EPA/540/AR-93/517
April 1993
Toronto Harbour Commissioners (THC)
Soil Recycle Treatment Train
Applications Analysis Report
Risk Reduction Engineering Laboratory
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, Ohio 45268
Printed on Recycled Paper
-------
Notice
The information in this document has been funded by the U.S. Environmental Protection Agency under Contract No. 68-CO-
0048 and the Superfund Innovative Technology Evaluation (SITE) Program. It has been subjected to the Agency's peer
review and administrative review, and it has been approved for publication as a U.S. EPA document. Mention of trade names
or commercial products does not constitute an endorsement or recommendation for use.
11
-------
Foreword
The Superfund Innovative Technology Evaluation (SITE) Program was authorized in the 1986 Superfund Amendments. The
Program is a joint effort between EPA's Office of Research and Development & Office of Solid Waste and Emergency
Response. The purpose of the program is to assist the development of hazardous waste treatment technologies necessary to
implement new cleanup standards which require greater reliance on permanent remedies. This is accomplished through
technology demonstrations designed to provide engineering and cost data on selected technologies.
This project consists of a demonstration of the Toronto Harbour Commissioners (THC) Soil Recycle Treatment Train. The
Treatment Train consists of three processes. The first process utilizes an attrition soil wash process to separate relatively
uncontaminated soil from a more heavily contaminated fine slurry. The contaminated fine slurry is then further processed
in a metals removal process or a bioslurry reactor process or both to remove organic contaminants and heavy metals
contamination. The Toronto Harbour Commissioners conducted a long-term evaluation of this treatment train at a 55 tons per
day pilot plant at 185 Cherry Street in the port of Toronto, located in Toronto, Ontario, Canada. The SITE project examined
in detail the processing of soil from one of the sites being evaluated in the overall project. THC has estimated that as much
as 2,200,000 tons of soil from locations within the Toronto Port Industrial District may require some form of treatment due
to heavy metals and/or organic contamination. The goals of this study were to evaluate the technical effectiveness and
economics of a treatment process sequence and to assess the potential applicability of the process to other wastes and/or other
Superfund and hazardous waste sites.
Additional copies of this report may be obtained at no charge from EPA's Center for Environmental Research Information,
26 West Martin Luther King Drive, Cincinnati Ohio, 45268, using the EPA document number found on the report's front
cover. Once this supply is exhausted, copies can be purchased from the National Technical Information Service, Ravensworth
Bldg., Springfield, VA, 22161,703-487-4600. Reference copies will be available at EPA libraries in their Hazardous Waste
Collection.
E. Timothy Oppelt, Director
Risk Reduction Engineering Laboratory
U.S. Environmental Protection Agency
-------
Abstract
The Toronto Harbour Commissioners (THC) have developed a soil treatment train designed to treat inorganic and organic
contaminants in soils. THC has conducted a large-scale demonstration of these technologies in an attempt to establish that
contaminated soils at the Toronto Port Industrial District can be treated to attain contaminant levels below the THC Criteria
Levels for Industrial Soils without utilizing incineration processes.
The THC's treatment train evaluated during this SITE Demonstration consists of three soil remediation technologies: an
attrition soil washing technology, inorganic removal by chelation, and a chemical and biological treatment to reduce organic
contaminants. The overall process sequence is determined by the specific contaminants in the soil to be treated.
Sampling, data collection and analysis as part of the THC demonstration were conducted under the SITE program utilizing
appropriate analytical procedures as specified in SW846 to provide a consistent basis for comparing these technologies to other
technologies evaluated under the SITE program.
Based on the results of the SITE demonstration project at the THC Soil Recycling Demonstration Project, Toronto, Ontario,
Canada and information concerning the overall THC project, several conclusions can be drawn.
• The primary developer's claim that the gravel, sand, and fine soil products will meet the THC criteria for reuse as fill
material at industrial/ commercial sites was achieved by the gravel and sand products, representing 79.6 percent of
products. The fine soil representing 18.8 percent of the products exhibits significant reduction in PAH compounds as a
result of biological processing but did not meet the criteria level of 2.4 mg/kg for benzo(a)pyrene.
• The attrition soil wash plant produced a gravel (<1.97 in; >0.24 in) and a sand (<0.24 in; >0.0025 in) that achieved the
primary THC criteria. It should be noted that the only parameter which exceeded this THC criteria in the feed was
naphthalene. The process exhibited removal rates for organic contaminants of 67 percent or greater for the gravel product
which accounted for 11.5 percent of the product output. The sand product exhibited organic removal rates of 78 percent
or greater while accounting for 68.1 percent of the product output The process concentrated the organic contaminants
into a contaminated fine slurry (<0.0025 in) which accounted for 18.8 percent of the process output while accounting for
74 percent or more of the organic contaminants.
• The metals contamination levels actually encountered during pilot-scale processing of the test soil were so low that there
was no need to use the metals removal process. Limited data were developed for the efficiency of the metals removal
process by sampling a run of a metals-rich slurry from another soil. The reactor achieved the following removal
efficiencies: copper-96 percent, lead-71 percent, nickel-71 percent and zinc-64 percent. Higher removal efficiencies are
claimed by the developer when processing more highly contaminated soils.
• The bioslurry process exhibited limited reduction in oil and grease. A similar comparison for other parameters yielded
the following: TKPH reduction of 60 percent, naphthalene at least 97 percent, and benzo(a)pyrene approximately 70
percent.
IV
-------
Contents
Page
Foreword . iii
Abstract . , iv
Tables . . . ..>..... ix
Figures xi
Abbreviations xii
Conversion Factors xiii
Acknowledgment xiy
1. Executive Summary . 1
1.1 Introduction .1
1.2 Conclusions . : 1
1.2.1 THC Treatment Train 2
1.2.2 Soil Wash Process 2
1.2.3 Bioslurry Process 2
1.2.4 Metals Removal Process 3
1.2.5 Process Costs 3
1.3 Summary of Suitability of THC Treatment Train for CERCLA Corrective Actions 3
1.3.1 Overall Protection of Human Health and the Environment 3
1.3.2 Compliance with ARARs 3
1.3.3 Long Term Effectiveness and Permanence . . . 3
1.3.4 Reduction of Toxicity Mobility and Volume Through Treatment 3
1.3.5 ShortJTerm Effectiveness 3
1.3.6 Implementability 4
1.3.7 Cost 4
1.4 Discussions of Conclusions 4
1.4.1 Soil Washing . . 4
1.4.2 Bioslurry Reactor 5
1.4.3 Metals Removal Process 5
1.5 Costs 5
2. Introduction 7
2.1 The SITE Program 7
2.2 SITE Program Reports 8
2.3 Key Contacts 8
3. Technology Applications Analysis 9
3.1 Introduction 9
3.2 Conclusions . . . 9
3.2.1 Overall Process Train 9
-------
Contents (Cont'd)
Page
3.2.2 Individual Process 9
3.2.2.1 Soil Washing 9
3.2.2.2 Bioslurry Process 10
3.2.2.3 Metals Removal Process 10
3.3 Technology Evaluation 10
3.3.1 Soil Washing 11
3.3.2 Bioslurry Reactor 13
3.3.3 Metals Removal Process 13
3.4 Applicable Wastes 14
3.5 Site Characteristics 15
3.6 Environmental Regulation Requirements 15
3.7 Materials Handling Requirements 16
3.8 Personnel Issues 17
4. Economic Analysis 18
4.1 Introduction 18
4.2 Conclusions , 18
4.3 Issues and Assumptions 19
4.3.1 Waste Volumes and Site Size 19
4.3.2 System Design and Performance Factors 19
4.3.2.1 Soil Wash 19
4.3.2.2 Bioslurry Process 19
4.3.2.3 Metals Removal Process 19
4.3.3 Manpower Requirements '. 19
4.3.4 Financial Assumptions 20
4.4 Results , 20
4.4.1 Remediation of Hypothetical Site 20
4.4.2 Sensitivity of Costs to Fines Content of Soil 21
4.4.3 Other Limitations of Cost Analysis 22
4.5 Full Scale (55 ton/hour) Facility 22
Appendix A - Process Description of THC Soil Recycling Treatment Train 23
A.I Attrition Soil Washing 23
A.2 Biological Treatment System 24
A.3 Metals Removal Process 24
A.4 Water Use 25
A.5 Air Supply and Emissions Control 25
Appendix B - Vendor's Claims 27
Appendix C - Site Demonstration 28
C.I Introduction 28
C.2 Feed Characteristics and Variability 28
C.2.1 General 28
C.2.2 SITE Sampling 28
VI
-------
Contents (Cont'd)
Page
C.3 Attrition Soil Wash Process 1 . 29
C.3.1 Feed 29
C.3.2 Products 29
C.3.2.1 Gravel (Through 1.97 inch; greater than 0.24 inch) 29
C.3.2.2 Sand (Through 0.24 inch; greater than 0.0025 inch) 31
C.3.2:3 Coal/Peat Waste (Through 0.24 inch, greater than 0.0025 inch) 31
C.3.2.4 Contaminated Fines (Less than 0.0025 inch) 31
C.3.2.5 Waste Water Streams 31
C.3.3 Mass Balance 33
C.3.3.1 Site Demonstration Sampling 33
C.3.3.2 Discussions of Mass Balance Results . •. 33
C.3.4 Discussion of Soil Wash Process Results 33
C.4 Bioslurry Reactor Process 34
C.4.1 Results and Discussions 34
C.5 Metals Removal Process 37
C.6 Emissions Sampling ?. . 38
Appendix D-l - Cost Analysis for Treatment of 22,000 Tons of Contaminated Soil Using the THC
Treatment Plant 39
D.I Introduction 39
D.2 Basis for Economic Analysis 40
D.2.1 Permitting and Regulatory Costs 40
D.2.2 Site Preparation Costs 40
D.2.3 Equipment Costs 41
D.2.3.1 Attrition Soil Washer 41
D.2.3.2 Biological Treatment Process .41
D.2.3.3 Metals Removal Process •. 41
D.2.4 Start-Up . 41
D.2.5 Labor .41
D.2.6 Consumables and Supplies 42
D.2.6.1 Attrition Soil Wash . . 42
D.2.6.2 Biological Treatment Process 42
D.2.6.3 Metals Removal Process 42
D.2.7 Utilities , 42
D.2.8 Effluent Treatment and Disposal ; 43
D.2.9 Residuals/Waste Shipping, Handling and Transport Costs 43
D.2.10 Analytical Costs 43
D.2.11 Demobilization Costs 43
D.3 Results 44
Case Study-2 - Attrition Soil Wash Process Results for Soil B 46
Case Study-3 - Attrition Soil Wash Process Results for Soil A 47
Vll
-------
Contents (Cont'd)
Page
Appendix D-4 - Bioslurry Reactor Process Results at the THC Recycle Treatment Plant for Soil B 48
D.4.1 Oil and Grease 48
D.4.2 PAH Compounds 48
Appendix D-5 - Metals Removal Process Evaluation for Soil A '. 51
vui
-------
Tables
Number
1. THC Target Criteria for Selected Parameters for Soils for
Commercial/Industrial Land Use and Results of Demonstration
Page
2. Selected Feed and Product Characteristics of the Attrition Soil Wash Process 12
3. Characteristics of Soil Wash Product Streams (based on SITE mass balance and SITE
demonstration analytical results) .- 12
4. Selected Feed and Product Characteristics of the Bioslurry Reactor Process 13 -
5. Selected Heavy Metals Data for Removal of Metals for the Liquid Stream by the
THC Metals Removal Process • ^
6. Summary of Manpower Requirements THC Treatment Train
7, Capital Cost for THC Treatment Train
20
20
8. Treatment Cost Summary for a Hypothetical Remediation of 22,000 tons of Soil with 16.5
Percent Fines and Both Organic and Inorganic Contaminants , 21
B-l THC Target Criteria for Commercial/Industrial Land Use 27
C-l Concentration of Selected Parameters in the Feed Soil THC Attrition Soil Wash Process 29
C-2 THC Attrition Soil Wash Process Concentration of Selected Parameters in Gravel <1.97 in.,
>0.24 in •
C-3 THC Attrition Soil Wash Process Concentration of Selected Parameters in Clean Sand <0.24
in., >0.0025 in
30
32
C-4 THC Attrition Soil Wash Process Concentration of Selected Parameters in Coal/Peat Waste ....... 32
C-5 THC Attrition Soil Wash Process Concentration of Selected Parameters in Contaminated Fines
<0.0025 inch ............................................. •
C-6 Selected Characteristics of Water Recycled to THC Attrition Wash Process
C-7 Selected Feed and Product Characteristics of the Attrition Soil Wash Process 35
C-8 Partition of Selected Parameters in the Product Streams of the Attrition Wash Process
(based on THC estimates of overall product yields for this soil) 35
IX
-------
Tables (Cont'd)
Number
Page
C-9 Partition of Selected Parameters in the Product Stream of the Attrition Wash Process
based on data developed during SITE demonstration 35
C-10 Concentration of Selected Parameters of the Contaminated Slurry Feed to the THC
Bioslurry Reactors 36
C-ll THC Bioslurry Process Concentration of Selected Parameters in Discharge Slurry from
Bioslurry Reactors - Batch 2C . .. 36
C-12 THC Bioslurry Process Concentration of Selected Parameters in Discharge Slurry from
Bioslurry Reactors - Batch 2A 36
C-13 THC Bioslurry Process Bioslurry Reactor Inlet and Outlet Concentrations for Selected
Parameters .....' 37
C-14 Metals Removal Process - Inlet and Outlet to Tubular Reactor Data for Selected Metals 38
D-l Treatment Cost Summary for a Hypothetical Remediation of 22,000 tons of Soil with 16.5
Percent Fines and Both Organic and Inorganic Contaminants 40
i,
D-2 Cost Per Ton of Feed Soil Based on 53 Tons per Day of Feed and 33 Percent Fines in the
THC Treatment Train 45
D-3 Cost Per Ton of Feed Soil Based on 106 Tons per Day of Feed Soil and 16.5 Percent Fines
in the THC Treatment Train ; 45
D-4 Cost per Ton of Feed Soil Based on 159 Tons Per Day of Feed Soil and 11 Percent Fines
in the THC Treatment Train ; 45
D-5 Cost Per Ton of Soil Actually Processed Based on Throughput rate of 0.73 Tons/hr.
and Continuous Operation 45
D-2-1 Selected Feed and Product Stream Parameters for Attrition Soil Wash Process Soil B,
THC Soil Recycle Treatment Plant 46
D-3-1 Selected Feed and Product Stream Parameters for the Attrition Soil Wash Process, Soil A,
THC Soil Recycle Treatment Plant
47
D-4-1 Oil and Grease Results for the Biological Treatment of Contaminated Fines from the High
Pressure Wash Process 4 49
D-4-2 Comparative Data for Specific PAH's for the Processing of Soil B Contaminated Fines from
the Attrition Soil Wash Process 49
D-4-3 Comparative Data for Specific PAH's for the Processing of Contaminated Fines for the High
Pressure Wash Process 50
D-5-1 Metals Removal Process Results Soil A Feed for Attrition Soil Wash Process . .. 51
-------
Figures
Number
Page
1. Partition of Feed Soil to Product Streams THC Treatment Train (Based on SITE
Demonstration Data) ;.... 10
2. Simplified Process Flow Diagram , 11
3. Simplified Process Flow Diagram for Soil Wash Process Showing Product Fractions on a
Weight Basis 11
A-l Simplified Process Flow Diagram for Soil Wash Process , 24
A-2 Simplified Process Flow Diagram for Bioslurry Reactor Process ;. 24
A-3 Simplified Process How Diagram Metals Removal Process .. 25
C-l Simplified Process Flow Diagram for Soil Wash Process Showing Product Fractions on a
Weight Basis 33
D-l Daily Mass Flows for Hypothetical Case Treatment of 22,000 Tons of Contaminated Soil 39
D-2-1 Partition of Feed Soil to Product Streams in Attrition Soil Wash Process, Soil B, Overall
THC Project 46
D-3-1 Partition of Feed and Product Stream in Attrition Wash Process, Soil A Overall THC
Project .'• • 47
XI
-------
Abbreviations
ARAR Applicable or Relevant and Appropriate Requirements
CERCLA Comprehensive Environmental Response, Compensation, and Liability Act of 1980
cfm Cubic feet per minute
EPA Environmental Protection Agency
HSWA Hazardous and Solid Waste Amendments to RCRA - 1984
ORD Office of Research and Development
OSWER Office of Solid Waste and Emergency Response
PAH Polynuclear Aromatic Hydrocarbon
PID Port Industrial District
POTW Publicly-Owned Treatment Works
mg/kg Milligrams per kilogram
MOE Ontario Ministry of the Environment
NPDES National Pollutant Discharge Elimination System
RCRA Resource Conservation and Recovery Act
SARA Superfund Amendments and Reauthorization Act
SITE Superfund Innovative Technology Evaluation
TCLP Toxicity Characteristic Leaching Procedure
THC Toronto Harbour Commissioners
TRPH Total Recoverable Petroleum Hydrocarbons
Xll
-------
Conversion Factors
English (US)
Factor
Area:
Flow Rate:
Length:
Mass:
Volume:
1ft2
Iin2
1 gal/min
1 gal/min
1 Mgal/d
1 Mgal/d
1 Mgal/d
1ft
lin
lyd
lib
lib
1 ton
1ft3
1ft3
Igal
Igal
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
9.2903 x 10'2
6.4516
6.3090 x lO'5
6.3090 x 10'2
43.8126
3.7854 x 103
4.3813 x 10'2
0.3048
2.54
0.9144
4.5359 x 102
0.4536
0.9072
28.3168
2.8317 x lO'2
3.7854
3.7854 x 10"3
Metric
m'
cm2
m3/s
L/s
L/s
m3/d
m3/s
m
cm
m
g
kg
Kkg
m
ft = foot, ft2 = square foot, ft3 = cubic feet
in = inch, in2 = square inch
yd = yard
Ib = pound
gal = gallon
gal/min (or gpm) = gallons per minute
Mgal/d (or MOD) = million gallons per day
m = meter, m2 = square meter, m3 = cubic meter
cm = centimeter, cm2 = square centimeter
L = liter
g = gram
kg = kilogram
m3/s = cubic meters per second
L/s = liters per second
m3/d = .cubic meters per day
xm
-------
Acknowledgment
This report was directed and coordinated by Ms. Teri Richardson, EPA SITE Project Manager in the Risk Reduction
Engineering Laboratory - Cincinnati, Ohio.
This report was prepared for EPA's Superfund Innovative Technology Evaluation (SITE) Program by Mr. Leo C. Ehrenreich,
Mr. Andrew Matuson, Mr. Joseph Peters, Mr. Joseph Evans and supporting staff at Science Applications International
Corporation (SAIC) for the U.S. Environmental Protection Agency under Contract No. 68-CO-0048. The Work Assignment
Manager for this project was Mr. Leo Ehrenreich.
The cooperation and participation of Mr. Dennis Lang of the Toronto Harbour Commissioner staff, Dr. Diana Murato of
Zenon Environmental Inc., Ms. Natalie Dame, Ms. Lucille Hicks and Mr. Al Rouse of SNC-Lavalin, Dr. Irving DeVoe of
DeVoe Environmental Laboratory throughout the course of the project and in review of this report are gratefully
acknowledged.
Finally, the project could not have been carried out without the efforts of the many SAIC, S-Cubed, and Aerovironment
personnel who were responsible for the actual sample collection and analyses.
xiv
-------
Section 1
Executive Summary
1.1 Introduction
The Toronto Harbour Commissioners (THC) have developed
a soil treatment train designed to treat inorganic and organic
contaminants in soils. THC has conducted a large-scale
demonstration of these technologies in an attempt to
establish that contaminated soils at the Toronto Port
Industrial District can be treated to attain contaminant levels
below the Ontario Ministry of the Environment (MOE)
Criteria Levels for Industrial Soils without utilizing
incineration processes. Table 1 presents the MOE Criteria
plus additional target criteria set by the developer, the THC.
Collectively, these criteria are referred to as the "THC
criteria".
The THC's treatment train evaluated during the SITE
demonstration consists of three soil remediation technologies:
an attrition soil washer to segregate the soil into
uncontaminated coarse material and highly contaminated
fines, a metals removal process by chelation, and chemical
and biological treatment for reduction of organic
contaminants. The overall process sequence is determined
by the specific contaminants in the soil to be treated.
Sampling, data collection, and analysis were conducted under
the SITE program to provide a consistent basis for
comparing these technologies to other technologies.
1.2 Conclusions
Based on the results of the SITE demonstration project at the
THC Soil Recycling Demonstration Plant, Toronto, Ontario,
Canada and information concerning the overall THC project
several conclusions can be drawn:
Table 1. THC Target Criteria for Selected Parameter for Soils for Commercial/Industrial Land Use and Results of Demonstration
THC Target THC Target Medium
Parameter Course Textured & Fine Textured Feed4 Fine*
Soil1 Soil Soil Gravel4 Sand4 Soil
Conventional
Oil and Grease (%) 1 1
TRPH (mg/kg)
Total Metals (mq/kq)
Copper 225 300
Lead 750 1000
Zinc 600 800
Organic Compounds (mg/kg)
Naphthalene 8.03 8.03
Benzo(a)pyrene 2.42 2.4*
1 . Defined as greater than 70% sand and less than 1 7%
organic matter.
2. Clean-up levels are shown for organic compounds.
If soils exceed these levels.then the soil is
considered hazardous and remediation is required.
3. If these trigger levels are exceeded, the MOE
will make a determination on a case by case basis
regarding the need for remediation.
0.82 0.33 0.22 2.5
2500 800 620 5400
18.3 6.4 13.8 84
115.0 45.3 46.0 548
82.5 46.0 34.0 343
11.2 2.5 2.1 1.3(6)
1.9 0.6 0.5 (2.6)(7)
4. Average of six composite samples.
5. Average of six sample's from biosluny reactor batch 2.
6. Values reported is estimated detection limit for this parameter.
7. Values shown is below quantitation limit for procedures.
Values shown is estimated.
-------
1.2.1 THC Treatment Train
• The primary developer's claim for the production of
gravel and sand that meet the THC Target criteria for
medium to fine soil suitable for industrial/commercial
sites was achieved for the sand and gravel products.
The fine soil from the biological treatment process
exhibited anomalous oil and grease behavior and,
although exhibiting significant reduction in PAH.
compounds, did not meet the target level of 2.4 ppm
for benzo(a)pyrene.
• An assessment of the developer's claims relative to
metals treatment was not possible since soil excavated
for this study did not exhibit the metal contamination
levels expected based on earlier field sampling.
Limited data was obtained for this process by sampling
another soil with moderate metals contamination.
• The hydrocyclone device used for final dewatering of
the fine soil did not produce a dry product. As a
result, the final product from the process was a slurry.
The use of this technology was an attempt to find a
less expensive alternative to filter press technology,
and was not a significant component in the total
treatment train demonstration.
1.2.2 Soil Wash Process
• The attrition soil wash plant produced a gravel (<1.97
in; >0.24 in) and a sand (<0.24 in; >0.0025 in) that
met the THC Target criteria. The only parameter
which exceeded the THC criteria in the feed soil was
naphthalene. The process exhibited removal rates for
organic contaminants (oil & grease, total recoverable
petroleum hydrocarbons (TRPH), naphthalene, benzo
(a) pyrene) of 67 percent or greater for the gravel
product. This product accounted for 11.5 percent of
total process mass output while accounting for 4
percent or less of the organic contaminants in the
product streams.
* Removal rates for organic contaminants (oil & grease,
TRPH, naphthalene, benzo(a)pyrene) were 78 percent
or greater for the sand. This product accounted for
about 68.1 percent of the process output while
accounting for 15 percent or less of the organic
contaminants in the product stream.
• The process concentrated the organic contaminants into
a contaminated fine slurry (<0.0025 in) which
accounted for about 18.8 percent of the process output
mass while accounting for 74 percent or more of the
organic contaminants.
The process also produced a contaminated coal/peat
product (<0.24 in; >0.00025 in) which represented
about 1.6 percent of the process output while
accounting for 6 percent or more of the organic
contaminants. This waste stream will require disposal
(most likely by incineration).
The feed soil exhibited low heavy metals contaminant
levels (copper 18 ppm, lead 115 ppm and zinc: 83
ppm). The wash process concentrated these
contaminants in the fine slurry (18.8 percent of the
process mass output) accounting for 59 percent or more
of these metals hi the process output streams.
1.2.3 Bioslurry Process
• The clean fine soil product resulting from the bioslurry
process did not meet the primary objective when
assessed using the appropriate analytical procedures
from SW-846 as universally applied in SITE
evaluations. The developer has investigated other
analytical procedures they believe may be appropriate
for slurries with high biomass content that may yield
different results. The problem parameters were oil &
grease and benzo(a)pyrene. The benzo(a)pyrene
• concentration, although reduced by the process, did not
meet the THC Target Criteria level of 2.4 ppm.
• The bioslurry process provided limited reduction in oil
and grease when comparing inlet to output samples. A
similar comparison for other parameters yields the
following reductions: Total Recoverable Petroleum
Hydrocarbons (TRPH) 60 percent; naphthalene at least
97 percent; and benzo(a)pyrene approximately 70
percent.
• Emission sampling of the ventilation system serving the
biological treatment system did not detect PAH
compounds, but detection limits were very high due to
a high concentration of light hydrocarbons in the
exhaust stream. These light hydrocarbons were
tentatively identified as a petroleum distillate in the
range of diesel oil to Stoddard solvent (C9 - C16
paraffins). Total gaseous, non-methane organic
compounds were detected at levels which indicate 220
Ibs per day of emissions. (The data illustrate that
significant air stripping is occurring in the bioreactor,
and this must be accounted for in the design.) The
bioslurry process was developed to collect and treat
volatilized hydrocarbons in two biofilters. These active
filtration units were followed by an activated carbon
bed to polish the air and remove any residual
contaminant. Stack testing by the developer indicates
hydrocarbon emissions are below detection levels.
-------
1.2.4 Metals Removal Process
• The metals contamination levels actually encountered
eliminated the need for utilizing the metals removal
process for this soil. Limited data were developed for
the efficiency of the metals removal process by sampling
a process run of a metal-rich slurry from another soil.
The reactor achieved the following removal efficiencies
based on metals concentrations in the inlet versus the
outlet samples: copper-96 percent, lead-71 percent,
nickel-71 percent and zinc-64 percent.
• The metals removal process became fouled with oil and
grease forcing the operation to shut down prematurely.
This may be a limitation on the process in that slurries
with free oil and grease cannot be processed directly.
This problem may be overcome by treating the organic
contaminant first and then utilizing the metals removal
process.
1.2.5 Process Costs
• The costs of the treatment system were examined on
both an integrated and on a unit process basis. This will
allow the decision maker to estimate costs for other soil
applications based on the processes that would be
required for treating the specific soil. The cost
information was developed by THC based on analysis of
the overall THC demonstration. The overall cost of
operation of a 6.6 tons per hour soil wash, metals
removal and bioslurry treatment train is estimated at
$219 per ton. The individual process costs that make up
this estimate are:
Soil Washing: $80/ton of feed soil.
Metals Removal: $96/ton of feed soil.
Bioslurry Process: $43/ton of feed soil.
• The developer estimates that treatment costs using a 50-
60 tons per hour fixed facility operating continuously at
full capacity would be about $116 per ton of raw feed
assuming the fines require metals removal and organics
reduction.
1.3 Summary of Suitability of THC Treatment
Train for CERCLA Corrective Actions
1.3.1 Overall Protection of Human Health and the
Environment
The technology provides a means of removing organic and
metallic contaminants from the soil which should leave the
remaining soil relatively uncontaminated and suitable for a
broader range of uses.
1.3.2 Compliance with ARARs
Data developed during this study suggests the soil washing
can reduce organic contaminants by 65 percent or more of
the levels in the feed soil, and also reduce metals
contaminant levels by 50 percent or more in the products
that represent 70 to 80 percent of the feed. Fines can be
further treated using the metals removal process which can
achieve removals of 60 to 90 percent of the metals present
in the fines. Higher metals removal can be achieved using
a multiple pass configuration but with an attendant increase
in cost. The bioslurry reactor process exhibits removal in
the 70 percent range for PAH contaminants. Where
contaminant removal of these magnitudes would be useful at
a specific site, a treatability experiment to establish likely
removal rates may be warranted.
13.3 Long Term Effectiveness and Permanence
The processes remove significant portions of the
contaminants from the soil with the fines. If the residual
levels in the treated soil do not pose a health or
environmental risk, this represents a permanent remediation.
13.4 Reduction of Toxicity, Mobility, and Volume
Through Treatment
• While some reductions in toxicity are accomplished as a
function of the removal rates, highly hazardous
constituents may require more complete removal.
• The process does not appear to provide any additional
immobilization of the remaining contaminants.
• Two products, other than treated soil, which represent a
small fraction of the feed soil are produced. A coal/peat
waste stream which amounts to 1.6 percent of the feed
will require disposal, most likely by incineration. The
heavy metals will represent a very small fraction of the
feed and are recovered in metallic form by
electrowinning. This product may represent a recycling
opportunity.
1J.5 Short-Term Effectiveness
• The protection of the community during remedial actions
will center on the excavation and transportation of the
-------
soil to the process units. Vapor releases and fugitive
dust would be the primary concerns.
Worker protection would require careful attention to
health and safety and workplace monitoring.
Environmental releases to wastewater and air emissions
are expected to be minimal during processing.
1.3.6 Implementability
• Reliability of the soil washing process has been
established by a decade of use in Europe. The long term
reliability of the metals removal and bioslurry reactor
processes have not been established.
• The unit evaluated is capable of processing 50 to 150
tons per day of feed soil. Actual production levels will
be a function of the amount of fines in the soil and the
removal levels required to achieve acceptable levels of
contaminants in the clean soil products.
• The process units evaluated have been designed to be
trailer transportable. Assembly will require the use of a
crane and experienced personnel. Process operation will
require experienced operators.
• The soil washing technology could be utilized with
incineration of the contaminated fines for total organics
removal. If necessary, the metals removal process could
be used after incineration for removal of heavy metals
from the incineration residue.
• The effectiveness of the process can be monitored by
sampling of the soil product streams.
13.7 Cost
• Capital cost of the 6.6 ton per hour trailer transportable
process units is estimated at $2,250,000.
• Operating costs are a function of the amount of
throughput fines in the soil to be treated, the
contaminants present, and the removal rates required to
treat the contaminated slurry. In the case of 33 percent
fines, single pass metals removal and biological
treatment with 10 days detention, the total costs have
been estimated at $219 per ton of feed soil. This
includes $80 per ton of feed soil for soil washing, $96
per ton of feed soil for metals removal, and $43 per ton
of feed soil for biological treatment
THC has provided an estimate of the cost of treatment in
a fixed facility with a 55 ton/hour continuous soil feed
rate of $116 per ton of feed.
1.4 Discussion of Conclusions
The SITE program evaluation and the developer's more
extensive demonstration at the Toronto Harbour
Commissioners Soil Recycling Demonstration plant at
Toronto, Ontario, Canada has utilized a process scheme that
concentrates contaminants in a fine slurry stream using a soil
wash process and subsequent treatment of the fine slurry
with processes that remove a significant portion of the
contaminants. Because of the nature of this SITE study and
the process scheme itself, the following discussion is
presented in terms of the process units evaluated, i.e. Soil
Washer, Bioslurry Reactor and Metals Removal Process.
An extensive Quality Assurance (QA) program was
conducted by SAIC in conjunction with EPA's QA program,
including audits and data review along with corrective action
procedures and special studies to resolve specific data
quality problems. These programs are the basis for the
quality of the data derived from the SITE demonstration.
Discussion of the QA program and the results of audits, data
reviews, and special studies can be found in the Technology
Evaluation Report.
1.4.1 Soil Washing
The conclusions presented earlier in this section are based
primarily on the data developed during the SITE
demonstration.
The development of true mass balance data was precluded
by the size of the pilot facility and its 6.6 ton per hour feed
rate and the fact that the SITE demonstration sampling was
not the primary objective of the operator. Rough material
balance data were developed by using the same volume-
based approach the operator used in monitoring production.
The developer's overall mass balance for feed and products
for the entire 1040 ton run of this soil compared well with
data gathered during the processing of 122 tons of this soil
during the SITE sampling event.
When evaluating removal efficiencies, the SITE developed
estimates for mass balance were used. The conclusions
drawn would not be materially affected if the THC-
developed findings were used.
The analysis of samples of the recycled water stream used
in the soil wash process indicates that the contaminants of
-------
interest do not report to the aqueous phase. Therefore the
assessment of removal efficiencies was based on the analysis
of the product samples and the mass balance.
1.4.2 Bioslurry Reactor
The soil wash process produces a fine slurry product stream
containing about 70 percent of the organic contaminants
originally present in the feed soil while accounting for a
small fraction of the original soil mass. In the SITE
demonstration, the contaminated fine soil accounted for
about 19 percent of the feed by weight The THC project
has established an objective of using processes other than
incineration, which they recognize would have acceptance
problems in the Toronto area. This led the developer to
consider a biological treatment system, which has the
additional potential advantage of reduced cost.
The developer planned to use a continuous process for this
biological treatment system but early experience with the
bioslurry reactor process disclosed variable analytical results.
As a result, the developer had not moved beyond batch
evaluations at the time of the SITE sampling. EPA's plan,
which was designed to sample the process during steady-
state operation was, therefore, not possible to achieve. An
alternative approach was adopted for the SITE sampling,
which involved extensive sampling of the discharge from
two bioslurry reactor batches. The first batch was
accumulated from the first four days of fine slurry
production from the soil wash process. A total residence
time in the biosystem of 41 days was utilized. The second
batch, accumulated primarily during the SITE demonstration,
had a total residence time in the system of 30 days. Erratic
analytical results made an assessment of optimum residence
time very difficult. As a result, the residence times used
should not be considered as optimized.
The conclusions listed earlier in this section for the bioslurry
reactor process are based primarily on the data developed
during the SITE demonstration and reinforced by similar
results obtained by the developer.
The developer believes that anomalously high oil and grease
analytical results are caused by extraction of the biomass in
the analytical procedure. The Total Recoverable Petroleum
Hydrocarbon (TRPH) reductions observed during the SITE
study provide some support for this hypothesis since the
TRPH reduction is considerably greater than the oil and
grease reduction. TRPH levels achieved suggest that some
hydrocarbon contamination remains after treatment. The
developer is continuing the evaluation and development of
analytical procedures that may be appropriate for soils with
high biomass content. At this point, however, the fine soil
product does not meet the THC Target Criteria for oil and
grease when this parameter is assessed using SW-846
Method 9071.
The benzo(a)pyrene concentration in the biologically treated
fine soil slightly exceeds the THC Target Criteria when
assessed utilizing SW-846 techniques. Different results may
be obtained with other procedures. It may be possible to
further optimize the biological system, perhaps with the
addition of other cultures specifically selected for PAH
digestion capability.
1.4.3 Metals Removal Process
The actual soil processed during the SITE demonstration was
not contaminated with heavy metals. As a result, there was
no need to run this soil through the metals removal process.
At the time of the SITE evaluation, the metals removal
process was just being restarted after a long period of
inactivity. The acidified fine slurry from another soil
produced by the soil wash process had been sitting in the
tank for about one month. Because the sampling team was
on site for the SITE demonstration, sampling of this material
was used to provide some information concerning the metals
removal process. The process also differed from normal
operation in that the tank agitator was shut down. It was
only possible to sample the inlet and outlet of the tubular
reactor. Sampling of the original soil feed and effective
sampling of soil particles which settled in the feed tank was
not possible. The data developed are, therefore, limited to
use in assessing the effectiveness of the tubular
reactor/contactor and its solid chelating agent in reducing the
metals content of a slurry stream. The SITE demonstration
results were consistent with the developer's experience.
1.5 Costs
Cost data were developed for the system as demonstrated at
the Toronto Harbour Commissioners Soil Recycling
Demonstration Plant by THC. The estimate is based on an
analysis of the cost information developed during the
approximately nine months of operation of the facility. The
costs developed assume the facility is being operated to
process soil without conflicting information-gathering
objectives.
The THC cost estimates were developed in Canadian dollars.
The costs presented in this report have been converted to
U.S. dollars by multiplying by an exchange rate factor of
0.8.
The cost estimates for the current pilot facility, as well as
the full- scale plant, do not include the cost of disposal of
the coal/peat fraction or costs associated with effective
dewatering of the final fine product.
-------
The cost estimates for the current pilot facility, as well as
the full- scale plant, do not include the cost of disposal of
the coal/peat fraction or costs associated with effective
dewatering of the final fine product.
-------
Section 2
Introduction
2.1 The SITE Program
The EPA's Office of Solid Waste and Emergency
Response (OSWER) and the Office of Research and
Development (ORD) established the Superfund Innovative
Technology Evaluation (SITE) Program in 1986 to
promote the development and use of innovative
technologies to clean up Superfund sites across the
country. Now in its seventh year, the SITE Program is
helping to provide the treatment technologies necessary to
meet new federal and state clean-up standards aimed at
permanent remedies, rather than short-term corrections.
The SITE Program includes three components: the
Demonstration Program, the Emerging Technologies
Program and the Measurements and Monitoring
Technologies Program.
The major focus has been on the Demonstration Program,
which is designed to provide engineering and cost data on
selected technologies. EPA and the developers
participating in the program share the cost of the
demonstration. Developers are responsible for
demonstrating their innovative systems at sites, usually
Superfund sites agreed to by EPA and the developer. EPA
is responsible for sampling, analyzing, and evaluating all
test results. The outcome is an assessment of the
technology's performance, reliability, and cost. This
information, used hi conjunction with other data, enables
EPA and state decision-makers to select the most
appropriate technologies for the clean-up of Superfund
sites.
Developers of innovative technologies apply to the
Demonstration Program by responding to EPA's annual
solicitation. To qualify for the program, a new technology
must be at the pilot- or full-scale and offer some advantage
over existing comparable technologies. Mobile
technologies are of particular interest to EPA.
Once EPA accepts a proposal, EPA and the developer
work with the EPA Regional Offices and state agencies to
identify a site containing wastes suitable for testing the
capabilities of the technology. EPA prepares a detailed
sampling and analysis plan designed to evaluate the
technology thoroughly and to ensure that the resulting data
are reliable. This project had a somewhat different nature.
The Toronto Harbour Commissioners (THC) had developed
a demonstration project to evaluate an approach for
remediation of a large number of industrial/commercial
sites located in the Toronto Port Industrial District (PID).
This demonstration involved the operation of a Pilot
Demonstration Plant for approximately nine months to
demonstrate the feasibility of recycling soil with both
organic and inorganic, contamination as well as developing
information for the eventual design of a full-scale facility
based on the technologies evaluated. -THC, in this case,
did not fit the classical developers role in a typical SITE
demonstration. When the program was initiated, THC had
no business interest hi the technologies being evaluated.
During the course of the demonstration some changes hi
the relationship between THC and its contractors took
place which resulted in THC taking a partnership interest
hi the metals removal process technology.
EPA was offered the opportunity to • participate in this
project. After meeting with the THC and discussing then-
plan, an approach was developed by EPA. Normally a
demonstration may require a few days to several months,
depending on the type of process and the quantity of waste
needed to assess the technology. Thus, while it may be
possible to obtain meaningful results in a demonstration of
one week using an incineration process, where
contaminants are destroyed hi seconds, this is not the case
for a process sequence such as that offered by the Toronto
Harbour Commissioners Soil Recycling Demonstration,
where operational reliability, integration of outputs from
one unit to others, and biological and system acclimation
and stability must be examined. In order to evaluate such
parameters, THC determined that a minimum of six
months of operations was necessary to evaluate the
complete process train while processing three different
soils from the PID. EPA elected to sample the process
-------
during the processing of Soil B, which based on field
sampling was expected to exhibit relatively high organic
(oil and grease, PAH compounds) and inorganic (heavy
metals) contaminants. The sampling undertaken by EPA
was of relatively short duration but it was expected that
when the results were combined with THC data, a sound
basis for analysis of the technology would be obtained.
Ultimately, the Demonstration Program leads to an
analysis of the technology's overall applicability to
Supcrfund problems.
The second principal element of the SITE Program is the
Emerging Technologies Program, which fosters the further
investigation and development of treatment technologies
that are still at the laboratory scale. Successful validation
of these technologies could lead to the development of
systems ready for field demonstration. A third component
of the SITE Program, the Measurement and Monitoring
Technologies Program, provides assistance in the
development and demonstration of innovative technologies
to better characterize Superfund sites.
2.2 SITE Program Reports
The results of the SITE Demonstration Program are
reported in two documents, the Technology Evaluation
Report and the Applications Analysis Report. The
Technology Evaluation Report provides a comprehensive
description of the demonstration and its results for
engineers responsible for detailed evaluation of the
technology relative to other specific sites and waste
situations. These technical evaluators will want to
understand thoroughly the performance of the technology
during the demonstration, and the advantages, risks, and
costs of the technology for the given application.
The Applications Analysis Report is directed to officials
responsible for selecting and implementing remedial
actions for specific sites. This report provides sufficient
information for a preliminary determination of whether the
technology merits detailed consideration as an option in
cleaning up a specific site. If the candidate technology
described in the Applications Analysis appears to meet the
needs of the site engineers, a more thorough assessment
can be made based on the Technology Evaluation Report
and information from remedial investigations for the
specific site. In summary, the Applications Analysis will
assist in determining whether the specific technology
should be considered further as an option for a particular
clean-up situation.
Each SITE demonstration evaluates the performance of a
technology while treating the particular waste matrix found
at the demonstration site. Additional data from other
projects carried out by the developer also are presented
where available.
Usually, the waste and/or soil at other sites requiring
remediation will differ in some way from the waste matrix
tested. Waste characteristic differences could affect waste
treatability and use of the demonstration technology at
other sites. Successful demonstration of a technology at
one site does not ensure that the same technology or
configuration will work equally well at other locations.
The operating range over which the technology performs
satisfactorily can only be determined by examining a broad
range of wastes and sites. This report provides an
indication of the applicability of the Attrition Soil Washer,
the Bioslurry-Reactor, and the Metals Removal Process,
both as individual operating units and as an integrated
system, by presenting and examining the SITE
demonstration test data and data from the developer that
are available from other applications of the technology.
To enable and encourage the general use of demonstrated
technologies, EPA considers the probable applicability of
each technology to sites and wastes in addition to those
tested, and strives to estimate the technology's likely costs
hi these applications. The results of these analyses are
made available through the Applications Analysis Report.
2.3 Key Contacts
For more information on the demonstration of the THC
Soil Recycle System for contaminated soil please contact:
1. Technology Developer concerning the process:
Mr. Dennis Lang
The Toronto Harbour Commissions
60 Harbour Street
Toronto, Ontario, Canada M5J 1B7
(416) 863-2047
FAX: (416) 863-4830
2. EPA Project Manager concerning the SITE
Demonstration:
Ms. Teri Richardson
Risk Reduction Engineering Laboratory
26 West Martin Luther King Drive
Cincinnati, Ohio 45268
(513) 569-7949
-------
Section 3
Technology Applications Analysis
3.1 Introduction
This section addresses the potential applicability of the
Toronto Harbour Commissioners Soil Recycle System to
other soils and Superfund site situations where petroleum
hydrocarbons, polynuclear aromatic hydrocarbons and
heavy metals are the pollutants of primary interest. The
demonstration at the Toronto Harbour Commissioners' Soil
Recycle Demonstration Plant provides a data base for use
in assessing the effectiveness and applicability of the
technology to other cleanups. This data base is
complemented by information from further studies of the
same soil, as well as other soils and wastes conducted by
THC during the first nine months of 1992.
3.2 Conclusions
3.2.1 Overall Process Train
Based on the results of the testing conducted during this
evaluation, the primary developer claim, the production of
gravel, sand and fine soil that meet the THC Target criteria
(see Table 1) for medium to fine soil suitable for
industrial/commercial sites, was not achieved. The
problem appears to center on the biological treatment
process, which exhibited variable behavior with regard to
the oil and grease parameter. Although exhibiting
significant reduction in PAH compounds, the process did
not meet the target level of 2.4 ppm for benzo(a)pyrene.
An assessment of the developer's claims relative to metals
treatment was not possible since the 1040 tons of soil
excavated for this study did not exhibit the metals
contamination levels expected based on the field sampling.
The developer employed a hydrocyclone device for final
dewatering of the clean fine soil. This technology was
not successful and as a result the final product from the
process was a slurry. Fine product dewatering will
require further evaluation by the developer or will require
another technology.
3.2.2 Individual Processes
3.2.2.1 Soil Washing
The attrition soil wash plant produced a gravel and a sand
product that met the primary THC Target criteria. It
should be noted that the only parameter that exceeded the
THC criterion in the feed was naphthalene. Nevertheless,
the process exhibited removal rates for organic.
contaminants (oil & grease, TRPH, naphthalene,
benzo(a)pyrene) of 67 percent or greater for the gravel
product. This product accounted for 11.5 percent of total
process mass output (dry weight basis) and 4 percent or
less of the organic contaminants in the product streams.
This process exhibited removal rates for organic
contaminants (oil & grease, TRPH, naphthalene, benzo(a)
pyrene) of 78 percent or greater for the sand product. This
product accounted for 68.1 percent of the process mass
output while accounting for 15 percent or less of the
organic contaminants in the product stream.
The process concentrated the organic contaminants into a
fine slurry stream that accounted for about 18.8 percent of
the process mass output and 74 percent or more of the
organic contaminants.
The process also produced a contaminated coal/peat
product which represented 1.6 percent of the process
output and accounted for 6 percent or more of the organic
contaminants. This waste stream will require disposal
(most likely by incineration).
The feed soil exhibited low heavy metals contaminant
concentrations (copper-17 ppm, lead-115 ppm andzinc-83
ppm). The wash process concentrated these contaminants
in the fine slurry which accounted for 18.8 percent of the
-------
process output and 59 percent or greater of these metals in
the process output streams.
32.22 Biosluny Process
The clean fine soil product resulting from the bioslurry
process did not meet the primary objective when assessed
using the appropriate analytical procedures from SW846 as
universally applied in SITE evaluations. The developer has
investigated other analytical procedures they believe may be
appropriate for soils with high biomass concentrations that
may yield different results. The problem parameters were
oil & grease and benzo(a)pyrene. The benzo(a)pyrene
concentration, although reduced by the process, did not meet
the THC Target Criteria level of 2.4 ppm.
The bioslurry process provided limited reduction in oil and
grease when comparing inlet to output samples. A similar
comparison for other parameters yields the following
reduction: Total Recoverable Petroleum Hydrocarbons
(TRPH) 52 percent; naphthalene at least 97 percent; and
benzo(a) pyrene approximately 70 percent.
objective was to determine whether the processes operating
in an integrated manner can meet the THC criteria for return
of the soil to the site. The primary process is a soil attrition
wash process that segregates a contaminated soil into (a)
washed gravel, (b) sand, and (c) fine soil. Each output
retains whatever contaminants are absorbed, adsorbed or
otherwise integrally mixed with the solids. Because of the
increasing surface area per unit weight, the fine soil contains
a disproportionate fraction of most contaminants, while the
gravel is relatively uncontaminated. Investigations carried
out by others have established that such soil wash processes
can typically handle feed soils with up to 25-35% fine soil.
For the fine soil to be returned as "clean" further treatment
would usually be required, such as the biodegradation of
organics and/or heavy metals removal also studied in this
demonstration. Figure 1 presents a simplified diagram
illustrating the partition of feed and contaminants to the
product streams.
FIGURE 1
PARTITION OF FEED SOIL TO PRODUCT STREAMS.
THC TREATMENT THAIN(BASED ON SITE DEMONSTRATION DATA)
3223 Metals Removal Process
The metals contamination concentrations of the soil that was
moved to the pilot facility for processing were low and
eliminated the need for utilizing the metals removal process
for this soil. Limited data were developed for the efficiency
of the solid chelating agent and tubular reactor process by
sampling a process run of a metal-rich slurry for another soil
which had been processed earlier. The reactor achieved the
following removal efficiencies based on metals
concentrations in the inlet versus the outlet samples -
copper-96 percent, lead-71 percent, nickel-71 percent and
zinc-63 percent. No assessment of the process ability to
achieve the THC Target Criteria was possible because of the
sampling circumstances.
During the sampling, the metals removal process became
fouled with oil and grease forcing premature termination of
the operation. This represents an operational constraint in
that if slurries exhibit free oil and grease and metal
contamination the free oil and grease should be reduced
prior to application of the metals extraction process.
Optimization of the materials management at that specific
site may also avoid this constraint.
2000 « OF FEED
16.4 * OF O&G
9.0 * OF TRPH
.23 * OF LEAD
OF BENZO(>)PYRENE (B(a)P)
ATTRITION SOIL WASH PROCESS
COAL/
PEAT
CONTAMINATED
FINE SLURRY(I)
WEIGHT %
OtG (2)
TRPH (2)
LEAD (2)
(B(«)P) (2)
210 *
10.5
3.7 %
2.7 %
3.5 %
2.5%
1
90*
2.9
10 %
8.4%
3.3%
14.7%
1405 •
70.2
16.1%
13.8%
38.7 %
15.1%
I
335*
16. 7
70.2%
74.1%
55.4%
87.7%
RETURN
TO SITE
I INCINERATION I
OR LANDFILL I
RETURN
TO SITE
BIOLOGICAL
TREATMENT I
1.MASS FRACTION OF CONTAMINATED FINES ESTIMATED. BASED ON DIFFERENCE
(CONTAMINATED FINES:FEED-( GRAVEL«COAUPEAT» SAND)
2.PERCENTAGE OF CONTAMINANT BASED ON TOTAL CONTAMINANTS IN PRODUCT STREAMS
3.3 Technology Evaluation
This SITE program evaluation demonstrated a process
scheme that involves three processes to remediate soils
contaminated with organics and/or heavy metals. The
Figure 2 provides a more detailed schematic of the overall
treatment train in a configuration that would be used for a
soil with significant organic and inorganic heavy metals
contamination.
10
-------
FIGURE 2
SIMPLIFIED PROCESS FLOW DIAGRAM
Aetd I r""""™™"•"! Nautralln
Laacb H I"1""" » and
I | Raactor Dawatar
n n i—
1 1 Chalatlng
I T Ag.nl
•— Raganarattng -^
The results and discussion focus on naphthalene and
benzo(a)pyrene because these contaminants exceeded the
THC Criteria in the feed or one of the products. Other PAH
contaminants were examined but did not exceed the THC
criteria in the feed or products. For simplicity, the results
are presented only for naphthalene and benzo(a)pyrene.
33.1 Soil Washing
The conclusions presented earlier in this section are based
primarily on the data developed during the SITE
demonstration. Additional data are presented in Appendix
D.
The THC evaluation of the attrition soil wash process for
this soil was conducted over a two month period. The feed
soil exhibited much higher (by a factor of 3) oil and grease
contamination than observed during the site evaluation.
THC's results indicated that the gravel product did not meet
the THC, oil and grease criterion, however the sand product
did meet the criteria during the THC evaluation.
The development of true mass balance data was precluded
by the size of the pilot facility and its 6.6 ton per hour feed
rate and the fact that the SITE demonstration sampling was
not a primary objective of the operation. Rough material
balance data were developed by using data the operator used
in monitoring production.
A mass balance for the three day SITE demonstration using
bucket counts and actual density measurement also was
determined. The mass balance results are presented in
Figure 3.
FIGURE 3
SIMPLIFIED PROCESS FLOW DIAGRAM FOR SOIL WASH PROCESS
SHOWING PRODUCT FRACTIONS ON A WEIGHT BASIS
Coal/
Paat
SOIL >.24 IN
THC-0.105
SITE-0.115
Sand
>.Q025 IN
THC-0.702
SITE-0.681
•
-------
Table 2. Selected Feed and Product Characteristics of the Attrition Soil Wash Process
Percent of Output Based
on Site Demo. Data
Percent of Output Based
on THC Overall Analysis
OH & Grease (mg/kg)
TRPH (mg/kg)
Copper (mg/kg)
Lead (mg/kg)
Zinc (mg/kg)
Naphthalene (mg/kg)
Benzo (a) Pyrene
(mg/kg)
Feed
Soil"'
—
8,200
(6.708-9.700)3
2,500
(2,270-3,430)
18.3
(9.2-42.2)
115
(63.3-127)
82.5
(40.4-181)
11.2
(5.3-18)
1.9
(0.9-2.9)
THC
Criteria
—
—
10,000
—
225
750
600
8
2.4
<1.97 in.
>0.24 in.
Gravel'1'
11.5
10.5
3,300
(1,200-10,400)
800
(270-1,370)
6.4
(0.7-12.1)
45.3
(3.2-117)
46
(2.3-98.6)
2.5
(0.9-2.9)
0.6
(0.2-1.0)
<0.24 in.
Coal/Peat
Fraction'2'
1.6
2.5
38,000
(17,600-51,600)
11,900
(4,760-16,280)
32.9
(22.8-41.7)
406
(12.9-749
210
(46.8-406)
64
(34-1.10)
14.5
(9.6-23)
<0.24 in.
>0.0025 in.
Sand'1'
68.1
70.2
2,200
(1 ,400-3,900)
620
(380-960)
13.8
(32-32.4)
46
(23.6-82.9)
34.1
(15.9-71.4)
2.1
(1.5-3.1)
0.5
(0.2-1.2)
<0.0025 in.
Contam.
Fines'1'
18.8
16.7
40,000
(26,900-50,500)
14,000
(8,500-19,800)
83.1
(48.2-135)
522
(421-680)
344
(192-593)
51.7
(17-82)
10.0
(9.0-12.0)
(1) Average of six composite samples.
(2) Average of three composite samples.
(3) Range of results.
Table 3. Characteristics of Soil Wash Product Streams (based on SITE mass balance and Site Demonstration Analytical
Results)
Fraction of Output
Oil & Grease
TRPH
Copper
Lead
Zinc
Naphthalene
Benzo(a)pyrene
<1.97in.
>0.24 in.
Gravel
0.115
0.038'1'
. (33)'2'
0.028
(24)
0.028
(24)
0.037
(32)
0.053
(50)
0.024
(21)
0.028
(24)
<0.24 in.
Coal/Peat
Fraction
0.016
0.061
(381)
0.057
(356)
, 0.020
(125)
0.046
(289)
0.057
(230)
0.082
(513)
0.091
(569)
<0.24 in.
>0.0025 in.
Sand
0.681
0.149
(22)
0.127
(19)
0.358
(53)
0.223
(33)
0.262
(38)
0.113
(17)
0.142
(21)
<0.0025 in.
Contaminated
Fines
0.188
0.752
(400)
0.788
(419)
0.594
(316)
0.694
. (369)
0.628
(334)
0.781
(415)
0.740
(394)
(1) Weight fraction of the specific parameter found in the product stream as a fraction of the total weight in all product streams.
(2) Percent of expected value based on feed concentration of respective contaminants and weight fraction of product stream.
12
-------
33.2 Bioslurry Reactor Effectiveness
The soil wash process produces a contaminated fine soil
slurry. This product stream contains much of the organic
contaminants originally present in the feed soil while
accounting for a small fraction of the original soil. In the
SITE demonstration, the contaminated fine soil accounted for
about 19 percent of the feed by weight. The THC project
has established an objective of using processes other than
incineration, which they recognize would have acceptance
problems in the Toronto area. This led the developer to the
use of a biological treatment system which has the additional
potential advantage of reduced cost, particularly when
compared to incineration.
The developer's early experience with the bioslurry reactor
process disclosed variable results. As a result, the developer
had not moved beyond batch evaluations at the time of the
SITE sampling. The SITE project plan, that was designed
to sample a continuous process when it approached steady-
state operation, was, therefore, not possible. An alternative
approach was adopted that involved extensively sampling the
discharge from two bioslurry reactor batches. The first
batch accumulated from the first four days of fine slurry had
a total process time in the biosystem of 41 days; the second
batch had a total process time in the system of 30 days. The
information available for evaluation is therefore somewhat
restricted. The inlet and outlet results for selected
parameters are presented in Table 4.
Erratic analytical results with process samples taken by THC
The conclusions listed earlier in this section for the bioslurry
reactor process are based primarily on these data and are
confirmed by similar results obtained by the developer.
The developer believes that anomalously high oil and grease
analytical results are caused by the extraction of biomass in
the analytical procedure with a resultant high oil and grease
analytical result. The Total Recoverable Petroleum
Hydrocarbon (TRPH) reductions observed provide some
support for this hypothesis since this parameter exhibits
much higher reductions then does oil and grease. The TRPH
levels still present do suggest that considerable hydrocarbon
contamination remains after the treatment. The fine soil
product does not meet the THC Target Criterion of oil and
grease when this parameter is assessed using SW-846
Method 9071.
The benzo(a)pyrene concentration in the treated fine soil just
exceeds the THC Target Criterion. It may be possible to
further optimize the biological system, perhaps with the
addition of other cultures specifically selected for PAH
digestion capabilities.
3.3.3 Metals Removal Process
The actual soil processed during the SITE demonstration was
not contaminated with concentrations of heavy metals that
exceeded the THC criteria. Consequently, there was no need
to operate the metals removal process. At the time of the
Table 4. Selected Feed and Product Characteristics of the Bioslurry Reactor Process.
Contaminated Bioslurry Bioslurry
MOE Fine Reactor Reactor
Criteria Slurry"' Batch 1ra Batch 2(2)
Oil & Grease 1.0% 4.00% 4.98% 2.53%
(2.7-S.4)4 (3.96-6.08) (3.98-2.17)
TRPH .- 1.4% .78% .54%
(.85-1.98) (.68-.9S) (.S9-.76)
Naphthalene 8 mg/kg 51.7mg/kg <14!5) mg/kg <13(5) mg/kg
(17-82) <16-<11
Benzo(a)pyrene 2.4 mg/kg 10 mg/kg 3.1 mg/kg 2.6 mg/kg
(8.4-12) (2.0-5.1) (2.3-3.4)
Removal
Efficiency
%n
6
52
9>>
71
(1) Average of 6 composite samples.
(2) Average of 6 samples taken at 20 minute intervals during discharge of batch.
(3) Removal efficiency based on average value for both batches.
(4) Range of results.
(5) Value reported is average of quantitation limit reported. Detection limit is at least a factor 10 less than the quantitation limit.
(6) Removal efficiency calculated from detection limit estimated by dividing quantitation limit by 10.
made an assessment of the residence time required to
achieve satisfactory results very difficult. As a result, the
residence time utilized should not be considered as optimum.
SITE demonstration sampling, the metals removal process
was just being restarted after a long shut-down period. The
metals removal feed tanks contained material from the end
of a soil wash run on a different soil concluded about one
month earlier. Because the sampling team was on site for
13
-------
the SITE demonstration, a decision was made to sample the
inlet and outlet of the tubular reactor even though samples
of the soil fed to the system could not be obtained. In
addition, no method to effectively sample any soil particles
which settled in the feed tank was available. The process
also differed from normal operation in that the tank agitator
was shut down prior to starting to pump the slurry to the
tubular contactor. The data developed is, therefore, limited
to providing information on which to assess the effectiveness
of the tubular reactor contactor and its solid chelating agent
in reducing the metals content of a slurry stream. Our
results were consistent with the developers experience.
Selected heavy metal data for removal of metals from the
liquid stream by the THC metals removal process is
presented in Table 5.
Table 5. Selected Heavy Metals Data for Removal of
Motals from the Liquid Stream by the THC
Metals Removal Process.
Metal
Copper
Lead
Nickel
Zinc
Influent
mg/kg
51.1
(49.2-53.2)1
100.5
(94.2-112)
11.7
(10.7-12.7)
277
(264-294)
Effluent
mg/kg
1.8
(0.9-3.0)
29.0
(13.5-46)
3 3
(0.9-7.3)
101
(53-183)
Removal %
96
71
71
63
1 Range of values.
The developer has information on this process as applied to
several soils. In general, the particular solid chelating agent
used removes copper most effectively, while lead and nickel
are removed at a somewhat lower effectiveness, followed by
zinc with a removal rate of about 60 percent.
3.4 Applicable Wastes
It should be emphasized that treatability tests should be
undertaken with any candidate soil. In the case of this
technology train, an evaluation of each process being
considered to treat a specific candidate soil would be
required.
There are some general applicability guides that may be
useful in assessing if treatability testing should be
considered.
The overall treatment approach requires that the
contamination of interest can be concentrated in a fine soil
fraction which then can be economically processed. This
requires that the fine soil fraction not represent too great a
percentage of the overall soil. The developer, estimates that
soil fines should not normally exceed 30 to 35 percent by
weight of the overall soil feed. The lower the fine soil
concentration in the specific soil, the more favorable the
potential economics of the process should be.
The soil wash process is generally tolerant of normal swings
in soil particle size. Potential problems arise if metal wire
or fibrous vegetation (roots) in the feed soil are common.
This leads to operational problems, particularly for the
cleanup of the gravels and fine sand fraction and can affect
production costs adversely. Another problem could be
encountered if the soil exhibits wide swings in the coarse
material content If the maximum concentration of coarse
material is known at the design phase, it can be accounted
for, but if the design capacity of the trommel washer is
exceeded, this could limit the production rate.
The soil wash process is not suited to reduce inorganic target
compounds in a soil in which the target compounds are
present as a result of the minerals widely dispersed in the
soil particles. In this case, little partition by particle size can
be expected.
The process configuration utilized depends on the target
contaminants being essentially non-soluble in water. If
soluble components are present, the ability to reuse water
may be affected and some treatment for the aqueous phase
may be necessary.
The metals treatment process is not tolerant of free oil and
grease. In order to be useful for a soil with free oil and
grease, prior treatment will be required.
The metals treatment process may be tailored to specific
metals by the selection of ion exchange chelating media. In
general, the process depends on being able to dissolve the
metals of interest at acidity levels compatabile with the
chelating resin system.
The metals treatment process uses an acid solubilization step
to make the metals available for removal. The developer has
indicated that if the soil matrix contains considerable free
calcium carbonate or other carbonates foaming problems
may arise when the soil is acidified. In addition, the soluble
components may cause handling or dewatering problems
when the process effluent is neutralized.
3.5 Site Characteristics
14
-------
The size and nature of a site that requires remediation may
have a considerable effect on the decision to utilize this
treatment approach. The volume of material that must be
remediated should be in the tens of thousands of tons in
order to warrant the use of these technologies. The
. technology should produce a large volume of clean product
soil that can be returned to the excavation site. The type
and amount of debris on the site may also be a
consideration. Material larger than 2 inches must be
removed before the soil can be fed to the wash process.
Metal fragments must also be removed as part of a
pretteatment operation. If the amount of material or the
operational difficulty in removing the debris is excessive, the
site may not be suitable for this technology.
This SITE demonstration did not investigate the impact of
soil characteristics and particle size distribution on the
properties of the output stream. These factors can be
expected to have an effect on the masses of the various
output streams and may affect throughput rates and the
partition of the contaminants to the various product streams.
The need for treatability evaluation is therefore further
emphasized.
The THC demonstration plant was located on a prepared site
in close proximity to the location of the soil sites to be
evaluated. The soil wash plant and the metals removal
process were designed in trailer transportable modules that
can be transported and reassembled for use at a specific site.
The bioslurry reactors require relatively large tanks (20,000
gallons), which were designed to be the largest tanks that
could still be transported by trailer. The facility at Toronto
was located on a paved pad and fully enclosed in a
temporary building to allow operation during the relatively
harsh Ontario winter season. The facility requires power and
a water source. A source of fuel, to maintain water
temperature above 55° F, such as natural gas, propane, or
fuel oil would provide a cost saving when compared to
water heating with electric power. The site is designed to
collect all storm runoff and to store it for use in the process.
The specific water balance at a site would depend on rainfall
and amount of water that leaves the process with product
streams. If water must be discharged, a site-specific
determination will be required to determine if treatment is
necessary prior to discharge to a POTW or to surface waters.
In general, a provision should be available to allow
discharge if required. The recycled water at the THC site
did not show partition of the pollutants to the aqueous phase,
but this will be a factor controlled by the nature of the
contaminants present.
The use of contaminated water in the process may provide
a net benefit at specific sites. For example, if groundwater
at a site is contaminated, the metals removal process may
also treat this water.
Climate may play a role in determining the type of structure
in which the process train would be housed. The soil wash
and metals removal process wiU require at least a covered
structure. The bioslurry reactors are closed tanks, and,
therefore, could be located on an open pad. If the climate
at a site would be expected to exhibit severe winter
temperatures, the overall process should be located in an
enclosure or heating of tanks and the transfer line may be
required. Adverse winter conditions could also cause
problems due to the soil freezing, which could effect soil
excavation and external materials transfer operations at the
facility.
Generally, the process will consume water' due to the
moisture leaving with the product streams. In climates
where seasonable imbalances in precipitation are common,
a provision to obtain water for use during dry periods may
be appropriate.
3,6 Environmental Regulation Requirements
The THC program is aimed at providing an approach for soil
remediation at industrial and commercial sites. The primary
regulatory agency responsible is the Province of Ontario
Ministry of the Environment. The specific permit issues for
the Toronto facility have been addressed by THC.
In the United States, under the Comprehensive
Environmental Response, Compensation, and Liability Act
of 1980 (CERCLA) and the Superfund Amendments and
Reauthorization Act of 1986 (SARA), EPA is responsible for
determining the methods and criteria for the removal of
waste and residual contamination from a site. The utility
and cost effectiveness of the THC Treatment System would
be dependent on the extent of decontamination necessary for
site restoration and the combination of treatment units
appropriate to achieve the required clean-up levels for a
particular site. If a waste exhibits a characteristic hazard
(e.g., TCLP leachate toxicity) or is a listed hazardous waste,
treatment will be required. Specific treatment levels to allow
the return of product streams to the excavation site must be
established at each site by the responsible agency or
agencies. Nevertheless, since the use of remedial actions by
treatment that".... permanently and significantly reduces the
volume, toxicity, or mobility of hazardous substances" is
strongly recommended (Section 121 of SARA), the THC
Attrition Soil Washer System would appear to be an
attractive candidate for consideration for remediation of sites
contaminated with hydrophobic organic chemicals and/or
heavy metals.
SARA also added a new criterion for assessing cleanups that
includes consideration of potential contamination of the
ambient air. This is in addition to general criteria requiring
15
-------
that remedies be protective of human health and the
environment. Other than normal concerns for workers
handling large volumes of contaminated soils and the dust
generated during the excavation and movement of soil to the
plant, there appears to be minimal opportunity for exposure
by workers or neighbors to the contaminants. Since the soil
washing is a wet process and all conveyors and process
vessels are hooded and ventilated, exposure in the facility
Should be limited. The ventilating system for the plant will
require treatment of the air prior to discharge. Air drawn
from the bioslurry reactors does contain hydrocarbons from
stripping action. The ventilating air collected from the soil
wash plant also contains volatile organics and the metals
treatment process requires treatment to control acid gases.
Permits will be required for each of the emission points from
the air treatment systems employed.
Additional regulatory aspects that might be addressed include
permits for wells that might be drilled to treat groundwater
(and provide water for soil processing) and any excavation
authorization that may be necessary. Runoff from soil piles
awaiting treatment may require treatment in systems that
require permits. Depending on the size of the site being
remediated and the roles of the bioslurry reactor, storage
tanks may be necessary as reservoirs and to provide needed
equalization. Such tanks may require permits, spill
contingency plans, etc. depending on their size and whether
they are above or below ground. For a large site and a large
soil washer system processing as much as 55 tons/hour,
water storage capacity would be large enough to require
basins instead of tanks. This would raise additional
regulatory questions about liners, secondary containment,
leachate collection, etc.
Even if the overall process train achieves a condition
whereby all water would be recycled during operation,
discharge of the residual water and decontamination of all
equipment will be necessary at the termination of operation.
Depending on the contaminants present, this water may be
suitable for direct discharge or discharged to a POTW with
some treatment. A NPDES permit or sewer discharge
permit would be required. While the SITE project is
exempted from permit requirements under the Resource
Conservation and Recovery Act of 1976 (RCRA), the
Hazardous and Solid Waste Amendments of 1984 (HSWA),
and state regulations, a commercial site will require a RCRA
permit for the entire treatment system to operate as a
hazardous waste treatment facility. This would include
storage tanks, all treatment equipment/reactors, effluents, and
if applicable, air emissions.
3.7 Materials Handling Requirements
Soil Excavation - The soil to be treated is excavated and
transported to a covered shed prior to processing. The
excavation and transport involve conventional earth moving
equipment, such as front-end loaders and a dump truck.
Soil Washer - Materials handling is a significant labor and
therefore cost factor for both the feed to the process, as well
as the removal of solid product stream at the THC soil wash
plant. The soil is removed from the storage shed utilizing a
front-end loader and is then slowly fed to a vibratory grizzly.
The soil drops to a belt conveyor that runs the soil to a
rotating permanent magnetic separator. The output from this
magnetic separator drops to a belt conveyor and constitutes
the feed to the soil wash process. The sand product is
conveyed by belt conveyors from the density separators to
its product bin. The solid products are collected in three
sided bins, which allows the periodic removal of the
products using a small front-end loader. The coal/peat
product is collected in a self-dumping hopper. The product
solids are loaded into a dump truck and returned to the
excavation site. Slurry product from the wash plant is
pumped to the metals removal process or to the bioslurry
reactor process depending on the nature of the contaminants.
The pilot facility materials handling was dictated by the need
to maintain flexibility and meet space constraints. During
the design phase of a- full-scale facility project, significant
materials handling changes would allow considerable
savings.
Bioslurry Reactors - Material is moved from tank to tank
utilizing diaphragm pumps. Material is discharged using
permanently installed centrifugal pumps. The process was
equipped with an automatic nutrient feeder operated by
peristatic pumps, however the operator preferred to add the
nutrients manually through ports on the top of the tanks.
Filtered air for the aeration system is fed from a compressor
located outside the building through a manifold to the
bioslurry reactors.
Metals removal process - Material handling in the metals
removal process involves pumping of slurries. The final
product is a slurry that is either pumped to the bioslurry
reactor process or returned to the excavation site after
dewatering depending on the prior processing history of the
soil and the contaminants originally present.
Fine Product Dewatering - The developer incorporated a
system for dewatering using high pressure hydrocyclones to
evaluate the performance of this technology that promised a
considerable cost saving. The system was not successful in
achieving meaningful dewatering of the fine soil product.
As a result, the slurry product was returned by tank truck to
16
-------
the excavation site or pumped directly to the site if
geography allowed. The developer will need to evaluate
other dewatering processes such as sedimentation or other
forms of filtration. The very fine particle size of the slurry
may make this a difficult dewatering problem but an
acceptable technology from mineral processing or sludge
dewatering almost certainly can be found.
3.8 Personnel Issues
Soil Washer - The attrition soil washer evaluated as part of
the soil recycling demonstration is automated in the sense
that the material moves through the system without direct
action by the operator. The wash plant itself is not labor
intensive but does generally require the availability of two
operators to monitor soil, slurry, and water flows and to
make equipment adjustments and repairs as required.
The materials handling labor requirements for this unit are
one front-end loader operator on a full-time basis to move
soil to the soil washer to load the pretreatment grizzly and
remove solid products from the plant.
The processing of soils with hazardous contaminants will
demand a high level of attention to worker health and safety.
The pilot unit has been provided with extensive hoods and
ventilation to handle volatile organics released during the
wash process and associated handling. In all cases, a
comprehensive workplace and personnel health monitoring
program tailored to the particular contaminants found in the
soil being treated will be required. In general, worker
contact with the feed or products is incidental to their work
rather than routinely necessary.
Bioslurry Reactor Process - The bioslurry reactors utilize
manually operated pumps for the transfer of slurries. There
is little direct contact with the slurry in routine operation. A
single operator, working half time on the bioslurry process
and half time on the plants water treatment and management,
is used on a one shift a day basis. If overflows from the
reactors occur as a result of foaming, which has been
encountered periodically, the operator is assisted by a
general laborer in clean-up efforts. Spill response and clean-
up must be appropriate for the particular hazards associated
with the specific contaminants present in the soil being
treated.
V
Metals Removal Process - The metals removal process is
highly automated and incorporates modern computer
monitoring and control. Dkect contact by the operator with
the process equipment or material is not routine. The
process does require two full-time operators to make any
adjustments that may be required as well as to initiate
repairs and to respond to spills or other upsets. This process
is a continuous process'and runs well once equilibrium
conditions are established. Therefore, by its nature it should
be a round-the-clock operation and operators are required for
120 hour per week of operation. An additional operator may
be required to handle periodic operation of the
electrowinning process as well as support for the primary
process.
This process utilizes acids and bases to effect the metals
removal process. Routine contact with these materials or the
soil being processed is not .required. Personal protective
clothing and.gear is required for non-routine situations. Spill
and emergency response plans and training are a necessity.
17
-------
Section 4
Economic Analysis
4.1 Introduction
The primary purpose of this economic analysis is to provide
cost information useful in understanding the likely costs of
applying the THC treatment train at a production level of
approximately 6.6 tons of dry soil feed per hour to the initial
soil wash process. With this cost information and a
knowledge of the basis for its development, it should be
possible to develop cost estimates for other soil or
production levels. An overall cost estimate for a plant with
a soil feed rate of 55 ton per hour is also provided.
This economic analysis is based on assumptions and costs
provided by THC or its contractors. This estimate is based
on an analysis of costs incurred during the 9 months of plant
operation experience accumulated in 1992. THC provided
a cost analysis based on an assumption of 33 percent fines
in the soil. This represents a worst case scenario for costs.
Several other cases have been examined in order to highlight
the importance of the amount of fines in the overall costs for
the treatment train. The THC analysis was provided in
Canadian dollars. We have converted to U.S. currency by
using an exchange rate of $0.80 U.S. to $1.00 Canadian.
Comments on the cost analysis and discussion of cost
Clements in general represent the author's engineering
judgement An effort has been made to present the cost
analysis in a manner that will allow the reader to vary the
basis to fit a particular situation or to evaluate the sensitivity
of cost to a particular assumption.
Certain costs have not been included in this analysis because
they would be site specific. These include plant site
preparation, soil excavation, and transportation to the plant
for treatment. The cost of disposal of the two waste
products from the process have not been included because
they will be site specific. The wastes involved are the
coal/peat product and the metals recovered in the
clectrowinning used in the metals removal process.
Cost figures provided here are based on an analysis of the
actual operation of the actual plant and actual personnel.
The analysis involved identifying achievable long term
production levels and utilizing actual cost experience to
project costs when production is the primary goal of the
operation.
4.2 Conclusions
• Based on an assumption of 33 percent fines and a 6.6
ton per hour dry solids feed rate, the estimated total cost
for the THC treatment train is $220 per ton.
• The individual process costs on the same basis are:
Soil Washing: $80/ton of soil treated.
Bioslurry Process: $43/ton of soil feed.
Metals Removal: $96/ton of soil feed.
TOTAL:
$219/ton of soil feed.
Projected costs of a dedicated full scale 55 ton per hour
of feed soil (33% fines) facility are:
Soil Wash
Bioslurry
Metals Removal
Total
$ 43/ton
23
51
$117/ton
The projected costs for the pilot-scale unit are quite
sensitive to the percentage of fines in the feed soil. This
occurs because the bioslurry and metals removal
processes are required to treat all the fine slurry. These
process throughput rates therefore can limit the amount
of time the wash plant can be operated. Assuming 16.5
percent fines, consistent with THC results for several
soils, the total costs would drop to about $ 136/ton.
18
-------
If 11 percent fines is assumed, the total costs are
estimated at about $109/ton.
The actual cost for a specific soil will also be a function
of the relative difficulty in treatment in the bioslurry
reactor system. The THC cost estimate is based on
throughput rate that would result in a retention time in
the reactors of about 10 days. If longer retention is
required, more reactors will be required or the amount of
time the soil wash process operates must be decreased.
The actual cost for a specific soil will also be a function
of the relative difficulty in treatment for metals removal.
Soils with higher metals contamination levels may
require lower throughput rates or multiple passes through
the tubular contractor.
4.3 Issues and Assumptions
This section summarizes the major issues and assumptions
used to evaluate the cost of the THC soil treatment process.
In general, the assumptions are based on information
provided by THC or its contractors. The basic cost
information provided has been used in an analysis to
iilusbate the sensitivity of costs to the percent fines in the
soil. The costs discussed are based on the experience
developed during the first 9 months of 1992 during which
the plant was operated for the THC demonstration. The
process units used are the units included in the nominal 6.6
ton per hour of feed soil plant discussed. THC has also
provided an overall estimate for a 55 ton/hour plant.
43.1 Waste Volumes and Site Size
The volume of soils that may require treatment at the Port
Industrial District (PID) have been estimated at a level
approaching 2,200,000 tons. For purposes of this analysis,
a hypothetical case for a site that contains 22,000 tons of
soil requiring remediation will be examined. Soil from the
site is assumed to have a fines content of 16.5 percent and
to contain contaminants which will require biological
treatment and metals removal treatment This case is
developed in detail in Appendix D.
4.3.2 System Design and Performance Factors
The THC treatment train consists of three process units.
Each of the process units has been designed so that the
system consists of a number of trailer transportable modules.
The individual processes are discussed below.
4.3.2.1 SoU Wash
The soil wash plant has a demonstrated throughput rate of
about 6.6 tons per hour. At that rate it produces enough fine
slurry to feed the 24 hour throughput of the metals removal
process during an 8 hour shift, if the soil feed contains 33
percent fines. In the event the soil being processed
contained about 16.5 percent fines, the wash plant could be
operated for 16 hours per day, and, similarly, if the soil
contained about 11 percent fines, the plant could be operated
on a 24 hour basis and the metals removal process could be
operated at a sufficient rate to maintain the fines production.
43.2.2 Bioslurry Process
The biological system has a total of 6 tanks with a total
capacity of approximately 120,000 gallons. This includes 2
tanks normally used as feed hold tanks and one tank which
was intended for digestion of the biomass. If all of these
tanks are operated as batch bioslurry reactors, a detention
time of about 10 days based on a rate of 475 gallons per
hour is implied. If longer detention is required to treat either
high contaminant levels or biologically refractory
contaminants, then the capacity of the other plant processes
will have to be reduced.
43.23 Metals Removal Process
The metals removal process appears to perform satisfactory
when operating at a feed rate of about 475 gallons per hour
of slurry with a solids content of about 24 percent by
weight. This feed level results in the treatment of 0.56 tons
per hour of solid on a dry basis. If contamination levels are
such that high removal rates are not required, then higher
throughput rates can be used. Conversely, if very high
removals are required, a multiple pass configuration may be
required with a resulting decrease in the throughput rates.
43.3 Manpower Requirements
The staffing levels required are presented in Table 6. The
biological process operator manages the water in the plants
collection and recirculation system in addition to the
operation in the biological system. The maintenance
mechanic monitors the air handling system and assists the
process operators, in maintaining their systems. The
maintenance mechanic is scheduled for the day shift.
Routine preventative maintenance is performed by the
operator at shift change. Major maintenance is performed on
the soil washer on the off shift by using the operators on
overtime. Labor rates were not provided by THC in their
cost analysis. Instead, overall labor cost was provided with
19
-------
staffing information. A technical manager at one half time
and a site manager and clerk as well as a scientist who
provides sampling and data analysis service are allocated
equally to the three processes in the total labor cost'
Table 6. Summary of Manpower Requirements THC Treat-
ment Train.
Per Shift
Total
Per Day"'
Attrition Son Wash
Motals Removal
Biological Process
Maintenance
Sits Supervision
Material Handling
Technical Supervision
Sampling & Analysis
2 Operators
1 Laborer
4 Operators
2 Laborers
2 Operators
1 Operator
1 Mechanic
1 Manager
1 Clerk
2 Laborers
0.5 Manager
1 Scientist
6 Operators
1 Operator
1 Mechanic
1 Manager
1 Clerk
3 Laborers
0.5 Manager
1 Scientist
11 Operators
5 Laborers
1 Mechanic
1 Site Manager
1 Clerk
1 Scientist
1/2 Technical Manager
(1) Based upon operation of wash plant 16 hours per day and
operation of metals removal and biological system 24
hours per day.
4.3.4 Financial Assumptions
For the purposes of this analysis, capital equipment costs are
separated for the complete process units. Capital equipment
costs were amortized over a 10 year period with no salvage
value taken at the end of the period. An interest rate, to
reflect the time-value of money was included by the
developer. The interest rate used by the developer based on
an analysis of the developer's data is 20%. The reader is
cautioned that interest rates in Canada are considerably
higher than in the U.S. at this time. However, it is clear that
a return on capital is also included. Capital costs
information supplied by THC is presented in Table 7.
Table 7. Capital Cost for THC Treatment Train.
Attrition Soil Wash $1,200,000
Biological Treatment System 240,000
Metals Removal Process 800,00
Total $2,240,000
4.4 Results
4.4.1 Remediation of Hypothetical Site
Table 8 shows the total cleanup cost for the hypothetical
treatment of 22,000 tons of contaminated soil described in
detail in Appendix D-l in the existing THC Treatment Plant
of $3,217,800. The remediation of this hypothetical site
would require 229 operating days or just under one year to
complete soil processing. The costs are also itemized by
cost category and treatment process. The soil wash process
accounts for about 50 percent of the total cost while the
metals removal process accounts for about 35 percent of
total cost and the biological treatment accounts for the
remaining 15 percent The soil wash process will process
the entire 22,000 tons of feed while the other processes are
required to treat only the contaminated fines, which, for our
analysis, amounted to approximately 3650 tons. When
considering the overall treatment train, the largest cost
components are labor (56%), equipment costs (20%) and
electrical energy (12%); consumables (10%) and analytical
cost (3%) account for the remaining costs.
Based on the hypothetical case of 22,000 tons dry basis of
contaminated soil treated, the total estimated unit cost is
$147/ton; the breakdown of costs by technology is shown
below.
Unit Cost
Ton
Attrition Soil Washer
Slurry Bioreactor Process
Metals Removal Process
Total.
73
22
52
$147
These estimates do not include site preparation; permitting
and startup costs. Cost for disposal or treatment of effluents
and residuals also did not apply at this demonstration. One
of the waste products, the coal/peat material may require
disposal by incineration; and thus could represent a
significant'cost factor.
20
-------
Table 8. Treatment Cost Summary for a Hypothetical Remediation of 22,000 tons of Soil with 16.5 Percent Fines and Both Organic
and Inorganic Contaminants.
Cost Component
Soil
Wash
Biological Metals
Treatment % Removal
Total
1. Site Preparation Costs
2. Permitting & Regulatory
Costs
3. Equipment Costs
4. Startup
5. Labor
6. Consumables & Supplies
Chemicals
Maintenance Supplies
. 7. Utilities
Electric
8. Effluent Treatment &
Disposal
9. Residuals/Waste Shipping,
Handling & Transport Cost
10. Analytical Costs
11. Facility Modification,
Repair & Replace
12. Demobilization Cost
Total
Cost/Ton
N/A
N/A
N/A
N/A
N/A
$317,300
N/A
$872,300
$66,800
$53,400
20
55
4
3
N/A
$71,100
N/A
$259,800
$26,800
$13,800
15
54
6
3
N/A
$246,900
N/A
$656,900
$100,000
$43,400
22
57
9
4
N/A
$635.300
N/A
$1,789,000
$193,600
$110,600
20
56
6
3
$233,200 15
N/A
N/A
$53,200 3
N/A
0
$1,596,200 100%
$72.55
$83,400 17 $66,800
N/A
N/A
$26,800 6
N/A
N/A
$26,800
$383,400 12
N/A
N/A
$106,800 3
N/A N/A N/A
00 0
$481,700 100% $1,140,800 100% $3,218,700 100%
$21.90 $51.85 $146.30
4.4.2 Sensitivity of Costs to Fines Content of Soil
The hypothetical case cost estimate is based on a fines
content of 16.5 percent The estimated cost per ton is quite
sensitive to the percent of fines present. This occurs because
the metals removal and or biological treatment capacity can
limit the utilization rate of the wash plant.
If the feed soil contains 33 percent fines, the wash plant
would be operated 40 hours per week to support the
operation of the metals removal process for 120 hours per
week. Similarly, at 16.5 percent fines the wash plant could
be operated 80 hours per week and at 11 percent fines the
wash plant could be operated for 120 hours per week.
Cost estimates for these cases are summarized below.
Cost $/ton of feed soil
33% 16.5% 11%
Fines Fines Fines
Attrition Soil Process 80 67 63
Biological Treatment 43 21 14
Metals Removal Process 96 48 32
Total . 219 136 109
These cost estimates do not have any allowance for
operating downtime other than that already built into the
THC analysis. The cost in the hypothetical case study
provides for an additional 10 percent downtime.
The metals removal process and the biological treatment
system are only required to process the fine slurry. The
21
-------
cost of operating these processes at the nominal 0.73
Ion/hour process rates for fines are:
Unit Cost
$/Ton Actually Processed
Biological Treatment Process 128
Metals Removal Process 287
4.4.3 Other Limitations of Cost Analysis
The reader is cautioned that the costs accounted for in this
analysis do not include some site specific elements that
could significantly effect final costs. In addition capital and
operating cost for an appropriate dewatering process must
also be included. THC has assumed an operating throughput
rate for the metals removal process somewhat higher than
those observed during the demonstration. The relatively
long process times for the bioslurry reactor process actually
used during the demonstration would result in the cost
estimate given for the biological process being low. If
retentions of 30 to 40 days as observed are required, the
biological process cost could increase by a factor of 3 to 4.
Careful treatability experiments will be required to refine
cost estimates.
The developer has included the costs of the ion exchange
chelating resin in the capital cost of the facility. If the
chclating resin must be replaced before the 10 year life
assumed, or replenished, a significant additional cost could
be incurred. Data on the expected life of the chelating resin
has not been developed at this time.
4,5 Full Scale (55 Ton/Hour) Facility
THC has provided a cost estimate for a facility that would
process 55 tons per hour on a dry weight basis of feed soil
on a continuous basis. The general scale-up assumptions are
discussed by process below.
Soil Washing - The 55 ton/hr plant would employ a scaled-
up wash plant that would be operated on a continuous basis.
A single large process unit is planned. Improvement in
materials handling for the feed and product solids such as
transportable product hoppers, would be employed, to return
soil to the excavation site. Operator labor is expected to
remain almost the same as with the 6.6 ton/hr plant. A full
time mechanic would be assigned to each shift.
Biological Treatment System - The scaled-up plant would
utilize bioreactors of increased diameter and thus achieve
greatly increased capacity. Transfer and nutrient additions
could be automated so that only minimal operator input is
required.
Metals Removal Process - The scaled-up plant would utilize
somewhat scaled up process units but multiple units still will
be required. The high level of automation and computer
control are expected to allow continued operation with two
operators per shift supported by the availability of the
mechanic mentioned above.
The THC cost estimates for this facility are given below.
Treatment Cost
$/Ton of Feed Soil
Attrition Soil Wash
Biological Treatment Process
Metals Removal Process
Total
43
23
11
$117
These estimates are based on the discussion above and the
use of a scaling algorithm by THC and they are not as
reliable as the costs discussed for the existing system.
22
-------
Appendix A
Process Description of THC
Soil Recycling Treatment Train
The overall project includes the evaluation of a high
pressure soil wash process and an attrition wash process
integrated with the metals removal process and a bioslurry
reactor. The treatment facilities are enclosed in a
temporary building approximately 90 feet wide, 200 feet
long and 40 feet high. The SITE demonstration focused
on the treatment of soil from a refinery site in the PID.
The THC, through its contractor, excavated approximately
1040 tons of the top 6 feet of this soil using a front-end
loader. The soil was transported to an enclosed storage
building at the test facility. The soil was fed to the
treatment plant at a rate of about 6.6 tons per hour. The
feed process consists of using a front-end loader to move
the soil from the storage building and dumping it onto a
vibratory grizzly with 1.97 inch openings. The output of
the grizzly is then run over a rotating permanent type
magnetic separator to remove tramp iron. The material
leaving the magnetic separator is then fed to the attrition
wash plant by conveyor. THC is simply putting the rejects
from the grizzly and the tramp iron aside during this
demonstration. This is, therefore, considered a pre-
treatment and was not sampled as part of this program.
When a full-scale plant is designed, the material separated
in the pre-treatment would be washed with a spray device
and then be recycled as scrap iron, or, in the case of the
plus 1.97 inch debris (concrete, bricks, etc.), will be
crushed for return to the soil site from which, it came.
A.1 Attrition Soil Washing
Soil washing is the first of the technologies in the
integrated treatment train. Because the large majority of
contaminated soils encountered at the FED are sandy, silty
soils, soil washing is an economical and effective process
to separate contaminants from the bulk of the soil. The
soil washing method used during the demonstration uses
scrubbing action and selected chemicals to separate
contaminants from the larger soil particles. The rotary
trommel washer removes particles larger than 0.24 inch as
a gravel fraction. The contaminated <0.24 inch soil and
washwater pass through the screen in the trommel washer
into a holding tank where belt-type oil skimmers remove
free oil from the water. The remaining soil and washwater
are pumped through a separation hydrocyclone where the
contaminated fines (less than 0.0025 inch) are separated
from the coarser soil particles. Larger sand particles are
easily separated from the fines where the contaminants are
concentrated. The fines are pumped to a lamellar separator
and then to a gravity thickener, while the coarse sand is
pumped to the attrition scrubbers.
There are three attrition scrubbing cells that act to agitate
the soil particles, causing them to rub against each other
and scrub the fine particles and contaminants off the
surfaces of the soil particles. The slurry of the soil and
washwater is scrubbed in the first cell, then pumped to the
second cell for further scrubbing, and then pumped to the
third cell for final scrubbing. Potentially, detergents or
surfactants may be added to the third cell and acids or
bases, if required, to aid in dislodging contaminants from
the soil particles or in dissolving certain contaminants.
The treatment processes subsequently used to treat the
contaminated slurry restrict the types of chemicals which
can be used in this treatment train.
Scrubbed particles and washwater from the attrition
scrubbing units are pumped to a second hydrocyclone at
the top of the plant, where sand particles (>0.0025 inch)
are separated from the process water and the remaining
fines. The sand stream from this separator is then put
through a density separator to remove the light materials,
such as coal, wood, and peat particles from the heavier soil
particles. The coal and peat are collected separately, as a
potentially contaminated waste stream. The sand is
discharged by conveyor to a collection bin and is combined
with the gravel from the trommel washer for return to the
23
-------
original site. This "clean" material is expected to include
approximately 70 to 80 percent of the soil feed to the wash
plant.
Contaminated fines with a grain size smaller than 0.0025
inch, pass through the lamellar separator and sludge
thickener to remove water. The contaminated slurry from
the sludge thickener is fed into two large holding tanks at
the front end of the metals removal system or directly to
the bioslurry reactor process. The contaminated slurry is
expected to represent approximately 15 to 30 percent of the
soil feed to the wash plant.
The contaminated process water removed by the lamellar
separator and sludge thickener is discharged to an outdoor
storage pond for recycle. Any sludge recovered from the
ponds is then added to the deep cone sludge thickener
where it joins the slurry for further treatment. The soil
washing flow diagram is shown in Figure A-l.
FIGURE A.I
SaWUflEO PHOCEM FLOW OIAORAM FOR SOU. WASH PROCESS
FMd
H.pp.r
«1.9T IN
Trammel
Wither
SOIL >M IN
I
Thlokttntr
The biological system is prepared by culturing a bacteria
population from the bacteria that have developed in the soil
on-site. This is accomplished by pumping a limited
amount of fine slurry obtained from the soil wash process
directly to the bioreactors without passing through the
metals extraction process where the highly acidic
conditions would destroy the desired bacteria. This allows
the development of a bacterial population in the bioreactor
based on strains in the soil to be treated. Fine slurry is
accumulated until a single reactor is fully charged.
Nutrients in the form of urea and phosphoric acid solutions
are added periodically. In addition, periodic additions of
oxidant may be made.
The final slurry is dewatered once the organics content in
the slurry is reduced to a target level, or no further bio-
reduction is occurring, as indicated by periodic sampling
and analysis. During this study the slurry was returned to
the excavation site without dewatering because the high
pressure cyclone dewatering system employed was not able
to achieve meaningful dewatering.
The biological treatment process is shown in Figure A-2.
FIGURE A-2
SIMPLIFIED FLOW OIAQRAM
BIOSLURRY REACTOR PROCESS
SLURRY TO BIOLOGICAL OR
METALS REMOVAL PROCESS
SLURRY TO DEWATEHINO
• OR METALS REMOVAL PROCESS
A.2 Biological Treatment System
The biological treatment technology being evaluated is
referred to as the Bioslurry Reactor Process. This process
involves a series of reactors (tanks) where organic
contaminants are treated. Prior to the introduction to the
reactor, the slurry is pretreated with a proprietary inorganic
oxidant.
The slurry awaiting treatment of its organic contaminants
is gently mixed in two surge tanks to promote contact
between the contaminants and the oxidant. The slurry is
then pumped to one of three 20,000 gallon upflow
bioreactor tanks normally used in pilot operation.
Submerged pumps and the upflow of air for the medium to
fine bubble aerators provide constant mixing conditions
and the suspension of fines.
A.3 Metals Removal Process
The contaminated slurry from the attrition wash plant or
the bioslurry reactor process is fed into two large holding
tanks in the central area of the facility, at the front end of
the metals removal process. The slurry consists of
approximately 24% solids by weight and 76% process
water. Mild acid is added to the slurry from the acid
storage tanks to desorb and solubilize any metal
contaminants from the soil particles. The identity of the
acids used has not been disclosed.
The contaminated slurry is then pumped into the first
tubular reactor. This screw-type rotary reactor brings the
slurry into countercurrent contact with solid metals
chelating agents that have an affinity for specific metal
contaminants. From here, the slurry, which now contains
only soil particles, organic contaminants, residual metals
not removed by the process, and process water, is pumped
to a holding tank, where it is neutralized.
24
-------
The solid dictating agent, which moves countercurrent to
the slurry, now contains the extracted metals. The solid
chelating material is selected from a family of metals
specific ion exchange chelating resins to preferentially
remove heavy metals. It is washed to remove solid soil
particles and is fed through a second tubular reactor where
a mild acid is used to break the bond between the chelating
agent and the contaminant metals. The chelating agent is
then recycled to the first reactor for reuse in the metals
extraction process. Meanwhile, the metal/acid mixture is
recycled hi the second reactor until it becomes sufficiently
rich hi metals to be pumped to an electrowinning unit,
where the metals are then removed by electrolysis. The
result of the build-up of metal concentration in the
regenerating acid will be some reduction hi the absorption
capacity of the resin beads being returned to the slurry
contactor, however the system has been designed to
provide excess absorption capacity of the chelating resin hi
relationship to the metals being absorbed. Little change hi
performance is expected. Another, more long term
deterioration of the resins absorption capacity is associated
with the oxidation of the active sites on the resin bead.
This is expected to be a reaction measured in months to
years and should not effect this demonstration.
Nevertheless, resin replacement costs can be a significant
cost factor hi such a system. The metals may be removed
singly or as one composite mass. During the
electrowinning the metals-depleted acid is then pumped
back to the holding tanks either for reuse as regenerating
acid or it may be neutralized and become a part of
contaminated slurry. The metals extraction process is
shown schematically in Figure A-3.
FIGURE A-3
SIMPLIFIED PROCESS FLOW DIAGRAM
METALS REMOVAL PROCESS
CONTAMINATED SLURRY
Tubular
Raaotor
"1
TO DEWATERINQ
OR BIOLOGICAL TREATMENT
A.4 Water Use
The facility was designed with an integrated water recycle
scheme. The site was graded and paved to collect • all
precipitation in lined ponds which would supply water for
the operation. The design called for minimal discharge of
water primarily because considerable water was expected
to leave the plant with the clean soil fractions. The design
also provided for a process water pond that would receive
water from the wash plant and the water separated from
the final treated slurry. The process pond would recycle
water for use hi the soil wash plant and for ion exchange
resin bead washing hi the metals extraction process.
Approximately 60 percent of the water hi the tested fines
is recovered and recycled. During the THC demonstration
excess water was accumulated at tunes due to heavy
rainfall. This water was treated prior to discharge to the
sanitary sewer.
Water can be pumped from Lake Ontario to use for make-
up during periods hi which make-up water was required.
A. 5 Air Supply and Emissions Control
The air for the bioslurry reactors is taken hi through two
intake units, filtered, and pumped to the bioslurry reactors.
It is then exhausted into an air treatment system consisting
of two biofilters and a carbon adsorption unit. Power for
drawing the ah from the bioslurry reactors through the
biofilters is provided by one of two 5,000 cfm pumps.
Air collected from the metals removal process is passed
through a caustic scrubber unit to remove any acid that
might otherwise be taken into the biofilters. The air
stream results from maintaining a slight negative pressure
on all tanks and reactors which contain acid. In addition
both tubular reactors are open to the atmosphere to allow
feed of materials. The ends of the reactor are hooded to
collect any acid gases so that they do not cause health or
safety problems in the work area. The acid removed is
either recycled or is neutralized and discharged to a
holding tank as an addition to the slurry. The air itself is
then passed through the common system of biofilters.
The "biofilters" consist of modules 10 x by 10 ft x 40 ft.
The module is filled with peat. The ah is introduced into
a perforated pipe distribution system on the floor of the
module. These filters are expected to provide adsorption
of organics and continuing biological activity under
summer conditions to consume the material adsorbed.
Under the cold conditions actually experienced during the
demonstration, biological activity is unlikely, but the
elimination of any mists or particles is expected then when
the warm temperatures occur in the summer this adsorbed
material undergoes biodegradation. The air is collected
from the ah space at the top of the module and routed to
the final 10ftxlOftx20ft activated carbon filter. Air
exhausted from the activated carbon filter is discharged
through a 39 foot high stack. The developer reports that
no measurable contaminant emissions were ever detected
25
-------
leaving the biofilters. The absence of organic
contaminants upon analysis of the carbon, hi the carbon
filter following the biofilters, at the end of the 9-month
project has confirmed that all volatile hydrocarbons were
retained and actively biodegraded within the biofilters. In
a full scale plant requiring year-round biodegradation in the
biofilters the biofilters could be heated to promote
biodegradation. This capability was available for the
demonstration project but heating the biofilters never
became necessary.
Air is collected from the conveyors and open tanks in the
soil wash area by enclosing these areas with hoods and
shrouds. This ah- is drawn through an activated carbon
filter by one of, the 5000 cfm fans and mixes with air
drawn off the metals removal and biological systems for
treatment hi the common biological filter system and final
activated carbon filter before discharge through the
common stack.
26
-------
Appendix B
Vendor's Claims
The THC demonstration was conducted to evaluate the
ability of an integrated soil treatment train, which includes
a soil washing process, a biological treatment process, and
a metals removal process to treat contaminated soils so that
the treated soil meets target criteria for proposed land use
applicable to soils for commercial/industrial sites. The
criteria have been developed by THC by combining existing
criteria for conventional pollutants and metals with a site
specific criteria developed for a contaminated soil associated
with a refinery site. Collectively, these criteria are referred
to as the THC Criteria.
The THC claims the technology will meet the following
performance criteria.
1. Produce the following soil fractions from the soil
washer, each of which will meet the THC Target
criteria for coarse textured soils described in Table
B-l for both organic and inorganic compounds
independent of the soils initial contaminant levels.
A. Clean gravel (less than 1.97 in; greater than
0.24 inch).
B. Clean sand (less than 0.24 in; greater than
0.0025 inch).
2. Produce a fine soil fraction (less than 0.0025 in)
after metals removal and/or biological treatment
which will meet the THC Target criteria for fine
textured soils described in Table B-l for both
organic and inorganic compounds independent of
the soil's initial contaminant levels.
Table B-1.
THC Target Criteria for Soils for Commercial/
Industrial Land Use
Coarse Textured Medium and Fine
Parameter
Conventional
pH (recommended range)
Oil and Grease (%)
Total Metals
(Units mg/kg)
Arsenic
Barium
Cadmium
Chromium (total)
Cobalt
Copper
Lead
Mercury
Molybdenum
Nickel
Selenium
Silver
Zinc
Organic Compounds
(Units mg/kg)
Naphthalene
Phenanthrene
Anthracene
Fluoranthene
Pyrene
Benzo(a)anthracene
Chrysene
Benzo(b)fluoranthene
Benzo(k)fluoranthene
Benzo(a)pyrene
Benzo(a,h)anthracene
1 . Defined as greater than 70%
matter.
Soil1
6-8
1
40
1500
6
750
80
225
750
1.5
40
150
10
40
600
(8.0)3
(28.0)3
(12.0)3
302
(48)3
(15.8)3
(28)*
(2.4)3
13.22
2.42
1.82
sand and
2. Clean-up levels are shown for organic <
Textured Soil
6-8
1
50
2000
8
1000
100
300
1000
2
40
200
10
50
800
(8.0)3
(28.0)3
(12.0)3
302
(48)3
(15.8)3
(28)*
(2.4)3
13.22
2.42
1.82
less than 17% organic
compounds. If soils
exceed these levels, then the soil is considered hazardous and
remediation is required.
3. If these trigger levels are exceeded, the THC will make a deter-
mination on a case by case basis regarding the need for
remediation.
27
-------
Appendix C
Site Demonstration
Soil Recycling Treatment Train
The Toronto Harbour Commissioners
C.I Introduction
The Toronto Harbour Commissioners (THC) have developed
a soil treatment train designed to treat inorganic and organic
contaminants in soils. THC has conducted a large-scale
demonstration of these technologies in an attempt to
establish that contaminated soils at the Toronto Port
Industrial District can be treated to attain contaminant levels
below the THC Target Criteria Levels for Industrial Soils
without utilizing incineration processes. This Superfund
Innovative Technology Evaluation (SITE) of the on-going
THC Demonstration was undertaken to provide a consistent
basis for comparing these technologies to other technologies
evaluated under the SITE program.
C.2 Feed Characteristics and Variability
C.2.1 General
The soil processed during the Sum evaluation was
designated as Soil B by THC. It was excavated from a site
immediately adjacent to the process plant. Characterization
of the site and limited predemonstration sampling conducted
in early 1992 indicated that the soil exhibited relatively high
organic and inorganic contamination. When large volumes
of the soil were excavated and processing initiated, the
inorganic contamination levels were found to be quite low.
Another long term variation in the soils composition was
noted in the under 1.97 inch, greater than 0.24 inch fraction
removed by the trommel washer. During apresampling visit
and familiarization sampling early in the soil run this
fraction was relatively minor in volume and was largely
pebble-like material not much over the 0.24 inch in size.
When sampling was conducted, this fraction accounted for
approximately 10 percent of the feed mass and included
relatively large coal and wood fragments as well as much
larger smooth (river gravel-like) pebbles. As a result of the
appearance of this fraction, the analytical extraction
procedure was modified and an approach for separating these
large particles from the feed soil and extracting them
separately in bulk was also adopted.
C.2.2 SITE Sampling
During the course of the three day sampling event, four hour
composite samples were accumulated by hourly grab
sampling of the feed soil from the conveyor that feeds the
wash plant trommel washer. Therefore, each day'two
composite samples were taken during the normal 8 hours of
wash plant operation. The composite samples were analyzed
for the following characteristics: O&G (oil and grease),
TRPH (Total Recoverable Petroleum Hydrocarbons), SVOC
(Semi Volatile Organic Compounds), total metals, mercury,
total cyanide, reactive sulfide, PSD, (Particle Size
Distribution), pH and % moisture. The total metals and
SVOC analyses call for the extraction of several grams of
sample. The presence of the relatively large "rocks" in the
feed led to a modification of the procedure for these
analyses. The samples-were separated into a "soil" fraction
and a "rock" fraction using a number 4 sieve. The soil was
extracted using the usual 2 gram sample while the entire
"rock" fraction from a 500 ml sampling bottle was extracted
without crushing the "rock".
Table C-l presents the results of these analyses for selected
parameters. The feed soil appears to just exceed the THC
Target Criterion for naphthalene and to just approach the
criterion level for oil and grease and benzo(a)pyrene. The
conventional parameters (pH, % moisture, O&G and TRPH)
exhibit moderate variability while the metals and the two
PAH compounds of interest exhibit considerable variability.
A comparison of the data for the soil and "rock" fraction
28
-------
TABLE C-1. CONCENTRATION OF SELECTED PARAMETERS IN THE FEED SOIL THC ATTRITION SOIL WASH PROCESS
Soil
pH
% Moisture .
Oil & Grease
mg/kg
TRPH mg/kg
Cu mg/kg
Pb mg/kg
Zn mg/kg
Naphthalene
mg/kg
Benzo(a)pyrene
mg/kg
Rocks
Cu mg/kg
Pb mg/kg
Zn mg/kg
Naphthalene
mg/kg
Benzo(a)pyrene
mg/kg
THC
Criteria
6-8
'
10,000
—
225
750
600
8.02
2.4
225
750
600
8.02
2.4
Sample
1
8.49
7.49
7800
2270
9.2
106
40.4
15
(1.6)'
4.3
26.4
19.3
7.6
(1.1)
Sample
2
8.59
8.51
6700
2700
12.3
63.3
56.6
7.7
(0.93)
6.8
93.7
28.3
6.6
(0.55)
Sample
3
8.69
7.53
9000
3250
9.9
68.4
40.9
18.0
(1.7)
20.5
112
94.3
16.0
(1.1)
Sample
4
8.28
9.07
8100
3430
15.4
97.4
83.5
13.0
2.9
19.6
114
72.7
5.1-
(1.2)
Sample
5
8.17
12.6
9700
2550
20.6
177
92.8
8.0
(2.5)
24.7
195
219
8.8
2.2
Sample
6
8.22
9.88
8100
2040
42.2
177
181
5.3
(1.9)
34.9
175
211
16.0
4.4
Average
9.18
8200
2540
18.3
115
72.5
11.15
(1.92)
18.45
119
107
10.0
(1.76)
Standard
Deviation
1.91
1030
416
12.4
50.8
52.9
4.9
.(0.7)
11.4
60.3
87.8
4.8
(1.4)
1. () Indicates value reported is below quantitation limit but above detection limit. Value should be considered an estimate.
2. If these trigger levels are exceeded, the MOE will make a determination on a case by ease basis regarding the need for further
remediation.
indicates the two fractions are equivalent for the metal and C.3.2 Products
PAH compounds examined.
C.3 Attrition Soil Wash Process
C.3.1 Feed
The feed soil discussed for the overall process is the feed
soil for the attrition wash process.
C.3.2.1 Gravel (Through 1.97 inch, greater than 0.24
inch)
This product is produced by the trommel washer, which
removes material smaller than 0.24 inch from the coarse
material. THC estimated this fraction as 10.5 percent of
the feed on a dry basis. Data collected during the SITE
sampling indicated that this product accounted for 11.5
percent of the feed on a dry weight basis. Considering the
limitation on the estimating technique used, this would
appear to be excellent agreement. During the three day
29
-------
sampling event, six composite samples were developed by
compositing four hourly grabs. This resulted in two 4 hour
composites for each day of operation. Each of these
composites was analyzed for the same group of parameters
listed for the feed samples. SVOC and total metals
extractions were performed on bulk samples without
sample crushing.
Table C-2 presents analytical results for selected
parameters for these samples. The average values reported
meet all the THC Target criteria for coarse soils. An
examination of this data indicates that Sample No. 6
exhibited higher oil and grease contamination and very
much higher (10 tunes or more) heavy metals
contamination than for the other samples. TRPH and PAH
values did not exhibit the same behaviors. The sample
team had noted that this product stream had become very
dirty during the course of the third day of sampling and
appeared to be coated with an oily paste of fines. An
examination of feed soil data for the same tune frame
(Sample No. 6 Table 1) shows this same tendency but not
nearly as dramatically as does "clean gravel" Sample No.
6. If the data are excluded, it results in a dramatic drop in
the average as well as the standard deviation. Sample No.
6 appears to be from a different population than the other
five samples; since it appeared visually to be contaminated,
the analytical results should not be suspect. Possible
explanation centers around two possibilities.
1. During the third sample day it was raining steadily.
The soil is fed to the grizzly by slowly dumping the
contents of the front end loader bucket onto the grizzly.
The grizzly is located outside of the building so the soil
was exposed to the rain for the period of 8 to 10
minutes required to feed the material slowly. This may
have caused fines and oil material to concentrate on the
large gravel in such a manner that it was difficult to
remove in the trommel washer.
2. Soil had been moved from the excavation site to an
enclosed shed for drying and to facilitate feed
pperations. It is possible that some migration of oily
fine contaminated materials caused a concentration of
these materials in the bottom areas of the storage piles.
The material being fed during this sample may have
contained more of this material than normal because the
loader was raking the bottom of depleted piles.
There is no proof that either explanation is valid but the
second hypothesis appears to be more sound.
Table C-2. THC Attrition Soli Wash Process Concentration of Selected Parameters in Gravel <1.97in.; >0.24in.
OH & Grease
mg/kg
TRPH mg/kg
Cu mg/kg
Pb mg/kg
Zn mg/kg
Naphthalene
Benzo(a)pyrene
pH
% Moisture
Sample
1
1200
269
.72
3.22
2.26
2.9
(700)2
8.79
7.48
Sample
2
1900
579
7.57
56
36.1
2.1
(380)
8.82
10.29
Sample
3
1300
543
1.84
9.84
7.6
1.8
(170)
8.68
3.00
Sample
4
1800
1481
9.8
117
85.5
1.3
(250)
8.62
6.47
Sample
5
3400
1571
12.1
40.4
98.6
2.8
990
8.43
8.43
Sample
6
10400
443
52,1
702
544 '
3.8
1000
9.11
7.38
Average
3333
814
14.0
155
129
2.5
(582)
8.74
7.18
Standard
Deviation
3550
562
19.2
271
207
896
368
0.23
2.4
1 Values of X and SX calculated without data from composite sample No. 6.
2 Indicates value reported is below quantitation limit but above detection limit. Value should be considered an estimate.
30
-------
Since the contamination level in the "clean gravel" was
visible by inspection, it would be possible in practice to
recycle this material to the feed and reprocess it. In
addition, the sample only exceeded the THC Target Criterion
for oil and grease by a slight amount and would have met all
other criteria. In subsequent analysis of the data, data from
Sample No. 6 were excluded for the three metal parameters
where the results deviated most from the prior samples.
This anomalous behavior may be important if the soil to be
treated is very high in oil and grease contents. In such
cases, the use of surfactants may be a necessity, or,
alternately, modification of the trommel washer may be
required.
C.3.2.2 Sand (Through 0.24 inch; greater than 0.0025
inch)
The sand product is separated from the fines in the soil by
utilizing a hydrocyclone classifier. The nominal cut point
for this classification is reported to be 0.0025 inch. The
coarse cut from the classification is passed over a vibratory
sieve that dewaters and removes low density particles (coal
& wood fragments, peat).
THC reported that this fraction accounted for 70.2 percent of
the feed on a dry basis. Data collected during the three days
of SITE sampling indicated 68.1 percent of feed on a dry
basis for this product.
Once again composite samples were obtained in the same
manner as the feed and gravel and analyzed for the same
parameters. •
Table C-3 presents the analytical results. The average values
and the individual composite data all meet the THC Criteria
for fine soil.
Metals levels for Samples No. 5 and 6 appear higher than
the prior two days' samples but do not exhibit the wide
departure seen hi Sample No. 6 for the clean gravel fraction.
reporting to this fraction. A single composite sample for
each day of sampling was accumulated by taking a grab
sample every two hours during the course of a normal 8
hour operating day. The samples were submitted for
analysis for oil & grease, TRPH, SVOC and total metals.
Table C-4 presents the analytical results for these samples.
This waste exceeds the THC Target criteria for oil and
grease, also naphthalene and benzo(a)pyrenei
C.3.2.4 Contaminated Fines (Less than 0.0025 inch)
The fines separated from the coarse soil particles by the
classifying cyclones are treated with a flocculent to aid
settling and are accumulated in a slurry underflow from an
inclined plate settling tank. The slurry is transferred
continuously to a deep cone settling tank, which was to be
used for further concentration of the solids but is being used
simply as a holding tank. THC reports the approximate
solid content of the slurry is 24 percent by weight. An
estimate of the solids content for the SITE sampling period
based on mass balance information and estimated volume of
slurry produced is 34 percent solids. An estimate of the
solids content based on calculations using moisture content
levels in the samples of contaminated slurry leads to a 33
percent solid by weight estimate. It therefore appears that
the 33-34 percent solid level is most representative for our
sampling period.
THC reports an overall estimate for this product of 16.7
percent of the feed on a dry basis. Data collected during the
SITE sampling resulted in an estimate of 18.8 percent of the
feed on a dry basis for this product stream.
The contaminated slurry was sampled by combining four
hourly grabs into a composite sample. This produced two
composites per day for each of the three days of sampling.
The samples were analyzed for the same parameters as ,the
other fractions. The results of these analyses are presented
in Table C-5. They indicate the contaminated fines exceed
the THC criteria for O&G, naphthalene and benzo(a)pyrene.
C.3.2.3 Coal/Peat Waste (Through 0.24 inch, greater than
0.0025 inch)
Coal/peat waste is separated from the clean sand fraction
using a vibratory dewatering screen. The lighter particles
are vibrated up a screen to separate them from the heavier
soil particles. This stream is expected by THC to be a waste
product that they hope to find a use for as boiler fuel. It is
predominantly coal particles and fragments of wood in
various stages of decay. THC reported about 2.5 percent of
the feed on a dry basis reports to this waste product SITE
sampling found 1.6 percent of the feed on a dry basis
C.3.2.5 Waste Water Streams
The wash water utilized in the THC attrition wash process
is recycled from a holding pond located adjacent to the
building. A grab sample of the pond waste water was
obtained on the first and third day of sampling in the area
near the intake for the recycle pump. The samples were
analyzed for the primary parameters being tracked in the
soil. Table C-6 presents the results of these analyses for
selected parameters. In general, it appears that the
31
-------
Table C-3. THC Attrition Soil Wash Process Concentration of Selected Parameters in Clean Sand <0.24 in.; >0.0025in.
Oil & Grease
mg/kg
TRPH mg/kg
Cu mg/kg
Pb mg/kg
Zn mg/kg
Naphthalene
mg/kg
Benzo(a)pyrene
mg/kg
PH
Sample
1
1.500
561
3.6
27.9
15.9
1.5
(0.24)1
9.01
Sample
2
1,400
383
3.1
42.4
18.5
1.5
(0.57)
8.38
Sample
3
1,500
684
4.6
23.6
20.1
2.0
(0.24)
8.06
Sample
4
2,500
731
6.3
31.0
31.4
2.3
(0.50)
8.95
Sample
5
2,300
561
32.7
82.9
71.4
3.1
1.20
8.51
Sample
6
3,900
963
32.4
68.4
47.5
1.9
(0.41)
8.33
Average
2,183
647
13.8
46.0
34.1
2.050
(0.53)
Standard
Deviation
960
196
14.6
24.2
21.7
599
356
1 () Indicates value reported is below the quantitation but above the detection limit. Value reported should be considered an
estimate.
Table C-4. THC Attrition Soil Wash Process Concentration of Selected Parameters in Coal/Peat Waste
Oil & Grease mg/kg
TRPH mg/kg
Cu mg/kg
Pb mg/kg
Zn mg/kg
Naphthalene mg/kg
Benzo(a)pyreno
mg/kg
Sample
1
17,600
4,740
22.8
129
46.8
34.0
(11.0)1
Sample
2
45,200
16,200
34.1
339
176
110.0
(23.0)
Sample
3
51,600
14,600
41.7
749
406
48.0
(9.6)
Average
38,100
11,850
32.9
406
210
64.0
(14.5)
Standard
Deviation
18,070
6,210
9.5
315
182
40.45
7.4
1 () Indicates value is below quantitation limit for procedure. Value shown is estimated.
Table C-5. THC Attrition Soil Wash Process Concentration of Selected Parameters in Contaminated Fines <0.0025 inch
Oil & Grease
mg/kg
TRPH mg/kg
Cu mg/kg
Pb mg/kg
Zn mg/kg
Naphthalene
mg/kg
Benzo(a)pyrene
mg/kg
Sample
1
40,000
12,300
57.4
421
217
49.0
(9.0f
Sample
2
33,300
8,500
48.2
334
192
52.0
<32.0
Sample
3
50,500
19,800
76
525
250
82.0
(9.6)
Sample
4
54,300
18,100
..(')
..«)
..(')
45.0
(11.0)
Sample
5
35,300
13,600
135
680
593
65.0
(12.0)
Sample
6
26,900
12,200
99
651
467
(17.0)
(8.4)
Average
40,000
14,080
83.1
522
344
51.7
(10.0)
Standard
Deviation
10,520
4,170
34.9
148
177
21.7
11.5
1 Sample bottle broken in shipping.
2 () indicates value is below quantitation limit for procedure. Value shown is estimated.
32
-------
contaminants of interest do not partition to the waste water
stream for this soil.
Table C-6. Selected Characteristics of Water Recycled to THC
Attrition Wash Process
Oil & Grease mg/1
TRPH mg/l
Cu ug/1
Pb ug/1
Znug/l
Naphthalene ug/1
Benzo(a)pyrene ug/1
Day
1
<5
<.44
(12)
<21
61
<10
<10
Day
3
<5
1.15
11
(50)
46
<10
<10
C.3.3 Mass Balance
Overall Soil B Run:
THC provided a summary of their overall run on Soil B. A
summary of that data is presented in Figure C-i.
FIGURE C-1
SIMPLIFIED PROCESS FLOW DIAGRAM FOR SOIL WASH PROCESS
SHOWING PRODUCT FRACTIONS ON A WEIGHT BASIS
Coil/
P..I
THC-0.025
SITE-0.016
I Density
Separator
I
Sand
».0025 IN
THC-0.702
SITE-0.681
C.3.3.1 Site Demonstration Sampling
A mass balance was calculated for the period during which
the SITE sampling occurred. This data is also summarized
in Figure C-1.
C.3.3.2 Discussion of Mass Balance Results
The mass balance is based on an engineering approach to
estimate the mass balance when the volume of materials
being handled and an existing plant configuration preclude
actual measurements. The approach involved counting the
number of front end loader buckets of feed and products
each day, measuring volumes and bulk densities of feed and
products periodically, and using this information to estimate
the mass balance of solids. The slurry solids are estimated
by the difference between the feed and product solids.
Considering these limitations, the overall THC estimate and
that developed for the SITE sampling time period agree
quite well. Determining slurry solids by difference is a
weakness in this approach. Water sampling data does
suggest little loss to the wash water.
C.3.4 Discussion of Soil Wash Process Results
Table C-7 presents a summary of the data from analytical
results for the individual feed and product stream. The
values presented are the averages for the composite samples.
The data for the feed soil were used without adjustment for
"rocks" since the data suggested no such adjustment was
needed. The trommel oversize fraction metals data are
based on the averages of 5 composites with metals data from
the sixth sample excluded as discussed earlier. The percent
recovery columns on the right were calculated by summation
of the mass of each constituent accounted for in each
product stream and dividing by the mass of the constituent
in the feed soil. That is:
CiXi
% Recovery = I, x 100
Cf
where Ci = concentration of a contaminant in a product
stream
Xi = mass fraction of the product stream
Cf = concentration of the contaminant in the feed
Percent recovery was calculated based on the overall THC
mass balance as well as the mass balance developed during
the SITE sampling. All of the percent recoveries exceed 100
percent, but in general the deviation from 100 is not
alarming when one considers the uncertainties in sampling,
analyses, and the mass balance estimates. In general, the
percent recovery values agree quite well between the overall
mass balance approach (THC) and the SITE sampling mass
balance.
33
-------
The data from Table C-7 were used to calculate the
percentage of each contaminant by product stream. This
information is presented in Table C-8 on the basis of THC
overall mass balance estimate and in Table C-9 based on
the SITE demonstration mass balance. In each case, the
process shows the recovery of a high proportion of the
contaminants in the fine slurry with significant reductions
in the contaminants in the product gravel and sand.
Removal percentages for individual contaminants can be
calculated from the number in parentheses in Table C-8
and C-9 by subtracting that number from 100%. Negative
numbers result when there is an apparent concentration of
the contaminant. In general, the contaminated fine slurry
contains about 4 times the concentration of organic
constituents as present in the feed soil.
C.4 Bioslurry Reactor Process
The developer had configured the biological treatment
system to allow either batch or continuous operation. The
developer planned to run batches of slurry to define desired
operating and retention times and then to shift to a
continuous or at least semi-continuous operation. The
sampling plan had been developed for a continuous process
so that a steady state or near steady state condition would
be available for sampling. In fact, THC had problems with
analytical turnaround time and erratic analytical results for
oil and grease and benzo(a)pyrene which turned out to be
controlling parameters for the process. As a result, THC
had not progressed beyond batch operation of the system
at the time of the SITE sampling. The procedure in effect
was to accumulate a biotreatment batch over a period of
several days of 8 hour per day operation of the soil wash
plant. Contaminated slurry was pumped periodically from
the wash plant and treated with the proprietary oxidant hi
a flash mix tank. The slurry from a days production was
held overnight in a agitated storage tank before being
transferred to the bioslurry reactor. In some cases, several
days of slurry production were accumulated in the storage
tank before transfer to the bioreactor. The bioslurry
reactor is aerated to keep the slurry in suspension.
Nutrient addition is begun' after the. entire batch has been
transferred to the bioslurry reactor. A batch would consist
of 13,000 to 18,500 gallons of slurry. This means that
three to five days of operation of the soil wash plant might
constitute a batch depending upon the operation time of the
soil wash plant, the amount of fines and the concentration
of fines in the slurry. Nutrients are added in solution form
at a dosing level based on the solids content usually every
other day. THC will not provide specific information on
the nutrient or oxidant additions for each batch based on a
claim that it is proprietary process information.
A sampling team returned on two different dates to sample
the discharge of two bioslurry batches. The first batch was
identified as batch 2c which was accumulated during the
period of March 25 through March 31, 1992 and was
initiated on nutrients on April 1, 1992. This batch was
discharged by pumping the slurry to the original
excavation site on May 11, 1992. This results in a
retention from the time of nutrient addition to discharge of
41 days. Seven grab samples were taken over the 100
minutes required for discharge.
The second batch sampled was identified as batch 2a. It
was accumulated primarily during the period of SITE
sampling of the soil wash process. The actual dates are
April 14 through April 21, 1992. Nutrient addition was
initiated on April 22, 1992. This batch was discharged to
the original excavation site on May 22, 1992. This results
in a retention time from first nutrient addition to discharge
of 30 days. Seven grab samples were taken over the 120
minutes required for discharge.
The developer determined the retention time required by
periodically sampling the batch and comparing the results
to the criteria. Erratic.analytical results that the developer
believes resulted from the high biological content of the
samples prevented reliable, optimization of the retention
times.
C.4.1 Results and Discussion
Characterization data for the contaminated slurry from the
attrition soil wash process are applicable to the feed to the
bioslurry process. These data are reproduced in Table C-
10. Data from the sampling of the discharge of the batch
2c are presented in Table C-ll and similar data for batch
2a are presented in Table C-12.
Both bioslurry batches exceeded the THC Target Criterion
for oil and grease which is 1 percent for medium and fine
soils. Batch 2c exhibited an oil and grease value of about
5 percent while batch 2a showed an average value of 2.5
percent. The developer believes this is occurring because
the oil and grease procedure is extracting biological fats
and oils from the biomass present.
Both batches also exceed the THC Target Criterion for
benzo(a)pyrene which is 2.4 mg/kg. Batch 2c had an
average benzo(a)pyrene level of 3.2 mg/kg and batch 2a
had 2.6 mg/kg. The benzo(a)pyrene levels in the discharge
were above the detection limit but below the quantitation
level for this analysis. This occurred because the samples
had a much higher than expected organic content perhaps
because of high microbial content. This required the
laboratory to extract only 10 percent of one original size
34
-------
Table C-7. Selected Feed and Product Characteristics of the Attrition Soil Wash Process.
Percent of Feed Based
on Site Demo. Data
Percent of Feed Based
on THC Overall Analysis
Oil & Grease mg/kg
TRPH mg/kg
Copper mg/kg
Lead mg/kg
Zinc mg/kg
Naphthalene mg/kg
Benzo(a)pyrene mg/kg
Feed
, Soil01*
-
8233
2542
18.3
115
82.5
11.15
(1.91)m
<1.97in.;
>0.24 in.
Clean
Gravef91
11.5
10.5
3333
814
6.4
45.3
46
2.62
(0.58)
<0.24 in.
Coal/Peat
Fraction1*
1.6
2.5
38,100
11,850
32.9
406
210
64
(14.5)
<0.24 in.;
>0.0025 in.
Clean
Sand®
68.1
70.2
2183
621
13.8
46
34.1
2.05
(0.53)
<0.0025 in.
Cent.
Fines'"
18.8
16.7
40,000
14,000
83.1
522
344
51.7
(10.0)
%
Recovery1*
116
124
. 137
117
111.
107
129
%
Recovery"1
120
131
144
122
117
112
133
(1) Feed soil characteristics were calculated from rock and fines analytical data using a weight basis.
(2) Average of six composite samples.
(3) Average of three composite samples.
(4) Percent recovery determined by comparison of the total contaminant accounted for in each product with the feed material based
on overall product fraction analysis provided by THC.
(5) Percent recovery determined by comparison of the total contaminant accounted from each product with the feed material based
on measurements during the SITE demonstration.
(6) () indicates value reported is below quantitation limit but above detection limit, value should be considered an estimate.
Partition ot Sttocud Paranuun In the Product Strum of the Attrition Won
Tibia C-9.
Partition of Sotoctod Parameter. In tin Product Strum of the Attrition Won
Fraction of Feed
Oil i Grease
TRPH
Copper
Lead
Zinc
Naphthalene
Benzo(a)pyrene
<1.97 in;
>.24in
Trommel
Oversize
.105
.037"'
(35)«
.027
(26)
.027
(26)
.035
(34)
.055
(52)
.023
(22)
.025
(24)
<.24 in;
Coat/Peat
Fraction
.025
.100
(400)
.094
(376)
.033
(131)
.076
(302)
.035
(139)
.134
(536)
.147
(588)
<.24 in;
>0.0025 in
Clean
, Sand
.702
.161
(23)
.138
(20)
.387
(55)
.241
(34)
.262
(38)
.121
(22)
.151
(22)
>0.0025 in
Contaminated
Fines
.167
.702
(420)
.741
(444)
.554
(332)
.647
(388)
.628
(334)
.723
(433)
.677
(405)
nuuw
r Fraction of Feed
Oil & Grease
TRPH
Copper
Lead
Zinc
Naphthalene
, Benzo(a)pyrene
rm B**TO vn IMIV «
<1.97in;
>0.24 in
Trommel
Oversize
.115 '
.038"'
(33>'»
.028
(24)
.028
(24)
.037
(32)
.053
(50)
.024
(21)
.028
(24)
<.24in
Coal/Peat
Fraction
.016
.061
(381)
.057
(356)
.020
(125)
.046
(289)
.057
(230)
.082
(513)
.091
(569)
<.24 in;
>0.0025 in.
Clean
Sand
.681
.149
(22)
.127
(19)
.358
(53)
.223
(33)
.262
(38)
.113
(17)
.142
(21)
>0.0025 in
Contaminated
Fines
.188
.752
(400)
.788
(419)
.594
(316)
.694
(369)
.628
(334)
.781
(415)
.740
(394)
(1) Weight fraction of the specific parameter found in the product stream as a fraction of the
total weight in aK product streams.
(2) Percent of expected value based on feed concentration of respective contaminants and weight
fraction of product stream.
(1) Weight fraction of the specific parameter found in the product stream as a fraction of the
total weight in all product streams.
(2) Percent of expected value based on food concentration of respective contaminants and weight.
fraction of product stream.
35
-------
Table C-10. Concentration of Selected Parameters of the Contaminated Slurry Feed to the THC Biosluny Reactors.
Oil & Grease
mg/kg
TRPH mg/kg
TOC mg/kg
Cu mg/kg
Pbmg/kg
Znmg/kg
Naphthalene
mg/kg
Banzo(a)pyrene
mg/kg
Sample
1
40,000
12,300
117.000
57.4
421
219
49.0
(9.0)
Sample
2
33,300
8,500
102,000
48.2
334
192
52.0
<32.0
Sample
3
50,500
19,800
143.000
76.0
525
250
82.0
(9.6)
Sample
4
54,300
18,100
113,000
45.0
(11.0)
Sample
5
35,300
13,600
130,000
135
680
593
65.0
(12.0)
Sample
6
26,900
12,200
94,700
99
651
467
(17.0)*
(8.4)
Average
40,000
14,100
116,600
83.1
522
344
51.7
- (10.0)
Standard
Deviation
10,500
11,417
17,800
34.9
148
177
21.7
1.48
•() Indicates value la below quantitaSon limit for procedure. Value shown is estimated.
Table C-11. THC Bloslurry Process Concentration of Selected Parametera In Discharge Slurry from Bloslurry Reactors
- Batch 2c
Sample Sample Sample Sample Sample Sample Sample Standard
1 2 3 4 5 6 7 Average Deviation No
Oil & Grease
mg/kg
TRPH mg/kg
Cu mg/kg
Pbmg/kg
Znmg/kg
Naphthalene
mg/kg
Benzo(a)pyrene
mg/kg
60,800*
9530
113
846
469
<16.0
(2.3)'
47,300
7260.
99.4
718
420
<14.0
(4.5)
NR
7400
91.5
643
385
<12.0
(2.0)
56,600
7620
111
769
464
<16.0
(5.7)
39,600
6870
91.6
652
389
<13.0
(2.7)
40,500
6800
89.8
477
462
<15.0
(2.7)
54,1003
9270
111
719
504
<16.0
(2.1)
49,800
7820
101
689
442
-
(3.15)
8750
1120
10.4
116
447
--
1.41
6
7
7
7
7
7
1 () indicates value is below quantitaBon limit for procedure. Value shown is estimated.
Tabto C-12. THC Bloslurry Process Concentration of Selected Parametera in Discharge Slurry from Biosluny Reactors
- Batch 2a
Sample Sample Sample Sample Sample Sample Sample Standard
1 2-3 4 " 5 6 7 Average Deviation No
Oil & Grease
mg/kg
TRPH mg/kg
Cu trig/kg
Pb mg/kg
Znmg/kg
Naphthalene
mg/kg
23.100
4320
898
574
370
<14.0
39,600
6580
89.4
583
360
<14.0
NR
7560
108
713
438,
<16.0
22,000
3930
75.9
505
316
<11.0
23,300
5380
69.3
452
285
<12.0
21.700
5470
70
474
293
<11.0
22,2003
4870
82.5
534
340
<12.0
25,300
5440
83.6
548
343
7030
1270
13.6
87.4
52.7
6
7
7
7
7
6enzo(a)pyrene (2.4)'
mg/kg
(2.3)
(2.8)
(2.9)
(3.4)
(2.6)
(2.6) (2.6) 0.212
0 Indicates value is below quantitation limit for procedure. Value shown is estimated.
36
-------
sample and resulted in much higher quantitation levels than
were expected. A NBS library search was conducted in an
attempt to distinguish the identity of the compounds
causing the large background interference in these samples.
It is difficult to narrow down the exact nature of the
interfering compounds but there appears to be large
amounts of unsaturated hydrocarbons and oxygenated
hydrocarbons present. This observation fits well with the
THC biomass theory.
The THC target criteria for benzo(a)pyrene of 2.4 mg/kg
is based on the proposed Province of Ontario target level.
Canadian (federal) and European criterion for benzo(a)
pyrene is 10 mg/kg.
The same interference had an adverse effect on
naphthalene analysis which is a compound that exceeded
the THC Target Criterion in the feed soil. Naphthalene
was not detected in the discharge from either bioslurry
reactor batch but the quantitation limits did not allow a
definitive statement. As a partial remedial action, the
extracts from one sample of each batch were reanalyzed to
establish that storage of the extracts had not had a
significant effect on the GC/MS results. The extracts were
then spiked with 5 ppm of naphthalene and benzo (a)
pyrene and reanalyzed. The analytical variability of the
replicates was quite low, and the spike recovery was
excellent. The purpose of analyzing these samples was to
demonstrate that the instrument detected concentrations
below the quantitation limit with a reproducible degree of
precision. The net result is that we can conclude that if
naphthalene was present at the THC Target Criterion level
of 8 ppm, it would have been detected. The
reprbducibility and excellent spike recovery for the
benzo(a)pyrene suggest the levels reported are good
estimates.
Another approach to estimating actual naphthalene levels
was to examine the minimum estimated values reportable
by the method. The rationale being that if naphthalene
were present at that level it would have also been
estimated. Therefore, the naphthalene level must be below
the lowest estimated value. This results in a conclusion
that naphthalene concentration is below 1.6 mg/kg.
Table C-13 summarizes the comparison of bioslurry system
inlet and outlet for bioslurry batch 2a. The results for
bioslurry batch 2c are not directly related to the SITE inlet
concentrations but appear to provide similar results.
C.5 Metals Removal Process
The low level of metals contamination found in Soil B
resulted in THC not running this soil through the metals
Table C-13. THC Blotluny ProcM* Bkwluny Reactor Into! and
Outlet Concentration* for Selected Parameter*
Contaminated Bioslurry Apparent
Fine Slurry Batch 2a Discharge Removal %
Oil & Grease mg/kg
TRPH mg/kg
Cu mg/kg
Pb mg/kg
Zn mg/kg
Benzo(a)pyrene mg/kg
Naphthalene mg/kg
Naphthalene mg/kg
Naphthalene mg/kg
40,000
14,000
83.1
522
344
(10.0)'
57.7
<8.4'
<{1.6)
25,300
5,440
83.6
548
343
(2.6)
<13.
-------
Composite samples of the influent and effluent were
accumulated by taking hourly grabs over a four hour
period. During the first sampling day, two composites (#1,
#2) were accumulated. During the second day of
sampling, the first four hour composite (#3) was
accumulated as planned. During the accumulation of the
second composite (#4), the contents of the first tank were
exhausted. The feed was initiated from the second tank.
Composite #4 which was the second -composite of the
second sampling day was terminated after 2 hours and a
new composite sample (#5) for the new feed tank was
initiated. After accumulating 2 hourly grabs, the operator
noticed that the media was being fouled with oil and the
run was terminated. The reactor and media required
extensive cleanup and, as a result, operations were not
resumed during the SITE sampling time frame. The cause
of the oil contamination was later identified as the contents
of the second feed tank. THC had processed the fines
generated by the soil wash process while processing
roughly 830 tons of this soil without encountering this
problem. A good explanation has not emerged but a
definite process limitation has been identified. Plans to
confirm operating flow rates on the third day of sampling
were precluded by the process shutdown. The developer
reports that slurry feed rate was normally 8 gallons per
minute with a 24 percent solids level. This results in the
actual processing of about 0.55 tons per hour of dry solids.
The composite samples were analyzed for total metals.
The slurries proved amenable to extractions as a liquid.
Table C-14 presents the analytical results for the composite
samples. The inlet metals concentrations are very
consistent including composite sample #5 which was
obtained during operation from the second feed tank.
Outlet metals values exhibit greater variation from
composite, sample to composite sample. Table C-14 also
presents percentage removal information by metal based on
comparison of the composite average inlet and outlet
concentrations. The values obtained are in the range of
expected results based on THC experience.
C.6 Emissions Sampling
The ventilation system for the bioslurry process was
sampled for gaseous emissions in an effort to establish the
types of emission control which might be required. Minor
amounts of volatile organics were detected. Analysis of
SVOC's was handicapped by the poor detection limits as
a result of high concentrations of non-target hydrocarbons
which were tentatively characterized between diesel
distillates and Stoddard solvent (C9 to C16 parafines). Total
gaseous non-methane organic compounds were detected at
levels which indicate 220 pounds per day of emissions
from the overall bioslurry system. It is reasonable to
expect this emissions rate would be highly variable
depending upon the specifics characteristics of the soil
being processed as well as operating rates. The
significance of this result is that air stripping in the
bioslurry reactors is responsible for removing at least part
of the hydrocarbons present. Adequate emissions control
will be essential in application of this technology. The
THC facility has in place a biological filter system and
carbon adsorption beds for emissions control. These
treatments were intentionally over designed to meet
regulatory concerns. No effort was made to assess the
effectiveness of the control measure. Stack testing by the
developer indicates hydrocarbon emissions are below
detection.
TaW« C-14. Matals Removal Process - Inlet and Outlet to Tubular Reactor Data for Selected Metals.
Total Metal (mg/L)
INLET METALS
Copper
Lead 100
Nickel 11.2
Zkic 264
Sample
1
49.2
97.8
12.7
270
Sample
2
50.2
94.2
10.7
264
Sample
3
50.0
98.4
11.7
273
Sample
4
53.2
112.0
12.0
294
Sample
5
52.2
100.5
11.7
277
Standard %
Average Deviation Removal
51.0 1.53
6.8
.8
12
OUTLET METALS
Copper
Lead 22.0
Ntekal 4.7
2nc 55.4
1.6
41.6
7.3
103
3.0
28.6
(1.2)*
110
(.9)*
13.5
(.9)*
53
1.76
39.3
2.6
183
1.7
29.0
3.3
100.9
1.8
11.8
2.7
52.9
.8
71
77
64
' () Indicates value is below quantrtatlon limit for procedure. Value shown is estimated.
38
96
-------
Appendix D-l
Cost Analysis for Treatment of 22,000 Tons of
Contaminated Soil Using the THC Treatment Plant
D.I Introduction
The volume of soil that may require treatment at the Port
Industrial District has been estimated at 2,200,000 tons. For
purposes of this analysis we have constructed a hypothetical
case in which 22,000 tons of soil on a dry basis with a fines
content of 16.5 percent which requires treatment for heavy
metals and organic contaminants will be processed in the
existing THC Treatment Plant.
Figure D-l presents a process flow diagram with average
daily flows indicated for this hypothetical case.
FIGURE D-1
DAILY MASS FLOWS FOR HYPOTHETICAL CASE TREATMENT
OF 22,000 TONS OF CONTAMINATED SOIL
Coil/
Sind p.lt
73 TONS 2.6 TONS
•)"H Blorvaetor
17.6 TONS
L*
Acid
L..ch
Flocculatlon
S«dlm«nl«1
* 1 Cont.minat.d J Qrcvltv
on 1 Fin** n Thfekcner
L I" CtT.micil
P |Pr«tr*ilm«nt
17.6 TONS
Cont.mln.ted .lurry to
R>
r
bul*r
actor
Nautrallz*
_^ D*wat«r
* Fine J
17.6 TONS
c
R*g«n«ratlng
Acid
This economic analysis is based on assumptions and costs
provided by THC or its contractors. This estimate is based
on an analysis of costs incurred during the 9 months of plant
operation experience accumulated in 1992. THC provided
a cost analysis based on an assumption of 33 percent fines
in the soil. This represents a worst case scenario for costs.
Several other cases have been examined in order to highlight
the importance of the amount of fines in the overall costs for
the treatment traim The THC analysis was provided in
Canadian dollars. It has been converted to U.S. currency by
using an exchange rate of $0.80 U.S. to $1.00 Canadian.
Comments on the cost analysis and discussion of cost
elements in general represent the author's engineering
judgement An effort has been made to present the cost
analysis in a manner that will allow the reader to vary the
basis to fit a particular situation or to evaluate the sensitivity
of cost to a particular assumption.
Cost figures provided here are based on analysis of the
actual operation of the actual plant and actual personnel.
The analysis involved identifying achievable long term
production levels and utilizing actual cost experience to
project costs when production is the primary goal of the
operation. The costs presented include a profit for the
developers. This "profit" is recovered in the equipment cost
as well as a loading on labor. The exact nature of the
"profit" has not been disclosed.
Utilization Rates and Maintenance Schedules - The
processing of 22,000 tons of soil would require about 208
days of operation. In order to account for scheduled
maintenance and unscheduled shutdowns due to equipment
problems, a 10 percent factor has been assumed. This
results in 229 day operation being required and an effective
operating rate of 96 tons/day of feed soil. Costs for labor
and equipment were increased to reflect this allowance.
Consumables, utilities, and analytical costs were not factored
since these elements are not consumed during downtime
periods.
39
-------
Financial Assumptions - For the purposes of this analysis,
capital equipment costs are separated for the complete
process units. Capital equipment costs were amortized over
a 10 year period with no salvage value taken at the end of
the period. Interest rates, time-value of money were
included by the developer. The effective rate used by the
developer, based on an analysis of the data provided is 20%.
The reader is cautioned that interest rates in Canada are
considerably higher than in U.S. at this time, however it is
clear that a return on capital is also included here.
D.2 Basis for Economic Analysis
In order to compare the cost effectiveness of technologies in
the SITE program, EPA breaks down costs into 12
categories shown in Table D-l using the assumptions already
discussed. The assumptions used for each cost factor are
described in more detail below.
D.2.1 Permitting and Regulatory Costs
Permitting and regulatory costs are generally the obligation
of the responsible party (or site owner). These costs may
include actual permit costs, system health/safety monitoring
and analytical protocols. Permitting and regulatory costs can
vary greatly because they are very site- and waste-specific.
No permitting costs are included in this analysis; however,
depending on the treatment site, this may be a significant
factor since permitting can be expensive and a time-
consuming activity. THC has obtained the permits required
for its facility however, they are based upon the facility
being completely removed after the evaluation.
D.2.2 Site Preparation Costs
The amount of preliminary preparation will depend on the
site and is assumed to be performed by the responsible party
(or site owner). Site preparation responsibilities
Table D-1. Treatment Cost Summary for a Hypothetical
Organic and Inorganic Contaminants.
Remediation of 22,000 tons of Soil with 16.5 Percent Fines and Both '
Cost Component
1. Site Preparation Costs
Soil
Wash <
N/A
Biological
/o Treatment %
N/A
Metals
Removal %
N/A
Total %
N/A
2. Permitting & Regulatory
Costs
3. Equipment Costs
4. Startup
5. Labor
6. Consumables & Supplies
Chemicals
Maintenance Supplies
7. Utilities
Electric
8. Effluent Treatment &
Disposal
9. Residuals/Waste Shipping,
Handling & Transport Cost
10. Analytical Costs
11. Facility Modification,
Repair & Replace
12. Demobilization Cost
Total
Cost/Ton
N/A
$317,300 20
• (•
N/A
$872,300 55
$66,800
$53,400
4
3
$233,200 15
N/A
N/A
$53,200 3
N/A
0
$1,596,200 100%
$72.55
N/A
$71,100
N/A
$259,800
15
54
N/A
N/A
$26,800 6
N/A
$246,900
N/A
$656,900
22
57
$83,400 17 $66,800
N/A
N/A
$26,800
N/A N/A
0 0
$481,700 100% $1,140,800
$21.90 $5.1.85
N/A
$635.300
N/A
$1,789,000
100%
20
56
$26,800 6 $100,000 9 $193,600 6
$13,800 3 $43,400 4 $110,600 3
$383,400 12
N/A
N/A
$106,800 3
N/A
0
$3,218,700 100%
$146.30
40
-------
include site design and layout, surveys and site logistics,
legal searches, access rights and roads, and preparations for
support facilities, decontamination facilities, utility
connections, and auxiliary buildings. These preparation
activities have been undertaken by THC at this location.
A specific provision has therefore not been included in the
cost analysis.
D.2.3 Equipment Costs
Capital equipment costs are broken down into the three
technologies demonstrated under the SITE program, i.e.,
Attrition Soil Washer, Biological Treatment Process, and
a Metals Removal Process. The equipment was acquired
in 1991 and the capital installed costs for each technology
has been provided by THC in Canadian dollars. This
estimate includes the allocation of the primary plant air
handling system costs equally among the three processes.
D.2.3,1 Attrition Soil Washer
The unit utilized during the THC demonstration is the
same unit which is used in this hypothetical case. It
utilizes a system of trailer transportable modular units
which are assembled at the site into an integrated unit. It
is designed to provide flexibility so that it can be used with
a variety of feed soils. The unit was supplied as a package
by a supplier who designed the unit based on experience
with similar units in Europe. The unit employs mineral
processing equipment from North America, if available.
THC leased the unit with the operators for this
demonstration. The cost analysis is based on the purchase
of an equivalent unit with operation by THC. The capital
cost for the installed unit, including a carbon adsorption
unit for ah" emissions is reported to be $1,200,000 U.S.
The cost recovery for the 22,000 ton case would be
$317,300, which includes the amortized cost of equipment
plus rental equipment and building charges.
D.2.3.2 Biological Treatment Process
The biological treatment system has a reported installed
cost of $240,000 U.S. The equipment cost for our case of
$71,100 U.S. includes the cost of rental equipment and a
building charge.
D.2.3.3 Metals-Removal Process
This unit is also a trailer transportable modular design.
The unit incorporated by THC is the first unit of this size
manufactured anywhere. The equipment is of a unique
design which allows the contacting of metals-rich high
solids content slurry with solid chelating agent beads
without plugging or fouling and restricting the flow
through the media. The installed cost of the unit, including
an acid gas scrubber for air emissions, is reported to be
$800,000 U.S. This results in a equipment cost for this
case of $246,900 U.S., which includes the amortized cost
of equipment plus rental equipment and building charges.
D.2.4 Start-up
The facility being utilized in the hypothetical case is the
one currently located at the THC facility. Start-up with a
new soil is very rapid with adjustments to accommodate
the soil tending to evolve during early operation. Starting
costs have not been broken out by THC and have not been
included here.
If the plant is relocated to a new site, the following
considerations should be made. In general, the
transportation cost for the process units will be a function
of how far the units must be moved to the new site.
Assembly is a labor intensive operation consisting of
unloading modules from truck and trailers used for
transportation, as well as the actual assembly. A crane will
be required for these operations. A two'week time frame
for set-up which would involve operators familiar with the
assembly of the plant would be required as a minimum.
The cost of health and safety training and monitoring have
not been included in this analysis. Depending upon the
specific contaminants present in the soil to be treated, these
costs would be significant. As a minimum, any local
manpower utilized will require OSHA 40 hour hazardous
waste training if a superfund site is involved or hazardous
materials are to be processed.
D.2.5 Labor
THC has provided labor cost data in Canadian dollars by
process and staffing levels but has not provided specific
cost per hour for the various labor classifications.
Additional labor included an allocation of materials
handling labor and a maintenance (parts and labor)
element. One-half of the maintenance cost has been
allocated to labor and the other half to maintenance parts
and consumables. The labor dollars reported include labor
rate and fringe benefits and an allocation of technical
management, site supervisor, a QC person, and a clerk.
Included in overhead are elements such as potable water,
telephones, office trailer rentals, site security and snow
removal. The cost data provided by THC were based on
operations with a feed soil fine concentration of 33.30
4.1
-------
percent. This example is based on a 16.67 percent fines
soil, such as encountered during the SITE demonstration.
The costs presented are based on operating the wash plant
for two shifts. THC labor cost elements were doubled for
the wash plant. The cost data provided by THC results in
a fully loaded average of $42 per hour for the 17.5 people
normally included.
Estimate labor cost for the hypothetical case are:
Soil Wash $872,300
Biological Treatment $259,800
Metals Removal $656,900
D.2.6 Consumables and Supplies
The three processes each consume chemicals utilized in the
respective treatments. THC has not disclosed the identity
of specific chemicals being utilized so the cost information
is aggregated by process. The cost information provided
by THC aggregated maintenance, labor, and parts and
materials in one cost element. This element has split one-
half to maintenance materials and the other half as labor.
Safety equipment and supplies were included in the .site
overhead which was allocated to labor. A discussion of
the chemicals utilized and maintenance materials by
process follows.
D.2.6.1 Attrition Soil Wash
Chemicals utilized are flocculents consumed in thickening
the contaminated slurry. Total cost of chemicals of
$66,800 was calculated for this process in this hypothetical
case.
The maintenance supplies would include fuel for
equipment, lubricants, and parts such as bearing and seal
materials as well as parts for the conveyor system which
feeds the trommel washer. The wash plant is a damp,
harsh environment with a considerable number of high
speed pumps and washer cells. In addition, vibratory
equipment is utilized. Maintenance expense for this
hypothetical case was estimated as $53,400.
D.2.6.2 Biological Treatment Process
The biological treatment system consumes the inorganic
oxidant, phosphoric acid solution and urea solution in
processing the slurry. Chemicals costs for the hypothetical
case are estimated to total $26,800.
Maintenance parts and supplies would include lubricants
for the primary compressor, spare parts for the compressor
and the transfer pumps utilized. These costs were
estimated at $13,800.
D.2.6.3 Metals Removal Process
The cost of the solid chelating agent beads is included hi
the capital cost and thus amortized over a 10 year period.
This assumes little attrition or chemical degradation of the
media will occur. It is too early to judge the wisdom of
this assumption since a considerable period of operation
will be required to establish useful life information for the
media. This process utilizes a mineral acid to dissolve
heavy metals prior to its removal by the chelating agent.
A second acid is utilized to regenerate the solid chelating
agent. The slurry is neutralized using a caustic solution
prior to being pumped to the biological treatment system
or returned to the excavation site. The total cost for
process chemicals for the hypothetical case is estimated at
$100,000.
Maintenance materials for this process can be expected to
primarily center on the pumps used to transfer the acidified
slurry through the process. This is a very harsh application
and parts availability did cause delays during the overall
THC demonstration. The estimated maintenance supply
cost for the hypothetical case is $43,400.
D.2.7 Utilities
The THC demonstration plant was designed utilizing
electrical energy for all requirements. This approach was
adopted since permits were required for any fossil fueled
boilers or process equipment. The attrition soil wash
process requires water at a temperature of at least 55°F
(13°C). This facility utilized an electric powered steam
boiler to generate steam for heating the soil wash plant
water recycle stream. Operations of the facility through
the first half of 1992 suggest that this boiler consumes
more electrical energy than the rest of the facility
combined. THC took this into consideration and than
allocated the remaining electrical energy cost to the
respective processes based on installed horsepower and
operating tunes. Common support, primarily the air
handling system, was allocated equally among the three
processes. Bioslurry process costs are primarily for the
compressor to provide process air. The cost of electrical
energy at the site is $0.104 U.S. per KWH. The resulting
electrical cost allocations for our hypothetical case are:
Attrition Soil Wash $233,200
Biological Process $83,400
Metals Removal Process $68,800
42
-------
Process water was obtained from the collection of
precipitation runoff supplemented as required by pumping
water directly from Lake Ontario. No specific cost for
water was included.
D.2.8 Effluent Treatment & Disposal
The process, even with effective dewatering in place, can
be expected to use some water since a considerable amount
of water leaves the process with the products. In the case
of the demonstration, the contaminants present did not
partition to the aqueous phase. During the nine month
THC demonstration water from excess precipitation was
discharged to the local POTW. The sedimentation
available hi the basin system was sufficient to meet TSS
and oil and grease discharge criteria. No significant cost
factor was involved.
Air emission controls for the overall system include a
multichamber biological filter system followed by a carbon
adsorption bed polishing step. THC has developed data
which suggest this system results in emissions without
detectable hydrocarbons. In addition, the carbon appeared
new. Additional operating experience will be required to
establish the frequency at which the biological media (peat)
and the carbon must be replaced and disposed of. No
attempt was made to estimate these costs.
The overall process generates two solid waste streams that
will require use or disposal approaches. The first stream
is the coal/peat material removed in the soil washer density
separator. This material is primarily <.24 inch coal and
fragments of wood and roots which are hi various stages
of decay. Depending on the contaminants present, this
material could be used as a fuel hi an industrial boiler. If
hazardous contaminants are present, it may require
disposal, most likely by incineration. The stream
accounted for 2-3 percent of the feed soils examined by
THC. This waste was not disposed of during the THC
demonstration but could result in considerable cost if
incineration were required. For example, hi this
hypothetical case this waste would amount to 550 ton. If
incineration could be assumed to cost $1000/ton the cost
incurred would be $550,000 and would represent a
significant cost factor.
In a full scale facility it may be desirable, depending on
the characteristics of the soil, to remove the coal and wood
debris that reports to the coarse gravel product (1.97 inch
>.24 inch). This could be achieved with a vibratory
density separator similar to that employed on the clean fine
sand. This would generate an additional waste stream
which would require a use or disposal.
The metals removed by the electrowinning in the metals
removal process generally represent a small fraction of the
feed soil on a weight basis. The developer believes that
the metals values may be recoverable. In any event the
heavy metals removed are highly concentrated so that the
volume of hazardous material is greatly reduced. No
estimate of cost associated with utilizing or disposing of
this waste has been developed.
D.2.9 Residuals/Waste Shipping, Handling and
Transport Costs
Waste disposal costs including storage, transportation and
treatment costs would be the obligation of the responsible
party. Because of the nature of the soils treated at the
THC demonstration, residuals requiring special handling
were not generated.
In cases where hazardous contaminants are present,
residual or solid wastes would consist of contaminated
health and safety gear, used filters, personal protective
clothing, activated carbon, etc. Landfilling or incineration
would be the anticipated disposal method for these types
of materials. In cases where such materials will require
disposal the costs may be significant and should be
included.
D.2.10 Analytical Costs
Analytical costs have been estimated for the treatment train
based on a weekly provision for process assessment and
quality control. The budgets provided for this hypothetical
case are:
Attrition Soil Wash $53,200
Biological Process $26,800
Metal Removal $26,800
If hazardous components are present in the feed soil,
sampling of the products prior to their return to a site
would be required by the appropriate regulatory agency.
The cost for the testing will require assessment based on
the specific contaminants and the requirements of the
regulatory agency.
D.2.11 Demobilization Costs
Some of these costs would be site-specific. See Section D
2.4 on start-up for an understanding of what may be
involved. No demobilization costs have been included hi
this analysis.
43
-------
D.3 Results
These cost estimates are summarized below.
Table D-l shows a total cleanup cost for the hypothetical
treatment of 22,000 tons of contaminated soil in the
existing THC Treatment Plant of $3,218,000. The costs
are also itemized by cost category and treatment process.
The soil wash process accounts for about 50 percent of the
total cost while the metals removal process accounts for
about 35 percent of total cost and the biological treatment
accounts for the remaining 15 percent. The soil wash
process will process the entire 22,000 tons of feed while
the other processes are required to treat only the
contaminated fines, which for this analysis amounted to
approximately 3650 tons.. When considering the overall
treatment train, the largest cost components are labor
(56%), equipment costs (20%), and electrical energy
(12%), consumables (10%) and analytical cost (3%)
account for the remaining costs.
Based on this hypothetical case of 22,000 tons dry basis of
contaminated soil treated, the total estimated unit cost is
$147/ton; the breakdown of costs by technology is shown
below.
Cost $/ton of feed soil
33% Fines 16.5% Rnes11% Fines
Attrition Soil Washer
Biological Treatment Process
Metals Removal Process
Total
Unit Cost
$/ton
73
22
• 52
$147
This cost estimate is based on a fines content of 16.5
percent. The estimated cost per ton is quite sensitive to
the percent of fines present. This occurs because the
metals removal and or biological treatment capacity can
limit the utilization of the wash plant if this treatment is
operated at .73 ton per hour throughput. There is no magic
in that throughput rate since the throughput required to
meet a specific required metal removal or biological
treatment may vary. The .73 ton throughput rate is simply
a good operating assumption. Tables D-2, D-3 and D-4
illustrate the effect of different fines concentration on cost
if the metals removal and biological system are limited to
.73 ton/hr throughput. The case illustrated in Table D-2 is
for a soil fine concentration of 33 percent which THC
provided as the base case. In general, this is considered
the upper limit of fines content applicability for the overall
treatment strategy. This case would utilize the wash
process only about 40 hours per week. Table D-3 and D-4
illustrate the cases in which the soil wash plant could be
operated 80 hours per week and 120 hours per week
respectively as a result of the respective fine contents.
Attrition -Soil Process 80
Biological Treatment 43
Metal Removal Process 96
Total
219
67
21
48
136
63
14
32
109
These cost estimates do not have any allowance for
operating downtime other than that already built into the
THC analysis.
Cost of the metals removal process and biological
treatment system are expressed on a per unit of throughput
basis. Table D-5 is based on a 0.73 ton dry basis per hour
throughput. Viewed on this basis the estimated costs are
as follows:
Unit Cost
$/ton actually
processed
Attrition Wash Plant
.Biological Treatment Process
287
128
The reader is cautioned that the costs accounted for in this
analysis do not include some site specific elements which
could significantly effect final costs. In addition capital
and operating cost for an appropriate dewatering process
must also be included. If incineration of the coal/peat
waste is required, the cost would be a significant factor.
THC has assumed an operating throughput rate for the
metals removal process somewhat higher than those
observed during the demonstration. The relatively long
process times used for the bioslurry reactor process during
the demonstration if required would result in the cost
estimate for the biological process being low. If retentions
of 30 to 40 days are required, the biological process cost
could increase by a factor of 3 to 4. Careful treatability
studies to establish technical suitability and to refine the
cost estimates will be necessary.
44
-------
Tabla 0-2.
Coat Par Ton of Feed Soil Baaad on S3 Tona Par Day of Faad and 33
Percent Finaa In tha THC Treatment Train
Attrition Biological Metals
Soil Wash Treatment Removal
Process Process Process
Total
Table D-4. Coat Par Ton of Feed Soil Baaad on 159 Tona Per Day of Feed Soil and
11 Percent Flnee In the THC Treatment Train.
Attrition Biological Metals
Soil Wash Treatment Removal
Process Process Process Total
Labor
Manpower
Maintenance
Materials Handling
Purchased Material & Services
Analytical Charges
Chemicals
Energy
Electrical
Equipment & Building
Equipment
Rental Equipment
Building
$28.36
4.84
5.19
2.41
3.03
10.58
21.81
2.27
1.81
$17.14
2.49
3.03
2.41
1.51
7.57
4.36
2.27
1.81
$47.14
7.86
3.03
' 2.41
9.07
6.64
14.53
3.78
1.81
$92.64
15.19
11.25
7.23
13.61
24.19
40.70
8.30
5.43
labor
Manpower
Maintenance
Materials Handing
Purchased Material a Services
Analytica] Charges
Chemicals
Enemy
Electrical
Equipment & Building
Equipment
Rental Equipment
BuBdng
Total
$28.36
4.84
5.19
2.41
3.03
10.58
7.28
.75
.60
$63.04
$5.72
.83
1.01
.81
.50
2.52
1.45
.75
.60
$14.19
$15.71 $49.79
2.62 8.29
1.01 7.21
.81 4.03
3.03 6.56
2.01 15.11
4.84 13.57
1.26 2.76
.60 1.80
$31.89 $109.12
Total
$80.30
$42.54
$95.67
$218.56
Table CM.
Coat Per Ton of Feed Soil Baeed on 108 Tone Per Day of Feed Soil and
18.5 Percent Fine* In the THC Treatment Train.
Attrition Biological Metals
SoH Wash Treatment Removal
Process Process Process
Labor
Manpower $28.36 _ $8.57 $23.57
Maintenance 4.84 1.24 3.44
Materials Handing 5.19 1.52 1.52
Purchased Material & Services
Analytical Charges 2.41 1'.22 1.22
Chemicals 3.03 1.22 4.54
Energy
Electrical 10.58 3.78 3.03
Equipment a Building
Equipment 10.90 1.10 7.29
Rental Equipment 1.14 1.14 1.90
Building .91 .91 .91
Total
$60.50
10.02
8.23
4.85
8.74
17.39
' 19.28
4.18
2.73
Tabte D-5. Coat Per Ton of Soil Actually Proteased Baaed on Through-
put Rate of .73 Ton/Hr and Continuous Operation.
Biological
Treatment Metals Removal
Process Process
($/Ton) ($/Ton)
Total
$67.36
$20.70
$47.91
$135.97
Labor
Manpower
Maintenance
Materials Handing
Purchased Material & Services
Analytical Charges
Chemicals
Enemy
Electrical
Equipment & Building
Equipment
Rental Equipment
Building
$51.40
7.44
9.07
7.26
4.54
82.68
13.08
6.80
5.44
$141.40
23.59
9.07
7.26
27.22
43.62
11.34
5.44
Total
$127.71
$287.08
45
-------
Case Study D-2
Attrition Soil Wash Process Results for Soil B
THC's contractors excavated and processed 1040 tons of a
soil designated Soil B from a former refinery site located in
the PID. The soil was processed in the attrition soil wash
plant during the period including March 19, 1992 to May
14, 1992.
Xenon Environmental Laboratories, Inc. was retained to
sample the process feed and product streams on four days
during the course of the run. The sampling dates were at
least one week apart. Samples were accumulated by
compositing hourly grab samples over an eight hour period.
Table D-2-1 presents the average results for the four sample
events for selected parameters. The partitioning of some
key contaminants in the product streams based on this data
FIGURE D-2-1
PARTITION OF FEED SOIL TO PRODUCT STREAMS IN ATTRITION
WASH PROCESS., SOIL B, OVERALL THC PROJECT
FEED 2000 •
75.6 * OtQ
.298 * LEAD
.0094 » BENZO (I) PYflENE
ATTRITION SOIL WASH PROCESS
COAL/
PEAT
CLEAN
SAND
CONTAMINATED
FINE SOIL "••
in Figure D-2-1.
WEIGHT
WEIGHT %
OtO(1)
LEAD(I)
(• (•) P)
210 *
10.5
18.9 %
43.« %
13 %
50*
2.S
18.2 %
9%
, 1.9%
1404 t
70.2
10.4%
20 %
19.1%
334*
t».r
54.8%
30.4%
0%
BIOLOGICAL
TREATMENT
Ttbl» D-M.
StIMM FMd md Product Stnrni PimrMtcra tor Attrition Soil Wuh Prae*M,
Soil B, THC Soil Rcoyeto TiMtmrnt Ptant
FMdSol
Gnvtf
Contimin»t»d
Cl**n S«nd Finn
P*re*M of F*«d la
Tronnntl Wtshtr
040, X
Copptr, mg*g
Lt»dmg/i
-------
Case Study D-3
Attrition Soil Wash Process Results for Soil A
THC's contractor processed 820 tons of a soil designated
Soil A from a former auto/metal salvage site located in the
PID. The soil was processed in the attrition soil wash plant
during the period including February 11,1992 to March 18,
1992. This soil contained wire and roots from vegetation
which caused problems when this fibrous material blinded
screens or caused flow restrictions in process piping.
Xenon Environmental Laboratories, Inc. was retained to
sample the process feed and product streams on four days
during the course of the run. The sampling dates were at
least one week apart. Samples were accumulated by
compositing hourly grab samples over an eight hour period.
Table D-3-1 presents the average results for the four sample
events for selected parameters. The partitioning of some
key contaminants in the product streams based on this data
is illustrated in Figure D-3-1.
FIGURE D-3-1
PARTITION OF FEED AND PRODUCT STREAMS IN ATTRITION
WASH PROCESS. SOU. A, OVERALL THC PROJECT
FEED 2000 f
5.6 * OiG
.58 * COPPER
.44 * LEAD
.79 * ZINC
.001 « BENZO (•) PYRENE (B (1) P)
ATTRITION SOIL WASH PROCESS
COAL/
PEAT
CLEAN
SAND
CONTAMINATED
FINE SOIL
WEIGHT
% OF FEED
oto
COPPER
LEAD
ZINC
IB («) P)
280 »
1 4
18.9 *0)
20.4 %
14.7 *
22.9 %
2.1 %
30*
1.5
5.2 %
8.4%
2.5%
2.1 %
11.5 %
1326 *
66.3
18.1 %
29.7 %
36.6 %
32.3 %
9.8 %
3 6 4 It
18.2
56.8 *
41.5 %
46.2 %
42.7 %
69.6 %
( 1 )PERCENTAGE OF CONTAMINANT BASED OH TOTAL CONTAMINANT IN PRODUCT STREAMS
Table D-3-1. Selected Feed and Product Stream Parameters for the Attrition Soil Wash Process,
Soil A, THC Soil Recycle Treatment Plant
Feed Soil
Gravel
Coal/Peat
Contaminated
Clean Sand Fines
Percent of Feed to
Trommel Washer
O&G, %
Copper, mg/kg
Lead mg/kg
Zinc, mg/kg
Phenanthrene mg/kg
Pyrene, mg/kg
Benzo(a)pyrene, mg/kg
0.28
282
219
394
0.92
0.76
0.51
14
0.68
331
315
1057
ND
,,HD
0.20
1.5
1.65
1268
499
917
28.8
18.3
16.8 ,
66.3
0.15
102
166
314
0.34
0.22
0.20
18.2
1.49
518
763
1515
5.9
8.6
5.2
47
-------
Case Study D-4
Bioslurry Reactor Process Results at the
THC Soil Recycle Treatment Plant for Soil B
An assessment of the bioslurry reactor process for the
treatment of contaminated fines produced by the attrition
soil wash process and the high pressure wash process for
Soil B from a refinery site located in the PID was
conducted during the THC Soil Recycle project. The
evaluation consisted of the treatment of a series of soil
batches.
below the 5000 mg/kg THC criteria for mineral O&G attained.
This was achieved after 50 days of biodegradation, a lengthy
time for treatment. On the other hand, it is the limit of
contamination which would be treatable hi mesophilic
bioreactors such as the ones operated here. Faster treatment
could be obtained with thermophilic bioreactors, but it would
involve heating to startup the high-temperature biodegradation.
D.4.1 Oil and Grease
Considerable effort was devoted to the development of
analytical procedures to allow reporting of total oil and
grease as well as the separate mineral (oil) and animal
(grease) components of this parameter. In general, the
attainment of total oil and grease at the 1.0 percent
target level was not achievable. At least a part of the
problem is associated with relatively high levels of
animal grease resulting from extraction of the biomass
in the treated soil.
Table D-4-1 presents oil and grease (O&G) and
component data for the processing of a batch of Soil B
from the high pressure soil wash process evaluation.
The initial levels of oil and grease were high, but these
levels were brought down steadily as a result of
biodegradation, with residual mineral O&G levels
(further corrected for the presence of polar compounds)
D.4.2 PAH Compounds
The analysis of PAH compounds also required the development
of sampling and analytical procedures that will allow the
reliable determination of PAH concentration levels hi the slurry
from the bioslurry reactors. The development of these
procedures is an ongoing program.
Results of the PAH treatment of several batches of Soil B
contaminated fines generated by the attrition soil wash process
are presented in Table D-4-2. Similar data for contaminated
fines generated using the high pressure wash process are
presented in fable D-4-3.
The biodegradation of benzo(a)pyrene (BAP) to the 2.4 mg/kg
level has shown to be an obstacle in the THC refinery soils.
Although the percentage of reduction of BAP is significant
(above 60%), the criteria level of 2.4 mg/kg has only been
achieved for Batch #4, for fines from the attrition soil wash
process.
48
-------
Table D-4-1. Oil and Grease Results for the Biological Treatment of Contaminated Fines from the
High Pressure Wash Process
Date
Days of Biodeg.
Component
Oil (Mineral)
Oil (Mineral -
Methanol)
Grease (Animal)
Total Oil & Grease
(Freon)
Average 6
Samples
4-Aug.
0
Stand. Method
mg/kg
52167
42500
52500*
105167
4278-1196
TK-101
8-Aug.
4
Stand. Method
mg/kg
35000
29000
140000
170000
4278-1303
TK-101
20-Aug.
16
Stand. Method
mg/kg
30000
30000
23000
54000
4278-1451
TK-101
2-Sep.
29
Stand. Method
mg/kg
16000
16000
22000
38000
4278-1497
TK-101
9-Sep.
36
Stand. Method
mg/kg
11000
6000
9000
20000
4278-1504
TK-101
23-Sep.
50
Stand. Method
mg/kg
4500
3700
8500
13000
' Note: Samples had undergone some anaerobic biodegradation during shipping, explaining the initial high animal O&G counts
Table D-4-2. Comparative Data for Specific PAHs for the Processing of Soil B Contaminated
Fines from the Attrition Soil Wash Process
# days biodegradation
Component
Phenanthrene
Benzo(a)anthracene
Chrysene
Benzo(b)fluoranthene
Benzo(k)fluoranthene
Benzo(a)pyrene
Dibenzo(a,h)anthracene
4278-0581
Fines '
Before tmt
0
mg/kg
32
19
26
15
1.2
16
ND
4278-0649
R2B
Batch #1
30
mg/kg
5.9
4.9
8.6
9.4
2.7
10
2.0
4278-0769
R2C
Batch #2
37
mg/kg
3.9
1.1
1.0
2.3
ND
3.9
ND
4278-1038
R2B
Batch #4
34
mg/kg
3.4
0.55
0.83
0.96
ND
1.2
ND
49
-------
Table D-4-3. Comparative Data for Specific PAHs for the Processing of Contaminated Fines for
the High Pressure Wash Process
# days biodegradation
Component
Phenanthrene
Benzo(a)anthracene
Chrysene
Benzo(b)fluoranthene
Benzo(k)fluoranthene
Benzo(a)pyrene
Dibenzo(a,h)anthracene
4278
1182
Before tmt
0
mg/kg
72
13
22
9.1
2.3
12
ND
4278-1042
R3
27
mg/kg
44
8.5
16
6.8
1.5
6.3
1.6
4278-1497
TK-101
30
mg/kg
3.5
1.6
2.3
3.1
0.74
5.7
1.3
50
-------
Case Study D-5
Metals Removal Process Evaluation for Soil A
THC's contractors excavated about 820 tons of soil from
a site within the PID which had been utilized as an
automobile and metal salvage yard. This soil was
designated as Soil A. The soil was processed in the
attrition, soil washer incorporated in the THC Soil Recycle
Project. The contaminated fines produced by the soil wash
processes were processed hi the metals removal process
prior to treatment hi the bioslurry reactor process.
Table D-5-1 presents feed concentrations and treated fines
concentrations for two 24-hour processing periods for Soil
A contaminated fines prepared with the attrition soil wash
process. Percent removals calculated from the feed
properties are also presented in Table D-5-1.
Table D-5.1 Metals Removal Process Results Soil A Feed for Attrition Soil Wash Process
Metals
Run #1(1) 2/20/92 Run#2(1> 2/21/92
Feed Product %(2) Feed Product %(2)
Total Metals Total Metals Removal Total Metals Total Metals Removal
Cu mg/kg
Ni mg/kg
Pb mg/kg
Zn mg/kg
-s 568
298
800
1601
120
46
150
300
79
84
81
81
1223
469
1687
3072
169
84
211
211
86
82
87
93
1 Each run represented a 24-hour operating period composite sample
product concentration
2 Percent removal for specific metal removal = 1.0 -
feed concentration
x100
*U.S. GOVERNMENT PRINTING OFFICE: 1993-753-008
51
-------
------- |