EPA/ROD/R03-95/206
1995
EPA Superfund
Record of Decision:
SALTVILLE WASTE DISPOSAL PONDS
EPA ID: VAD003127578
OU03
SALTVILLE, VA
09/29/1995
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SALTVILLE WASTE DISPOSAL PONDS
SUPERFUND SITE
SALTVILLE, VIRGINIA
RECORD OF DECISION
OPERABLE UNIT 2
(POND 5 AND POND 6)
PREPARED BY
THE U.S. ENVIRONMENTAL PROTECTION AGENCY
SEPTEMBER 1995
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RECORD OF DECISION
SALTVILLE WASTE DISPOSAL PONDS SUPERFUND SITE
TABLE OF CONTENTS
PART I - DECLARATION
1. 0 SITE NAME AND LOCATION 1
2 . 0 STATEMENT OF BASIS AND PURPOSE 1
3 . 0 ASSESSMENT OF THE SITE 1
3.0 DESCRIPTION OF THE SELECTED REMEDY 1
5 . 0 STATUTORY DETERMINATIONS 2
PART II - DECISION SUMMARY
1.0 SITE NAME, LOCATION, AND DESCRIPTION 4
2 . 0 SITE HISTORY AND ENFORCEMENT ACTIVITIES 5
3.0 HIGHLIGHTS OF COMMUNITY PARTICIPATION 8
4 . 0 SCOPE AND ROLE OF RESPONSE ACTION 8
5 . 0 SUMMARY OF SITE CHARACTERISTICS 9
5.1 Physical Features
9
5.2 Nature and Extent of Contamination in Ponds 5 and 6
16
6. 0 SUMMARY OF SITE HUMAN HEALTH RISKS 19
6.1 Data Collection and Evaluation 20
6.2 Exposure Assessment 21
6. 3 Toxicity Assessment 21
6. 4 Human Health Effects 25
6.5 Risk Characterization 25
7.0 DESCRIPTION OF ALTERNATIVES 27
7 .1 Pond 5 Alternatives 27
7 . 2 Pond 6 Alternatives 33
8 . 0 SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES 36
8.1 Overall Protection of Human Health and the
Environment 38
8 . 2 Compliance with ARARs 39
8 . 3 Long-Term Effectiveness and Permanence 41
8.4 Reduction of Toxicity, Mobility, or Volume through
Treatment 41
8.5 Short Term Effectiveness 42
8.6 Implementability 43
8.7 Cost 44
8 . 8 State Acceptance 45
8 . 9 Community Acceptance 45
9. 0 SELECTED REMEDY AND PERFORMANCE STANDARDS 45
9.1 Pond 5 46
9.1.1 Multi-Layered Cap 47
9.1.2 Ground water Interceptor System 47
9.1.3 Pond 5 Treatment Facility 47
9.2 Pond 6 49
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9.2.1 Permeable Soil Cover 49
9.2.2 Decant Structure Discharge Neutralization.... 50
9.2.3 Contingent Remedial Action: Cap and Vertical
Barrier Wall 50
9. 3 Common Elements 51
9.3.1 Long-term Monitoring 51
9.3.2 Site Maintenance 51
9.3.3 Institutional Controls 52
10.0 STATUTORY DETERMINATIONS 52
10.1 Protection of Human Health and the Environment 52
10.2 Compliance with Applicable or Relevant and Appropriate
Reguirements 53
10.3 Cost-Effectiveness 53
10.4 Utilization of Permanent Solutions and Alternative
Treatment (or Resource Recovery) Technologies to the
Maximum Extent Practicable 53
10.5 Preference for Treatment as a Principal Element ....54
11.0 DOCUMENTATION OF SIGNIFICANT CHANGES 55
PART III - RESPONSIVENESS SUMMARY
A. OVERVIEW 57
B COMMENTS RECEIVED DURING THE PUBLIC MEETING 57
C. WRITTEN COMMENTS FROM OLIN CORPORATION 61
D. WRITTEN COMMENTS FROM OTHER CITIZENS 66
LIST OF TABLES
Table 1 - Exposure Point Concentrations 20
Table 2 - Exposure Assessment Factors 22
Table 3 - Slope Factors and Reference Doses 24
Table 4 - Summary of Site Risks 27
Table 5 - Present Worth Costs 45
LIST OF FIGURES
Figure 1 - Site Location 4
Figure 2 - Geologic Map of Site Area 11
Figure 3 - Pond 5 Boring Locations 17
APPENDICES
Appendix A - Administrative Record Index
Appendix B - Glossary
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RECORD OF DECISION
SALTVILLE WASTE DISPOSAL PONDS SUPERFUND SITE
PART I - DECLARATION
1.0 SITE NAME AND LOCATION
Saltville Waste Disposal Ponds Superfund Site
Operable Unit 2 (Pond 5 and Pond 6)
Saltville, Virginia
2.0 STATEMENT OF BASIS AND PURPOSE
This Record of Decision ("ROD") presents the final remedial action selected for Operable Unit 2 (Pond 5 and
Pond 6) of the Saltville Waste Disposal Ponds Superfund Site ("Site"), located in Saltville, Virginia. This
remedial action was chosen in accordance with the Comprehensive Environmental Response, Compensation, and
Liability Act of 1980, as amended ("CERCLA"), 42 U.S.C. §§ 9601 et seg., and the National Oil and Hazardous
Substances Pollution Contingency Plan ("NCP"), 40 C.F.R. Part 300. This decision document explains the
factual and legal basis for selecting the remedial action and is based on the Administrative Record for this
Site. An index of documents included in the Administrative Record maybe found at Appendix A of the ROD.
Although the Virginia Department of Environmental Quality ("VDEQ") has commented on the selected remedy and
such comments have been incorporated into the ROD, the Commonwealth has not concurred with this ROD.
3.0 ASSESSMENT OF THE SITE
Pursuant to duly delegated authority, I hereby determine, pursuant to Section 106 of CERLCA, 42 U.S.C. §
9606, that actual or threatened releases of hazardous substances from this Site, as discussed in Section 6.0
(Summary of Site Risks) of Part II of this ROD, if not addressed by implementing the remedial action
selected in this ROD, may present an imminent and substantial endangerment to public health, welfare, or the
environment.
4.0 DESCRIPTION OF THE SELECTED REMEDY
The selected remedy for the Pond 5 area consists of the following major components:
! Installation of a multi-layered cap over the entire
Pond 5 area;
! Ground water interceptor system;
! Revision of the effluent discharge limit for the
existing Pond 5 Treatment Facility to achieve the
current Virginia surface water standard for mercury and
any modification of the Pond 5 Treatment Facility
necessary to achieve the revised discharge limit;
The selected remedy for Pond 6 and consists of the following components:
! A permeable soil cover over the entire Pond 6 area,
approximately 40 to 45 acres, including the demolition
debris burial area;
! A pH adjustment system to neutralize the discharge from
the Pond 6 decant structure;
The selected remedy for Pond 6 includes the following contingent remedial action which shall be reguired if
mercury contamination from the buried debris is demonstrated to be migrating toward the river through the
ground water in Pond 6:
! Isolation of Former Chlorine Plant Site demolition
debris buried in the eastern end of Pond by vertical
barrier wall and a multi-layered cap over the two to
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three acres where the debris is buried.
Elements common to the selected remedies for both Pond 5 and Pond 6 include:
! Institutional controls;
! Maintenance of the Site security and maintenance
programs;
! Long-term monitoring.
5.0 STATUTORY DETERMINATION
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. The remedy utilizes permanent solutions and alternative treatment technologies to the
maximum extent practicable for this Site, and, in the case of contaminated ground water collected at the Pond
5 decant structure, satisfies the statutory preference for remedies that employ treatment as a principal
element in order to reduce toxicity, mobility, or volume. EPA also evaluated remedies that
employ treatment to address the mercury-contaminated waste material at the Site, however, the large volume of
such waste material precludes a remedy in which contaminants could be excavated and treated effectively.
Because this remedy will result in hazardous substances remaining onsite above health-based levels, a review
will be conducted within five years after initiation of the remedial action to ensure that the remedy
continues to provide adeguate protection of human health and the environment.
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Thomas C. Voltaggio Date
Director
Hazardous Waste Management Division
Region III
Environmental Protection Agency
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RECORD OF DECISION
SALTVILLE WASTE DISPOSAL PONDS SUPERFUND SITE
PART II - DECISION SUMMARY
1.0 SITE NAME, LOCATION, AND DESCRIPTION
The Saltville Waste Disposal Ponds Superfund Site ("Site") is part of Olin Corporation's former Saltville
facility located along the north bank of the North Fork of the Holston River ("river") between the towns of
Saltville and Allison Gap, in western Smyth and eastern Washington Counties, Virginia (Figure 1). The river
forms the southern border of the site and Virginia state Route 611 runs along the northern border at the foot
of Little Mountain. The Site consists of the Former Chlorine Plant Site and two waste ponds, Ponds 5 and 6,
and areas to which contamination has migrated, including the river. Pond 5 and its dikes cover an area of
about 76 acres. Pond 6 is immediately west and downstream of Pond 5. Pond 6 and its dikes cover an area of
about 45 acres. The Former Chlorine Plant Site is about 1/2 mile upstream of Pond 5 and has an area of about
4 acres.
Figure 1 - Site Location
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2.0 SITE HISTORY AND ENFORCEMENT ACTIVITIES
From approximately 1895 to 1972, the Saltville facility was owned and used by Olin Corporation ("Olin") or
its predecessors (Olin Mathieson Chemical Corporation, Mathieson Chemical Corporation and Mathieson Alkali
Works) as the location for various chemical manufacturing operations. Mathieson Chemical Corporation
constructed a mercury cell chlor-alkali plant (also referred to as the chlorine plant) in 1950. The plant
produced chlorine gas and sodium hydroxide by passing brine, obtained by solution mining salt deposits in the
area, between electrodes. The cathode used in this process contained mercury and leakage from the electrode
is considered the source of mercury in the pond wastes. The electrical current passing through the brine
caused the formation of chlorine gas at the anode through electrolytic oxidation. At the same time a sodium
amalgam was formed at the cathode. The amalgam was passed into a decomposing tower where the sodium was
separated by flushing the water from the sodium hydroxide. Some of the mercury was lost in the production
process and was solubilized and passed into Pond 5 in the wastewater.
Pond 5 was operated from approximately 1925 to 1971 and Pond 6 was put into service in 1964. The ponds were
primarily used for the containment of ammonia soda ash wastes. In 1951, Pond 5 began receiving
mercury-contaminated wastewater from the mercury cell chlor-alkali plant. Pond 6 also shows evidence of
receiving mercury-contaminated wastewater but not to the extent believed to be in Pond 5. The intent of the
settling ponds was to allow wastewater to percolate into the pond solids and allow mercury to adsorb onto the
fine, alkaline particles of the ammonia soda ash waste.
The dikes containing the ponds were constructed of rockfill cores (starter dikes) and built up with
accumulations of slaker wastes. The slaker wastes were primarily composed of spent coke and roasted
limestone waste. Surface water discharge from Pond 5 is controlled by a decant structure located at the
southwest corner of the pond. The decant structure consists of a concrete riser and a pipe culvert which
extends from the river through the bottom of the dike to the river. A similar decant structure exists for
Pond 6 at its southeastern end. Since 1978, discharge from these structures have kept the water level in the
ponds beneath the surface of the settled solids.
The Pond 5 dikes are approximately 100 feet high and the depth of settled solids varies from about 35 feet to
70 feet, with an average of about 63 feet. The Pond 6 dike are approximately 35 feet high and the depth of
the solids varies from about 20 feet to 30 feet. Vegetation on the site is moderate and consists
predominantly of weeds and grasses, brush, and some young trees with trunk diameters of 6 inches or less.
The chlorine plant began operations in 1951 and continued operations through 1972. In 1969, after Swedish
scientists discovered that inorganic mercury discharges to natural waters caused adverse health and
environmental effects due to methylation, the U.S. Army and Federal Water Pollution Control Authority began
to limit mercury discharges to navigable waters by permits. In order to control discharge to the river, Olin
redirected most mercury-contaminated wastewater from the chlorine plant to Pond 5.
The process and washdown wastewater was conveyed to the eastern end of Pond 5 separately from the ammonia
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soda ash waste slurry. The wastewater was discharged on the surface of Pond 5 near the eastern edge and
directed around the northern perimeter by berms built on the surface of the pond.
Pond 6 began operating in 1964 and was used to settle ammonia soda ash waste. Mercury contamination has been
detected in Pond 6. Based on current knowledge of the chlorine plant operation, it is possible that the
mercury-contaminated weak brine purge water from the chlorine plant may have been used to help slurry the
ammonia soda ash waste generated from another process independent of the chlorine plant and pumped to Pond 6.
Olin believes that Pond 6 may have been discharged into Pond 6 late in the operation of the chlorine plant.
This would account for the mercury contamination in Pond 6.
After Olin shut down the Saltville facility in 1972, Olin began demolition activities of the chlorine plant.
Some of the debris from the demolition of the plant was placed at the eastern edge of Pond 6. It was placed
on the lower bench of the dike between Pond 5 and Pond 6. The debris consisted mostly of brick, concrete,
and steel from the buildings at the former chlorine plant. No sampling of the debris was conducted prior to
disposal. The debris was covered with locally-obtained soil. The demolition of the process eguipment was
completed in June 1973. Process mercury was removed from the eguipment and shipped
to Olin plants in Georgia and Alabama for re-use. The eguipment was cleaned with wash water which was
allowed to percolate into the soils at the Former Chlorine Plant Site. The process eguipment was then buried
in the easternmost end of Pond 6 and covered with clean fill.
Environmental studies of the Site began in conjunction with heightened concern about mercury discharges
nationwide. An investigation of the plant site and adjacent flyer by Olin, the Commonwealth of Virginia, and
local agencies during the late 1960's revealed mercury contamination at the Site including in the river. In
1970, as a result of mercury concentrations found in fish, both Virginia and Tennessee placed a ban on
fishing in the river. Both bans were later modified (Tennessee's in 1972, Virginia's in 1974) to permit
fishing on a catch and release basis.
In 1978, a Task Force was formed which included the Virginia State Water Control Board, Virginia Attorney
General's Office, Tennessee and Virginia State Departments of Health, Tennessee Valley Authority, and EPA.
The Task Force reguired Olin to conduct studies to identify the sources of mercury-contamination at the
Saltville facility, and negotiated cleanup measures with Olin to reduce mercury input to the river.
Under a special order issued in 1982 by the Virginia State Water Control Board, Olin dredged contaminated
sediments from a 1000 foot section of the river adjacent to the Former Chlorine Plant Site. The excavated
sediments were placed on the Former Chlorine Plant Site and covered with 2 feet of clay and 6 inches of
topsoil. This project was supplemented by the construction of a diversion ditch around the western, upstream
side of Pond 5 (the Western Diversion Ditch) to reduce surface water flow onto the pond.
EPA proposed the Saltville Waste Disposal Ponds Site for inclusion on the National Priorities List ("NPL") in
December 1982, and placed the Site on the NPL on September 8, 1983, 48 Fed. Reg. 40658. In July 1986 and
August 1986, EPA conducted a risk assessment and feasibility study ("FS"), respectively. These reports were
based on existing data and available information supplied by the Saltville Task Force and Olin. EPA
did not perform a remedial investigation ("RI") at this Site, because of the available data and continuing
sampling effort being conducted under the 1982 special order between Olin and the Virginia State Water
Control Board. EPA decided to conduct a risk assessment based on all available data to determine if data
gaps existed. Several data gaps were identified in the 1986 risk assessment. The 1986 FS developed
alternatives based on the available data; however, more data was deemed necessary to develop a final cleanup.
Based on the 1986 risk assessment and FS, EPA issued a Record of Decision ("ROD") on June 30, 1987. An
interim remedial alternative with additional RI/FS studies was selected to remediate the immediate threat.
Olin entered into a Consent Decree with EPA in 1988, agreeing to implement the
interim remedial actions and to conduct the additional RI/FS studies.
In June 1989, Olin submitted the Work Plan for the additional RI/FS studies. Field activities for the RI/FS
began in December 1988. EPA agreed to permit Olin to begin installation of ground water wells prior to final
Work Plan approval. The final RI and risk assessment reports were accepted by EPA in December 1994, and the
final FS was accepted by EPA in January 1995.
3.0 HIGHLIGHTS OF COMMUNITY PARTICIPATION
Pursuant to Section 113(k)(2)(B)(i)-(v) of CERCLA, 42 U.S.C. § 113(k)(2)(B)(i)-(v), the RI/FS reports and the
Proposed Plan for Operable Unit 2 of the Site were released to the public for comment on January 18, 1995.
These documents were made available to the public in the Administrative Record located in the EPA
Docket Room in EPA's Region III Philadelphia Office, and the Smyth-Bland Regional Library, Saltville Branch,
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Saltville, Virginia. The notice of availability of these documents was published in the Smyth County News
and Saltville News Messenger on January 18, 1995 and January 20, 1995, respectively.
A public comment period on the documents was held from January 18, 1995 to February 17, 1995. EPA received a
reguest for a 60-day extension to the public comment period on February 2, 1995. As a result, EPA granted a
31-day extension whereby the closing date for the public comment period was extended to March 20, 1995.
EPA held a public meeting in Saltville on February 1, 1995. In addition, informal public availability
sessions were conducted by EPA at the Saltville Town Hall on March 15-16, 1995. At the meeting and the
availability sessions, representatives from EPA answered guestions about conditions at the Site and the
remedial alternatives under consideration. Responses to the comments received during the public comment
period are included in the Responsiveness Summary, which is a part of this ROD
4.0 SCOPE AND ROLE OF RESPONSE ACTION
As with many Superfund sites, the problems at the Saltville Waste Disposal Ponds Site are complex. At the
time EPA issued the Proposed Plan in January 1995, EPA had organized the work at the Site into the following
Operable Units ("OUs"):
! interim remedial actions;
! Site ground water, Ponds 5 & 6, and the Former Chlorine
Plant Site; and
! impact to the river.
EPA selected the interim remedial actions in a ROD issued on June 30, 1987. These actions involved the
design and construction of a surface water diversion ditch around the eastern side of Pond 5, as well as a
treatment plant to handle ground water collected at Pond 5. Both of these interim remedial actions are
complete and operational. The interim remedial actions addressed the most immediate needs of the overall
cleanup process at the Site (i.e., to divert the majority of the surface water from coming in contact with
the mercury-contaminated waste in Pond 5 and treat the ground water from Pond 5 discharging to the river via
the Pond 5 decant structure).
The operable unit evaluated in the January 18, 1995 Proposed Plan addressed remediation of the source
materials (process waste contained in Pond 5 and Pond 6 and the contaminated soils and sediment at the Former
Chlorine Plant Site) and ground water. However, after considering the comments provided by the public on the
Proposed Plan, EPA decided that this ROD will address only Pond 5 and Pond 6. The Former Chlorine Plant Site
(including ground water beneath that area) will be addressed along with the impact of mercury contamination
on the river as the final operable unit for the Site.
5.0 SUMMARY OF SITE CHARACTERISTICS
5.1 Physical Features
Surface Features and Resources. The topography of the Site area is rugged, lying within the Appalachian
Valley and Ridge Physiographic Province of western Virginia. The surface features of the Site and
surrounding area reflect the local geologic conditions. The North Fork of the Holston River in Smyth and
Washington Counties has incised its channel into soft shales and siltstones. More competent rock forms the
ridges to the north and south of the Site.
The Site includes two drained settling ponds impounded by steep dikes along the river. The dikes are
approximately 35 and 100 feet high for Ponds 6 and 5, respectively. The surfaces of the ponds are relatively
level and support a moderate growth of grasses. Pond 5 covers approximately 76 acres. It is one and three
guarters miles long and one guarter mile wide. Pond 6 covers approximately 45 acres. Pond 6 is three
guarter miles long and slightly less than one guarter mile wide.
The Pond 5 decant structure was constructed in the southwest corner of the pond at the time the pond was
built. It was designed to control the water elevation within Pond 5 and to drain excess water to the river
as the process wastes settled. A similar decant structure exists at Pond 6 and extends to the base
of Pond 6. The decant structure of Pond 6 is located in the southeast section of Pond 6.
A diversion ditch was installed around the western perimeter of Pond 5 in 1982-1983 to divert the majority of
surface water flowing onto the pond from Little Mountain. An Eastern Diversion Ditch around the eastern
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portion of Pond 5 was constructed in 1991 as part of the Operable Unit 1 Interim Remedial Actions.
The Eastern Diversion Ditch collects the remaining surface water flow from Little Mountain A high, chain link
fence bounds Ponds 5 and 6 on three sides, but not on the side bordering the river.
The Former Chlorine Plant Site is located approximately one-half mile upstream and east of the ponds and
covert approximately four acres. Two feet of clay and six inches of topsoil were installed over the Former
Chlorine Plant Site area pursuant to a special order issued in 1982 by the Virginia State Water Control
Board. Rip-rap was installed along the river bank adjacent to the Former Chlorine Plant Site following the
1982 remedial activities to prevent river bank erosion.
Geology. The Site lies on the river flood plain within the river valley drainage basin and is located
between Little Mountain to the north and the limestone bluffs south of the Site and river. Geology of the
Saltville area is structurally complex with Mississippian sedimentary rock formations and the older Cambrian
sedimentary rock formations mapped as occurring in the Pond 5, Pond 6 and Former Chlorine Plant Site area.
The Greendale Syncline and the Saltville thrust fault are the two major structural features which occur in
the study area. The axis of the Greendale Syncline is mapped as occurring 2000 feet southeast of the river
and trends northeast. The southeastern limb of the syncline (i.e., southeast of the synclinal axis) is
overturned and the syncline is recumbent. (See RI Figure 4-10). The Site, however, is located on the mapped
northwestern limb of the syncline. At the Site, the bedding trend is reported as approximately North 60
degrees East with a dip approximately 30 degrees to the southeast. The Saltville Thrust Fault which is the
other major structural feature is located over a mile southeast of the river and has thrust the older
Cambrian sedimentary formations onto the younger Mississippian formations.
The tectonic forces that formed these features were largely compressional and are responsible for formation
of the northeasterly trending valleys and ridges of the Appalachian Mountain Valley and Ridge Physiographic
Province. A fracture trace analysis of aerial photographs suggests that there are strong lineations
(potential fractures) in directions parallel to bedding strike and dip as well as North 65 degrees West (See
RI Figure 4-3).
At the Site, overlying weathered bedrock are alluvial deposits upon which the dike, pond and Former Chlorine
Plant Site fill were placed. The alluvium consists of sand, gravel, silt, and clay river sediment and flood
plain deposits. Colluvium, which consists of sandy silts and silty sands with varying degree of coarse sand
to fine gravel-sized sandstone and siltstone fragments, was encountered on the slope of Little Mountain. The
bedrock stratigraphy associated with the Greendale Syncline and pertinent to the Site consists of six
formations of Mississippian age. The formations were formed as a result of a marine
depositional environment. Figure 2 is a geologic map which depicts the Site.
North-northwest of the Site the Price Formation is mapped as outcropping at the southern slopes of Little
Mountain along State Route 611. The Price Formation is described as medium to thinly bedded greenish gray
guartzose sandstones. The upper 40 feet is interbedded with thin coal lamination and several thin coal beds.
The upper contact with the overlying MacCrady Formation forms the knobs between swales along State Route 611
up to the western end of Pond 5.
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The MacCrady Formation was subdivided into three distinct members based upon occurrence and economic
interest. The three members consist of a lower sandstone-siltstone member, a middle dolomitic member, and an
upper plastic shale member. The thickness of the formation varies greatly in the short distance between
Allison Gap and Saltville. This thickness variation has been attributed to the deformation of the formation
during the folding of the bedrock which has thickened the plastic shale member in the recumbent southeastern
limb of the Greendale Syncline. The thickness of the plastic shale member is approximately 30 feet at
Allison Gap and around 1500 feet in Saltville, as observed in the exploratory boreholes and brine wells less
than a mile to the south-southeast of the Site. Cooper (1966) observed that the salt-bearing portions of the
formation comprised a tectonic breccia with a characteristic salmon-red color due to dissemination of red to
maroon plastic shales within the salt matrix. Evaporite occurrence in the
plastic shale member on the northwestern limb (i.e., at the Site) of the Greendale Syncline is rare and
discontinuous if present. The Little Valley Formation overlies the MacCrady Formation.
The Little Valley Formation is mapped as immediately underlying the majority of the Site. The formation is
comprised of slightly to heavily weathered calcareous shales, sandstones and siltstones, intercalated with
limestone and dolostone beds. The formation generally weathers to a yellowish-gray to brown color. Crinoid
columnals, brachiopods, corals and bryozoan fossil fragments can be found in highly weathered shales exposed
on the Site and west of Pond 6.
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The Hillsdale Limestone Formation overlies the Little Valley Formation and at the lower contact it consists
of a black cherty limestone overlain with a black fossiliferous limestone. This formation is mapped at the
southernmost portion of the Site in the river at the roadway bridge adjacent to the Former Chlorine Plant
Site and has a reported overall thickness in the Greendale Syncline of approximately 250 feet. The Ste.
Genevieve Formation immediately overlies the Hillsdale Limestone Formation.
The higher elevations of the sinkhole knobs and pasture land across the river from the Pond 5 dike are formed
by limestone members of the Ste. Genevieve Formation. At the higher elevations, outcrops are of slightly to
moderately weathered, medium to thickly bedded dark gray, weathering to light gray limestone. This formation
is reported to have crinoid fossils.
Some solution features have been noted along the axis of the Greendale Synclinal axis in this formation.
Site surface mapping and subsurface drilling activities identified the presence of an upper weathered and
fractured bedrock zone extending to depths of 20 feet. Along the flank of Little Mountain and the northern
Pond 5 and Pond 6 margins, some sliding of rock blocks along bedding planes has occurred where the river
in its older channel (under Pond 5) undercut the dipping rock strata that form the lower slopes of Little
Mountain.
The North Fork of the Holston River in Smyth and Washington Counties has incised its channel into shales and
siltstones of the MacCrady and Little Valley Formations. These rock types are significantly easier to erode
than the hard sandstones and limestones of the Price and Lower Little Valley/Hillsdale Limestone Formations
that form the ridges to the north and south of the Site. Significantly, the soft shales and siltstones also
weather to form clay and silt residual soils which are more impervious to ground water seepage. This may
explain the success of the waste ponds in impounding water during the operation of
Olin's plant.
Soils. Beneath the waste in Ponds 5 and 6 and the Former Chlorine Plant Site, alluvial deposits of sand,
gravel, and silt are found within the old river flood plain. Residual soil and fractured bedrock are found
overlying competent rock strata. The waste within the ponds is up to 70 feet thick and its
geotechnical behavior and characteristics are similar to those of a normally consolidated to slightly
overconsolidated clay. A pronounced fracture system is visible on the pond surfaces. The fracture system
formed initially due to consolidation of the waste during placement and became more pronounced following
rapid draining of the ponds in 1978. The fracture system continues to be visible because the fractures are
developing as the process of consolidation continues. The major waste fractures in Pond 5 trend from the
swales along Little Mountain, toward the decant structure at the southwest edge of the pond and along the
west, north and east edges of the pond where settlements have been pronounced.
Hydrogeology. The focus of the field hydrogeologic investigations in the RI was the Pond 5 area and the
eastern and southeastern margin of Pond 6. The Former Chlorine Plant Site was the subject of two previous
hydrogeologic studies conducted in 1976 and 1982. The 1976 study was completed following demolition and
removal of the chlorine plant eguipment and the 1982 study was completed prior to encapsulation of sediments
removed from the river and capping of the Former Chlorine Plant Site. The site hydrogeologic conditions have
been grouped into categories of the Ponds 5 and 6 hydrogeology, the bedrock hydrogeology, and the Former
Chlorine Plant Site.
Overall shallow ground water flow within the ammonia soda ash waste and the underlying alluvium is toward the
south from Little Mountain to the river. Discharge from pond 5 occurs principally through the decant
structure (which is pumped to the Pond 5 treatment plant), and to a lesser extent as seepage through the dike
just above the upstream shale blanket covering the rockfill core of the dike. A highly fractured area of
waste in the west-central portion of Pond 5 appears to act as a ground water sink, diverting much of the flow
in the pond toward the decant structure located in the dike at the southwestern margin
of Pond 5.
The deep portions of the bedrock underlying the Site may be subdivided into a series of hydrostratigraphic
units based primarily upon detailed descriptions of bedrock lithology, fracture freguency and orientation and
overall geologic structure. The RI focused upon the upper shallow bedrock zone and the interaction between
this portion of the flow system and the Pond 5 flow regime.
The upper shallow bedrock is more highly weathered and fractured than the deep bedrock and may be
distinguished from the deep bedrock by its structural characteristics and permeability contrast. The
upper-most fractured bedrock zone is approximately 15 to 20 feet thick and extends across the base of Pond 5
immediately below the alluvium. Evidence from the hydrogeologic investigation indicates that the upper
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weathered bedrock zone behaves as an integrated flow system. In general, hydraulic conductivity values
appear to be greater in the upper portions of the bedrock where fracture distribution, freguency, and
weathering are most prevalent.
Ground water flow in the highly weathered upper bedrock is generally toward the south from Little Mountain to
the river. Little Mountain likely serves as the principal mechanism of recharge to the shallow bedrock, and
the river as the main area of discharge. The ground water sink created by the fracture network in the Pond 5
fill near the decant structure seems to affect the flow of ground water in the upper bedrock flow system.
Ground water flow occurs at the Former Chlorine Plant Site in the fill/alluvium and bedrock underlying the
area. Flow in the deeper bedrock is probably confined to individual rock units (i.e., individual beds of
sandstone/siltstone or limestone) and along the principal hydraulic conductivity parallel to bedding strike.
The shortest and most preferential ground water path is through the alluvium/fill beneath the Former Chlorine
Plant Site to the river. Discharge of deep bedrock ground water is most likely along bedding strike to the
river upstream of the Former Chlorine Plant Site or to Robertson Branch Creek.
The geometric mean of hydraulic conductivity of the upper bedrock aguifer through variable head tests
(commonly referred to as slug testing) was estimated as 2.1 E-5 cm/sec. For the deeper bedrock the geometric
mean of hydraulic conductivity was estimated as 3.4 E-6 cm/sec. Pressure packer testing was also performed
and the geometric mean of hydraulic conductivity of the upper bedrock and deeper bedrock was estimated as 1.7
E-4 cm/sec and 5.2 E-5 cm/sec, respectively. Overall, the distribution of hydraulic conductivity values in
the bedrock, both by area and with depth, suggest a high degree of heterogeneity throughout the bedrock flow
system. The estimated average linear velocity using an effective porosity of 1 percent would range from 0.23
ft/day up to 3.5 ft/day, and with an effective porosity of 10 percent
would range from 0.023 ft/day up to 0.35 ft/day.
The reported hydraulic conductivity for the alluvium and ammonia soda ash waste from rising head slug test
results in the RI was 5.9 E-04 cm/sec and 6.2 E-07 cm/sec, respectively. In general, it is anticipated that
the pond fill and a ammonia soda ash waste possess highly variable hydraulic properties, owing to the
irregular size and distribution of fractures and the heterogeneous nature of the fill and waste. Fractures
in the ammonia soda ash waste have been observed to collapse and at other times to open at the pond surfaces
most likely as a result of surface water flow, changing moisture content, and the response of the relatively
weak pond material to consolidation and erosion.
Site Drainage. Within the Pond 5 sub-watershed, five swales on the upgradient ridge of Little Mountain
conduct flow downgradient to the river, passing beneath State Route 611 and Pond 5 along the way. Currently,
water flowing in the western four of the five swales within the sub-watershed is conveyed through culverts
beneath the highway, downhill into energy dissipators, and then into the Western Diversion Ditch that has
been constructed along and just above the northern margin of the Pond 5. The Western Diversion Ditch
discharges downstream of the Pond 5 decant structure outlet. Water flowing in the eastern-most swale is
diverted around the east end of Pond 5 through the recently constructed Eastern Diversion Ditch. The outlet
of the ditches is the North Fork of the Holston River. The peak discharge of
high intensity storm runoff from the ditches bypasses the Pond 5 system, and is effectively removed from the
sub-watershed.
Like Pond 5, Pond 6 also lies on the valley floor on the north bank of the river, against the flank of Little
Mountain to the north. The Pond 6 dike, separating the pond from the river, is similar in construction and
composition to the Pond 5 dike. Adjacent to Pond 6, the river is flowing down strike on bedrock in a confined
channel defined by a weak zone in the bedrock formation. Pond 6 is immediately downstream and to the west of
Pond 5. Little Mountain to the north of Pond 6 can be characterized as having identical hydrologic
properties as the section of the mountain to the north of Pond 5. The swales
convey water down the mountain, under State Route 611 through culverts, and through the Pond 6 system to the
river.
Unlike the Pond 5 system, flowing surface water in the swales cross a wide, flat area immediately adjacent to
the north side of Pond 6. This flat area serves as a natural energy dissipator, reducing the velocity of the
flows prior to their reaching the margin of the pond. Because of the low surface water velocities, no
diversion structures, catch basins, or flow monitoring systems have been established within the Pond 6
sub-watershed.
The sub-watershed containing the Former Chlorine Plant Site is very small, containing little more than the
plant site itself, as a result of drainage controls associated with State Route 634 and a road between the
plant site and the Saltville wastewater treatment plant. Improvements to State Route 634 associated with
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the new bridge across the river have included surface water ditches, catchment basins, french drains, and
shallow soil grouting along the east side of the highway. As a result, the new roadway improvements have
become a sub-watershed boundary for the northeast and east sides of the plant site, preventing all runon from
surrounding high ground to the north and east. A french drain to the north of the Site along Ice House Road
accomplishes the same function on the north margin of the Site. The Former Chlorine Plant Site sub-watershed
is bounded by Robertson Branch Creek to the west and by the river to the south.
5.2 Nature and Extent of Contamination in Ponds 5 and 6
An investigation to determine the extent of mercury in Pond 5 was conducted by Harza Engineering in 1979.
The investigation involved drilling nineteen boreholes in the Pond 5 material at the locations shown on
Figure 3. The results indicate that the upper 17 feet to 20 feet of the Pond 5 solids contain an estimated
93% of the total amount of mercury in Pond 5. The highest mercury concentrations were found in boreholes 14,
15, and 21 at the west end of the pond; boreholes 5, 10, and 13 at the northeast corner of the pond; and
borehole 2 at the far east end of the pond. The upper 17.5 feet of these areas, with an
area of about 29 acres, account for an estimated 69% of the total amount of mercury in the pond. The average
mercury concentration in the waste for these areas is 28 mg/kg, while the average concentration in the upper
layers of the rest of the pond is 7 mg/kg. Similar results were obtained during an investigation conducted
by Olin and Law Engineering in 1981. Fourteen boreholes were drilled and soil samples extracted and analyzed
for mercury concentration. Mercury concentrations noted in the 1981 investigation ranged from 0.1 mg/kg to
39.9 mg/kg. All of the samples taken within the upper 20 feet of the Pond 5 surface contained more that 3
mg/kg.
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Very low to non-detectable levels of total mercury in the monitoring wells (except for the anomalous results
at well MW-10S) indicate that downward migration of mercury to the base of the ponds is intercepted by flow
within the waste fractures/crevasses, the former river channel (in the case of Pond 5), or a layer of
alluvial sediments in the former river flood plain. These levels of total mercury also indicate, based on the
bedrock ground water sample results, that there does not appear to be migration of waste particles with
mercury from the ponds to the bedrock underlying the ponds.
Results of laboratory analyses in ground water samples taken during the 1994 RI indicate that organic
constituents are not present above levels of concern in the ground water and outfall discharge streams. Low
concentrations of acetone, methylene chloride, chloroform, and toluene were detected in some of the
samples.
One round of inorganic/metal analyses was performed on ground water samples from monitoring wells in and
around Ponds 5 and 6 during the 1994 RI. These results indicate that while mercury is the primary
constituent of concern at the Site, several other metals were detected in the ground water. While
concentrations are below the level of concern for drinking water, the concentrations of arsenic, chromium,
copper, manganese, lead, and selenium were above concentrations in the one available background well.
6.0 SUMMARY OF SITE HUMAN HEALTH RISKS
A Baseline Risk Assessment was prepared as part of the 1994 RI in order to identify and define possible
existing and future human health risks associated with exposure to the chemicals present at the Site if no
action were taken. The Baseline Risk Assessment provides the basis for taking action at the Site and
indicates the exposure pathways that need to be addressed by the remedial action. The Baseline Risk
Assessment conducted for the Site evaluates risk associated with Pond 5, Pond 6, the Former Chlorine Plant
Site, and the North Fork of the Holston River. Only human health risks associated with Pond 5 and Pond 6 are
presented here since Ponds 5 and 6 are the focus of this ROD.
6.1 Data Collection and Evaluation
The data collected and described in the previous section were evaluated for use in the Baseline Risk
Assessment. This evaluation involves reviewing the quality of the data and determining which data are
appropriate to use to quantitatively estimate the risks associated with Site soil, sediment, surface
water, and ground water.
For estimating soil exposure, results of a November 1979 sampling program were also included to supplement
more recent samples from Pond 5. The data were reviewed with regard to difference in mercury concentrations
at different locations and exposure potential. Depending on the distribution of the data
set, either the 95 percent upper confidence limit ("UCL") on the arithmetic mean, or the back-transformed 95
percent UCL on the arithmetic mean of log transformed data was used in the risk calculations. In some
instances, however, the 95 percent UCL was found to exceed the maximum detected concentration. In these
cases, the maximum detected concentration was used in the risk calculation. Table 1 summarizes the exposure
point concentrations used in the Baseline Risk Assessment.
Table 1 - Exposure Point
Concentrations
Soil/Waste
Ingestion/Dermal Contact
(mg/kg)
Contaminants Pond 5 Pond 6
Chloroform 3.00E-03[1] 2.00E-02
Acetone 4.10E-02
Tolulene 3.00E-03
Mercury
(Inorganic) 1.64E+02 7.83E+01
Sodium 1.89E+03 1.19E+03
[1] Concentrations are presented using scientific notation. A value expressed as l.OE-01 is
equivalent to 0.01, otherwise expressed as 1.0 x 10-1.
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6.2 Exposure Assessment
There are three basic steps involved in an exposure assessment: 1) identifying the potentially exposed
populations, both current and future; 2) determining the pathways by which these populations could be
exposed; and 3) guantifying the exposure. Under current Site conditions, children (age 6-10) could be
potentially exposed to the soil/waste in Pond 5 and Pond 6 by trespassing on the ponds and coming in contact
with contaminated soil/waste. This exposure pathway also includes incidental ingestion of soil/waste that
could occur by actions such as placing contaminated hands or objects in the mouth.
Potential future risks were evaluated based on the assumption that land use at Pond 5 and Pond 6 could change
in the future. The potential future use was assumed to be either residential or industrial. Although
industrial use is the most likely scenario, residential use was considered because residential development
has occurred previously on other waste disposal ponds associated with the Site. The potentially exposed
populations and pathways under these future use assumptions would include those described above along with
the following:
! Adults and children living in residences on Pond 5 and Pond
6 and coming in contact with and incidentally ingesting the
contaminated soil/waste (NOTE: Drinking contaminated ground
water was not considered as a pathway for exposure because
naturally occurring levels of salt present in the ground
water (similar to seawater) render it undrinkable);
! Adults working at industrial facilities constructed on Pond
5 and Pond 6 and coming in contact with and incidentally
ingesting contaminated soil.
In order to guantify the potential exposure associated with each pathway, assumptions must be made with
respect to the various factors used in the calculations. Table 2 summarizes the values used in the Baseline
Risk Assessment. These values represent reasonable maximum exposure ("RME") levels.
6.3 Toxicity Assessment
The purpose of the toxicity assessment is to weigh available evidence regarding the potential for particular
contaminants to cause adverse effects in exposed individuals. Where possible, the assessment provides a
guantitative estimate of the relationship between the extent of exposure to a contaminant and
the increased likelihood and/or severity of adverse effects.
A toxicity assessment for contaminants found at a Superfund site is generally accomplished in two steps: 1)
hazard identification; and 2) dose-response assessment. Hazard identification is the process of determining
whether exposure to an agent can cause an increase in the incidence of a particular adverse health effect
(e.g., cancer or birth defects) and whether the adverse health effect is likely to occur in humans. It
involves characterizing the nature and strength of the evidence of causation.
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Table 2 - Exposure Assessment Factors
Exposure Factors
INGESTION EXPOSURE PATHWAY
Ingestion Rate:
Soil
Exposure Frequency:
Soil (RME)
DERMAL CONTACT EXPOSURE PATHWAY
Skin Surface Area
Exposed:
Soil
Skin Adherence
Factor:
Soil
Exposure Duration:
Soil
Exposure Frequency:
Soil (RME)
Exposure Assessment Constants
Exposure Duration
Body Weight
Averaging Time:
Carcinogens
Noncarcinogens
Trespasser
(age 6-10)
Current
120 mg/day
26 days/yr
2,526 cm2
1.0 mg/cm2
5 years
26 days/yr
5 years
27 kg
70 years
5 years
Future
120 mg/day
2,526 cm2
1.0 mg/cm2
5 years
84 days/yr
5 years
27 kg
70 years
5 years
Resident
Child
200 mg/day
1,006 cm2
1.0 mg/cm2
6 years
350 days/yr
6 years
15 kg
70 years
6 years
Adult
100 mg/day
2,750 cm2
1.0 mg/cm2
24 years
350 days/yr
24 years
70 kg
70 years
24 years
Industrial
Worker
50 mg/day
2,750 cm2
1.0 mg/cm2
25 years
250 days/yr
25 years
70 kg
70 years
25 years
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Dose-response evaluation is the process of quantitatively evaluating the toxicity information and
characterizing the relationship between the dose of the contaminant administered or received and the
incidence of adverse health effects in the administered population. From this quantitative dose-response
relationship, toxicity values (e.g, reference doses and slope factors) are derived that can be used to
estimate the incidence of or potential for adverse effects as a function of human exposure to the agent.
These toxicity values are used in the risk characterization step to estimate the likelihood of adverse
effects occurring in humans at different exposure levels. For the purpose of the Baseline Risk Assessment,
contaminants were classified into two groups: potential carcinogens and noncarcinogens. The risks posed by
these two types of compounds are assessed differently because noncarcinogens generally exhibit a threshold
dose below which no adverse effects occur, while no such threshold has been proven to exist for carcinogens.
As used here, the term carcinogen means any chemical for which there is sufficient evidence that exposure may
result in continuing uncontrolled cell division (cancer) in humans and/or animals, conversely, the term
noncarcinogen means any chemical for which the carcinogenic evidence is negative or insufficient.
Slope factors have been developed by EPA' s Carcinogenic Assessment Group for estimating excess lifetime
cancer risks associated with-exposure to potentially carcinogenic contaminants of concern. Slope factors,
which are expressed in units of (mg/kg-day)-1, are multiplied by the estimated intake of a potential
carcinogen, in mg/kg-day, to provide an upper-bound estimate of the excess lifetime cancer risk associated
with exposure at that intake level. The term "upper bound" reflects the conservative estimate of the risks
calculated from the slope factor. Use of this approach makes underestimation of the actual cancer risk
highly unlikely. Slope factors are derived from the results of human epidemiological studies or chronic
animal bioassays to which animal-to-human extrapolation and uncertainty factors have been applied (e.g., to
account for the use of animal data to predict effects on humans). Slope factors used in the
Baseline Risk Assessment for contaminants found at the site are presented in Table 3.
Reference doses ("RfDs") have been developed by EPA to indicate the potential for adverse health effects from
exposure to contaminants of concern exhibiting noncarcinogenic effects. RfDs, which are expressed in units of
mg/kg-day, are estimates of lifetime daily exposure levels for humans, including sensitive
individuals. Estimated intakes of contaminants of concern from human epidemiological studies or animal
studies to which uncertainty factors have been applied account for the use of animal data to predict effects
on humans. Reference doses used in the Baseline Risk Assessment for contaminants found at the Site are
presented in Table 3.
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Table 3 - Slope Factors and Reference Doses
Analyte
Acetone
Chloroform
Methylene
chloride
Tetrachloro-
ethylene
Toluene
Arsenic
Cobalt
Copper
Lead
Inorganic Mercury
Organic Mercury
Sodium
Thallium
Vanadium
Slope Factors (mg/kg-day) -1
Oral Dermal Class
ND ND D
0.0061 0.0061 B2
0.0075
0.052
ND
1.75
ND
ND
ND
ND
ND
ND
ND
ND
0.0075
0.052
ND
1.79
ND
ND
ND
ND
ND
ND
ND
ND
B2
B2
D
A
D
D
B2
D
D
D
D
D
Reference Dose
Oral
0.1
0.01
0.06
0.01
0.2
0.0003
0.18
0.0371
ND
0.0003
0.0003
ND
0.00008
0.007
(mg/kg-day)
Dermal
0.1
0.01
0.06
0.01
0.2
0.000294
ND
ND
ND
0.00006
0.000285
ND
0.00008
0.00021
Key:
ND - Not determined
Class = EPA Weight-Of-Evidence Class for Carcinogenicity
A Human Carcinogen - sufficient evidence from epidemiological studies to
support a causal association between exposure and cancer
B Probable Human Carcinogen
Bl ! At least limited evidence of carcinogenicity to humans from epidemiological
studies
B2 ! Usually a combination of sufficient evidence of carcinogenicity in animals
and inadeguate evidence of carcinogenicity in humans
C Possible Human Carcinogen - limited evidence of carcinogenicity in animals in
the absence of human data
D Not Classified - inadeguate evidence of carcinogenicity in animals
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6.4 Human Health Effects
The unacceptable risk levels at the Site are primarily associated with potential exposure to mercury. The
general health effects of mercury are summarized below. Human exposure to inorganic mercury is mainly
through inhalation or ingestion. The inhalation pathway was not evaluated guantitatively in the Baseline Risk
Assessment because air sampling results at the Site showed very low mercury levels. Most dietary inorganic
mercurials dissociate to divalent mercury in the gastrointestinal tract and are poorly absorbed.
Occupational studies have demonstrated that chronic exposure to metallic mercury vapor via inhalation
primarily affects the central nervous system and the kidneys. Non-specific effects associated with the
lowest exposure levels (<100 *g mercury/m3) include insomnia, anxiety, and biochemical alterations.
Exposures greater than 1 mg mercury/m3 can result in memory loss, personality changes, body tremors, and
damage to lung tissue. No effects have been observed from exposure to mercury vapor at air concentrations of
approximately 1 *g mercury/m3 or less. Effects on both the nervous system and the kidneys are usually
reversible, particularly if the effects are mild. In its carcinogen weight-of-evidence categories, EPA
places inorganic mercury in Group D, which includes compounds for which there is inadeguate evidence for
carcinogenicity in animals or humans (See Table 3).
Human exposure to Organic (usually methyl) mercury is mainly through ingestion. Methyl mercury compounds are
known to be toxic via oral exposure, and prenatal and newborn infants are particularly susceptible.
Subchronic methyl mercury poisoning occurred in humans eating contaminated fish from Minamata Bay, Japan,
from 1953 to the 1960's. The median level of total mercury in fish in Minamata Bay was estimated to be about
11 mg/kg fresh weight. Methyl mercury poisoning also occurred from eating bread produced from seed grain
dressed with methyl mercury fungicide. Nerve damage causing "pins and needles" sensations in
the hands and feet occurred at an estimated body burden of 25 mg of methyl mercury. No confirmed positive
report of methyl mercury carcinogenicity in humans has appeared to date, and animal experiments have
generally yielded negative results.
6.5 Risk Characterization
The risk characterization process integrates the toxicity and exposure assessments into a guantitative
expression of risk. For carcinogens, the exposure point concentrations and exposure factors discussed earlier
are mathematically combined to generate a chronic daily intake value that is averaged over a lifetime (i.e.,
70 years). This intake value is then multiplied by the toxicity value for the contaminant (i.e., the slope
factor) to generate the incremental probability of an individual developing cancer over a lifetime as a
result of exposure to the contaminant. These probabilities are generally expressed in
scientific notation (e.g., 1.0 x 10-6, otherwise expressed as 1E-6). An excess lifetime cancer risk of 1.0 x
10-6 indicates that, as a reasonable maximum estimate, an individual has a 1 in 1,000,000 chance of
developing cancer as a result of site-related exposure to a carcinogen over a 7--year lifetime under the
specific exposure conditions at a site. The generally acceptable excess cancer risk range, as defined by
Section 300.430 (e) (2) (i) (A) (2) of the NCP, 40 C.F.R. § 300.430 (e) (2) (i) (A) (2), is between 1.0 x 10-4
and 1.0 x 10-6.
The potential for noncarcinogenic effects is evaluated by comparing an exposure level over a specified time
period (i.e., the chronic daily intake) with the toxicity of the contaminant for a similar time period (i.e.,
the reference dose). The ratio of exposure to toxicity is called a hazard guotient A Hazard
Index ("HI") is generated by adding the appropriate hazard guotients for contaminants to which a given
popular on may reasonably be exposed. Any media with an HI greater than 1.0 has the potential to adversely
affect health.
Under potential current use of the Site, the Baseline Risk Assessment estimates that children trespassing on
Pond 5 or Pond 6 would not be exposed to unacceptable noncarcinogenic or carcinogenic risk from the
soil/waste. Under potential future use of the Site, the Baseline Risk Assessment estimates that
children trespassing on Pond 5 could be exposed to a noncarcinogenic risk level from mercury in the
soil/waste that is at the threshold for adverse effects (HI of 1.0). Also, under the conditions assumed for
potential future use of the Site, unacceptable noncarcinogenic risks from mercury could be experienced by any
future children or adults living on Pond 5 (His of 9.0 and 2.0, respectively) and by children living on Pond
6 (HI of 4.0). With potential future industrial use, workers at an industrial facility on Pond 5 could be
exposed to a noncarcinogenic risk level that is at the threshold for adverse effects (HI of 1.0). Workers at
an industrial facility on Pond 6 would not be exposed to unacceptable noncarcinogenic risks. Under potential
future use of the Site, the Baseline Risk Assessment estimates that there are no unacceptable carcinogenic
risks posed for trespassers, residents or industrial workers.
Also, under potential future use of the Site, the Baseline Risk Assessment estimates that there are no
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unacceptable non-carcinogenic risks posed for Pond 6 trespassers, adult residents on Pond 6 or industrial
workers on Pond 6. The noncarcinogenic and carcinogenic risks associated with both potential current and
future uses of the Site are summarized in Table 4.
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Exposed
Population
Trespasser
Resident-Adult
Resident-Child
Worker
Table 4 - Summary of Site Risks2
Current Use
Future Use
Hazard
Media Index
Soil/Waste:
Pond 5 0.4
Pond 6 0.2
Soil/Waste
Pond 5
Pond 6
Soil/Waste
Pond 5
Pond 6
Soil/Waste
Pond 5
Pond 6
Cancer Hazard
Risk Index
5 x 10-13 1.
NA 0.
2.
0.
9.
4.
1.
0.
0
6
0
9
0
0
0
5
Cancer
Risk
2 x 10-12
NA
3 x 10-11
NA
3 x 10-11
NA
5 x 10-12
NA
NA- Not Analyzed
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Actual or threatened releases of hazardous substances from this Site, if not addressed by implementing the
response action selected in this ROD, may present an imminent and substantial endangerment to public health,
welfare, or, the environment.
7.0 DESCRIPTION OF ALTERNATIVES
The FS Report discusses the alternatives evaluated for the Site and provides supporting information relating
to the alternatives presented in this ROD. The alternatives included here are numbered to correspond with
those found in the FS Report.
Values in bold are risks that pose an unacceptable threat to human health.
7.1 Pond 5 Alternatives
The alternatives for Pond 5 are as follows:
Alternative
Alternative
Alternative
Alternative
Alternative
Alternative
Alternative
Alternative
Alternative
Alternative
PSA:
P5B:
P5C-1:
P5F:
P5F-X:
P5G-1:
P5H:
P5I:
P5J:
P5J-1:
No Action
Institutional Controls, Monitoring, and
Site Maintenance
Pond 5 Treatment Facility Upgrade
Ground water Management and Multi-
layered Cap with Synthetic Liner
Ground water Management and RCRA Cap
with Pond 5 Treatment Facility Upgrade
Ground water Management, Surcharging,
and Gapping with Dike and Pond Materials
Ground water Management, Surcharging,
and Capping with Synthetic Liner
In-Situ Treatment, Stabilization/
Chemical Fixation, and Permeable Cover
In-Situ Treatment, Stabilization/
Solidification of Upper 20 Feet of
Soil/Waste, and Permeable Cover
In-Situ Treatment, Stabilization/
Solidification of Upper 20 Feet of
Soil/Waste in Areas of Suspected Highest
Mercury Concentration, Multi-layered Cap
Alternative PSA:
No Action
Estimated Capital CostsS:
Estimated Annual Operation
and Maintenance ("O&M") Costs4:
Estimated Present Worth CostsS:
Estimated Implemention Time:
$ 0
$ 212,000
$6,350,000
Immediate
The NCP reguires that EPA consider a "No Action" alternative for every site to establish a baseline for
comparison to alternatives that do reguire action. This "No Action" alternative assumes that the interim
action reguired by the interim remedial action ROD issued on June 30, 1987, will be maintained, but that Site
maintenance and monitoring programs which have been implemented will not continue.
3 Estimated Capital Costs represent the present worth of all capital costs.
4 Estimated Annual Operation and Maintenance Costs represent the total present worth of
annual costs divided by the life of the project (30 years).
5 Estimated Present Worth Costs represent the present worth of all capital costs and the
total present worth of O&M costs for a project life of 30 years. Present worth analysis is
used to evaluate expenditures that occur over different time periods by discounting all
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future costs to a common base year, in this case the current year. This allows the cost of
remedial action alternatives to be compared on the basis of a single figure representing
the amount of money that, if invested in the base year and disbursed as needed, would be
sufficient to cover all costs associated with the remedial action over its planned life.
The planned life of each alternative is 30 years.
Alternative P5B: Institutional Controls, Monitoring, and Site
Maintenance
Estimated Capital Costs: $ 0
Estimated Annual O&M Costs: $ 279,000
Estimated Present Worth Costs: $8,382,000
Estimated Implementation Time: Immediate
This alternative reguires continuation of the existing maintenance programs and institutional controls.
Components of this alternative include continuation of outfall monitoring, ground water monitoring, and
maintenance of the Western and Eastern Diversion Ditches to intercept runoff from Little Mountain;
maintenance of existing institutional controls (e.g. fencing, deed restrictions, and security measures); and
operation and maintenance of the existing Pond 5 Treatment Facility.
Deed restrictions would restrict future land use and prohibit the installation of wells on Pond 5. Site
security measures would be formalized and the existing fencing maintained.
The Site maintenance program would include regular, documented inspections of the overall Site, fencing,
access roads, monitoring wells, and existing drainage controls/appurtenances. The developing vegetative
growth on Pond 5 would be enhanced and maintained through top-seeding and fertilization.
Alternative P5C-1: Pond 5 Treatment Facility Upgrade
Estimated Capital Costs: $ 1,825,000
Estimated Annual O&M Costs: $ 285,000
Estimated Present Worth Costs: $10,376,000
Estimated Implementation Time: 3 years
This alternative includes the institutional controls, monitoring, and Site maintenance of Alternative P5B,
and adds treatment of the point source effluent from the Pond 5 outfall to a level in compliance with the
current Virginia surface water standards. The currently operating Pond 5 Treatment Facility designed in
accordance with the interim remedial action ROD would be modified, if necessary, to meet the current Virginia
surface water standards. For cost estimating purposes, EPA assumed that modifications to the Pond 5
Treatment Facility would be reguired to achieve the current Virginia surface water standards,
however, the need for actual modifications would depend on the operational efficiency of the existing
facility.
Alternative P5F: Ground water Management and Multi-layered Cap
with Synthetic Liner
Estimated Capital Costs: $16,130,000 to $19,055,000
Estimated Annual O&M Costs: $ 120,000
Estimated Present Worth Costs: $19,752,000 to $22,650,000
Estimated Implementation Time: 3 years
This alternative includes the institutional controls, monitoring, and Site maintenance of Alternative P5B and
adds: (1) a system to intercept, collect, and convey the shallow ground water flow from Little Mountain away
from Pond 5; and (2) a multi-layered cap over the Pond 5 area. This alternative includes operation and
maintenance of the existing Pond 5 Treatment Facility for four years during construction of the cap.
Alternative P5F-X6: Ground water Mangement and RCRA Cap with
Pond 5 Treatment Facility Upgrade
Estimated Capital Costs: $26,876,000 to $29,801,000
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Estimated Annual O&M Costs: $ 120,000
Estimated Present Worth Costs: $30,471,000 to $33,396,00
Estimated Implementation Time: 4 years
This alternative includes the institutional controls, monitoring, and Site maintenance of Alternative P5B and
adds (1) a system to intercept, collect, and convey the shallow ground water flow from Little Mountain away
from Pond 5; (:) a multi- layered cap over the Pond 5 area that is constructed in accordance with Resource
Conservation and Recovery Act ( "RCRA" ) Subtitle "C" reguirements; and (3) modifications, if necessary, to
the existing Pond 5 Treatment Facility to enable the treatment facility effluent to meet current Virginia
surface Water standards. This alternative reguires that any needed modifications to the existing Pond 5
Treatment Facility occur initially in the remedial action phase, and the operation and
maintenance of the facility be continued until the collected pond water/ground water meets Virginia surface
water standards without treatment.
Alternative P5G-1: Ground water Management, Surcharging, and
Capping with Dike and Pond Materials
Estimated Capital Costs: $11,471,000 to $13,654,000
Estimated Annual O&M Costs: $ 140,000
Estimated Present Worth Costs: $15,674,000 to $17,857,000
Estimated Implementation Time: 6 years
6 For cost estimating purposes, the cost to modify the Pond 5 Treatment Facility is the cost
of the Treatment Facility Upgrade in Alternative P5C-1.
This alternative includes the institutional controls, monitoring, and Site maintenance of Alternative P5B,
and adds: (1) a system to intercept, collect, and convey the shallow ground water flow from Little Mountain
away from Pond 5; (2) fracture sealing and surcharging of the Pond 5 materials; and (3) shaping
and capping Pond 5 with dike and pond materials. The purpose of fracture sealing is to close the major paths
by which water infiltrates and migrates through Pond 5. Fracture sealing is generally accomplished by
pressure injection of a slurry into fractures or voids. Excavated pond materials would be processed
to ensure uniformity and adjusted for moisture content, then backfilled to form the cap. This alternative
includes operation and maintenance of the existing Pond 5 Treatment Facility for seven years during
construction of the cap.
Alternative P5H: Ground water Management, Surcharging, and
Capping with Synthetic Liner
Estimated Capital Costs: $13,287,000 to $15,346,000
Estimated Annual O&M Costs: $ 140,000
Estimated Present Worth Costs: $17,490,000 to $19,550,000
Estimated Implementation Time: 6 years
This alternative includes the institutional controls, monitoring, and Site maintenance of Alterative P5B, and
adds: (1) a system to intercept, collect, and convey the shallow ground water flow from Little Mountain away
from Pond 5; (2) surcharging of the Pond 5 materials; and (3) shaping with dike materials and capping Pond 5
with a synthetic liner. Compared to Alternative P5G-1, this alternative substitutes a synthetic liner for
remolded dike/pond materials as the barrier zone. Fracture sealing is not included in this alternative.
This alternative includes operation and maintenance of the existing Pond 5 Treatment Facility during
construction of the cap.
Alternative P5I: In-Situ Treatment, Stabilization/Chemical
Fixation, and Permeable Cover
Estimated Capital Costs: $62,501,000 to $142,602,000
Estimated Annual O&M Costs: $ 139,000
Estimated Present Worth Costs: $66,675,000 to $146,776,000
Estimated Implementation Time: 6 years
This alternative includes the institutional controls, monitoring, and Site maintenance of Alternative P5B,
and adds: (1) a system to intercept, collect, and convey the shallow ground water flow from Little Mountain
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away from Pond 5; (2) stabilization/chemical fixation of the pond mass; and (3) a permeable soil cover.
In-situ treatment involves stabilization of mercury using a chemical reagent (additive). The material in
Pond 5 would be treated with a chemical reagent that reacts with the mercury to keep the mercury from moving
to the ground water and to the river. It would be necessary to utilize a specialized
mixing system that injects the reagent solution into the soil/waste and provides mechanical mixing. Backhoe
mounted systems typically are effective to approximately 20 feet. Deep soil augers could be used, if
necessary, to extend to the full depth of the pond. After stabilization, the surface would be graded to
promote drainage, covered with 18 inches of soil, and seeded. This alternative includes operation and
maintenance of the existing Pond 5 Treatment Facility during stabilization/fixation of the pond mass which is
estimated to be seven years.
Alternative P5J: In-Situ Treatment, Stabilization/
Solidifieaticm of Upper 20 Feet of
Soil/Waste, and Permeable Cover
Estimated Capital Costs: $84,115,000 to $85,504,000
Estimated Annual O&M Costs: $ 139,000
Estimated Present Worth Costs: $88,290,000 to $89,678,000
Estimated Implementation Time: 6 years
This alternative includes the institutional—controls, monitoring, and Site maintenance of Alternative P5B,
and adds: (1) a system to intercept, collect, and convey the shallow ground water flow from Little Mountain
away from Pond 5; (2) stabilization/solidification of the upper 20 feet of the Pond 5 soil/waste mass; and
(3) a permeable soil cover. The soil/waste mass in the upper 20 feet would be stabilized by application of
reagents and/or inert additives and mixed to produce a stable material that would inhibit infiltration of
rainwater into the pond and prevent the leaching of mercury from the stabilized mass. Based on the
historical data and known operational procedures of the chlorine plant, mercury was deposited along with the
ammonia soda ash waste during the period that the top 20 feet of pond material was accumulated. It is
estimated that 93% of the total mercury in Pond 5 is contained in the upper 20 feet
of the pond material. After stabilization, the surface would be graded to promote drainage, covered with 18
inches of soil, and seeded. This alternative includes operation and maintenance of the existing Pond 5
Treatment Facility during stabilization/solidification of the upper 20 feet of the Pond 5 soil/waste mass.
Alternative P5J-1: In-Situ Treatment, Stabilization/
Solidification of Upper 20 Feet of
Soil/Waste in Areas of Suspected Highest
Mercury Concentration, Multi-layered Cap
Estimated Capital Costs: $25,679,000 to $28,692,000
Estimated Annual O&M Costs: $ 139,000
Estimated Present Worth Costs: $29,854,000 to $32,866,00
Estimated Implementation Time: 6 years
This alternative includes the institutional controls, monitoring, and Site maintenance of Alternative P5B,
and adds: (1) a system to intercept, collect, and convey the shallow ground water flow from Little Mountain
away from Pond 5; (2) the stabilization/solidification of the upper 20 feet of soil/waste material in the
areas of Pond 5 with the highest mercury contamination (approximately 11 acres); and (3) a multi-layered cap.
This alternative is based on the estimate that 93% of the total mercury in Pond 5 was deposited in the top 20
feet. Further, the data indicates that 70% of the mercury within the top 20 feet of the soil/waste is located
in the eastern, western, and northern guadrants of Pond 5 (presented in order of decreasing mercury
concentration). Eleven acres within those guadrants were identified for stabilization. The area not
stabilized, approximately 71 acres, would be graded utilizing dike material as fill. Measures such as
pre-loading with dike material or geosynthetics would be employed to improve the stability of the subgrade.
Fill would be placed to shade the surface to provide a free draining surface. After the shaping of the pond
surface is completed, a flexible membrane liner would be placed on top of the prepared surface. A
geocomposite would be placed above the liner to serve as a drainage layer. An 18 inch vegetative soil zone
would be placed above the geocomposite and seeded. This alternative includes operation and maintenance of
the existing Pond 5 Treatment Facility during the stabilization/ solidification of the top 20 feet of
soil/waste material in the areas with the highest mercury contamination (approximately 11 acres) and
construction of the multi-layered cap.
7.2 Pond 6 Alternatives
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The alternatives for Pond 6 are as follows:
Alternative P6A:
Alternative P6B:
Alternative P6C:
Alternative P6D:
Alternative P6D-1:
Alternative P6E
No Action
Institutional Controls, Maintenance,
Monitoring, and pH Adjustment
Permeable Soil Cover
Permeable Soil Cover and Localized
Containment of Demolition Debris with
Vertical Barrier Wall and RCRA Cap
RCRA Cap, Localized Containment of
Demolition Debris with Vertical Barrier
Wall, and Surface water Management
Permeable Soil Cover and Consolidation
of Demolition Debris onto Pond 5
Alternative P6A:
No Action
Estimated Capital Costs:
Estimated Annual O&M Costs:
Estimated Present Worth Costs:
Estimated Implementation Time:
$0
$0
$0
Immediate
This alternative assumes the present institutional controls and Site maintenance and monitoring programs will
not be continued. It is further assumed that residential development could occur on the Site. Drinking
water would be provided by the local water utility. The installation of private wells for
drinking water would not be feasible due to the low yield and high salt content of the groundwater.
Alternative P6B:
Institutional Controls, Maintenance
Monitoring, and pH Adjustment
Estimated Capital Costs:
Estimated Annual O&M Costs:
Estimated Present Worth Costs:
Estimated Implementation Time:
$ 601,000
$ 53,000
$2,190,000
1 year
This alternative includes maintenance of outfall monitoring, an expanded ground water monitoring program,
Site maintenance, and institutional controls (e.g., maintenance of fencing, deed restrictions, and security
measures). Deed restrictions would restrict future land use and the installation of wells on Pond 6. The
Site security measures would be formalized and the existing fencing maintained. The Site maintenance program
would include regular, documented inspections of the overall Site, including fencing, access roads,
monitoring wells, and existing drainage control structures. The existing maintenance program would be
expanded to include measures such as top-seeding and fertilization to enhance the existing vegetation.
Additional monitoring wells would be installed in the vicinity of the demolition debris and spaced around
Pond 6 in order to monitor the subsurface flow of ground water and provide data to evaluate water guality
over time. A pH adjustment system would also be provided at the existing Pond 6 outfall to neutralize the
discharge.
Alternative P6C:
Permeable Soil Cover
Estimated Capital Costs:
Estimated Annual O&M Costs:
Estimated Present Worth Costs:
Estimated Implementation Time:
$4,545,000
$ 62,000
$6,408,000
3 years
This alternative includes the reguirements of Alternative P6B and adds a permeable soil cover over Pond 6,
including the demolition debris burial area. Measures to improve the stability of the subgrade may be
necessary. After shaping of the subgrade is completed, a minimum of twelve inches of soil fill will be
placed on the improved subgrade, then covered with six inches of topsoil, fertilized, and seeded.
Alternative P6D:
Permeable Soil Cover and Localized
Containment of Demolition Debris with
Vertical Barrier Wall and RCRA Cap
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Estimated Capital Costs: $5,598,000
Estimated Annual O&M Costs: $ 62,000
Estimated Present Worth Costs: $7,462,000
Estimated Implementation Time: 3 years
This alternative includes the requirements of Alternative P6B and adds: (1) containment of the demolition
debris from the former chlorine plant; and (2) a permeable soil cover over Pond 6 (except for the demolition
debris burial area). Containment measures for the debris area would include a vertical barrier
wall placed around the perimeter of the debris and a multi-layered cap that is constructed in accordance with
RCRA Subtitle "C" requirements. With respect to the remainder of Pond 6 (i.e., the area other than the
debris area), measures to improve the stability of the subqrade may be necessary. After shapinq of the
subqrade is completed, soil fill would be placed on the improved subqrade to a minimum thickness of twelve
inches, then covered with six inches of topsoil, fertilized and seeded.
Alternative P6D-1: RCRA Cap, Localized Containment of Demolition
Debris with Vertical Barrier Wall, and
Surface Water Manaqement.
Estimated Capital Costs: $12,686,000
Estimated Annual O&M Costs: $ 65,000
Estimated Present Worth Costs: $14,628,000
Estimated Implementation Time: 4 years
This alternative includes the requirements of Alternative P6B and adds: (1) containment of the demolition
debris from the former chlorine plant; (2) a multi-layered cap over the entire Pond 6 area, includinq the
demolition debris area, that is constructed in accordance with RCRA Subtitle "C" requirements; and (3)
surface water manaqement. Containment measures for the debris area would include a vertical barrier wall
placed around the perimeter of the debris. To implement the surface water manaqement component included in
this alternative, a system would be implemented to intercept, collect and convey the surface water
runoff from Little Mountain away from Pond 6.
Alternative P6E: Permeable Soil Cover and Consolidation of
Demolition Debris onto Pond 5
Estimated Capital Costs: $11,596,000
Estimated Annual O&M Costs: $ 62,000
Estimated Present Worth Costs: $13,460,000
Estimated Implementation Time: 3 years
This alternative includes the requirement of Alternative P6B and adds (1) a low permeability soil cover over
Pond 6; (2) removal of the demolition debris from the former chlorine plant; and (3) final disposition of the
demolition debris to Pond 5.The buried debris from the demolition of the former chlorineplant would be
excavated from Pond 6 with conventional earthwork equipment, hauled, and spread over a prepared area within
Pond 5. The resultinq excavation at Pond 6 would be backfilled with local
material and qraded to promote proper drainaqe.
8.0 SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES
The remedial action alternatives described above were evaluated usinq the followinq criteria, as required
under Section 300.430 (e) (9) (iii) of the NCP, 40 C.F.R. § 300.430 (e) (9) (iii) :
Threshold Criteria: Statutory requirements that each alternative must satisfy in order to be eliqible for
selection.
1) Overall Protection of Human Health and the Environment.
Evaluation of the ability of each alternative to provide
adequate protection of human health and the environment in
the lonq and short-term and of how risks posed throuqh each
exposure pathway are eliminated, reduced, or controlled
throuqh treatment, enqineerinq controls, or institutional controls.
2) Compliance with Applicable or Relevant and Appropriate
-------
Requirements ( "ARARs" )
Evaluation of the ability of each alternative to attain
applicable or relevant and appropriate requirements under
federal environmental laws and state environmental or
facility sitinq laws or provide qrounds for invokinq a
waiver established under CERCLA.
Primary Balancinq Criteria: Technical criteria upon which the detailed analysis of the alternatives is
primarily based.
3) Lonq-Term Effectiveness and Permanence
Evaluation of expected residual risk and the ability of each
alternative to maintain reliable protection ot human health
and the environment over time after cleanup requirements
have been met.
4) Reduction of Toxicity, Mobility, or Volume throuqh Treatment
Evaluation of the deqree to which an alternative employs
treatment methods to reduce the toxicity, mobility, or
volume of hazardous substances at the Site.
5) Short-Term Effectiveness
Evaluation of the period of time needed for each alternative
to achieve protection and any adverse impacts on human
health and the environment that may be posed durinq the
construction and implementation period.
6) Implementability
Evaluation of the technical and administrative feasibility
of each alternative, includinq the availability of materials
and services.
7) Cost
Section 121 of CERCLA, 42 U.S.C. § 9621, requires selection
of a cost-effective remedy that protects human health and
the environment and meets the other requirements of the
statute. Alternatives are compared usinq present worth
cost, which includes all capital costs and the operation and
maintenance costs incurred over the life of the project.
Capital costs include expenditures necessary to implement a
remedial action (e.g., construction costs). All costs
presented are estimates calculated for comparison purposes only.
Modifying Criteria: Criteria considered throuqhout the development of the preferred remedial alternative and
formally assessed after the public comment period, which may modify the preferred alternative.
8) State Acceptance
Assessment of technical and administrative issues and
concerns that the State may have reqardinq each alternative.
9) Community Acceptance
Assessment of issues and concerns the public may have
reqardinq each alternative based on a review of public
comments received on the Administrative Record and the
Proposed Plan.
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8.1 Overall Protection of Human health and the Environment
Pond 5 Alternatives P5F through P5J-1 provide adequate protection of human health by preventing exposure to
the contaminated soil/waste material and reducing the discharge of mercury to the river. Each of these
alternatives requires monitoring of the river and nearby ground water to ensure that the mercury remains at
acceptable levels for protection of human health and the environment.
Alternatives P5I, P5J, and P5J-1 offer advantages over the other alternatives because they provide for active
treatment of the contaminated pond material, which would minimize migration of contaminants and diminish
loading of contaminants to the river. Alternatives P5F, P5F-X, P5G-1, and P5H all include an
impermeable cap which would inhibit migration of contaminants into ground water by reducing the amount of
precipitation that may infiltrate and mobilize contaminants in the wastes, and would prevent exposure of
ecological receptors to mercury-contaminated waste. Alternative P5F-X is advantageous over the other capping
alternatives (P5F, P5G-1, and P5H) due to the reduced permeability and superior performance of the RCRA
Subtitle "C" cap.
Alternatives PSA, P5B, and P5C-1 contain no provisions for preventing exposure to contamination, and are not
protective of human health and the environment. Although Alternative P5C-1 includes measures for reducing
the mercury in the Pond 5 effluent to acceptable levels, none of these alternatives would prevent
receptors from exposure to the mercury-contaminated waste. Since Alternatives PSA, P5B, and P5C-1 do not
meet the threshold criterion of protection of human health and the environment, they will not be discussed in
the remainder of this section.
Pond 6 Alternatives P6C through P6E provide adequate protection of human health by preventing exposure to the
contaminated pond material. Each of these alternatives requires monitoring of the river and nearby ground
water to ensure that the mercury remains at acceptable levels for protection of human health and the
environment.
Alternatives P6D, P6D-1, and P6E offer advantages over the other alternatives because they include remedial
actions to specifically address the demolition debris from the former chlorine plant buried in Pond 6. Both
Alternatives P6D and P6D-1 require containment measures to isolate the buried debris.
Alternative P6E would excavate the buried debris from Pond 6 and consolidate this material with the waste
material n Pond 5. Alternative P6D-1 is increasingly more protective as it adds a RCRA Subtitle C cap over
the entire Pond 6 area to stop rainfall and surface water runoff from contacting the pond material. In
addition, Alternative P6D-1 adds a component to prevent surface water runoff from contacting the pond
material.
Alternatives P6A and P6B contain no provisions for preventing exposure to contamination, and are not
protective of human health and the environment. Since Alternatives P6A and P6B do not meet the threshold
criterion of protection of human health and the environment, they will not be discussed in the remainder
of this section.
8.2 Compliance with ARARs
The Federal and State requirements or criteria with which a Superfund remedy must comply are called
Applicable or Relevant and Appropriate Requirements. In this section of the ROD, EPA has identified certain
ARARs which the alternatives are required to meet. A complete discussion of ARARs for the selected remedies
for Pond 5 and Pond 6 appears in Sections 9.1.1 through 9.3.3 of this ROD. Because the Commonwealth of
Virginia administers an authorized state RCRA program, the Virginia Hazardous Waste Management Regulations
("VHWMR") will serve as the governing ARAR in place of the Federal RCRA regulations
contained in Volume 40 of the Code of Federal Regulations, except for the Land Disposal Restrictions ("LDRs")
set forth in 40 C.F.R. Part 268. (At this time, Virginia does not have authorization for administering
LDRs).
Pond 5 Of the alternatives being considered (P5F through P5J-1), Alternatives P5F, P5G-1, and P5H will not
meet the action-specific closure requirements for a surface impoundment closed as a landfill specified under
VHWMR Section 9.10F and 40 C.F.R. § 264.310, and will not be discussed as viable options in the
remainder of this section. Alternatives P5F-X, P5I, P5J, and P5J-1 will meet these closure requirements.
Alternatives P5F-X, P5I, P5J, and P5J-1 will meet the chemical-specific ARAR for Surface water discharge to
the river by achieving a maximum mercury concentration equal to or less than the effluent discharge limit
that will be established by the Virginia Department of Environmental Quality ("VDEQ"), under its
Virginia Pollutant Discharge Elimination System ("VPDES") regulations (VR 680-14-01), administered by VDEQ
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pursuant to Section 304 of the Clean Water Act. Virginia surface water standards are "in stream" maximum
concentrations that will be used by the VPDES program to determine maximum allowable concentrations in
surface water discharges. In accordance with the Virginia surface water standards, when calculating the
maximum allowable discharge concentration for the protection of aguatic life (chronic toxicity), the effect
of dilution is based on the lowest flow over a seven-day period with a recurrence interval of ten years. The
current Virginia surface water standard for mercury is 0.012 ug/1.
The treatment of groundwater in Alternatives P5F-X, P5I, P5J, and P5J-1 may result in the generation of
sludges or other metal-containing waste. Any sludges or other metal-containing waste would be evaluated in
accordance with the hazardous waste identification reguirements of 40 C.F.R. Part 261, Subpart C and
VHWM Part III. If temporary onsite storage of sludges and other metal-containing waste becomes necessary
prior to transporting off-site for treatment and disposal, such storage shall be in compliance with VHWMR
Part IX. On-site management of any sludges or other metal-containing wastes found to exhibit characteristic
of a hazardous waste would comply with the substantive reguirements of 40 C.F.R. Part 262 and VHWMR Part VI
that pertain to generators of hazardous waste. In addition, preparation of waste for off-site disposal will
comply with 40 C.F.R. Part 263 and VHWMR Part VII. Transportation of sludges and other metal-containing
waste shall be in compliance with 40 C.F.R. Part 263 and MR Part VII, and 49 C.F.R. Parts 107 and 171-179
regulating the transportation of hazardous waste, and Virginia Regulations Governing the Transportation of
Hazardous Materials (VR 672-30-1). The groundwater collected and treated under these alternatives will be
treated to meet the substantive reguirements of the VPDES regulations prior to discharge to the river,
including effluent discharge limits and monitoring reguirements. Treatment of the Pond 5 effluent will
continue until the completed remedial action has demonstrated through monitoring results that the Pond 5
effluent complies with the VPDES reguirements without treatment.
Alternatives P5F-X, P5I, P5J, and P5J-1 will comply with the substantive reguirements of the following
Federal and State environmental laws and regulations: stormwater effluent flow reguirements of VPDES,
stormwater management reguirements of the Virginia Stormwater Management Act and Virginia Stormwater
Management Regulations (VR 215-02-00), Virginia Erosion and Sediment Control Regulations (VR 625-02-00),
Virginia Impounding Structure Regulations (VR 625-01-00); Federal reguirements for the protection of
floodplains and wetlands (Executive Orders 11988 and 11990) and the Virginia Water Protection Program
Regulations (VR 680-15-02); Federal reguirements for the protection of endangered species (16 U.S.C. § 1531
et seg.; 50 C.F.R. Part 402) and the Virginia Endangered Species Act (Code of Virginia §§ 29.1 - 563); and
the Archaeological and Historical Preservation Act of 1974 (16 U.S.C. § 469 and 36 C.F.R.
Part 65).
Pond 6 Alternatives P6C through P6E will meet the chemical-specific ARAR for surface water discharge to the
river described above for Pond 5. Monitoring of the Pond 6 effluent has indicated that the mercury
concentration in the discharge from Pond 6 has typically been non-detectable. Alternatives P6C through P6E
will also comply with the substantive reguirements of the Federal and State environmental laws described
above for Pond 5.
8.3 Long-Term Effectiveness and Permanence
Alternatives P5F-X, P5I, P5J, and P5J-1 all have the potential to provide long-term effectiveness.
Alternative P5F-X provides containment of the Pond 5 wastes through a highly impermeable cap. Capping is a
proven technology a properly maintained cap would provide long-term isolation of source materials and risk
reduction. In addition, this alternative provides for the treatment of Pond 5 effluent to Virginia surface
water standards and will continue to do so until monitoring of the Pond 5 effluent demonstrates that the
Virginia surface water standards are met without treatment.
Alternatives P5I, P5J, and P5J-1 employ a method of in-situ treatment of the contaminated pond material.
These alternatives would involve the use of a chemical reagent to react with the waste material rendering it
less permeable and reduce the mercury to a less soluble form (i.e., less susceptible to transport by
water). The effectiveness of the in-situ treatment alternatives in eliminating leachable mercury cannot be
accurately predicted without additional field studies; however, treatment of waste typically provides a
greater degree of long-term effectiveness.
Pond 6 Alternatives P6C, P6D, P6D-1, and P6E all have the potential to provide long-term effectiveness.
These alternatives all include, either as the remedy or a component of the remedy, a permeable soil cover
and/or a RCRA Subtitle "C" cap that would eliminate direct contact with the contaminated waste material and a
pH adjustment component to neutralize the Pond 6 effluent. Although the presence of mercury in Pond 6 has
been established, there have not been significant concentrations of mercury measured at the Pond 6 outfall.
The mercury concentration in the Pond 6 outfall has usually been non-detectable.
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EPA recognizes that the permeable cover component in Alternative P6C does not eliminate the possibility of
mercury in Pond 6 migrating through the subsurface and entering the river via the Pond 6 decant structure or
possibly migrating through the Pond 6 dike. To account for this uncertainty, a detailed long-term monitoring
plan will be developed for the Site.
Alternatives P6D and P6E supplement the permeable soil cover with additional components to isolate or remove
the former chlorine plant buried debris and therefore provide higher degrees of long-term effectiveness than
Alternative P6C. Furthermore, Alternative P6D-1 supplements a RCRA Subtitle C compliant cap for the entire
Pond 6 area with containment of the demolition debris using a vertical barrier wall and therefore provides a
higher degree of long-term effectiveness than Alternatives P6C or P6D.
8.4 Reduction of Toxicity, Mobility, or Volume through Treatment
Pond 5 Only Alternatives P5I, P5J, and P5J-1 include measures to reduce the mobility of the mercury through
treatment. None of the alternatives reduce the toxicity or the guantity of mercury in the soil/waste in Pond
5. The Pond 5 Treatment Facility would be used to some extent in all of these alternatives to address
contaminated water collected from Pond 5. The duration of the facility's operation will depend on the
effectiveness of the ground water controls and/or the treatment technologies of the respective alternatives.
The carbon adsorption components of the ground water treatment process will produce contaminated sludges and
materials which will have to be disposed of offsite.
Alternative P5F-X provides in-place containment of Pond 5 waste material, which does not reduce the toxicity
or volume of these wastes. However, the cap would decrease the mobility of contaminants by reducing the
amount of water that may infiltrate the wastes and cause contaminants to move into the ground water.
Pond 6 The alternatives being considered for the Pond 6 area would not result in any overall reduction of
toxicity, mobility, or volume of contaminants through treatment. Alternatives P6C and P6D provide for a
permeable soil cover to reduce erosion of surface pond material containing mercury and the neutralization
of the Pond 6 effluent to reduce the alkalinity of the pond effluent discharged to the river. Alternatives
P6D, P6D-1, and P6E provide measures to reduce the potential mobility of the mercury from the buried
demolition debris area. Alternative P6E provides for the consolidation of the mercury-contaminated
demolition debris to the Pond 5 area.
8.5 Short Term Effectiveness
Pond 5 Institutional controls and Site access limitations have been implemented and are currently maintained
at the Pond 5 area. In the short term, Alternatives P5F-X through P5J-1 would be effective in maintaining the
existing level of protection. All alternatives provide for continued operation of the Pond 5 Treatment
Facility. Alternative P5F-X would reguire that any modifications to the Pond 5 Treatment Facility needed to
achieve the current Virginia surface water standard for mercury would be completed in the initial phase of
remedial action. All other alternatives provide for the continued operation of the existing facility during
the remedy implementation period. The alternatives anticipate that the Pond 5 effluent will meet the
Virginia surface water standard without treatment after implementation of the remedy is complete. In this
respect, Alternative P5F-X may provide a higher degree of short-term
effectiveness than those alternatives which do not reguire potential modifications to the Pond 5 Treatment
Facility to achieve the Virginia surface water standards.
Implementation of these alternatives would present a potential for exposure of workers to Site contaminants
during cap construction activities, in-situ treatment activities, installation of ground water monitoring and
extraction wells, construction of any needed modifications to and operation of the
Pond 5 Treatment Facility, and sampling activities. In addition, workers would be exposed to normal
construction hazards. However, these risks would be reduced to acceptable levels by following proper health
and safety practices.
Implementation of each of these alternatives would pose an additional short-term risk to workers and
neighboring populations as a result of the generation of dust during the cap construction or in-situ
treatment activities. An air monitoring program would be implemented to ensure that unacceptable air
releases do not occur.
Pond 6 Institutional controls and Site access limitations have been implemented and are currently maintained
at the Pond 6 area. In the short-term, Alternatives P6C through P6E would be effective in maintaining the
existing level of protection. These alternatives include a pH neutralization component which would result in
a neutral discharge of Pond 6 effluent to the river.
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Implementation of the Pond 6 alternatives would present a potential for exposure of workers to Site
contaminants during cap construction activities, installation of the vertical barrier wall around the buried
debris (if required), installation of ground water monitoring and extraction wells, and sampling
activities. In addition, workers would be exposed to normal construction hazards. However, these risks
would be reduced to acceptable levels by following proper health and safety practices.
Alternative P6E would pose an additional short-term risk to workers and neighboring populations as a result
of the generation of dust during the excavation and consolidation of buried debris to the Pond 5 area. An
air monitoring program would be implemented to ensure that unacceptable air releases do not
occur. This additional risk inherent in these activities would be addressed in the Site Health and Safety
Plan.
8.6 Implementability
Pond 5 Alternatives P5F-X through P5J-1 will require construction activities on the surface of Pond 5 and
therefore have uncertainties in implementability associated with the properties of the pond material. The
capacity of the pond material to bear the weight of the cap and/or construction equipment must be addressed
during remedial design if one of these alternatives is implemented. The use of geosynthetics as a possible
component of the final cap is recognized as being implementable and effective for RCRA Subtitle "C"
applications. Geosynthetics have been used successfully in providing a base upon which fill can be placed
over an unstable subsoil. Consideration of settlement of the Pond 5 waste material must be included in the
design and implementation of Alternatives P5F-X through P5J-1 for Pond 5.
Ion exchange is a ground water treatment technology that could be used if modification of the Pond 5
Treatment Facility is necessary in Alternative P5F-X. This technology has been successfully demonstrated in
full-scale operations or the removal of mercury. However, a treatability study may be necessary to ensure
that this technology could be used effectively if modification of the Pond 5 Treatmet Facility is
needed to meet the current Virginia surface water standard for mercury.
Alternatives P5I, P5J, and P5J-1 have uncertainty relative to their effectiveness in adequately stabilizing
the pond material to immobilize the mercury. Proper mixing of reagents with the pond material presents some
uncertainty. Field treatability studies would be required to determine the appropriate reagent/additive, the
method of application, and the limits of treatment. Verification of the success of these alternatives would
require an extensive quality assurance plan.
Alternatives P5J and P5J-1 call for treatment of the top 20 feet of the Pond 5 material. There remains some
uncertainty regarding the migration of mercury to lower depths within Pond 5 if only the top 20 feet of pond
material were stabilized.
Worker exposure and protective equipment requirements for construction activities can be readily achieved for
all of the alternatives. All alternatives which include construction activities on the surface of the pond
would provide appropriate measures to-control fugitive emissions and would provide for monitoring of the air
for mercury.
Pond 6 Alternatives P6C through P6E would require construction activities on the surface of Pond 6 and
therefore have uncertainties associated with the properties of the pond material as discussed above for Pond
5.
Worker exposure and protective equipment requirements for construction activities can be readily achieved for
all of the alternatives. All alternatives which include construction activities on the surface of the pond
would provide appropriate measures to control fugitive emissions and would provide for monitoring of the air
for mercury.
8.7 Cost
The estimated present worth costs of the viable alternatives remaining for Pond 5 and Pond 6 are presented in
Table 5. These costs represent the "present worth value" of all future costs activities (capital costs and
operation and maintenance costs) associated with each alternative.
Table 5 - Present Worth Costs
Pond 5 Pond 6
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Alternative P5F-X
Alternative P5I
Alternative P5J
Alternative P5J-1
State Acceptance
$30,471,000 - $33,396,000
$66,675,000 - $146,776,000
$88,290,000 - $89,678,000
$29,854,000 - $32,866,000
Alternative P6C
Alternative P6D
Alternative P6D-1
Alternative P6E
$ 6,408,000
$ 7,462,000
$14,628,000
$13,460,000
VDEQ had the opportunity to review and comment on all the documents in the Administrative Record and on the
draft ROD. Although the Commonwealth's comments have been incorporated into the ROD, the Commonwealth of
Virginia has not concurred with this ROD.
8.9 Community Acceptance
The community has been in general agreement with the alternatives for Ponds 5 and 6 selected in this ROD.
The company that owns the Site has, however, indicated its opposition to some components of the chosen
alternatives. Oral and written comments on the remedial alternatives evaluated by EPA for implementation
at Ponds 5 and 6 are included in Part III (Responsiveness Summary) of this ROD.
9.0 SELECTED REMEDY PERFORMANCE STANDARDS
Based upon consideration of the reguirements of CERCLA, the detailed analysis of the alternatives using the
nine criteria, and public comments, EPA has determined that Alternative P5F-X (Ground water Management and
RCRA Cap with Pond 5 Treatment Facility Upgrade) is the most appropriate remedy for Pond 5, and
a modified version of Alternative P6D is the most appropriate remedy for Pond 6 of the Saltville Waste
Disposal Ponds Superfund Site.
Alternative P5F-X and the modified Alternative P6D for Ponds 5 and 6, respectively, meet the threshold
criteria of overall protection of human health and the environment and compliance with ARARs, and provide the
best balance of long-term effectiveness and permanence, reduction of toxicity, mobility or volume of
contaminants through treatment, short-term effectiveness, implementability, and cost.
As indicated earlier in this document, EPA has elected to defer a decision on the remedy for the Former
Chlorine Plant Site. After a detailed review of the comments received during the public comment period, EPA
concluded that there remains a high degree of uncertainty regarding the level of mercury migrating to the
river from the Former Chlorine Plant Site. To make the appropriate remedy decision for this area, EPA
believes additional data is reguired to further characterize the impact that mercury contamination at the
Former Chlorine Plant Site ishaving on the river. Additional study will be conducted concurrently with the
ongoing study of the river. A separate Proposed Remedial Action Plan documenting EPA's preferred
remedial action for the final operable unit at the Site will address both the river and the Former Chlorine
Plant Site.
9.1 Pond 5
The selected remedy for the Pond 5 area considers of the following major components:
Installation of a multi-layered cap over the entire Pond 5 area;
Ground water interceptor system;
Revision of the effluent discharge limit for the
existing Pond 5 Treatment Facility to achieve the
current Virginia surface water standard for mercury and
any modification of the Pond 5 Treatment Facility
necessary to achieve the revised discharge limit;
Institutional Controls;
Maintenance of the Site security and maintenance programs;
Long-term Monitoring.
The specific reguirements and performance standards for the first three components listed above are presented
in the following section. The remaining components are also common to the selected remedy for Pond 6 and the
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requirements for these components are presented in Section 9.3.
9.1.1 Multi-Layered Cap
1. A multi-layered cap shall be installed over Pond 5 in
accordance with RCRA Subtitle C requirements, 40 C.F.R. Part
264, Subparts G and N, and VHWMR § 10.13.K, to reduce the
infiltration of surface water and miqration of contaminants
into the qround water. The cap shall cover the entire Pond
5 area of approximately 75 to 80 acres.
2. Air monitorinq for dust and Site contaminants shall be
performed in accordance with the federal Clean Air Act, 42
U.S.C. § 7401 et seq., and 40 C.F.R. Part 50, to ensure any
air emissions conform with the National Primary and
Secondary Ambient Air Quality Standards. Fuqitive dust
emissions shall also be controlled in accordance with the
Virqinia Air Pollution Control law, Code of Virqinia §§
10.1-1300 et seq., and the Virqinia Requlations for the
Control and Abatement of Air Pollution, VR § 120-01.
3. Erosion and sediment control measures shall be implemented
and maintained in accordance with the substantive
requirements of the Virqinia Erosion and Sediment Control
Law, Code of Virqinia §§ 10.1-560 et seq., and the Virqinia
Erosion and Sediment Requlations, VR § 625-02-00. An
erosion and sediment control plan shall be prepared and
submitted to EPA for approval durinq the remedial desiqn phase.
4. All equipment used durinq excavation of contaminated soil
shall be decontaminated before enterinq uncontaminated
areas. The desiqn and specifications for the
decontamination facilities shall be approved by EPA as part
of the remedial desiqn. Any discharqe of water qenerated
from Site decontamination activities shall be in compliance
with the Virqinia State Water Control Law, Code of Virqinia
§§ 62.1-44.2 et seq., and the Virqinia State Water Control
Board Requlations (VR 680-21-00).
9.1.2 Ground water Interceptor System
1. An interceptor system shall be constructed to minimize the
upqradient subsurface flow (i.e., fracture flow from Little
Mountain) from cominq in contact with the contaminated waste
material in Pond 5. The standards and specifications for
the qround water interceptor system shall be approved by EPA
durinq the remedial desiqn phase.
9.1.3 Pond 5 Treatment Facility
1. Water collected throuqh the Pond 5 decant structure shall be
conveyed to the existinq Pond 5 Treatment Facility, treated,
and discharqed to the river in accordance with effluent
limits and flow rates established by the VDEQ Water Division
under the Virqinia State Water Control Law, Code of Virqinia
§§ 62.1-44.2 et seq., and the Virqinia Pollutant Discharqe
Elimination System Requlations (VR 680-14-01). The existinq
effluent limit shall be modified to be in compliance with
the current Virqinia surface water standard for mercury.
2. Process modifications to the existinq Pond 5 treatment
Facility may be required to attain compliance with the
modified effluent limit. EPA shall determine if
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modifications are necessary during the remedial design
phase. If modifications are necessary, these modifications
shall be implemented upon EPA approval of the final design
standards and specifications for the needed modifications.
3. Sludges and other metal-containing waste generated by the
groundwater treatment process shall be tested using Toxicity
Characteristic Leaching Procedure to determine if they
exhibit characteristics of hazardous waste, pursuant to 40
C.F.R. Part 261, Subpart C and VHWMR Part III. Sludges and
other metal-containing waste that do not exhibit hazardous
characteristics during testing shall be disposed of off-site
at a permitted RCRA Subtitle D facility; sludges and other
metal-containing waste that exhibit hazardous
characteristics shall be transported off-site for treatment
and disposal at a permitted RCRA Subtitle C facility or an
approved alternative. If temporary onsite storage of sludges
and other metal-containing waste becomes necessary prior to
transporting off-site for treatment and disposal, such
storage shall be in compliance with VHWMR § 9.8 Use and
Management of Containers, or § 9.9 Tanks. On-site
management-of any sludges or other metal-containing waste
found to exhibit a characteristic of a hazardous waste shall
comply with the substantive reguirements of 40 C.F.R. Part
262 and VHWMR Part VI that pertain to generators of
hazardous waste. Preparation and transportation of sludges
and other metal-containing waste shall be in compliance with
40 C.F.R. Part 263 and VHWMR Part VII, and 49 C.F.R. Parts
107 and 171-179 regulating the transportation of hazardous
waste, and Virginia Regulations Governing the transportation
of Hazardous Materials (VR 672-30-1). Waste disposal shall
comply with regulations found at 40 C.F.R. § 300.440.
4. Chemical monitoring shall be performed to evaluate the
performance of the Pond 5 Treatment Facility and detect any
impacts to the river. The monitoring reguirements shall be
developed during the remedial design in accordance with the
Virginia State Water Control Law, Code of Virginia §§ 62.1-
44.2 et seg., and Virginia Pollution Discharge Elimination
System Regulations (VR 680-14-00), and reguire EPA approval.
9.2 Pond 6
The selected remedy for Pond 6 is a combination of Alternatives P6C and P6D identified in the FS Report and
the Proposed Plan. The selected remedy for Pond 6 and the contingent remedial action consists of the
following components:
! A permeable soil cover over the entire Pond 6 area of
approximately 40 to 45 acres, including the demolition
debris burial area;
! A pH adjustment system to neutralize the discharge from
the Pond 6 decant structure;
! Institutional controls;
! Maintenance of the Site security and maintenance programs;
! Long-term monitoring, including installation of
monitoring well (s) downgradient of buried debris.
The following additional remedial action shall be reguired if mercury contamination from the buried debris is
demonstrated to be migrating toward the river through the ground water in Pond 6:
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! Isolation of Former Chlorine Plant Site demolition
debris buried in the eastern end of Pond 6 by vertical
barrier wall and a multi-layered cap over the two to
three acres where the debris is buried.
9.2.1 Permeable Soil Cover
1. A uniform and compacted layer of soil shall be placed over
the entire area of Pond 6, approximately 40 to 45 acres.
This soil cover shall (1) prevent human contact with the
waste material in the Pond 6 area; (2) be capable of
supporting a vegetative cover; and (3) be sufficiently
compact so as not to crack excessively when dry. The cover
shall be maintained to ensure continued compliance with
these reguirements.
2. Vegetation shall be established on the Pond 6 soil cover to
stabilize the soil surface and minimize erosion. Mulch
shall be applied to regraded areas where necessary to
control erosion, promote germination of seeds, and increase
the moisture retention of the soil.
3. Air monitoring, erosion and sediment control, and
decontamination shall be performed in accordance with the
reguirements identified for the Pond 5 multi-layered cap in
Sections 9.1.1(2), (3), and (4), respectively, of this ROD.
9.2.2 Decant Structure Discharge Neutralization
1. A pH adjustment system shall be constructed to neutralize
the discharge from the Pond 6 decant structure to an
acceptable range. The acceptable range will be determined
by-the VDEQ Water Division in accordance with Virginia State
Water Control Law, Code of Virginia §§ 62.1-44.2 et seg.,
and Virginia Pollutant Discharge Elimination System
Regulations (VR 680-14-01). The system to be used to comply
with the established pH range and the specifications of the
pH adjustment system shall be approved by EPA during the
remedial design.
9.2.3 Contingent Remedial Action: Cap and Vertical Barrier Wall
1. One or more ground water monitoring wells (i.e., trigger
wells) shall be installed downgradient of the Pond 6 buried
debris area for the purpose of detecting any mercury that
may be migrating toward the Pond 6 decant structure and
ultimately discharged into the river. The location of the
monitoring well(s), the appropriate screening interval(s),
and the freguency of sampling shall be determined during
remedial design.
2. Ground water modeling shall be conducted to estimate the
concentration of mercury in a trigger well that could result
in a discharge from the Pond 6 decant structure exceeding
the Virginia surface water standard for mercury.
Conservative assumptions shall be used in the model because
of the uncertainties inherent in such calculations. EPA
shall determine, based on this ground water modeling and any
other information deemed appropriate, the mercury
concentration (i.e., action level) which, if exceeded in any
of the newly installed ground water monitoring wells and in
a subseguent confirmatory sample, shall trigger
implementation of the contingency actions to isolate the
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debris buried in Pond 6.
3. If the mercury concentration in a ground water monitoring
well installed to detect migration of contamination from the
debris buried in Pond 6 exceeds the action level established
by EPA in Section 9.2.3(2), above, a confirmatory sample
shall be collected and analyzed for mercury. If the
analytical result from the confirmatory sample also exceeds
the action level, the contingency actions described below in
Section 9.2.3(3)(a) and (b) shall be implemented.
a. A multi-layered cap shall be installed over the
demolition debris burial area in accordance with the
reguirements identified for the Pond 5 multi-layered
cap in Section 9.1.1, above, of this ROD. The cap
shall cover the entire buried debris area,
approximately two to three acres.
b. Vertical barrier walls shall be placed around the
perimeter of the debris to contain the waste. The
appropriate process option to satisfy this reguirement
and the standards and specifications for implementation
shall be approved by EPA during remedial design.
9.3 Common Elements
The following remedial action components and performance standards are reguired for both the Pond 5 and Pond
6 selected remedies:
9.3.1 Long-term Monitoring
1. A long-term groundwater monitoring program shall be
implemented to evaluate subsurface flow conditions and water
guality in the Pond 5 and Pond 6 areas, specifically the
seepage of contaminated ground water migrating through the
dikes to the river. The number of new wells, the exact
location of the new wells, and the associated screen depth
of the new wells shall be approved by EPA during the
remedial design. Supplemental sampling of existing onsite
wells may be incorporated into the long-term monitoring
program. Samples shall be collected and analyzed for
mercury on a guarterly basis for a period of 30 years. The
Pond 6 decant structure outfall shall be sampled and
analyzed for mercury and pH guarterly for a period of 30
years.
9.3.2 Site Maintenance
1. A long-term Site maintenance program shall be implemented.
The program will include regular, documented inspections of
the overall Site including but not limited to, security
fencing, access roads, monitoring wells, the Eastern
Diversion Ditch, the Western Diversion Ditch, the Pond 5
dike, the Pond 6 dike and the Pond 5 Treatment Facility.
Documented inspections shall also include inspection of the
remedial action components reguired under this ROD (i.e.,
the Pond 5 RCRA Subtitle "C" cap, the Pond 5 ground water
interceptor system, the Pond 6 permeable cover, and the Pond
6 neutralization system) as construction is completed and
the components become operational and functional. If any of
the components are found to be in a state of disrepair,
those items shall be repaired and documented in an
inspection report. The freguency and duration of
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inspections and procedure for reporting will be determined
by EPA during the remedial design.
2. Maintenance of the Pond 5 cap shall be performed in
accordance with 40 C.F.R. Part 264, Subpart G and N, and
VHWMR §10.6.H. and S10.13.K to prevent degradation of the
cap and to ensure long-term effectiveness.
3. Inspection and maintenance of Pond 5 and Pond 6 impoundment
structures (i.e., the dikes) shall comply with Virginia
Impounding Structure Regulations (VR 625-01-00).
4. The existing fence shall be maintained in a manner
sufficient to prevent unauthorized access to the Pond 5 and
Pond 6 areas.
9.3.3 Institutional Controls
1. A deed restriction shall be placed on the Pond 5 and Pond 6
property prohibiting development of the properly or the use
of the ground water from that area as a potable source.
10.0 STATUTORY DETERMINATIONS
EPA's primary responsibility at Superfund sites is to select remedial actions that are protective of human
health and the environment. In addition, Section 121 of CERCLA 42 U.S.C. § 9621, establishes several other
statutory requirements and preferences. These requirements and preferences specify that, when complete, the
selected remedial action for a site must Comply with applicable or relevant and appropriate requirements
established under Federal and State environmental laws, unless a statutory waiver is justified. The selected
remedy must also becost-effective and utilize permanent solutions and alternative
treatment technologies or resource recovery technologies to the maximum extent practicable. The statute also
contains a preference for remedies that employ treatment as a principal element.
10.1 Protection of Health and the Environment
The selected remedies for Ponds 5 and 6 will provide adequate protection of human health and the environment
as follows:
Pond 5 The selected remedy for Pond 5 will effectively isolate
the Pond 5 soil/waste and minimize migration of mercury from Pond
5 thus addressing the human health concerns presented in the
Baseline Risk Assessment. The remedy addresses all exposure
pathways identified in the Baseline Risk Assessment. Moreover,
operation of the Pond 5 Treatment Facility in compliance with the
current Virginia surface water standards will provide increased
protection of human health and the environment.
Pond 6 The selected remedy for Pond 6 will effectively cover the
Pond 6 soil/waste and address the human health concerns presented
in the Baseline Risk Assessment and all exposure pathways
identified in the Baseline Risk Assessment.
10.2 Compliance with Applicable or Relevant and Appropriate Requirements
Under Section 121(d) of CERCLA, 42 U.S.C. § 9621(d), and EPA guidance, remedial actions at Superfund sites
must attain legally applicable or relevant and appropriate Federal and State environmental standards,
requirements, criteria, and limitations (collectively referred to as ARARs). Applicable requirements are
those substantive environmental protection requirements, criteria, or limitations promulgated under Federal
or State law that specifically address hazardous material found at the site,
the remedial action to be implemented at the site, the location of the site, or other circumstances at the
site. Relevant and appropriate requirements are those which, while not directly applicable to the site,
nevertheless address problems or situations sufficiently similar to those encountered at the site that their
use is well suited to that site.
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The selected remedy will comply with all applicable or relevant and appropriate requirements. These ARARs
are presented in Section 8.2 (Compliance with ARARs) and Section 9.0 (Selected Remedy and Performance
Standards).
10.3 Cost-Effectiveness
Section 300.430(f)(1)(ii)(D) of the NCP, 40 C.F.R. § 300.430 (f)(1)(ii)(D), requires EPA to evaluate
cost-effectiveness by first determininq if the alternative satisfies the threshold criteria: protection of
human health and the environment and compliance with ARARs. The effectiveness of the alternative is
then determined by evaluatinq the followinq three of the five balancinq criteria: lonq-term effectivenessand
permanence, reduction of toxicity, mobility, or volume throuqh treatment, and short-term effectiveness. EPA
has determined that the selected remedies for Pond 5 and Pond 6 satisfy the threshold criteria and most
effectively address the contaminated soil/waste material. The estimated present worth costs are $30,471,000
to $33,396,000 for Pond 5 and $6,408,113 for Pond 6. The Pond 5 costs are presented as a ranqe since the
specifications of the qround water interceptor system and the total cappinq area have not been defined. The
selected remedies for Ponds 5 and 6 are cost effective because their costs are proportional to their overall
effectiveness.
10.4 Utilization of Permanent Solutions and Alternative Treatment (or Resource Recovery) Technoloqies to
Maximum Extent Practicable
Pond 5 EPA has determined that the selected remedy represents the maximum extent to which permanent solutions
and alternative treatment technoloqies can be utilized in a cost-effective manner at Ponds 5 and 6. The
qround water treatment system (Pond 5 Treatment Facility) will siqnificantly reduce the mercury
concentration in the qround water collected at the Pond 5 decant structure. To address Pond 5 soils/waste
throuqh alternative treatment technoloqies, several technoloqies were evaluated. In-situ stabilization
treatment was carried throuqh for detailed evaluation; however, this technoloqy would not achieve qreater
overall remedial protection for the added costs.
Pond 6 The selected remedy does not include treatment technoloqies. The monitorinq data collected at the
Pond 6 decant structure indicates non-detectable concentrations of mercury, indicatinq that the mercury
contained in the Pond 6 waste material does not appear to be mobile. As a protective measure, monitorinq
will be continued at the Pond 6 decant structure and a monitorinq well will be installed directly
downqradient of the suspected source material (i.e., the Former Chlorine Plant Site debris buried in the Pond
6 area) to provide early detection of mercury miqration toward the river. Althouqh treatment alternatives
were evaluated for Pond 6, they were screened out since they would not achieve qreater overall remedial
protection for the added costs.
10.5 Preference for Treatment as a Principal Element
Pond 5 The selected remedy for Pond 5 utilizes treatment for the Pond 5 qroundwater flow collected at the
Pond 5 decant structure and conveyed to the Pond 5 Treatment Facility. The qround water will be treated to
reduce mercury levels such that the treated water complies with acceptable levels established by the VDEQ
Water Division. The remaininq components of the Pond 5 selected remedy do not utilize treatment
technoloqies. This is primarily due to the moderate levels of mercury found throuqhout the Pond 5 waste
material coupled with the extremely larqe volume of waste material within Pond 5 (approximately 76 acres).
Pond 6 The are no treatment technoloqies identified in the Pond 6 selected remedy. As discussed in Section
10.4, above, the monitorinq data collected at the Pond 6 decant-structure indicates non-detectable
concentrations of mercury, indicatinq that the mercury contained in the Pond 6 waste material does not
appear to be mobile. Moreover, as in Pond 5, the samplinq of the waste material conducted throuqhout the
Pond 6 area (surface to 10 foot depth) indicates that there are relatively low level mercury concentrations
found throuqhout the larqe volume of waste material in Pond 6 (approximately 45 acres).
11.0 DOCUMENTATION OF SIGNIFICANT CHANGES
EPA issued the Proposed Remedial Action Plan for OU2 of the Saltville Waste Disposal Ponds Site for public
review and comment on January 18, 1995. EPA's review of all written and verbal comments received durinq the
comment period has resulted in siqnificant chanqes to the preferred alternatives for the Former
Chlorine Plant Site and Pond 6 areas.
Because of the hiqh concentrations of mercury found in the soil at the Former Chlorine Plant Site area and
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the potential for this mercury to migrate to and impact the river, EPA's preferred alternative for this area
in the Proposed Remedial Action Plan called for permanent treatment of this source material via a
thermal process known as retorting. This process would provide a permanent long-term solution for the Former
Chlorine Plant Site area of the Site. During the public comment period, EPA received significant adverse
comments on the retorting process identified in the preferred alternative for the Former Chlorine Plant Site.
EPA has considered these comments and decided to defer the remedy selection decision for this area until
additional data can be collected.
As noted in Section 9.0 of this ROD, the uncertainty of whether mercury is migrating to the river from the
Former Chlorine Plant Site necessitates additional characterization of the impact of mercury contamination in
this area. Additional investigation will be conducted concurrently with the ongoing study of the North Fork
of the Holston River under Operable Unit 3. A Proposed Remedial Action Plan for Operable Unit 3,
documenting the EPA preferred alternative for remedial action for the North Fork of the Holston River, will
also include a preferred alternative for the remedial action for the Former Chlorine Plant Site.
With regard to Pond 6, the selected remedy has been changed from the preferred alternative documented in the
Proposed Remedial Action Plan. The preferred alternative was identified in the Proposed Remedial Action Plan
as Alternative P6D from the FS Report. The primary components of this alternative consisted
of a permeable cover over the entire Pond 6 area, a system to neutralize the outfall at the Pond 6 decant
structure, and localized containment of the buried demolition debris in the northeastern end of Pond 6 with
vertical barrier walls and a RCRA Subtitle C compliant cap. The selected remedy in this ROD is not
Alternative P6D, but a combination of Alternatives P6C and P6D, which were evaluated in the Proposed Remedial
Action Plan. The selected remedy for this area as set forth in this ROD provides that the localized
containment of the demolition debris with vertical barrier walls and a RCRA Subtitle C compliant cap (over
the buried debris area) will be implemented only if monitoring of the ground water in Pond 6 downgradient of
the buried debris indicates mercury is migrating to the river. In essence, the
isolation of the buried debris has become a contingency component of the selected remedy for Pond 6, subject
to ground water monitoring results.
One or more ground water monitoring wells will be installed in Pond 6 downgradient of the buried debris for
the purpose of detecting any mercury that may be migrating toward the Pond 6 decant structure and ultimately
discharging into the North Fork of the Holston River. The location of the monitoring well(s),
the appropriate screening interval(s), and the freguency of sampling will be determined during remedial
design.
EPA believes that the existing Site data is not conclusive regarding the issue of mercury contamination
migrating from the buried debris in Pond 6. No existing ground water monitoring wells are located directly
downgradient of the buried debris. As a result, EPA has selected remedy for Pond 6 that is fully
protective of human health and the environment, meets ARARs, and allows for supplemental remedial action
predicated upon ground water monitoring.
The Pond 6 preferred alternative in the Proposed Remedial Action Plan also stated that the remedy would be
upgraded to include a RCRA Subtitle C compliant cap over the entire Pond 6 area and surface water management
controls should monitoring indicate migration of mercury from Pond 6 at unacceptable levels. The selected
remedy for Pond 6 set forth in this ROD does not include this provision. The selected remedy reguires that
long-term monitoring be conducted to detect migration of mercury to the North Fork of the Holston River. If
unacceptable levels of mercury migration are detected, the need for supplemental
remedial actions will be evaluated at that time based on the new information.
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RECORD OF DECISION
SALTVILLE WASTE DISPOSAL PONDS SUPERFUND SITE
PART III - RESPONSIVENESS SUMMARY
This Responsiveness Summary documents public comments expressed to EPA on the Proposed Remedial Action Plan
for Operable Unit 2 ("OU2") of the Saltville Waste Disposal Ponds Superfund Site ("Site") and EPA's responses
to those comments. The information is organized as follows:
A. Overview
B. Comments Received During the Public Meeting
C. Written Comments Received from Olin Corporation
D. Written Comments Received from Other Citizens
A. OVERVIEW
EPA held a public comment period from January 18, 1995 through March 20, 1995, to receive comments from the
public on the Remedial Investigation and Feasibility Study ("RI/FS") reports and the Proposed Remedial Action
Plan ("Proposed Plan") for OU2 of the Saltville Waste Disposal Ponds Superfund Site. EPA held a public
meeting on February 1, 1995, at 7:00 p.m. at the Northwood High School, in Saltville, Virginia. The public
meeting was attended by EPA and VDEQ staff, local residents, representatives and consultants of Olin
Corporation, public officials, and members of the press. The transcript of the public meeting is in the
Administrative Record for the Site.
The purpose of the meeting was to present and discuss the findings of the RI/FS and to apprise the meeting
participants of EPA's preferred remedial alternatives for OU2. Comments received during the meeting and
written comments received throughout the public comment period are presented below along with EPA's
response.
B. COMMENTS RECEIVED DURING THE PUBLIC MEETING
1. The Mayor of Saltville read a prepared statement announcing his appreciation of the cooperative
relationships the Town of Saltville has achieved with EPA and other government agencies over the past few
years, which has lead to significant accomplishments toward cleaning up the Site. The Mayor further stated
concerns of many of the Saltville citizens with the retort process preferred by EPA for the Former Chlorine
Plant Site area and questioned the need to disturb that area of the Site.
EPA Response: EPA appreciates the recognition by the Mayor of the efforts the Agency has made to work with
the community to address the cleanup of the Site. As to the Former Chlorine Plant Site, EPA has carefully
considered all the comments submitted by the public and determined that additional information is needed to
make a decision on the cleanup in this area. In the Proposed Plan, EPA recommended treating the soils and
sediments located at the Former Chlorine Plant Site based in part on the belief that the
mercury present in these materials is migrating to the North Fork of the Holston River. The owner of the
Site, Olin Corporation, and many in the local community believe that the mercury in the Former Chlorine Plant
Site area is not migrating and/or can be readily contained.
Understanding and predicting how mercury contamination at the Former Chlorine Plant Site will migrate over
time is difficult. During the RI/FS process, a model (i.e., mathematical equation) was used to estimate the
migration of mercury to the river. This model relied on numerous assumptions in instances were appropriate
data were not available. At this point, EPA is requiring that additional data be gathered to try to
understand the migration process more clearly. Although this additional data will not allow EPA to predict
future mercury migration with absolute certainty, EPA believes it will be in a better position to
make a final determination on an appropriate remedy for the Former Chlorine Plant Site if it has the
additional data. The Former Chlorine Plant Site will be addressed as part of Operable Unit 3 for the Site
along with an evaluation of the North Fork of the Holston River.
A prepared statement was read at the public meeting by a representative of Olin Corporation ("Olin" or the
"Company"), the potentially responsible party for the Site. The following comments summarize the issues
raised by the Company on the Proposed Plan.
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2. The Company contends that EPA' s proposed alternatives for the Site were not included in the FS
report, particularly EPA's preferred alternative for the Former Chlorine Plant Site calling for on-site
retorting of contaminated soils and sediments. The Company therefore contends that the public was not given
an adeguate opportunity to understand the impacts of the retorting alternative.
EPA Response: The purpose of the RI/FI is to provide sufficient information to enable EPA to identify a
preferred alternative. EPA is not reguired to use the information in the RI/FS reports in the exact format
in which it is presented, particularly with regard to remedial alternatives. EPA often finds, as it did in
this case, that, in the process of developing the Agency's preferred alternative, parts of various
alternatives evaluated in the FS need to be combined to create what the Agency believes is
the best alternative. As part of the Proposed Plan, EPA conducts a comparative analysis of the preferred
alternative and the other alternatives considered in the Proposed Plan. The comparative analysis sets forth
the Agency's reasoning for selecting the preferred alternative. This is what EPA did in the Proposed Plan
for this Site.
For the on-site retorting alternative for the Former Chlorine Plant Site presented in the Proposed Plan, EPA
used the information developed in the FS for Alternative P5L for Pond 5. This alternative included the use
of on-site retorting to treat the mercury-contaminated waste in Pond 5. Alternative P5L was not retained as a
final alternative for Pond 5 because of the high cost of treating the large volume of material in Pond 5;
however, the retorting technology itself was not considered ineffective. The level of detail and analysis
provided in the FS for retorting was similar to that provided for the other treatment alternatives evaluated.
In considering alternatives for the Proposed Plan, EPA determined that the FS provided sufficient information
to develop an on-site retorting alternative for the Former Chlorine Plant Site. EPA supplemented the
Administrative Record to show how the cost estimate for this alternative was developed. EPA believes that
the Administrative Record available when the Proposed Plan was issued provided the
public with sufficient information to evaluate all the alternatives proposed.
The Company's specific concerns with the retorting alternative have been carefully considered by EPA and, as
addressed in the previous response, EPA is deferring a decision on the remedy for the Former Chlorine Plant
Site until additional data can be collected.
NOTE: This Responsiveness Summary will not address additional
specific comments made by the public on the preferred alternative
for the Former Chlorine Plant Site since a remedy for that area
of the Site is not part of this Record of Decision. Issues
raised by the public about the remedy for the Former Chlorine
Plant Site will be considered as this area is re-analyzed as part
of Operable Unit 3. Upon conclusion of the RI/FS process for
Operable Unit 3, EPA will issue a Proposed Remedial Action Plan
identifying the Agency's preferred alternatives for the Former
Chlorine Plant Site and the North Fork of the Holston River. At
that time, the public will have the opportunity to comment on the
Proposed Plan for Operable Unit 3 prior to EPA's selection of a
final remedy for the Former Chlorine Plant Site and the North
Fork of the Holston River. The remainder of this Responsiveness
Summary will focus on comments relating to the Pond 5 and Pond 6
remedies.
3. The Company stated support for the construction of a cap over Pond 5. The Company contends, however,
that EPA's addition of two feet of clay as a component of the cap would reguire transportation of 14,000
truck loads of clay through the community, resulting in noise, traffic congestion, possible accidents, and
wear and tear on roads and bridges. In addition, the Company contends that using clay as a
component of the cap would be technically impractical due to the physical characteristics of the Pond 5 waste
material.
EPA Response: As to the Company's estimated number of truck loads of clay reguired, EPA does not have the
basis for this estimate, which appears to be high. If the design process determines that clay is a necessary
component of the multi-layered cap, EPA believes that this material could be transported safely through the
community of Saltville. Regardless of whether a clay layer is specified for cap construction or not,
disruptions such as those mentioned by the commentor may result from any type of construction.
Developing specifications to minimize the disruptions, such as using the Pond 5 access road in lieu of the
road through the community of Perryville, will be addressed during the remedial design process.
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The selected remedy for Pond 5 includes construction of a multi-layered cap in accordance with RCRA Subtitle
C requirements (40 C.F.R. Part 264, Subparts G and N) and VWMR § 10.13.K. These requirements provide the
performance standards that the multi-layered cap must meet, but do not state how the cap must be desiqned to
meet these performance standards. A two-foot clay layer is often a component of a
multi-layered cap; however, if the performance standards can be met by usinq other components, EPA is not
requirinq the use of clay. The actual components of the multi-layered cap will be determined durinq the
enqineerinq remedial desiqn process.
4. The Company stated support for coverinq Pond 6 with soil. The Company contends, however, that there
is no potential that rainwater enterinq Pond 6 will carry mercury with it to the river.
EPA Response: Waste material was collected and analyzed for mercury at 30 samplinq points in and around Pond
6 durinq the RI. The hiqhest mercury concentration detected in Pond 6 was 78.3 mq/kq, and the averaqe
concentration across the Pond 6 was 20 mq/kq. Althouqh mercury is typically not detected in the discharqe at
the Pond 6 outfall, low concentrations of mercury are occasionally reported. EPA
does not believe the potential for mercury miqration in Pond 6 can be determined based on the limited data
available. Lonq-term monitorinq for both Pond 5 and Pond 6 is required as part of the selected remedy to
ensure that mercury contamination remains effectively contained within the pond areas.
5. The Company expressed concern with the component of EPA's preferred alternative for Pond 6 that
requires isolation of the buried debris from the former chlorine plant. The Company stated that the
isolation of the buried debris is overly protective and unnecessary.
EPA Response: EPA is concerned that the debris buried in Pond 6 contains elevated mercury concentrations and
qround water in the area of the debris shows elevated mercury levels. The preferred alternative for Pond 6
in the Proposed Plan included isolation of this buried debris by cappinq and installinq a vertical barrier
wall around the debris area. After considerinq the comments from the Company and the public on isolation of
the buried debris, EPA concluded that mercury miqration in Pond 6 cannot be determined based on the limited
data available. As a result, EPA decided to revise the Proposed Plan preferred alternative for Pond 6 when
selectinq the remedy for Pond 6 in the ROD. The Pond 6 remedy selected in the ROD requires the isolation
measures only if additional data from monitorinq in the vicinity of the buried debris shows that mercury
contamination at unacceptable levels is miqratinq throuqh the qround water to the river.
C. WRITTEN COMMENTS FROM OLIN CORPORATION
The followinq comments are those submitted in writinq by the potentially responsible party durinq the comment
period. Any comments addressed in the previous section are not repeated here. Aqain, as noted above,
comments relatinq to the Former Chlorine Plant Site have not been included because this ROD does not select a
remedy for that area of the Site.
1. The Company contends that the Pond 5 Treatment Facility does not need to be upqraded. The Company
believes that the existinq plant is capable of reducinq the mercury concentration to a level that would cause
the effluent from the Pond 5 Treatment Facility to be in compliance with the current Virqinia surface water
standards.
EPA Response: The existinq Pond 5 Treatment Facility was constructed as required under the Operable Unit One
(OU1) Interim Remedial Measures ROD, issued on June 30, 1987. At that time, the promulqated Virqinia surface
water standard for chronic toxicity of mercury in freshwater was 0.05 •g/l. The allowable concentration of
mercury in the Pond 5 Treatment Facility effluent was stated in the OU1 ROD as 20
• g/l, based on the existinq surface water standard. The current promulqated Virqinia surface water standard
for chronic toxicity of mercury in freshwater is 0.012 •g/l. The remedy selected in this ROD includes
continued operation and maintenance of the Pond 5 Treatment Facility and, therefore, the current standard is
an applicable or relevant and appropriate requirement ("ARAR"). The allowable concentration of mercury in
the Pond 5 Treatment Facility effluent will be revised by the VDEQ Water Division and will
be based on the current Virqinia surface water standard in conjunction with various other factors.
EPA aqrees that the available monitorinq data collected from the Pond 5 Treatment Facility effluent reveals
that mercury concentrations are siqnificantly below the 20 • g/l discharqe limit. However, EPA cannot
determine if the present discharqe from the Pond 5 Treatment Facility is in compliance with the current
Virqinia surface water standard for mercury because that revised discharqe limit has not yet
been established by the VDEQ Water Division. The revised discharqe limit will be determined durinq the
desiqn process and EPA will evaluate the available data to determine the need for Pond 5 Treatment Facility
upqrades at that time.
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2. The Company contends that the material from Olin's former chlorine plant operation was a wastewater
rather than a sludge and, therefore, was not regulated as a listed waste under RCRA. The Company further
contends that the waste constituents are mainly calcium carbonate, calcium chloride,
sodium carbonate, and sodium chloride, which are components of ammonium soda ash found in Ponds 5 and 6, and
are not hazardous.
EPA Response: As a matter of policy, EPA has consistently stated that while certain wastewaters may not be
subject to RCRA, such wastewaters can generate sludges that will meet the listing definition for hazardous
waste under RCRA. Historically, EPA has regulated sludges that are removed from wastewater treatment unit
tanks and impoundments or left in place in impoundments under RCRA. However, if wastewater which is a RCRA
listed waste is discharged to a unit, then any material that did not pass through the unit, but instead
settled, precipitated, or remained after evaporation, would be a sludge. Many facilities had "finishing"
ponds that would seguentially allow more materials to settle out prior to discharge, and these materials,
even if from non-listed wastewaters, became sludges that were listed hazardous wastes under RCRA.
EPA reguires the material in Ponds 5 and 6 to be regulated as a K106 listed hazardous waste under RCRA. K106
listed hazardous waste is wastewater treatment sludge from the mercury cell process in chlorine production.
The presence of mercury in the wastes in Ponds 5 and 6 has been clearly documented. Soda ash is a main
constituent of the K106 listing, as are some of the other components identified in the Company's comment.
However, K106 is listed solely for the toxic constituent mercury.
3. The Company contends that RCRA regulations do not apply retroactively, and RCRA cannot be considered
an ARAR for the Pond 5 activities.
EPA Response: The issue of retroactive application of RCRA applies to actions that involve excavation or
reprocessing of wastes that were disposed of prior to the enactment of RCRA. If a waste would be considered
a RCRA listed hazardous waste today, but was disposed of before 1980 when RCRA was enacted, EPA reguires that
the waste still be regulated as a RCRA listed waste if the waste is being placed in another location or
regenerated in some manner. EPA's position has been upheld by several court decisions. (The First Third LDR
Rule published on August 17, 1988, in the Federal Register at 53 Fed. Reg. 31147, provides further
background.) The remedy selected for Pond 5 will reguire excavation to regrade the waste material in order to
appropriately install the multi-layered cap. Therefore, EPA is reguiring that RCRA be applied retroactively
to management of the waste in Pond 5.
4. The Company contends that RCRA is not an applicable or relevant and appropriate reguirement for the
multi-layered cap proposed in the remedy for Pond 5.
EPA Response: As discussed in Comment 2., above, EPA believes the waste in Pond 3 can be characterized as
K106 listed hazardous waste under RCRA. Therefore, RCRA can be considered applicable to the remedy
reguirements for Pond 5. Even if some guestion existed as to whether the RCRA K106 listed hazardous waste
classification was directly applicable, EPA would consider RCRA to be relevant and appropriate. EPA OSWER
Directive 9234.2-04FS, entitled "RCRA ARARs: Focus on Closure Reguirements" (October 1989), clearly indicates
that where a cap is part of the remedy and the waste, even if not RCRA waste, is similar in nature to a RCRA
waste, the cap should meet the substantive reguirements of RCRA. The Company itself identified the RCRA
regulations at 40 C.F.R. 264, Subpart G - Closure and Post-Closure, as an action-specific ARAR in the
Feasibility Study ("FS") report.
5. The Company contends that long-term effectiveness, short-term effectiveness, and reduction of
toxicity, mobility or volume through treatment are satisfied to the/same degree by Alternatives P5F and
P5F-X. Overall, the Company contends that the comparative analysis reveals that Alternative P5F, the
company's preferred alternative, represents a better balance of the National Oil and Hazardous Substances
Pollution Contingency Plan ("NCP") criteria than alternative P5F-X.
EPA Response: The primary differences between these alternatives are that Alternative P5F-X reguires that
the cap for Pond 5 comply with the reguirements for closure under RCRA Subtitle C and that the existing Pond
5 Treatment Facility comply with the current Virginia surface water standard, while Alternative P5F does not.
One of the threshold criteria that the NCP establishes is compliance with ARARs. Alternatives that do not
meet this criterion, or are not protective of human health and the environment, are not evaluated further.
If the multi-layered cap described in Alternative P5F is determined to be in compliance with RCRA Subtitle C
and if the existing Pond 5 Treatment Facility effluent is determined to be in compliance with the current
Virginia surface water standard for mercury, these two alternatives are essentially the same. However, the
information needed to make these determinations is not currently available. EPA modified
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Alternative P5F by incorporating the necessary ARARs, thereby creating Alternative P5F-X. These
modifications ensure that the alternative meets the threshold criterion reguiring compliance with ARARs.
As to the criteria for long-term effectiveness, short-term effectiveness, and reduction of toxicity, mobility
or volume through treatment, Alternative P5F would not be as effective in meeting the criteria because
Alternative P5F does not include upgrades to the Pond 5 Treatment Facility to comply with the current
Virginia surface water standard for mercury and does not reguire a RCRA Subtitle C compliant cap.
6. The Company contends that Alternative P6D (EPAs preferred alternative for Pond 6 in the Proposed
Plan) and Alternative P6D-1 (a contingent action to be implemented at Pond 6 if monitoring indicates
migration of mercury from Pond 6 in unacceptable levels) do not increase overall protection of human health
and the environment more than other less costly alternatives.
EPA Response: EPA agrees that existing data do not currently support the need to implement the vertical
barrier walls and RCRA Subtitle C compliant cap over the buried debris area, components which are included in
Alternatives P6D and P6D-1 for Pond 6. Mercury is typically not detected in the discharge at the Pond 6
decant structure outfall. However, EPA also recognizes that effective long-term monitoring of Pond 6,
particularly in the area of the buried debris, must be implemented to ensure that mercury contamination in
Pond 6 is being properly contained. After reviewing comments received during the public comment period
and re-evaluating the existing data, EPA decided not to select the Pond 6 preferred alternative set forth in
the Proposed Plan (Alternative P6D, with P6D-1 as a contingent action) as the selected remedy for Pond 6.
The selected remedy for Pond 6 in the ROD is Alternative P6C (Permeable Soil Cover), with a contingency to
install the additional components of Alternative P6D for isolation of the buried debris if monitoring data
indicates that unacceptable levels of mercury are migrating toward the river. If the
contingent remedial action must be implemented, isolation of the buried debris would be accomplished with a
vertical barrier wall around the buried debris and & cap over the buried debris area that complies with RCRA
Subtitle C and VHWMR § 10.13.K.
7. As with Pond 5, the Company contends that RCRA is not an appropriate ARAR for Pond 6.
EPA Response: See responses to Comments C.2, C.3, and C.6, above.
8. The Company Contends that EPA failed to follow its own guidance documents regarding oversight of a
PRP conducting a RI/FS. Specifically, the Company believes it should have been given the opportunity to
develop and evaluate the alternatives that EPA wanted to include in the Proposed Plan since the Company was
performing the RI/FS.
EPA Response: As discussed in the response to Comment B.2, EPA often finds during the process of developing
a Proposed Plan that components of several alternatives set forth in the FS report should be combined to
address the problems at a site. EPA does not typically allow the potentially responsible party ("PRP") who
has prepared the RI/FS report the opportunity to revise the document again to include
EPA's preferred alternative, particularly if all the components of the preferred alternative are discussed in
the Fs report (albeit not necessarily set forth as a single alternative) and sufficient information is
available to allow an evaluation. Revisions generally result in substantial delay. Therefore, if EPA has
sufficient information in the FS report, as it believes it did in this case, the preference is to proceed
with preparation of the Proposed Plan and not reguire additional document revisions after EPA has reviewed
the RI/FS and decided on a preferred alterative. The appropriate forum for the PRP to comment on EPA's
preferred alternative is during the formal public comment period, not through the less formal document
revision process. This approach is consistent with Agency policy and guidance and with the NCP.
Over an approximate two-year period beginning in December 1992, the Company submitted four versions of the FS
report for Operable Unit 2 Of the Site. EPA's comments on the draft documents focused primarily on the
Company's need to include a full range of alternatives for remediation of the Site, not just those the
Company thought were appropriate. This was a particular concern with regard to the Former Chlorine Plant
Site. After the third submission in February 1994, EPA determined that sufficient information was available
for the Agency to proceed with development of its preferred alternatives. EPA believed that any further
reguest for the Company to expand the range of alternatives in the FS would not yield productive results and
would lead to unnecessary delay. Final revisions, as reguested by EPA, were made and the final FS report was
submitted in January 1995. The final revisions involved removing references to the ecological risk
assessment which is being conducted as part of Operable Unit 3.
EPA believes that the appropriate level of oversight of the Company was provided during preparation of the
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RI/FS. EPA further believes that the process followed in preparing the Proposed Plan was not only
appropriate, but necessary to achieve fair and open public input into the remedy selection process.
D. WRITTEN COMMENTS FROM OTHER CITIZENS
1. EPA received three hundred fifty-five signatures on several petitions which stated the following:
It is better to leave the Former Chlorine Plant Site
undisturbed than to excavate contaminated soil.
Mercury discharge from this Site is minimal and can be
controlled by Olin's alternative.
It is better not to place a heavy cap on Pond 5 since
it may settle and not perform as needed.
It is better to minimize truck traffic and other
disruptions to the community, and Olin's alternatives do this.
It is hoped that Pond 6 can be preserved for future
feasible and possible constructive uses.
EPA Response: The first element of the Petition was addressed in EPA's response to Comment B.I, above, and
the second and third elements were addressed in EPA's response to Comment B.3, above. With regard to the
preservation of Pond 6 for future feasible and possible constructive uses, EPA believes that the physical
behavior of the Pond 6 waste material is likely to be a more limiting factor than the mercury contamination.
EPA believes the final remedy adeguately addresses the risk presented by the Site and
protects human health and the environment. EPA further believes that restoring the Pond 6 area for
constructive use may reguire measures beyond those reguired under this ROD.
2. Several citizens expressed concern that Olin has spent more than 20 million dollars on the Site and
that EPA is going to extremes by reguiring additional remedial actions and expense.
EPA Response: EPA believes that selected remedial actions are necessary to address the risk to human health
presented by the Site. In addition, EPA believes that the remedies selected in this ROD provide an
appropriate balance among the nine criteria the Agency is reguired to consider in selecting an appropriate
remedy for a Superfund site. Cost effectiveness is among the criteria evaluated.
3. One commentor stated that money is not being spent wisely for the problems of the Site, and any
additional expenditures should be spent where it can do the most good for all citizens of the Saltville area.
On this topic, another commentor noted that "[t]his is a pure example of waste of money when our area could
use money for medical benefits, educational benefits and recreational benefits for our youth." Another
commentor noted that spending millions on the "Muck Ponds" would not help the citizens of Saltville or future
generations.
EPA Response: Under the Superfund program, EPA is responsible for protecting human health and the
environment. EPA believes that efforts being taken through this ROD to control the release of mercury at the
site will benefit future generations in Saltville by protecting human health and the environment.
4. One commentor stated that the weight of a thick cap on Pond 5 would cause problems and that a lighter
cap would be better on the soft muck. Several commentors also stated that adding top soil to Ponds 5 and 6
would help those areas.
EPA Response: As stated in the response to Comment B.3, above, EPA is reguiring that the multi-layered cap
constructed over Pond 5 comply with RCRA Subtitle C and VHWMR § 10.13.K reguirements. These reguirements
establish the performance standards that the cap must meet (e,g., the cap must be less permeable than any
bottom liner system or natural subsoils present), but do not specify details such
as the thickness of the cap or materials to be used. The details are determined during the engineering
design process. The physical behavior and characteristics of the pond waste material will need to be
considered during the design process to determine the appropriate components of the multi-layered cap. Top
soil and vegetation will be included as components of both the Pond 5 cap and the Pond 6 permeable soil
cover.
5. The Commonwealth of Virginia, Office of the Governor, expressed concern that many elements of EPA's
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preferred alternatives do not recognize the findings of the extensive Site investigation and FS undertaken by
Olin Corporation with the consent and supervision of EPA and VDEQ.
EPA Response: As discussed in the responses to Comments B.2 and C.8, above, EPA believes the alternatives
presented in the Proposed Plan were based on information developed during the RI/FS process. EPA and VDEQ
were closely involved with the oversight of the RI/FS conducted by the Company. To the extent possible, the
information used in developing the preferred alternatives, including the technologies, costs, and
implementation schedules, were derived from the RI/FS. EPA produced an independent cost estimate for the
preferred alternatives set forth in the Proposed Plan to adjust for cost of a RCRA Subtitle C compliant cap,
as called for in the preferred alternatives (i.e., covering all of Pond 5 in Alternative P5F-X and covering
the buried debris area in Alternative P6D). These cost estimates were entered into the Administrative Record
to supplement the cost information contained in the OU2 FS report. EPA has revised its preferred
alternatives set forth in the Proposed Plan and has selected final remedies for Ponds 5 and 6 in this ROD
after considering new information and concerns from the citizens of the community and other members of the
public. In essence, the public participation process has worked as intended under the NCP.
6. One commentor guestioned why the calculation of non-carcinogenic risk from the Site based on current
conditions does not consider operation of the recently in, trailed Pond 5 Treatment Facility.
EPA Response: In accordance with EPA guidance, risk is calculated based on analytical data that reflects
existing conditions. EPA agrees that the Pond 5 Treatment Facility will effectively reduce discharge of
mercury to the river, but risk is not calculated based on potential future improvements in water and sediment
guality. This approach is used because of the difficulties that exist in predicting future environmental
conditions. For example, the water and sediment guality in the river are influenced by factors other than
the effluent from the Pond 5 Treatment Facility. Factors such as sediment contamination from historical
deposition of mercury and possible mercury-contaminated seepage through the pond dikes need to be considered.
The Baseline Risk Assessment conducted for the Site found that individuals coming in direct contact with
river water and sediment do not face an unacceptable risk. Eating fish caught in the river, on the other
hand, does pose an unacceptable risk. Because mercury is very persistent in the environment, the levels
currently present in aguatic organisms are expected to remain for a long time. EPA is reguiring long-term
monitoring as part of this remedy and additional assessment of the river will be performed as part of the
Operable Unit 3 RI/FS process.
7. One commentor guestioned why the RI/FS expects residents to violate 44 times each year the fish
consumption ban issued for the river.
EPA Response: A fish consumption rate of 9,855 grams per year (i.e., the eguivalent of two meals of fish per
month) was used in the Baseline Risk Assessment. This value is approximately one-half the EPA Superfund
default value for fish consumption. EPA allowed a reduction in the consumption rate to be used in the
Baseline Risk Assessment in part because of the fish consumption ban. Compliance with fishing bans is
difficult to monitor and EPA does not believe that it is reasonable to assume that no one eats fish from the
river. EPA uses conservative assumptions for the exposure parameters since these values represent the
reasonable maximum exposure (RME) that an individual could be expected to encounter. The RME is defined as
the highest exposure that is reasonably expected to occur at a site. The intent of the RME is to estimate a
conservative exposure case (i.e., well above the average case) that is still within the range of possible
exposures. Uncertainty is evaluated under this approach.
8. One commentor recommended that EPA recalculate the hazard indices assuming that the existing fences
and clay cover on the Former Chlorine Plant Site would be maintained. The commentor contends that tax
dollars could be better spent elsewhere if the evaluation under these scenarios resulted in hazard indices of
less than one.
EPA Response: The purpose of the Baseline Risk Assessment is to evaluate the risk if no action is taken to
address the problems at a site. If no unacceptable risks exist under such a scenario, EPA would not reguire
any cleanup action. If the Baseline Risk Assessment indicates that a site can potentially pose an
unacceptable risk, alternatives are evaluated to determine the best way to prevent that unacceptable risk
from occurring. Maintenance of fences and clay covers are actions that could be considered as an
alternative for addressing site risks, however, these actions should not be assumed to occur for the purpose
of calculating the Hazard Indices in the Baseline Risk Assessment.
9. One commentor suggested the EPA provide calculations of incremental risk reduction based on projected
dollar expenditures for each alternative discussed in the Proposed Plan (e.g., calculate the decrease in the
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Hazard Index and increase in projected cost for Pond 5 if a RCRA cap versus a synthetic liner is installed).
EPA Here: EPA agrees that such calculations would be beneficial if they could be made. Unfortunately, the
environmental results of specific cleanup actions can rarely be quantified precisely enough to perform this
type of calculation. In the example cited, a RCRA multi-layered cap is designed to provide several degrees
of protection in the event any one component of the cap fails. Typically, a synthetic liner is one of the
components of a RCRA cap. If the synthetic liner is punctured or deteriorates over time,
other components of the remedy serve as a back up system to ensure cap failure does not occur. If a
synthetic liner is used alone without any additional components, the risk of cap failure increases.
The purpose of the nine criteria used by EPA to evaluate alternatives is to provide a qualitative assessment
of the tradeoffs that occur with various cleanup alternatives. To continue the above example, the RCRA cap
would be considered to provide a greater degree of long-term effectiveness and permanence than the synthetic
liner. On the other hand, the synthetic liner will be less expensive. The two threshold criteria which must
be met for an alternative to be considered as viable are (1) protection of
human health and the environment, and (2) compliance with ARARs. RCRA Subtitle C and VHWMR § 10.13.K are
ARARs for Pond 5 and, therefore, the cap to be constructed must be in compliance with RCRA Subtitle C in
order to satisfy the threshold criteria of compliance with ARARs.
10. One commentor questioned why there is a need for a cap over Pond 5 or Pond 6 since there is a ground
water recovery and treatment system.
EPA Response: The waste material in Ponds 5 and 6 has the potential to pose an unacceptable health risk to
individuals who come in direct contact with the material. The cap on Pond 5 and the permeable soil cover on
Pond 6 will address the risk exposure pathway of dermal contact. The purpose of the ground water recovery
and treatment system is to reduce the mercury concentration in ground water from Pond 5 collected at the
decant structure to an acceptable level before it is discharged to the river. The ground water
recovery and treatment system does not eliminate exposure to individuals that can occur by direct contact
with the surface of the waste material. The multi-layered cap required for Pond 5 and the soil cover
required for Pond 6 will eliminate this exposure pathway.
11. One commentor stated the there was no analysis in the published reports to model the time and expense
of treating ground water for the ponds with and without a cap.
EPA Response: As discussed in the response to Comment D.9 above, the ability to reliably predict the
specific environmental results of cleanup actions (e.g., the rate that pollutants can be removed from the
ground water) is difficult. Currently, rainwater that falls on Pond 5 moves down through the waste material
and comes in contact with the mercury contamination. As a result, the water transports the mercury through
the waste material and eventually to the decant structure where it is collected for
treatment By the Pond 5 Treatment Facility. By placing a multi-layered cap over Pond 5, rain water will no
longer move into the waste material and transport the mercury to the decant structure. Therefore, if a cap
is installed on Pond 5, the expense of treating mercury-contaminated water will be reduced. Any modeling to
predict the reduction in the level of mercury in the ground water or the decrease in treatment expense, with
or without a cap, would rely heavily on assumptions. These assumptions would include, but not be limited to,
total quantity of mercury contained in the ponds, flow rates, mercury removal rates, treatment plant
efficiency, and the overall effectiveness of capping. EPA does not believe that such an analysis would have
contributed any substantial information to the decision-making process.
12. One commentor stated overall support for the EPA preferred alternatives but questioned how EPA will
monitor the clean-up process.
EPA Response: EPA or an EPA contractor will maintain a field presence at the Site to document remedial
actions and ensure all performance standards of the selected remedies are achieved.
Section 300.430(f)(4)(ii) of the National Contingency Plan (NCP) states that:
If a remedial action is selected that results in
hazardous substances, pollutants, or contaminants
remaining at the site above levels that a]low for
unlimited use and unrestricted exposure, the lead
agency shall review such action no less often than
every five years after initiation of the selected
remedial action.
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EPA will conduct five-year reviews to evaluate whether the response action remains protective of human health
and the environment. If protectiveness is being ensured by eliminating the exposure pathways, as is the case
in Pond 5 with containment by capping, the Pond 5 Treatment Facility, and institutional controls, and in Pond
6 by the permeable soil cover and institutional controls, then the review should focus on whether the cap
remains effective, the treatment plant is operational and functional, and the
controls remain in place.
Under CERCLA, EPA may terminate statutory five-year reviews when no hazardous substances, pollutants, or
contaminants remain at the site above levels that allow for unrestricted use and unlimited exposure. Reviews
should be discontinued only if appropriate monitoring shows that contamination levels have been reduced to
allow for unrestricted use of the site. Reviews should be continued if reguirements promulgated or modified
after signature of the ROD result in a determination that the remedy is no
longer protective.
13. Several citizens supported EPA's preferred alternatives, but stated that taxpayers' dollars should
not be used to pay for the cleanup.
EPA Response: If the potentially responsible party does not agree to implement the remedy selected in this
ROD, EPA will use Superfund money to pay for the cleanup. Superfund money comes mainly from taxes on the
chemical and petroleum industries, not from general taxpayers' dollars
14. Several citizens, while supporting the EPA preferred alternatives, voiced concern about the health of
the children of Saltville and the future generations impacted by the Site and other contamination in the
Saltville area.
EPA Response: EPA believes the containment remedies selected for Ponds 5 and 6 will be protective of
children since the risk exposure pathways are eliminated. Also, as stated in the response to Comment D.12,
above, if hazardous substances, pollutants, or contaminants remain at the Site above levels that allow for
unlimited use and unrestricted exposure, EPA is reguired to conduct site-wide five-year reviews to verify
that the implemented remedies are effective and will remain effective in providing protection
for future generations.
When contamination has been identified outside the limits of the Superfund National Priorities List ("NPL")
Site at Saltville, EPA has conducted investigations and removal actions, when necessary, to address the
problem. Removal actions have been and/or are being conducted at the power plant site, graveyard dump site,
and new bridge area. EPA will continue to conduct these removal actions whenever
appropriate in addition to the remedial cleanup process at the Superfund NPL Site.
15. One commentor guestioned whether the mercury contamination in the North Fork of the Holston River
could affect their livestock and poultry that drink from the river downstream from the Site, or family
members who drank water from a well located approximately 150 feet from the river.
EPA Response: EPA has no data to indicate that mercury contamination has impacted ground water (i.e., the
water that would be found in a well) downstream from the Site. The data from the Remedial Investigation
("RI") indicates that the shallow ground water is contaminated in isolated areas with-elevated mercury levels
greater than the Maximum Contaminant Level ("MCL") of 2 ug/1. The majority of the ground water monitoring
results indicate low level (at or slightly exceeding the MCL) to non-detectable mercury
concentrations at the Pond 5 and Pond 6 areas of the Site. An MCL is defined as the maximum permissible level
of a contaminant in water which is delivered to any user of a public water system.
The data does not suggest that the contaminated shallow ground water would flow parallel to the river for any
significant distance, resulting in migration outside the Site area in a direction to the west and east of the
Site boundary. Rather, the data indicates that shallow ground water flows and discharges to the North Fork
of the Holston River, generally to the south. Conseguently, wells located outside the Site area, and not
immediately adjacent to the Site are unlikely to be impacted with mercury contamination.
In order to properly evaluate whether the commentor's residential well could be impacted with mercury from
the Site, information regarding the well location and construction is needed. If anyone has continued
concern about the guality of water in a well used for drinking water, EPA recommends that the local Board of
Health be contacted.
A detailed investigation of the North Folk of the Holston River, including sampling of the surface water,
sediment, and biota, is being conducted as part of Operable Unit Three ("OU3") of the Site. Since that study
has not yet been completed, EPA has not yet reached any conclusions regarding the guality of the surface
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water or sediment in the river downstream from the Site. It should be noted that there currently is a ban
against the consumption of fish from the river. EPA will make the findings of the RI/FS for
OU3 available to the community when it is completed in approximately one year.
16. One citizen stated that EPA's preferred alternatives are a good start, but voiced concern that there
is contamination in places other than Ponds 5 and 6.
EPA Response: Evidence or knowledge of contamination outside the limits of the Superfund NPL Site should be
brought to the attention of the EPA Region III Office of Superfund or the Virginia Department of
Environmental Quality, for an investigation. EPA's Superfund emergency response program has been
investigating several areas in Saltville where hazardous substances allegedly have been disposed and will
continue to do so if information becomes available.
17. One citizen asked how long it will take to flush out the contaminants from the Site.
EPA Response: As discussed in the responses to Comments D.9 and D.ll, the ability to reliably predict the
environmental results of cleanup actions is limited. With respect to Ponds 5 and 6, significant movement of
mercury has only been detected at Pond 5. The purpose of the cleanup actions for Pond 5 is to contain the
mercury in place, not "flush" the mercury out of the waste material. By effectively containing the waste
material, the migration pathways for the mercury and the risk exposure pathways (e.g., dermal contact,
ingestion, etc.) by which the contamination can spread and pose risk are reduced or eliminated. An
interceptor system is also proposed as part of the containment system for Pond 5 to collect and divert
shallow ground water flow away from the pond. Long-term monitoring is reguired at both Pond 5 and Pond 6 to
ensure mercury is not released to the river in the future.
18. One commentor asked what the schedule of events will be for the cleanup of the Site.
EPA Response: After issuance of this ROD, the potentially responsible party will be given the opportunity to
negotiate a judicial consent decree with EPA and the United States Department of Justice to implement the
remedy. This process normally reguires six to nine months. The next phase of the project is remedial
design, which is estimated to take 18 to 24 months to complete. Following EPA approval of the design,
on-site construction will begin. EPA estimates that construction will reguire 4 to 7 years to complete.
19. One commentor asked how EPA determines the feasibility of long-term extracting and treating the
ground water if the aguifer cannot be remediated.
EPA Response: In general, extraction and treatment technology can effectively remove hazardous constituents
from ground water to acceptable levels. The problem with this technology is that, in many cases, the system
will operate indefinitely because a continuing source of contamination exists. In these situations, this
technology can stop the spread of ground water contamination, but cannot eliminate the source of the
contamination itself. The length of time that a system needs to operate cannot be predicted with any degree
of accuracy. A decision to stop operating the system could only be supported by monitoringdata. Typically,
an extraction and treatment system would be combined with other remedial technologies that attempt to treat
or contain the source of the contamination, such as capping or interceptor trenches.
20. One commentor asked if age dating of ground water would be. used to determine the source of the
contamination.
EPA Response: EPA does not believe that age dating is necessary to identify the source of the ground water
contamination. The RI has identified the sources of mercury contamination in the ground water beneath the
ponds as the waste materials contained in the ponds. Mercury in the ponds originated in the electrolytic
process that occurred at the former chlorine plant. Mercury cells were used as the cathode at the chlorine
plant and some mercury was lost in the process. The mercury was passed to Pond 5 in the
wastewater. Mercury has also been found in the waste at Pond 6, however, mercury is generally not detected
in the discharge at the Pond 6 decant structure outfall. Olin believes that wastewater containing mercury
may have been discharged into Pond 6 late in the operation of the chlorine plant. Olin believes that all of
the wastewater containing mercury went to Pond 5 until at least 1969. Olin also
believes that it is possible that weak brine pure discharge waters from the chlorine plant may have been used
to help slurry the ammonia soda ash waste the long distance from the Solvay process plant (a process
independent of the chlorine process) to Pond 6. EPA believes the current data sufficiently characterizes the
source and does not believe that age dating would provide significant additional information.
Measuring naturally occurring or introduced elements which can be radioactive (such as tritium and Carbon 14)
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can help determine the ground water recharge areas, ground water flow patterns and the age of ground water.
Ground water age dating is not routinely performed at EPA Superfund site investigations since it would only
provide interpretive information on ground water flow patterns. Ground water flow patterns are routinely
evaluated during EPA studies through use of data from regional geologic publications and the installation and
testing of monitoring wells. EPA's approach in identifying the Source of contamination at a site is
basically to collect all historical data and direct soil, sediment and ground water sampling and chemical
analysis to identify the source and its extent.
21. One commentor asked what compounds other than mercury were found in the aguifer.
EPA Response: Mercury is the primary contaminant of concern. Arsenic at slightly elevated levels was
detected at the Former Chlorine Plant Site, but EPA believes this may be naturally occurring. Further
sampling will be conducted to confirm the natural occurrence of arsenic. Section 5.2 in Part II of the ROD
(Nature and Extent of Contamination in Ponds 5 and 6) discusses the contaminants detected during
the RI.
22. One commentor asked what alternative would be proposed if ground water is contaminated at the Site.
EPA Response: The ground water at the Site is contaminated. The ground water characteristics are described
in the RI/FS and summarized in Section 5.2 in Part II of the ROD. EPA's selected remedy for Pond 5 reguires
that contaminated ground water be collected in the Pond 5 decant structure and pumped
to the existing Pond 5 Treatment Facility. This extraction and treatment system will reduce the
concentrations of mercury in the Pond 5 ground water to acceptable levels prior to discharge to the river.
The mercury concentration in the ground water at the Pond 6 decant structure is typically non-detectable,
therefore, such ground water does not reguire treatment for removal of mercury. Long-term monitoring is
reguired as part of the remedy to ensure that direct discharges to the river remain non-detectable.
23. One commentor asked how long it would take for the mercury to reach the fractures in the bedrock
surface.
EPA Response: Mercury contamination in Ponds 5 and 6 is not expected to migrate to fractures in the bedrock
surface. The bottom layer of Ponds 5 and 6 has been described as cemented alluvium which is a very tight
geologic layer. The pathway for mercury migration at the ponds is toward the decant structures. Mercury has
not been detected in any significant levels in bedrock wells at Pond 5 or Pond 6.
24. One commentor asked if the mercury has already migrated to the aguifer, and if so, whether it will
remain there indefinitely as a deep contaminating source indefinitely.
EPA Response: Based on the monitoring well results, the shallow aguifer is contaminated with mercury at
elevated levels in isolated areas where waste is in direct contact with the ground water. At Ponds 5 and 6,
the deeper bedrock aguifer monitoring well results also detected contamination with mercury but at very low
levels. The low concentrations of mercury detected in the bedrock aguifer do not support the potential of
its occurrence as a source in the bedrock aguifer beneath the Pond 5 and Pond 6 areas of the Site. This may
be due in part to the occurrence of the cemented alluvium directly beneath the majority of both Pond 5 and
Pond 6, which would serve to prevent migration of mercury vertically to the bedrock aguifer. The water
elevation data further suggest that the preferential shallow ground water flow path is in a lateral direction
toward the decant structures. Long-term ground water monitoring is included in the selected remedies in
order to provide EPA with data to ensure that the remedies chosen for Ponds 5 and 6
continue to be protective of human health and the environment. It is also important to note that further
information will be gathered in the Former Chlorine Plant Site area of the Site to evaluate the extent of
mercury contamination in the aguifer from sources at the Former Chlorine Plant Site.
25. One commentor asked if flow rates are available for ground water at the Site.
EPA Response: Aguifer tests such as packer testing and slug testing were performed at monitoring wells and
borings in order to estimate the hydraulic conductivity of the alluvium, waste, and bedrock across the Site.
The estimated geometric mean hydraulic conductivity values from each method for the bedrock aguifer and
alluvium/fill are in the RI. The gradient of the water table and potentiometric surface of the bedrock
aguifer was estimated in the RI as well as from several rounds of water elevation data. These
data were used to estimate the average linear velocity of ground water flow in the bedrock aguifer and in the
alluvium/fill. The average linear velocity during a high water elevation was estimated to range from 0.33
ft/day up to 3.2 ft/day for effective porosities of 1 percent, and 0.033 ft/day up to 0.32 ft/day for
effective porosities of 10 percent. Calculations were also performed from data collected during low water
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elevation period with the average linear velocity estimated range from 0.23 ft/day up to 3.5 ft/day assuming
an effective porosity of 1 percent, and from 0.023 ft/day up to 0.35 ft/day assuming an effective
porosity of 10 percent. For a more detailed explanation of how the average linear velocity estimates were
derived, Section 5 of the OU2 RI report provides a more detailed explanation of the hydrogeologic properties.
This report is available for your review in the information repository at the Smyth-Bland Regional Library,
Saltville Branch.
26. One commentor asked what will happen if the Site cannot be fully remediated and whether we would
accept that all sites cannot be remediated.
EPA Response: EPA believes the Saltville site can be effectively remediated. Due to the volume of waste,
the low concentrations of mercury, and the physical characteristics (i.e., the dikes and decant structures)
of the ponds, EPA believes that containment is an appropriate remedy for Ponds 5 and 6. Although containment
leaves the waste in place, the goal of containment is to eliminate the pathways by
which the contamination could spread and eliminate the exposure pathways. EPA believes that the selected
remedies for Pond 5 and Pond 6 will be protective and remediate these areas of the Site.
27. The U.S. Department of the Interior stated that an ecological risk assessment has not been conducted
for OU2, but is needed to determine whether implementation of the OU2 remedial alternatives will effectively
eliminate ecological risk to terrestrial receptors at the Site. The U.S. Department of the Interior also
stated that an ecological risk assessment is needed to determine whether implementation of any of the OU2
remedial alternatives would effectively and permanently eliminate future releases of
mercury and associated ecological risk to aguatic receptors in the river.
EPA Response: A comprehensive ecological risk assessment for the entire Site is being conducted as part of
the Operable Unit 3 RI/FS for the Site. EPA believes the remedy selected in this ROD is protective of
terrestrial receptors at the Site. Both ponds will be covered to prevent wildlife from coming in direct
contact with the waste material. In addition, discharge of mercury to the river will be reduced to levels
that are consistent with the Virginia surface water standards for the protection of aguatic life. EPA
recognizes that the presence of mercury contamination in the river from historical activities at the Site
still results in an adverse impact on the river ecosystem. This impact, however, will be the focus of the
comprehensive ecological risk assessment to be performed as part of Operable Unit 3.
28. The U.S. Department of the Interior asked why EPA has not consulted with the Fish and Wildlife
Service with respect to the application of the Endangered Species Act to remedial action at the Site.
EPA Response: EPA has consulted with the Fish and Wildlife Service throughout the RI/FS process for this
Site on an informal basis. EPA will conduct the formal consultation reguired under the Endangered Species
Act during the remedial design phase of the project.
29. The U.S. Department of the Interior asked how the preferred alternatives for Ponds 5 and 6 would
provide long-term isolation of source materials and risk reduction.
EPA Response: For Pond 5, the primary pathway for release of mercury into the river is ground water
migration via the Pond 5 decant structure. All flow through the Pond 5 decant structure is now transferred
to the Pond 5 Treatment Facility; therefore, the direct pathway for mercury migration to the river is
eliminated and risk reduction is achieved. The mercury concentration at the Pond 6 decant
structure is typically non-detectable, therefore, risk reduction is not necessary. Long-term monitoring is
reguired as part of the remedy to ensure that direct discharges to the river remain non-detectable and in
compliance with the remedy. Risk from contact with the mercury-contaminated waste materials in the ponds is
reduced by construction of a RCRA multi-layered cap on Pond 5 and a permeable soil cover on
Pond 6.
EPA believes that long-term isolation will be achieved by the selected remedies and will be ensured by the
reguired long-term monitoring. Moreover, the statutory five-year review process will supplement the
long-term monitoring to ensure the selected remedies are effective.
30. The U.S. Department of the Interior stated that if removing the mercury from Pond 5 and Pond 6 is not
feasible, additional information should be provided in the ROD analyzing how the cap and Treatment Facility
for Pond 5 and permeable soil cover for Pond 6 are expected to perform long-term under the unstable condition
of the pond material, erosion, and flooding. The U.S. Department of the Interior
further notes that contingencies should be included in the selected remedies to protect the environment and
trust resources from structural or treatment failures of the selected remedies.
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EPA Response: The performance of the components of the selected remedies relative to physical site
characteristics, while maintaining compliance with ARARs, are technical/engineering matters that will be
addressed in the remedial design phase of the project. As stated in the response to Comment D.29, above,
long-term monitoring and statutory five-year reviews will supplement the selected remedies to ensure
long-term effectiveness. Contingencies with respect to potential failure of specific aspects of the selected
remedies will also be addressed during remedial design.
Potential structural failure of the existing Pond 5 dike is discussed in Section 3 of the OU2 RI report. The
Pond 5 dike stability analysis in that section concludes that the dike is stable against large scale slope
failure under current drained pond conditions. The analyses also indicated that the dike would be stable
under flooded conditions and maximum credible earthguake loading.
With regard to potential failure of the Pond 5 Treatment Facility, EPA believes there is sufficient storage
capacity with the existing 2 million gallon egualization pond and the capacity of Pond 5 itself to minimize
the potential of untreated water being released to the North Fork of the Holston River.
31. The U.S. Department of the Interior stated that a combination of Alternatives P5F-X (the selected
remedy) and P5J-1 would offer the highest degree of ecological protection, given the alternatives in the
Proposed Plan.
EPA Response: EPA believes that the highest degree of ecological protection would be offered by the complete
removal of all waste material from Pond 5 and Pond 6; however, this is not technically feasible due to the
extremely large volume of material.
EPA further believes that implementation Alternatives P5F-X and P5J-1 is not cost-effective and does
not provide a sufficient degree of additional risk reduction to warrant Supplementing Alternative P5F-X (the
selected remedy) with the in-situ treatment technology described in Alternative P5J-1.
EPA maintains that the selected remedy for Pond 5, Alternative P5F-X, is protective of human health and the
environment, complies with ARARs, and is the most appropriate remedy for Pond 5 when evaluated with respect
to the nine selection criteria listed in the NCP.
32. The U.S. Department of the Interior stated that, with respect to the preferred alternative for Pond
6, the Proposed Plan does not explain what the unacceptable levels are for triggering the contingent remedial
action for Pond 6 (a RCRA Subtitle C compliant cap over the entire Pond 6 area, instead of over just the
buried debris area, and surface water management).
EPA Response: Although the preferred alternative for Pond 6 set forth in the Proposed Plan includes the
contingent remedial action described in the comment, EPA revised the preferred alternative, including the
contingent remedial action, in selecting the remedy for Pond 6 in this ROD. The contingent remedial action
with respect to the selected remedy for Pond 6 in the ROD is isolation of the Former Chlorine Plant Site
debris buried in the eastern end of Pond 6. As stated in Section 9.2.3(2) in Part II of the ROD:
Ground water modeling shall be conducted to estimate the concentration of mercury in a trigger well that
could result in a discharge from the Pond 6 decant structure exceeding the Virginia surface water standard
for mercury. Conservative assumptions shall be used in the model because of the uncertainties inherent in
such calculations. EPA shall determine, based on this ground water modeling and any other information deemed
appropriate, the mercury concentration (i.e., action level) which, if exceeded in any of the newly installed
ground water monitoring wells and in a subseguent confirmatory sample, shall trigger implementation of the
contingency actions to isolate the debris buried in Pond 6.
33. The U.S. Department of the Interior stated a preference for excavation and removal of the former
chlorine plant debris buried in the eastern end of Pond 6, as opposed to isolation of the debris area which
was included in the preferred alternative for Pond 6 in the Proposed Plan.
EPA Response: The currently available data is inconclusive regarding migration of mercury from the buried
debris area of Pond 6. The selected remedy for Pond 6 includes isolation of the former chlorine plant debris
buried in the eastern end of Pond 6 (using vertical barrier walls and a cap over the debris area that
complies with the performance standards of RCRA Subtitle C and VHWMR §f 10.13.K) as a contingent remedial
action for Pond 6. The contingent remedial action will be triggered if ground water monitoring
indicates that mercury from the buried debris area is migrating to the river at unacceptable levels as
discussed in Section 9.2.3 in Part II of the ROD. New wells will be installed in appropriate locations on
Pond 6 to provide early detection of mercury migration from the buried debris area.
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Since the data is inconclusive regarding the migration of mercury from the buried debris area, EPA believes
that removal is not warranted and risk reduction is sufficiently addressed by dedicated monitoring of the
buried debris area and the contingent remedial action.
34. The U.S. Department of the Interior stated that ground water monitoring wells should be installed to
detect the movement of contaminants in the water leaving Ponds 5 and 6.
EPA Response: The selected remedies for Pond 5 and 6 do include ground water monitoring to detect the
migration of mercury in Ponds 5 and 6. As stated in Section 9.3.1 in Part II of the ROD:
A long-term ground water monitoring program shall be
implemented to evaluate subsurface flow conditions and
water guality in the Pond 5 and Pond 6 areas,
specifically the seepage of contaminated ground water
migrating through the dikes to the river. The number
of new wells, the exact location of new wells, and the
associated screen depth of the new wells shall be
approved by EPA during the remedial design.
Supplemental sampling of existing onsite wells may be
incorporated into the long-term monitoring program.
Samples shall be collected and analyzed for mercury on
a guarterly basis for a period of 30 years. The Pond 6
decant structure outfall shall be sampled and analyzed
for mercury and pH guarterly for a period of 30 years.
35. The U.S. Department of the Interior guestioned why measures to divert surface water runoff away from
Pond 6 were not implemented for Pond 6 as they were for Pond 5.
EPA Response: At this point it is not deemed necessary to divert surface water runoff from entering Pond 6.
Although the presence of mercury in Pond 6 has been established, there have not been significant
concentrations of mercury measured at the Pond 6 decant structure outfall. The concentration of mercury in
the Pond 6 outfall is usually non-detectable. Long-term monitoring of the Pond 6 decant structure outfall
and dike areas will detect whether this changes in the future. Pond 6 ground water is believed to
be an isolated flow system. Unlike Pond 5, fracture flow of ground water from Little Mountain does not
appear to contribute to the Pond 6 hydrogeological system.
36. The U.S. Department of the Interior stated that the ROD should explain how the river environment will
be monitored and what action will be taken to prevent or mitigate any adverse impacts to the river during
implementation of the OU2 remedy. The U.S. Department of the Interior further recommends that sediment and
surface water from the river be analyzed for mercury, supplemented by toxicity testing using
sediment and surface water.
EPA Response: A determination of any adverse impacts to the river that will result from implementing the OU2
remedies will be made during remedial design. If it is determined that adverse impacts to the river will, in
fact, occur as a result of implementing the OU2 remedies, then the action which must be taken to prevent or
mitigate such impacts will also be determined during remedial design. General concerns regarding any
erosion, storm water runoff, and fugitive dust that may result from implementation of the OU2 remedial
actions will be addressed during the remedial design.
Surface water and sediment sampling of the North Fork of the Holston River has been conducted by Olin on a
guarterly basis in the past and will continue. Fish collection has been conducted by Olin on an annual basis
and will continue. An RI/FS for Operable Unit 3, including an ecological risk assessment, studying the
impact of contamination on the river, is ongoing and anticipated to be completed in the summer of 1996.
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SALTVILLE WASTE DISPOSAL AREAS OU2
ADMINISTRATIVE RECORD FILE *
INDEX OF DOCUMENTS
I. SITE IDENTIFICATION
1. Report: Investigation of Mercury Occurrence, Former
Chlorine Plant Site. Saltville, Virginia, prepared by
HARZA Engineering Company, 10/76. P. 100001-100075. A
transmittal letter to Mr. A.A. Stein, Olin Corporation,
from Mr. D.E. Kleiner, HARZA Engineering Company, dated
November 22, 1976, is attached.
++ 2. Report: Geohydrologic Study, Former Chlor-Alkai Plant
Site, Saltville. Virginia, prepared by Olin
Corporation, 9/82. P. 100461-100503. A transmittal
letter is attached.
++ 3. Report: 1984 Supplement to Geohydrologic Study, Former
Chlor-Alkai Plant Site, Saltville, Virginia, September
1982, 1984. P. 300001-300016.
* Administrative Record File available 12/12/90 updated 1/18/95
and 11/24/95.
++ These documents can be found in the Administrative Record File
for Saltville Waste Disposal Area OU1.
II. REMEDIAL ENFORCEMENT PLANNING
1. Consent Decree between the United States of America and
Olin Corporation, 9/15/88. P. 200001-209050.
2. Letter to U.S. EPA Region III, from Mr. Robert L.
Ceilings, Morgan, Lewis & Bockius, re: Notification by
the Olin Corporation of a dispute and invocation of
dispute resolution concerning the Proposed Remedial
Action Plan and the Feasibility Study, 1/27/95. P.
3. Letter to Ms. Gwen E. Pospisil, U.S. EPA from Mr.
Robert L. Ceilings, Morgan, Lewis & Bockius, re:
Reguest for a 60 day extension of the public comment
period concerning the Proposed Plan, 2/2/95. P.
4. Letter to Mr. Robert L. Ceilings, Morgan Lewis &
Bockius, from Mr. Russell Fish, U.S. EPA re:
Notification that EPA will extend the deadline for the
public comment period concerning the Proposed Plan by
31 days to March 20, 1995, 2/10/95. P.
5. Letter to Mr. Robert L. Ceilings, Morgan Lewis &
Bockius, from Ms. Gwen E. Pospisil, U.S. EPA, re:
EPA's acceptance of Olin Corporation's reguest to defer
dispute resolution until the end of the public comment
period for the Proposed Plan, 2/13/95. P.
6. Letter to Mr. Keith D. Roberts, Olin Chemicals, from
Mr. Russell H. Fish, U.S. EPA, re: Transmittal of a
copy of the meeting summary report from the February
21, 1995, meeting between EPA and Olin Chemicals,
3/1/95. P. The meeting summary dated February 24,
1995, is attached.
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7. Memorandum to file from Ms. Jan Nation and Ms. Gwen E.
Pospisil, U.S. EPA, re: Summary of a meeting on March
2, 1995, between Olin Corporation and U.S. EPA,
concerning technical issues related to the Proposed
Plan, 9/25/95. P.
8. Letter to Mr. Robert L. Ceilings, Morgan Lewis &
Bockius, from Ms. Gwen E. Pospisil, U.S. EPA, re:
Proposal to defer the dispute resolution process, 3/23/95. P.
9. Letter to Ms. Gwen E. Pospisil, U.S. EPA, from Mr.
Robert L. Ceilings, Morgan, Lewis & Bockius, re: Olin
Corporation's proposal for deferral of the dispute
resolution process, 4/4/95. P.
10. Letter to Mr. Robert L. Ceilings, Morgan, Lewis &
Bockius, from Ms. Gwen E. Pospisil, U.S. EPA, re:
Notification that EPA will not agree to certain
conditions proposed in Mr. Ceilings' letter of April 4,
1995, concerning deferral of dispute resolution, (see
entry 9, Section II), 4/10/95. P.
11. Notes from a meeting between U.S. EPA and Counsel for
Olin Corporation, re: The Proposed Plan and a proposal
to defer the dispute resolution process, 4/17/95. P.
12. Letter to Ms. Gwen E. Pospisil, U.S. EPA, from Mr.
Robert L. Ceilings, Morgan, Lewis & Bockius, re:
Confirmation of a verbal agreement between Olin
Corporation and EPA to defer the dispute resolution
process, 5/30/95. P.
13. Letter to Mr. Robert L. Ceilings, Morgan, Lewis &
Bockius, from Ms. Gwen E. Pospisil, U.S. EPA, re:
Transmittal of the signed letter agreement to postpone
the dispute resolution, 5/31/95. P. The signed letter
agreement dated May 30, 1995, is attached.
14. Letter to Ms. Gwen Pospisil, U.S. EPA, from Ms. Sara
Alyea Anderson, Morgan, Lewis & Bockius, re: Summary
of a telephone conference call concerning the status of
the selection of a remedy for the site and the
possibility of a meeting to further clarify these
issues, 8/28/95. P.
15. Letter to Mr. Keith D. Roberts, Olin Chemicals, from
Mr. Russell H. Fish, U.S. EPA, re: Transmittal of the
summary report for the August 25, 1995, conference call
between EPA and Olin, 9/25/95. P. The summary report
dated September 22, 1995, is attached.
III. REMEDIAL RESPONSE PLANNING
* 1. Report: Saltville RI/FS Final Work Plan, prepared by
CH2M-H111, 3/89. P. 300001-3000052.
2. Report: Work Plan, Remedial Investigation/ Feasibility
Study. Operable Unit #2. Groundwater and Source Area
Studies, Saltville Waste Disposal Site, Saltville,
Virginia, prepared by Olin Chemicals Group, 6/89. P.
300053-300430.
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3. Letter to Mr. Verrill Norwood, Olin Chemicals, from Mr.
Paul Leonard and Ms. Lesley Brunker, U.S. EPA, re:
Approval of RI/FS, 9/22/89. P. 300431-300431.
4. Report: Saltville Subcontract Documents for Laboratory
Services, prepared by CH2M-Hill Southeast Inc.,
10/17/89. P. 300432-800557.
5. Letter to Mr. Verrill Norwood, Olin Chemicals, from Mr.
Paul Leonard, U.S. EPA, re: Issuance of conditional
approval of Operable Unit #2 and #3 Sampling and
Analytic Plan, 1/18/90. P. 300888-300624. The plan
for OU2 is attached.
6. Report: Alternative Remedial Contracting Strategy;
Program Sampling and Analysis Plan, Saltville RI/FS
Oversight, prepared by CH2M-H111, 4/90. P. 300625-300826.
7. Memorandum to Mr. Steve Druschel, CH2M-H111, from Mr.
Russell Fish, U.S. EPA, re: Continued concerns
involving the groundwater flux calculations for the
Former Chlorine Plant Site, 3/31/94. P. 300827-300827.
8. Memorandum to Mr. Brian Marshall, CH2M-H111, from Mr.
Russell Fish, U.S. EPA, re: Follow up on technical
issues concerning mercury loading to the North Fork of
the Holston River from the Former Chlorine Plant Site,
6/9/94. P. 300828-300828.
9. Memorandum to Mr. Russell Fish, U.S. EPA, from Mr.
Brian Marshall, CH2M-H111, re: Review of the cost
estimate and assumptions for the retort treatment of
mercury-laden material at the Former Chlorine Plant
Site, 9/23/94. P. 300829-300835.
Table 4-1, Micro Workplan Spreadsheet, of this report has been
placed in the Confidential Business Information section of the
file located at EPA Region III Headguarters, Philadelphia, PA.
10. Memorandum to Mr. Russell Fish, U.S. EPA, from Mr.
Brian Marshall, CH2M-H111, re: Evaluation and cost
comparison of the proposed cap alternatives for Ponds 5
and 6, 10/24/94. P. 300836-300839.
11. Memorandum to Mr. Russell Fish, U.S. EPA, from Mr.
Brian Marshall, CH2M-H111, re: Evaluation and cost
comparison of the proposed multilayer cap in
Alternative P6D and a RCRA cap, 10/28/94. P. 300840-300842.
12. Report: Human Health Risk Assessment, prepared by ABB
Environmental Services, Inc., 11/94. P. 300843-301265.
13. Memorandum to Risk-Based Concentration Table mailing
list from Mr. Roy L. Smith, U.S. EPA, re: Fourth
guarter Risk-Based Concentration Table, 11/8/94.
P. 301266-301286.
14. Report: Remedial Investigation Report Executive
Summary, Volume I, prepared by Golder Associates,
12/94. P. 301287-301371.
15. Report: Remedial Investigation Report, Volume 2,
prepared by Golder Associates, 12/94. P. 301372-301680.
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16. Report: Remedial Investigation Report, Volume 3,
prepared by Golder Associates, 12/94. P. 301681-302178.
17. Report: Remedial Investigation Report, Volume 4,
prepared by Golder Associates, 12/94. P. 302179-302656.
18. Report: Remedial Investigation Report, Volume 5,
prepared by Golder Associates, 12/94. P. 302657-303214.
19. Report: Remedial Investigation Report, Volume 6,
prepared by Golder Associates, 12/94. P. 303215-304020.
20. Memorandum to Mr. Russell Fish, U.S. EPA, from Mr.
Brian Marshall, CH2M-H111, re: Transmittal of two
documents pertaining to estimates of mercury loading to
the North Fork of the Holston River (NFHR) from the
Former Chlorine Plant Site (FCPS), 1/4/95. P. 304021-
304058. A response package entitled Mercury Loading to
the NFHR at the FCPS dated April 11, 1994, and a
memorandum regarding recalculation of the mass loading
of mercury to the NFHR dated July 5, 1994 are attached.
21. Report: Feasibility Study, Volume 1, prepared by Olin
Corporation, 1/95. P. 304059-304515A.
22. Report: Feasibility Study, Volume 2, prepared by Olin
Corporation, 1/95. P. 304516-304933.
23. Proposed Remedial Action Plan, Saltville Waste Disposal
Ponds, 1/95. P. 304934-304964.
24. Report: Geographic Distribution of Mercury in Asiatic
Clams, Corbicula Fluminea. From the North Fork Holston
River. Virainia, prepared by U.S. Fish and Wildlife
Service, 1/93. P.
25. Letter to Mr. Russell H. Fish, U.S. EPA, from Mr.
Jeffrey T. Howard, Virginia Department of Environmental
Quality (VDEQ), re: Comments concerning the risk
assessment for Operable Unit 3 (OU3) and Operable Unit
4 (OU4) at the site, 5/5/93. P.
26. Letter to Mr. Keith D. Roberts, Olin Chenicals, from
Mr. Russell H. Fish, U.S. EPA, re: Transmittal of the
Saltville Site Review and Update, prepared by the
Agency for Toxic substances and Disease Registry
(ATSDR), 5/17/93. P. The Site Review and Update,
dated September 9, 1992, is attached.
27. Letter to Mr. Russell H. Fish, U.S. EPA, from Mr. Keith
D.2 Roberts, Olin Chemicals, re: Comments concerning
the ATSDR Site Review and Update, 6/21/93. P. A list
of Olin's comments and a memorandum, dated June 17,
1993, providing the comments of ABB Environmental
Services, Inc. concerning the ATSDR Site Review and
Update are attached.
28. Letter to Mr. Jeffrey T. Howard, VDEQ, from Mr. Russell
H. Fish, U.S. EPA, re: Reguest for comments concerning
the draft Feasibility Study for Operable Unit 2 (OU2)
and identification of State applicable or relevant and
appropriate reguirements (ARARs), 6/22/93. P.
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29. Letter to Mr. Russell H. Fish, from Mr. Paul Spaulding,
VDEQ, re: VDEQ's intention to respond to EPA's request
for potential ARARs during the ongoing review of the
OU2 Feasibility Study, 7/20/93. P.
30. Letter to Mr. Russell H. Fish, U.S. EPA, from Mr.
Jeffrey T. Howard, VDEQ, re: Comments concerning the
revised Remedial Investigation Report for OU2, 7/28/93.
P. A list of VDEQ's comments is attached
31. Letter to Mr. Russell H. Fish, U.S. EPA, from Mr. Don
Henne, U.S. Department of the Interior (DOI), re: A
status report on the preparation of the EPA-requested
Preliminary Natural Resources Survey (PNRS) for the
site, 10/29/93. P.
32. Letter to Mr. Thomas C. Voltaggio, U.S. EPA, from Mr.
Jonathan P. Deason, U.S. DOI, re: Preparation of a
PNRS, 11/10/93. P. A report entitled Technical
Analysis of the Saltville Waste Disposal Site, prepared
by U.S. DOI, is attached.
Letter to Mr. Russell H. Fish, U.S. EPA, from Mr.
Jeffrey T. Howard, VDEQ, re: Comments concerning the
draft Feasibility Study for OU2, 3/22/94. A list of
VDEQ's comments is attached.
34. Facsimile transmittal to Mr. Russell H. Fish, U.S. EPA,
from Mr. Paul Spaulding, VDEQ, re: Notification of
Potential Virginia ARARs for OU2 of the Saltville Site,
11/14/94. P.
35. Letter to Mr. Thomas C. Voltaggio, U.S. EPA, from Mr.
Don Henne, U.S. DOI, re: Comments on the draft
Proposed Remedial Action Plan, 11/25/94. P.
36. Letter to Mr. Keith D. Roberts, Olin Chemicals, from
Mr. Russell H. Fish, U.S. EPA, re: Notification of
EPA's approval of the Feasibility Study, 3/23/95. P.
37. Record of Decision, Saltville Waste Disposal Ponds
Superfund Site, Operable Unit 2 (Pond 5 and Pond 6),
9/29/95. P.
COMMUNITY INVOLVEMENT/CONGRESSIONAL CORRESPONDENCE/IMAGERY
1. U.S. EPA Fact Sheet, re: Site status, Saltville Waste
Disposal Superfund Site, Smyth County, Virginia, 7/93. P.
2. Report: Community Relations Plan for the Saltville
Waste Disposal Superfund Site, prepared by Dynamac
Corporation, 1/10/94. P.
3. U.S. EPA Community Update, re: Site status, Saltville
Waste Disposal Ponds Superfund Site, Smyth County,
Virginia, 7/94. P.
4. Press Release from U.S. EPA Environmental News entitled
"U.S. EPA and VDEQ Representatives Available to Answer
Citizen Questions or Concerns About Saltville, Virginia
Waste Disposal Superfund Site," 7/19/94. P.
5. U.S. EPA Public Notice, Saltville Waste Disposal Site,
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re: EPA seeks public comments on the Proposed Remedial
Action Plan and announces public meeting Saltville
News-Messenger, 1/4/95. P.
6. Press Release from U.S. EPA Environmental News entitled
"EPA Schedules Public Hearing for Saltville Superfund
Cleanup," 1/18/95. P.
7. Newspaper article entitled "$57 Million Cost for
Saltville Site," Roanoke Time and World News, 1/21/95. P.
8. Olin Chlor-Alkali Products Memorandum to Concerned
Citizens of Saltville and Surrounding Communities, re:
Comments concerning EPA's proposed plan for OU2 of the
Saltville Waste Disposal Site, 1/27/95. P.
9. Letter to Mr. Russell Fish, U.S. SPA, from Ms. Nila
Webb, re: Comments on EPA's proposal to continue
remediation activities at the Former Chlorine Plant
Site, 1/31/95. P.
10. U.S. EPA Community Update, re: Site status, Saltville
Waste Disposal Site, 2/95. P.
11. U.S. EPA Flyer, Saltville Waste Disposal/Site, re:
Notice of public meeting on February 1, 1995, on the
Proposed Plan for OU2 cleanup. P.
12. Transcript of U.S. SPA OU2 proposed plan Public
meeting, Saltville Waste Disposal Site, 2/1/95. P.
13. Letter to Mr. Russell Fish, U.S. EPA, from Mr. Charles
C. Norris, re: Comments on the Proposed Plan for OU2,
2/1/95. P.
14. Letter to Mr. Russell Fish, U.S. EPA, from Mr. Edward
T. Asbury, re: Comments on EPA's Proposed Plan,
2/1/95. P.
15. Letter to Mr. Russell Fish, U.S. EPA, from Mr. Carl
Slate, re: Comments on EPA's Proposed Plan, 2/2/95. P.
16. Letter to Mr. Russell Fish, U.S. EPA, from Mr. C.W.
Barbrow, Jr., re: Comments on EPA's Proposed Plan,
2/2/95. P.
17. Letter to Mr. Russell Fish, U.S. EPA, from Mr. Owen
Cox, Smythe County Board of Supervisors, re: Comments
on EPA's Proposed Plan, 2/2/95. P.
18. Letter to Mr. Russell Fish, U.S. EPA, from Mr. Madison
E. Marye, Commonwealth of Virginia Senate, re:
Comments on EPA's Proposed Plan, 2/3/95. P.
19. Letter to Mr. Russell Fish, U.S. EPA, from Mr. Leroy
Marshall, re: Comments on EPA's Proposed Plan,
2/10/95. P.
20. Letter to Mr. Pat Gaughn, U.S. EPA, from Mr. Richard
Raione, re: Comments on the Remedial Investigation/
Feasibility Study Report (RI/FS) and EPA's Proposed
Plan, 2/10/95. P.
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21. Letter to Mr. Russell Fish, U.S. EPA, from Mr. Richard
Raione, re: Comments on the RI/FS and EPA's Proposed
Plan, 2/10/95. P.
22. Letter to Mr. Russell Fish, U.S. EPA, from Mr. William
C. McAllister, Comments on EPA's Proposed Plan,
2/13/95. P. A newspaper editorial from the Saltville
News Messenger entitled "EPA Urged to Take a Second
Look" is attached.
23. Letter to Mr. Russell Fish, U.S. EPA, from Mr. Robert
R. Spurling III, re: Comments on the Proposed Plan,
2/13/95. P.
24. Petitions in opposition to EPA's plans to remediate the
Saltville site and in support of Olin's alternatives to
EPA's plans, 2/13/95. P.
25. Petitions in opposition to EPA's plans to remediate the
Saltville site and in support of Olin's alternatives to
EPA's plans, 2/14/95. P.
26. Letter to Mr. Russell Fish, U.S. EPA, from Ms. Florence
C. Jackson, 2/14/95. P.
27. Letter to Mr. Russell Fish, U.S. EPA, from Mr. Frank E.
Lewis, Mayor, and Council, Town of Saltville, re:
Comments on the Proposed Plan, 2/14/95. P.
28. U.S. EPA Public Notice, Saltville Waste Disposal Site,
re: EPA extends the public comment period for the
Proposed Plan until March 20, 1995, Smyth County News,
2115195. P.
29. Letter to Mr. Russell Fish, U.S. EPA, from Mr. Harry S.
Dunham, re: Comments on EPA's Proposed Plan, 2/15/95. P.
30. Letter to Mr. Russell Fish, U.S. EPA, from L.D.
Allison, re: Comments on EPA's Proposed Plan, 2/15/95. P.
31. Letter to Mr. Russell Fish, U.S. EPA, from Mr. Stanley
M. Cabill, re: Comments on EPA's Proposed Plan,
2/15/95. P. Two photographs of the town are attached.
32. Letter to Mr. Russell Fish, U.S. EPA, from Mr. Barnes
L. Kidd, Virginia House of Delegates, re: Comments on
EPA's Proposed Plan, 2/16/95. P.
33. Letter to Mr. Madison E. Marye, Commonwealth of
Virginia Senate, from Mr. Russell H. Fish, U.S. EPA,
re: A reply to the Senator's February 3, 1995 letter
concerning the site, 2/16/95. P.
34. U.S. EPA Public Notice, Saltville Waste Disposal Site,
re: EPA extends the public comment period for the
Proposed Plan until March 20, 1995, The Saltville News-
Messenger, 2/17/95. P.
35. Letter to Mr. Russell Fish, U.S. EPA, from Mr. Robert
L. Elmore, re: Comments on EPA' s Proposed Plan,
2/17/95. P.
36. Letter to Mr. Russell Fish, U.S. EPA, from Mr. Henry C.
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Everhart, re: Comments on EPA's Proposed Plan,
2/17/95. P.
37. Letter to Mr. Russell Fish, U.S. EPA, from C.R. Jones,
Jr., re: Comments on EPA's Proposed Plan, 2/20/95. P.
38. Letter to Mr. Russell Fish, U.S. EPA, from Mr. Frank E.
Lewis, Mayor, Town of Saltville, re: Comments on EPA's
Proposed Plan, 2/20/95. P.
39. Letter to Mr. Russell Fish, U.S. EPA, from Mr. Fred M.
Dye, Jr., et al., re: Request for 120 day extension of
the comment period, 2/23/95. P.
40. Letter to Ms. Ellen Stein from Mr. Patrick Gaughan,
U.S. EPA, re: Transmittal of the public meeting
transcript and an update of recent activities
surrounding the Proposed Plan, 2/24/95. P.
41. Press Release from Olin Corporation entitled "Olin's
Saltville Superfund Site Clean-up Plan Provides Long-
Term Protection with Minimal Impact on Community,"
2/22/95. P.
42. Letter to Mr. Peter H. Kostmayer, U.S. EPA, from Ms.
Becky Norton Dunlop, Secretary of Natural Resources,
Commonwealth of Virginia, re: Comments concerning
EPA's Proposed Plan, 2/27/9S. P.
43. Press Release from U.S. EPA Environmental News entitled
"EPA Extends Invitation to Citizens for Informal Talks
on Saltville Clean-up," 2/28/95. P.
44. Letter to Mr. Russell Fish, U.S. EPA, from Mr. Ed Val,
TSI Environmental, re: Follow-up letter to telephone
conversation concerning Former Chlorine Plant Site,
3/3/95. P.
45. Letter to Mr. Peter H. Kostmayer, U.S. EPA, from Mr.
Charles S. Robb and Mr. John Warner, United States
Senate, re: Comments on the Proposed Remedial Action
Plan, 3/6/95. P.
46. Letter to Mr. Stanley M. Cahill, from Mr. Russell H.
Fish, U.S. EPA, re: A response to. Mr. Cahill's
February 15, 1995, letter concerning the site, 3/6/95. P.
47. Letter to Mr. Russell H. Fish, U.S. EPA, from Mr.
Robert 0. Cahill, re: Comments on EPA's Proposed Plan,
3/8/95. P.
48. Letter to Mr. Abraham Ferdas, U.S. EPA, from Mr. Peter
W. Schmidt, Director, Department of Environmental
Quality, Commonwealth of Virginia, re: Transmittal of
comments concerning technical review of the Proposed
Remedial Action Plan, 3/8/95. P. The comments are attached.
49. Newspaper articles entitled "Citizens Petition EPA" and
"EPA Sessions Rescheduled," The Saltville News-
Messenger, 3/10/95. P.
50. Newspaper article entitled "EPA Sessions Rescheduled,"
"Smyth County News, 3/11/95. P.
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51. Newspaper article entitled "Saltville Petition Supports
EPA's Cleanup Proposal," Smyth County News, 3/11/95. P.
52. Newspaper article entitled "State Backs Olin in EPA
Dispute Over Site Cleanup," Richmond Times-Dispatch,
3/11/95. P.
53. Letter to Mr. Russell H. Fish, U.S. EPA, from Ms. Jane
Knox, re: Comments on the Proposed Remedial Action
Plan, 3/14/95. P.
54. Letter to Mr. Russell H. Fish, U.S. EPA, from Mr. Troy
T. DuGuay, International Environmental Trading Company,
re: Comments on the Proposed Remedial Action Plan,
3/15/95. P.
55. Newspaper article entitled "EPA Says Olin May be
Monitored 'Forever'," Bristol Herald-Courier, 3/16/95. P.
56. Letter to Mr. Thomas C. Voltaggio, U.S. EPA, from Mr.
Don Henne, U.S. Department of the Interior, re:
Comments on the Proposed Remedial Action Plan, 3/16/95. P.
57. Letter to Mr. Russell H. Fish, U.S. EPA, from Dale
Surber, re: Comments on the Proposed Remedial Action
Plan, 3/16/95. P.
58. Newspaper article entitled "EPA Sells Cleanup Plan to
Skeptical Saltville," Roanoke Times and World-News,
3/17/95. P.
59. Letter to Mr. Russell H. Fish, U.S. EPA, from Mr. & Ms.
Kenneth E. Ray, re: Comments on the Proposed Remedial
Action Plan, 3/17/95. P.
60. Newspaper article entitled "EPA Discusses Cleanup Plan
with Saltville Citizens," Smyth County News, 3/18/95. P.
61. Report: Comments on EPA's Proposed Remedial Action
Plan. Operable Unit Two, prepared by Olin Corporation,
3/20/95. P. A cover letter to Mr. Thomas C. Voltaggio,
U.S. EPA, from Mr. Robert L. Ceilings, Morgan, Lewis &
Bockius, dated March 20, 1995, concerning Olin
Corporation's position on EPA's Proposed Remedial
Action Plan and a transmittal letter to Mr. Russell H.
Fish, U.S. EPA, from Mr. Keith D. Roberts, Olin
Corporation, dated March 20, 1995, are attached.
62. Letter to Mr. Thomas C. Voltaggio, U.S. EPA, from Ms.
Sara Alyea Anderson, Morgan, Lewis & Bockius, re:
Transmittal of Table A-2 to Olin Corporation's comments
on the Proposed Plan which was not transmitted along
with the rest of the comments, 3/20/95. P. The table
is attached.
63. Newspaper article entitled "Don't Go Down to the
Basement," The Saltville News Messenger, 3/24/95. P.
64. Newspaper article entitled "Mercury Moonshine," The
Saltville News Messenger, 3/24/95. P.
65. Letter to Honorable Becky Norton Dunlop, Secretary of
Natural Resources, Commonwealth of Virginia, from Mr.
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Peter H. Kostmayer, U.S. EPA, re: A response to the
Secretary's February 27, 1995, letter concerning the
site and an update on recent activities concerning the
Proposed Plan, 3/27/95. P.
66. Letter to Mr. Dickie Dye from Mr. Russell H. Fish, U.S.
EPA, re: Response to guestions relating to the
Operable Unit 2 Proposed Plan and the site, 4/13/95.
P. A copy of Mr. Dye's letter (undated) containing the
guestions is attached.
67. Letter to Mr. Russell H. Fish, U.S. EPA, from Mr.
Stanley M. (Rusty) Cahill, re: Follow up to May 2,
1995, telephone conversation and guestions concerning
the site, 5/15/95. P. The following are attached:
a) Reference List;
b) Questions;
c) Photographs of the area surrounding the site;
d) ATSDR Public Health Statement concerning
Mercury, dated December 1989.
68. Letter to Mr. Stanley M. Cahill, from Mr. Russell H.
Fish, U.S. EPA, re: Status of EPA's response to Mr.
Cahill's guestions, 6/9/95. P.
69. Letter to Mr. Stanley M. Cahill, from Mr. Russell H.
Fish, U.S. EPA, re: Response to correspondence and
photographs of May 15, 1995, concerning remedies at the
site, 6/22/95. P. Questions/responses about concerns
at the site and a reference concentration for chronic
inhalation exposure - Mercury, elemental are attached.
70. Letter to Mr. Barnes L. Kidd, Commonwealth of Virginia
House of Delegates, from Mr. Peter H. Kostmayer, U.S.
EPA, re: A response to Mr. Kidd's February 3, 1995
letter concerning the site, (undated).
71. Letter to Mr. Russell H. Fish, U.S. EPA, from Danny and
Sherry Neal, re: Support of EPA's efforts at the site,
(undated). P.
72. Letter to Mr. Russell H. Fish, U.S. EPA, from Henry and
Bessie Neal, re: Support of EPA's efforts at the site,
(undated). P.
73. Letter to Mr. Russell H. Fish, U.S. EPA, from Rick and
Charlene McCoy, re: Support of EPA's efforts at the
site, (undated). P.
74. Letter to Mr. Russell H. Fish, U.S. EPA, from Robert L.
(Joe) and Darlene Nutter, re: Support of EPA's efforts
at the site, (undated). P.
75. Letter to Mr. Russell H. Fish, U.S. EPA, from Mr. Wm.
Reece Smith, Sr., re: Support of EPA's efforts at the
site, (undated). P.
76. Letter to Mr. Russell H. Fish, U S. EPA, from Sonny and
Dottie Neal, re: Comments on EPA's proposed
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alternatives for cleanup of the site, (dated). P. An
envelope is attached.
77. Letter to Mr. Russell H. Fish, U.S. EPA, from Bobby and
Doris Poore, re: Comments on EPA's proposed
alternatives for cleanup of the site, (undated). P.
An envelope is attached.
78. Letter to Mr. Russell H. Fish, U.S. EPA, from Carlton
and Frankie Swartz, re: Support of EPA's efforts at
the site, (undated). P. An envelope is attached.
79. Letter to Mr. Russell H. Fish, U.S. EPA, from Vernon
and Pearl Smith, re: Support of EPA's efforts at the
site, (undated). P. An envelope is attached.
80. Letter to Mr. Russell H. Fish, U.S. EPA, from Ms. Lisa
Null, re: Support of EPA's efforts at the site, (undated). P.
81. Letter to Mr. Russell H. Fish, U.S. EPA, from Ms. Diana
Dye, re: Support of EPA's efforts at the site,
(undated). p.
82. U.S. EPA Public Notice, Saltville Waste Disposal Site,
re: Announcement of the Record of Decision for the
site, Bristol Herald Courier/Virginia-Tennessean,
10/4/95. P.
SITE SPECIFIC GUIDANCE DOCUMENTS
1 U.S. EPA Technical Guidance Document: Final Covers on
Hazardous Waste Landfills and Surface Impoundments,
prepared by the U.S. EPA Office of Solid Waste and
Emergency Response, 7/89.
EPA/530-SW-89-047
2. U.S. EPA Technology Fact Sheet, A Citizen's Guide to
Thermal Desorption, prepared by the U.S. EPA Office of
Solid Waste and Emergency Response, 3/92
EPA/542/F-92/006
3. Excerpts from Abstract Proceedings of a U.S. EPA
Workshop on Removal, Recovery, Treatment and Disposal
of Arsenic and Mercury, 8/92.
EPA/600/R-92/105
4. Toxicological Profile for Mercury, prepared by Clement
International Corporation for the U.S. Department of
Health and Human Services, Public Health Service,
Agency for Toxic Substances and Disease Registry,
10/92.
5. U.S. EPA Engineering Bulletin, Thermal-Desorption
Treatment, prepared by the U.S. EPA Office of Emergency
and Remedial Response, 2/94.
EPA/540/S-94-501
INDEX FOR THE U.S. EPA COMPENDIUM OF CERCLA RESPONSE SELECTION
GUIDANCE DOCUMENTS AND CERTAIN DOCUMENTS FORM THE COMPENDIUM
1. Index for the U.S. EPA Compendium of CERCLA Response
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Selection Guidance Documents, 3/28/91.
2. Guidance for Conducting Remedial Investigations and
Feasibility Studies Under CERCLA, prepared by Office of
Solid Waste and Emergency Response (OSWER)/Office of
Emergency and Remedial Response (OERR), 10/1/88.
OSWER Directive 9355.3-01
EPA/540/G-89/004
Compendium Document No. 2002*
3. CERCLA Compliance with Other Laws Manual (Draft),
prepared by OERR, 8/8/88.
OSWER Directive 9234.1-01
EPA/540/G-89/006
Compendium document No. 3002*
4. CERCLA Compliance With Other Laws Manual, Part II:
Clean Air Act and Other Environmental Statutes and
State Reguirements, prepared by OERR, 8/1/89.
OSWER Directive 9234.1-02
EPA/540/G-89/009
Compendium Document No. 3013*
5. RCRA ARARs: Focus on Closure Reguirements [Quick
Reference Fact Sheet], prepared by OSWER, 10/1/89.
OSWER Directive 9234.2-04FS
Compendium Document No. 3017*
6. The Feasibility Study - Development and Screening of
Remedial Action Alternatives [Quick Reference Fact
Sheet], prepared by OSWER, 11/1/89.
OSWER Directive 9355.3-01FS3
Compendium Document No. 2018*
* These documents are available for review at the U.S. EPA
Docket Room, Region III, 841 Chestnut St., 9th Floor,
Philadelphia, Pennsylvania.
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APPENDIX B
GLOSSARY
Administrative Record - EPA's official compilation of documents, data, reports, and other information
supporting selection of a response action. The record is placed in the information repository to allow
public access to the material.
Background - The average concentration of a contaminant in the Site area either naturally occurring or from
external sources unrelated from the Site.
CERCLA - See SUPERFUND below.
Groundwater - Water found beneath the earth's surface that fills pores between soil, sand, and gravel
particles to the point of saturation. Ground water often flows more slowly than surface water. When it
occurs in sufficient guantity, ground water can be used as a water supply.
Hazard Index (HI) - The HI is the measurement expressing the overall potential for noncarcinogenic effects
posed by contaminants. An HI greater than 1 is characterized as presenting an unacceptable noncarcinogenic
risk
Information Repository - A location where documents and data related to the Superfund project are placed by
EPA to allow access to the material by the public.
MCL - The Maximum Contaminant Level or MCL is the maximum permissible level of a contaminant in water which
is delivered to any user of a public water system.
National Oil and Hazardous Substances Pollution Contingency Plan (NCP) - The federal regulation that guides
determination of the sites to be corrected under the Superfund program and the program to prevent or control
spills into surface waters or other portions of the environment.
National Priorities List (NPL) - EPA's list of the most serious uncontrolled or abandoned hazardous waste
sites identified for possible long-term remedial action under Superfund. A site must be on the NPL to
receive money from the Trust Fund for remedial action. The list is based primarily on the score a site
receives from the Hazard Ranking System. EPA is reguired to update the NPL at least once a year.
Record of Decision (ROD) - A public document that explains which cleanup alternative(s) will be used at
National Priorities List sites.
Remedial Investigation and Feasibility Study (RI/FS) - An in-depth study designed to gather the data
necessary to determine the nature and extent of contamination at a Superfund site; establish criteria for
cleaning up the site; identify preliminary alternatives for remedial actions; and support the technical and
cost analyses of the alternatives. The remedial investigation is usually done with the feasibility study.
Together they are usually referred to as the "RI/FS".
Resource Conservation and Recovery Act (RCRA) - A federal law that established a regulatory system to track
hazardous substances from the time of generation to disposal. The law reguires safe and secure procedures to
be used in treating, transporting, storing, and disposing of hazardous substances.
Risk Assessment (RA) - The gualitative and guantitative evaluation performed in an effort to define the risk
posed to human health and/or the environment by the presence or potential presence and/or use of specific
pollutants.
Scientific Notation - In dealing with particularly large or small numbers, scientists and engineers have
developed a "short hand" means of expressing numerical values. For example: 1,000,000 can be written as 1 x
10-6 and 1/1,000,000 can be written as 1 x 10-6.
SUPERFUND (Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA)) - The program
operated under the legislative authority of CERCLA and Superfund Amendments and Reauthorization Act (SARA)
that funds and carries out the EPA solid waste emergency removal and long-term remedial activities. These
activities include establishing the National Priorities List, investigating sites for inclusion on the list,
determining their priority level on the list, and conducting and/or supervising the ultimately determined
cleanup and other remedial activities.
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Surface Water - All water naturally open to the atmosphere (rivers, lakes, reservoirs, streams, impoundments,
seas, estuaries, etc.) and all spring wells, or other collectors which are directly influenced by surface
water.
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