United States
Environmental Protection
Agency
Office of Research and
Development
Washington DC 20460
EPA/540/R-94/508
September 1995 '
vvEPA
J.R. Simplot Ex-Situ
Bioremediation
Technology for Treatment of
Dinoseb-Contaminated Soils
Innovative Technology
Evaluation Report
SUPERFUND INNOVATIVE
TECHNOLOGY EVALUATION
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CONTACT
Wendy Davis-Hoover is the EPA contact for this report. She is presently with the newly
organized National Risk Management Research Laboratory's new Land Remediation and Pollution
Control Division in Cincinnati, OH (formerly the Risk Reduction Engineering Laboratory). The
National Risk Management Research Laboratory is headquartered in Cincinnati, OH, and is now
responsible for research conducted by the Land Remediation and Pollution Control Division in
Cincinnati.
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EPA/540/R-94/508
September 1995
J.R. SEMPLOT
EX-SITU BIOREMEDIATION TECHNOLOGY
FOR TREATMENT OF
DEVOSEB-CONTAMINATED SOILS
INNOVATIVE TECHNOLOGY EVALUATION REPORT
NATIONAL RISK MANAGEMENT RICSEARCH LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
CINCINNATI, OHIO 45268
Printed on Recycled Paper
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NOTICE
The information in this document has been prepared for the U.S. Environmental Protection Agency's
(EPA's) Superfund Innovative Technology Evaluation (SITE) Program under Contract No. 68-CO-0048.
This document has been subjected to EPA's peer and administrative reviews and has been approved for
publication as an EPA document. Mention of trade names of commercial products does riot constitute an
endorsement or recommendation for use.
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FOREWORD
The U.S. Environmental Protection Agency is charged by Congress with protecting the Nation's land, air,
and water resources. Under a mandate of national environmental laws, the Agency strives to formulate
and implement actions leading to a compatible balance between human activities and the ability of natural
systems to support and nurture life. To meet this mandate, EPA's research program is providing data and
technical support for solving environmental problems today and building a science knowledge base
necessary to manage our ecological resources wisely, understand how pollutants affect our health, and
prevent or reduce environmental risks in the future.
The National Risk Management Research Laboratory is the Agency's center for investigation of
technological and management approaches for reducing risks from threats to human health and the
environment. The focus of the Laboratory's research program is on methods for the prevention and
control of pollution to air, land, water and subsurface resources; protection of water quality in public water
systems; remediation of contaminated sites and ground water; and prevention and control of indoor air
pollution. The goal of this research effort is to catalyze development and implementation of innovative,
cost-effective environmental technologies; develop scientific and engineering information needed by EPA
to support regulatory and policy decisions; and provide technical support and information transfer to
ensure effective implementation of environmental regulations and strategies.
This publication has been produced as part of the Laboratory's strategic long-term research plan. It is
published and made available by EPA's Office of Research and Development to assist the user community
and to link researchers with their clients.
E. Timothy Oppelt, Director
National Risk Management Research Laboratory
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TABLE OF CONTENTS
Section
Page
NOTICE ii
FOREWORD iii
LIST OF TABLES vii
LIST OF FIGURES vii
ACKNOWLEDGEMENTS viii
Executive Summary ,, 1
Section 1 Introduction 5
.1 Background 5
.2 Brief Description of Program and Reports 6
.3 The SITE Demonstration Program 7
.4 Purpose of the Innovative Technology Evaluation Report (ITER) 8
.5 Technology Description 8
1.6 Key Contacts 9
Section 2 Technology Applications Analysis 11
2.1 Key Features of the J.R. Simplot Ex-Situ Bioremediation Technology 11
2.2 Technology Performance versus ARARs during the Demonstration ..'..- 12
2.3 Operability of the Technology 18
2.4 Applicable Wastes 19
2.5 Availability and Transportability of Equipment 20
2.6 Materials Handling Requirements 21
2.7 Range of Suitable Site Characteristics 22
2.8 Limitations of the Technology 23
2.9 ARARs for the J.R. Simplot Ex-Situ Bioremediation Technology 24
2.9.1 Comprehensive Environmental Response, Compensation, and
Liability Act (CERCLA) 25
2.9.2 Resource Conservation and Recovery Act (RCRA) 26
2.9.3 Clean Air Act (CAA) 28
2.9.4 Safe Drinking Water Act (SDWA) 28
2.9.5 Toxic Substances Control Act (TSCA) 28
2.9.6 Occupational Safety and Health Administration Requirements (OSHA) . . 29
Section 3 Economic Analysis 30
3.1 Introduction 30
3.2 Conclusions . 30
3.3 Issues and Assumptions 31
3.4 Basis for Economic Analyses 34
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Section
TABLE OF CONTENTS (Continued)
Page
3.4.1 Site and Facility Preparation Costs 35
3.4.2 Permitting and Regulatory Costs 39
3.4.3 Equipment Costs 39
3.4.4 Startup and Fixed Costs 40
3.4.5 Labor Costs 41
3.4.6 Supplies Costs 42
3.4.7 Consumables Costs 42
3.4.8 Effluent Treatment and Disposal Costs 42
3.4.9 Residuals and Waste Shipping, Handling and Transport Costs 43
3.4.10 Analytical Costs 43
3.4.11 Facility Modification, Repair and Replacement Costs 43
3.4.12 Site Restoration Costs 44
Section 4 Treatment Effectiveness During the SITE Demonstration 45
4.1 Background 45
4.2 Detailed Process Description 46
4.3 Methodology 49
4.4 Performance Data 54
4.4.1 Chemical Analysis 54
4.4.2 Physical Analysis 58
4.5 Process Residuals 58
Section 5 Other Technology Requirements 61
5.1 Environmental Regulation Requirements 61
5.2 Personnel Issues 61
5.3 Community Acceptance 62
Section 6 Technology Status 64
6.1 Previous Experience 64
6.2 Scaling Capabilities 64
References 66
VI
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TABLE OF CONTENTS (Continued)
Section Page
Appendix A Vendors Claims 67
A. 1 Introduction 67
A.2 Process 68
A.3 Cost 69
A.4 Technical Information 69
A.5 Advantages 70
A.6 Limitations 70
LIST OF TABLES
Table Page
Table ES-1 Evaluation Criteria for the J.R. Simplot Ex-Situ Bioremediation Technology 3
Table 2-1 Federal and State ARARs for the J.R. Simplot Ex-Situ Bioremediation Technology 13
Table 3-1 Estimated Costs for Treatment Using the J.R. Simplot Ex-Situ
Bioremediation Technology 32
Table 3-2 Items Included in This Cost Estimate 33
Table 3-3 Detailed Costs for Treatment Using the J.R. Simplot Ex-Situ ,
Bioremediation Technology 36
Table 4-1 Other Compounds Reduced During the Demonstration Test 56
Table 4-2 Compounds Unaffected by the J.R. Simplot Ex-Situ Bioremediation Technology . 58
Table 4-3 Summary of Pre-Treatment Metals Data 59
LIST OF FIGURES
Figure Page
Figure 3-1 Estimated Costs for the J.R. Simplot Ex-Siitu Bioremediation Technology .... 38
Figure 4-1 J.R. Simplot Process Flow Diagram for the Bioremediation of Dinoseb-
Contaminated Soil During the Demonstration Test 48
Figure 4-2 Monitored Parameters during Demonstration Test 53
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ACKNOWLEDGEMENTS
This report was prepared under the direction of Dr. Wendy Davis-Hoover, the EPA Technical Project
Manager for this SITE Demonstration at the National Risk Management Research Laboratory (formerly
the Risk Reduction Engineering Laboratory) in Cincinnati, Ohio. It was prepared for EPA's Superfund
Innovative Technology Evaluation (SITE) Program by the Process Technology Division of Science
Applications International Corporation (SAIC). Contributors and reviewers for this report were Dr. Ron
Lewis and Mr. Robert Stenberg of the EPA-NRMRL.
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EXECUTIVE SUMMARY
This report summarizes the findings of an evaluation of the J.R. Simplot Ex-Situ Bioremediation
Technology on the degradation of dinoseb (2-.yec-butyl-4,6-dinitrophenol) an agricultural herbicide. This
technology was developed by the J.R. Simplot Company (Simplot) to biologically degrade dinoseb and
other nitroaromatic contaminants in soil. This technology is also known as the Simplot Anaerobic
Bioremediation (SABRE™) system. Engineering assistance was provided to Simplot by Envirogen, Inc.
This evaluation was conducted under the U.S. Environmental Protection Agency (EPA) Superfund
Innovative Technology Evaluation (SITE) Program. A companion evaluation is also being performed on
this technology to determine its effectiveness in biodegrading another nitroaromatic compound, TNT
(2,4,6-trinitrotoluene).
Conclusions
Based on this SITE Demonstration, the following conclusions may be drawn about the applicability of
the J.R. Simplot Ex-Situ Bioremediation Technology:
The J.R. Simplot Ex-Situ Bioremediation Technology can reduce levels of dinoseb in soil
by >99.8% in less than 23 days at an average temperature of 18°C based on an average
pre-treatment soil concentration of 27.3 mg/kg (dry basis) and a final post-treatment
concentration below the detection limits of the analytical instrumentation. The 95%
confidence interval about the pre-treatment soil was 26.4 mg/kg to 28.3 mg/kg.
Anaerobic biodegradation of dinoseb may be achieved without the identification of known
toxic intermediates by HPLC and GC/MS analysis.
The preferred operating temperature range of the bioreactor is 35 to 37°C (1). However,
the process successfully operated during the SITE Demonstration with an average
bioreactor temperature of 18°C.
Although beyond the process design, other compounds such as 2,6-dichloro-4-nitroaniline
(nitroaniline); parathion; malathion; and 4,4'-DDT were estimated to be reduced from
parts-per-million levels in the pre-treatment soil to below their respective analytical
detection limits in the post-treatment slurry. Atrazine levels in the post-treatment slurry
were estimated to be approximately half the levels found in the pre-treatment slurry,
however, the negative process control showed a greater decrease in the levels of this
compound. The process was estimated to have no effect on compounds such as
chlordane (alpha, gamma, and technical); and endosulfan (I and II).
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The cost associated with this technology for treatment of 3,824 m3 (5,000 yd3) of
dinoseb-contaminated soil in four lined pits is approximately $127/m3 ($97/yd3). This
does not include costs for excavating the dinoseb-contaminated soil. Depending on site
characteristics, an additional cost of up to $131/m3 ($100/yd3) may be assessed to the
client by the developer for additional technical assistance, soil nutrients, a carbon source,
and other process enhancements.
Other conclusions that may be drawn regarding this technology, based on treatability studies and other
pertinent information include:
The presence of heavy metals in the feed soil does not adversely affect the process. As
this technology is a sulfate reducing process, toxic metals in the feed soil, such as:
cadmium, lead, etc, are converted into their sulfide forms, therefore making the metals
less toxic (2). Simplot claims that this technology is less susceptible to the effects of
toxic metals than other bioremediation systems.
If the feed soil contains > 1,000 mg/kg of hydrocarbons as measured by EPA Method
418.1 (Total Recoverable Petroleum Hydrocarbons) then the hydrocarbons will be toxic
to the microorganisms (2). However, the cloud point separation technique can be used
to remove the hydrocarbons from soil prior to initiation of the J.R. Simplot
bioremediation technology.
The Simplot system can handle most types of soil, however, pre-processing of the soil
is required prior to feeding it to the bioreactor. This pre-processing may take longer for
soils with a high clay content than for sandy type soils, thus increasing the cost of
remediation. If the soil to be treated contains large rocks or debris, then this larger
fraction must be passed through a soil washing system to remove surface contamination
and separate the fine materials. The washwater and the fines are then added to the
bioreactor for treatment. Alternatively, the larger fraction may be crushed and treated
in the bioreactor.
Treatability studies and, to a limited extent, the Demonstration Test have shown that
continuous mixing of the bioreactor is not required (3). A static system can achieve
acceptable results provided that the soil, water, and carbon source are well-mixed during
loading of the bioreactor.
The J.R. Simplot Ex-Situ Bioremediation Technology was evaluated based on the nine criteria used for
decision-making in the Superfund Feasibility Study (FS) process. Table ES-1 presents the evaluation.
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Table ES-1. Evaluation Criteria for the J.R. Simplot Ex-Situ Bioremediation Technology (page 1 of 2)
Overall Protection of
Human Health and the
Environment
Compliance with
Federal ARARs
Long-Terni•
Effect! veness|aifd
Performance
Short-Term
Effectiveness
Reduction of Toxfcity);
Mobility, or Volume;
through Treatment ;
Provides both short- and long-
term protection by eliminating
exposure to contaminants in
soil.
Prevents groundwutcr
contamination and off-site
migration.
Requires measures to protect
workers and community
during excavation, handling,
and treatment.
Requires compliance with
RCRA treatment, storage, and
land disposal regulations (for
hazardous waste).
Excavation, construction, mid
ope nit ion of on-sitc treatment
unit may require compliance
with location-specific ARARs.
Emission controls are needed
to ensure compliance with air
quality standards if volatile
compounds arc present.
Wustcwuter discharges to
POTW or surface bodies
requires compliance with
Clean Water Act regulations.
Effectively removes
contamination.
Involves wcll-dcinonslruled
technique for removal of
contaminants.
Presents potential short-term
risks to workers and nearby
community, including noise
exposure and exposure to
airborne contaminants (e.g.,
dust, volatile organic
compounds, etc.) released-into
the air during excavation and
handling. These can be
minimized with correct
handling procedures and
borders.
Provides reduction in
conlitminntion levels; duration
of treatment determines final
contaminant levels.
Reduces toxicity and mobility;
of soil contaminants through
treatment.
Does not produce any known
toxic intermediates as a result
of biodegrudulion when
conducted properly.
If not fully dried, increases
volume of treatment material
by addition of water to create
a slurry.
(Continued)
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Table ES-1. Evaluation Criteria for the J.R. Simplot Ex-Situ Bioremediation Technology (page 2 of 2)
Jmplemenlability
Cost
Community Acceptance
State Acceptance
Major equipment is limited to
bioreuctor and agitation/suspension
devices.
Support equipment includes
eajj|moving equipment (for
eicavfltion, screening, and loading of
btoreuctor) and monitoring equipment
(for monitoring pH, redox potential,
and temperature).
Once on-site, the small portable
bioreactor can be assembled and ready
to Joad within two days. The lined
pits, or larger modular bioreactor
requires approximately four days.
After excavation, biorcaclor loading
activities (soil and water) are a
function of treatment volume.
After treatment is complete, the small
bioreactor can be emptied and
demobilized in three days. Treated
soil can be placed in the excavated
area and used as nil material. For
lined pits and erected bioreuclors, the
integrity of the liners can be breached
when treatment is complete, and the
liner abandoned in place.
$127/m3 (S97/yd3) for treatment in
four lined pits, remediating a total of
3,824 mj (5,000 yd3) of soil.
Actual cost is site-specific and
dependent upon: the volume of soil,
soil characteristics, contaminants
present, and original and target
cleanup levels. Cost data presented in
this table are for treating dinoscb- .
contaminated soil similar to the SITE
Demonstration treatment soil. Costs
presented are also based on a 30 day
batch treatment time.
Depending on site characteristics, an
additional cost of up to S131/m3
($IOO/yd3) may be assessed to the
client by the developer for additional
technical assistance, soil nutrients, a
carbon source, and other process
enhancements.
Minimal short-term risks presented to
the community makes this technology
favorable to the public.
Public knowledge of common
bioremedialion applications (e.g.,
wastewater treatment) eases
community acceptance for hazardous
waste treatment using this technology.
Use of naturally-selected
microorganisms makes treatment by
lliis technology a favorable option to
the community.
Low levels of noise exposure may
impact community in the immediate
vicinity.
If remediation is conducted as part of a
RCRA corrective action, Hate
regulatory agencies may require
permits to be obtained before
implementing the system. These may
include a permit to operate the
treatment system, an air emissions
permit (if volatile compounds are
present), a permit to store
contaminated soil for more than 90
days, and a wastewater discharge
permit.
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SECTION 1
INTRODUCTION
This section provides background information about the Superfund Innovative Technology Evaluation
(SITE) Program, discusses the purpose of this Innovative Technology Evaluation Report (ITER), and
describes the J.R. Simplot Ex-Situ Bioremediation Technology. For additional information about the
SITE Program, this technology, and the demonstration site, key contacts are listed at the end of this
section.
1.1 Background
In 1987, the J.R. Simplot Company began working with researchers at the University of Idaho to develop
a process to anaerobically degrade nitroaromatic compounds. In September 1990, the process was
accepted into the SITE Emerging Technologies Program. A treatability study funded by this Program
was performed by the University of Idaho on 9,000 kg (9.9 tons) of soil contaminated with dinoseb. The
results of this treatability study showed that the process could degrade dinoseb from approximately 20
mg/kg to below the analytical detection limit in 15 days. A transient unidentified intermediate was
formed by the process, but the concentration of this intermediate was reduced to near the analytical
detection limit within 45 days (3). In April 1992, the J.R. Simplot Company applied and was accepted
into the SITE Demonstration Program. A full-scale demonstration of the technology was performed at
an airport where the soil was contaminated with dinoseb. This evaluation of the J.R. Simplot Ex-Situ
Bioremediation Technology is based primarily on the results of the SITE Demonstration conducted at the
afore-mentioned airport with supporting information from the bench-scale treatability studies conducted
by the University of Idaho.
The J.R. Simplot Ex-Situ Bioremediation Technology is a simple bioenhancement process that treats soils
contaminated with nitroaromatic compounds by the addition of naturally selected anaerobic soil
microorganisms. The process is initiated under aerobic conditions, but anaerobic conditions are quickly
achieved under designed parameters, thus enabling the microbes to degrade the nitroaromatic
contaminants completely. As claimed by the developer, anaerobic degradation of nitroaromatics by the
J.R. Simplot process takes place without the formation of any known toxic polymerization products.
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1.2 Brief Description of Program and Reports
The SITE Program is a formal program established by the EPA's Office of Solid Waste and Emergency
Response (OSWER) and Office of Research and Development (ORD) in response to the Superfund
Amendments and Reauthorizatton Act of 1986 (SARA). The SITE Program promotes the development,
demonstration, and use of new or innovative technologies to clean up Superfund sites across the country.
The SITE Program's primary purpose is to maximize the use of alternatives in cleaning hazardous waste
sites by encouraging the development and demonstration of new, innovative treatment and monitoring
technologies. It consists of four major elements:
• the Demonstration Program,
• the Emerging Technology Program,
• the Monitoring and Measurement Technologies Program, and
• the Technology Transfer Program.
The objective of the Demonstration Program is to develop reliable performance and cost data on
innovative technologies so that potential users may assess the technology'^ site-specific applicability.
Technologies evaluated are either currently available or close to being available for remediation of
Superfund sites. SITE Demonstrations are conducted on hazardous waste sites under conditions that
closely simulate full-scale remediation conditions, thus assuring the usefulness and reliability of
information collected. Data collected are used to assess: (1) the performance of the technology, (2) the
potential need for pre- and post-treatment processing of wastes, (3) potential operating problems, and (4)
the approximate costs. The demonstrations also allow for evaluation of long-term risks.
The Emerging Technology Program focuses on conceptually proven bench-scale technologies that are in
an early stage of development involving pilot or laboratory testing. Successful technologies are
encouraged to advance to the Demonstration Program.
Existing technologies that improve field monitoring and site characterizations are identified in the
Monitoring and Measurement Technologies Program. New technologies that provide faster, more cost-
effective contamination and site assessment data are supported by this program. The Monitoring and
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Measurement Technologies Program also formulates the protocols and standard operating procedures for
demonstration methods and equipment.
The Technology Transfer Program disseminates technical information on innovative technologies in the
Demonstration, Emerging Technology, and Monitoring and Measurement Technologies Programs through
various activities. These activities increase the awareness and promote the use of innovative technologies
for assessment and remediation at Superfund sites. The goal of technology transfer activities is to develop
interactive communication among individuals requiring up-to-date technical information.
The results of Demonstration Program are published in four basic documents: the SITE Demonstration
Bulletin, the Technology Capsule, the Innovative Technology Evaluation Report (ITER), and the
Technology Evaluation Report (TER). The SITE Demonstration Bulletin provides preliminary results
of the field demonstration. The Technology Capsule provides relevant information on the technology,
emphasizing key features of the results of the SITE field demonstration. The ITER provides detail
information on the technology and the results of the SITE field demonstration. The TER contains the
raw data collected during the field demonstration and provides a quality assurance review of this data.
Both the SITE ITER and TER are intended for use by remedial managers making a detailed evaluation
of the technology for a specific site and waste.
1.3 The SITE Demonstration Program
Technologies are selected for the SITE Demonstration Program through annual requests for proposals.
ORD staff reviews the proposals to determine which technologies show the most.promise of use at
Superfund sites. Technologies chosen must be at the pilot- or full-scale stage, must be innovative, and
must have some advantage over existing technologies. Mobile technologies are of particular interest.
Once the EPA has accepted a proposal, cooperative agreements between the EPA and the developer
establish responsibilities for conducting the demonstration and evaluating the technology. The developer
is responsible for demonstrating the technology at the selected site and is expected to pay any costs for
transport, operations, and removal of the equipment. The EPA is responsible for project planning,
sampling and analysis, quality assurance and quality control, preparing reports, disseminating
information, and transporting and disposing of treated waste materials.
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1.4 Purpose of the Innovative Technology Evaluation Report (ITER)
This ITER provides information on the J.R. Simplot Ex-Situ Bioremediation Technology tor treatment
of dinoseb-contaminated soils and includes a comprehensive description of this demonstration and its
results. The ITER is intended for use by EPA remedial project managers, EPA on-scene coordinators,
contractors, and other decision-makers carrying out specific remedial actions. The ITER is designed to
aid decision-makers in further evaluating specific technologies for further consideration as applicable
options in a particular cleanup operation. This report represents a critical step in the development and
commercialization of a treatment technology.
To encourage the general use of demonstrated technologies, the EPA provides information regarding the
applicability of each technology to specific sites and wastes. The ITER includes information on cost and
site-specific characteristics. It also discusses advantages, disadvantages, and limitations of the technology.
Each SITE Demonstration evaluates the performance of a technology in treating a specific waste. The
waste characteristics of other sites may differ from the characteristics of the treated waste. Therefore,
a successful field demonstration of a technology at one site does not necessarily ensure that it will be
applicable at other sites. Data from the field demonstration may require extrapolation for estimating the
operating ranges in which the technology will perform satisfactorily. Only limited conclusions can be
drawn from a single field demonstration.
1.5 Technology Description
The J.R. Simplot Ex-Situ Bioremediation Technology is designed to destroy nitroaromatic compounds
without forming any toxic intermediate compounds. The theory of operation behind the Simplot
technology is that soils contaminated with nitroaromatic compounds may be treated using an anaerobic
consortium. A consortium may be defined as a group of different populations of microorganisms in close
association that form a community structure with a certain symbiosis or interrelationship. Each
population contributes to the general welfare of the group. An anaerobic consortium is a group of
different populations of microorganisms that symbolically exist without oxygen. Studies have found that
anaerobiosis with redox potential less than -100 mV promotes the establishment of an anaerobic microbial
consortium that degrades nitroaromatic compounds completely (1). Under aerobic or microaerophilic
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conditions, degradation of nitroaromatic compounds may form polymerization products that are potentially
toxic. Anaerobic degradation of nitroaromatics using the J.R. Simplot technology takes place without the
formation of these polymerization products.
Execution of the Simplot bioremediation technology is carried out by mixing a carbon source (a J.R.
Simplot Company potato-processing by-product) with contaminated soil and then adding water and buffers
to create a slurry. This prompts aerobic microorganisms to consume oxygen, thus creating anaerobic
conditions in the treatment slurry. These conditions subsequently stimulate anaerobic microorganisms
to consume toxins present in the slurry. The appropriate microorganisms are often indigenous to the
treatment soil, however, treatment soils may also be inoculated with the necessary consortium to enhance
degradation rates. For small soil volumes (less than 31 m3), treatment may take place in small, mobile
bioreactors. For larger soil volumes, treatment may take place in large modular bioreactors or lined pits.
Section 4.2 provides the specific details of the process design used during the Demonstration Test.
Section 4.3 discusses the methodology behind the treatment and testing performed.
1.6 Key Contacts
Additional information on the J.R. Simplot Ex-Situ Bioremediation Technology and the SITE Program
can be obtained from the following sources:
The J.R. Simplot Ex-Situ Bioremediation Technology
Technical:
Russ Kaake, PhD
J.R. Simplot Company
P.O. Box 912
Pocatello, ID 83201
Phone: 208/234-5367
Fax: 208/234-5339
Marketing:
Tom Yergovich
J.R. Simplot Company
P.O. Box 912
Pocatello, ID 83201
Phone: 208/238-2850
Fax: 208/238-2760
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The SITE Program
Robert A. Olexsey, Director
Superfund Technology Demonstration Division
U.S. Environmental Protection Agency
26 West Martin Luther King Drive
Cincinnati, Ohio 45268
Phone: 513/565-7861
Fax: 513/565-7620
Wendy Davis-Hoover, PhD
EPA SITE Technical Project Manager
U.S. Environmental Protection Agency
5995 Center Hill Avenue
Cincinnati, Ohio 45268
Phone: 513/569-7206
Fax: 513/569-7879
Information on the SITE Program is available through the following on-line information clearinghouses:
• The Alternative Treatment Technology Information Center (ATTIC) System (operator:
301/670-6294) is a comprehensive, automated information retrieval system that integrates
data on hazardous waste treatment technologies into a centralized, searchable source.
This data base provided summarized information on innovative treatment technologies.
• The Vendor Information System for Innovative Treatment Technologies (VISITT)
(hotline: 800/245-4505) data base currently contains information on approximately 231
technologies offered by 141 developers.
• The OSWER CLU-In electronic bulletin board contains information on the status of SITE
technology demonstrations. The system operator can be reached at 301/585-8368.
Technical reports may be obtained by contacting the Center for Environmental Research Information
(CERI), 26 West Martin Luther King Drive in Cincinnati, Ohio, 45268 at 513/569-7562.
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SECTION 2
TECHNOLOGY APPLICATIONS ANALYSIS
This section of the report addresses the general applicability of the J.R. Simplot Ex-Situ Bioremediation
Technology to contaminated waste sites. The analysis is based primarily on this SITE Demonstration,
and conclusions are based extensively on these data since only limited information is available on other
applications of the technology. This SITE Demonstration was conducted on soil contaminated with
dinoseb (2-$ec-butyl-4,6-dinitrophenol). A companion SITE Demonstration of this technology is being
performed on soil contaminated with TNT (2,4,6-trinitrotoluene), and another Innovative Technology
Evaluation Report will be provided at a later date.
2.1 Key Features of the J.R. Simplot Ex-Situ Bioremediation Technology
The J.R. Simplot Ex-Situ Bioremediation Technology has several unique features that distinguish it from
most bioremediation technologies. Bioremediation using this technology is anaerobic. The anaerobic
consortium used for degradation of nitroaromatic compounds is a consortium that has been naturally
selected, and not genetically engineered. For the Demonstration Test, the necessary microorganisms were
indigenous to the local soil.
Initially, consumption of oxygen by aerobic microorganisms is promoted by the addition of a carbon
source. This carbon source is a J.R. Simplot Company potato-processing by-product. This potato starch
mixture is made up of 42% solids: 215 mg of starch per gram; 6.7 mg of total nitrogen per gram;
2.6 x 104 culturable heterotrophic bacteria per gram; and 8 x 103 culturable amolytic bacteria per gram.
This starch by-product is normally discarded by the potato-processing industry, but in this case is
beneficially utilized by the bioremediation system. The potato-processing by-product was used as a
carbon source for the purpose of this demonstration because it was readily available to the J.R. Simplot
Company. Any other carbon source may also be used but only this specific starch was used during
treatability studies.
The degradation of dinoseb using this bioremediation technology is not as temperature dependent as other
biological systems. Optimal temperatures for dinoseb degradation using the Simplot Process are 35 to
37°C. Despite average slurry temperatures of 18°C during the Demonstration Test, the Simplot Process
11
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was still able to degrade dinoseb to below the analytical detection limit in less than 23 days. However,
the degradation rate can be restricted if freezing conditions exist. This problem can be overcome by
adding heaters to the system, but at an additional cost to the remediation. The temperature dependence
of degradation of other nitroaromatic compounds has not yet been determined for comparison with other
biological systems.
The Best Demonstrated Available Technology (BDAT) for dinoseb-contaminated soil is incineration. The
destruction and removal efficiency (DRE) for incineration is > 99.99%. This Demonstration Test has
shown that treatment by the J.R. Simplot Ex-Situ Bioremediation Technology can attain >99.8%
removal. Removal efficiency was determined based upon remediation of the treated soil to levels below
the analytical detection limits. Treatment by bioremediation may be more time-consuming than
incineration since the amount of contamination that is biologically degraded is a function of time,
however, any alternative technology that can economically compete with incineration is of interest to
remedial managers.
The J.R. Simplot Ex-Situ Bioremediation Technology is a cost-effective treatment method. The cost
associated with this technology for biodegradation of dinoseb is approximately $127/m3 ($97/yd3) for
3,824 m3 (5,000 yd3) of soil treated in four lined pits. This cost is based on a 30 day batch treatment
time. It does not include expenditures incurred for excavating the dinoseb-contaminated soil. The J.R.
Simplot Company may also impose a cost of up to $131/mJ ($100/yd?) to these estimated costs. This
additional cost is dependent on site characteristics and is used for additional technical assistance, soil
nutrients, and other process enhancements provided by the developer. The total costs for treatment using
the J.R. Simplot Ex-Situ Bioremediation Technology are substantially lower than costs for other
technologies suitable for the destruction of dinoseb.
2.2 Technology Performance versus ARARs during the Demonstration
Federal and state applicable or relevant and appropriate regulations (ARARs) for the J.R. Simplot Ex-Situ
Bioremediation Technology are presented in Table 2-1. The performance of the technology during the
Demonstration Test with respect to ARARs is discussed below.
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Table 2-1. Federal and State ARARs for the J.R. Simplot Ex-Situ Bioremediation Technology (page 1 of 3)
Process Activity ARAR
Description
Basis
Response
Waste characterization
(untreated waste)
RCRA 40 CFR Part 261
or state equivalent
TSCA 40 CFR Part 761
or state equivalent
Standards that apply to identification
and characterization of waste to be
treated
Standards that apply to the treatment
and disposal of wastes containing
PCBs
A requirement of RCRA prior to
managing and handling the waste
During waste characterization, PCBs
may be identified in contaminated
soil, and arc therefore subject to
TSCA regulations
Chemical and physical analyses
must be performed.
Chemical and physical analyses
must be performed. If PCBs are
identified, soils will be managed
according to TSCA regulations.
Soil excavation
Clean Air Act 40 CFR
50.6, and 40 CFR 52
Subpart K or state
equivalent
RCRA 40 CFR Part 262
or slate equivalent
Regulations governing the
inunitgctnenl of toxic pollutants and
particulale matter in the air
Fugitive air emissions may occur
during excavation and material
handling and transport
Standards that apply to generators of Soils lire excavated for treatment
hazardous waste
If necessary, the waste material
should be watered down or covered
to eliminate or minimize dust
generation.
If possible, soils should be fed
directly into the bioreuctor for
treatment.
Storage prior to
processing
RCRA 40 CFR Part 264 Standards applicable to the storage
or state equivalent . of hazardous waste
Excavation and prc-lrcatment
screening may generate hazardous
wastes that ir.ua! be stored in waste
piles
If stored in a waste pile, the
material should be placed on and .
covered with plastic, and secured to
minimize fugitive air emissions and
volatilization. The time between
excavation and treatment (or
disposal if material is unsuitable for
treatment) should be minimized.
Waste processing
RCRA 40 CFR Part 254
or state equivalent
Standards applicable to the treatment
of hazardous waste at pcnnitlcd and
interim status facilities
Treatment of hazardous waste must
be conducted in u manner that meets
the operating and monitoring
requirements; the treatment process
may occur in u small, portable
biorcactor or in a large, constructed
biorcactor.
Equipment must be maintained
daily. Integrity of bioreaclor must
be monitored and maintained to
prevent leakage or failure. If
treatment standards are not met, the
bioreactor must be decontaminated
when processing is complete.
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Table 2-1. Federal and State ARARs for the J.R. Simplot Ex-Situ Bioremediation Technology (page 2 of 3)
Process Activity ARAR
Description
Basis
Response
Storage after processing
RCRA 40 CFR Part 264
or slate equivalent
Standards that apply to the storage
of hazardous waste
The treated material will remain in
the biorcactor until it has been
characterized and a decision on final
disposition tins been made.
Oversize material unsuitable for
processing may be stored in a waste
pile.
Biorcactors must continue to be
well-maintained. If stored in a
waste pile, oversize material should
be placed on and covered with
plastic, and tied down to minimize
fugitive emissions and volatilization.
The material should be disposed of
or otherwise treated as soon as
possible.
Waste characterization
(treated waste)
RCRA 40 CFR Part 261
or stale equivalent
TSCA 40 CFR Part 761
or stale equivalent
Standards ihnt apply to waste
characteristics
Standards thai apply to the treatment
and disposal of wastes containing
PCBs
A requirement of RCRA prior to
managing and handling the waste; it
must be determined if treated
material is RCRA hazardous waste.
Treated wastes may still contain
PCBs
Chemical and physical analyses
must be performed on treated wastes
and on oversize material prior to
disposal.
Chemical and physical analyses
must be performed on treated wastes
and on oversize material prior to
disposal. A proper disposal method
must be selected if PCBs arc found.
On-siic/off-sitc disposal
RCRA 40 CFR Part 264
or state equivalent
Standards that apply to landfilling
hazardous waste
TSCA 40 CFR Part 761
or state equivalent
Standards that restrict the placement
of PCBs in or on the ground
Treated wastes and/or oversize
material may still contain
contaminants in levels above
required cleanup action levels and
therefore be subject to LORs
Treated wastes and/or oversize
material containing less than SO ppm
PCBs may be lundfillcd or
incinerated. Treated wastes and/or
oversize greater than 50 ppm must
be incinerated.
Treated wastes and/or oversize
material still defined as hazardous
must be disposed of at a permitted
hazardous waste facility, or approval
must be obtained from the lead
regulatory agency to dispose of the
wastes on-site.
If untreated wastes contained PCBs,
then treated wastes and oversize
material should be analyzed for PCB
concentration. Approved PCB
landfills or incinerators must be
used for disposal.
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Table 2-1. Federal and State ARARs for the J.R. Simplot Ex-Situ Bioremediation Technology (page 3 of 3)
Process Activity ARAR
Description
Basis
Response
On-sile/off-site disposal
(continued)
RCRA 40 CFR Part 268
or state equivalent
SARA Section I21(d)(3)
Standards that restrict the placement
of certain wastes in or on the
ground
Requirements for the off-site
disposal of wastes from a Superfund
site
The nature of the waste may be
subject to the LDRs
The waste is being generated from a
response action authorized under
SARA
The waste must be characterized to
determine if the LDRs apply. If so,
waste must be handled in
accordance with LDRs.
Wastes must be disposed of at a
RCRA-pcrmitted hazardous waste
facility.
Transporttilion for off-
site disposal
RCRA 40 CFR Part 262
or state equivalent
RCRA 40 CFR Part 263
or stale equivalent
Manifest requirements and
packaging and labelling
requirements prior to transporting
Transportation standards
The treated waste and/or oversize
material may need to be manifested
and managed as a hazardous waste
Treated wastes and/or oversize
material mny need to be transported
as hazardous wastes
An identification (ID) number must
be obtained from EPA.
A transporter licensed by EPA must
be used to transport the hazardous
waste according to EPA regulations.
Wuslcwatcr discharge
Clean Water Act 40
CFR Parts 301, 304,
306. 307, 308, 402, and
403
Standards that apply to discharge of
wustewatcr into POTWs or surface
water bodies
The wastewatcr may be a hazardous
waste
Determine if wastewater could be
directly discharged into a POTW or
surface water body. If not, the
wastewater may need to be further
treated to meet discharge
requirements by conventional
processes. An NPDES permit may
be required for discharge to surface
waters
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Prior to treatment, the soil was characterized by performing chemical and physical analyses. The
treatment soil was analyzed for dinoseb, pesticides, chlorinated herbicides, and metals. Tests were also
performed to characterize the soil type; particle size distribution and Atterberg limits of the soil were
determined. The soil was found to contain dinoseb, a RCRA-listed waste (P020), and high levels of other
pesticides and herbicides including 2,6-dichloro-4-nitroaniline (nitroaniline); atrazine; and technical
chlordane. Low levels of malathion; parathion; endosulfan; and 4,4'-DDT were also detected. The soil
was classified as a clayey sand with gravel. The results of these analyses indicated that, because it was
RCRA-listed, the soil was subject to RCRA regulations. (Only soils that are defined as hazardous by
bearing a RCRA characteristic or RCRA listing are subject to RCRA regulations). Because of the
dinoseb contamination, the soil was also classified as an extremely hazardous soil according to the
Washington State Department of Ecology (WAC 173-303-9903). The soil did not contain PCBs, and
therefore the ARARs pertaining to materials contaminated with PCBs were not applicable to this situation.
It is unlikely that soil with PCB contamination would be treated by the J.R. Simplot Ex-Situ
Bioremediation Technology because PCBs are not amenable to remediation by this technique.
During excavation, the soil was watered down to minimize dust generation. No volatile contaminants
were present in the treatment soil, therefore, volatile air emissions were not a concern during excavation.
Although it was not possible to feed the soils directly into the bioreactor because of the logistical
considerations associated with sampling during the Demonstration Test, the stockpiled excavated soil was
kept covered with plastic and fed to the bioreactor as soon as it was sampled. During normal operation
of the J.R. Simplot Ex-Situ Bioremediation Technology, it is anticipated that excavated soils may be
screened, and then homogenized with the carbon source and fed directly into the bioreactor. In the
future, Simplot will mix the carbon source directly with the slurry water before soil addition.
Before it was fed into the bioreactor, the Demonstration Test soil was screened to remove rocks and other
debris greater than 12.7 mm (0.5 in) in diameter. Because dinoseb is water-soluble, this oversize fraction
was rinsed with water to remove surface contamination. The oversize material was kept covered prior
to the rinsing activities. In cases where a large portion of oversize material is present, a separate soil or
rock washing technology may be used to treat this fraction. In some cases, it may be possible to crush
the rocks and then feed them into the bioreactor. It should be noted that, although soil or rock washing
reduces the volume of contaminated material, waste requiring further treatment or disposal will remain.
In some cases, the contaminated material resulting from soil or rock washing may be treated by the J.R.
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Simplot Ex-Situ Bioremediation Technology, If stored in a waste pile, the oversize material must be kept
covered. If treated by a separate technology, the length of time that the oversize material is stored before
treatment must be minimized.
Treatment of the Demonstration Test soil took place in a bioreactor that was maintained on a regular
basis. The integrity of the bioreactor was monitored and maintained to prevent leakage or failure.
Once treatment was complete, the post-treatment slurry was sampled and analyzed for dinoseb, pesticides,
and chlorinated herbicides. According to a case-specific ruling by the Washington State Department of
Ecology (WADOE), the soil was no longer considered to be hazardous if dinoseb levels were reduced
below the specified cleanup objective. The results of the analyses indicated that dinoseb in the post-
treatment slurry was below the analytical detection limit;; and below the cleanup objective specified by
the WADOE, therefore, the post-treatment slurry was not handled as hazardous waste.
The treated material remained in the bioreactor until the results of post-treatment analyses were obtained
and verified. The integrity of the bioreactor continued to be monitored and maintained. The treatment
slurry was pumped from the bioreactor without the need for decontamination based on analytical results.
In cases where the cleanup objective is not met, the bioreactor must be decontaminated when processing
is complete. Oversize material that was excavated and rinsed during the Demonstration Test was stored
in a waste pile to be used as fill. Oversize material that was excavated but not rinsed was stored in a
waste pile on top of plastic liners. The pile was also covered with plastic and tied down. This material
will be cleaned by a rock or soil washing technique with the washwater being remediated at a later date.
Alternatively, the material may be correctly disposed of at a permitted facility.
Using a conservative approach, personal protective equipment and debris contaminated during the
Demonstration Test were handled as hazardous waste. An EPA identification number was obtained and
the waste was transported (accompanied by a hazardous waste manifest) by a licensed transporter to a
RCRA-permitted facility for disposal. The oversize traction, if not treated on-site, must be transported
off-site for treatment or for disposal at a RCRA-permitted facility, Wastewater generated during the
demonstration was suitable tor discharge into the local sewage treatment plant.
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2.3 Operability of the Technology
The J.R. Simplot Ex-Situ Bioremediation Technology is a simple system. The system consists solely of
the bioreactor equipped with agitation/suspension devices and monitoring equipment. Support equipment
is only required to excavate, screen, and homogenize the soil and to load the bioreactor prior to
treatment. During treatment, support equipment is not required. Small, portable bioreactors are mobile
and operated by trained personnel. Large, modular bioreactors or lined pits may be erected on-site with
minimal effort. The system may operate unattended for several days at a time, if necessary. The
bioreactor appeared to be free of operational problems during the demonstration in Ellensburg,
Washington.
Several operating parameters influence the performance of the J.R. Simpiot Ex-Situ Bioremediation
Technology. These parameters are-continually monitored. The technology is dependent on pH, redox
potential, and temperature. The pH must be regulated by .the addition of acids and/or phosphate buffers.
For this Demonstration Test, monobasic potassium phosphate and 45.8 kg (100.7 Ibs) of 182.75 kg
(402.05 Ibs) of dibasic potassium phosphate were used. These buffers were selected based upon previous
treatability studies conducted on the Bowers Field soil. Based on a limited parametric study, it appears
that the preferred pH range for dinoseb degradation is between 7.5 and 8.0 (I), However, wide
variations in the pH of the slurry at the outset of treatment during the demonstration (i.e., pH as low as
6.2 in the solid phase and as high as 10.5 in the liquid phase) did not seem to adversely affect the
behavior of the consortium. Small amounts of sulfuric acid were added to the system at various intervals
to correct the pH. The total quantity of sulfuric acid added was not recorded since the quantities were
minor. Anaerobic conditions suitable for the microorganisms that are capable of degrading dinoseb exist
when the redox potential is less than -100 mV (I). These anaerobic conditions are achieved when aerobic
microorganisms consume oxygen from the soil and lower the redox potential. The treatment slurry
should be mildly agitated to keep the solid fraction in suspension during treatment. This enables the
contaminant to pass to the liquid phase. Rigorous mixing should not be performed to avoid aerating the
slurry and recreating aerobic conditions. Treatability studies have shown that continuous mixing is not
required (3). A static system is known to achieve acceptable results when the soil, water, and carbon
source are well-mixed during loading of the bioreactor. Temperature is a third parameter that may
influence the performance of the J.R. Simplot Ex-Situ Bioremediation Technology. During the parametric
study mentioned above, it was also found that a suitable operating temperature is between 35 and
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37°C (1). Successful treatment was achieved however, in 23 days during the Demonstration Test with
bioreactor temperatures at an average of 18°C.
During the demonstration, excavated soil was screened to separate rocks and debris greater than 12.7 mm
(0.5 in) in diameter. The screening process was much more time consuming than originally anticipated,
partially due to inappropriately sized equipment. Additionally, rinsing of the resulting oversize fraction
was not completed because of poor equipment selection and difficulties in operation. The pug mill
utilized for homogenization of the pre-treatment soil and the J.R. Simplot Company potato-processing
by-product was undersized and proved to be a significant impediment to efficient mixing operations. This
portion of treatment (screening, rinsing, and homogenization) was highly labor intensive. Important
knowledge and experience about full-scale operations were gained during the Demonstration Test.
To determine the amount of soil treated, the volume of the excavated soil may be measured
geometrically, or the volume of soil fed into the bioreactor may be determined by counting the number
of loads deposited onto the conveyor. Both techniques were employed during the SITE Demonstration.
To determine the amount of water added, the volume of water in the bioreactor may be measured
geometrically before the addition of any soil, or the volume of water fed into the bioreactor may be
determined by using a totalizing flowmeter. Again, both techniques were employed during the SITE
Demonstration. This information is required to ensure that a correct ratio of soil to water is established
and maintained in the treatment slurry. Accurate measurements of these quantities were also required
during the Demonstration Test to facilitate calculations for the dinoseb concentration in the treatment
slurry.
2.4 Applicable Wastes
The J.R. Simplot Ex-Situ Bioremediation Technology is suitable for soils and liquids contaminated with
dinoseb. The medium to be treated must be free of toxic metals or any other compounds that may be
detrimental to the appropriate microorganisms (e.g., hydrocarbons). To date, the levels of toxic metals
that affect this technology have not been determined. Simplot claims that the presence of heavy metals
in the feed soil will not adversely affect the process. Since this technology is a sulfate reducing process,
toxic metals in the feed soil, such as: cadmium, lead, etc are converted into their sulfide forms. This
makes the metals innocuous. Simplot claims that this process is less susceptible to the effects of toxic
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metals than other bioremediation systems. J.R. Simplot claims that greater than 1,000 ppm of total
recoverable petroleum hydrocarbons (TRPH) is considered toxic to the microorganisms (2). Although
high levels of hydrocarbons may inhibit the performance of the microorganisms, the hydrocarbons can
be removed from the soil prior to bioremediation by using a cloud-point separation technique. This
technique incorporates the addition of a surfactant/water solution to the waste. Heat aids the separation
of the organic phase from the aqueous phase, and gravity aids the separation of the solid phase. The
hydrocarbon waste stream generated by this technique must be treated using an alternate technology or
disposed of at a permitted facility. The J.R. Simplot Ex-Situ Bioremediation Technology has been
demonstrated on dinoseb (2-jec-butyl-4,6-dinitrophenol). It is also being demonstrated on another
nitroaromatic compound, TNT (2,4,6-trinitrotoluene), in a separate SITE Demonstration.
Simplot claims that any soil type can be treated, provided that the soil (or liquid) is thoroughly mixed
with the carbon source (J.R. Simplot Company potato-processing by-product). The soil itself need not
contain the microorganisms necessary to degrade the contaminants since the bioreactor can be inoculated
with the appropriate microorganisms. These microorganisms can be obtained from previous site
remediations or treatability studies. If the soil to be treated contains large rocks or debris, then this larger
t
fraction must be passed through a soil washing system to remove surface contamination and separate the
fine material. The washwater and the fines may subsequently be treated in the bioreactor. Alternatively,
the larger fraction may be crushed to an appropriate size and then fed into the bioreactor. During the
Demonstration Test, the soil was screened at 12.7 mm (0.5 in) diameter. However, Simplot claims that
rocks and debris up to 38.1 mm (1.5 in) diameter can be remediated. Soil washing of the oversize
fraction was attempted by Simplot during the Demonstration Test. Because of inadequate equipment and
lack of pertinent experience, the soil washing operations were not completed as part of the demonstration.
For future operations, it is anticipated that, if required, this portion of treatment will be performed by
an independent rock or soil washing vendor.
2.5 Availability and Transportability of Equipment
Currently, the J.R. Simplot Company does not own any bioreactors, but rents and modifies mobile tanks
to accommodate small-scale treatment. The small, portable tanks are wheel-mounted and can be
transported by licensed haulers. For large-scale treatment where the treatment volume exceeds 31 m3 (40
yd3), modular, fabricated tanks or lined pits are likely to be used. The large tanks are bolted together
20
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on-site and rented on a case-by-case basis, the lined pits are excavated on-site. Each large tank or lined
pit can treat up to 956 m3 (1,250 yd3) of soil. If the treatment volume exceeds 956 m3, multiple tanks
or lined pits can be used simultaneously. Agitation/suspension devices (mixers) and monitoring
equipment can easily be transported by freight. Support equipment may be obtained locally and
transported to the site by freight. Once all the equipment is on-site, the small portable system can be
assembled in approximately two days. The larger erected tanks or lined pits can be assembled in four
to six days.
Demobilization activities include emptying the bioreactor, decontaminating on-site equipment (if
necessary), disconnecting utilities, disassembling equipment, and transporting equipment off-site.
Demobilization requires approximately three days for the small portable bioreactor. For the larger
erected tanks or lined pits, the bioreactor can be emptied by breaching the integrity of the liner and
removing the walls of erected tanks or by abandoning the lined pits in place.
2.6 Materials Handling Requirements
Before treatment can commence, the soil must be excavated, staged, screened, homogenized with the J.R.
Simplot Company potato-processing by-product, and loaded into the bioreactor. Soils should be kept
moist if fugitive emissions or airborne particulates are expected. If present in the soil, most VOCs will
volatilize into the atmosphere unless strict preventative measures are undertaken. These measures may
include covering the excavated material and/or operating in an enclosed environment. At sites where
VOCs are the primary contaminants, treatment by the J.R. Simplot Ex-Situ Bioremediation Technology
is not recommended.
When the treatment soil contains large rocks or other debris, it must be passed through a vibrating screen
(or other size-separating device) to remove the oversize material. Large clumps of soil which pass
through the screen must also be broken apart to increase the surface area and thereby increase the number
of sites available for attack by the microorganisms. The oversize fraction may be crushed or washed on-
site using a separate rock or soil washing technology. The waslvwater generated by soil washing may be
treated in the bioreactor. If not treated by an alternate technology on-site, the oversize material must be
transported off-site for treatment or proper disposal at a permitted facility.
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At some sites, water may be available from the facility or from a local water source. At remote
locations, water may need to be transported, to the site in water trucks. For treatment of 30 m3 (39 yd3)
in a 75,700-L (20,000-gal) portable bioreactor, approximately 29,000 L (7,650 gal) of water are required.
For large-scale treatment, the volume of water required will vary and is based on the amount of soil
treated and the composition of the soil. In either case, approximately one liter (0.26 gal) of water is
required for each kilogram (2.2 Ib) of soil treated.
The J.R. Simplot Company potato-processing by-product that is mixed with the treatment soil as a carbon
source for the microorganisms is generally transported to the site in 208-L (55-gal) drums or,
alternatively, in a tanker truck. When stored for extended periods of time or when exposed to heat, the
J.R. Simplot Company potato-processing by-product begins to naturally ferment, causing an increase in
pressure inside the drums. When handling this material, particularly when opening the drums, strict
precautions must be followed to avoid ruptures of the J.R. Simplot potato-processing starch by-product
drums. Drum lids may be pierced to provide an escape route for gases that build up during fermentation.
The size of the hole should be minimized to control the release of foul odors associated with
fermentation.
The treated slurry is pumped from the bioreactor at the conclusion of successful treatment. Wastewater
with few suspended solids may be discharged into a publicaUy owned treatment works (POTW) or a
surface water body. The remaining sludge can be pumped into lined pits for evaporation of the liquid
phase with the dried product being used as fill material.
2.7 Range of Suitable Site Characteristics
Locations suitable for on-site treatment using the J.R. Simplot Ex-Situ Bioremediation Technology must
be able to accommodate utilities, support facilities, and support equipment. These requirements are
discussed below.
Utilities required for the Simplot bioremediation system are limited to water and electricity. For
treatment using a bioreactor, water is needed to create a treatment slurry in the bioreactor. As mentioned
above, approximately one liter (0.26 gal) of water is required for each kilogram (2.2 Ib) of soil added
to the reactor. Water is also required for cleanup and decontamination activities, if necessary. The J.R.
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Simplot Ex-Situ Bioremediation Technology requires a three-phase 480-voIt electrical circuit to power
the agitators, and screening and homogenization equipment. The current needed is a Function of the size
of the equipment. Additional power is required for on-site office trailers, if present. Compressed air
may be required if the bioreactor is to be lanced. During the demonstration, the bioreactor was lanced
by placing the suction end of a diaphragm pump into the settled sediment and pumping the sediment into
a more well-mixed region of the bioreactor.
Support facilities include a contaminated soil staging area, a treated slurry storage area, a drum storage
area, and an office area. The treated slurry that is generated must be stored in soil piles or in cleared
areas and allowed to dry before it is suitable for use as clean fill. Drums containing nutrients (J.R.
Simplot Company potato-processing starch by-product) and waste personal protective equipment (PPE)
must be stored in a drum storage area. In addition, a tank storage area to store water and wastewater
may be required at some sites. These support facilities must be contained to control run-on and run-off.
Mobile trailers may be used as office space on-site. These office trailers must be located outside the
treatment area.
Support equipment tor the J.R. Simplot bioremediation system includes earth-moving equipment,
conveyor belts, a vibrating screen (or other size-separating device), and homogenization equipment.
Earth-moving equipment (including backhoes, front-end loaders, and bobcats) is needed to excavate and
move soils. Earth-moving equipment is also needed to load soils onto the vibrating screen and the
conveyor belts. Conveyor belts are required to move the screened soil into the homogenization equipment
and the bioreactor. The vibrating screen is used to remove large rocks and other debris, and the
homogenization equipment is utilized to blend the nutrients into the soil (if not blended with the water)
before treatment. A container for wastewater (if not discharged into the sewer) may also be necessary.
2.8 Limitations of the Technology
According to the developer, the scope of contaminants suitable for treatment using the J.R. Simplot Ex-
Situ Bioremediation Technology is limited to nitroaromatic compounds. This SITE Demonstration was
conducted to evaluate the performance of the technology with respect to dinoseb only. The behavior of
other compounds was noted during the demonstration, and therefore data regarding the degradation (or
lack of degradation) of these compounds are also presented in this report.
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It has been established that high levels of hydrocarbons are toxic to the microorganisms necessary for
biodegradation of nitroaromatic compounds. However, by using a cloud-point separation technique prior
to bioremediation, hydrocarbons can be removed from the soil. When using the cloud-point separation
technique, surfactant and water are added to the waste in designated proportions, and the mixture is
subjected to heat. This allows the organic phase to separate from the aqueous phase (containing the
dinoseb contamination), while the solid phase simply separates by gravity. This technique produces an
additional organic waste stream that must be treated by a separate technology or disposed of at a
permitted facility.
The presence of heavy metals in the feed soil does not adversely affect the process. As this technology
is a sulfate reducing process, toxic metals in the feed soil, such as: cadmium, lead, etc, are converted
into their sulfide forms, therefore making the metals less toxic (2). Simplot claims that this technology
is less susceptible to the effects of toxic metals than other bioremediation systems.
Because the performance of the technology is temperature-sensitive, cold climates may adversely affect
the rate of biodegradation. This was not a significant consideration during treatment in Ellensburg,
Washington when temperatures were approximately at 18°C, below that considered optimal by the
parametric study (1), but other tests have indicated that treatment with operating temperatures
substantially below the 35 to 37°C range slows the rate of degradation, as expected. At an additional
cost, heaters may be installed to compensate for cold temperatures.
The execution of this technology may be limited by the availability of tanks for use as bioreactors. This
limitation can be overcome by purchasing or fabricating bioreactors as required. For large-scale
treatment, space requirements may also restrict the use of this technology.
2.9 ARARS For the J.R. Simplot Ex-S5tu Bioremediation Technology
This subsection discusses specific federal environmental regulations pertinent to the operation of the J.R.
Simplot Ex-Situ Bioremediation Technology including the transport, treatment, storage, and disposal of
wastes and treatment residuals. These regulations are reviewed with respect to the demonstration results.
State and local regulatory requirements, which may be more stringent, must also be addressed by
remedial managers. Applicable or relevant and appropriate requirements (ARARs) include the following:
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(1) the Comprehensive Environmental Response, Compensation, and Liability Act; (2) the Resource
Conservation and Recovery Act; (3) the Clean Air Act; (4) the Safe Drinking Water Act; (5) the Toxic
Substances Control Act; and (6) the Occupational Safety and Health Administration regulations. These
six genera! ARARs are discussed below; specific ARARs that may be applicable to the J.R. Simplot Ex-
Situ Bioremediation Technology are identified in Table 2-1.
2.9.1 Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA)
The CERCLA of 1980 as amended by the Superfund Amendments and Reauthorization Act (SARA) of
1986 provides for federal funding to respond to releases or potential releases of any hazardous substance
into the environment, as well as to releases of pollutants or contaminants that may present an imminent
or significant danger to public health and welfare or to the environment.
As part of the requirements of CERCLA, the EPA has prepared the National Oil and Hazardous
Substances Pollution Contingency Plan (NCP) for hazardous substance response. The NCP is codified
in Title 40 Code of Federal Regulations (CFR) Part 300, and delineates the methods and criteria used to
determine the appropriate extent of removal and cleanup for hazardous waste contamination.
SARA states a strong statutory preference for remedies that are highly reliable and provide long-term
protection and directs EPA to do the following:
• use remedial alternatives that permanently and significantly reduce the volume, toxicity,
or mobility of hazardous substances, pollutants, or contaminants;
• select remedial actions that protect human health and the environment, are cost-effective,
and involve permanent solutions and alternative treatment or resource recovery
technologies to the maximum extent possible; and
• avoid off-site transport and disposal of untreated hazardous substances or contaminated
materials when practicable treatment technologies exist [Section 121(b)].
In general, two types of responses are possible under CERCLA: removal and remedial action. The J.R.
Simplot Ex-Situ Bioremediation Technology is likely to be part of a CERCLA remedial action. Between
1986 and 1992, ex-situ biorernediation technologies were selected with increasing frequency as source
control remedies at 33 Superfund sites (4).
25
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Remedial actions are governed by the SARA amendments to CERCLA. As stated above, these
amendments promote remedies that permanently reduce the volume, toxicity, and mobility of hazardous
substances, pollutants, or contaminants. When using the J.R. Simplot Ex-Situ Bioremediation
Technology, the total volume of material undergoing treatment is increased because water is added to the
contaminated soil to provide a treatment slurry. Even so, the volume of identified contaminants in the
soil is reduced by biological degradation of these compounds. Some biodegradation processes form toxic
intermediates which were not previously present in the contaminated media. The J.R. Simplot Ex-Situ
Bioremediation Technology anaerobically degrades nitroaromatic contaminants without the formation of
known toxic intermediates, and thus reduces the volume, toxicity, and mobility of the contaminants.
On-site remedial actions must comply with federal and more stringent state ARARs. ARARs are
determined on a site-by-site basis and may be waived under six conditions: (1) the action is an interim
measure, and the ARAR will be met at completion; (2) compliance with the ARAR would pose a greater
risk to health and the environment than noncompliance; (3) it is technically impracticable to meet the
ARAR; (4) the standard of performance of an ARAR can be met by an equivalent method: (5) a state
ARAR has not been consistently applied elsewhere; and (6) ARAR compliance would not provide a
balance between the protection achieved at a particular site and demands on the Superfund for other sites.
These waiver options apply only to Superfund actions taken on-site, and justification for the waiver must
be clearly demonstrated.
2.9.2 Resource Conservation and Recovery Act (RCRA).
RCRA, an amendment to the Solid Waste Disposal Act (SWDA), is the primary federal legislation
governing hazardous waste activities and was passed in 1976 to address the problem of how to safely
dispose of the enormous volume of municipal and industrial solid waste generated annually. Subtitle C
of RCRA contains requirements for generation, transport, treatment, storage, and disposal of hazardous
waste, most of which are also applicable to CERCLA activities. The Hazardous and Solid Waste
Amendments (HSWA) of 1984 greatly expanded the scope and requirements of RCRA.
RCRA regulations define hazardous wastes and regulate their transport, treatment, storage, and disposal.
These regulations are only applicable to the J.R. Simplot Ex-Situ Bioremediation Technology if RCRA-
defined hazardous wastes are present. If soils are determined to be hazardous according to RCRA (either
26
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because of a characteristic or a listing carried by the waste), all RCRA requirements regarding the
management and disposal of hazardous waste must be addressed by the remedial managers. Criteria for
identifying characteristic hazardous wastes are included in 40 CFR Part 261 Subpart C. Listed wastes
from specific and nonspecific industrial sources, off-specification products, spill cleanups, and other
industrial sources are itemized in 40 CFR Part 261 Subpart D. For the Demonstration Test, the
technology was subject to RCRA regulations because dinoseb is a RCRA-listed waste (P020). RCRA
regulations do not apply to sites where RCRA-defined hazardous wastes are not present.
Generally, hazardous wastes listed in 40 CFR Part 261 Subpart D remain listed wastes regardless of the
treatment they may undergo and regardless of the final contamination levels in the resulting effluent
streams and residues. This implies that even after remediation, "clean" wastes are still classified as
hazardous because the pre-treatment material was a listed waste. For the SITE Demonstration Test in
Ellensburg, Washington, the WADOE determined that if dinoseb contamination could be reduced to
below a specified cleanup objective, the material would no longer be designated a hazardous waste. This
cleanup objective was based on risk-related studies conducted by the WADOE. Because the J.R. Simplot
Company met these cleanup objectives during the Demonstration Test, the treated material was not
considered a hazardous waste. For cases where the pre-treatment waste is defined as hazardous because
it carries a characteristic (not a listing), it is anticipated that, once the contaminated material is treated
by the J.R. Simplot Ex-Situ Bioremediation Technology, it will no longer be a hazardous waste.
Contaminated PPE is subject to land disposal restriction (LDR) under both RCRA and CERCLA only
if it contains more than 5% contamination per square inch.
For generation of any hazardous waste, the site responsible party must obtain an EPA identification
number. Other applicable RCRA requirements may include a Uniform Hazardous Waste Manifest (if the
waste is transported), restrictions on placing the waste in land disposal units, time limits on accumulating
waste, and permits for storing the waste.
Requirements for corrective action at RCRA-regulated facilities are provided in 40 CFR Part 264, Subpart
F (promulgated) and Subpart S (partially promulgated). These subparts also generally apply to
remediation at Superfund sites. Subparts F and S include requirements tor initiating and conducting
RCRA corrective action, remediating groundwater, and ensuring that corrective actions comply with other
environmental regulations. Subpart S also details conditions under which particular RCRA requirements
27
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may be waived for temporary treatment units operating at corrective action sites and provides information
regarding requirements for modifying permits to adequately describe the subject treatment unit.
2.9.3 Clean Air Act (CAA)
The CAA requires that treatment, storage, and disposal facilities comply with primary and secondary
ambient air quality standards. During the excavation, transportation, and treatment of soils, fugitive
emissions are possible. Fugitive emissions include (1) volatile organic compounds and (2) dust which
may cause semivolatile organic compounds and other contaminants to become airborne. Soils must be
watered down or covered with industrial strength plastic prior to treatment to prevent or minimize the
impact from fugitive emissions. State air quality standards may require additional measures to prevent
fugitive emissions. The J.R. Simplot Ex-Situ Bioremediation Technology is not designed to treat soils
contaminated with volatile compounds. However, if volatile compounds are present, the system may be
modified to include a cover, an exhaust fan, and carbon adsorbers or biotllters to treat volatile emissions
generated by excavation of the soil.
2.9.4 Safe Drinking Water Act (SDWA)
The SDWA of 1974, as most recently amended by the Safe Drinking Water Amendments of 1986,
requires the EPA to establish regulations to protect human health from contaminants in drinking water.
The legislation authorized national drinking water standards and a joint federal-state system for ensuring
compliance with these standards.
The National Primary Drinking Water Standards are found in 40 CFR Parts 141 through 149.
Wastewater generated by the J.R. Simplot Ex-Situ Bioremediation Technology during the degradation of
dinoseb is anticipated to be acceptable for discharge into a POTW. Analyses of the wastewater and
approval by the local authorities will confirm this assumption.
2.9.5 Toxic Substances Control Act (TSCA)
The TSCA of 1976 grants the EPA authority to prohibit or control the manufacturing, importing,
processing, use, and disposal of any chemical substance that presents an unreasonable risk of injury to
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human health or the environment. These regulations may be found in 40 CFR Part 761; Section 6(e)
deals specifically with PCBs. Materials with less than 50 ppm PCB are classified as non-PCB; those
containing between 50 and 500 ppm are classified as PCB-contaminated; and those with 500 ppm PCB
or greater are classified as PCB. PCB-contaminated materials may be disposed of in TSCA-permitted
landfills or destroyed by incineration at a TSCA-approved incinerator; PCBs must be incinerated. Sites
where spills of PCB-contaminated material or PCBs have occurred after May 4, 1987 must be addressed
under the PCB Spill Cleanup Policy in 40 CFR Part 761, Subpart G. The policy establishes cleanup
protocols for addressing such releases based upon the volume and concentration of the spilled material.
The J.R. Simplot Ex-Situ Bioremediation Technology is not suitable for PCB-contaminated wastes;
alternative treatment must be undertaken to treat this type of contamination.
2.9.6 Occupational Safety and Health Administration (OSHA) Requirements
CERCLA remedial actions and RCRA corrective actions must be performed in accordance with the
OSHA requirements detailed in 20 CFR Parts 1900 through 1926, especially Part 1910.120 which
provides for the health and safety of workers at hazardous waste sites. On-site construction activities at
Superfund or RCRA corrective action sites must be performed in accordance with Part 1926 of OSHA,
which describes safety and health regulations for construction sites. State OSHA requirements, which
may be significantly stricter than federal standards, must also be met.
All technicians operating the J.R. Simplot bioremediation system and all workers performing on-site
construction are required to have completed an OSHA training course and must be familiar with all
OSHA requirements relevant to hazardous waste sites. For most sites, minimum PPE for workers will
include gloves, hard hats, steel-toe boots, and Tyvek® suits. Depending on contaminant types and
concentrations, additional PPE may be required. Noise levels are not expected to be high, with the
possible exception of noise caused by pre-treatment excavation and soil handling activities. During this
time, noise levels should be monitored to ensure that workers are not exposed to noise levels above a
time-weighted average of 85 decibels over an eight-hour day. If noise levels increase above this limit,
then workers will be required to wear ear protection. The levels of noise anticipated are not expected
to adversely affect the community.
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SECTION 3
ECONOMIC ANALYSIS
3.1 Introduction
The primary purpose of this economic analysis is to provide a cost estimate (not including profit) for
commercial remediation of dinoseb-contaminated sites utilizing the J.R. Simplot Ex-Situ Bioremediation
Technology. This analysis is based on the results of a SITE Demonstration Test that utilized a small-scale
bioreactor with a soil batch capacity of 31 m3, and also information provided by Simplot on future plans
to remediate 3,824 m3 (5,000 yd3) sites. This economic analysis estimates expenditures for remediating
a total volume of 3,824 m3 of treatment soil in four lined pits utilizing the J.R. Simplot Ex-Situ
Bioremediation Technology.
Remediation is anticipated to be performed in four lined pits. Each of the four lined pits are assumed
to be 50 feet wide, 340 feet long, four feet deep, and to have a one-foot berm. They are each capable
of treating 956 m3 of soil using the J.R. Simplot Bioremediation Technology. Thus, throughout this cost
estimate they will be referred to as "956-m3" lined pits. Each pit is double lined with 30-miI HOPE and
has an 8-ounce geotextile underlayment beneath the liners. A hydro-mixer is used to agitate the treatment
slurry. This is a device that Simplot has developed to mix the soil with the water.
The actual Demonstration Test treated approximately 30 m3 (39 yd3) of soil with an average dinoseb (2-
sec-butyl-4,6-dinitrophenol) contamination level of 27.3 mg/kg (dry basis). The soil was classified as
a clayey sand with gravel. Treatment of the soil during the Demonstration Test required 23 days. For
the purpose of this economic analysis batch treatment times are assumed to be 30 days. The total
treatment period for treating 3,824 m3 of soil in four lined pits is approximately two months. This total
treatment time includes: excavation of the pits, soil processing, and remediation. It does not include
excavation of the treatment soil and demobilization.
3.2 Conclusions
Estimated costs for four 956-m3 lined pits remediating a total volume of 3,824 m3 of soil are
approximately $127/m3 ($97/yd3). Table 3-1 breaks down these costs into categories and lists each
30
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category's cost as a percent of the total cost. Costs that are assumed to be the obligation of the
responsible party or site owner have been omitted from this cost estimate and are indicated by a.line (—)
in Table 3-1. Categories with no costs associated with this technology are indicated by a zero (0) in
Table 3-1. These total costs do not include additional charges that may be imposed by the J.R. Simplot
Company. These additional costs may total up to $131/m3 ($100/yd3), depending on site-specific
information.
Costs presented in this report are order-of-magnitude estimates as defined by the American Association
of Cost Engineers, with an expected accuracy within +50% and -30%; however, because this is an
innovative technology, the range may actually be wider,.
3.3 Issues and Assumptions
The cost estimates presented in this analysis are representative of charges typically assessed to the client
by the vendor, but do not include profit. As mentioned above, the total costs do not include an additional
expense that may be charged by the J.R. Simplot Company. Depending on site characteristics, this
additional expense may include supplementary technical assistance, soil nutrients and enhancements, and
a carbon source. This could total up to S131/m3 ($100/ydJ) to the cost of remediation.
Many actual or potential costs that exist were, not included as part of this estimate. They were omitted
because site-specific engineering designs that are beyond the scope of this SITE project would be
required. Also, certain functions were assumed to be the obligation of the responsible party or site owner
and were not included in the estimates.
Costs that were considered to be the responsible party's (or site owner's) obligation include: preliminary
site preparation, excavation of the dinoseb-contaminated soil, permits and regulatory requirements,
initiation of monitoring and sampling programs, effluent treatment and disposal, environmental
monitoring, and site cleanup and restoration. These costs are site-specific. Thus, calculations are left
to the reader so that relevant information may be obtained'tor specific cases. Whenever possible,
applicable information is provided on these topics so that the reader can independently perform the
calculations required to acquire relevant economic data. Table 3-2 lists a summary of the expenditures
included in the total estimated costs.
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Table 3-1. Estimated Costs for Treatment Using The J.R. Simplot
Ex-Situ Bioremediation Technology
Bioremediation Lined Pit Size
Number of Lined Pits
Total Treatment Volume
Batch Treatment Time
Approximated Total Project Period
Site Facility Preparation Costst
Permitting & Regulatory Costs
Annualized Equipment Costs
Startup & Fixed Costs
Labor Costs
Supplies Costs
Consumables Costs
Effluent Treatment & Disposal Costs
Residuals & Waste Shipping, Handling, & Transport Costs
Analytical Costs
Facility Modifications, Repair, & Replacement Costs
Site Restoration Costs
Total Costs
986 m3(I.250yd3)
4
3,824 m3 (5,000 yd3)
30 Days
2 Months
*"»' W Tot!, Cost
32.37 24.75 25.4%
—
27.18 20.78 21.3%
18.41 14.08 14.5%
12.97 9.91 10.2%
0.16 0.12 0.1%
34.28 26.21 26.9%
—
0. 12 0.09 0. 1 %
1.67 1.28 1.3%
0.22 0.17 0.2%
—
S127/m3 S97/ydJ
t This does not include costs for excavation of the contaminated soil. It does include excavation cost for
constructing the lined pits.
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Table 3-2. Items Included in This Cost Estimate
Cost Item
Included in
Treatment Costs?
Costs for Site Design and Layout
Survey and Site Investigations Costs
Costs for Preparation of Support Facilities
Costs for Excavation of Contaminated Material
Costs for Excavation of Lined Pits
NO
NO
NO
NO
YES
Costs for Construction of the Lined Pits
Costs for Screening and Loading the Contaminated Soil into the Lined Pits
Permitting and Regulatory Costs •
Equipment Costs Incurred During Treatment
YES
YES
NO
YES
YES
Insurance, Taxes, and Contingency Costs
Costs for Initiation of Monitoring Programs
Labor Costs Incurred During Treatment
Labor Costs Incurred During Demobilization and Site Restoration
Travel Costs
YES
NO
YES
NO
YES
Supplies Costs
Consumables Costs (Fuel, Water, and pH Adjustment Chemicals)
Costs for the J.R. Simplot Potato-Processing By-Product (Starch)
Effluent Treatment and Disposal Costs
«.H^
YES
YES
NO
NO
YES
Environmental Monitoring Analytical Costs
Simplot Monitoring Analytical Costs
Design Adjustments, Facility Modifications, & Equipment Replacement Costs
Maintenance Materials Costs.
Site Restoration & Demobilization Costs (Including Drying the Slurry)
NO
YES
NO
YES
NO
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Other important assumptions regarding operating conditions and task responsibilities that could
significantly impact the cost estimate results are presented below:
• Operating hours during treatment are assumed to be eight hours a day, five days a week.
Site preparation operations are assumed to be 10 hours a day for seven days a week. Site
preparation operations will take approximately four weeks.
• The soil being treated is similar to the dinoseb-contaminated soil treated during the
Demonstration Test.
• A sufficient water supply of at least 200 gpm is available on-site. Costs will significantly
increase if wells must be constructed and/or if water must be transported to the site..
• Operations take place in mild weather. If not, provisions for heating the bioreactor tanks
will increase the treatment costs.
• The batch treatment time is 30 days. Costs will be directly effected if the treatment rate
increases or decreases.
• Four lined pits are used to treat the dinoseb-contaminated soil. If Simplot scales their
process up differently (such as using modular erected bioreactors, or different sizes and
numbers of lined pits), then the treatment costs will vary.
3.4 Basis for Economic Analysis
The cost analysis was prepared by breaking down the overall cost into 12 categories:
Site and facility preparation costs,
Permitting and regulatory costs,
Equipment costs,
Startup and fixed costs,
Labor costs,
Supplies costs,
Consumables costs,
Effluent treatment and disposal costs,
Residuals and waste shipping, handling, and transport costs,
Analytical costs,
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• Facility modification, repair, and replacement costs, and
• Site restoration costs.
These 12 cost categories reflect typical cleanup activities encountered on Superfund sites. Each of these
cleanup activities is defined and discussed, forming the basis for the detailed estimated costs presented
in Table 3-3. The estimated costs are shown graphically in Figure 3-L The 12 cost factors examined
and assumptions made are described in detail below.
3.4.1 Site and Facility Preparation Costs
For the purposes of these cost calculations, "site" refers to the location of the contaminated soil. For
these cost estimates, it is assumed that the space available at the site is sufficient for a configuration that
would allow the J.R. Simplot Ex-Situ Bioremediation lined pits to be located near the contaminated soil.
Thus, costs for transportation of the contaminated soil from the site to a separate facility where the Ex-
Situ Bioremediation lined pits are located is not required for this cost estimate.
It is assumed that preliminary site preparation will be performed by the responsible party (or site owner).
The amount of preliminary site preparation required will depend on the site. Site preparation
responsibilities include site design and layout, surveys and site logistics, legal searches, access rights and
roads, preparations for support and decontamination facilities, utility connections, excavation of the
dinoseb-contaminated soil, and fixed auxiliary buildings. Since these costs are site-specific, they are not
included as part of the site preparation costs in this cost estimate.
For the purposes of these cost calculations, installation costs are limited to shipping cost for the liners,
and construction of the four lined pits. Shipping costs for all of the liners are estimated at a total cost
of $2,400. Excavation costs for the lined pits is limited to rental equipment, fuel for the equipment,
equipment operators, and labor to install the liners and geotextile underlayment for the liner. Excavation
rental equipment includes: five 1-yd3 excavators (each $2,100/wk). three 10-yd* box dump trucks (each
$600/wk), and one backhoe ($700/wk) each rented for approximately three weeks. Fuel requirements
are approximated at 3-gals/hr for each excavator, 2-gals/hr for each dump truck, and 3-gals/hr for the
backhoe. Fuel cost are estimated a $1.00 per gallon. Equipment operators include five excavator
operators (each $25/hr), three dump truck operators (each $25/hr), one backhoe operator ($25/hr), and
35
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Table 3-3. Detailed Costs for Treatment Using the J.R Simplot Ex-Situ
Bioremediation Technology (page 1 of 2)
Bioremediation Lined Pit Size
Number of lined Pits
Total Treatment Volume
Batch Treatment Time
Approximated Total Project Period
986m3 (1,250 yd3)
4
3,824 m3 (5,000 yd3)
30 Days
2 Months
$/m3 $/yd3
Site and Facility Preparation Costs
Site design and layout
Survey and site investigations
Legal searches, access rights & roads
Preparations for support facilities
Auxiliary buildings
Excavation of the contaminated soil
Technology-specific requirements
Transportation of waste feed
Total Site and Facility Preparation Costs
Permitting and Regulatory Costs
Permits
System monitoring requirements
Development of monitoring and protocols
Total Permitting and Regulatory Costs
Equipment Costs
Annual ized equipment cost
Support equipment cost
Equipment rental
Total Equipment Costs
Startup and Fixed Costs
Working capital
Insurance and taxes
Initiation of monitoring programs
Contingency
and Fixed Costs
32.37
32.37
0.46
24.88
1.84
27.18
17.97
0.22
0.22
18.41
24.75
24.75
0.35
19.02
1.41
20.78
13.74
0.17
0.17
14.08
Supervisors
Health & Safety
Technicians
General'
Secretary
Rental car
Travel
Total JLabor Costs
3.44
0.71
4.79
2.51
0.52
0.37
0.63
12.97
2.63
0.54
3.66
1.92
0.40
0.28
0.48
9.91
(Continued)
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Table 3-3. Detailed Costs tor Treatment Using the J.R. Simplot Ex-Situ
Bioremediation Technology (page 2 of 2)
Bioremediation Lined Pit Size
Number of Lined Pits
Total Treatment Volume
Batch Treatment Time
Approximated Total Project Period
986 mj( 1,250 yd3)
4
3,824 m3 (5,000 yd3)
30 Days
2 Months
Supplies Costs
Personal protective equipment
Total Supplies Cost
Consumables Costs
Fuel
Water
pH adjustment chemicals
Total Consumables Costs
Effluent Treatment and Disposal Costs
On-site facility costs
Off-site facility costs
-wastewater disposal
-monitoring activities
Total Effluent Treatment and Disposal Costs
Residuals & Waste Shipping, Handling & Transport Costs
Preparation
Waste disposal
Total Residuals & Waste Shipping, Handling & Transport Costs
Analytical Costs
Operations
Environmental monitoring
Total Analytical Costs
Facility Modification, Repair, & Replacement Costs
Design adjustments
Facility modifications
Maintenance materials
Equipment replacement
Total 'Facility Modification, Repair, & Replacement Costs
Site Restoration Costs
Site cleanup and restoration
Permanent storage
Total Site Restoration Costs
$/mJ
0.16
0.16
0.21
0.06
34.01
34.28
0.12
0.12
1.67
1.67
0
0
0.22
0
0.22
S/yd-'
0.12
0.12
0.16
0.05
26.00
26.21
0.09
0.09
1.28
1.28
0
0
0.17
0
0.17
TOTAL COSTS
$127/m3 $97/yd3
37
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$34.28/m3 (A)
S32.37/rr? (B)
$27.18/m3 (C)
(G,H,&I)
.67/nr3 (F)
312.97/m3 (E)
$18.41/nP (D)
] (A) Consumables Costs ($34.28/m3)
(B) Site Facility Preparation Costs ($32.37/m3)
(C) Annualked Equipment Costs ($27.18/m3)
(D) Startup & Fixed Costs ($18.4 1/m3)
OE) Labor Costs ($12.97/m3)
* Permitting & Regulatory Costs
(F) Analytical Costs ($1.67/m3)
(G) Facility Modifications, Repak, & Replacement Costs ($0.22/m3)
(H) Supplies Costs ($0.16/m3)
(I) Residuals & Waste Shipping, Handling. & Transport Costs (SO. 12/m3)
* Effluent Treatment & Disposal Costs
* Site Restoration Costs
*.
These costs are not included in this economic analysis.
Figure 3-1. Estimated Costs for the J.R. Simplot Ex-Situ Bioremediation Technology
one supervisor ($40/hr) for 10 hrs per day for approximately 17 days. Liner installation requires 12
general labors at $20/hour/person for 16 hours per lined pit and liner installation equipment (estimated
at a total of $2,700).
Technology-specific site preparation requirements for the Ex-Situ Bioremediation Unit consist of: soil
screening; and soil and water loading into the bioreactor.
Equipment necessary for technology-specific site preparation for treatment includes: a vibrating screen,
a conveyor belt, and a 50-kW diesel generator.
38
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3.4.2 Permitting and Regulatory Costs
Permitting and regulatory costs are generally the obligation of the responsible party (or site owner), not
that of the vendor. These costs may include actual permit costs, system monitoring requirements, and
the development of monitoring and analytical protocols. Permitting and regulatory costs can vary greatly
because they are 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 activities can be very
expensive and time-consuming.
3.4.3 Equipment Costs
Equipment costs include purchased equipment, purchased support equipment, and rental equipment.
Support equipment refers to pieces of purchased equipment and/or sub-contracted items that will only be
used for one project.
Purchased Eciuipment Costs
The purchased equipment costs are presented as annualized equipment costs, prorated based on the
amount of time the equipment is used for the project. The annualized equipment cost is calculated using
a 5-year equipment life and a 10% annual interest rate. The annualized equipment cost is based upon
the writeoff of the total initial capital equipment cost and scrap value (5,6) (assumed to be 10% of the
original equipment cost) using the following equation:
Where
V
V.
n
i
Capital recovery - (V -
is the cost of the original equipment,
is the salvage value of the equipment,
is the equipment life (15 years), and
is the annual interest rate (6%) (5,6).
Q"
(1 + i)"' -1
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For this cost estimate, purchased equipment includes: four hydro-mixers (used for 7 weeks) at a total
cost of $40,000, and four data loggers (used for 7 weeks) at a total cost of $1,000. The total cost of the
purchased equipment is thus $41,000. This total cost is used to calculate the prorated annualized
purchased equipment cost.
Support Equipment Costs
For estimating purposes, support equipment includes: double liners, geotextile underlayment fofr the
liner, and 2 inches of sand between the liners for each pit ($22,700 per pit), a decontamination area
($300), four area lights ($245 each), and 12 probes to measure temperature, pH, and reduction potehiial
($250 each). This support equipment will not be used on subsequent projects, and therefore these costs
are not prorated.
Rental Equipment Costs
Rental equipment includes: a bobcat at $l,650/month for two months, an office trailer at $330/month
for two months, a telephone at $30/month for two months, portable toilet facilities at $30/month for two
months, and a 50-kW generator at $l,500/month for two months.
3.4.4 Startup and Fixed Costs
Working capital is based on the amount of money currently invested in supplies and consumables. The
working capital cost of supplies and consumables is based on maintaining a one-month inventory of these
items. (See "Supplies Costs" and "Consumables Costs" for the specific amount of supplies and
consumables required for the operation of the system. These quantities were used to determine the
amount of supplies and consumables required to maintain a one-month inventory of these items.)
Insurance and taxes are usually approximately 1 % and 2 to 4% of the total purchased equipment capital
costs, respectively. The cost of insurance for a hazardous waste process can be several times more.
Insurance and taxes together are assumed for the purposes of this estimate to be 10% of the purchased
equipment capital costs (6).
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The cost for the initiation of monitoring programs has not been included in this estimate. Depending on
the site and the location of the system, however, local authorities may impose specific guidelines for
monitoring programs. The stringency and frequency of monitoring required may have significant impact
on the project costs. Simplot does plan to monitor pH, redox potential, and temperature within the
bioreactor using probes and data loggers. The cost of the data logger is included under purchased
equipment, and the cost of the probes is included under support equipment in the "Equipment Costs"
section.
A contingency cost of 10% of the equipment capital costs is allowed for any unforeseen or unpredictable
cost conditions, such as strikes, storms, floods, and price variations (6,7).
3.4.5 Labor Costs
Labor costs are limited to labor rates, per diem, daily transportation, and travel. Labor rates include
overhead and administrative costs. Per diem is estimated at $70/day/person. Daily transportation
includes a rental car and fuel at $50/day. Round trip travel costs are assumed to be $600/round
trip/person. Only supervisors, health and safety engineers, and technicians require per diem, daily
transportation to the site, and round trip air travel to the site location. Support secretaries provide
assistance from the home office and are not required to be present on-site. Loader operators and general
operators are assumed to be local hires that will be trained and supervised by Simplot personnel. Thus,
loader operators and general operators do not require per diem or daily transportation to the site.
For this cost estimate, operating labor time on-site is assumed to be eight hours a day, five days a week.
Labor requirements include: one supervisor at $70/hour for four weeks; one health and safety engineer
at $55/hour for one week; two technicians at $45/hour/person for four weeks; two general labors at
$15/hour/person for eight weeks; and one secretary at $25/hour for two hours a day, five days a week
for 8 weeks. Travel includes four round trips (one trip for the supervisor, one trip for the health and
safety engineer, and two trips total for the two technicians).
41
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3.4.6 Supplies Costs
Supplies costs for this cost estimate are limited to personal protective equipment (PPE). The cost of PPE
is estimated at $3 per set of PPE. It is assumed that 200 sets of PPE will be required.
3.4.7 Consumables Costs
Consumables required for the operation of the J.R. Simplot Ex-Situ Bioremediation Technology are
limited to buffer, fuel, electricity, and water. For the purposes of this economic analysis it is assumed
that the cost of the buffer is $34/m3 ($26/yd3) of treatment soil.
The fuel required for the Ex-Situ Bioremediation Unit is estimated at 380 L/week (100 gal/week) for eight
weeks.
The water rate is assumed to be $0.05/1,000 L ($0.20/1,000 gal). Approximately 4,660,000 L
(1,230,000 gals) of water are required for treatment of 3,824 m3 of soil using the J.R. Simplot Ex-Situ
Bioremediation Technology.
3.4.8 Effluent Treatment and Disposal Costs
One effluent stream is anticipated from the J.R. Simplot Ex-Situ Bioremediation Technology. This is the
treated slurry from the Ex-Situ Bioremediation Unit. It is anticipated that the solid phase of the treated
slurry can be dried and replaced within the excavated area or used as fill material. In states where
cleanup levels have not been established or when cleanup levels are not met, then disposal of the soil at
a RCRA-permitted facility may be necessary. The liquid'phase of the slurry is anticipated to be non-
hazardous and suitable for disposal to a local POTVV. In some cases with the proper permits it may be
possible that the integrity of the liner can be intentionally breached when treatment is complete, and the
liner abandoned in place.
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3.4.9 Residuals and Waste Shipping, Handling and Transport Costs
Waste disposal costs including storage, transportation and treatment costs are assumed to be the obligation
of the responsible party (or site owner). It is assumed that the only residuals or solid wastes generated
from this process will be used PPE and decontamination water. The disposal cost tor 208-L (55-gaI)
drums of used PPE and/or decontamination water is estimated at $225/208-L drum. For this cost
estimate, it is assumed that two 208-L drums of used PPE and decontamination water will be generated.
3.4.10
Analytical Costs
Only spot checks executed at Simplot's discretion (to verify that equipment is performing properly and
that cleanup criteria are being met) are included in this cost estimate. The client may elect, or may be
required by local authorities, to initiate a planned sampling and analytical program at their own expense.
The cost for Simplot's spot checks is estimated at $200 per sample. For the purposes of this cost
estimate, it is assumed that there will be 32 samples analyzed.
The analytical costs associated with environmental monitoring (not process monitoring) have not been
included in this estimate due to the fact that monitoring programs are not typically initiated by Simplot.
Local authorities may, however, impose specific sampling and monitoring criteria whose analytical
requirements could contribute significantly to the cost of the project.
3.4.11
Facility Modification, Repair and Replacement Costs
Maintenance costs are assumed to consist of maintenance labor and maintenance materials. Maintenance
labor and materials costs vary with the nature of the waste and the performance of the equipment. For
estimating purposes, the annual maintenance labor and materials cost is assumed to be 10% of the
purchased equipment capital costs. Costs for design adjustments, facility modifications, and equipment
replacements are not included in this cost estimate.
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3.4.12
Site Restoration Costs
Site restoration requirements will vary depending on the ruture use of the site and are assumed to be the
obligation of the responsible party. Therefore, no site cleanup and restoration costs are included in this
cost estimate.
44
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SECTION 4
TREATMENT EFFECTIVENESS DURING THE SITE DEMONSTRATION
This section presents the results of the SITE demonstration in Ellensburg, Washington and discusses the
effectiveness of treatment at the Bowers Field site by the J.R. Simplot Ex-Situ Bioremediation
Technology.
4.1 Background
Bowers Field is a county-owned airport located in rural Ellensburg, Washington. State regulatory
agencies have detected dinoseb contamination at this site. Dinoseb (2-jt'c-butyl-4,6-dinitrophenol) is
nitroaromatic compound used as an agricultural herbicide to defoliate potatoes and other legumes. It is
a RCRA-listed waste bearing a P020 waste code. It is conjectured that the airport soil was previously
contaminated with dinoseb by crop-dusting activities.
The fixed base operator at the airport contracted with the J.R. Simplot Company to clean up dinoseb-
contaminated soil at Bowers Field. The cleanup was initiated in cooperation with the EPA under the
SITE Demonstration Program. A partial site characterization was performed in November 1992 by
Science Applications International Corporation (SAIC), a contractor to the EPA. The investigation was
not intended to fully characterize the site, but to identify approximately 30 m3 of dinoseb-contaminated
soil for use in a SITE Demonstration Test. The results of the site characterization indicated that the
levels of dinoseb contamination ranged from < 1 mg/kg (the analytical detection limit for these analyses)
to 292 mg/kg. Average concentration of dinoseb in the test soil was estimated at approximately 50
mg/kg. Neither volatile nor semivolatile organic compounds were detected. Other pesticides, herbicides,
and metals were identified as contaminants in the soil. Dinoseb was the only target analyte selected for
the Demonstration Test.
The only critical objective for the Demonstration Test was based on the developer's claim—that dinoseb
contamination in soil could be reduced by at least 95% using their technology. This critical objective was
to determine the effectiveness of the J.R. Simplot Ex-Situ Bioremediation Technology in degrading
dinoseb in the test soil based on the concentration in the pre-treatment slurry (dry basis) and the post-
treatment slurry (dry basis). Results were to be reported as percent reduction in the slurry (dry basis).
45
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Non-critical objectives for the Demonstration Test were:
• to determine if the reduction of dinoseb contamination was a result of the J.R. Simplot
Ex-Situ Bioremediation Technology;
• to determine if the reduction of dinoseb contamination was a result of biodegradation;
• to determine the relative toxicity of the test soil before and after treatment;
• to determine the presence of 6-amino-4-nitro-2-j6'C-butylphenol (a previously identified
intermediate) in the soil before and after treatment;
• to determine if pesticides and herbicides other than dinoseb were present in the test soil
and, if so, to establish their levels of contamination;
• to determine the metals contamination in the soil before treatment;
• to determine the type of soil being remediated;
• to evaluate the effect of pH, temperature, and redox potential; and
• to develop operating costs.
The use and manipulation of microorganisms for treatment of waste, particularly wastewater, has been
applied for many years. Bioremediation, or enhanced microbial treatment, now has many other
applications including soils, sludges, groundwater, process water, and surface waters. Treatment may
take place under aerobic or anaerobic conditions. Although bioremediation has met much success,
polymerization products that are potentially toxic are often formed under aerobic or microaerophilic
conditions. The J.R. Simplot Company has developed a simple bioenrichment procedure that achieves
anaerobic conditions under which a microbial consortium can degrade nitroaromatic compounds in soil
without the formation of known toxic polymerization products.
4.2 Detailed Process Description
The J.R. Simplot Ex-Situ Bioremediation Technology takes place in a bioreactor. Portable tanks with
a volume of 75,700 L (20,000 gal) are used to treat up to 31 m? (40 yd3) of soil; for larger volumes of
soil, excavated, lined, in-ground pits approximately 15.2 m (50 ft) wide, 104 m (440 ft) long, and 1.2
m (4 ft) deep can be used, or, erected modular tanks with a volume of 2.84 million L (750,000 gal) are
46
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used. Both can treat up to 956 m3 (1,250 yd') of soil. V/hen the treatment volume exceeds 956 m3,
multiple lined pits or multiple modular bioreactors may be used simultaneously.
Simplot utilized a portable tank as the bioreactor during the Demonstration Test because the volume of
test soil was small—only 30 m3 (39 yd3). The bioreactor for these tests was 12.2 m long, 2.4 m wide,
and 2.6 m tall (40 ft x 8.0 ft x 8.5 ft). To facilitate mixing, water was placed in the bioreactor with
the soil in a ratio of approximately I L (0.26 gal) water to 1 kg (2.2 Ib) soil. Nutrients (J.R. Simplot
Company potato-processing by-product) and pH-regulating agents were added to induce the aerobic
microorganisms to consume oxygen from the soil. This lowered the redox potential (EJ and created
anaerobic conditions. Tests have shown that anaerobic conditions with Eh less than -100 mV promote
the establishment of the anaerobic microorganisms capable of degrading dinoseb and other nitroaromatic
compounds (1).
Figure 4-1 shows the flow diagram for the Simplot process as operated during the Demonstration Test.
Initially, the excavated test soil was sent through a vibrating screen to remove large rocks and other
debris greater than 12.7 mm (0.5 in) in diameter. Since dinoseb is water-soluble, the rocks and debris
at the Bowers Field site were rinsed with water to remove dinoseb contamination from the surface.
Rinsing activities were not completed during the Demonstration Test due to the large percentage of
material that was greater than 12.7 mm in diameter. The oversize material will be treated by a separate
soil or rock washing technology or properly disposed of at a later date. The rinse water .that was
generated was combined with make-up water and placed in the bioreactor. A total volume of 28,900 L
(7,640 gals) of make-up water was added to the bioreactor to provide the 1-L to 1-kg (0.26-gal to 2.2-lb)
ratio required for treatment. Acids and phosphate buffers were added to the system to correct the pH.
Batches of treatment soil and J.R. Simplot Company potato-processing by-product (2% by weight) were
mixed together in a pug mill (homogenization unit) and added to the bioreactor by conveyor until all of
the treatment soil was in the bioreactor. After the soil, water, and nutrients were loaded in the
bioreactor, the mixture was augmented with 0.02 m3 (a 5-gallon pail) of soil previously treated by the
Simplot process during treatability studies for this site. This previously-treated soil contained the
naturally selected indigenous microorganisms necessary for degradation of dinoseb using the J.R. Simplot
Ex-Situ Bioremediation Technology. The soil .at Bowers Field already contained the necessary
microorganisms, however, the treatment slurry was augmented so that dinoseb degradation rates would
be enhanced.
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Contaminated Soil
oo
Starch
Addition
Vibrating Screen
I
contaminated
soil > 12.7 mm
contaminated
soil < 12.7 mm
Homogenization
(using a pug mill)
Augmentation Soil
Screen Overs
Washing
Clean Rejects
Water From
Screen Overs
Washing
Clean rejects if contaminants in the soil are water soluble.
Make-up
Water
and
Buffer
tj-
,
A.
pH, Redox
Potential, &
Temperature
Probe
Figure 4-1. J.R. Simplot Process Flow Diagram for the Bioremediation of
Dinoseb-Contaminated Soil During the Demonstration Test
-------
The bioreactor was loosely covered and equipped with three mixers for agitation. The mixers were
installed to achieve a well-mixed slurry in the bioreactor, however, "dead spots" (i.e. settled sediment
that did not receive agitation) occurred in the bioreactor due to insufficient mixing of the slurry by the
agitators. Although previous testing indicated that the effect of the dead spots on the J.R. Simplot Ex-
Situ Bioremediation Technology is not significant, the bioreactor was lanced to agitate these dead spots.
This was accomplished by placing the suction end of a diaphragm pump into the settled sediment and
pumping the sediment into a more well-mixed region of the bioreactor. The bioreactor was also equipped
with instrumentation to monitor pH, temperature, and redox potential. A limited study has shown that
suitable operating conditions are temperatures between 35 and 37°C, pH below 8.0 (ideally between 7.5
and 8.0 for dinoseb degradation), and redox potential <-100 mV //;.
4.3 Methodology
Prior to commencement of the Demonstration Test, SAIC determined that evaluation of the J.R. Simplot
Ex-Shu Bioremediation Technology would begin after the excavated soil was screened. Therefore,
sampling of the pre-treatment feed soil for all parameters occurred after the soil had been excavated and
passed through the screening process. For informational purposes, three composite samples of the pre-
screened material were collected for particle size and Atterberg limits determination to evaluate the type
of soil that could be processed by the overall system (including screening).
Excavation of the test soil was performed by the J.R. Simplot Company, assisted by Envirogen, Inc.
Simplot and Envirogen determined the location of the soil to be excavated based on the findings of the
site characterization previously performed by SAIC. The soil was stockpiled until excavation activities
were complete. Excavated soil was then passed through a vibrating screen to separate out rocks and other
debris greater than 12.7 mm (0.5 in) in diameter. Each fraction (the screened test soil and the oversize
material) was placed in a separate lined area and covered for storage before sampling and processing.
The screened soil pile was leveled and shaped into a flat, truncated pyramid-like form. All sides of the
pile were measured so that the total soil volume could be geometrically determined. Seven soil density
samples were collected in metal sleeves of known mass and volume. The volume of each metal sleeve
was determined on-site using a calibrated Vernier caliper. The mass of each metal sleeve was also
determined on-site using a certified calibrated balance. The soil density and total soil volume were used
49
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to determine the mass of treatment soil. Three composite samples were collected from this pile for
particle size and Atterberg limits determination.
The screened soil was placed in wheelbarrows to facilitate loading of the soil into a hopper that fed the
homogenization unit (pug mill). J.R. Simplot Company potato-processing by-product was added to the
soil prior to homogenization by the pug mill. Soij samples were collected from each wheelbarrow before
the soil was fed to the pug mill and before the starch by-product was added. Samples of the J.R. Simplot
Company potato-processing by-product were collected for dinoseb, pesticides, chlorinated herbicides, and
metals analyses. These samples were held for analysis, unless it was found that the post-treatment
samples had elevated .concentrations from the pre-treatment samples for dinoseb, pesticides, chlorinated
herbicides, and/or metals. Thus, these samples would help determine if the potato-processing by-product
had introduced dinoseb, pesticides, chlorinated herbicides and/or metals to the bioreactor. Since the
post-treatment samples did not have elevated concentrations from the pre-treatment samples, the potato-
processing by-product samples were not analyzed.
In order to measure the variability of dinoseb contamination in the treatment soil, a grab sample was
collected from every wheelbarrow fed into the hopper as mentioned above. After each four grab samples,
the soil was homogenized and appropriate aliquots were collected. A total of 61 primary samples were
collected for dinoseb analysis. Four field duplicates and four field triplicates were collected for dinoseb
analysis to measure sampling and compositing variability. Matrix spike (MS) and matrix spike duplicate
(MSD) analyses were performed on aliquots of five dinoseb samples. Gas chromatograph/mass
spectrometer (GC/MS) confirmation of dinoseb was also performed on aliquots of four samples previously
analyzed by high performance liquid chromatography (HPLC). These GC/MS scans, along with the
HPLC scans, also allowed the identification and quantification of other compounds present.
A negative process control was set up prior to the start of the Demonstration Test as a means of
comparing naturally occurring dinoseb degradation to degradation by the Simplot process. Grab samples
were collected from each wheelbarrow to comprise a composite sample of the entire feed stream for the
negative process control. The sample was homogenized and placed in a covered 19-L (5-gal) container
near the bioreactor. As microorganisms are indigenous to the site, it is expected that some natural
degradation will occur, however, the rate of degradation is unknown at this time. No amino derivative
or any other known toxic derivatives were found in the negative control, indicating that this natural
50
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process was not similar to the process occurring within the bioreactor. Due to uncertainties in the
statistical evaluation, this presumed natural degradation will not be discussed further in this report and
will be left for reader interpretation.
Thirteen samples each were collected for pesticides, chlorinated herbicides, and metals analysis. These
samples were collected in a manner similar to the dinoseb samples except a grab sample was obtained
from each of twelve separate wheelbarrows before the soil was homogenized and aliquots were collected.
One field duplicate each was collected for pesticides, chlorinated herbicides, and metals analysis. The
MS/MSD analyses were performed on aliquots of one pesticide and one chlorinated herbicide sample.
The MS and analytical duplicate (AD) analyses were performed on aliquots of one metals sample.
Grab samples were collected from each wheelbarrow to comprise composite samples of the entire feed
stream for toxicity tests. These toxicity tests included earthworm reproduction, early seedling growth,
root elongation, and herbicide bioassay screening. Reference samples for the toxicity tests were also
collected to compare to the toxicity of uncontaminated soil with dinoseb-contaminated soil. Except for
having no contamination, this soil had the same characteristics and composition as the treatment soil.
Although appropriate samples were collected, the toxicity tests were not performed. Since there were
other toxic pesticides present in the test soil, it was determined at the beginning of.testing that the toxicity
analysis would be misleading. As toxicity tests are also expensive, it was decided that toxicity analysis
should not be performed.
Because dinoseb is water soluble, the oversize material was washed with water to remove surface
contamination. The washwater was collected and then sampled. Samples were analyzed for dinoseb,
pesticides, chlorinated herbicides, and metals. Approximately 570 L (150 gal) of washwater was added
to the bioreactor. Washing activities were not completed during the Demonstration Test, and the
unwashed portion of the oversize material must be either cleaned using a separate soil or rock washing
technology (with the washwater and fines being placed in the bioreactor for treatment at a later date) or
properly disposed of at a permitted facility.
Based on the amount of soil to be treated, a total of 28,900 L (7,640 gal) of make-up water was added
to the bioreactor. This water was sampled before introducing the soil into the bioreactor. Samples were
analyzed for dinoseb, pesticides, chlorinated herbicides, and metals.
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After the soil, water, and nutrients were added, a sterile process control was set up at the start of the
Demonstration Test by collecting slurry directly from the bioreactor. This sample was to be sterilized
to destroy any existing microorganisms and then returned to the vicinity of the bioreactor. Degradation
of dinoseb in the bioreactor and lack of degradation in the sterile control under similar conditions would
indicate that dinoseb degradation in the bioreactor was biological. The abiotic control was analyzed and
found not to be sterile although it was exposed to 1.56 MRads of gamma radiation. Thus, it was decided
that it not be used as a control.
Monitored parameters during remediation were pH, temperature, and redox potential. Measurements of
these parameters were taken every 15 seconds and recorded by computer. During the course of
remediation, conditions more than sufficient for anaerobic dinoseb degradation (Eh<-200 mV) were
achieved in three days, and the pH stabilized at 7.1 as seen in Figure 2. However, due to the unusually
cool summer experienced in the Pacific Northwest during 1993, the temperature in the bioreactor
averaged only 18°C. This was lower than the preferred bioreactor temperature of 35 to 37°C (1).
According to the developer, treatment time was expected to be approximately six weeks. Therefore, after
23 days (the anticipated midpoint), 10 samples were obtained to determine the progress of the
remediation. Analysis of these mid-point samples indicated that the dinoseb had been completely
degraded. Full post-treatment sampling of the bioreactor was then initiated.
All post-treatment slurry samples were obtained from random locations within the bioreactor. A total
of 39 post-treatment slurry samples were collected and analyzed for dinoseb. Four field duplicate samples
were collected for dinoseb to measure sampling variability. The MS/MSD analysis was performed on
aliquots of four dinoseb samples, and GC/MS confirmation was performed on aliquots of four dinoseb
samples. These GC/MS scans, along with the HPLC scans, also allowed the identification and
quantification of other compounds present.
Six primary samples each were collected for pesticides and chlorinated herbicides analysis. One field
duplicate sample each was collected to assess the sampling variability for pesticides and chlorinated
herbicides. The MS/MSD analysis was performed on aliquots of one pesticide and one chlorinated
herbicide sample.
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s
£
CJ
t-t
4)
cu
i
25
20
15
10
5
0
•Temperature
•pH
Day 0 to Bay 23
•Redox
Day 6 to Day 23
Figure 4-2. Monitored Parameters during Demonstration Test
53
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Slurry samples were obtained for the post-treatment toxicity tests. Samples were collected for earthworm
reproduction, early seedling growth, and root elongation toxicity tests. As stated previously, the toxicity
tests were not performed.
4.4 Performance Data
This section presents the performance data gathered by the testing methodology described above. Results
are presented and interpreted below.
4.4.1 Chemical Analyses
Dinoseb: A total of 110 primary samples (61 pre-treatment, 10 mid-point, and 39 post-treatment) were
analyzed by the SAIC Analytical Laboratory for dinoseb using a high performance liquid chromatography
(HPLC) method developed specifically for this demonstration (8). This method is given in the SITE
Technology Evaluation Report for this demonstration. This method gave analytical detection limits of
0.03 mg/kg for the solid samples and 0.015 mg/L for the liquid samples. (Because the mid-point samples
were not concentrated in the laboratory, detection limits for these samples were 0.15 mg/kg for the solid
phase and 0.15 mg/L for the liquid phase.) The average concentration of dinoseb in the feed soil, on a
dry basis, was 27.3 mg/kg with a range of 14.0 to 34.2 mg/kg. The 95% confidence interval around this
average was 26.4 to 28.3 mg/kg. No dinoseb was found in the pre-treatment make-up water samples.
Upon arrival in the laboratory, the post-treatment slurry samples were phase separated, and the solid and
liquid phases were analyzed separately. No dinoseb was found in either the solid phase or the liquid
phase of the post-treatment slurry samples. Based on the average pre-treatment slurry concentration (on
a dry basis) and the analytical detection limit for the post-treatment slurry samples (on a dry basis), the
percent reduction of dinoseb in the slurry was > 99.8% . The concentration of dinoseb in the pre- and
post-treatment slurries was determined, on a dry basis, using the following expression:
\Slurry\Dry
(Wet solid x Sy) + (Liquid x L}
=
where:
Wet Solid
Sr
Liquid
Concentration of the wet solid phase in mg/kg.
Weight fraction of wet solid phase.
Concentration of the liquid phase in mg/kg.
Weight fraction of liquid phase.
54
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Using the pre- and post-treatment concentrations of dinoseb in the bioreactor (analytical detection limit
in the case of post-treatment samples), on a dry basis, the percent reduction was determined.
,
Percent Removal=\ 1 — '- xlOO%
I CJ
where:
Cf
C,
Post-treatment slurry dinoseb concentration in mg/kg (dry basis).
Pre-treatment slurry dinoseb concentration in mg/kg (dry basis).
No known intermediates from the degradation of dinoseb were found by HPLC analysis. To investigate
this further, GC/MS scans were run on four selected pre-treatment and four selected post-treatment
samples. These analyses confirmed that no known intermediates had been formed during remediation.
Additionally, no new peaks were observed on the post-treatment sample chromatograms.
Analysis of the negative process control before and after treatment indicated that dinoseb, nitroaniline,
and atrazine in the soil naturally degraded during the treatment period. However, dinoseb and
nitroaniline levels in the negative process control were only reduced by,26.8% (from 28.0 mg/kg to 20.5
mg/kg, on a dry basis) and 51.0% (from 10.2 mg/kg to 5.0 mg/kg. on a dry basis), respectively. This
is lower than the reduction of dinoseb and nitroaniline levels achieved in the bioreactor: >99.8% and
>87.3% (on a dry basis), respectively. The accelerated rates-of dinoseb and nitroaniline degradation
seen in the bioreactor can therefore be attributed to the J.R. Simplot Ex-Situ Bioremediation Technology.
All of the negative control data is based upon only 3 pre- and 3-post treatment measurements. Therefore,
statistical evaluations indicating degradation is somewhat uncertain. The level of atrazine in the negative
process control was reduced by 88.3% (from 55.6 mg/kg to 6.5 mg/kg, on a dry basis) while that in the
bioreactor was only reduced by 52.5%. Degradation of atrazine is not attributed to the J.R. Simplot Ex-
Situ Bioremediation Technology since natural degradation rates were greater than those seen in the
bioreactor.
Pesticides and Herbicides: Samples were analyzed by Lockheed Analytical Laboratory for pesticides
using SW-846 Method 8080 and for chlorinated herbicides using SW-846 Method 8150. Compounds
were also detected by the HPLC and GC/MS scans performed by the SAIC Analytical Laboratory on
aliquots collected for dinoseb analysis. Table 4-1 presents a summary of the average pre- and post-
55
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Table 4-1. Other Compounds Reduced During the Demonstration Test
Compound
Average Pre-Treatment
Slurry Concentration
on a Dry Basis
(mg/kg)
Average Post-Treatment
Slurry Concentration
on a Dry Basis
(mg/kg)
Atrazine*
Nitroaniline*
Malathionf
Parathion*
53.7
11.9
1.60
2.30
25.5
<1.51
<1.51
<1.5I
Based on high performance liquid chromatography (HPLC) analyses.
f Based on gas chromatography/mass spectrometry (GC/MS) analyses.
treatment slurry concentrations of the compounds reduced during the Demonstration Test. Although not
attributed to the J.R. Simplot Bioremediation Technology (based on the results of the'negative process
control discussed above), a >52.5 percent reduction was observed for atrazine (see Table 4-1). On a
dry basis, the average pre-treatment slurry concentration of 2,6-clichk>ro-4-nitroaniIine (nitroaniline) was
11.9 mg/kg. Like dinoseb, this nitroaromatic compound was also degraded to below its analytical
detection limit in the post-treatment slurry samples. Based on pre- and post-treatment results in the slurry
on a dry basis, nitroaniline was reduced by > 87.3% (see Table 4-1). Further inspection of Table 4-1
does not indicate significant reductions of malathion or parathion. However, it is quite evident from the
chromatograms that these compounds were present in the pre-treatment soil. The chromatograms for the
post-treatment solid and liquid phases did not show any indication of the presence of these compounds.
Malathion; parathion; and 4,4'-DDT were reduced from, parts-per-million levels to below their analytical
detection limits. Quantification of atrazine. nitroaniline, malathion, and parathion was possible through
the use of standards. The 4,4'-DDT was identified in the pre-treatment samples, but no peaks could be
found for this compound in the post-treatment samples. Accurate quantification of 4,4'-DDT could not
be performed because a standard was not readily available. However, based on column manufacturer's
recommendations and the peak height, the 4,4'-DDT concentration in the pre-treatment samples is
estimated to be on the order of a part per million. The data presented in Table 4-1 are from the SAIC
56
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analyses alone. The methods used were not SW-846 methods, but rather methods that were specifically
developed for this particular project. Details of the methods used can be found in Appendix A and
Appendix F of the Quality Assurance Project Plan (8).
The process had no noticeable effect on chlordane (alpha, garnma, and technical) and endosulfan (I and
II). In each case, the change in average concentration was within the limits of analytical error, and
definitive conclusions regarding changes in concentrations cannot be made. Table 4-2 presents a data
summary (pre- and post-treatment slurry concentrations, on a dry basis) for compounds that were detected
but appeared to be unaffected by the J.R. Simplot Ex-Situ Bioremediation Technology. Analytical Data
listed in Table 4-2 is from SW-846 Method 8080.
Metals: Pre-treatment soil and make-up water samples were analyzed for ICP metals using SW-846
Method 6010. Samples were also analyzed for mercury using SW-846 Method 7470/71. Metals
concentrations in the pre-treatment soils and make-up water were at levels generally found in natural soils
and potable water, and were not thought to be toxic to the microorganisms. Although the post-treatment
slurry samples were collected, they were not analyzed for metals. The metals concentrations were not
expected to change due to remediation. Table 4-3 presents a summary of the pre-treatment metals data
for the soil and the make-up water.
Toxicity: It was anticipated that the toxicity tests could be performed simultaneously on the pre- and post-
treatment soils to determine if the relative toxicity of the soil had changed because of the degradation of
dinoseb. However, it was found that the levels of pesticides and herbicides (in addition to dinoseb) in
the pre-treatment soil negated the relevance of the analyses. To determine if the relative toxicity changes
because of this process, toxicity testing (including earthworm reproduction, early seedling growth, root
elongation, and herbicide bioassay screening) will be performed during the TNT SITE demonstration and
reported in the associated Innovative Technology Evaluation Report (ITER).
Sterile Process Control: Immediately after collection, the sterile process control was shipped to the
laboratory for sterilization using gamma radiation. The process control was subjected to 1.56 MRads of
gamma radiation from a cobalt 66 source. However, it was found, by performing biological counts, that
the control was not sterile. The control could not be further subjected to gamma radiation due to
mechanical problems with the radiation source.
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Table 4-2. Compounds Unaffected by the J.R. Simplot Ex-Situ Bioremediation Technology
Compound
Chlordane (alpha)
Chlordane (gamma)
Chlordane (technical)
Endosulfan I
Endosulfan II
Average Pre-Treatment Soil
Concentration on a Dry Basis
(mg/kg)
1.92
2.21
25.7
2.72
2.12
Average Post-Treatment
Solid Phase Concentration
on a Dry Basis
(mg/kg)
1.74
1.97
16.9
1.61
2.52
4.4.2 Physical Analyses
Prior to treatment in the bioreactor, the soil was screened to separate out material greater than 12.7 mm
(0.5 in) in diameter. Particle size distribution was determined for the soil both before and after the
screening process. Atterberg limits were also determined for the soil before and after the screening
process. The soil was determined to be a clayey sand with gravel. The density of the screened soil was
determined to be 1.22 g/cm3 (76.2 Ibs/ft?). Density data were used to determine the total mass of soil
treated.
4.5 Process Residuals
Three process waste streams were generated by implementation of the J.R. Simplot Ex-Situ
Bioremediation Technology. These streams were the treated soil, wastewater, and the rocks and debris
with diameters greater than 12.7 mm (0.5 in). Prior to the Demonstration Test at Bowers Field, the
Washington State Department of Ecology (WADOE) established a dinoseb clean-up level below which
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Table 4-3. Summary of Pre-Treatment Metals Data
Compound
Aluminum
Barium
Beryllium
Calcium
Chromium
Cobalt
Copper
Iron
Lead
Magnesium
Manganese
Nickel
Potassium
Sodium
Vanadium
Zinc
Average Soil
Concentration on a Dry Basis
(mg/kg)
16,400
122
1.1
5,800
21.8
12.3
27.9
36,900
22.1
4,990
584
25.5
2,310
634
110
181
Average Make-Up Water
Concentration
(Mg/L)
267
200
5.0
18,600
10.0
50.0
25.0
4,490
100
10,400
24.6
40.0
2,220
9,040
50.0
51.2
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the soil no longer presented a hazard to human health and, therefore, would no longer be considered
hazardous. After treatment in the bioreactor at Bowers Field, the dinoseb concentrations in the treated
soil and liquid were below the analytical detection limits as noted in Section 4.4.1 of this report. The
treated soil was then replaced within the excavated area and used as fill material. In states where clean-
up levels have not been established or when the clean-up levels are not met, then disposal of the soil at
a RCRA-permitted facility may be necessary. If nitroaromatic compounds other than dinoseb are
remediated, then disposal of the soil at a RCRA-permitted facility is only required if components of the
waste are listed or the material has hazardous waste characteristics.
Water was used to wash the dinoseb from the separated rocks and debris. This was performed by the
J.R. Simplot Company during the Demonstration Test; however, when the percentage of oversize material
becomes excessive, a separate soil or rock washing vendor may provide assistance in this task. The rinse
water was then added to the bioreactor with the make-up water to be remediated by the process. After
treatment in the bioreactor at Bowers Field, the dinoseb concentration in the water was below the
analytical detection limit. In most instances, the wastewater can be disposed through a publicly owned
treatment works (POTW), assuming the appropriate permits have been obtained.
The third waste stream—the untreated rocks and debris—may present a disposal problem. During the
Demonstration Test, only a portion of the rocks and debris greater than 12,7 mm (0.5 in) in diameter
were washed. Logistical difficulties in executing the washing procedures left a large portion of the
oversize material untouched. When material greater than 12.7 mm in diameter represents a high
percentage of the excavated soil, a separate soil or rock washing technology is required for clean-up of
this fraction or the material must be transported off-site for disposal at a RCRA-permitted facility. For
the oversize material that was washed during the Demonstration Test, it was assumed that the washing
process transferred the dinoseb from the rocks to the rinse water since dinoseb is highly water soluble.
The decontaminated rocks and debris were then replaced in the excavated area as fill material. In cases
where the nitroaromatic compound is not water soluble, the soil washing process separates the coarse
fraction from the fine particles (where contamination is greatest) and then places the fine particles into
the bioreactor. The oversize rocks and debris from the soil washing process may still require disposal
at a RCRA-permitted facility.
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SECTION 5
OTHER TECHNOLOGY REQUIREMENTS
5.1 Environmental Regulation Requirements
Before implementing the J.R. Simplot Ex-Situ Bioremediation System, state regulatory agencies may
require a number of permits to be obtained. A permit may be required to operate the system. A permit
is required for storage of contaminated soil in a waste pile for any length of time and for storage in drums
on-site for greater than 90 days. At the conclusion of treatment, permits may be required to discharge
the wastewater into a publically owned treatment works (POTW). A national pollutant discharge
elimination system (NPDES) permit may be required to discharge into surface waters. If air emissions
are generated, an air emissions permit will be necessary. If off-site disposal of contaminated waste is
required, the waste must be taken off-site by a licensed transporter to a permitted landfill.
Section 2 of this report discusses the environmental regulations that apply to this technology. Table 2-1
presents a summary of the Federal and State ARARs for the J.R. Simplot Ex-Situ Bioremediation
Technology.
5.2
Personnel Issues
For pre-treatment operations (excavation, assembly, and loading), the number of workers required is a
function of the volume of soil to be remediated. During the Demonstration Test, three workers and one
supervisor were required for all operations through loading of Che bioreactor. Once the reactor is loaded,
a Simplot employee familiar with the system and any contaminant-specific requirements will fine-tune the
system to ensure that appropriate operating conditions are established and maintained. During treatment,
only one technician is required to operate the J.R. Simplot Ex-Situ Bioremediation System. This
technician will be trained by a Simplot supervisor. The training will be specific to the J.R. Simplot Ex-
Situ Bioremediation System. Treatment will take place 24 hours a day, however, it is anticipated that
the technician will only be present for approximately one hour each day. During this time, all system
parameters will be checked and any required modifications will he made. If necessary, the system may
operate unattended for several days at a time. For the larger, modular hioreactors, eight workers are
required for 16 hours to erect each bioreactor, and 12 workers are required for 16 hours to install the
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liner for each bioreactor. For lined pits, heavy equipment operators are required to excavate the pits,
and 12 workers are required tor 16 hours to install the liner in each pit.
The health and safety issues for personnel using the Simplot system for waste treatment are generally the
same as those that apply to all hazardous waste treatment facilities. The regulations governing these
issues are documented in 40 CFR 264 Subparts B through G, and Subpart X.
Emergency response training for operations of the J.R. Simplot Ex-Situ Bioremediation System is the
same as the general training required for operation of a treatment, storage, and disposal (TSD) facility
as detailed in 40 CFR 264 Subpart D. Training must address fire-related issues such as extinguisher
operation, hoses, sprinklers, hydrants, smoke detectors and alarm systems. Training must also address
contaminant-related issues such as hazardous material spill control and decontamination equipment use.
^
Other issues include self-contained breathing apparatus use, evacuation, emergency response planning,
and coordination with outside emergency personnel (e.g., fire/ambulance).
For most sites, personal protective equipment (PPE) for workers will include gloves, hard hats, steel-toed
boots, and Tyvek® suits. Depending on contaminant types and concentrations, additional PPE may be
required. Noise levels should be monitored during excavation and pre-treatment screening,
homogenization, and loading activities to ensure that workers are not exposed to noise levels above a
time-weighted average of 85 decibels, over an 8-hour day. If operation of the J.R. Simplot Ex-Situ
Bioremediation System increases noise levels above this limit, workers will be required to wear additional
protection.
5.3 Community Acceptance
Potential hazards related to the community include exposure to volatile pollutants (if present) and other
paniculate matter released to air during soil excavation and handling. Air emissions can be managed by
watering down the soils prior to excavation and handling, and covering the stockpiled soil with plastic
sheeting. Depending on the scale of the project, the biodegradation process may require contaminated
soils to remain stockpiled on-site for extended periods of time. This could expose the community to
airborne emissions for several months. Community exposure to stockpiled soils may be minimized by
excavating in stages, limiting the amount of soil excavated to the amount of soil that can be treated at once.
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The J.R. Simplot potato-processing starch by-product used as a carbon source at the onset of treatment
may be stored in 208-L (55-gal) drums on-site. Once the drums are opened, the potato-processing starch
by-product gives off a foul odor in the immediate vicinity. This odor intensifies over time as the starch
by-product ferments in the drums. The odor may be minimized by storing the drums in a shaded area
to reduce the rate of fermentation. Keeping the drums sealed when not in use will also reduce the odor
that escapes into the ambient air.
During bioremediation, the treatment slurry may also give off a foul odor caused by the enhanced
microbial activity. The odor is not pervasive and only penetrates airspace in the immediate proximity
of the treatment area; covering the bioreactor may minimize this odor.
Noise may be a factor to neighborhoods in the immediate vicinity of treatment. Noise levels may be
elevated during excavation, screening, and homogenization since heavy equipment is used for these
activities. During actual treatment, however, the noise generated by the bioreactor and associated
equipment is expected to be minimal.
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SECTION 6
TECHNOLOGY STATUS
This section discusses the experience of the developer in performing treatment using the J.R. Simplot Ex-
Situ Bioremediation Technology. It also examines the capability of the developer in using this technology
at sites with different volumes of contaminated soil.
6.1 Previous Experience
In addition to the demonstration performed on dinoseb in Ellensburg, Washington, the J.R. Simplot
Company is also participating in a second SITE Demonstration to evaluate the ability of this technology
to degrade another nitroaromatic compound. TNT (2,4,6-trinitrotoIuene). at the Weldon Spring Ordnance
Works in Weldon Spring, Missouri. The pre-treatment level of TNT in the test soil at this site is
approximately 1,500 mg/kg. The treatment is being performed using a bioreactor identical to the one
used in Ellensburg, Washington. These two bioreactors are the latest in the line of development for this
process. Prior to these demonstrations, biodegradation of nitroaromatics using this technology had only
been achieved in treatability studies performed by the University of Idaho.
The J.R. Simplot Company has no experience in the remediation of contaminated sites. To overcome
this hurdle, Simplot intends to form partnerships with respected environmental remediation companies
to implement this technology. For the two SITE Demonstrations, Envirogen Inc. has teamed with
Simplot to provide the necessary expertise in performing full-scale operations.
6.2 Scaling Capabilities
To date, this SITE Demonstration represents the largest scale of remediation performed using the J.R.
Simplot Ex-SStu Bioremediation Technology. During the demonstration, a small portable bioreactor was
used to degrade 30 m3 of dinoseb contaminated soil in Ellensburg, Washington. An identical bioreactor
is currently being used to perform the same scale of remediation at the TNT site in Weldon Spring,
Missouri.
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Simplot (in cooperation with an environmental remediation company) has proposed that the remediation
of greater volumes of soil will require the use of lined, excavated pits or, alternatively, using modular
tanks. A scenario has been proposed by Simplot in which the remediation of up to 7,646 m3 (10,000 yd3)
could be accomplished. This scenario involves the rotating use of four-3,800,000-L (750,000-gal) tanks
over a complete project period of seven months. This period includes excavation, tank erection,
remediation, and demobilization. Each tank would be lined with a 30-mil liner and used to remediate
two 956 m3 (1,250 yd3) batches of soil. It is assumed that the remediation of each batch of soil would
take approximately 30 days, similar to the remediation time required during SITE Demonstration. The
maximum rock size that could be handled would be 38.1 mm (1.5 in) in diameter; all larger rocks would
be crushed to this diameter.
This scenario is being proposed to remediate the entire Bowers Field site in Ellensburg, Washington.
In Reedley, California, excavated pits are being proposed to bioremediate dinoseb contaminated soil. In
addition, excavated pits are being used to destroy TNT contamination at a site in Bangor, Washington.
The economic analysis given in Section 3 of this report is based on this remediation effort.
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REFERENCES
Kaake, R.H.; Crawford, D.L.; and Crawford, R.L. 1994. "Optimization of an Anaerobic
Bioremediation Process of Soil Contaminated with the Nitroaromatic Herbicide Dinoseb
(2-rec-Butyl-4,6-Dinitrophenol)." R.E. (ed.), Proceedings of the Second In Situ and On-
Site Bioreclamation Symposium. Battelle, Columbus, Ohio. In press.
Personal Communications with R.H. Kaake.
3. Roberts, D.J.; Kaake, R.H.; Funk, S.B.; Crawford, D.L.; and Crawford, R.L. 1993.
"Anaerobic Remedition of Dinoseb from contaminated Soil: An On-Site Demonstration."
Appl. Biochem. Biotechnol. In press.
4. U.S. Environmental Protection Agency. 1993. Office of Solid Waste and Emergency Response.
Technology Innovation Office. Innovative Treatment Technologies: Annual Status Report
(Fifth Ed). U.S. Government Printing Office, Washington, D.C. EPA 542-R-93-003.
5. Douglas, J.M. Conceptual Design of Chemical Processes; McGraw-Hill, Inc. New York, 1988.
6. Peters, M.S.; Timmerhaus, K.D. Plant Design and Economics for Chemical Engineers. Third
Edition. McGraw-Hill, Inc. New York, 1980.
7. Garrett, D.E. Chemical Engineering Economics. Van Nostrand Reinhold. New York, 1989.
8. Science Applications International Corporation. "Quality Assurance Project Plan, Superfund
Innovative Technology Evaluation: J.R. Simplot Bioremediation Process (Dinoseb) at
Bowers Field in Ellensburg, Washington," 1993.
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APPENDIX A
VENDOR'S CLAIMS
This appendix was generated and written solely by the J.R. Simplot Company. The statements presented
herein represent the vendor's point of view and summarize the claims made by the vendor, the J.R.
Simplot Company, regarding their Ex-Situ Bioremediation Technology. Publication herein does not
represent the EPA's approval or endorsement of the statements made in this section; the EPA's point of
view is discussed in the body of this report.
A.I Introduction
The Simplot Bioremediaton Process offers a bioremediation alternative to cleaning soils and water
contaminated with nitroaromatics. Nitroaromatics have become serious environmental contaminants at
both private and military locations nationwide. Examples of nitroaromatic contaminants include nitrotolu-
ene explosives, as well as many pesticides, including dinoseb, a herbicide banned because of health
concerns.
The Simplot Process was demonstrated to degrade dinoseb (2-rcc-butyl-4,6-dinitrophenol) to non
detectable limits (15 ppb) which is less than the maximum allowable concentration specified by the
Federal government. The Simplot process is an anaerobic bioslurry for the degradation of nitroaromatic
compounds in soil or aqueous phases. In this demonstration, the Simplot Process was used to clean soil
contaminated with the herbicide dinoseb which is a RCRA-listed waste (PO20).
The Simplot Process was demonstrated by the J.R. Simplot Company and Envirogen, Inc. at Bowers
Field, a former crop dusting site in Ellensburg, Washington. Dinoseb contamination had occurred at this
site, beginning in the 1940's until the 1970's. At Ellensburg, Dinoseb was degraded to less than
detection limits in soils and water, from a beginning concentration of 28 ppm, resulting in overall
reduction greater than 99.9%.
Other agricultural chemicals were also found in the Ellensburg soil. These included DDT, malathion,
parathion, nitroanaline, atrazine, chlordane and endosulfan. The Simplot Process was entirely effective
in the presence of these co-contaminants.
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Optimal temperatures for The Simplot Process have been determined to be between 35 and 37°C. The
summer of 1993 in the Ellensburg area was cold and wet, resulting in average ambient temperatures that
did not exceed 18°C. The Simplot Process was entirely effective, even with sub-optimal temperatures,
resulting in total degradation of dinoseb within 23 days.
The Simplot Process, developed by the University of Idaho and the J.R. Simplot Company, with patents
pending, is licensed exclusively to the J.R. Simplot Company.
A.2 Process
The Simplot Process begins when contaminated soil is placed in a bioreactor with specially prepared
water in a one-to-one ratio by weight. Water is prepared by adding nutrients, pH buffers, and a special
carbon source (a Simplot potato starch byproduct). Addition of the excess carbon source to the reactors
results in the consumption of dissolved oxygen by aerobic bacteria, rapidly establishing anaerobic
conditions. The process is illustrated on the next page.
Before soil is added to the bioreactor, a consortium of enhanced dinoseb-degrading anaerobic bacteria is
introduced to the conditioned water, to increase the rate of nitroaromatic degradation. The enhanced
anaerobic bacteria are stimulated to grow and degrade dinoseb to short chain organic acids, without
formation of potentially toxic polymerization products. After the treatment is complete and the soil is
returned to site, aerobic bacteria can degrade the short-chain organic acids to C02 and water.
The Simplot Process has been demonstrated successfully on a variety of soil types, from sandy soils to
tight clays. Rates of degradation are slightly delayed in heavier soil textures. The Simplot Process makes
use of feasibility testing to optimize the rate of degradation for each site by altering inputs on a site-by-
site basis.
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The Simplot Process
lJhmptot
tno«ulun
[
I (UAon _J
I Souro* J I
Sol
IvibndnQ —*J| ContMtlMtodl—Jl
8cf»«t J I Ov«f«fao | [
Ctotn
Ovuratt*
1^ . I
W>»K I
pH Buffer
«NuMMt
A.3 Cost
Cost of the Simplot Process is less than half the cost of thermal processes including incineration. Savings
of transportation and related costs result because soil remains on site. Cost for a typical agricultural site
can be as low as $250 per cubic yard. Costs are dependent on site characteristics and cost per cubic yard
of soil will be lower with greater quantities.
A.4 Technical Information
This technology is designed to treat soils contaminated with nitroaromatic contaminants. Anaerobic
microbial mixtures have been developed for the pesticide dinoseb and for TNT. These contaminants can
be reduced to less than one part per million in most soils. The proprietary inoculum used by the Simplot
Process consists of a variety of microbial genera, developed at the University of Idaho through selection
of anaerobic microbes that have been most effective in degrading nitroaromatic compounds.
Anaerobic microbial mixtures have been developed by the University of Idaho for Simplot for both the
pesticide dinoseb (2-sec-butyl 4,6-dinitro-phenol) and trinitrotoluene (TNT).
The consortium becomes active at redox potential of -200 mV or lower.
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r
The initial step in the metabolism of nitroaromatic compounds is a reduction of the nitro substituents to
amino groups, producing aminonitro compounds. These intermediates are further degraded to simple
organic acids, and hydroxylated aromatics, which can be subsequently mineralized by indigenous bacteria.
A.5 Advantages
• Dinoseb concentrations have been reduced by more than 99.9% using The Simplot
Process, achieving cleanup levels below the analytical detection limit of 15 ppm.
• Complete anaerobic biodegradation of dinoseb is achieved without the formation
(accumulation) of toxic intermediates.
• Breakdown of dinoseb compounds is complete, resulting in innocuous byproducts, mainly
CO,.
• Dinoseb is degraded using The Simplot Process at temperatures considerably lower than
is required for other biological remediation methods.
• Periodic mixing is sufficient for optimum degradation.
• The Simplot Process has been proven effective in the presence of other commonly found
contaminants on agricultural sites, including nitroanaline, parathion, malathion and
atrazine.
• The Simplot Process is a cost-effective alternative to traditional technologies for both
large and small sites. Costs are often less than half of the cost to incinerate. Total costs
are site-specific and determined by treatability studies.
• Remediated soils are rich in organic content and with high nutrient value, suitable for
returning to the site.
• Liability is reduced because contaminated soil is remediated without being transferred off-
site.
• Treatment of any contaminated site is completed within one season.
A.6 Limitations
• Each site must be individually assessed by treatability studies.
• Presence of co-contaminants may require additional processing, or may be unsuitable for
the Simplot process.
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