September 2006
NSF 06/ARS1/EPADWCTR
EPA/600/R-06/099
Environmental Technology
Verification Report
Removal of Arsenic in Drinking Water
ARS USA, LLC
ARS CFU-50 ARC Electroflocculation and
Filtration Water Treatment System
Prepared by
NSF International
Under a Cooperative Agreement with
U.S. Environmental Protection Agency
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THE ENVIRONMENTAL TECHNOLOGY VERIFICATION
PROGRAM
U.S. Environmental Protection Agency NSF International
ETV Joint Verification Statement
TECHNOLOGY TYPE: ELECTROFLOCCULATION AND MEDIA FILTRATION
USED IN DRINKING WATER TREATMENT SYSTEMS
APPLICATION: REMOVAL OF ARSENIC IN DRINKING WATER
TECHNOLOGY NAME: ARS CFU-50 APC ELECTROFLOCCULATION AND
FILTRATION WATER TREATMENT SYSTEM
COMPANY: ARS USA, LLC
ADDRESS: PO Box 1170 PHONE: (505)771-4344
Bernalillo, NM 87004 FAX: (505) 771-4345
WEB SITE: www.arsusa.com
EMAIL: info@arsusa.com
The U.S. Environmental Protection Agency (EPA) supports the Environmental Technology Verification
(ETV) Program to facilitate the deployment of innovative or improved environmental technologies
through performance verification and dissemination of information. The goal of the ETV Program is to
further environmental protection by accelerating the acceptance and use of improved and more cost-
effective technologies. ETV seeks to achieve this goal by providing high-quality, peer-reviewed data on
technology performance to those involved in the design, distribution, permitting, purchase, and use of
environmental technologies.
ETV works in partnership with recognized standards and testing organizations, stakeholder groups
(consisting of buyers, vendor organizations, and permitters), and with the full participation of individual
technology developers. The program evaluates the performance of innovative technologies by developing
test plans that are responsive to the needs of stakeholders, conducting field or laboratory tests (as
appropriate), collecting and analyzing data, and preparing peer-reviewed reports. All evaluations are
conducted in accordance with rigorous quality assurance protocols to ensure that data of known and
adequate quality are generated and that the results are defensible.
NSF International (NSF), in cooperation with the EPA, operates the Drinking Water Systems (DWS)
Center, one of six technology areas under the ETV Program. The DWS Center recently evaluated the
performance of an electroflocculation and media filtration system for the removal of arsenic from
drinking water. This verification statement provides a summary of the test results for the ARS CFU-50
APC Electroflocculation and Filtration Water Treatment System (ARS CFU-50 APC). The NSF Drinking
Water Treatment Systems Laboratory (DWTS) was the field testing organization (FTO) that performed
the verification testing. The verification report contains a comprehensive description of the complete
verification test.
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ABSTRACT
Verification testing of the ARS CFU-50 APC Electroflocculation and Filtration Water Treatment System
(ARS CFU-50 APC) for arsenic removal was conducted at the Town of Bernalillo Well #3 site from April
18 through May 2, 2006. The source water was chlorinated groundwater from two supply wells, and the
feed water for the verification test was withdrawn from the pressure tank at the site. Verification testing
was conducted at the operating conditions specified by the manufacturer. The feed water, with a pH in
the range of 7.6 to 7.9, was pumped into a reaction vessel where electricity is applied to aluminum and
graphite plates to create flocculent to which arsenic adsorbs. When operated under the manufacturer's
specified conditions at this site, at an average flow rate of 32.1 gallons per minute (gpm), the ARS
CFU-50 APC reduced the total arsenic concentration from an average of 12 micrograms per liter ((ig/L)
in the feed (untreated) water to 6 (ig/L in the filtrate (treated) water.
TECHNOLOGY DESCRIPTION
The following technology description was provided by the manufacturer and has not been verified.
The ARS CFU-50 APC is a standard, full-scale, modular system for the removal of arsenic and other
contaminants from water. The ARS CFU-50 APC is a self-contained, complete system that connects to a
water supply source. If the source is not pressurized, a pump, supplied with the unit, is used to pump the
water through the treatment system. The ARS CFU-50 APC requires a three-phase 480-volt AC electric
power source to operate the reaction vessel, programmable logic controller (PLC), and ancillary
equipment. The system used for this test is designed to treat flows up to a maximum flow rate of
approximately 35 gpm (50,000 gallons per day [gpd]), from either a pressurized or unpressurized water
source.
Untreated/contaminated water enters the unit through a regulated influent pipe. The flocculent generation
and decontamination process occurs in the reaction vessel in a continuous process. Flocculent particles in
the holding pipe/tank are subject to further growth and reaction after the electrolytic process. Sand filters
separate the flocculent from the treated water. The filter surfaces are cleaned by automatic backwashing,
and the flocculation sludge is flushed into the floe water reservoir tank. The low volume, thickened
flocculation sludge accumulated in the floe water reservoir tank is pumped into the filter press by a pump,
where it is pressed into a filter cake. After the treated water passes through the filter press, it is stored in
the clean water tank for later use in filter backwashing and rinsing. As the clean water tank level reaches
its maximum level, it is pumped out of the unit through the filtrate water pipe.
The ARS CFU-50 APC treatment system is fully automated and programmed to control all aspects of the
treatment and filter operation. The control system automatically initiates backwash cycles based on an
inlet pressure level set by the operator. The backwash cycle time is a fixed time duration that is
programmed in the PLC. The control system monitors data from the system operation. This information is
available to the on-site operator.
VERIFICATION TESTING DESCRIPTION
Test Site
The Bernalillo Well #3 site is a fenced property that includes a building that houses the well pump and
chlorination equipment, a primary storage tank (approximately 1,000,000 gallons [gal]), and a secondary
storage tank (approximately 200,000 gal). Water pumped at the site is a mixture from two wells, both of
which pump water from the Rio Grande Group aquifer. The average daily water use for the Town of
Bernalillo is approximately 2,000,000 gpd. Water quality data based on data collected between June 2002
and March 2004 shows total arsenic in the combined well water ranges from 14 to 68 (ig/L and the
primary arsenic species is arsenic (V). The water has a total hardness of approximately 70 to 90
milligrams per liter (mg/L) as CaCO3 and the pH is approximately 7.3.
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Methods and Procedures
Operations, sampling, and analyses were performed in accordance with the Product Specific Test Plan
(PSTP) developed and approved for this verification test. The PSTP included a Quality Assurance Project
Plan (QAPP) to assure the quality of the data collected and to provide an accurate evaluation of the
treatment system under field conditions. Testing included characterization of the feed water, an arsenic
loss test (no electricity supplied to the reaction vessel), and a 14-day verification test.
The verification test was performed from April 18, through May 1, 2006. The ARS CFU-50 APC was
operated for the 14-day verification test by using water supplied from the Town of Bernalillo. Flow rate,
production volume, water temperature, and system pressure were monitored and recorded daily. Feed and
filtrate (treated) water samples were analyzed on-site for pH, temperature, turbidity, free and total residual
chlorine, color, and dissolved oxygen (DO) by the field operator. Grab samples were collected and
delivered to the NSF Analytical Laboratory and were analyzed for alkalinity, aluminum, calcium,
magnesium, iron, manganese, sulfate, chloride, total organic carbon (TOC), total suspended solids (TSS),
and fluoride. Samples for total arsenic were collected daily, plus 14 samples were collected during a
48-hour intensive survey. In addition to the samples for total arsenic, arsenic samples were speciated
during the test to determine the soluble arsenic concentration and the concentrations of arsenic (III) and
the arsenic (V) present in the soluble fraction.
Complete descriptions of the verification testing results and quality assurance/quality control (QA/QC)
procedures are included in the verification report.
VERIFICATION OF PERFORMANCE
System Operation
ARS performed the system startup and shakedown testing, which included optimization of the electrical
feed rates (30 amps) to the reaction vessel. The verification test was conducted under the manufacturer's
specified operating conditions. The backwash system was set to backwash when the pressure differential
across the filter exceeded 15 pounds per square inch (psi).
System pressure was monitored at the filter influent and filtrate. Head loss fluctuated between 6.4 and
15.9 psi during the inspections. The ARS CFU-50 APC PLC was not programmed to record pressure
differentials at the start of backwash cycles, so the pressure differential evaluation for this verification
was limited to whether the differential exceeded 15 psi during the time the FTO personnel inspected the
device.
During the test, there were a total of four incidences (April 20, 21, 28, and 30) where a sensor triggered
the PLC to shut down operations. During each incident, the sensor indicated that either the floe water
reservoir tank had exceeded capacity or the filter press alarm went off. In each instance, the filter press
had clogged to a point where it was prohibiting sufficient filtration to maintain the device's rated
throughput. ARS personnel recommended that the filter press be cleaned a minimum of once every 24
hours to prevent the ARS CFU-50 APC from automatically shutting down. After each shutdown incident,
FTO personnel cleaned the filter press and resumed operation in accordance with the startup procedures
outlined in the ARS Operations and Maintenance (O&M) manual. As a result of these incidents, the ARS
CFU-50 APC experienced approximately 36 hours of downtime during the 14-day verification test.
The filtrate flow rate was 32.1 gpm over the 14 days. The total filtrate volume produced each day was
also consistent, except for those days when operating time was lost due to the filter press alarm shutting
down the system.
Water Quality Results
The results of total arsenic analyses are shown in Figure VS-1. The feed water total arsenic averaged
12 (ig/L with most of the arsenic as arsenic (III), but with some arsenic (V) also present. The filtrate water
total arsenic concentration averaged 6 (ig/L. The data collected during the 48-hour intensive survey were
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consistent with the data collected each day during the verification test. There was no indication of any
transient or short time changes in the arsenic concentration or in any other monitored parameters.
16 -,
*% -%
%
%
Date
-Feed Filtrate
Figure VS-1. Total Arsenic Results.
The feed and filtrate water alkalinity averaged 130 mg/L as CaCO3, indicating that the treatment process
had no impact on the alkalinity. The pH of the feed and filtrate water had a median value of 7.7.
Aluminum was detected in four of the 14 feed water samples, at concentrations ranging from 13 to
84 (ig/L, while the remaining ten feed water samples had aluminum concentrations below the 10 (ig/L
detection limit. In the filtrate, the average aluminum concentration was 560 (ig/L, and ranged from 200 to
890 (ig/L. The average filtrate aluminum concentration was 20 times greater than the feed water average
concentration and significantly higher than the National Secondary Drinking Water Regulation range of
50 to 200 (ig/L. Furthermore, operation of the ARS CFU-50 APC increased the turbidity levels in the
filtrate water. The feed water turbidity averaged 0.30 Nephelometric Turbidity Units (NTU), and ranged
from 0.20 to 0.45 NTU, while the filtrate water averaged 0.80 NTU, and ranged from 0.35 to 1.2 NTU.
Turbidity and aluminum data during the 48-hour intensive survey were similar to those during the 14-day
test. The turbidity and aluminum data indicated that filtration mechanisms more efficient than those
currently utilized in the ARS CFU-50 APC were required to bring these parameters closer to the feed
water concentrations or within the EPA regulations. The ARS CFU-50 APC had little or no impact on
free chlorine, total chlorine, DO, chloride, sulfate, TOC, fluoride, calcium, or magnesium concentrations.
Manganese and iron concentrations were consistently below detection limits in both the feed and filtrate
water.
Backwash was initiated automatically based on pressure differential. Backwash waste was treated by a
filter press designed to remove the solids (floe) from the backwash water. The filtrate from the filter
press was transferred back to the reaction vessel for re-treatment. The backwash cycle was set for a fixed
time duration of 120 seconds for backwash and 30 seconds for rinsing. The combined backwash and
rinsing resulted in approximately 250 gallons of waste per backwash sequence. Solids retained in the
filter press were removed manually during filter press maintenance. At the end of testing, approximately
572,550 gallons of water were treated, and approximately 1,425 pounds of solids (wetted floe) was
created. This calculates to an approximate suspended solids concentration of 300 mg/L. The backwash
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September 2006
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solids were not considered a hazardous waste, based on Toxicity Characteristic Leaching Procedure
(TCLP) metals analyses, which were below the regulatory limits under the Resource Conservation and
Recovery Act (RCRA).
Operation and Maintenance Results
The ARS CFU-50 APC was found to be easy to operate and required little time for daily maintenance.
The field staff was on-site for two to three hours per day. Most of the time on-site was spent performing
field activities, including flow checks, calibrations, cleaning the filter press, and other verification-related
activities.
The ARS CFU-50 APC O&M manual provides a detailed description of the system, appropriate safety
precautions, and detailed descriptions of operating procedures, capability and operation of the computer
control system, and specific instructions for utility operators. The maintenance section of the manual
includes some descriptions of required maintenance, but refers the reader to the individual equipment
literature supplied by the various pump and instrument manufacturers. A review of the O&M manual
shows that the manual is well organized and easy to read.
The ARS CFU-50 APC was equipped with two sand filters, so that one filter could be in operation while
the other was in backwash mode or standby. During the testing at this installation, there were no
conditions where the pressure differential across both sand filters required that both filters backwashed at
the same time. Issues regarding the efficacy of the filtration process, as shown in the aluminum and
turbidity data, were noted during the verification test.
Backwash waste was treated by a filter press designed to remove the solids from the backwash water.
During the testing, when the flocculent caked in the filter press to a point where water would no longer
pass through it, the PLC shut down the entire system, as it was programmed to do. When this occurred,
field personnel cleaned the filter press and restarted the system. Verification testing substantiated the
importance of the filter press and its appropriate maintenance as a critical aspect of the function of the
ARS CFU-50 APC.
The system PLC was designed to operate and monitor many of the operating functions of the device. The
PLC readings were easy to use, but required an understanding of the PLC operating keys to display the
readings. The PLC was not programmed to record data, so readouts on component performance, such as
flow, pressure, and electrical settings had to be monitored and recorded manually. Because the PLC did
not record data, information regarding the duration of filter runs, frequency of backwash cycles, and the
pressure differentials across the sand filters could not be accurately recorded. The PLC was designed to
shut the entire system down in the event any sensor recorded a condition outside preset operating limits.
This condition was experienced four times during the verification. The cause of each shutdown was the
filter press clogging to a point where water could not pass through it at the system's rated throughput.
During each shutdown condition, after the filter press was cleaned, the alarm conditions in the PLC were
cleared and the system was restarted without difficulty.
Electrical power consumption was estimated based on the floe pump, clean water pump, backwash pump,
reaction vessel, waste pump, and miscellaneous other devices (air compressor, PLC, lights, etc.). The
power consumption was estimated to be 4.2 kilowatt hours (KwH).
Quality Assurance/Quality Control
NSF provided technical and QA oversight of the verification testing as described in the verification
report, including an audit of nearly 100% of the data. The NSF QA department conducted a technical
systems audit during testing to ensure the testing was in compliance with the test plan and performed a
QA review of the analytical data. A complete description of the QA/QC procedures is provided in the
verification report.
06/ARS1/EPADWCTR The accompanying notice is an integral part of this verification statement. September 2006
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Original signed by Original signed by
Sally Gutierrez September 22, 2006 Robert Ferguson September 12, 2006
Sally Gutierrez Date Robert Ferguson Date
Director Vice President
National Risk Management Research Laboratory Water Systems
Office of Research and Development NSF International
United States Environmental Protection Agency
NOTICE: Verifications are based on an evaluation of technology performance under specific,
predetermined criteria and the appropriate quality assurance procedures. EPA and NSF make no
expressed or implied warranties as to the performance of the technology and do not certify that a
technology will always operate as verified. The end-user is solely responsible for complying with
any and all applicable federal, state, and local requirements. Mention of corporate names, trade
names, or commercial products does not constitute endorsement or recommendation for use of
specific products. This report is not an NSF Certification of the specific product mentioned
herein.
Availability of Supporting Documents
Copies of the ETV Protocol for Equipment Verification Testing for Arsenic Removal
dated September 2003, the product-specific test plan, the verification statement, and the
verification report (NSF Report #06/ARS1/EPADWCTR) are available from the
following sources:
(NOTE: Appendices are not included in the verification report. Appendices are available
from NSF upon request.)
1. ETV Drinking Water Systems Center Manager (order hard copy)
NSF International
P.O. Box 130140
Ann Arbor, Michigan 48113-0140
2. NSF web site: http://www.nsf.org/info/etv (electronic copy)
3. EPA web site: http://www.epa.gov/etv (electronic copy)
06/ARS1/EPADWCTR The accompanying notice is an integral part of this verification statement. September 2006
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September 2006
Environmental Technology Verification Report
Removal of Arsenic in Drinking Water
ARS USA, LLC
ARS CFU-50 APC Electroflocculation and Filtration
Water Treatment System
Prepared for:
NSF International
Ann Arbor, Michigan 48105
Prepared by:
NSF International
Under a cooperative agreement with the U.S. Environmental Protection Agency
Jeffrey Q. Adams, Project Officer
National Risk Management Research Laboratory
U.S. Environmental Protection Agency
Cincinnati, Ohio 45268
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Notice
The U.S. Environmental Protection Agency (EPA), through its Office of Research and
Development, has financially supported and collaborated with NSF International (NSF) under
Cooperative Agreement No. R-82833301. This verification effort was supported by the Drinking
Water Systems (DWS) Center, operating under the Environmental Technology Verification
(ETV) Program. This document has been peer reviewed, reviewed by NSF and EPA, and
recommended for public release.
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Foreword
The U.S. Environmental Protection Agency (EPA) is charged by Congress with protecting the
Nation's land, air, and water resources. Under a mandate of national environmental laws, the
Agency strives to formulate and implement actions leading to a compatible balance between
human activities and the ability of natural systems to support and nurture life. To meet this
mandate, EPA's research program is providing data and technical support for solving
environmental problems today and building a science knowledge base necessary to manage our
ecological resources wisely, understand how pollutants affect our health, and prevent or reduce
environmental risks in the future.
The National Risk Management Research Laboratory (NRMRL) is the Agency's center for
investigation of technological and management approaches for preventing and reducing risks
from pollution that threaten human health and the environment. The focus of the Laboratory's
research program is on methods and their cost-effectiveness for prevention 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.
Sally Gutierrez, Director
National Risk Management Research Laboratory
in
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Table of Contents
Verification Statement VS-i
Notice ii
Foreword iii
Table of Contents iv
List of Figures v
List of Tables v
Appendices vi
Abbreviations and Acronyms vii
Acknowledgements viii
Chapter 1 Introduction 1
1.1 ETV Purpose and Program Operation 1
1.2 Testing Participants and Responsibilities 1
1.2.1 NSF International 2
1.2.2 Field Testing Organization 2
1.2.3 Manufacturer 3
1.2.4 Analytical Laboratory 3
1.2.5 U.S. Environmental Protection Agency 4
1.3 Verification Testing Site 4
1.3.1 Site Background Information 4
1.3.2 Source/Feed Water Quality 4
1.3.3 Test Site Description 5
Chapter 2 Equipment Capabilities and Description 7
2.1 Description of Equipment 7
2.2 Engineering and Scientific Concepts 7
2.2.1 Physicochemical Efficient Mechanisms 8
2.3 Description of Treatment Train and Unit Processes 8
2.4 Description of Physical Construction and Components 12
2.5 Chemical Consumption and Production of Waste Material 12
2.5.1 Chemical Consumption 12
2.5.2 Waste Production and Physical and Chemical Nature of Wastes 13
2.6 Licensing Requirements 13
2.7 Statement of Performance Objectives 13
2.8 Advantages of the ARS CFU-50 APC Process 14
2.9 Potential Limitations of the Equipment 14
Chapters Methods and Procedures 15
3.1 Quantitative and Qualitative Evaluation Criteria 15
3.2 Key Water Quality Parameters 15
3.3 Operations and Maintenance 15
3.4 Environmental Technology Verification Testing Plan 16
3.4.1 Task A: Raw Water Characterization 16
3.4.2 TaskB: Arsenic Loss Test 16
3.4.3 Task C: Verification Test Procedures 16
3.5 Operation and Maintenance 18
3.5.1 Operability Evaluation 18
iv
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Chapter 4 Results and Discussion 19
4.1 Introduction 19
4.2 Equipment Installation, Start-up, and Shakedown 19
4.2.1 Flow Measurement 19
4.3 Task A: Raw Water Characterization 20
4.4 Task B: Initial Test Runs 21
4.4.1 Arsenic Loss Test 21
4.5 TaskC: Verification Test 24
4.5.1 Operating Results 24
4.5.2 Arsenic Results 25
4.5.3 Feed and Filtrate Water Quality Results 29
4.6 Operations and Maintenance Findings 40
4.6.1 Electrical Consumption 41
4.6.2 Sand Filters 41
4.6.3 Filter Press 42
4.6.4 Backwash Water Frequency and Quality 42
4.6.5 Programmable Logic Controller 43
4.7 Quality Assurance/Quality Control 44
4.7.1 Documentation 44
4.7.2 Quality Audits 44
4.7.3 Data Quality Indicators 45
4.7.4 Effect of Sample Preservative on Arsenic Speciation 52
4.7.5 Deviations from PSTP 53
Chapters References 54
List of Figures
Figure 2-1. ARS CFU-50 APC schematic view 9
Figure 2-2. ARS CFU-50 APC right isometric view 11
Figure 2-3. ARS CFU-50 APC skid-mounted unit photograph 11
Figure 4-1. Verification test daily arsenic results 29
Figure 4-2. Verification test pH results 31
Figure 4-3. Verification test turbidity results 33
Figure 4-4. Verification test alkalinity results 35
Figure 4-5. Verification test aluminum results 37
List of Tables
Table 1-1. Raw Water Quality Data 5
Table 2-1. Test System Operating Conditions 10
Table 2-2. ARS CFU-50 APC System Specifications 10
Table 3-1. Key Filtrate Water Quality Parameters 15
Table 4-1. Feed Water Characterization Data - April 18, 2006 20
Table 4-2. TaskB Arsenic Loss Test Operating Data 21
Table 4-3. Task B Arsenic Loss Test Water Quality Results 23
Table 4-4. Operating Data 25
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Table 4
Table 4
Table 4
Table 4
Table 4
Table 4
Table 4
Table 4
Table 4
Table 4
Table 4
Table 4
Table 4
Table 4
Table 4
Table 4
Table 4
Table 4
Table 4
Table 4
Table 4
Table 4
-5. Daily Total Arsenic Results (|ig/L) 26
-6. Total Arsenic Results for 48-Hour Intensive Survey (|ig/L) 27
7. Arsenic Speciation Data (|ig/L) 28
8. pH Results (S.U.) 30
9. pH Results for the 48-Hour Intensive Survey (S.U.) 30
10. Bench Top Turbidity Results 32
11. Bench Top Turbidity Results for the 48-Hour Intensive Survey 33
12. Alkalinity Results 34
13. Alkalinity Results for the 48-Hour Intensive Survey 35
14. Aluminum Results 36
15. Aluminum Results for the 48-Hour Intensive Survey 37
16. Total and Free Residual Chlorine and DO 38
17. Total and Free Residual Chlorine and DO Results for 48-Hour Survey 39
18. Other Water Quality Parameters 40
19. Power Consumption 41
20. Backwash Solids - TCLP and CAWET Analyses 43
21. Field Instrument Calibration Schedule 46
22. Flow Meter Calibration Data 47
23. Precision Data - Field Duplicates for Laboratory Parameters 49
24. Precision Data - Field Duplicates for Field Parameters 50
25. Completeness Results 52
26. Deviations from PSTP 53
Appendices
Appendix A - Operation and Maintenance Manual
Appendix B - Product Specific Test Plan
Appendix C - Spreadsheets
Appendix D - Field Data Logbook and Calibration Records
Appendix E - NSF Laboratory Data Reports
Appendix F - TriMatrix Laboratories Data Report for TCLP and CAWET Analyses
VI
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Abbreviations and Acronyms
ARS
CAWET
°C
c.u.
DO
DWS
DWTS
EPA
ETV
ft2
FTO
gpm
gpd
hp
KwH
LCS
mg/L
mm
MSDS
NC
NIST
NR
NRMRL
NSF
NTU
O&M
ORD
PLC
psi
PSTP
QA/QC
QAPP
RCRA
%RSD
S.U.
TCLP
TOC
TSS
VAC
ARS USA, LLC (formerly known as Advanced Remediation Systems
USA, LLC)
California Waste Extraction Test
Degree Celsius
Color Units
Dissolved Oxygen
Drinking Water Systems
NSF International Drinking Water Treatment Systems Laboratory
U.S. Environmental Protection Agency
Environmental Technology Verification
Square Feet or Square Foot
Field Testing Organization
Gallon(s) Per Minute
Gallon(s) Per Day
Horsepower
Kilowatt-hour
Laboratory Control Sample
Milligram(s) per Liter
Millimeter
Material Safety Data Sheets
Not Calculated
National Institute of Standards and Technology
Not Recorded
National Risk Management Research Laboratory
NSF International
Nephelometric Turbidity Unit(s)
Operation and Maintenance
Office of Research and Development
Programmable Logic Controller
Pounds per Square Inch
Product Specific Test Plan
Quality Assurance/Quality Control
Quality Assurance Project Plan
Resource Conservation and Recovery Act
Percent Relative Standard Deviation
Standard Units
Toxicity Characteristic Leaching Procedure
Total Organic Carbon
Total Suspended Solids
Microgram(s) per Liter
Volts Alternating Current
vn
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Acknowledgements
The Field Testing Organization (FTO), NSF International (NSF) Drinking Water Treatment
Systems Laboratory (DWTS), was responsible for all elements in the testing sequence, including
collection of samples, calibration and check of instrumentation, data collection and analysis, data
management, data interpretation, and the preparation of this report.
NSF International Drinking Water Treatment Systems Laboratory
789 N. Dixboro Road
Ann Arbor, Michigan 48105
Contact Person: Mr. Robert Herman
The laboratory selected for the analytical work for this test was:
NSF International Chemistry Laboratory
789 N. Dixboro Road
Ann Arbor, Michigan 48105
Contact Person: Dr. Kurtis Kneen
The manufacturer of the equipment was:
ARS USA, LLC
PO Box 1130
Bernalillo, NM 87004
Contact Person: Mr. Norbert Barcena
The NSF DWTS wishes to thank the following participants:
Mr. Bruce Bartley, Mr. Patrick Davison, and Ms. Angela Beach of the NSF Environmental
Technology Verification (ETV) Drinking Water Systems (DWS) Center for their support,
guidance, and program management.
The Town of Bernalillo staff, including Mr. Bill Plata and Mr. Les Swindle, for providing access
to the test site.
ARS for supplying the verification test unit and support services during the start-up period. Mr.
Andrew Polnicki coordinated building and shipping of the test unit, and worked at the site to
optimize the operation of the system and provide training to the NSF field operators. Ms. Lauren
Bull provided logistical assistance. Their work is greatly appreciated.
Vlll
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Chapter 1
Introduction
1.1 ETV Purpose and Program Operation
The U.S. Environmental Protection Agency (EPA) has created the Environmental Technology
Verification (ETV) Program to facilitate the deployment of innovative or improved
environmental technologies through performance verification and dissemination of information.
The goal of the ETV Program is to further environmental protection by accelerating the
acceptance and use of improved and more cost-effective technologies. ETV seeks to achieve this
goal by providing high-quality, peer-reviewed data on technology performance to those involved
in the design, distribution, permitting, purchase, and use of environmental technologies.
ETV works in partnership with recognized standards and testing organizations; with stakeholder
groups consisting of buyers, vendor organizations, and permitters; and with the full participation
of individual technology developers. The program evaluates the performance of innovative
technologies by developing test plans responsive to the needs of stakeholders, conducting field
demonstrations, collecting and analyzing data, and preparing peer-reviewed reports. All
evaluations are conducted in accordance with rigorous quality assurance protocols to ensure that
data of known and adequate quality are generated and that the results are defensible.
The EPA has partnered with NSF International (NSF) under the ETV Drinking Water Systems
(DWS) Center to verify the performance of small drinking water systems that serve small
communities. A goal of verification testing is to enhance and facilitate the acceptance of small
drinking water treatment equipment by state drinking water regulatory officials and consulting
engineers, while reducing the need for testing of equipment at each location where the
equipment's use is contemplated. NSF meets this goal by working with manufacturers and NSF-
qualified Field Testing Organizations (FTOs) to conduct verification testing under the approved
protocols. It is important to note that verification of the equipment does not mean the equipment
is "certified" by NSF or "accepted" by EPA. Rather, it recognizes that the performance of the
equipment has been determined and verified by these organizations for those conditions tested by
the FTO.
The DWS Center evaluated the performance of the ARS CFU-50 APC Electroflocculation and
Filtration Water Treatment System (ARS CFU-50 APC), manufactured and distributed by ARS
USA, LLC, which is a granular media filtration system used in drinking water treatment system
applications for reduction of arsenic and dissolved iron in groundwater. This document provides
the verification test results for the ARS CFU-50 APC.
1.2 Testing Participants and Responsibilities
The ETV testing of the ARS CFU-50 APC was a cooperative effort among the following
participants:
NSF
NSF International Drinking Water Treatment Systems Laboratory (DWTS)
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ARS
The Town of Bernalillo, New Mexico
EPA
The following is a brief description of all of the ETV participants and their roles and
responsibilities.
1.2.1 NSF International
NSF is an independent, not-for-profit testing and certification organization dedicated to public
health and safety and to the protection of the environment. Founded in 1946 and located in Ann
Arbor, Michigan, NSF has been instrumental in the development of consensus standards for the
protection of public health and the environment. NSF also provides testing and certification
services to ensure products bearing the NSF Name, Logo and/or Mark meet those standards. The
EPA partnered with NSF to verify the performance of drinking water treatment systems through
the EPA's ETV Program.
NSF provided technical oversight of the verification testing and conducted an audit of the field
analytical and data gathering and recording procedures. NSF also provided review of the
Product Specific Test Plan (PSTP) as well as this report.
Contact Information:
NSF International
789 N. Dixboro Road
Ann Arbor, Michigan 48105
Contact: Bruce Bartley, Project Manager
Phone: (734) 769-8010
Fax: (734) 769-0109
Email: bartley@nsf.org
1.2.2 Field Testing Organization
The DWTS conducted the verification testing of the ARS CFU-50 APC. The DWTS is an NSF-
qualified FTO for the ETV DWS Center.
The FTO provided all needed logistical support, established a communications network, and
scheduled and coordinated activities of all participants. The FTO was responsible for ensuring
the testing location and feed water conditions were such that the verification testing could meet
its stated objectives. The FTO prepared the PSTP; oversaw the pilot testing; managed,
evaluated, interpreted, and reported on the data generated by the testing; and evaluated and
reported on the performance of the technology. The FTO was responsible for completing the
raw water characterization testing, monitoring the ARS CFU-50 APC during the arsenic loss
testing (24 hour test), and conducting the verification test over 14 calendar days.
DWTS employees conducted the on-site analyses and data recording during the test. The FTO's
Project Manager and Project Director provided oversight of the daily tests.
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Contact Information:
NSF International Drinking Water Treatment Systems Laboratory
789 N. Dixboro Road
Ann Arbor, Michigan 48105
Contact Person: Mr. Robert Herman
Phone: (734) 769-5349
Fax: (734) 827-7143
Email: herman@nsf.org
1.2.3 Manufacturer
The treatment system was the ARS CFU-50 APC Electroflocculation and Filtration Water
Treatment System for the removal of arsenic from drinking water. The manufacturer was
responsible for supplying a field-ready electroflocculation and filtration system equipped with all
necessary components, including treatment equipment, instrumentation and controls, and an
operation and maintenance (O&M) manual. The manufacturer was responsible for providing
logistical and technical support, as needed, as well as technical assistance to the FTO during
operation and monitoring of the equipment undergoing field verification testing.
Contact Information:
ARS USA, LLC
PO Box 1170
Bernalillo, NM 87004
Contact Person: Mr. Norbert Barcena
Phone: (505) 771-4344
Fax:(505) 771-4345
Email: norbert@arsusa.com
1.2.4 Analytical Laboratory
The NSF Chemistry Laboratory in Ann Arbor, Michigan performed all water quality analyses.
Contact Information:
NSF International Chemistry Laboratory
789 N. Dixboro Road
Ann Arbor, Michigan 48105
Contact Person: Dr. Kurtis Kneen
Phone: (734) 827-6874
Fax: (734) 827-7765
Email: kneen@nsf.org
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Backwash toxicity analyses were performed by:
Contact Information:
TriMatrix Laboratories, Inc.
5555 Glenwood Hills Parkway, SE
Grand Rapids, Michigan 49588
Phone:(810)220-2075
Fax:(810)220-2803
Contact: Mr. Michael W. Movinski, Vice President, Sales and Marketing
Email: mmtrimatrix@comcast.net
1.2.5 U.S. Environmental Protection Agency
The EPA, through its Office of Research and Development (ORD), has financially supported and
collaborated with NSF under Cooperative Agreement No. R-82833301. This verification effort
was supported by the DWS Center operating under the ETV Program. This document has been
peer reviewed, reviewed by NSF and EPA, and recommended for public release.
1.3 Verification Testing Site
1.3.1 Site Background Information
The Bernalillo Well #3 site is less than one acre and includes a two-room building which houses
the well pump in one room and the chlorination equipment in the other room. The site also
includes a primary storage tank (approximately 1 million gallons) and secondary storage tank
(approximately 200,000 gallons). The two tanks are connected to each other as well as to
Well #3 and Well #4. The water storage tanks are fixed wall tanks that do not have bladder
inserts. When the water level in the storage tank drops below a preset level, Well #3 is activated
to supplement water from Well #4. Once a preset limit is met, the pumps shut off. Chlorine is
immediately added to the water from the wells prior to delivery to the storage tank.
The average daily water use for the Town of Bernalillo is approximately two million gallons per
day (gpd). Well #3 typically produces approximately 600 to 800 gallons per minute (gpm) when
it is operating, and Well #4 typically produces approximately 1,200 to 1,600 gpm. According to
the Town of Bernalillo, both wells pump water from the Rio Grande group aquifer. Well #3 is
approximately 660 feet deep and Well #4 is approximately 970 feet deep.
The supply water for the test is provided from the storage tanks at Well #3, and includes a blend
of water from the two wells. The ARS CFU-50 APC unit was located on the grounds of the
Well #3 site. The site was secured with a fence and locked gate, and provided ample space for
adding the piping needed for the test unit and for storage of basic supplies and equipment needed
during the testing.
1.3.2 Source/Feed Water Quality
Table 1-1 presents raw water quality for samples taken from samples collected and analyzed by
ARS between January and April 2006, when the site was evaluated. The water had total hardness
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of approximately 70-90 milligrams per liter (mg/L) as CaCOs and the pH is normally
approximately 7.3, based on data collected between June 2002 and March 2004. Water quality
data show that total arsenic concentration varies between 14 and 68 micrograms per liter (|ig/L).
The predominant arsenic species is arsenic (V).
Table 1-1. Raw Water Quality Data
Concentration
Parameter Units Range
Total arsenic
Total aluminum
Total iron
Total manganese
Total magnesium
Total calcium
|ig/L
|ig/L
mg/L
Hg/L
mg/L
mg/L
14
<1
0.25
<1
9.7
71
-68
-4
-0.46
-7
-12
-86
1.3.3 Test Site Description
Structural
The ARS CFU-50 APC system was housed in an 8 foot by 20 foot shipping container. The
containerized system is located next to the water supply building. The water supply from the
pressurized main system storage tank was piped to the treatment unit. This test site provided the
following advantages:
Full electrical supply;
Building enclosing the wells and pressure holding tank;
Ease of accessibility; and
All required utilities, including raw water supply, power, and drain locations for the
discharge of the filtrate and backwash water to the sanitary sewer system.
Handling of Filtrate
The ARS CFU-50 APC does not have separate discharge ports for backwash or overflow. Water
used for backwash is filtered through a filter press and returned to the reaction vessel for re-
treatment. For the purposes of this study, all treated water (filtrate) was discharged to one of the
potable water storage tanks maintained by the Town of Bernalillo.
Handling of Residuals
Residual solids are removed from the backwash water with a filter press. Residual solids were
stored in 55-gallon drums on-site prior to disposal.
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Discharge Permits
No special discharge permits were required for the discharge of the filtrate, and backwash water
from the test unit is recycled back to the reaction tank. The filter cake was characterized as part
of the study (see Section 4.6). Previous tests conducted by the vendor indicate this material is
non-hazardous.
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Chapter 2
Equipment Capabilities and Description
The equipment capabilities and description provided in this section were provided by the vendor
and does not represent verified information. The ETV evaluation focused on the ability of the
device to remove arsenic from drinking water. Claims beyond arsenic removal are made by the
vendor but were not verified as part of this study.
2.1 Description of Equipment
The ARS CFU-50 APC is a standard, full-scale, modular system supplied by ARS for the
removal of arsenic and other contaminants from water. The ARS CFU-50 APC is a self-
contained, complete system that connects to a water supply source. If the source is not
pressurized, a pump, supplied with the unit, is used to pump the water through the treatment
system. The ARS CFU-50 APC requires a three-phase 480-volt AC electric power source to
operate the reaction vessel, programmable logic controller (PLC), and ancillary equipment. The
system used for this test is designed to treat flows up to a maximum flow rate of approximately
35 gpm (50,000 gpd), from either a pressurized or unpressurized water source. Additional
information on the equipment installation requirements and operation of the equipment is
provided in the O&M manual, included Appendix A.
The ARS CFU-50 APC treatment system is fully automated and programmed to control all
aspects of the treatment and filter operation. The control system automatically initiates backwash
cycles based on an inlet pressure level set by the operator. The backwash cycle time is dependent
on the water quality conditions and the amount of solids generated in the electroflocculation
process. The control system monitors data from the system operation. This information is
available to the on-site operator. Although the system is designed for automatic, unattended
operation, the following information is available to an on-site operator:
Pressure at key points of the device;
Flow rates and throughput totals;
Sand filter data: regeneration interval, total in-process times, current status (on-
line, back flushing, standby, etc.);
Electrical process parameters (current and voltage);
Fault/alarm conditions, based on vessel levels, flow rate, pressure levels, gas
levels, air pressure loss, etc.;
Maintenance messages (for example, filter press cleanout required); and
Oxygen and hydrogen monitor readings.
2.2 Engineering and Scientific Concepts
The ARS CFU-50 APC treatment system relies on electroflocculation which develops an
aluminum flocculent similar to alum and ferric flocculants. The ARS CFU-50 APC flocculent
generates various hydroxyl water complexes that combine with cations and other contaminants
within the source water. ARS claims there are several significant differences between the ARS
process and the chemical processes:
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The ARS flocculent is generated without the addition of any chemical agents (the anode
plate is the source of the aluminum used in the flocculation process);
The ARS flocculent does not require any pretreatment or post treatment;
The ARS flocculent does not begin with a salt molecule and therefore does not affect a
change on water salinity;
The ARS process works in a pH range of 4.5 to 8.5. Higher pH ranges can be reduced
through a non-chemical ARS method; and
The ARS flocculent particles are a fraction of the size generated through chemical means,
resulting in floes with extremely high surface area to volume ratios, making the ARS
process more effective in removing arsenic.
These claims were not verified as part of the ETV study.
2.2.1 Physicochemical Efficient Mechanisms
The following two processes are running simultaneously during electrolytic water treatment:
Electrolytic decomposition of water, and
Dissolution of the anodes accompanied by the formation of metal polyhydroxides and
metal water complexes.
The main advantage of electrolytically-formed flocculent is their adsorbing power. In this
respect, they are highly active and show a very good binding capacity for divalent metallic ions.
According to the manufacturer, the ARS process has delivered excellent results for the treatment
of galvanizing wastewaters, dying backwaters, grinding wastewaters, lye solutions, emulsions,
tannery backwaters and similar wastewaters.
Electrolytic water decomposition contributes considerably to the efficiency of complex
procedures. Hydrogen and oxygen are released in a sequence of complex mechanisms. This so-
called nascent hydrogen or oxygen offers a very high potential of reduction and oxidation, which
provides for numerous secondary reactions with the water contents.
2.3 Description of Treatment Train and Unit Processes
With ARS, a floe of mixed oxide containing the arsenic contaminant is formed without the
addition of chemicals. Flocculation is accomplished in a single reaction process, removing heavy
metals. Water with minimum electrolytic conductivity is treatable in the reaction tank. Water
with high saline content is managed by regulating the process current level.
Figure 2-1 is a schematic of the primary components in the ARS CFU-50 APC treatment system.
In the switch cabinet (E), all processes are controlled and monitored. The power supply (P)
converts the AC electric current to a regulated fixed DC current. Untreated/contaminated water
enters the unit through a regulated influent pipe (1). The flocculent generation and
decontamination process occurs in the reaction tank in a continuous process (2). Flocculent
particles in the holding pipe/tank (3) are subject to further growth and reaction after the
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electrolytic process. The water and floe combination is pumped from the reaction vessel, through
the floe pipes, to the sand filters with the filter influent pump. This pump operates continuously
while the device is in operation. Filters (4) separate the flocculent from the treated water. The
filter surfaces are cleaned by automatic backwashing, and the flocculation sludge is flushed into
the floe water reservoir tank (5). The low volume, thickened flocculation sludge accumulated in
the floe water reservoir tank is pumped into the filter press (7) by a pump where it is pressed into
a filter cake by a filter press. The filter cake must be manually removed from the filter press.
After the treated water passes through the filter, it is stored in the clean water tank (6) for later
use in filter backwashing and rinsing. As the clean water tank level reaches its maximum level, it
is pumped out of the unit through the filtrate water pipe (8).
Figure 2-1. ARS CFU-50 APC schematic view.
The backwash cycle is triggered by an increase in influent pressure across the operating filter
module. The pressure trigger for backwash cycles is set based on local requirements and
operating characteristics at the site. The cycle is set based on experience at a site and is typically
set to ensure that at a filter module is backwashed at least once every two days. The backwash
and rinse cycle uses treated water for the backwash water source. Backwash and rinse is
accomplished by pumping treated water at a rate of approximately 100 gpm (14 gpm per square
foot of filter surface area) through the filter module. Backwash is accomplished in an up flow
mode, expanding the granular media bed, and flushing the solids from the media. Rinse is
accomplished in a downward flow mode, compressing the granular media bed, and flushing the
solids from the media. Approximately 250 to 300 gallons of water is used for each five-minute
backwash/rinse cycle. Backwash water from the test system is collected in a waste tank to allow
later dewatering. During the dewatering process, this water is discharged back to the reaction
vessel, resulting in zero water loss.
For the ETV test, the feed water was obtained from the water storage tanks at the Bernalillo test
site. The ARS system was equipped with a pump to draw water from the tank into the ARS
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system. A pressure regulator and a flow control valve was installed downstream of a double
back flow preventer to control the flow rate of feed water to the system. A flow meter was used
to monitor the flow rate and total flow of feed water to the treatment portion of the process.
A summary of standard operating conditions is provided in Table 2-1 and the ARS CFU-50 APC
system specifications are provided in Table 2-2. Additional equipment information is provided
in the O&M manual (Appendix A). Figures 2-2 and 2-3 show a schematic and photograph of a
typical system.
Table 2-1. Test System Operating Conditions
Parameter
Specification
Filtrate flow rate
Backwash flow rate
Backwash flow velocity
Backwash water per cycle
Pressure maximum for backwash initiation
Feed water pressure
Source water pressure
35 gpm (50,000 gpd)
lOOgpm
14 gpm/square foot (ft2)
250 - 300 gallons
15 pounds per square inch (psi)
>20 psi
>14psi
Table 2-2. ARS CFU-50 APC System Specifications
Manufacturer
Model
Reactor tank dimensions
Filter area per module
Filter module diameter
Media depth
Number of filter modules
Filter pressure rating
Media per filter module
Effective size
Uniformity coefficient
Skid
Piping
ARS USA, LLC
ARS CFU-50 APC
48 in. outer diameter, 48 in. tall
7.1ft2
36 inches
29 inches
2 (alternating in operation)
100 psi max operating pressure
Single media #20 silica sand
0.47 millimeter (mm)
1.42
8 ft x 20 ft shipping container
Schedule 80 PVC
10
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-Reactor Plates
Water IN pipe
Reactor Tank
Back wash Pump
Clean water tank
Pressure tank
Clean Floe pipe
Clean water pump
Top Manifiold
Backwash rinse pipe
Bottom Manifold
Back wash tank
Figure 2-2. ARS CFU-50 APC right isometric view.
Figure 2-3. ARS CFU-50 APC skid-mounted unit photograph.
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2.4 Description of Physical Construction and Components
The ARS CFU-50 APC system is a skid mounted, self-contained unit. The granular media filter
modules are steel tanks with inlet flow distributors, media support plates, and associated fittings,
valves, and piping. The maximum operating pressure is approximately 40 psi. The standard unit
is 20 ft (L) x 8 ft (W) x 8.75 ft (H). The main system components are (refer to Figure 2-1 for a
schematic view of the components):
1. Influent water plumbing - To control and regulate influent water flow.
2. Reaction vessel, which consists of the following components:
Reaction tank - Polyethylene tank for containing electroflocculation equipment.
Reaction frame - Polyethylene frame for holding reaction plates.
Spacer plates - Polyethylene spacers to maintain plate alignment.
Anode plates - Aluminum.
Cathode plates - Graphite.
Level sensor - To monitor and control the tank water level.
3. Floe water plumbing - Conveys treated slurry of floe and water from the reaction tank to
the filters. The filter influent pump pumps the water through the plumbing, and operates
continuously when the device is in operation. The floe water plumbing consists of six-
inch diameter serpentine pipe, which provides approximately 90 seconds of water and
floe contact time.
4. Filter and filter manifolds - 36-inch diameter, 29-inch deep single media sand filters,
used one at a time. One filter is staged and ready for use as back pressure builds in the
other filter. The filter also has a control manifold on the top and the bottom of the filters
to facilitate backwashing and rinsing.
5. Flocculent tank - A 500-gallon holding tank to temporarily store the wastewater
generated from the backwash/rinse cycles. Water from this tank is transferred to the filter
press (item 7) to remove the accumulated solids.
6. Clean water tank and plumbing - A 500-gallon tank to store treated water for use in back
washing and rinsing.
7. Filter press and plumbing - A plumbing system to force water through a plate and frame
filter press to dewater the floe from the treatment process. After separation, the remaining
water is then pumped back to the reaction vessel for recirculation.
8. Effluent plumbing - To discharge the treated water from the system.
E. Electrical switch cabinet.
P. Power supply.
Additional specifications and information are provided in the O&M manual (Appendix A).
2.5 Chemical Consumption and Production of Waste Material
2.5.1 Chemical Consumption
The ARS CFU-50 APC uses the aluminum from the anodes to create a flocculent. There are no
additional chemicals added or consumed in the process.
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2.5.2 Waste Production and Physical and Chemical Nature of Wastes
The waste material from the ARS CFU-50 APC is limited to a small amount of hydrogen gas and
filter cake, consisting of the flocculated materials.
Pages 61-65 of the O&M manual provide information on the filter press and its required
maintenance (cleaning). The filter cake was stored on-site, pending characterization and disposal
at the end of the testing. Water removed during filtration and filter cake production was pumped
back into the reaction vessel for recirculation.
Some hydrogen is released to the atmosphere by the electrolysis process. Ventilation devices are
built into the system as is a hydrogen monitor to insure that hydrogen concentration remains well
below the lower explosive limit (four percent). Additional ventilation is provided if hydrogen
buildup of one percent is detected, and if this does not mitigate the situation, an alarm state is
entered when the level reaches two percent (one-half of the lower explosive limit), automatically
stopping the process. ARS claims that no hydrogen buildup (to even one percent) has ever been
observed except when ventilation was disabled to test the monitor and control logic.
Hydrogen is not classified as an atmospheric pollutant. The ventilation equipment dilutes the
hydrogen with a sufficient quantity of air so that measurement of the resulting output is within
the error band of the monitoring instrument. Insufficient hydrogen is generated to make capture
for use as a possible fuel a viable option.
ARS also claims that an immeasurable quantity of oxygen is released as free gas. Most of the
oxygen resulting from electrolysis is utilized in oxidizing reactions associated with the floe
formation.
2.6 Licensing Requirements
There are no special licensing requirements to operate the ARS CFU-50 APC equipment during
the ETV test.
2.7 Statement of Performance Objectives
The statement of performance objective tested in the verification is:
The ARS CFU-50 APC process is capable of reducing arsenic concentrations from a water
source flowing at a maximum of 35 gpm with a total arsenic concentration of approximately 14
to 68 |ig/L and a pH of approximately 7.3 to maintain an effluent arsenic concentration less than
10 |ig/L after treatment.
Sampling and analysis of the test site indicated that arsenic concentrations in the 14 to 68 |ig/L
range would be achieved during the verification test. However, during the verification test, the
arsenic concentrations in the feed water ranged only from 11 to 14 |ig/L. An evaluation of the
analytical data and the test site could not identify a cause for this decrease in arsenic
concentrations. This is discussed in greater detail in Chapter 4.
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2.8 Advantages of the ARS CFU-50 APC Process
According to ARS, the main advantages of the ARS CFU-50 APC process for removing arsenic
from water are:
The process does not require the addition of any water treatment chemicals;
The process is flexible and adaptable to the degree of impurities in the source water;
The process operates over a wide pH range;
The flocculent created during the electrolytic flocculation are easily settleable;
The electrolytic flocculation process creates nascent hydrogen and oxygen, which can also
treat organic compounds, and remove unwanted odors;
The electrolytic flocculation process can also remove variety of metals and radiological
elements (Hg, Pb, Cr, Zn, Cd, Mo, Ni, Ur, etc.); this claim is outside the protocol and was not
verified during this test; and
The electrolytic flocculation process can also remove a variety of polar and cleavable
chemicals (not verified during this testing).
The verification testing did not include an evaluation of all of the aforementioned vendor
performance claims.
2.9 Potential Limitations of the Equipment
Potential limitations of the ARS CFU-50 APC process for the treatment of raw drinking water
with respect to source water quality are (note: these limitations were not verified as part of the
verification test):
Poor water quality in source water can cause high solids loadings to the filter, increasing
backwash frequency and quantity of solids generated;
While the system is automated and operation should be easy, a moderate level of operator
skill may be required for successful use of the system. Variable source water quality may
require adjustment of the power setting in order to maintain optimal removal efficiency;
Anodes need replenishment to ensure adequate flocculent generation;
Possible passivation of the plates over days or weeks as a result of insulation buildup on the
anode and cathode plates, depending on the mineral content of the water. This may increase
maintenance requirements;
Electrical power consumption settings need to be calibrated to account for source water with
high salinity; and
For source water with fluctuating target contaminant concentrations, the electrical power
consumption settings need to be set to target the highest contaminant concentration; when
target contaminant concentrations are at the lower end of the range, treatment will still occur,
however, the higher power consumption setting will increase operating costs.
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Chapter 3
Methods and Procedures
The testing methods and procedures were specified in the Product Specific Test Plan for the
Advanced Remediation Systems USA, LLC ARS CFU-50 APC Electroflocculation and Filtration
Water Treatment System for Arsenic Removal from Drinking Water (NSF International, March
2006). The PSTP, included in Appendix B, is summarized in this section. Deviations to the
PSTP are summarized in Section 4.8 of this report.
3.1 Quantitative and Qualitative Evaluation Criteria
As defined in the ETV protocol, the objectives of the verification are to evaluate equipment in
the following areas:
Report the actual results obtained by the equipment as operated under the conditions at the
test site;
The measurement of residual materials generated during testing;
The impacts on performance of any variations in feed water quality or process variation;
The logistical, human and other resources necessary to operate the equipment; and
The reliability, ruggedness, ranges of usefulness and ease of operation of the equipment.
3.2 Key Water Quality Parameters
Key water quality parameters used for evaluation of the ARS CFU-50 APC are listed in
Table 3-1. The Water Quality and Inorganic Parameter columns are the key parameters for
evaluating the treatment process and water quality. The parameters listed in the Other
Parameters column should not have an immediate impact on the treatment process, but are
important parameters in drinking water supplies.
Table 3-1. Key Filtrate Water Quality Parameters
Water Quality
Temperature
Alkalinity
Hardness
pH
Turbidity
Residual Chlorine
Inorganic Parameters
Arsenic (speciation) «
Iron «
Aluminum «
Total suspended solids
(TSS) «
«
«
«
Other Parameters
Manganese
True Color
Total Organic Carbon
(TOC)
Chloride
Sulfate
Fluoride
Dissolved Oxygen (DO)
3.3 Operations and Maintenance
ARS provided a draft O&M manual with the ARS CFU-50 APC, which is included in Appendix
A. As part of the verification testing, the ETV DWS Center reviewed the O&M documentation
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for the ARS CFU-50 APC. Results of the review are included in this ETV report. In addition,
the following aspects of operability are addressed in the report:
Fluctuation of flow rates and pressures through the unit;
Presence of devices to aid the operator with flow control adjustment;
Availability of pressure measurement;
Measurement of feed water rate of flow;
Adequacy and ease of use of the PLC control system;
Ease of operating the computer control system;
Generation of residual materials; and
Availability of process data to the operator.
3.4 Environmental Technology Verification Testing Plan
The PSTP for the verification test was prepared in accordance with the ETV Protocol. The PSTP
divided the work into three main tasks (A, B, C) with Task C, the verification test itself, divided
into six tasks. The PSTP included a Quality Assurance Project Plan (QAPP), which specified
procedures to be used to ensure the accurate documentation of both water quality and equipment
performance.
An overview of each task is provided below with detailed information on testing procedures
presented in later sections.
3.4.1 Task A: Raw Water Characterization
The objective of Task A was to obtain a chemical and physical characterization of the raw water.
Information on the groundwater supply that provides the raw water was needed to aid in
interpretation of feed water characterization. Grab samples of the raw water were analyzed for
the parameters indicated in Table 3-1.
3.4.2 Task B: Arsenic Loss Test
During Task B, The ARS CFU-50 APC was run without supplying electrical power to the
reaction vessel to evaluate the arsenic loss across the treatment train without powering the
electroflocculation process.
The system was flushed to remove treated water from the tanks and piping, the filters were
backwashed, and the waste material was removed. Following system clean out, the system was
operated continuously for 24 hours. Feed water and filtrate samples were collected at six-hour
intervals and analyzed for the parameters indicated in Table 3-1, in accordance with the PSTP.
3.4.3 Task C: Verification Test Procedures
Task 1: Verification Testing Runs
The ARS CFU-50 APC was operated over a 14-day timeframe to collect data on equipment
performance and water quality for purposes of performance verification. During this timeframe,
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operational problems with the filter press caused the system to shut down, resulting in an actual
operation time of 287 hours, less than identified in the PSTP. The operational problems are
described in greater detail in Chapter 4. Daily measurements and observation of operating
parameters were made, and samples collected of the feed water and filtrate for analysis. Testing
included one 48-hour intensive survey period. Results are presented in Chapter 4.
Task 2: Raw Water, Feed Water, and Filtrate Water Quality
During verification testing, feed water and filtrate water samples were collected and appropriate
sample analyses performed. Samples were analyzed for aluminum to monitor the
electroflocculation process, arsenic to evaluate arsenic removal, and other water quality analyses,
such as pH, turbidity, hardness, alkalinity, etc., to monitor the impact of the treatment process on
water quality.
Task 3: Operating Conditions and Performance
During verification testing, operating conditions and performance of the water treatment
equipment were documented. Equipment performance information collected included data on
filtrate flow rate and total filtrate volume produced, pressure differential across the granular
media filters, electrical energy used and maintenance required during operation.
The PSTP called for collection of other filter operation data, including filter run lengths,
frequency and duration of backwash cycles, and volume of water treated per filter run. This
information was not collected during the testing, as described in Chapter 4.
Task 4: Total Arsenic Removal
Total arsenic in the feed and filtrate samples were measured to evaluate total arsenic removal
during verification testing. Samples were collected daily over the 14-day period. This test phase
included a 48-hour intensive sampling period that occurred at the end of the first week of testing.
During this phase, samples were collected at the start (hour 0) and after hours 1, 3, 6, 12, 18 and
24; the filter was then backwashed and samples were collected at the same time intervals over
the next 24 hours as during the first 24 hours.
All samples were analyzed for total arsenic, aluminum, pH, iron and residual chlorine. Other
water quality parameters were analyzed at less frequent intervals. Speciation of arsenic was
completed on samples collected at hours 0, 24 and 48 of the intensive sampling period.
Task 5: Data Management
The objective of this task was to establish an effective field protocol for data management at the
field operations site, and for data transmission between the FTO and the ETV DWS Center.
Master field logs were prepared and field sheets for data collection were used to ensure all
scheduled activities were performed. The logs were delivered to the ETV DWS Center project
coordinator on a weekly basis.
17
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Task 6: Quality Assurance/Quality Control (QA/QC)
An important aspect of verification testing was the development of specific QA/QC procedures.
The objective of this task was to assure accurate measurement of operational and water quality
parameters during the verification test. Weekly and one-time QA/QC verifications were
specified in the QAPP in Chapter 5 of the PSTP. Equipment flow rates were documented on a
daily basis, and a daily walkthrough was completed to verify that each piece of equipment or
instrumentation was operating properly. An audit of the FTO was also conducted during the
testing.
3.5 Operation and Maintenance
An O&M manual was received from ARS when the ARS CFU-50 APC was installed. NSF
reviewed the O&M manual and evaluated the instructions and procedures for their applicability
during the verification test and for overall completeness.
3.5.1 Operability Evaluation
The basis of the review and evaluation for equipment operability during verification testing was
formed from the factors listed below. These aspects of plant operation are reported, to the extent
practical, in Chapter 4 of this report.
The factors considered included:
Can automatic backwash be initiated by:
- Reaching a set value for head loss?
- Default minimum time?
Is granular media pressure differential measurement provided?
Is rate of flow of feed water measured?
Is backwash rate of flow measured and variable?
Is backwash duration (time) variable?
Other factors and questions included:
Does the equipment have sensors or monitoring equipment that can detect an equipment
malfunction, unsatisfactory filtrate water quality, or operating conditions that exceed
allowable limits?
If so, during such situations can the equipment be automatically shut down?
Upon automatic shutdown, can notification be provided if the operator is not present?
18
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Chapter 4
Results and Discussion
4.1 Introduction
The verification test program for the ARS CFU-50 APC began with equipment installation at the
Bernalillo Well #3 site in Bernalillo, New Mexico, in April 2006 and ended with the completion
of the verification test on May 2, 2006. The test site was described in Section 1.3. The ARS
CFU-50 APC was described in Chapter 2.
The equipment was installed prior to the beginning of the ETV tests. Raw water characterization
samples were collected on February 24 and March 9, 2005, prior to ETV tests. The arsenic loss
test was performed from May 1-2, 2006. The 14-day verification test, including a 48-hour
intensive survey, was performed from April 18 through May 1, 2006.
This chapter presents a summary of the water quality and operating data collected during the
verification test. Activities and data collected during the start-up and shakedown of the
equipment, and the raw water characterization were performed prior to the actual 14-day
verification test. The arsenic loss test was performed immediately after the 14-day verification
test. The results from the 14-day verification test are presented, including data on the feed and
filtrate water arsenic concentration and other water quality parameters. Operating data are
presented to describe the flow rates, volume of treated water produced, backwash information,
pressure differential across the sand filter, electrical power, and related operating information.
QA/QC information, as described by the QAPP in the PSTP for this verification test, is presented
at the end of the chapter.
4.2 Equipment Installation, Start-up, and Shakedown
At the beginning of the ETV project, ARS and FTO personnel performed a thorough evaluation
of the installation. This included ARS training FTO personnel on operations, maintenance of the
device for FTO personnel, and FTO personnel conducting an evaluation on such things as how
and where water samples would be collected, where critical flow and pressure readings would be
read and recorded, a full evaluation of the PLC's operating capabilities, maintenance
requirements (especially how to maintain the filter press), emergency/safety considerations, and
startup/shutdown operations). Based on tests conducted by ARS prior to ETV testing, it was
determined that 30 amps of electrical power would need to be delivered to the reaction vessel in
order to reduce the arsenic concentrations to a level consistently below 10 |ig/L.
4.2.1 Flow Measurement
As part of normal operating conditions, the feed and filtrate water pumps, which pump water into
the reaction vessel and drinking water reservoir tank, respectively, shut off intermittently, as
controlled by the PLC. A high water level sensor in the reaction vessel would shut off the feed
water flow when actuated, and the high and low level sensors in the drinking water reservoir tank
would actuate the filtrate water pump. The instantaneous flow rate readings noted by the FTO
were recorded when the respective pumps were operating. The actual flow rate through the
system is less than either of the readings from these flow monitors. For the purposes of this
19
-------
verification, the average flow through the system was calculated by dividing the total volume of
treated water for each test, which was recorded by the totalizer; and by the total operating time,
which was recorded by the PLC or by FTO personnel.
4.3 Task A: Raw Water Characterization
ARS and the Town of Bernalillo characterized the raw water prior to the start of ETV testing.
This characterization demonstrated that the raw water posed a challenge sufficient to verify the
performance of the ARS CFU-50 APC, while not creating conditions that were disadvantageous
to the device's performance. Since the data were not collected by an ETV-approved testing
organization, it was not included as part of the ETV study.
Samples of the feed water from the combined water tanks were collected on the first day of the
verification testing and are used for the "raw" water characterization. The data for these samples
are presented in Table 4-1.
Table 4-1. Feed Water Characterization Data - April 18, 2006
Parameter
pH
Temperature
Turbidity (bench top)
Alkalinity
Free Chlorine
Total Chlorine
DO
True Color
Total Arsenic
Dissolved Arsenic
Arsenic (III)
Arsenic (V)
Iron
Aluminum
Manganese
Chloride
Sulfate
TOC
Fluoride
Calcium
Magnesium
Hardness(3)
Units
Standard Units (S.U.)
°C
Nephelometric Turbidity
Units (NTU)
mg/L CaCO3
mg/L
mg/L
mg/L
Color Units (C.U.)
Mg/L
Mg/L
Mg/L
Mg/L
mg/L
Mg/L
Mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L as CaCO3
Result
7-8(1)
20.2
0.47
130
0.71
0.84
7.40
Q(2)
14
12
20
<2
<0.02
71
<1
180
110
0.3
0.3
74
11
230
pH samples analyzed with Litmus paper due to instrument malfunction.
(2) Analyzed on Day 2.
(3) Calculated from calcium and magnesium concentrations.
20
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4.4 Task B: Initial Test Runs
4.4.1 Arsenic Loss Test
The arsenic loss test, to determine if arsenic is removed and retained by the system without
electricity supplied to the reaction vessel, was performed over a 24-hour period on May 1-2,
2006, after Task C had been completed. The PSTP specifies that a shakedown and arsenic loss
test be run on the verified device prior to the start of the Task C test. For this installation, ARS
had conducted numerous verification runs prior to the start of verification, and had the system
ready for verification when FTO personnel arrived. Prior to the start of the arsenic loss test, the
cathodes and anodes were removed from the reaction vessel, so it was decided to conduct the
Task C test first. The cathodes and anodes were removed after the Task C test was complete.
Prior to the start of the arsenic loss test, the storage tanks within the system were emptied, the
sand filters were backwashed, and feed water was run through the device for approximately 270
minutes to flush out the flocculent materials. The automated backwash cycle was also disabled,
so that a single sand filter was challenged for the entire test duration.
The operating data and results from the 24-hour arsenic loss test are shown in Table 4-2. Based
on the flow monitor readings, the feed flow rate averaged 36.1 gpm and the filtrate flow rate
averaged 50.2 gpm. However, as noted in Section 4.2.1, these flow readings were taken when
the respective pumps were operating, and they do not always operate as part of normal
operations. The total volume processed over the 24-hour period was 44,755 gallons, which
results in a calculated average flow rate of 31 gpm. The filtrate pressure increased over the
24-hour period from 7.5 psi to 15.5 psi as the sand bed became compacted and charged with
contaminants.
Table 4-2. Task B Arsenic Loss Test Operating Data
Day Hour
1 0
6
2 12
18
24
Feed
Pressure
(psi)
18
17
18
16
16
Filtrate
Pressure
(psi)
7.5
11.2
11.5
15.4
15.5
Pressure
Delta(1)
(psi)
10.5
5.8
6.5
0.6
0.5
Total Volume
Treated
(gal)
0
10,779
24,590
35,236
44,755
Flow Rate(2)
(gpm)
~
29.9
34.2
32.6
31.1
(1) Pressure Delta is the pressure differential or head loss through the filter as measured by the pressure
difference between the feed and filtrate.
(2) Flow rate is calculated by dividing the total volume treated by 60 times the hour.
21
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Table 4-3 presents the water quality for the arsenic loss test. The statistical calculations of these
data are presented in Appendix C. There was no loss of arsenic through the system over the
24-hour test, with both the feed and filtrate water total arsenic averaging 11 |ig/L. Arsenic (III)
was the predominant arsenic species in the feed water. Aluminum concentrations increased
slightly through the system. All other water quality indicators remained steady and passed
through the filter.
22
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Table 4-3. Task B Arsenic Loss Test Water Quality Results
Parameter
pH
Temperature
Turbidity (bench top)
Alkalinity
Free Residual Chlorine
Total Residual Chlorine
True Color
Calcium
Magnesium
Hardness0 -1
Total Arsenic
Dissolved Arsenic
Arsenic (III)
Arsenic (V)
Iron
Aluminum
Manganese
Chloride
Sulfate
Fluoride
TOC
DO
Units
S.U.
°c
NTU
mg/L as CaCO3
mg/L
mg/L
C.U.
mg/L
mg/L
mg/L
Mg/L
Mg/L
Mg/L
Mg/L
mg/L
Mg/L
Mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
Feed Water
0 hours 6 hours 12 hours 18 hours
7.6 7.7 7.7 7.7
23.7 22.7 21.7 23.7
0.28 0.20 0.17 0.31
140 140 140
0.58 0.57 0.51
0.59 0.60 0.58
-
-
-
-
10 13 11
11
9
2
<0.02 <0.02 <0.02
<10 <10 23
.
170
110
.
-
7.09 6.95 6.78 7.31
24 hours
7.8
24.1
0.21
93
0.52
0.55
1.0
93
11
280
9
11
6
5
<0.02
27
<1
170
110
0.3
<0.1
7.27
0 hours 6 hours
7.8 7.8
24.0 23.0
0.17 0.30
160
0.58
0.60
-
-
-
11
10
11
<2
<0.02
33
-
170
110
-
-
6.80 6.85
Filtrate
12 hours 18 hours 24 hours
7.8 7.8 7.8
22.2 23.7 24.5
0.21 0.19 0.14
140 140 140
0.58 0.55 0.53
0.64 0.61 0.58
2.0
90
12
270
11 12 11
11
6
5
<0.02 <0.02 <0.02
27 25 28
<1
170
100
0.3
<0.1
6.66 7.02 6.74
Calculated from calcium and magnesium concentrations.
23
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4.5 Task C: Verification Test
4.5.1 Operating Results
The ARS CFU-50 APC was set to the operating criteria established by ARS prior to ETV testing.
Electrical power settings to the reaction vessel and other operational settings were set and
verified prior to the start of testing. The verification test was started on April 18, 2006.
Table 4-4 shows the daily operating data for the verification test. During the test, there were a
total of four incidents (April 20, 21, 28, and 30) where a sensor triggered the PLC to shut down
operations. During each incident, the sensor indicated that either the floe water reservoir tank
(see Figure 2-1) had exceeded capacity or the filter press alarm went off. Under the FTO's
supervision, ARS personnel analyzed the incidents and determined that in each instance, the
filter press had clogged to a point where it was prohibiting sufficient filtration to maintain the
device's rated throughput. ARS personnel recommended that the filter press be cleaned a
minimum of once every 24 hours to prevent the ARS CFU-50 APC from automatically shutting
down. After each shutdown incident, FTO personnel cleaned the filter press and resumed
operation in accordance with the startup procedures outlined in the ARS O&M manual. As a
result of these incidents, the ARS CFU-50 APC experienced approximately 36 hours of
downtime during the 14-day verification test.
The flow rate noted in Table 4-4 was calculated by dividing the volume of water treated by the
device by the operating time. It is not associated with the instantaneous readings of any
particular pump. During days when the device was functioning properly, the typical volume of
water produced ranged from approximately 45,000 to 47,000 gpd or approximately 31.3 to 32.6
gpm. During these days, the average flow rate was 32.1 gpm. Over the entire test duration
(approximately 287 hours), the filtrate flow rate was approximately 30.7 gpm. The filter influent
pump was programmed to operate at a near-constant flow rate of 35 gpm. The difference in the
flow rate for the device as a whole and this pump can be attributed to recirculated backwash
water.
The system pressure was monitored at the feed and filtrate water locations (upstream and
downstream of the sand filters). The FTO technician recorded the pressure readings in Table 4-4
manually as part of routine sampling and inspections. The ARS CFU-50 APC backwash cycles
were programmed to initiate when the pressure differential reached 15 psi. The FTO pressure
readings were not scheduled to evaluate whether the pressure differential reached 15 psi.
Furthermore, the ARS CFU-50 APC PLC was not programmed to record pressure differentials at
the start of backwash cycles, so the pressure differential evaluation for this verification was
limited to whether the differential exceeded 15 psi during the time the FTO personnel inspected
the device. There was one instance (April 28) when the pressure differential reached 15.9 psi;
otherwise, the pressure differential noted by FTO personnel during sampling and inspection was
below the 15 psi threshold, and averaged 10.9 psi during the inspections.
The amperage to the reaction vessel remained constant at 30 amps throughout the verification
test, while the voltage averaged 4.23 volts and ranged between 3.84 and 5.51 volts.
24
-------
Table 4-4. Operating Data
Date
4/18/06
4/19/06
4/20/06
4/21/06
4/22/06
4/23/06
4/24/06
4/25/06
4/26/06
4/27/06
4/28/06
4/29/06
4/30/06
5/01/06
Number of
samples
Average
Maximum
Minimum
Std.
Deviation
95% Conf.
Interval
Total
Filtrate
Volume
(gal)
0
44,394
91,380
110,415
158,678
204,385
249,651
297,422
343,835
389,460
428,847
463,324
482,300
527,779
NC
NC
NC
NC
NC
NC
Flow
Rate(1)
(gpm)
~
30.8
29.3
29.7
30.8
31.0
31.1
31.4
31.5
31.5
31.3
30.6
29.1
30.6
13
30.7
31.5
29.1
0.81
30.1-31.2
Pressure (psi)
Feed
18
19
18
18
19
17
18
18
17
18
21
18
18
18
14
18
21
17
0.97
18-19
Filtrate
7.4
10.3
9.3
5.0
9.0
10.6
10.5
7.6
4.0
7.4
5.1
4.1
4.3
7.7
14
7.3
10.6
4
2.4
5.7-9.0
Delta
10.6
8.7
8.7
13.0
10.0
6.4
7.5
10.4
13.0
10.6
15.9
13.9
13.7
10.3
14
10.9
15.9
6.4
2.7
9.1-12.7
Operating
Electrical Power(2) Time
Amps
30
30
30
30
30
30
30
30
30
30
30
30
30
30
14
30
30
30
0
30-30
Volts
NR
NR
3.94
3.84
NR
4.14
3.97
3.98
4.02
4.11
4.06
4.57
4.37
5.51
11
4.23
5.51
3.84
0.47
3.85-4.60
(hours)
16
40
52
62
86
110
134
158
182
206
228
252
276
287
NC
NC
NC
NC
NC
NC
(1) The flow rate was calculated by dividing the total filtrate volume by the operating time and multiplying the
quotient by 60 minutes/hour.
(2) Average of three contactors.
NC = Not calculated.
NR = Reading not recorded.
4.5.2 Arsenic Results
The determination of total arsenic removal using the ARS CFU-50 APC was the primary
objective of the verification test. The arsenic results for the feed and filtrate water monitored
daily during the verification test are presented in this section. Also included are the results from
the 48-hour intensive survey, when samples for arsenic analysis were collected on a more
frequent basis. The total arsenic data are presented in Tables 4-5 and 4-6. Arsenic speciation
data are presented in Table 4-7. Figure 4-1 shows the arsenic results plotted for the 14-day
verification test.
25
-------
Table 4-5. Daily Total Arsenic Results (ug/L)
Date
4/18/06
4/19/06
4/20/06
4/21/06
4/22/06
4/23/06
4/24/06
4/25/06
4/26/06
4/27/06
4/28/06
4/29/06
4/30/06
5/01/06
Number of samples
Average
Maximum
Minimum
Std. Deviation
95% Conf. Interval
Feed
14
11
11
13
11
11
11
12
11
11
12
11
12
12
14
12
14
11
0.9
(11-12)
Filtrate
6
5
6
5
4
5
6
6
5
6
6
5
7
6
14
6
7
4
0.8
(5-6)
Based on the daily sample results, the total arsenic in the feed water averaged 12 |ig/L. Over the
14-day period, the maximum total arsenic was 14 |ig/L in the feed water and the minimum was
11 |ig/L. The arsenic speciation data for the feed water showed that most of the arsenic was
present as arsenic (III), with some arsenic (V) also present. The average total arsenic
concentration in the filtrate was 6 |ig/L, with a minimum concentration of 4 |ig/L and a
maximum concentration of 7 |ig/L.
The data collected during the 48-hour intensive survey were consistent with the data collected
each day during the verification test. There was no indication of any transient or short time
changes in the arsenic concentration or other monitored parameters.
26
-------
Table 4-6. Total Arsenic Results for 48-Hour Intensive Survey (ug/L)
Date
4/25/06
4/25/06
4/25/06
4/25/06
4/25/06
4/26/06
4/26/06
4/26/06
4/26/06
4/27/06
4/27/06
Number of samples
Average
Maximum
Minimum
Std. Deviation
95% Conf. Interval
Time (hours)
0
1
3
6
12
18
24
30
36
42
48
Feed
12
12
9
11
11
10
11
10
12
13
11
11
11
13
9
1.1
(10,12)
Filtrate
6
5
6
5
5
5
5
6
6
6
6
11
6
6
5
0.5
(5,6)
27
-------
Table 4-7. Arsenic Speciation Data (jig/L)
Total Arsenic
Date
4/18/06
4/19/06
4/20/06
4/21/06
4/22/06
4/23/06
4/24/06
4/25/06
4/26/06
4/27/06
4/28/06
4/29/06
4/30/06
5/01/06
Day 1
Day 2
Day 3
Day 4
Day 5
Day 6
Day 7
Day 8
Day 9
Day 10
Day 11
Day 12
Day 13
Day 14
Number of samples
Average
Maximum
Minimum
Std. Deviation
95% Conf.
Interval
Feed
14
11
11
13
11
11
11
12
11
11
12
11
12
12
14
12
14
11
0.9
(11-12)
Filtrate
6
5
6
5
4
5
6
6
5
6
6
5
7
6
14
6
7
4
0.8
(5-6)
Dissolved Arsenic
Feed
12
11
10
12
3
10
10
11
11
10
10
10
11
11
14
10
12
3
2.2
(8-12)
Filtrate
18,000(2)
3
4
-
8
3
4
4
3
4
4
4
6
4
12
4
8
3
1
(2-6)
Arsenic (III)(1)
Feed
20
<1
16
7
<1
2
14
7
15
<1
12
6
10
12
14
9
20
<1
6
(4-14)
Filtrate
8
4
5
16
<1
9
7
1
4
7
<1
9
2
4
14
6
16
<1
4
(1-10)
Arsenic (V) (1)
Feed
<1
10
<1
5
2
8
<1
4
<1
9
<1
4
1
<1
14
4
10
<1
3
(
-------
16
_ 14
|> 12
7T 10
"c
a) 8
I 6
0
W \
^.
Date
Figure 4-1. Verification test daily arsenic results.
4.5.3 Feed and Filtrate Water Quality Results
Water quality data were collected each day for pH, temperature, turbidity, and chlorine (total and
free residual). Samples for aluminum and alkalinity analyses were also collected daily. DO was
monitored daily in the feed and filtrate water, as it can affect the oxidation of aluminum and
arsenic (III). Iron was collected on a daily basis. Other water quality parameters, including
calcium, magnesium, manganese, sulfate, chloride, fluoride, TOC, and color, were monitored on
a weekly basis. All of the field data log sheets and NSF laboratory reports are included in
Appendices D and E.
Tables 4-8 and 4-9 present the individual pH measurements for the daily samples and for the
48-hour intensive survey. Figure 4-2 shows the pH for the feed and filtrate water from the daily
samples. During the verification test, the feed water pH was steady in the range of 7.6-7.8, with
a median of 7.7. The filtrate pH was very similar to the feed water pH, as expected. The filtrate
pH ranged from 7.7-7.9, with a median value of 7.7. The pH during the 48-hour intensive survey
was monitored frequently and displayed similar results to the daily pH levels found over the
14-day verification test.
29
-------
Table 4-8. pH Results (S.U.)
Date Feed
4/18/06 7-8(1)
4/19/06 7.7
4/20/06 7.7
4/21/06 7.7
4/22/06 7.7
4/23/06 7.6
4/24/06 7.8
4/25/06 7.7
4/26/06 7.7
4/27/06 7.7
4/28/06 7.7
4/29/06 7.8
4/30/06 7.7
5/01/06 7.8
Number of samples 1 3
Median 7.7
Maximum 7.8
Minimum 7.6
Filtrate
70)
7.7
7.7
7.8
7.7
7.7
7.8
7.7
7.7
7.7
7.7
7.7
7.9
7.7
13
7.7
7.9
7.7
(1) pH samples analyzed with Litmus paper due to
instrument malfunction; this data was not used in
the statistical calculations.
Table 4-9. pH Results for the 48-Hour Intensive Survey
Time ,
Date ,u , Feed
(hours)
4/25/06 0 7.7
4/25/06 1 7.7
4/25/06 3 7.7
4/25/06 6 7.7
4/25/06 12 7.7
4/26/06 18 7.8
4/26/06 24 7.7
4/26/06 30 7.7
4/26/06 36 7.7
4/27/06 42 7.7
4/27/06 48 7.7
Number of samples 1 1
Median 7.7
Maximum 7.8
Minimum 7.7
(S.U.)
Filtrate
7.7
7.7
7.6
7.7
7.7
7.8
7.7
7.6
7.7
7.7
7.7
11
7.7
7.8
7.6
30
-------
7.9 n
7.8
7.7 -
7.6
^
^
Date
Figure 4-2. Verification test pH results.
Tables 4-10 and 4-11 present the individual turbidity measurements for the daily turbidity levels
and for the 48-hour intensive survey. Figure 4-3 shows the turbidity for the feed and filtrate
water from the daily samples. The filtrate turbidity was higher than the feed turbidity throughout
the verification test, averaging 0.80 NTU in the filtrate and 0.30 NTU in the feed water. Results
during the 48-hour intensive survey were very similar to the daily results over the 14-day
verification test, averaging 0.90 NTU in the filtrate and 0.30 in the feed water. The increase in
turbidity is likely attributable to the fine nature of the flocculent formed during the
electroflocculation process.
-------
Table 4-10. Bench Top Turbidity Results
Date
4/18/06
4/19/06
4/20/06
4/21/06
4/22/06
4/23/06
4/24/06
4/25/06
4/26/06
4/27/06
4/28/06
4/29/06
4/30/06
5/01/06
Number of samples
Average
Maximum
Minimum
Std. Deviation
95% Conf. Interval
Turbidity
Feed
0.47
0.19
0.23
0.30
0.31
0.30
0.42
0.26
0.37
0.21
0.20
0.30
0.18
0.26
14
0.30
0.45
0.20
0.09
(0.25-0.35)
(NTU)
Filtrate
0.79
0.93
1.06
0.45
0.90
1.21
1.08
1.00
0.55
0.87
0.63
0.49
0.37
1.06
14
0.80
1.2
0.35
0.27
(0.65-1.0)
32
-------
Table 4-11. Bench Top Turbidity Results for the 48-Hour Intensive Survey
Bench Top Turbidity (NTU)
ooooo-».-».-».
dk>ji.cr>bodk>ji>.
oooooooo
Date Time
4/25/06
4/25/06
4/25/06
4/25/06
4/25/06
4/26/06
4/26/06
4/26/06
4/26/06
4/27/06
4/27/06
Number of samples
Average
Maximum
Minimum
Std. Deviation
95% Conf. Interval
(hours)
0
1
3
6
12
18
24
30
36
42
48
Turbidity (NTU)
Feed Filtrate
0
0
0
0
0
0
0
0
.26 1.00
.55 1.06
.28 1.00
.26 0.44
.32 1.00
.31 0.85
.37 0.55
.19 0.90
0.22 0.91
0
0
.24 1.19
.21 0.87
11 11
0.30 0.90
0
0
0
.55 1.2
.20 0.45
.10 0.20
(0.20-0.35) (0.70-1.1)
S\ !
\ /
^ V
\j* **
^j^"^
\
\
' V-
A
/
M
^
/
/ 1- _1
\/ Feed
v / -"-Filtrate
vy
^^ ^*
-
i i
\
Date
I
I i
Figure 4-3. Verification test turbidity results.
33
-------
Table 4-12 presents the alkalinity during the verification test. The feed water averaged 130 mg/L
as CaCOs and was stable throughout the test. The maximum feed water concentration was
140 mg/L and the minimum was 93 mg/L. The filtrate alkalinity also averaged 130 mg/L, with a
maximum of 150 mg/L and a minimum of 130 mg/L. Figure 4-4 presents the alkalinity results
for the feed and filtrate water during the verification test. The alkalinity concentration during the
48-hour intensive survey was slightly higher in the filtrate (130 mg/L) than in the feed water
(140 mg/L), as shown in Table 4-13.
Table 4-12. Alkalinity Results
Date
Alkalinity (mg/L as CaCO3)
Feed Filtrate
4/18/06
4/19/06
4/20/06
4/21/06
4/22/06
4/23/06
4/24/06
4/25/06
4/26/06
4/27/06
4/28/06
4/29/06
4/30/06
5/01/06
Number of samples
Average
Maximum
Minimum
Std. Deviation
95% Conf. Interval
130
140
140
140
140
140
140
140
140
140
140
93*
130
120
14
130
140
93
13
(121-139)
130
130
130
130
130
130
150
130
130
130
140
140
130
140
14
130
150
130
6.3
(130-130)
NR = Not Recorded.
= Result considered anomalous, but was used in statistical evaluations.
34
-------
160 -i
Date
Figure 4-4. Verification test alkalinity results.
Table 4-13. Alkalinity Results for the 48-Hour Intensive Survey
Date
Time
(hours)
Alkalinity (mg/L as CaCO3)
Feed Filtrate
4/25/06
4/26/06
4/27/06
0
24
48
140
140
140
130
130
130
Table 4-14 and Figure 4-5 present the total aluminum concentrations measured in the feed and
filtrate water during the verification test. Aluminum was detected in four of the 14 feed water
samples, at concentrations ranging from 13 to 84 |ig/L, while the remaining ten feed water
samples had aluminum concentrations below the 10 |ig/L detection limit. NSF QA conducted an
evaluation of the four samples where aluminum was detected to evaluate whether the
concentrations could be the result of laboratory error. The evaluation yielded no explanation
attributable to the laboratory testing procedures that would indicate a false positive result. In the
filtrate, the average aluminum concentration was 560 |ig/L, and ranged from 200 to 890 |ig/L.
This average filtrate aluminum concentration is 20 times greater than the feed water average
concentration and significantly higher than the National Secondary Drinking Water Regulation
range of 50 to 200 |ig/L. The electroflocculation process used by this technology generates
aluminum hydroxide flocculent used in the removal of arsenic. It appears that there is an excess
of aluminum hydroxide generated in the process, which can not all be removed by the filters,
resulting in an aluminum concentration in the filtrate above the EPA secondary regulation for
aluminum (200 |ig/L).
35
-------
Table 4-14. Aluminum Results
Aluminum (ug/L)
Date
4/18/06
4/19/06
4/20/06
4/21/06
4/22/06
4/23/06
4/24/06
4/25/06
4/26/06
4/27/06
4/28/06
4/29/06
4/30/06
5/1/06
Number of samples
Average
Maximum
Minimum
Std. Deviation
95% Conf. Interval
Feed(1)
71
<10
<10
48
<10
<10
79
<10
<10
<10
<10
84
<10
13
14
28
84
<10
29
(8-47)
Filtrate
540
770
700
200
680
870
780
580
310
580
400
340
250
890
14
560
890
200
230
(400-720)
(1) Concentrations reported as <10 set equal to the detection limit
for calculating statistics.
The aluminum concentrations during the 48-hour intensive survey are presented in Table 4-15.
The results during the 48-hour intensive survey were similar to the results from the 14-day
verification test. During the intensive survey, aluminum was detected in two of the eleven feed
water samples at concentrations of 77 and 79 |ig/L. The filtrate water had an average aluminum
concentration of 550 |ig/L, and ranged from 220 |ig/L to 740 |ig/L.
36
-------
0)
₯
3
c
E
_3
<
Feed
Filtrate
Secondary MCL
Date
Figure 4-5. Verification test aluminum results.
Table 4-15. Aluminum Results for the 48-Hour Intensive Survey
Date
4/25/06
4/25/06
4/25/06
4/25/06
4/25/06
4/26/06
4/26/06
4/26/06
4/26/06
4/27/06
4/27/06
Number of samples
Average
Maximum
Minimum
Std. Deviation
95% Conf. Interval
Time (hours)
0
1
3
6
12
18
24
30
36
42
48
Aluminum (j
Feed(1)
<10
<10
<10
<10
79
77
<10
<10
<10
<10
<10
11
22
79
<10
28
(< 10-44)
Ag/L)
Filtrate
580
600
640
220
610
610
310
570
610
740
580
11
550
740
220
150
(430-670)
Concentrations reported as <10 set equal to the detection limit for calculating
statistics.
37
-------
Chlorine is added to the water by the Town of Bernalillo prior to delivery to the storage tanks.
FTO personnel measured residual chlorine (total and free) and DO daily. Table 4-16 shows the
residual chlorine and DO data for the feed and filtrate water. During the verification test, the
total residual chlorine in the feed water ranged from 0.28 to 0.84 mg/L, averaging 0.58 mg/L.
The feed water DO ranged from 5.53 to 8.57 mg/L, and averaged 7.01 mg/L. The filtrate water
averaged 0.50 mg/L total residual chlorine and 6.82 mg/L DO. The free residual chlorine in the
feed water averaged 0.50 mg/L and the filtrate averaged 0.44 mg/L. The data from the 48-hour
intensive survey, presented in Table 4-17, is similar to the verification test results.
Table 4-16. Total and Free Residual Chlorine and DO
Date
4/18/06
4/19/06
4/20/06
4/21/06
4/22/06
4/23/06
4/24/06
4/25/06
4/26/06
4/27/06
4/28/06
4/29/06
4/30/06
5/01/06
Number of
samples
Average
Maximum
Minimum
Std. Deviation
95% Conf.
Interval
Free Chlorine
(mg/L)
Feed Filtrate
0.71
0.50
0.48
0.69
0.51
0.19
.(2)
0.35
0.47
0.56
0.51
0.52
0.54
0.50
13
0.50
0.71
0.19
0.13
(0.41-0.
0.84
0.43
0.41
0.59
0.37
0.42
(2)
0.16
0.39
0.40
0.44
0.42
0.45
0.41
13
0.44
0.84
0.16
0.15
60) (0.33-0.55)
Total Chlorine
(mg/L)
Feed Filtrate
0.84
0.60
0.54
0.74
0.57
0.28
.(2)
0.45
0.55
0.63
0.57
0.55
0.61
0.57
13
0.58
0.84
0.28
0.13
(0.48-0.67)
0.92
0.52
0.45
0.65
0.48
0.47
.(2)
0.23
0.45
0.47
0.51
0.45
0.50
0.46
13
0.50
0.92
0.23
0.15
(0.40-0.61)
DO
(mg/L)
Feed Filtrate
7.4
6.48
5.65
7.77
7.24
5.53
6.66
6.95
7.75
6.50
6.25
8.57
8.10
7.27
14
7.01
8.57
5.53
0.89
(6.41-7.
J1)
6.51
5.97
7.51
6.95
5.91
7.52
6.74
7.29
6.63
6.42
7.04
6.86
7.27
13
6.82
7.52
5.91
0.52
61) (6.44-7.19)
collected.
(2)No data collected due to equipment malfunction.
38
-------
Table 4-17. Total and Free Residual Chlorine and DO Results for 48-Hour Survey
Free Chlorine
Time
Date (hours)
4/25/06
4/25/06
4/25/06
4/25/06
4/25/06
4/26/06
4/26/06
4/26/06
4/26/06
4/27/06
4/27/06
Number of samples
Average
Maximum
Minimum
Std. Deviation
95% Conf. Interval
0
1
3
6
12
18
24
30
36
42
48
(mg/L)
Feed Filtrate
0.35
0.54
0.5
0.55
0.54
0.57
0.47
0.53
0.53
0.56
0.56
11
0.52
0.57
0.35
0.06
(0.47-0.
0.16
0.41
0.41
0.46
0.45
0.44
0.39
0.39
0.38
0.45
0.4
11
0.39
0.46
0.16
0.08
57) (0.33-0.46)
Total Residual Chlorine
(mg/L)
Feed Filtrate
0.45
0.60
0.57
0.60
0.59
0.53
0.55
0.57
0.55
0.52
0.63
11
0.56
0.63
0.45
0.05
(0.52-0.
0.23
0.47
0.46
0.50
0.48
0.52
0.45
0.47
0.52
0.56
0.47
11
0.47
0.56
0.23
0.08
60) (0.40-0.53)
DO
(mg/L)
Feed Filtrate
6.95
-
-
-
-
-
7.75
-
-
-
6.50
3
7.07
7.75
6.50
NC
NC
6.74
-
-
-
-
-
7.29
-
-
-
6.63
3
6.89
7.29
6.63
NC
NC
NC = Not calculated.
The results for the other water quality parameters are shown in Table 4-18. Statistical results are
presented in Appendix C. The feed water concentrations were stable throughout the test. The
feed and filtrate water showed similar average concentrations of chloride, sulfate, TOC, fluoride,
calcium, magnesium, hardness, manganese, iron, and true color. The ARS CFU-50 APC had
little or no impact on these water quality parameters.
Temperature was monitored daily in the feed and filtrate water. The feed water averaged a
temperature of 22.4°C and the filtrate averaged 22.7°C.
39
-------
Table 4-18. Other Water Quality Parameters
Parameter
Chloride
Sulfate
TOC
Fluoride
Calcium
Magnesium
Hardness
Manganese
Iron(1)
True Color
Units
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
Mg/L
mg/L
C.U.
4/18/06
Feed Filtrate
180
110
0.3
0.3
74
11
230
<1
<0.02
-
180
110
0.3
0.3
74
11
230
<1
<0.02
-
4/19/06
Feed Filtrate
-
-
-
-
93 90
-
-
-
<0.02 <0.02
0 0
4/26/06
Feed Filtrate
180
110
0.2
0.3
93
12
282
<1
<0.02
5
170
100
<0.1
0.3
89
11
268
<1
<0.02
6
4/27/06
Feed Filtrate
170
110
<0.1
0.3
93
11
278
<1
<0.02
0
170
110
<0.1
0.3
84
12
259
<1
<0.02
1
(; Iron was collected on a daily basis; all but one result were non-detect.
4.6 Operations and Maintenance Findings
FTO personnel operated the ARS CFU-50 APC during the 14-day verification period. FTO
personnel found it was easy to operate and required little time for daily maintenance. The FTO
was on site for two to three hours per day, with most of the time being spent performing ETV-
related activities, including flow checks, calibrations, and similar activities. Typical monitoring
or maintenance on the unit would be rather minimal, and would primarily be related to cleaning
the filter press or performing routine inspections.
ARS provides an O&M manual for each system. The draft O&M manual for the ARS CFU-50
APC, included in Appendix A, provides a good description of the system, appropriate safety
precautions, detailed descriptions of operating procedures, the capability and operation of the
computer control system, and specific instructions for utility operators.
The O&M manual provides detailed information on the various modes that can be used for
operating the equipment. The modes are preprogrammed operating conditions that include filter
backwash triggers and the manner in which the PLC responds to various signals and alarms. The
PLC discussion is thorough, and the programming provides good operating flexibility for the
operator.
The O&M manual also describes the tanks, piping, and filter units, with information on the
connections for each vessel. Instructions for items to check prior to start-up are included in the
descriptions.
The system is automated, and all equipment appeared sturdy and properly selected for the
process. Overall, the ARS CFU-50 APC appears well suited to small or medium-sized
installations where an operator is not present at all times, provided the filter press is sufficiently
sized and maintained.
40
-------
The ARS CFU-50 APC includes a flow totalizer and flow rate meter for the filtrate water. The
system has pressure gauges on the feed and filtrate lines that provide pressure data for
monitoring pressure differential (head loss) across the filters. This information is monitored by
the PLC and is available to the operator for review.
Findings on specific components within the ARS CFU-50 APC are noted in the following
sections.
4.6.1 Electrical Consumption
The electrical use by the ARS CFU-50 APC is primarily for the reaction vessel, floe water pump
(downstream of the reaction vessel), the clean water pump, waste pump, with negligible power
being consumed by a backwash pump, PLC, air compressor, and other instrumentation. The test
system used a 480 volts alternating current (VAC), 3 Phase, 60-ampere and a 120 VAC, 1-phase,
20-ampere electrical supply. The test system had two 3 horsepower (hp) centrifugal pumps, one
to pump water from the reaction vessel which ran constantly, and one to pump clean water from
the device which ran about 66% of the time the device is operational. The reaction vessel
consumed power at an average of 4.2 volts and 30 amperes. The waste pump is a 0.5 hp, 110
VAC pump, which ran about 25% of the time the device, is operational. The backwash pump is
a 5 hp pump, which ran less than 5% of the time the device is operational. The PLC and air
compressor power consumption was considered negligible. Unadjusted horsepower (not
adjusted for efficiency factor) is equal to 746 watts per hp. The itemized power consumption
usage, approximately 4.2 Kilowatt-hour (KwH), is outlined in Table 4-20.
Table 4-19. Power Consumption
, Power Consumption
Component , TT, r
_ (KwH)
Reaction vessel 0.13
Filter influent pump 2.3
Clean water pump 1.5
B ackwash pump 0.19
Waste pump 0.09
PLC, air compressor Negligible
Total power consumption 4.2
4.6.2 Sand Filters
The ARS CFU-50 APC is equipped with two sand filters, so one filter can operate while the
other is in backwash mode or standby. Backwash water is stored in the backwash water
reservoir, then filtered through a filter press, with the treated water returned to the reaction vessel
for re-treatment. During the testing at this installation, there were no conditions where the
pressure differential across both sand filters required that both filters backwash at the same time.
One filter was always available for filtering the flocculent from the treated water.
Issues regarding the efficacy of the filtration process were noted during the verification test, as
shown in the turbidity data, with the filtrate water being consistently higher than the feed water.
41
-------
As noted in Table 4-10 and Figure 4-3, on average, the filtrate turbidity was 0.8 NTU while the
feed turbidity was 0.3 NTU. Also, as summarized in Table 4-14 and shown in Figure 4-5, the
aluminum concentrations in the filtrate water were consistently higher than the concentrations in
the feed water, with the aluminum concentrations in the filtrate water exceeding the EPA
National Secondary Drinking Water Regulations. The turbidity and aluminum data indicate that
filtration mechanisms beyond those currently utilized in the ARS CFU-50 APC would be
required to bring these concentrations closer to the feed water concentrations or within the EPA
secondary regulations.
4.6.3 Filter Press
Backwash waste is treated by a filter press designed to remove the solids (flocculent) from the
backwash water. The filtrate from the filter press was transferred back to the reaction vessel for
re-treatment. During the testing, when the flocculent caked in the filter press to a point where
water would no longer pass through it, the PLC shut down the entire system, as it is programmed
to do. The procedures outlined in the O&M manual provide clear instructions on cleaning the
filter press and resuming operation after cleaning. Page 65 of the O&M manual notes, "The use
and operation of the filter press should not interfere with the normal and continuous use of the
treatment unit.. .However, the treatment unit will only run for a limited time with the filter press
disabled. The filter press is a vital aspect of the treatment unit and must be supported
appropriately." Verification testing substantiated the importance of the filter press and its
appropriate maintenance as a critical aspect of the function of the ARS CFU-50 APC device.
4.6.4 Backwash Water Frequency and Quality
The ARS CFU-50 APC operates with an automated backwash sequence where backwash water
is passed through a filter press. The backwash sequence uses water from the clean water storage
tank. The backwash water is stored in the flocculent water reservoir tank prior to treatment in
the filter press, where solids are removed and the filtered water is returned to the reaction vessel.
The backwash cycle was set for a fixed time duration of 120 seconds for backwash and 30
seconds for rinsing. The combined backwash and rinsing resulted in approximately 250 gallons
of waste per backwash sequence. Solids retained in the filter press are removed manually during
filter press maintenance. Since the ARS CFU-50 APC does not have a separate backwash waste
stream, the evaluation of the backwash water frequency and quality during the verification was
limited to TSS analysis. The sample was collected from the flocculent water reservoir tank,
which was equipped with a mixer and a sample port near the bottom of the tank. This sample
yielded a concentration of 1,200 mg/L.
After the two weeks of operation, approximately 150 gallons of filter press sludge consisting of
hydrated floe was removed from the filter press. The density of the floe is approximate 9.5
pounds per gallon, so approximately 1,425 pounds of hydrated floe was created. During this
timeframe, approximately 572,550 gallons of water was treated. By dividing the weight of the
hydrated flocculent by the volume of water treated, an approximate suspended solids (flocculent)
concentration of 300 mg/L was generated by the reaction vessel.
42
-------
Local disposal requirements determine whether filter press sludge is characteristically hazardous,
due to elevated arsenic (or other constituent) concentrations. A sample of the solids accumulated
over the 14-day test, which were placed in a 55-gallon drum and stored near the device, was
collected and analyzed by the Toxicity Characteristic Leaching Procedure (TCLP) and the
California Waste Extraction Test (CAWET). This sample represented a composite of all solids
generated during the verification test. The filter cake sludge was not considered a hazardous
waste based on the arsenic concentrations, which were below the 5 mg/L limit under the
Resource Conservation and Recovery Act (RCRA). Table 4-19 presents the results of the TCLP
and CAWET analyses. The laboratory test report received from TriMatrix Laboratories is
included in Appendix F.
Table 4-20. Backwash Solids - TCLP and CAWET Analyses
Parameter
Arsenic
Barium
Cadmium
Chromium
Copper
Lead
Mercury
Nickel
Selenium
Silver
Zinc
Units
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
TCLP
0.18
1.5
<0.010
0.74
0.23
<0.050
O.0002
<0.010
<0.10
<0.010
0.94
CAWET
3.7
<3.5
<0.01
2.5
3.1
<0.50
<0.0002
<0.10
<1.0
<0.10
<2.5
4.6.5 Programmable Logic Controller
The system PLC is designed to operate and monitor many of the operating functions of the
device. The PLC was not programmed to record data, so readouts on component performance,
such as flow, pressure, electrical settings, and other operational conditions had to be monitored
and recorded manually. The PLC readings were easy to use, but required an understanding of
the PLC operating keys to display the readings.
The PSTP specified an evaluation of the length of filter runs, backwash cycle frequency, and the
pressure differentials across the sand filters as part of the study. The PLC was not programmed
to record data on pressure differentials or the time at which backwash cycles were initiated.
Generally, this data would serve as the basis for such an evaluation. Without the PLC recording
this data, it would have had to be collected by the FTO technician manually monitoring the sand
filters, and recording the backwash start time and operating pressure. NSF concluded that, since
the ARS CFU-50 APC is designed to remove the flocculent material from the backwash and
return the treated water back to the reaction vessel for treatment with little or no operator
involvement, collection of the data would be imprecise and difficult to evaluate, since
backwashing could have occurred during periods when FTO personnel were not on site.
43
-------
The PLC is designed to shut the entire system down in the event any sensor records a condition
that is outside preset operating limits. This condition was experienced four times during the
verification, resulting from the filter press being clogged to a point where no water passed
through it. This resulted in high water levels in the Flocculent Water Reservoir, during which
the PLC shut the system down as it was programmed to do. During each shutdown condition,
after the filter press was cleaned, the alarm conditions in the PLC were cleared and the system
was restarted with no difficulty.
4.7 Quality Assurance/Quality Control
As described in the PSTP, included in Appendix B, a structured QA/QC program was
implemented as part of this verification to ensure the quality of the data being collected. A
QAPP was developed as part of the PSTP and was followed by the field staff and laboratory
during the testing period. Adherence to the established procedures ensured that the data
presented in this report are sound, defensible, and representative of the equipment performance.
4.7.1 Documentation
The FTO recorded on-site data and calculations in a field logbook and prepared field log sheets.
Daily measurements were recorded on specially prepared data log sheets. The operating logbook
included calibration records for the field equipment used for on-site analyses. Copies of the
logbook, the daily data log sheets, and calibration log sheets are included Appendix D.
Data from the on-site laboratory and data log sheets were entered into Excel spreadsheets, which
were used to calculate various statistics (average, mean, standard deviation, etc.). The data in the
spreadsheets were proofread by the initial data entry person and confirmed by NSF DWS Center
staff by a 100% check of the data entries to confirm the information was correct. The
spreadsheets are presented in Appendix C.
Samples collected and delivered to the NSF Chemistry Laboratory for analysis were tracked.
Each sample was assigned a location name, date, and time of collection, and the parameters were
written on the label. The laboratory reported the analytical results using the NSF Chemistry
Laboratory management system reports. These reports were received and reviewed by the NSF
DWS Center coordinator. These laboratory data were entered by DWS Center personnel into the
data spreadsheets, corrected, and verified in the same manner as the field data. NSF laboratory
reports are included in Appendix E.
4.7.2 Quality Audits
The NSF QA department performed an on-site audit on April 23 to review the field procedures,
including the collection of operating data and performance of on-site analytical methods. The
PSTP requirements and QAPP were used as the basis for the audit. The NSF QA auditor
prepared an audit report, noting the following deficiencies:
1. The operations log does not indicate visitors to the site.
2. Photographs were not logged in the field logbook.
44
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3. The standard concentrations used for the turbidimeter are not as listed on the checklist.
4. Pressure gauge accuracy was checked by another calibrated pressure gauge but not
checked with a dead weight pressure tester as indicated in the checklist.
5. The checklist indicated the thermometer would be calibrated monthly. However, the
thermometer tag indicated it would be calibrated every six months.
6. The checklist indicates that the DO meter would be air calibrated. However, a liquid
calibration method is used.
7. There are no Material Safety Data Sheets (MSDS) sheets at the site or the laboratory.
8. There is no eyewash station at the laboratory.
FTO personnel addressed deficiencies 1 and 2 immediately. Deficiencies 3 through 6 pertained
to correlating the calibration methods used by FTO personnel with the documentation noted in
the PSTP and checklist. MSDS information for the laboratory was attainable through NSF's on-
line database, which was accessible to the FTO personnel via computer. A portable eyewash
station was in the process of being procured for the laboratory, but the project concluded prior to
delivery.
The NSF QA Department reviewed the Chemistry Laboratory analytical results for adherence to
the QA requirements for calibration, precision, and accuracy detailed in the project QAPP, and
for compliance with the laboratory quality assurance requirements. The laboratory raw data
records (run logs, bench sheets, calibrations records, etc.) are maintained at NSF and are
available for review.
4.7.3 Data Quality Indicators
The data quality indictors established for the ETV project and described in the QAPP included:
Representativeness;
Accuracy;
Precision; and
Completeness.
4.7.3.1 Representativeness
Representativeness refers to the degree to which the data accurately and precisely represent the
conditions or characteristics of the parameter represented by the data. In this verification testing,
representativeness was ensured by FTO personnel executing consistent sample collection
procedures in accordance with established approved procedures, and following specific sample
preservation, packaging, and delivery procedures. Approved analytical methods were used to
provide results that represent the accurate and precise measurements of drinking water. For
equipment operating data, representativeness entailed collecting and documenting a sufficient
quantity of data during operation to be able to detect a change in operations. For most water
treatment processes involving total arsenic removal, detecting a ±10% change in an operating
parameter is sufficient. The primary operating parameter for this verification test was filtrate
volume treated per day and water quality (e.g. total arsenic concentrations, fouling parameter
concentrations, etc.). For this verification, the total arsenic concentrations were somewhat lower
45
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than the concentrations measured during prior sampling events (see Table 1-1), but the
concentrations were consistent, and other parameters were within ranges that would not impact
the performance of the ARS CFU-50 APC device. Thus, these data were judged to be
representative and were included in the data set for the verification test.
4.7.3.2 Accuracy
On-Site Equipment Accuracy and Calibration
On-site equipment, including ARS CFU-50 APC flow meters and DWTS on-site analytical
equipment, were tested for accuracy through regular calibration checks. Meters and gauges were
checked at the frequencies presented in Table 4-20. The calibration records for pH, turbidity,
total and free residual chlorine, and DO were recorded in the field calibration log (Appendix D).
Calibrations were performed at the frequency required, and were within the specified QC
objectives on all days analyses were performed.
The ARS CFU-50 APC had a filtrate water flow rate and totalizer meter. The "bucket and
stopwatch" technique was used to determine the accuracy of the flow meters. Table 4-21 shows
the calibration data. All calibrations were within the defined objective of ±10%.
Table 4-21. Field Instrument Calibration Schedule
Instrument
Pressure Gauges
Flow Meter
Totalizer Meter
Bench Top Turbidimeter
Calibration Method
dead weight calibration tester,
evaluation against another calibrated
gauge, or manufacturers certification
volumetric "bucket & stop watch"
volumetric "bucket & stop watch"
secondary turbidity standards
primary turbidity standards
Frequency
once during
testing
weekly
weekly
daily
weekly
Acceptable
Accuracy
± 10%
± 10%
± 1.5%
PE sample
Portable pH/ISE Meter
with Combination pH/
Temperature Electrode
Portable Colorimeter
Thermometer (National Institute
of Standards and Technology
(NIST)-traceable)
DO
three-point calibration using
4.0, 7.0 and 10.0 buffers
chlorine check standard
calibration against NIST traceable
air calibration method or zero
method, as recommended by the
meter manufacturer
daily
daily
twice
annually
daily
±5%
± 25%
±5%
± 10%
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Table 4-22. Flow Meter Calibration Data
Date
4/21/06
4/27/06
4/30/06
Feed
Calibration Flowmeter
Result Reading
(gpm) (gpm)
37.3
36.4
36.6
36.3
35.1
34.9
Filter Influent
Calibration Flowmeter
Result Reading
(gpm) (gpm)
32.8
31.3
34.1
34.3
32.6
35.8
Laboratory Analyses
Accuracy for the laboratory analyses is quantified as the percent recovery of a parameter in a
sample to which a known quantity of that parameter was added. Equation 4-1 is used to
calculate accuracy:
Accuracy = Percent Recovery = 100 x [(Xkn0wn - Xmeasured) + X^own] (4-1)
where Xkn0wn = known concentration of measured parameter
= measured concentration of parameter
Accuracy also incorporates calibration procedures and use of certified standards to ensure the
calibration curves and references for analysis are near the "true value." Accuracy of analytical
readings is measured through the use of spiked samples and laboratory control samples (LCS).
The percent recovery is calculated as a measure of the accuracy.
The QAPP and the NSF Chemistry Laboratory QA/QC requirements established the frequency
of spike sample analyses at 10% of the samples analyzed. LCS are also run at a frequency of
10%. The recovery limits specified for the parameters in this verification were 70-130% for
laboratory -fortified samples and 85-115% for LCS. The NSF QA department reviewed the
laboratory records and found all analyses for all sample groups were within the QC requirements
for recovery. Calibration requirements were also achieved for all analyses.
The arsenic speciation resin columns were tested to ensure proper separation and recovery of the
arsenic species. Each lot of the arsenic speciation resin was checked once against samples with
known concentrations of As (III) and As (V). This QC check assured that the resin was properly
prepared. The NSF Chemistry Laboratory maintained the documentation for the column checks.
4. 7.3.3 Precision
Precision refers to the degree of mutual agreement among individual measurements and provides
an estimate of random error. Analytical precision is a measure of how far an individual
measurement may be from the mean of replicate measurements. The relative standard deviation
recorded from sample analyses was used to quantify sample precision. The percent relative
standard deviation was calculated using the equation presented as Equation 4-2:
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Percent Relative Standard Deviation = S(100) / Xaverage (4-2)
where: S = standard deviation
Xaverage = the arithmetic mean of the recovery values
Standard Deviation is calculated in Equation 4-3:
Standard Deviation = I ±> (Xi-X)2 (4-3)
where: X; = individual measured values
X = arithmetic mean of the measured values
n = number of determinations
Acceptable analytical precision for the verification test was set at a percent relative standard
deviation (%RSD) for drinking water samples of 30%. Field duplicates were collected to
incorporate both sampling and analytical variation to measure overall precision against this
objective. The laboratory precision for the methods selected was tighter than the 30% overall
requirement, generally set at 20% based on the standard NSF Chemistry Laboratory method
performance.
Field Duplicates
Field duplicates were collected for all analyses (field lab and analytical laboratory) to monitor
overall precision. The field duplicates included samples for both sample locations: feed and
filtrate water.
Tables 4-21 and 4-22 summarize the results for the field duplicate samples. The precision for
analyses performed in the laboratory, as measured by these field duplicates, met the overall QC
objective of 30% RSD for most samples. All precision values for the arsenic duplicate data,
except for one arsenic III set with a %RSD of 85%, met the QC objective of 30% RSD. Three
aluminum and both TOC duplicates were above the maximum precision of 30%. It is unknown
why the three aluminum samples had high precision (54-110%); however, the verification test
data also had high variation of aluminum in the feed water, ranging from <10 |ig/L to 84 |ig/L.
The high precision values for the TOC samples can be attributed to the low concentrations of
TOC.
The field analyses data for field duplicates were acceptable for all parameters. The true color
data had two precision values of 141%, however, this was due to one sample reading at 0 C.U.
and the other sample at 1 C.U.
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Table 4-23. Precision Data - Field Duplicates for Laboratory Parameters
Total Arsenic
Date
4/18/06
4/24/06
5/01/06
Rep 1
14
11
12
Feed Water
Rep 2
15
13
12
%RSD
4.9
12
0
Rep 1
6
6
6
Filtrate
Rep 2
5
6
7
%RSD
13
0
11
Dissolved Arsenic
Date
4/18/06
5/01/06
Rep 1
12
11
Feed Water
Rep 2
12
11
%RSD
0
0
Rep 1
18000(1)
4
Filtrate
Rep 2
4
5
%RSD
16
Arsenic III
Date
4/18/06
5/01/06
Rep 1
20
12
Feed Water
Rep 2
5
10
%RSD
85
13
Rep 1
8
4
Filtrate
Rep 2
7
5
%RSD
9
16
Alkalinity (mg/L as CaCO3)
Date
4/18/06
5/01/06
Rep 1
130
120
Feed Water
Rep 2
140
150
%RSD
5
16
Rep 1
Filtrate
Rep 2
%RSD
- -
Aluminum
Date
4/18/06
4/24/06
5/01/06
Rep 1
71
79
13
Feed Water
Rep 2
75
<10
<10
%RSD
3.9
110
18
Rep 1
540
780
890
Filtrate
Rep 2
240
650
240
%RSD
54
13
81
Other Parameters
Parameter
Chloride (mg/L)
Sulfate (mg/L)
Calcium (mg/L)
Magnesium
(mg/L)
Manganese
Fluoride (mg/L)
Iron (mg/L)(2)
TOC (mg/L)
Rep 1
180
110
74
11
<1
0.3
<0.02
0.3
Feed Water
Rep 2
180
120
76
10
<1
0.3
<0.02
0.1
%RSD
0
6
1.9
6.7
0
0
0
71
Rep 1
180
110
74
11
<1
0.3
<0.02
0.3
Filtrate
Rep 2
180
110
76
10
<1
0.3
<0.02
<0.1
%RSD
0
0
1.9
6.7
0
0
0
71
Note: For the statistical calculations, all non-detect data were used as the minimum reporting limit.
(1) This dissolved arsenic concentration was considered an outlier and was not used for statistical purposes.
(2) Additional iron duplicate samples were collected; all duplicate set results were non-detect.
49
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Table 4-24. Precision Data - Field Duplicates for Field Parameters
pH (S.U.)
Date
4/18/06(1)
4/25/06
4/26/06
4/30/06
Rep 1
7-8
7.7
7.7
7.7
Feed Water
Rep 2
7-8
7.8
7.8
7.7
%RSD
0
0.91
0.91
0
Rep 1
7.0
7.7
7.7
7.9
Filtrate
Rep 2
7.0
7.6
7.8
7.9
%RSD
0
0.92
0.91
0
Temperature (°C)
Date
4/18/06
4/25/06
4/30/06
Rep 1
20.2
22.8
23.2
Feed Water
Rep 2
20.2
22.8
23.2
%RSD
0
0
0
Rep 1
20.8
23.5
23.2
Filtrate
Rep 2
20.8
23.5
23.2
%RSD
0
0
0
True Color (C.U.)
Date
4/19/06
Rep 1
0.0
Feed Water
Rep 2
1
%RSD
141
Rep 1
0.0
Filtrate
Rep 2
1
%RSD
141
Turbidity (Bench Top) (NTU)
Date
4/18/06
4/30/06
Rep 1
0.47
0.18
Feed Water
Rep 2
0.51
0.15
%RSD
5.8
13
Rep 1
0.79
0.37
Filtrate
Rep 2
0.83
0.35
%RSD
3.5
3.9
Free Residual Chlorine (mg/L)
Date
4/18/06
4/25/06
4/30/06
Rep 1
0.71
0.35
0.54
Feed Water
Rep 2
0.71
0.35
0.42
%RSD
0
0
18
Rep 1
0.84
0.16
0.45
Filtrate
Rep 2
0.84
0.16
0.50
%RSD
0
0
7
Total Residual Chlorine (mg/L)
Date
4/18/06
4/25/06
4/30/06
Rep 1
0.84
0.45
0.61
Feed Water
Rep 2
0.84
0.45
0.61
%RSD
0
0
0
Rep 1
0.92
0.23
0.50
Filtrate
Rep 2
0.92
0.23
0.52
%RSD
0
0
3
DO (mg/L)
Date
4/18/06
4/30/06
Rep 1
7.40
8.1
Feed Water
Rep 2
7.42
7.74
%RSD
0.19
3.21
Rep 1
6.50
6.86
Filtrate
Rep 2
6.55
6.46
%RSD
0.54
4.25
pH samples analyzed with Litmus paper due to instrument malfunction.
50
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Laboratory Analytical Duplicates
The NSF Chemistry Laboratory precision was monitored during the verifications test in
accordance with QAPP and the NSF quality assurance program. Laboratory duplicates were
analyzed at 10% frequency of samples analyzed. The NSF QA department reviewed the
precision information and determined that the laboratory data met QC precision requirements.
4.7.3.4 Method Blanks
The laboratory included method blanks as part of the standard analysis procedures. Method
blanks were analyzed in accordance with the approved methods. The NSF QA department
reviewed the laboratory data and found the method blanks to be acceptable. No data were
flagged as having been affected by method blank results.
4.7.3.5 Completeness
Completeness is defined as the following (Equation 4-4) for all measurements:
%C = (V/T)X100 (4-4)
where: %C = percent completeness
V = number of measurements judged valid
T = total number of measurements
Completeness refers to the amount of valid, acceptable data collected from a measurement
process compared to the expected amount to be obtained.
The completeness objective for data generated during this verification test was based on the
number of samples collected and analyzed for each parameter and/or method. A completeness
objective of 90% applied to: arsenic, aluminum, alkalinity, iron, temperature, pH, daily bench
top turbidity, residual chlorine, and DO. Samples for these parameters were collected and
analyzed at the frequency specified in the PSTP and QAPP for the verification test. All of the
weekly parameters met or exceeded the completeness objective of 80%. A completeness
objective of 90% applied to the following operating parameters: feed and filtrate flow rate and
pressure differential across the filter. The completeness objective was met for these parameters.
Table 4-24 provides a summary of the completeness results for the verification test.
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Table 4-25. Completeness Results
n ± Percent ,
Parameter . Comment
Completeness
. . 1 All scheduled samples and analyses completed for total
and speciation requirements.
Aluminum 100 All scheduled samples and analyses completed.
Iron 100 All scheduled samples and analyses completed.
pH 100 All required daily measurements recorded.
Bench top Turbidity 100 All required daily measurements recorded.
,_.,,,,. __ One daily analysis missed due to equipment
Total Residual Chlorine 93 ,,, /
malfunction.
T-, T> -j i m. n-3 One daily analysis missed due to equipment
Free Residual Chlorine 93 ,,, /
malfunction.
T-, , j TTU * el n * m mn All required daily measurements recorded, except for
Feed and Filtrate Flow Rate 93-100 r-u ^ n . A -i o« n^
one nitrate flow rate on April 25, 2006.
Feed and Filtrate Pressure 100 All required daily measurements recorded.
4.7.4 Effect of Sample Preservative on Arsenic Speciation
The arsenic speciation data in the feed water reports variable concentrations of arsenic III
ranging from non-detectable to 20 |ig/L. This data appeared anomalous, given the consistent total
arsenic concentrations in the feed water ranging from 11 to 14 |ig/L. The arsenic speciation was
conducted in the field using an acceptable method by the EPA and was audited by NSF QA. The
field speciation method requires filtration of the sample and preservation with nitric or sulfuric
acid.
The feed water was chlorinated (0.7 mg/L free chlorine) and had a high pH (7.5 - 7.8 S. U.).
The feed water had no detectable concentrations of iron. Aluminum was detected at a
concentration of 27 mg/L. The likely source of the aluminum was the ARS reaction vessel or
filter press. Chlorination probably facilitated the rapid oxidation of arsenic (III) to (V) such that
even short time delays in field speciation could result in variable speciation data exhibited in the
report. In the speciation method, the sample is filtered and preserved with sulfuric acid to fix
arsenic (III). With rapid oxidation induced by chlorination, the time to filter the sample could
affect speciation results.
In order to verify the arsenic speciation results, NSF conducted a brief study to ascertain
whether the time of preservation affected arsenic speciation concentrations. Samples were
collected in the field in which one sample was unpreserved and the other sample was preserved
with sulfuric acid to fix arsenic (III). Samples were then sent to NSF's laboratory.
Upon arrival at the laboratory, speciation was performed on the samples. The samples were
filtered and passed though the resin column. The results indicated that the sample preserved
52
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immediately in the field with sulfuric acid had arsenic (III) at a concentration of 15 ng/L, while
the unpreserved water had a non-detectable arsenic (III) concentration.
This evaluation suggests that the arsenic (III) data are related to the rate of oxidation due to the
chlorination, and the inherent variation of chlorine dosing time versus sample collection and
speciation. Even a small amount of delay in field speciation steps may have influenced the
arsenic speciation result.
4.7.5 Deviations from PSTP
During testing, the FTO implemented some testing procedures or methodologies that were
different from those specified in the PSTP. These deviations are addressed in various sections
throughout the verification report, and are summarized in Table 4-26, and do not appear to have
any impact on the findings or conclusions in this verification.
Table 4-26. Deviations from PSTP
PSTP
Section
No.
Description
Reason for Deviation
3.5
4.4.3
4.5
4.5.5.4
Evaluation of length of filter
runs between backwash cycles
and change in pressure across
filter media over time
The arsenic loss test was to be
conducted prior to starting the
verification test (Test C).
Test C will be run for a
continuous 320-hour period.
Evaluation of suspended solids
in backwash limited to one
sample.
The system PLC was not designed to record data on when the
backwash cycles are initiated. Manual recording of pressure
would have provided imprecise information of filter run time
and pressure increases overtime.
ARS personnel operated the system prior to the ETV
verification, and indicated that the system was ready for
operation once the FTO personnel mobilized to the test site.
NSF, ARS, and the FTO agreed that the operating conditions
configured by ARS were sufficient to begin the verification
test (Test C) without first conducting the arsenic loss test.
The filter press caused conditions where the system would
shut down resulting in only 287 hours during the 14-day
period of evaluation.
The ARS CFU-50 APC does not have a separate discharge
mechanism for backwash. Solids were evaluated by
weighing the solids extracted from the filter press.
53
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Chapter 5
References
EPA/NSF ETV Protocol for Equipment Verification Testing for Arsenic Removal, U.S. EPA/NSF
International. September 2003.
Product Specific Test Plan for the Advanced Remediation Systems USA, LLC ARS CFU-50 APC
Electroflocculation and Filtration Water Treatment System for Arsenic Removal from Drinking
Water. NSF International. March 2006.
Standard Methods for the Examination of Water and Wastewater, 20th edition, APHA, AWWA,
and WEF, Washington D.C. 1999.
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