PB96-964305
EPA/ROD/R07-96/087
March 1997
EPA Superfund
Record of Decision:
Weldon Spring Former Army
Ordnance Works, Operable Unit 1;
Soils and Pipeline,
St. Charles County, MO
9/26/1996
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DEPARTMENT OF THE ARMY
CORPS OF ENGINEERS
KANSAS CITY DISTRICT
DECISION
'
:fPilillli;lilllilililii?:>AND PIPELINE
SEPTEMBER 1996
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RECORD OF DECISION
FORMER WELDON SPRING ORDNANCE WORKS
WELDON SPRING, MISSOURI
OPERABLE UNIT 1: SOILS AND PIPELINE
Prepared By:
DEPARTMENT OF THE ARMY
CORPS OF ENGINEERS
KANSAS CITY DISTRICT
With Technical Assistance From:
IT CORPORATION
9233 WARD PARKWAY
KANSAS CITY, MISSOURI 64114
SEPTEMBER 1996
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1.0 DECLARATION
SITE NAME AND ADDRESS
Former Weldon Spring Ordnance Works
(Name as shown on National Priorities List is Weldon Spring Former Army Ordnance Works)
Weldon Spring, Missouri
Operable Unit 1: Soils and Pipeline
CERCLIS I.D. NO. MO 5210021288
STATEMENT OF BASIS AND PURPOSE
This decision document presents the selected remedial action for Operable Unit 1 at the Former
Weldon Spring Ordnance Works (WSOW), in Weldon Spring, Missouri, chosen in accordance
with the Comprehensive Environmental Response, Compensation and Liability Act of 1980
(CERCLA), as amended by the Superfund Amendments and Reauthorization Act of 1986
(SARA), and, to the extent practicable, the National Oil and Hazardous Substances Pollution
Contingency Plan (NCP). The decision is based on the administrative record for this site.
The remedy was jointly selected by the U.S. Army and U.S Environmental Protection Agency
(EPA). This Declaration is the section of the Record of Decision signed by the EPA Regional
Administrator and Army representatives. The State of Missouri (Department of Natural
Resources) participated in selection of the remedy but declined to sign the Record of Decision.
ASSESSMENT OF THE SITE
Actual or threatened releases of hazardous substances from this site, if not addressed by
implementing the response action selected in this Record of Decision (ROD), may present a
current or potential threat to public health, welfare, or the environment.
DESCRIPTION OF THE SELECTED REMEDY
This remedial action is for Operable Unit 1 of two planned for the Weldon Spring Ordnance
Works site. The selected remedy for Operable Unit 1 incorporates both treatment and
containment technologies for remediation of soil and pipeline media at the site. The remedy
includes incineration of nitroaromatics-contaminated soils and wooden pipeline, stabilization and
on-site landfill of lead-contaminated soils, and on-site landfill of construction debris separated
from the contaminated soils. These proven technologies will substantially reduce risks associated
with the contaminated materials that represent the principal threat at the site, and provide for
permanent destruction of the nitroaromatics contamination. The selected remedy also eliminates
a source of nitroaromatics to the groundwater.
Major components of the selected remedy are:
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Clearing and grubbing to access the contaminated areas and pipeline
Excavation of contaminated soils and debris with levels above the Remediation Goals of
57 ppm for TNT, 2.5 ppm for DNT, 500 ppm for lead, 10 ppm for PCBs, or 10 ppm
for PAHs.
Excavation of an estimated 83,300 feet of explosives-contaminated wooden pipeline
buried at average depths of less than 5 feet.
Transportation of contaminated soils and pipeline from excavation sites to the
pretreatment, treatment (incinerator), or containment (landfill) locations.
Debris separation by screening or comparable classification process to remove materials
either too large or not appropriate for incineration. Separated materials may also be
spray washed to remove surface contamination above Remediation Goals, or shredded
and returned to the waste stream for incineration.
Removal of steel bands from wooden pipeline prior to the shredding process.
Shredding of the wooden pipeline under controlled conditions to minimize the possibility
of detonation.
Incineration of contaminated soils and shredded pipeline material on-site in a rotary kiln
incinerator unit.
Testing of ash to determine if it meets treatment criteria and to determine if it is
acceptable for use as backfill on site.
Stabilization of soils above lead TCLP limits and some incinerator ash with binder
materials to prevent leaching of contaminants.
Landfill of treated and untreated lead-contaminated soils and other contaminated materials
not suitable for incineration in an on-site landfill designed to meet appropriate Federal
and State requirements based on the types of waste.
On-site landfill of PAH-contaminated soils and PCB-contaminated soils with PCB
concentrations less than 50 ppm.
Landfill of screened materials (oversized fraction) and non-hazardous construction debris
in the same landfill as the lead-, PAH-, and PCB-contaminated soils. For placement of
non-hazardous debris, this on-site landfill must be designed to at least meet Federal and
State solid waste landfill requirements.
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• Backfill of excavations with treated soil (passing TCLP) from the incineration process
and revegetation of the backfilled areas.
• Treatment of contaminated wastewater and storm water runoff.
• Contingency for off-site disposal of treated wastewater and storm water runoff at a
publicly owned treatment works in the event that short-term generation exceeds capability
to reuse the water in the incinerator.
• Abandonment of wells no longer in use (in accordance with Missouri 10 CSR 23-4),
removal of underground storage tanks (in accordance with Missouri 10 CSR 20-10),
demolition of laboratory building S-22, and other miscellaneous remedial actions.
• Contingency for off-site disposal of small quantities of hazardous wastes, such as listed
waste U105 or U106 (DNT-contaminated soils from DNT lines) or soils with PCB
concentrations above 50 ppm, if encountered, that would otherwise require more
stringent design of on-site treatment/disposal facilities.
Wastes from other sites or facilities will not be accepted for treatment and/or disposal at WSOW
under this remedy.
STATUTORY DETERMINATIONS
The selected remedy is protective of human health and the environment, complies with Federal
and State requirements that are legally applicable or relevant and appropriate to the remedial
action, and is cost-effective. This remedy utilizes permanent solutions and alternative treatment
technologies to the maximum extent practicable and satisfies the statutory preference for
remedies that employ treatment that reduces toxicity, mobility, or volume as a principal element.
Five-year reviews as specified in CERCLA Section 121(c) will be required for this remedy
because hazardous substances will remain on-site (i.e., in a landfill) above health-based
Remediation Goals.
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LEAD AND SUPPORT AGENCY ACCEPTANCE
OF THE RECORD OF DECISION.
FORMER WELDON SPRING ORDNANCE WORKS.
OPERABLE UNIT l! SOILS AND PIPELINE
Signature sheet for the following Record of Decision for Operable Unit 1; Soils and Pipeline,
final action at the Former Weldon Spring Ordnance Works between the U.S. Army and the U.S.
Environmental Protection Agency.
Clair F. Gill
Major General, U.S. Army
Commanding Officer
U.S. Army Engineer Center and Fort Leonard Wood
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LEAD AND SUPPORT AGENCY ACCEPTANCE
OF THE RECORD OF DECISION.
FORMER WELDON SPRING ORDNANCE WORKS.
OPERABLE UNIT Is SOILS AND PIPELINE
Signature sheet for the following Record of Decision for Operable Unit 1; Soils and Pipeline,
final action at the Fonner Weldon Spring Ordnance Works between the U.S. Army and the U.S.
Environmental Protection Agency.
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LEAD AND SUPPORT AGENCY ACCEPTANCE
OF THE RECORD OF DECISION.
FORMER WELDQN SPRING ORDNANCE WORKS.
OPERABLE UNIT l! SOILS AND PIPELINE
Signature sheet for the following Record of Decision for Operable Unit 1; Soils and Pipeline,
final action at the Former Weldon Spring Ordnance Works between the U.S. Army and the U.S.
Environmental Protection Agency.
Dennis Grams
Regional Administrator, Region VII
U.S. Environmental Protection Agency
Date
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TABLE OF CONTENTS
Page
1.0 DECLARATION 1
LEAD AND SUPPORT AGENCY ACCEPTANCE 4
TABLE OF CONTENTS i
LIST OF TABLES ii
LIST OF FIGURES ii
LIST OF ACRONYMS AND ABBREVIATIONS iii
2.0 DECISION SUMMARY 7
2.1 SITE NAME, LOCATION, AND DESCRIPTION 7
2.2 SITE HISTORY AND ENFORCEMENT ACTIVITIES 8
2.3 HIGHLIGHTS OF COMMUNITY PARTICIPATION 12
2.4 SCOPE AND ROLE OF OPERABLE UNIT 13
2.5 SUMMARY OF SITE CHARACTERISTICS . 15
2.6 SUMMARY OF SITE RISKS 18
2.7 DESCRIPTION OF ALTERNATIVES 24
2.7.1 Alternative 1 No Action 26
2.7.2 Alternative 3 Containment (Landfill) Plus Some Incineration . . 26
2.7.3 Alternative 4 Biological Treatment (Composting) 27
2.7.4 Alternative 6 Incineration, Rotary Kiln 28
2.7.5 Alternative 10 Incineration and Landfarming 29
2.8 SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES . . 30
2.9 SELECTED REMEDY 35
2.10 STATUTORY DETERMINATIONS 39
2.10.1 Protection of Human Health and the Environment 39
2.10.2 Compliance with Applicable or Relevant and Appropriate
Requirements 40
2.10.3 Cost Effectiveness 40
2.10.4 Use of Permanent Solutions and Alternative Treatment
Technologies to the Maximum Extent Practicable 41
2.10.5 Preference for Treatment Which Reduces Toxicity, Mobility
or Volume 41
2.11 DOCUMENTATION OF SIGNIFICANT CHANGES 52
3.0 RESPONSIVENESS SUMMARY 53
3.1 OVERVIEW 53
3.2 BACKGROUND ON COMMUNITY INVOLVEMENT 53
3.3 SUMMARY OF PUBLIC COMMENTS AND AGENCY RESPONSES . . 55
3.3.1 Remedial Alternative Preferences 55
3.3.2 Air Emission Concerns with the Preferred Alternative 59
3.3.3 Other Environmental Concerns with the Preferred Alternative . 63
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3.3.4 Feasibility Concerns with Any WSOW Remediation 65
3.3.5 Procedural and Legal Issues 67
GLOSSARY 73
USTOFTABLES
TABLE NO. TITLE PAGE
1 SITE AREAS AND SOIL VOLUMES TO BE REMEDIATED 16
2 SUMMARY OF HEALTH RISKS IDENTIFIED IN WSOW BASELINE
RISK ASSESSMENT (ASSUMING NO REMEDIATION OCCURS) 24
3 REMEDIATION GOALS FOR WSOW 39
4 APPLICABLE OR RELEVANT AND APPROPRIATE REQUIREMENTS 42
LIST OF FIGURES
FIGURE NO.
1 REGIONAL MAP FOR FORMER WELDON SPRING ORDNANCE
WORKS 9
2 SITE MAP FOR FORMER WELDON SPRING ORDNANCE WORKS 10
3 AREAS CONTAINING TNT AND DNT CONTAMINATION GREATER
THAN REMEDIATION GOALS 17
4 AREAS CONTAINING LEAD CONTAMINATION GREATER THAN
THE REMEDIATION GOAL 19
5 AREAS CONTAINING PCB AND PAH CONTAMINATION GREATER
THAN REMEDIATION GOALS 20
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LIST OF ACRONYMS AND ABBREVIATIONS
AAP
AEC
ARARs
BRA
CERCLA
CFR
cu yd
DNR
DNT
DOE
DRE
EPA
FS
gr/dscf
MDNR
mg/kg
NCP
NPL
O&M
OU
PAHs
PCBs
PIC
POHC
ppm
PRO
RCRA
RDX
RI
ROD
SARA
SITE
TCL
TCLP
TNT
TUHC
WAA
WSOW
WSSRAP
WSTA
Army Ammunition Plant
Army Environmental Center (formerly U.S. Army Toxic and Hazardous
Materials Agency, USATHAMA)
Applicable or Relevant and Appropriate Requirements
Baseline Risk Assessment
Comprehensive Environmental Response, Compensation, and Liability Act
Code of Federal Regulations
Cubic yard
Department of Natural Resources
Dinitrotoluene
Department of Energy
Destruction and Removal Efficiency
U.S. Environmental Protection Agency
Feasibility Study
grains/dry standard cubic foot
Missouri Department of Natural Resources
Milligrams per kilogram
National Contingency Plan
National Priorities List
Operation and maintenance
Operable Unit
Polynuclear Aromatic Hydrocarbons
Polychlorinated biphenyls
Products of Incomplete Combustion
Principal Organic Hazardous Constituent
Parts per million
Preliminary Remediation Goal
Resource Conservation and Recovery Act
Cyclotrimethylenetrinitramine
Remedial Investigation
Record of Decision
Superfund Amendments and Reauthorization Act
Superfund Innovative Technology Evaluation
Target Cleanup Level
Toxicity Characteristic Leaching Procedure
Trinitrotoluene
Total Unburned Hydrocarbons
War Assets Administration
Weldon Spring Ordnance Works
Weldon Spring Site Remedial Action Project
Weldon Spring Training Area
111
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This page intentionally left blank.
IV
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2.0 DECISION SUMMARY
2.1 SITE NAME. LOCATION. AND DESCRIPTION
The WSOW site is a former explosives production facility which manufactured trinitrotoluene
(TNT) and dinitrotoluene (DMT) for use during World War II. It is located in St. Charles
County, Missouri about 30 miles west of St. Louis and about 14 miles southwest of the City of
St. Charles, as shown in Figure 1. It is bisected by State Highway 94, bounded on much of the
north by U.S. Highway 40-61, and bounded on much of the south by the Missouri River. The
area of the full Ordnance Works site during production was 17,232 acres, which is
approximately the extent of the designated NPL site, as shown in Figure 2.
Within the immediate vicinity of the WSOW site, most of the land is currently farmland but the
area to the northeast is rapidly being developed into single-family and multi-family residential
areas. There have been dramatic increases in population in recent years in nearby incorporated
areas such as O'Fallon, St. Peters, and Cottleville. Office buildings have been built in Missouri
Research Park.
The site itself attracts over 1,000,000 visitors per year for fishing, hunting, and nature studies
at the Busch and Weldon Spring Conservation Areas. Natural resources include several heavily
wooded areas, the most diversified flora of any part of the state, migratory bird refuge areas,
37 lakes, and numerous fishing ponds.
Topography of the site is hilly, varying from gently rolling in the north to rugged in the south.
The northern half of the site drains northeastward through a series of creeks and man-made lakes
to Dardenne Creek, which is a tributary of the Mississippi River. The southern portion of the
site is more steeply sloped and heavily wooded, and drains southeastward into Little Femme
Osage Creek and the Missouri River.
The southernmost portion of the site is in the floodplain of the Missouri River and contains a
well field for St. Charles County's water systems. The shallowest aquifer under the northern
part of the site is found near the top of bedrock, generally at depths of 20 to 50 feet. This
aquifer is not widely used as a water supply.
The former Ordnance Works property, which at the present time includes the Weldon Spring
Training Area (WSTA), Busch Conservation Area, the Weldon Spring Conservation Area,
Francis Howell High School, Weldon Spring Heights and the Missouri Research Park, now has
relatively few of the 1,038 structures that comprised the explosives production facility. During
initial decontamination activities and subsequent cleanup efforts, the production equipment was
dismantled and salvaged and most of the buildings were either burned or demolished. With the
exception of a few administrative buildings on WSTA, 100 storage bunkers, the residences in
Weldon Spring Heights, and a few storage buildings at Francis Howell High School, only
concrete foundations remain.
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An underground wooden pipeline system was constructed in 1941-42. The system was used to
transport wastewater resulting from purification of TNT and DMT from settling tanks at the TNT
and DNT production lines to three treatment plants along the southern boundary of the WSTA
site. Another run of the pipeline then carried treated and untreated wastewater from the
treatment plants to a final discharge point off WSTA to the southeast, from where it reportedly
reached the Missouri River by surface flow. There were also instances of settling tank and
pipeline overflow directly to the surface drainage system after the treatment plants were installed
and running. Approximately 83,300 feet of buried pipeline are believed to remain at WSTA.
Several areas within WSOW were used for disposal of Ordnance Works wastes and debris.
These sites included three dumps, a landfill, eight burning grounds, and seven wastewater
lagoons. All of these former disposal sites were located during the recent Remedial
Investigation, but only six of the burning grounds and three lagoons were found to have any
contamination remaining.
2.2 SITE HISTORY AND ENFORCEMENT ACTIVITIES
The land for WSOW was obtained in late 1940 and early 1941 by direct purchase and
condemnation from farmers in St. Charles County. Ninety percent of the acreage was farmland
prior to acquisition. Construction of the 18 nearly identical and independent TNT manufacturing
plants and 2 DNT plants began in May 1941 and progressed from east to west across what is
now the Army's Weldon Spring Training Area (WSTA) property.
The WSOW was operated under contract by the Army to Atlas Powder Company, and had
approximately 5,200 employees in 1943 during its peak production of about 164,000 tons
annually. In January 1944, the TNT and DNT plants and support facilities were taken out of
operation and placed on standby status. During this period, most of the production equipment
and buildings were disassembled, cleaned, repaired, and "mothballed". In July 1944,
reactivation was ordered and the entire WSOW was reassembled. Production continued until
August 1945 when the contractor was notified to cease operations.
The Army's Ordnance Department reassumed operation of WSOW from Atlas Powder Company
in November 1945. By April 1946, the facility was declared surplus property; ownership was
transferred from the Army to the War Assets Administration (WAA) in September 1946. In
1949, the WAA distributed the bulk of the 17,232 acres to state and local jurisdictions, leaving
only the current WSTA and the U.S. Atomic Energy Commission's former Uranium Feed
Material Plant site under Federal ownership. The Uranium Feed Material Plant is now under
Department of Energy (DOE) jurisdiction and is a separate 226 acre National Priorities List
(NPL) site totally within the boundaries of the WSOW site. This site is named the Chemical
Plant Area of the Weldon Spring Site, is being investigated and remediated by DOE, and is not
part of the WSOW project. Its location is shown in Figure 2.
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DRAWN
BY
R. DOLACK
20 FEB 96
CHECKED BY
APPROVED BY
DRAWING ,.„«,.-,
NUMBER 312263
WELDON
SPRING
ORDNANCE
WORKS
SCALE (APPROXIMATE)
\G3/ 0 2.5 5.0 7.5 lO.Omil.!
1 INCH EQUALS APPROXIMATELY 5.5 MILES.
ST. LOUIS
FIGURE 1
REGIONAL MAP
FOR FORMER WELDON
SPRING ORDNANCE WORKS
PREPARED FOR
U.S. ARMY CORPS OF ENGINEERS
KANSAS CITY DISTRICT
...Creating a Safer Tomorrow
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DRAWN I R. DOLACK
BY I 20 FEB 96
CHECKED BY
APPROVED BY
DRAWING -,.-,„,.-, .,Q
NUMBERT312263-A39
LEGEND
BURNING BURNING GROUNDS/DUMPS
GROUND 7 AND NUMBER
TNT OR DNT LINE AND NUMBER
LAB BUILDING S-22
WASTEWATER TREATMENT
PLANT AND NUMBER
WELDON SPRING
SELLITE/ACID PLANTS
IN-LINE SETTLING TANKS
W.S.T.A. BOUNDARY
W.S.O.W. BOUNDARY
ROADS
KATY TRAIL STATE PARK
(FORMER M.K.T. RAILROAD)
FIGURE 2
SITE MAP
FOR FORMER WELDON
SPRING ORDNANCE WORKS
PREPARED FOR
U.S. ARMY CORPS OF ENGINEERS
KANSAS CITY DISTRICT
...Creating a Safer Tomorrow
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Although only small interim actions have been undertaken since WSOW was added to the NPL
list, at least five cleanups were performed to remove contaminants from the former TNT
manufacturing activities at WSOW. The first cleanup occurred in early 1944 during the period
the facility was on standby status. It was performed by Atlas Powder Company, the facility
contractor. Remediation methods included washing equipment with soda ash solution, steaming,
flushing with water, excavation and removal of contaminated soils, burning, and controlled
flashing.
The second cleanup was conducted from August 1945 through August 1946 by Atlas Powder
Company and the Corps of Engineers. Although there was very little documentation of this
cleanup action, it was assumed that Atlas' procedures were similar to their 1944 decontamination
effort (USATHAMA, 1977). Many of the same personnel were involved and a detailed written
methodology had been prepared during the 1944 cleanup. Following this decontamination and
return of the facility to the Ordnance Department and subsequently to the War Assets
Administration, most of the decontaminated equipment was salvaged or redistributed to other
government agencies and explosives' manufacturers.
The third cleanup is actually a group of three efforts that took place during the 1950s. For
several months after the General Services Administration (GSA), successor to the War Assets
Administration, assumed custody of the WSTA portion of the Ordnance Works in 1950, GSA
staff regraded and hauled soil from the TNT lines and removed scrap materials. Prior to
transfer of the 226 acres to the Atomic Energy Commission in 1956, the Army and the Atomic
Energy Commission decontaminated that site in 1955. This included removal of 28,250 cubic
yards of contaminated soil and 21,500 linear feet of buried TNT wastewater pipeline from the
area that had been TNT plants 1, 2, 3, and 4. Also, 59 buildings were burned and eight more
structures were razed. Although much of the 1955 decontamination effort was outside the
current WSTA boundaries, the eastern edge of WSTA received extensive remediation activity
at this time. During approximately this same time period (late 1956) in a remedial action
unrelated to the property transfer, an additional 136 buildings were destroyed by burning and
20 were dismantled and/or sold in a cleanup effort called Cox's Program.
In 1962-63, a fourth cleanup was undertaken by the U.S. Army Support Center in St. Louis,
who had assumed custody of the area in 1959. In coordination with the Corps of Engineers and
ordnance experts, equipment was removed from 23 buildings and the buildings demolished.
A fifth cleanup in which the wastewater incineration plants were dismantled and shipped to
another TNT facility took place from 1965 to 1967. Additional equipment including
transformers, utility poles, electrical and communications cables were removed and 70 buildings
were demolished. In 1967, seven miles of railroad track were removed and shipped to other
installations.
Although the former WSOW property has been divided and is now owned by various
organizations, the WSTA has always been under the jurisdiction of the federal government. As
recently as the 1980s, there was no state enforcement for the cleanup of federal facilities and
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remediation activities at WSTA were initiated internally by the Army. The site was added to
the National Priorities List on February 21, 1990 and is now being remediated under the
guidelines established in a three-party Interagency Agreement (IAG) dated March 4, 1991
(effective date August 8, 1991) between the U.S. EPA, the Army, and the Missouri Department
of Natural Resources (MDNR). The Army is the lead agency for this site.
Several site assessments with limited scopes were conducted in the WSTA portion of the site
during the 1980s. However, these were internal investigations by the Army and were not
conducted with EPA and MDNR oversight. In 1988, the Army initiated the first investigation
of WSTA to be conducted through the Installation Restoration Program (IRP). A comprehensive
Remedial Investigation (RI) of the WSTA portion of the site was performed with field work
lasting through 1989. This was followed in 1990 and 1991 by a companion RI (also under
CERCLA) for the remainder of WSOW (outside WSTA) after the entire site was placed on the
NPL on February 21, 1990.
During the RI work, some locations where acute exposures could potentially occur were
identified. These were addressed immediately as removal actions. Removal actions to date at
WSOW have included fencing of all eight burning grounds, removal of interior wallboards from
Building S-64 in the Box Factory area, and collection and disposal of TNT "nuggets" from the
surface of burning ground 1 and other site areas.
2.3 HIGHLIGHTS OF COMMUNITY PARTICIPATION
The Remedial Investigation/Feasibility Study (RI/FS) process was conducted in accordance with
CERCLA requirements to document the comprehensive remedial activities and proposed
remedial plan for the WSOW site. Primary documents developed during the RI/FS process
included the RI report, Baseline Risk Assessment, FS report, and Proposed Plan for Operable
Unit 1. These reports were released to the public between May and December 1993 and have
been made available for public review as part of the administrative record file at the WSOW Site
Office since December 1, 1993. These reports were also available to potentially affected
persons and the public in an information repository at the St. Charles City/County Library,
Kisker Road Branch. Notices of availability of these documents were published in the St. Louis
Post-Dispatch on December 2 and 5, 1993 and in the St. Charles, St. Peters, O'Fallon, and
Wentzville Journals (St. Charles Suburban Journals) on December 22 and 29, 1993 and January
5 and 9, 1994.
A public comment period for this remedial action was initially declared from December 1, 1993
through January 14, 1994 to provide a reasonable opportunity for comment and to disseminate
information regarding the Proposed Plan. In response to a timely request from the Sierra .Club,
the public comment period was extended to February 14, 1994 in accordance with provisions
of the National Contingency Plan. Notice of this extension was published in the St. Charles
Suburban Journals on January 23, 1994.
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A public meeting was held on December 14, 1993 at the Holiday Inn in Wentzville (in the
affected area), in accordance with Section 117(a)(2) of CERCLA. The public meeting was
advertised in the Post-Dispatch announcements listed above, in St. Charles Suburban Journal
newspapers on November 25, December 7 and December 12, 1993, in a newsletter with
circulation of about 250 distributed in early November 1993, and with more than 2,000 mailed
fliers. At this meeting, representatives from the U.S. Army and U.S. EPA informed the public
of the preferred alternative, sought public comments, and answered questions about the remedial
alternatives under consideration and about the site. A transcript of the public meeting is
included in the administrative record.
All comments received prior to the end of the comment period, including those verbal comments
made at the public meeting, are addressed in the Responsiveness Summary in Section 3.0 of this
Record of Decision. Additional actions taken by the Army and EPA prior to and during the
comment period to increase public participation in the remedy selection process include:
• Quarterly newsletters beginning in October 1992
• Technical Review Committee meetings with community representation
• Information repositories established at St. Charles County Public Library (Kisker Branch)
and WSOW Site Office
• An availability session at the site in October 1993 to informally answer citizen questions
and discuss concerns
• Two focus group sessions held in October 1993 to identify concerns and community
reactions to the preferred alternative of incineration
• Information telephone line manned 40 hours per week.
All public participation requirements of CERCLA Sections 113(k) and 117 were met with the
actions described above.
This decision document presents the selected remedial action for Operable Unit 1 at the Former
Weldon Spring Ordnance Works site in St. Charles County, Missouri, chosen in accordance with
CERCLA, as amended by SARA and, to the extent practicable, the National Contingency Plan.
The decision for this site is based on the administrative record.
2.4 SCOPE AND ROLE OF OPERABLE UNIT
Response actions for the site will be organized into two discrete portions (Operable Units) due
to the complexity of the problems associated with the site. This ROD addresses Operable Unit
(OU) 1, remediation of soils and pipeline. Groundwater will be addressed as OU 2. If
monitoring during the ongoing groundwater RI/FS indicates that remediation is required for the
groundwater OU, it would be addressed in the future in a separate ROD and remedial action.
The scope of the response action for OU 1 is to excavate and treat soils and the pipeline with
contaminant concentrations above Remediation Goals, and to dispose of treated residues in a
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permanent manner consistent with CERCLA 121(b), EPA, and MDNR requirements. This
response action will then allow full and unimpeded use of WSTA for military activities and other
parts of WSOW for occupational, recreational, and ecological activities. The selected action will
remove the risk of adverse health effects from long-term exposure to soils and safety concerns
from the pipeline. Another objective of the action is to properly dispose of construction debris,
materials, and equipment from the ordnance works era that may contain trace amounts of TNT
or other contamination, or non-hazardous materials that may simply need to be permanently
removed from the site.
The contaminated soils and pipeline are the principal threats to human health and the
environment at the site because of the risks from possible ingestion of or dermal contact with
the contaminated soils. The purpose of this response action is to prevent current or future
exposure to the contaminated soils and to reduce contaminant migration into groundwater.
In addition to providing treatment of soils and pipeline by the primary technology of
incineration, the selected alternative includes several other processes that aid in fulfilling the
goals identified above:
Clearing and grubbing
Excavation of contaminated soils and pipeline
Separation of construction debris by screening, followed by shredding or spray washing
Removal of steel bands from pipeline
Pipeline shredding
Testing of soils and incinerator ash to verify attainment of Remediation Goals
Stabilization of soils above lead TCLP limits
Disposal of stabilized and unstabilized lead-contaminated soils in on-site landfill
Disposal of construction debris in an on-site landfill
Disposal of miscellaneous non-hazardous materials in accordance with state solid waste
regulations
Backfill of excavations with incinerated soil
Treatment of contaminated wastewater and storm water runoff
Abandonment of wells no longer in use, removal of underground storage tanks,
demolition of laboratory building S-22, and other miscellaneous remedial actions.
As part of the overall site cleanup strategy, the selected action for OU 1 will eliminate known
sources of groundwater contamination at WSOW. This action is therefore expected to prevent
further migration of nitroaromatics in soils and its leaching into groundwater. While the
removal of contaminated soil in the OU 1 action is expected to indirectly reduce groundwater
contaminant concentrations, the amount of improvement cannot be estimated quantitatively.
Therefore, the Army, EPA, and MDNR have agreed to address the soil and groundwater
contamination on separate schedules to permit accelerated cleanup of the soil.
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2.5 SUMMARY OF SITE CHARACTERISTICS
The two Remedial Investigations and their supplemental investigations were used to identify the
types, quantities, and locations of contaminants in different media throughout the 17,000+ acre
WSOW study area. Results of the RI work are summarized by contaminant below. Estimates
of the volumes of soil that need to be remediated by site area are presented in Table 1.
Nitroaromatics. Nitroaromatics concentrations (mainly TNT) decreased quickly with depth in
shallow soils. Deeper soil borings indicated little or no nitroaromatics contamination below 5
feet in depth. Other nitroaromatics (e.g., 2,4-DNT and 2,6-DNT) were found in surface and
shallow subsurface soils much less frequently and at lower concentrations than TNT. These
nitroaromatic compounds were detected in soils at concentrations of up to 510,632 ppm for
TNT, and 7,100 ppm and 220 ppm for the 2,4- and 2,6-DNT isomers, respectively. The most
highly contaminated surface soils were found in the wash house, grainer house, settling tank,
and burning ground areas. "Nuggets" of fairly pure TNT have occasionally been found in the
burning grounds. The locations of areas which are contaminated by nitroaromatics above their
respective cleanup levels are shown in Figure 3.
TNT contamination within surface soil, shallow subsurface soil, groundwater and springs appears
to be mainly derived from residual surface soil contamination from previous manufacturing,
production, and disposal activities. Although at least five site soils remediations have been
implemented since closure of the Ordnance Works, TNT-contaminated soils remain because
previous cleanup standards were not as comprehensive as present day requirements.
Concentrations of nitroaromatics in the groundwater were more varied than those found in the
soils. Of the 59 monitoring wells on the WSOW site, 36 have never had measured
nitroaromatics concentrations above 1 ppb. The monitoring wells that had concentrations above
1 ppb in general had detectable levels of most of the nitroaromatic compounds in one or more
of the sampling rounds to date. The compounds routinely detected were TNT, 2,4-DNT, 2,6-
DNT, 4-amino-2,6-DNT, 2-amino-4,6-DNT, trinitrobenzene, and nitrotoluene. However, the
specific nitroaromatics present in groundwater samples at each monitoring well changed from
one sampling round to the next. These same factors were noted for the spring water.
The wooden pipeline has been opened and sampled at about 20 locations along the estimated
length of 83,300 feet remaining in the ground. About half the locations had a visible orange or
red residue that contained TNT concentrations above 10,000 ppm. Limited testing of pipeline
residue samples for sensitivity and reactivity indicated that some of the samples were reactive,
or capable of being detonated given a sufficient stimulus. Other nitroaromatic compounds or
metals were not found in the residue samples.
Metals. Lead was measured at elevated levels at several locations in the WSOW surface soils.
The highest concentration of lead measured was 126,000 ppm. Locations with lead above 500
ppm, shown in Figure 4, included the TNT and DNT production lines, wastewater treatment
15
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TABLE 1
SITE AREAS AND SOIL VOLUMES TO BE
SITE AREA
TNT production lines
(wash houses, grainer
houses, settling tanks,
tramways, nitrating
houses)
Wastewater treatment
plants
In-line settling tanks
Sellite/acid plants
Burning grounds
Laboratory building
Mechanical City
Bunkers
Regraining Area
Former lagoon 1
(contains no water)
ESTIMATED
VOLUME
(CUYD)
17,300
w/TNT
1000
50
20
10
<10
<10
1,000
200
700
10
10,000
w/TNT
30
10
100
30
50
40
CONTAMINANTS
TNT
DNT
Lead
PCBs
PAHs
TNT
Lead
PCBs
TNT
TNT
Lead
PAHs
TNT
DNT
Lead
TNT
Lead
Lead
TNT
DNT
NO. OF
SAMPLE
POINTS1
109
8
18
6
2
1
1
1
6
2
14
1
39
4
1
1
1
3
1
2
REMEDIATED
CONCENTRATIONS (ppm)
LOW HIGH AVERAGE
61
2.7
600
10
16.6
63
566
27
194
106
662
17.4
64
4.5
1,140
78
49,100
547
152
6.8
150,809
25
126,000
23
25.5
63
566
27
47,133
3,097
10,200
17.4
510,632
7,100
1,140
78
49,100
949
152
7.2
8,191
7.1
15,325
14.7
19.6
63
566
27
11,012
1,602
3,267
17.4
18,399
1,798
1,140
78
49,100
724
152
7.0
Above Remediation Goals
16
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DRAWN
BY
R. DOLACK
20 FEB 96
CHECKED BY
APPROVED BY
DRAWING
NUMBER 312263-A42
AUGUST A. BUSCH MEMORIAL CONSERVATION AREA
DOE WELDON SPRING
SITE CHEMICAL
PLANT AREA
BG05/06
BG07
BG01
RG03
SCALE (APPROXIMATE)
BG01
LI
1250 2500
3750 5000f««1
LEGEND
TNT CONTAMINATION ABOVE 57 PPM
AND GRID DESIGNATION
DNT CONTAMINATION ABOVE 2.5 PPM
AND GRID DESIGNATION
W.S.T.A. BOUNDARY
ROADS
FIGURE 3
AREAS CONTAINING
TNT AND DNT CONTAMINATION
GREATER THAN
REMEDIATION GOALS
PREPARED FOR
U.S. ARMY CORPS OF ENGINEERS
KANSAS CITY DISTRICT
. .Creating a Safer Tomorrow
-------
plants, sellite/acid plant areas, burning ground 1, the bunker drains, and Mechanical City. High
lead levels were found also in many areas of burning ground 1 (up to 49,100 ppm) in both
surface soils and in borings.
Other potentially hazardous metals were found at elevated levels only in isolated samples: for
example, cadmium and silver in Mechanical City, silver and thallium at Busch Railhead Area,
mercury at Lab Building S-22, arsenic in Lagoon 7, arsenic and barium at Building S-106
foundation, selenium in Lake 4, barium and beryllium in one stream drainage each, and arsenic
in one off-site residential well. There were no obvious explanations for these high individual
concentrations. Because of their limited occurrences, these high metals concentrations did not
indicate health risks in the risk assessment and do not require remediation (see Section 2.6
below). Most of the production areas sampled had background levels (naturally-occurring
concentrations) of these metals in soil.
Other Chemicals. PCB analyses were performed on most of the surface soil samples from
WSTA. Only seven of the samples were above the 10 ppm cleanup level indicated in EPA's
PCB Spill Cleanup Policy and the highest result was 42 ppm. Since no PCB concentrations
above 50 ppm have been found, these soils may be placed in an on-site landfill without special
consideration as a TSCA regulated waste. Phthalates were detected in several soil samples at
WSTA, but phthalates can be laboratory contaminants and are also ubiquitous in many
environmental settings because they are contained in plastics. Several different polynuclear
aromatic hydrocarbons (PAHs) such as benzo(a)pyrene, fluoranthene, chrysene, and
benzo(k)fluoranthene were identified in surface soil samples on WSTA. PAHs are also
ubiquitous at low levels since they are found in asphalt, tars, combustion products, and coal.
The highest measured carcinogenic PAH concentration was 110 ppm, and only four samples had
carcinogenic PAH concentrations above 10 ppm. The locations of soil contaminated by other
chemicals which will require remediation are shown in Figure 5.
2.6 SUMMARY OF SITE RISKS
The Baseline Risk Assessment for WSOW was conducted during 1992 and 1993 to define the
existing and future human health and environmental risks associated with the chemicals found
in surface soil, surface water, groundwater, springs, and sediments at the WSOW site. Health
risks were determined for 18 different recreational, occupational, and residential exposure
scenarios at more than 70 locations in two main site areas: Weldon Spring Training Area
(WSTA) and WSOW outside WSTA. These areas were addressed separately because of
differences in accessibility, frequencies of exposure, and levels of contamination.
Chemicals of Potential Concern. All sampling data from the two RIs were evaluated
statistically to identify chemicals of potential concern for inclusion in the risk assessment. After
screening to remove chemicals that were at background levels or infrequently detected, the
following numbers of chemicals were included in the risk assessment for each subarea:
18
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DRAWN
BY
R. DOLACK
CHECKED BY
20 FEB 96
APPROVED BY
DRAWING ,. ---, ..,
NUMBER 312263-A45
• B62
AUGUST A. BUSCH MEMORIAL CONSERVATION AREA
• B24
B50
DOE WELDON SPRING
SITE CHEMICAL
PLANT AREA
BG01
MC23
SCALE (APPROXIMATE)
J2TD
3750 S000f«»l
LEGEND
LEAD CONTAMINATION ABOVE 500 PPM
AND GRID DESIGNATION
W.S.T.A. BOUNDARY
ROADS
FIGURE 4
AREAS CONTAINING LEAD
GREATER THAN THE
REMEDIATION GOAL
PREPARED FOR
U.S. ARMY CORPS OF ENGINEERS
KANSAS CITY DISTRICT
...Creating a Safer Tomorrow
-------
DRAWN
BY
R. DOLACK
CHECKED BY
05 APR 96
APPROVED BY
DRAWING, „,--
NUMBER 312263-A44
AUGUST A. BUSCH MEMORIAL CONSERVATION AREA
DOE WELDON SPRING
SITE CHEMICAL
PLANT AREA
OTA
•
A4
SCALE (APPROXIMATE)
3750 SOOOfMt
LEGEND
PCB CONTAMINATION ABOVE 10 PPM
AND GRID DESIGNATION
CARCINOGENIC PAH CONTAMINATION
ABOVE 10 PPM AND GRID DESIGNATION
W.S.T.A. BOUNDARY
ROADS
FIGURE 5
AREAS CONTAINING
PCB AND PAH CONTAMINATION
GREATER THAN
REMEDIATION GOALS
PREPARED FOR
U.S. ARMY CORPS OF ENGINEERS
KANSAS CITY DISTRICT
...Creating a Safer Tomorrow
-------
WSTA - 14 metals
8 nitroaromatics
32 organic compounds, including 17 PAHs and 4 phthalates
WSOW - 4 metals
(outside 5 nitroaromatics
WSTA) 13 organic compounds
Exposure Assessment. The populations at risk of exposure to these chemicals were identified
for the same two subareas:
WSTA - Military personnel training
Permanent staff at WSTA
WSOW - Recreational users of WSOW (hikers, hunters, fishermen)
(outside Occupational, MDC staff
WSTA) Occupational, Howell High School
Students at Howell High School
Future risks were also estimated in the risk assessment. Most future site exposures were
predicted to be the same as present exposures because of a critical assumption that future land
use would remain as a military training facility and wildlife areas rather than be converted to
residential use (reference: Year 2000 Master Plan, St. Charles County Planning Department).
The exposure pathways that were identified for each of these populations were:
• Incidental ingestion of soil (eating and drinking)
• Dermal absorption (skin contact)
• Inhalation (breathing)
• Ingestion of groundwater
The probability of significant exposures by other pathways was considered low. Only the first
three pathways are applicable when evaluating risks associated with direct contact with
contaminated soil. Risks associated with the ingestion of contaminated groundwater will be
assessed in detail during the study of the groundwater operable unit.
For purposes of calculating exposure, concentrations of chemicals in the soil were assumed to
be the 95 percent upper confidence limit of the arithmetic mean of sampling data. Using these
concentrations and exposure factors obtained from EPA's Risk Assessment Guidance for
Superfund, chronic daily intake factors for each chemical within each exposure pathway for a
given population at risk were calculated.
Human health risks from exposure to hazardous chemicals at the site were calculated for two
classes of chemicals: carcinogenic, or cancer-causing, and noncarcinogenic, causing toxic or
21
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adverse health effects other than cancer (such as liver disease or nervous system disorders). The
risk assessment defined unacceptable exposure as: (1) an additional risk of being afflicted with
cancer of more than 1 in 1,000,000, or (2) a daily body uptake (through ingestion, inhalation,
or absorption) of a noncarcinogenic chemical greater than EPA's published reference dose for
that chemical. Where several chemicals were present at a location, the risks were considered
to be additive. Also, for persons who were routinely exposed at several different locations on
the WSOW site, the risks associated with each location were assumed to be cumulative; total
risks for those persons were calculated by adding each area's risk.
Toxicity Assessment. The basic toxicity information and health effects criteria used to calculate
risk for the identified chemicals were obtained from EPA databases—Integrated Risk Information
System (IRIS) and Health Effects Assessment Summary Tables (HEAST). The reported toxicity
value for carcinogenic effects is the cancer slope factor (CSF) and for noncarcinogenic health
effects is the reference dose (RfD).
Risk Characterization. The risk assessment indicated that potential excess cancer risks (greater
than 1 in 1,000,000) were associated with skin contact and inadvertent ingestion of soils
containing TNT, DNT, polynuclear aromatic hydrocarbons (PAHs), and PCBs by personnel in
training and administrative roles at the Army's WSTA. The exposure assessment showed that
recreational users in Busch and Weldon Spring Conservation Areas were estimated to be at
greatest potential risk from contact with soils and nuggets containing TNT and DNT in burning
ground 1 and containing PCBs in Mechanical City. The risks associated with reasonable
maximum exposures to these chemicals at the locations noted above are summarized in Table
2. All other hazardous chemicals in the soil exposure scenarios evaluated in the risk assessment
showed risks considered to be acceptable, including several metals found at elevated levels in
only a few samples.
The risk assessment used an EPA-required model to estimate the risk of exposure to lead in soil
on site. This model is based on exposure for children ages infant to 7 years. It showed no
impact from occupational exposures on WSTA, where most of the lead-contaminated soils were
found. Other WSOW areas where lead was found at elevated levels included recreational
exposures which were appropriate for small children. In these areas, lead was found at such
scattered or infrequently visited locations that the model showed relatively low risk levels.
Therefore, based on the modeling procedures used in the Baseline Risk Assessment, it was
indicated that soil lead concentrations did not cause an excessive human health risk.
However, lead was found at many locations in the soils at WSTA and in the Conservation Areas
in concentrations above those established to be protective for Superfund sites. The cleanup of
lead at all areas within WSOW is therefore based on the EPA Interim Guidance on Establishing
Soil Lead Cleanup Levels at Superfund Sites.
Risk assessment results are summarized in Table 2. A copy of the Baseline Risk Assessment
for WSOW, which contains detailed information on site risks, can be found in the administrative
record at the WSOW Site Office or at the Kisker Road Branch of St. Charles Library.
22
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The risk assessment indicated that actual or potential exposures to hazardous substances from
this site, if not addressed, may present a current or potential threat to public health, welfare, or
the environment.
The wooden pipeline system was not included in the risk assessment because it is buried at an
average depth of 4 feet and persons would not come in direct contact with it repeatedly. The
hazard from the pipeline is primarily safety-related rather than health-related, i.e., accidentally
digging into the buried pipeline is more likely to cause injury from detonation than from
exposure to the TNT inside the pipeline. TNT residue inside the pipeline is also a potential
source of groundwater contamination.
Media
TABLE 2
SUMMARY OF HEALTH RISKS IDENTIFIED IN
WSOW BASELINE RISK ASSESSMENT
(ASSUMING NO REMEDIATION OCCURS)
Type Exposure WSOW Location Chemicals
Carcinogenic
Risk
Surface soil Recreational
Occupational
Burning ground 1
Mechanical City
WSTA admin, area
Sediments
Recreational
TNTA,
DNT
PCBs
TNTB,
PCBs,
many PAHs
WSTA training area TNT0,
DNT,
many PAHs
Beryllium0
Lagoon 1 DNT
Stream n. of WSTA Beryllium0
4.0 x ID'5
1.9 x 10'5
2.8 x 10^
3.4 x 10-5
2.9 x lO'5
3.3 x 10-5
5.5 x 10-6
1.5 x lO'5
6.5 x 10"6
2.4 x 10'5
NDE .
2.2 x ID'5
A Also has a noncarcinogenic hazard index of 6.2, where any number above 1.0 is a
potential health risk.
B Also has a noncarcinogenic hazard index of 8.
c Also has a noncarcinogenic hazard index of 1.3.
D Believed to be naturally-occurring level of beryllium.
E Not determined in BRA, risk based on levels above Remediation Goals for DNT.
Environmental Assessment. The risk assessment included an environmental assessment which
concluded that some animals at WSOW may be at risk due to concentrations of nitroaromatics
and metals in the soils. Specific species potentially affected included wild turkey, long-tailed
23
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weasel (an endangered species), and white-tailed deer. Biologists working in wildlife
management in the two Conservation Areas on WSOW were not able to confirm that these
populations are under stress. The contaminated soils have not affected critical habitat on the
Conservation Areas because of the relatively few acres impacted by contamination.
2.7 DESCRIPTION OF ALTERNATIVES
The alternatives presented here were initially developed for the WSOW Feasibility Study, and
keep the identifying numbers they were given in the FS report. From a preliminary group of
10 alternatives in the FS, the following five survived the screening analysis and were retained
for detailed evaluation:
Alternative 1 No Action
Alternative 3 Containment (Landfill) Plus Some Incineration
Alternative 4 Biological Treatment (Composting)
Alternative 6 Incineration, Rotary Kiln
Alternative 10 Incineration and Landfarming
As the above alternatives were developed and described in the FS, they had components
addressing groundwater contamination. However, ground water has subsequently been split into
a separate operable unit from the surface soil and pipeline media in the WSOW remediation
process. Therefore, the groundwater components are not described or discussed at this time.
Common Elements. Except for the no action alternative, all of the alternatives considered for
the site include a number of common components. These components are described here to
avoid repetition in the later descriptions of alternatives.
All four alternatives include excavation of contaminated soils from locations throughout the site
and transportation of these soils to central treatment and disposal areas on the WSTA portion
of the site. They all include sampling in the excavations and additional sampling following
treatment to assure that all soils above the Remediation Goals are removed and that treatments
are effective. The estimated total volumes of soils by contaminant (as measured in place) are
28,600 cu yd for nitroaromatics, 1,550 cu yd for lead, and 100 cu yd for PCBs and PAHs/ For
Alternative 10, landfarming, only 12,600 cu yd of nitroaromatics-contaminated soils would be
excavated, with the remainder being treated in place. These estimates were prepared in
accordance with FS guidelines which are accurate from -30 to +50 percent.
Excavated areas would be backfilled with clean soil and incinerator ash or regraded, with runoff
controls being implemented during periods that these excavated areas are left exposed. The
excavated areas would subsequently be revegetated for erosion control and habitat restoration
as part of the remedial action.
"For purposes of comparison, 10 cu yd is approximately one dump truck load.
24
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The excavated materials from burning ground 1 and potentially some of the other soils would
be pretreated by screening to separate large pieces of construction debris from the
contaminated soil. The portion of the debris which is unsuitable for incineration or biological
treatment would be spray washed to remove surface contamination and placed in an on-site
landfill. The estimated total volume of debris to be landfilled is 3,900 cu yd.
For all of the final alternatives except no action, the wooden pipeline would be excavated by
trenching and pretreated prior to its primary treatment. In all cases, pretreatment would consist
of removing the steel bands from the outside of the pipeline sections and shredding the sections
so the contaminated wood is more acceptable for treatment. The estimated quantity of pipeline
to be excavated and pretreated is 83,300 feet (just over 2,000 cu yd prior to shredding). Special
procedures and precautions, such as wetting the pipeline interior and avoiding impact or
compression of pipeline sections, will be required during trenching and shredding to prevent a
detonation risk due to the high concentrations of TNT in the residue inside the pipeline. Because
of the relatively high risks associated with the trenching and shredding operations, these
procedures will be subjected to an explosives hazard analysis and U.S. Army Safety Office
review prior to implementation.
Treatment and disposal of lead-contaminated soils in all the alternatives under consideration
involve stabilization of the soils exceeding lead TCLP levels with a chemical binding agent prior
to placement in the landfill. The landfill would also contain construction debris and small
volumes of PCB- and PAH-contaminated soils excavated and would be designed to meet
applicable Federal and State requirements, including linings and leachate collection system. A
RCRA permit would not be needed to construct this landfill because CERCLA remedial actions
conducted entirely on-site are exempt from Federal, state, or local permits according to
CERCLA Section 121(e). The volume of stabilized soil would be slightly more than 1,600 cu
yd. If it is determined that some incinerated soils do not meet regulatory TCLP levels, then
those soils would also be stabilized and landfilled.
The Army has implemented a surface water monitoring program to measure quality and quantity
of water leaving the site. Surface water monitoring will continue during and after remediation
to ensure that this response action has no adverse effect on surface water quality.
Many of the procedures in this plan entail generation of wastewater. This wastewater, along
with any surface water contaminated as a result of this action, will be treated to appropriate
Federal, State, and local standards prior to any discharge.
The final common elements of all the alternatives are groundwater monitoring, well
abandonment, and contaminated soil removal as means of improving groundwater quality. These
are the groundwater process options that are being implemented as a part of the soil/pipeline
remediation to determine whether they constitute a sufficient response to the on-site groundwater
condition. Because these actions are so closely tied to the soil remedial options, they are
included as parts of all the soil and pipeline remediation alternatives.
25
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2.7.1 Alternative 1 No Action
This alternative must be retained in the analysis in accordance with the Superfund Amendments
and Reauthorization Act (SARA). It provides a baseline against which other alternatives can be
compared. The no action alternative would not alter site conditions; all areas having
concentrations of contaminants exceeding cleanup levels would remain as is. Monitoring would
be performed to verify changes in contaminant levels in problem areas to determine if there have
been improvements as a result of natural degradation of contaminants. Because this alternative
would leave hazardous substances on site, reassessment of site conditions would be performed
every five years in accordance with CERCLA Section 121(c). Even though groundwater
monitoring and five-year reassessments would be required if no action were taken, zero costs
have been assigned to this alternative so that it remains an absolute baseline condition for
comparison of other alternatives. The no action alternative would be appropriate only if it is
apparent that concentrations of nitroaromatics and lead in soils and the pipeline are immobile and
do not and will not present a threat to public health, safety or the environment.
Estimated capital costs: $0
Estimated annual O & M costs: $0
Estimated present worth of
capital and 0 & M costs: $0
Estimated implementation time: none
2.7.2 Alternative 3 Containment (Landfill} Plus Some Incineration
This alternative provides for containment of low-level nitroaromatics-contaminated soils (< 2,000
ppm) in an on-site double-lined landfill, and incineration of the pipeline material and highly
TNT-contaminated soils (> 2,000 ppm). The on-site landfill would have design requirements
as specified by RCRA regulations and would also comply with Missouri landfill siting
regulations. Two important provisions of the Missouri siting regulations are that the bottom of
the lowest liner must be 30 feet above the uppermost regional aquifer and the requirement that
a collapse potential evaluation be conducted. This landfill would be constructed adjacent to the
landfill for lead-contaminated soils described under Common Elements, but the nitroaromatics-
contaminated soils would be placed in a separate cell for two reasons: (1) TNT-contaminated
soils would not need to be stabilized, and (2) they would not be compacted or placed under a
permanent lined cap in order to allow aeration and possible biodegradation in the cell for
approximately a 10 year period. Like the adjoining cell for lead soils, this one would include
a lined bottom and sides, a leachate collection system, and a leak detection system. The cell
would be constructed to hold at least 16,000 cu yd of low-level TNT-contaminated soils, and
would be located on the WSTA portion of WSOW if a site acceptable under Missouri's siting
regulations can be found.
A transportable rotary kiln incinerator would be set up on the WSTA portion of the site for
thermal treatment of the pipeline and highly TNT-contaminated soils. The incineration system
26
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and operation would be identical to that described for Alternative 6 (incineration), except that
the operating time would be less due to the lower volume to incinerate. Under this alternative,
an estimated 12,700 cu yd of soil and less than 2,000 cu yd of shredded pipeline are to be
incinerated. At previous nitroaromatics-contaminated sites, rotary kiln incinerators have been
able to reduce TNT concentrations by 99.99 percent to final levels of less than 1 ppm.
The incinerated soil would be returned to excavation areas and used as backfill unless it does
not pass the lead TCLP test. The incinerated pipeline material would also be backfilled if it
passes TCLP and no longer exhibits the characteristic of reactivity.
Estimated capital costs: $14,414,000 (includes contract to operate incinerator)
Est. annual O & M costs (30 yr): $ 105,000 ($25,000 for landfill, $80,000 for ground-
water monitoring)
Estimated present worth of
capital and O & M costs: $16,443,000
Estimated implementation time: 1 year (does not include incinerator set up and trial burn)
2.7.3 Alternative 4 Biological Treatment (Composting}
The nitroaromatics-contaminated soil volume of about 28,600 cu yd (as measured in place) plus
the pipeline volume of 2,000 cu yd would be mixed with nutrients and amendments such as
straw, manure, or wood chips and formed into compost piles. Microbial activity requires a
period of 30 to 40 days to degrade the nitroaromatics and reduce associated toxicity in the
compost mixture. According to laboratory and field studies of contaminated soils in the 0.1 to
5 percent TNT range, the soil must be diluted to at least three times its volume with bulking
agents (amendments) to provide an adequate food source for the microorganisms that accomplish
the treatment and to allow air circulation through the pile. The ratio assumed in the FS was 30
percent soil, 70 percent amendments. This results in approximately 100,000 cu yd of compost
to be treated.
In the FS, the static pile version of composting, which utilizes fixed piping throughout the piles
and a blower to provide aeration, was chosen for WSOW because of its combination of process
control and cost-effectiveness. However, recent comparative testing by the Army Environmental
Center (AEC) has indicated that the mixing provided by windrow composting is more important
to improving treatment efficiency than aeration. Windrows are long narrow piles on concrete
pads that are turned daily or every other day with mechanical equipment to provide mixing,
temperature control, and aeration. Windrow composting is estimated by AEC to be about 35
percent more expensive than static pile composting, but it has a higher probability of achieving
the Remediation Goal of 57 ppm for TNT in soil than the static pile method. The costs shown
below are for windrow composting rather than the static pile costs from the FS.
Treating nitroaromatics by composting is an innovative treatment technology, which is a
desirable feature under CERCLA. The AEC studies show that windrow composting can reduce
27
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TNT concentrations to less than 30 ppm and can reduce the overall toxicity of the soil by 90 to
98 percent. Lab-scale studies on the pipeline material from WSOW indicate that initial
concentrations of 26,000 ppm could be reduced to less than 50 ppm as long as nutrients and
other food sources are available in the compost. Composting has not been tested on the pipeline
material in pilot-scale or full-scale tests.
Studies to date have not been able to demonstrate mineralization (complete degradation to
and water) of the nitroaromatics. These same studies have shown that transformation products
have relatively low toxicity, and may be bound to humic matter in the compost. Therefore, the
composted material would probably require land disposal (in a landfill) and long-term
management to prevent direct contact with WSTA personnel.
Estimated capital costs: $16,351,000
Est. annual O & M costs (30 yr): $ 130,000 ($50,000 for landfill and compost residue,
$80,000 for groundwater monitoring)
Estimated present worth of
capital and O & M costs: $18,349,000
Estimated implementation time: 3 years
2.7.4 Alternative 6 Incineration. Rotary Kiln
A transportable rotary kiln incinerator would be set up on the WSTA portion of the site to treat
contaminated soils and pipeline. The incineration system consists of several interrelated
processes: mechanical feed system, refractory-lined rotary kiln, secondary combustion chamber
(afterburner), heat exchanger, air pollution control system, induced draft fan, and stack. A
gravity feed system is preferable for wastes containing explosives because it reduces the risk of
detonation of materials during the feed process.
The incineration process operates continuously to reduce thermal stress on the refractory material
from repeated heating and cooling. To maintain continuous operation, soils would be stockpiled
in a temporary storage building. This stockpile should be about 1,500 cu yd, or large enough
to support the incinerator during shutdown of excavation operations. A weekly throughput of
1,500 cu yd would imply an incinerator capacity of 10 to 20 ton/hr.
Based on current estimates from the Feasibility Study, a total of about 30,700 cu yd (as
measured in place) of nitroaromatics-contaminated soils and the pipeline would be incinerated.
This thermal destruction process is capable of reducing nitroaromatics concentrations in the feed
material by 99.99 percent, with virtually no detectable concentrations in the ash. Incinerated
soils and pipeline ash that meet regulatory TCLP levels and established remediation goals will
be backfilled on-site.
The incinerator will be required to be in compliance with all Federal, State, and local laws and
regulations. An operating permit is not required for the incinerator, but all substantive
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conditions and requirements of a permit, such as air emission rates, retention times, and
operating temperatures, must still be met.
Estimated capital costs: $21,319,000 (includes contract to operate incinerator)
Est. annual O & M costs (30 yr): $ 105,000 ($25,000 for landfill, $80,000 for ground-
water monitoring)
Estimated present worth of
capital and O & M costs: $22,933,000
Estimated implementation time: 1 year (does not include set up and trial burn times)
2.7.5 Alternative 10 Incineration and Land/taming
This alternative was developed to consider possible advantages of in place biological treatment
of low-level TNT-contaminated soils (< 2,000 ppm) combined with the more expensive
technology of incineration to treat highly contaminated soils and the pipeline. Rotary kiln
incineration in this alternative is used to treat soils with greater than 2,000 ppm of TNT or soils
in areas where landfarming would not be feasible or appropriate. The total amount of materials
to be incinerated is 14,600 cu yd, which consists of 12,600 cu yd of soil and 2,000 cu yd of
shredded pipeline. The incineration process would be operated as described for Alternative 6.
Landfarming involves the application of inorganic nutrients and tilling of soils to promote natural
biological degradation of organic compounds. Design and engineering are mainly tasks of
specifying proper field conditions to encourage microbial growth. For applications where the
distribution of contaminants and geological conditions may vary over a wide range, critical
factors would be delivery of oxygen (if the process is aerobic), addition of nutrients (nitrogen,
phosphorous, trace elements), removal of toxic levels of chemicals, maintenance of proper soil
moisture, and adjustments of pH and temperature.
Landfarming has not been demonstrated in the field for treating nitroaromatics chemicals such
as TNT that are resistant to degradation. Therefore, this alternative has a higher degree of
uncertainty associated with it than incineration or composting. Limited lab-scale studies have
shown some promise in implementing landfarming for the degradation of nitroaromatic
compounds. Field studies are planned at WSOW to determine treatment efficiencies and time.
Landfarming would require frequent confirmatory testing to assess progress in degradation.
Estimated capital costs: $13,577,000 (includes contract to operate incinerator)
Est. annual O & M costs (3 yr): $ 246,000
Est. annual O & M costs (30 yr): $ 105,000 ($25,000 for landfill, $80,000 for ground-
water monitoring)
Est. present worth of
capital and O & M costs: $15,858,000
Estimated implementation time: Unknown for landfarming, 1 yr for incineration (does not
include incinerator set up and trial burn time)
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2.8 SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES
EPA has identified nine evaluation criteria against which final remedial action alternatives are
to be evaluated. The purpose of these criteria is to focus the evaluation of alternatives to address
statutory requirements identified in Section 121 of CERCLA and Section 300.430(f) of the
National Contingency Plan. This enables the Army and EPA to determine the most appropriate
solution for the specific problems at an NPL site. These statutory requirements and EPA
program goals include protection of human health and the environment, compliance with
Applicable or Relevant and Appropriate Requirements (ARARs), preference for permanent
solutions with treatment as a principal element (to the maximum extent practicable), and cost-
effectiveness (see Section 2.10). EPA's nine evaluation criteria are summarized below:
1. Overall protection of human health and the environment addresses whether a remedy
provides adequate protection (of human health and the environment) and describes how
risks posed through each exposure pathway are eliminated, reduced, or controlled
through treatment, engineering controls, or institutional controls.
2. Compliance with ARARs addresses whether or not a remedy will meet all of the
applicable or relevant and appropriate requirements of other Federal and State
environmental statutes and/or provide grounds for invoking a waiver.
3. Long-term effectiveness and permanence refers to the capability of a remedy to
maintain reliable protection of human health and the environment over time once cleanup
goals have been met.
4. Reduction of toxicity, mobility, or volume through treatment addresses the statutory
preference for selecting remedial actions that permanently and significantly reduce the
toxicity, mobility, or volume of hazardous substances at a site by evaluating the extent
to which this is achieved by each alternative.
5. Short-term effectiveness evaluates the period of time needed to achieve protection, and
any adverse impacts on human health and the environment that may be posed during the
construction and implementation period until cleanup goals are achieved.
6. Implementability is the technical and administrative feasibility of a remedy, including
the availability of materials and services needed to implement a particular option.
7. Cost includes estimated capital and operation and maintenance costs as well as net
present worth costs.
8. State acceptance indicates whether MDNR agrees with the selected remedy; this section
incorporates the agency's comments and concerns.
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9. Community acceptance addresses the formal comments made by the community on the
preferred alternative and other alternatives under consideration.
The first two criteria are considered threshold criteria and must be met by each remedial action
alternative in order to be eligible for selection. The next five criteria are considered primary
balancing criteria and are evaluated together to identify the advantages and disadvantages
between alternatives at the specific site so that the best option will be chosen. The last two are
considered modifying criteria and are to be considered during remedy selection based on
comments received on the Proposed Plan. This section profiles the expected performance of the
five final alternatives in terms of these nine evaluation criteria, and provides the rationale for
remedy selection.
Overall Protection. All of the final alternatives except no action (Alternative 1) would provide
adequate protection of human health and the environment by eliminating, reducing, or
controlling risk through treatment, containment, or institutional controls. Alternative 6
(incineration) provides the greatest overall protection by treating the nitroaromatics-contaminated
soils and pipeline by incineration and lead-contaminated soils by stabilization/landfill, and would
be able to exceed the protection established by the Remediation Goals. At other explosives-
contaminated sites, the thermal destruction process has reliably reduced nitroaromatics
concentrations in soils by 99.99 percent to final concentrations less than 1.0 ppm. Chemical
stabilization has been proven to be an effective technology to remediate lead-contaminated soils.
The no action alternative is not protective of human health and the environment, so it is not
considered further as a realistic option.
The biological treatments employed in Alternatives 4 (composting) and 10 (landfarming) provide
protection that possibly meets the levels of the Remediation Goals but leaves residual
contamination of TNT or transformation products. Biological treatment is currently shown to
be less reliable than thermal treatment or containment. Also, it cannot easily treat nuggets of
TNT because of localized toxicity. In the case of composting for TNT, it also leaves poorly
defined transformation products that are not mineralized (degraded to inorganic end products
such as CO2 and water). These biodegradation products could under certain conditions have
residual toxicity.
An on-site landfill for isolation of lead-, PCB-, and PAH-contaminated soils is included in all
of the alternatives except no action. Landfill disposal includes chemical stabilization treatment
for lead-contaminated soils exceeding the lead TCLP level. Alternative 3, the
containment/landfill alternative, also provides for containment of nitroaromatics-contaminated
soils of less than 2,000 ppm. Containment is as effective as incineration in reducing exposures
to the toxic chemicals, but does so by isolating the contaminated soils from the environment
rather than by destroying the chemicals. The disadvantage of landfilling is that the protection
is not permanent. Landfills have a finite life and may result in a future requirement to rebuild
or replace the landfill.
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Compliance With ARARs. All of the final alternatives except no action can meet their
respective applicable or relevant and appropriate requirements of Federal and State
environmental laws. Chemical-specific ARARs and "to be considered" levels for soils are met
by basically the same methods by all alternatives—incineration or biotreatment for nitroaromatics
and landfill with stabilization as needed for lead, PCBs, and PAHs. Wastes with explosives
concentrations high enough to be reactive (i.e., detonation will propagate throughout the
material) must be treated to nonreactive levels before they can be placed in landfills, according
to EPA's RCRA regulations. However, the reactivity characteristic would be removed by either
incineration or biotreatment, so these treated wastes would no longer be considered hazardous
for final disposal purposes. Location-specific ARARs (such as the Endangered Species Act) for
the WSOW site and action-specific ARARs (such as the Missouri landfill siting regulations) for
each of the remedial alternatives that were identified in the Feasibility Study can be achieved.
Compliance of the selected alternative with ARARs is verified in detail in Section 2.10,
Statutory Determinations.
Long-term Effectiveness and Permanence. Alternative 6 (incineration) provides a permanent
and irreversible destruction of nitroaromatics-contaminated materials. This results in virtually
no risk of future exposure from treated material for this part of the alternative. The removal
and destruction of nitroaromatics from the soil has a positive indirect effect in that it also
removes a potential source of groundwater contamination. Incineration is a proven technology.
The other technologies considered for the remediation of nitroaromatics in soil and pipeline are
either developmental or only provide partial destruction with disposal of the treated soil being
an issue. The biotreatment processes in particular rely on treatment conditions that cannot be
achieved under all circumstances and could produce transformation products over an extended
time that are of unknown composition and toxicity. Incinerated soil can be backfilled throughout
the site, but biotreated (composted) soil would probably have to be isolated and monitored over
an extended period (possibly years). Landfarming (Alternative 10) would leave the soil in place,
and would entail land use restrictions until verification of degradation is made.
The landfill for lead-contaminated soils would isolate the lead and therefore reduce exposure
risks for the life of the landfill facility (at least 30 years). However, the landfill would require
long-term operation and maintenance as a permanent facility and would not reduce the toxicity
of its contents. Stabilization of lead-contaminated soils failing lead TCLP is intended to reduce
potential for mobility and exposure, and therefore to improve the long-term effectiveness of the
landfill components of each alternative.
Reduction of Toxicity, Mobility, or Volume. Reduction in toxicity, mobility, or volume of
hazardous wastes is met by all the alternatives (except no action) to varying degrees. The
incineration alternative is most effective in this category because it accomplishes all three of the
objectives. The biological treatments reduce toxicity and possibly mobility, but they would
increase volume in the case of composting (Alternative 4). Landfill options have no effect on
toxicity, decrease mobility, and may increase volume (by addition of stabilizing chemicals, etc.).
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Stabilization is needed as part of the landfill components to satisfy the statutory preference for
alternatives that provide treatment.
Short-term Effectiveness. All the final alternatives except no action include pipeline trenching
and excavation of burning ground 1, both of which involve significant worker risks from
exposure and from potential TNT detonation. All four alternatives include pipeline trenching
and excavation of burning ground 1. This means that the relative differences in risks among
alternatives is small. Other major construction phase risks are those associated with operation
of the incinerator (Alternatives 3, 6, and 10); the repeated potential exposures and space
requirements associated with landfarming (Alternative 10); the danger of pipeline shredding (all
alternatives); and potential contacts during the long time required for composting (Alternative
4). These are all primarily remediation worker risks, and can be decreased considerably by
proactive worker protection plans. The non-reducible worker risks associated with incineration
are greater than those for landfarming or composting. Stabilization and landfilling do not have
significant worker risks.
During remediation, the selected incineration alternative will also have air emissions. As part
of the remedial design, atmospheric dispersion modeling and risk assessment calculations will
be conducted to assure that the emissions do not cause unacceptable health risks to receptor
populations on-site or off-site. The analyses will include determination of impacts from air
emissions of metals in the soil and products of incomplete combustion as well as nitroaromatics
not destroyed by the incineration.
Implementation time for Alternative 6 would be one to two years according to the Feasibility
Study, not including time to establish operating performance standards. In comparison,
landfilling for nitroaromatics-contaminated soils (Alternative 3) would also require one to two
years, composting (Alternative 4) would take about three years, and landfarming (Alternative
10) would take an undetermined period (for estimating purposes, a 3 to 4 year period has been
assumed). The biotreatment alternatives' time estimates do not include time prior to
implementation needed for site-specific treatability studies, including optimization studies needed
to establish the most effective mixture of nutrients and moisture.
Implementability. All of the final alternatives except no action have a landfill operation and
all except no action and composting have some incineration. While these two process options
(landfill and incineration) require large efforts for design and implementation, they are both
proven technologies that could be completed in one to two years on the WSOW site. The
landfill component of any alternative will have operation and maintenance requirements for at
least 30 years, which is a major implementation and administrative effort.
Incineration is a complex operation that is anticipated to have some downtime and require the
most attention during operation, but no major problems are anticipated since this technology has
been used extensively. Incineration also requires monitoring of stack emissions, ambient air
quality, and ash quality throughout the implementation period. In contrast, composting and
landfarming are not mechanically complex and need a much lower level of attention over a more
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extended treatment period. Incineration requires more skilled laborers than the other
alternatives, but availability of a qualified labor pool is not expected to be an issue because the
site is located in a major metropolitan area of almost 3 million people.
The two alternatives with biotreatment components, composting (4) and landfarming (10), will
both require optimization/treatability studies prior to full-scale remediation and are therefore less
easily implemented.
Incineration of 30,000 or more cubic yards of contaminated material is usually bid by an
experienced group of firms that use mobile incinerators. Performance requirements in the
contract assure that treatment levels and discharge conditions are met. No Federal, state, or
local permits are required for remedial actions conducted entirely on a CERCLA site, where
such remedial action is selected and carried out in compliance with CERCLA. However, state
technical requirements for operation may still be imposed. State conditions are most likely to
have an impact on the implementability of the incineration alternatives.
Composting (Alternative 4) requires the least amount of construction, while the three alternatives
with some incineration (3, 6, and 10) all have larger construction requirements. Other
implementability concerns such as property access, transportation of wastes, and laboratory
ability to accommodate required samples do not differ significantly between alternatives and
therefore do not enter into the evaluation.
Cost. Alternative 6 (incineration) has the highest present worth cost of the four under active
consideration at $22,933,000. Alternative 10 (landfarming) has the lowest present worth cost
at $15,858,000. However, the landfarming process is unproven on nitroaromatics-contaminated
soils, so its cost estimate has a much higher uncertainty than that for incineration. Alternative
4 (composting), which has a present worth cost of $18,349,000, also has a high uncertainty
associated with its costs because they are based primarily on pilot-scale installations for TNT
rather than full-scale applications.
State Acceptance. MDNR has been actively involved in the entire RI/FS process for WSOW
leading to the development of this ROD, including being a party to the Interagency Agreement,
participating in all technical review and public meetings, oversight of field work, and review and
comment on all draft project documents. The agency continues to work toward a final decision
for timely remediation of the site.
At the December 1993 public meeting on the Proposed Plan, MDNR reserved the right to
consider public comments before concurring with the proposed alternative of on-site incineration
and landfill. The agency subsequently requested that the following additional information be
provided before it could support the Proposed Plan:
• Technical data from comprehensive test burns of similar wastes at Army Ammunition
Plant sites such as Cornhusker, Louisiana, and Savanna.
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• Evaluation of existing and planned off-site commercial incinerators for treatment of soils
and pipeline.
• Evaluation of results of anaerobic bioremediation pilot study recently performed at
wsow.
MDNR agreed to a 30 day extension in the public comment period for agency and public review
of the requested information.
The Army provided all the available requested information directly to MDNR and placed it in
the administrative record for public review. MDNR has notified the Army that the data
provided is adequate and no further information has been requested.
Community Acceptance. Public opinion in the community of St. Charles County, as measured
by written and public meeting comments, was mixed toward the selected remedy of on-site
incineration and landfill. Elected officials in the area did not endorse or oppose the selected
alternative. Planned community relations activities such as public meetings, availability sessions,
preparation of information repositories, and focus group sessions were conducted in St. Charles
County.
However, most of the comments came from persons in other parts of the St. Louis metropolitan
area who were opposed to incineration. Most of these comments were relative to air pollution
emissions from incinerators: an additional source in a metropolitan area with already poor air
quality; dispersion over a wide area of unburned site contaminants; generation of new toxic
compounds by the incineration process; and excess emissions during incinerator upset conditions.
There were also concerns expressed about spreading radioactive materials originally from the
DOE site through the incinerator's emissions. All these concerns have been responded to in the
Responsiveness Summary (Section 3.0) of this ROD and will be further addressed with
engineering and operating safeguards specified for the incineration process to prevent harmful
levels of air pollutants from being discharged by the incinerator.
2.9 SELECTED REMEDY
The remedy selected on the basis of conformity with the nine EPA evaluation criteria is
Alternative 6, Rotary Kiln Incineration. Under this alternative, nitroaromatics-contaminated
soils and wooden pipeline will be treated by incineration, lead-contaminated soils will be
stabilized if needed to meet lead TCLP requirements and placed in the on-site landfill, and
construction debris separated from the contaminated soils will also be disposed of in the on-site
landfill.
The treatment methods specified in the selected remedy will substantially reduce risks associated
with the contaminated materials that represent the principal threat at the site. Incineration and
stabilization are both proven technologies for treating nitroaromatics and lead in soils,
respectively. The most important factors in choosing the selected remedy are: (1) it will provide
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a permanent solution through destruction of nitroaromatics-contaminated materials; (2) it uses
proven treatment technologies to the maximum extent practicable while providing the best
balance of tradeoffs with respect to the evaluation criteria; and (3) it significantly reduces the
toxicity, mobility, and volume of the principal contaminants (nitroaromatics) at the site and
reduces the mobility of the other principal site contaminant (lead). Also, the incineration ash
(incinerated soil that passes TCLP) can be backfilled on-site with no long-term waste
management requirements.
Major components of the selected remedy are:
• Excavation of contaminated soil with levels above the Remediation Goals. This includes
TNT above 57 ppm, DNT above 2.5 ppm, lead above 500 ppm, total PCBs above 10
ppm, and PAHs above 10 ppm.
• Excavation of an estimated 83,300 feet of wooden pipeline buried at average depths of
4 feet. This includes necessary clearing and grubbing to access the pipeline, which is
located almost entirely within the boundaries of WSTA.
• Transportation of contaminated soils and pipeline from excavation sites to the
pretreatment and treatment (incinerator) or containment (landfill) locations, and storage
prior to treatment in accordance with RCRA substantive standards.
• Debris separation by screening to remove materials either too large or not appropriate
for incineration. Separated materials will either be shredded and returned to the waste
stream to be incinerated or sprayed with high pressure water to remove surface
contamination prior to landfill disposal.
• Removal of steel bands from wooden pipeline prior to the shredding process.
• Shredding of the wooden pipeline to reduce it to a size that is more acceptable for
incineration and that can be handled by the incinerator feed system. Shredding will be
done under controlled conditions to prevent detonation.
• Incineration of contaminated soils and debris (above Remediation Goals) and shredded
pipeline material on-site in a rotary kiln incinerator unit constructed and operated in
accordance with RCRA substantive requirements. Air emissions from the incinerator will
be controlled to levels required by MDNR regulations.
• Testing of ash to determine if it is below Remediation Goals, below TCLP levels, and
below land disposal restriction levels. If all criteria are satisfied (and the ash is not listed
waste generated from incineration of DNT-contaminated soil from the DNT lines), then
the ash can be used as backfill.
• Stabilization of lead-contaminated soils and some incinerator ash that do not pass lead
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TCLP with binder materials to prevent leaching of contaminants.
• Landfill of stabilized lead-contaminated soils and stabilized incinerator ash in an on-site
landfill designed to meet applicable Federal and State criteria.
• On-site landfill of PAH-contaminated soils and PCB-contaminated soils with PCB
concentrations less than 50 ppm.
• Landfill of screened materials and non-hazardous construction debris in the on-site
landfill designed to at least meet appropriate solid waste landfill requirements.
• Backfill of excavations with ash from the incineration process that passes TCLP (except
soils from DNT lines) and revegetation of the backfilled areas. The ash can be used as
backfill because it is not a RCRA listed waste.
• Treatment of contaminated wastewater and storm water runoff.
• Contingency for off-site disposal of treated wastewater and storm water runoff at a
publicly owned treatment works in the event that short-term generation exceeds capability
to reuse the water in the incinerator.
• Abandonment of wells no longer in use (in accordance with Missouri 10 CSR 23-4),
removal of underground storage tanks (in accordance with Missouri 10 CSR 20-10),
demolition of laboratory building S-22, and other miscellaneous remedial actions.
• Contingency for off-site disposal of small quantities of hazardous wastes, such as listed
waste U105 or U106 (DNT-contaminated soils from DNT lines) or soils with PCB
concentrations above 50 ppm, if encountered, that would otherwise require more
stringent design of on-site treatment/disposal facilities.
This remedy will remove the remaining ordnance works-related contamination from the WSOW
site so that it can be fully utilized for current and future land uses, which include wildlife
management and military training. These actions will address the direct threat by remediating
surface soil and pipeline media site-wide, and will also reduce the indirect threat of groundwater
contamination to the extent that either the soil or pipeline serve as a source of the groundwater
contamination.
Wastes from other sites or facilities will not be accepted for treatment and/or disposal at WSOW
under this remedy.
Total implementation time for the selected remedy is estimated to be less than two years, with
more than six months of that time devoted to mobilization of the incineration unit and trial burn
requirements. Excavation, landfill construction and placement, incineration, and site restoration
are expected to take one to two years.
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The estimated present worth costs for the selected remedy are $22.9 million based on the
conceptual design for the Feasibility Study. These costs are broken down as follows:
Contaminated soil excavation $ 1.9 million
Debris separation 0.1
Pipeline excavation 0.7
Pipeline shredding 0.2
Incineration 12.4
Stabilization 0.1
Landfill of lead-contaminated soils 0.2
Landfill of construction debris 0.5
Backfill and regrading 0.1
Other construction 0.2
Engineering 1.6
Remediation oversight 0.8
Operation and maintenance 1.6
Contingencies 2.5
The operation and maintenance costs are for the 30-year period following remediation and are
estimated at $105,000 per year ($25,000 for landfill monitoring and $80,000 for groundwater
monitoring) with a discount rate of 5 percent.
The selected alternative will achieve the Remediation Goals shown in Table 3. The three soil
contaminants with risk-based Remediation Goals (TNT, DNT, PAHs) are based on excess
carcinogenic risks of 1 x 10"6. This relatively high degree of protection was established because
the site is primarily a Conservation Area with free public access. The Remediation Goal for
PCBs in soil is based on an ARAR, the EPA PCB Spill Cleanup Policy (40 CFR Part 761); the
Remediation Goal for lead is based on "To Be Considered" material (guidance rather than
regulation), the EPA Interim Guidance on Establishing Soil Lead Cleanup Levels at Superfund
Sites (OSWER Directive #9355.4-02).
TABLE 3
REMEDIATION GOALS FOR WSOW
REMEDIATION SOURCE
CHEMICAL GOAL, me/kg (pom) REMEDIATION GOAL
2,4,6-TNT 57 10'6 risk, residential exposure
2,4- and 2,6-DNT 2.5 lO"6 risk, residential exposure
Total PCBs 10 EPA PCB Spill Cleanup Policy
Total carcinogenic PAHs 10 10"6 risk on WSTA
Lead 500 EPA Superfund Site Lead Policy
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2.10 STATUTORY DETERMINATIONS
In accordance with the statutory requirements of Section 121 of CERCLA, as amended, remedial
actions that are selected are required to:
• Be protective of human health and the environment
• Comply with applicable or relevant and appropriate requirements (ARARS)
• Be cost-effective
• Use permanent solutions and alternative treatment technologies to the maximum extent
practicable
• Satisfy the preference for treatment which, as a principal element, reduces toxicity,
mobility or volume
The manner in which the remedial action for WSOW satisfies the above requirements is
discussed in the following sections.
The selected remedy must undergo five-year reviews as specified in CERCLA Section 121(c)
because hazardous substances will remain on-site in a landfill above health-based Remediation
Goals.
2.10.1 Protection of Human Health and the Environment
The selected remedy will reduce risks to future users of the site through removal and rotary kiln
incineration of soils contaminated by nitroaromatics; removal and incineration of the pipeline;
and removal, stabilization and on-site landfilling of lead-contaminated soils. The remedy
includes excavation and incineration of all soils with TNT or DNT concentrations above the risk
based Remediation Goals given in Table 3. These goals provide for excess carcinogenic risk
from exposure to site soils of less than 1 x 10"6 based on assumed residential use of the site;
actual use of the site will be recreational and occupational, which generally results in less
frequent exposures to contaminated media. No unacceptable short-term risks or cross-media
impacts will be caused by implementing this remedy.
Soils contaminated by PCBs and PAHs above their Remediation Goals of 10 ppm will also be
excavated and landfilled. The PCB goal is based on the EPA's PCB Spill Cleanup Policy. The
PAH goal is based on the risk assessment previously discussed (Section 2.6) and is for
occupational and recreational usage of the site.
The pipeline does not currently present a health risk as it is unlikely that people would come into
direct contact with it repeatedly. The hazard from the pipeline is primarily safety-related rather
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than health-related, i.e., accidental rupture of the buried pipeline is more likely to cause injury
from detonation than from exposure to the TNT inside the pipeline. The pipeline will be
removed and incinerated, based on the non-quantified safety risk.
Lead was not found to pose a hazard to human health and the environment through current risk
assessment guidance (See Section 2.6). Lead was, however, found at many locations in the soils
at WSTA and in the Conservation Areas in concentrations above those established to be
protective for Superfund sites. The cleanup of lead at WSOW is therefore based on the EPA
Interim Guidance on Establishing Soil Lead Cleanup Levels at Superfund Sites, which was
included as To Be Considered material during determination of ARARs for the site. The
cleanup level is 500 ppm in soils.
2.10.2 Compliance with Applicable or Relevant and Appropriate Requirements
The selected remedy will comply with applicable or relevant and appropriate requirements
(ARARs). The ARARs are presented in Table 4 according to chemical-specific, location-
specific, and action-specific requirements. The incinerator and landfill will be located within
the areal extent of contamination or in some suitable area in very close proximity to the
contamination necessary for implementation of the response action. Excavation, incineration,
and landfilling are actions which will be conducted entirely on-site and for which no Federal,
State, or local permits will be required [CERCLA § 121(e)(l), 42 U.S.C. 9621(e)(l) and the
National Contingency Plan § 300.400(e)]. The on-site actions must comply with the substantive
requirements of any Federal or State environmental laws that are ARARs.
2.10.3 Cost-Effectiveness
The selected remedy has been estimated to cost $22.9 million and require 1 to 2 years to
complete. These figures are estimates developed during the Feasibility Study and may change
as detailed engineering design is completed. The selected remedy is cost-effective because it
involves proven technologies which will effectively achieve the Remediation Goals. Other
alternatives involve lower cost, but cost estimates for these remedies are more uncertain as they
involve technologies which have not yet been tested and proven. The potential for schedule
delays and resultant increased costs is reduced by the use of a proven technology.
2.10.4 Use of Permanent Solutions and Alternative Treatment Technologies to the Maximum
Extent Practicable
The selected remedy utilizes proven treatment technologies which provide permanent solutions
to the maximum extent possible and provides the best balance of tradeoffs among the alternatives
with respect to the evaluation criteria, especially the five balancing criteria. Alternative
treatment technologies which provide permanent solutions are not available for lead. Alternative
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technologies such as biotreatment for nitroaromatics have not yet reached the stage of
development where they may be relied on for remediation for the types of soils at WSOW.
Alternative treatments for PCBs and PAHs, given their relatively small site impact, would not
be cost effective. The selected remedy will result in the permanent removal through incineration
of nitroaromatics contaminants above Remediation Goals for the site. Lead-, PCB-, and PAH-
contaminated soils will be landfllled in an appropriate landfill which will significantly reduce
contaminant mobility.
2.10.5 Preference for Treatment Which Reduces Toxidtv. Mobility or Volume
The principal threat to human health at WSOW is from incidental ingestion and dermal contact
with contaminated soil. The selected remedy provides treatment of this contaminated soil that
significantly reduces the toxicity, mobility and volume of the principal contaminants
(nitroaromatics) at the site and reduces the mobility of the other principal site contaminant (lead).
The toxicity and volume of nitroaromatics-contaminated soils and sediments will be reduced
through incineration. Destruction of these contaminants means their mobility would also no
longer be of concern. The mobility of the lead, PCBs, and PAHs will be reduced by landfilling
and, in the case of lead exceeding TCLP levels, stabilization.
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TABLE 4
APPLICABLE OR RELEVANT AND APPROPRIATE REQUIREMENTS
CHEMICAL SPECIFIC
Citation
40CFR261.23
40 CFR 26 1.24 and
10 CSR 25-4.261
Toxicity Characteristic
Leaching Procedure (TCLP)
Federal Register Volume
55, March 29, 1990
40 CFR 26 1.24 and
10 CSR 25-4.261
Toxicity Characteristic
Leaching Procedure (TCLP)
Federal Register Volume
55, March 29, 1990
40 CFR 26 1.32
Contaminant
Reactivity
Characteristic
2,4-
Dinitrotoluene
(EPA Haz.
Waste Code
D030)
Lead (EPA
Hazardous
Waste Code
D008)
Haz. Wastes
from specific
sources:
Kill, K044,
K047
Medium
Soil
Pipeline
Soil
Soil
Pipeline,
WWTP
sludges,
wastes
Requirement
If the medium has any of the properties
described in 261.23(a), it is a hazardous
waste with EPA Haz. Waste No. D003
0.13 mg/1 RCRA TCLP level
If the extract from the TCLP contains a
concentration equal to or greater than
0. 13 mg/1 (or at the quantitation limit, if
0.13 mg/1 is lower than the quantitation
limit) of 2,4 DNT, the waste is
considered hazardous
5 mg/1 RCRA TCLP level
If the extract from the TCLP contains a
concentration equal to or greater than 5
mg/1 of lead, the waste is considered
hazardous
Kill- washwaters from production of
DNT via nitration of toluene; K044 -
wastewater treatment sludges from
manufacturing and processing of
explosives; K047 - pink/red water from
TNT operations
Discussion
RCRA substantive requirements for the treat-
ment/storage/disposal of hazardous wastes
are relevant and appropriate for those wastes
Wastes to be landfilled at the site which have
concentrations above this level must go into
Subtitle C landfill; below this level can go
into Subtitle D landfill.
Wastes to be landfilled at the site which have
concentrations above this level must go into
Subtitle C landfill; below this level can go
into Subtitle D landfill.
K044 and K047 are listed solely because
they exhibit the characteristic of reactivity.
Kill is listed because of the presence of
DNT. Any residues from the treatment of
Kill waste is still considered a hazardous
waste and must be disposed of in a Subtitle
C landfill once LDRs are met.
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Citation
Contaminant
Medium
Requirement
Discussion
40CFR261.33
Discarded
commercial
chemicals,
off-spec.
products,
container and
spill residues:
U105, U106.
Soil
If the medium from the DNT production
lines contains 2,4-DNT (U105) or 2,6-
DNT (U106), the wastes are hazardous
wastes
RCRA substantive requirements for the treat-
ment/storage/disposal of hazardous wastes
are relevant and appropriate for those
wastes. Since these wastes are listed wastes,
any residue from the treatment of the waste
are still considered hazardous wastes and
must be disposed of in a Subtitle C landfill
once LDRs are met.
40CFR761,SubpartD,
Subpart G [PCB Spill
Cleanup Policy], Federal
Register Volume 52, No. 63
April 2, 1987
PCBs
Soil
Cleanup Level of 10 ppm for unrestricted
access; Action Level of 50 ppm
This requirement was used in the
development of the remediation goal for
PCBs.
40 CFR 61, Subpart M,
National Emission Standards
Co Hazardous Air Pollutants
40 CFR 61.140, 61.141,
61.145,61.150,61.154,
61.155
Asbestos
Air,
Build-
ings,
Debris
61.140-Applicability
61.141 - Definitions
61.145 - Demolition and renovation
61.150 - Standard for waste disposal
61.154 - Active waste disposal sites
61.155 - Operations that convert asbestos
containing waste into
nonasbestos material
Warning signs should be posted, and no
visible discharge should occur during the
collection, processing, packaging,
transportation, or deposition of friable
asbestos containing material. This
requirement must be met during excavation
and landfill activities at the site.
40 CFR 50.4
40 CFR 50.6
40 CFR 50.8
40 CFR 50.9
40CFR50.il
40 CFR 50.12
National Ambient Air
Quality Standards
Sulfur dioxide
Particulate
Carbon
monoxide
Ozone
Nitrogen
dioxide
Lead
Air
80 ug/m3 annual arithmetic mean, 365
ug/m3 24 hr, not more than once/year
150 ug/m3 24 hr, not more than once/yr
10 mg/m3 8 hour average and 40 mg/m3
1 hour average, not more than once/year
235 ug/m3
100 ug/m3 annual arithmetic mean
1.5 ug/m3 maximum arithmetic mean
averaged over a calendar quarter
Emissions will be controlled during remedial
activities to address this standard.
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Citation
10 CSR 10-5.050
Restriction of Participate
Matter Emissions from
Industrial Processes
10 CSR 10-5.090
Restriction of Emission of
Visible Air Contaminants
10 CSR 10-5.150
Emission of Sulfur
Compounds Restricted
Missouri Air Pollution Con-
trol Regulations; Air Qual-
ity Standards and Air
Pollution Control Regs, for
the St. Louis Metro. Area
10 CSR 10-6.010
Ambient Air Quality
Standards
10 CSR 10-6.060
Missouri Air Quality
Standards
10 CSR 10-6.170
Missouri Air Quality
Standards
Contaminant
Participate
Visible
Emissions
Sulfur
Compounds
Particulate,
Lead, et al.
Particulate,
lead, asbestos,
et al.
Particulate
Matter
Medium
Air
Air
Air
Air
Air
Air
Requirement
Particulate matter shall not exceed a
concentration of 0.30 grain/ft3 of exhaust
gas.
Regulates visible discharge of air
contaminants
Regulates emission of sulfur compounds
Ambient air quality standards are set
Requires permits for air emissions. Sets
de minimis levels for emissions.
Prevent fugitive dust emissions from
escaping property boundaries of origin.
Discussion
This requirement must be met during
excavation and incineration activities.
This requirement must be met during
incineration.
This requirement must be met during
incineration.
Substantive requirements of this rule must be
met.
Substantive requirements of this rule must be
met.
This requirement must be met during
excavation and landfill activities at the site.
To Be Considered (TBC)
EPA Directive )5<9355.4-02
EPA Interim Guidance on
Establishing Soil Lead
Cleanup Levels at
Superfund Sites
Lead
Soil
Remediation goal of 500 ppm was
established based on this guidance.
Removal of soils exceeding this goal will be
accomplished during cleanup.
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LOCATION SPECIFIC
Citation
Location
Requirement
Discussion
50 CFR 17.402
40 CFR 6.302(h)
Endangered Species Act
of 1973, as amended
Wildlife
Areas/Critical
Habitat
The effects of No Action remedial construction
and discharge activities must be considered if
endangered species are impacted.
Remedial actions undertaken are not likely to
jeopardize any threatened or endangered species
nor destroy any critical habitat. Efforts will be
made to ensure that no critical habitat is impacted.
3 CSR 10-4.110
Missouri Wildlife Code
Site
Wildlife, including their homes and eggs
should not be taken, molested, hunted,
trapped, killed or transported except under
permitted conditions.
No wildlife will be actively taken, molested or
disturbed during remediation. Efforts will be
made to minimize potential impacts to wildlife.
3 CSR 10-4.110
Missouri Wildlife Code
Streams, Lakes
Prohibits placing deleterious substances into
waters of the state in quantities sufficient to
injure fish, except as approved by the state.
Runoff from excavation activities could impact
nearby streams and lakes. Design will include
controls to minimize such impacts.
40 CFR 4.302(a)
Fish and Wildlife
Coordination Act
Streams, Lakes
Protection of fish and wildlife is required when
federal agency proposes modification of stream
or water body, or areas affecting stream or
water body.
Runoff from excavation activities could impact
nearby streams and lakes. Design will include
controls to minimize such impacts.
3 CSR 10-4.111
Missouri Wildlife Code
Site
Endangered species should not be pursued,
taken, possessed or killed.
No adverse impacts to threatened or endangered
species are expected to result from remedial
activities. Efforts will be made to ensure that no
critical habitat is impacted.
3 CSR 10-4.115
Missouri Wildlife Code
Wildlife Areas
Digging and other soil disturbance is
prohibited in wildlife areas unless specifically
authorized.
Authorization by wildlife area authorities
(Missouri Department of Conservation) will be
obtained before any excavation or other activities
are performed in the wildlife areas.
10 CSR 20-7.031
Portion of
Dardenne Creek
watershed
Listed in water quality standards as
metropolitan no-discharge watershed.
Specific limitations for this category of waters are
contained in the permit regulation, 10 CSR 20-
7.015.
40CFR264.18b
RCRA Treatment,
Storage and Disposal
Facilities
Floodplain
Facilities must be designed, constructed,
operated and maintained to avoid washout by
100 year flood.
All treatment, storage and disposal facilities areas
will be located beyond areas affected by 100 year
flood.
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Citation
Location
Requirement
Discussion
Federal Executive Order
11988 and Missouri
Governor's Executive
Order 82-19
Floodplain
Adverse impacts associated with activities in a
floodplain should be avoided to the maximum
extent practicable.
All treatment, storage and disposal locations will
be located outside of floodplains. Efforts will be
made to limit any activities (i.e. excavation) in
floodplains.
40 CFR 230 and 232
Clean Water Act;
Disposal Sites, Dredged
or Fill Material
Wetlands
Dredge or fill material is not to be discharged
into or removed from a wetland without a
permit
No permit is required for excavation activities
because the wetlands are within an NPL site and
therefore exempt. No compensation for remed-
iation because it allows for return of habitat usage.
Federal Executive Order
11990 Protection of
Wetlands
Wetlands
Adverse impacts associated with the
destruction or loss of wetlands should be
avoided to the maximum extent practicable.
All treatment, storage and disposal areas will be
located outside of wetland areas. Efforts will be
made to limit any activities (i.e. excavation) in
wetland areas.
o\
36 CFR 800
National Historic Preser-
vation Act and 88 Stat
174 Archeological and
Historic Preservation Act
Site
Significant artifacts must be recovered and
preserved if terrain alteration threatens
scientific or archeological site.
If significant archeological artifacts are found,
provision will be made for their preservation.
ACTION SPECIFIC
Citation
Action
Requires
Discussion
40 CFR 241
Guidelines for Land
Disposal of Solid Waste
Landfllling of
Solid Waste
Guidelines for location selection, design,
construction, monitoring of solid waste
landfills
All solid waste (non-hazardous) will be disposed in
landfill in accordance with these guidelines.
40 CFR 257
Solid Waste Disposal Act,
as amended; Criteria for
Classification of Solid
Waste Disposal Facilities
and Practices
Landfllling of
Solid Waste
Environmental performance standards
including floodplains, endangered species,
surface water, groundwater, air and safety
standards
Solid waste landfill will conform to these standards.
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Citation
40 CFR 258, Subparts A-
F
Solid Waste Disposal Act,
as amended; Criteria for
Municipal Solid Waste
Landfills
10 CSR 80
Missouri Solid Waste
Rules
40 CFR 264.251
40 CFR 26 1.20-24,
261.30 Subpart D
Solid Waste Disposal Act,
as amended; Identification
and Listing of Hazardous
Wastes
40 CFR 268
Land Disposal Restrictions
40 CFR 268.9
40CFR261.3(e)(2)(iii)
40 CFR 761 Toxic
Substances Control Act
Polychlorinated Biphenyls
(PCBs) Manufacturing,
Processing, Distribution
and Use Prohibitions
Action
Landfilling of
Solid Waste
Landfilling of
Solid Waste
Temporary
Waste Piles
Landfilling and
Treatment of
Wastes
Landfilling of
Hazardous Waste
Special rules
regarding
characteristic
wastes
PCB Removal,
Storage and
Incineration
Requires
A - Purpose, scope, and applicability
B - Location restrictions
C - Operating criteria
D - Design criteria
E - Groundwater monitoring and corrective
action
F - Closure and post-closure care
Permitting, training, site selection, design
and operation, and monitoring of solid waste
landfills
Requirements for liners, leachate collection
system, setting of waste pile
Identification of hazardous wastes; wastes are
hazardous either by listing or characteristics;
the following on-site wastes may be listed:
K044 - wastewater treatment sludges from
the manufacture of explosives; K047 -
pink/red water from TNT operations; and
U105 or U106 - DNT from DNT lines.
Hazardous wastes must be treated to remove
hazardous characteristics before landfilling.
Requirements for meeting Land Disposal
Restrictions of Characteristic Wastes
Regulations for PCB management, storage
and incineration
Discussion
These requirements will be considered in selecting
the solid waste landfill location, designing the
landfill and disposing of the wastes.
Solid waste disposal will comply with the
substantive requirements of this regulation.
The stockpiled soil/pipeline must meet the
substantive requirements for temporary waste piles.
RCRA hazardous wastes must be treated and
disposed according to substantive requirements of
RCRA guidance.
AH RCRA hazardous waste will be handled in
accordance with substantive requirements of land
disposal restrictions.
Disposal of the stabilized lead contaminated soil in
a Subtitle D land disposal facility may be performed
if the waste no longer exhibits a characteristic and
the requirements in 40 CFR 268.9(d) are met.
All PCB wastes will be handled in accordance with
the provisions of these regulations.
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Citation
Action
Requires
Discussion
40 CFR 264 Subparts B,
C, D, I, J, L.
Solid Waste Disposal Act,
as amended; Standards for
Owners and Operators of
Hazardous Waste
Treatment, Storage and
Disposal Facilities
Hazardous Waste
Handling and
Storage
Requirements for handling and storage of
RCRA hazardous wastes
All excavated RCRA hazardous wastes will be
handled and stored in accordance with the
substantive technical requirements of this
regulation.
10 CSR 25 1-13
Missouri Hazardous Waste
Regulations
Hazardous Waste
Handling and
Storage
State requirements for hazardous waste
handling and storage
All excavated RCRA hazardous wastes will be
handled and stored in accordance with any more
stringent technical requirements of this regulation.
40 CFR 264 Subpart G
Solid Waste Disposal Act,
as amended; Closure and
Post-closure
Hazardous Waste
Landfill Closure
Requirements for closure of waste facilities
such as a land disposal unit (landfill)
Hazardous waste landfill closure and post-closure
activities will meet the substantive requirements of
the RCRA regulations.
oo
40 CFR 264 Subpart N
Solid Waste Disposal Act,
as amended; Landfills
Hazardous Waste
Landfill Design
and Construction
Requirements for design, construction and
operation of RCRA (Subtitle C) landfills
Hazardous waste landfill design, construction and
operation will meet the substantive requirements of
the RCRA regulations.
10 CSR 25-7.264
Missouri Hazardous Waste
Regulations; Landfill
Hazardous Waste
Landfill Design
and Construction
State requirements for design, construction
and operation of RCRA (Subtitle C) landfills
The design and operation of the landfill will meet
any more stringent regulations of the State of
Missouri.
40 CFR 264, Subpart O,
Solid Waste Disposal Act,
as amended; Incinerators
Hazardous Waste
Incineration
Permitting, design, construction, and
operating parameters for hazardous waste
incinerators, e.g., participate emissions <
0.08 gr/dscf, HC1 < 1.8 kg/hr, ORE >
99.99%
Hazardous waste incinerator design, construction
and operating parameters will meet the substantive
requirements of the RCRA regulations.
40 CFR 266 Subpart H
Solid Waste Act, as
amended: Hazardous
Wastes Burned in Boilers
and Industrial Furnaces
Hazardous Waste
Incineration
ORE > 99.99%, participate emissions <
0.08 gr/dscf, carbon monoxide < 100 ppm
hourly average, Tier I and II screening for
metals
Incinerator design and operation will meet the
substantive requirements of the RCRA regulations.
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Citation
Action
Requires
Discussion
10 CSR 25-13.010,
Subsection O, Missouri
Hazardous Waste Regs.;
Polychlorinated Biphenyls
Hazardous Waste
Incineration
Incinerators burning PCBs must achieve a
Destruction and Removal Efficiency of
99.9999%
Does not apply to WSOW because PCB materials
are defined as greater than 50 ppm, and highest
measured PCB in soil at WSOW was 42 ppm.
Federal Register Vol. 56
No. 21, Jan. 31, 1991 (55
FR3871)
Backfilling of
Incinerated
Pipeline (K047)
or Soil/Sludges
Classified as
K044
Requirement to remove the characteristic
from the hazardous waste. K047 and K044
wastes are listed hazardous wastes due to the
characteristic of reactivity
If the hazardous characteristic is removed from
such a listed waste and the treatment standard for
the listed waste is met, it is no longer considered a
hazardous waste, and therefore need not be dis-
posed in a Subtitle C facility. The characteristic of
reactivity is removed by incineration of the waste.
40 CFR 122-125
NPDES Requirements
Storm Water
Runoff
Requirements for NPDES for storm water
runoff
On-site storm water discharges will be subject to
substantive requirements of NPDES regulations.
Any off-site discharges would be subject to NPDES
permit. However, no off-site discharges are
anticipated.
10 CSR 20-6.200
Missouri Storm Water
Regulations
Storm Water
Storm water runoff permitting requirements
Substantive permit requirements will be met.
off-site discharges are anticipated.
No
10 CSR 23-4
Missouri Monitoring Well
Construction Code
Well
Construction
Monitoring well construction and piezometer
installation, as well as plugging and
abandonment must follow this guidance
All monitoring wells and piezometers will be
constructed and abandoned in accordance with state
code.
10 CSR 20-7 and 20-8
Missouri Effluent
Limitations Standards
Water Treatment
State requirements for water treatment
facilities, including design guidelaine and
construction permits
Any treated waters to be discharged are subject to
these effluent limitations.
10 CSR 20-7.031
Missouri Water Quality
Standards; Missouri Clean
Water Law
Surface and
Ground Water
Discharges
Prohibits deleterious discharge to waters of
the State of Missouri
Any discharge to surface or ground waters will
meet the standards and provisions of the Federal
Clean Water Act, the Missouri Water Pollution
Control Regulations and Missouri Water Quality
Standards.
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Citation
Action
Requires
Discussion
40CFR264.114
Solid Waste Disposal Act,
as amended; Disposal or
Decontamination of
equipment, structures and
soils
Decontamination
All equipment, structures, and soils used
on/with RCRA hazardous materials must be
properly decontaminated or disposed
Closure and post-closure activities will meet the
substantive requirements of the RCRA regulations.
49 CFR 107, 171-172
Department of
Transportation Rules for
Transportation of
Hazardous Materials
Transportation of
Hazardous Waste
Requirements for off-site transportation of
hazardous wastes
This requirement will be complied with if
hazardous wastes are transported over public
roadways (e.g., Highway 94 travelling from
burning grounds).
49 CFR 263
Solid Wastes
Transportation of
Solid Waste
Requirements for off-site transport of solid
wastes
This requirement will be complied with if solid
wastes are transported over public roadways (e.g.,
from burning grounds).
CERCLA § 300.440
Procedures for Planning
and Implementing Off-site
Response Actions
Off-site Disposal
of Small
Quantities of
Hazardous
Wastes
EPA must determine the acceptability of any
facility selected for off-site disposal of
CERCLA wastes
EPA will evaluate the facility for relevant violations
or releases prior to the facility's initial receipt of
any CERCLA waste.
10 CSR 25-6.263
Missouri Hazardous Waste
Regulations; Standards for
Transporters of Hazardous
Waste
Transportation of
Hazardous Waste
Requirements for off-site transportation of
hazardous wastes
This requirement will be complied with if
hazardous wastes are transported over public
roadways (e.g., from burning grounds).
Noise Control Act, as
amended; Noise Pollution
and Abatement Act
All
The public should be protected from noises
that jeopardize human health and welfare
Noise control procedures and design will be
incorporated into all activities expected to generate
significant noise levels.
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Citation
Action
Requires
Discussion
29 CFR 1904, 1910.95
and 1910.120, 1926
Subparts C, D, E, and P.
OSHA General Industry
and Construction Stds.
F.A.R. Clause 52.236-13:
Accident Prevention
All
Required worker safety training and
procedures
Regulations will be complied with during all on-site
activities.
29 CFR 1910.1001,
Subpart G. OSHA Occu-
pational Health and
Environmental Control
Standard
Asbestos
Abatement
Asbestos management activities required for
worker protection
Regulation will be complied with during asbestos
abatement activities.
SARA 120
Weldon Spring Ordnance
Works, Interagency Agree
ment between EPA,
Missouri Dept of Natural
Resources and U.S. Army
All
Agreement on responsibilities for site
investigation and remediation
Implementation of remedial action must consider
the requirements of any proposed standards and
comply with new criteria that become final prior to
implementation.
To Be Considered (TBC)
Draft EPA Strategy for
Combustion of Hazardous
Wastes, May 1993
Incineration
Site-specific risk assessments for direct and
indirect exposures;
Enhanced public participation, including
public comment on trial bum plan;
Upgraded particulate emission standards
(0.015 gr/dscf) and dioxin/furan emission
limits (30 ng/dscm);
EPA to conduct RCRA-type inspections of
Superfund on-site incinerators
The combustion strategy is not meant to directly
apply to Superfund sites where incinerators are
constructed solely for remediation purposes, but it
is to be regarded as TBC guidance. The Army has
agreed to perform the required risk assessments and
will try to meet the particulate emission goals set by
the strategy.
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2.11 DOCUMENTATION OF SIGNIFICANT CHANGES
The Proposed Plan for the WSOW site was released for public comment on December 1, 1993.
As a result of information obtained after the Proposed Plan was prepared and comments received
from review agencies, four significant changes from the preferred alternative in the Proposed
Plan have been made, as described below.
First, the contingency option for biotreatment of nitroaromatics-contaminated soils and pipeline
instead of incineration has been deleted. Deletion of the biotreatment option was based on
available data from an EPA-sponsored study of anaerobic bioslurry recently conducted at WSOW
which showed residual TNT concentrations as high as 240 ppm in the bioslurry after 150 days
of treatment. The three conditions specified in the Proposed Plan that were to be met for
biotreatment to replace incineration were: (1) the process must consistently reduce TNT in soils
to concentrations below the Remediation Goal of 57 ppm; (2) the process must have a treatment
cost per cu yd that is equal to or lower than incineration; and (3) demonstration of effectiveness
must be available in time to be implemented at WSOW. With the data now available, it was
concluded that none of the three conditions would be met. Also, the process did not treat
materials larger than 1/2 inch diameter, was not effective in mixing the WSOW clay soils, and
appeared to be only partially successful in breaking down small nuggets or chunks of TNT.
The second change was deletion of the requirement for a hazardous waste, or RCRA Subtitle
C, landfill to hold the stabilized lead-contaminated soil and pipeline ash. If the stabilization
treatment is successful in removing the lead TCLP characteristic and incineration is successful
in removing the reactivity characteristic from the K047 (red water) waste in the pipeline, then
these treated materials are no longer hazardous wastes and can be disposed of in a solid waste
landfill.
The third significant change was provision for off-site disposal of small volumes of hazardous
wastes such as incinerated DNT-contaminated soil from the DNT lines or soils with PCB
concentrations above 50 ppm, if encountered. Either of these materials would require more
stringent design criteria for on-site treatment and disposal and, for small quantities, could more
economically be disposed of at a commercial facility off-site.
The fourth change was to use the DOE landfill at the Weldon Spring Chemical Plant NPL site
rather than a separately constructed and maintained facility at WSOW for all specified landfill
disposal. Because WSOW completely surrounds the DOE NPL site, use of this landfill is
considered on-site disposal for purposes of CERCLA requirements.
The Army reviewed all written and verbal comments submitted during the public comment
period. Following review of these comments, it was determined that only the changes identified
above were needed to the remedy originally identified in the Proposed Plan—Alternative 6,
Rotary Kiln Incineration.
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3.0 RESPONSIVENESS SUMAfARY
In December 1993, the U.S. Army released the Proposed Plan for the former Weldon Spring
Ordnance Works Operable Unit 1: Soils and Pipeline. The public comment period for the
Proposed Plan extended from December 1, 1993 to February 14, 1994. During this period, 28
comment letters were received from citizens and public interest groups. The Army and EPA
sponsored a public meeting on the Proposed Plan on December 14, 1993, during which the
preferred alternative was explained and the two agencies responded to 18 oral and written
comments.
This Responsiveness Summary serves two functions. First, it provides the decision-maker with
information about the views of the community regarding the proposed remedial action.
Secondly, it digests and documents the comments made to the Proposed Plan at the public
meeting and in written comments received prior to the close of the public comment period, and
provides the Army/EPA responses to major comments.
3.1 OVERVIEW
The preferred alternative selected jointly by the Army and EPA and presented in the Proposed
Plan for Operable Unit 1 at WSOW was on-site incineration of nitroaromatics-contaminated
surface soils and wooden pipeline, plus stabilization and landfill of lead-contaminated soils.
The nearby community of St. Charles County offered only a few opinions on the Proposed Plan,
despite several community relations activities providing information before and during the public
comment period. Three of the four St. Charles county residents who commented either at the
public meeting or in writing favored incineration and the other one was undecided.
Most commenters from other parts of the metropolitan area were opposed to incineration. Many
expressed concern about the condition of the environment in the St. Louis area and viewed the
WSOW site and the proposed incinerator as one more contributor to declining quality of the
environment. Their primary concern was air pollution from the incinerator, including the
suspected emission of radioactive materials into the atmosphere. Other alternatives proposed by
these commenters included landfilling all wastes (four commenters), bioremediation (three
commenters), and delay the selection or remediation until a safer option is developed (six
commenters).
3.2 BACKGROUND ON COMMUNITY INVOLVEMENT
Even before the designation of WSOW as a National Priorities List (NPL) site in February 1990,
efforts were underway to inform the public of remedial actions at the site and involve them in
the decision-making process. Community relations activities have increased during the past two
53
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years with the strong encouragement of EPA Region VII and Missouri DNR. Some of the major
activities aimed at involving the community and obtaining their feedback have been:
1. A community survey in September 1991 including 75 personal interviews with
community leaders, nearby residents, and interested citizens to determine the best
methods of communicating with the public.
2. A Community Relations Plan dated March 1992 outlining the approach and proposed
activities.
3. Quarterly newsletters beginning in October 1992 distributed to more than 250
addressees. This newsletter is available to any local citizen who requests to be included
on the mailing list.
4. Public meetings in January 1987, June 1988, May 1989, November 1992, and December
1993 to report progress and solicit comments.
5. Technical Review Committee representation by the Francis Howell School District,
Weldon Spring Heights subdivision, DOE, and citizen environmental groups.
6. Information repositories established in 1992 at St. Charles County Public Library
(Kisker Branch) and WSOW Site Office with copies of all project reports.
7. An availability session at the site in October 1993 to informally answer citizen questions
and discuss concerns.
8. Two focus group sessions held in October 1993 to identify concerns and community
reaction to the preferred alternative of incineration.
9. Information telephone line manned 40 hours per week by WSOW Environmental
Coordinator.
Key public issues that emerged from the community survey, public meetings, availability
session, and telephone inquiries prior to the Proposed Plan were:
Boundaries of the NPL site from persons interested in buying property in the area
Health impacts associated with consumption of fish from the Conservation Area
Concern about a thorough, cost-effective, and timely cleanup of the site
Further contamination that might be spread during the cleanup process
Potential for additional development of the area for public use.
Prior to the public meeting on December 14, there were no significant concerns raised by the
public relating to remedy selection.
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Despite the substantial community relations effort, public interest in the WSOW site has been
limited due at least in part to the high profile of the adjacent DOE NPL site. According to the
1991 community survey, about 80 percent of persons surveyed who considered themselves at
least "somewhat familiar' with the Weldon Spring site were not aware that the Army and DOE
are responsible for two separate NPL sites in the area. This lack of differentiation is supported
by the large number of commenters on the Proposed Plan for WSOW who were highly
concerned about the incinerator emitting radioactive material into the air when extensive testing
and analyses reported in the Remedial Investigation have shown that the TNT-contaminated soils
being burned do not have radioactivity levels above natural background levels.
3.3 SUMMARY OF PUBLIC COMMENTS AND AGENCY RESPONSES
This summary includes both statements made at the December 14 public meeting and written
comments received during the public comment period. Oral comments are identified by their
page number in the official public meeting transcript. Copies of the official public meeting
transcript and comment letters are included as part of the administrative record.
Individual comments are grouped into common issues to avoid repetitiveness in the responses.
The issues are in turn organized into five broad categories:
• Remedial Alternative Preferences
• Air Emission Concerns with the Preferred Alternative
• Other Environmental Concerns with the Preferred Alternative
• Feasibility Concerns with any WSOW Remediation
• Procedural and Legal Issues
3.3.1 Remedial Alternative Preferences
ISSUE 1. Other alternatives would be safer for human health and the environment than
incineration. A decade's experience has shown that hazardous waste incinerators never work
as designed, create pollution themselves, and periodically explode.
Response: The impacts on health and the environment attributed to incineration are all
associated with the short time period that the incinerator is in operation, approximately one year
in the case of WSOW. These comments do not consider the much longer time after the active
remediation when humans and the environment would be at risk from partially treated or
contained hazardous wastes resulting from use of other alternatives at the WSOW site. Short-
term effects during remediation collectively are only one of nine criteria in the selection of the
remedial alternative. In the Feasibility Study, it was determined that incineration was not as
effective as several of the other alternatives in protecting against adverse impacts during the
construction and implementation period, but was a better alternative when all the criteria
including long-term effectiveness were evaluated. For example, composting leaves large
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amounts of treated compost that must be isolated from human contact because of possible
hazardous residuals; landfills have the potential to leak or fail after their design life; and
anaerobic bioslurry at its present stage of development cannot treat a substantial part of the
WSOW wastes and would require a much longer remediation time than incineration. Also,
regulations on incinerator operations create a series of safeguards that protect human health and
the environment during the temporary operating period.
ISSUE la. The commenter strongly believes that incineration is the best solution for organic
compounds in soil and supports the Proposed Plan (Transcript page 44).
Response: The Army and EPA agree with the commenter that incineration is the best solution
for remediation of organic contaminants present in the soils at WSOW.
ISSUE 2. On-site containment of WSOW soils should be reconsidered in lieu of incineration
to avoid releasing radioactive materials or hazardous chemicals into the air. Also, incinerator
ash will have to be landfilled, so the soils should just be landfilled initially and the incinerator
should not be built.
Response: Landfilling or on-site containment is not a preferred strategy according to law
(CERCLA Section 121(b)). As indicated in the Feasibility Study and Proposed Plan, this
alternative does not provide permanent remediation and requires long-term monitoring and
periodic review. Also, it does not constitute treatment, which is a preference under CERCLA
Section 121 (b). The potential for release of hazardous chemicals into the air by the incinerator
is discussed in Issues 8 through 15 below.
All of the incinerator ash will be tested for Toxicity Characteristic Leaching Procedure (TCLP)
for lead. Those portions which are not characteristic can be backfilled into excavations or
elsewhere on-site.
ISSUE 3. The Army's preference for incineration is not adequately supported by data or reports
from other Army Ammunition Plant (AAP) sites where TNT-contaminated soils were burned or
by any test data on WSOW soils (Transcript page 71).
Response: Test data from trial burns for Cornhusker AAP and Savanna Army Depot were
subsequently provided to this commenter, Missouri DNR. These data showed that Destruction
and Removal Efficiency (DRE = [Mass feed rate of TNT - Mass stack emission rate of TNT]
x 100%/Mass feed rate of TNT) for TNT at both Cornhusker and Savanna exceeded 99.9999
percent, versus the requirement of 99.99 percent. Paniculate emissions were 0.002 and 0.008
grains/dry standard cubic foot (gr/dscf) in the two trial burns, compared to a maximum
allowable of 0.08 gr/dscf. A test conducted at Louisiana AAP did not include stack sampling
for TNT or particulates, but showed performance better than that required by Louisiana
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Department of Environmental Quality. Copies of these test reports are included in the
administrative record.
Data from 1990 laboratory tests of pipeline and soil samples from WSOW (IT Corporation,
Weldon Spring TNT Incineration Treatability Testing Report, May 1990) concluded that these
materials could be successfully incinerated. More extensive testing for incineration
characteristics will be performed prior to the WSOW design phase, including ultimate analysis,
moisture content, percent organics, percent ash, percent sulfur, percent halogens, alkaline
content, and heating value, for representative incinerator feed samples.
ISSUE 4. The use of an existing or planned off-site commercial incinerator instead of on-site
incineration of contaminated soils and pipeline should be evaluated (Transcript pages 48 to 50).
Response: Off-site incineration was evaluated in the screening process of the Feasibility Study
as part of Alternative 3 and found to be too costly. As a result of comments at the Public
Meeting and in letters about the preferred alternative, additional investigation of off-site
incineration was undertaken. The four closest commercial hazardous waste incinerators are the
Chemical Waste Management incinerator at Sauget, Illinois; the River Cement kiln in Festus,
Missouri; the Continental Cement kiln in Hannibal, Missouri; and the proposed ICI/Atlas facility
in Joplin, Missouri. However, it appears that none of these incinerators would be able to accept
TNT-contaminated soils from WSOW. The Sauget incinerator, which was the source of the
preliminary cost data in the Feasibility Study, is not presently permitted to accept CERCLA
hazardous wastes due to serious operating violations. The determination of unacceptability is
explained in an EPA Region V letter dated July 15, 1993 and confirmed by subsequent
complaints filed by the State of Illinois in Circuit Court in September 1993 (see WSOW
Administrative Record). The River Cement facility has also received an Unacceptability Notice
for off-site CERCLA waste, dated September 30, 1993 from EPA region VII. The Continental
Cement kiln does not currently accept TNT-contaminated soils. For Continental Cement to be
able to accept TNT-contaminated soils, the facility would have to conduct a trial burn under
maximum worst case operating conditions. Continental Cement will not risk damaging the kiln
to conduct such a trial burn and would decline this waste. The proposed Joplin ICI/Atlas
incinerator is designed for disposal of explosives and munitions, but could not economically treat
the wastes generated at WSOW. Currently, the incinerator has not been built nor has a trial
burn been performed. It is anticipated that wastes from WSOW or wastes with similar
characteristics would need to be included in the trial burn for the ICI/Atlas incinerator.
The incinerator proposed for WSOW is not expected to experience the types of difficulties
encountered by these commercial hazardous waste incinerators because it will have a much more
uniform feed than these units and will be able to closely control average contaminant
concentrations and characteristics of soil/pipeline charged to the incinerator. The WSOW
incinerator will also have daily on-site inspection by the Army and frequent inspections by EPA
and MDNR.
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ISSUE 5. Information on the bioremediation pilot study currently being conducted at WSOW
should be evaluated prior to the selection of a preferred alternative (Transcript pages 60, 61).
If necessary, remediation should be delayed by 5 to 10 years to permit further development of
bioremediation or other processes that pose fewer risks at a reasonable cost (Transcript pages
20, 36, 67). Also, the Proposed Plan indicates that bioremediation of much of the soil would
cost only about two-thirds as much as incineration.
Response: Data from the anaerobic bioslurry pilot study indicates that this process would not
be ready for application at WSOW in the near future. During the pilot study, several operational
problems were encountered. The process as evaluated did not accept material larger than 1/2
inch diameter. After approximately 150 days of treatment, not all treated material met target
cleanup levels. Finally, in its current stage of development, the process may be more expensive
than incineration when costs for treating material larger than 1/2 inch by another process are
included.
Maintenance of the present site remediation schedule is important to prevent dermal contact with
contaminated soils and to prevent further releases of contaminants from the soil to the
groundwater.
The preliminary cost estimates do show that bioremediation is less expensive than incineration,
but the actual cost of a biological treatment alternative could easily exceed that of thermal
treatment due to the high degree of uncertainty associated with an unproven technology such as
bioremediation in comparison with an established technology such as incineration.
ISSUE 6. Incineration should go forward expeditiously, as time is money and this problem
could be studied indefinitely. A vocal minority has stopped or slowed several cleanup efforts
(Transcript page 70).
Response: The Army agrees that site cleanup must be accomplished as expeditiousiy as
possible. The Army must balance the mandate for a prompt, efficient, and health-protective
cleanup of the site with adherence to all CERCLA requirements, including that public concerns
with the Proposed Plan be considered and addressed. To date, the site investigation and remedy
selection phases at WSOW have been completed expeditiously.
ISSUE 7. Missouri DNR and U.S. EPA comments should be considered before deciding on a
final remedy.
Response: EPA and the Army are jointly responsible for selecting the final remedy at this
Federal facility (see 40 CFR 300.430), so EPA has a much larger role than submitting comments
for consideration. The Interagency Agreement for the WSOW dated March 4, 1991 (effective
date August 8, 1991) provides for involvement of the EPA and Missouri Department of Natural
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Resources in the remedial decision process. The State's involvement in selection of the remedial
action is also provided under Section 121(f) of CERCLA.
ISSUE 7a. Two pending or recent reports of the National Academy of Sciences on technologies
for disposal of chemical weapons may be helpful in identifying an alternative to incineration
(Transcript page 75).
Response: The chemical weapons that these reports address include canisters of pure or nearly
pure, extremely toxic gases and liquids and slurries with high concentrations of explosives. At
WSOW, the primary problem is treatment and disposal of 30,000 cubic yards or more of soil
contaminated with relatively small amounts of TNT. Although these reports have been added
to the WSOW administrative record, they have little or no applicability to remediation of the
WSOW soils.
3.3.2 Air Emission Concerns with the Preferred Alternative
ISSUE 8. The soil to be incinerated at WSOW may contain radioactive materials that have
never been tested for, such as thorium-230 and radon-222, from the neighboring DOE WSSRAP
site. Testing and, if necessary, removal of these radioactive materials should be done prior to
incineration because of the potential for spreading them through air emissions from the
incinerator (Transcript pages 19, 22, 36, 37, 53, 73).
Response: At least two comprehensive radiological surveys were done during the mid-1980s
to search for radioactive soil and water contamination on Weldon Spring Training Area and
other parts of the WSOW site near the DOE site. The surveys were conducted by the Army
Environmental Hygiene Agency and Oak Ridge Associated Universities. Six small areas on
WSTA plus a similar number of "vicinity properties" on Busch and Weldon Spring Conservation
Areas with low-level uranium, radium, and thorium contamination were found, marked, and
fenced for later remediation by DOE. Also, during the Remedial Investigation many soil
samples were analyzed for gross alpha and beta radiation, but none above background were
found.
Although not warranted by the sampling data and other information available, as a result of the
high level of public concern over this issue, additional soil samples will be taken from planned
excavation areas near the DOE site for radiological testing (e.g., TNT lines 3 through 6 and
lagoon 1), which will include testing for thorium-230. If any elevated levels of radiological
contamination are found in the WSOW soils, the soils will not be treated and their removal and
disposal will be undertaken by DOE. Any soils disposed of by DOE would not be incinerated.
ISSUE 9. The allowable air emissions from the incinerator (0.01 percent of input by DRE
requirement) may cause health effects on the surrounding community, including a high school
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less than 1 mile away. There are approximately 200,000 residents within a 10-mile radius of
the site (Transcript pages 20, 32, 38, 39).
Response: Air dispersion modeling and a risk assessment of the impact of projected incinerator
emissions on receptors in the surrounding community are required in fulfilling the substantive
requirements of an air permit. This modeling/risk assessment activity will assure that the risks
to human health and the environment are within currently acceptable limits. The modeling and
risk assessment will determine risk-based emission rates that will result in 1 x 10* (1 in
1,000,000) risk under worst case exposure assumptions. Achieving these emission rates will be
a requirement, as well as complying with all the RCRA emission limits (see Issue 36).
ISSUE 10. Heavy metal contaminants in the soil such as lead may volatilize at high
temperatures in the incinerator, pass through the air pollution control equipment as vapors, and
result in health risks as they are dispersed in the air (Transcript page 73).
Response: Most heavy metals in the soil are converted to metal oxides or salts at the high
temperatures found in hazardous waste incinerators, and remain in the incinerated soil (bottom
ash). Some of the metals and oxides volatilize in the combustion chamber, but they are likely
to recondense in the quenching (cooling) section of the incinerator or be removed as paniculate
matter in the air pollution control scrubber. The health risks associated with minute amounts
of heavy metals that are emitted from the incinerator stack will be estimated with dispersion
modeling and indirect risk assessments as discussed above in the response to issue 9. Also,
there are stringent metals emission limitations in EPA's boiler and industrial furnace (BIF)
regulations (February 21, 1991).
ISSUE 11. The soils to be incinerated probably contain unknown, unique, or undetected
chemicals (e.g., RDX) or mixtures of chemicals that are more toxic than TNT or that form other
deadly compounds in the incineration process (Transcript pages 20, 44). More than 90 percent
of the chemicals in stack gases have not been identified.
Response: The soils have been analyzed for a wide variety of hazardous chemicals, so
incineration of unknown or undetected chemicals is unlikely. RDX was analyzed in some of the
past samples, and will be included in all nitroaromatics analyses in the future.
A number of chemicals are emitted from a hazardous waste incinerator. Some are hazardous,
others are not. Complete identification is not possible due to the very high number of
compounds that can be formed in combustion reactions. Many compounds are present at
concentrations below detection limits, and health effects for all such substances have not been
determined. However, the bulk of total unburned hydrocarbons (TUHC) by weight is usually
methane and PAHs.
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While the specific compounds which may be emitted have not been completely identified, the
risks from unknown compounds may be estimated. One way to estimate the risk is by using
data for the TUHC and toxicity data for a known compound(s). For conservative estimates a
high toxicity value may be chosen and applied to the total quantity of TUHC. Alternate
estimates could be made using a weighted average of toxicity values for organic compounds
known to be present in the emissions. The risk from such estimates may be added to the risk
from compounds with known quantities and toxicities (e.g., Principal Organic Hazardous
Constituents measured during the trial bum) to get total risk. Estimated risks determined by
using total TUHC and the weighted average approach for incinerators achieving greater than
99.99 percent destruction have been reported to be below health-based levels.
ISSUE 12. There is currently no method for continuous monitoring of contaminants being
discharged to the air by incinerators. One-time testing is done during optimum conditions and
ignores upset conditions. During combustion upsets and explosions, unburned wastes and
products of incomplete combustion (PICs) will be released. Therefore, actual emissions may
be much more than the allowable limits or tested rates (Transcript pages 38, 45, 73).
Response: Stack emissions cannot be monitored continuously for nitroaromatic compounds.
However, stack emissions will be monitored continuously for parameters such as carbon
monoxide and oxygen which indicate the efficiency of the combustion process. In addition,
incinerator operating conditions such as opacity, temperature, and gas flow rate will be measured
continuously to assure that the unit is operated under the conditions which were determined to
be safe during the trial burn. When a monitor senses levels of any monitored parameter outside
the predetermined design range, the waste feed will be automatically shut down. Operation of
the incinerator in this manner assures that emissions are always within the allowable limits.
ISSUE 13. Products of incomplete combustion (PICs) are always generated in an incinerator.
They can be as much as 1 percent of the waste going in, and can be much more toxic than the
original chemicals being burned (Transcript page 39). The destruction efficiency is a misleading
measurement because it ignores the PICs formed during the combustion process.
Response: PICs are formed by all combustion processes, not just by incinerators (e.g.,
automobiles, furnaces, fireplaces, power plants). The formation of PICs can be minimized by
maintaining the initial combustion products under high temperature and oxidizing conditions for
an extended time. In an incinerator, this is accomplished by using more than one combustion
chamber, specially engineered turbulent mixing, and confirmatory monitoring of parameters such
as carbon monoxide and temperature. A large post-flame combustion zone or secondary
combustion chamber is used to provide an adequate buffering zone for assured destruction of
PICs. EPA imposes minimum temperature and retention times to assure minimal PIC formation
based on trial burn results.
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Testing has shown that PIC emissions from state-of-the-art incinerators are very low. This
research has shown that, under the conditions tested, PIC concentrations are about the same as
the Principal Organic Hazardous Constituent (POHC) concentrations tracked during trial bums.
Air pollution control devices also remove PICs with the same efficiency as they remove POHCs.
In addition, there is no evidence that PICs are necessarily more toxic than compounds that have
been selected as POHCs. In fact, data from incinerators has shown that some PICs are non-
hazardous. For example, methane constitutes 20 to 50 percent by weight of PICs and is not a
hazardous chemical.
ISSUE 14. Of all the chemicals emitted by incinerators, polychlorinated dioxins and furans pose
the greatest threat to health and the environment. Incinerators are the largest single contributors
to dioxin in the environment, and high burn temperatures do not necessarily eliminate them.
Because there are sources of chlorine in the WSOW soil, dioxins and furans will be formed.
Response: The information cited on dioxin and furan emissions is related to municipal solid
waste incinerators, not hazardous waste incinerators. EPA has examined dioxin/furan emissions
from 17 hazardous waste incinerators and kilns, and only five emitted detectable levels of
dioxins or furans. All of these five were in the parts-per-trillion range, and were determined
to not pose significant health risks. None of the facilities tested was found to be discharging
2,3,7,8-TCDD, the most toxic dioxin isomer.
The nitroaromatic compounds that are the primary contaminants being incinerated at WSOW
contain no chlorine. Based on soil sampling data, less than 100 cubic yards of the soils being
incinerated contain detectable levels of chlorine-containing organic compounds, and these are
present at low part-per-million concentrations. Therefore, it is not expected that detectable
levels of dioxins/furans will be formed in the incinerator at WSOW.
ISSUE 15. Many chemicals in the incinerator feed are identified by EPA as carcinogens or
teratogens, including PAHs, benzene, PCBs, DNT, and atrazine. Even at 99.99 percent
destruction and with scrubbers, tons of pollutants will be released from the stack—even higher
concentrations of toxic substances than in the waste (Transcript pages 19, 41).
Response: All of the chemicals listed in the above comment, with the possible exception of
DNT, are present in less than one percent of the soils to be incinerated and at concentrations of
only a few parts per million when they are present. Therefore, the total weight to be incinerated
of any of these chemicals is estimated to be less than 50 Ib. With a minimum destruction and
removal efficiency of 99.99 percent, emissions of these chemicals are assured to be less than
one-tenth of an ounce (0.005 Ib) over the 1 to 2 year incineration period.
The primary contaminant in the soil being remediated, TNT, will be present in the incinerator
feed at an estimated average concentration of 6800 ppm. Based on the Feasibility Study estimate
of 35,000 tons of TNT-contaminated soils to be incinerated and the minimum 99.99 percent
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destruction efficiency, fewer than 48 Ib of TNT will be emitted from the incinerator stack during
the entire operating time at WSOW.
Claims of massive emissions of toxic organic chemicals from the incinerator are not accurate.
They are based on the incorrect assumption that the total weight of material fed into the
incinerator is composed of hazardous chemicals. In fact, the material to be incinerated is almost
entirely soil and water with minute amounts of contaminants by weight.
ISSUE 16. Air monitoring sites and ambient air limits should be specified.
Response: An Air Quality Monitoring and Control Plan with ambient air monitoring and
specific air quality action levels will be prepared during the Remedial Design. This plan will
assure that concentrations of critical chemicals above risk-determined levels do not occur during
on-site remediation operations (including excavation and pretreatment as well as incineration).
Ambient monitoring will include at least the following three locations: DOE site, Francis
Howell High School, and Busch Conservation Area Headquarters.
3.3.3 Other Environmental Concerns with the Preferred Alternative
ISSUE 17. Incinerators also produce toxic bottom ash and fly ash that create disposal problems.
Response: The incinerated soil, or bottom ash, and fly ash will be tested after incineration to
determine if it is hazardous. Any ash that fails the testing will be disposed in an appropriate on-
site landfill.
ISSUE 18. One location where toxins can be released is at the base of the incinerator kiln,
where leaks can cause loss of charged material.
Response: Spillage of contaminated soil from the feed system at the front end of the kiln or of
incinerated soil from the ash collection/handling system at the discharge end of the kiln is not
equivalent to releasing hazardous chemicals into the environment. Design of the remedial action
would ensure that any spillage would be minimized or eliminated. Any spilled solids would be
kept within a containment area from which they would be recovered and returned to the
appropriate part of the incinerator's material handling system.
Loss of airborne materials from the base of the kiln is controlled by maintaining a negative air
pressure at openings so that outside air is drawn into the incinerator rather than air in the kiln
leaking out. The specifications, operations manual, and inspection list will all have provisions
to prevent the occurrence or continuance of fugitive emissions from the incinerator.
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ISSUE 19. Water from the incinerator scrubber will be released into the Missouri River with
inadequate treatment (Transcript page 74).
Response: It is expected that scrubber water and rinse water will be recycled to minimize the
volumes of wastewater that will require disposal. Treatment and testing will be performed prior
to discharge. Effluent from the wastewater treatment system will meet all applicable discharge
requirements, and will likely be land applied on-site rather than discharged into the Missouri
River.
ISSUE 20. There are a number of toxic waste sites in close proximity to each other at Weldon
Spring. The combined risks from their releases on humans and the environment needs to be
determined.
Response: Risk assessments have been or will be performed for cumulative effects of different
wastes on WSOW under existing and future conditions and during cleanup (incineration).
Similar risk assessments have been done by DOE for their site. Research has shown that health
impacts from hazardous chemicals and from radiation exposure are not additive (Reference:
U.S. EPA, Risk Assessment Guidance for Superfund. Health Evaluation Manual. Part A. Office
of Solid Waste and Emergency Response, Publication No. 9285.701A, 1989).
The additive impacts of air emissions from more distant hazardous waste incineration sources
such as Times Beach and medical waste incinerators could be estimated by use of a regional
dispersion model, and would be expected to show combined concentrations at any intermediate
locations to be less than maximum ground-level impacts near any one of the sources. It is
expected that emissions from motor vehicles, coal-fired power plants, fireplaces and furnaces
would have much greater impacts on air quality than emissions from the proposed incinerator
for WSOW.
ISSUE 21. Transporting and storing materials to be incinerated are additional sources of
pollution.
Response: All necessary precautions will be taken during transport to minimize the probability
of any spillage. The contaminated soils and pipeline will be transported on designated roadways
within the site to minimize interaction with public traffic. These roads and vehicles will be
operated and maintained to prevent any losses of contaminated materials to the surrounding site
areas. If any spills or leaks do occur, contractors working at the site will be required to
immediately clean them up. No transport of contaminated materials off the WSOW site is
planned. The covered temporary storage facilities will be operated in accordance with RCRA
temporary storage facility requirements, and therefore not be sources of pollution.
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ISSUE 22. Do not proceed with incineration unless the health and well-being of nearby
residents can be guaranteed. Also, there should be proof that no harm will be done to plants
or animals on or near the site.
Response: The potential for exposure to contaminated soils continues to exist and the soils
continue to act as a probable source of ground water contamination, resulting in an unacceptable
risk to public health and the environment. A remedy that is compatible with regulatory
requirements and provides protection of human health and the environment must be selected; no
action or delayed action would not be a satisfactory alternative.
The incineration alternative will reduce risk to levels calculated to be appropriate for residential
exposure.
As part of the design phase of the WSOW cleanup, the Army will perform a risk assessment of
the impact of air emissions from incineration on nearby residents to assure that risks are at an
allowable level before proceeding with the remediation. The risk assessment will also evaluate
environmental effects of the projected incinerator emissions.
3.3.4 Feasibility Concerns with Anv WSOW Remediation
ISSUE 23. The contamination may extend beyond the areas being remediated. As an example,
the buried pipeline extends 83,300 feet, which would be beyond the site boundaries.
Response: The site is defined as the 17,232 acres of the former Weldon Spring Ordnance
Works minus the 226 acres of the DOE site. It extends from Highway 40-61 on much of the
north to the Missouri River on the south. The Remedial Investigation identified the extent of
contamination at WSOW with more than 17,500 samples taken over a four year period.
Additional sampling will be done at the time of soil and pipeline excavation to assure that
contaminated materials are removed and treated.
The pipeline is not a single straight-line conduit across the site. Instead, it is a system of
relatively short segments that connected each of the TNT and DNT production areas to one of
three former wastewater treatment plants. Pipeline segments remaining in the ground are
estimated to total 83,300 feet, and all are within the WSOW NPL boundaries. One segment of
about 1,500 feet is located southeast of the U.S. Army's Weldon Spring Training Area (but still
within WSOW).
ISSUE 23a. What specific means will be in place to guarantee that collected contaminants do
not seep into the Weldon Spring groundwater (Transcript pages 32, 58)?
Response: Following excavation, the contaminated soils will be temporarily stored in covered,
floored buildings until they are incinerated. Incineration will be used to reduce the levels of
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contaminants in soils to levels that are below Remediation Goals. Thus, excavation and
incineration of contaminated soils will virtually eliminate further infiltration of contaminants into
groundwater. Therefore, excavation and incineration of contaminated soils will reduce rather
than add to groundwater contamination.
ISSUE 24. All of the locations with TNT contamination at WSOW cannot be excavated and
incinerated in one to two years.
Response: The time estimate of 1 to 2 years was developed in the Feasibility Study, and was
based on remediation times at other similar incineration sites such as Cornhusker and Louisiana
Army Ammunition Plants. A more detailed evaluation of scheduling during design could
indicate that a longer time is required; there is no restriction on the site cleanup that would
preclude a longer remediation period. The 1 to 2 year estimate does not include trial burn time,
which may take up to an additional year, for a total on-site time for the incinerator of up to 3
years.
ISSUE 25. The landfill for lead-contaminated soils should be designed to meet RCRA standards
and made as safe as possible. Some agency should check to determine that it is safe since the
Army does not plan to obtain a permit (Transcript page 74).
Response: The landfill for lead-contaminated soils will be designed to at least meet RCRA
Subtitle D standards, which include bottom lining, leachate collection system, and a cover with
lower permeability than the bottom liner. In addition, lead-contaminated soils and wastes placed
in this landfill will be chemically stabilized to further curtail their migration. Location of the
landfill will comply with Missouri DNR's landfill siting requirements. All design plans and
specifications will be reviewed for technical adequacy and regulatory compliance and
approved/disapproved by EPA Region VII and Missouri DNR as part of the Remedial Design
review process.
ISSUE 25a. How will soil that is contaminated with lead be separated from soil contaminated
with TNT? What about soil contaminated with both (Transcript pages 51, 52)?
Response: There is little overlap between lead-contaminated soils and TNT-contaminated soils.
When both contaminants are present, the soils will be incinerated, with the ash then being tested
for lead using the Toxicity Characteristic Leaching Procedure and, if it fails, being stabilized
and placed in an appropriate on-site landfill. The air pollution control system will be designed
to prevent lead emissions from exceeding regulatory levels.
ISSUE 26. All necessary permitting requirements for treatments with off-site discharges should
be met by the Army (Transcript page 21).
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Response: All treatments will take place on-site. Under Section 121(e) of CERCLA, remedial
actions which take place on a CERCLA National Priorities List site are exempt from all Federal,
State, and local permits, as long as the substantive requirements of those permits are met. The
Army intends to meet all design requirements, perform all siting and impact evaluations, perform
all environmental monitoring, and meet any other technical requirements associated with
obtaining permits for the proposed incinerator operation at WSOW. However, the Army does
not intend to follow the administrative procedures of a permit application and review process.
The Interagency Agreement requires the Army to submit all design plans to EPA and Missouri
DNR for review, comment, and approval.
ISSUE 27. The wastes at WSOW have not been adequately characterized, e.g., toxicity,
corrosivity, reactivity, thermal instability, fuming, odors, shock sensitivity, and heat value.
Without this information, the incinerator cannot be properly designed or operated.
Response: Some incineration characteristics of the pipeline have been determined and reported,
but this data was not presented in the Proposed Plan because of the intended overview nature
of that document. For example, average moisture was 59.7 percent, heat value was 5100 Btu/lb,
average organic chlorine was 17 ppm, and no heavy metals were found. Some pipeline samples
were found to be reactive. Additional information specific to incineration characteristics of soils
will be generated in predesign investigations: ultimate analysis (includes carbon, hydrogen,
oxygen, nitrogen, sulfur, ash, moisture), percent organics, percent chlorine or halogens, alkaline
content, and heating value. The predesign phase of the WSOW project allows the Army to
collect this treatment-specific information prior to design and remediation.
ISSUE 28. Our reputation as a world leader is at stake. If foreign governments follow our
example with this cleanup, it may prove disastrous and ruin the U.S.' reputation as an ethical
scientific leader.
Response: The process for selecting the cleanup alternative has followed all Environmental
Protection Agency evaluation requirements. The recommended alternative is the only proven
method at this time for permanently treating TNT-contaminated soils. Incineration technology
is well developed, and is being used around the world to destroy hazardous as well as other
wastes.
3.3.5 Procedural and Legal Issues
ISSUE 29. The public comment period should be extended four weeks (ending February 11,
1994) to allow questions to be answered and comments prepared. A followup to one letter
requesting an extension asked 14 specific questions and indicated a statement of the
organization's position would be submitted by February 11.
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Response: The public comment period was extended 31 days to February 14, 1994 in
accordance with CERCLA Section 300.430(f)(3)(i)(C) that requires a minimum 30 day extension
if so requested in a timely manner by any member of the public. The original comment period
was 45 days, from December 1, 1993 to January 14, 1994.
ISSUE 30. Do not allow wastes from other sites to be stored or incinerated at WSOW
(Transcript pages 21, 30, 57, 58).
Response: The Army has committed at the Public Meeting that no wastes from other sites will
be brought to WSOW for storage or incineration, and intends to firmly abide by that
commitment. The ROD will include specific language that no off-site wastes will be stored or
treated at WSOW.
ISSUE 31. The worst location for a hazardous waste incinerator is adjacent to and upwind of
a densely populated metropolitan area. There should be evacuation plans for those living or
working near the incinerator (Transcript page 38).
Response: The incinerator is proposed to be located in the Weldon Spring Training Area
(WSTA) portion of the WSOW site, which is remote from any populated areas. Wildlife areas
extend in all directions for a distance of almost 3 miles. Within the wildlife areas there are
some occupational exposures. WSTA has continuous perimeter fencing for security purposes.
This location is well suited for siting of a hazardous waste treatment facility because of the
buffer area surrounding the site and the low population densities even beyond the unpopulated
buffer area. The densely populated St. Louis metropolitan area is not in the prevailing
downwind direction from the site.
A contingency plan will be submitted by the incinerator contractor and approved by the Army,
EPA, and the State prior to startup. This plan will fully describe emergency responses in case
of an accident or explosion at the site, including evacuation plans for any workers or students
determined to be within a distance of potential danger. The plan will also describe the fail-safe
features of the incinerator and how they are designed and operated to protect against releases or
reactions that might otherwise occur during upset conditions.
ISSUE 32. The Proposed Plan does not address wastewaters in settling lagoons or explosive
wastes in the Weldon Spring quarry (Transcript page 74).
Response: Remediation of surface waters is not included in the Proposed Plan for Operable Unit
1, soils and pipeline, at WSOW. However, waters in the former lagoons were sampled during
the Remedial Investigation, and contaminants were not detected. Sediments from the bottoms
of the lagoons were also sampled, and only Lagoon 1 had contaminants—levels of DNT slightly
above the Remediation Goal of 2.5 milligram/kilogram (mg/kg). Lagoon 1 sediments are
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included in the listing of areas to be remediated. Additional lagoon sediment sampling will be
performed during Predesign Investigations to supplement the previous findings.
The Weldon Spring Quarry and its remediation, including explosives wastes, are the
responsibility of the U.S. Department of Energy.
ISSUE 33. Future military plans for use of the area should not rush studies of alternate ways
to dispose of these wastes. Also, the site should not be used for military purposes until the
cleanup is completed.
Response: The schedule for remediation at WSOW was set in 1990 by an Interagency
Agreement among EPA, Missouri DNR, and the Army. Military plans for use of the area were
not a factor in determining the schedule. Portions of the site that are free of contamination are
currently being used for military training.
ISSUE 34. The Corps of Engineers cannot be trusted with a technically advanced toxic waste
incinerator when they have trouble with simple earthen levees (reference to 1993 Midwest
floods).
Response: The U.S. Army Corps of Engineers Kansas City District has already administered
the design, operation, and successful remediation of three TNT-contaminated soil incineration
projects (Cornhusker Army Ammunition Plant (AAP), Louisiana AAP, and Savanna Army
Depot). The Corps of Engineers is currently involved in administering the design and operation
of a TNT-contaminated soil incineration project at Alabama AAP.
Of the 89 Federally owned levees constructed and operated by the Kansas City and St. Louis
Districts of the Corps of Engineers, 14 were overtopped and two failed prior to being
overtopped in the 1993 flood. The design levels of flood protection were exceeded for all of
these failed levees. The flood of 1993 is estimated to have been between a 175 year and 500
year flood event, depending on the location along the rivers. Of the failed levees, four were
designed for a 100 year flood and the remaining 12 were designed for less than 50 year floods.
All privately owned levees along the Missouri River were either overtopped or failed during this
flood.
ISSUE 35. In every instance where a hazardous waste incinerator has been installed, property
values have been dramatically lowered. Have there been any studies of property values around
the other five Army explosives-contaminated waste incinerators (Transcript page 72)?
Response: The source of data on property values near hazardous waste incinerators is not cited
in the comment. It is likely that such statistics refer to commercial installations that would be
operated as permanent facilities. In contrast, the transportable incinerator proposed for WSOW
would be installed and in operation for about 2 years and would then be removed. Property
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values should not be depressed after completion of the cleanup and, in fact, might increase
because the site will have been remediated. It should also be noted that there is no private
property in the immediate vicinity of the proposed incinerator location, so property owners
would not be adversely impacted during the incineration period by nearby truck traffic, an
unsightly industrial operation, or noise.
No information was located on property value impacts at any of the other Army incineration
sites.
ISSUE 36. Statements that the incinerator will comply with all Federal, State, and local
regulations are misleading because St. Charles County has no incinerator regulations and the
State and Federal ones are far too lax.
Response: The host of regulations and operating requirements that a hazardous waste incinerator
located in Missouri must comply with are extensive. These regulations include:
• Performance Standards -
(1) At least 99.99% DRE for all designated POHCs
(2) Hydrochloric acid emissions less than 4.0 Ib/hr
(3) Paniculate matter less than 0.08 gr/dscf
• Operating Requirements -
(1) Operation must be within limits established in the trial burn for carbon
monoxide, waste feed rate, combustion temperature and gas velocity
(2) Fugitive emissions must be controlled by keeping the combustion zone totally
sealed or maintaining combustion zone pressure lower than atmospheric
pressure
(3) The incinerator must have an automatic waste feed cut off when conditions
deviate from those in requirement (1)
(4) All incinerator equipment and monitoring devices must be inspected and tested
at least daily.
In addition, the incinerator operator must demonstrate that no persons in the vicinity of the
incinerator are exposed to health risks greater than 1 x 10 "6 as a result of incinerator emissions.
ISSUE 37. The public should be protected from the excess health risks currently at the site and
users informed of the risks.
Response: All locations outside WSTA where nitroaromatics have been found in the soil are
presently fenced and posted to prevent public access. Military personnel involved in training
activities at Weldon Spring Training Area are restricted to portions of the site that have been
sampled and determined to be safe for such activities.
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ISSUE 38. A commenter was surprised to learn at the end of October that the Army was
proposing to use an incinerator on-site at Weldon Spring. Citizens should have been given the
opportunity at least a year ago at a scoping meeting to voice their opinions on incineration
(Transcript page 35).
Response: A public meeting was held by the Army on November 20, 1992 at Francis Howell
High School to discuss the recently completed Remedial Investigation and the Feasibility Study,
then in preparation. Incineration was prominently discussed as one of the alternatives being
evaluated and as the only proven technology for treating TNT-contaminated soils. More than
50 persons attended that meeting; none expressed concerns with use of incineration at WSOW.
Results of the Feasibility Study and articles on incineration have since been featured in editions
of the widely-distributed WSOW Newsletter to further inform the public and attempt to draw
citizen comments.
ISSUE 39. A worker safety plan should be prepared and a comprehensive health record kept
for each worker (Transcript page 38).
Response: The Site Safety and Health Plan for construction phase workers will be prepared by
the incineration contractor and approved by the Army and EPA. It will require maintenance of
detailed health records for all site workers.
ISSUE 40. After the ROD, what role will the public have in monitoring the cleanup activities
(Transcript page 33)?
Response: The Army and EPA will continue community relations efforts throughout the project
and are committed to reporting progress through public forums such as newsletters, Technical
Review Committee meetings, and public availability sessions.
ISSUE 41. There are reports of cost overruns on many Superfund projects nationally. The cost
assessments for this project should be done objectively and should evaluate ways to save money
during the cleanup (Transcript page 58).
Response: The cost data for the different alternatives in the Feasibility Study and Proposed Plan
were prepared on a consistent basis so that comparisons would be objective. Cost is only one
of nine criteria in the selection of a preferred alternative, and is not a determining factor in the
evaluation nor is it to be afforded priority over the two statutorily emphasized factors. Cost
savings are best identified in the design phase rather than during the selection process.
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GLOSSARY
Administrative Record—A file which is
maintained and contains all information used by
the lead agency to make its decision on the
selection of a response action under CERCLA.
Aeration-Addition of air to a substance to
promote degradation of contaminants.
Air Pollution Control System—Part of an
incineration system that assures combustion
gases meet RCRA emission standards.
Anaerobic Bioslurry—Process by which
contaminants are mineralized under anaerobic
(no oxygen present) conditions in a slurry
mixture of equal volumes of water and
contaminated material.
Applicable or Relevant and Appropriate
Requirements (ARARs)-The federal and state
requirements that a selected remedy will attain.
These requirements may vary among sites and
alternatives.
Background Levels—Naturally occurring levels
of compounds in soil, sediment, water, and air.
Baseline Risk Assessment (BRA)-Study that
determines contaminants of concern based on the
potential for contact.
Bi-tri Nitrating Houses-Building where final
nitration is performed resulting in TNT.
Biodegradation—A process by which
microscopic living organisms are used to help
decompose contaminants.
Bioremediation-Remediation technology in
which biological methods are employed
(composting).
Burning Grounds—Areas throughout the site
where TNT and DNT waste powder and
contaminated building materials were burned and
buried during cleanup activities.
Composting—A biodegradation process in which
materials (such as manure or straw) are added to
contaminated material to enhance decomposition.
Comprehensive Environmental Response,
Compensation, and Liability Act (CERCLA)-
The federal law that addresses problems
resulting from releases of hazardous substances
to the environment, primarily at inactive sites.
DNT (2,4- or 2,6-Dinitrotoluene)-Co-
contaminant explosive associated with TNT;
considered to be a probable human carcinogen.
Feasibility Study (FS)-The second of a two-
part study which evaluates several remedies that
are designed to address contamination identified
during the Remedial Investigation.
Grainer House—Building in TNT manufacturing
process where purified TNT is crystallized into
granules and dried before being packaged.
Groundwater-Underground water that fills the
spaces between rock, sand, soil, or gravel
particles to the point of saturation.
Heat Exchanger—Cools combustion gases from
the incinerator prior to entering the air pollution
control system.
Incineration—A treatment process that destroys
organic wastes burning materials that contain
chemical contamination.
Induced Draft Fan—Creates air flow through
the incinerator and combustion gas treatment
systems.
Inorganic Nutrients—inorganic materials such as
potassium and phosphorus that promote
microbial activities in biological treatment processes.
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Institutional Controls—Enforced restrictions to
prevent contact with contamination.
Leachate-The water and dissolved constituents
which percolates through a given material.
Leachate is usually sampled, collected and
discharged, or treated and disposed off-site.
Mechanical City—Area along south edge of
production area where construction and
maintenance shops, such as electrical and
plumbing, were located.
Media—Materials or substances such as soil,
sediment, groundwater, and air which are being
studied.
Microbial Activity—Natural degradation of a
contaminant by the use of bacteria.
Microorganism—An organism of microscopic
size.
Mineralization—Complete degradation of
contaminants to carbon dioxide (CO^ and water.
Mineralize—Degrade to inorganic end products
such as C02 and water.
National Priorities List (NPL)-A federal roster
of waste sites targeted for priority cleanup under
Superfund regulations.
Nitroaromatics-Nitrated compound containing
at least one benzene ring.
Operable Unit (OU)—An action taken to address
part of an overall site cleanup.
Optimization Studies—Studies performed on
materials to be treated to fine tune the treatment
process.
Ordnance—Military supplies, including weapons
and ammunition.
Organic Compounds—Carbon compounds
which tend to dissolve readily in water.
Phthalates—Semivolatile compounds commonly
found in plastics.
Polychlorinated Biphenyls (PCBs)-A dielectric
oil formerly used in transformers.
Polynuclear Aromatic Hydrocarbons (PAHs)-
Multiple ring compounds containing only carbon
and hydrogen; common to petroleum products.
Reactivity—A characteristic of some chemical
compounds whereby they can suddenly release
large amounts of heat or pressure when
subjected to a sudden impact, elevated
temperatures, or water.
Record of Decision (ROD)—A legal document
issued after a Remedial Investigation and
Feasibility Study that sets forth the selected
remedy for cleanup of a site.
Reference Dose—An estimate of an exposure
level determined by EPA to be without an
appreciable risk of adverse non-cancer effects.
Refractory-lined—A heat resistant material
lining the rotating kiln of an incinerator.
Remediation Guidelines—Contaminant levels
established as cleanup criteria.
Responsiveness Summary—A portion of the
Record of Decision in which public comments to
the Proposed Plan, RI/FS report, and
information in the Administrative Record are
summarized, and responses to comments are
made.
Remedial Investigation (RI)-The first part of
a two-part study which determines how much
and what kind of contamination exists at a
Superfund site.
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Resource Conservation and Recovery Act
(RCRA)-A federal law that established
requirements for the storage, treatment, and
disposal of hazardous wastes.
Rotary Kiln—A cylindrical incinerator that
rotates to feed and improve the overall
combustion of contaminated materials.
Sensitivity—The potential for materials to
respond to changes in temperature, pressure, and
moisture.
Settling Tanks—Collected wastewater from the
manufacturing lines to be pumped to the
treatment plants.
Subtitle C-Part of RCRA that specifies the
design criteria for hazardous waste landfills.
Superfund Innovative Technology Evaluation
(SITE)-EPA program to assist in the
development of hazardous waste treatment
technologies necessary to implement new
cleanup standards which require greater reliance
on permanent remedies.
Superfund Amendments and Reauthorization
Act (SARA)-Passed by Congress in 1986 to
update and improve CERCLA.
Superfund—The common name given to the
CERCLA amendments.
Toxicity Characteristic Leaching Procedure
(TCLP)—Extraction procedure to determine the
leaching characteristic of a particular waste.
TNT (2,4,6-TrinitrotoIuene)-A common
nitroaromatic explosive; considered to be a
possible human carcinogen.
Transformation Products—Chemical
compounds resulting from the breakdown or
alteration of contaminants.
Wash House—Building in which crude TNT is
washed, purified, and centrifuged before being
sent to the Grainer House.
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