&EPA
United States
Environmental Protection
Agency
Office of
Research and Development
Cincinnati, OH 45268
EPA/540/R-01/501
May 2002
EcoMat Inc.'s Biological
Denitrification Process
Innovative Technology
Evaluation Report
SUPERFUNO INNOVATIVE
TECHNOLOGY EVALUATION
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EPA/540/R-01/501
May 2002
EcoMat Inc.'s Biological
Denitrification Process
Innovative Technology Evaluation Report
National Risk Management Research Laboratory
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, Ohio 45268
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Notice
The information in this document has been funded by the U.S. Environmental Protection Agency
(EPA) under Contract Nos. 68-C5-0036 and 68-COO-179 to Science Applications International
Corporation (SAIC). It has been subjected to the Agency's peer and administrative reviews and has
been approved for publication as an EPA document. Mention of trade names or commercial products
does not 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 meetthis 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 (NRMRL) is the Agency's center for
investigation of technological and management approaches for preventing and reducing risks from
pollution that threatens human health and the environment. The focus of the Laboratory's research
program is on methods and theircost-effectiveness forprevention and control of pollution to air, land,
water, and subsurface resources; protection of water quality in public water systems; remediation of
contaminated sites, sediments and ground water; prevention and control of indoor air pollution; and
restoration of ecosystems. NRMRL collaborates with both public and private sector partners to foster
technologies that reduce the cost of compliance and to anticipate emerging problems. NRMRL's
research provides solutions to environmental problems by: developing and promoting technologies
that protect and improve the environment; advancing scientific and engineering information to support
regulatory and policy decisions; and providing the technical support and information transfer to ensure
implementation of environmental regulations and strategies at the national, state, and community
levels.
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.
Hugh W. McKinnon, Director
National Risk Management Research Laboratory
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Abstract
This report summarizes the findings of an evaluation of a biodenitrification (BDN) system developed
by EcoMat Inc. of Hayward, California (EcoMat). This evaluation was conducted between May and
December of 1999 under the U.S. Environmental Protection Agency Superfund Innovative
Technology Evaluation (SITE) Program; it was conducted in cooperation with the Kansas Department
of Health and Environment (KDHE). The demonstration site was the location of a former public water
supply well in Bendena, Kansas. The well water is contaminated with high levels of nitrate. Based on
historical data, nitrate concentrations in the water have ranged from approximately 20 to 130 ppm,
well above the regulatory limit of 10 mg/l. Low concentrations of volatile organic compounds (VOCs),
particularly carbon tetrachloride (CCI4), have been a secondary problem. The overall goal of EcoMat
was to demonstrate the ability of its process to reduce the levels of nitrate in the groundwater to an
acceptable concentration, thus restoring the water supply well as a drinking water source.
EcoMat's process is a two component process consisting of 1)an exs/fuanoxicbiofilterBDN system,
and 2) a post-treatment system. The BDN system utilizes specific biocarriers and bacteria to treat
nitrate-contaminated water, and employs a patented reactorfor mixing the suspended biocarriers and
retaining biocarrier within the reactors to minimize solids carryover. Methanol is added to the system
as a carbon source for cell growth and for inducing metabolic processes that remove free oxygen
and encourages the bacteria to consume nitrate. EcoMat's post-treatment system can be subdivided
into two primary treatment parts: one part for oxidation and a second part for filtration. The oxidation
treatment is intended to oxidize residual nitrite back to nitrate, oxidize any residual methanol, and
destroy bacterial matter exiting the BDN system. The oxidation treatment may consist of ozonation
or ultraviolet (UV) treatment, or a combination of both. Filtration usually consists of a clarifying tank
and one or more filters designed to remove suspended solids generated from the BDN process.
The demonstration consisted of four separate sampling events interspersed over a 7% month period
of time. During these events EcoMat operated its system to flow between three and eight gallons per
minute. During this same time period nitrate levels in the well water varied from greater than 70 mg/l
to approximately 30 mg/l. For Event 1, chlorination was the only post-treatment used. Post-treatment
for Event 2 consisted of clarification; sand filtration; cartridge filtration using 20um rough filters; and
UV oxidation. Post-treatment for Event 3 consisted of ozone; UV oxidation; clarification; cartridge
filtration using 20um rough filters, Sum high efficiency filters, carbon adsorption, and 1um polishing
filters. Post-treatment for Event 4 consisted of chlorination, clarification, Sum high efficiency filtration,
air stripping, and 1um polishing filtration.
The primary objective of the study focused on three performance estimates. The first performance
estimate was to determine if the BDN portion of the process was capable of reducing combined
nitrate-N/nitrite-N (total-N) to less than 10.5 mg/l. The second performance estimate included
evaluation of the post-treatment for its ability to produce treated groundwater that would meet
applicable drinking water standards with respect to nitrate-N, nitrite-N, and total-N, using a level of
significance of 0.10. This required reducing high levels of nitrate-N to less than 10.5 mg/l, maintaining
nitrite-N levels to less than 1.5 mg/l, and achieving a total-N level of less than 10.5 mg/l. When
rounded to whole numbers, these performance estimates would meet the regulatory maximum
contaminant limits (MCLs) of 10, 1, and 10 mg/l for nitrate-N, nitrite-N, and total-N respectively. The
IV
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Abstract (Cont'd)
third performance estimate involved evaluating the final effluents for other parameters, such as
turbidity, pH, residual methanol, suspended solids, and biological material.
Results for the final system outfall indicate that when the post BDN effluent contains nitrite-N levels
in excess of the regulatory limit of 1 mg/l the EcoM at post-treatment components failed to adequately
and reliably reduce the nitrite-N levels to below the 1 mg/l level. The post-treatment system was
varied considerably throughout the demonstration. For Event 1, chlorination was the only post-
treatment used. Post-treatment for Event 2 consisted of clarification; sand filtration; cartridge filtration
using 20um rough filters; and UV oxidation. Post-treatment for Event 3 consisted of ozone; UV
oxidation; clarification; cartridge filtration using 20um rough filters, Sum high efficiency filters, carbon
adsorption, and 1um polishing filters. Post-treatment for Event 4 consisted of chlorination,
clarification, Sum high efficiency filtration, air stripping, and 1um polishing filtration. Comparison of
samples collected immediately upstream and immediately downstream of the post-treatment systems
indicated that none of the combinations used were effective for removing residual methanol. In all
instances methanol levels were virtually the same or higher in final effluent exiting the post-treatment
systems.
Since the post-treatment system implemented by EcoMat varied foreach of the four events, data from
the four events was first analyzed separately. Formal statistical analyses were used to address the
first two performance estimates discussed above, using a significance level of 0.10. The overall
conclusion from these tests was that:
• Events 1 and 2 were found to be successful in meeting the first two performance goals for
significantly reducing levels of nitrate-N and nitrite-N after BDN and after post treatment.
• Event 3 and 4 were not shown to be successful in significantly reducing levels of nitrate-N
and nitrite-N after BDN and after post treatment.
Daily dissolved oxygen (DO) field measurements indicated that the de-oxygenating step of EcoMat's
BDN process may not have been optimized throughout the demonstration, and especially during
Events 3 and 4. The desired DO level of partially biodenitrified (partial BDN) water in the De-
oxygenating Tank is <. 1 mg/l. However, DO values below 1 mg/l were measured only during the first
two events.
The effectiveness of the post-treatment systems were variable for different parameters. Comparison
of samples collected immediately upstream and immediately downstream of the post-treatment
systems indicated that none of the combinations used were effective for removing residual methanol
to the demonstration objective of £ 1 mg/l. In all instances, downstream methanol levels were virtually
the same or higher than upstream methanol levels. Methanol concentrations averages in final effluent
were between 15 and 98 mg/l during the four events, the first two events appear to have had a
substantial beneficial impact on solids carryover. Residual bacterial content in the final effluent,
decreased significantly in Events 3 and 4, likely the result of adding "high efficiency" (Sum) and
"polishing" (1 urn) filters to the post-treatment system. Nevertheless, the levels of total heterotrophic
and facultative anaerobe bacterial matter measured in the final effluent for all events was well above
corresponding inlet water levels.
An economic analysis was also conducted for estimating the cost of implementing EcoMat's biological
denitrification technology at full-scale. For a 100 gpm system, the estimated cost to treat nitrate-
contaminated groundwater over a one year period is $490,000, or approximately $0.012/gal. The
cost over 5, 10,or 15 years is estimated to increase to approximately$730,000 ($0.0034/gal.);
$1,000,000 ($0.0024/gal.) and $1,300,000 ($0.002/gal.), respectively.
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Contents
Notice ii
Foreword iii
Abstract iv
Tables ix
Figures xi
Abbreviations and Acronyms xii
Acknowledgments xiv
Executive Summary ES-1
1.0 Introduction 1
1.1 Background 1
1.2 Brief Description of the SITE Program 2
1.3 The SITE Demonstration Program and Reports 2
1.4 Purpose of the Innovative Technology Evaluation Report (ITER) 2
1.5 Technology Description 3
1.6 Key Contacts 4
2.0 Technology Applications Analysis 5
2.1 Key Features of the BDN and Post-Treatment Processes 5
2.2 Operability of the Technology 6
2.3 Applicable Wastes 7
2.4 Availability and Transportability of Equipment 7
2.5 Materials Handling Requirements 8
2.6 Range of Suitable Site Characteristics 8
2.7 Limitations of the Technology 9
2.8 ARARS for the EcoMat BDN Technology 10
2.8.1 Comprehensive Environmental Response, Compensation, and
Liability Act (CERCLA) 10
2.8.2 Resource Conservation and Recovery Act (RCRA) 12
2.8.3 Clean Air Act (CAA) 12
2.8.4 Clean Water Act (CWA) 12
2.8.5 Safe Drinking Water Act (SDWA) 13
2.8.6 Occupational Safety and Health Administration (OSHA)
Requirements 13
3.0 Economic Analysis 15
3.1 Introduction 15
3.2 Conclusions 19
3.3 Factors Affecting Estimated Cost 19
3.4 Issues and Assumptions 19
VI
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Contents (Cont'd)
3.4.1 Site Characteristics 19
3.4.2 Design and Performance Factors 19
3.4.3 Financial Assumptions 20
3.5 Basis for Economic Analysis 20
3.5.1 Site Preparation 20
3.5.2 Permitting and Regulatory Requirements 21
3.5.3 Capital Equipment 21
3.5.4 Startup and Fixed Costs 22
3.5.5 Labor 22
3.5.6 Consumables and Supplies 23
3.5.7 Utilities 24
3.5.8 Effluent Treatment and Disposal 25
3.5.9 Residuals Shipping and Disposal 25
3.5.10 Analytical Services 25
3.5.11 Maintenance and Modifications 25
3.5.12 Demobilization 26
4.0 Demonstration Results 27
4.1 Introduction 27
4.1.1 Project Background 27
4.1.2 Project Objectives 27
4.2 Detailed Process Description 27
4.2.1 BDN System 28
4.2.2 Post-Treatment System 31
4.3 Field Activities 31
4.3.1 Pre-Demonstration Activities 31
4.3.2 Sample Collection and Analysis 32
4.3.3 Process Monitoring 32
4.3.4 Process Residuals 32
4.4 Performance and Data Evaluation 34
4.4.1 Event 1 34
4.4.2 Event 2 45
4.4.3 Event 3 54
4.4.4 Event 4 65
4.4.5 Inter-Event Comparison 74
4.4.6 Data Quality Assurance 76
5.0 Other Technology Requirements 80
5.1 Environmental Regulation Requirements 80
5.2 Personnel Issues 80
5.3 Community Acceptance 80
6.0 Technology Status 81
VII
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Contents (Cont'd)
6.1 Previous Experience 81
6.2 Ability to Scale Up 81
7.0 References 82
Appendix A- Developer Claims and Discussion A-1
VIM
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Tables
Table Page
2-1
3-1
3-2
4-1
4-2
4-3
4-4
4-5
4-6
4-7
4-8
4-9
4-10
4-11
4-12
4-13
4-14
4-15
4-16
4-17
4-18
4-19
4-20
4-21
4-22
4-23
4-24
4-25
4-26
4-27
4-28
4-29
4-30
4-31
4-32
4-33
Federal and State ARARS for the EcoMat BDN Process
Cost Estimates for Initial Year of 1 00 GPM BDN System, Online 80%
Cost Estimates for EcoMat's BDN System for Multi-Year Treatment Scenarios . . .
Demonstration Objectives
Summary of Laboratory Analyses Conducted for the Demonstration
Summary of Field Measurements Conducted for the Demonstration
Event 1 - Summary Statistics
Event 1 - Nitrate-N and Nitrite-N Results
Event 1 - Summary of Treatment Effectiveness
Event 1 - Dissolved Oxygen Measurements
Event 1 - pH Measurements
Event 1 - Turbidity Measurements
Event 1 - TSS Results
Event 1 - Microbial Results (TCH, FA, and FC)
Event 1 - Methanol Results
Event 1 - Supplemental Analyses Results
Event 2 - Summary Statistics
Event 2 - Nitrate-N and Nitrite-N Results
Event 2 - Summary of Treatment Effectiveness
Event 2 - Dissolved Oxygen Measurements
Event 2 - pH Measurements
Event 2 - Turbidity Measurements
Event 2 - TSS Results
Event 2 - Microbial Results (TCH, FA, and FC)
Event 2 - Methanol Results
Event 2 - Supplemental Analyses Results
Event 3 - Summary Statistics
Event 3 - Nitrate-N and Nitrite-N Results
Event 3 - Summary of Treatment Effectiveness
Event 3 - Dissolved Oxygen Measurements
Event 3 - pH Measurements
Event 3 - Turbidity Measurements
Event 3 - TSS Results
Event 3 - Microbial Results (TCH, FA, and FC)
Event 3 - Methanol Results
Event 3 - Supplemental Analyses Results
... 11
16
... 17
... 29
33
33
... 36
... 37
... 38
... 39
... 39
... 40
41
... 42
... 43
43
... 46
... 47
... 48
... 49
... 49
... 50
50
... 51
... 52
53
... 55
... 56
... 58
... 59
... 59
... 60
60
... 61
... 62
... 63
IX
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Tables (Cont'd)
4-34 Event 4 - Summary Statistics 66
4-35 Event 4 - Nitrate-N and Nitrite-N Results 67
4-36 Event 4 - Summary of Treatment Effectiveness 68
4-37 Event 4 - Dissolved Oxygen Measurements 69
4-38 Event 4 - pH Measurements 69
4-39 Event 4 - Turbidity Measurements 70
4-40 Event 4 - TSS Results 70
4-41 Event 4 - Microbial Results (TCH, FA, and FC) 72
4-42 Event 4 - Methanol Results 73
4-43 Event 4 - Supplemental Analyses Results 73
4-44 Inter-Event Comparison of Demonstration Criteria for Final Effluent 76
4-45 Nitrate Matrix Spike Percent Recovery Summary 78
4-46 Nitrite Matrix Spike Percent Recovery Summary 78
4-47 Nitrate MS/MSD Relative Percent Difference Summary 78
4-48 Nitrite MS/MSD Relative Percent Difference Summary 78
4-49 Nitrate Field Duplicate Summary 79
4-50 Nitrite Field Duplicate Summary 79
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Figures
Figure Page
3-1 Cost Distributions - EcoMat Biodenitrification Multi-Year Treatment Scenarios 18
4-1 Flow Diagram Showing EcoMat's Treatment System and Sample Collection Points ... 28
4-2 Detailed Schematic of the EcoMat Denitrification Reactor 30
4-3 Event 1 - Treatment Effectiveness for Averaged Test Results 35
4-4 Event 1 - Comparison of Flow Rate Fluctuation and Final Effluent Total-N
Concentrations 44
4-5 Event 2 - Treatment Effectiveness for Averaged Test Results 45
4-6 Event 2 - Comparison of Flow Rate Fluctuation and Final Effluent Total-N
Concentrations 54
4-7 Event 3 - Treatment Effectiveness for Averaged Test Results 55
4-8 Event 3 - Comparison of Flow Rate Fluctuation and Final Effluent Total-N
Concentrations 64
4-9 Event 4 - Treatment Effectiveness for Averaged Test Results 65
4-10 Event 4 - Comparison of Flow Rate Fluctuation and Final Effluent Total-N
Concentrations 74
4-11 Inter-Event Comparison - Treatment Effectiveness for Nitrate-N/Nitrite-N 75
XI
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Abbreviations and Acronyms
AQCR
AQMD
ATTIC
ARARs
BDN
cm3
CAA
CCI4
CERI
CERCLA
CFR
CSCT
cfu
CWA
Dl
DO
EcoMat
EDA
FA
FC
FS
FID
ft2
gpm
GC/MS
G&A
g/cm3
HSWA
ICP
ITER
KDHE
kW/Hr
LDR
LOS
m3
MS/MSD
MCLs
MCLGs
MDL
MeOH
mg/l
Air Quality Control Regions
Air Quality Management District
Alternative Treatment Technology Information Center
Applicable or Relevant and Appropriate Requirements
Biodenitrification
Cubic centimeter
Clean Air Act
Carbon tetrachloride
Center for Environmental Research Information
Comprehensive Environmental Response, Compensation, and Liability Act
Code of Federal Regulations
Consortium for Site Characterization Technologies
Colony forming units
Clean Water Act
Deionized
Dissolved oxygen
EcoMat Inc. of Hayward, CA
Exploratory data analysis
Facultative anaerobes
Fecal coliform
Feasibility study
Flame lonization Detector
Square feet
Gallons per minute
Gas chromatography/mass spectroscopy
General and administrative
Gram per cubic centimeter
Hazardous and Solid Waste Amendments
Inductively coupled plasma spectroscopy
Innovative Technology Evaluation Report
Kansas Department of Health and Environment
Kilowatts per hour
Land disposal restriction
Level of significance
Cubic meter
Matrix spike/matrix spike duplicate
Maximum contaminant levels
Maximum contaminant level goals
Method detection limit
Methanol or methyl alcohol
Milligrams per liter
XII
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Abbreviations and Acronyms (Cont'd)
MPN Most probable number
NAAQS National Ambient Air Quality Standards
NCR National Oil and Hazardous Substances Pollution Contingency Plan
NIST National Institutes of Standards and Technology
NOAA National Oceanographic and Aeronautic Administration
NPDES National Pollutant Discharge Elimination System
NPL National Priorities List
NRMRL National Risk Management Research Laboratory (EPA)
NSCEP National Service Center for Environmental Publications
Nitrate-N A measure of nitrate in which each mg/l of nitrate-N equates to 4.4 mg/l of nitrate
Nitrite-N A measure of nitrite in which each mg/l of nitrite-N equates to 3.2 mg/l of nitrite
ND N on-detectable, not detected, less than detection limit
NPDWS National primary drinking water standards
NTU Normal turbidity unit
OSHA Occupational Safety and Health Administration
ORD Office of Research and Development (EPA)
OSWER Office of Solid Waste and Emergency Response (EPA)
OSC On-scene coordinator
PLFA Phospholipid fatty acids
POTW Publicly owned treatment works
PPE Personal protective equipment
POL Practical quantitation limit
POA Project Objective Agreement
PVC Polyvinyl chloride
PWS Public water supply
POTW Publicly owned treatment works
QAPP Quality assurance project plan
RPD Relative percent difference
RI/FS Remedial Investigation / Feasibility Study
RPM Remedial project manager
RCRA Resource Conservation and Recovery Act
SAIC Science Applications International Corporation
SARA Superfund Amendments and Reauthorization Act
SDWA Safe Drinking Water Act
SOP Standard operating procedure
SW-846 Test methods for evaluating solid waste, physical/chemical methods
SWDA Solid Waste Disposal Act
SITE Superfund Innovative Technology Evaluation
S.U. Standard units
TER Technology Evaluation Report
TCH Total culturable heterotrophs
TOC Total organic carbon
TSCA Toxic Substances Control Act
TSD Treatment, storage, and disposal
THM Trihalomethanes
ug/l Micrograms per liter
UV Ultraviolet
US EPA United States Environmental Protection Agency
VOC Volatile organic compound
WSR Wilcoxon signed rank
XIII
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Acknowledgments
This report was prepared under the direction of Dr. Ronald Lewis (retired) and Mr. Randy Parker, the
EPA Technical Project Managers for this SITE demonstration at the National Risk Management
Research Laboratory (NRMRL) in Cincinnati, Ohio. EPA NRMRL peer review of this report was
conducted by Mr. Vicente Gallardo. Mr. Andrew Matuson of Science Applications International
Corporation (SAIC) served as the SITE work assignment manager for the implementation of
demonstration field activities and completion of all associated reports.
The demonstration required the combined services of several individuals from EcoMat Inc., the
Kansas Departmentof Health Services (KDHE), the town of Bendena, KS,and SAIC. Peter Halland
Jerry Shapiro of EcoMat, Inc. served as logistical and technical con tacts for the developer. Rick Bean
of the KDHE was instrumental for making provisions for the treatment shed and associated utilities,
and for conducting additional sampling and analysis independent of the SITE Program. Iraj Pourmirza
of the KDHE Bureau of Water- Water Supply Section provided technical support regarding drinking
water issues. The cooperation and efforts of these organizations and individuals are gratefully
acknowledged.
This report was prepared by Joseph Tillman, Susan Blackburn, Craig Chomiak, and John Nicklas,
of SAIC. Mr. Nicklas also served as the SAIC QA coordinator for data review and validation. Joseph
Evans (the SAIC QA Manager), Dr. Herbert Skovronek, and James Rawe, all of SAIC, internally
reviewed the report. Field sampling and data acquisition was conducted by William Carrier, Dan Patel,
Steve Stavrou, and Joseph Tillman.
Cover Photographs: Clockwise from top left are 1) "EcoLink" - synthetic polyurethane cubes, 1 cm on a side,
used as biocarrier medium; 2) Gas detector tube monitoring above overflow tank (dark tank in background is
the "EcoMat Reactor", also known as "R2"); 3) Concrete cap for 23 ft. ID Public Water Supply Well # 1 (vent
pipe visible on right side of cap); 4) Post-BDN effluent discharging to overflow tank; 5) Overview of
biodenitrification system - Overflow tank (front), 2 m3 EcoMat Reactor (center), and De-oxygenating Tank (far
right); 6) Portion of post-treatment system (clarifying tank at left); and 7) Shed for housing treatment system.
XIV
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Executive Summary
This re port summarizes the findings of an evaluation of the
EcoMat Biodenitrification (BDN) treatment process. The
process was tested for treating ground water contaminated
with high levels of nitrate at the location of a former public
water supply well in Bendena, Kansas. This evaluation
was conducted under the U.S. Environmental Protection
Agency (EPA) Superfund Innovative Technology
Evaluation (SITE) Program.
It should be noted that BDN processes have been used for
some years for treatment of wastewater and groundwater.
However, the technology has been known in the past to be
applied to the treatment of groundwater for drinking water
purposes. Thus, the SITE Program's interest was to
evaluate such an application.
Overview of Site Demonstration
The EcoMat BDN process is a type of fixed film
bioremediation that uses specific biocarriers and bacteria
to treat nitrate-contaminated water. Fixed film treatment
allows rapid and compact treatment of nitrate with minimal
byproducts. Unique to the EcoMat system is a patented
mixed reactor that retains the biocarrier within the system,
thus minimizing solids carryover. Methanol is added to the
system as a source of carbon for cell growth and for
inducing metabolic processes that remove free oxygen and
encourage the bacteria to consume nitrate. Methanol is
also important to assure that the nitrate conversion results
in the production of nitrogen gas rather than the
intermediate nitrite, which is considered to be more toxic.
EcoMat's BDN system was evaluated under the SITE
Program at the location of a former public water supply well
#1 (PWS) in Bendena, Kansas. The primary contaminant
in the well water was nitrate. Based on historical data,
nitrate concentrations in the water ranged from
approximately 20 to 130 ppm, well above the regulatory
limit of 10 mg/l. Low concentrations of VOCs, particularly
carbon tetrachloride (CCI4), were a secondary problem.
The overall goal of EcoMat was to demonstrate the ability
of its process to reduce the levels of nitrate in the extracted
groundwater and restore the public water supply well as a
drinking water source.
The central goal of EcoMat was to demonstrate that its
system could produce groundwaterfrom PWS Well # 1 that
would be in compliance with the drinking water MCLs for
nitrate-N, nitrite-N, and total-N, while at the same time
meeting requirements for other parameters such as
turbidity, pH, residual methanol, suspended solids, and
biological material. With respect to both the BDN and post-
treatment components of the system, EcoMat proposed the
following three performance estimates:
With incoming groundwater having nitrate-N of 20
mg/l or greater, and operating at a flow through
rate of 3-15 gpm, the BDN unit would reduce the
combined nitrate-N and nitrite-N level (total-N) in
PWS Well #1 groundwater to at or below a
combined concentration of 10 mg/l.
The post treatment or polishing unit would produce
treated groundwater meeting applicable drinking
waterstandards with respect to nitrate-N (10 mg/l),
nitrite-N (1 mg/l), and total-N (10 mg/l).
Coupled with the planned or alternative post-
treatment, the product water would consistently
meet drinking water requirements, except for
residual chlorine. Specifically it would not contain
turbidity of greater than 1 NTU, detectable levels
of methanol (1 mg/l), or increased levels of
biological material or suspended solids, and would
have a pH in the acceptable 6.5-8.5 range.
For the purposes of these evaluations, demonstration
criteria were chosen that, when rounded to the nearest
whole number, they would be consistent with the Kansas
Department of Health and Environment (KDHE) MCL
values. The KDHE MCL values for nitrate-N, nitrite-N, and
total-N were 10,1, and 10 mg/l, respectively. Thus, values
less than the nitrite-N demonstration criterion of 1.5 mg/l
(i.e., <_ 1.49 mg/l) would reduce to 1 mg/l. Values less than
the nitrate-N and total-N demonstration criterion of 10.5
mg/l (i.e., <_ 10.49 mg/l) would reduce to 10 mg/l.
ES-1
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Conclusions from this SITE Demonstration
Since the post-treatment system implemented by EcoMat
varied foreach of the fourevents, data from thefourevents
were first analyzed separately. Formal statistical analyses
were used to address the first two performance estimates
previously discussed (i.e., total-N level less than 10 mg/l,
and nitrate-N and nitrite-N levels less than 10 mg/l and 1
mg/l, respectively), using a significance level of 0.10. The
overall conclusion from these tests was that:
• Events 1 and 2 were determined successful in
meeting the 1st and 2nd performance goals.
Concentrations of total-N, nitrate-N, and nitrite-N
were significantly reduced to below MCLs
immediately following BDN treatment and after
post treatment.
• Event 3 and 4 were determined not successful in
meeting the 1st and 2nd performance goals for
significantly reducing levels of total-N, nitrate-N,
and nitrite-N after BDN and after post treatment.
A number of additional conclusions may be drawn from the
evaluation of the EcoMat BDN and post-treatment
processes as a whole, based on extensive analytical data
supplemented by field measurements. These include:
The filtration systems incorporated following the
first event appear to have had a substantial
beneficial impact on solids carryover. Based on
laboratory and field measurements, the Sum high
efficiency and 1 urn polishing filters used during the
last two events produced better results for
reduction of biological material, total suspended
solids, and turbidity in the final effluent.
Specific to turbidity, which has a secondary
drinking water criterion of 1 Normal Turbidity Unit
(NTU), average field measurement results for
Events 3 and 4 final effluents were 1.2 and 0.96
NTU, respectively. These results were improved
in comparison to the 1.8 NTU average value for
Event 2 final effluent, in which "sand filtration" and
"rough filtration" (20um) were used; and where
greatly improved in comparison to the 4.4 NTU
average value for Event 1 final effluent, in which
no filtration was used.
Total suspended solids (TSS) laboratory results
were similar to the turbidity field measurements.
The demonstration criterion for TSS in finaleffluent
was to be less than or equal to that of the inlet
water, in which TSS was consistently measured to
be below the detection limit of 5 mg/l for all four
events. TSS results for Event 1 were consistently
above this 5 mg/l threshold and averaged 10 mg/l.
During Events 2, 3, and 4 TSS was measured
above 5 mg/l in 3 of 9, 7of 9, and 7 of 8 of the final
effluentsamples collected,respectively. However,
the average TSS value forthese events was below
the detection limit of 5 mg/l.
The demonstration criterion for residual bacterial
content in the final effluent was also to be less
than or equal to that of the inlet water. The highest
bacterial counts in final effluent occurred for Event
2. This was likely due to the fact that no
disinfection (i.e., chlorine, ozone, etc.) was used
and that"rough"filtration (20 um)was the smallest
filtration size used during Event 2. Residual
bacterial content in the final effluent, decreased
significantly in Events 3 and 4, likely the result of
adding "high efficiency" (Sum) and "polishing"
(1um) filters to the post-treatment system.
Nevertheless, the levels of total heterotrophic and
facultative anaerobe bacterial matter measured in
the final effluent for all events was well above
corresponding inlet water levels.
None of the post treatment system combinations
used during the demonstration was effective in
removing residual methanol to the demonstration
objective of £ 1 mg/l. Methanol concentration
averages in final effluent were between 15 and 98
mg/l during thefourevents. Methanol was actually
measured on average to be higher in the final
effluent samples than in post BDN samples
(collected upstream of the post-treatment system)
for three of the four events. This may be an
anomaly attributable to ongoing methanol
degradation in the post BDN samples prior to
analysis. The final effluent samples were
disinfected (preserved)so thatfurtherreaction was
halted.
There appears to be an inverse correlation
between flow rate and nitrate removal (i.e., higher
flow rate correlating to less effective nitrate
removal), based on a per sample round
comparison of system flow rate and Total-N
concentration in finaleffluent. However, it was not
possible to confirm that this was a cause/effect
relationship because of (a) the narrow range of
flows actually investigated and (b) variations in
performance that occurred or became necessary
due to upsets, and other operational problems.
ES-2
-------
pH was not altered by the EcoMat BDN or post-
treatment systems. For Events 1 and 2 there was
a very slight increase in pH from the inlet water to
the post BDN effluent. No discernable change in
pH between inlet water and final effluent was
measured for Event 3. For Event 4, the pH values
for inlet water ranged from 8.3 - 9.2 (outside of the
acceptable drinking water limits of 6.5-8.5). Final
effluent pH values were slightly lower and ranged
from 6.8 - 8.9.
Daily dissolved oxygen (DO) field measurements
indicated thatthe de-oxygenating step of Eco Mat's
BDN process may not have been optimized. The
desired DO level of partially biodenitrified (partial
BDN) water in the de-oxygenating tank is <_1 mg/l.
However, DO values below 1 mg/l were measured
only during the first two events. Average DO
during Events 1 and 2 were 1.1 and 1.0 mg/l,
respectively. DO in partial BDN effluent during
Event 3 were consistently measured above 1 mg/l
and averaged 2.1 mg/l. DO in partial BDN effluent
during Event 4 was also consistently measured
above 1 mg/l and averaged 2.8 mg/l. Because
Events 3 and 4 had poorer nitrate removal than
Event 1 and 2, the inability to optimize the de-
oxygenating step of the BDN process during the
last two events could have negatively impacted
results.
The quality assurance analyses of critical sample
data indicated adequate data quality was achieved
for evaluating the EcoMat technology. With
respect to data accuracy, the overall
demonstration recovery average for 44 nitrate-N
MS/MSD sample sets was approximately 95%.
The overall demonstration recovery average for44
nitrite-N MS/MSD sample sets was approximately
96%. With respect to data precision, the overall
demonstration average relevantpercentdifference
for those MS/MSD sets for nitrate-N and nitrite-N
were 2.7 and 2.1, respectively.
Carbon tetrachloride, which had been historically
detected in PWS Well #1 water, was not detected
in inlet water or final effluent samples. Thus, the
effectiveness of any of the post-treatment
combinations for treating this compound could not
be evaluated.
For a 100 gpm system, the estimated cost to treat
nitrate-contaminated groundwater over a one year
period is $490,000, or approximately $0.012/gal.
The cost over 5, 10,or 15 years is estimated to
increase to approximately$730,000 ($0.0034/gal.);
$1,000,000 ($0.0024/gal.) and $1,300,000
($0.002/gal.), respectively.
ES-3
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Section 1.0
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
EcoMat Inc.'s Biological Denitrification (BDN) process. Key
contacts are listed at the end of this section for inquiries
regarding additional information about the SITE Program,
this technology, and the demonstration site.
1.1 Background
The EcoMat Inc. BDN process was demonstrated under
the Superfund Innovative Technology Evaluation (SITE)
Program at a former public water supply (PWS) well in
Bendena, Kansas. The demonstration project, which
occurred in cooperation with the Kansas Department of
Health and Environment (KDHE), evaluated an ex situ
anoxic BDN technology developed by EcoMat Inc. of
Hayward, California. The technology is a type of fixed-film
biofilter that uses specific biocarriers and naturally
occurring anoxic bacteria to treat nitrate contaminated
water. During this demonstration the technology was part
of an overall system that included four different
combinations of post-treatment systems. Each of the four
post-treatment systems included an oxidation component
to convert residual nitrite back to nitrate. A filtration
component was included in three of the fourpost-treatment
systems to remove suspended solids. Both the biological
denitrification process and post-treatmenttechnology were
evaluated during this demonstration.
The well of concern, the Bendena Rural Water District #2
Public Water Supply (PWS) Well #1, and surrounding
monitoring wells have been the subject of numerous
groundwater investigations since 1985. Historical data
from these investigations revealed elevated concentrations
of nitrate and carbon tetrachloride (CCI4). The data show
that nitrate concentrations in the groundwater range from
approximately 20 to 130 ppm, which is well above the
National Primary Drinking WaterStandards(NPDWS) limit
of 10 mg/l. The historical data show a history of CCI4
concentrations between 2 ug/l and 31 ug/l (the current
MCLforCCI4is 5 ug/l).
Numerous sampling investigations at PWS Well #1 have
been unsuccessful in identifying the specific source of
contamination for both nitrate and CCI4. Since the land
surrounding the city is primarily agricultural, non-point
runoff of contaminated surface water from agricultural land
was considered as a possible contamination source for
nitrate. This explanation was not supported by the low
concentrations of ammonia (< 0.8 mg/l) found in
groundwater samples. There was also reason to suspect
an industrial leak upgradient of the well as the source of
nitrate, but this has not been confirmed.
The demonstration project, which occurred between May
and December 1999, consisted of four separate sampling
events. During these events, EcoMat operated its system
with a flow rate between approximately three and eight
gallons per minute. During this time period, nitrate levels
in the well water varied from greater than 70 mg/l to
approximately 30 mg/l.
The overall goal of EcoMat was to demonstrate the ability
of its process to reduce the levels of nitrate in the extracted
groundwater and restore the public water supply well as a
drinking water source. Specifically, the Primary Objectives
for this SITE demonstration included the following:
demonstrate, that with an incoming groundwater
nitrate-N concentration of 20 mg/l or greater, and
operating at a flow rate of 3 to 15 gpm, the BDN
unit will reduce the combined nitrate-N and nitrite-
N (i.e., total-N) level in the PWS Well
#1groundwater to less than 10.5 (which would
reduce to less than orequal to the MCL of 10 mg/l
when rounded to a whole number).
demonstrate that the post-treatment unit will
produce treated groundwater that will meet
applicable drinking water standards with respect to
nitrate-N (i.e., to less than 10.5 mg/l), nitrite-N (i.e.,
to less than 1.5 mg/l) and combined nitrate-N and
-------
nitrite-N (i.e., to less than 10.5 mg/l). These
demonstration criteria would reduce to less than or
equal to the MCLs of 10, 1, and 10 mg/l when
rounded to whole numbers).
and remediation at Superfund sites. The goal of
technology transfer activities is to develop interactive
communication among individuals requiring up-to-date
technical information.
1.2 Brief Description of the SITE Program 1.3
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
Reauthorization 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 three major elements:
the Demonstration Program,
the Consortium for Site Characterization
Technologies (CSCT), 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 can assess the
technology's site-specific applicability. Technologies
evaluated are either available commercially or close to
being available for full-scale remediation of Superfund
sites. SITE demonstrations usually are conducted at
hazardous waste sites under conditions that closely
simulate full-scale remediation conditions, thus assuring
the usefulness and reliability of the information collected.
Data collected are used to assess: (1) the performance of
the technology; (2) the potential need for pre- and post-
treatment of wastes; (3) potential operating problems; and
(4) the approximate costs. The demonstration also
provides opportunities to evaluate the long term risks and
limitations of a technology.
Existing and new technologies and test procedures that
improve field monitoring and site characterizations are
explored in the CSCT Program. New monitoring
technologies, or analytical methods that provide faster,
more cost-effective contamination and site assessment
data are supported by this program. The CSCT 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 and CSCT Programs through various
activities. These activities increase awareness and
promote the use of innovative technologiesforassessment
The SITE Demonstration Program and
Reports
In the past technologies have been selected for the SITE
Demonstration Program through annual requests for
proposal (RFP). EPA reviewed proposals to determine the
technologies with promise for use at hazardous waste
sites. Several technologies also entered the program from
current Superfund projects, in which innovative techniques
of broad interest were identified for evaluation under the
program.
Once the EPA has accepted a proposal, cooperative
arrangements are established among EPA, the developer,
and the stakeholders. Developers are responsible for
operating their innovative systems at a selected site, and
are expected to pay the costs to transport equipment to the
site, operate the equipment on-site during the
demonstration, and remove the equipment from the site.
EPA is responsible for project planning, sampling and
analysis, quality assurance and quality control, preparing
reports, and disseminating information. Usually, results of
Demonstration Programs are published in three
documents: the SITE Demonstration Bulletin, the
Technology Capsule, and the Innovative Technology
Evaluation Report (ITER). The Bulletin describes the
technology and provides preliminary results of the field
demonstration. The Technology Capsule provides more
detailed information aboutthe technology, and emphasizes
key results of the SITE field demonstration.
The ITER provides detailed information on the technology
investigated, a categorical cost estimate, and all pertinent
results of the SITE field demonstration. An additional
report, the Technology Evaluation Report (TER), is
available by request only. The TER contains a
comprehensive presentation of the data collected during
the demonstration and provides a detailed quality
assurance review of the data.
For the EcoMat Inc. Biological Denitrification process
demonstration, there is a SITE Technology Bulletin,
Capsule, and ITER; all of which are intended for use by
remedial managers for making a detailed evaluation of the
technology for a specific site and waste. A TER is also
submitted for this demonstration to serve as verification
documentation.
1.4 Purpose of the Innovative Technology
Evaluation Report (ITER)
This ITER provides information on both 1) EcoMat Inc.'s
Biological Denitrification process for treatment of nitrate in
-------
waterand on 2) the post-treatment system fortreatment of
organics (e.g., VOCs, methanol), solids and microbes in
water. This report 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 (OSCs), contractors, and other decision-
makers carrying out specific remedial actions. The ITER
is designed to aid decision-makers in evaluating specific
technologiesforfurtherconsideration 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
desirable 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 matrix. The
characteristics of other wastes and 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
Fixed film bioremediation using a biocarrier is the treatment
of contaminated groundwater using bacteria appropriate to
the contaminants of concern attached to some form of
supporting substrate. Using EcoMat's patented mixed
reactor, the biocarrier is designed to be retained in the
system, thereby minimizing solids carryover. In the case
of the Bendena water well, elevated nitrate in the
groundwater is the primary problem; low concentrations of
volatile organic compounds (VOCs) (particularly CCI4) are
a secondary problem. Fixed film treatment allows rapid
and compact treatment of nitrate with minimal byproducts.
Methanol is added as a source of carbon forthe metabolic
processes and cell growth of the bacteria that convert the
nitrate to nitrogen gas.
The mechanism for anoxic biodegradation of nitrate
consists of initial removal of excess oxygen followed by
two sequential reactions as shown in the following
equations.
Denitrification Step 1:
Oxygen Removal:
CH3OH + 1 .5O2
CH3OH
3NO
3NO + CO
2H2O
Denitrification Step 2:
CH3OH
2NO
N + CO + 2OKT
H2O
(2)
(3)
Overall Denitrification Reaction:
5CH3OH
6NO
3N + 5CO + 6OKT
7H2O (4)
CO
2H2O
(1)
Note: The subsequent discussion refers to nitrate- and
nitrite-nitrogen values (nitrate-N and nitrite-N, respectively),
in which each mg/l of nitrate-N is equivalent to 4.4 mg/l of
nitrate and each mg/l of nitrite-N is equivalent to 3.2 mg/l of
nitrite.
Available oxygen must first be consumed to a dissolved
oxygen concentration of < 1 mg/l so that the bacteria are
forced to substitute the nitrate as the electron acceptor
(Equation 1 ). The nitrate is then reduced to nitrite (Equation
2). In Equation 3, the nitrite is further reduced to nitrogen
gas. The overall denitrification reaction is presented in
Equation 4.
Nitrite production is an intermediate step and there is no a
priori reason to assume that the second reaction is at least
as fast and/or favored as the first reaction in the presence
of a specific bacterial population. Consequently, any
evaluation scheme must establish that there is no buildup
of nitrite, particularly since the nitrite-nitrogen MCL is 1
mg/l, one-tenth that of nitrate. High concentrations of
nitrate and high nitrate/methanol ratios may also affect the
concentration of residual nitrite.
The effluent from the denitrification system will contain
small amounts of bacteria and suspended solids which
must be removed by a post-treatment system, and also
may contain some concentration of nitrite. EcoMat can
incorporate an oxidation component (ozonation and/or
ultraviolet (UV) disinfection) into its post-treatment system
to accomplish some degree of chlorinated hydrocarbon
destruction as well as oxidation of remaining nitrite back to
nitrate, oxidation of any residual methanol, and destruction
of bacterial matter. A filtration component can also be
incorporated into the post-treatment system to remove
suspended solids. Although ozonation and UV oxidation
may also result in disinfection of treated water, additional
chlorination would also be required before the treated water
could be used as a drinking water supply in Kansas.
Although this demonstration is being carried out on drinking
water, anoxic BDN using a biocarrier should be applicable
to industrial waste waters as well as leachate from
commercial, industrial, and hazardous waste sites
containing various levels of nitrate. The presence of other
contaminants could play a significant role in the
effectiveness and viability of the overall treatment system.
The post treatment system components selected for the
Bendena site were intended to produce final effluent that
met drinking water standards for nitrate and nitrite and to
-------
also provide some removal of methanol. If the planned
ozonation system proved to be inadequate for VOC
removal, EcoMat had planned to reactivate an inactive air
stripper at the site. With more complex waste waters, the
post-treatment system may play a larger role in the overall
effectiveness of the total system.
Design of the treatment process/system for a particular site
requires the characterization of the contaminant types,
concentrations, and variability in the water source that will
become the feed to the system. This information is used to
properly size the BDN unit and the post-treatment system.
For the Bendena site, it was also necessary to assure that
discharge of the treated water to a septic system did not
unintentionally recharge the aquifer in such a way as to
significantly alter (decrease) the nitrate (or chlorinated
hydrocarbon) content of the aquifer feeding PWS Well#1.
1.6 Key Contacts
Additional information regarding EcoMat Inc.'s Biological
Denitrification process, the company's other treatment
processes, and the SITE Program can be obtained from
the following sources:
Technology Developer
EcoMat Inc.
Peter Hall
26206 Industrial Blvd.
Hayward, CA 94545
Phone: (510) 783-5885
Fax: (510) 783-7932
e-mail: info@ecomatinc.com
www.ecomatinc.com
The SITE Program
Mr. Robert A. Olexsey
Director, Land Remediation and Pollution Control Division
National Risk Management Research Laboratory
U.S. Environmental Protection Agency
26 West Martin Luther King Drive
Cincinnati, OH 45268
(513)569-7861
FAX: 513-569-7620
Mr. Randy Parker
U.S. EPA SITE Project Manager
National Risk Management Research Laboratory
U.S. Environmental Protection Agency
26 West Martin Luther King Drive
Cincinnati, OH 45268
(513)569-7271
e-mail: Parker.Randy(5).epa.qov
Information on the SITE Program is available through the
following on-line information clearinghouses:
• The SITE Home page (www.epe.gov/ORD/SrTE)
provides general program information, current
project status, technology documents, and access
to other remediation home pages.
• The OSWER CLU-ln electronic bulletin board
(http://WWW.clu-ln.org) 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 writing to
USEPA/NSCEP, P.O. Box 42419, Cincinnati, OH 45242-
2419, or by calling 800-490-9198.
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Section 2.0
Technology Applications Analysis
This section addresses the general applicability of the
EcoMat Inc. BDN Technology to sites containing
groundwater contaminated with nitrate. The analysis is
based on results from and observations made during the
SITE Program demonstration and from additional
information received from EcoMat Inc. SITE demonstration
results are presented in Section 4 of this report. The
vendor had the opportunity to discuss the applicability,
other studies and performance of the technology in
Appendix A.
2.1 Key Features of the BDN and Post-
Treatment Processes
The EcoMat Inc. BDN Technology is designed to quickly
and effectively treat nitrate-contaminated groundwater
while generating minimal byproducts. This system is
appropriate for treating potential drinking water supplies
and may also be effective in treating industrial wastewater
or leachate from commercial, industrial, and hazardous
waste sites. The system may be most suitable for treating
water supplies in agricultural regions that are subject to
increased nitrate concentrations due to seasonal fertilizer
application. The system can also treat inorganic pollutants,
other than nitrate, through cultivation of different types of
microbes.
The EcoMat Inc. BDN Technology is a fixed-film
bioremendiation process using a biocarrier and bacteria
appropriate to the contaminant of concern. In the case of
the Bendena water well, the contaminant of concern is
nitrate. EcoMat's patented mixed reactor retains the
biocarrier in the system, thereby minimizing solids
carryover. In addition, the fixed film treatment allows rapid
and compact treatment of nitrate with minimal byproducts.
Overall, the denitrification process is intended to convert
nitrates in the groundwater to nitrogen gas. In addition to
demonstrating EcoMat's BDN Technology, the project also
included demonstration of a post-treatment system
designed to destroy or remove any intermediate
compounds potentially generated during the biological
breakdown of the nitrate (e.g., nitrite), and also remove
small amounts of bacteria and suspended solids that are
not attached to the biocarrier. Treatment of VOCs present
in the influent can also be accomplished by the post-
treatment system by incorporating traditional treatment
methods, such as ozonation and air stripping.
The denitrification process is accomplished in two reactors.
Reactor 1 (R1), referred to as the "De-oxygenating Tank,"
includes bioballs loaded with denitrifying bacteria. These
bacteria are fed a 50 percent aqueous methanol solution to
act as a carbon source for the metabolic processes that
remove free oxygen and to act as a carbon source for cell
growth. The second reactor (R2), which receives the de-
oxygenated water from Reactor 1, is packed with 1-cubic
centimeter (cm3) cubes of a synthetic sponge-like
polyurethane biocarrier called "EcoLink." The Ecolink
medium hosts the colonies of bacteria cultured for
degrading nitrate. An important feature to this medium is
that small contiguous holes are incorporated into the
medium to maximize surface area for the active bacteria
colony and to permit the exit of the nitrogen gas formed
during the denitrification process.
Reactor 2 also includes a specially designed mixing
apparatus to direct the incoming de-oxygenated water into
a circular motion, thus keeping the media in constant
circulation and maximizing contact between the water and
media. Methanol is also fed to this reactor to encourage
nitrate consumption and to act as a carbon source for the
anaerobic bacteria degrading the nitrate to nitrogen gas.
The effluentfrom R2 received additional treatment, referred
to here as post-treatment. During the course of the
demonstration, four different combinations of post-
treatment were incorporated into the overall treatment
system. Each of the four systems utilized during the
demonstration incorporated one or more oxidation
components, such as chlorination, ultraviolet (UV) light, or
ozonation. In addition to destroying any active bacteria
exiting the BDN system, the oxidation component was
-------
designed to oxidize: 1) residual nitrite back to nitrate 2)
residual methanol, and 3) VOCs in the water (e.g., CCI4).
During the majority of the demonstration, the post-
treatment system also incorporated a filtration component
designed to remove suspended solids generated from the
BDN process. In addition to using a clarifying tank, a
variety of filter combinations were used, including a sand
filter, a carbon filter, and different sized cartridge filters (i.e.,
rough, high efficiency, and polishing filters).
The developer believes that the denitrification technology
is capable of effectively converting nitrate and methanol to
nitrogen gas and carbon dioxide. This aspect was of
primary interestforthis demonstration. The developeralso
claims that the post-treatment or polishing step can 1)
oxidize any residual nitrite to nitrate, 2) oxidize residual
methanol, 3) destroy bacterial matter exiting the EcoMat
reactor, and 4) remove suspended solids. No claim was
made concerning the removal of VOC's.
2.2 Operability of the Technology
The prime factor in determining the effectiveness of the
EcoMat Inc. BDN Technology is the growth of a healthy
population of naturally-occurring anoxic bacteria
(denitrifiers) to reduce nitrate to nitrogen gas and carbon
dioxide in the presence of methanol. The growth of these
denitrifiers is dependant upon a numberof factors including
nitrate-N concentration, pH, temperature, and carbon
concentration. In addition, continuous operation with
minimal process disruptions, includingshutdowns, is critical
to maintaining a healthy microbial population. Overall, the
EcoMat technology is designed to provide optimum
conditions for growing and sustaining an active bacteria
colony.
The EcoMat technology is an ex situ process consisting of
a BDN and a post-treatment system. The BDN system
includes two reactors in series, followed by an overflow
tank. Each reactor is two cubic meters in size with a water
capacity of approximately 1,100 gallons. The first reactor
(R1), referred to as the "Deoxygenating Tank" is equipped
with ports for both the tank's influent and effluent, and a
methanol feed. The second reactor (R2), referred to as the
"EcoMat Reactor," is also equipped with ports for the
influent, effluent, and methanol feed. The final component
of the BDN system is a small overflow tank capable of
holding approximately 200 gallons.
Prior to system start-up, a shakedown period is required to
begin BDN by developing the necessary biological growth
on the "biocarrier" in the bioreactor chamber under full
recycle. The shakedown period normally takes
approximately six weeks. This 6-week period gives the
system operators an opportunity to adjust water flow and
methanol feed rates based on observed nitrate and nitrite
concentrations and other factors.
Since each of the reactors maintains large populations of
sensitive microbes, continuous operation of the system is
critical. The growth of denitrifying bacteria on the biocarrier
in the Deoxygenating Tank is dependent upon achieving
both a relatively low dissolved oxygen concentration (e.g.,
~1 mg/l) and an environment rich in carbon. As a result,
methanol is routinely fed to the De-oxygenating Tankto act
as the source of carbon. To ensure that a healthy
population of denitrifiers is maintained, routine monitoring
of the methanol concentration is performed.
The Deoxygenating Tank requires little attention and
maintenance. The groundwater simply enters the top of
the reactor, flows through the bioballs and exits the bottom
of the reactor. Level switches near the top of the tank
control flow into the tank; these do require routine service.
Continuous operation ofthe EcoMat Reactor is also critical.
Specialized bacteria for degrading nitrate are cultured in
this reactor. Since an anaerobic environment is necessary
to accomplish denitrification, dissolved oxygen levels are
routinely monitored to ensure a concentration of less than
1.0 mg/l.
The EcoMat Reactoris equipped with a patented mixerthat
is designed to circulate the water within the reactor without
the aid of moving parts. This reactor contains EcoLink
media which also are circulated by the mixing apparatus.
Like the de-oxygenating tank, the EcoMat Reactor also
requires minimal operational attention and maintenance.
The most common maintenance activity would be periodic
replacement of the EcoLink biocarrier, which occasionally
becomes overloaded and falls out of suspension.
Specific to the demonstration, delivery ofthe groundwater
to the treatment system was accomplished by a
submersible pump installed within PWS Well #1. The
submersible pump was originally controlled by a float
switch in Reactor #1. To prevent potential burn-out of the
submersible pump, the float switch was replaced first with
a pressure switch and finally with a "flapper." The line
delivering the groundwater to the treatment system was
equipped with a totalizer to monitor flow rate. Totalizers
were also installed at the treatment system discharge point
and on the recycle line for the SITE evaluation.
The post-treatment system included different treatment
components during each ofthe four demonstration events.
The four post-treatment scenarios are presented below.
Event 1 - Chlorination
Event 2 - Clarification, Sand &
Rough (20um) Filtration,
and UV Oxidation
EventS- Ozone, UV Oxidation,
Clarification, Rough
(20um) & High Efficiency
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(5|jm) Filtration, Carbon
Adsorption, & Polishing
(1 |jm) Filtration
Event 4 - Chlorination,
Clarificatio n, High
Efficiency (5|jm filter)
Filtration, Air Stripping,
and Polishing (20|jm)
Filtration
Each component used in the post-treatment system was
purchased "off the shelf" from equipment suppliers.
Operation of the equipment was learned in the field during
the demonstration period and appropriate adjustments to
feed and flow rates were made to maximize the
effectiveness of treatment. General maintenance of the
post-treatment system during the demonstration included
flushing out the entire post-treatment system, back
washing of the sand filter, drainage of the clarifier, and
replacement of the cartridge filters.
Both the BDN and post-treatment systems were installed
inside a storage building that was twelve feet wide, twenty
feet long, and twelve feet high. The shed was equipped
with 1) electricity to operate pumps and provide heat, 2) a
potable water supply for cleanup and decontamination
activities, and 3) a telephone and facsimile machine
hookup. The shed also provided sufficient work space and
room for storage of equipment and reagents.
The process, including both the BDN and the post-
treatment system, was designed to operate unattended;
however, during the four sampling events seven system
shutdown periods required the presence of on-site
personnel to address the operational problems and bring
the system back online. Shutdowns were caused by a
combination of mechanical problems and electrical storms
causing power outages. Numerous shutdowns during
sampling Event 2 resulted in a decision to abort the event
and restart when mechanical problems were corrected. It
should be noted that additional shakedown periods were
required after some of the shutdowns to reestablish
microbial populations in the reactors.
2.3 Applicable Wastes
The EcoMat BDN technology is an ex situ fixed- film BDN
system designed to destroy or remove nitrates in water. In
addition to using the technology on a potential drinking
water source during this demonstration, the technology
should be applicable to industrial wastewaters and
leachate from commercial, industrial, and hazardous waste
sites containing elevated nitrate concentrations.
During the demonstration, a post-treatment system
designed to remove chlorinated hydrocarbons from water
was also evaluated. The developer also claims that the
technology is suitable for treating other types of inorganic
pollutants since the EcoMat reactor can effectively cultivate
microbes that can degrade different contaminants.
An EcoMat biological reactor is currently being used at a
Department of Defense facility in Southern California to
treat perchlorate. Also, there are EcoMat systems installed
at aquariums for removing nitrate from saltwater.
2.4 Availability and Transportability of
Equipment
The EcoMat Biological Denitrification and Post-Treatment
Process requires a level pad, ideally concrete, and a
heated building. The size of the pad and building is
dependent on the size of the process installed at a
particular site. EcoMat has indicated that it is feasible to
install a treatment system outside, which may be
necessary for very large systems. In such instances, heat
tracing would be installed to provide temperature control.
At the Bendena site, the process consisted of a
Deoxygenating Tank, the EcoMat Reactor, an overflow
tank, and the post-treatment system (ozone unit, UV
treatment, clarifier, sand filter, cartridge filters, air stripper,
and carbon filters). This entire process (except for the
existing air stripper) and necessary support equipment fit
inside a shed that was twelve feet wide, twenty feet long,
and twelve feet high. Since this system is designed to be
unattended, a trailer or additional office space in the
building housing the process should not be necessary.
Equipment and supplies associated with the process were
transported to the site by one truck. Each two cubic meter
(m3) reactor tank was delivered to the site in halves to
permit for easy handling and assembly. The remainder of
the treatment units and associated equipment can be
handled and installed by one person.
Depending on well availability at sites intending to use this
technology, a drill rig with associated drilling equipment
mightbe necessary. Fortunately, during this demonstration
a former railroad well constructed in the early 1900's
served as the source for the nitrate-contaminated
groundwater. The total well depth is 73.4 feet below
ground surface (bgs) and the static water level is
approximately 45 bgs; the inside well diameter is
approximately 23 feet.
During the demonstration the EcoMat BDN and Post-
Treatment systems required periodic maintenance of a
number of process units and replacement was necessary
for a number of units. Some of the equipment changes
necessary during system operation included new pressure
switches for controlling tank levels, new PVC piping and
hoses to rectify leaks, and new filters to prevent filter
microbial buildup. All replacement equipment was either
purchased locally or delivered to the site via courier.
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Treated water from the system was discharged to a 1,000
gallon septic system specifically purchased and installed
for the demonstration. Heavy equipment such as a
backhoe may be required for septic system installation.
If the application for septic system installation had been
denied due to reasons such as a percolation, slope, depth
to groundwater, etc., other discharge options would have
been investigated. During this demonstration numerous
options were available including discharge to 1) a down
slope drainage network, 2) a return line back to the PWS
Well #1, or 3) the ground up gradient of PWS Well #1.
Ultimately, the intent of this system is to treat the water to
meet drinking water standards. Therefore, in an actual
installation treated water would be routed directly into the
distribution system for delivery to customers in the
community. Therefore, the availability and transportability
of equipment related to delivery of water into a specific
distribution system would need to be investigated.
2.5 Materials Handling Requirements
The major materials handling requirement for the EcoMat
BDN and Post-Treatment systems was installation of the
individual process units which make-up the treatment
system. The KDHE provided a shed and a pumped line
from PWS Well #1 to the shed. The shed included all
necessary services such as potable water, electricity, heat
and a phone line.
The entire system was delivered to the site on one truck.
Installation of the system required the support of one
person over a period of approximately one week. All
process unitsand associated equipmentaresmall and light
enough to permit this one person to unload and install the
equipment.
Prior to beginning the demonstration, a variety of activities
were necessary to prepare the BDN and Post-Treatment
systems for start-up, including a shake down of the
equipment. The materials handling requirements for
bringing water from the well were minimal since a pumping
and groundwater delivery system had already been
installed within the PWS well.
The shakedown period simply involved developing the
necessary biological growth on the "biocarrier" in the
bioreactor chamber. With the exception of more frequent
sampling and adjustments to water flow and methanol feed
rates, the activities performed during the shakedown period
were no different from those that would be performed
during routine operation of the system under normal
conditions.
If the BDN and Post-Treatment systems are utilized to treat
groundwater, installation of one or more wells may be
necessary. Drilling services are generally subcontracted to
a company which has both the required equipment (drill
rigs, augers, samplers) and personnel trained in drilling
operations and well construction. If work is to be
performed on a hazardous waste site, drilling personnel
must have the OSHA-required 40-hour health and safety
training. Once the well(s) are drilled each must be
equipped with a pump to deliver the groundwater to the
treatment system. An equalization tank may be necessary
to store the feed water rather than pumping directly to the
system. All pumps chosen must be able to perform under
a variety of conditions.
Depending on the characteristics of the source water,
installation of a pretreatment system may be required.
Parameters in the source water that may cause inhibition
of the BDN system include pH, dissolved oxygen,
temperature, and heavy metals.
The BDN system does not generate any hazardous
residuals; however, extremely small quantities of non-
hazardous residuals are generated by various units in the
post-treatment system. Sludge is generated by the
clarifying tank and the cartridge filters periodically become
clogged and need to be flushed or replaced. Residuals
generated during the demonstration included spent filter
cartridges and biocarrier media; these were placed in
plastic trash bags and discarded in an on-site dumpster.
2.6 Range of Suitable Site Characteristics
Locations suitable for on-site treatment using the EcoMat
Denitrification and Post-Treatment System must be able to
provide relatively uninterrupted electrical power and
potable water for cleanup activities. Electrical power was
required fora control panel equipped with high level alarms
and reset buttons, and for operation of several electrically
driven pumps throughout the system, including a
submersible pump to draw water from the well. Power was
also required to provide heat to the shed via an electrical
heater. Heat was necessary to maintain a minimum water
temperature of 60°F in the treatment system and to protect
equipment and personnel during cold temperatures.
Overall, the EcoMat Biological Denitrification System
requires a 115-volt, 3-phase electrical service. During the
four demonstration sampling events the average and
maximum energy usage for the overall system were 8.2
kW-hr and 12.6 kW-hr, respectively.
There were minimal storage space requirements for
process chemicals. Process chemicals required for the
demonstration included 50% methanol aqueous solution
and a liquid chlorine solution. The methanol solution was
stored in a 100-gallon plastic tank nearthe de-oxygenating
and EcoMat reactors. The chlorine solution was stored in
a 5-gallon pail beside the post- treatment system. Any
reagents required for system monitoring (e.g., Nitrate-N,
Nitrite-N, DO, pH, etc.) were stored in small Styrofoam
shipping containers on shelving inside the shed. All
process residuals (spent filters and biocarriers, clarifier
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sludge) were placed in plastic trash bags and stored in the
shed until final disposal as domestic trash.
2.7 Limitations of the Technology
The EcoMat BDN technology is a treatment system
designed to remove excess nitrate and, with appropriate
post-treatment may also remove chlorinated hydrocarbons
(e.g., CCI4), methanol, and microorganisms. The maximum
removal of nitrates was achieved during the demonstration
when the flow through the system was in the 3.0 - 5.0 gpm
range. At this flow rate it is obvious that the system would
not be appropriate for supplying large residential
communities with adequate supplies of treated water. The
system may be more applicable to reducing or eliminating
nitrate in small community water supplies, in industrial
wastewaters, orin the leachate fromcommercial, industrial,
or hazardous waste sites.
The growth of healthy microbial populations within each of
the system's reactors is the key factor in determining the
effectiveness of the technology. The growth of these
organisms is dependant upon factors such as a sufficient
source of carbon, a continuous low dissolved oxygen
concentration (< 1.0 mg/l), an acceptable steady pH and
temperature range, and intimate contact between the
biocarrier and contaminated water. Also, like most
biological systems, the system can be inhibited by toxics
(e.g., heavy metals) in the source water. Many of these
factors are dependent upon a system that has minimal
operational/mechanical problems and system shutdowns.
During the course of the demonstration project, the
EcoMat Biological Denitrification System, which is designed
to operate unattended, had numerous
operational/mechanical problems that required immediate
attention from on-site demonstration staff. System
shutdowns occurred on approximately seven occasions;
two of which occurred due to electrical storms and five
occurring from system mechanical problems. A number of
other operational problems occurred, impacting effluent
quality but not causing system shutdown.
The majority of operational/mechanical problems
encountered during the demonstration were remedied
quickly; normally within minutes to a couple hours of
learning of the problem. However, during the second
sampling event, a faulty compressor switch in the de-
oxygenating tank caused a chain-reaction of other
problems downstream of the tank, thereby forcing the
demonstration team to abort the event.
It should be noted that the SITE team was not present
during periods between the four events to monitor system
perturbations (if they occurred). System shutdowns
occurring during demonstration events that were not
caused by an electrical storm are summarized below:
Just prior to starting Event 2 (in July 1999)
compressor switches in the de-oxygenating tank
failed to monitor the water level in the tank. This
prevented the switch from controlling the
submersible pump delivering waterfrom the well to
the system. The malfunctioning switches were
replaced with a "flapper" to control flow to the tank.
This delayed the start of Event 2.
Replacement of the compressor switch in the de-
oxygenating tank required system shutdown and
drainage of the tank. This maintenance activity
caused the biocarrier to settle in the EcoMat
reactor and clog the lower perforated screen used
to separate the biocarrier mixing zone from the
lower portion of the reactor. EcoMat drained the
water level in the tank to allow pressure washing
of the screen. The draining disrupted the microbe
colonies and further delayed the start of Event 2.
Activation of the high level alarm occurred on four
separate occasions while no high levels were
observed. The high level alarm shuts off the pump
routing water to the EcoMat reactor. The
shutdowns occurred twice during the aborted
Event 2 in early July 1999, and twice again during
Event 3 in October 1999.
Towards the end of Event 3, a high level alarm
was activated and the system was shut down due
to excessive biological growth occurring on one of
the post-treatment system filters. The filters were
bypassed to complete the sampling event.
As stated earlier, other problems encountered during the
demonstration affected the concentrations of parameters
that are critical to treatment effectiveness and compliance
with federal drinking water standards. These problems are
summarized below.
During Event4 EcoMat discovered airentering the
de-oxygenating reactor via the reactor feed pump.
This increased thedissolved oxygen concentration
in the reactor and disrupted the anoxic
environment inhabited by the denitrifiers. EcoMat
switched pumps to mitigate the problem.
An ozone leak was found in the post-treatment
system at the start of Event 3. This leak reduced
the system's ability to oxidize residual nitrite to
nitrate, oxidize residual methanol, and destroy
bacteria. EcoMat replaced a leaking hose soon
after the leak was discovered via gas detector tube
monitoring.
The pump feeding methanol either malfunctioned
or was inadvertently turned off during Event 4.
With no methanol being fed into the system, there
was no carbon source for bacterial cell growth and
nitrate consumption was reduced.
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Significant solids carryover from the BDN system
to the post-treatment system caused unexpected
frequent maintenance on the filters and clarifier.
This occurred routinely during Event2, when filters
were first incorporated into the post-treatment
system. Maintenance activities included replacing
filters, back washing filters, and draining the
clarifier. Also, large concentrations of heterotrophic
bacteria and high turbidity readings in the system's
final effluent made the water unacceptable for
drinking purposes.
High methanol concentrations (range: 14.6 - 98
mg/l) in the final effluent also made this water
unacceptable for drinking purposes. These high
methanol concentrations were caused by
excessive feed rates, or by the failure of the post-
treatment systems to oxidize residual methanol.
2.8 ARARS for the EcoMat BDN
Technology
This subsection discusses specific federal environmental
regulations pertinent to the operation of the EcoMat
Biological Denitrification and Post-Treatment processes
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: (1) the Comprehensive
Environmental Response, Compensation, and Liability Act;
(2) the Resource Conservation and Recovery Act; (3) the
Clean Air Act; (4) the Clean Water Act; (5) the Safe
Drinking Water Act, and (6) the Occupational Safety and
Health Administration regulations. These six general
ARARs are discussed below; specific ARARs that may be
applicable to the EcoMat BDN and Post-Treatment
Process are identified in Table 2-1.
2.8.1 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. It
directs EPA to do the following:
• use remedial alternatives that permanently and
significantly reduce the volume, toxicity, or the
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. Superfund
removal actions are conducted in response to an
immediate threat caused by a release of a hazardous
substance. Many removals involve small quantities of
waste of immediate threat requiring quick action to alleviate
the hazard. 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
or pollutants. The EcoMat BDN and post-treatment
systems are likely to be part of a CERCLA remedial action
since the toxicity of the contaminants of concern is reduced
by either denitrification or oxidation. Remedial actions are
governed by the SARA amendments to CERCLA. 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 ata particular site and demands on the
Superfund RPM for other sites. These waiver options
apply only to Superfund actions taken on-site, and
justification for the waiver must be clearly demonstrated.
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Table 2-1. Federal and State ARARs for the EcoMatBDN Process.
Process
Activity
Characteriza-
tion of
untreated
waste
Waste
Processing
Storage of
auxiliary
wastes
Determination
of cleanup
standards
Waste disposal
ARAR
RCRA: 40
CFR Part 261
(or state
equivalent)
RCRA: 40
CFR Part 264
(or state
equivalent)
CAA: 40 CFR
Part 50
(or state
equivalent)
RCRA: 40
CFR Part 264
Sub-part J
(or state
equivalent)
RCRA: 40
CFR Part 264
Subpart I
(or state
equivalent)
SARA:
Section
121(d)(2)(ii);
SDWA: 40
CFR Part 141
RCRA: 40
CFR Part 262
CWA: 40 CFR
Parts 403
and/or 122
and 125
Description
Standards that
apply to
identification and
characterization of
wastes.
Standards apply to
treatment of
wastes in a
treatment facility.
Regulations govern
toxic pollutants,
visible emissions
and particulate
matter.
Regulation governs
standards for tanks
at treatment
facilities.
Regulation covers
storage of waste
materials
generated.
Standards that
apply to surface &
groundwater
sources that may
be used as drinking
water.
Standards that
pertain to
generators of
hazardous waste.
Standards for
discharge of
wastewater to a
POTW or to a
navigable
waterway.
Basis
Chemical and physical properties of
waste determine its suitability for
treatment by the EcoMat BDN
Process.
Applicable or appropriate for the
EcoMat BDN Process.
During process operations, any off-
gases (i.e., from ozonation, air
stripping, etc.) must not exceed limits
set for the air district of operation.
Standards for monitoring and record
keeping apply.
Storage tanks for liquid wastes (e.g.,
decontamination waste) must be
placarded appropriately, have
secondary containment and be
inspected daily.
Potential hazardous wastes remaining
after treatment (i.e., spent biocarrier,
etc.) must be labeled as hazardous
waste and stored in containers in good
condition. Containers should be stored
in a designated storage area and
storage should not exceed 90 days
unless a storage permit is obtained.
Applicable and appropriate for the
EcoMat BDN Process used in projects
treating groundwater for use as
drinking water.
Waste generated by the EcoMat
process which may be hazardous is
limited to spent carbon, well purge
water, spent media or biocarriers,
clarification/filtration residual wastes,
and decontamination wastes.
Applicable and appropriate for well
purge water and decontamination
wastewater generated from process.
Response
Chemical and physical analyses
must be performed to determine
if waste is a hazardous waste.
When hazardous wastes are
treated, there are requirements
for operations, record keeping,
and contingency planning.
Off-gases may contain volatile
organic compounds or other
regulated substances; although,
levels are likely to be very low.
If storing non-RCRA wastes,
RCRA requirements may still be
relevant and appropriate.
Applicable for RCRA wastes;
relevant and appropriate for
non-RCRA wastes.
Remedial actions of surface and
groundwater are required to
meet MCLGs or MCLs
established under SDWA.
Generators must dispose of
wastes at facilities that are
permitted to handle the waste.
Generators must obtain an EPA
ID number prior to waste
disposal.
Discharge of wastewater to a
POTW must meet pre-treatment
standards; discharges to a
navigable waterway must be
permitted under NPDES.
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2.8.2 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. It 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 EcoMat Biological Denitrification and
Post-Treatment processes if RCRA defined hazardous
wastes are present.
Hazardous wastes that may be present include the
aqueous waste to be treated, spent media or biocarriers
from each of the reactors, and the residual wastes
generated from any process included in the post-treatment
system, such as clarification and filtration. If wastes are
determined to be hazardous according to RCRA (either
because of a characteristic or a listing carried by the
waste), essentially all RCRA requirements regarding the
management and disposal of this hazardous waste will
need to be addressed by the remedial managers. Wastes
defined as hazardous under RCRA include characteristic
and listed wastes.
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.
RCRA regulations do not apply to sites where RCRA-
defined wastes are not present.
Unless they are specifically delisted through delisting
procedures, hazardous wastes listed in 40 CFR Part 261
Subpart D currently 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, treated
wastes are still classified as hazardous wastes because
the pre-treatment material was a listed waste.
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 off-site), 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. These subparts also
generally apply to remediation at Superfund sites.
Subparts F and S include requirements for 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 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.
2.8.3 Clean Air Act (CAA)
The CAA establishes national primary and secondary
ambient air quality standards for sulfur oxides, particulate
matter, carbon monoxide, ozone, nitrogen dioxide, and
lead. It also limits the emission of 189 listed hazardous
pollutants such as vinyl chloride, arsenic, asbestos and
benzene. States are responsible for enforcing the CAA.
To assist in this, Air Quality Control Regions (AQCR) were
established. Allowable emission limits are determined by
the AQCR, or its sub-unit, the Air Quality Management
District (AQMD). These emission limits are based on
whether or not the region is currently within attainment for
National Ambient Air Quality Standards (NAAQS).
The CAA requires that treatment, storage, and disposal
facilities comply with primary and secondary ambient air
quality standards. Emissions from post-treatment systems
associated with EcoMat's Biological BDN may need to
meet current air quality standards. For example, the
ozonation system may be regulated by state or local
agencies. Also, State air quality standards may require
additional measures to prevent emissions, including
requirements to obtain permits to install and operate
processes (e.g., air strippers for control of VOCs).
2.8.4 Clean Water Act (CWA)
The objective of the Clean Water Act is to restore and
maintain the chemical, physical and biological integrity of
the nation's waters by establishing federal, state, and local
discharge standards. If treated water is discharged to
surface water bodies or Publicly Owned Treatment Works
(POTW), CWA regulations will apply. A facility desiring to
discharge water to a navigable waterway must apply for a
permit under the National Pollutant Discharge Elimination
System (NPDES). When a NPDES permit is issued, it
includes waste discharge requirements. Discharges to
POTWs also must comply with general pretreatment
regulations outlined in 40 CFR Part 403, as well as other
applicable state and local administrative and substantive
requirements.
The demonstration did have a variety of available options
for disposal of the water. These options included
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discharge 1) to a 1 000 gallon septic system, 2) to a nearby
down gradient drainage network, 3) back down PWS Well
#, and 4) into the ground down gradient of PWS Well #1.
After careful review, option #1 was selected as the most
viable.
Treated effluent from the SITE demonstration was
discharged to an on-site 1000 gallon septic system at a
rate of approximately 7,200 gallons per day. Permission
for septic system installation and discharge to the system
was required by Doniphan County, KS. The county
required the completion of a Sewage Facility
Application/Permit. Approval for discharge to the septic
system was granted by the KDHE.
The only listed option that would have been regulated
under the CWA and required a NPDES permit would have
been discharge to a nearby down gradient drainage
network. It should be noted that depending on the levels
of contaminants and perm it limitations, additional treatment
may be required prior to discharge.
2.8.5 Safe Drinking Water Act (SDWA)
The SOW A 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 (NPDWS)
are found in 40 CFR Parts 141 through 149. Parts 144 and
145 discuss requirements associated with the underground
injection of contaminated water. If underground injection of
wastewater is selected as a disposal means, approval from
EPA or the delegated state for constructing and operating
a new underground injection well is required.
Since the actual intent of the EcoMat BDN Process is to
render the water as drinkable (i.e., reducing nitrate-N and
nitrite-N to below their respective MCLs of 10 and 1 mg/l),
in most cases treated effluent would be discharged directly
into the commu nity water system. For example, the treated
effluent could be routed to 1) a water supply tank, 2) to an
existing drinking water treatment system, or 3) a
distribution system. If the final effluent of the system were
to be used for drinking purposes while providing no
additional treatment, the quality of the water would need to
meet NPDWS.
During the demonstration elevated concentrations of both
heterotrophic bacteria and methanol were found in the
treated effluent. Heterotrophic bacteria, which are
measured to determine how effective treatment is at
controlling microorganisms, have no reported health
effects. 40 CFR 141.72 of the NPDWS states that in lieu
of measuring the residual disinfectant concentration in the
distribution system, heterotrophic bacteria, as measured by
the heterotrophic plate count, may be performed. If
heterotrophic bacteria concentrations are found above
500/100 ml in the distribution system, the minimum residual
disinfectant concentration is not in compliance with the
NPDWS. There are no standards or health advisories for
methanol in the NPDWS. The agency delegated for
enforcement of the NPDWS would need to be notified of
these elevated concentrations well before supplying this
water to customers.
The NPDWS also have turbidity standards which must be
met. A standard of 1.0 turbidity unit (NTU), as determined
by a monthly average must be met. During the
demonstration the calculated averages for three of the four
sampling events were above the 1.0 NTU limit.
2.8.6 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.
If working at a hazardous waste site, all personnel involved
with the construction and operation of the EcoMat BDN
treatment process are required to have completed an
OSHA training course and must be familiar with all OSHA
requirements relevant to hazardous waste sites. Workers
on hazardous waste sites must also be enrolled in a
medical monitoring program. The elements of any
acceptable program must include: (1) a health history, (2)
an initial exam before hazardous waste work starts to
establish fitness for duty and as a medical baseline, (3)
periodic examinations (usually annual) to determine
whetherchanges due to exposure may have occurred and
to ensure continued fitness for the job, (4) appropriate
medical examinations after a suspected or known
overexposure, and (5) an examination at termination.
For most sites, minimum PPE for workers will include
gloves, hard hats, steel-toe boots, and Tyvek® coveralls.
Depending on contaminant types and concentrations,
additional PPE may be required, including the use of air
purifying respirators or supplied air. Noise levels are not
expected to be high, except during well installation which
will involve the operation of drilling equipment. During
these activities, 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
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be required to wear hearing protection. The levels of noise community, but this will depend on proximity to the
anticipated are not expected to adversely affect the treatment site.
14
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Section 3.0
Economic Analysis
3.1 Introduction
The purpose of this economic analysis is to estimate costs
(not including profits) for commercial treatment of
groundwater contaminated with elevated levels of nitrate
utilizing the EcoMat BDN Process.
The treatment system evaluated at Bendena was operated
in an approximate range of 3-8 gpm during the SITE
demonstration. This pilot-scale treatment system is
considered by EcoMat to have an extremely low capacity
for producing drinking water. The full-scale systems that
EcoMat plans to design, own and operate for drinking
water applications are 10 to 50 times the size of the pilot
unit used at Bendena. Therefore, this analysis will present
a cost estimate based on a 100 gpm system.
The costs associated with implementing the EcoMat
designed and operated process have been broken down
into 12 cost categories that reflect typical cleanup activities
at Superfund sites. They include:
(1) Site Preparation
(2) Permitting and Regulatory Activities
(3) Capital Equipment
(4) Start-up and Fixed
(5) Labor
(6) Consumables and Supplies
(7) Utilities
(8) Effluent Treatment and Disposal
(9) Residuals Shipping, & Disposal
(10) Analytical Services
(11) Maintenance and Modifications
(12) Demobilization
To reasonably estimate costs for the technology, some
basic assumptions have been made regarding the overall
size of the reactors, treatment flow rate, level of nitrate
contamination, presence of othercontaminants (otherthan
nitrate), treatment duration, and the level of post-treatment
required to meet standard Safe Drinking Water criteria for
general parameters.
The EcoMat BDN Process is ex-situ and is designed to
operate on a continual pump and treat mode. Standard
sized tanks are used as the reactors and holding tanks.
The only specialized mechanical equipment used is the
patented mixing apparatus that is fitted into the standard-
sized reactor tank. EcoMat prefers to install and own their
treatment systems, and then service the systems with local
contractors. EcoMat would then bill monthly for the
service. However, this cost estimate assumes the site
owner will purchase the treatment system and pay for
setup, monitoring, and maintenance.
Table 3-1 presents a categorical breakdown of estimated
costs for the one year's treatment of groundwater, using a
100 gpm BDN system, atan assumed online factor of 80%
(42 million gallons treated annually). Table 3-2 projects the
first year cost estimates to approximate costs for the same
100 gpm capacity and at the same assumed on-line factor
of 80% for multi-year treatment (e.g., 5,10, and 15 years).
Figure 3-1 graphically illustrates the percentage of total
cost that each of the twelve cost components comprise, for
each treatment scenario.
As with all cost estimates, caveats may be applied to
specific cost values based on associated factors, issues,
and assumptions. The major factors that can affect
estimated costs are discussed in subsection 3.3. The
issues and assumptions made regarding the specific
treatment system used for this economic analysis are
incorporated into the cost estimate. They are discussed in
subsection 3.4.
The basis for costing each of the individual 12 categories
in Table 3.1 is discussed in detail in subsection 3.5. Much
of the information presented in this subsection has been
derived from observations made and experiences gained
from the SITE demonstration that was conducted as four
separate sampling events interspersed over an
approximate 7V2 month period at the location of a former
public water supply well in Bendena, Kansas. Other cost
information has been acquired through subsequent
discussions with EcoMat and by researching current
15
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Table 3-1. Cost Estimates for Initial Year of 100 GPM BDN System, Online 80%.
Cost Category
1 . Site Preparation
Treatment System Delivery
Heated Building Enclosure
Utility Connections
2. Permitting & Regulatory Activities
Permits
Studies and Reports
3. Capital Equipment
Biodenitrification/Post-Treatment Systems
In-line Nitrate Analyzer (two cells)
In-line Dissolved Oxygen Meter
Portable Water Quality Instrumentation
Pressure Washer
4. Startup & Fixed (10% of Capital Equipment)
5. Labor
System Design
Site Setup (EcoMat)
(Contractor)
Startup Testing (EcoMat)
Performance Monitoring/Maintenance
Remote Monitoring (EcoMat)
On-site Monitoring (Contractor)
6. Consumables and Supplies
Methanol (99% + grade)
EcoLink Biocarrier
Hypochlorite solution (for chlorination)
Post-Treatment Media
7. Utilities
8. Effluent Treatment & Disposal
9. Residuals Shipping & Disposal
10. Analytical Services
Nitrate-N/Nitrite-N in Water
Methanol in Water
Fecal Coliform
Trihalomethanes
Sample Shipments
11. Maintenance & Modifications
12. Demobilization
1 Cost value rou nded to two sign if leant digits.
2 Value increased to account for 10% QA sam pies.
Quantity
1
1
1
1
1
1
2
1
100
40
400
80
210
310
1,200
0.2
600
NA
175,000
NA
NA
27
27
27
27
54
1
NA
Units
Each
Each
Each
Each
Each
Each
Each
Each
Hours
Hours
Hours
Hours
Hours
Hours
Gallons
m3
Gallons
NA
kW-hr
NA
NA
Each
Each
Each
Each
Each
Year
NA
Unit Cost
$5,000
$60,000
$2,000
$250,000
$8,000
$2,000
$600
$2,800
$80
$80
$50
$80
$80
$50
$0.65
$6,000
$6.00
NA
$0.07
$0000.00
$0000.00
$15
$100
$15
$150
$30
$2,640
NA
Total Initial
$- 1s1 Yr.
$5,000
$60,000
$2,000
$10,000
$20,000
$250,000
$8,000
$2,000
$1,200
$2,800
$8,000
$3,200
$20,000
$6,400
$16,800
$15,500
$780
$1,200
$3,600
NA
$12,300
$0000.00
$0000.00
$405
$2,700
$405
$4,050
$1,620
$2,640
NA
Year Cost 1
$/Category
$67,000
$30,000
$264,000
$26,400
$69,900
$5,580
$12,300
$9,940
$2,640
$490,000
16
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Table 3-2. Cost Estimates for EcoMat's BDN System for Multi-Year Treatment Scenarios.
Cost Category
1. Site Preparation
Treatment System Delivery
Heated Building Enclosure
Utility Connections
2. Permitting/Regulatory Activities
3. Capital Equipment
4. Startup & Fixed
5. Labor
System Design 2
Site Setup 2
Startup Testing 3
Pert Monitoring/Maintenance
6. Consumables & Supplies
Methanol
Hypochlorite Solution
EcoLink Biocarrier
Post-Treatment Media
7. Utilities (Electricity)
8. Effluent Treatment & Disposal
9. Residuals Shipping & Disposal
10. Analytical Services
Nitrate in water
Methanol in water
Fecal Coliform
Trihalomethanes
QA samples (10%)
Sample Shipments
11. Maintenance & Modifications
12. Demobilization
TOTAL COSTS 1
Initial Year
$67,000
$5,000
$60,000
$2,000
$30,000
$264,000
$26,400
$69,900
$8,000
$23,200
$6,400
$32,300
$5,580
$780
$3,600
$1,200
$000.00
$12,300
NA
NA
$9,940
$405
$2,700
$405
$4,050
$756
$1,620
$2,640
$000.000
$490,000
5 Years
$67,000
$5,000
$60,000
$2,000
$30,000
$264,000
$26,400
$225,000
$8,000
$23,200
$32,000
$162,000
$27,900
$3,900
$18,000
$6,000
$000.00
$61,500
NA
NA
$15,900
$645
$4,300
$705
$6,450
$1,210
$2,580
$13,200
$000,000
$730,000
10 Years
$67,000
$5,000
$60,000
$2,000
$30,000
$264,000
$26,400
$418,200
$8,000
$23,200
$64,000
$323,000
$55,800
$7,800
$36,000
$12,000
$000.00
$123,000
NA
NA
$23,500
$945
$6,300
$1,220
$9,450
$1,790
$3,780
$26,400
$000.000
$1,000,000
15 Years
$67,000
$5,000
$60,000
$2,000
$30,000
$264,000
$26,400
$612,200
$8,000
$23,200
$96,000
$485,000
$83,700
$11,700
$54,000
$18,000
$000.00
$184,500
NA
NA
$31,100
$1,250
$8,300
$1,670
$12,500
$2,370
$4,980
$39,600
$000,000
$1,300,000
1 Total costs have been rounded to two significant digits.
2 Designates a one time cost incurred for all scenarios.
3 Startup testing is assumed to be repeated once per year.
17
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IQ
I
CO
O
o
1,500,000
1,250,000
1,000,000
ro
a
CD
3
5;
I
750,000
500,000
3
S-
CD
w
o
CD
250,000
01
Extended Treatment Scenarios
• D •
5-Yrs 10-Yrs 15-Yrs
Not
Applicable
600,000
450,000
300,000
0)
a
150,000
75,000
Total Treatment
/ Permitting Labor \ Utilities
Site7 Etc ' \
Preparation Capital Consumables
Equipment & Supplies
Analytical
Demobilization
Effluent Treatment/
Residuals Shipping
& Disposal
Maintenance &
Modifications
Major Technology Cost Catagories
-------
estimates for specific cost items related to the technology.
Certain actual or potential costs were omitted because site-
specific engineering aspects beyond the scope of this SITE
Demonstration project would be required. Certain other
functions were assumed to be the obligation of the
responsible parties and/or site owners. Although these
costs are also not included in the estimate, they are still
shown as line items on Tables 3.1 and 3.2 to emphasize
that those costs need to be accounted for.
It should be emphasized that the cost figures provided in
this section are "order-of-magnitude" estimates, generally
+ 50% 1-30%.
3.2 Conclusions
The majority of the information for the costs (as well as
some actual costs) to treat groundwater using the EcoMat
BDN System at a flow rate of 100 gpm were provided by
EcoMat. These estimates, along with otherconclusions of
the economic analysis, are presented below:
(1) For a 100 gpm system, the estimated cost to treat
nitrate-contaminated groundwater over a one year
period is $490,000, or approximately $0.012/gal.
The cost over 5, 10,or 15 years is estimated to
increase to approximately $730,000 ($0.0034/gal.);
$1,000,000 ($0.0024/gal.) and $1,300,000
($0.002/gal.), respectively.
(2) The largest cost components for the one-year
application of a 100 gpm EcoMat BDN system are
capital equipment (54%), labor (14%), and site
preparation (14%); accounting for over 80% of the
total cost. As the treatment duration increases
overtime, the impact of capital equipment and site
preparation diminish considerably. Shortly
following five years of treatment, labor becomes
the dominant cost component and the impact of
consumables and supplies becomes more
significant.
(3) The cost of implementing the EcoMat
Biodenitrification System may be less or more
expensive than the estimate given in this economic
analysis depending on several factors. If water
recovery wells are not already present at the site,
their installation would be a significant added cost
to the site owner, especially if the water source is
deep (these costs are not directly associated with
the EcoMat treatment process and thus have not
been included in the estimate). Other factors
include, but are not limited to, the nitrate
concentration in the water and the presence of
other contaminants that would require increased
post-treatment or pretreatment.
3.3 Factors Affecting Estimated Cost
There are a number of factors that could affect the cost of
treatment of nitrate-contaminated groundwater using an ex
situ bioremediation treatment technology. An important
factor for initial consideration is the ability to supply
contaminated water at an economically viable flow rate
(which is dependent on aquifer characteristics). Other
important factors include, but are not limited to, the inlet
nitrate concentration (as measured as nitrate-N), the
presence of other contaminants in the inlet water, and the
level of pre-or post-treatment required.
The aquifer yield will affect the size and number of pumping
wells required to attain sufficient flow rate to allow
treatment to be economically feasible. For aquifers that are
capable of yielding high flow rates, the numberof wells that
are required to be installed and the depth at which they
must be screened can significantly impact startup costs,
but this would affect any system.
3.4 Issues and Assumptions
This section summarizes the major issues and
assumptions used to estimate the cost of implementing the
EcoMat BDN Process at full-scale. In general, the
assumptions are based on information provided by
EcoMat and observations made during the demonstration.
3.4.1 Site Characteristics
The site characteristics used for this economic analysis
are considered to be significantly differentfrom those found
at the Bendena site. The Bendena demonstration site
consisted of a former railroad well constructed in the early
1900's. Pre-demonstration pump testing of this well at just
20 gpm over a 5-day period depleted nearly 30 percent of
the well volume. Thus, the aquifer recharge would not be
sufficient for adequately supplying a 100 gpm treatment
system. Also, nitrate levels in the well water were
measured as high as 100 ppm. Such levels of nitrate in a
well are uncommon and EcoMat has costed their treatment
system to be contingent on an inlet nitrate level of 20 mg/l.
For the purposes of this analysis, there are three major
assumptions that have been made regarding site
characteristics: 1) the aquifer being treated is capable of
supplying groundwater to one or more wells at a rate equal
to or greater than 100 gpm for an extended time period; 2)
no additional wells are required, and 3) that nitrate-N levels
will be consistently above the regulatory limit of 10 mg/l but
will not exceed 20 mg/l.
3.4.2 Design and Performance Factors
Design and performance factors would include designing
the properly-sized treatment system and process
parameters to adequately treat nitrate-contaminated
19
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groundwater at a rate of 100 gpm. If need be, a
groundwater recovery system may also need to be
designed and would include locating and installing
groundwaterrecovery wells and theassociated pumps and
piping to route the inlet water to the treatment system. For
this cost estimate an assumption is made that sufficient
groundwaterrecovery wells and piping are already present
at the site.
The developer (EcoMat)designs the properly-sized system
anticipated fora particular site. Once designed the system
components are manufactured or purchased off-site,
usually from one or more vendors. The components are
then shipped from the plant(s) to the site location, where
EcoMat assembles the system.
With respect to the pilot-scale unit used at Bendena,
EcoMat has indicated that a 100 gpm system would be
scaled-up in physical size by a factor of between two and
three times that of the pilot unit.
3.4.3 Financial Assumptions
All costs are presented in Year 2001 U.S. dollars without
accounting for interest rates, inflation, or the time value of
money. Insurance and taxes are assumed to be fixed
costs lumped into "Startup and Fixed Costs" (see
subsection 3.5.4). Any licensing fees passed on by the
developer, for using the EcoMat patented mixed reactor
and implementing technology-specific functions, would be
considered profit. Therefore, those fees are not included
in the cost estimate.
3.5 Basis for Economic Analysis
The 12 cost categories reflect typical clean-up activities
encountered at Superfund sites. In this section, each of
these activities will be defined and discussed. Combined,
these 12 cost categories form the basis for the detailed
estimated costs presented in Tables 3-1 and 3-2. The
labor costs that are continually repeated for each scenario
are grouped into two labor categories, one category for
developer labor (i.e., EcoMat) and one category for
developer contractor labor (see subsection 3.5.5).
3.5.1 Site Preparation
Site preparation forimplementing the EcoMat BDN system
technology can be subdivided into three distinct phases.
These include the initial design of the treatment (system
design), shipping and assembly of the designed system
(site setup) and conducting initial shakedown/recycle
testing. The first two phases are one time occurrences. The
shakedown and recycle phase may have to be repeated if
the system stops operating for a substantial period of time
during the treatment process.
All three of these phases are discussed in the following
subsections. However, the majority of the costs associated
with site preparation is labor (labor costs are presented in
subsection 3.5.5). Therefore, the only costs discussed in
this subsection are non-labor costs associated with site
setup phase (see 3.5.1.2). The total non-labor cost of site
preparation for the beginning operation of the system is
estimated to be approximately $67,000, which would be a
one time cost.
3.5.1.1 System Design
System design consists of obtaining the anticipated
contaminant range from the prospective customer and then
selecting the proper sized system components necessary
for treating that influent at a specified flow rate. EcoMat
does not conduct treatability testing on the water matrix
(i.e., influent); however, they do have small reactors that
could be used for such a purpose. Generally speaking, the
system design does not include the means forpumpingthe
water matrix from its source to the BDN system.
EcoMat has indicated thatthe design of a 100 gpm system
would not radically change from the design of the pilot unit
used at Bendena, however the scale-up factor would be
between two and three. Therefore the deoxygenating tank
(R1) would have an approximate capacity of 2,600 gallons
and the EcoMat Reactor (R2) would be on the order of 5
cubic meters (the R2 unit at Bendena was 2 cubic meters).
The cost of system design has been estimated by EcoMat
to correlate to approximately 100 hours (see subsection
3.5.5 - Labor).
3.5.1.2 Site Setup
The second phase of site preparation is site setup. This
phase includes shipping the treatment system components
from one or more of EcoMat's suppliers to the site. The
costs of shipping will vary depending on location and
distance the site is from the supplier(s). EcoMat roughly
estimates shipping costs at 2% of the treatment system
capital cost. For a 100 gpm treatment unit, this would be
approximately $5,000 (see subsection 3.5.3 for capital
costs).
Once at the site the entire treatment system is normally
housed in a shed or building that provides security and
temperature control. Therefore, if an appropriate existing
structure does not exist at the site, one has to be
assembled or built. EcoMat has estimated that a building
twice the size of the Bendena shed would be required to
accommodate a 100 gpm system. It is feasible to install a
system outside, which may be necessary for even larger
systems. In such instances, heattracing would be installed
to provide temperature control where needed.
At the Bendena site, the KDHE provided for the 20 ft. x 15
ft. building and all associated utility hookups at an
approximate cost of $40,000 (which included construction
20
-------
labor costs). The cost of a structure about twice that size
(i.e., 40 ft. x 30 ft.), not including utility hookups, is
estimated at approximately $60,000.
At the Bendena site, electrical hookups, communications,
and water supply were also provided by the KDHE and
incorporated into the total cost estimate for the shed.
Electrical power is required for operating pumps, control
panels, etc. for the system; lighting, etc. A water hookup
is needed for power washing equipment components (e.g.,
filters, etc.). For this cost estimate, utility hookups are
estimated to be a one time charge of $2,000.
It is assumed that the site used for this cost estimate is
secured and cannot be easily vandalized. The treatment
system itself would, in most cases, be installed within a
secured building, as previously discussed. If security
became an issue with a larger outdoor system, then a
fence would need to be erected. Assuming no costs for
security, the total site setup costs for initiating the activities
are estimated to total approximately $67,000. This cost
value represents the total non-labor cost estimated for the
Site Preparation category.
3.5.1.3 Shakedown and Recycle
Once the full treatment system has been assembled, there
is a period of time necessary to acclimate the microbial
colony to the biocarrier(s), and the inlet water, make
adjustments to methanol feed rates, and check operation
of system components. Once this steady-state is reached
the system can continually operate effectively as long as
there are no significant shutdowns.
The overwhelming majority of the cost associated with the
shakedown and recycle process is labor, which is
discussed in subsection 3.5.5. The cost of consumables
specifically associated with conducting shakedown and
recycle activities are negligible with respect to total annual
consumables (consumable costs are discussed in
subsection 3.5.6).
3.5.2 Permitting and Regulatory Requirements
Several types of permits may be required for implementing
a full-scale remediation. The types of permits required will
be dependent on the type and concentration of the
contamination, the regulations covering the specific
location, and the site's proximity to residential
neighborhoods.
At the Bendena site, treated water was discharged to a 300
foot long, 1,000 gallon capacity lateral septic system
purchased and installed for the demonstration. The KDHE
acquired the necessary permits for discharging the treated
water to the septic system located in an adjacent field in
this manner. Although, ozone treatment and an air stripper
were used during portions of the demonstration, a permit
was not required.
The non-analytical costs incurred for ultimately receiving
approval from the regulatory agency to install the treatment
system are included under the Permitting and Regulatory
Activities category. These costs would include the
preparation of site characterization reports that establish a
baseline for the site contamination, the design feasibility
study for the pilot system, potential meetings with
regulators for discussing comments and supplying other
related documentation, and for acquiring approval for
installing and implementing the treatment.
Based on past experience, permitting feesforimplementing
the full-scale treatment system are assumed to be about
$10,000. It should be noted that actual permitting fees are
usually waived for government-conducted research type
projects (e.g., SITE Demonstrations).
Depending upon the classification of the site, certain RCRA
requirements may have to be satisfied as well. If the site
is an active Superfund site, it is possible that the
technology could be implemented under the umbrella of
existing permits and plans held by the site owner or other
responsible party. Certain regions or states have more
rigorous environmental policies that may result in higher
costs for permits and verification of treatment performance.
Added costs may result from investigating all of the
regulations and policies for the location of the site, and for
conducting a historical background check for fully
understanding the scope of the contamination. From
previous experiences, the associated cost with these
studies and reports is estimated to be $20,000.
The total cost of all necessary permitting and other
regulatory requirements is estimated to be approximately
$30,000.
3.5.3 Capital Equipment
Most of the capital equipment cost data directly associated
with the BDN and post-treatment system have been
supplied by EcoMat. Specific capital equipment associated
with their system includes high density polyethylene tanks,
high capacity pumps, electronic control systems, a
patented mixing apparatus, system piping and valves,
rotometers, and various off-the-shelf post-treatment units.
Some of the monitoring equipment costs are based on the
SITE Program's experience during the demonstration and
from other similar products. It is assumed that all
equipment parts will be a one time purchase and will
have no salvage value at the end of the project.
EcoMat has provided an approximate lump sum cost
estimate of $250,000 for a 100 gpm treatment system
capable of treating a water matrix having nitrate levels of
20 mg/l. This value does not include the installation of
groundwater wells, groundwater pumps, or piping
installation required to supply inlet water to the treatment
system (at the Bendena site the groundwater supply
delivery system consisted of a single submersible pump
21
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that supplied the BDN system with groundwater at flow
rates varying between 3 and 8 gpm). The $250,000 value
also does not include costs for disassembly, shipping and
reclaiming system components.
In addition to the main components of the EcoMat BDN and
post- treatment systems, in-line monitoring equipment
would be an additional capital cost. The most important
monitoring instrumentation required for a full-scale system
would be an in-line nitrateanalyzerequipped with two cells;
one for monitoring inlet water nitrate levels and one for
monitoring either post BDN or final effluent nitrate levels.
The estimated cost for a direct read nitrate analyzer is
$8,000.
Dissolved oxygen is another important parameter that
requires close monitoring, as evidenced during the
demonstration. Since the time of the demonstration,
EcoMat has incorporated a dissolved oxygen monitoring
unit into theirsystem to immediately identify irregularities in
DO. A microprocessor-based DO meter installed within the
BDN system is estimated to cost $2,000. Other portable
instrumentation required formonitoring parameters such as
pH, temperature, and turbidity are estimated to collectively
cost about $1,200.
Although an industrial pressure washer could be rented on
an as-need-basis, it will be assumed that a dedicated
pressure washer would be purchased for EcoMat's full-
scale unit. This would allow for quicker response to any
periodic clogging of filters and reactor screens (which
occurred during the demonstration) and the cost would be
relatively minor with respect to the cost of the treatment
system itself or renting the equipment over several years.
A combination steam cleaner/pressure washer is estimated
to cost roughly $2,800.
The total cost of all of the necessary capital equipment for
a full-scale 100 gpm system is estimated to be
approximately $264,000.
3.5.4 Startup and Fixed Costs
From past experience, the fixed costs for this economic
analysis are assumed to include only insurance and taxes.
They are estimated as 10 percent of the total capital
equipment, or $26,400.
3.5.5 Labor
Included in this subsection are the core labor costs that are
directly associated with the EcoMat BDN System. These
costs comprise the bulk of the labor required for the full
implementation of the technology. It is assumed for this
cost analysis that the treatment system will be fully
automated and will operate continuously without major
interruption at the designed flow rate. Non-core labor
costs, associated with periodic system adjustments (i.e.,
chemical adjustments), regulatory sampling requirements,
maintenance activities, and site restoration, are discussed
in subsections 3.5.10, 3.5.11 and 3.5.12, respectively.
For the purchased EcoMat treatment system, assembly is
a labor intensive operation consisting of unloading
equipment from trucks and trailers, as well as actual
assembly. EcoMat will have significant hands-on
involvement during the site setup phase of the project and
early stages of a field project to ensure proper assembly
and startup of their technology. EcoMat's labor hours, as
specified in Tables 3-1 and 3-2, would include overseeing
and training local contractors on the operation of the
system and making the proper adjustments to the system
during the shakedown and recycle operation. Once the
system is acclimated and operating ata steady state, labor
should become minimal.
The hourly labor rates presented in this subsection are
loaded, which means they include base salary, benefits,
overhead, and generaland administrative (G&A) expenses.
Travel, per diem, and standard vehicle rental have not
been included in these figures. The labortasks have been
broken down into four subcategories, each representing
distinct phases of technology implementation. They
include 1) System Design 2) Site Setup; 3) Startup Testing;
and 3) Performance Monitoring & Maintenance.
3.5.5.1 System Design
System design consists of obtaining the anticipated
contaminant range from the prospective customer and then
selecting the properly-sized system components necessary
for treating that influent at a specified flow rate. Specific
tasks may include preparation of design parameters and
detailed process flow schematics (including piping
designs), logistics for procuring the specific system
components, and calculating feed rates for methanol
solution and other additives. EcoMat has estimated
system design labor at 1 00 hours. Assuming a loaded rate
of $80/hr for an EcoMat process design engineer (or
comparable professional) to conduct this task, labor for
system design is estimated at $8,000.
3.5.5.2 Site Setup
Site setup includes labor costs that are not already
included in the system design. These costs would
therefore include the labor to assemble the system
components and associated monitoring equipment once at
the site; organization and storage of the initial year's
supplies (e.g., methanol, filter cartridges, etc.); and
arranging for and overseeing the utility hookups. Due to
the importance of these initial activities, it is assumed that
the developer will be on-site to direct and assist
subcontracted personnel.
It is assumed that the developer will supply one senior level
process engineer, billing out at an estimated $80/hour, to
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perform oversight duties. It is also assumed that the
developer will contract out for supplying a local field team
consisting of two technical staff personnel. The average
hourly loaded rate for these two individuals is estimated to
be $50/hour. To complete the aforementioned tasks for a
100 gpm system, EcoMat has estimated 40 hours of their
time ($3,200) and 400 contractor hours ($20,000).
Therefore, total labor for the site setup phase has been
estimated at approximately $23,200.
3.5.5.3 Startup Testing
The EcoMat process requires a period of time for
developing the necessary biological growth on the
biocarrier in the EcoMat Reactor under a full recycle mode.
EcoMat refers to this startup testing phase as the
"Shakedown and Recycle Operation." The shakedown and
recycle operation for the SITE demonstration took
approximately eightweeks. EcoMat has indicated thatthis
process can be completed in about half of that time under
closer control and that the time period does not vary
significantly with the size of the project. They have
estimated 80 hours of laborforcompleting this task, which
at an $80/hr rate would total $6,400. The shakedown and
recycle mode must be repeated if the system goes down
for an extended period to re-acclimate the microorganisms
(this was necessary during the demonstration). For this
cost it will be assumed that system startup will have to be
repeated at least once annually. Thus the $6,400 labor
cost will be incurred each and every year of operation.
3.5.5.4 Performance Monitoring & Maintenance
Although the full-scale system is assumed to be fitted with
an on-line nitrate/nitrite analyzer and other automated
systems (i.e., for metering the proper amount of methanol
solution, chlorination, etc.), the full-scale system would still
require both remote (off-site) and on-site monitoring to
ensure reliable and consistent system performance.
Off-site monitoring of the full-scale treatment system would
at minimum be capable of continuously tracking inlet and
effluent nitrate and nitrite levels, dissolved oxygen levels,
and system disruptions as indicated by the control panel
alarms (i.e., high tank level alarms, pump malfunctions,
high dissolved oxygen levels, etc.).
Actual on-site observation would also be necessary, as
would routine maintenance site visits. Observing the
system is required to visualize biocarrier suspension in the
EcoMat reactor. Periodic maintenance of the system is
required forfilter backflushing, adjusting methanol solution
feed rate, washing the bioballs in the deoxygenating
reactor, replenishing hypochlorite solution supply, etc.
With respect to a 100 gpm system, EcoMat has estimated
their off-site monitoring labor at four hours per week and
contracted on-site labor at six hours per week. Assuming
the same labor rates of $80/hr and $50/hr for EcoMat and
contractor labor, respectively, the weekly labor cost for
performance monitoring is estimated at $620/week. This
weekly cost would equate to $32,300 annually.
Total labor costs for the first year of treatment operation
would total approximately $69,900. Although labor
comprises only about 14% of the total first year treatment
costs, laboris projected to become the highestannualcost
category over time. Labor costs at five, ten and 15-years
of operation are estimated to comprise roughly 30%, 42%,
and 47% of the total annual costs, respectively.
3.5.6 Consumables & Supplies
Due to the higher initial capital costs, consumables and
supplies comprise a relatively small initial year cost
component (i.e., slightly more than 1 % of the first year total
cost) for the EcoMat system. As the capital cost impact
diminishes over time, the consumables and supplies costs
gradually increase in significance. Potential consumables
and supplies costs for the EcoMat Biodenitrification
process can be associated with four subcategories: 1)
Nutrients and growth substrate; 2) Biocarrier media; 3)
Post-treatment consumables; and 4) Equipment rentals.
3.5.6.1 Nutrients and Growth Substrate
Growth substrate includes any consumable supply that is
added to the BDN system to specifically sustain or
enhance the viability of microbes used to degrade nitrate
and nitrite. The primary substrate is a 50% aqueous
methanol solution thatis added to both the de-oxygenating
reactor tank and the EcoMat reactor.
During the demonstration, the methanol solution feed rate
roughly ranged from 7-10 liters per day. EcoMat has
indicated that three times that feed rate would be required
for a 100 gpm system. Therefore, a high range of 30
liters/day of "solution" would provide a conservative
estimate. That daily feed rate would total approximately
8,800 liters of "solution" consumed per year for a system
on-line 80%. Thus, approximately 4,400 liters (about 1,200
gallons) of methanol would be consumed annually.
EcoMat has indicated that they have a supplier that
provides bulk purchases of methanol at a cost of $0.65 per
gallon. Using that value, the annual cost of the methanol
would be $780. The remainder of the methanol "solution"
consists mostly of water.
Nutrient supplements are also sometimes used. For the
demonstration, a small amount of food grade phosphoric
acid was added to the methanol solution to achieve a
phosphorus concentration of about 0.75 ppm. The cost of
the non-methanol portion of the solution is considered
negligible and therefore is not included.
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In some cases, additional substrates may be utilized. For
example, during the demonstration, molasses was added
to "kick start" the system. However, supplements such as
molasses are notalways needed and its cost is considered
negligible and is not included here.
3.5.6.2 Bio carrier Media
The "EcoLink" biocarrier material is not replaced as long as
it remains in suspension. Overloading does occur,
therefore, after a significant period of time the EcoLink
must be replaced before they sink and clog screens.
EcoMat has indicated that a 100 gpm system requires
about two m3of EcoLink, which presently costs $6,000 per
cubic meter. The developer has also estimated that
approximately ten percent of the volume of EcoLink used
in any sized system needs "refreshing" on an annual basis.
Therefore, an annual cost of $1,200 for EcoLink biocarrier
is assumed for this cost estimate.
The bioballs used in the deoxygenating reactor tank are
also a type of biocarrier. However, they can last indefinitely
if periodically washed. For this reason, they are not
considered as consumable. The labor cost of maintaining
the bioballs is included in subsection 3.5.5.4
3.5.6.3 Post-Treatment Consumables
Post-treatment consumables would potentially include any
chemical treatment added to the post-BDN effluent. Also
included would be absorption and filtration media that
would be spent over an indefinite time period and need
replacement. Examples of such post-treatment media
would be sand (used in sand filtration), spent activated
carbon, spent filter cartridges, etc.
It is assumed for this cost estimate that chlorination would
likely be required when implementing the EcoMattreatment
system for drinking water applications. EcoMat has
indicated that they would use a 25% solution of liquid
hypochlorite for full-scale chlorination post-treatment. For
a 100 gpm system, they have estimated hypochlorite
consumption at 2 gallons per day at a cost of
approximately $6 pergallon. This daily rate would correlate
to approximately 600 gallons of hypochlorite consumed
annually at an estimated cost of $3,600.
During the demonstration, EcoMat replaced the paperfilter
cartridges being used with cleanable metal cartridges.
Activated carbon was used for one event only, and the
sand filter was periodically flushed. For this cost estimate,
it will be assumed the cleanable metal filter cartridges
would also be used for a larger 100 gpm system. It will
also be assumed that activated carbon will not be required
and thatthecostof replacing sand filtration media would be
negligible. Thus the cost of post-treatment consumables
would consist solely of the hypochlorite cost, about $3,600
annually.
3.5.6.4 Equipment Rentals
Equipment rentals would be an alternative to purchasing
dedicated equipment for the full-scale treatment system.
For example, a pressure washer could be rented for
flushing out metal cartridge filters and reactor screens
during periodic maintenance. A conservative costestimate
for renting a heavy duty pressure washer is $300/week.
Assuming that pressure washing would be required
quarterly, the annual rental charge would be approximately
$1,200 per year. Since this annual cost exceeds 40% of
the estimated purchase price, purchase of a pressure
washer is the more economical choice.
It should be noted that other equipment listed in the cost
estimate as a capital expense may also be rented. During
the demonstration, the SITE Program rented a colorimeter,
pH/conductivity meter, a temperature/DO meter, a turbidity
meter, and water level meter. However, as is the case with
the pressure washer, the rental costs of these items for
indefinite periods is not cost effective, especially when the
periodic shipping charges are included.
Since equipment that could be rented have been included
as capital cost items, no rental costs are included in the
cost estimates on Tables 3-1 and 3-2.
The total estimated cost of consumables and supplies for
the initial year of treatment is $5,580. The cost is estimated
to increase proportionately with treatment duration.
3.5.7 Utilities
The main utility required for the EcoMat treatment system
is electricity. Atthe Bendena site the electrical hookup and
service were provided by the State of Kansas. The
electricity provided the power needed to operate the
system pumps and control panels, the submersible pump
in the well, and outlets used forthe building heaterand the
telephone/facsimile machine. The SITE Program recorded
electric meter readings before, during, and at the
conclusion of the demonstration. During the approximate
7% month period of time encompassed by the four
sampling events, a total of approximately 26,400 kW-hr
was used. Power usage rates varied in a range of 5.0-1 0.4
kW. EcoMat has projected a 100 gpm system to utilize
approximately 2.5 times the power of the pilot-scale
system; which would correlate to a range of 12.5 - 26 kW
of power. Conservatively using 20 kW as the power usage
fora 100 gpm system, the numberof kW-hrs used annually
would be approximately 20 kW x 24 hr/day x 7 days/wk. x
52 wk./yr or approximately 175,000 kW-hrs. Assuming a
utility charge of $0.07/kWh, the cost of operation of the 100
gpm treatment system for a year would thus be about
$12,300. (Note: It is assumed that electric usage will
continue when the system is off-line for testing and other
maintenance activities.) It should be noted that electricity
cost can vary greatly depending on geographical location.
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There is also a need for a water line to operate a pressure
washer for maintenance activities. However, the water
usage is sporadic and is not expected to be substantial.
Therefore, water usage is considered negligible for
estimating utility costs.
3.5.8 Effluent Treatment and Disposal
For this technology successful treatment will mean that the
effluent will become drinking water. Therefore, it is
assumed that there will be no effluent treatment and
disposal expense. It is assumed that the minimal amount
of wastewater generated from periodic power washing of
metal filter cartridges and reactor filter screens can be
discharged either to a land septic system (as was the case
at Bendena), or to a local POTW.
3.5.9 Residuals Shipping and Disposal
The only residuals generated during the demonstration
were spent filter media (cartridges and carbon) and spent
biocarrier media. Since levels of residual methanol are low
in these wastes, most if not all of this material would be
classified as non-hazardous and can be disposed of as
such.
It should be noted that if carbon is used to treat hazardous
organic contaminants, any spent carbon could be classified
as a hazardous waste, and thus require disposal as
hazardous waste.
For this cost estimate, it is assumed that no hazardous
waste will be generated during treatment. Residuals
would be discarded as non-hazardous solid waste.
Disposal costs are, therefore, considered negligible for this
cost estimate.
3.5.10 Analytical Services
Although nitrate and nitrite levels would be monitored
continuously by an on-line nitrate analyzer, the state or
local regulatory agency would still require independent
analysis of effluent samples at some specified frequency.
Based on discussions with the Public Works Supply
Section of the KDHE, the required monitoring fora water
treatment system such as EcoMat's would include four
specific drinking water criteria. These four criteria would
include nitrate-N/nitrite-N (which is conducted as a single
analysis), methanol, Fecal Coliform, and trihalomethanes
(THMs). A likely monitoring schedule fora nitrate treatment
system producing drinking water would include the
following final effluent analyses at the indicated frequency:
(1) Nitrate and nitrite quarterly;
(2) Methanol quarterly;
(3) Trihalomethanes (THM) quarterly; and
(4) Fecal Coliform twice a month.
The required monitoring would be conducted quarterly for
the duration of the life of the treatment system, but would
be at an increased level for the first 8 weeks of operation.
For estimating the cost of the analytical services category,
it is assumed that the treatment system effluent will be
sampled three times a week for the first 8 weeks of
operation (for a total of 24 samples) and then a total of
three times for the remainder of the first year of operation
in accordance with a quarterly sampling schedule.
Therefore, a total of 27 effluent samples will be collected
during the initial year of system operation and four effluent
samples will be collected for each successive year.
The resulting first year total of 27 water samples, analyzed
for nitrate-N/nitrite-N at an estimated cost of $15 per
sample, methanol at an estimated cost of $100 per sample,
Fecal Coliform atan estimated $15 persample, and THMs
at an estimated $150 per sample would total to
approximately $7,560. Assuming an increase of sample
cost of 10 percent to cover QA samples, the total cost for
the first year samples is estimated at $8,320. The total cost
for each subsequent year of quarterly monitoring would be
around $1,120. Again, assuming a 1 0 percent increase in
costs to cover QA samples, the total cost for each
subsequent year is estimated at about $1,230.
It is anticipated that the VOC (methanol) and biological
analyses would be conducted at separate off-site
laboratories. The holding time requirements for nitrate-
N/nitrite-N analyses and Fecal Coliform would necessitate
near immediate shipments to those off-site laboratories,
allowing for no holdovers. Therefore, separate shipments
would be required for each. As a result there would be 54
overnight shipments to the offsite laboratories during the
first year of operation and eight shipments for each
successive year. At an estimated $30/shipment for these
small sample sets, the total cost of sample shipping
services is estimated to be about $1,600 the first year and
$240 each successive year.
It should be noted that the stringency and frequency of
monitoring required may have a significant impact on this
cost category.
3.5.11 Maintenance and Modifications
Once the treatment system is in full operation (following the
shakedown and recycling phase) monitoring and periodic
maintenance are necessary to maintain the required level
of the treatment.
For this cost estimate it will be assumed that most of the
system operation will be monitored remotely from off-site.
Based on the observations made during the SITE
demonstration, the mostly likely maintenance problems
would involve system disruptions due to clogged filters or
screens. The cost associated with these problems is
mostly labor and did not involve the purchase of
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replacement parts during the demonstration (see
subsection 3.5.5.4). It is assumed that system components
having high replacement costs (such as pumps) will
operate for the full duration of treatment if maintained
properly. Components that were replaced during the
demonstration included those having a relatively low cost
(such as malfunctioning switches and level sensors).
EcoMat has estimated non-labor cost of maintenance to
be approximately 1 percentof the treatment system capital
cost annually, which is roughly $2,600.
3.5.12 Demobilization
In general, EcoMat believes that much of the equipment
comprising the biodenitrification treatmentsystem (if notall)
will be reusable. The end use of the equipment would be
determined on a case-by-case basis. Demobilization
would be performed at the conclusion of the entire project,
which is dependent on the total treatment time. It is
possible that treatment would be indefinite or would be of
long enough duration that the equipment components
would be fully depreciated, thus essentially making the cost
of disassembly and shipment to a second location
prohibitive. In eithercase, this cost estimate assumes that
the responsible party owns the system through their capital
cost investment. Therefore, demobilization is not an issue,
and all equipment has zero salvage value.
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Section 4.0
Demonstration Results
4.1 Introduction
4.1.1 Project Background
EcoMat's BDN Process was evaluated under the SITE
Program at the former PWS Well #1 in Bendena, Kansas.
The primary contaminant in the well water is nitrate-N,
which historically has been measured at concentrations
rangingfrom approximately 20 to 130 ppm, wellabovethe
regulatory limit of 10 mg/l. VOCs, notably CCI4, have been
a secondary problem. The overall goal of EcoMat was to
demonstrate the ability of their process to reduce the levels
of nitrate-N in the groundwaterand restore the public water
supply well as a drinking water source.
The SITE demonstration occurred between May and
December of 1999 and was conducted in cooperation with
the KDHE. The study consisted of four separate sampling
events interspersed over a 7/4 month time period. During
these four events EcoMat operated its system at flows
between three and eight gpm. During this same time
period well water nitrate-N levels varied from greaterthan
70 mg/l to approximately 30 mg/l.
During the four sampling events, the SITE Program
collected water from four specific sample taps located
along EcoMat's process. Sampling rounds were
scheduled at pre-specified intervals, and consisted of
collecting the water samples from the four sample locations
atthe approximate same time. By following this procedure
the data collected simultaneously from the four sample
locations could be compared to one another. A total of 119
samples from each of the four sampling locations were
collected for the four field events (28 for Event 1; 31 for
Event 2; and 30 each for Events 3 and 4).
The four sample points, as shown on Figure 4-1, are:
1. An untreated ("InletWater")sample pointlocated
between PWS Well # 1 and the Deoxygenating
Tank(S1);
2. A "Partial BDN Treatment"sample point located
between the Deoxygenating Tank and EcoMat
Reactor (S2);
3. A "Post BDN" sample point located between the
EcoMat Reactor and post-treatment system (S3);
4. A "Final Effluent" sample point located
downstream of the post-treatment system (S4).
4.1.2 Project Objectives
Specific objectives for this SITE demonstration were
developed and defined prior to the initiation of field work.
These objectives were subdivided into two categories;
primary and secondary. Primary objectives are those goals
of the project that need to be achieved to adequately
compare demonstration results to the claims made by the
developer. The field measurements required for achieving
primary objectives are referred to as critical
measurements. Critical measurements were formally
evaluated against regulatory limits using statistical
hypothesis tests (which are detailed in the TER).
Secondary objectives are other goals of the project
developed for acquiring additional information of interest
about the technology, but are not directly related to
validating developer claims. The field and laboratory
measurements required forachieving secondary objectives
are considered to be noncritical. Therefore, the analysis of
secondary objectives was more qualitative in nature and
involved observations made by summarizing data in tables
and graphs.
Table 4-1 presents the one primary and seven secondary
objectives of the demonstration, and summarizes the
method(s) by which each was evaluated. Except for the
cost estimate (Objective 8), which is discussed in Section
3, each ofthese objectives is addressed in this section.
4.2 Detailed Process Description
A process flow diagram of the EcoMat treatment systems
used for the demonstration is presented in Figure 4-1. As
illustrated, there are two majorcomponents comprising the
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INLET WATER MeOH
(FROM PWS # 1) (50%Aqueous
Solution)
(S) = Sample
v?^y Collection
Point
R1
Deoxygenating
Tank
EcoMat Reactor \ /perforated piat»
-^Downcomer
Biodenitrification
Post-Treatment
Figure 4-1. Flow Diagram Showing EcoMat's Treatment System and Sample Collection Points
process: a BDN system and a post-treatment system. The
BDN system is a type of fixed film bioremediation in which
specific biocarriers and bacteria are used to convert
nitrates in the groundwater to nitrogen, thus reducing
nitrate-N concentrations to acceptable levels. The post-
treatment system is designed to either destroy or remove
any intermediate compounds potentially generated during
the biological breakdown of nitrate, and to remove small
amounts of bacteria and suspended solids that are not
attached to the biocarrier. The post-treatment system
shown in Figure 4-1 is a compilation of the different
combinations that were used during the demonstration. As
illustrated, the post-treatment system can incorporate
traditional methods for treating other contaminants (e.g.,
VOCs) that may be present in the influent. Both the BDN
and post-treatment systems are discussed in greater detail
in the following subsections.
4.2.1 BDN System
EcoMat's BDN system is designed to allow for rapid and
compact treatment of nitrate with minimal byproducts.
Unique to EcoMat's process is a patented mixed reactor
that is designed to retain the biocarrier within the system,
thus minimizing solids carryover. A detailed schematic of
the EcoMat denitrification reactor flow pattern is shown in
Figure 4-2.
A 50 percent aqueous methanol (MeOH) solution is added
to the system to provide an oxygen scavenger for BDN and
a source of carbon for cell growth. The resulting oxygen-
deficient environment encourages the bacteria to consume
nitrate. Methanol is also important to assure that
conversion of nitrate proceeds to the production of nitrogen
gas rather than to the intermediate nitrite, which is
considered to be more toxic.
The mechanism for anoxic biodegradation of nitrate
consists of an initial reaction for removal of excess oxygen
followed by two sequential denitrification reactions. This
mechanism can be expressed as three separate equations
as follows:
Oxygen Removal
CH3OH + 1.502 > C02 + 2H20 (1)
Denitrification Step 1:
CH3OH + 3NO3- > 3NO2- + CO2 + 2H2O (2)
Denitrification Step 2:
CH3OH + 2NO2- > N2 + CO2 + 2OH' + H2O (3)
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Table 4-1. Demonstration Objectives.
Objective
Description
Method of Evaluation
Primary Objective
Objective 1 Evaluate the performance of the EcoMat BDN and post-treatment
process components, separately; with respect to the following
performance estimates:
I. With incoming groundwater having nitrate-N concentrations of 20
mg/l or greater, and operating at a flow through rate of 3-1 5 gpm,
the BDN u nit would red uce the combined nitrate-N and nitrite-N
(total-N) concentration from PWS Well #1 groundwater to at or
below a total-N concentration of 10 mg/l.
II. The post treatment unit(s) will produce treated groundwater that
will meet applicable drinking water standards with respect to
nitrate-N, nitrite-N, and the combined nitrate-N plus nitrite-N.
III. Coupled with planned or alternative post-treatment, the product
water will consistently meet drinking water requirements, except
for residual chlorine. Specifically it will not contain turbidity of
greater than 1 NTU, detectable levels of methanol (1 mg/l), or
increased levels of biological material or suspended solids, and
will have a pH in the acceptable 6.5-8.5 range.
Collect post BDN effluent and final effluent samples from
two critical outfalls, interspersed over a period of four
events. Determine nitrate-N and nitrite-N concentrations
in those effluent samples via EPA Standard Method
300.0.
Note: Forthe purpose of performance evaluation, effluent
nitrate-N (and similarly the total-N) concentrations of
10.49 mg/l were to be rounded down to 10 mg/l and
therefore considered as meeting the MCL and 10.50 mg/l
were to be rounded up to 11 and therefore considered as
failing the MCL. Similarly, nitrate-N concentrations of
1.49 mg/l were to be rounded down to 1 mg/l and
therefore considered as meeting the MCL and 1.50 mg/l
were to be rounded up to 2 mg/l and therefore considered
as failing the MCL. These decisions were based on
discussions with the KDHE and reflect its current
practices.<10.5 mg/l when rounded to three significant
digits). The detailed statistical equations and data
analysis procedures used for evaluating the
demonstration data are included in the TER.
Secondary Objectives
Objective 2 Evaluate the performance of EcoMat's combined BDN and post-
treatment system components with respect to influent nitrate-N
concentration and with respect to time and/or water flow.
Plot the Objective 1 data versus 1) the influent
concentration from PWS Well # 1 and 2) the average flow
rate for each event.
Objective 3 Demonstrate that at least 90% of the final effluent samples
(downstream of post-treatment) analyzed during the demonstration
period for methanol, turbidity, and biological materials meet
drinking water requirements or at least do not provide cause for
concern where numerical values cannot be used for guidance.
Collect samples for methanol, total heterotrophs, fecal
coliform, and facultative anaerobes analyses at a
frequency of one per day from all four outfalls and
conduct daily turbidity measurements collected at inlet
water, post BDN, and final effluent sample streams.
Objective 4 Evaluate the percent mass removal of nitrate-N during each
sampling period over the course of the demonstration.
Calculate the total inlet and final effluent nitrate-N masses
in grams; determine mass removed as a total and
percentage.
Objective 5 Evaluate the effectiveness of the post-treatment system in
removing suspended solids, biologically active materials, methanol,
and VOCs of interest (e.g., carbon tetrachloride, benzene and
tetrachloroethylene).
Collect daily samples at all four outfalls for TSS analysis.
Collect inlet water, post-BDN, and final effluent samples
for VOC analysis at a frequency of three per event, and
conduct PLFA analysis at least once at all four outfalls.
Objective 6 Evaluate the necessity of the post-treatment system for
contributing to nitrate and nitrite mass removal.
Compare nitrate-N and nitrite-N mass results before and
after post-treatment.
Objective 7 Evaluate the effectiveness of each post-treatment system used
during the demonstration for removing suspended solids, bacterial
material, methanol and other VOCs.
Compare the data acquired for Objective 3 on an inter-
event basis.
Objective 8 Collect and compile information and data pertaining to the cost of
implementing the EcoMat BDN Process and necessary post-
treatment for the removal of excessive levels of nitrate in drinking
water supplies.
Acquire cost estimates from past SITE experience and
from developer. Cost treatment for a full-scale system
similar in design to the pilot unit used at Bendena. Break
down estimates into 12 cost categories that reflect typical
cleanup activities at Superfund sites. (See Section 3)
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Injector
Perforated
y Plate-
Downcomer
TUV-3
CIRC
PUMP
Figure 4-2. Detailed Schematic of the EcoMat Denitrification Reactor.
30
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Overall Denitrification Reaction:
5CH3OH + 6NO3-
3N + 5CO + 6OhT
7H2O (4)
Note: The subsequent discussion refers to nitrate-N and
nitrite-N values, in which each mg/l of nitrate-N is
equivalent to 4.4 mg/l of nitrate and each mg/l of nitrite-N
is equivalent to 3.2 mg/l of nitrite.
In the first step, aerobic/facultative bacteria consume
oxygen in the process of metabolizing methanol for energy
and biomass production. For the first denitrification step
(Equation 2) to occur, it is essential that the dissolved
oxygen (DO) concentration be less than 1 mg/l. Under
these anoxic conditions, the bacteria are forced to
substitute the nitrate as the electron acceptor and the
nitrate is reduced to nitrite. In the third equation, the nitrite
is further reduced to nitrogen gas. Nitrite production is an
intermediate step and there is no apr/or/reason to assume
that the second reaction (Equation 3) is at least as fast as
and/or favored over the first reaction (Equation 2) in the
presence of a specific bacterial population. Consequently,
any evaluation scheme must establish that there is no
buildup of nitrite, particularly since the nitrite-N maximum
contaminant level (MCL) is only 1 mg/l, one tenth that of
nitrate-N. High concentrations of nitrate and high
nitrate/methanol ratios tend to increase the concentration
of residual nitrite-N.
BDN is conducted in two reactors, identified as R1 and R2
on Figure 4-1. The majority of the oxygen removal step
(Equation 1 ) is conducted within R1, which EcoMat refers
to as the "Deoxygenating Tank". Inside this tank are
bioballs (a standard type of biocarrier) which have been
loaded with de-nitrifying bacteria purchased from a
commercial vendor. These aerobic bacteria initially reduce
DO levels of the contaminated influent. A 50 percent
aqueous MeOH solution is metered to the tank to
encourage the bacteria to begin consuming nitrate in the
resulting oxygen deficient water.
The de oxygenated water is pumped from the bottom of R1
to the bottom of R2, which is referred to by the developer
as the "EcoMat Reactor". R2 is packed with a synthetic
polyurethane biocarrier called "EcoLink", which serves as
the biocarrier for a colony of additional bacteria that are
also cultured for degrading nitrate. The EcoLink media are
1-cm3 cubes of sponge-like material that provide a large
surface area for growing and sustaining an active bacteria
colony. The cubes have contiguous holes so that bacteria
can populate them and nitrogen gas can exit. A special
additive to the polyurethane makes the surface more
hospitable to the bacteria.
Specially designed mixing apparatus within R2 directs the
inflowing water into a circular motion, which keeps the
suspended media circulating and enablesthe contaminated
waterto have intimate contactwith the bacteria. Perforated
plates at the bottom and top of R2 retain the EcoLink
biocarrier within the reactor, while permitting passage of
the water. Before the production of nitrogen gas starts the
specific gravity of EcoLink is slightly greater than that of
water. Within R2, the majority of denitrification (Equations
2 and 3) is conducted by the established anaerobic
bacteria colonies that are continually fed methanol as a
carbon source. After a sufficient retention time the
denitrified water drains by gravity to an overflow tank,
which allows for a continuous and smooth transfer to the
post-treatment system.
4.2.2 Post-Treatment System
The post-treatment system can be comprised of two
primary treatment components; an oxidation component
and a filtration component. The oxidation component is
intended to oxidize residual nitrite back to nitrate, oxidize
any residual methanol, and destroy bacterial matterexiting
the EcoMat Reactor (R2). The oxidation component may
consist of chlorination, ozonation, or UV treatment; or a
combination of the three. During the demonstration,
chlorination was used fortwo events, UV was used forone
event, and an ozone/UV combination was used for one
event.
The filtration component usually consists of a clarifying
tank and one or more filters designed to remove
suspended solids generated from the BDN process.
During the demonstration, a variety of filter combinations
were used, including a sand filter, and a series of variable-
sized cartridge filters. The cartridge filters that were used
included "rough filters" (20um), "high efficiency filters"
(Sum), and "polishing filters" (1um). Carbon cartridge filters
and an air stripper were used during Events 3 and 4,
respectively, to remove small amounts of CCI4.
4.3 Field Activities
4.3.1 Pre-Demonstration Activities
To confirm contaminant concentrations for the
demonstration and assist in sizing the system, pre-
demonstration samples were taken from PWS Well # 1
over a nine-day period (September 22-30,1998). Since the
pilot-scale system was expected to be operated within the
3-15gpm range, it was decided to pump ground water from
the well at 10 gpm during the nine-day period. To provide
an indication of the variation in nitrate-N concentrations,
one sample was collected every two hours over a four-hour
period, at the same times each day. It was also realized
during the pre-demonstration activities that pumping at a
rate of 20 gpm over a five-day period lowered the water
level in the well by about 10 feet, over 20 percent of the
water column. When the pumping rate was reduced to
about 10 gpm, there was little drawdown in the well.
31
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4.3.2 Sample Collection and Analysis
The sampling strategy for evaluating the effectiveness of
EcoMat's BDN Process was developed around comparing
the post BDN and final effluent (after post-treatment) data
to applicable regulatory limits. This comparison addresses
the project Primary Objective as presented in Table 4-1.
As was explained previously, there were four separate
treatment events during the demonstration. These events
were partially determined based on anticipated changesto
the post-treatment system. The events were spread out
over several months to allow for evaluating the EcoMat
technology over a longer time duration.
The goal of the sampling strategy was to collect sufficient
samples at each critical outfall during each event so that
statistical hypothesis tests could be conducted with an a
error rate = O.IOand a (3error rate = 0.10. (The method for
calculating the number of samples is presented in more
detail in the TER). Using 5.5 mg/l as an estimate of the
population variance in the final effluent nitrate-N + nitrite-N
(total-N) measures, the number of sampling rounds
required per event was found to be 29.
The SITE Program conducted on average ~ 30 sample
sampling rounds for each event. Since the samples were
collected at each of the four locations at the same time, the
resulting sample sets were comparable for evaluating the
EcoMat process at different points of the process; either on
a "per sample round" or "per event" basis. In order to
achieve some I eve I of "flushing" between sampling rounds,
the daily sampling frequency during each event was
dependent on the water flow rate through the system.
Because the flow rate was varied for each event, the
number of daily sampling rounds for collecting sample sets
varied from 3 to 5 per day.
The effectiveness of the post-treatment systems for all
events was evaluated by collecting samples immediately
downstream of the BDN system ("post BDN"), and
immediately downstream of the developer-selected post-
treatment components ("final effluent"); then comparing the
sample results from the two outfalls with respect to a
variety of microbial and water quality parameters. These
parameters included, but were not limited to, residual
methanol, total suspended solids (TSS), turbidity, total
culturable heterotrophs (TCH), Fecal Coliform (FC), and
facultative anaerobes (FA). Phospholipid fatty acids (PLFA)
were analyzed for on a very limited basis. Since these
limited PLFA results do not impact any developer claims,
those results are presented in the TER only.
Table 4-2 presents a summary of the laboratory analyses
conducted on samples collected from each of the four
sampling points monitoring the EcoMattreatment process,
and for the methanol feed (the main additive for the
process). All samples collected were grab samples.
4.3.3 Process Monitoring
Process monitoring was conducted on a routine daily basis
during all four sampling events. Table 4-3 presents the
type of process monitoring conducted during the
demonstration, the frequency and location of that
monitoring, and the instrumentation used. Details are
provided in the following subsections.
4.3.3.1 Nitrate-N and Nitrite-N Colorimeter Testing
Although daily samples were being collected during each
event for laboratory nitrate-N and nitrite-N analyses,
colorimeter testing was also conducted daily to
approximate real time values forthose critical parameters.
These measurements aided the developer in making
adjustments to its system and aided the analytical
laboratory in determining calibration ranges. An on-line
nitrate monitor was also installed to provide a continuous
record of nitrate entering and leaving the treatment system,
but the unit could not be operated routinely and no useful
records were obtained.
4.3.3.2 Process Flow Rate
Flow measurements were taken from a totalizer meter to
ensure that sampling rounds were being conducted atthe
properly-spaced time intervals (i.e., the treated water
correlated to the previous sampling round had exited the
entiretreatmentsystem).The flow measurements were also
used for later calculation of flow rates that could be
correlated to analytical results for each sampling round
conducted. A calibration check of the Neptune totalizer
gauge was conducted for each event to assure accuracy
of the meter.
4.3.3.3 General Water Quality Parameters
Daily measurements of general water quality parameters
were taken at all four outfalls to monitor parameters that
either could directly affect biological activity (e.g.,
temperature and DO) or were to be used to evaluate
system performance with respect to secondary objectives
(e.g., pH and turbidity). All water quality parameters were
measured with field instrumentation thatwas calibrated per
manufacturer instructions prior to taking the
measurements.
4.3.4 Process Residuals
During the demonstration the developer was responsible
for disposing of process residuals. These mostly included
spent cartridge filters, spent biocarrier, and spent carbon.
Due to the fact that nitrate and nitrite are non-hazardous
with respect to RCRA regulations, and that VOC
concentrations were negligible, all residuals from the
process were considered non-hazardous. Thus the spent
32
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Table 4-2. Summary of Laboratory Analyses Conducted for the Demonstration.
PARAMETER
Test
Method
SAMPLE LOCATION POINTS
INLET
WATER
PARTIAL
BDN
POST
BDN
FINAL
EFFLUENT
METHANOL
FEED
Chemical Analyses
Nitrate-N
Nitrite-N
TSS
Methanol
VOCs
Total Metals
Sulfate
Alkalinity
Total Solids
Phosphate
Ammonia
Total Organic Carbon
EPA 300.0
EPA 300.0
EPA 160.2
SW 801 5
SW 8260
SW 301 0/6020
EPA 300.0
EPA 310.1
EPA 160.3
EPA 300.0
EPA 350.2
SW 9060
Each Round 1
Each Round 1
1 per day
1 per day
3 per Event
3 per Event
3 per Event
3 per Event
3 per Event
3 per Event
3 per Event
3 per Event
Each Round 1
Each Round 1
1 per day
1 per day
—
—
—
—
—
—
—
—
Each Round 1
Each Round 1
1 per day
1 per day
3 per Event
3 per Event
3 per Event
3 per Event
3 per Event
3 per Event
3 per Event
3 per Event
Each Round 1
Each Round 1
1 per day
1 per day
3 per Event
3 per Event
3 per Event
3 per Event
3 per Event
3 per Event
3 per Event
3 per Event
—
—
—
—
2 per Demo.
—
—
—
—
—
—
—
Microbial Analyses
Total Heterotrophs
Fecal Coliform
Facultative Anaerobes
PLFA
SOP
SOP
SM9215M
SOPGCLIP
1 per day
1 per day
1 per day
1 for Event 1
1 per day
1 per day
1 per day
1 for Event 1 ;
1 for Event 4
1 per day
1 per day
1 per day
1 for Event 1 ;
1 for Event 4
1 per day
1 per day
1 per day
1 for Event 1
—
—
—
—
1 Refers to a round of samples collected from the process sample location points (Figure 4-1) at approximately the same time.
Dashed line indicates that samples collected at that location were not analyzed for that parameter.
Table 4-3. Summary of Field Measurements Conducted for the Demonstration.
PARAMETER
Nitrate-N
Nitrite-N
Flow Rate
PH
Conductivity
Dissolved Oxygen
Temperature
Turbidity
INSTRUMENTATION
Hach DR-890 Colorimeter
Hach DR-890 Colorimeter
Neptune Totalizer
YSI Mod. 63 pH/Cond. meter
YSI Mod. 63 pH/Cond. meter
YSI M95 DO meter
YSI M95 DO meter
LaMotte 2020 Turbidmeter
SAMPLE LOCATION POINTS
INLET
WATER
1 per day
—
Each Round
1 per day
1 per day
1 per day
1 per day
1 per day
PARTIAL
BDN
—
—
Each Round
1 per day
1 per day
1 per day
1 per day
1 per day
POST
BDN
1 per day
1 per day
Each Round
1 per day
1 per day
1 per day
1 per day
1 per day
FINAL
EFFLUENT
—
—
Each Round
1 per day
1 per day
1 per day
1 per day
1 per day
1 In addition, daily water levels of PWS Well #1 were recorded and electric usage was periodically recorded during each Event.
Dashed line indicates that samples collected at that location were not analyzed for that parameter.
33
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filter cartridges, carbon, biocarrier, etc. were simply
collected in a trash container and disposed of in a solid
waste dumpster.
The final effluent was deemed non-hazardous by the
KDHE, who arranged for a permitto discharge the treated
water to a septic system installed in an agricultural field
downgradient of the EcoMat treatment shed and PWS
Well#1.
4.4 Performance and Data Evaluation
This subsection presents in summary form the
performance data obtained during the EcoMat SITE
Demonstration conducted from May to December, 1999.
The data are presented in two ways. Subsections 4.4.1
through 4.4.4 evaluates each sampling event (i.e., Events
1 through 4, respectively), independently, with respect to
the objectives listed in Table 4-1. Subsection 4.4.5, on the
other hand, compares all four events. The latter inter-event
comparison may provide the reader with a better
understanding of the overall demonstration. Subsection
4.4.6 summarizes data quality assurance aspects of the
demonstration.
Since the post-treatmentsystemwas varied foreach event,
the data from the four events were initially analyzed
separately. Then a comparison between events was
performed. The level of significance (LOS) or a error rate
was set to 0.10 for the various statistical tests performed.
These tests included the Shapiro-Wilk tests of Normality
followed by either the Wilcoxon Signed Rank test or the
Student's t-test. The Wilcoxon Signed Rank (WSR) test is
a non-parametric, one-sample test, used to test the median
against a fixed threshold such as a regulatory limit. The
one-sample Student's t-test is a para metric test which tests
the mean against a fixed threshold.
Within each of these subsections, the following discussions
are presented in sequence:
• a summary of the effectiveness of the EcoMat
BDN and post-treatment systems at the various
sampling points.
• results of the statistical analysis that were
conducted to compare post BDN and final effluent
data to the appropriate regulatory limits.
• an evaluation ofthe BDN system.
• post-treatment system performance.
• a summary on the mass removal of nitrate.
• a discussion ofthe possible relationship between
system performance and flow rate.
To evaluate the post BDN and final effluent data against
regulatory limits, the following analytical strategy was used.
For each separate event, an Exploratory Data Analysis
(EDA) was conducted forthe post BDN combined nitrate-
N/nitrite-N (total-N), the final effluent nitrate-N, the final
effluent nitrite-N, and the final effluent total-N. The EDA
consisted of graphing the data in several formats and
calculating summary statistics (i.e., mean, median, and
standard deviation). These graphs and summary statistics
were used to make preliminary assumptions about the
shape ofthe distributions ofthe variables. This information
was needed in order to identify the appropriate statistical
hypothesis tests forthe data.
After reviewing the graphs and summary statistics,
Shapiro-Wilk tests of Normality were performed. Based on
the results of these tests, either the WSR test or the
Student's t-test was chosen as the appropriate hypothesis
test (i.e., the non-parametric WSR test was chosen when
the data did not fit either a normal or log-normal distribution
and the Student's t-test was chosen when the data
resembled a normal distribution). When the WSR test was
used the mean of the variable was evaluated against the
appropriate demonstration criterion. When the Student's t-
test was used the median of the variable was evaluated
against the appropriate demonstration criterion.
The demonstration criterion was the regulatory limit when
rounded to a whole number. The post BDN total-N was
tested against the demonstration criterion of < 10.5 mg/l
(i.e., regulatory limit = 10 mg/l), using an a error rate of
0.10. The final effluent had to meet a combined criteria
where the mean or median nitrate-N was < 10.5 mg/l (i.e.,
regulatory limit = 10 mg/l), the mean or median nitrite-N
was < 1.5 mg/l (i.e., regulatory limit = 1 mg/l), and the mean
or median total-N was below 10.5 mg/l (i.e., regulatory limit
= 10 mg/l). All three of these criteria had to be met in
order for the technology to be considered successful.
Therefore, a family-wise a error rate was set at 0.10 for
these three tests.
4.4.1 Event 1
4.4.1.1 Summary
Event 1 was an 11-day sampling episode conducted May
5-15, 1999. During Event 1 a total of 28 sampling rounds
were conducted and -42,000 gallons of nitrate-
contaminated well water passed through EcoMat's
treatment system at an average flow rate of 3 gpm. Based
on average flow rate and an estimated retention capacity
of 1,300 gallons for the reactor tanks, the sample rounds
were conducted three times per day and approximately
seven hours apart.
Figure 4-3 separately illustrates the effectiveness of the
EcoMat BDN and post-treatment systems evaluated during
Event 1, on an averaged basis (Note: the term average is
also referred to as the mean in subsequent discussions).
The top illustration shows BDN effectiveness for reducing
nitrate in the well water as a step-by-step process. As
34
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80
60
°E
Oi-
40
20
INLET
WATER
(from PWS
Well#1)
PARTIAL BDN
TREATMENT
N (R1 Effluent)
R1
De-
Oxygenating
Tank
46
(43/3)
Event 1
Flow @ 3 gpm
Legend
46 = Total-N concentration (mg/l)
(43/3) = Nitrate-N / Nitrite-N concentration (mg/l)
BDN = Biodenitrification
ND = Not detected > detection limits
R2
EcoMat
Reactor
POST BDN
TREATMENT
(R2 Effluent)
1.9
(0.9/1)
POST
TREATMENT
(see below)
FINAL
EFFLUENT
2.1
> (1.7/0.4)
Event 1 Post-Treatment Effectiveness
Post BDN
MeOH = 5.8 |\ ^
TSS = 12 I \ /
Turbidity = 2.8 ) ( C
TCH = 2.4x106 / V^
FC = 0 /
FA = 3.6x106
Final
^- — -^ [\ MeOH
\ I \ TSS =
Effluent
= 15
10
Jhlorination ) } Turbidity = 4.4
/ / TCH =
^- — ^ I/ FC = 0
v FA = 3
2.7x10b
.4x105
Figure 4-3. Event 1 - Treatment Effectiveness for Averaged Test Results.
illustrated, the nitrate-N concentration in PWS Well #1 was
in excess of 70 mg/l during the first event in May of 1999.
This high level of nitrate-N was reduced by about 38%
during the partial BDN treatment process that occurred in
the first reactor (R1). A small amount of nitrite, 3 mg/l,
remained from the nitrate-nitrite conversion. Subsequent
treatment in the EcoMat Reactor (R2) further reduced the
mean nitrate-N concentration from 43 mg/l to 0.9 mg/l and
reduced the mean nitrite-N level from 3 mg/l to 1 mg/l.
Thus, a mean total-N concentration of 1.9 mg/l was
attained by BDN treatment for Event 1 effluent samples.
Post-BDN and final effluent samples had essentially the
same total-N concentration. Mean total-N concentrations
for post-BDN and final effluent sam pies were 1.9 mg/l and
2.1 mg/l, respectively. However, the mean nitrate-N
concentration increased approximately twofold and the
mean nitrite-N concentration decreased by more than half.
35
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At these low levels, variability in laboratory analyses may
be an explanation, although continued biological activity
between the BDN and post-treatment processes may also
be a contributing factor. Alternatively, the post-treatment
chlorination may simply be re-oxidizing nitrite back to
nitrate.
As shown in the bottom illustration of Figure 4-3, the only
post-treatment conducted during Event 1 was chlorination.
The addition of chlorine had little effect on mean
concentrations of methanol. The mean methanol and
turbidity levels actually increased following post-treatment,
while mean TSS concentrations remained essentially the
same. As a disinfecting agent, the chlorination may have
had a modest impact on residual biological material.
Although TCH remained essentially the same, FA counts
were measured on average to decrease by one order of
magnitude. There was no growth for FC, thus there was
no measured post-treatment effect for that parameter.
4.4.1.2 Event 1 Statistical Analysis
The summary statistics for the critical measurements are
presented in Table 4-4. The nitrate-N, the nitrite-N, and
the total-N results for the four sampling locations, for all 28
tests comprising Event 1 are shown in Table 4-5. The
average (i.e., mean) values from these data were used in
generating Figure 4-3. These data were also used to
evaluate the Primary Objective (Objective 1).
Table 4-4. Event 1 - Summary Statistics.
Critical
Measurement
Post BDN Total-N
Final Effluent
Nitrate-N
Final Effluent
Nitrite-N
Final Effluent
Total-N
Mean
(mg/l)
1.917
1.654
0.410
2.064
Median
(mg/l)
1.270
1.600
0.113
1.676
Standard
Deviation (mg/l)
1.474
1.509
0.424
1.445
The EDA showed that the data for all four measurements
from Event 1 more closely resembled a lognormal than a
normal distribution. However, normality and lognormality
were rejected for all measurements, using an a error rate
of 0.10. (In other words, at the selected or error rate of
0.10, these data did not fit either a normal or a lognormal
distribution). Therefore, the non-parametric WSR was
chosen foranalyzing the data and the median was used as
the appropriate measure of central tendency.
Statistical hypothesis tests that we re conducted yielded the
following results:
• Part I: Post BDN median total-N of 1.27 mg/l was
significantly below the criterion of 1 0.5 mg/l.
• Part II: Final Effluent met the combined criterion.
The median total-N of 1.68 mg/l was significantly
below the criterion of 10.5 mg/l.
Based on the results of these 2 hypothesis tests, Event 1
was shown to be successful in reducing levels of nitrite-N
and nitrate-N to below regu latory limits, with a LOS of 0.10.
A more detailed explanation ofthese results is presented
in the TER.
4.4.1.3 General Evaluation of BDN System
Table 4-6 presents a summary of all performance criteria
results for Event 1. This includes the post-BDN and final
effluent nitrate-N, nitrite-N, and total-N data for each ofthe
28 Event 1 tests. Also included are the additional analytical
and field measurement data for specific outfalls that were
used for evaluating other performance criteria. As shown,
the objectives regarding reductions in nitrate-N, nitrite-N,
and total-N in final effluent were attained for all 28 sample
sets. However, other performance criteria results indicated
the need for more substantial post-treatment, especially for
treating residual methanol and removing microbial matter.
The daily DO measurements in Table 4-7 are key
indicators for evaluating the effectiveness of the
deoxygenating step required for triggering the anaerobic
BDN process. The data show that the deoxygenating
process was effective in reducing an average inlet water
DO of 10 mg/l to approximately 1 mg/l in partially treated
water exiting the Deoxygenating Tank.
4.4.1.4 General Evaluation of Post-Treatment System
Presented in this subsection are the field and laboratory
measurement data that were used primarily for evaluating
the post-treatment component of EcoMat's process during
Event 1 (Objective 5). Parameters included pH, turbidity,
TSS, microbial analyses, methanol, and "supplemental
analyses" which included a variety of parameters sampled
and analyzed on a limited basis.
The daily pH measurements in Table 4-8 show a slight
increase in pH to occur following BDN treatment. The post-
treatment chlorination that followed BDN may have caused
a very slight upward shift in the pH range. This negligible
effect was expected since chlorination is not a pH-altering
post-treatment (i.e., as opposed to ozone).
The daily turbidity measurements in Table 4-9 are
considered a gross indicator measurement for evaluating
the production of solids in the BDN system and a measure
of the effectiveness of the post-treatment system in
removing solids carryover. Since there is a secondary
criteria drinking water standard associated with turbidity,
each day of sampling was evaluated independently to
36
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Table 4-5. Event 1 - Nitrate-N and Nitrite-N Results (mg/l).
Sample Inlet Water
Round 1
Nitrate-N Nitrite-N Total-N2
1 77.9 <0.076 77.9
2 77.7 <0.076 77.7
3 79.2 <0.076 79.2
4 79.3 <0.076 79.3
5 79.5 <0.076 79.5
6 79.2 <0.076 79.2
7 79.7 <0.076 79.7
8 78.6 <0.076 78.6
9 74. 3 J <0.076 74. 3 J
10 73. 7 J <0.076 73. 7 J
11 73.7 <0.076 73.7
12 72.4 <0.076 72.4
13 73.4 <0.076 73.4
14 71.4 <0.076 71.4
15 72.2 <0.076 72.2
16 73.6 <0.076 73.6
17 72.4 <0.076 72.4
18 69.8 <0.076 69.8
19 71.0 <0.076 71.0
20 72.2 <0.076 72.2
21 71.0 <0.076 71.0
22 71.5 <0.076 71.5
23 69.7 <0.076 69.7
24 69.6 <0.076 69.6
25 68.9 <0.076 68.9
26 69.1 <0.076 69.1
27 69.2 <0.076 69.2
28 67.9 <0.076 67.9
Mean3 74 J ND 74 J
Partial BDN
Nitrate-N Nitrite-N Total-N2
34.9 4.8 39.7
47.9 2.9 50.8
50.0 2.6 52.6
47.7 3.3 51.0
50.5 2.9 53.4
49.7 3.6 53.3
43.3 J 3.8 47.1 J
49.1 3.3 52.4
38. 7 J 4.6J 43. 3 J
46.1 J 2.9 J 49.0 J
48.5 2.9 51.4
42.0 3.7 45.7
42.2 2.9 45.1
43.0 2.5 45.5
39.9 2.8 42.7
45.2 2.5 47.7
41.6 2.9 44.5
41.3 2.8 44.1
43.8 2.4 46.2
43.3 2.5 45.8
41.1 2.6 43.7
42.8 2.6 45.4
43.0 2.5 45.5
39.8 3.6 43.4
39.1 2.7 41.8
40.9 2.7 43.6
19.3 1.4 20.7
42.4 2.5 44.9
43 J 3.0J 46 J
Post BDN
Nitrate-N Nitrite-N Total-N2
1.2 1.3 2.5
1.2 0.67 1.87
4.7 1.1 5.8
3.7 1.4 5.1
0.63 0.64 1.27
2.4 1.4 3.8
0.76 0.74 1.5
1.3 0.82 2.12
0.65J 0.42J 1.07J
0.72J R NC
3.7 2.3 6.0
0.77 0.92 1.69
0.47 0.87 1.34
0.92 0.86 1.78
0.22 0.77 0.99
0.14 1.0 1.14
0.21 0.79 1.0
0.27 0.91 1.18
0.084 0.97 1.05
0.068 0.69 0.76
0.14 0.93 1.07
0.07 1.1 1.17
0.22 1.3 1.52
0.23 1.0 1.23
0.085 1.1 1.19
0.057 1.2 1.26
< 0.056 0.88 0.88
0.14 1.3 1.44
0.9J 1.0J 1.9J
Final Effluent
Nitrate-N Nitrite-N Total-N2
2.5 <0.15 2.65
2.2 <0.15 2.35
5.3 0.26 5.56
3.8 1.3 5.10
2.1 < 0.076 2.18
2.9 1.0 3.90
1.2 0.51 1.71
0.087 < 0.076 0.16
1.7J < 0.076 1.78
1.6J < 0.076 1.68
6.2 < 0.076 6.28
2.2 < 0.076 2.28
1.6 < 0.076 1.68
1.7 < 0.076 1.78
1.5 < 0.076 1.58
0.57 0.83 1.40
0.097 0.78 0.88
0.14 0.83 0.97
< 0.056 0.86 0.92
< 0.056 0.67 0.73
1.4 < 0.076 1.48
1.8 < 0.076 1.88
1.8 < 0.076 1.88
1.6 < 0.076 1.68
0.13 1.1 1.23
< 0.056 1.1 1.16
1.46 < 0.076 1.54
0.57 0.88 1.45
1.7J 0.4 2.1
1 Represents a sample set in which samples from all four locations were collected at the approximate same time.
2 Represents combined Nitrate-N and Nitrite-N in which values < the detection limit were considered zero for summing totals.
3 Means are rounded to two significant digits. Values < detection limit considered zero for calculating means.
J = Estimated value. R = Value rejected by QC. NC = Not calculated. ND = Not detected at or above MDL
37
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Table 4-6. Event 1 - Summary of Treatment Effectiveness.
Nitrate-N/Nitrite-N Results (mg/l)
Post BDN Final Effluent
Sample
Round1
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
Mean5
Total-N 2
2.5
1.87
5.8
5.1
1.27
3.8
1.5
2.12
1.07 J
R
6.0
1.69
1.34
1.78
0.99
1.14
1.0
1.18
1.05
0.76
1.07
1.17
1.52
1.23
1.19
1.26
0.88
1.44
1.9 J
Nitrate-N
2.5
2.2
5.3
3.8
2.1
2.9
1.2
0.087
1.7 J
1.6 J
6.2
2.2
1.6
1.7
1.5
0.57
0.097
0.14
< 0.056
< 0.056
1.4
1.8
1.8
1.6
0.13
< 0.056
1.46
0.57
1.7J
Nitrite-N
<0.15
<0.15
0.26
1.3
< 0.076
1.0
0.51
< 0.076
< 0.076
< 0.076
< 0.076
< 0.076
< 0.076
< 0.076
< 0.076
0.83
0.78
0.83
0.86
0.67
< 0.076
< 0.076
< 0.076
< 0.076
1.1
1.1
< 0.076
0.88
0.4
Total-N 2
2.65
2.35
5.56
5.10
2.18
3.90
1.71
0.16
1.78
1.68
6.28
2.28
1.68
1.78
1.58
1.40
0.88
0.97
0.92
0.73
1.48
1.88
1.88
1.68
1.23
1.16
1.54
1.45
2.1
Final Effluent - Other Performance Criteria
Flow
(gpm)
—
3.2
3.1
3.1
3.1
0.024
5.3
—
—
2.6
2.8
3.1
2.9
3.5
3
3
3.1
2.8
2.8
2.9
3
3
3.2
2.9
3
2.9
2.9
3
3
MeOH TSS Turbidity
(mg/l) (mg/l) (NTU)
91 9 8.6
—
—
<0.23 9 3.1
—
— —
<0.23 6 3.1
—
—
5 10.5 5.2
—
3.4 10 4.8
—
7.8 11.5 5.0
—
—
<0.23 10 2.0
—
—
<0.23 11.3 2.8
—
—
27 10.5 6.2
—
—
<0.23 14.2 2.8
—
26 1 1 4.8
14.6 10.3 4.4
pH 3 Total Heterotrophs
(SU) (CFU/ml)3
7.7/8.6 1,300/NG
—
—
7.7/8.2 2,300/2,000,000
—
— —
7.5/7.5 NG/ 4,500,000
—
—
8.1/8.2
—
8.1/7.7
—
7.7/8.2 NG/670
—
—
7.8/8.1 3,200/3,200,000
—
—
7.8/8.3 1,000/7,200,000
—
-
7.7 / 8.2 1 ,800 / 1 ,300
—
—
—
—
—
7.5-8.6 1,400/2,700,000
Represents a sample set in which samples from all four locations were collected at the approximate same time.
Total-N is equal to the combined Nitrate-N + Nitrite-N concentration.
3 The first value represent the inlet water and the second value represents the final effluent.
4 Flow rate value represents a likely interruption in the system followed by increased flow to compensate.
5 All values, except for pH, are means, rounded to two significant digits. Values < detection limit considered zero when calculating means.
R = Value rejected by QC. J = Estimated value. Dashed line indicates that samples collected at that location were not analyzed for that param eter.
38
-------
Table 4-7. Event 1 - Dissolved Oxygen Measurements (mg/l).
DATE
5-5-99
5-5-99
5-6-99
5-7-99
5-8-99
5-9-99
5-1 0-99
5-1 1 -99
5-1 2-99
5-1 3-99
5-1 4-99
5-1 5-99
TIME
INTERVAL
1000-1100
1600-1625
0930
1130
1000
1630
0930
2030
0945
0900
0945
-0730
Associated
Round Nofs.)1
1
2-3
4-6
7,8,9
10-11
12-13
14,15,16
17,18,19
20,21,22
23,24,25
26-27
28
Mean 2
SAMPLE POINT
Inlet Water
9.76
9.78
10.68
8.91
11.40
10.98
12.04
9.66
9.52
9.48
9.67
9.61
10
Partial BDN
2.34
1.10
1.10
1.02
0.92
0.95
1.05
0.65
1.28
1.00
0.91
0.72
1.1
Post BDN
6.17
4.65
5.70
5.30
5.80
6.35
5.65
4.50
4.50
4.90
4.85
4.92
5.3
Final Effluent
7.00
6.78
6.35
6.90
5.90
7.95
7.15
4.52
4.20
5.35
5.02
5.90
6.1
1 Sample rounds conducted closest in time to the measurement are bolded. 2 Mean values are rounded to two significant digits.
Table 4-8. Event 1 - pH Measurements.
DATE
5-5-99
5-5-99
5-6-99
5-7-99
5-8-99
5-9-99
5-1 0-99
5-1 1 -99
5-1 2-99
5-1 3-99
5-1 4-99
5-1 5-99
TIME
INTERVAL
1000-1100
1445-1500
0727-1100
1315-1330
0758-081 0
1455-1510
0837-0850
0805-0825
0832-0859
0942-0955
...
...
Associated
Round Nofs.)1
1
2-3
4-6
7,8,9
10-11
12-13
14,15,16
17,18,19
20,21,22
23,24,25
26-27
28
Range 2
SAMPLE POINT
Inlet Water
7.74
7.67
7.66
7.50
8.10
8.07
7.70
7.79
7.79
7.65
...
...
7.5-8.1
Partial BDN
7.81
7.73
7.66
7.5
7.58
7.5
7.79
7.75
7.78
7.74
...
...
7.5-7.8
Post BDN
8.43
8.24
8.21
7.2
8.20
7.5
8.0
8.05
8.15
8.12
...
...
7.2 -8.4
Final Effluent
8.61
8.45
8.21
7.5
8.23
7.7
8.20
8.12
8.25
8.21
...
...
7.5 -8.6
1 Sample rounds conducted closest in time to the measurement are bolded. 2 Range values are rounded to two significant digits.
Dashed line indicates that samples collected at the locations were not analyzed for that parameter.
39
-------
Table 4-9. Event 1- Turbidity Measurements (NTU).
DATE
5-5-99
5-6-99
5-7-99
5-8-99
5-9-99
5-10-99
5-11-99
5-12-99
5-13-99
5-14-99
5-15-99
TIME
INTERVAL
1 000-1 1 00
0727-1 1 00
0941 -0950
0835-0844
1555-1610
0752-0800
0758-0820
0847-0855
0847-0855
1005-1010
0715
Associated
Round No(s.)1
1
4-6
7,8,9
10-11
12-13
14,15,16
17,18,19
20,21,22
23,24,25
26-27
28
Mean3
SAMPLE POINT
Inlet Water
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
Partial BDN
...
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
Post BDN
4.4
3.4
2.95
1.69
2.14
2.68
2.31
2.85
2.62
2.61
3.63
2.8
Final Effluent
8.6
3.10
3.13
5.15
4.81
5.03
2.00
2.82
6.18
2.75
4.82
4.4
Pass/
Fail2
F
F
F
F
F
F
F
F
F
F
F
0/11
Sample rounds conducted closest in time to the measurement are bolded.
A sample round is considered passing ifthe final effluent value is <_ 1 NTU. In the last row, the number of passing values is shown in
the numerator; the total number of values (pass + fail, minus any blankvalues) is shown in the denominator.
3Mean values are rounded to two significant digits.
Dashed line indicates that sam pies collected at that location were not analyzed for that parameter.
determine if final effluent met the goal of £ 1 normal
turbidity units (NTU) (Objective 3). The readings indicate
turbidity to be measured consistently above that goal
each day ofsampling and to average 4.4 NTU.
The TSS data in Table 4-10 provide information on the
amount of solids added to the inlet water by the BDN
process during Event 1. More importantly, the laboratory-
derived TSS data can be used in conjunction with the field
turbidity measurements to assess the effectiveness of the
post-treatment system for removing those solids. The data
show the in let water to be essentially free of TSS (i.e., only
one value was above the MDL). As would be expected,
the post-treatment chlorination used during Event 1 had no
effect on the increased TSS levels produced during BDN.
The average post BDN and final effluent values were
essentially the same (12 mg/l and 10 mg/l, respectively).
On a per round basis, all final effluent values were greater
than their paired inlet water values.
The Event 1 microbial results presented in Table 4-11
include data for the three separate types of microbial
analyses conducted: TCH, FA, and FC. Inlet water, post
BDN, and final effluent outfalls were sampled for these
parameters.
The results of the TCH analyses can be used to measure
the additional bacteria produced by EcoMat's BDN process
(relative to inlet water) and to determine how effective the
post-treatment system was for removing the increased
level of bacteria. The data indicated that the TCH
population associated with the BDN process effluentwas,
on average, three orders of magnitude higher than TCH
levels in the well water. The carryover of this bacteria from
the BDN process to the final effluent was measured, on
average, to exceed 100 percent. Final effluent TCH values
were measured to be less than corresponding inlet water
TCH values in only two ofthe seven sampling rounds.
The FA analyses provide a useful measure of the
production of active biodenitrifying bacteria during the BDN
process. The concentration of these bacteria in inlet water
gives some indication of the character and quality of the
well water. Their numbers would be expected to greatly
increase in the post-BDN effluent and then greatly
decrease in final effluent due to post-treatment.
The FA data followed the expected pattern onlyto a certain
degree. The average ofthe FA plate count mean in inlet
water was increased by three orders of magnitude in post
BDN effluent. However, the post-treatment effectiveness
for reducing FA in final effluent was inconsistent. Final
effluent plate count means for individual samples ranged
from < 1000 cfu/ml to > 800,000 cfu/ml. The final effluent
40
-------
Table 4-10. Event 1- TSS Results (mg/l).
Sample Round
No.
1
4
7
10
12
14
17
20
23
26
28
Mean 2
SAMPLE POINT
Inlet Water
<5
<5
< 5
5.5
< 5
<5
< 5
<5
< 5
<5
< 5
<5
Partial BDN
—
—
—
—
—
—
—
—
—
—
—
—
Post BDN
15.2
7.5
8
14.7
9.5
12.7
12
13.3
14
12.7
14
12
Final Effluent
9
9
6
10.5
10
11.5
10
11.3
10.5
14.2
11
10
Pass/
Fail1
F
F
F
F
F
F
F
F
F
F
F
0/11
1 A sample round is considered passing if the final effluent value is <_the inlet water value. In the last row, the number of pass ing
values is shown in the numerator; the total numberofvalues(pass+ fail, minusanyblankvalues) isshown in the denominator.
Mean values are rounded to two significant digits. Values < detection limit are considered zero when calculating means.
mean value was less than the inlet water mean value for
only one sample round.
A possible contributing factorto the high variability of post-
treatment performance on FA could have been the lack of
controlled chlorination. At least on one occasion during
Event 1, the chlorine tablets being used were completely
depleted without being replenished for an indefinite time
period. This lapse was recorded to occur a couple of hours
after round #20 samples were collected and almost a day
before round #23 samples were collected. Round #20 and
the preceding round #17 had the two poorest results with
respectto large percentage increases in FA as measured
from post-BDN to final effluent (i.e., > 100 % carryover from
BDN); whereas for round #23 the final effluent was
measured to have had less than 6% of the post-BDN plate
count mean.
TheFCanalysescanbeusedtocomparethequalityofthe
inlet water with final effluent. Ideally, there should be no
increase. Since fecal coliform are aerobic, they could
become dormant during the BDN process and difficult to
measure among the other bacteria. For Event 1, there was
no growth of FC measured in inlet water, nor was there any
growth for the post-BDN and final effluent streams.
Table 4-12 presents the Event 1 laboratory results for
methanol analyses conducted on inlet water, post-BDN
effluent, and final effluent. There were small detectable
concentrations of methanol in three of the eleven inlet
watersamples. Round #1 results indicate that initially there
may have been a larger than expected imbalance in the
methanol-nitrate ratio, causing excess methanol in the
post-BDN effluentto carry overto the final effluent. For all
subsequent test samples, methanol was not detectable in
the post-BDN effluent, indicating that most of the carbon
source had been used up in the BDN process. There is no
explanation why detectable concentrations of methanol
were measured in five of the final effluent samples
corresponding to the post-BDN samples showing no
detectable concentrations of methanol. The post-treatment
chlorination was primarily used as a disinfectant and
should not have impacted methanol concentrations.
Table 4-13 presents the results of supplemental analyses
that were carried out on a limited number of samples to
obtain general background information on the technology.
These analyses included VOCs, total metals, sulfate,
alkalinity, total solids, phosphate, ammonia, and total
organic carbon (TOC).
CCI4, which had been historically detected in PWS Well#1
water, was not detected in the inlet water sample nor in
effluent samples. A small concentration of the VOC
chloroform, which is a also a trihalomethane (THM), was
detected in the final effluent. It is possible that chloroform
is a reaction by-product of CCI4 and chlorine in the
presence of organic matter.
The majority ofthe supplementalanalyses results indicates
the BDN and post-treatment systems to have little to no
effect on the measured parameters. The increase in TOC
41
-------
Table 4-11. Event! - Microbial Results.
Sample
Round
No.
1
4
7
14
17
20
23
Avg.
TOTAL CULTURABLE HETEROTROPHS - Plate Count Mean (cfu/ml)2
Inlet
Water 2
1,300
2,300
NG
NG
3,200
1,000
1,800
1,400
Post
BDN2
90,000
29,800
28,000
15,000
4,500,000
11,300,000
680,000
2,400,000
Final
Effluent 2
NG
2,000,000
4,500,000
670
3,200,000
7,200,000
1,300
2,700,000
% Carryover
from BDN
0%
6,700 %
16,000%
4.5%
71 %
64%
0.2 %
113%
% Change from
Inlet Water
- 100 %
+ 870 %
NC
NC
+ 1 ,000 %
+ 7,200 %
-28 %
+ 19,000%
Pass/
Fail3
P
F
F
F
F
F
P
2/7
FACULTATIVE ANAEROBES - Plate Count Mean (cfu/ml)2
1
4
7
14
16
17
20
23
Avg.
23,000
4,600
3,500
250
—
280
260
440
4,600
150,000
17,000,000
5,300,000
810,000
—
380,000
360,000
1 ,300,000
3,600,000
6,600
620,000
350,000
...
330
810,000
480,000
76,000
335,000
4.4%
3.6%
6.6 %
...
NC
213%
133%
5.8%
9.3 %
-71 %
+ 13,000%
+ 9,900 %
...
NC
+ 290,000 %
+ 190,000 %
+ 17,000%
+ 7,300 %
P
F
F
...
—
F
F
F
1/6
FECAL COLIFORM (Fecal coliforms/100ml)
1
4
7
14
17
20
23
Avg.
NG
NG
NG
NG
NG
NG
NG
NG
NG
NG
NG
NG
NG
NG
NG
NG
NG | NC
NG | NC
NG | NC
NG | NC
NG | NC
NG | NC
NG | NC
NG | NC
NC
NC
NC
NC
NC
NC
NC
NC
...
—
...
—
...
—
...
...
1 Post-treatment for Event 1 consisted solely of chlorination.
2 Plate count mean = average of three separate analyses, reported in colony forming units per milliliter.
3 A sample round is considered passing if the final effluent value is £ the inlet water value. In the last row for each parameter, the number
of passing values is shown in the numerator; the total number of values (pass + fail, minus any blank values) is shown in the
denominator.
NG = No growth; for purposes of percent change calculations, it is assumed that this value is zero.
NC = Not calculated; when the initial reading to be used in a calculation indicated no growth, no calculation was performed.
Dashed line indicates that samples collected at that location were not analyzed for that parameter.
42
-------
Table 4-12. Event 1- Methanol Results (mg/l).
Sample
Round
N"
1
4
7
10
12
14
17
20
23
26
28
Mean 2
SAMPLE POINT
Inlet Water
1
<0.23
2.5
< 0.23
<0.23
< 0.23
3.9
< 0.23
<0.23
< 0.23
0.7
Partial BDN
...
Post BDN
64
<0.23
<0.23
<0.23
<0.23
<0.23
<0.23
<0.23
<0.23
<0.23
<0.23
5.8
Final Effluent
91
<0.23
<0.23
5
3.4
7.8
<0.23
<0.23
27
<0.23
26
15
Pass/
Fail 1
F
P
P
F
F
F
P
P
F
P
F
5/11
1 A sample round is considered passing if the final effluent value is < 1 mg/l. In the last row, the number of passing values is shown
in the nu merator; the total number of values (pass + fail, minus any blankvalues) is shown in the denominator.
Mean values are rounded to two significant digits. Values < detection limit are considered zero when calculating means.
Dashed line indicates that samples collected at that location were not analyzed for that parameter.
Table 4-13. Event 1 - Supplemental Analyses Results (mg/l).1
Sample
Round
N"s
7,14,20
7,14,20
7,14,20
7,14, 20
7,14,20
7,14, 20
7,14,20
7,14, 20
7,14, 20
7,14,20
7,14,20
7,14,20
7,14, 20
7,14,20
Analyte 2
CCL
Chloroform
Total Solids
Ammonia
Total Organic Carbon
Sulfate
Phosphate
Alkalinity
SAMPLE POINT
Inlet Water
< 0.001
< 0.001
855
< 0.8
1.2
106*
< 0.082*
166
Partial BDN
—
—
—
—
Post BDN
< 0.001
< 0.001
602
<0.8
6.47
102
1.21
373
Final Effluent
< 0.001
0.006
635
< 0.8
6.07
104
367
Metals
Barium
Calcium
Potassium
Magnesium
Sodium
Phosphorus
0.08
150
1.8
42
12
<0.37
—
—
—
0.074
130
1.8
42
13
0.61
0.073
130
1.8
42
14
0.65
Values are the mean of the three test results (except where indicated) and are rounded to a maximum three significant digits.
2Exceptfor CCI4 onlyThe SW-846 Method 8260 contaminants with mean values above detection limits are reported.
Metals analyzed for included Ag, Al, Ba, Be, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Mo, Na, Ni, P, Sb, and Zn.
Dashed line indicates that samples collected at that location were not analyzed for that parameter; and no pass/fail determination was made.
* Two samples collected only.
43
-------
following BDN is likely attributable to the carryover of
biological material and methanol. The increased alkalinity
following BDN is consistent with the slight increase in pH
(refer to Table 4-8). The small amount of phosphate and
phosphorus measured in the effluent samples is residuum
from the 50% methanol solution, which contains food grade
phosphoric acid.
4.4.1.5 Mass Removal of Nitrate
The percent mass removal of nitrate, as measured as
Nitrate-N, was estimated for Event 1 (Objective 4). A total
of approximately 42,000 gallons, or about 160,000 liters of
well water was treated during Event 1. Each mg/l of nitrate-
N is equivalent to 4.4 mg/l of nitrate. Since the mean
nitrate-N concentration for Event 1 inlet water was 74 mg/l,
the total mass of nitrate treated during Event 1 would be
(74x4.4) mg/lx 160,000liters= 52,000,000 mg. The mean
nitrate-N concentration for Event 1 final effluent was 1.7
mg/l. The total mass of nitrate in the final effluent = (1.7 x
4.4) mg/l x 160,000 liters = 1,200,000 mg. Therefore, the
mass removal of nitrate during Event 1 would be
approximately 52,000,000 mg-1,200,000 mg = 51,000,000
mg (a 98% reduction in nitrate). This would correlate to
51,000 grams or 112 pounds. However, the contribution of
nitrite should not be discounted since it can be re-
converted to nitrate. Including the nitrite that remains in the
final effluent, the mass removal would be 111 pounds.
4.4.1.6 System Performance Vs. Flow Rate
The performance of EcoMat's combined BDN and post-
treatment system components were evaluated with respect
to water flow through the system (Objective 2). The
variation in inlet water flow rate during Event 1 was
compared with the total-N concentrations in the final
effluent. Figure 4-4 directly compares the Event 1
fluctuation for inlet water flow rate to the Event 1 fluctuation
in total-N final effluent concentrations forthe same sample
rounds. There is a similar pattern to both of the plots that
suggests a relationship between flow rate and BDN
effectiveness (i.e., lower flow rates corresponding to more
effective BDN). This is evident where the somewhat sharp
decrease in flow rate occurred about one quarter the way
I
2-
1-
Sample
Round No.
Final Effluent
Total-N(mg/l)
28
Figure 4-4. Event 1 - Comparison of Flow Rate Fluctuations and Final Effluent Total-N Concentrations.
44
-------
through the event correlates to a sharp reduction in total-N
concentration. However, elsewhere during the event there
are variations in the total-N values that cannot be
correlated with fluctuations in flow; these may correspond
to upsets in the treatment process. The plots in Figure 4-
4 also indicate that once the system was kept at a
consistent flow rate (i.e., the average event flow rate of 3
gpm), the BDN performance remained stable and quite
effective.
4.4.2 Event 2
4.4.2.1 Summary
Event 2 was a 10-day sampling episode conducted August
3-12, 1999. During Event 2, a total of 31 sampling rounds
were conducted and ~ 45,000 gallons of nitrate-
contaminated well water passed through EcoMat's
treatment system at an average flow rate of 3.5 gpm.
Based on this average flow rate, and on an estimated
retention capacity of 1,300 gallons for the reactor tanks,
sampling rounds were normally conducted four times per
day at approximately QVz hour intervals.
Figure 4-5 separately illustrates the effectiveness of the
EcoMat BDN and post-treatment systems evaluated during
Event 2. The nitrate-N in PWS Well #1 had a mean
concentration of 68 mg/l during the second event. This
mean inlet water concentration was slightly less than for
Event 1 (74 mg/l), possibly due to inflow of clean water into
the aquifer as contaminated water was removed. During
the partial BDN treatment process that occurred in the first
reactor (R1), the nitrate-N levels were reduced by about
40%, with a small amount of nitrite remaining from the
nitrate to nitrite conversion. Subsequent treatment in the
EcoMat Reactor (R2) further reduced the nitrate-N
concentration from a mean of 41 mg/l to a mean of 4.6
mg/l. The mean nitrite-N concentration increased from
1mg/l to 1.5 mg/l between partial BDN and post-BDN
samples. A mean total-N concentration of 6.1 mg/l was
attained by the BDN treatment for Event 2 samples.
During Event 2 post-treatment consisted of an initial
separation of suspended solids in a clarifying tank
("clarification"), followed by sand and cartridge filtration and
finally by UV oxidation. The post-treatment had no effect on
nitrite-N concentrations and only a minimal effect on
nitrate-N concentrations. The mean values for total-N
concentrations for post-BDN and final effluent samples
were 6.1 mg/l and 5.6 mg/l, respectively.
20
PARTIAL BDN
TREATMENT
(R1 Effluent)
42
(41/1)
Event 2
Flow @ 3.5 gpm
Legend
42 = Total-N concentration (mg/l)
(41/1) = Nitrate-N / Nitrite-N concentration (mg/l)
BDN = Biodenitrification
ND = Not detected > detection limits
R2
EcoMat
Reactor
POST BDN
TREATMENT
(R2 Effluent)
— _ 6.1
(4.6/1.5)
FINAL
EFFLUENT
Event 2 Post-Treatment Effectiveness
Post BDN
MeOH = 88
TSS = 13
Turbidity = 4.7
TCH = 2.9x10"
FC = 51
FA = 8x106
Final Effluent
MeOH = 98
TSS = < 5
Turbidity = 1.8
TCH = 1.8x107
FC = 42
FA = 3.2 X 10s
Figure 4-5. Event 2 - Treatment Effectiveness for Averaged Test Results.
45
-------
4.4.2.2 Event 2 Statistical Analysis
The summary statistics for the critical measurements are
presented in Table 4-14. Nitrate-N, nitrite-N, and total-N
results for the four sampling locations for all 31 sample
rounds comprising Event 2 are shown in Table 4-15. The
mean values from this data were used in generating Figure
4-5. This data was also used to evaluate the Primary
Objective (Objective 1).
Table 4-14. Event 2 - Summary Statistics.
Critical
Measurement
Post BDN
Total-N
Final Effluent
Nitrate-N
Final Effluent
Nitrite-N
Mean
(mg/l)
6.145
4.132
1.459
Median
(mg/l)
4.600
2.220
1.200
Standard
Deviation
(mg/l)
3.781
4.237
1.155
The EDA indicated that the data from Event 2 more closely
resembled a lognormal than a normal distribution. When
Shapiro-Wilk tests were run, both normality and
lognormality were rejected forall measurements exceptthe
final effluent nitrite-N data, which fit a lognormal
distribution. However, the presence of one extreme point
may have biased the results. Therefore, the non-
parametric WSR was chosen for analyzing all of the data
and the median was used as the appropriate measure of
central tendency.
Statistical hypothesis tests that we re conducted yieldedthe
following results:
• Part I: Post BDN median total-N of 4.60 mg/l was
significantly below the criterion of 1 0.5 mg/l.
• Part II: Final Effluent met all criteria. The median
nitrate-N, nitrite-N, and total-N concentrations
were 2.22, 1.20, and 3.61 mg/l, respectively.
These values were below their respective criterion
of 10.5, 1.5, and 10.5 mg/l.
Based on the results of these 2 hypothesis tests, Event 2
was shown to be successful in reducing levels of nitrite-N
and nitrate-N to below regulatory limits.
4.4.2.3 General Evaluation of BDN System
Table 4-16 presents a summary of all performance criteria
results for Event 2. This includes the post-BDN and final
effluent nitrate-N, nitrite-N, and total-N data for each ofthe
31 Event 2 tests. Also included are the additional analytical
data and field measurement results that were used for
evaluating other performance criteria. On a per round
basis, the objectives regarding reductions in nitrate-N,
nitrite-N, and total-N in the final effluent were attained for
17 of the 31 sample rounds. Other performance criteria
results shown in Table 4-16 indicate the need for more
substantial post-treatment, especially for treating residual
methanol and removing microbial matter.
The daily DO measurements in Table 4-17 show that for
approximately the first half of the event (i.e., rounds 1-14)
the daily measured DO in the partially treated BDN effluent
was consistently above 1 mg/l. Then, for the remainder of
the event, DO was consistently below 1 mg/l. The
deoxygenating process was effective in reducing the mean
inlet water DO of approximately 9 mg/l down to
approximately 1 mg/l in partially treated water exiting the
Deoxygenating Tank.
4.4.2.4 General Evaluation of Post-Treatment System
The field and laboratory measurements used primarily for
evaluating the post-treatment component of EcoMat's
Process during Event2 (Objective 5) included pH; turbidity;
TSS; microbial analyses; methanol; and "supplemental
analyses".
The daily pH measurements in Table 4-18 indicate a very
slight increase in alkalinity from inlet water to post BDN
effluent. However, there was essentially no change in pH
range in the final effluent following post-treatment.
The daily turbidity measurements in Table 4-19 indicate
turbidity to be consistently above the secondary drinking
water criterion of 1 NTU. However, the mean NTU of 1.8
was much improved over the Event 1 turbidity results.
The TSS data in Table 4-20 show that the inlet water
contain no detectable levels of TSS and post BDN effluent
to contains, on average, 13 mg/l of TSS. The final effluent
data indicated the post-treatment system had a positive
effect on reducing TSS levels, on average to less than 5
mg/l, most likely due to filtration. Six of nine final effluent
values were less than their paired inlet water values.
Table 4-21 presents the laboratory results for Total TCH,
FC, and FA at each of the four outfalls. An additional
sample was collected immediately upstream of the UV
oxidation unit and analyzed for TCH and FC to evaluate
that unit independently of the remainder of the post-
treatment system (refer back to Figure 4-5).
The results ofthe TCH analyses indicated that the TCH
population associated with the BDN process was, on
average, three orders of magnitude higherthan TCH levels
in the well water. On average, approximately 6 percent of
this bacteria carried over from the BDN process to the final
effluent. This marked a substantial improvement from the
first Event when no filtration was used. However, all seven
final effluent TCH values were measured to be above the
46
-------
Table 4-15. Event 2 - Nitrate-N and Nitrite-N Results (mg/l).
Sample Inlet Water
Round1
Nitrate- Nitrite- Total-
N N N2
1 71.5 < 0.076 71.5
2 71.3 < 0.076 71.3
3 71.4 < 0.076 71.4
4 72.0 < 0.076 72.0
5 71.5 < 0.076 71.5
6 72.9 < 0.076 72.9
7 73.1 < 0.076 73.1
8 73.1 < 0.076 73.1
9 67.0 < 0.076 67.0
10 65.6 < 0.076 65.6
11 66.5 <1.9 66.5
12 69.3 < 0.076 69.3
13 68.7 < 0.076 68.7
14 68.5 < 0.076 68.5
15 69.8 < 0.076 69.8
16 69.8 < 0.076 69.8
17 67.5 < 0.076 67.5
18 67.5 < 0.076 67.5
19 66.7 < 0.076 66.7
20 64.4 < 0.076 64.4
21 65.2 < 0.076 65.2
22 63.2 < 0.076 63.2
23 64.0 < 0.076 64.0
24 65.7 < 0.076 65.7
25 66.1 < 0.076 66.1
26 66.2 < 0.076 66.2
27 67.0 < 0.076 67
28 65.7 < 0.076 65.7
29 67.2 < 0.076 67.2
30 67.6 < 0.076 67.6
31 66.4 < 0.076 66.4
Mean3 68 ND 68
Partial BDN
Nitrate- Nitrite- Total-
N N N2
54.1 0.29 54.4
58.7 0.17 58.9
32.4 0.73 33.1
42.6 0.22 42.8
53.4 0.21 53.6
27.1 1.7 28.8
49.1 0.69 49.8
45.4 0.74 46.1
41.2 0.85 42.1
42.8 0.99 43.8
36 <1.9 36
43.3 0.86 44.2
47.2 1.16 48.4
38.1 1.37 39.5
41.4 1.3 42.7
49.3 0.99 50.3
47.2 0.99 48.2
41 1.5 42.5
38.3 1.3 39.6
38.4 1.4 39.8
37.8 1.5 39.3
41.3 1.3 42.6
37.8 1.3 39.1
39.1 1.1 40.2
37.8 1.1 38.9
35.6 1.4 37.0
38.4 1.1 39.5
36.2 1.2 37.4
35.7 1.4 37.1
35.3 1.3 36.6
34.5 1.4 35.9
41 1.0 42
Post BDN
Nitrate- Nitrite- Total-
N N N2
6.6 0.34 6.9
14.4 0.52 14.9
6.8 0.72 7.5
11.9 0.19 12.1
12.5 0.88 13.4
12.3 6 18.3
4.6 1.5 6.1
4 0.94 4.9
2.7 0.82 3.5
1.8 0.77 2.6
3 1.6 4.6
3.34 1.52 4.9
4.8 2.11 6.9
2.42 0.813 3.2
2.9 1.6 4.5
6.3 2.6 8.9
5.8 2.9 8.7
4 2.1 6.1
3.1 1.8 4.9
2.8 1.5 4.3
2 1.4 3.4
3.7 1.9 5.6
2.2 1.2 3.4
2.7 1.4 4.1
2.7 1.5 4.2
2.5 1.6 4.1
2.5 1.5 4.0
2.2 1.3 3.5
2.4 1.4 3.8
2.2 1.4 3.6
2.2 1.3 3.5
4.6 1.5 6.1
Final Effluent
Nitrate- Nitrit Total-
N e-N N2
5.2 0.37 5.6
13.2 0.48 13.7
10.8 0.94 11.7
9.6 0.28 9.9
11.1 0.79 11.9
18.6 6.7 25.3
4.1 1.7 5.8
2.8 0.81 3.6
1.2 0.74 1.9
1.5 0.76 2.3
2.2 1.6 3.8
1.7 0.95 2.7
2.54 1.8 4.3
1.34 0.73 2.1
3.5 1.9 5.4
6.0 2.8 8.8
6.1 2.9 9.0
3.5 2.1 5.6
3.1 1.9 5.0
2.1 1.4 3.5
1.1 0.99 2.1
3.1 1.8 4.9
1.5 1.0 2.5
1.7 1.3 3.0
1.5 1.3 2.8
2.1 1.5 3.6
1.7 1.4 3.1
1.6 1.1 2.7
1.5 1.2 2.7
0.9 1.0 1.9
1.2 0.98 2.2
4.1 1.5 5.6
Represents a sample set in which samples from all four locations were collected at the approximate same time.
2 Represents combined Nitrate-N and Nitrite-N. Values < the detection limit were considered 0.0 when summing totals.
3 Means are rounded to two significant digits. Values < detection limit are considered zero when calculating means.
ND = Not detected at or above MDL.
47
-------
Table 4-16. Event 2 - Summary of Treatment Effectiveness.
Nitrate-N/Nitrite-N Results
Sample
Round1
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
Mean 2
Post
Total-N1
6.9
14.9
7.5
12.1
13.4
18.3
6.1
4.9
3.5
2.6
4.6
4.9
6.9
3.2
4.5
8.9
8.7
6.1
4.9
4.3
3.4
5.6
3.4
4.1
4.2
4.1
4.0
3.5
3.8
3.6
3.5
6.1
Nitrate-
5.2
13.2
10.8
9.6
11.1
18.6
4.1
2.8
1.2
1.5
2.2
1.7
2.5
1.3
3.5
6.0
6.1
3.5
3.1
2.1
1.1
3.1
1.5
1.7
1.5
2.1
1.7
1.6
1.5
0.9
1.2
4.1
(mg/l)
Final Effluent
Nitrite-N Total-N1
0.37
0.48
0.94
0.28
0.79
6.7
1.7
0.81
0.74
0.76
1.6
0.95
1.8
0.73
1.9
2.8
2.9
2.1
1.9
1.4
0.99
1.8
1.0
1.3
1.3
1.5
1.4
1.1
1.2
1.0
0.98
1.5
5.6
13.7
11.7
9.9
11.9
25.3
5.8
3.6
1.9
2.3
3.8
2.6
4.4
2.1
5.4
8.8
9.0
5.6
5.0
3.5
2.1
4.9
2.5
3.0
2.8
3.6
3.1
2.7
2.7
1.9
2.2
5.6
Flow
(qpm)
2.9
2.5
3.1
3.9
4.4
3.4
2.9
2.7
2.7
3.2
3.5
1.6
2.6
3.3
4.7
4.5
—
—
4
3.7
—
4
3.9
4
3.9
3.9
3.6
3.8
3.8
3.8
3.5
Final Effluent - Other Performance Criteria
MeOH TSS Turbidity pH 2 Total Heterotrophs 2
(mg/l) (mg/l) (NTU) (SU) (CFU/ml)
—
34 5.6 2.7 7.8/7.6 5,000/380,000
—
—
—
70 6 2.6 8.2/7.9 27,000/3,300,000
—
—
7.4/7.8
180 <5 2.3 — 17,000/250,000
—
110 <5 2.4 7.5/7.8
—
—
39 < 5 1 .6 7.5 / 8.2 28,000 / 620,000
—
94 <5 1.2 7.6/8.4 33,000/130,000
—
—
7.6/7.7
100 <5 1.1 — 370,000/25,000,000
—
—
—
77 9 1.2 7.4/8.3 230,000/97,000,000
—
—
—
180 <5 1.5 7.4/8.2
...
98 <5 1.8 7.4-8.4 100,000/18,000,000
Total-N is equal to the combined Nitrate-N + Nitrite-N concentration.
2The first value represent the inlet water and the second value represents the final effluent.
All values, except for the pH range, are means rounded to two significant digits. Values < detection limit are considered zero when calculating means.
Dashed line indicates that samples collected at that location were not analyzed for that parameter.
48
-------
Table 4-17. Event 2 - Dissolved Oxygen Measurements (mg/l).
DATE
8-4-99
8-5-99
8-6-99
8-7-99
8-8-99
8-9-99
8-1 0-99
8-1 1 -99
8-1 2-99
TIME
INTERVAL
0945-1015
1000-1054
0900- 1 000
0820-0842
1440-1523
0830-0955
0845-0950
0800-0837
0830
Associated
Round No(s.)1
2-3,4,5
6-7,8,9
10-11,12
13,14
15,16
17-18,19,20
21-22,23,24
25,26,27,28
29-30,31
Mean 2
SAMPLE POINT
Inlet Water
—
8.70
8.74
9.45
8.85
9.33
8.8
9.09
8.81
9.0
Partial BDN
1.65
1.78
1.14
1.45
0.72
0.61
0.5
0.5
0.67
1.0
Post BDN
5.88
5.90
5.89
5.61
6.14
6.30
5.90
6.30
5.40
5.9
Final Effluent
2.11
4.55
0.51
1.03
5.9
4.30
4.64
3.55
0.5
3.0
1 Sample rounds conducted closest in time to the measurement are bolded.
2 Mean values are rounded to two significant digits.
Dashed line indicates that samples collected at that location were not analyzed for that parameter.
Table 4-18. Event 2 - pH Measurements.
DATE
8-4-99
8-5-99
8-6-99
8-7-99
8-8-99
8-9-99
8-1 0-99
8-1 1 -99
8-1 2-99
TIME
INTERVAL
0920-1016
0956-1054
0919-1006
0821-0843
1445-1524
0855-0956
0921-0934
0804-0830
0915-0925
Associated
Round No(s.)1
2-3,4,5
6-7,8,9
10-11,12
13,14
15,16
17-18,19,20
21-22,23,24
25,26,27,28
29-30,31
Range 2
SAMPLE POINT
Inlet Water
7.76
8.18
7.35
7.45
7.48
7.56
7.64
7.44
7.39
7.4-8.2
Partial BDN
7.5
7.72
7.57
7.25
7.39
7.75
7.67
7.61
7.58
7.4-7.8
Post BDN
7.62
7.72
8.01
7.91
8.19
8.46
8.39
8.36
8.25
7.6-8.5
Final Effluent
7.61
7.91
7.82
7.84
8.19
8.38
8.38
8.32
8.2
7.6 -8.4
1 Sample rounds conducted closest in time to the measurement are bolded.
2 Range values are rounded to two significant digits.
49
-------
Table 4-19. Event 2 -Turbidity Measurements (NTU).
DATE
8-4-99
8-5-99
8-6-99
8-7-99
8-8-99
8-9-99
8-10-99
8-11-99
8-12-99
TIME
INTERVAL
0931-1018
1003-1056
0925-1008
0825-0845
1448-1526
0855-0958
0921-0953
0804-0843
0915-0925
Associated
Round Nofs.)1
2-3,4,5
6-7,8,9
10-11,12
13,14
15,16
17-18,19,20
21-22,23,24
25,26,27,28
29-30,31
Mean3
SAMPLE POINT
Inlet Water
0.45
0.30
0.15
0.0
0.45
0.0
0.05
0.00
0.00
0.16
Partial BDN
0.95
0.35
0.85
0.9
0.25
0.3
0.4
0.25
0.5
0.53
Post BDN
8.3
4.7
7.2
7.6
2.7
5.0
4.5
2.2
0.5
4.7
Final Effluent
2.7
2.6
2.3
2.4
1.6
1.2
1.1
1.2
1.5
1.8
Pass/
Fail2
F
F
F
F
F
F
F
F
F
0/9
1 Sample rounds conducted closest in time to the measurement are bolded.
2 A sample round is considered passing if the final effluent is <1 NTU. In the last row, the number of passing values is shown in the
numerator; the total number of values (pass + fail, minus any blank values) is shown in the denominator.
3 Mean values are rounded to two significant digits. Values < detection limit considered zero when calculating means.
Table 4-20. Event 2 - TSS Results (mg/l).
Sample
Round No.
3
7
11
13
16
18
22
26
30
Mean 2
SAMPLE POINT
Inlet Water
<5
<5
<5
< 5
<5
< 5
<5
< 5
<5
<5
Partial BDN
...
—
...
—
...
—
...
—
...
—
Post BDN
23
17.1
11
8
10.4
12
13.3
17.8
<5
13
Final Effluent
5.6
6
<5
< 5
<5
< 5
<5
9
<5
<5
Pass/
Fail 1
F
F
P
P
P
P
P
F
P
6/9
1 A sample round is considered passing if the final effluent value is < the inlet water value. In the last row, the number of passing values
is shown in the numerator; the total number of values (pass + fail, minus any blank values) is shown in the denominator.
2 Mean values are rounded to two significant digits. Values < detection limit considered zero when calculating means.
Dashed line indicates that samples collected at that location were not analyzed for that parameter.
50
-------
Table 4-21. Event 2 - Microbial Results.1
Sample
Round
No.
3
7
11
16
18
22
26
Avg.
TOTAL CULTURABLE HETEROTROPHS - Plate Count Mean (cfu/ml)2
Inlet
Water 2
5,000
27,000
17,000
28,000
33,000
370,000
230,000
101,000
Post
BDN2
7,300,000
117,000,000
33,000,000
880,000,000
420,000,000
470,000,000
97,000,000
289,000,000
Final H % Carryover
Effluent ' 1 from BDN
380,000 | 5.2 %
3,300,000 | 2.8 %
250,000 | 0.8 %
620,000 | 0.7 %
130,000 | 0.03%
25,000,000 | 5.4 %
97,000,000 | 100%
18,100,000 | 6.3%
% Change from
Inlet Water
+ 7,600 %
+ 12,000%
+ 1 ,500 %
+ 2,200 %
+ 390 %
+ 6,800 %
+ 42,000 %
+ 18,000%
Pass/
Fail3
F
F
F
F
F
F
F
0/7
FACULTATIVE ANAEROBES - Plate Count Mean (cfu/ml)2
3
7
11
16
18
22
26
Avg.
2,900
3,100
320
220
520
2,400
3,400
1,840
360,000
760,000
320,000
1 1 ,000,000
9,600,000
19,000,000
15,000,000
8,000,000
85,000 | 24 %
70,000 | 9.2 %
150,000 | 53%
37,000 | 0.3 %
3,600,000 | 38 %
1 1 ,000,000 | 58 %
7,400,000 | 49 %
3,190,000 | 40 %
+2,800 %
+ 2,200 %
+ 47,000 %
+ 17,000%
+ 690,000 %
+ 460,000 %
+ 220,000 %
+ 170,000%
F
F
F
F
F
F
F
0/7
FECAL COLIFORM (Fecal coliforms/100ml)
3
7
11
16
18
22
26
Avg.
232
190
335
278
27
73
62
170
135
22
2
62
2
28
105
51
NG | 0 %
1 73 | 790 %
28 | 1 ,400 %
88 | 1 40 %
NG | 0 %
3 | 11 %
3 | 2.9 %
42 | 82 %
-100%
-9.1 %
-92%
-32 %
-100%
-96 %
-95%
- 75 %
P
P
P
P
P
P
P
7/7
1 Post-treatment for Event 2 consisted of clarification, followed by sand filtration, cartridge filtration, and UV oxidation.
2 Plate count mean = average of three separate analyses, reported in colony forming units per milliliter.
3 A sample round is considered passing if the final effluent value is £ the inlet water value. In the last row, the number of passing
values is shown in the numerator; the total number of values (pass + fail, minus any blank values) is shown in the denominator.
NG = No growth.
NC = Not calculated.
51
-------
corresponding inlet water values. Thus, the secondary
criterion was not met for TCH. The pre-UV oxidation mean
value for TCH was two orders of magnitude lowerthan the
final effluent plate count mean average, indicating thatthe
clarification and filtration preceding UV oxidation may have
been the only effective post-treatment. Based on the limited
results, UV was, at best, non-effective and, at worst,
detrimental with respect to TCH treatment. It is not clear
whether the UV oxidation system was correctly sized for
the role or whether other factors adversely affected its
utility.
As was the case with Event 1, the FA data followed the
expected pattern to a certain degree. The average ofthe
FA plate count means for inlet water increased by three
orders of magnitude in post BDN effluent. The post-
treatment effectiveness was improved over Event 1, but
was inconsistent. Final effluent plate count means for
individual sample rounds ranged from 37,000 cfu/ml to
11,000,000 cfu/ml. None ofthe final effluent mean values
was less than the inlet water mean value. Thus, the
secondary criterion was not met for FA. The sharp
increase (i.e., two orders of magnitude) for final effluent FA
values, starting midway through Event 2, could have been
the result of filter breakthrough.
For Event 2, the FC values in final effluent were below inlet
watervalues, both on a per round and total average basis.
Thus, the secondary criterion was met for FC. The pre-UV
oxidation sample indicated UV oxidation to have no positive
Table 4-22. Event 2- Methanol Results (mg/l).
effect on FC (refer back to Figure 4-5).
The methanol results in Table 4-22 indicate that methanol
was not detected in inlet water samples, but was detected
in all post BDN and final effluent samples. The mean
methanol concentrations in post BDN and final effluent
were 88 and 98 mg/l, respectively. The post BDN and final
effluent values were alsoverysimilaron a per round basis,
indicating that the UV oxidation post-treatment had no
effect on reducing residual methanol concentrations. The
secondary criterion of < 1 mg/l was, therefore, not met for
any of the sample rounds.
Table 4-23 presents results of supplemental analyses for
all outfalls sampled. The majority of these results indicate
thatthe BDN and post-treatment systems to had little to no
effect on the measured parameters. The mean
concentration of CCI4 detected in the inlet water during
Event 2 was small (i.e., 1.4 ug/l). CCI4 was not detected in
effluent samples. This indicates that the compound was
either volatilized or biodegraded during the BDN process.
The only other VOC detected was chloroform, which was
measured at a low concentration in the final effluent.
The somewhat significant increase in TOC following BDN
can be attributed to the carryover of biological material
and/or methanol. The increased alkalinity following BDN is
consistent with the slight increase in pH (refer to Table 4-
18). The small amounts of phosphate and phosphorus
measured in effluent samples is residuum from the 50%
Sample Round
No.
3
7
11
13
16
18
22
26
30
Mean2
SAMPLE POINT
Inlet Water
<0.23
<0.23
<0.23
<0.23
< 0.23
<0.23
< 0.23
<0.23
< 0.23
<0.23
Partial BDN
...
—
—
...
—
...
—
...
—
...
Post BDN
46
73
160
90
21
60
100
68
170
88
Final Effluent
34
70
180
110
39
94
100
77
180
98
Pass/
Fail 1
F
F
F
F
F
F
F
F
F
0/9
1 A result is considered passing if the final effluent value is < 1 mg/l. In the last row, the number of passing values is shown in the
numerator; the total number of values is shown in the denominator.
2 Mean values are rounded to two significant digits. Values < detection limit considered zero for calculating means.
NG = No growth.
Dashed line indicates that samples collected at that location were not analyzed for that parameter.
52
-------
Table 4-23. Event 2 - Supplemental Analyses Results (mg/l).
SAMPLE
ROUND NOs.
7, 16, 26
7,16,26
7, 16, 26
7, 16, 26
7, 16, 26
7, 16, 26
7, 16, 26
7, 16, 26
7, 16, 26
7, 16, 26
7, 16, 26
7, 16, 26
7, 16, 26
7. 16. 26
Analyte 2
CCI4
Chloroform
Total Solids
Ammonia
Total Organic Carbon
Sulfate
Phosphate
Alkalinity
SAMPLE POINT
Inlet Water
< 0.001 4
< 0.001
877
< 0.8
1.1
80
< 0.082
162
Partial BDN
Post BDN
< 0.001
< 0.001
612
< 0.8
47
77
1.2
374
Final Effluent
< 0.001
0.002
600
< 0.8
45
76
370
Barium
Calcium
Potassium
Magnesium
Sodium
Phosphorus
0.078
130
1.8
37
12
<0.35
0.073
123
1.7
37
13
1.3
0.072
123
1.6
38
13
1.3
Values are the Mean of the three test results and are rounded to a maximum three sign if leant dig its.
2Exceptfor CCI4 only SW-846 Method 8260 contaminants with mean values above detection limits are reported.
Metals analyzed for included Ag, Al, Ba, Be, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Mo, Na, Ni, P, Sb, and Zn.
Dashed line indicates that sam pies collected at that location were not analyzed for that parameter.
methanol solution, which contains food grade phosphoric
acid.
4.4.2.5 Mass Removal of Nitrate
The percent mass removal of nitrate, measured as Nitrate-
N, was estimated for Event 2 (Objective 4). A total of
approximately 45,000 gallons, or about 170,000 liters of
well water was treated during Event 2. Each mg/l of nitrate-
N is equivalent to 4.4 mg/l of nitrate. Since the mean
nitrate-N concentration forEvent2 inlet waterwas about68
mg/l, the total mass of nitrate treated during Event 2 would
be (68 x 4.4)mg/l x 170,000 liters = 51,000,000 mg. The
mean nitrate-N concentration for Event 2 final effluent was
4.1 mg/l. The total mass of nitrate in the final effluent = (4.1
x 4.4) mg/l x 170,000 liters = 3,000,000 mg. Therefore the
mass removal of nitrate during Event 2 would be
approximately52,000,000 mg-3,000,000 mg = 49,000,000
mg (a 94% reduction in nitrate). This correlates to 49,000
grams or 108 pounds. Adding the nitrite-N in the final
effluent would reduce the removal by 2 pounds.
4.4.2.6 System Performance Vs. Flow Rate
The performance of EcoMat's combined BDN and post-
treatment system components were evaluated with respect
to water flow through the system (Objective 2). The
variation in inlet water flow rate during Event 2 was
compared with the total-N concentrations in the final
effluent. Figure 4-6 directly compares the Event 2
fluctuation for inlet water flow rate to the Event 2 fluctuation
in total-N final effluent concentrations throughout the
duration of Event 2. As was the case with the first event
the flow rate and final effluent total-N concentrations
patterns are similarto one another; although there was a
lot more variability during the first half of the eventtesting.
Nonetheless, the inverse relationship showing lower flow
rates consistent with increased BDN effectiveness is still
apparent. Similarto Event 1 a rather sharp decrease in
flow rate occurred about one quarter the way through the
event and correlated to a sharp reduction in total-N
concentration. The plot in figure 4-6 also indicates that the
system became stabilized past the halfway point of Event
2. Once again, other operating factors may mask the
expected correlation of flow and denitrification.
53
-------
5-1
4 —
3 -
2-
1 -
Sample
Round No.'
Inlet Water
Flow (gpm)
-20
- 16
— 8.0
-4.0
12
16
20
24
28
Figure 4-6. Event 2 - Comparison of Flow Rate Fluctuations and Final Effluent Total N-Concentrations.
4.4.3 Events
4.4.3.1 Summary
Event 3 was a 9-day sampling episode conducted October
20-28,1999. During Event 3, a total of 30 sampling rounds
were conducted and ~ 49,000 gallons of nitrate-
contaminated well water passed through EcoMat's
treatment system at an average flow rate of 4 gpm. Flow
rates among the individual sampling rounds varied
considerably, ranging between ~2 and 7 gpm. Based on
the average flow rate, and an estimated retention capacity
of 1,300 gallons forthe reactor tanks, the sampling rounds
were normally conducted three times per day. However,
due to the high variability in flow rate, the sample rounds
were conducted at intervals anywhere between 3-7 hours
apart.
Figure 4-7 illustrates the effectiveness of the EcoMat BDN
and post-treatment systems used for Event 3. The mean
nitrate-N concentration in PWS Well #1 during Event 3
was 38 mg/l. This concentration was significantly less than
that measured for Event 2, which occurred approximately
21/2 months earlier. During the partial BDN in the first
reactor (R1), the mean nitrate-N levels were reduced by
about 47%, with a small amount of nitrite generated by the
nitrate to nitrite conversion. Subsequent treatment in the
EcoMat reactor (R2) further reduced the mean nitrate-N
concentration from of 20 mg/l to 7.7 mg/l. The average
nitrite-N concentration increased from 1.3 mg/l to 2.9 mg/l
between partial and post-BDN samples. Mean total-N
effluentconcentrationofapproximatelyl 1 mg/l was attained
by the BDN treatment for Event 3 samples.
Event 3 post-treatment consisted of ozone followed by UV
oxidation followed by clarification. Clarification was followed
by "rough" filtration, "high efficiency" filtration, carbon
adsorption, and "polishing" filtration. The post-treatment
system had no effect on nitrate-N or nitrite-N levels. When
rounded to two significant digits, the mean total-N
concentrations for post-BDN and final effluent samples
were -11 mg/l and 9.9 mg/l, respectively.
54
-------
60 i—
40
20
INLET
WATER
(from PWS
Well#1)
38
(38/ND)
^
f
PARTIAL BDN
7 TREATMENT
v (R1 Effluent)
R1
De-
Oxygenating
Tank
>
A
Event 3
Flow© 4.1 gpm
Legend
21 = Total-N concentration (mg/l)
(20/1 .3) = Nitrate-N / Nitrite-N concentration (mg/l)
BDN = Biodenitrification
Nn = Nnt Hetarterl > Hatertinn limits
_21_r>( __ A POST BDN
(20/1. 3K
'
KZ
EcoMat
Reactor
L J
TREATMENT
(R2 Effluent)
11 ,. Post
(7.7/2.9) Treatment
(See below)
FINAL
EFFLUENT
^ g_g
^ (8.3/1.6)
0 —
Event 3 Post-Treatment Effectiveness
Post BDN
MeOH = 41
TSS = < 5
Turbidity = 1.3
TCH = 6.7x106
FC = 50
FA = 6x105
Final Effluent
MeOH = 41
TSS = < 5
Turbidity = 1.2
TCH = 6.9x105
FC = 5
FA = 1.7 x 10s
Figure 4-7. Event 3 - Treatment Effectiveness for Averaged Test Results.
4.4.3.2 Event 3 Statistical Analysis
The summary statistics for the critical measurements are
presented in Table 4-24. Nitrate-N, nitrite-N, and total-N
results for the four sampling locations for all 30 Event 3
sample rounds are shown in Table 4-25. The mean values
from these data were to evaluate the primary objective
(Objective 1) and for generating Figure 4-7.
Table 4-24. Event 3 - Summary Statistics.
Critical
Measurement
Post BDN Total-N
Final Effluent
Nitrate-N
Final Effluent
Nitrite-N
Final Effluent
Total-N
Mean
(mg/l)
10.613
8.347
1.545
9.897
Median
(mg/l)
10.950
8.350
1.400
9.825
Standard
Deviation (mg/l)
3.706
2.854
0.851
2.978
The EDA indicated that the data from Event 3 closely
resembled a normal distribution, except for the post BDN
data. When Shapiro-Wilk tests were run, normality was
accepted for all variables except the post BDN data. For
these data neither the normal nor lognormal distribution
was shown to fit the data. Therefore, the non-parametric
WSR was chosen for analyzing the post BDN data and the
median was used as the appropriate measure of central
tendency. The Student's t-test was chosen for analyzing
the otherthree measurements (i.e., final effluent nitrate-N,
final effluent nitrite-N, and final effluent total-N), thus the
mean was used as the appropriate measure of central
tendency.
Statistical hypothesis tests thatwere conducted yielded the
following results:
Part I: For the Post BDN total-N data, both the
mean of 10.613 mg/l and the median of 10.950
mg/l were above the criterion of 10.5 mg/l. Thus,
no statistical test was needed to determine thatthe
Post BDN data did not meet that criterion.
55
-------
Table 4-25. Event 3 - Nitrate-N and Nitrite-N Results (mg/l).
Inlet Water
Sample
Round1 Nitrate- Nitrite- Total-
N N N2
1 43.9 < 0.076 43.9
2 41.8 < 0.076 41.8
3 44.1 < 0.076 44.1
4 45.7 < 0.076 45.7
5 45.3 < 0.076 45.3
6 41. 8 J < 0.076 41 .8 J
7 41.1 <0.076 41.1
8 41.8 < 0.076 41.8
9 40.3 < 0.076 40.3
10 40.4 < 0.076 40.4
11 38.5 < 0.076 38.5
12 40.3 < 0.076 40.3
13 38.9 < 0.076 38.9
14 39.0 < 0.076 39.0
15 38.7 < 0.076 38.7
16 36.9 < 0.076 36.9
17 36.8 < 0.076 36.8
18 37.3 < 0.076 37.3
19 36.8 < 0.076 36.8
20 37.1 < 0.076 37.1
21 36.6 < 0.076 36.6
22 35.4 < 0.076 35.4
23 35.5 < 0.076 35.5
24 35.3 < 0.076 35.3
25 34.8 < 0.076 34.8
26 34.7 < 0.076 34.7
27 33.7 < 0.076 33.7
28 33.6 < 0.076 33.6
29 32.7 < 0.076 32.7
30 31.4 < 0.076 31.4
Mean2 38 J ND 38 J
Partial BDN
Nitrate- Nitrite- Total-
N N N2
10 1.4 11.4
22.3 1.7 24
19.9 1.4 21.3
23.7 1.8 25.5
22.4 1.8 24.2
18.7 1.7 20.4
21.6 1.5 23.1
7.6 1.8 9.4
17.3 3.0 20.3
23.9 0.74 24.6
26.9 0.96 27.9
27.1 1.1 28.2
26.3 1.1 27.4
24.6 1.1 25.7
23.7 0.88 24.6
22.3 0.89 23.2
22.5 0.77 23.3
14.4 0.76 15.2
24.1 0.66 24.8
25 0.63 25.6
23 0.69 23.7
22.4 0.88 23.3
21.8 0.78 22.6
20 0.91 20.9
14.1 2.9 17
10 3.0 13
13.3 1.9 15.2
15.2 1.7 16.9
7.5 0.99 8.49
19 0.8 19.8
20 1.3 21
Post BDN
Nitrate- Nitrite- Total-
N N N2
3.9 4.0 7.9
6.4 2.6 9.0
6.4 3.0 9.4
6.6 2.0 8.6
12 3.0 15
6.7 3.2 9.9
10.1 2.8 12.9
7.2 3.4 10.6
10.5 2.8 13.3
7.5 2.5 10
12.5 2.9 15.4
12.2 3.7 15.9
12.1 3.7 15.8
11.4 3.7 15.1
9.2 1.8 11
8.8 3.3 12.1
8.5 3.1 11.6
<.056 0.19 0.19
8.7 2.2 10
10.1 2.9 13
9.6 3.2 12.8
8.9 3.7 12.6
8.3 3.4 11.7
7.0 3.2 10.2
4.5 2.5 7.0
2.5 2.6 5.1
8.0 3.0 11
4.8 3.3 8.1
0.15 1.2 1.35
7.4 3.0 10.4
7.7 2.9 11
Final Effluent
Nitrate- Nitrite- Total-
N N N2
1.7 0.44 2.14
5.3 0.85 6.15
8.9 0.95 9.85
7.6 <0.076 7.6
13.3 1.1 14.4
9.4 1.1 10.5
9.9 1.1 11
11 1.4 12.4
8.2 1.3 9.5
7.4 1.1 8.5
12.2 1.3 13.5
12.6 2.5 15.1
12.7 2.4 15.1
11.8 2.1 13.9
9.1 3.5 12.6
8.6 1.8 10.4
7.8 2.0 9.8
5.4 1.5 6.9
8.4 0.84 9.24
11.1 1.1 12.2
6.6 1.4 8.0
9.1 1.6 10.7
8.3 <0.076 8.3
9.4 0.38 9.78
5.5 3.0 8.5
2.5 2.6 5.1
7.8 2.6 10.4
5.2 2.5 7.7
5.6 1.9 7.5
8.0 2.0 10
8.4 1.5 9.9
1 Represents a sample set in which samples from all four locations were collected at the approximate same time.
2 Represents combined Nitrate-N and Nitrite-N. Values below the detection limit were considered 0.0 when summing totals.
3 Means are rounded to two significant digits. Values < detection limit considered zero when calculating means.
J = Estimated value. ND = Not detected at or above MDL.
56
-------
• Part II: Final Effluent did not meet its performance
estimate since the nitrite-N mean was above the
1.5 mg/l criterion.
Based on the results of these 2 hypothesis tests, Event 3
was not shown to be successful in reducing levels of nitrite-
N and nitrate-N to below regulatory limits.
4.4.3.3 General Evaluation of BDN System
Table 4-26 presents the post-BDN and final effluent nitrate-
N; the nitrite-N; and total-N results for the four sampling
points for each of the 30 Event 3 sampling rounds. Also
included in Table 4-26 are additional analytical data and
field measurement results that were used for evaluating
other performance criteria. A total of 11 of the 30 sample
rounds showed reductions in nitrate-N, nitrite-N, and total-
N in the final effluent to below the respective regulatory
criteria (when the results are rounded to the nearest whole
number). Results for other performance criteria indicated
a steady improvement in mean turbidity values with
substantially less biological carryover than in the first two
events. However, those same results indicated thatneither
the ozone nor the UV oxidation treatment was effective in
reducing mean residual methanol concentrations to below
1 mg/l.
The daily DO measurements in Table 4-27 showed DO in
the partially treated BDN effluent to be consistently above
1 mg/l and to average slightly over 2 mg/l for the entire
event. Although the deoxygenating process was effective
in reducing mean inlet water DO of 9.5 mg/l down to ~ 2
mg/l, the elevated DO values are an indicator that
anaerobic processes were not optimized. This was a likely
contributing factor to the poorer performance of Event 3
with respect to nitrate-N and nitrite-N reduction. Also, the
addition of ozone as a post-treatment step did not
significantly increase the DO of the final effluent.
4.4.3.4 General Evaluation of Post-Treatment System
The field and laboratory measurements used primarily for
evaluating the post-treatment component of the EcoMat's
Process during Events (Objective 5) included pH, turbidity,
TSS, microbial analyses, residual methanol, and
"supplemental analyses".
The daily pH measurements in Table 4-28 showed little to
no change between all four sample points. Potential pH-
altering post-treatment units used during Event 3, such as
ozone, apparently had no impact on pH.
The daily turbidity measurements in Table 4-29 indicate
that although just two of nine final effluent values were
measured below the secondary drinking water criteria of 1
NTU, the 1.2 mean value of NTU in the final effluent
showed continued improvement from Events 1 and 2.
The TSS data in Table 4-30 showed that the inlet water
contained no detectable levels of TSS and the post BDN
effluent to contain detectable levels of TSS in six of the
nine rounds. The final effluent data indicated that the post-
treatment system had a positive effect on reducing TSS
levels in all but one of those rounds, and that the final
effluent mean TSS value was below the detection limit.
Two of nine final effluent values were higher than their
paired inlet water value. Thus, the secondary criteria was
met for seven of nine rounds. Therefore, the combination
of filters used for Event 3 was, for the most part, effective.
Table 4-31 presents the laboratory results for Total TCH,
FC, and FA at each of the four outfalls. An additional
sample was collected immediately upstream of the UV
oxidation unit and analyzed for TCH and FC to evaluate
that post-treatment system independently of ozone
treatment (refer to Figure 4-7).
The results of the TCH analyses indicated the TCH
population associated with the BDN process was, on
average, two orders of magnitude higher than TCH levels
in the well water. On average, approximately 10 percent of
this bacteria carried over from the BDN process to the final
effluent (similar to that measured for Event 2). And, like
Event2, all seven final effluentTCH values were measured
to be above their paired inlet water values. Thus, the
secondary criterion was not met for TCH.
The pre-UV oxidation mean value for TCH (obtained from
the added sample point upstream of the UV oxidation unit)
was the same order of magnitude as the average of the
mean inlet water values. Therefore, the ozone treatment
may not have had any effect on TCH. The post-treatment
train downstream of the ozone unit may have had all of the
impact for reducing TCH levels in final effluent.
Like the two previous events, the FA data generally
followed the expected pattern of greatly increasing in the
post-BDN effluent and then greatly decreasing in final
effluent due to post-treatment (the values for round # 23
were an exception). The average of the FA plate count
mean values in inlet water was increased by one order of
magnitude in post BDN effluent. The post-treatment
effectiveness was improved over both previous events, but
the results were skewed by the unexplainable final effluent
mean value for round # 23. Only one of the final effluent
mean values was less than the corresponding inlet water
mean value. Thus, the criterion was not met for FA. (It
should also be noted that the inlet water in round #19
exhibited an unusually high FA).
For Event 3, a small amount of FC was measured in final
effluent of round 1 only. There was no FC measured in the
paired inlet water sample for round 1. Conversely, there
was FC measured in the last inlet water sample collected
(round 30). A similar number of colonies was measured in
the corresponding post BDN sample, but no FC was
measured in the final effluent. On a per round basis the
57
-------
Table 4-26. Event 3 - Summary of Treatment Effectiveness.
Nitrate-N/Nitrite-N Results
Sample
Round1
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
Mean4
Post BDN
Total-N
7.9
9.0
9.4
8.6
15
9.9
12.9
10.6
13.3
10
15.4
15.9
15.8
15.1
11
12.1
11.6
0.19
10
13
12.8
12.6
11.7
10.2
7.0
5.1
11
8.1
1.35
10.4
11
Nitrate-N
1.7
5.3
8.9
7.6
13.3
9.4
9.9
11
8.2
7.4
12.2
12.6
12.7
11.8
9.1
8.6
7.8
5.4
8.4
11.1
6.6
9.1
8.3
9.4
5.5
2.5
7.8
5.2
5.6
8
8.4
(mg/l)
Final Effluent
Nitrite-N Total-N2
0.44
0.85
0.954
<0.076
1.1
1.1
1.1
1.4
1.3
1.1
1.3
2.5
2.4
2.1
3.5
1.8
2.0
1.5
0.84
1.1
1.4
1.6
<0.076
0.38
3.0
2.6
2.6
2.5
1.9
2.0
1.5
2.14
6.15
9.85
7.6
14.4
10.5
11
12.4
9.5
8.5
13.5
15.1
15.1
13.9
12.6
10.4
9.8
6.9
9.24
12.2
8
10.7
8.3
9.78
8.5
5.1
10.4
7.8
7.5
10
9.9
Flow
(gpm)
—
3.9
4.4
2
5
3.6
5
4.3
4.9
3.6
4.6
4.9
4.7
5.7
4.3
4.7
4.3
2.3
4.8
5
4.6
4.5
4.5
7.2
3.3
4
5
5.2
3.3
4.8
4.2
Final Effluent - Other Performance Criteria
MeOH TSS Turbidity pH 3 Total Heterotrophs 3
(mg/l) (mg/l) (NTU) (SU) (CFU/ml)
59 <5 1.4 8.1/7.9 46,000/310,000
—
—
32 <5 1.1 8.1/8.2
42,000/360,000
—
—
—
62 <5 1.0 8.1/8.0 18,000/110,000
—
—
—
27 <5 0.64 8.2/8.0
—
—
—
35 5 1.0 8.1/8.0
—
34 7 1.8 8.2/8.0 180,000/630,000
—
—
—
54 <5 1.1 — 17,000/49,000
—
—
—
30 <5 1.9 8.1/8.1 14,000/240,000
—
—
33 <5 0.84 8.2/8.1 120,000/3,200,000
41 <5 1.2 7.9-8.2 63,000/690,000
1 Represents a sample set in which samples from all four locations were collected at the approximate same time.
2Total-N is equal to the combined Nitrate-N + Nitrite-N concentration.
3 The first value represent the inlet water and the second value represents the final effluent.
4 All values, except forthe pH range, are means rounded to two significant digits. Values < detection limit considered zero for calculating means.
Dashed line indicates that sam pies collected at that location were not analyzed for that param eter.
58
-------
Table 4-27. Event 3 - Dissolved Oxygen Measurements (mg/l).
DATE
10-20-99
10-21-99
10-22-99
10-23-99
10-24-99
10-25-99
10-26-99
10-27-99
10-28-99
TIME
INTERVAL
1300
1100
0800
0900
1400
1045
1630
1130
0800
Associated
Round No(s.)1
1,2,3
4,5,6,7
8,9,10,11
12-13,14
15,16,17
18-19,20,21
24,25
26,27,28,29
30
Mean
SAMPLE POINT
Inlet Water
9.20
9.18
9.18
9.25
10.0
9.62
—
9.37
10.3
9.5
Partial BDN
1.90
1.91
1.91
2.56
2.59
2.62
—
1.66
1.66
2.1
Post BDN
3.9
3.24
0.6*
4.1
3.74
2.10
—
2.65/0.2*
2.22
3.1/0.4
Final Effluent
4.88
8.67
7.90
1.23
0.44
6.51
—
3.21
3.68
4.6
1 Sample Rounds conducted closest in time to the measurement are bolded.
2 Mean values are rounded to two significant digits.
3 Average of two readings.
* Measurement taken inside R2 tank due to air bubbles in hose.
Dashed line indicates that samples collected at that location were not analyzed for that parameter.
Table 4-28. Events - pH Measurements.
DATE
10-20-99
10-21-99
10-22-99
10-23-99
10-24-99
10-25-99
10-26-99
10-27-99
10-28-99
TIME
INTERVAL
1300
1100
0800
0900
1400
1045
1630
1130
0800
Associated
Round No(s.)1
1,2,3
4,5,6,7
8,9,10,11
12-13,14
15,16,17
18-19,20,21
24,25
26,27,28,29
30
Range
SAMPLE POINT
Inlet Water
8.08
8.05
8.09
8.22
8.10
8.19
—
8.11
8.15
8.1 -8.2
Partial BDN
8.09
7.94
8.03
8.12
8.06
8.03
—
8.14
8.06
7.9 -8.1
Post BDN
8.15
8.15
8.16
8.17
8.17
8.15
—
8.21
8.18
8.2 -8.2
Final Effluent
7.93
8.17
8.03
8.00
7.98
8.02
—
8.10
8.06
7.9-8.2
1 Sample rounds conducted closest in time to the measurement are bolded.
2 Range values are rounded to two significant digits.
Dashed line indicates that samples collected at that location were not analyzed for that parameter.
59
-------
Table 4-29. Event 3 - Turbidity Measurements (NTU).
DATE
10-20-99
10-21-99
10-22-99
10-23-99
10-24-99
10-25-99
10-26-99
10-27-99
10-28-99
TIME
INTERVAL
1300
1100-1400
0800-0900
0900
1400
1045
1630
1130
0800
Associated
Round(s)1
1,2,3
4,5,6,7
8,9,10,11
12-13,14
15,16,17
18-19,20,21
24,25
26,27,28,29
30
Mean3
SAMPLE POINT
Inlet Water
—
0.13
0.10
0.32
0.18
0.65
0.17
0.21
0.15
0.24
Partial BDN
—
0.38
0.65
0.39
1.38
...
1.60
—
4.25
1.4
Post BDN
—
1.20
2.14
0.86
1.10
1.51
1.09
1.67
0.95
1.3
Final Effluent
1.4
1.07
1.03
0.64
1.02
1.82
1.06
1.86
0.84
1.2
Pass/
Fail2
F
F
F
P
F
F
F
F
P
2/9
1 Sample rounds conducted closest in time to the measurement are bolded.
2 A round is considered passing if the final effluent is < 1 NTU. In the last row, the number of passing values is shown in the numerator;
the total number of values (pass + fail, minus any blank values) is shown in the denominator
3 Mean values are rounded to two significant digits.
Dashed line indicates that samples collected at that location were not analyzed for that parameter.
Table 4-30. Event 3 -TSS Results (mg/l).
Sample
Round No.
1
4/5
9
13
17
19
23
27
30
Mean2
SAMPLE POINT
Inlet Water
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
Partial BDN
—
...
—
...
—
...
—
...
—
...
Post BDN
6
5
6
<5
<5
5
5.3
8
<5
<5
Final Effluent
<5
<5
<5
<5
5
7
<5
<5
<5
<5
Pass/
Fail1
P
P
P
P
F
F
P
P
P
7/9
1 A round is considered passing if the final effluent value is < the inlet water value. In the last row, the number of passing values is
shown in the numerator; the total number of values (pass + fail, minus any blank values) is shown in the denominator.
2 Mean values are rounded to two significant digits. Values < detection limit considered zero when calculating means.
Dashed line indicates that samples collected at that location were not analyzed for that parameter.
60
-------
Table 4-31. Events - Microbial Results.1
Sample
Round
No.
1
5
9
19
23
27
30
Avg.
TOTAL CULTURABLE HETEROTROPHS - Plate Count Mean (cfu/ml)2
Inlet
Water 2
46,300
42,000
17,700
183,000
17,300
14,200
120,000
62,900
Post
BDN2
3,100,000
7,550,000
3,370,000
5,150,000
4,230,000
21,300,000
1,970,000
6,670,000
Final H % Carryover
Effluent2 | from BDN
305,000 I 9.8 %
362,000 | 4.8 %
113,000 I 3.4%
632,000 | 12%
49.0004 I 1 .2 %
240,000 | 1.1 %
3,160,000 I 160%
694,000 | 10%
% Change from
Inlet Water
+ 660 %
+ 860 %
+ 640 %
+ 350 %
+ 280 %
+ 1 ,690 %
+ 2,600 %
+ 1,100%
Pass/
Fail3
F
F
F
F
F
F
F
0/7
FACULTATIVE ANAEROBES - Plate Count Mean (cfu/ml)2
1
5
9
19
23
27
30
Avg.
2,300
3,300
2,000
350, OOO4
470
1,000
2,100
51,600
240,000
1,100,000
430,000
1,900,000
190,000
65,000
290,000
602,000
16,000 | 6.7%
3,500 I 0.3 %
7,100 | 1.7%
1,5004 I 0.1 %
12,000,000" | 6,300%
2,200 I 3.4 %
8,400 | 2.9 %
1,720,000 | +290%
+ 700 %
+ 6.1 %
+360 %
- 99 %
+ 2,500,000 %
+ 220 %
+ 400 %
+ 3,300 %
F
F
F
P
F
F
F
1/7
FECAL COLIFORM (Fecal coliforms/100ml)
1
5
9
19
23
27
30
Avg.
NG
NG
NG
NG
NG
NG
378
54
NG
NG
NG
NG
NG
NG
348
50
33 I NC
NG | NC
NG I NC
NG | NC
NG I NC
NG | NC
NG I 0 %
5 | 10%
NC
NC
NC
NC
NC
NC
-100%
- 91 %
F
—
—
—
—
—
P
1/2
1 Post-treatment for Event 3 consisted of chlorination, ozonation, UV treatment, a clarifying tank, high efficiency filtration,
carbon filtration, and polishing filtration.
2 Plate count mean = average of three separate analyses, reported in colony forming units per milliliter.
3 A round is considered passing if the final effluent value is < the inlet water value. In the last row, the number of passing values is
shown in the numerator; the total number of values (pass + fail, minus any blank values) is shown in the denominator.
4 Anomalous results indicate potential problems with sampling or labeling. No corrective action is required. Data are suspect
and should be used with extreme caution.
NG = No growth. NC = Not calculated.
61
-------
criterion for FC was met for one of two rounds for which
any FC growth occurred; no growth occurred in the inlet
water, post-BDN, orfinaleffluentforthe otherfive tests. No
FC was detected in the single analysis of the sample
collected between the ozone and UV oxidation treatment
units during the 3rd round of Event 3 (refer to Figure 4-7).
Thus, no evaluation of UV oxidation effectiveness can be
made with respect to FC based on these limited data.
The laboratory results in Table 4-32 indicate that methanol
was not detected in inlet water samples, but was detected
in all post BDN and final effluent samples. The mean
concentration of methanol in post BDN and final effluent
were both 41 mg/l. The post BDN and final effluent values
were very similar on a per round basis, indicating that the
combined ozone and UV oxidation post-treatment had no
effecton reducing residual methanol concentrations. Thus,
the secondary criterion of achieving a final effluent with <
1 mg/l methanol was not met.
Table 4-33 presents the results of supplemental analyses
for all outfalls sampled. The majority of the supplemental
analyses results indicates the BDN and post-treatment
systems to have little to no effect on the measured
parameters. As was the case with the previous event, a
small average concentration of CCI4 (i.e., 19 ug/l) was
detected in the inlet water during Event 3. Based on a post
BDN mean value of 10 ug/l and a final effluent estimated
mean value of 1ug/l for CCI4, the post-treatment system
(likely the UV oxidation) may have contributed to the
Table 4-32. Event 3 - Methanol Results (mg/l).
reduction of that VOC contaminant.
The increase in TOC following BDN can be attributed to
the carryover of biological material and/or methanol. The
increased alkalinity following BDN is consistent with the
slight increase in pH (refer to Table 4-28). The small
amounts of phosphate and phosphorus measured in the
effluent samples is residuum from the 50% methanol
solution, which contains food grade phosphoric acid.
4.4.3.5 Mass Removal of Nitrate
The percent mass removal of nitrate, measured as Nitrate-
N, was estimated for Event 3 (Objective 4). A total of
approximately 49,000 gallons, or about 185,000 liters of
well water was treated during Event 3. Each mg/l of nitrate-
N is equivalent to 4.4 mg/l of nitrate. Since the mean
nitrate-N concentration for Event 3 inlet water was 38 mg/l,
the total mass of nitrate treated during Event 3 final effluent
was (38 x 4.4) mg/l x 185,000 liters = 31,000,000 mg. The
mean nitrate-N concentration for Event 3 final effluent was
8.3 mg/l. The total mass of nitrate in the final effluent = (8.3
x4.4) mg/l x 185,000 liters = 6,800,000 mg. Therefore the
mass removal of nitrate during Event 3 would be
approximately 31,000,000 mg-6,800,000 mg = 24,000,000
mg (a 77% reduction in nitrate). This correlates to 24,000
grams or 53 pounds. Considering the residual nitrite-N in
the final effluent, the nitrate-N reduction would decrease to
51 pounds.
Sample
Round No.
1
4/5
9
13
17
19
23
27
30
Mean2
SAMPLE POINT
Inlet Water
<0.23
<0.23
<0.23
<0.23
<0.23
<0.23
<0.23
<0.23
<0.23
<0.23
Partial BDN
...
...
...
...
...
...
...
...
...
...
Post BDN
83
33
34
38
42
31
49
35
26
41
Final Effluent
59
32
62
27
35
34
54
30
33
41
Pass/
Fail1
F
F
F
F
F
F
F
F
F
0/9
1 A round is considered passing if the final effluent value is < 1 mg/l. In the last row, the number of passing values is shown
in the numerator; the total number of values (pass + fail, minus any blank values) is shown in the denominator.
2 Mean values are rounded to two significant digits. Values < detection limit considered zero when calculating means.
Dashed line indicates that samples collected at that location were not analyzed for that parameter.
62
-------
Table 4-33. Event 3 - Supplemental Analyses Results (mg/l).1
Sample
Round No.
4/5,17,27
4/5,17,27
4/5,17,27
4/5,17,27
4/5,17,27
4/5,17,27
4/5,17,27
4/5,17,27
4/5,17,27
4/5,17,27
4/5,17,27
4/5,17,27
4/5,17,27
Analyte *
CCI4
Total Solids
Ammonia
Total Organic
Sulfate
Phosphate
Alkalinity
SAMPLE POINT
Inlet Water
0.019
582
<0.8
1.1
59
< 0.082
157
Partial BDN
...
—
...
—
...
—
...
Post BDN
0.01
459
<0.8
24
55
1.4
252
Final Effluent
o.oou
467
<0.8
21
56
1.4
250
Metals
Barium
Calcium
Potassium
Magnesium
Sodium
Phosphorus
0.069
103
1.4
28
13
<0.37
—
...
—
—
...
—
0.068
103
1.2
29
15
1.6
0.067
102
1.2
30
16
1.6
1 Values are the mean of the three test results and are rounded to a maximum three significant digits.
2 Except for CCI4 only SW-846 8260 contaminants with mean values above detection limits are reported.
Metals analyzed for included Ag, Al, Ba, Be, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Mo, Na, Ni, P, Sb, and Zn.
J = Estimated average value. Dashed line indicates that samples collected at that location were not analyzed for that parameter.
4.4.3.6 System Performance Vs. Flow Rate
The performance of EcoMat's combined BDN and post-
treatmentsystem components wereevaluated with respect
to water flow through the system (Objective 2). The
variation in inlet water flow rate during Event 3 was
compared with the total-N concentrations in the final
effluent. Figure 4-8 directly compares the Event 3
fluctuation for inlet water flow rate to the Event 3 fluctuation
in total-N final effluent concentrations on a perround basis.
The patterns for both plots reflect the high variability in flow
rate for Event 3, but still do suggest an inverse correlation
with system performance. Again, a relationship between
lowerflow rate and increased BDN effectiveness is evident
where the somewhat sharp decrease in flow rate occurred
about one quarter the way through the event, which
correlates with a reduction in total-N concentration. The
plots in Figure 4-8 also indicate that the system was never
really stabilized which in large part was due to system
perturbations that disrupted Event 3.
63
-------
5-
4-
3-
2 -
1 -
Sample
Round No.
Event 3
12
16
20
I
24
28
1-28
-24
• 20
16
-12
-8.0
-4.0
Figure 4-8. Event 3 - Comparison of Flow Rate Fluctuation and Final Effluent Total-N Concentration.
64
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4.4.4 Event 4
4.4.4.1 Summary
Event 4 was an 8-day sampling episode conducted
December 7-14, 1999. During Event 4 a total of 30
sampling rounds were conducted and • »61,000 gallons of
nitrate-contaminated well water passed through EcoMat's
treatment system at an average flow rate of 6 gpm. The
flow rate among the 30 sampling rounds ranged between
4.7and 8.3 gpm. Based on an estimated retention capacity
of 1,300 gallons for the reactor tanks, the sampling rounds
were conducted • »2 to 3/4 hours apart and from three to
five times per day.
Figure 4-9 illustrates the effectiveness of the EcoMat BDN
and post-treatment systems evaluated during Event 4. The
mean nitrate-N concentration in PWS Well #1 had
continued to drop in the six-week period since the Event 3
testing in October. The mean concentration of nitrate-N in
the well water during the fourth event was 34 mg/l. During
the partial BDN in the first reactor (R1), the mean nitrate-N
levels were reduced by about 44% to 19 mg/l, with a small
amount of nitrite left over from the nitrate to nitrite
conversion. Subsequent treatment in the EcoMat reactor
(R2) further reduced the mean nitrate-N concentration from
19 mg/l to 8 mg/l. The mean nitrite-N concentration
increased from 1.3 mg/l to 3.2 mg/l between partial BDN
and post-BDN samples. A mean total-N concentration of
approximately 11 mg/l was attained by the BDN treatment
for Event 4 samples.
Event 4 post-treatment consisted of chlorination followed
by clarification, "high efficiency" filtration, air stripping, and
"polishing" filtration. The post-treatment system had no
effect on nitrite-N levels; mean nitrate-N concentrations
were reduced from 3.2 to 0.81 mg/l. The mean total-N
concentrations for post-BDN and final effluent samples
were 11.2 mg/l and 11.9 mg/l, respectively.
60 t—
40
20
INLET
WATER
(from PWS
Well#1)
J4
(34/ND)
PARTIAL BDN
•\7 TREATMENT
. ^ (R1 Effluent)
R1
r\ i
De-
Oxygenating
Tank
V J
s~ ^s.
20 t>
(19/1)
R2
EcoMat
Dp9f*t/\r
POST BDN
TREATMENT
(R2 Effluent)
11 r.
(8/3) V
Event 4
Flow @ 6.2 qpm
20 = Total-N
Legend
concentration (mg/l)
(19/1) = Nitrate-N / Nitrite-N concentration (mg/l)
BDN = Biodenitrification
ND = Not detected > detection limits
Post
Treatment
(See below)
V S
FINAL
— D> 12
(11/0.8)
Event 4 Post-Treatment Effectiveness
Post BDN
MeOH = 27
TSS = < 5
Turbidity = 1.1
TCH = 3.5x106
FC = >7
FA=1.9x105
Final Effluent
MeOH = 42
TSS = < 5
Turbidity = 0.96
TCH = 4.5x105
FC = 9
FA = 2x104
Figure 4-9. Event 4 - Treatment Effectiveness for Averaged Test Results.
65
-------
4.4.4.2 Event 4 Statistical Analysis
The summary statistics for the critical measurements are
presented in Table 4-34. Nitrate-N, nitrite-N, and total-N
results for the four sampling locations for all 30 tests
comprising Event 4 are shown in Table 4-35. The mean
values from these data were used in generating Figure 4-9.
Table 4-34. Event 4 - Summary Statistics.
Critical
Measurement
Post BDN Total-N
Final Effluent
Nitrate-N
Final Effluent
Nitrite-N
Final Effluent
Total-N
Mean
(mg/l)
11.197
10.63
0.870
1 1 .993
Median
(mg/l)
10.550
11.750
0.076
12.076
Standard
Deviation (mg/l)
5.079
5.023
1.523
5.324
These data were also used to evaluate the Primary
Objective (Objective 1).
The EDA showed that the data from Event 4 closely
resembled a normal distribution, exceptforthe finaleffluent
nitrite-N data which had a large percentage of non-detects.
When Shapiro-WiIk tests were run, normality was accepted
forall measurements except the final effluent nitrite-N data.
Forthesedata neitherthe normal norlognormal distribution
was shown to fit. Therefore, the non-parametric WSR was
chosen foranalyzing the final effluent nitrite-N data, butthe
Student's t-test was chosen for analyzing the post BDN
total-N, final effluent nitrate-N, and final effluent total-N.
Statistical hypothesis tests thatwere conducted yielded the
following results:
Part I: For the Post BDN total-N data, both the
mean and median were above 10.5 mg/l, so no
statistical test was needed to determine that the
Post BDN data did not meet the regulatory limit.
• Part II: Final Effluent did not meet its performance
estimate criteria since both the nitrate-N mean and
median concentrations were > 10.5 mg/l.
Based on the results of these 2 hypothesis tests, Event 4
was not shown to be successful in reducing levels ofnitrite-
N and nitrate-N to below regulatory limits.
4.4.4.3 General Evaluation of BDN System
Table 4-36 presents the post-BDN and final effluent nitrate-
N; nitrite-N and total-N results for the four sampling points
for each of the 30 Event4 sampling rounds. Also included
in Table 4-36 are additional analytical data and field
measurement data that were used for evaluating other
performance criteria. A total of 11 of the 30 sample rounds
showed reductions in nitrate-N, nitrite-N, and total-N in the
final effluent to below the respective regulatory criteria
(when rounding results to the nearest whole number).
Other performance results indicated that, on average, the
Event 4 filtration achieved the best removal of biological
carryover among all four events, although the levels were
still well above inlet water levels. The secondary criteria
results also indicated that the air stripping treatment was
not effective in reducing residual methanol levels to near
the desired level of 1 mg/l.
The daily DO measurements in Table 4-37 show that DO
in the partial BDN effluent was consistently above 1 mg/l,
averaged close to 3 mg/l, and was highly variable over the
entire event. System disruptions, including unexplainable
shut-offs of the methanol feed pump, contributed to the
erratic DO levels. Elevated DO values are an indicator that
anaerobic processes were not optimized and likely
contributed to the poor performance of Event 4 with respect
to nitrate-N and nitrite-N removal.
4.4.4.4 General Evaluation of Post-Treatment System
The field and laboratory measurements that were used
primarily for evaluating the post-treatment component of
EcoMat's process during Event 4 (Objective 5) included
pH, turbidity, TSS, microbial analyses, methanol, and
"supplemental analyses".
The daily pH measurements in Table 4-38 indicated a
continued increase for the inlet water from PWS Well # 1,
as compared to previous events. However, the pH range
appears to decrease following BDN treatment.
Although two final effluent pH values were slightly outside
of the acceptable drinking water standard range of 6.5 -
8.5, the pH values forfinal effluentwere improved over inlet
water values.
The final effluent turbidity measurements in Table 4-39
were consistently the lowest of all four events, indicating
improved post-treatment effectiveness with respect to
turbidity. Five of seven final effluent measurements, and
the mean of the seven measurements, were below the
criterion of 1 NTU.
Table 4-40 presents the Event 4 laboratory results for TSS.
As was the case for Event 3, the data show that the inlet
water and post BDN effluent contain detectable levels of
TSS in just two of the eight samples. The final effluent data
indicated that the post-treatment system had a positive
effect on reducing TSS levels in both of those sample
rounds, and that the final effluent mean TSS value was
below the detection limit. One of eight final effluent values
was higher than the paired inlet water value. Thus, the
66
-------
Table 4-35. Event 4 - Nitrate-N and Nitrite-N Results (mg/l).
Sample Inlet Water
Round1
Nitrate- Nitrite- Total-
N N N2
1 34.8 < 0.076 34.8
2 35 < 0.076 35
3 35 < 0.076 35
4 34.8 < 0.076 34.8
5 34.6 < 0.076 34.6
6 35.3 < 0.076 35.3
7 35.3 < 0.076 35.3
8 33.9 < 0.076 33.9
9 34.5 < 0.076 34.5
10 34 < 0.076 34
11 33.5 < 0.076 33.5
12 33.5 < 0.076 33.5
13 33.6 < 0.076 33.6
14 33.6 < 0.076 33.6
15 33.2 < 0.076 33.2
16 34 < 0.076 34
17 33.9 < 0.076 33.9
18 33.8 < 0.076 33.8
19 33 < 0.076 33
20 33.9 < 0.076 33.9
21 33.1 < 0.076 33.1
22 33 < 0.076 33
23 33.3 < 0.076 33.3
24 33 < 0.076 33
25 32.8 < 0.076 32.8
26 33.2 < 0.076 33.2
27 33.3 < 0.076 33.3
28 32.8 < 0.076 32.8
29 33.6 < 0.076 33.6
30 33.6 < 0.076 33.6
Mean3 34 < 0.076 34
Partial BDN
Nitrate- Nitrite- Total-
N N N2
25.4 0.68 26.1
27 0.43 27.4
26.8 0.39 27.2
25.6 0.48 26.1
27.4 0.48 27.9
26.6 0.5 27.1
18.3 1.4 19.7
19.8 1 20.8
19.1 0.92 20.0
21.1 1.1 22.2
17.1 1.5 18.6
20.3 0.65 21
20.7 1.5 22.2
20.6 1.6 22.2
21.3 1.4 22.7
13.5 2.4 15.9
15.3 2.5 17.8
22.3 1.3 23.6
10.8 <0.076 10.8
17.8 1.8 19.6
29.2 0.1 29.3
32.4 <0.076 32.4
15 <0.076 15
15.4 <0.076 15.4
9.4 <0.076 9.4
14.5 <0.076 14.5
13.4 2.3 15.7
14 2.3 16.3
7.9 1.4 9.3
7.9 1.2 9.1
19 0.98 20
Post BDN
Nitrate- Nitrite- Total-
N N N2
13.9 4 17.9
15.5 3.7 19.2
13 4.4 17.4
12.1 4.2 16.3
14.8 3.9 18.7
14 3.9 17.9
7 4 11
9.1 3.1 12.2
8.4 3.3 11.7
9.1 3.5 12.6
4.5 2.9 7.4
5.6 3.5 9.1
8 3.4 11.4
8.3 3.8 12.1
14.1 2.7 16.8
3 2.5 5.5
5.8 3.1 8.9
7 3.1 10.1
2.5 2.4 4.9
5.7 2.6 8.3
6.4 2.2 8.6
16.5 4.4 20.9
9.4 4.4 13.8
5 3.3 8.3
2.3 3.4 4.7
5.8 3 8.8
5.5 3.3 8.8
4.4 3 7.4
1.4 1.4 2.8
1.3 1.1 2.4
8.0 3.2 11
Final Effluent
Nitrate- Nitrite- Total-
N N N2
14.6 3.8 18.4
15.8 3.7 19.5
19.4 <0.076 19.4
16.8 <0.076 16.8
18.9 <0.076 18.9
18.6 <0.076 18.6
15.3 <0.076 15.3
12 <0.076 12
12.8 <0.076 12.8
13.8 <0.076 13.8
8.8 <0.076 8.8
10.6 <0.076 10.6
12 <0.076 12
12.1 0.73 12.8
17 <0.076 17
5.0 <0.076 5.0
7.6 <0.076 7.6
9.0 <0.076 9.0
5.1 <0.076 5.1
9.3 <0.076 9.3
12.5 <0.076 12.5
16.6 4.5 21.1
11.5 4.6 16.1
4.9 3.6 8.5
2.3 2.4 4.7
7.2 1.1 8.3
9.0 <0.076 9.0
7.6 <0.076 7.6
3.3 <0.076 3.3
2.5 <0.076 2.5
11 0.81 12
1 Represents a sample set in which samples from all four locations were collected at the approximate same time.
2 Represents combined Nitrate-N and Nitrite-N. Values below the detection limit were considered 0.0 when summing totals.
3 Means are rounded to two significant digits. Values < detection limit considered zero when calculating means.
67
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Table 4-36. Event 4 - Summary of Treatment Effectiveness.
Nitrate-N/Nitrite-N
Sample
Round
No.
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
Mean3
Post BDN
Total-N1
17.9
19.2
17.4
16.3
18.7
17.9
11
12.2
11.7
12.6
7.4
9.1
11.4
12.1
16.8
5.5
8.9
10.1
4.9
8.3
8.6
20.9
13.8
8.3
4.7
8.8
8.8
7.4
2.8
2.4
11
Results
(mg/l)
Final Effluent
Nitrate-N
14.6
15.8
19.4
16.8
18.9
18.6
15.3
12
12.8
13.8
8.8
10.6
12
12.1
17
5
7.6
9
5.1
9.3
12.5
16.6
11.5
4.9
2.3
7.2
9
7.6
3.3
2.5
11
Nitrite-N
3.8
3.7
<0.076
<0.076
<0.076
<0.076
<0.076
<0.076
<0.076
<0.076
<0.076
<0.076
<0.076
0.73
<0.076
<0.076
<0.076
<0.076
<0.076
<0.076
<0.076
4.5
4.6
3.6
2.4
1.1
<0.076
<0.076
<0.076
<0.076
0.81
Total-N1
18.4
19.5
19.4
16.8
18.9
18.6
15.3
12
12.8
13.8
8.8
10.6
12
12.8
17
5.0
7.6
9.0
5.1
9.3
12.5
21.1
16.1
8.5
4.7
8.3
9.0
7.6
3.3
2.5
12
Flow
(gpm)
7.9
7.9
6.7
7.7
7.7
7.5
7.1
7.9
8.3
5.9
5.5
7.7
7.4
8
5
6.2
5.5
5.2
6.8
6
5.3
6
5.9
5.4
6.7
6.1
6.2
4.7
4.7
6.2
Final Effluent - Other Performance Criteria
MeOH TSS Turbidity pH 2 Total Heterotrophs 2
(mg/l) (mg/l) (NTU) (SU) (CFU/ml)
<0.23 <5 0.85 9.0/6.8 22,000/1,400,000
—
—
—
33 <5 1.3 9.0/8.4
—
34,000/8,300
—
—
—
43 6 1.7 8.7/8.9 600,000/2,000
—
—
—
—
38 <5 0.95 9.2/8.2 9,800/1,200,000
—
—
20 <5 0.77 9.1/8.1
—
—
29 <5 0.77 9.1/8.3 5,200/1,300,000
—
—
43 <5 0.40 8.3/8.6 480,000
—
—
—
91 <5 — 9.0/8.2 5,200 / NG
37 <5 0.96 6.8-9.1 97,000/450,000
1 Total-N is equal to the combined Nitrate-N + Nitrite-N concentration.
2 The first value represents the inlet water and the second value represents the final effluent.
3 All values, except for the pH range, are means rounded to two significant digits. Values < detection limit considered zero when calculating means.
Dashed line indicates that samples collected at that location were not analyzed for that parameter.
68
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Table 4-37. Event 4 - Dissolved Oxygen Measurements (mg/l).
DATE
12-7-99
12-8-99
12-9-99
12-10-99
12-11-99
12-12-99
12-13-99
12-14-99
TIME
INTERVAL
Not Available
1200
0915
Not Available
Not Available
Not Available
Not Available
Not Available
Associated
Round No(s.)
1-5
6-10
11-15
16-18
19-21
22-24
25-29
30
Mean1
SAMPLE POINT
Inlet Water
9.55
9.55
9.51
9.66
10.32
9.56
9.70
10.1
9.7
Partial BDN
5.65*
3.70
1.50
1.87
2.10
4.56**
1.34
1.28
2.8
Post BDN
—
4.89
—
3.88
3.65
—
—
...
4.1
Final Effluent
9.55
9.60
9.75
9.55
9.58
9.61
9.60
9.56
9.6
1 Mean values are rounded to two significant digits.
* Discovered methanol feed pump off. Turned on 1 hour later.
** Discovered methanol feed pump off. Turned on 2 hours later.
Dashed line indicates that samples collected at that location were not analyzed for that parameter.
Table 4-38. Event 4 - pH Measurements
DATE
12-7-99
12-8-99
12-9-99
12-10-99
12-11-99
12-12-99
12-13-99
12-14-99
TIME
INTERVAL
Not Available
Not Available
Not Available
Not Available
Not Available
Not Available
Not Available
Not Available
Associated
Round No(s.)
1-5
6-10
11-15
16-18
19-21
22-24
25-29
30
Range1
SAMPLE POINT
Inlet Water
9.04
9.04
8.65
9.20
9.10
9.05
8.31
9.04
8.3 -9.2
Partial BDN
7.48
8.59
8.47
8.19
8.32
8.38
8.10
7.96
7.5 -8.6
Post BDN
—
8.25
8.40
8.13
8.33
8.45
8.88
8.30
8.1 -8.9
Final Effluent
6.79
8.37
8.93
8.15
8.10
8.27
8.63
8.17
6.8 -8.9
1 Range values are rounded to two significant digits.
Dashed line indicates that samples collected at that location were not analyzed for that parameter.
69
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Table 4-39. Event 4 - Turbidity Measurements (NTU).
DATE
12-7-99
12-8-99
12-9-99
12-10-99
12-11-99
12-12-99
12-13-99
12-14-99
TIME
INTERVAL
1330
1000-1500
0815
0830
0715-1110
1445
0705
0830
Associated
Round No(s.)
1-5
6-10
11-15
16-18
19-21
22-24
25-29
30
Mean2
SAMPLE POINT
Inlet Water
0.05
0.00
0.00
0.03
0.00
0.05
0.00
0.05
0.02
Partial BDN
—
—
—
...
...
—
—
...
...
Post BDN
—
2.3/1.3
2.2/1.7
1.9/1.0
0.9/1.0
0.9/0.75
1 .3/0.9
...
1.6/1.1
Final Effluent
0.85
1.3
1.7
0.95
0.77
0.77
0.40
...
0.96
Pass/
Fail1
P
F
F
P
P
P
P
...
5/7
1 A round is considered passing if the final effluent is < 1 NTU. In the last row, the number of passing values is shown
in the numerator; the total number of values (pass + fail, minus any blank values) is shown in the denominator.
2 Mean values are rounded to two significant digits.
Dashed line indicates that samples collected at that location were not analyzed for that parameter.
Table 4-40. Event 4 -TSS Results (mg/l).
Sample
Round No.
2
6
12
17
20
23
26
30
Mean
SAMPLE POINT
Inlet Water
<5
<5
<5
<5
<5
<5
<5
<5
<5
Partial BDN
—
...
—
...
—
...
—
...
...
Post BDN
<5
<5
12
<5
<5
6
<5
<5
<5
Final Effluent
<5
<5
6
<5
<5
<5
<5
<5
<5
Pass/
Fail1
P
P
F
P
P
P
P
P
7/8
1 A round is considered passing if the final effluent value is < the inlet water value. In the last row, the number of passing values is shown
in the numerator; the total number of values (pass + fail, minus any blank values) is shown in the denominator.
2 Mean values are rounded to two significant digits. Values < detection limit considered zero when calculating means.
Dashed line indicates that samples collected at that location were not analyzed for that parameter.
70
-------
secondary drinking water criterion was met for seven of
eight rounds, which indicated that the filter combination
used for Event 4 was, for the most part, effective.
Table 4-41 presents the laboratory results for TCH, FA,
and FC, at each of the four outfalls. The data indicated the
TCH population associated with the BDN process was, on
average, two orders of magnitude higher than TCH levels
in the well water. On average, approximately 13 percent of
this bacteria carried over from the BDN process to the final
effluent. This carryover was similar to that measured for
Events 2 and 3, which also had filtration incorporated into
the post-treatment system. However, unlike the previous
two events, four of the seven final effluent TCH values
were measured to be below the corresponding inlet water
values on a per-round basis. Thus, the secondary criteria
for TCH was met for those tests, but not on an overall
average basis.
Like the previous three events, the FA data for Event 4
followed the expected pattern of greatly increasing in the
post-BDN effluent and then greatly decreasing in the final
effluent. The average of the FA plate count mean in the
inlet water was increased by three orders of magnitude in
post BDN effluent. The post-treatment was effective in
reducing the average mean post BDN effluent by one order
of magnitude. The average mean carryover for the seven
tests measured was 11 percent and four of the seven final
effluent mean values were less than the inlet water mean
value. Thus, the secondary criterion for FA was met for
those sample rounds, but not met on an overall average
basis.
For Event 4, FC was detected in six of the seven inlet
water samples collected. Of these six samples FC carried
over to final effluent in only the first sample (although the
FC in this sample was measured at a concentration above
that of the inlet water). The secondary criterion for FC was
met for five of six sample rounds. Comparable to Event 3,
results showed that on average, the majority of FC was
removed during Event 4 post-treatment.
Table 4-42 presents the Event 4 laboratory results for
methanol analyses conducted on inlet water, post-BDN
effluent, and final effluent. Methanol was detected in two
of eight inlet water samples at low (estimated)
concentrations. Methanol was also detected in all post
BDN and final effluent samples (many concentrations were
estimated values). The mean methanol concentrations in
post BDN and final effluent were 27 and 42 mg/l,
respectively. With the exception of sample rounds 12 and
17, the post BDN and final effluent values were similar on
a per round basis. This indicates thatthe air stripping post-
treatment did not have a measured effect on reducing
residual methanol concentrations, except possibly for
round 2, where an estimated 1mg/l of methanol in post
BDN effluent was not detected in the paired final effluent
sample. Thus, the secondary criteria of achieving a final
effluent with < 1 mg/l methanol was not met as a mean,
nor for 7 of the 8 sampling rounds.
Table 4-43 presents the results of supplemental analyses
for all outfalls sampled. Most of the results of these
supplemental analyses indicate that the BDN and post-
treatment systems had little to no effect on the measured
parameters. The only VOC detected in the inlet water was
a small amount of CCI4. Since CCI4 was not detected in
either the post BDN or final effluents, it is likely that the
0.007 mg/l of that compound was volatilized or degraded
during the BDN process.
The increase in TOC following BDN can be attributed to
carryover of biological material and/or methanol. The
subsequent drop in TOC in final effluent may be an
indication of a positive post-treatment impact (e.g.,
filtration). The increased alkalinity following BDN, unlike the
other three events, does not correlate with the slight
decrease in pH measurements recorded for the final
effluent (refer to Table 4-38). The small amounts of
phosphate and phosphorus measured in the effluent
samples is residuum from the 50% methanol solution,
which contains food grade phosphoric acid.
4.4.4.5 Mass Removal of Nitrate
The percent mass removal of nitrate, measured as Nitrate-
N, was estimated for Event 4 (Objective 4). A total of ~
61,000 gallons (-230,000 liters) of well water was treated
during Event 4. Each mg/l of nitrate-N is equivalent to 4.4
mg/l of nitrate. Since the mean nitrate-N concentration for
Event 4 inlet water was about 34 mg/l, the total mass of
nitrate treated during Event 4 was (34 x 4.4) mg/l x 230,000
liters = 34,000,000 mg. The mean nitrate-N concentration
for Event 4 final effluent was 11.4 mg/l. The total mass of
nitrate in the Event 4 final effluent = (11 x 4.4) mg/l x
230,000 liters = 11,000,000 mg. Therefore, the mass
removal of nitrate would be about 34,000,000 mg -
11,000,000 mg = 23,000,000 mg (a 68% reduction in
nitrate). This correlates to 23,000 grams or 51 pounds.
4.4.4.6 System Performance Vs. Flow Rate
The performance of EcoMat's combined BDN and post-
treatmentsystem components were evaluated with respect
to water flow through the system (Objective 2). The
variation in inlet water flow rate during Event 4 was
compared with the total-N concentrations in the final
effluent. Figure 4-10 directly compares the Event 4
fluctuation for inlet water flow rate to the Event 4 fluctuation
in total-N final effluent concentrations on a perround basis.
As was the case with third event, Event 4 was typified by
rather high variability in flow rate and system performance.
The pattern for both of the plots reflects a very close
relationship between flow rate and system performance.
There is also an obvious trend of steady flow rate reduction
coupled with a steady BDN improvement from start to
71
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Table 4-41. Event 4 - Microbial Results.1
Sample
Round
No.
2
8
12
17
23
26
30
Avg.
TOTAL CULTURABLE HETEROTROPHS - Plate Count Mean (cfu/ml)2
Inlet
Water 2
21,500
33,500
600,000
9,800
5,200
4,000
5,200
97,000
Post
BDN2
7,500,000
5,800,000
3,800,000
1,950,000
1,970,000
1,800,000
1,700,000
3,500,000
Final
Effluent 2
1,370,000
8,300
2,000
670
1,300,000
480,000
0
450,000
% Carryover
from BDN
18%
0.14%
0.05 %
0.03 %
66%
27%
0%
13%
% Change from
Inlet Water
+ 6,400 %
- 75 %
- > 99 %
- 93 %
+ 25,000 %
+ 12,000%
- 100 %
+ 460 %
Pass/
Fail3
F
P
P
P
F
F
P
4/7
FACULTATIVE ANAEROBES - Plate Count Mean (cfu/ml)2
2
8
12
17
23
26
30
Avg.
180
190
260
180
1,200
440
340
400
88,000
90,000
440,000
130,000
380,000
120,000
80,000
190,000
9,200
58
28
6
130,000
440
2,400
20,300
10%
0.06 %
0.01 %
0.01 %
34%
0.4 %
3%
11 %
+ 5,100%
- 70 %
- 89 %
- 97 %
+ 11,000%
0.0 %
+ 700 %
+ 5,100%
F
P
P
P
F
P
F
4/7
FECAL COLIFORM (Fecal coliforms/100ml)
2
8
12
17
23
26
30
Avg.
40
94
158
210
38
55
NG
85
48
TNC
NG
NG
NG
NG
NG
>7
62
NG
NG
NG
NG
NG
NG
9
130%
0%
0%
0%
0%
0%
NC
NC
1.6
-100%
- 100%
-100%
- 100%
-100%
NC
- 89 %
F
P
P
P
P
P
—
5/6
1 Post-treatment for Event 4 consisted of chlorination, clarification, high efficiency filtration, air stripping, and polishing filtration.
2 Plate count mean = average of three separate analyses, reported in colony forming units per milliliter.
3 A result is considered passing if the final effluent value is < the inlet water value.
NG = No growth. NC = Not calculated. TNC = Too Numerous to Count.
72
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Table 4-42. Event 4 - Methanol Results (mg/l).
Sample
Round No.
2
6
12
17
20
23
26
30
Mean2
SAMPLE POINT
Inlet Water
2.8 J,
<0.23
<0.23
<0.23
<0.23
<0.23
<0.23
0.3 J,
0.4 J
Partial BDN
—
—
—
—
—
—
—
—
...
Post BDN
1 J
14
4.1 J,
5.1 J2
37 J2
32 J2
43 J2
79 J2
27
Final Effluent
<0.23
33
43 J2
38
55 J2
29 J2
43
91
42
Pass/
Fail1
P
F
F
F
F
F
F
F
1/8
1 A round is considered passing if the final effluent value is < 1 mg/l. In the last row, the number of passing values is shown
in the nu merator; the total number of values (pass + fail, minus any blank values) is shown in the denominator.
2 Mean values are rounded to two significant digits. Values < detection limit considered zero when calculating means.
J1 These values should be considered estimates due to the uncertainty in the low end of the curve.
J2 These values should be considered estimates due to the possibility of peak interferences from a second peak.
Dashed line indicates that sam pies collected at that location were not analyzed for that param eter.
Table 4-43. Event 4 - Supplemental Analyses Results (mg/l).1
Sample Round
Nos.
6,17,27
6, 17,27
6,17,27
6, 17,27
6,17,27
6, 17,27
6,17,27
6,17,27
6,17,27
6, 17,27
6,17,27
6, 17,27
6,17,27
Analyte 2
CCI4
Total Solids
Ammonia
Total Organic Carbon
Sulfate
Phosphate
Alkalinity
SAMPLE POINT
Inlet Water
0.007
365
<0.8
< 1
54.8
< 0.082
147
Partial BDN
—
—
—
—
—
—
—
Post BDN
< 0.005
437
<0.8
49.8
54.8
1.4
225
Final Effluent
< 0.003
495
<0.8
16.2
54.7
0.84*
229
Metals
Barium
Calcium
Magnesium
Sodium
Phosphorus
0.061
82
Potassium
23
13
<0.37
—
—
1.1
—
—
—
0.055
91
—
25
15
1.5
0.052
87
1.21.1
25
33
1.5
1 Values are the mean of the three test results and are rounded to a maximum three significant digits.
2 Except for CCI4 only SW-846 Method contaminants with mean values above detection limits are reported.
Metals analyzed for included Ag, Al, Ba, Be, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Mo, Na, Ni, P, Sb, and Zn.
73
-------
10 -I
8 —
6 —
4 —
2 —
Sample
Round No."
Final Effluent
Total-N (mg/l)
Inlet Water
Flow (gpm)
\
12
-20
- 16
-12
-8.0
-4.0
16
20
24
28
Figure 4-10. Event 4 - Comparison of Flow Rate Fluctuation and Final Effluent Total-N Concentration
finish. The only exception to this pattern is an abrupt sharp
increase in the total-N levels about 3/4 of the way through
the event. This anomalous peak is believed to be the result
of an inadvertent shut off of the methanol feed pump that
disrupted the treatment system.
4.4.5 Inter-Event Comparison
This section evaluates the overall demonstration
performance of the EcoMat BDN treatment system with
respect to nitrate-N, nitrite-N, total-N and several key field
and analytical parameters. Direct comparisons are made
among the four events in order to investigate possible
reasons for variable performance.
4.4.5.1 BDN Performance
Figure 4-11 shows the mean total-N concentrations for
each individual event plotted against one another. The
mean nitrate-N and nitrite-N concentrations for all tests
conducted during a particular event are presented as data
pairs in boxes. Several observations can be made from this
figure. First, for all four events, the concentration of nitrate-
N in the untreated inlet water from PWS Well # 1 was well
in excess of both the 10 mg/l MCL and the 20 mg/l
threshold set for the demonstration. The inlet water nitrate-
N concentrations were considerably higher for Events 1
and 2, as compared to Events 3 and 4. Based on daily
water level measurements taken during all four events,
there was a significant water level drop of approximately 14
feet in PWS Well # 1 between Events 2 and 3. Thus, there
may have been a corresponding drop in the amount of
nitrate being flushed into the well during the dryer months
preceding Events 3 and 4.
Figure 4-11 also illustrates that, during the initial stages of
BDN, the nitrate-N concentrations were reduced by similar
percentages for all four events (i.e., 52-60%), while at the
same time small amounts of nitrite-N were being generated
from the reduction of nitrate. Following BDN, the mean
nitrate-N concentrations were further reduced to below 10
mg/l, and mean nitrite-N concentrations increased forthree
of the four events. Following post-treatment the mean
nitrite-N concentrations were reduced forallevents, except
for Event 2, where the mean nitrite-N level remained
essentially the same. As expected, there was no
appreciable difference in the mean final effluent nitrate-N
concentration, following post-treatment.
74
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60
Combined
NCV/NCV
Concantration
(mg/l)
INLET
WATER
LEGEND
43/3 = N03-N/N02-N Concentration in mg/l
(Rounded to two significant digits)
BDN = Biodenitrification
ND = Not detected at or above detection limits
PARTIAL BDN
TREATMENT
FINAL
EFFLUENT
Figure 4-11. Inter-Event Comparison - Treatment Effectiveness for Nitrate-N/Nitrite-N
4.4.5.2 Final Effluent Water Quality
Table 4-44 summarizes relevant criteria-oriented final
effluent data collected during the demonstration as
averages for all four events. Except for the relevant
process parameters, all values represent final effluent
means. The mean DO levels for water exiting the
deoxygenating tank have been included due to the
importance of that field measurement in determining proper
anoxic conditions. In general terms, the final effluent mean
nitrate-N concentrations increased when the DO was not
maintained near the desired 1 mg/l level.
The increased post-treatment following the first event had
less impact than anticipated (e.g., neither the carbon
filtration employed during Event 3 nor the air stripping
employed during Event4 appears to have had a significant
impact on methanol levels in the final effluent). Although
TSS and turbidity improved to or near acceptable
concentrations when filtration was employed, carryover of
biological material from the EcoMat reactor to the final
effluent remained considerable.
None of the oxidation post-treatments (chlorination, UV
oxidation, or ozone) appeared to have any beneficial
effects on residual bacterial matter, methanol destruction,
or re-oxidation of nitrite to nitrate. It is not known whether
this was due to inappropriate sizing, variability in feed rate
or other, unknown factors. There also was some question
whether ongoing biodegradation was occurring in some
sample containers between collection and analysis. This
could have taken place in BDN samples, resulting in lower
methanol results before post-treatment, but would have
been inhibited in oxidized samples. The overall EcoMat
process appears to have little impact on pH.
75
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Table 4-44. Inter-Event Comparison of Demonstration Criteria for Final Effluent.1
Parameter
Criterion
SAMPLING EVE NT
Event 1
(May 6-1 5)
Event 2
(August 3-12)
Event 3
(October 20-28)
Event 4
(December 7-14)
Process Parameters
Flow (dom)
Total Gallons Treated
DO in Partial BDN Effluent (mq/l)
3-15
...
...
3.0
42,000
1.1
3.5
45,000
1.0
4.2
49,000
2.1
6.2
61,000
2.8
Biodenitrification Parameters
Nitrate-N (mg/l)
Nitrite-N (mg/l)
Total-N (mg/l) 2
< 10
<1
< 10
4.1
1.5
5.6
8.3
1.5
9.9
11
0.8
12
Post-Treatment Parameters
Post-Treatment System
Residual Methanol (mg/l)
Turbidity (NTU)
Total Suspended Solids 3
pH Range (min-max)
Total Heterotrophs (% change)
Fac. Anaerobes (% change)
Fecal Coliform (% change)
< 1 mg/l
<1 NTU
< inlet water
6.5-8.5
< inlet water
< inlet water
< inlet water
>• Chlorination
>• Clarification
>• Sand Filtration
>• Rough Filtration
- UV Oxidation
15 98
4.4
<5/ 10
7.5-8.6
+ 19,000
+ 7,300
NC
1.8
<5/<5
7.6-8.4
+ 18,000
+ 170,000
-75
>• Ozone
- UV Oxidation
-Clarification
>• Rough Filtration
- High Eff. Filtration
>• Carbon Filtration
>• Polishing Filtration
41
1.2
<5/<5
7.9-8.2
+ 1,100
+ 3,300
-91
>• Chlorination
>• Clarification
- High Eff. Filtration
>• Air Stripping
>• Polishing Filtration
37
0.96
<5/<5
6.8-8.9
+ 460
+ 5,100
-89
1 Values are means that have been rounded to a maximum two significant digits. Bolded values meet criteria; shaded boxes denote best result of
the four events.
2 Total-N is equal to the combined Nitrate-N + Nitrite-N.
4.4.6 Data Quality Assurance
This section of the ITER contains a review of the critical
sample data and associated QC analyses that were
performed to determine whether the data collected were of
adequate quality to provide proper evaluation of the
project's technical objectives. A more detailed summary
and discussion of quality assurance/quality control
information regarding the EcoMat SITE demonstration is
included in the TER. The results of the critical
measurements designed to assess the data quality
objectives are summarized in the following subsections.
4.4.6.1 Accuracy
Accuracy objectives for nitrate-N and nitrite-N were
assessed by the evaluation of 46 spiked duplicates
analyzed in the same manner as the samples. Recovery
values for the critical compounds were well within project
objectives, with two exceptions. Two of the samples
contained sufficient chemical (intentionally introduced into
the EcoMat treatment stream for this same purpose) to
convert the nitrite spike added to nitrate. The chemicals
added, or treatments, were done to convert the nitrite to
nitrate and assist in meeting the 1 ppm concentration limit
for nitrite. The following adjustments were done:
Event 1- Chlorination-calcium hypochlorite-
pool filter chlorine tablets
Event 2 - UV oxidation
Event 3 - Ozone and UV oxidation
Event 4 - Chlorine liquid
76
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Oxidation of the nitrite to nitrate likely continued after
sample collection. This oxidation reaction is part of the
treatment process. Any residual nitrite in the samples
would be considered more hazardous in terms of health
effects and therefore the oxidation reaction which is
considered beneficial, would convert residual nitrite to
nitrate, with total nitrate levels still expected to be below 10
ppm. Chemicals added in the final stage of treatment were
specifically designed for this purpose. This explains poor
recoveries of some of the matrix spikes for nitrite.
Therefore, this is not believed to be an analytical problem.
It is likely that residual chemicals (e.g..chlorine and ozone)
continued to react with samples after spike addition and
prior to analysis. Low recoveries for matrix spikes in these
samples should therefore be treated as a "matrix problem"
due to a continued oxidation reaction. LCS results are
therefore considered as the "analytical indicator" showing
reasonable recovery of nitrite for these particular sample
batches. The preceding text explains the rationale for
addition of oxidizing agents.
The two spike recovery values (one from each of the
chemically treated Events 1 and 4) are not included in the
statistical evaluation of the spikes; therefore, a total of 44
of the 46 matrix spike/matrix spike duplicate (MS/MSD)
sample sets are used in the statistical evaluation.
Recovery for nitrate-N averaged 95.4% and for nitrite-N the
average recovery was 95.8% (Tables 4-45 and 4-46).
4.4.6.2 Precision
Precision was assessed through the analysis of 44
duplicate spikes. Again, 46 MS/MSD were performed by
the laboratory; however, due to the conversion of nitrite to
nitrate by the sample only 44 are statistically evaluated.
Data quality objectives forprecision, established as relative
percent difference (RPD) values less than 15%, were met
with one exception. Nitrate-as-nitrogen RPDs averaged
2.7% and nitrite-as-nitrogen RPD values averaged 2.1%
(Tables 4-47 and 4-48).
4.4.6.3 Detection Limits
Detection limits were established so as to be sufficiently
below the concentration of interest (established by
regulatory limits) for nitrite and nitrate. Nitrite had a
detection limit of 0.076 mg/l with a concentration of interest
(decision point) of 1 mg/l. Nitrate had a detection limit of
0.056 mg/l with a concentration of interest (decision point)
of 10 mg/l. The concentration of interest for methanol was
established by the project since there is no regulatory level
for methanol in drinking water. The methanol concentration
of interest was established as 1.0 mg/l with a detection limit
of 0.23 mg/l.
4.4.6.4 Comparability
Comparability was achieved through the use of QAPP
approved EPA protocols and verified by the validation of
analytical data, which indicated that QAPP and method-
specified criteria were met.
4.4.6.5 Completeness
Sufficient samples were collected to satisfy statistical
completeness requirements. A minimum of 28 sample sets
were collected for each event for evaluating nitrate and
nitrite treatment effectiveness.
4.4.6.6 Representativeness
Representativeness refers to the degree with which a
sample exhibits average properties of the waste stream at
the particular time being evaluated. This is assessed in
part by the analysis of field duplicates, which also provide
insight into the homogeneity, or heterogeneity, of the
matrix. Field duplicate samples have, inherent in the result,
combined field and analytical variability. For this project,
the primary sample and duplicate sample were collected
immediately after each other. These indicated reasonable
agreement in results, with RPD values for field duplicates
from all four events generally less than 25%. The average
RPD for nitrate was 10.9% and for nitrite 4.3% (Tables 4-
49 and 4-50).
77
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Table 4-45. Nitrate Matrix Spike Percent Recovery Summary.
Event
Event 1 (May 99)
Event 2 (August 99)
Event 3 (November 99)
Event 4 (December 99)
Overall Demonstration
Recovery Range
87.8% to 103.1%
86.9% to 105.4%
86.8% to 107.6%
89.4% to 108.1%
86.8% to 107.6%
Number of Duplicate Pairs
n=14
n=10
n=12
n=8
n=44
Percent Recovery Average
95.3%
93.7%
96.8%
95.7%
95.4%
Table 4-46. Nitrite Matrix Spike Percent Recovery Summary.
Event
Event 1 (May 99)
Event 2 (August 99)
Event 3 (November 99)
Event 4 (December 99)
Overall Demonstration
Recovery Range
83.1% to 104.8%
92.0% to 103.4%
91. 6% to 107.1%
95.6% to 107.8%
83.1% to 107.8%
Number of Duplicate Pairs
n=14
n=10
n=12
n=8
n=44
Percent Recovery Average
90.8%
96.5%
99.0%
98.7%
95.8%
Table 4-47. Nitrate MS/MSD Relative Percent Difference Summary.
Event
Event 1 (May 99)
Event 2 (August 99)
Event 3 (November 99)
Event 4 (December 99)
Overall Demonstration
MS/MSD RPD Range
0.0% to 9.7%
1.4% to 4.9%
0.0% to 24.2%
0.2% to 3.8%
0.0% to 24.2%
Number of Duplicate Pairs
n=14
n=10
n=12
n=8
n=44
Average MS/MSD RPD
2.6%
2.9%
3.6%
1.5%
2.7%
Table 4-48. Nitrite MS/MSD Relative Percent Difference Summary.
Event
Event 1 (May 99)
Event 2 (August 99)
Event 3 (November 99)
Event 4 (December 99)
Overall Demonstration
MS/MSD RPD Range
0.4% to 7.1%
0.3% to 5.9%
0.0% to 6.5%
0.0% to 8.3%
0.0% to 8.3%
Number of Duplicate Pairs
n=14
n=10
n=12
n=8
n=44
Average MS/MSD RPD
2.1%
1 .4%
2.1%
3.1%
2.1%
78
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Table 4-49. Nitrate Field Duplicate Summary.
Event
Event 1 (May 99)
Event 2 (August 99)
Event 3 (November 99)
Event 4 (December 99)
Overall Demonstration
RPD Range
0.0% to 108%
0.0% to 4. 7%
0.0% to 3.2%
0.0% to 23.9%
0.0% to 108%
Number of Field Duplicates
n=7
n=6
n=5
n=7
n=25
Average RPD
31.9%
0.8%
1 .5%
5.4%
10.9%
Table 4-50. Nitrite Field Duplicate Summary.
Event
Event 1 (May 99)
Event 2 (August 99)
Event 3 (November 99)
Event 4 (December 99)
Overall Demonstration
RPD Range
3.4% to 16.0%
0.0% to 3.5%
0.0% to 5.8%
0.0% to 5.9%
0.0% to 16.0%
Number of Field Duplicates
n=7
n=5
n=4
n=4
n=20
Average RPD
7.7%
1 .0%
3.5%
3.4%
4.3%
79
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Section 5.0
Other Technology Requirements
Regu lation
5.1 Environmental
Requirements
State and local regulatory agencies may require permits
prior to implementing a BDN technology. Most federal
permits will be issued by the authorized state agency. An
air permit issued by the state Air Quality Control Region
may be required if an air stripper is utilized as part of the
post-treatment system (i.e., if the air emissions are of toxic
concern or anticipated to be in excess of regulatory
criteria). Wastewater discharge permits may be required if
any such wastewater were to be discharged to a POTW.
If remediation is conducted at a Superfund site, federal
agencies, primarily the U.S. EPA, will provide regulatory
oversight. If off-site disposal of contaminated waste is
required, the waste must be taken to the disposal facility by
a licensed transporter. Section 2 of this report discusses
the environmental regulations that may apply to the EcoMat
Inc. BDN treatment process.
5.2 Personnel Issues
The number of personnel required to operate the EcoMat
Biodenitrification technology should be small and is not
critically dependent on the size of the treatment system.
Large systems may, however, require extensive site
preparation and assembly operations that may require
several individuals (inclusive of contractors), especially if
there are constraints on time. For smaller treatment
systems, requiring minimal site preparation, as few as one
person may be needed to assemble and conduct the initial
startup testing of the system.
During the demonstration EcoMat, in most instances, had
one company employee at the pilot unit. They also had
one local person to periodically monitor the system and
collect samples in their absence. Estimated labor
requirements for a full-scale 100 gpm system are
discussed in detail in Section 3 of this report.
During the demonstration sampling events, two SITE team
members were required to conduct field measurements
and to collect and prepare samples. Personnel present
during sample collection activities at a hazardous waste
site must have current OSHA health and safety
certification. Although the BDN technology targets nitrate
and other inorganic contaminants, gas detection tubes
should be used to monitor the air in the vicinity of the
treatment system to monitor for sulfide, chlorine, ozone,
and other potential gases. Respiratory protective
equipment may be needed in rare instances, but are not
anticipated.
At sites with greater complexity and risk, the personnel
protective equipment (PPE) for workers will include steel-
toed shoes or boots, safety glasses, hard hats, and
chemical resistant gloves. Depending on contaminant
types, additional PPE (such as respirators) may be
required. Noise levels would usually not be a concern.
However, loud pumps for larger systems could create
appreciable noise. Thus, noise levels should be monitored
to ensure that workers are not exposed to noise levels
above the time weighted average of 85 decibels over an 8-
hour day. If this level is exceeded and cannot be reduced,
workers would be required to wear hearing protection.
5.3 Community Acceptance
Potential hazards to a surrounding community may include
exposure to air emissions of VOCs, if those contaminants
are also present in the water stream (along with the
nitrates). Ozone and chlorine emissions are also possible
if such post-treatment is incorporated.
Overall, there are few environmental disturbances
associated with the BDN processes. No appreciable noise
is anticipated beyond that generated by the short term use
of power washing equipment (used during general
maintenance), or by excessively loud pumps. Since most
units are contained in a secured building, disturbances
from the system are kept within the building confines.
80
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Section 6.0
Technology Status
6.1 Previous Experience
The pilot-scale treatment system that was set up at the
Bendena, Kansas site was EcoMat's first application of
their BDN technology for treatment of contaminated
groundwater. Prior to this project, EcoMathas applied their
technology to the commercial aquarium industry where
health of the fish is a prime economic concern. EcoMat is
presently the only company to provide the denitrification
technology for the aquarium industry. EcoMat's systems
are applied at the following aquariums.
The John G. Shedd Aquarium (Chicago)
The Albuquerque Biological Park Aquarium
Biodome de Montreal
New Jersey State Aquarium
Sea World of Florida
Large Aquarium System
Colorado's Ocean Journey (Denver)
Based on their experience gained during the SITE
Demonstration in Bendena, EcoMat has improved
dissolved oxygen monitoring by inserting a dissolved
oxygen meter into their system.
Currently, EcoMat has installed a small reactor to remove
perchlorate from a Department of Defense facility in
Southern California (see Appendix A). To treat perchlorate,
the process operates on the same principle as for nitrate
treatment. In the absence of both dissolved oxygen and
nitrate, the bacteria take oxygen from perchlorate and yield
a simple chloride ion.
In-house research is being conductedforthe nitrification of
ammonia. EcoMat has slightly modified their pilot-scale
reactor to permit the addition of large amounts of air into
the reactor. The bacteria used for nitrification are very
differentfrom denitrification bacteria, in that they are highly
sensitive to a number of parameters. EcoMat uses an on-
line fermentation process to continually produce them.
6.2 Ability to Scale Up
EcoMat has sold systems treating less than one gpm to
aquariums and has supplied reactors as large as three
cubic meters. They currently have a single reactor design
that would treat influent at a flow rate of 200 gpm. EcoMat
has also indicated that there is no upper limit to capacity to
their technology. For very large systems multiple reactors
would be used.
81
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Section 7.0
References
EcoMat Inc. Internet Web Site, www.ecomatinc.com
Evergreen Analytical Laboratory. June3,1999; September
5, 1999; November 23, 1999; January 5, 2000; Analytical
Results (Data Packages) for samples submitted for SAIC
Project - EcoMat Inc.'s Biological Denitrification and
Removal of Carbon Tetrachloride.
Hall, P.J. August, 2000. Perchlorate Remediation ata DOD
Facility (not published).
MicrobacLaboratories, Inc. -BioRenewal Division. May 27,
1999; September 1,1999; November 16, 1999; December
28, 1999. Results from Anaerobic Plate Count Analyses in
Connection with the EcoMat site located in Bendena, KS.
Microbial Insights, Inc. May 3, 1999. Microbial
Characterization for EcoMat Inc.'s Biological Denitrification
Process: Analysis of Water Samples by PLFA, Total
Culturable Heterotrophs, and Fecal Coliforms.
SAIC. April 1999. Quality Assurance Project Plan for
EcoMat Inc.'s Biological Denitrification and Removal of
Carbon Tetrachloride at the Bendena site, Doniphan
County, Kansas.
Shapiro, J.L., P. Hall, and R. Bean. January 2000. Ground
Water Denitrification at a Kansas Well. Presented at the
Technology Expo and International Symposium on Small
Drinking Water and Wastewater Systems, Phoenix,
Arizona.
82
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Appendix A
Developer Claims and Discussion
-------
Note: Information contained in this appendix was
provided by EcoMat, Inc. and has not been
independently verified by the U.S. EPA SITE Program
A.1 Case Study - Perchlorate Remediation
at a DOD Facility
The site is a Department of Defense facility located in
Southern California. Under the Installation Restoration
Program (IRP), Earth Tech, Inc. has a contract to provide
environmental services, including evaluating the
perchlorate levels in shallow groundwaterunderthe facility.
The test water that they pump from this activity is
temporarily stored in Baker tanks on the site. The major
contaminant in this water is perchlorate, at concentrations
varying from 300 ppb to 1000 ppb. Beginning in October
1999 Earth Tech evaluated EcoMat's ability to remediate
perchlorate and in December 1999 they contracted with
EcoMat to provide a small system forremoving perchlorate
from the test water.
A.1.1 Project Activity
EcoMat designed a system to achieve the removal of
perchlorate from the Bakertanks within a period of several
months. At the beginning there was not sufficient
information to determine the hydraulic residence time for
removal of perchlorate down to non-detectable levels, so
the system was designed for a residence time of
approximately one-half hour with an active volume of 200
liters. Given average tank volumes of 20,000 gallons this
would enable complete reduction in a period of seven days
after the bacteria are firmly established.
EcoMat had designed and built an identical system and
installed it in the John G. Shedd Aquarium in Chicago. The
design is described in the following section. It was built on
a single skid in our Hayward facility. Denitrification bacteria
which had been exposed to perchlorate were placed in the
reactors and then the entire skid was loaded onto a panel
truck and driven down to Southern California. At the site,
it was lifted off the truck and placed in a temporary shelter
near the Baker tanks, and started up. Within a few days it
was functioning and reducing perchlorate. After the first
few days the system's operation was transferred to Earth
Tech, with telephone contact and advice from EcoMat.
After several months during which various operating
problems were dealt with, the tanks were completely clean
of perchlorate, below the detectable concentration. The
system was then moved to a similar site on the base,
where it remains in operation.
A.1.2 System Design
The system is best described using a flow diagram (see
Figure A-1). Water is drawn from the Baker tank into the
top of the deaeration reactor. This reflects a basic
understanding by EcoMat that a two-stage process works
best for biological oxygen removal. In the deaeration tank
there is a large number of ordinary bio-balls that provide
surface for bacterial growth. The reactor is designed to
reduce the dissolved oxygen concentration from saturation
down to a concentration of 0.5-1.0 ppm. This is the
optimum concentration for either denitrification or
perchlorate remediation. If the dissolved oxygen
concentration rises above one ppm, the remediation is
ineffective, and if itdrops to near-anaerobic concentrations,
the threat ofsulfate attack arises. Hydrogen sulfide can be
injurious to the bacteria, stopping the remediation activity.
Although the bacteria can be revived very easily by
restarting the process, time is wasted if oxygen levels are
not monitored.
From the bottom of the deaeration reactor, water is then
drawn into the bottom of the Hall reactor. This patented
reactor is the key element of EcoMat's process. It is
designed to hold a mass of floating media and maintain
continuous circulation of the media along with the water in
the reactor. This mixing is attained without any internal
moving parts, but rather, by external pump re-circulation
(as shown in Figure 4-2 of the ITER). Continuous
circulation is extremely important as it provides for uniform,
low concentrations of the contaminant under ALL influent
contaminant concentrations. This factor is key to EcoMat's
success in both denitrification as well as perchlorate
remediation as it puts no upper limit on the allowable inlet
concentrations.
At this point we must say more about the EcoLink media
(see ITER cover). This is a polyurethane-based sponge
that is cut into one-centimeter cubes. The media last for a
very long time— up to several years. They are kept
reasonably clean and capable of supporting bacteria
colonies by virtue of their gentle collisions with each other
and with the walls of the reactor. When functioning to
produce a gas, as in denitrification, the size of the
interstitial spaces within the sponge is designed to permit
passage of gas out, as well as passage of water into, these
spaces. At the same time, the surface area involved is
sufficiently great to provide for large bacteria
concentrations and high interaction efficiency.
The overflow from the Hall reactor is recycled back into the
deaeration reactor during the startup period to form
colonies of bacteria. In normal operation the effluent is
discharged from the system. In cases where drinking
water purity is desired, a post-treatment system can be
added to the process to control the small amount of
biosolids that leaves the system. This is the only residual
stream that results from the process. In case of upset
conditions, water can be returned to the Baker tanks.
Both reactors require feed of a carbon source (electron
donor) to feed the bacteria. EcoMat has studied a variety
of available sources and we find that the best one is
methanol. Methanol residual of less than 2 ppm is
A-1
-------
BflKER
TANK
/~\ U-1 *»-! I
-S« * >
s
fi-1 '
j
,
TUU-2
^ TtUl-1
i .- r~
DR1
mtat
M
Figure A-1. EcoMat Perchlorate Removal System.
considered non-hazardous and EcoMat's systems normally
run at undetectable concentrations (below 0.5 ppm).
Methanol is notonly the lowestcostcommercially available
carbon source but it also maintains the lowest level of
biosolids. Alternative carbon sources, such as ethanol,
tend to "gum up" the works. The major requirement for
methanol is for removal of dissolved oxygen in the
deaeration reactor, as oxygen levels are so much greater
than perchlorate levels in the first stage of the process. For
fire safety reasons, the methanol is dissolved in water
(generally 50%). The rate of feed of methanol is so small
that even if it were to exit unused, the concentration would
not reach hazardous levels.
It should be noted that while the bacteria involved in
denitrification are hardy, best operations are realized when
temperatures are controlled between limits of 8 °C and 35
°C. During normal flow, the influent water maintains
adequate temperature control. During startup, when
recirculation is 100% care should be taken to turn on the
circulation pump in the Hall reactor for a relatively small
time period each day.
The way the system works is that the bacteria can "eat" a
constant rate of contaminant. Thus, the flow rate of water
through the system isn't a significant parameter in the
design. The most significant system size factor, which
determines the basic system size, is the total amount of
material that is to be removed per day. This number is the
product of the flow times the concentration. For example,
for a system that will remediate 1000 gpm of water having
a concentration of 10 ppm, the amount of contaminant to
be removed is 120 pounds per day. For this example,
EcoMat estimates that it can build, own and operate this
system, at the currently demonstrated sizing criteria, at
total cost to the customer of $.50 per thousand gallons.
A.1.3 Operations
The system was built on a skid that is four feet by four feet
in size. Startup operations involve continuously recycling
the water through the reactors while feeding methanol and
assuring that there is adequate perchlorate in the water.
This recirculation need not be constant, and in warm
weather, when the bacteria might overheat, it is best to
circulate for no more than a few hours per day. Periodic
measurements are made of the dissolved oxygen levels
leaving the de-aeration reactor. When the dissolved
oxygen level is below 1.0 ppm the system can be opened
in stages, until it is wide open. After start-up, operations
remain continuous, and it is only necessary to check the
system once daily to be sure that no spurious upset has
taken place. The methanol source only needs to be
replenished every few weeks.
At this DOD site there were a number of upsets,
particularly during the early operating days. First, someone
driving by pulled the main power plug! A few days passed
before the operators realized that there was something
A-2
-------
wrong. During that time, the bacteria used up all of the
oxygen and perchlorate and started producing hydrogen
sulfide. The system turned black and smelled
characteristically of that material. The system was re-
started and within a few days it returned to normal
operation.
Importantly, Earth Tech (the contractor using EcoMat's
system at the site) was not concerned with optimizing the
time for performing the remediation of the water from the
Baker tanks. With a retention time of one half-hour, the
remediation proceeded sufficiently rapidly. However,
based upon EcoMat's denitrification experience, much
shorter retention times may be feasible for perchlorate
remediation, further reducing the cost of new systems.
EcoMat is pursuing this possibility.
A.1.4 Results
Measurements were made by Earth Tech on a regular
basis. As a result of the "closed loop" feature, it was
possible to control the outlet so that only when the effluent
perchlorate concentrations were below the allowable level
(ND) would water be discharged to a cleaned water baker
tank. Initial results during the startup period were as
follows in Table A-1 (in micrograms per liter):
A.1.5 Future Plans
Reactors 15 times the size of the subject reactor are
currently in operation, and EcoMat has designed reactors
as large as 100 cubic meters. The reactors may be
ganged together to provide adequate volume for any flow
rate. EcoMat plans to offer its perchlorate remediation
process to customers as a build-own-operate package,
Table A-1
DATE
2/17
2/18
2/21
3/06
3/07
3/08
3/09
3/10
3/15
3/23
INLET
350
390
390
350
370
340
320
320
260
300
OUTLET
210
160
410*
ND
ND
9
ND
19
24**
ND
* Power loss
** New Tank. When the Baker tanks were emptied, the
system was moved to another location at the DOD site,
where it is presently in operation.
with pricing in the range of $.50/1,000 gallons.
A.1.6 Conclusions
It appears to EcoMat that this system is one of the most
inexpensive ways to remediate perchlorate from water. For
very large systems it would be cost effective to implement
on-line measurement capabilities with SCADA systems to
transmit data to a remote operations center, facilitating
satisfactory operations.
A-3
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