March 2002
NSF02/18/EPADW395
Environmental Technology
Verification Report
Physical Removal of Cryptosporidium
oocysts, E. co//, and Bacillus spores in
Drinking Water
Pall Corporation
Microza™ Microfiltration 3-inch Unit,
Model 4UFD40004-45
Manchester, New Hampshire
Prepared by
NSF International
Under a Cooperative Agreement with
U.S. Environmental Protection Agency
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THE ENVIRONMENTAL TECHNOLOGY VERIFICATION
PROGRAM
xvEPA
>ge
ETV Joint Verification Statement
U.S. Environmental Protection Agency NSF International
TECHNOLOGY TYPE: MICROFILTRATION USED IN PACKAGED DRINKING
WATER TREATMENT SYSTEMS
APPLICATION: REMOVAL OF CRYPTOSPORIDIUMQQC\$1$,E. COLI,
AND BACILLUS SPORES IN MANCHESTER, NEW
HAMPSHIRE
TECHNOLOGY NAME: MICROFILTRATION USING MICROZA™ 3-INCH UNIT
MODEL 4UFD40004-45
COMPANY: PALL CORPORATION
ADDRESS: 25 HARBOR PARK DRIVE PHONE: (516)484-3600
PORT WASHINGTON, NY 11050 FAX: (516) 484-6844
WEB SITE: www.pall.com
EMAIL: tony.wachinski@pall.com
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 substantially 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; stakeholders groups which
consist 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 ETV Drinking Water Systems (DWS)
Pilot, one of 12 technology areas under ETV. The DWS Pilot recently evaluated the performance of the
Pall Corporation Microza™ Microfiltration (MF) System Module used in package drinking water
treatment system applications. This verification statement provides a summary of the test results for the
Microza™ MF Unit. University of New Hampshire (UNH) Water Treatment Technology Center, an NSF-
qualified field testing organization (FTO), performed the verification testing.
02/18/EPADW395 The accompanying notice is an integral part of this verification statement. March 2002
VS-i
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ABSTRACT
Verification testing of the Pall Corporation Microza™ MF System equipped with a 3-inch filter module,
took place between April 30 and August 9, 2000 in Manchester, New Hampshire. The source water was
drawn from a canal connected to Lake Massabesic, the public reservoir that serves the Town of
Manchester. The source water contained low alkalinity (3.5 mg/1), with turbidity levels that averaged 0.8
NTU and ranged between 0.07 and 3.8 NTU. The source water had a close to neutral pH at 6.4 (ranged
from 5.5 to 7.2), and a TOC concentration in mg/1 of between 4.68 and 5.09 with an average of 4.83. The
average feed water temperature was 19 °C. Large blooms of algae, diatoms, and zooplankton occurred in
the raw water during the testing. These blooms usually do not occur in such abundance at this time of
year. Use of a source water with high concentrations of algae and/or iron bacteria in the feed water is not
typical for MF technology and presented a worst case scenario feed water and a severe use condition for
the Pall unit.
The test unit produced an average of 2.3 gpm of filtrate when operating at an average recovery rate of
90%. The average transmembrane pressure and specific flux during the verification study were 14.22 psi
and 3.60 gfd/psi, respectively. Microbial seeding challenges involving Cryptosporidium oocysts, E. coli,
and Bacillus spores were performed on May 3rd, June 21st and August 9th, 2000. The first test on May 3rd
was performed at the beginning of a filter run to assess the performance on a clean membrane. The other
two challenge tests were performed when the transmembrane pressure (TMP) approached its 30 psi limit
to assess the performance of the membrane under stress from maximum allowed differential pressure. As
a result of the three Cryptosporidium oocyst seeding studies, the membrane demonstrated 6.6, 4.1, and 5.6
logic removals of Cryptosporidium oocysts, respectively. Cryptosporidium oocysts were not detected in
the filtrate. As a result of three E. coli challenges, the membrane demonstrated 6.7, 3.9, 6.5 logic removal
of E. coli, respectively. E. coli was detected in the filtrate in two of the E. coli challenge events. The
results of two of the Bacillus spore challenges (the results of the Bacillus spore seeding on June 21st were
inconclusive) indicate a 4.0 and 7.1 logic removal of Bacillus spores, respectively. Bacillus spores were
not detected in the filtrate during two of the challenges. Turbidity levels were reduced 96% on average.
The algae in the source water reduced run times by at least 75% as estimated by the manufacturer, who
anticipated run times on the order of 30 days between cleanings. The frequency of membrane fouling
indicates that some sort of pre-filter would be necessary in order to achieve longer run times at this
location. For additional information on operation and maintenance of the system on a cleaner water
source, refer to a previous ETV Report (#00/09/EPADW395) for testing of this system at a site in
Pittsburgh, Pennsylvania.
TECHNOLOGY DESCRIPTION
The unit is identified as the 3-inch Microza™ Test Skid, model number 4UFD40004-45, LGV3L, serial
number 2114562. The unit has a 3-inch diameter membrane filter module with 75 square feet of
membrane contact area, and is designed to filter up to 4 gpm. The manufacturer reports that the
maximum membrane pore size as determined by the use of ASTM Method F316-86 is less than 0.3
microns (um) diameter. Power requirements for the unit are 240 volts, at 20 amps under full load.
This model is specifically targeted for applications requiring a relatively low flow rate, such as would be
required for a package plant, or for a small commercial operation, school, campground, or swimming
pool. It would also be appropriate for a common water supply system for a small community. The
Microza™ MF module consists of pressure-driven hollow fibers of poly vinylidene fluoride (PVDF). The
maximum pressure differential across the membrane fibers is 30 psi. The unit is portable, light weight,
and mounted on a steel skid with casters. The operation of the system and the monitoring of operational
parameters are controlled by a Supervisory Control and Data Acquisition (SCADA) system, mounted on
the filter unit. The unit, therefore, should be operated in an enclosure.
02/18/EPADW395 The accompanying notice is an integral part of this verification statement. March 2002
VS-ii
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VERIFICATION TESTING DESCRIPTION
Test Site
A canal connected to Lake Massabesic, the water source for Manchester, New Hampshire was chosen as
the site to challenge the MF filter unit. Lake Massabesic is a natural lake and is located roughly 3.5
miles east of the downtown Manchester business area. The lake has a surface area of about 2,500 acres.
The storage capacity of the lake is close to 15 billion gallons, and is the runoff repository for a 42-square
mile (26,880 acres) watershed. During testing the canal became stagnant and subject to seasonal warming
and subsequent algal growth. Large blooms of algae, diatoms, and zooplankton occurred in the raw water
during the testing. Use of a source water with high concentrations of algae and/or iron bacteria in the feed
water is not typical for MF technology and presented a worst case scenario feed water and a severe use
condition for the Pall unit.
Methods and Procedures
Water quality data were collected on the source water and the filtrate produced by the Pall Microza™ MF
System and analyzed using Standard Methods for the Examination of Water and Wastewater, 20th Edition
(APHA, 1998) and/or EPA approved methods. Turbidity, temperature, pH, flow rate, particle counts, and
pressure were measured and logged in the field. The analysis of TOC and UV absorbance were performed
at the laboratory at UNH. Alkalinity, hardness, TSS, and TDS, were analyzed at either Research
Laboratories Inc., or at Analytics Environmental Laboratory Inc., State certified testing laboratories in
Portsmouth, NH. Analysis for detection of Cryptosporidium was performed at Analytical Services, Inc. in
Williston, Vermont. Analysis of E. coli, and Bacillus spores were performed at the microbiology
laboratory at UNH in conjunction with Analytical Services, Inc.
VERIFICATION OF PERFORMANCE
System Operation
The system was operated for thirteen (13) separate filter runs for a total of 436 hours between April 30,
2000, and July 26, 2000. Table VS-1 presents the system performance data for the thirteen (13) filter runs.
The average filtrate flow rate was 2.3 gpm, with a maximum value of 6.3 gpm and a minimum value of
1.8 gpm. Transmembrane pressure averaged 14 psi, with a maximum value of 30 psi, and a minimum
value of 2.9 psi. The specific flux averaged 3.6 gfd/psi, with a maximum value of 14 gfd/psi and a
minimum value of 1.3 gfd/psi. A summary of the system performance data is in the table below.
Table VS -1. System Performance Data for 13 Filter Runs
Feed Feed Feed Feed Filtrate Filtrate
Flow Pressure Temperature Turbidity Flow Pressure
(gpm) (psi) (°C) (NTU) (gpm) (psi)
Filtrate Retentate Transmembrane Specific
Turbidity Pressure Pressure Flux
(NTU) (psi) (psi) (gfd/psi)
Average
Minimum
Maximum
Std Dev
95% Conf.
Interval
2.50
1.80
9.80
0.63
(2.49,
2.51)
17.47
0.04
36.13
6.61
(17.35,
17.59)
18.88
11.44
35.26
3.14
(18.82,
18.94)
0.80
0.07
3.79
0.28
(0.79,
0.81)
2.30
1.80
6.26
0.43
(2.29,
2.31)
4.20
0.00
31.68
2.83
(4.15,
4.25)
0.03
0.00
0.32
0.01
(0.03,0.03)
15.35
0.00
34.43
7.18
(15.22,
15.48)
14.22
2.87
30.23
5.25
(14.12,14.32)
3.60
1.27
14.19
1.36
(3.57,3.63)
Note: Results corrected for AS and RF procedures.
Reverse filtration (RF) and air scrub (AS) operation were initially set to repeat every 30 and 60 minutes
respectively for a set duration of 60 seconds. The effectiveness of this cleaning procedure varied with the
02/18/EPADW395
The accompanying notice is an integral part of this verification statement.
VS-iii
March 2002
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water quality. It was found that the intensity of the operation had a greater impact on performance than
the frequency. In other words, adjustments in the duration of the AS and RF procedures produced
improved operational results rather than increasing the frequency. A chemical cleaning took place every
time the transmembrane pressure exceeded 30 psi, or if the system shut down due to fouling of the
membrane. Four chemical cleaning events took place during the testing period. The chemical cleanings
were performed using the manufacturer's recommended procedures and it took approximately three hours
to accomplish each cleaning. The membrane passed the integrity test after each cleaning operation was
performed.
Water Quality Results
The system effectively removed microbiological and particulate contaminants from the feed water during
the verification study. Microbial seeding challenges involving Cryptosporidium oocysts, E. coli, and
Bacillus spores were performed on May 3rd, June 21st and August 9th, 2000. The first test on May 3rd was
performed at the beginning of a filter run on a new clean membrane, and the other two tests were
performed when the TMP approached its 30 psi limit. The membrane demonstrated 6.6, 4.1, and 5.6 logio
removals of Cryptosporidium oocysts, respectively, during the challenge studies. Cryptosporidium
oocysts were not detected in the filtrate samples. The samples collected during the May 3rd
Cryptosporidium challenge were analyzed outside the method's specified hold time; however, the
deviation is not expected to influence the sample results because the samples were analyzed for total cyst
concentration and not viability (see Quality Control Section of report for discussion). The membrane
demonstrated 6.7, 3.9, 6.5 logio removal ofE. coli, respectively, during the challenge studies. E. coli was
detected in the filtrate in two of the E. coli challenge events. The results of two of the Bacillus spore
challenges (the results of the Bacillus spore seeding on June 21st were inconclusive) indicated a 4.0 and
7.1 logio removal of Bacillus spores. Bacillus spores were not detected in the filtrate during two of the
challenges. The logio removals for E. coli and Bacillus spores were calculated based on a 100 mL
sample. The logio removals of the microorganisms seeded were limited by the concentration which was
present in the stock feed solution, the percentage of the filtrate sampled, and the percent recovery of the
analytical methodology.
The raw water particle count concentration of Cryptosporidium-sized particles (2 to 5 micron) and
cumulative particles (>2 micron) averaged 3,120 and 5,601 counts/ml, respectively. The filtrate particle
count concentration averaged 1.7 and 3.1 counts/ml, respectively. Percent reduction for both
Cryptosporidium-sized particles (2 to 5 micron) and cumulative particles (>2 micron) was 99.94%.
Turbidity was reduced from an average of 0.80 NTU in the feed water to 0.03 NTU in the filtrate.
Operation and Maintenance Results
The system evaluated in this study was highly automated, making day-to-day operation simple and
straightforward. Aside from the chemical cleaning, labor was spent after start-up to adjust feed flow and
adjust the reverse filtration and air scrub run time and frequency to enhance performance. The
adjustments were accomplished via computer programming with the exception of valve adjustments
performed manually to regulate the retentate flow. The water quality and the environmental conditions at
the site required that three mechanical changes be made in the system. The demand for compressed air
required that a larger compressor be used instead of the original supplied with the system. The maximum
temperature setting allowed within the enclosed SCADA system was increased from the original factory
setting to allow for the high air temperatures at tie site. A solenoid valve that controlled one of the
pneumatic flow control valves also failed and was replaced with another that was supplied with the
membrane system.
The system operation was terminated seven times because the TMP termination criteria (30 psi) was
reached. The terminations were believed to be a direct result of high concentrations of algae and/or iron
bacteria in the feed water. Use of a source water with high concentrations of algae and/or iron bacteria in
02/18/EPADW395 The accompanying notice is an integral part of this verification statement. March 2002
VS-iv
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the feed water is not typical for MF technology and presented a worst case scenario feed water and a
severe use condition for the Pall unit. For additional information on operation and maintenance of the
system, refer to a previous ETV Report (#00/09/EPADW395), which documents operation and
maintenance results on a cleaner water source.
The Operation and Maintenance manual is well written and easy to follow. Sections include: System
Description, Module Installation and Rinse-Up, Safety Instruction, System Operation, System Control
Interface, and Clean-In-Place Procedures. The only technical assistance required that was not covered in
the manual was membrane fouling caused by algae in the source water, system shutdown caused by an
undersized compressor and the adjustment of factory settings to compensate for the higher than
anticipated temperatures within the SCADA system due to the abnormally high ambient temperatures at
the site.
Original Signed by Original Signed by
E. Timothy Oppelt 04/08/02 Gordon Bellen 04/11/02
E. Timothy Oppelt Date Gordon Bellen Date
Director Vice President
National Risk Management Research Laboratory Federal Programs
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 a NSF Certification of the specific product mentioned herein.
Availability of Supporting Documents
Copies of the EPA/NSF ETV Protocol for Equipment Verification Testing for Physical
Removal of Microbiological and Paniculate Contaminants dated May 1999, the
Verification Statement, and the Verification Report (NSF Report #02/18/EPADW395)
are available from the following sources:
(NOTE: Appendices are not included in the Verification Report. Appendices are
available from NSF upon request.)
1.) Drinking Water Systems ETV Pilot Manager (order hard copy)
NSF International
P.O. Box 130140
Ann Arbor, Michigan 48113-0140
2.) NSF web site: http://www.nsf.org/etv (electronic copy)
3.) EPA web site: http://www.epa.gov/etv (electronic copy)
02/18/EPADW395 The accompanying notice is an integral part of this verification statement. March 2002
VS-v
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March 2002
Environmental Technology Verification Report
Physical Removal of Cryptosporidium oocysts, E. coli, and Bacillus
spores in Drinking Water
Pall Corporation
Microza™ Microfiltration 3-inch Unit,
Model 4UFD40004-45, LGV3L
Manchester, New Hampshire
Prepared for:
NSF International
Ann Arbor, Michigan 48105
Prepared by:
University of New Hampshire Water Treatment Technology Center
Mark Arenberg, Project Director
Dr. M. Robin Collins, Director
Durham, NH 03824
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. CR 824815. This verification effort was supported by Drinking
Water Treatment Systems Pilot operating under the Environmental Technology Verification
(ETV) Program. This document has been peer reviewed and reviewed by NSF and EPA and
recommended for public release.
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Foreword
The following is the final report on an Environmental Technology Verification (ETV) test
performed for NSF International (NSF) and the United States Environmental Protection Agency
(EPA) by the University of New Hampshire (UNH) Water Treatment Technology Center , in
cooperation with the Pall Corporation. The testing was conducted between April 30 and July 26,
2000 at the intake site for the water treatment facility in Manchester, New Hampshire.
Throughout its history, the EPA has evaluated the effectiveness of innovative technologies to
protect human health and the environment. A new EPA program, the Environmental
Technology Verification Program (ETV) has been instituted to verify the performance of
innovative technical solutions to environmental pollution or human health threats. ETV was
created to substantially accelerate the entrance of new environmental technologies into the
domestic and international marketplace. Verifiable, high quality data on the performance of new
technologies is made available to regulators, developers, consulting engineers, and those in the
public health and environmental protection industries. This encourages more rapid availability
of technology to better protect the environment.
The EPA has partnered with NSF, an independent, not-for-profit testing and certification
organization dedicated to public health, safety and protection of the environment, to verify
performance of small package drinking water systems that serve small communities under the
Drinking Water Treatment Systems (DWTS) ETV Pilot. A goal of verification testing is to
enhance and facilitate the acceptance of small package 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 will meet
this goal by working with manufacturers and NSF-qualified Field Testing Organizations (FTO)
to conduct verification testing under the approved protocols.
The ETV DWTS is being conducted by NSF with participation of manufacturers, under the
sponsorship of the EPA Office of Research and Development, National Risk Management
Research Laboratory, Water Supply and Water Resources Division, Cincinnati, Ohio. It is
important to note that verification of the equipment does not mean that 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.
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Table of Contents
Section Page
Verification Statement VS-i
Title Page i
Notice ii
Foreword iii
Table of Contents iv
Abbreviations and Acronyms viii
Acknowledgements x
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 Source Water 4
1.3.2 Effluent Discharge 6
Chapter 2 Equipment Description and Operating Processes 7
2.1 Equipment Description 7
2.1.1 Background Engineering Concepts 7
2.1.2 Physical Characteristics 8
2.2 Operating Process 11
2.2.1 Forward Flow 11
2.2.2 Reverse Filtration 11
2.2.3 Air Scrub 12
2.2.4 Clean-In-Place 12
2.2.4.1 Chemical and Raw Material Usage 12
2.2.5 Operation Limitations 13
2.2.6 Performance Range 13
2.2.7 Operator Skill/Licensing Requirements 14
2.2.8 Application of Equipment 14
Chapter 3 Methods and Procedures 15
3.1 Start-up Testing 15
3.2 Verification Testing 15
3.3 Verification Testing Schedule 15
3.4 Verification Testing Tasks 15
3.4.1 Task 1: Membrane Flux and Operation 16
3.4.2 Task 2: Cleaning Efficiency 18
3.4.3 Task 3: Finished Water Quality 21
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3.4.4 Task 4: Reporting of Maximum Membrane Pore Size 22
3.4.5 Task 5: Membrane Integrity Testing 23
3.4.6 Task 6: Data Management and Reporting Protocols 23
3.4.7 Task?: QA/QC Plan 24
3.4.7.1 Overall Project Quality Objectives 24
3.4.7.2 Field Investigation Quality Objectives 25
3.4.7.3 Laboratory Quality Objectives 26
3.4.7.4 Criteria 27
3.4.7.5 Control of Procedures 27
3.4.7.6 Chain-of-Custody 27
3.4.7.7 Documentation 27
3.4.7.8 QC Samples 28
3.4.7.9 Identification of Samples 29
3.4.7.10 Handling 29
3.4.7.11 Sample Transport 29
3.4.7.12 Calibration of Field Instruments 30
3.4.7.12.1 General Field Equipment Verification 30
3.4.7.12.2 Specific Equipment QA Verification 30
3.4.7.13 Maintenance 33
3.4.7.14 Laboratory QA/QC 33
3.4.7.15 Project Quality Assessment 34
3.4.7.15.1 Data Quality Assessment 34
3.4.7.15.1.1 Overall Project Assessment 34
3.4.7.15.1.2 Field Data Quality Assessment 34
3.4.7.15.1.3 Data Quality Assessment 34
3.4.7.15.2 On-Site Audit 35
3.4.7.15.3 Corrective Procedures 35
3.4.7.16 Certification of UNH Laboratories 35
3.4.8 Task 8: Microbial Removal Challenge 36
3.4.9 Task 9: Operation and Maintenance Manual Evaluation 37
Chapter 4 Results and Discussion 38
4.1 Introduction 38
4.2 Membrane Flux and Operation 38
4.2.1 Operation 38
4.2.2 Flowrate 40
4.2.3 Pressure 41
4.2.4 Temperature 41
4.2.5 Membrane Flux 41
4.3 Cleaning Efficiency 42
4.4 Finished Water Quality 43
4.4.1 Particle Counts 43
4.4.2 Turbidity 47
4.4.3 Phytoplankton Analysis 48
4.4.4 Other Water Quality Parameters 49
4.5 Task 4: Reporting ofMaximum Membrane Pore Size 51
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4.6 Task 5: Membrane Integrity Testing 51
4.7 Task 6: Data Management 52
4.8 Task?: QA/QC 52
4.9 Task 8: Microbiological Removal Challenge 54
4.10 Task 9: Evaluation of O&M Manual 57
4.11 Equipment Characteristics Results 57
4.11.1 Qualitative 58
4.11.1.1 Susceptibility to Changes in Environmental Conditions 58
4.11.1.2 Equipment Safety 58
4.11.2 Quantitative 58
4.11.2.1 Power Usage 59
4.11.2.2 Consumables 59
4.11.2.3 Waste Disposal 59
4.11.2.4 Length of Operating Cycle 59
References 60
Tables
VS-1 System Performance Data for 13 Filter Runs VS-iii
1-1 Estimated Water Quality Data for Manchester Water Treatment Facility 4
1-2 Feed Water Quality 5
1-3 Feed Water On-line Turbidity and Particle Counts 5
2-1 Typical MF Filter Performance 14
3-1 Analytical and Operational Data Collection Schedule 20
3-2 QA/QC Criteria Objectives 29
4-1 Filter Run Schedule 39
4-2 Summary of Filter Performance 42
4-3 Evaluation of Cleaning Efficiency 43
4-4 Raw Water Particle Counts 44
4-5 Filtrate Particle Counts 44
4-6 Average Particle Count Removal Percentage 44
4-7 On-Line Feed and Filtrate Turbidity Data 47
4-8 Feed Water Phytoplankton Analysis 49
4-9 Feed Water Quality 50
4-10 Filtrate Water Quality 50
4-11 Summary of Raw and Filtrate Water Quality Naturally Present
Microbial Constituents 51
4-12 Feed and Filtrate Cryptosporidium Results 54
4-13 Feed and Filtrate Bacillus Spore Results 55
4-14 Feed and Filtrate E. coli Results 56
VI
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Photograph of the Pall Microza™ System 8
Schematic of the Pall Microza™ System 9
Transmembrane Pressure 41
Specific Flux at 20°C 42
Cumulative Particle Counts for Test Period 2 on Logo Scale 45
Cumulative Particle Counts for Test Period 3 on Logo Scale 45
Cumulative Particle Counts for Test Period 4 on Logo Scale 46
Cumulative Particle Counts for Test Period 5 on Logo Scale 46
Cumulative Particle Counts for Test Period 9 on Logo Scale 47
Turbidity Profile 48
Bar Chart of Logo Removal of Seeded Cryptosporidium 55
Bar Chart of Logo Removal of Seeded Bacillus Spores 56
Bar Chart of Logo Removal of Seeded E. coli 57
Appendices
Appendix A
Appendix B
Appendix C
Appendix D
Appendix E
Appendix F
Appendix G
Appendix H
Appendix I
Appendix J
Operations and Maintenance Manual
Field Logbook
Fats, Oil and Grease Laboratory Analytical Reports
Algae Laboratory Analytical Reports
Operational Data
Cleaning Efficiency Data
Analytical Laboratory Reports for Water Quality Parameters
Cryptosporidium Laboratory Analytical Reports
E. coli, Bacillus Spore, and Total Coliform Laboratory Analytical Reports
QA Documentation
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Abbreviations and Acronyms
A/D Analog-to-Digital
AS Air Scrub
AST Analytical Services, Inc.
C Degrees Celsius
CIP Clean in place
CLP Contract Laboratory Program
C12 Chlorine
D.O. Dissolved Oxygen
DE Diatomaceous Earth
DI Deionized (water)
DOC Dissolved Organic Carbon
DQO Data Quality Objectives
DWTS Drinking Water Treatment System
EPA United States Environmental Protection Agency
ESWTR Enhanced Surface Water Treatment Rule
ETV Environmental Technology Verification
FOD Field Operations Document
FTO Field Testing Organization
g/L Grams per liter
GAC Granulated Activated Carbon
GFD Gallon per square foot per day
GPM Gallons per Minute
HP Horse Power
L Liters
MF Microfiltration
mg/L milligram per liter
MSDS Material Safety Data Sheets
NF Nanofiltration
NHDES New Hampshire Department of Environmental Services
NPT National Pipe Thread
NSF NSF International
NTIS National Technical Information Service
NTU Nephelometric Turbidity Units
PARCC Precision, Accuracy, Representativeness, Completeness, and Comparability
PFW Particle Free Water
PM Preventative Maintenance
ppm Parts per million
PQL Practical Quantitation Limits
psi Pounds per square inch
PVC Polyvinyl Chloride
PVDF Polyvinylidene Fluoride
QA Quality Assurance
QC Quality Control
RF Reverse Filtration
Vlll
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RO Reverse Osmosis
RPD Relative Percent Difference
RSD Relative Standard Deviation
SCADA Supervisory Control and Data Acquisition
SCFM Standard cubic feet per minute
SDWA Safe Drinking Water Act
SWTR Surface Water Treatment Rule
THMFP Trihalomethane Formation Potential
TMP Transmembrane pressure
TOC Total Organic Carbon
UF Ultrafiltration
UNH University of New Hampshire
WTTC Water Treatment Technology Center
IX
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ACKNOWLEDGMENTS
The Field Testing Organization, University of New Hampshire Water Treatment Technology
Center, was responsible for all elements in the testing sequence, including collection of samples,
calibration and verification of instruments, data collection and analysis, data management, data
interpretation and the preparation of this report.
University of New Hampshire Water Treatment Technology Center
Dr. M. Robin Collins, Director
Room 348, Environmental Technology Building
University of New Hampshire
Durham, NH 03824
Phone: (603)862-1407
Fax: (603)862-2364
e-mail: robin.collins@unh.edu
In addition to the UNH laboratory, the laboratory selected for microbiological analysis analytical
work of this study was:
Analytical Services, Inc.
Mr. Paul Warden, Vice President
50 Allen Brook Lane
P.O. Box 515
Williston, VT 05495
Phone: (802)878-5138
Fax: (802)878-6765
e-mail: pwarden@asimicro.com
Other analytical services were provided by the following two laboratories:
Research Laboratories, Inc.
Ms. Russ Foster
124 Heritage Avenue, Unit 10
Portsmouth, NH 03801
Phone: (603)436-2001
Fax: (603)430-2100
Analytics Environmental Lab, Inc.
Mr. Steve Kuollmeyer
195 Commerce Way, Suite E
Portsmouth, NH 03801
Phone: (603)436-5111
Fax: (603)430-2151
x
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The Manufacturer of the Equipment was:
Pall Corporation
Dr. Anthony M. Wachinski
25 Harbor Park Drive
Port Washington, NY 11050
Phone: (516) 484-3600 ext. 6844
Fax: (516)484-7795
e-mail: tony.wachinski@pall.com
University of New Hampshire Water Treatment Technology Center wishes to thank Mr. David
Paris Director of the Manchester Water Treatment Plant and his associates for their extraordinary
support and accommodation during this ETV project.
XI
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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 substantially 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; stakeholders
groups which consist 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, collecting and analyzing data, and preparing peer reviewed
reports. Evaluations are conducted in accordance with rigorous quality assurance protocols to
verify 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 Treatment
Systems (DWTS) Pilot, one of 12 technology areas under ETV. The DWTS Pilot evaluated the
performance the Pall Corporation Microza™ Microfiltration System, which is a hollow fiber
membrane microfiltration (MF) system used in package drinking water treatment system
applications. The field testing evaluated the system's capability of reducing turbidity and also
included microbial challenges to evaluate the system's ability to physically remove
Cryptosporidium, E. coli, and Bacillus spores. This document provides the verification test
results for the Pall Corporation Microza™ Microfiltration System.
1.2 Testing Participants and Responsibilities
The ETV testing of the Pall Microza™ Microfiltration System was a cooperative effort between
the following participants:
NSF International
U.S. Environmental Protection Agency
The University of New Hampshire Water Treatment Technology Center
Pall Corporation
Manchester New Hampshire Water Treatment Plant at Lake Massabesic, Manchester,
New Hampshire
The following is a brief description of each ETV participant and their roles and responsibilities.
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1.2.1 NSF International
NSF is a not-for-profit standards and certification organization dedicated to public health safety
and 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
that products bearing the NSF Name, Logo and/or Mark meet those standards. The EPA
partnered with the NSF to verify the performance of drinking water treatment systems through
the EPA's ETV Program.
NSF provided technical and primarily quality oversight of the verification testing. An audit of
the field analytical and data gathering and recording procedures was conducted. NSF also
provided review of the Field Operations Document (FOD) to assure its conformance with
pertinent ETV generic protocol and test plans. NSF also conducted a review of this report and
coordinated the EPA and technical reviews of this report.
Contact Information:
NSF International
789 N. Dixboro Rd.
Ann Arbor, MI 48105
Phone: 734-769-8010
Fax: 734-769-0109
Contact: Bruce Bartley, Project Manager
Email: bartley@nsf.org
1.2.2 Field Testing Organization
The University of New Hampshire (UNH) Water Treatment Technology Center, conducted the
verification testing of the Pall Corporation Microza™ Microfiltration System. The UNH Water
Treatment Technology Center is a NSF-qualified Field Testing Organization (FTO) for the
DWTS ETV Pilot.
The FTO was responsible for conducting the verification testing. The FTO provided logistical
support, established a communications network, and scheduled and coordinated activities of the
participants. The FTO was responsible for selecting the testing location and feed water
conditions such that the verification testing could meet its stated objectives. FTO employees
performed the onsite analyses and recorded data during the testing. The FTO also prepared the
FOD, oversaw the testing, managed, evaluated, interpreted and reported on the data generated by
the testing, as well as evaluated and reported on the performance of the package system.
Contact Information:
University of New Hampshire Water Treatment Technology Center
Room 348, Environmental Technology Building
University of New Hampshire
Durham, NH 03824
Phone: (603)862-1407
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Fax: (603)862-2364
Contact Person: Dr. M. Robin Collins, Director
Email: robin.collins@unh.edu
1.2.3 Manufacturer
The treatment system is manufactured by the Pall Corporation. The manufacturer was
responsible for supplying a field-ready Microza™ MF System equipped with the necessary
components including treatment equipment, instrumentation and controls and an operations and
maintenance manual. The manufacturer was responsible for providing logistical and technical
support as needed as well as providing technical assistance to the FTO during operation and
monitoring of the equipment undergoing field verification testing.
Contact Information:
Pall Corporation
25 Harbor Park Drive
Port Washington, NY 11050
Phone: (516)484-3600 ext. 6844
Fax: (516)484-7795
Contact Person: Dr. Anthony M. Wachinski
e-mail: tony.wachinski@pall.com
1.2.4 A nalytical Laboratory
Analytical Services, Inc. (ASI) was responsible for the analyses and laboratory QA/QC
procedures for the microbiological samples, including bacterial samples, algae, and
Cryptosporidium. E. coli and Bacillus spore analyses were performed by UNH in conjunction
with ASI.
Contact Information:
Analytical Services, Inc.
50 Allen Brook Lane
P.O. Box 515
Williston, VT 05495
Phone: (802)878-5138
Fax: (802) 878-6765
Contact Person: Mr. Paul Warden, Vice President
e-mail: pwarden@asimicro.com
All other analytical services were performed by the following two laboratories:
Research Laboratories, Inc.
124 Heritage Ave., Unit 10
Portsmouth, NH 03801
Phone: (603)436-2001
Fax: (603)430-2100
Contact Person: Russell Foster
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Analytics Environmental Lab Inc.
195 Commerce Way
Portsmouth, NH 03801
Phone: (603)436-5111
Fax: (603430-2151
Contact Person: Stephen Knollmeyer
1.2.5 U.S. Environmental Protection Agency
The EPA through its Office of Research and Development has financially supported and
collaborated with NSF under Cooperative Agreement No. CR 824815. This verification effort
was supported by DWTS Pilot 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
The verification testing occurred at the Low Service Pumping Station of the Manchester Water
Works located at 567 Cohas Avenue in Manchester, NH. The 3-inch Test Skid filter unit was
housed at the electric power generation site at the facility. The facility had adequate power and
direct access to the water supply source, which is located less than 50 m away from the proposed
demonstration/study site. The facility was secured, especially in the evenings and is
conveniently located with respect to the environmental engineering laboratories at the UNH
WTTC. The location had laboratory facilities that were conducive for measuring on-site water
quality and operational parameters including pH, D.O., temperature, flow rates, and head loss.
Storage facilities were also available for storing sample bottles until they were used. There was
ample staging area available for the preparation and packaging of sample bottles for transport to
the FTO labs.
1.3.1 Source Water
The testing was arranged to take place at the Manchester Water Treatment Facility using water
from their intake from Lake Massabesic. Estimated water quality parameters for the Treatment
Facility's intake are presented in the following table.
Table 1-1. Estimated Water Quality Data for Manchester Water Treatment Facility
Parameter Range of Estimated Results
Turbidity (NTU) 0.8-4.0
Total Coliform (#7100 ml) 1-150
pH 6-7
TOC/DOC (mg/1) 2-4
Trihalomethane Formation Potential (ug/1) 80-160
Note: This data is provided as an estimate of the water quality and was not verified by the verification organization.
The testing site was relocated to another water intake on the Treatment Facility's property due to
concerns by the Manchester Water Treatment Facility of the seeding with microorganisms. The
intake source water used during the verification testing of the Pall unit was water from a canal
that receives its water from Lake Massabesic. The Manchester Water Treatment Facility
indicated that this other intake had water quality similar to their intake for the Treatment Facility.
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Unfortunately the water in the canal became stagnant during the testing due to lack of use of the
canal water by a local power facility. The water during verification testing contained high
amounts of algae as a result. Use of a source water with high concentrations of algae and/or iron
bacteria in the feed water is not typical for MF technology and presented a worst case scenario
feed water and a severe use condition for the Pall unit.
The source water for the verification testing was from a canal connected to Lake Massabesic.
Lake Massabesic is located roughly 3.5 miles east of the downtown Manchester business area,
and has a surface area of about 2,500 acres. The storage capacity of the lake is close to 15 billion
gallons, and is the runoff repository for a 42-square mile watershed.
A summary of the feed water quality data during the verification test period is presented in Table
1-1 and Table 1-2. In addition to the information listed below, a quantitative analysis of the
algae analyses are included in Chapter 4.
Table 1-2. Feed Water Quality
Date
5/11/00
5/12/00
6/9/00
6/14/00
6/21/00
6/27/00
Average:
Maximum Value:
Minimum Value:
TOC UV Absorbance
(mg/L)
4.77
4.69
4.76
—
5.09
—
4.83
5.09
4.69
(I/cm)
0.136
0.133
0.125
—
0.119
—
0.128
0.136
0.119
Total
Total
Iron Manganese Alkalinity Hardness
(mg/L)
—
—
0.073
0.16
—
0.18
0.14
0.18
0.073
(mg/L)
—
—
0.015
0.013
—
0.014
0.014
0.015
0.013
(mg/L) (mg
—
—
—
—
3.5
—
NA
NA
NA
CaCo3/L)
—
—
—
—
11.2
—
NA
NA
NA
TDS
(mg/L)
—
—
—
—
79
—
NA
NA
NA
TSS
(mg/L)
—
—
—
—
<4
—
NA
NA
NA
— = Sample not collected on this date.
NA=Statistical calculations not performed because sample size = 1.
Table 1-3. Feed Water On-line Turbidity and Particle Counts
Cumulative Particle Counts
Date Turbidity (2->15um)
(NTU) (particles/mL)
Average:
Minimum value:
Maximum value:
95% Confidence Interval:
0.80
0.07
3.79
(0.79, 0.81)
5601
877
17891
(5533, 5670)
1.3.2 Effluent Discharge
The effluent of the treatment unit was clear and odorless. After samples were collected, the
effluent and source water were stored in 60 gallon juice drums. The drums were discharged to
an approved outfall site that emptied into the Merrimack River watershed. Discharge permits
were not required.
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The caustic/chlorine cleaning solutions, the citric acid cleaning solutions, and the rinse solutions
were kept separate in plastic storage barrels. After the project was completed they were
transported to UNH and were subsequently disposed of by the Hazardous Waste Management
Department at UNH.
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Chapter 2
Equipment Description and Operating Processes
2.1 Equipment Description
The equipment tested was a package sized, portable microfiltration plant manufactured by Pall
Corporation. The unit is identified as the 3-inch Microza™ Unit, model number 4UFD40004-45,
LGV3L, serial number 2114562. The unit has a 3-inch diameter membrane filter module with
75 square feet (ft2) of membrane contact area, and is designed to filter up to 4 gpm. Power
requirements are 120 volts, at 20 amps under full load.
This model is specifically targeted for applications requiring a relatively low flow rate, such as
would be required for a package plant, or for a small commercial operation, school, campground,
or swimming pool. It would also be appropriate for a common water supply system for a small
community. The Microza™ Microfiltration module consists of pressure-driven hollow fibers of
PVDF. The maximum pressure differential across the membrane fibers is 30 psi. The unit is
portable, light-weight, mounted on a steel skid with casters. The operation of the system and the
monitoring of operational parameters are controlled by a SCADA system, mounted on the filter
unit. The unit, therefore, should be operated in an enclosure.
2.1.1 Background Engineering Concepts
Microfiltration is a mechanical, pressure driven filtering process whereby a porous membrane
provides a mechanical barrier to the particulates in the source feed water. Typical membranes
used are categorized as spiral wound, hollow-fiber (HF), tubular, cassette, cartridge, or flat sheet.
The membrane used in this particular unit are of the hollow-fiber category, with nominal pore
size of 0.1 |j,m.
The microfiltration modules resemble vertical liquid-liquid heat exchangers. Two plates are
vertically separated by several feet. Each plate consists of solidified seating material, which
resembles a one inch thick disk of ice holding a circular bunch of hollow cattail reeds. The
module has an outer cylinder case which seals against the circumference of the plates. Forcing
water inside the case presses it around reed-like membrane fibers. These are permeable and
much of the water sieves through the membrane where it flows away in the hollow membrane
interior. Particles greater than the effective porosity of the fibers do not pass through the
membrane, and are carried away in a recirculating flow.
The modules are composed of an outer shell of PVC, nominally 3" in diameter, and 42" in length
(actual dimensions are 140 x 2227 mm). Empty weight is about 45 pounds. Inside the module are
hundreds of fine (1.4 mm outside, 0.8 mm inside diameter) fibers fabricated from PVDF for the
MF modules. The total surface area of each module, based on outside fiber diameter, is
approximately 75 square feet. The fibers contain thousands of micro-pores in the range of 0.004
to 0.1 |j,m in diameter. These pores sieve particulate matter passing through the membrane
surface. The method used to fabricate the fibers results in a tough skin on the inner and outer
surfaces, making the fibers robust and long-lived. This double skin is unique to the Microza™
membrane, and also allows equal flow in either direction, as required.
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The fibers are potted in epoxy, and arranged so that the feed flow enters the bottom of the
module and flows on the outside of the fbers. Water passes into the fiber interior core via the
pores. Contaminates which cannot pass through the pores remain exterior to the filter module.
Water that enters the fiber cores is channeled to the filtrate plenum. This "outside- in" flow path
provides for a larger effective membrane area, and allows higher flux rates than most other
membrane modules.
2.1.2 Physical Characteristics
The Microza™ MF system module, pumps, tanks, and SCADA unit are mounted on a mobile
steel skid, equipped with industrial-grade casters. The overall footprint of the filter unit is 34
inches wide by 90 inches long. The unit height overall is approximately 78 inches. It is
designed to pass through most doorways. A photograph of the system is shown in Figure 2-1. A
schematic of the three-inch diameter module filter system is shown in Figure 2-2.
Figure 2-1. Photograph of the Pall Microza™ System
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:.--:;. :
* . AV " -
\
*r^v
— 4 _!; , - i o ^
:. 1
T
,' " ~i i »
Ur - H-_ - -
Figure 2-2. Schematic of the Pall Microza™ System
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The system is designed to intercept the flow from the customer's feed connection, and deliver
treated filtrate to the downstream distribution system. Feed water connection to the source is by
a 1-inch line leading to the filter feed water tank.
A prefilter is connected in the feed line upstream of the filter module to capture particles larger
than typically one-tenth the diameter of the hollow-tube fiber. The prefilter is manufactured by
Filter Specialists, Inc. (FSI). The prefilter used on the Pall filter unit is a model number
BPEM400P 3P prefilter. It consists of a disposable bag filter made of polyester nylon mesh with
a pore size of 400 um. The bag is attached to a polypropylene ring.
Two 24-gallon tanks are mounted on one end of the filter skid. Both tanks are regulated with
float valves, consisting of float balls connected to a needle metering valve by a float rod. The
first of these tanks is the feed water tank. Water enters this tank from two sources. The primary
source is the raw feed water. Source water is brought to the tank via an 1-inch line. The
secondary inflow source is the excess recirculation (XR) flow. A variable speed pump delivers
the feed water from the tank to the bottom of the module. Approximately 90% of feed water
flows through the hollow-tube fibers, and flows out the top of the filter module as filtrate. The
remaining 10% of the feed water flows by the outside of the filter fibers, collecting particles in
the near vicinity of the fibers and transporting them away from the fiber surfaces. This flow is
the excess recirculation, which recycles back into the feed tank.
The second tank, for Reverse Filtration (RF), is fed by the filtrate from the filter module. The
filtrate discharge from the filter module is run to a tee fitting. One branch of the tee is connected
to a float valve in the RF tank. This branch siphons off a small percentage of the filtrate flow for
the Reverse Filtration membrane cleaning process. The RF cleaning is performed regularly, at
15-30 minute intervals. The filtrate water in the RF tank is pumped back through the filter
module in the reverse direction, at a rate 1.5 times the filter rate (6 gpm) for typically less than
one minute, to dislodge the particles from the outside of the hollow-tube fibers. The discharge
from the RF filtration is through the XR port at the top of the module, and is run back into the
feed water tank.
The filtrate from the forward filter flow flows from the second branch of the tee in the discharge
line through a 1-inch diameter pipe. This discharge is not at high pressures, rather the discharge
is designed to collect in a holding tank that stores the treated water at atmospheric pressure. The
system is not designed to deliver water flow under significant pressure. Two in-line electronic
flow meters provide continuous monitoring and back-up monitoring of the flow rate.
There is also a 1-inch alternate source clean water line provided to supplement the water from
the RF tank. This source is used in the event that the RF tank is exhausted, and during clean-in-
place (CIP) procedures. A variable speed centrifugal pump controls the flow out of each tank.
Pressure transducers are installed in the feed water and filtrate lines to measure the pressure
differential across the filter module. Flow is controlled by solenoid valves on the various water
lines, which in turn are controlled by the SCADA system. In addition, a compressed air line is
connected to the filter module at the feed water end for the air scrubbing cleaning procedure.
This is also regulated by an electrically actuated valve and the SCADA system. The air flow is
monitored by a flow meter on the air line, which also is connected to the SCADA system. The
10
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SCADA system monitors flow rates and cumulative volumes of filtrate and waste, tank levels,
in-line temperature, turbidity, and particle counts.
The SCADA computer controls are mounted on the unit in a panel opposite the feed and
retentate tanks. The control panel provides real-time monitoring of flow rate, pressures across
the filter module, and turbidity of filtrate waters. The pumps are variable speed pumps, which
are controlled remotely at the control panel. The system may operate in two modes, manual or
automatic. In automatic mode, the computer controls the valves, and pump speeds for regular
filter operation and periodic RF, and air scrubbing cleaning. CIP procedures are performed in
manual mode. Chemicals are added to the feed tank during this procedure.
2.2 Operating Process
2.2.1 Forward Flow
During normal flow, the module receives inlet flow. This flow enters the bottom of the module,
and flows up the module on the outside of the hundreds of hollow fibers that run the length of the
module. Of this, 95% 'permeates' through the fiber surface, travels up the inside of the hollow
fiber, and flows into the Reverse Filtration Tank before leaving the system as clean water. The
remaining 5% is recycled back to the Feed Tank as Excess Recirculation (XR). This XR flow
prevents the accumulation of air that may come out of solution in the module, and helps to
ensure even flow distribution throughout the module.
2.2.2 Reverse Filtration
As water is filtered through the membrane surface, a cake of rejected particulates accumulates on
the surface of the fibers. With greater accumulation, this deposition gradually impedes the filtrate
flow. To maintain stable flow over the short term, a periodic cleaning cycle, called a Reverse
Filtration (RF) Cycle, is performed. RF typically takes place every 15-30 minutes. During the
RF cleaning mode, the feed flow is stopped, and filtrate is pumped backwards through the
module from the inside of the fibers out through the pores. Typically, the RF rate of flow is fixed
at around 1.5-2 times the forward flow rate, washing away the accumulated particulates. The
reverse flow is short lived - a typical RF duration could be 20 seconds of every 24 minutes. This
RF water exits the XR port rear the top of the module, and is returned to the Feed Tank. In
permanent installations, RF is generally diverted to a drain to prevent the concentrated
particulates from reentering the flow path. Drainage of RF constitutes the majority of the lost
feed flow (approximately 5%).
To aid in cleaning the module, and particularly in removing biogrowth on the membrane
surfaces, chlorine, in the form of 12.5% sodium hypochlorite, is injected into the RF flow stream
at a concentration of approximately 20 mg/L. Valves direct all chlorine-laden RF clean flow into
a drain, consequently, no chlorine residual is sent in the MF filtrate to sensitive downstream
processes such as Reverse Osmosis.
11
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2.2.3 Air Scrub
Occasionally, RF is not totally effective in cleaning the membrane fibers and a more vigorous
cleaning is required. Pall Corporation calls the more vigorous cleaning method used Air
Scrubbing (AS), which is a two step process. The first step consists of bubbling about 3 SCFM
of compressed air through each module with no water flow. The air is introduced into the feed
connection of the module. Gaseous air will not pass through the fibers, and will stay on the feed
side of the membrane. The air bubbles shake the fibers intensely, sloughing off material that
resists the RF cycle.
The second part of the AS cycle serves as a rinse and flush. Air is still bubbled up through the
module, but water is also circulated through the feed side of the module, which is even more
effective in cleaning the module surface. Air Scrubbing is an energetic process, and increases
the wear on the hollow fibers. For this reason, the AS frequency and duration must be kept to
the minimum required to keep the modules clean.
2.2.4 Clean-In-Place
The RF and AS membrane regeneration procedures need to be supplemented with periodic
chemical cleaning to remove gradually accumulated foulants that are resistant to daily RF/AS
procedures. The Clean-in-Place (CIP) process requires scheduled down-time. The entire system
is taken off-line for several hours. In new systems, the CIP cycle is initially scheduled every two
to three months. As flow or incoming particulate levels increase, it is likely that the CIP
frequency will increase, accordingly.
The CIP process is performed manually on this particular filter unit. (CIP is generally automated
for larger, permanent systems). The system is drained, and then refilled with filtrate. Sodium
hydroxide and sodium hypochlorite are added to the filtrate, which is then circulated through the
system in normal forward flow for 45 minutes. The same procedure then occurs with citric acid.
If metals were suspected to be the primary foulant, a citric acid cleaning would be performed in
the same manner before the caustic/chlorine cleaning. The solution is drained to waste, and fresh
filtrate (or other clean water) is circulated to rinse the system. Once the pH of the rinse is
acceptable (matches the normal pH of the fresh filtrate water used for the rinse), the rinse is
drained and the MF system is ready to resume operation.
2.2.4.1 Chemical and Raw Material Usage
Clean-in-Place procedures are typically performed once every two to three months when the
module is new depending on feed water quality. For each chemical cleaning the following
materials are required:
• 60 gallons (240 L) of DI, RO, NF, softened, or distilled water, preferably heated to
about 100 °F (40 °C). High purity water is preferred to avoid unintentional reactions.
Cleanings during the verification testing were performed with tap water because this
was deemed appropriate for this application.
• 100 ml of 12.5% Sodium Hypochlorite.
• 340 ml of 50% Sodium Hydroxide.
12
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• 2.5 LB (1.1 Kg) of dry citric acid.
No other chemicals or raw materials are used for the filter unit.
2.2.5 Operation Limitations
Microfiltration has excellent performance records for the mechanical removal of particulates and
turbidity. The primary limitation of the technique is its inability to remove or treat dissolved
species. Microfiltration, due to the average pore size of tie membranes, is not effective at
removing dissolved trihalomethane precursors. It is capable of treating water with relatively
high turbidity levels, however high turbidity levels shorten the run times between cleaning, with
corresponding higher operating costs. Microfiltration is not regarded as a highly effective
removal mechanism for viruses. The viruses are removed by filtering through smaller pores of
the membrane, and those pores over which particle cake has formed.
In a MF system, the life of the filter may be limited by fracturing of the membrane fibers. When
the fibers break, short-circuiting of flow occurs, and the filter module exhibits a particulate
break-through. A significant, abrupt change in the particles observed in the filtrate line might be
an indication that there is a fiber break. The air integrity test that is performed on start-up of a
membrane system is designed to verify initial membrane integrity. The life of the hollow-tube
fibers is dependent on the feed water quality. High levels of turbidity and particulates will
require more frequent cleaning. The more frequent use of the air scrubbing technique reduces
the expected life of the fibers.
2.2.6 Performance Range
The unit tested is rated for 4 gpm, or a flux rate of 120 GFD. The maximum operating pressure
differential is 30 psi. In a previous ETV study, this particular unit was tested in February and
March 1999 as a package plant to treat water from the Pittsburgh, Pennsylvania Highland
Reservoir No. 1. The testing was performed according to ETV protocols. Treatment
performance during this testing included influent water with 0.1 NTU and results of the study
indicated a 6 logo reduction in Cryptosporidium oocysts. The feed water for the Pittsburgh
study was very clean, with source water turbidity in the range of 0.1-0.14 NTU, no coliform
bacteria, TDS of 200 ppm, and TOC at 2-2.5 ppm.
The testing of this unit for this ETV project was performed in New Hampshire, with different
water quality parameters, as discussed in Section 1.3.1. The manufacturer reports Pall
Microza™ systems have successfully treated waters with 40-50 NTU turbidity levels. However,
turbidity levels this high did not occur during the verification test and therefore, could not be
verified.
Typical MF filtration performance compiled from P.L. Dwyer (1996) for microbiological
challenges on various hollow-fiber MF filter units using distilled water is described in Table 2-1.
13
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Table 2-1. Typical MF filter performance
Parameter Removals
Cryptosporidium >4.91ogio
E. coli >7.8 logic
Turbidity to less than 0.1 NTU
2.2.7 Operator Skill/Licensing Requirements
The system requires a degree of specialized training, which is typically provided by the
manufacturer prior to signing over a new filter unit. Technical support is also available from the
manufacturer. Operators are also trained in the special handling requirements for safe use of the
chemicals required for cleaning. The manufacturer has complied specific safety guidelines for
the operation of this unit. Special licensing is not required to operate this piece of equipment.
2.2.8 Application of Equipment
This MF filter unit is portable, and operates at a relatively low flow rate. As such, when
combined with storage, it is well suited for applications of low demand, such as a campground,
school, small community, industrial processes, or small commercial operations. It is also used as
a package unit for larger industrial and municipal applications. The results from testing this MF
filter unit are expected to be applicable to larger MF filter units with multiple modules.
14
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Chapter 3
Methods and Procedures
The objectives of the verification testing were met through nine-tasks involving the evaluation of
membrane flux and recovery, the cleaning efficiency of the membranes, the water quality of the
filtrate, the membrane pore size distribution reporting by the manufacturer, and the membrane
module integrity. Data management and QA/QC are included in the list of tasks. The eighth task
was the microbiological challenges. The final task involved the evaluation of the Pall
Corporation O&M manual for this unit. The nine tasks were developed to be performed during
test runs lasting one complete cleaning cycle, or a minimum of 30 days for each verification test
period.
3.1 Start-up Testing
Initial testing included set-up and trial runs to establish the optimal settings for the filter unit,
including RF and AS cleaning cycle frequency, duration, and flow rate. The initial testing was
also the period used to make final adjustments in the field set-up and operational procedures.
Water quality parameters were monitored during the initial testing phase. The parameters
monitored included pH, temperature, particle counts, and turbidity. Temperature, turbidity and
particle counts were measured on a continuous basis using in-line sensors and/or flow cells for
sensor probes. The data were collected using the SCADA system, or an external laptop
computer to log the data. The computer also provided real-time monitoring of the following
filter operational parameters: flows and pressures. Where appropriate, periodic samples were
collected of both feed water and filtrate, and were analyzed for microbiological contaminants,
including E. coll and Bacillus spores.
3.2 Verification Testing
The verification testing task marks the second phase of testing in which filter runs were
performed and monitored on feed water sources designed to demonstrate the capability of the
filter unit according to the manufacturer's guidelines. The verification testing was designed for
continuous monitoring and testing of the filter equipment under routine operating conditions for
a complete cleaning cycle or of 30 continuous days of operation.
3.3 Verification Testing Schedule
The verification testing period occurred from April 30, 2000 to July 26, 2000. An additional
microbial seeding challenge occurred on August 9, 2000.
3.4 Verification Testing Tasks
The following is a description of each of the nine verification tasks.
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3.4.1 Task 1: Membrane Flux and Operation
The purpose of Task 1 was to quantify operational characteristics of the MF equipment under the
particular feed water quality at the field test site. The specific operational characteristics
evaluated under this task include the membrane flux rates, the rate of decline of the flux rate, and
the product water recoveries. The rate of flux decline provided an indication of the run duration
before cleaning is required. Data was collected on the flow and pressure differential across the
filter module over the period of flux decline.
The following were the experimental objectives of this task:
1. Establish the appropriate operational conditions for the membrane equipment for the
field site feed water quality,
2. Establish the product water recovery for the MF unit,
3. Establish the rate of flux decline over a period of extended operation.
The feed water quality was also established, and monitored throughout the filter run.
The 3-inch Test Skid MF unit was operated according the manufacturer's membrane system
operation manual until a complete cleaning cycle was required. A copy of the specific operating
instructions from the operation manual is presented in Appendix A. The filter was operated with
the frequency of RF and AS cleaning determined during the first phase initial testing. The
criteria for terminating a filter run and performing a CIP cleaning procedure was when the other
methods, RF and AS, could not adequately restore the system to the normal transmembrane
pressure and the transmembrane pressure reaches approximately 30 psi.
Operational data was monitored on a continuous basis during the test run. The parameters
monitored included the filtrate flow rate, RF flow rate, product water recovery, filtrate flux,
transmembrane pressure, feed water temperature, and power consumption. The majority of these
parameters were monitored electronically by the system control interface (SCADA system).
Operational parameters that were not monitored by the SCADA system were monitored by using
laptop computers. Data was downloaded every 2 minutes or every 10 minutes during the test
period.
The data collected for each of the monitored parameters was incorporated into a spreadsheet.
Time record histories are presented graphically for the transmembrane pressure, feed water
temperature, filtrate flux, and power consumption.
The filtrate flux was computed according to:
where: Jt = filtrate flux at time t (gfd, L/(h-m2))
Qp = filtrate flow (gpd, L/H)
S = membrane surface area
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Filtrate flux results are reported with indication of the time interval after initiation of the
experimental test run. The filtrate flux is corrected for the feed water temperature by the
following:
O YP-0.0239(T-20°C)
(2)
where: Jt = instantaneous flux (gfd, L/(h-m2))
QP = filtrate flow (gpd, L/h)
T = temperature, (°C)
S = membrane surface area (ft2, m2)
The transmembrane pressure is calculated by the following:
(3)
PI = Pressure Inside Membrane
P0 = Pressure Outside Membrane
Pp = Filtrate Pressure
Data pertaining to the cleaning process, frequency, amount used of each chemical as well as
clean water usage, is presented in tabular format. In addition, data is graphically presented for
the temperature corrected specific flux rate, transmembrane pressure, and feed water
temperature.
The term specific flux is used to refer to filtrate flux that has been normalized for the
transmembrane pressure. The specific flux is calculated by the following:
Jtm ~ Jt •=• Pi
tm
where Jta = specific flux at time t
(gfd/psi, L/(hr-m2)/bar)
Jt = filtrate flux at time t (gfd, L/(hr-m2))
Pta = transmembrane pressure (psi, bar)
The recovery of filtrate from feedwater is given as the ratio of filtrate flow to feedwater flow as
in the following equation:
%System Recovery = 100 x ( Qp /Qf)
where Qp = filtrate flow (gpd, L/h)
Qf = feed flow to the membrane (gpd, L/h)
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3.4.2 Task 2: Cleaning Efficiency
The objective of this task is to evaluate the effectiveness of the manufacturer's specific chemical
cleaning procedures in restoring the finished water productivity to the membrane system.
Chemical cleaning is an integral element of the operation and maintenance of a MF membrane
system. The Pall Corporation 3-inch Microza™ filter system was run until the transmembrane
pressure reached 30 psi. This occurred at intervals of between 8 hours and 3 days. The
membrane was unable to reach the 30-day cleaning cycle due to the presence of algae in the feed
water and was cleaned four times during testing. Please refer to Phytoplankton Analysis data in
section 4.4.3.
Since the cleaning solutions selected can be water quality specific, the feed water quality was
measured at the time of cleaning. The initial testing evaluated the effectiveness of several
cleaning solutions prior to the verification test run. The following procedure was used to
perform a chemical CIP procedure on the test filter unit.
CIP materials and procedural guidelines are as follows:
Materials required:
• 60 gallons (240 L) of DI, RO, NF, softened, or distilled water, preferably heated to
about 100 °F (40 °C). Fligh purity water is preferred to avoid unintentional reactions.
Cleanings during the verification testing were performed with tap water because this
was deemed appropriate for this application.
• 100 ml of 12.5% Sodium Hypochlorite.
• 340 ml of 50% Sodium Hydroxide.
• 2.5 LB (1.1 Kg) of dry citric acid.
Note that the sequence of chemicals can be reversed depending on the water chemistry.
For instance, if metals are present in the water in large quantities, the acid step is usually
performed first.
Recommended Procedure:
Although a form of this procedure is contained in the O&M manual, this procedure is specific to
the unit.
1. The feed connection can be disconnected to isolate the system, if required. If the normal
drainage system cannot accept small amounts of high and low pH water, as well as free
chlorine content of up to 200 ppm, alternate provisions for gravity drainage of this liquid
must be made.
2. Put the system in Manual Mode, and drain completely. Close all valves.
3. Add 15 gallons (60 L) of water to the feed tank.
4. Open HV14 (Filtrate Recycle). Start the Feed Pump and adjust speed until flow through FT1
(Flow Transmitter 1, Feed) is about 50% of normal forward flow. Adjust HV5 (Excess
Recirculation adjustment valve) so that the filtrate flow through FT2 (Flow Transmitter 2,
Filtrate) is about two thirds of the flow through FT1.
5. Add first step chemicals. The caustic/chlorine step is usually first. If so, add the sodium
hydroxide and sodium hypochlorite to the feed tank. The amounts listed above should give a
0.2N solution of sodium hydroxide, and 200 ppm of chlorine.
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6. After 5 minutes, check the pH and free chlorine content of the water, if possible. pH should
be 11.5 - 12.5. Free chlorine should be at least 50 ppm. If the measured values are too low,
adjust as required.
7. Circulate for 30 minutes, then drain the system.
8. Fill the feed tank with 15 gallons (60 L) of water, and circulate for 5 minutes. Drain.
9. Fill the feed tank with 15 gallons (60 L) of water, and add the second chemical, typically the
citric acid (to give a 2% w/w solution). Circulate for 30 minutes. Drain.
10. Fill the feed tank with 15 gallons (60 L) of water, and circulate for 5 minutes. Check pH,
then drain.
11. If pH in Step 10 is acceptable, the system can be put back in operation. Otherwise, repeat
rinse with feed water as required.
During the cleaning process the following parameters were documented in a water resistant
logbook:
cleaning chemicals used and their respective order of usage;
quantities of cleaning chemicals used;
hydraulic conditions of cleaning;
duration of each cleaning step;
• initial and final temperatures of chemical cleaning solution; and
quantity and pH of residual waste volume to be disposed.
Once the system was cleaned, it was put back on line, and the operational characteristics
following the cleaning process were monitored. The operational characteristics monitored
included the filtrate flux, transmembrane pressure, and the rejection capabilities of the filter unit.
In addition to the operational parameters, selected water quality parameters were monitored
before, during, and after cleaning. The pH, turbidity and TDS of each cleaning solution were
measured by the SCADA system and by sampling from the effluent periodically during the
cleaning process according to the schedule presented in Table 3-1. In addition, the concentration
of chlorine was measured in the filtrate water prior to cleaning, and again immediately following
the cleaning procedure. Physical observations of the water effluent, such as color, or visible
turbidity were noted in the logbook at the time of observation.
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Table 3-1. Analytical and Operational Data Collection Schedule
Parameter Frequency
pH of cleaning solution initial 1/episode
pH of cleaning solution during process 1 /episode
pH of cleaning solution final 1 /episode
IDS of cleaning solution initial I/episode
IDS of cleaning solution during process I/episode
IDS of cleaning solution final I/episode
Turbidity of cleaning solution initial 1/episode
Turbidity of cleaning solution during process 1/episode
Turbidity of cleaning solution final 1/episode
Oxidant residual initial (if used) 1/episode
Oxidant residual final (if used) 1/episode
Visual observation of backwash waste initial 1/episode
Visual observation of backwash waste final 1/episode
Flow of MF unit prior to cleaning 1/episode
Pressure of MF unit prior to cleaning 1/episode
Temperature of MF unit prior to cleaning 1/episode
Flow of MF unit after cleaning 1/episode
Pressure of MF unit after cleaning 1/episode
Temperature of MF unit after cleaning 1/episode
The information gathered during the Task 2 activities was entered into a spreadsheet. The
efficacy of chemical cleaning was evaluated by the recovery of specific flux after chemical
cleaning, calculated according to the following equation:
(3) recovery of specific flux =100x
Jsi
where: Jsf = Specific flux (gfd/psi, L/(h-m2)/bar) at end of current run (final)
Jsi = Specific flux (gfd/psi, L/(h-m2)/bar) at beginning of subsequent run (initial).
Comparisons were made of the recovery of specific flux and the initial specific flux (Jsi)
measured for the subsequent filtration run with the recoveries and initial specific flux from
previous or historic cleaning for the same filter unit, to evaluate the potential for irreversible loss
of specific flux and projections for usable membrane life.
In addition to the specific flux recovery, the loss of specific flux from the beginning of testing
was computed by the following equation:
(4) Loss = 100 x,
JsiO
where: JsiO = Specific flux (gfd/psi, L/(h-m2)/bar) at the time zero point of membrane testing
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3.4.3 Task 3: Finished Water Quality
Water quality data was collected for the feed water and membrane filtrate water, as shown in the
sampling schedule below, during the membrane test runs of Task 1. The filter unit was operated
until the transmembrane pressure reached 30 psi. At this point the filter unit was shut down and
the membrane was chemically cleaned. The terminal conditions were defined by the
manufacturer in the operation manual.
Water quality parameters were monitored during tie filter run. Both the feed water and the
filtered water was tested for the following parameters:
• total alkalinity, once per month
• hardness, once per month
• total organic carbon (TOC), weekly
• dissolved organic carbon (DOC), weekly
• total dissolved solids (TDS), every two weeks
• total suspended solids (TSS), every two weeks
• iron, every two weeks
• manganese, every two weeks
• color, weekly
• total coliform bacteria, weekly
• Bacillus spores, twice during test period
algae, weekly
• UV254 absorbance, weekly
dissolved oxygen, daily
• temperature, continuous basis
• pH, twice per week
• turbidity, continuous basis
• particle counts, continuous basis.
Task 3 evaluated the rejection effectiveness of the filter and addressed the primary objective set
out for the verification testing. The goal of this portion of the ETV was to demonstrate the unit's
ability to produce water that would comply with current regulations in the Surface Water
Treatment Rule (SWTR) and Enhanced Surface Water Treatment Rule (ESWTR).
Temperature of the feed water was measured using in-line sensors and/or flow cells for sensor
probes. Data for temperature, flow rate, turbidity, particle counts and transmembrane pressure
were collected using either the SCADA system provided with the unit, or a separate laptop
computer. Turbidity measurements were recorded with two in-line turbidimeters, one in the feed
water line, and one to measure the filtered water. In-line turbidity measurements were checked
with a bench top meter on a daily basis. Particle counts were made on a continuous basis for the
feed water and filtered water using in-line particle counters. The dissolved oxygen was
measured on a daily basis. The pH was measured at least twice per week.
Samples for total alkalinity and total hardness were collected once during the cleaning cycle or
30 day period, in the middle of the filter run. TDS and TSS were collected every two weeks
during the filter run. The results of the TSS analyses constructed a mass balance of suspended
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solids through the membrane system. Samples for the remaining parameters were collected on a
weekly basis during the filter runs.
Total coliform sampling was performed on a weekly basis and samples for indigenous Bacillus
spores were collected two times during the test. The bacteria samples were collected from a tap,
on both sides of the filter unit, that was sterilized with Clorox bleach. The samples were then
immediately preserved with 0.008% Na2S2O3 and by placing them in coolers with ice. The
samples were delivered to the laboratory within 24 hours of sampling. The total coliform
bacteria counts and Bacillus spore analyses were performed by the UNH Water Treatment
Technology Center laboratories.
Samples for algae analysis were collected on a weekly basis (or daily if an algae bloom occurs),
preserved with Lugol's solution according to Standard Method 10200B, and placed in a cooler at
4° C for transport to the laboratory within 24 hours. Parameters that have holding times greater
than 24 hours were transported to the laboratory in coolers at 4°C within a 24-hr period as well.
Total organic carbon and UV Absorbance at 254 nm were analyzed by the UNH Water
Treatment Technology Center laboratories.
Operating conditions and operation resources were recorded on a regular or continuous basis
throughout each filter test run. The operating conditions included the flow rate, transmembrane
pressure, number of cleanings, flow rate through the filter, total gallons filtered, filtrate flux,
power consumption, and operator hours. The terminal conditions used to halt a filter run were
also recorded for chemical cleaning operations performed during the testing period. Operation
parameters during cleaning were also recorded in a logbook.
Filter cleaning operations performed during the test runs were fully documented as to the
operating conditions at the time of the decision to clean the filter, the times for cleaning, and the
time that the filter unit was brought back on-line. This data was available from the filter unit
SCADA system for the RF and AS cleaning. Similar records were recorded in the logbook for
CIP chemical cleanings. Records were kept on the chemical and clean water usage and clean
water. Records were kept in a field book, and transcribed to an Excel spreadsheet, where the
data was analyzed and presented in tabular and graphical form. Logs were also kept of operator
hours and activities, to evaluate the number of man-hours required to operate the system, as well
as establish the level of skill required.
A daily log was maintained of hydrologic, and unusual, events within the feed water watershed
during the verification testing filter runs. The criteria for recording events were if the event had
a potential effect on the feed water quality during the test runs. Hydrologic events such as
rainfall, snowmelt, temperature fluctuations, flood events, etc. were noted. Anthropogenic
activities which changed the source water quality were recorded and placed in the files.
3.4.4 Task 4: Reporting of Maximum Membrane Pore Size
Manufacturers typically report an average pore size for their membrane systems. Membranes
have a distribution of pore sizes, which is represented by the mean value. The maximum pore
size in the distribution, however, has significance with respect to the maximum size particles that
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are physically able to pass through the membrane. Quantifying the pore size distribution is
necessary to assess the potential for the membrane to remove microorganisms of particular size.
The objective of this task was to report the maximum membrane pore size, and the 90%
membrane pore size. The Manufacturer was contacted to provide pore size distribution test
results.
3.4.5 Task 5: Membrane Integrity Testing
The objective of this task was to demonstrate that the membrane integrity was maintained
throughout the test. The membrane was monitored to evaluate whether the integrity of the
membrane had been compromised during the testing program. Compromises in the case of the
Pall Corporation Microza™ hollow-tube membrane system are defined as broken membrane
fibers. When the fibers break, water can enter the open end of the hollow tube, which has a
much larger diameter than the maximum pore size of the filter, and consequently
microorganisms would be able to pass through the filter module.
The membrane integrity was evaluated by both an indirect and a direct method. The indirect
method was the continuous measurement of particle counts with an in-line particle counter in
both the feed and filtered water line. An increase in the particle counts for the filtered water
following a cleaning event may be indicative of broken membrane fibers.
The direct method of evaluating the membrane integrity was performed by the air pressure-hold
test, where minimal loss of the held pressure (generally less than 1 psi every 5 minutes) at the
filtrate side indicates a passed test, while a significant decrease of the held pressure indicates a
failed test. Integrity testing was performed as per manufacturer's specification after each
membrane chemical cleaning. The test involved fully wetting the membrane, draining the water
from the membrane cartridge, opening the filtrate lines to the air and applying 20 psi of
compressed air to the feed water side of the membrane. Less than a loss of 1 psi of air pressure
over a 5-minute time period indicated a successful air integrity test. The time was measured with
a stopwatch and the pressure gauge was monitored visually at one-minute intervals.
3.4.6 Task 6: Data Management and Reporting Protocols
Data collection of most of the operating parameters was performed using either the SCADA
system of the filter unit, or a laptop computer in conjunction with an analog-to-digital converter.
Data was collected and organized into text files using a custom Visual Basic program. The text
files were formatted so that they are readily imported into Microsoft Excel spreadsheets or
Microsoft Access data files.
The operational data collected in this manner included the transmembrane pressure; filter flow
rate; specific flux, and time of operation. In addition, water quality data were also collected on a
continuous basis. Temperature and turbidity were recorded at regular intervals throughout the
test using flow through cells with appropriate probes and meters coupled to the data logger.
Particle counts from the in-line particle counters were also monitored on a continual basis
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throughout the tests. The data logging programs wrote data to external files on the hard drive,
and a copy of the data files were made to a floppy disk for back-up.
Real-time operational measurements were recorded manually and logged in a dedicated logbook
containing water resistant rag-content paper (Appendix B). Photocopies were made of each
day's data entry in the logbook at the end of each day, signed, dated, and placed in the equipment
testing files. The logbook remained at the test site in a secure location during the testing period.
Data entry logs included the name of the technician, date and time of entries, and notations on
hydrologic conditions for that day. Parameters that were recorded manually included power
consumption rate, cumulative power consumed, chemical cleaning times, chemicals and
consumption, clean water and consumption, duration of filter cleaning, operator's hours and
tasks, and sampling data. Sampling data included the date and time of grab sample collection,
samplers, number and size of sample containers filled, preservatives used, and analyses to be
performed. Unusual events or problems that occurred during the sampling or operation of the
filter were noted in the logbook.
The data collected in the logbook was entered into an Excel spreadsheet or an Assess Database
file on a daily basis, thus providing for real-time analyses of the operational data. A hard copy of
the data entry was generated following each day's data entry, and was checked against the
originals for errors. Data errors were noted on the hard copy, and corrected in the database.
Hard copies were then made of the corrected spreadsheet or database file, and rechecked.
Water quality samples collected during the testing period were recorded into the logbook, and
also recorded onto a chain-of-custody form. This form subsequently accompanied the samples to
their final destination, typically the laboratory. Possession changes were documented on the
chain-of-custody form. Following the analysis of each sample, a copy of the chain-of-custody
form was maintained in the project files. Each filter lun was designated with an unique
identification number, which was written on each sample container. The identification number
was used in the laboratory to maintain continuity, and to keep track of the analyses results.
3.4.7 Task?: QA/QCPlan
This Quality Assurance/Quality Control Plan describes the procedures that the UNH WTTC and
AST took to assure the quality of information collected for the verification test. Quality
Assurance (QA) is a set of planned and systematic actions to ensure that data collected during the
investigation were valid, sound, and retrievable. QA helps to avoid data omissions and
oversights. These measures are essential in optimizing the usefulness of the data and ultimately
in generating accurate conclusions from the data. When specific items of equipment or
instruments were used, the objective of QA/QC procedures were to maintain the operation of the
equipment or instruments with the ranges specified by the Manufacturer or by Standard
Methods.
3.4.7.1 Overall Project Quality Objectives
Data Quality Objectives (DQO) were quantitative and qualitative statements specifying the
quality of the environmental data required to achieve the objectives of the FOD. DQO define the
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confidence level of the data that is acceptable for each specific activity during the investigation
with regard to both sampling error and analytical error.
Ideally, a confidence level of 100% was the goal; however, the variables associated with the
processes (field and laboratory) inherently contribute to reducing this confidence level. In order
to achieve the DQO, specific data quality requirements such as criteria for accuracy and
precision, sample representatives, data comparability and data completeness were specified.
The quality indicators used in this program are precision, accuracy, representativeness,
completeness, and comparability (PARCC). The definitions are as follows:
Precision - a measure of the reproducibility of measurements under a
given set of conditions. This measurement is calculated by either Relative
Percent Difference (RPD) or Relative Standard Deviation (RSD).
Accuracy - a measure of how close the data come to the true value.
Accuracy measures the amount of bias present in the measurement system.
Representativeness - the degree to wnich data accurately and precisely
represent selected characteristics of the media sampled.
Completeness - the amount of valid data obtained compared to the amount
that was expected under "normal" conditions.
Comparability - an expression of confidence with which one data set can
be compared with another.
3.4.7.2 Field Investigation Quality Objectives
The objectives with respect to the field investigation were to maximize the confidence in the data
in terms of PARCC. Field duplicates and field blanks were collected to measure precision and
accuracy. The data quality objective for field duplicates is to achieve precision consistent with
the Laboratory Duplicate Precision required in EPA's Certification Laboratory Program (CLP).
Precision was calculated as Relative Percent Difference (RPD) if there were only two (2)
analytical points and Relative Standard Deviation (RSD) if there were more than two (2)
analytical points.
Submission of field and method blanks checked accuracy. Submission of blanks monitored
errors associated with the sampling process, field contamination, sample presentation, and
sample handling. The data quality objective for field blanks met or exceed those criteria
established in the EPA's CLP. In the event that the blanks were contaminated and/or poor
precision is obtained the associated data was qualified. Through the submission of field QC
samples the distinction was made between laboratory problems, sampling technique, and sample
matrix variability.
The data quality objective for the completeness of data with respect to the sampling (field
investigation) was that data be within an appropriate confidence level. Efforts were made to
obtain valid data for sampling points, particularly those sampling points classified as critical
points. Critical-point samples were selected as subsequent QC samples (duplicate and matrix
spikes).
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In order to establish a degree of comparability such that observations and conclusions could be
directly compared with historical data, standardized methods of field analysis, sample collection,
holding times, and sample preservation were used. In addition, field conditions were considered
prior to sampling, in order to attain a high degree of data comparability.
3.4.7.3 Laboratory Quality Objectives
The laboratory demonstrated analytical precision and accuracy, through analysis of laboratory
duplicates and matrix spike duplicates. Laboratory accuracy was demonstrated by the addition
of surrogate and matrix spikes. Accuracy was measured by percent recovery. The percent
recovery for the matrix spikes was calculated according to:
(5) %Recovery=
SA
where:
SSR = spiked sample results,
SR = sample result,
SA = spike amount added.
Laboratory blanks and controls were used to determine accuracy. The percent recovery for
laboratory control samples were calculated by the following:
Measured Concentration
(6) %Recovery = - = -
True _ Concentration
Precision was presented as RPD and RSD, whichever is applicable to the specific type of QC
sample. The RSD was calculated by the following:
s
(7) %Relative Standard Deviation = 100 x=
X
where:
S = standard deviation
X = arithmetic mean of the recovery values.
The standard deviation is given by:
(8)
where: Xi = individual recovery values,
n= number of determinations.
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3.4.7.4 Criteria
The laboratory was expected (as an ideal objective) to achieve EPA approved practical
quantitation limits (PQL) for samples analyzed. However, it should be noted that actual
detection limits are sample-specific and depend on variables such as dilution factors, sample
matrices and the specific analyte. The handling of data reported at, or near, the PQL was done
cautiously, since the stated data-quality objectives for accuracy and precision may not translate
well in certain cases.
3.4.7.5 Control of Procedures
Procedures used in this investigation were assessed for correctness prior to their implementation.
These procedures, including sampling techniques, analytical techniques, data compilation, data
analysis, and data reporting, were in accordance with accepted professional standards and
methods. The Project Director approved analytical procedures prior to their implementation. To
verify the correct application of procedures, work described in the FOD was documented to
provide a paper trail from data collection to the reporting stages of the project. Changes to the
proposed procedures were approved by the Project Director. The Project Director insured that
updated procedures were distributed to appropriate personnel.
3.4.7.6 Chain-of-Custody
The primary objective of the Chain-of-Custody procedure is to create an accurate written record
that can be used to trace the possession and handling of samples collected. Chain-of-Custody
started in the laboratory with the bottles the laboratory provided for sampling. It followed those
containers through sample collection, analysis, and up to their final disposition. Sample custody
during the sampling phase of this project was maintained by the samplers, who were responsible
for documenting each sample transfer and maintaining custody of the samples until they were
relinquished to the laboratory personnel. Chain-of-Custody forms from the testing are provided
in the appropriate appendices.
3.4.7.7 Documentation
During the sampling process information was recorded on the Chain-of-Custody form, sampling
data sheet, and in the field notebook.
Chain-of-Custody - The Chain-of-Custody was used for tracking the sample
through phases of handling.
Field Logbook - The logbook was used to record operational, maintenance, and
hydrologic data. Entries were recorded documenting each sampling event, the
conditions at the time of sampling, and the personnel making the measurements.
The logbook was also used to document necessary or appropriate deviations from
standard sampling methodology.
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3.4.7.8 QC Samples
To obtain a quantitative measure of the reproducibility of the sampling and analysis results, QC
samples were collected or supplied. QC samples included trip blanks, field blanks, duplicates,
triplicates, and matrix spikes. Table 3-2 presents the QA/QC criteria objectives.
Trip (Travel) Blank
A Trip Blank was provided by the laboratory and accompanied the sample containers
throughout the collection activity. One trip blank accompanied each sample shipment or
cooler of samples and was not opened until analysis.
Field Blank
A Field Blank consists of a sample of deionized water (supplied by the laboratory) that
has been put through the decontaminated sample-collection equipment and into sample
bottles. One Field Blank was collected for each day of sampling.
Duplicate Sample
A Duplicate Sample was collected in a manner that produces two samples with a high
degree of homogeneity. Samples were collected from the same collection container. If a
large quantity of water was needed for a number of analyses then each collection was
among a pair of sample bottles. Duplicate samples were collected during the verification
testing. One set of duplicate samples was collected during each microbiological
challenge. The duplicate sample was given a fictitious number so that the laboratory did
not know it was a duplicate sample, and was sent to the laboratory as a "blind" duplicate.
Sample Spikes and Performance Evaluation Samples
Spikes for microbiological analyses were prepared by the laboratory, with a frequency of
one per week, or one per every 10 samples analyzed. The spikes were used by the
laboratory to evaluate the accuracy of the analytical instruments. A performance
evaluation sample for turbidity was analyzed just prior to the start of each verification
testing run, as part of an on-site QA evaluation of turbidity measurement techniques.
Triplicate Sample
For every 10 samples collected, one sample was collected in triplicate to be used for the
laboratory's QC testing. Triplicates were collected in the same manner as the Duplicate
Samples.
Method Blanks
Laboratory-grade Milli-Q water was used for method blanks, to evaluate the baseline of
the analytical instrument. A method blank was collected for every ten samples analyzed.
It provided the means to evaluate interference from the sample bottle and sample
preparation methodology. If measurable quantities were reported in the method blank, all
containers were cleaned again, or the laboratory methods modified until subsequent
method blanks contain no significant concentrations.
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Table 3-2. QA/QC Criteria Objectives
QA/QC Sample Type Objective for Aqueous
Parameter Samples
Precision Duplicates/Replicates Less than 15% RPD
(Blind or Labeled)
Laboratory Duplicates Less than 15% RPD
(Unspiked)
Laboratory Duplicate Consistent with current
(Matrix Spike Duplicate) EPA CLP
Accuracy Field or Trip blanks Less than the PQL
Laboratory blanks Consistent with current
EPA CLP
3.4.7.9 Identification of Samples
An identification number was assigned to each sample as soon as it was obtained. The number
was unique to each sample. The number was written on the sample label and recorded on the
Chain-of-Custody form. If the sample was subdivided, each subsample was assigned its own
identification number, which retains each subsample's association with the original sample.
Additional information written on the label included time and date of sample, sampler's initials,
preservatives used, test site identification, and parameters analyzed.
3.4.7.10 Handling
Samples were handled in a way that does not adversely affect their future use. Containers were
free of foreign substances, particularly any substance which would have changed the sample or
interfere with required analyses and tests. The laboratory provided containers of appropriate size
and material for each type of analysis. The samples were fixed with the appropriate preservative.
Samples analyzed were stored in a manner which prevented changes in temperature and which
protected the sample from breakage. In the field, samples were kept in iced coolers with an
internal temperature sufficient to maintain the integrity of the sample. Each sample container
was placed in a plastic bag and sealed to prevent cross contamination with other samples.
Samples not sent to the laboratory on the day of collection were placed in a controlled
refrigerated storage unit on the site, which provided protection against damage or loss until
samples were sent to the laboratory. Samples placed in this storage overnight included samples
for TOC, UV, iron, and manganese. Temperature of this storage unit was not monitored. It is
possible that this storage unit may have adversely affected results of the TOC and UV samples, if
the unit was not maintained at an appropriate temperature.
3.4.7.11 Sample Transport
Samples were packed to prevent breakage and ice packs were used to maintain an internal
temperature sufficient to protect the integrity of the samples. The Chain-of-Custody
accompanied the samples from the time of collection until they were received by the laboratory.
Each party handling the samples were required to sign the Chain-of-Custody signifying receipt.
A copy of the completed form was provided by the laboratory along with their report of results.
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3.4.7.12 Calibration of Field Instruments
Field instruments were used to measure parameters of temperature, pH, dissolved oxygen,
particle counts, and turbidity. Several of these parameters were measured on a continuous basis
using flow-through cells and in-line probes. Separate probes were calibrated and used to spot
check the in-line instrument calibration. For example, a bench-top turbidimeter was used to
check the calibration of the in-line turbidimeters.
A log was kept of the calibration check activities by the field personnel. It included the date of
the calibration check, concentration of the check standard, the reading obtained, whether it was
reset, the reading after resetting, and the initials of the person doing the calibration check.
3.4.7.12.1 General Field Equipment Verification
Quality Assurance verifications were performed on tie measurement devices on the filter unit
itself, and also on the instrumentation used to characterize the feed water and filtered water. The
equipment on the filter unit itself requiring calibration included the flow meter, tank level
sensors, in-line turbidimeters, and temperature sensors.
The flow through the filter was monitored by in-line flow meters coupled to a data logger. The
feed and filtered water flow meter flowrates were verified volumetrically at the beginning of
testing using a bucket-and-stop-watch technique.
The pressure gages used to measure the pressure head differential were calibrated prior to the
test. Pressure differential was measured on a continuous basis using pressure transducers. The
calibration curve of the transducers was established prior to testing, and was rechecked before
each verification testing run. Daily readings were made of pressure gages, recorded in the
logbook, and compared to the data logger readout as a check on the performance of the
transducers. If a significant discrepancy was noted, the manual reading frequency of the gages
were increased, and the data validity of each evaluated by the end-of-run recalibrations.
All tubing and piping was inspected for both the filter unit and the flow-through cells used for
continuous field parameter measurement. The tubing was inspected prior to the test for excess
sediment build-up, and cracking. Leaks were fixed upon discovery.
3.4.7.12.2 Specific Equipment QA Verification
A routine daily walk-through during testing was established to verify that each piece of
equipment or instrumentation was operating properly. Operational records were displayed on the
SCADA system and checked for abnormalities. Daily readings of the in-line flow meter, and the
pressure gages were taken, along with daily calibration checks of the in-line turbidimeters, and
particle counters, and field parameter instruments. The individual calibration requirements for
each instrument used in the testing are described below.
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EH
Analyses for pH was performed according to Standard Methods 4500-H+. A 2 point calibration
of the pH meter used in this study was performed once per day when the instrument was in use.
Certified pH buffers in the expected range were used. The pH probe was stored in the
appropriate solution defined in the instrument manual. Transport of carbon dioxide across the
air-water interface can confound pH measurement in poorly buffered waters. Measurement of
pH was performed in a confined flow-through cell for a continuous record, which also
minimized the effects of carbon dioxide loss to the atmosphere.
Temperature
Readings for temperature were conducted in accordance with Standard Methods 2550. Raw
water temperatures were measured electronically on a continuous basis in a flow-through cell.
The temperature meter had a precision of at least 0.1 °C, and was calibrated weekly against a
precision thermometer certified by the National Institute of Standards and Technology (NIST).
Dissolved Oxygen
Analysis for dissolved oxygen (D.O.) was performed according to Standard Method 4500-O
using the membrane electrode method. The techniques described for sample collection was
followed very carefully to avoid causing changes in dissolved oxygen during the sampling event.
Samples taken for dissolved oxygen were analyzed immediately using the D.O. membrane-
electrode probe.
Bench-top Turbidimeters
Turbidity analyses were performed according to Standard Methods 2130 with either a bench-top
or in-line turbidimeter. In-line turbidimeters were used for measurement or turbidity in the
filtrate water and feed water.
During each verification testing period, the bench-top turbidimeters remained on continuously.
Once each turbidity measurement was completed, the bench-top unit was switched back to its
lowest setting. Glassware for turbidity measurements were cleaned and handled using lint-free
tissues to prevent scratching. Sample vials were stored inverted to prevent deposits from
accumulating on the bottom surface of the cell.
Grab samples were collected daily for analysis using a bench-top turbidimeter. Readings from
this instrument served as reference measurements throughout the study. The bench-top
turbidimeter was calibrated within the expected range of sample measurements at the beginning
of package plant operation and on a weekly basis using primary turbidity standards of 0.1, 0.5,
and 3.0 NTU. Secondary turbidity standards were obtained and checked against the primary
standards. Secondary standards were used on a daily basis to verify calibration of the
turbidimeter and to recalibrate when more than one turbidity range was used.
-------
The method for collecting grab samples consisted of the following: running a slow, steady
stream from the sample tap; triple-rinsing a dedicated sample beaker in this stream; allowing the
sample to flow down the side of the beaker to minimize bubble entrainment; double-rinsing the
sample vial with the sample; carefully pouring from the beaker down the side of the sample vial;
wiping the sample vial clean; inserting the sample vial into the turbidimeter; and recording the
measured turbidity. For the case of cold water samples that cause the vial to fog preventing
accurate readings, the vial was allowed to warm up by partially submersing it into a warm water
bath for approximately 30 seconds.
In-line Turbidimeters
In-line turbidimeters were used for feed water and filter water monitoring during verification
testing and were calibrated and maintained as specified in the manufacturer's operation and
maintenance manual. It was necessary to verify the in-line readings using a bench-top
turbidimeter at least daily; although the mechanism of analysis was not identical between the two
instruments the readings were comparable. Should these readings suggest inaccurate readings
then the in-line turbidimeters were recalibrated. In addition to calibration, periodic cleaning of
the lens was conducted, using lint- free paper, to prevent particle or microbiological build-up that
could produce inaccurate readings. Daily verification of the sample flow rate was performed
using a volumetric measurement. The in-line turbidimeter flowrates were checked daily to verify
that the flow was within the manufacturers recommended range of 250-750 mL/minute.
Instrument bulbs were replaced on an as- needed basis. It was verified that the LED readout
matched the data recorded on the data acquisition system.
In-line Particle Counters
In-line particle counters were employed for measurement of particle concentrations in both feed
waters and filtrate waters. Laser light scattering or light blocking instruments were used in the
verification testing.
The following particle size ranges (as recommended by the AWWARF Task Force) were
monitored during the verification testing:
• 2-3 urn
3-5
5-7
• 7- 10
• 10-15 urn
Problems experienced with the particle counting instrument were documented in the daily
logbook. Modifications or remedial actions were also documented in the logbook. The flow
through the particle counters was verified volumetrically on a daily basis and the flow was also
checked so that the flow was within the manufacturer recommended limits of approximately 100
mL/minute ±5%.
32
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The use of particle counting to characterize feed water and filtered water quality was planned as
one surrogate method for evaluation of microbiological contaminant removal, and was supported
by analytical sampling results for Cryptosporidium (size range 2 to 5 micron). The particle
sensor selected for this project was capable of measuring particles as small as 2 |j,m.
Performance criteria included less than a ten percent coincidence error for any one measurement.
Calibration. Calibration of the particle counter was performed by the instrument manufacturer.
The particle counters used during verification testing were Met One particles counters model #
PCXCE155B. Both particle counters were manufactured in November 1999 and were factory
calibrated by the manufacturer on November 17, 1999 according to the labels affixed to the
particle counters. Field verification of the particle counter calibration was not performed
according to the ETV Protocol; however the raw water particle counter measurements were
compared to another Met One particle counter that was also simultaneously measuring the raw
water particles. No significant deviation between the two particle counters was noted.
Maintenance. The need for routine cleaning of the sensor cell is typically indicated by: 1)
illumination of the sensor's "cell" or "laser" lamps, 2) an increase in sampling time from
measurement to measurement, or 3) an increase in particle counts from measurement to
measurement. During the phase 1 initial testing, the sensor's "cell" and "laser" lamps and the
sampling time were checked periodically.
3.4.7.13 Maintenance
Routine Preventive Maintenance (PM) was conducted on instruments used in the field.
Maintenance was based on the recommendations of the instrument manufacturer and experience
gained through use of the instrument in the field. A log of these activities was kept and detailed
the PM performed, when it was performed, and the name of the person doing the work.
3.4.7.14 Laboratory QA/QC
The laboratory was responsible for timely analysis of the samples according to approved
methods. The analysis report included the following:
• Method of analy si s,
• Detection limits,
• Copy of the Chain-of-Custody,
• Analysis results of samples listed on the Chain-of-Custody,
• Analysis results of QA/QC samples,
• Documentation of analytical problems encountered and the corrective procedures taken to
solve those problems.
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3.4.7.15 Project Quality Assessment
3.4.7.15.1 Data Quality Assessment
Overall data quality was assessed by a thorough understanding of the Data Quality Objectives
(DQOs) developed for the FOD.
3.4.7.15.1.1 Overall Project Assessment
The project data was closely monitored for accuracy, precision and completeness by:
1) Maintaining thorough documentation of all decisions made during each
phase of sampling.
2) Field and Laboratory Audits
3) Thoroughly reviewing (validating) the analytical data as they were
generated by the laboratory
4) Providing appropriate feedback as problems arose in the field or at the
laboratory
3.4.7.15.1.2 Field Data Quality Assessment
To assure 1hat field data were collected accurately and properly, the Project Director
issued specific written instructions to personnel involved in field data acquisition. These
instructions, in the form of a sampling and analysis plan, were written for each different
type of sampling effort. The QA personnel performed field audit(s) during the
investigation to document that the appropriate procedures were being followed with
respect to sampling. These audits included a thorough review of the field books used by
the project personnel to verify that tasks were performed as specified in the instructions.
Evaluation of field blanks and other field QC samples provided indications of data
quality. If a problem arose, corrective procedures were instituted for future field efforts.
3.4.7.15.1.3 Data Quality Assessment
A preliminary review was performed to verify necessary paperwork (Chain-of-Custody,
analytical reports, laboratory personnel signatures) and deliverables. A detailed quality
assurance review was performed by the QA personnel to verify the qualitative and
quantitative reliability of the data as they were presented. This review included a detailed
review and interpretation of data generated. The primary tools used included guidance
documents, established (contractual) criteria, and professional judgment. Once the
laboratory analytical data were validated, the data were assessed by comparison with
analytical results obtained from previous samplings.
34
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A quality assurance report was prepared for each testing event based upon the review of
the analytical data. This report stated the qualitative and quantitative reliability of the
analytical data. The report consisted of a general introduction section, followed by
qualifying statements that were taken into consideration for the analytical results to best
be utilized. During the course of the data review, a documentation package was prepared
which provided the backup information, which accompanied qualifying statements
presented in the quality assurance review.
Once the review had been completed, the QA personnel submitted the data to the Project
Director. The approved data tables and quality assurance reviews were signed and dated
by the QA personnel.
3.4.7.15.2 On-Site Audit
An on-site audit was conducted during field activities to review field-related quality-assurance
activities. The audit was conducted by the QA personnel. This audit took the form of a checklist
that assisted the QA personnel in checking the necessary quality-assurance details.
Specific elements of the on-site audit included the verification of the following:
Completeness and accuracy of sample Chain-of-Custody forms, including
documentation of times, dates, transaction descriptions, and signatures.
• Completeness and accuracy of sample identification labels, including notation
of time, date, location, type of sample, person collecting sample, preservation
method used, and type of testing required.
• Completeness and accuracy of field notebooks, including documentation of
times, dates, sampling method used, sampling locations, number of samples
taken, name of person collecting samples, types of samples, results of field
measurements, and problems encountered during sampling.
• Adherence to sample collection, preparation, preservation, and storage
procedures.
3.4.7.15.3 Corrective Procedures
Field quality assurance activities were reported to the Project Director. Problems encountered
during the study affecting quality assurance were reported on a Corrective Procedures Form.
The appropriate sampler was responsible for initiating the corrective procedures and for
providing that action was taken in a timely manner, and that the desired results were produced.
Corrective procedures that were implemented were reported to the Project Director.
3.4.7.16 Certification of UNH Laboratories
The UNH Environmental Engineering Laboratories are not State or EPA certified because of the
nature of the educational mission of the University. However, the UNH FTO laboratories
underwent internal and NSF QA audits as part of the testing protocol. Analytical procedures that
were performed in the UNH Laboratories included TOC/DOC, UV254 absorbance, alkalinity,
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and hardness. Microbiological analyses {Cryptosporidium, E. coli, and Bacillus) were performed
by Analytical Services, Inc. (AST) in Williston, VT. Analytical Services, Inc. are State certified
and are teamed with UNH to perform E. coli and Bacillus spore analyses. Other parameters, e.g.
turbidity, particle counts, temperature, pH, and D.O., were performed on site.
The results of the Quality Assurance/Quality Control Plan are included in the data attached in
respective Appendices. Quantification of data precision and statistical uncertainty, the results of
the field and control blanks, and other notes pertaining to this subject are provided in Appendix
J. During the testing period, field blanks and control blanks showed expected results. Duplicate
and triplicate samples that did not fall into statistical viability were discarded and the entire test
was repeated.
3.4.8 Task 8: MicrobialRemoval Challenge
This task was designed to address the primary objective of the verification testing, to evaluate the
removal of microorganisms Cryptosporidium, E. coli, and Bacillus spores. The Microza™ filter
accomplishes this task through direct filtration through the hollow-tube membrane. Seeding of
Cryptosporidium oocysts E. coli and Bacillus spores occurred on May 3, 2000, June 21, and
August 9, 2000. The addition of seed microorganisms was performed immediately after
chemical cleaning, and again at 85% of the terminal transmembrane pressure threshold of 30 psi.
Each challenge was performed as a batch-seeding test. Each microorganism used for challenge
testing was seeded to a constant volume of feed water (between 200 and 275 gallons). Sufficient
volume of stock suspension was created in the seeding tank to sustain membrane operation for a
minimum of 30 minutes. For the protozoa seeding studies, the target final seeding concentration
in the feed water tank was approximately 7 logic. For the E. coli and Bacillus spores seeding
studies, the target final seeding concentration in the feed water tank was approximately high
enough to demonstrate at least 3 logic removal of E. coli and Bacillus spores.
The feed suspension of protozoa and bacteria was prepared in the seeding tank by adding the
concentrated stock suspensions of organisms into an appropriate tank. This reservoir was
connected to the feed water line of the filter. The water in the seed lank was completely mixed
during preparation of the seeded feed water and throughout the filtration period. After the
addition of protozoa and bacteria to the seeding tank and before the initiation of filtration,
samples were collected to establish the initial concentration of the microorganisms. Once
started, filtration continued as per normal operation, with transmembrane pressure, filtrate flux
and recirculation rate (where appropriate) monitored by the SCADA system. Sample volumes of
the feed water, filtrate water and backwash (RF) water were recorded. Filtrate water from the
microbiological challenges was discharged to waste.
During the protozoa studies, a minimum of three replicates of the filtered water samples was
prepared for analysis. Each sample was collected in sterile laboratory approved containers,
stored in a refrigerated environment, and processed within 24 hours. Cryptosporidium samples
were analyzed by AST according to EPA Method 1622. E. coli and Bacillus spore samples were
analyzed by UNH Laboratories according to Proposed Method 19 (ASTM 1994).
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3.4.9 Task 9: Operation and Maintenance Manual Evaluation
The Operation and Maintenance (O&M) manual supplied by Pall Corporation for the Microza™
MF 3-inch filter unit was evaluated by UNH throughout the course of the initial testing and
verification testing program. The 27 page document provided detailed information of the RF, AS
and chemical cleaning procedures, as well as graphical guidance to the use of the SCADA
system.
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Chapter 4
Results and Discussion
4.1 Introduction
The testing of the Pall Corporation 3-inch Microza™ Microfiltration system was initiated on
April 30, 2000 and ran intermittently due to stoppages for cleaning and other site related
stoppages until July 26, 2000. Table 4-1 presents the filter run schedule. A total of thirteen filter
runs were performed ranging from approximately 4 hours to 79 hours in length. The system
module ran for a total of 436 hours during the test period. The longest period of consecutive run
time occurred between June 11, 2000 and June 14, 2000. An additional microbial challenge
employing Cryptosporidium, E. coli, and Bacillus spores was performed on August 9, 2000, and
the operating conditions and results are discussed in Section 4.9.
Data was collected during the various phases of the testing procedure according to the methods
and procedures outlined in Chapter 3. The data logbook is provided as Appendix B. The results
of the verification test summarized in this chapter are presented according to the following tasks:
• Membrane Flux and Operation
• Cleaning Efficiency
• Finished Water Quality
• Reporting of Maximum Membrane Pore Size
• Membrane Integrity Testing
• Data Management
• Quality Assurance / Quality Control
• Microbiological Challenges
• Evaluation of O&M Manual
The verification testing process was initiated after a 5-day startup period where the flow rate,
operating pressures, and cleaning regimen was established. During this startup period, it was
determined that the target feed flow rate was 4 gpm with a 90% feed water recovery, and the
Reverse Filtration and Air Scrub would cycle every 30 and 60 minutes, respectively.
4.2 Task 1: Membrane Flux and Operation
4.2.1 Operation
The system was a self contained unit that monitored feed temperature, feed and filtrate flow
rates, feed and filtrate turbidity, and feed, filtrate and retentate pressures. Adjustments were
made either by computer touch screen, or by manually turning valves to stabilize flow within the
system. One full day with a system instructor was sufficient to initiate testing.
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Table 4-1.
Filter Run
#1
#2
#3
#4
#5
#6
#7
#8
#9
#10
#11
#12
#13
Filter Run Schedule
Start
4/30/00 12:50 pm
5/3/00 2:40 pm
5/9/00 5: 22pm
5/1 8/00 2:27 pm
6/2/00 4:28 pm
6/6/00 5: 13pm
6/7/00 12:11 pm
6/11/00 12:05 am
6/20/00 11:22 am
7/5/00 11:19 am
7/10/00 9:50 am
7/12/00 11:09 am
7/26/00 12:55 pm
End
5/2/00 11:22 am
5/4/00 12:42pm
5/12/00 2:41 pm
5/19/00 8:37 pm
6/3/00 7:47 am
6/6/00 9: 13pm
6/10/00 12:46 pm
6/14/007:51 pm
6/23/00 10:28 am
7/5/00 12:03 am
7/10/00 4:28 pm
7/12/00 4:40 pm
7/26/00 6: 5 1pm
Length of Run
(hours, minutes)
55 hours, 17 minutes
22 hours, 2 minutes
68 hours, 57 minutes
30 hours, 10 minutes
1 5 hours, 1 9 minutes
4 hours
70 hours, 35 minutes
79 hours, 46 minutes
70 hours, 52 minutes
43 minutes
6 hours, 38 minutes
5 hours, 5 1 minutes
5 hours, 56 minutes
Cumulative Run Time
(hours, minutes)
55 hours, 17 minutes
77 hours, 1 9 minutes
146 hours, 16 minutes
176 hours, 26 minutes
191 hours, 45 minutes
195 hours, 45 minutes
266 hours, 20 minutes
346 hours, 6 minutes
416 hours, 58 minutes
417 hours, 41 minutes
424 hours, 1 9 minutes
430 hours, 10 minutes
436 hours, 6 minutes
Reason for Run Termination
Compressor Failure
Water shut off at plant
Water shut off at plant
Water shut off at plant
TMP limit reached due to rust flakes in feed
water when system was put back on line
Solenoid valve failed
Water shut off at plant
TMP limit reached due to algae and iron
bacteria
Same as above
Same as above
Same as above
Same as above
Same as above
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The membrane system performed well mechanically during the testing period. The only
difficulties encountered were associated with the air compressor and the pneumatic solenoid
valves, which controlled the automatic flow valves and cooling system for the SCADA unit. The
original compressor supplied with the membrane system was not large enough to handle the
periods of peak demand for air caused by the conditions at the site (hot and humid). The problem
was solved with the installation of a larger compressor on June 6, 2000. The maximum
temperature setting within the SCADA system also was elevated to a slightly higher level to
accommodate the conditions at the site. Solenoid valves were re-taped with teflon tape to stop
air leaks, and one solenoid valve was replaced with a spare solenoid valve. The air compressor
was drained periodically to minimize the build up of water in the pressure tank and to prevent
moisture from entering the air delivery system. The desiccant that protects the compressed air
system was dried once during the testing period.
4.2.2 Flowrate
The target flowrate for the membrane system was 4 gpm. During the course of testing the filtrate
flowrate averaged 2.3 gpm for the cumulative run times and ranged from 1.8 to 6.3 gpm. The
variability in flow was due to the high fouling associated with the large amount of algae and
diatoms in the feed water. During the microbial challenges, the concern was to stress the system
under high and low transmembrane pressures. To accommodate this, the flowrate was adjusted to
create a stable testing condition throughout the challenge period. The retentate flow rate was
targeted at 10% of the feed flowrate. When the system was operating in automatic mode, the
pump varied its output according to the set filtrate flowrate. The power ramped up to provide the
necessary filtrate flow until a manually set parameter was reached. During the test period, the
pump operated between 40 and 60% of its total power capacity.
The variation in flowrate was primarily due to the seasonal algal blooms experienced during the
test period. High levels of either turbidity or particle counts were not detected. Samples of the
background water were collected and analyzed for Fats, Oils, and Greases (FOG), on May 8,
2000 (during a time when eels clogged the intake structure), but found no significant levels of
any FOG material (Appendix C). The only major variation found between the background water
conditions during the test period and the background water conditions anticipated was the high
levels of algae, diatoms, and zooplankton. Feed water analysis of these parameters occurred on
May 12, May 18, June 9, and June 21, 2000. According to local Limnologists and plant
biologists, these species would be common to this particular reservoir system in the Northeast
during spring conditions, however, the length and severity of the episode was considered
unusual. Filtrate samples were not collected for phytoplankton analyses. Algae was analyzed in
the raw water to assess if algae were fouling the membrane. The presence of algae in the feed
water was assessed to be a membrane foulant and appears to have shortened filter runs. The
algae shortened reduced run times by at least 75% as estimated by the manufacturer, wno had
anticipated run times on the order of 30 days between cleanings. A discussion of the results of
the feed water algae testing can be found in Section 4.4.3 and the analytical reports can be found
in Appendix D.
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4.2.3 Pressure
The system operated with TMP ranging from 2.9 to 30 psi with an average TMP of 14 psi. The
uppermost value that signaled an automatic air scrub and reverse filtration was set to 30 psi. The
inlet pressure to the pump averaged 8 psi. Figure 4-1 illustrates the TMP over the thirteen filter
runs.
Transmembrane Pressure
30.0
100 200 300
Test Period Time (hours)
400
Figure 4-1. Transmembrane Pressure
4.2.4 Temperature
The feed temperature ranged between 11.4and 35.3 °C, and averaged 19°C throughout the test
period. The filtrate temperature was checked in the field daily and did not vary from the feed
water temperature. During periods when the system was in recirculation mode for cleaning
purposes, the temperature of the filtrate increased but did not exceed 25° C.
4.2.5 Membrane Flux
The specific flux of the system averaged 3.60 gfd/psi and ranged from 1.27 to 14 gfd/psi. The
values of specific flux were normalized to 20°C. The statistical values of the specific flux were
calculated with operational data excluding AS and RF cycles. A summary of the filter
performance is presented in Table 4-2. The graph of the specific flux during the filter runs
appears in Figure 4-2. During the test verification period, the data for two filter runs#2 and
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#4was downloaded every 10 minutes with the SCADA system. All other filter run data was
collected at 2 minute time intervals. A printout of the SCADA information is provided in
Appendix E.
Table 4-2. Summary of Filter Performance
Feed Feed Feed
Flow Pressure Temperature
(gpm) (psi) ("O
Average
Minimum
Maximum
Std Deviation
95% Conf. Int.
2.50
1.80
9.80
0.63
(2.49, 2.51) (17.35,
17.47
0.04
36.13
6.61
17.59) (18.82,
18.88
11.44
35.26
3.14
18.94)
Filtrate Filtrate Retentate Transmembrane Specific
Flow Pressure Pressure Pressure Flux
(gpm)
2.30
1.80
6.26
0.43
(2.29, 2. 31) (4.
(psi) (psi)
4.20
0.00
31.68
2.83
15, 4.25) (15.22,
15.35
0.00
34.43
7.18
15.48)
(psi) (gfd/psi)
14.22
2.87
30.23
5.25
(14.12, 14.32) (3
3.60
1.27
14.19
1.36
.57, 3.63)
Specific Flux (@ 20 °C)
200 300
Test Period Time (hours)
Figure 4-2. Specific Flux at 20°C
4.3 Task 2: Cleaning Efficiency
The AS and RF cycles were initially set at 60 and 30 minutes, respectively. During the course of
testing the frequency of cleaning cycles was tested to optimize performance. To reduce the rate
of increase of the TMP, the frequency of the cleaning cycles was increased to every 40 and 20
minutes for the AS and the RF, respectively. This change did not dramatically alter the rate of
the increase of the TMP and the frequencies were reset to every 60 and 30 minutes. After a
chemical cleaning of the membrane on June 7, 2000, the duration of the RF was increased from
30 seconds to 60 seconds and the frequency of the AS was increased from every 60 minutes to
every 30 minutes. Prior to the adjustment the TMP had been rapidly increasing. The new
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cleaning regimen lowered TMP from 15 psi to a steady 10 psi. When the filtrate flow rate was
increased from 2.1 to 2.5 gpm, the TMP resumed its increase. The more rigorous cleaning was
not sufficient to offset the impact of the higher filtrate flow rate. The results of this portion of
the study could be attributed to the type of biological fouling caused by algae, which were
present in the feed water. The air scrub appeared to be the more effective than the reverse
filtration cleaning method for these feed water conditions.
Typical product water recovery during the operation of the unit was 93.3%, which equates to
93.3% of the filtrate flow was available for consumption and 6.7% was used for cleaning the
membrane (backwashing).
Four chemical cleanings took place during the testing. The chemical cleaning was effective in
consistently returning the TMP to starting levels of 11 psi on average. The first cleaning showed
a complete recovery of specific flux. The second, third and fourth cleanings showed improved
recovery of the original flux but not a complete recovery. The manufacturer indicated that the
algae or other aquatic organisms may have irreversibly fouled the membrane. It may be that the
cleaning times should have been longer or the cleaning solution warmer than was available at the
site. Table 4-3 summarizes the cleaning efficiency evaluation. Further details of the cleaning
events are in Appendix F.
Table 4-3. Evaluation of Cleaning Efficiency
Clean Number Clean Date Specific Flux at
20oC Before
Clean, Jsf
(gfd/psi)
Start (Jsio)
Cleaning 1
Cleaning 2
Cleaning 3
Cleaning 4
4/30/00 11.4
5/9/00 6.4
5/18/00 3.7
6/7/00 2.5
7/10/00 3.0
Specific Flux at
20oC After
Clean, Jsi
(gfd/psi)
11.9
5.7
6.2
7.8
Recovery of
Specific Flux
100(l-M/Jsi)
%
46
35
60
62
Loss of Original
Specific Flux
100(l-(Jsi/Jsio))
%
-4
50
46
32
Before a run was initiated and after a chemical cleaning was performed, an integrity test (air
pressure hold test) was performed. The membrane held pressure for 5 minutes during each
integrity test.
4.4 Task 3: Finished Water Quality
4.4.1 Particle Counts
The raw water particle count concentration of Cryptosporidium-sized particles (2-5 micron) and
cumulative particles (2->15 micron) averaged 3,120 and 5,601 counts/ml, respectively. The
filtrate particle count concentration averaged 1.7 and 3.1 counts/ml, respectively. Percent
reduction for both Cryptosporidium-sized particles (2-5 micron) and cumulative particles (2->15
micron) was 99.94%. Tables 4-4 and 4-5 present the raw water and filtrate water particle counts
during testing. Table 4-6 presents the percent removal of particles. Results were computed using
43
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filter run data from the following time periods when the particle counters were on-line during the
verification test period.
• Filter Run #2 - 14:40 May 3, 2000 to 12:42 May 4, 2000
• Filter Run #3-17:17 May 9, 2000 to 14:45 May 12, 2000
• Filter Run #4 - 14:27 May 18, 2000 to 20:37 May 19, 2000
• Filter Run #5-16:40 June 2, 2000 to 7:56 June 3, 2000
• Filter Run #9-11:14 June 20, 2000 to 10:31 June 23, 2000
Total data collection time for particle counts was approximately 209 hours. Problems were
experienced in retrieving the data during some portions of the verification period, therefore
particle count data is not presented from all thirteen filter runs. This problem was attributed to a
data transmission connection between the computer and the particle counters.
Table 4-4. Raw Water Particle Counts (counts/mL)
Average
Minimum
Maximum
95% Conf
Interval
No. of Samples
2-3
1366
5
4180
(1344, 1387)
6266
Raw
3-5 2-5 5
1755 3120
5 10
8662 12672
(1717,
1792) (3064, 3177)
6266 6266
Water Particle Count Size (Jim)
-7 7-10 10-15 >
504
o
3
4593
(484,
523) (345,
6266
357
2
2961
369) (897,
6266
15 Cumulative
925 695 5601
1 1 877
4140 2948 17891
953) (673,718) (5533,5670)
6266 6266 6266
Table 4-5. Filtrate Particle Counts (counts/mL)
Average
Minimum
Maximum
95% Conf
Interval
No. of Samples
2-3
0.83
0
606
(0.60, 1.07)
6266
Filtrate Particle Count Bin Size ( \Lm)
3-5 2-5 5-7 7-10
0.88
0
603
(0.64, 1.12) (1
6266
1.72
0
1209
.25,2.19)
6266
0.18
0
92
(0.14,0.22)
6266
0.16
0
69
(0.12,0.19)
6266
10- 15
0.58
0
205
(0.46,
0.70)
6266
> 15
0.43
0
116
(0.35,
0.52)
6266
Cumulative
3.1
0
1400
(2.5,3.7)
6266
Table 4-6. Average Particle
Removal %
2-3
99.94
Count Removal
Percentage
Particle Count Size (Jim)
3-5 2-5 5-7
99.95
99.94
99.96
7- 10
99.96
10-15
99.94
>15
99.94
Cumulative
99.94
44
-------
Figures 4-3 through 4-7 present the raw water and filtrate water particle counts for Filter Runs
#2, #3, #4, #5, and #9 in log scale. The data presented represents values collected at two-minute
intervals.
Total Particle Counts
(Filter Run #2)
60
65 70
Test Period Time (hours)
75
Figure 4-3. Cumulative Particle Counts for Test Period 2 on Logio Scale.
Total Particle Counts
(Filter Run #3)
100000.00
10000.00
1000.00
<-> O)
01 O
S.
0.01
0.00
75 80 85 90 95 100 105 110 115 120 125 130 135 140 145
Test Period Time (hours)
Figure 4-4. Cumulative Particle Counts for Test Period 3 on Log10 Scale
45
-------
Total Particle Counts
(Filter Run #4)
s±
• fl
i£
100000.00
10000.00
1000.00
100.00
10.00
1.00
0.10
0.01
0.00
Feed"
m&\vmsrou
Filtrate
145
150
155
160
165
170
175
180
Test Period Time (hours)
Figure 4-5. Cumulative Particle Counts for Test Period 4 on Logio Scale
Total Particle Counts
(Filter Run #5)
175
180 185
Test Period Time (hours)
190
195
Figure 4-6. Cumulative Particle Counts for Test Period 5 on Log10 Scale
46
-------
Total Particle Counts
(Filter Run #9)
345 350 355 360 365 370 375 380 385 390 395 400 405 410 415 420
Test Period Time (hours)
Figure 4-7. Cumulative Particle Counts for Test Period 9 on Logio Scale
4.4.2 Turbidity
During the verification testing, the feed water turbidity values averaged 0.80 NTU. The filtrate
averaged 0.03 NTU with a standard deviation of 0.01. Table 4-7 and Figure 4-8 represent the
on-line turbidity data from the SCAD A system during the test period. The printout of the on-line
turbidity data is provided in Appendix E.
Table 4-7. On-Line Feed
Average:
Maximum value:
Minimum value:
Std. Deviation:
95% Conf. Interval:
and Filtrate Turbidity
Feed
Turbidity
(NTU)
0.80
3.79
0.07
0.28
(0.79,0.81)
Data
Filtrate
Turbidity
(NTU)
0.03
0.32
0.00
0.01
(0.03,0.03)
Note: statistical analysis excludes RF and AS procedures.
47
-------
Turbidity Profile
o.o
200 300
Test Period Time (hours)
Figure 4-8. Turbidity Profile
4.4.3 Phytoplankton Analysis
Table 4-8 summarizes the results of the quantification and identification of the diatoms, algae,
and pollen in the raw water collected at various dates during the testing period. These
parameters were analyzed in the raw water to assess the type of contaminants that were fouling
the membrane during operation. Filtrate samples were not collected for phytoplankton analyses.
The analytical reports are provided in Appendix D.
48
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Table 4-8. Feed Water Phytoplankton Analysis (Dens
Taxon 5/12/00 5/18/00 6/9/00 6/21/00
(200X magnification)
(Diatoms)
Bacillariophyceae
(Algae)
Chrysophyceae
Chlorophyceae
Cyanobacteria
Others
(400X magnification)
Coccoid
cyanobacteria
Unicell
Pollen (grains/ml)
59
30
52
7
126
2219
425
0.04
141
59
66
7
141
3021
69
0.02
141
90
66
6
31
598
209
0.22
40
8
36
11
2
342
46
0.007
ities in no./mL)
Average Minimum
95
47
55
8
75
1545
187
0.07
40
8
36
6
2
342
46
0.007
Maximum
141
90
66
11
141
3021
425
0.22
The raw water phytoplankton levels are indicative of an average to above normal algal bloom for
lakes located in the Northeast, during spring conditions. The unusual wet and cool weather
experienced during the testing period appeared to have lengthened the duration of the algal bloom
well into the summer months.
4.4.4 Other Water Quality Parameters
The pH of the feed water averaged 6.4 with a maximum value of 7.2 and a minimum value of 5.5
during the testing period. Tables 4-9 and 4-10 summarize the results of the feed and filtrate
samples, respectively, for TOC and UV, and total iron, manganese, Hardness, TDS, and TSS.
Data indicates that dissolved organics and inorganics were not effectively removed by the MF
process, which was expected. Because only one sample was collected and analyzed for TSS and
that sample indicated that TSS was not detected in the feed water, the TSS mass balance
calculations were not completed. The presence of some TSS in the backwash (RF) could have
been algae in the raw water that adhered to the membrane or to the plumbing in the system.
Analytical reports can be found in Appendix G.
49
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Table 4-9. Feed Water Quality
Date
5/11/00
5/12/00
6/9/00
6/14/00
6/21/00
6/27/00
8/9/00
Average:
Maximum:
Minimum:
TOC
(mg/L)
4.77
4.69
4.76
—
5.09
—
—
4.83
5.09
4.69
UV
Absorbance
(I/cm)
0.136
0.133
0.125
—
0.119
—
—
0.128
0.136
0.119
Total
Iron
(mg/L)
—
—
0.073
0.16
—
0.18
0.13
0.14
0.18
0.073
Total
Manganese
(mg/L)
—
—
0.015
0.013
—
0.014
0.016
0.015
0.016
0.013
Alkalinity
(mg/L)
—
—
—
—
3.5
—
—
NA
NA
NA
Hardness
(mg CaCo3/L)
—
—
—
—
11.2
—
—
NA
NA
NA
TDS
(mg/L)
—
—
—
—
79
—
—
NA
NA
NA
TSS
(mg/L)
—
—
—
—
<4
—
—
NA
NA
NA
— = Sample not collected on this date.
NA=Statistical calculations not performed because sample size = 1.
Table 4-10. Filtrate Water Quality
UV
Date TOC Absorbance
(mg/L) (I/cm)
5/11/00
5/12/00
6/9/00
6/14/00
6/21/00
6/27/00
8/9/00
Average:
Maximum:
Minimum:
4.16
4.35
—
4.23
—
—
4.25
4.16
4.35
0.123
0.111
—
0.100
—
—
0.111
0.100
0.123
Total Total
Iron Manganese Alkalinity Hardness TDS TSS
(mg/L) (mg/L) (mg/L) (mg CaCo3/L) (mg/L) (mg/L)
—
—
—
—
0.03
NA
NA
NA
—
—
—
—
0.005
NA
NA
NA
—
—
3.0
—
NA
NA
NA
—
—
11.9
—
NA
NA
NA
—
—
76
—
NA
NA
NA
—
—
<4
—
NA
NA
NA
— = Sample not collected on this date.
NA=Statistical calculations not performed because sample size = 1.
Table 4-11 is a summary of the background raw water and filtrate total coliform, E. coli, Bacillus
spore, and heterotrophic plate count analyses for the verification period. A majority of
background filtrate samples did not show the presence of microbial contaminants but there were
samples that indicated their presence. It is not clear from the background data whether the filtrate
results were due to sample contamination, laboratory error or membrane performance. The
membrane system was not sterilized before background sampling events.
50
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Table 4-11. Summary Raw and Filtrate Water Quality Naturally Present Mcrobial Constituents
Total Total Bacillus Bacillus
Date
05/03/2000
05/03/2000
05/12/2000
05/12/2000
06/13/2000
06/13/2000
06/13/2000
06/21/2000
06/21/2000
07/03/2000
07/03/2000
07/03/2000
08/09/2000
08/09/2000
Average
Max
Min
StDev
95% C. I.
Coliform Coliform HPC HPC Spores Spores E. coli E. coli
Raw Filtrate Raw Filtrate Raw Filtrate Raw Filtrate
(#/100mL) (#/100mL) (#/mL) (#/mL) (#/100mL) (#/100mL) (#/100mL) (#/100mL)
87
72
250
450
2000
1600
...
11200
10000
760
650
...
44
5
2260
11200
5
3954
(23, 4497)
<1 — — 290 <1 10 <1
220 — 10
<1 19 <1 — — 300 <1
<1 13 <1 — — <1 <1
<1 26 <1 — — <1 <1
190 39 <1 — — <1 7
<1 ...
-------
was monitored visually at one-minute intervals. The integrity tests performed during the
verification testing period indicated the membrane was intact.
Another indication of possible membrane integrity failure is the presence of a high particle
counts level in the effluent. During the testing period, this occurrence was not observed. The
TMP rose above the maximum allowable pressure and shut down the unit before integrity failure
occurred. This was substantiated by the fact that the same membrane did not fail the integrity
tests during the test period.
4.7 Task 6: Data Management
Data from the SCADA system was set up to take readings on temperature, flow rate, turbidity,
transmembrane pressure, and retentate pressure. Data on particle counts were processed by use
of VISTA™ software. This software accompanied the HACK particle counters. This system
downloaded data every two minutes. Both the SCADA and VISTA data were then copied to an
EXCEL spreadsheet for data analysis. Other water quality data were compiled from reports and
field logbooks and transferred to an EXCEL spreadsheet for analysis. The EXCEL spreadsheet
format was used to perform statistical analysis on the data.
4.8 Task?: QA/QC
Quality assurance and quality control procedures were followed as described in Chapter 3 with
exceptions as noted below. Samples were collected in containers supplied by the respective
laboratories that performed the specific analysis. During the testing period, none of the testing
equipment needed to be changed or recalibrated due to mechanical failure. The protocol for
duplicate, field and trip blanks and samples was followed. The relative percent differences
calculated for feed water and filtrate water samples collected in duplicate and analyzed for TOC,
TDS, TSS, UV254, hardness, and alkalinity were all below 4%. Quality assurance (QA)
calculations are provided in Appendix J.
During the course of testing, weekly QA/QC checks were performed. This allowed the ability to
take inventory of sample containers, check chain of custody forms, and create a check list of
tasks that would performed before the next round of sampling occurred. The check list helped in
safety issues as well as QA/QC since many of the tasks involved standard housekeeping and
maintenance procedures.
The feed water and filtrate pressure gauges were checked against a NIST traceable pressure
gauge prior to the start of testing. The difference between the NIST traceable and the pressure
gauges used during testing was not greater than 3%, which was considered satisfactory. Results
are recorded on pages 1 and 2 of Logbook #1 in Appendix B.
The feed and filtrate flow meter readouts were verified volumetrically (bucket and stop watch) at
the start of testing. The meter values were within 6% of the values obtained volumetrically,
which was considered satisfactory. Results of this verification are recorded on page 2 of
Logbook #1 in Appendix B. Although the flow meter readouts are to be verified volumetrically
every two weeks during testing, the FTO elected to only perform this check at the start of testing.
52
-------
Because flow rate is a critical performance parameter, the lack of the verification is a variance
from the ETV test plan. The FTO notes that they did compare the feed and filtrate flow rates
throughout testing and they were found to be consistent with each other.
The comparison of the desktop turbidity values and the in-line turbidimeters were as expected.
Comparisons were performed on ten occasions during the months of May and June 2000. When
you have instruments in-line that are approximately two orders of magnitude greater in accuracy
than the bench top turbidimeter, the in-line values were expected to fall within the accuracy
range of the bench tops. To try and get more accurate comparisons, the samples were taken over
to the Manchester plant to analyze with their equipment. The relative percent difference of the
on-line and desktop turbidity readings of the raw water ranged from 3.4% to 15.4%. The RPD of
on-line and desktop turbidity readings of the filtrate ranged from 3.1% to 100%. Quality
assurance (QA) calculations are provided in Appendix J. Representatives from Hach were
present for the initial calibration of the turbidimeters, and provided insight as to how to maintain
accuracy during the testing period. The in-line turbidimeters maintained their stated accuracy
throughout the test period. Although daily checks of the in-line turbidimeter readings against a
calibrated bench-top turbidimeter are required, the FTO elected to do these checks on ten
occasions during four of thirteen filter runs. Because turbidity is a critical performance
parameter, the lack of sufficient daily checks is a serious variance from the ETV test plan. The
filtrate line however, was monitored by two inline Hach 1720D turbidimeters, one on the Pall
Membrane System and one on the FTO monitoring board. A comparison of the logbook entries
for the two inline turbidimeters showed that from May 10, 2000 to June 22, 2000, the Pall inline
turbidimeter averaged 0.031 +/- 0.001 NTU, while the FTO inline turbidimeter average 0.029 +/-
0.005 NTU. The summary data is included in Appendix J. Flow rates through the turbidimeters
were checked volumetrically each day by the FTO with a bucket and stopwatch method to assure
that flows were within the manufacturers specified range of 250-750 mL/minute. In-line
turbidimeter flowrates were not recorded in the FTO logbook and could not be independently
verified.
The particle counters used during verification testing were Met One particles counters model #
PCXCE155B. Both particle counters were manufactured in November 1999 and were factory
calibrated by the manufacturer on November 17, 1999 according to the labels affixed to the
particle counters. Field verification of the particle counter calibration was not performed
according to the ETV Protocol, however the raw water particle counter measurements were
compared to another Met One particle counter that was also simultaneously measuring the raw
water particles. No significant deviation between the two particle counters was noted. Flow
rates through the particle counters were checked volumetrically each day by the FTO with a
bucket and stopwatch method to assure that flows were within the manufacturers specified range
of approximately 100 mL/minute ± 5%. In-line particle counter flowrates were not recorded in
the FTO logbook daily and could not be independently verified.
During the course of the testing, samples not sent to the laboratory on the day of collection were
placed in a controlled refrigerated storage unit on the site, which provided protection against
damage or loss until samples were sent to the laboratory. Samples placed overnight in this
refrigerated storage unit included samples for TOC, UV, iron, and manganese. Temperature of
this storage unit was not monitored. It is possible that this storage unit may have adversely
53
-------
affected results of the TOC and UV samples, if the unit was not maintained at an appropriate
temperature.
The raw water and filtrate water samples collected on May 3, 2000 for Cryptosporidium analyses
were analyzed outside the specified hold time recommended in EPA Method 1622. Based on the
date of the analytical report, the possible hold time deviation was between 4-7 days. The hold
time deviation is not expected to influence the sample results because the samples were analyzed
for total cyst concentration and not viability. Since the hold time deviation was prior to sample
concentration, the up-take of the dye for the enumeration would not have been affected.
4.9 Task 8: Microbiological Removal Challenge
The Pall Corporation Microza™ Microfiltration 3-inch Unit was challenged three times with
Cryptosporidium oocysts (2-5 microns), E. coli (<2 microns) and Bacillus Spores (<2 microns).
During each challenge, a concentration of each microbial parameter was added to a known
volume of water and filtered by the membrane system. Samples of the feed and the filtrate were
collected and analyzed for each challenge. The challenges were performed at different intervals
of the testing period. The May 3rd challenge was performed at the beginning of a filter run on a
new clean membrane when the transmembrane pressure was at a low of approximately 8.2 psi.
The June 21st and August 9th challenges were performed near the end of a filter run when the
transmembrane pressure approached the 30 psi limit (performed at approximately 25 psi).
Cryptosporidium oocysts were not detected in the filtrate produced by the membrane system
during the three challenges. The first Cryptosporidium challenge test was performed on May 3rd,
2000 and the system demonstrated a 6.6 logic removal of Cryptosporidium. The May 3rd
Cryptosporidium sample was not processed within the method's specified holding time;
however, that is not expected to have influenced the sample results because the samples were
analyzed for total cyst concentration and not viability (see Section 4.8 for QA discussion). The
system demonstrated a 4.1 logic removal of Cryptosporidium during the June 21, 2000 challenge.
The third Cryptosporidium challenge was performed on August 9th and the system demonstrated
a 5.6 logic removal of oocysts. The SCAD A system was not functional during the August 9th
challenge, but operational parameters were noted in the logbook. The filtrate flow was 2.9 gpm,
TMP ranged from 24.9 to 32.8 psi, the raw water was pH 6.79, the temperature was 24 °C and
raw water turbidity was 1 NTU. Analytical reports are provided in Appendix H and results are
summarized in Table 4-12 and Figure 4-9.
Table 4-12. Feed and Filtrate Cryptosporidium Results
Sample Date
May 3rd*
feed
(#/20L)
May 3rd*
filtrate
(#/20L)
2.4 x 10b <1
4.4 x 106 <1
3.9 x 106 <1
Average:
3.6 x 106
<1
June 2 1st
feed
(#/20L)
June 2 1st
filtrate
(#/20L)
l.SxlO4 <1
5.5 x 103 <1
2.1 x 104 <1
1.4xl04 <1
August 9th
feed
(#/20L)
August 9th
filtrate
(#/20L)
3.8x10' <1
1.7 xlO5 <1
6.1xl05 <1
3.9 x 10s <1
*The samples were analyzed after the recommended hold time (see Section 4.8 for QA discussion).
54
-------
Cryptosporidium Oocyst Removals
Mav 3. 2000
.UUb+U/
1 .OOE+06 •
*- 1 .LMJh+Ub
1
c 1 .U(Jh+(J4
J2 1 .OOE+03 '
o 1 nnp-i.no -
•5
1 nnp^-nn -
2
' ^
~*^^.
~^>
August 9, 2000
June 21, 2000
I
^
^\^^^^
=».
*= Nl/ ^
1 23456789
Sampling Events
Figure 4-9. Bar Chart of Logic Removal of Seeded Cryptosporidium
The first Bacillus spore challenge test was performed on May 3rd, 2000 and the system
demonstrated a 4.0 logo removal of Bacillus spores. The second Bacillus spore challenge test
was performed on June 21st and the results were inconclusive because the influent sample result
revealed a too numerous to count (TNTC) level. The third Bacillus spore challenge test was
performed on August 9, 2000 and the system demonstrated a 7.1 logo removal. Bacillus spores
were not detected in the filtrate during two of the challenges. Analytical reports are summarized
in Appendix I. Log removal calculations are based on 100 mL samples. Results are summarized
in Table 4-13.
Table 4-13. Feed and Filtrate Bacillus Spore Results
May 3rd May 3rd
Feed Filtrate
(#/100mL) (#/100mL)
10,500 <1
11,000 <1
10,700 <1
Average: 10,700 <1
June 2 1st June 2 1st
Feed Filtrate
(#/100mL) (#/100mL)
TNTC 20
TNTC 10
TNTC 8
TNTC 14
August 9th August 9th
Feed Filtrate
(#/100mL) (#/100mL)
11,300,000 <1
12,000,000 <1
10,900,000 <1
11,400,000 <1
TNTC= Too numerous to count.
55
-------
Bacillus Spore Removals
August 9, 2000
•\ nnp-tfiR -, • • -XTx.
.uub+u/ -
E
. -\ nnc-i_n^
~- 1 .UUt+UD
•o
-i nnc-i_n^
1 .UUt+Uo
O
C A nnc_i_n>1
0) 1 .UUb+U4
o;
w) -i nnc_i_no
qj 1 .UUb+Uo
2 -i nnc_i_no
Q. 1 .UUb+Uz
(0
•tt ^ ^^c_i_^^
I.UUb+UI
•i nnp-i-nn -
1 .UUt+UU n
* 4^
May 3, 2000
^\
^- y ^
June 21, 2000
,/N.
^- \^/ -^
T1MTC T1SITC T1SITC
123456789
Sampling Events
Figure 4-10. Bar Chart of Logio Removal of Seeded Bacillus Spores
The first E. coli challenge test was performed on May 3rd, 2000 and the system demonstrated a
6.7 logo removal of E. coli. The second E. coli challenge test was performed on June 21st and
the system demonstrated a 3.9 logo removal of E. coli. The third E. coli challenge test was
performed on August 9, 2000 and the system demonstrated a 6.5 logo removal. Analytical
reports are summarized in Appendix I. Log removal calculations are based on 100 mL samples.
Results are summarized in Table 4-14.
Table 4-14. Feed and Filtrate E. coli Results
May 3rd May 3rd
Feed Filtrate
(#/100mL) (#/100mL)
5,200,000 <1
5,600,000 <1
5,450,000 <1
Average: 5,420,000 <1
June 2 1st June 2 1st
Feed Filtrate
(#/100mL) (#/100mL)
4,500,000 50C
4,300,000 54C
4,100,000 5 1C
4,300,000 52C
August 9th August 9th
Feed Filtrate
(#/100mL) (#/100mL)
17,000,000 6
16,500,000 2
17,300,000 6
16,900,000 5
56
-------
E. coli Removals
May 3, 2000 June 21, 2000 August 9, 2000
1 OOE+08 ~\ -/Ts. ./TS. -/TX.
_! .uub+u/ -
E
•o
O -1 nnc_i_nc
> 1 .UUb+Uo
o
o
o
I.UUb+UI
^ ^^ ^/T/u
^
n
n
123456789
Sampling Events
Figure 4-11. Bar Chart of Logio Removal of Seeded E. coli
E. coli was detected in the filtrate during the June 21st microbial challenges in low, but countable
numbers. Background samples taken prior to the challenge did not indicate contamination of the
filtrate line. E. coli was also detected during the final August 9, 2000 challenge in significantly
lower numbers, which were technically too few to count. The May ?d and August 9th results
considered together indicate that the June 21st results may have been partially due to sampling or
laboratory contamination. The background and microbial challenge results indicate however that
the membrane system was either not successful in removing all of the E. coli present in the raw
water or some contamination developed within the piping system.
4.10 Task 9: Evaluation of O&M Manual
The manual is well written and easy to follow. Sections include: System Description, Module
Installation and JAinse-Up, Safety Instruction, System Operation, System Control Interface, and
Clean-In-Place Procedures. The only technical assistance needed that the manual did not include
involved problems incurred with membrane failure due to the abundance of algal growth in the
source water, solenoid switch failure due to excessive water introduced by an undersized
compressor, and corrections in factory setting to alleviate overheating in the control panel during
normal operation.
4.11 Equipment Characteristics Results
The qualitative and quantitative factors of the equipment were identified during verification
testing, in so far as possible. The results of these factors are limited due to the relatively short
duration of the testing cycle.
57
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4.11.1 Qualitative
Qualitative factors that were examined during the verification testing were the susceptibility of
the equipment to changes in environmental conditions and equipment safety.
4.11.1.1 Susceptibility to Changes in Environmental Conditions
The membrane system tested was designed to be operated in an enclosed location. The system
was mounted on a stainless steel skid with wheels, which allowed it to be easily positioned once
on site. System operation was affected by the environmental conditions experienced at the site
during the testing period. The problems however, were readily resolved once they occurred.
The SCADA system for the unit shutdown because of the high temperatures at the test location
caused by the weather and the heat generated by pumps at the site. An adjustment of the
acceptable range of temperatures within the control panel resolved the emergency shutdown
problems. The air compressor (6.5 scfm) initially supplied with the membrane system was
sufficient for most conditions but was undersized for periods of extreme demand, which caused
the system to shutdown. The original compressor was replaced with a larger compressor (10.3
scfm). The larger compressor had sufficient capacity to supply enough compressed air for the
highest periods of demand. The pneumatic control valves for the flow control valves were
protected by a moisture trap and a canister containing desiccant. The trap was emptied
periodically and the desiccant was regenerated by removing it from the canister and drying it in
an oven. The compressor tank was drained periodically to minimize the accumulation of
moisture from the humid summer air and to avoid unnecessarily overloading the protective trap
and desiccant.
Changes in the environmental conditions of the raw water caused a degradation in feed water
quality, namely presence of algae. System operation was terminated seven times because the
TMP termination criteria (30 psi) was reached. The terminations were believed to be a direct
result of high concentrations of algae in the feed water. Use of a source water with high
concentrations of algae and/or iron bacteria in the feed water is not typical for MF technology
and presented a worst case scenario feed water for the Pall unit. For additional information on
operation and maintenance of the system, refer to a previous ETV Report (#00/09/EPADW395),
which documents operation and maintenance results on a cleaner water source.
4.11.1.2 Equipment Safety
There were no equipment safety incidents during the testing period. The system was well
contained and operating instructions were clear and manufacturer support, if problems arose, was
timely.
4.11.2 Quantitative
Quantitative factors that were examined during the verification testing were power usage,
consumables, waste disposal, and length of operating cycle.
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4.11.2.1 Power Usage
Average power usage during system operation was approximately 203 gallons/kWh.
4.11.2.2 Consumables
The cleaning chemicals used during the testing period were 680 grams of sodium hydroxide, 960
mL of 5.25% sodium hypochlorite and 3.0 kg of citric acid in the production of 56,500 gallons
of filtrate.
4.11.2.3 Waste Disposal
The two waste streams generated during the operation of the equipment were waste water from
the RF cycle and the chemical cleaning solution volumes. The approximate RF volume during
the testing period was 3800 gallons or 6.7% ( 6.7 gal/100 gal) of the total permeate produced.
Chemical cleaning volumes collected during the four chemical cleaning events were 135 gallons
of caustic/chlorine cleaning solution and 101 gallons of citric acid cleaning solution.
The caustic/chlorine cleaning solutions, the citric acid cleaning solutions, and the rinse solutions
were kept separate in plastic storage barrels. After the project was completed they were
transported to UNH and were subsequently disposed of by the Hazardous Waste Management
Department at UNH.
4.11.2.4 Length of Operating Cycle
Two operating cycles occurred during operation: the filtrate cycle and the interval between
chemical cleanings. The lengths of these cycles are site specific. The filtration cycle is the length
of time between reverse filtration (RF) and air scrub (AS) physical cleanings. The RF and AS
cleanings are an integral element of the daily operation of the membrane system. The RF cycle
was initially set to occur each 30 minutes for 30 seconds. During the course of testing, the
frequency and duration of RF and AS cycles were altered to optimize performance. To reduce
the rate of increase of the TMP, frequencies of the RF and AS cycles were changed to 20 and 40
minutes, respectively. This change did not dramatically alter the rate of increase to the TMP.
After a chemical cleaning, the duration of the RF was increased from 30 to 60 seconds and the
frequency of the AS was increased from every 60 minutes to every 30 minutes. The adjustment
stopped the rapid increase in the TMP and lowered the TMP from 15 psi to a steady 10 psi.
When the filtrate flow rate was increased from 2.1 to 2.5 gpm the TMP resumed its increase at a
similar rate. Four chemical cleanings took place during the 436 hours of testing (May 9, May 18,
June 7, and July 10). The chemical cleaning was effective in consistently returning the TMP to
starting levels of 11 psi on average. The results of this portion of the study could be attributed to
the biological fouling caused by the algae present in the feed water. The algae present in the raw
water reduced run times by approximately 75% as estimated by the manufacturer, who
anticipated run times on the order of 30 days between cleanings at this site.
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Reliability of non-hazardous surrogates for determining Cryptosporidium removal in bag
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carbon. Master of Science Thesis, University of New Hampshire, 1996.
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