the off-site area (across SC Road 53) from exposure to contaminated groundwater, if groundwater
were used as a potable water source, and (2) potential long-term ecological effects to the ecosystem
along the unnamed offsite tributary to Spears Creek (offsite area).
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RESULTS OF SITE CHARACTERIZATION

Site description and Recent Site Work: The Townsend Saw Chain Site is located along the north side of
Interstate highway 20 at the SC Road 53 exit (Pontiac), approximately 10 miles northeast of Columbia,
South Carolina. Groundwater, surface water, soil and sediment contamination at the Site resulted from
past wastewater disposal operations at the onsite manufacturing facility. The main Site contaminant is
hexavalent chromium (Cr 6+). The property has been owned since September 1994 by Deere and Company (John
Deere) . Two former owners/operators, Textron, Inc. and Dictaphone Corporation (Pitney-Bowes), are
responsible under Superfund for environmental cleanup work at the Site. Between 1992 and 1994, Textron,
Inc. conducted a Remedial Investigation (RI) at the Site, with EPA and SCDHEC oversight. A 1994 Interim
Remedial Action, designed to prevent further offsite migration of contaminated groundwater, was
essentially completed in December 1995 with the construction and start-up of the 5 well Interim Action
pump-and-treat system (IAPTS). Site soil contamination, and offsite surface water and sediment
contamination, were investigated further during 1995. The findings from this additional work are
included in the FS, which evaluates cleanup plans and technologies which could be used to address all
Site-related contamination. This document is available for public review as described on page 14.

Groundwater contamination has been, and remains, the main environmental problem at the Townsend Saw Chain
Site. The Remedial Investigation and subseguent work has confirmed that a large area underlain by
contaminated groundwater is present, both on the Deere & Company (formerly Homelite Textron) plant and
extending approximately 700 feet offsite, northeast of the property boundary along Spears Creek
Church Road (SC Road 53; see Figure 1 below).

The main Site contaminant is hexavalent chromium (Cr 6+), which occurs at levels from the detection limit
up to approximately 4 Milligrams per liter (mg/1). Nitrates occur in several wells above water guality
standards, and trace-level volatile organic compounds (VOCs) also occur in several wells. The VOCs occur
inconsistently and do not form a defined plume; a typical combined concentration, at any one well,
is less than 0.100 mg/1. The contaminant plumes of all of these substances are found in the shallow
aguifer, and are located approximately within the chromium groundwater plume shown in Figure 1.

As stated above, the limit of groundwater contamination is approximately 700 feet northeast of SC Road
53. There are private water supply wells located approximately one mile downgradient of this point; none
of these wells has shown any impact to date. There is also a small tributary which is fed almost
entirely by groundwater. In summary, based on RI and post RI groundwater guality data, the main
potential pathways through which contaminated groundwater could pose a risk to human health or the
environment, are 1) through consumption of impacted well water (human health) if groundwater were used as
a drinking water source, and/or 2) potential damage to the offsite tributary-area ecosystem through any
toxic effects attributable to site contaminants in surface water (surface water is discussed below).

Soil contamination, by hexavalent chromium, is present mainly in the former wasteponds area, as indicated
on Figure 1. Contamination is limited to the uppermost %-foot of surface soil. The levels present, up
to 279 mg/kg but generally much lower, do not pose a health threat to onsite workers, but are likely to
be impacting groundwater through leaching. Two other small "hotspot" areas of soil contamination are
being excavated and disposed of under the Interim Remedial Action, and are thus not addressed in the FS.

Surficial sediment around the seep which feeds the offsite tributary, contains elevated levels of
chromium. Based on work conducted in late 1995, the sediment appears to be binding up chromium in its
less-mobile trivalent form (Cr 3+). Sediment toxicity testing and biological evaluations conducted in
the 1994 Ecological Assessment (EA) , partly intended to generate a sediment cleanup goal, were
inconclusive. In EPA's judgement, while not of concern as a human health risk, the chromium levels could
nonetheless pose a long-term environmental hazard to plants and animals in and along this area.
Therefore, a small-scale action to address this sediment is warranted. The EA work on sediment toxicity
demonstrated the technical difficulties in accurately determining a sediment cleanup goal, and for this
reason, a specific number will not be set.

Surface water was also evaluated in the EA, which concluded that chromium-bearing surface water in the
tributary could potentially cause an impact to the stream ecosystem, although the results were not
conclusive. While clear-cut ecological effects are difficult to identify with certainty, the EA was more
conclusive in showing that any potential effects are limited to the upper portions of the tributary, and
do not extend to Spears Creek.
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RISK ASSESSMENT RESULTS

As part of the 1992-1994 RI, a Baseline Risk Assessment was completed by an EPA contractor (Dynarnac
Corporation) in 1993. The Assessment used analytical data from phases 1 and 2 of the RI. In 1994 and
1995, in support of the Interim Remedial Action and the Feasibility Study, additional soil and
groundwater data was generated. This new data, as well as new EPA policy guidance concerning land use in
the risk assessment process, were used in Section 1.5 of the recently-completed FS to revise the overall,
picture of human health risk attributable to the Site.

The Baseline Risk Assessment, as modified by the 1996 Addendum to the Baseline Risk Assessment (Appendix
B in the FS), describes the risks to human health which would result if the contamination present at the
Site is not cleaned up. The assessment proceeds in a series of steps. FM a list is generated of AU the
chemicals present and their concentrations. Next, the Assessment considers the present and future
population living on the Site - in this case, workers at the manufacturing facility, Site visitors or
trespassers, and offsite residents (children and adults). Then, from the present-use and likely
future-use scenarios, "pathways" through which persons could be exposed to the contaminants are
developed. Exposure pathways at a Site can include, for example, dermal (skin) contact with contaminated
soil, ingestion of contaminated soil, or ingestion of contaminated groundwater.

The pathways of exposure are then developed by making assumptions such as the length and number of times
exposed, how much of the chemical is ingested, along with certain other factors. Thus a calculation can
be made using known effects and reasonable exposure assumptions, and the health effects caused by the
contaminant. For each pathway, two calculations are made to account for the two general types of
contaminants: carcinogens, suspected or known to cause cancer, and noncarcinogens, substances which are
hazardous and cause damage to human health through other effects.

For carcinogens, the result is expressed as the excess cancer risk posed by Site contaminants. EPA has
established a range of 1 x 10 -4 to 1 x 10 -6 as acceptable limits for lifetime excess carcinogenic
risks. Excess risk in this range means that between one person in 10,000 (1 x 10 -4) and one person in
one million (1 x 10 -6) will risk developing cancer during a lifetime of exposure. For each pathway and
each medium, the cancer risk from each individual contaminant is added together, because in a "worst
case" scenario a person could be exposed through several or all of the possible pathways.

Noncarcinogenic risk is expressed as a Hazard Quotient (HQ). The HQ is ratio of the amount of the
chemical taken in, divided by the reference dose, which is an intake amount below which no adverse
effects are known to occur. As for cancer risk, for each pathway and medium, the HQs for the individual
contaminants are added together, giving a summary figure, the Hazard Index (HI). EPA generally reguires
that remedial actions be taken at sites which have a current land use HI, or future use HI, that is
greater than 1.0.

Carcinogenic risk and noncarcinogenic His were calculated for both (1) the current land use scenario,
with plant workers on the Site property and no current residents in the offsite area, and (2) the
anticipated future use scenario, which is continued light industrial use at the facility, with commercial
use along SC Road 53 and residential land behind (northeast of) the commercial-use strip.

The current situation at the Site has a total carcinogenic risk of 4 x 10 -7, which is below (less than)
the lower end of the acceptable risk range. The total noncarcinogenic risk is HI = 0.2, also below EPA's
acceptable limit (HI = 1.0). This means that there are currently no health risks posed to onsite
workers, and, because there is no current groundwater usage within the affected area, no health risks to
nearby residents through the use of contaminated groundwater.

Exclusively because of potential risk from drinking contaminated groundwater, the future use scenario,
under which offsite residents could use groundwater as a water supply, carries a carcinogenic risk of 8 x
10-5 for adults; 5 x 10 -5 for a child resident, which is within the range allowing EPA to undertake, or
reguire, remedial action (that is, excess risk of between 1 x 10 -4 to 1 x 10 -6). For noncarcinogenic
risk, the future use HI is 111 for the child resident, 46 for the adult, which is above the EPA "action"
benchmark of 1.0. The majority of the risk is posed by groundwater impacted by hexavalent chromium.
There are no future human health risks from offsite sediment or surface water in the offsite area
(including all offsite area zoned residential). In summary, the primary long-term human health risk
pathways at the Townsend Saw Chain Site are:

Present Land Use: None.

Future Land Use: Ingestion of groundwater(carcinogenic and noncarcinogenic risk.)
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A more detailed presentation on how Site risks are evaluated is presented in the Baseline Risk
Assessment, which is available at the information repository described on page 14. The reader should
keep in mind that the FS revises the portion dealing with Site soils, and that the FS presents the most
up-to-date overall assessment of Site risks.

GOALS OF THE CLEANUP

Under Superfund, the selected remedy for a site must protect human health and the environment, and must
meet all of the state and federal requirements which would apply to such an environmental cleanup action.
In the FS, from this starting point, general remedial action objectives, and eventually site-specific
remediation goals (also called cleanup standards or cleanup goals, i.e., specific numbers), are
developed.

The general objectives for remediation of each of the impacted media (soil, groundwater, surface water,
and sediment) at the Site are to prevent ingestion of, or contact with, those chemicals of concern at
levels that pose unacceptable health risks (human or ecological). Additionally, since contamination in
one medium can affect another, there are a number of additional goals, as follows:

Soil: Prevent the leaching of contamination into groundwater, which can render the groundwater unfit for
use as a water supply resource.

Groundwater: 1) Prevent or reduce the continued discharge of contaminated groundwater to surface water,
such that surface water quality standards are exceeded; 2) Reduce concentrations of chemicals of concern
so that normal productive use (as a potable water supply) is restored, if possible.

Sediment: Prevent exposure of the tributary ecosystem to chromium, and/or reduce levels of the chromium
such that no unacceptable ecological risks are presented (not a human-health risk).

Surface water: Reduce contamination to levels which 1) cannot pose ecological risk to tributary plants
and animals, and 2) are incapable of re-contaminating tributary sediment.

The Feasibility Study Fact Sheet (July 1996) presented a summary of the process by which Chemicals of
Concern (CCS) and remediation goals were established, which will not be repeated here. The remediation
goals for the Site are presented below in Table 1.
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TABLE 1 - REMEDIATION GOALS
TOWNSEND SAW CHAIN CO. SITE

Surface Soil (1) Chromium +6 16 mg/kg

Surface Water Chromium (2) 0.011 mg/1

Groundwater (3)

Chromium (total) 0.100 mg/1
Cadmium 0.100 mg/1
Cyanide 0.200 mg/1
Lead (4) 0.015 mg/1
Manganese (5) 0.078 mg/1
Nitrate 10.0 mg/1
Vanadium (5) 0.110 mg/1
1,1-dichloroethylene 0.007 mg/1
Trichloroethylene 0.005 mg/1
Tetrachloroethylene 0.005 mg/1

(1) Remedial goal is for the protection of groundwater from leaching. This remediation goal was
determined from leaching tests using Silt soils and a target groundwater level of 0.100 mg/1, the State
and Federal Maximum Contaminant Levels (MCL) for chromium

(2) State and Federal chronic ambient water quality criterion (AWQC) for chromium, measured as total Cr.
This goal a for the protection of the ecosystem in and along the offsite tributary. There is no human
health threat associated with chromium in surface water. There is used in this case due to the lack of
conclusive and verifiable information regarding impacts to tributary plants and animals; it is not based
on site-specific information.

(3) All goals represent State and Federal Maximum Contaminant Levels (MCLs),under the Safe Drinking Water
Act (1974), except as indicated in (4) and (5) below:

(4) EPA Action Level

(5) Baseline Risk Assessment, Townsend Saw Chain Site.
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ALTERNATIVES FOR SITE REMEDIATION

Cleanup options. Technologies which could be considered for Site cleanup operations are described in
detail in the FS. Each was then screened against a number of criteria, including Site soil and waste
characteristics, limitations of the technology, its technical effectiveness, ease or difficulty of
implementation, and cost effectiveness. The technologies which passed screening were assembled into five
soil and four groundwater remedial alternatives. These alternatives are described and evaluated in
detail in the FS, and were presented in summary form in the recent "Feasibility Study Fact Sheet" issued
by EPA in July, 1996. From these alternatives, EPA is selecting one groundwater alternative and one soil
alternative as its "preferred alternative," or remedy, for remediation of the Site. All of the remedial
alternatives are summarized in Table 2 below.

Although the table refers to "soil" and "groundwater" alternatives, it should be noted that the sediment
removal action described earlier, and continued operation of the Interim Action Pump-and-Treat System
(IAPTS) to reduce surface water contamination, are included within all.

Selecting a preferred alterative. The FS compares the alternatives to each other, based on the nine
criteria EPA uses to evaluate whether a remedial alternative can be chosen as the Site remedy. These
criteria include:

1. Overall Protection of Human Health and the Environment.
2. Compliance with ARARs.

These two criteria are considered "threshold criteria" and must be met in order for an alternative to be
selected.

Five primary balancing criteria are used to further choose the best alternative, from those which
meet the above two criteria:

3. Long-Term Effectiveness and Permanence.
4. Reduction of Toxicity, Mobility, or Volume.
5. Short-Term Effectiveness.
6. Implementability.
7. Cost Effectiveness.

The last two criteria are intended to address any technical or administrative issues and concerns the
State may have regarding a selected alternative, and potential issues and concerns the public may have
regarding the selected alternative:

8. State Acceptance.
9. Community Acceptance.

At this time, SCDHEC has informally indicated its concurrence with this Proposed Plan. DHEC personnel
are preparing formal comments on both the FS and the Proposed Plan. Public and community acceptance of
the selected alternative will be assessed thoroughly during review of any comments EPA and the State
receive on the FS and the Proposed Plan.

EPA'S PREFERRED ALTERNATIVE (SELECTED REMEDY)

EPA is proposing to select Alternatives S4 and GW4, both of which call for in-situ chemical treatment of
soil (S4) and groundwater (GW4) as the selected remedy. The remedy also includes operation of the IAPTS,
and the sediment removal action (ecosystem protection)as described in the FS.

Rationale. Alternative S4 (In-situ Chemical Treatment) is judged best among the soil alternatives. In
summary, although Alternatives S3 (Solidification/Stabilization) and S5 (Excavation and Offsite Disposal)
are reasonable candidates, S4 is superior to S3 based on long-term effectiveness and permanence, and
superior to both based on reduction in toxicity, mobility or volume, and cost-effectiveness.
Additionally, the FS concludes (and EPA agrees) that a cap (S2) may not meet all of the environmental
reguirements for a remedial action, and that excavation and offsite disposal (S5), in addition to its
costliness, could generate public concerns or contamination at the landfill site, simply transferring the
problem elsewhere.
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TABLE 2 - REMEDIAL ALTERNATIVES
TOWNSEND SAW CHAIN CO. SITE

SI NO ACTION
No actions taken. This would allow soils capable of leaching chromium to continue to affect groundwater and possibly lengthen the
time necessary to complete the cleanup. Site remediation goals as wells as state and federal environmental reguirements would not be
met. Costs, which consists of a status report every 5 years, total $34,000.

S2 RCRA CAP
The area of affected soils would be capped with a multilayer cover, and graded and vegetated for proper drainage. This alternative would
prevent contact with the soil contamination and reduce or prevent leaching to groundwater. Long-term effectiveness and permanence
may be guestionable, as is the degree to which all of the reguirements (ARARs) would be met. 4 Total costs are approximately $586,000.

S3 SOLIDIFICATION/STABILIZATION
The area of affected soil would be physically mixed and chemically treated to immobilize soil chromium. A solid mass resistant to
weathering, or "monolith," remains in place and is monitored to insure that it does not leach to groundwater. This alternative would
generally meet the Site remedial goals, although there is some guestion regarding long-term effectiveness and permanence. Total costs
are $810,000.

S4 INSITU CHEMICAL TREATMENT
Liguid solutions containing a reducing agent are percolated into affected (surface) soil and into contact with soil-borne hexavalent
chromium. The resulting reaction "locks up" the chromium in a non-toxic, immobile form incapable of contaminating groundwater.
This alternative can meet the Site remedial goals, and is cost-effective in attaining them. Total costs are $857,000.

S5 EXCAVATION AND OFFSITE DISPOSAL
Affected soils, which comprise approximately 2,600 cubic yards, would be excavated and transported to an approved hazardous waste
landfill for disposal. This alternative would generally meet Site remediation goals, although there are issues regarding proper treatment
at the landfill facility. Additionally, the alternative is very expensive, totaling 31,365,000.

GROUNDWATER (All include IAPTS operation)

GW1 No Action
Since there is currently a 5-well groundwater system currently in operation, this alternative will consist of operation of this system only,
with no other actions taken. While the system will capture and treat affected groundwater, the time reguired to cleanse the aguifer may
be very long, because chemical concentrations (and hence effectiveness) tend to drop off over time.

GW2 Groundwater Use Restrictions & Monitoring
Under this alternative, institutional controls such as deed restrictions are used to restrict usage of groundwater in the affected area.
Regular monitoring and assessment of groundwater movement and guality would occur. Although exposure may be prevented, this
alternative does not meet all of the Site remedial goals. Tow costs would be $4,078,000.

GW3A,B Groundwater Extraction, Treatment~ (A) Sprayfield or (B) Treatment Works Discharge

An expanded pump-and-treat system would be constructed and operated. While the length of treatment time may be reduced, long-
term problems in reaching the groundwater remedial goals would likely still occur. Costs total (A) $6,683,000 or (B) $6,813,000.

GW4 In-situ Chemical Treatment

Liguid solutions containing a reducing agent are delivered to the subsurface and placed into contact with hexavalent chromium in
groundwater. Technology has the potential to achieve a permanent reduction in the mobility, toxicity, and volume of contaminated
groundwater. Site remedial goals would be met cost-effectively. Total costs would be $3,282,000.
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For groundwater, Alternative GW4, In-situ Chemical Treatment, achieves the greatest degree of reduction
in toxicity, mobility and volume of the primary groundwater contaminant, hexavalent chromium. The
technology is considered "innovative" by EPA, which means that it has been applied at a limited number of
sites, and lacks the extensive cost and performance data that would predict certain success at this Site.
However, it has the potential to achieve a long-term, permanent removal of hexavalent chromium from the
affected groundwater, and can do so in a cost-effective manner. Groundwater treatment can be completed
in a much shorter length of time than with the pump-and-treat alternatives (GW3A and 3B) , based on EPA
and environmental industry experience to date with pump-and-treat. As with Alternative S4, Alternative
GW4 is more cost effective in achieving remediation goals than the other choices.

Description of the Remedy. The remedy consists of in-situ chemical treatment of both soil and
groundwater, described in the FS as Alternatives S4 (soil) and GW4 (groundwater). As described in the
FS, alternative GW4 (and thus the remedy) includes continued operation of the Interim Action
Pump-and-Treat System. EPA's selected remedy includes four remedy components, which are described below.
The descriptions are based on the recently-completed Feasibility Study.

Soil Treatment (Source Control)

In-situ chemical treatment, and specifically, in-situ chromium reduction, is a fairly new, innovative
technology in which a liguid solution containing a reducing agent is placed on, and percolated into,
chromium-bearing soils. Upon contact with the reducing agent, hexavalent chromium in the soils are
reduced to an insoluble, non-toxic, more stable chemical state. The treatment will be accomplished in-
situ, that is, with no excavation required; reagent may be simply percolated into the soil. This
technology is particularly applicable to sites with shallow soil impacts (<2 feet deep) such as the
Townsend Saw Chain Site.

To implement in-situ chemical treatment, first, surficial soils and sludges (up to 6 inches) within the
former wastewater pond area will be removed and disposed of offsite. This will remove the most highly
affected soils and break up the crusty top layer, improving contact of the treatment solution with the
chromium-impacted material. Introduction of the solution may be accomplished by one of any number of
means, including injection or use of surface application equipment, such as that in use at the onsite
sprayfields. The treatment solution percolates through impacted soils and reduces the hexavalent
chromium. Soil sampling will be undertaken to verify the effectiveness and permanence of the
reduction/immobilization effects. Targeted or repeated applications may be required to achieve the
remediation goals.

Pilot-scale treatability testing was conducted at the Site during late April - early May 1995, as
reported in the treatability study report entitled "Demonstration Study: In-situ Chromium Reduction in
Soil and Groundwater, Homelite - Textron" (at the information repository; see page 14). The EPA National
Risk Management Research Laboratory in Cincinnati, Ohio assisted in EPA's review of this work. The
Demonstration Study was not intended to determine all of the delivery methodologies, operating
parameters, and testing programs needed for full-scale implementation, but rather to demonstrate, in
onsite field trials, the basic chemical effect. Reduction of hexavalent chromium concentrations was
demonstrated in both soil and groundwater.

In-situ chemical treatment activities would be expected to occur over a period of approximately one year,
and for planning purposes, it is assumed that periodic soil sampling will be conducted for five years.
Reduction of hexavalent chromium to concentrations below levels of concern is likely to occur rapidly.
Additional treatability work will likely be needed to determine design parameters before full-scale
remediation. If needed, installation of in-situ chemical injection equipment should be implementable at
the Site without major technical or administrative difficulties. Dust control measures and personal
protective equipment will be required during the first stage of remedial activities, excavation of the
top 6 inches of soil, to prevent short-term exposures of the community and Site workers to contaminants.

In-situ chemical treatment of soils will cost about $769,000 in capital costs and $88,000 over five
years for operations and maintenance (O&M) costs, for a total cost of $857,000.

Groundwater Remediation

The groundwater remediation component of the remedy includes 1) In-situ Chemical Treatment of groundwater
and 2) continued operation of the IAPTS to capture and treat affected groundwater. As described above,
In-situ Chemical Treatment is a new, innovative technology which uses liquid solutions containing a
reducing agent. To remediate groundwater, the solutions are delivered into the saturated zone (into the
aquifer) to allow and foster contact between contaminated groundwater and the reductant solution. Upon
contact, the hexavalent chromium in the affected groundwater is reduced, and precipitates, forming an
inert, insoluble, non-toxic mineral containing chromium in its more stable (trivalent) chemical state.
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In-situ chemical treatment activities are expected to require a period of approximately one to two years.
Reduction of hexavalent chromium to levels below the remediation goal is expected to occur rapidly;
however, a phased approach to remediation would likely be undertaken. In conjunction with the existing
IAPTS, this alternative would provide a contained "treatment area" for groundwater, within which an
evaluation of the reduction/immobilization effects can be completed. In-situ chemical treatment
performance will depend in large measure on maintaining peak operating conditions and careful maintenance
of the delivery systems used to place the reductant solutions into contact with groundwater.
Specially-targeted or repeated applications may be required to achieve the remediation goals. Even using
a phased approach in-situ chemical treatment is expected to be conducted over a short time (one to two
years) , with minimal maintenance of treatment equipment required. Regular monitoring of the affected
groundwater will be required throughout the remediation process.

Chemical treatment conducted ex-situ (i.e. in treatment vessels) is a commonly-used technology for
treating groundwater affected by heavy metals, and is the technology currently in use for treating
groundwater at the Site. As an in-situ treatment, however, the technology is still being tested and
evaluated at a few sites around the United States. As is noted above under the soil remedy description,
pilot-scale treatability testing conducted at the Site during 1995 ("Demonstration Study: In-situ
Chromium Reduction in Soil and Groundwater, Homelite - Textron") showed that the basic chemical effect,
reduction of hexavalent chromium concentrations in groundwater, was occurring. Additional work will be
needed to determine design parameters before full-scale remediation can be completed.

Development and use of the in-situ approach in groundwater will require a remedial design phase
consisting of a planned, phased approach, which addresses 1) delivery strategies, 2) a strategy for
verifying non-reversibility of the chemical effect, and 3) a plan for evaluating how well the in-situ
reduction process is working )"how to measure success"). Even with careful planning, use of this
innovative process will involve a large degree of trial fieldwork and evaluation of effects.

Appropriate equipment is expected to be available as needed, and installation of it is unlikely to
involve any difficulties. Delivery options may include, alone or in combination, use of the current
sprayfield equipment multiple well points, or other simple technologies capable of delivering the
solutions to the affected groundwater.

During the treatment period, the IAPTS will remain operational and the remediation goals for all of the
groundwater chemicals of concern will be pursued. However, following in-situ chemical treatment, if
hexavalent chromium levels throughout the plume are successfully and substantially reduced to levels
below the groundwater remediation goal (0.1 mg/1) through the in-situ chromium, reduction treatment, EPA
may then elect to reevaluate the need for continued groundwater extraction and/or groundwater treatment
to address other COCs, as necessary, depending on the concentrations still present in the aquifer. This
could require EPA to modify the Site remedy in order to consider the need for and effectiveness of
continued pumping, and to allow consideration of other options, such as reduced or targeted pumping
targeted use of any new or innovative technologies as may become available, modeling or evaluation of
natural degradation processes, or others.

Initial-investment (capital) costs for In-situ Chemical Treatment of groundwater will total approximately
$2,624,000 over the first year (includes the cost of IAPTS construction), plus five years of O&M costs
totaling $658,000, for a complete groundwater remediation cost of $3,282,000.

Site Monitoring

A Site Monitoring Plan will be developed during the remedial design phase. As a minimum, site monitoring
will include the quarterly sampling presently conducted under the IAPTS operation (and the current
industrial wastewater permit from SCDHEC). The present sampling scheme consists of sampling and analysis
from fifteen monitor wells, two extraction wells, and surface water at the spring/seep which feeds the
unnamed offsite tributary. Although not described in the FS, monitoring will also include periodic
sampling of surface water for chromium at a minimum of one (1) downstream station on the tributary, in
the same manner as presently done for the seep water sample. The exact location of this station will be
determined during remedial design, but will be at, or upstream of, the confluence of the tributary and
Spears Creek. The purpose of this sample is to evaluate surface water quality.

Seep Area Sediment Removal (Remedial Action for Ecosystem Protection)

As described in the FS (Appendix G), a small-scale removal action will be conducted to remove an area of
sediment which contains significantly elevated levels of chromium. In a simple and direct manner, this
action will eliminate any potential harm or effects to tributary plants and animals. The estimated
volume of affected sediment is between 30 and 85 cubic yards. The action will be undertaken once EPA is
satisfied that the groundwater capture effect imposed by the IAPTS is sufficient to prevent sediment re-
contamination once the action is completed.
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Total cost of the remedy. The approximate total present worth cost of the selected remedy is $4,139,000.
Total capital costs are $3,393,000 and total O&M costs are $746,000.

WHAT COMES NEXT?

EPA is seeking public comments and input concerning the Alternatives EPA has selected as its preferred
alternative. At the public meeting to be held on September 17, 1996, EPA officials will describe the
cleanup plan, the strengths and weaknesses of the other cleanup alternatives, and EPA's reasons for
selecting these particular soil and groundwater remedial alternatives. Public guestions and comments
will be welcomed, and will be addressed at this meeting. A 30-day public comment period is being held
from September 6, 1996 to October 7, 1996 to provide all citizens an opportunity to contact EPA or SCDHEC
concerning the Site and EPA's Proposed Plan.

After reviewing public comments, guestions and concerns from the public meeting, and from written and
verbal comments received, EPA will publish a Record of Decision (ROD) documenting its selection of a
cleanup plan. All comments received will be discussed and considered in the ROD. EPA anticipates ROD
issuance in October or November 1996.

Please refer to page 14 of this publication for more information on how to contact the EPA and SCDHEC
staff working on this Site, and where more Site-specific documents and information can be reviewed.

SITE BACKGROUND

The Townsend Saw Chain Company Site is a small manufacturing facility located at the intersection of
Interstate Highway 20 and State Highway 53 (Spears Creek Church Road) in Pontiac, Richland County, South
Carolina.

The facility was owned by Textron, Inc., between 1971 and September 1994 and is presently owned by Deere
and Company (John Deere). (Textron remains responsible to EPA and SCDHEC for the ongoing environmental
cleanup work.) The plant property, approximately 50 acres in size, is surrounded by a barbed-wire fence.
The facility has been in operation since 1972 and is used for the manufacture of saw chains and chain saw
bars. Prior to 1972, between 1964 and 1970, Dictaphone Corporation manufactured specialized office
recording eguipment at the facility.

Between 1966 and 1981, under both Dictaphone and Textron, waste rinsewaters produced during metals-
plating and other processes were disposed of by direct discharge to the ground surface in the low-lying
"waste pond" areas adjacent to the facility on the north side. This discharge is the origin of the
onsite groundwater contamination. In 1982 the South Carolina Department of Health and Environmental
Control (SCDHEC) investigated the Site. Investigations since 1982 have confirmed the presence of
groundwater contaminated by chromium and nitrate onsite and offsite, as well as trace groundwater
concentrations of volatile organic compounds.

Since 1982, SCDHEC has continued to oversee Textron's investigation and cleanup program for groundwater.
In 1982, a groundwater treatment system was installed, consisting of five extraction (pumping) wells,
chemical treatment tanks, and a spray or irrigation field for disposal of the treated water. The system
currently in operation uses a similar, though more advanced, electrochemical treatment system.
Groundwater is extracted, chemically treated to acceptable standards, and then discharged to the spray
field. Performance of the system and conditions at the spray field are monitored by SCDHEC. In 1987,
SCDHEC identified problems in the treatment system's design and performance. To address those
deficiencies, a subseguent 1988 modification to the 1982 Court Order directed Textron to further
investigate and define the extent of groundwater contamination, and to investigate Site hydrogeology as
necessary to modify the system's design. A report with design revisions was submitted to SCDHEC in 1990,
and following SCDHEC review, again in December 1991. A modified permit for the system was issued by
SCDHEC in December 1993. The system redesign effort was conducted in conjunction with the Interim
Remedial Action design phase. The work was completed in December 1995, and operation of the expanded
pump-and-treat system began at that time.

Between 1985 and 1988, SCDHEC and EPA took the necessary steps to list the Site on the National
Priorities List (NPL), which places it in the Superfund program. During this period, investigations by
SCDHEC revealed above-background concentrations of lead, cadmium, arsenic, cyanide, nickel, and four VOCs
in groundwater at the Site. Chromium, lead, cadmium and arsenic were present above background levels in
sediments within the waste pond area, and a stream water sample taken just across Spears Creek Church
Road north of the Site contained chromium and four VOCs. Based on these results, the Site was then
ranked by EPA in 1987 using the Hazard Ranking System (HRS), which evaluates the potential for public
exposure to Site contamination. Because of the potential for migration of groundwater contaminants
offsite, and the large number of people in the surrounding area served by water wells, the Site was
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assigned a high HRS score and was proposed for listing on the NPL in June 1988. The Site was finalized
on the NPL in February 1990.

EPA and Textron signed an agreement in October 1991 under which Textron committed to conduct a Remedial
Investigation/Feasibility Study (RI/FS). Dictaphone Corporation was named as a PRP by EPA when the
Agency notified both Textron and Dictaphone that an RI/FS was required for the Site. Textron has
voluntarily undertaken all Superfund investigation and cleanup activities to date.

RI field work began in early May 1992. The initial (Phase I) work was followed by further investigation
of Site groundwater and soils (Phase II). Combined Phase I and II activities included the installation
and addition of 15 new monitoring wells to the previous monitor well network. In total, the RI sampling
included collection and laboratory analysis of approximately 200 samples of Site groundwater, surface and
subsurface soils, stream (surface) water, sediment, and air. Between January and July 1993, at the end
of Phase II work, three rounds of offsite shallow groundwater sampling were performed. These 49 offsite
groundwater samples suggested that the plume of contaminated groundwater was moving offsite, continuing
to enlarge, and potentially threatening downgradient water well users. After discussions with SCDHEC and
Textron in July 1993, EPA decided to move forward with an Interim Remedial Action at the Site. A public
meeting was held

in late August 1993, at Pontiac Elementary School, to discuss the proposed Interim Action and solicit
public comment. An Interim Record of Decision (ROD) requiring Textron to take actions to prevent the
continued offsite northeastward migration of contaminated groundwater was issued in by EPA December 1993.
EPA then issued a Unilateral Administrative Order (UAO) for implementing the Interim Remedial Action (the
"Interim Action") to Textron in May 1994. Textron voluntarily agreed to do all of the work outlined in
the UAO requirements.

During the summer of 1994 Textron retained SECOR International, Inc., to perform the environmental
activities comprising the Interim Action. The first step of the work involved a focused hydrogeologic
study in the area northeast of Spears Creek Church Road (the offsite area). After SECOR's work plans for
the hydrogeologic study and the Interim Remedial Action were approved by EPA, field work began in August
1994 and was completed in November 1994. A report summarizing the study findings, and serving as a
general basis for planning the offsite pump-and-treat system (the "IAPTS") was submitted to EPA in
January 1995. (The document, "Results of the Offsite Hydrogeologic Study," is among those placed at the
information repository.)

During June to December 1995, the Interim Action pump-and-treat system was constructed and new treatment
equipment connected to the wastewater treatment system. Full operations of the groundwater
pump-and-treat system began in December 1995. Preliminary data indicate that the system is capturing
affected groundwater in the offsite area.

Following revision of the draft, a final Feasibility Study for the Site has been completed and submitted
to EPA. The FS was summarized in a recent fact sheet (July, 1996). EPA is currently requesting public
input on its selected remedy for the Site. On September 17, 1996, EPA will hold a public meeting to
announce its selection of a remedial alternative (cleanup plan) for the full and final cleanup of the
Site. Please see page 14 for information concerning where to get more information, and on how and where
to send your comments.
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PUBLIC AND COMMUNITY REVIEW AND COMMENT

Written or verbal comments on this Proposed Plan, the Feasibility Study or any other issues related to
Site cleanup are welcomed, and are an important part of our decision-making process. The public comment
period begins on September 6, 1996 and ends on October 7, 1996. All written comments must be postmark
no later than October 7, 1996. Please send your comments to, or call:

Ralph 0. Howard, Jr., Remedial Project Manager
U.S. EPA Region IV, North Superfund Remedial Branch
100 Alabama Street, S.W., Atlanta, GA 30303
Toil-Free (800) 435-9233

We trust that the 30 day comment period will provide adeguate time for public input; however, the
comment period can be extended for an additional 30-day period, should the need arise. Additionally, EPA
and SCDHEC are available to meet with interested citizens and local officials to go over the proposed
plan in greater detail and to address any community concerns should they exists. For more information on
community involvement in the Superfund process, or at this Site, additional information, or matters
pertaining to the comment period, please contact:

Cynthia Peurifoy, Community Involvement Coordinator
U.S. EPA Region IV, North Superfund Remedial Branch
100 Alabama Street, S.W., Atlanta, GA 30303
Toil-Free (800) 435-9233

The Project Manager for the South Carolina Department of Health and Environmental Control can also be
contacted about this Site:

Yanging Mo, Site Project Manager
S.C.D.H.E.C., Bureau of Solid and Hazardous Waste Management
Division of Hydrogeology
2600 Bull Street, Columbia, SC 29201
(803) 896-4030

INFORMATION REPOSITORY LOCATION:

Richland County Public Library
7490 Park Lane Road
Columbia, South Carolina 29223
(803)736-6575

Information available for public review at this location includes background information on the Site and
on Superfund, as well as the Administrative Record (AR) for the Site. The AR contains all of the
documents EPA will use to select a final remedy for the Site. At present, it contains the RI/FS Work
Plans, a variety of correspondence about the Site, the Baseline Risk Assessment, and the final
EPA-approved RI Report. In a few weeks the Final, approved Feasibility Study and other correspondence
concerning the Site will be added as the RI/FS is completed. Citizens are encouraged to review this
material at their convenience. The AR is also available for review at the EPA Records Center, at the EPA
address listed above.
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GLOSSARY OF TERMS

Administrative Record - A file which is maintained and contains all information used by the lead agency
to make its decision on the selection of a response action under CERCLA. This file 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.

Applicable or Relevant and Appropriate Requirements (ARARs)- Requirements which must be met
by a particular response action under consideration, or by an alternative selected by EPA as a Site
remedy. "Applicable" requirements are those mandated under one or more Federal or State laws. "Relevant
and Appropriate" requirements are those which, while not directly applicable to the action, chemical or
location being considered, EPA judges to be appropriate for use in that particular case.

Aquifer - A geologic unit or formation capable of producing a large enough quantity of water to serve as
a source of drinking water, typically through wells or springs.

Baseline Risk Assessment - A statistical study in which the amount of damage a Superfund Site could
cause to human health and the environment is assessed. Objectives of a risk assessment are to: help
determine whether there is a need for action; help determine the levels of chemicals that can remain on
the Site and still protect health and the environment; and provide a basis for comparing different
cleanup methods.

Carcinogen - Any chemical or substance which is known, or suspected, to cause cancer in humans.

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. The Acts created a
special tax that goes into a Trust Fund, commonly known as Superfund, to investigate and clean up
abandoned or uncontrolled hazardous waste Sites. Under the program, EPA can either:

1) Pay for Site cleanup when parties responsible for the contamination cannot be located or are
unwilling or unable to perform the work,

2) Take legal action to force parties responsible for Site contamination to clean up the Site or
pay back the Federal government for the cost of the cleanup.

Chromium (Cr) - A lustrous, hard, steel-gray metallic element commonly found in the earth's crust.
Chromium is used in the production of stainless steel and for hardening other metals. Chromium solutions
are widely used in electrolytic plating operations to provide a hard, durable coating for metal parts.
Chromium occurs in two chemical forms, hexavalent (often abbreviated "Cr6+") and trivalent ("Cr3+").
The hexavalent form is more toxic, more mobile in groundwater, and is the form of Cr which is the cause
of concern at most hazardous waste sites (including this Site) .

Ecological Assessment - A scientific study conducted for the purpose of identifying, and/or evaluating,
ecological and biological damage to plants and animals in a particular area or habitat. An ecological
assessment often includes chemical testing of laboratory test organisms to identify toxic effects, as
well as an examination ("bioassessment") of native plants and animals in the area of interest.

Feasibility Study (FS) - See Remedial Investigation/Feasibility Study.

Groundwater - Water found beneath the earth's surface that fills pores within sand, silt, clay, soil, or
gravel. In aquifers, groundwater occurs in sufficient quantities to be used for drinking water,
irrigation and other purposes.

Hazard Ranking System (HRS) - A scoring system used by EPA and the state to evaluate relative risks
to public health and the environment from releases or threatened releases of hazardous substances. An
HRS score is calculated based on actual or potential release of hazardous substances through the air,
soils, surface water or groundwater. This score is a primary factor used to decide if a hazardous waste
Site should be placed on the National Priorities List.

Information Repository - A file containing current information, technical reports, and reference
documents regarding a Superfund Site. The information repository is usually located in a public building
that is convenient for local residents -- such as a public school, city hall, or library.
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Innovative Technology - A term referring to new, little-known treatment methods or technologies which
take advantage of recent scientific theories, developments or experiments. Typically, these technologies
lack the extensive cost or performance data that would allow routine use at Superfund sites. However,
innovative technologies have the potential to deliver significantly improved performance and cost-
effectiveness.

In-situ - This term describes treatments or processes which take place within the medium which is
affected, or within the medium to be treated. An in-situ treatment involves no excavation, extraction or
removal of the material to be treated.

Interim Remedial Action - A remedial action that is intended to address immediate potential threats which
could become worse unless action is taken immediately. An interim action is not an emergency action; any
situation that is an immediate threat to the public health and safety is addressed by EPA or the State as
an "emergency response action." Such actions usually include removal of hazardous wastes and/or
contaminated soil; thus they are referred to as "removals".

Maximum Contaminant Level (MCL) - Under the regulations which implement the Safe Drinking Water
Act (SDWA) , the MCL is the maximum allowable concentration of a contaminant in water delivered to any
user of a public water supply well or water supply system. MCLs are based on human health and
toxicological studies.

Mg/kg, mg/1 - The term mg/kg, or milligrams per kilogram, is a unit defining the amount (by weight) of
one substance within a fixed weight of another. One milligram is 1/1000 of a gram; one gram weighs about
the same as a postage stamp, or about 1/28 of an ounce. A kilogram eguals 2.2 pounds. The term mg/1
defines how many milligrams of a substance are present (usually dissolved) within a liter of liguid. One
liter is slightly more than one guart.

Monitoring Wells - Specially constructed water wells installed at specific locations on or near hazardous
waste Sites. Groundwater samples for laboratory analysis, and water table measurements, are taken from
such wells. Monitoring wells thus provide valuable data concerning the direction of groundwater flow and
the types and amounts of contaminants present.

National Priorities List (NPL) - EPA's list of the most serious uncontrolled or abandoned hazardous waste
Sites identified for possible long-term remedial response using money from the Trust Fund. The fist is
based primarily on the score a Site receives on the Hazard Ranking System.

Nitrate (NO 3) - A nitrogen compound consisting of, or containing, the radical NO 3. As a groundwater
contaminant, nitrates can result from agricultural use of fertilizers, or as wastewater from
manufacturing processes using compounds containing nitrates.

Offsite - The terms "offsite" and onsite are used in this Fact Sheet to distinguish the Site property,
bounded by 1-20 and Spears Creek Church Road (SC Road 53), from the offsite areas across Spears Creek
Church Road. However, under CERCLA, the "Site" includes those adjacent areas affected by contamination
originating from the Site.

Plume - A three-dimensional zone within the groundwater, i.e. having length, width and depth, which
contains contaminants and generally moves in the direction of, and with, groundwater flow.

Potentially Responsible Parties (PRPs) - Any individual(s) or company(s) (such as owners, operators,
transporters, or generators) potentially responsible for, or contributing to, the contamination problems
at a Superfund Site. Whenever possible, EPA compels PRPs, through administrative and legal actions, to
clean up hazardous waste Sites which they are responsible for.

Pump-and-Treat System - An active groundwater treatment system which extracts contaminated
groundwater from the subsurface by a network of extraction wells, and removes the contaminants from the
groundwater by various proven technologies.

RCRA, the Resource Conservation and Recovery Act - A 1976 Federal law which established a regulatory
system for tracking hazardous wastes, from the point of generation through disposal. The law reguires
that safe and secure procedures be used in transportation, treatment, storage, and disposal of hazardous
substances. RCRA is also designed to prevent the creation of abandoned uncontrolled hazardous waste
sites. Subtitle C is the portion of RCRA which regulates hazardous waste landfills, while Subtitle D
concerns non-hazardous waste landfills.
-------
Record of Decision (ROD) - A public document which explains how EPA reached a decision to select a
cleanup alternative to be used at a National Priorities List Site. The ROD is based on information and
technical analyses generated during the remedial investigation/feasibility study and upon consideration
of public comments and community concerns.

Remedial Investigation/Feasibility Study (RI/FS) - Two distinct but related studies, usually performed
concurrently, and together referred to as the "RI/FS". They are intended to gather the data necessary to
determine the type and extent of contamination at a Superfund Site; establish criteria for cleaning up
the Site; identify and screen cleanup alternatives for remedial action; and analyze in detail the
possible technologies that could be employed and the costs of the alternatives.

Superfund - The common name used for the Comprehensive Environmental Response, Compensation, and
Liability Act of 1980 (see also "CERCLA" above), as amended by the Superfund Amendments and
Reauthorization Act (SARA) of 1986.

Volatile Organic Compound (VOC) - An organic (carbon-containing) compound that evaporates (volatilizes)
readily at room temperature. Also called "solvents," VOCs such as trichloroethylene (TCE) and
tetrachloroethylene (also called perchloroethylene, or PCE) are common industrial contaminants at
environmental sites.
-------
REQUEST TO BE PLACED ON THE
TOWNSEND SAW CHAIN COMPANY SUPERFUND SITE MAILING LIST

If you would like your name and address placed on the mailing list for the Townsend Saw Chain Company
Superfund Site, please complete this form and return to: Cynthia Peurifoy, Community Relations
Coordinator, EPA-Region IV, North Superfund Remedial Branch, 345 Courtland Street, Atlanta, Georgia
30365, or call 1-800-435-9233.

NAME:

ADDRESS:
TELEPHONE:

AFFILIATION:
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Attachment B
Public Notice of Public Comment Period

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Attachment C

Letter (Public Comment) Concerning the Proposed Plan

SECOR
International Incorporated

October 7, 1996

Mr. Ralph Howard
Remedial Project Manager
USEPA, Region IV-WD-NSRB-SC
100 Alabama Street, SW
Atlanta, Georgia 30303

Re: Chromium Surface Water Remediation Goal for the Offsite Tributary
Townsend Saw Chain Site, Pontiac, South Carolina

Dear Mr. Howard:

SECOR International Incorporated (SECOR) representing Textron, Inc. (Textron) has prepared this letter
is to provide comment on the surface water remediation goal for total chromium in the offsite tributary
(OST) of Spears Creek at the Townsend Saw Chain Site, Pontiac, South Carolina (Site). In the Feasibility
Study for the Townsend Saw Chain Site, Pontiac, South Carolina, dated August 19, 1996 (SECOR, 1996) ,
a total chromium concentration of 11 Ig/L, based on the National Ambient Water Quality Criteria for the
Protection of Aguatic Life (AWQC) (USEPA, 1985), has been presented.

Chromium Surface Water Remediation Goal

It is the position of Textron that the use of the AWQC of 11 Ig/L for total chromium is overly
conservative and ignores site-specific information that was collected under the oversight of the United
States Environmental Protection Agency - Region IV (USEPA) and the South Carolina Department of Health
and Environmental Control (SCDHEC). This statement is supported by several factors:

• The AWQC does not represent site-specific conditions. A site-specific ecological assessment,
which guantified the potential impact on the OST by the presence of hexavalent chromium in
surface water, was performed by Shealy Environmental Services as part of the Remedial
Investigation activities (Aguaterra, 1994). Using the value of 11 Ig/L does not account for
this site-specific assessment.

The AWQC of 11 Ig/L is based on potential effects due to hexavalent chromium (USEPA, 1985), not
a total chromium concentration.

• In environmental conditions, the most significant form of chromium is the trivalent form.
Hexavalent chromium, in most natural water, is freguently not present or only found at very low
concentrations. In many streams there is enough organic matter in the water and the redox
and/or pH is such that any hexavalent chromium would be rapidly reduced to the much less toxic
trivalent chromium. The AWQC for trivalent chromium is 210 Ig/L(Suter and Mabrey, 1994).

Ambient Water Quality Criteria

The AWQC for hexavalent chromium of 11 Ig/L is based on non-site-specific studies. Based on the results
of the site-specific toxicity testing performed by Aguaterra, no adverse impacts to the test species were
seen at 11 Ig/L of total chromium (not until 49 Ig/L were the site-specific test species affected).
Therefore, the AWQC is likely over-protective of aguatic species in the OST. Further, the AWQC have not
been revised since 1985, so they do not incorporate any recent scientific findings from USEPA or other
researchers.
-------
Mr. Ralph Howard
USEPA, Region IV-WD-NSRB-SC
October 7, 1996
Page 2

Summary

Textron disagrees with the use of 11 Ig/L as the total chromium surface water remediation goal. Based
on the information presented above, we reserve the right to identify the final remediation goal after
completion of the proposed groundwater remediation activities. As presented in the Feasibility Study,
both the Interim Action Pump and Treat System (IAPTS) and the proposed remedial activities are designed
to prevent further migration of chromium in groundwater into the OST (SECOR, 1996). Based on surface
water analytical data collected in the past two years, the total and hexavalent chromium concentrations
have decreased. This decrease in concentration is likely due to past and ongoing remediation activities
(e.g., pumping and treating groundwater). This trend of decreasing concentrations is likely to continue
as a result of the one year that the IAPTS has been in operation and the future operation of the proposed
remediation system.

Once the groundwater remediation activities as described in the Feasibility Study have been completed,
additional discussion should occur regarding a surface water remediation level, considering site-specific
factors and any additional scientific findings regarding the toxicity of chromium in aguatic
environments. The analysts who conducted the ecological assessment (i.e., Aguaterra and Shealy)
recommended performing no active remediation of the surface water and sediment in the OST, as the impacts
are only slight to moderate and the treatment of the onsite groundwater (via the IAPTS and other
remediation activities) will likely result in the mitigation of the chromium in the OST (Aguaterra,
1994). SECOR and Textron concur.

References Cited

Aguaterra Engineering, Inc. 1994. Technical Memorandum of Ecological Assessment, Townsend Saw Chain
Site, Pontiac, South Carolina. May 6.

SECOR International Incorporated (SECOR). 1996. Feasibility Study, Townsend Saw Chain Site, Pontiac,
South Carolina. August.

Suter, G. W. And J.B. Mabrey. 1994. Toxicological Benchmarks for Screening Potential Contaminants
of Concern for Effects on Aguatic Biota. National Laboratory, Oak Ridge, Tennessee.

United States Environmental Protection Agency (USEPA). 1995. Ambient Water Quality Criteria for
Chromium - 1984. EPA 440/5-84-029.

Your guestions or comments are welcomed. Please contact Carol Maslanka (916-648-9160) or Mike Bedan
(303-545-2017) with guestions, comments, or reguests for additional information.

Sincerely,

SECOR International, Inc.

MEB/mb

cc: Gerald Benson, GEE
Robert Brayley, Textron
Jamison Schiff, Esg., Textron
Jim Plunkett, SECOR
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Attachment D

Proposed Plan Public Meeting Sign In Sheets

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Attachment E

Official Transcript of the Proposed Plan Public Meeting

PUBLIC HEARING

UNITED STATES EPA

SUPERFUND PROPOSED PLAN
TOWNSEND SAW CHAIN SUPERFUND SITE
PONTIAC, SOUTH CAROLINA

********

ORIGINAL

Tuesday, September 17, 1996

7:35 p.m. to 8:01 p.m.
CREEL COURT REPORTING, INC.
1720 Main Street, Suite 202 / Columbia, SC 29201
(803) 252-3445 / (800) 822-0896
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Townsend Saw Chain Superfund Site

1 MR. HOWARD: Good evening, my name is Ralph Howard, I'm the
2 EPA project manager for the Townsend Saw Chain
3 Superfund Site and our purpose tonight is to discuss
4 the site and specifically EPA' s proposed plan for
5 cleaning up this site for a final cleanup at the
6 Townsend site. These are the items I'd like to cover,
7 and you'll notice at the end of the evening we've
8 reserved some time for guestion and answer and some
9 comments, public comments, hopefully we'll have some
10 public arriving here, about the proposed plan and any
11 guestion you may have about the site, we'd like to
12 answer it at that time. Again, my name is Ralph
13 Howard, I'm EPA's project manager for the site, and a
14 good way to start is to introduce the other state and
15 federal officials here. From EPA also, Ms. Cynthia
16 Perifoy seated here to my right. Cynthia is the
17 community relations coordinator for EPA on the site and
18 she is concerned about your input and feelings about
19 what EPA is doing here. From the South Carolina
20 Department of Health and Environmental Control, DHEC,
21 we have a number of individuals present: Ms. Yanging
22 Mo is here somewhere, she is the state project manager.
23 Her supervisor is Mr. Kemp Coleman who is with the
24 Department of Geology at DHEC. Also Mr. Gary Stewart
25 is here, and Mr. Tom Knight, those gentlemen are from
Townsend Saw Chain Superfund Site

1 DHEC. Representing Textron is Mr. Jerry Benson, and
2 representing SECOR, who is the consultant for Textron,
3 is Mr. Tim Holbrook. To begin with, I should mention
4 about Superfund, what is Superfund and what is EPA
5 doing here. Superfund is a law passed by Congress in
6 1980, Comprehensive Environmental Response,
7 Compensation and Liability Act, or CERCLA is the
8 abbreviation, better known as Superfund, was
9 reauthorized by Congress in 1986 with a series of
10 amendments, and that's the federal law that is of
11 interest here tonight. A number of steps are involved
12 in Superfund. I've highlighted the two that are about
13 to occur, actually I could have highlighted step number
14 five of the proposed plan, which we are going to
15 discuss tonight. And again, this is specifically a
16 plan for final cleanup, long-term cleanup action at the
17 site. When a site is discovered and evaluated by EPA,
18 if the site conditions warrant, the site is listed on
19 the actual priorities list with the EPA, two things
20 then happen, a ... well, it's published in the federal
21 records, but, more importantly, studies are done to
22 determine how bad the site is and what should be done
23 to clean it up. Remedial investigation is a study in
24 which the contamination and its extent are determined
25 and a risk assessment is also done to try to evaluate

CREEL COURT REPORTING, INC.
1720 Main Street, Suite 202 / Columbia, SC 29201
(803) 252-3445 / (800) 822-0896
-------
Townsend Saw Chain Superfund Site

1 both qualitatively and quantitatively the risks posed
2 by the site to the human element environment if the
3 site is not addressed. Followinq that, a feasibility
4 study is done, and which was actually recently
5 completed at this site, in which all the potential ways
6 to clean up the site are considered and alternatives
7 are put toqether that utilize these methods of cleanup.
8 These alternatives are then evaluated one aqainst the
9 other and at the end of the feasibility study, EPA will
10 then select the alternative that is best suited to
11 clean up of the site. Under Superfund, EPA can elect
12 to clean up the site itself if no responsible parties
13 can be found, or private parties may be ... aqreements
14 are reached under which those parties perform the
15 cleanup, and in this case Textron, Incorporated, is the
16 responsible party at the site. You will notice that
17 community relations is shown as occurrinq throuqhout
18 the process and that is indeed the case, we'd like to
19 hear from you toniqht, and to pursue that topic
20 further, I'd like to ask Cynthia to have a word or two
21 about community relations.
22 MS. PERIFOY: Good eveninq. Aqain, I'm Cynthia Perifoy, and
23 I'm community relations coordinator for EPA for this
24 site and the sites, EPL sites in South Carolina. I
25 want to qo over a few ... a few items of interest which
Townsend Saw Chain Superfund Site

1 are appearinq on the slide. Our public comment period
2 ends October 7th, it doesn't end toniqht, we will take
3 comments that you miqht have throuqhout this period as
4 it states in the fact sheet, that can be extended if
5 need be for an additional 30 days. We do have an
6 administrative record available at the Richland County
7 Library on Parklane Road, that record is also available
8 at the EPA offices in Atlanta, even thouqh we just
9 moved, we probably can't find them, but they are
10 available for your review. I want to make it known
11 that the site is still available for the technical
12 assistance qrant. It will be available up until the
13 site qoes into a remedial action, I believe. So that
14 is a qrant that is available to communities for the
15 hirinq of a technical advisor to qo over the EPA
16 documents with you and to provide comments and some
17 explanations to community members. If there is anyone
18 that's interested in pursuinq that, I will be qlad to
19 work with them on that. Of course, we always
20 appreciate your feedback on our activities. We do have
21 an 800 number, which is 1-800-435-9233, it did not
22 chanqe. Call us and let us know other thinqs that we
23 can do that miqht be helpful. I want to take a little
24 time to set the staqe for toniqht's meetinq. As you
25 can tell, we have a court reporter here, we are havinq
CREEL COURT REPORTING, INC.
1720 Main Street, Suite 202 / Columbia, SC 29201
(803) 252-3445 / (800) 822-0896
-------
Townsend Saw Chain Superfund Site

1 a transcript done of this meeting for the record; we
2 ask you to identify yourself when you speak and make
3 sure that our court reporter can hear you. It's very
4 important that she hears everything and gets down
5 everything. She'll probably be giving us little
6 signals when she can't hear you, so please pay
7 attention to her, and I thank you.
8 MR. HOWARD: I neglected to mention two other attendees that
9 I should have who represent DHEC. Dr. Rose Litchett
10 is with us tonight, and Mr. Eric Melaro, they are both
11 with DHEC and they're with the area that has to do with
12 health/hazard evaluation. At the Townsend site,
13 despite the process I showed you earlier, there has
14 been some slight difference in what all activities that
15 have been conducted since 1994. On the top line here
16 you can see the rather standard remedial investigation
17 and feasibility study process which has continued
18 throughout this time. In late 1993, EPA and the
19 responsible party elected to break off from that
20 process and do what's called an Interim Remedial Action
21 which allowed us to proceed in a faster manner towards
22 groundwater cleanup. As I'll get to in a moment,
23 groundwater contamination has always been a main
24 concern at the Townsend site and this was a means to
25 move on that concern in a quicker manner. That's the
Townsend Saw Chain Superfund Site

1 middle track on this slide. Those activities are, for
2 the most part, completed as of December of this past
3 year when a ground work pump and treat system was
4 constructed and actually checked out and operation
5 began. That was in December '95. The lower item on
6 the slide refers to a preexisting DHEC requirement.
7 EPA began activities on the site in 1992. The Interim
8 Remedial Action essentially incorporated that
9 requirement resulting in an upgrade of the pump and
10 treat system. There is now a five well pump and treat
11 system operating on the site that has achieved control
12 of the groundwater problem that I'11 be further
13 discussing. As you see across the top line, a number
14 of activities have continued. The ecological work was
15 actually completed following all the remedial
16 investigation work. During 1995 a number of
17 Feasibility Study activities were pursued immediate to
18 August of 1996, as you see on the right. These are the
19 items that occurred in the Interim Remedial Action. I
20 wanted to illustrate the variety of activities that
21 were undertaken during that time. There was a
22 hydrogeologic study done to put a firm limit on where
23 the groundwater contamination was. That was completed
24 late in the year 1994. The groundwater pump and treat
25 system was then designed and constructed in the latter
CREEL COURT REPORTING, INC.
1720 Main Street, Suite 202 / Columbia, SC 29201
(803) 252-3445 / (800) 822-0896
-------
Townsend Saw Chain Superfund Site

1 part of 1995. There was a short period to obtain a
2 contractor. The system was inspected and operations
3 began in December of 1995. To understand the Townsend
4 site, the first item to be considered is the site
5 history. The origin of the problem concerning
6 groundwater is certain to have come from the first two
7 bullets that you see here. Wastewater practices in the
8 past being what they were, to process wastewater from
9 plating and other operations went directly to the
10 ground. There were, and still are, some low lying
11 areas to the north of the plant, which is located just
12 500 feet to the south of us here from the school
13 ground, and into those low lying areas went most of the
14 process water from both the previous owner, Dictaphone
15 Corporation, and then later Townsend Saw Chain company.
16 The facility was used by the Townsend Company to make
17 parts for chain saws. It was used by Dictaphone to
18 make recording eguipment. The potential for
19 groundwater contamination was realized early on. Since
20 1982, there has been rather continual DHEC oversight.
21 EPA became involved in 1985. Remedial actions were
22 actually initiated in 1982 when DHEC issued an order
23 requiring a pump and treat system be built. The
24 company built the system that captured and treated
25 groundwater and discharged that water to the spray
Townsend Saw Chain Superfund Site

1 field areas surrounding the site, that's the open
2 ground around the property. That effort began in 1982.
3 EPA again became involved in 1985 after notification
4 from the state and a site inspection was conducted. At
5 that time, it was found that the groundwater
6 contamination did extend beyond the plant to property
7 across the northeast, across Spears Creek Church Road
8 that this school is on, and that was of great concern.
9 It was also found to be coming out from a seep or
10 spring located northeast of the road. Steps were taken
11 during those years, in the latter eighties, to get the
12 site onto the National Priorities List. South Carolina
13 DHEC did require some modifications and upgrade to the
14 pump and treat system that was still operating in 1988.
15 That work continued on through final permit approval in
16 1993. And this was a conscious effort by EPA and DHEC
17 to avoid duplicating work that was being done anyway,
18 and that led to the pump and treat system that I
19 described earlier being completed this past December.
20 The site was listed eventually in 1990. There were
21 some concerns at that time about the school. In 1995,
22 as I mentioned, the pump and treat system came on line.
23 You see the other activities leading to tonight. The
24 best way to illustrate what's been found by the studies
25 is to show you an aerial photograph of the area and
CREEL COURT REPORTING, INC.
1720 Main Street, Suite 202 / Columbia, SC 29201
(803) 252-3445 / (800) 822-0896
-------
Townsend Saw Chain Superfund Site 10

1 some of the conclusions that were drawn by the remedial
2 investigation which concluded in late 1993. The scale
3 of this photograph is a little bit hard to determine,
4 but for reference, the exit that you see on 1-20, which
5 is down in the lower left here, from the upper to the
6 lower exit ramps is about 750 feet. Our studies in the
7 Remedial Investigation and in the Interim Remedial
8 Action show that the groundwater contamination extends
9 from the plant property, and I think I'11 have to go
10 point, but the plant is to the left of this slide,
11 extending up to the right some 750 feet. I'll walk up
12 there in a moment and point. There is also a tributary
13 shown again up into the right from the plant. I'll
14 walk over and point at those. Here's the plant, here's
15 the tributary and the groundwater flowing is like so.
16 This distance, 750 feet, the same as this. This line
17 shows red for vegetation by the way, and the red can be
18 interpreted as the more dense or vegetated land. But
19 this does give an illustration of the scope of the
20 problem and also the limited scope of that groundwater
21 problem. Over to the extreme right of this slide, the
22 dark blotch that you can see on the right most edge is,
23 in fact, the Wood Creek Lake. There is a number of
24 homeowners who have lake homes and they were concerned
25 about their drinking water. Those wells have been
Townsend Saw Chain Superfund Site 11

1 sampled three times since 1992 and have always been
2 found to be completely clean and unaffected. The
3 distance from that lake back to the limit of the
4 groundwater flow is approximately one mile and this
5 should be kept in mind. The two areas just to the
6 north of the site you may notice are gray blotches.
7 Those are, in fact, the low lying pond areas. This
8 photograph was taken in 1989, no water had been
9 discharged to that area for some seven years, but the
10 length of time over which water was put there has
11 obviously had an effect on the way the ground surface
12 is, and so forth, and, those are the origin of the
13 groundwater problem that show up guite clearly here.
14 During the Remedial Investigation not only was the
15 groundwater limit ... I'm sorry, the Remedial
16 Investigation and the Interim Remedial Action, not only
17 was the groundwater contamination limit established but
18 we learned more about where our soil problem was on
19 site. There isn't much of a soil problem at the site.
20 The wastewater ponds or the pond areas that are gray in
21 this photograph are themselves or do themselves contain
22 a significant amount of chromium, although chromium is
23 not a human health hazard, but the chromium is capable
24 of influencing groundwater, and that's not too
25 surprising given the number of years that water was
CREEL COURT REPORTING, INC.
1720 Main Street, Suite 202 / Columbia, SC 29201
(803) 252-3445 / (800) 822-0896
-------
Townsend Saw Chain Superfund Site 12

1 placed out onto those areas. We had two smaller areas
2 of soil contamination that don't really show on a
3 photograph of this scale, but they are very small and
4 are being handled outside of the Feasibility Study,
5 being handled under the Interim Remedial Action. That
6 is an explanation of the landfill operation of a small
7 amount of soil. Those had to do with the pipes that
8 deliver water out onto the waste ponds. That was all
9 soil contamination and I'11 show you a map in a moment
10 of exactly where that is. The little tributary I
11 pointed out, sediment and surface water in this
12 tributary are affected. Our Ecological Study was
13 intended to determine whether or not the ecosystem
14 problem was being caused. We also, of course, did a
15 Risk Assessment that considered that, as to whether it
16 was a human health problem, and I'll get to the Risk
17 Assessment in a moment. That study was ... that
18 Ecological Study was inconclusive in nailing down with
19 certainty that ecological problems were being caused by
20 site contamination. When I explained to the photograph
21 people which area I was interested in, they left the
22 yellow sticker right on the photograph and just took
23 the picture. This diagram shows you the groundwater
24 plume, as we call it, the three dimensional area in the
25 shallow aguifer that has contamination. It's important
CREEL COURT REPORTING, INC.
1720 Main Street, Suite 202 / Columbia, SC 29201
(803) 252-3445 / (800) 822-0896
Townsend Saw Chain Superfund Site 13

1 to note that our contamination is only in the
2 shallowest aguifer, we do not have a deep contamination
3 problem here. This is a recent map from approximately
4 three or four months ago, the last guarterly sampling.
5 As part of the pump and treat system, there are
6 guarterly samples collected. The darker areas
7 obviously represent the high levels of contamination.
8 To the west or to the left of this side, you can see
9 that the plume is contained within the property
10 boundary, and again to the right our distance off site
11 is approximately 750 feet. The tributary shows as the
12 dotted line at the top of this slide in the off site or
13 northeast area. This shows our soil contamination on
14 site. The highlighted areas have more than 10
15 milligrams per kilogram of hexavalent chromium which is
16 the form of chromium that caused this problem at the
17 Townsend site, both in groundwater and soil. The
18 highlighted areas have more than 10 milligrams, as I
19 mentioned; however, our cleanup standard is slightly
20 higher than this. In determining a cleanup standard,
21 a Feasibility Study, this is to give an idea of where
22 the worst soil is, and again you see the relationship
23 to the former waste ponds or the water ponds area.
24 Also, the hard line, by the way, is the limit of the
25 groundwater problem on this site property. As I

CREEL COURT REPORTING, INC.
1720 Main Street, Suite 202 / Columbia, SC 29201
(803) 252-3445 / (800) 822-0896
-------
Townsend Saw Chain Superfund Site 14

1 mentioned, a Risk Assessment was done in 1993 by a EPA
2 contractor and it was updated in 1996. The update
3 consists of an addendum to the Risk Assessment, which
4 included the Feasibility Study, and that's available
5 for your review at the locations Cynthia mentioned.
6 Our overall conclusions from the Baseline Risk
7 Assessment and from the Addendum were as shown here.
8 Groundwater use is the one to be concerned with in the
9 future, but it should be noted that you would have to
10 have a drinking water well in the area that's affected,
11 not simply in the off site area. You would then need
12 to be exposed to that groundwater as your drinking
13 water source for a number of years to ... I'm sorry, to
14 counter any possible health effects over the long term.
15 That could pose a risk under a future use scenario were
16 a groundwater well be installed at that location. We
17 do not have risk of surface water and sediment which
18 should be of interest, if you are walking around in
19 that area, you really do not need to fear anything as
20 far as surface water and sediment from the EPL
21 standpoint. And as I mentioned earlier, the soil
22 itself does not pose a risk to workers or site
23 trespassers or kids or anyone else. Before I mention
24 the goals a little bit that are presented here, it
25 should be noted that in view of the ecological ... the
Townsend Saw Chain Superfund Site 15

1 potential for ecological harm, EPA is requiring that
2 the responsible parties agree to conduct a small scale
3 sediment removal as a means toward ecological
4 protection. What this will do is, it will remove
5 sediment that even could cause ecological harm in the
6 off site areas as we saw in the map across that road,
7 across Spears Creek Church Road. That action would
8 eliminate the potential for harm to creatures living in
9 and along the tributary. We will only perform that
10 action, however, after ... or the responsible party
11 will perform that action after we are confident about
12 the pump and treat system and its ability to prevent
13 re-contamination of that sediment. We don't want to do
14 this twice. So our goals overall, based on what I've
15 just presented, are ... there's a good number of them
16 here. We have groundwater, soil, sediment and surface
17 water that are affected even though the problems
18 associated with each is different. For soil, our real
19 problem is to protect groundwater. For groundwater,
20 there are a number of things, the obvious one is not to
21 drink it, to prevent ingestion of it, but we also like
22 to keep it out of surface water so that it does not
23 cause, in turn, surface water problem. That problem
24 would be ecological in nature, by the way, not
25 human/health risk. We would also like to restore the
CREEL COURT REPORTING, INC.
1720 Main Street, Suite 202 / Columbia, SC 29201
(803) 252-3445 / (800) 822-0896
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Townsend Saw Chain Superfund Site 16

1 groundwater as a potential water source for people in
2 that area. For sediment, our problem is ecological and
3 we do want to take out any unacceptable ecological risk
4 out there. Ecological risks again are difficult to
5 guantify but they have a way of going up the food chain
6 and we would just like to prevent that entirely. And
7 finally, for sediment, our problem is ecological in
8 nature and we again want to protect the ecosystem, we
9 don't want to re-contaminate after we do the sediment
10 clean-up action. But as in Superfund and in most
11 environmental work, we must determine how good is good
12 enough and what are your standards going to be. These
13 are based on a number of things, federal laws, the
14 state laws. Regulations usually implement the laws, so
15 regulations have a bearing, as does the extent of the
16 contamination, as far as how bad is it and where does
17 it go? We have to look at sensitive environments and
18 you have to look at levels that will cause the problem
19 versus those that can be left alone. In our case, a
20 good bit of work went into the Feasibility Study to
21 determine these levels. Most of the groundwater
22 numbers represent federal standards that the state also
23 adheres to. The surface water standard is a federal
24 standard, and the surface soil number was determined,
25 site specifically, based on what would leach or could
Townsend Saw Chain Superfund Site 17

1 leach to groundwater. So the number on surface soil is
2 intended to prevent the soil from causing a groundwater
3 problem. In the Feasibility Study, the whole objective
4 or the whole point of the study was to come up with
5 alternatives, that is, different ways that one could go
6 about cleaning up the site. All the technologies that
7 you could use and all the methodologies you could use
8 are looked at and assembled into alternatives. An
9 alternative is a grouping of these methodologies or
10 technologies that you will use to clean up the site.
11 We always consider a no-action alternative to better
12 illustrate what will happen if nothing is done. You
13 may recognize this from the fact sheet and this is
14 simplifying it from there. If we don't take action
15 here to address soil, the most likely result is that
16 any soil that is affecting groundwater will continue to
17 do so. No action will be taken to actually clean up
18 the site or change anything about the soil, it will be
19 left as is. EPA does reguire a five year report and
20 there will be some status reporting to be done. That
21 will be the only costs. Another option would be to
22 simply cover the entire site with a cap to try to
23 prevent, in this case, prevent infiltration which could
24 take the chromium down into groundwater. It would not
25 be a human health problem here, although a cap would
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Townsend Saw Chain Superfund Site 18

1 prevent anyone for actually touching that soil and
2 messing around with it. You could also, by chemical
3 means, actually turn the entire soil area, and our
4 problem is shallow surface soil, by the way, you could
5 turn the entire thing into a model or block that itself
6 would not leach to groundwater. This can be expensive.
7 It would work but there are some guestions about it as
8 to its long-term effectiveness. There is also a new
9 methodology out there that EPA considers emerging, and
10 that is, it's not in routine use and it has no large
11 database or performance or cost data. However, the
12 methodology has promise and essentially what happens is
13 that the water solutions which contain a producing
14 agent actually cause a chemical change in the soil
15 which locks the soil up by changing its chemical makeup
16 into an insoluble or stable form. If this can be done
17 with hexavalent chromium, in this sites specific case,
18 that chromium is then not available to be ingested or
19 blown away or otherwise and released into the
20 environment. With groundwater our different
21 methodologies and technologies were assembled into four
22 potential actions as well. We looked at no action, of
23 course. There is a five-well pumping system in
24 operation, as I mentioned, and our no actions do
25 include this system operating, we're not simply going
Townsend Saw Chain Superfund Site 19

1 to turn it off, but that would be all that would be
2 done under this alternative. There are some problems
3 with continuing to pump and treat alone, even though
4 that was another alternative I mentioned, and you can
5 have an extremely long time frame involved to
6 accomplish that this way. You could also simply try to
7 restrict people's usage of that water by restrictions
8 and monitoring only of the groundwater in the affected
9 area. Unfortunately, this is difficult to do in real
10 life and impossible to enforce, but if you went that
11 route, you might could prevent exposure, probably could
12 if done properly. These involve some legal means,
13 including deed restrictions, and you see the costs.
14 Other options would include continuing to pump and
15 treat; in fact, expanding pump and treat to simply pump
16 more water and move more water off the moist area of
17 the site of the affected plume. This is expensive, but
18 more important, the same problems I mentioned earlier
19 can occur. It's possible that the concentrations would
20 drop but simply not very fast. When they do drop, they
21 tail off, and the outer years of operation of such a
22 system do not result in very much reduction in
23 contaminate levels at all, making it inefficient over
24 the long term. Finally, the same idea I mentioned for
25 soil, you can do an in-situ chemical treatment. Again,
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Townsend Saw Chain Superfund Site 20

1 this is an emerging technology, this is new, and the
2 same process I mentioned, you use a reducing agent to
3 actually change the form of that chromium within the
4 groundwater. It may sound complicated but it's
5 actually a rather simple instantaneous chemical change.
6 What has to be worked out here is, is it permanent,
7 does it stay gone, does it stay out of the groundwater?
8 There is some technical work to achieve this; however,
9 it does seem to have great potential. It's worth
10 noting in this regard that the levels of chromium in
11 soil are so much higher than the levels in groundwater.
12 One way to think of it is that there is plenty of room
13 in the soil matrix and simply adding chromium to that
14 matrix, a typical concentration would be a thousand
15 times higher in that soil than it would be in the
16 groundwater. In the case of chromium, if the standard
17 is multiplied by a thousand, the concentrations in soil
18 are still much greater than that number. There's room,
19 in other words, for this chromium to be bound up.
20 Those were our options ... and let me mention before I
21 get into this, that EPA ... the options for soil and
22 ground water and EPA' s preferred alternatives all
23 include the continued operation of the pump and treat
24 system, that is going to occur. They also include the
25 ecological action that I mentioned, the small scale
Townsend Saw Chain Superfund Site 21

1 sediment removal, and they mention ... I'm sorry, they
2 include site monitoring which is always reguired at a
3 Superfund site. The purpose of that is obviously to
4 show that you know where and how bad the problem still
5 is, and are you achieving the cleanup with your
6 remedial action. The action EPA proposes to choose,
7 which is referred to as the remedy or the preferred
8 alternative, includes a ... I'm sorry, an alternative
9 for soil and an alternative for groundwater. For soil
10 and for groundwater, we're proposing to choose the
11 in-situ chemical treatment. I've listed here the
12 components of what the remedy would be if we go this
13 course. Continued operation, as I mentioned, of the
14 pump and treat. All remedial actions of a Superfund
15 have to have a design base and then a remedial action
16 phase where you actually construct or do the remedy.
17 In this case, our remedial design will be rather
18 freewheeling, you could say, we've got to determine
19 exactly how to do it. It is an emerging technology,
20 there is limited information to draw on as to how to
21 plan and accomplish this, and I'm going to ask Mr. Tim
22 Holbrook here in a moment to try to shed some light on
23 their ideas about how it can be done and how it was
24 determined that this had problems at the site
25 concerning the insitu chemical treatment. But in
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Townsend Saw Chain Superfund Site 22

1 remedial design, you have to figure these things out,
2 the items I've listed. The remedial action, as planned
3 in the Feasibility Study would include actually hauling
4 away some of the most highly contaminated soil from the
5 surface and treating the rest using the in-situ chemical
6 treatment methodology. To put this very simply, you
7 use liguid solutions which are then either poured onto
8 the ground or delivered into the subsurface by whatever
9 means available to cause the chemical reaction. We
10 then must monitor and see that the action occurs, show
11 that it's happening and show that it stays that way.
12 It's guite a tall order and, for that reason, the
13 action is likely to include the things I've mentioned.
14 It may reguire phase activities. There will have to be
15 some consideration of how to evaluate that it is
16 working and that we're placing the solution in contact
17 with the groundwater, particularly on the groundwater
18 side of the remedy. As I mentioned, site monitoring
19 would be continued. We need to see that we're causing
20 an effect on the surface water downstream in the
21 tributary, and for that reason we've got to monitor in
22 one place at least downstream somewhere. We have a
23 continuation planned of the guarterly sampling that
24 occurs now and that does include sampling the seep or
25 spring that I mentioned, that sampling will continue.
Townsend Saw Chain Superfund Site 23

1 Finally, the small scale sediment removal, which we
2 will address and the remaining ecosystem concerns, et
3 cetera. I'd like to ask Tim Holbrook, if he would, to
4 explain a little bit more about in-situ chromium
5 production and what was done during the demonstrations,
6 and that was one of the activities that occurred during
7 1994 and 1995 that led to the responsible party's
8 interest and our interest in in-situ chromium
9 production.
10 MR. HOLBROOK: Thanks Ralph. First of all, just real briefly
11 before we get into the Demonstration Study, this
12 technology is considered innovative by EPA; in fact,
13 there's been an EPA site demonstration done in Turlock,
14 California. That's described very fully in the
15 appendix to the Feasibility Study. And there's also
16 been a demonstration project in New Hope, Pennsylvania,
17 that's been approved by the State and is referred to
18 there as well. SECOR, our company, is also involved in
19 other sites in California as a voluntary cleanup using
20 the same technology. The technology has been used very
21 successfully. Wastewater treatment, in fact, is
22 probably one of the chemicals used in the past to treat
23 the chromium, so that the process chemistry is very
24 well accepted. And in the soil and insuti environment,
25 there are certainly guestions that we need to address
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Townsend Saw Chain Superfund Site 24

1 those things specific, which is one of the reasons we
2 completed this study. Our objectives were to
3 demonstrate that the surface soils and the groundwater
4 could be treated effectively with a very simple
5 solution of . And there's two forms of chromium in
6 the groundwater as well as in the soil, one of which is
7 very soluble and one of which is not. The very
8 insoluble form is trivalent chromium and it is very
9 difficult to resoluablize, even though it's a solution.
10 The hexavalent chromium which roman numeral number six
11 indicates that it's a very soluble mobile and a very
12 toxic form of chromium. The ferrous sulfate is very
13 effective in changing the form of chromium from
14 hexavalent to trivalent chromium. So we did a couple
15 very interesting and very small scale experiments to
16 see if this would indeed work in a small setting. In
17 the overhead shot that Ralph showed earlier there was
18 a indicated waste pond area, these pits were dug in the
19 waste pond area that were about 18 inches deep and 4
20 feet by 10 feet. We weren't burying anybody, we were
21 doing an experiment. We lined the excavation with
22 plastic, we put the soils that were taken out of the
23 hole, we segregated them on plastic, and then placed
24 back in the hole in layers in which they came, so they
25 were representative, as much as we could,
Townsend Saw Chain Superfund Site 25

1 representative of the natural soils that are in the
2 waste pone area which was the highest chromium
3 concentration. The drain pipe you see there was used
4 to collect leachate after the various treatments of the
5 ferrous sulfate that were applied. The results of the
6 soil testing indicated that by applying a very small
7 concentration of ferrous sulfate, as little as eight
8 grams applied, we had a very significant decrease in
9 the concentration of the hexavalent chromium. The
10 original zero treatment, far on the left, results in
11 600 micrograms per kilogram concentration of hexavalent
12 chromium, with the eight milligrams added, it's about
13 half of that. And when we get to the 400 level, we had
14 a very difficult time finding any hexavalent chromium.
15 We were encouraged by this and feel that treatment
16 concentration is probably somewhere between eight and
17 400 milligrams level. This is strictly by treating the
18 soil with a very dilute solution and spray it over the
19 top of the soil, that's simply what we did. To
20 investigate this concept in the groundwater itself, we
21 used a couple of existing wells and a couple of
22 injection wells to inject, again, a very low
23 concentration of ferrous sulfate, and what we found
24 was, that when we injected ferrous sulfate solution and
25 monitored the guality of groundwater in the vicinity
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Townsend Saw Chain Superfund Site 26

1 and downgrading of that well, we saw a very substantial
2 decrease in the concentration of hexavalent chromium.
3 The green line indicates the treatment, which we added
4 the ferrous sulfate, and prior to adding the ferrous
5 sulfate we had a test in which we just had tap water
6 and chloride. That's the yellow line. So without the
7 treatment, we saw a decrease in concentration from
8 about 1500 micrograms to maybe 1,000 micrograms in the
9 groundwater. However, when we used the ferrous sulfate
10 treatment, we took that all the way from the 1500 or so
11 level down to non-detectable, less than about 10
12 micrograms per kilogram of hexavalent chromium. So
13 this indicated a very positive potential for the use of
14 this technology in the soils. A couple of other things
15 that we did to supplement this were, was to investigate
16 the long term stability of the treated soils. We
17 collected some soils that had been treated in the plots
18 that you saw earlier and subjected them to vigorous PH
19 testing under varied PH conditions which would simulate
20 successful rainfalls and the normal environment; in
21 fact, we even went as far as contacting the local
22 weather service and the USGS and constructing a
23 simulated rain itself that was comparable to rainfall
24 that you get in the area in terms of its chemicals
25 existing in the PH acid base. We used that to leach
Townsend Saw Chain Superfund Site 27

1 the soils that we obtained from the plots over several
2 weeks and found that we still were unable to leach out
3 the hexavalent chromium because it had changed to
4 trivalent chromium, which is insoluble. So that's one
5 of the things we did. The other thing we did was come
6 up with a leachability factor to be used in the
7 development of the remediation, and all that
8 information is provided in the appendices to the
9 Feasibility Study.
10 MR. HOWARD: Thank you. If you are-interested in the
11 specifics of what was done on both the Demonstration
12 Study and later the Feasibility Study concerning
13 feasibility and the stability of the reaction that Tim
14 and SECOR investigated, there is great detail on that
15 in the Feasibility study which contains the
16 Demonstration Study report as one of its appendices.
17 So you may wish to look further there. So from here we
18 go to ... we go eventually to cleanup, but we would
19 like to hear from you first. We have a legally
20 established public comment period which will extend for
21 another couple of weeks, three weeks now, through
22 October the 7th, at that time we will close the public
23 comment period and we will ... I will sit down and
24 address these concerns, letters, comments that I
25 receive concerning what EPA is doing. You see the
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Townsend Saw Chain Superfund Site 28

1 public meeting listed there tonight. In the record of
2 decision, which will be issued in November of this
3 year, EPA will address in writing all the concerns
4 brought to us and address those. EPA has on occasion
5 modified records of decision, modified the preferred
6 alternatives, none of those things are ... there's no
7 reason why those could not happen here as well if you
8 do not like what you're seeing. But we do plan to
9 issue the record of decision in November, again
10 depending on public comment. From there we arrange a
11 legal agreement with the responsible parties. Textron
12 has done all the work reguested of them to date and we
13 expect to, in fairly short order, reach a legal
14 agreement for continuing this action at the Townsend
15 site. Following that, the remedial design that I
16 described earlier would begin, obviously it begins with
17 planning. That would certainly be true in this case
18 where we are really starting from scratch as to the ...
19 we're not starting from scratch, but we are starting
20 with new innovative technology. We do have to plan out
21 very carefully that work. It's hard to predict exactly
22 when the first solutions might hit the ground or work
23 towards the groundwater, but certainly by next summer
24 we'd like to see activities underway in the remedial
25 action. So this is where we go from here and we'd
Townsend Saw Chain Superfund Site 29

1 certainly like to hear any concerns or guestions you
2 might have. I would ask that you identify yourself for
3 our court reporter so that she'll know who's asking the
4 guestion, and I will repeat guestions if they are
5 necessary, as necessary. Are there any guestions? If
6 there are any guestions at all, now is your chance.
7 (No guestions are posed)
8 All right, thank you for coming. Please stay
9 afterwards and talk with us if you will, we certainly
10 want to keep you informed. I appreciate your attending
11 tonight and, again, thanks for coming.
12 (There being nothing further, the hearing was adjourned at
13 8:01 p.m.)
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CERTIFICATE

This is to certify that the within Public Hearing,

consisting of Twenty-eight (29) pages, is a true and correct

transcript of the hearing; said hearing was reported by the

method of Stenomask with Backup.

I further certify that I am neither employed by nor

related to any of the parties in this matter or their counsel;

nor do I have any interest, financial or otherwise, in the

outcome of same.

IN WITNESS WHEREOF I have hereunto set my hand and

seal this 30th day of September, 1996.

Notary Public for South Carolina
My commission Expires: 3/6/1999
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APPENDIX B

STATE OF SOUTH CAROLINA CONCURRENCE LETTER
Mr. Ralph Howard
USEPA, Region IV-WD-NSRB-SC
October 7, 1996
Page 3
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