March 2012
NSF12/35/EPADWCTR
EPA/600/R-12/026
Environmental Technology
Verification Report
Removal of Viruses in Drinking Water-
Ultrafiltration Module with a Cut Fiber
Dow Chemical Company - Dow Water &
Process Solutions
SFD-2880 Ultrafiltration Module
Prepared by
NSF International
Under a Cooperative Agreement with
U.S. Environmental Protection Agency
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THE ENVIRONMENTAL TECHNOLOGY VERIFICATION
PROGRAM ^
f X
oEPA
ETV
U.S. Environmental Protection Agency
NSF International
ETV Joint Verification Statement
TECHNOLOGY TYPE: ULTRAFILTRATION MEMBRANE
APPLICATION: REMOVAL OF VIRUSES IN DRINKING WATER
PRODUCT NAME: SFD-2880 ULTRAFILTRATION MODULE
VENDOR: THE DOW CHEMICAL COMPANY - DOW WATER
SOLUTIONS
ADDRESS: 1691 SWEDE ROAD
MIDLAND, MI 48674
CONTACT: DARYL GISCH
PHONE: +1989-636-9254
EMAIL: DGISCH@DOW.COM
NSF International (NSF) manages the Drinking Water Systems (DWS) Center under the U.S.
Environmental Protection Agency's (EPA) Environmental Technology Verification (ETV) Program. The
DWS Center recently evaluated the performance of the Dow Water Solutions SFD-2880 ultrafiltration
(UF) module for removal of viruses under a scenario where one UF fiber was broken. The challenge test
was conducted under controlled laboratory conditions at NSF's testing laboratory in Ann Arbor, MI.
Testing of the SFD-2880 UF module was conducted to verify virus reduction following the requirements
of the Department of Health Victoria (Australia) Draft guidelines for validating treatment processes for
pathogen reduction, supporting Class A water recycling schemes in Victoria. The Department of Health
Victoria guideline is largely based on the product-specific challenge requirements of the EPA Long Term
2 Enhanced Surface Water Treatment Rule (LT2ESWTR) and accompanying EPA Membrane Filtration
Guidance Manual (MFGM).
EPA created the ETV Program to facilitate the deployment of innovative or improved environmental
technologies through performance verification and dissemination of information. The goal of the ETV
Program is to further environmental protection by accelerating the acceptance and use of improved and
more cost-effective technologies. ETV seeks to achieve this goal by providing high-quality, peer-
reviewed data on technology performance to those involved in the design, distribution, permitting,
purchase, and use of environmental technologies.
ETV works in partnership with recognized standards and testing organizations, stakeholder groups
(consisting of buyers, vendor organizations, and permitters), and with the full participation of individual
technology developers. The program evaluates the performance of innovative technologies by developing
test plans that are responsive to the needs of stakeholders, conducting field or laboratory tests (as
NSF 12/35/EPADWCTR The accompanying notice is an integral part of this verification statement. March 2012
VS-i
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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.
ABSTRACT
The purpose of this verification was a cut fiber challenge study for the Dow Chemical Company SFD-
2880 UF membrane module. MS2 coliphage virus was the surrogate challenge organism. The challenge
tests followed the requirements of the Department of Health Victoria (Australia) Draft guidelines for
validating treatment processes for pathogen reduction, supporting Class A water recycling schemes in
Victoria.
Five new fully integral modules were challenged with MS2. Then, one fiber in each module was cut, and
the modules were all tested again with MS2. The modules were operated at a target flux of 70 gallons per
square foot per day (gfd), which equates to a flow of 40.3 gallons per minute (gpm). The test data did not
show any significant reduction in virus removal with a cut-fiber, so a second round of testing was
conducted with higher MS2 challenge concentrations. For the retests, the cut-fiber challenges were
conducted first, followed by the intact module tests after the cut fibers were pinned. The average log
removal value (LRV) was calculated for each module, as well as LRVs for each feed/filtrate sample pair.
From this data, the LRVC.TEST was determined as the lowest mean LRV, and also the lowest sample pair
LRV. Table VS-i provides a summary of the LRVC.TEST data.
Table VS-i. LRVC-TEST for Each Round of Testing
Tests
Round 1
Round 2
Intact Modules
Mean LRV
3.73
2.59
Lowest LRV
3.44
2.39
Cut Fiber
Mean LRV
3.44
2.46
Lowest LRV
2.98
2.37
To evaluate whether there was significantly lower virus removal with a cut fiber, the LRVs for each
feed/filtrate sample pair were pooled together, and the paired-difference t statistic was calculated using
Microsoft® Excel®. The intact module vs. cut-fiber t statistic for the first round of tests is 1.15. This
value is below the critical t value of 2.15, indicating that virus removal was not significantly impacted by
the cut fiber. For the second round of tests, the paired-difference t statistic is 5.00, this time
demonstrating a statistically significant drop in LRV.
PRODUCT DESCRIPTION
The following information was provided by Dow and was not verified.
The Dow SFD-2880 UF membrane module measures 4.7 inches in diameter by 45.5 inches in length.
The membrane fibers are made of polyvinylidene fluoride (PVDF). Water flow through the membrane
fibers is outside to inside. The modules can operate in deposition (dead-end) or suspension modes. The
nominal pore size is 0.03 (im. The maximum recommended flux is 70 gfd, with a maximum
recommended feed pressure of 44 pounds per square inch (psi), and a maximum transmembrane pressure
of 30 psi.
NSF 12/35/EPADWCTR
The accompanying notice is an integral part of this verification statement.
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March 2012
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VERIFICATION TEST DESCRIPTION
Virus Surrogate
The modules were challenged with the MS2 coliphage virus (ATCC 15597-B1) as a surrogate for enteric
viruses, as required by the Victoria draft guidelines for virus removal credits. MS2 is generally accepted
as an enteric virus surrogate for size-exclusion technologies due to its small size (approximately 22-26
nanometers). The USEPA MFGM references MS2 as an acceptable surrogate for enteric viruses because
it is similar in size and shape to poliovirus and hepatitis virus.
Methods and Procedures
All tests were conducted at the NSF International testing laboratories following the requirements of the
EPA-approved Test/QA Plan for Validating the Dow Chemical Company SFD-2880 Ultraflltration
Membrane Module for Virus Reduction Following the Department of Health Victoria (Australia) Draft
Guidelines for Validating Treatment Processes for Pathogen Reduction. The Victoria guidelines support
the regulatory approval process for Class A water recycling schemes. For membrane filtration products,
the guidelines are largely based on the product-specific challenge requirements of the LT2ESWTR and
accompanying EPA MFGM.
The intact module and cut-fiber tests were conducted twice, in two separate rounds of testing. The second
round of testing was conducted because the data from the first round did not show any significant
reduction in virus retention between the intact and cut-fiber challenges. For the first round, NSF tested
the five intact modules in January 2011. Then Dow representatives visited the testing laboratory to cut
the fibers, and the cut-fiber tests were conducted in March 2011. As required in the Department of Health
Victoria guideline, one fiber in each module was cut as close as possible to the potting resin on the filtrate
end of the module. The retests were conducted in May 2011, with the cut-fiber tests conducted first,
followed by the intact module challenges after Dow representatives pinned the cut fibers. Each of the five
modules submitted for testing was challenged individually. The target flux for membrane operation was
Dow's maximum recommended value of 70 gfd at 25 °C, which equals a flow rate of 40.3 gpm. Before
and after each challenge test, each module was subjected to a pressure decay test to satisfy the non-
destructive performance test requirement in Section 3.6 of the MFGM.
Immediately prior to testing, each module was forward flushed at approximately 40 gpm. For the first
round of tests conducted in January and March, each module was flushed for five minutes. At the start of
the retest round in May, the laboratory engineer noticed that after five minutes of flushing, there were still
bubbles visible in the filtrate hose line. The engineer flushed Module 1 for an additional three minutes
until bubbles were no longer visible. The engineer had to flush Module 2 for a total of 22 minutes to clear
the bubbles. At this point, the engineer decided to install bleed valves in the reject port caps for Modules
3, 4 and 5 to allow for evacuation of the air. After the pressure decay tests for these three modules, the
bleed valve was opened and the flow of water started at 40 gpm. The valves were kept open until all the
air had escaped. This allowed the testing engineer to return to the flush time of five minutes.
The duration of each challenge test was approximately 35 minutes. The MS2 suspension was injected
into the feed stream at start-up, after 15 minutes of operation, and after 30 minutes of operation. After at
least one minute of injection to pass the equilibrium volume, grab samples were collected from the feed
and filtrate sample taps. After each round of sample collection, injection of the challenge organism
suspension was turned off, and clean feed water was pumped through the modules at 40 gpm until the
next sampling point.
VERIFICATION OF PERFORMANCE
The LT2ESWTR and MFGM specify that an LRV for the test (LRVc-TEsi) be calculated for each module
tested, and that the LRVs for each module are then combined to yield a single LRVC.TEST for the product.
NSF 12/35/EPADWCTR The accompanying notice is an integral part of this verification statement. March 2012
VS-iii
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If fewer than 20 modules are tested, as was the case for this verification, the LRVC_TEST is simply the
lowest LRV for the individual modules. However, the rule does not specify a method to calculate LRVC.
for each module. Suggested options in the MFGM include:
• Calculate a LRV for each feed/filtrate sample pair, then calculate the average of the individual
sample point LRVs;
• Average all of the feed and filtrate counts, then calculate a single LRV for the module; or
• Calculate a LRV for each feed/filtrate sample pair, select the LRV for the module as the lowest
(most conservative of the three options).
Options 1 and 2 give LRVc-iEsi values that are either identical, or only a few hundredths or less different,
so for this verification, options 1 and 3 are used to calculate LRVs.
First Roun d Results
The MS2 LRVs for the first round of tests are presented in Table VS-ii. The intact module LRVc-TEsi,
using the overall mean LRV calculations in Table VS-ii, is 3.73. The LRVC_TEST based on the lowest
individual sample pair log reduction is 3.44. Under the cut-fiber scenario, the LRVC.TEST from the overall
means is 3.44, while that from the lowest individual sample pair log reduction is 2.98.
Table VS-ii. First Round LRV Calculations
Module #
Module 1
Module 2
Module 3
Module 4
Module 5
Intact Modules
Mean LRV
3.92
3.73
4.55
3.82
4.17
Lowest LRV
3.85
3.44
4.09
3.65
3.90
Cut Fiber
Mean LRV
3.44
3.72
4.73
4.93
4.49
Lowest LRV
3.10
2.98
4.19
4.65
4.30
To evaluate whether there was significantly lower virus removal with a cut fiber, the LRVs for the
feed/filtrate sample pairs were pooled together, and the paired-difference t statistic was calculated using
Microsoft® Excel®. The mean LRV for all five intact modules is 4.04, with individual sample pair LRVs
ranging from 3.44 to 5.16. The mean LRV for the cut-fiber tests is actually higher, at 4.26, with a range
of 2.98 to 5.74. The paired-difference t statistic for the two sets of LRVs is 1.15, which is below the
critical t value of 2.15 (14 degrees of freedom) that denotes a significant difference with a confidence of
95%.
The intact module pressure decay rates ranged from 0.000 to 0.052 psi/min, while those for the cut-fiber
scenario ranged from 0.734 to 1.292 psi/min, indicating that there was indeed a significant integrity
breach.
A possible explanation for why there was no significant difference between the intact module and cut-
fiber scenarios arises from the testing engineer's observation of air bubbles in the filtrate during the pre-
test flushes for the retests, as discussed above. If a portion of the air introduced for the pressure decay test
was still trapped at the top of the module during the challenge test, the cut fiber at the top of the module
may have never been in contact with the challenge water during the first round of tests; it may have been
in a pocket of air trapped at the top of the module. This theory is bolstered by a comparison of the feed
pressure data for the first round of tests versus the retests. For the first round of tests, above 20 psi
driving pressure was needed for eight of the ten test runs to achieve the target flux, compared with less
than 18 psi for the retests. If air was trapped in the modules, thus occluding a significant portion of the
NSF 12/35/EPADWCTR
The accompanying notice is an integral part of this verification statement.
VS-iv
March 2012
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membrane surface area, a higher driving pressure would be needed to achieve the target flux, due to the
smaller surface area.
To attempt to discern a significant difference in LRV between the intact modules and modules with a cut
fiber, NSF and Dow decided to re-run the tests on the same five modules using a higher MS2 challenge.
Secon d Roun d Results
The LRVs for the second round of tests are displayed in Table VS-iii. The intact module LRVC.TEST,
using the overall mean LRV calculations in Table VS-iii, is 2.59. The LRVc-TEsi based on the lowest
individual sample pair log reductions is 2.39. Under the cut-fiber scenario, the LRVC.TEST from the
overall means is 2.46, while that from the lowest individual sample pair log reductions is 2.37. The intact
module pressure decay rates ranged from 0.000 to 0.035 psi/min, while those for the cut-fiber tests ranged
from 0.970 to 1.284 psi/min.
Table VS-iii. Second Round LRV Calculations
Module #
Module 1
Module 2
Module 3
Module 4
Module 5
Intact Modules
Mean LRV
3.39
3.10
3.36
3.27
2.59
Lowest LRV
3.23
2.90
3.09
3.04
2.39
Cut Fiber
Mean LRV
3.13
2.67
2.93
2.77
2.46
Lowest LRV
3.12
2.66
2.87
2.53
2.37
In contrast to the first round LRV data, the retest data set does show a statistically significant difference in
virus retention between the intact and cut-fiber scenarios. The mean LRV for all five intact modules is
3.14, with a range of 2.39 to 3.62. The mean LRV for the cut-fiber tests is 2.79, with a range of 2.37 to
3.14. The paired-difference t statistic for the two sets of LRVs is 5.00, which is above the critical t value
of 2.15 for a significant difference at the 95% confidence level.
The pressure decay rates indicated a catastrophic loss of membrane integrity, but the corresponding loss
of virus retention was not as large. For the retests, the cut-fiber pressure decay rates were approximately
30 times higher than those for the intact modules. This translates into an approximate 1.5 log loss of
membrane integrity. However, the MS2 reduction data only shows a mean LRV loss of 0.35 logs.
QUALITY ASSURANCE/QUALITY CONTROL (QA/QC)
NSF provided technical and quality assurance oversight of the verification testing as described in the
verification report, including a review of 100% of the data. NSF QA personnel also conducted a technical
systems audit during testing to ensure the testing was in compliance with the test plan. A complete
description of the QA/QC procedures is provided in the verification report.
NSF 12/35/EPADWCTR
The accompanying notice is an integral part of this verification statement.
VS-v
March 2012
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Original signed by Annette Gatchett
for Cynthia Sonich Mullin 05/04/12 Original signed by Pierre Sbabo 05/04/12
Cynthia Sonich-Mullin Date Pierre Sbabo Date
Director Vice President
National Risk Management Research Water Systems
Laboratory NSF International
Office of Research and Development
United States Environmental Protection
Agency
NOTICE: Verifications are based on an evaluation of technology performance under specific,
predetermined criteria and the appropriate quality assurance procedures. EPA and NSF make no
expressed or implied warranties as to the performance of the technology and do not certify that a
technology will always operate as verified. The end-user is solely responsible for complying with
any and all applicable federal, state, and local requirements. Mention of corporate names, trade
names, or commercial products does not constitute endorsement or recommendation for use of
specific products. This report is not an NSF Certification of the specific product mentioned
herein.
Availability of Supporting Documents
Copies of the test protocol, the verification statement, and the verification report (NSF
report # NSF 12/35/EPADWCTR) are available from the following sources:
1. ETV Drinking Water Systems Center Manager (order hard copy)
NSF International
P.O. Box 130140
Ann Arbor, Michigan 48113-0140
2. Electronic PDF copy
NSF web site: http://www.nsf.org/info/etv
EPA web site: http://www.epa.gov/etv
NSF 12/35/EPADWCTR The accompanying notice is an integral part of this verification statement. March 2012
VS-vi
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March 2012
Environmental Technology Verification Report
Removal of Microbial Contaminants in Drinking Water-
Ultrafiltration Module with a Cut Fiber
Dow Chemical Company - Dow Water Solutions
SFD-2880 Ultrafiltration Module
Prepared by:
NSF International
Ann Arbor, Michigan 48105
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, through its Office of Research and Development,
funded and managed, or partially funded and collaborated in, the research described herein. It
has been subjected to the Agency's peer and administrative review and has been approved for
publication. Any opinions expressed in this report are those of the author (s) and do not
necessarily reflect the views of the Agency, therefore, no official endorsement should be inferred.
Any mention of trade names or commercial products does not constitute endorsement or
recommendation for use.
11
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Table of Contents
Verification Statement VS-i
Title Page i
Notice ii
List of Tables iv
List of Figures iv
Abbreviations and Acronyms v
Chapter 1 Introduction 1
1.1 ETV Program Purpose and Operation 1
1.2 Purpose of Verification 1
1.3 Testing Participants and Responsibilities 2
Chapter 2 Product Description 3
2.1 UF Membrane General Description 3
2.2 SFD-2880 Membrane Module Description 3
Chapter 3 Methods and Procedures 5
3.1 Introduction 5
3.2 UF Fiber Cutting Procedure 5
3.3 Virus Surrogate 7
3.4 Test Apparatus 7
3.5 Test Water Composition 9
3.6 UF Module Conditioning 9
3.7 Test Rig Sanitization 9
3.8 UF Module Integrity Tests 10
3.9 Microbial Challenge Test Procedure 10
3.10 Analytical Methods 12
Chapter 4 Results and Discussion 13
4.1 Introduction 13
4.2 First Round Results and Discussion 13
4.3 Retest Results and Discussion 17
Chapter 5 Quality Assurance/Quality Control 21
5.1 Introduction 21
5.2 Test Procedure QA/QC 21
5.3 Sample Handling 22
5.4 Chemistry Laboratory QA/QC 23
5.5 Microbiology Laboratory QA/QC 23
5.6 Documentation 23
5.7 Data Review 23
5.8 Data Quality Indicators 23
Chapter 6 References 27
in
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Appendices
Appendix A Test/Quality Assurance Proj ect Plan
Appendix B Triplicate Challenge Organism Counts
List of Tables
Table 2-1. SFD-2880 Specifications 3
Table 2-2. Serial Numbers of Tested Modules 4
Table 3-1. Analytical Methods for Laboratory Analyses 12
Table 4-1. First Round Intact Module MS2 Challenge Results 14
Table 4-2. First Round Cut-Fiber MS2 Challenge Results 14
Table 4-3. First Round Pressure Decay Results 16
Table 4-4. First Round Module Operation Data 16
Table 4-5. First Round Feed Water Chemistry Data 17
Table 4-6. Retest Intact Module MS2 Challenge Results 17
Table 4-7. Retest Cut-Fiber Module MS2 Challenge Results 18
Table 4-8. Retest Pressure Decay Results 19
Table 4-9. Retest Module Operation Data 20
Table 4-10. Retest Feed Water Chemistry Data 20
Table 5-1. Flush Sample and Matrix Spike Results 22
Table 5-2. Completeness Requirements 25
Table B-l. First Round Intact Module MS2 Triplicate Counts B-l
Table B-2. First Round Cut-Fiber Module MS2 Triplicate Counts B-2
Table B-3. Retest Intact Module MS2 Triplicate Counts B-3
Table B-4. Retest Cut-Fiber Module MS2 Triplicate Counts B-4
List of Figures
Figure 2-1. Diagram of the SFD-2880 UF module 4
Figure 3-1. Photo of a cut fiber in one of the Dow SFD-2880 modules tested 6
Figure 3-2. Photo of a cut fiber leaking air 6
Figure 3-3. Schematic diagram of the test rig used for verification testing 7
Figure 3-4. Photo of test rig 8
Figure 3-5. Bleed valve installed on reject port cap 11
IV
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Abbreviations and Acronyms
ATCC American Type Culture Collection
°C degrees Celsius
cm centimeter
ETV Environmental Technology Verification
°F degrees Fahrenheit
ft foot(feet)
gfd gallons per square foot per day
gpm gallons per minute
in inch(es)
L liter
LRV log removal value
LT2ESWTR Long Term 2 Enhanced Surface Water Treatment Rule
m meter
MFGM Membrane Filtration Guidance Manual
mg milligram
mL milliliter
mm millimeter
MWCO molecular weight cutoff
NRMRL National Risk Management Research Laboratory
NSF NSF International (formerly known as National Sanitation Foundation)
NTU Nephelometric Turbidity Unit
ORD Office of Research and Development
PFU plaque forming unit
psi pounds per square inch
PVDF polyvinylidene fluoride
QA quality assurance
QC quality control
RPD relative percent difference
SM Standard Methods for the Examination of Water and Wastewater
TDS total dissolved solids
TMP trans membrane pressure
TOC total organic carbon
TSS total suspended solids
UF ultrafiltration
ug microgram
jam microns
uS microsiemens
USEPA U. S. Environmental Protection Agency
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Chapter 1
Introduction
1.1 ETV Program Purpose and Operation
The U.S. Environmental Protection Agency (USEPA) has created the Environmental Technology
Verification (ETV) Program to facilitate the deployment of innovative or improved
environmental technologies through performance verification and dissemination of information.
The goal of the ETV Program is to further environmental protection by accelerating the
acceptance and use of improved and more cost-effective technologies. ETV seeks to achieve this
goal by providing high-quality, peer-reviewed data on technology performance to those involved
in the design, distribution, permitting, purchase, and use of environmental technologies.
ETV works in partnership with recognized standards and testing organizations; with stakeholder
groups consisting of buyers, vendor organizations, and permitters; and with the full participation
of individual technology developers. The program evaluates the performance of innovative
technologies by developing test plans that are responsive to the needs of stakeholders;
conducting field or laboratory testing, collecting and analyzing data; and by preparing peer-
reviewed reports. All evaluations are conducted in accordance with rigorous quality assurance
protocols to ensure that data of known and adequate quality are generated and that the results are
defensible.
The USEPA has partnered with NSF International (NSF) under the ETV Drinking Water
Systems Center to verify performance of drinking water treatment systems that benefit the public
and small communities. It is important to note that verification of the equipment does not mean
the equipment is "certified" by NSF or "accepted" by USEPA. Rather, it recognizes that the
performance of the equipment has been determined and verified by these organizations under
conditions specified in ETV protocols and test plans.
1.2 Purpose of Verification
The purpose of this verification was a cut fiber challenge study for the Dow Chemical Company
SFD-2880 ultrafiltration membrane module. MS2 coliphage virus was the surrogate challenge
organism. The challenge tests followed the requirements of the Department of Health Victoria
(Australia) Draft guidelines for validating treatment processes for pathogen reduction,
supporting Class A water recycling schemes in Victoria. These requirements are largely based
on the USEPA Long Term 2 Enhanced Surface Water Treatment Rule (LT2ESWTR) and
Membrane Filtration Guidance Manual (MFGM). The Victoria guideline requires validation of
the critical limits for the direct integrity test and indirect integrity monitoring, and also
demonstration of the resolution and sensitivity of the direct integrity test and evidence showing
correlation between continuous indirect integrity monitoring and membrane integrity. These
requirements were not included in this verification, as these requirements are site-specific.
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This verification does not address long-term performance, or performance over the life of the
membrane. Also, this verification test did not evaluate cleaning of the membranes, nor any other
maintenance and operation.
1.3 Testing Participants and Responsibilities
The following is a brief description of each of the ETV participants and their roles and
responsibilities.
1.3.1 NSF International
NSF is an independent, not-for-profit organization dedicated to public health and safety, and to
protection of the environment. Founded in 1944 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. The USEPA partnered with NSF to verify the performance of drinking
water treatment systems through the USEPA's ETV Program.
NSF performed all verification testing activities at its Ann Arbor, MI location. NSF prepared the
test/QA plan, performed all testing, managed, evaluated, interpreted, and reported on the data
generated by the testing, and reported on the performance of the technology.
Contact: NSF International
789 N. Dixboro Road
Ann Arbor, MI 48105
Phone: 734-769-8010
Contact: Mr. Bruce Bartley, Project Manager
Email: bartley@nsf.org
1.3.2 U.S. Environmental Protection Agency
USEPA, through its Office of Research and Development (ORD), has financially supported and
collaborated with NSF under Cooperative Agreement No. R-82833301. This verification effort
was supported by the DWS Center operating under the ETV Program. This document has been
peer-reviewed, reviewed by USEPA, and recommended for public release.
1.3.3 Dow Chemical Company
The Dow Chemical Company supplied the tested membrane modules, and also provided
logistical and technical support, as needed.
Contact: The Dow Chemical Company - Dow Water Solutions
169 IN. Swede Road
Midland, MI 48674
Contact: Daryl Gisch
Phone: 989-636-9254
Email: dgisch@dow.com
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Chapter 2
Product Description
2.1 UF Membrane General Description
UF membranes remove contaminants from water through sieving based on the size of the
membrane pores relative to the physical size of the contaminant. A common arrangement for the
membranes is in hollow fibers, with the fibers "potted" in a resin. The flow of water through the
fibers can be either "inside-out" or "outside-in". UF membranes can be classified by pore size or
the molecular weight cutoff (MWCO) point. Pore sizes generally range from 0.01 to 0.05
microns (urn). Typical MWCO points are 10,000 to 500,000 Daltons, with 100,000 being a
common MWCO rating for drinking water treatment. With these specifications, UF membranes
can remove viruses, bacteria, and protozoan cysts, as well as large molecules such as proteins,
and suspended solids.
2.2 SFD-2880 Membrane Module Description
The Dow SFD-2880 is a polyvinylidene fluoride (PVDF) hollow fiber ultrafiltration membrane
module. The module specifications and operating parameters are listed in Table 2-1. The SFD-
2880 is a pressure driven module, with the normal operating flow orientation from the outside to
the inside of the fibers. The SFD-2880 is certified to NSF/ANSI Standard 61, which establishes
minimum public health related requirements for drinking water system components.
Table 2-1. SFD-2880 Specifications
Parameter
Dimensions:
Module outside diameter
Module length
Module volume
Nominal membrane pore size
Maximum membrane pore size
Average active membrane area (outer)
Operating Limits:
Filtrate flux range at 25°C
Flow range
Operating temperature range
Max. inlet module pressure
Max. transmembrane pressure (TMP)
Operating pH range
Max. NaOCl
Max. Total Suspended Solids (TSS)
Max. Turbidity
Specification
8.9 inches (in) (225 millimeters (mm))
92.9 in (2360 mm)
10.3 gallons (gal) (39 liters (L))
0.03 urn
0.05 urn
829 square feet (ft2) (77 square meters (m2))
24-70 gallons per square foot per day (gfd) (40-120 L/m2/hr)
13.6-40.9 gallons per minute (gpm) (3.1-9.3 nrVhr)
34-104 Fahrenheit (°F) (1-40 Celcius (°C))
44 pounds per square inch (psi) (3.0 bar)
30psi(2.1bar)
2-11
2,000 milligrams per L (mg/L)
lOOmg/L
300 Nephelometric Turbidity Units (NTU)
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A diagram of the SFD-2880 module is pictured in Figure 2-1. The module design allows for an
optional reject line connection, but this port was closed off for the challenge tests. The modules
were operated in dead-end mode.
3/8-J
Figure 2-1. Diagram of the SFD-2880 UF module.
Dow supplied five new UF modules for testing. There was no seasoning period, other than that
specified by Dow to sufficiently rinse out the membrane preservative and wet the membranes.
See Section 3.5 for a description of the UF module conditioning procedure. The serial numbers
of the tested modules are listed in Table 2-2. The modules were randomly selected by Dow
personnel from existing inventory. The module numbers in the first column are the numbers
used in Chapter 4 to identify each module.
Table 2-2. Serial Numbers of Tested Modules
Module
1
2
3
4
5
Serial Number
PE10K03682
PE10K03708
PE10K03508
PE10K03672
PE10K03705
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Chapter 3
Methods and Procedures
3.1 Introduction
The tests followed the procedures described in the Test/QA Plan for Validating the Dow
Chemical Company SFD-2880 Ultrafiltration Membrane Module for Virus Reduction Following
the Department of Health Victoria (Australia) Draft Guidelines for Validating Treatment
Processes for Pathogen Reduction. The Victoria Guidelines support the regulatory approval
process for Class A water recycling schemes. The Department of Health Victoria guideline
refers to the USEPA MFGM for the challenge testing requirements. The test/QA plan is
available from NSF upon request.
NSF International performed all testing activities in their Ann Arbor, Michigan laboratory. The
NSF Microbiology Laboratory performed all MS2 analyses. The intact module and cut-fiber
tests were conducted twice, in two separate rounds of testing. The second round of testing was
conducted because the data from the first round did not show any significant reduction in virus
retention between the intact and cut-fiber challenges. For the first round, NSF tested the five
intact modules in January 2011. Then Dow representatives visited the testing laboratory to cut
the fibers, and the cut-fiber tests were conducted in March 2011. See Section 3.2 for discussion
of the fiber cutting procedure. The retests were conducted in May 2011. The cut-fiber
challenges were conducted first, followed by the intact module challenges. Again, Dow
representatives visited the testing laboratory, this time to pin the cut fibers and to check for any
other integrity problems after the cut-fiber retests were completed.
3.2 UF Fiber Cutting Procedure
As required in the Department of Health Victoria guideline, one fiber in each module was cut as
close as possible to the potting resin on the filtrate end of the module. Dow representatives
drilled a hole through the wall of each module. Then, using needle-nosed pliers, they reached in
and pulled one fiber out into the opening, and cut out approximately one inch of the fiber. See
Figure 3-1 for a photo of a cut fiber in a module. In the photo, the potting resin starts
approximately at the bottom of the gray end cap visible at the top of the photo. They then
plugged the hole in the module wall. After a fiber was cut, the filtrate end cap was removed and
the Dow representatives applied a layer of water to the top of the potting resin, covering the fiber
outlets. Air pressure was then applied to the module to look for any other compromised fibers.
See Figure 3-2 for a photo of air coming out of the cut fiber, but from no other fibers in one of
the modules. If any other fiber leaks were detected, the fiber in question was plugged.
-------
Figure 3-1. Photo of a cut fiber in one of the Dow SFD-2880 modules tested.
Figure 3-2. Photo of a cut fiber leaking air.
-------
3.3 Virus Surrogate
The modules were challenged with the MS2 coliphage virus (ATCC 15597-B1) as a surrogate for
enteric viruses, as required by the Victoria draft guidelines for virus removal credits. MS2 is
generally accepted as an enteric virus surrogate for size-exclusion technologies due to its small
size (approximately 22-26 nanometers). The USEPA MFGM references MS2 as an acceptable
surrogate for enteric viruses because it is similar in size and shape to poliovirus and hepatitis
virus. The target feed concentration was 5xl05 plaque forming units per milliliter (PFU/mL) for
the first round of testing. For the second round, the target feed concentration was increased to
5xl06 PFU/mL in an attempt to discern a significant difference in virus retention between the
fully intact and cut-fiber scenarios.
The MS2 stock suspension was purchased from Biological Consulting Services of North Florida,
Inc.
3.4 Test Apparatus
The modules were tested in a test rig constructed specifically for these tests. The test rig
construction conformed to the requirements of the MFGM. See Figure 3-3 for a schematic
diagram of the test rig, and Figure 3-4 for a photo of the test rig.
Fillrate
Filtrate Sample
Pressure
Sensing
Port
Air Pressure
Regulator
**T^\ I
Ball
Valve
Pressure
Sensing
Centrifugal Pump
Figure 3-3. Schematic diagram of the test rig used for verification testing.
-------
Injection Port
(behind orange hose)
In-Line Static Mixer
(also behind orange hose)
Figure 3-4. Photo of the test rig.
-------
The challenge organisms were introduced into the feed water by intermittent injection during the
challenge tests. Injection and mixing of the organisms followed the guidelines of the MFGM.
Specifically, the total stock solution volume injected into the feed stream during each challenge
test was between 0.5 and 2 percent of the total spiked test solution volume, a chemical metering
pump that delivered a steady flow of the challenge solution was used, and the injection port
included a quill extending into the middle of the feed pipe. The static mixer was placed
downstream of the injection point, and more than ten pipe diameters upstream of the feed sample
tap, as suggested in the MFGM.
The feed and filtrate sample taps were located immediately upstream and downstream of the UF
module, as shown in Figure 3-4. Both had a quill extending into the middle of the pipe as
suggested in the MFGM. The taps were metal, and were flame-sterilized prior to sample
collection.
3.5 Test Water Composition
For the first round of tests in January and March of 2011, Ann Arbor municipal water was
treated by activated carbon filtration, reverse osmosis, ultraviolet disinfection, and deionization
at the NSF Laboratory to make the base water for the tests. A 4,000-gallon water supply tank
was filled with the base water. Sodium bicarbonate was added to the base water in sufficient
quantity to provide alkalinity at a target concentration of 100 ± 10 mg/L as calcium carbonate.
The pH was then lowered with hydrochloric acid into the target range of 7.5 ± 0.5.
For the May retests, the test water was Ann Arbor municipal water treated only by activated
carbon filtration and ultrafiltration upstream of the challenge organism injection point. No
sodium bicarbonate was added, and the pH was not adjusted. NSF had wished to switch from
deionized water to dechlorinated tap water due to limitations in the laboratory's deionized water
supply. In between the rounds of testing, NSF's State Advisory Panel approved the switch to de-
chlorinated tap water. Dow also approved of the change.
Immediately prior to each challenge test, feed samples were collected for analysis of total
chlorine, alkalinity, pH, temperature, total dissolved solids (TDS), total organic carbon (TOC),
and turbidity. These samples were collected prior to injection of the challenge organism.
3.6 UF Module Conditioning
The Dow SFD-2880 modules were "brand new" when challenged. Prior to testing, the modules
were rinsed and conditioned with the deionized water described in Section 3.4, following a
proprietary procedure supplied by Dow. Prior to the second round of testing, Dow requested that
each module be forward flushed at approximately 40 gpm for 30 minutes using tap water.
3.7 Test Rig Sanitization
The Dow module conditioning procedure included an hour long flush with a sodium
hypochlorite solution at approximately 400 mg/L of total chlorine. This procedure was sufficient
to sanitize the test rig prior to testing. The test rig plumbing was also sanitized in between each
challenge test. This was accomplished by connecting the feed and filtrate plumbing together,
and flushing for approximately ten minutes using tap water with injection of a sodium
-------
hypochlorite solution that was approximately 12% free chlorine. Then, injection of the
sanitizing solution was stopped and the plumbing was flushed with dechlorinated tap water until
the chlorine residual from the filtrate sample tap was <0.5 mg/L.
3.8 UF Module Integrity Tests
Before and after each challenge test, each module was subjected to a pressure decay test to
satisfy the non-destructive performance test requirement in Section 3.6 of the MFGM. The test
procedure followed ASTM D6908-03 Standard Practice for Integrity Testing of Water Filtration
Membrane Systems. The water was drained from the feed side of the membrane, but not the
filtrate side. Approximately 30 psi of pressure was applied to the feed side and the remaining
pressure was recorded every minute to chart the pressure decay. The test length was 10 minutes
for the intact module tests in the first round of testing, and 20 minutes for all subsequent tests.
The baseline decay rate of the pressurized portion of the test rig was also measured for the same
lengths of time once per day for each day of testing, with the exception of the cut-fiber tests in
the second round of testing. It was decided to eliminate this step for the cut-fiber tests since the
baseline decay rate of the test rig was so small compared to the pressure decay of the UF
modules with the cut fibers.
3.9 Microbial Challenge Test Procedure
Each of the SFD-2880 modules submitted for testing was challenged individually, as shown in
the photo of the test rig in Figure 3-4. The target flux for membrane operation was Dow's
maximum recommended value of 70 gfd at 25 °C, which equals a flow rate of approximately
40.3 gpm.
After completion of the pre-challenge pressure decay test described in Section 3.8, the module to
be tested was forward flushed at 40 gpm to force out the air introduced from the pressure decay
test. For the first round of tests conducted in January and March, each module was flushed for
five minutes. At the start of the retest round in May, the laboratory engineer noticed that after
five minutes of flushing, there were still bubbles visible in the filtrate hose line. The engineer
flushed Module 1 for an additional three minutes until bubbles were no longer visible. The
engineer had to flush Module 2 for a total of 22 minutes to clear the bubbles. At this point, it
was decided to install bleed valves in the reject port caps for Modules 3, 4 and 5 to allow
evacuation of the air. After the pressure decay tests for these three modules, the bleed valve was
opened and the flow of water started at 40 gpm. The valves were kept open until all the air had
escaped. This allowed the testing engineer to return to the flush time of five minutes. See Figure
3-5 for a photo of the bleed valve installed on Module 4.
At the end of the forward flush two feed and two filtrate samples were collected. One sample of
each process stream served as a negative control, and was analyzed for MS2. The second sample
pair was spiked with MS2 to serve as positive controls. The testing engineer spiked these
samples with a measured aliquot of the challenge suspension immediately after collection, and
the spiked samples were submitted to the NSF Microbiology Laboratory with the other samples
from that challenge test. The spiked samples served to verify that the MS2 was stable in the feed
and filtrate waters over the course of the test and up to the time that the samples were processed
by the Microbiology Laboratory.
10
-------
Figure 3-5. Bleed valve installed on reject port cap.
Each challenge test was approximately 35 minutes in length, with the MS2 suspension injected
into the feed stream at start-up, after 15 minutes of operation, and after 30 minutes of operation.
Sections 3.10.2, 3.10.4, and 3.12.4 of the MFGM describe the requirements for the challenge test
sampling plan. The MFGM requires that feed and filtrate samples not be collected until at least
three hold-up volumes of water spiked with MS2 have passed through the membrane, to allow
for establishment of equilibrium (equilibrium volume). The hold-up volume is defined as the
"unfiltered test solution volume that would remain in the system on the feed side of the
membrane at the end of the test." Dow's specification sheet for the SFD-2880 gives the module
volume as 10.3 gal. It is assumed that this volume is the total water holding volume of the
module, not just the volume of the feed side of the membranes. As such, its use as the hold-up
volume will add a safety factor to the hold-up volume calculation.
The MFGM also specifies that the challenge organism suspension be injected upstream of a
static mixer, and that the feed sample tap be at least 10 pipe diameters downstream of the static
mixer. Further, the feed sample tap shall be placed as close as possible to the module inlet. The
pipe and hoses used for the test rig were 2 inches in diameter (DN50) to match the inlet and
outlet fittings on the SFD-2880. Therefore, the feed sample tap was required to be least 20
inches downstream of the static mixer. As shown in Figure 3-4, the challenge suspension
11
-------
injection port and the static mixer are separated from the feed sample tap by a stretch of flexible
hose that was approximately 175 inches in length. One hundred and seventy-five inches of 2-
inch diameter pipe has a volume of approximately 2.6 gal. The maximum expected pipe volume
plus the module volume gives a hold-up volume of approximately 13 gal. If the hold-up volume
is 13 gal, then the equilibrium volume is 39 gal. The target challenge flow rate was 40.3 gpm, so
the MS2 suspension was injected for at least one minute prior to sampling to meet the
requirement of passing the equilibrium volume.
After at least one minute of injection at each challenge point, a grab sample was first collected
from the filtrate sample tap, and then from the feed sample tap. The sample taps were flame
sterilized prior to sample collection. Also, at least 100 mL was collected and discarded prior to
sample collection to flush the taps. After sample collection was complete, MS2 injection was
stopped, and the test water minus MS2 was pumped through the modules until the next sampling
point.
Note that the Victoria draft guidelines call for collection of three sample pairs at each collection
point, for a total of nine feed and nine filtrate samples. This did not occur for this verification
test. Instead, the testing engineer collected one feed and one filtrate sample at each sampling
point for a total of three samples from each process stream per test. These samples were analyzed
in triplicate to obtain nine feed counts and nine filtrate counts per test.
3.10 Analytical Methods
A list of laboratory analytical methods can be found in Table 3-1. Single samples of adequate
volume were collected for challenge organism enumeration, and were analyzed in triplicate.
Table 3-1. Analytical Methods for Laboratory Analyses
Parameter
Alkalinity (total, as CaCO3)
pH
IDS
Total Chlorine
TOC (mg/L)
Turbidity
MS2
Method
USEPA310.2
SM1 4500-H+ B
SM 2540 C
SM 4500-C1 G
SM5310C
SM2130
NSF 554
NSF Reporting Limit
5 mg/L
NA2
5 mg/L
0.05 mg/L
0.1 mg/L
0.1 NTU
1 PFU/mL
Sample Hold Time
14 days
none3
7 days
none3
28 days
none3
30 hours
(1) SM = Standard Methods
(2) Not Applicable
(3) Immediate analysis required
(4) Method published in NSF/ANSI Standard 55 - Ultraviolet Microbiological Water Treatment Systems. Method is similar to
EPA Method 1601.
12
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Chapter 4
Results and Discussion
4.1 Introduction
As discussed in Section 3.1, there were two rounds of testing conducted for this study. Each
module was tested twice as an intact, integral module, and twice with a cut fiber. The retests
were conducted because the data from the first round of tests failed to show any significant
difference in virus retention between the intact and cut-fiber scenarios.
For presentation of the challenge organism data in this chapter, the observed triplicate counts
were averaged by calculating geometric means. Geometric means <1 were rounded up to 1,
unless all three triplicate analyses had no organisms found. The virus counts in the "Overall
Mean" rows are also geometric means. The mean counts were logic transformed for the purpose
of calculating log removal values (LRV). The LRV's in the "Overall Mean" rows are the
arithmetic means of the individual sample point LRVs. The triplicate counts for each sample are
presented in Appendix B.
The LT2ESWTR and MFGM specify that an LRV for the test (LRVc-iEsi) be calculated for each
module tested, and that the LRVs for each module are then combined to yield a single LRVc-iEsi
for the product. If fewer than 20 modules are tested, as was the case for this verification, the
LRVc-iEST is simply the lowest LRV for the individual modules. However, the rule does not
specify a method to calculate the LRV for each module. Suggested options in the MFGM
include:
1. Calculate a LRV for each feed/filtrate sample pair, then calculate the average of the
individual sample point LRVs;
2. Average all of the feed and filtrate counts, and then calculate a single LRV for the
module; or
3. Calculate a LRV for each feed/filtrate sample pair, select the LRV for the module as the
lowest (most conservative of the three options).
Options 1 and 2 give LRVc-iEST values that are either identical, or within a few hundredths of
each other, so in this report options 1 and 3 were used to calculate the LRV for each module.
4.2 First Round Results and Discussion
The intact module MS2 challenge data from the first round of testing is presented in Table 4-1,
while the cut-fiber challenge data is presented in Table 4-2. The intact module LRVc-iEsi, using
the overall mean LRV calculations in Table 4-1, is 3.73. The LRVc-iEsi based on the lowest
individual sample pair log reductions is 3.44. Both LRVc-iEST values are from the Module 2
data. Under the cut-fiber scenario, the LRVc-iEST from the overall means is 3.44, while that from
the lowest individual sample pair log reductions is 2.98. These LRVc-iEsi values are from
Modules 1 and 2, respectively.
13
-------
Table 4-1. First Round Intact Module MS2 Challenge Results
Module
Module 1
Module 2
Module 3
Module 4
Module 5
Sample
Point
1 Minute
15 Minutes
30 Minutes
Overall Mean
1 Minute
15 Minutes
30 Minutes
Overall Mean
1 Minute
15 Minutes
30 Minutes
Overall Mean
1 Minute
15 Minutes
30 Minutes
Overall Mean
1 Minute
15 Minutes
30 Minutes
Overall Mean
Feed
Geometric Mean
(PFU/mL)
1.41xl06
1.69xl06
1.34xl06
1.47xl06
1.23xl05
2.7xl05
3.2xl05
2.2xl05
4.4xl05
3.7xl05
4.5xl05
4.2xl05
3.2xl05
3.8xl05
2.8xl05
3.2xl05
7.4xl05
5.9xl05
1.30xl06
8.3xl05
Log10
6.15
6.23
6.13
6.17
5.09
5.43
5.51
5.34
5.64
5.57
5.65
5.62
5.51
5.58
5.45
5.51
5.87
5.77
6.11
5.92
Filtrate
Geometric Mean
(PFU/mL)
1.69xl02
1.74xl02
1.90xl02
1.77xl02
4.5X101
3.7X101
4.2X101
4.1X101
3x10°
l.SxlO1
3.6X101
1.2X101
4.6X101
S.SxlO1
S.OxlO1
4.9X101
S.SxlO1
7.4X101
4.1X101
5.6X101
Log10
2.23
2.24
2.28
2.25
1.65
1.57
1.62
1.61
0.48
1.18
1.56
1.07
1.66
1.93
1.48
1.69
1.76
1.87
1.61
1.75
LRV
3.92
3.99
3.85
3.92
3.44
3.86
3.89
3.73
5.16
4.39
4.09
4.55
3.85
3.65
3.97
3.82
4.11
3.90
4.50
4.17
Table 4-2. First Round Cut-Fiber MS2 Challenge Results
Module
Module 1
Module 2
Module 3
Module 4
Module 5
Sample
Point
1 Minute
15 Minutes
30 Minutes
Overall Mean
1 Minute
15 Minutes
30 Minutes
Overall Mean
1 Minute
15 Minutes
30 Minutes
Overall Mean
1 Minute
15 Minutes
30 Minutes
Overall Mean
1 Minute
15 Minutes
30 Minutes
Overall Mean
Feed
Geometric Mean
(PFU/mL)
1.14xl05
l.lxlO5
l.OxlO5
l.lxlO5
2.93xl05
3.1x10"
2.8xl05
l.lxlO5
5.5xl05
6.3xl05
5.4xl05
5.7xl05
6.5xl05
4.0x10"
4.9x10"
5.0x10"
7.9x10"
9.0x10"
7.2x10"
8.0x10"
Log™
5.06
5.04
5.00
5.03
5.47
5.49
5.45
5.03
5.74
5.80
5.73
5.76
5.81
5.60
5.69
5.70
5.90
5.95
5.86
5.90
Filtrate
Geometric Mean
(PFU/mL)
l.OxlO1
7.6X101
S.OxlO1
3.9X101
7x10°
8.7X101
2.97xl02
5.7X101
1x10°
3.5X101
3.5X101
l.lxlO1
3x10°
6x10"
l.lxlO1
6x10"
1.2X101
4.5X101
3.2X101
2.6X101
Log™
1.00
1.88
1.90
1.59
0.85
1.94
2.47
1.75
0.00
1.54
1.54
1.03
0.48
0.78
1.04
0.77
1.08
1.65
1.51
1.41
LRV
4.06
3.16
3.10
3.44
4.62
3.55
2.98
3.72
5.74
4.26
4.19
4.73
5.33
4.82
4.65
4.93
4.82
4.30
4.35
4.49
14
-------
To evaluate whether there was significantly lower virus removal with a cut fiber, the LRVs for
the feed/filtrate sample pairs in Tables 4-1 and 4-2 were pooled together, and the paired-
difference t statistic was calculated using Microsoft® Excel®. The mean LRV for all five intact
modules is 4.04, with individual sample pair LRVs ranging from 3.44 to 5.16. The mean LRV
for the cut-fiber tests is actually higher, at 4.26, with a range of 2.98 to 5.74. These intact-
module LRV values are somewhat higher than those observed for the SFD-2880 during previous
ETV testing (mean LRV of 3.48, range of 2.37 to 4.58) (USEPA and NSF, 2011). The paired-
difference t statistic for the two sets of LRVs is 1.15, which is below the critical t value of 2.15
for a two-tailed test with an alpha (a) of 0.05 and 14 degrees of freedom. Therefore, the t statistic
does not indicate a significant difference in performance with a confidence of 95%.
A possible explanation for why there was no significant difference in virus removal between the
intact module and cut-fiber scenarios arises from the testing engineer's observation of air
bubbles in the filtrate during the pre-test flushes for the retests, as discussed in Section 3.9. If a
portion of the air introduced for the pressure decay test was still trapped at the top of the module
during the challenge test, the cut fiber at the top of the module may have never been in contact
with the challenge water during the first round of tests; it may have been in a pocket of air
trapped at the top of the module. This theory is bolstered by a comparison of the feed pressure
data for the first round of tests versus the retests. For the first round of tests, above 20 psi
driving pressure was needed for eight of the ten test runs to achieve the target flux, compared
with less than 18 psi for the retests. If air was trapped in the modules, thus occluding a
significant portion of the membrane surface area, a higher driving pressure would be needed to
achieve the target flux, due to the smaller surface area.
To attempt to discern a significant difference in LRV between the intact modules and modules
with a cut fiber, NSF and Dow decided to re-run the tests on the same five modules using a
higher MS2 challenge. The results and discussion for the retests are presented below in Section
4.3.
The pre-challenge and post-challenge pressure decay data for the first round of testing is
presented in Table 4-3. The intact module pressure decay rates were similar to those observed
by NSF for the SFD-2880 module during previous testing activities (USEPA and NSF, 2011),
ranging from 0.000 to 0.052 psi/min. The pressure decay rates for the cut-fiber scenario ranged
from 0.734 to 1.292 psi/min, indicating that there was indeed a significant integrity breach.
The module operational data for the first round of challenge tests is listed in Table 4-4 and the
water chemistry data is presented in Table 4-5. Many of the alkalinity measurements were below
the target range of 90-110 mg/L, but all of the pH readings were within the target range of 7.0-
8.0.
15
-------
Table 4-3. First Round Pressure Decay Results
Module
Module 1
Module 2
Module 3
Module 4
Module 5
Test
Intact Pre-Test
Intact Post-Test
Cut Fiber Pre-Test
Cut Fiber Post-Test
Intact Pre-Test
Intact Post-Test
Cut Fiber Pre-Test
Cut Fiber Post-Test
Intact Pre-Test
Intact Post-Test
Cut Fiber Pre-Test
Cut Fiber Post-Test
Intact Pre-Test
Intact Post-Test
Cut Fiber Pre-Test
Cut Fiber Post-Test
Intact Pre-Test
Intact Post-Test
Cut Fiber Pre-Test
Cut Fiber Post-Test
Starting
Pressure
(psi)
30.01
30.11
31.50
31.20
30.40
30.72
31.40
31.50
30.70
30.68
31.50
31.25
30.56
30.69
31.45
31.60
30.70
30.38
31.40
31.45
Final
Pressure
(psi)
29.81
30.03
9.95
5.13
30.12
30.07
8.18
8.59
30.54
30.46
14.00
16.58
30.22
30.32
8.09
16.39
30.54
29.90
6.00
14.99
Elapsed
Time
(min)
10.00
10.00
20.00
20.00
10.00
10.00
20.00
20.00
10.00
10.00
20.00
20.00
10.00
10.00
20.00
20.00
10.00
10.00
20.00
20.00
Decay
Rate
(psi/min)
0.020
0.008
1.078
1.304
0.028
0.065
1.161
1.146
0.016
0.022
0.875
0.734
0.034
0.037
1.168
0.761
0.016
0.048
1.270
0.823
Background
Decay Rate
(psi/min)
0.010
0.010
0.012
0.012
0.013
0.013
0.012
0.012
0.013
0.013
0.000
0.000
0.015
0.015
0.000
0.000
0.015
0.015
0.004
0.004
Corrected
Decay Rate
(psi/min)
0.010
-0.002
1.066
1.292
0.015
0.052
1.149
1.134
0.003
0.009
0.875
0.734
0.019
0.022
1.168
0.761
0.001
0.033
1.266
0.819
Table 4-4. First Round Module Operation Data
Challenge Test
Module 1 Intact
Module 2 Intact
Module 3 Intact
Module 4 Intact
Module 5 Intact
Module 1 Cut
Module 2 Cut
Module 3 Cut
Module 4 Cut
Module 5 Cut
Date
01/24/11
01/25/11
01/25/11
01/27/11
01/27/11
03/02/11
03/02/11
03/03/11
03/03/11
03/04/11
Filtrate Flow Rate
(gpm)
OMin.
40.6
40.9
40.6
40.3
40.7
40.5
40.8
41.1
39.7
40.5
30 Min.
40.5
40.1
40.1
40.7
40.0
40.4
40.2
40.6
40.3
40.6
Flux
(gfd)
OMin
70.5
71.0
70.5
70.0
70.7
70.3
70.9
71.4
69.0
70.3
30 Min
70.3
69.7
69.7
70.7
69.5
70.2
69.8
70.5
70.0
70.5
Feed Pressure
(psi)
OMin.
23.45
23.16
24.75
24.29
22.10
19.60
19.40
22.90
20.80
20.44
30 Min.
22.60
22.40
23.95
23.82
21.21
16.40
16.50
17.20
16.60
15.80
Filtrate Pressure
(psi)
OMin.
1.06
2.29
2.51
1.43
1.22
4.09
4.50
2.71
2.37
2.83
30 Min.
0.98
2.17
2.22
1.42
1.03
3.64
3.63
2.15
2.12
2.36
16
-------
Table 4-5. First Round Feed Water Chemistry Data
Challenge Test
Module 1 Intact
Module 2 Intact
Module 3 Intact
Module 4 Intact
Module 5 Intact
Module 1 Cut
Module 2 Cut
Module 3 Cut
Module 4 Cut
Module 5 Cut
Alkalinity
(mg/L
CaC03)
97
98
95
86
88
83
84
83
83
90
PH
7.41
7.17
7.38
7.69
7.52
7.80
7.80
7.84
7.82
7.94
Temp. (°C)
17.6
17.9
18.4
18.3
19.0
20.1
19.8
18.8
19.1
18.7
Total
Chlorine
(mg/L)
O.05
<0.05
O.05
<0.05
O.05
<0.05
O.05
<0.05
O.05
<0.05
TDS (mg/L)
110
110
120
130
100
110
100
100
100
110
TOC
(mg/L)
<0.1
0.1
0.1
<0.1
0.1
<0.1
<0.1
<0.1
0.4
<0.1
Turbidity
(NTU)
0.11
0.11
0.12
0.13
0.12
0.19
0.11
0.15
0.12
0.12
4.3 Retest Results and Discussion
The MS2 challenge retest data is displayed in Tables 4-6 and 4-7. The intact module LRVc-iEsi
from the overall means is 2.59. The LRVc-iEsi based on the lowest individual sample pair log
reductions is 2.39. Both LRVc-iEsi values are from the Module 5 data. Under the cut-fiber
scenario, the LRVc-iEST from the overall means is 2.46, while that from the lowest individual
sample pair log reductions is 2.37. Both of these LRVc-iEsi values also come from the Module 5
test data.
Table 4-6. Retest Intact Module MS2 Challenge Results
Challenge
Test
Module 1
Module 2
Module 3
Module 4
Module 5
Sample
Point
1 Minute
15 Minutes
30 Minutes
Overall Mean
1 Minute
15 Minutes
30 Minutes
Overall Mean
1 Minute
15 Minutes
30 Minutes
Overall Mean
1 Minute
15 Minutes
30 Minutes
Overall Mean
1 Minute
15 Minutes
30 Minutes
Overall Mean
Feed
Geometric Mean
(PFU/mL)
2.7xl06
2.8xl06
3.0xl06
2.8xl06
4.5xl06
3.9xl06
3.4xl06
3.9xl06
6.1xl06
5.4xl06
5.3xl06
5.6xl06
5.1xl06
4.1xl06
5.0xl06
4.7xl06
6.9xl06
5.2xl06
3.2xl06
4.9xl06
Log10
6.43
6.45
6.48
6.45
6.65
6.59
6.53
6.59
6.79
6.73
6.72
6.75
6.70
6.61
6.70
6.67
6.84
6.72
6.51
6.69
Filtrate
Geometric Mean
(PFU/mL)
6.9xl02
1.26xl03
1.79xl03
1.2xl03
1.60xl03
4.5xl03
4.3xl03
S.lxlO3
1.48xl03
2.3xl03
4.3xl03
2.4xl03
1.88xl03
3.7xl03
2.3xl03
2.5xl03
1.25xl04
1.24xl04
1.31xl04
1.26xl04
Log10
2.84
3.10
3.25
3.06
3.20
3.65
3.63
3.49
3.17
3.36
3.63
3.39
3.27
3.57
3.36
3.40
4.10
4.09
4.12
4.10
LRV
3.59
3.35
3.23
3.39
3.45
2.94
2.90
3.10
3.62
3.37
3.09
3.36
3.43
3.04
3.34
3.27
2.74
2.63
2.39
2.59
17
-------
Table 4-7. Retest Cut-Fiber Module MS2 Challenge Results
Challenge
Test
Module 1
Module 2
Module 3
Module 4
Module 5
Sample
Point
1 Minute
15 Minutes
30 Minutes
Overall Mean
1 Minute
15 Minutes
30 Minutes
Overall Mean
1 Minute
15 Minutes
30 Minutes
Overall Mean
1 Minute
15 Minutes
30 Minutes
Overall Mean
1 Minute
15 Minutes
30 Minutes
Overall Mean
Feed
Geometric Mean
(PFU/mL)
6.1xl06
5.4xl06
5.0xl06
5.5xl06
8.8xl05
7.9xl05
8.8xl05
8.5xl05
9.1xl05
8.3xl05
l.OxlO6
9.2xl05
3.0xl06
3.5xl06
3.6xl06
3.4xl06
1.9xl06
1.52xl06
1.21xl06
1.5xl06
Log10
6.79
6.73
6.70
6.74
5.94
5.90
5.94
5.93
5.96
5.92
6.01
5.96
6.48
6.54
6.56
6.53
6.28
6.18
6.08
6.18
Filtrate
Geometric Mean
(PFU/mL)
4.5xl03
4.0xl03
3.8xl03
4.1xl03
1.82xl03
1.72xl03
l.SlxlO3
1.78xl03
1.16xl03
1.13xl03
9.5xl02
l.lxlO3
4.3xl03
4.2xl03
l.lxlO4
5.8xl03
5.3xl03
5.3xl03
5.1xl03
5.2xl03
Log10
3.65
3.60
3.58
3.61
3.26
3.24
3.26
3.25
3.06
3.05
2.98
3.03
3.63
3.62
4.03
3.76
3.72
3.72
3.71
3.72
LRV
3.14
3.13
3.12
3.13
2.68
2.66
2.68
2.67
2.90
2.87
3.03
2.93
2.85
2.92
2.53
2.77
2.56
2.46
2.37
2.46
In contrast to the first round LRV data, the retest data set does show a stastically significant
difference in virus retention between the intact and cut-fiber scenarios. The mean LRV for the
intact modules is 3.14, with a range of 2.39 to 3.62. The mean LRV for the cut-fiber tests is
2.79, with a range of 2.37 to 3.14. The paired-difference t statistic for the two sets of LRVs is
5.00, which is above the critical t value is 2.15 for a significant difference at the 95% confidence
level.
The retest pressure decay data is displayed in Table 4-8. The observed pressure decay rates were
similar to those from the first round of tests in Table 4-3. The intact module pressure decay rates
ranged from 0.000 to 0.035 psi/min, while those for the cut-fiber tests ranged from 0.970 to
1.284 psi/min. Note that the test rig background pressure decay rates were not measured for the
cut-fiber tests, since the background decay rates measured during the first round of tests were so
low compared to the pressure decays attributed to the cut fibers.
The pressure decay rates indicated a catastrophic loss of membrane integrity, but the
corresponding loss of virus retention was not as large. For the retests, the cut-fiber pressure
decay rates were approximately 30 times higher than those for the intact modules. This
translates into an approximate 1.5 log loss of membrane integrity. However, the MS2 reduction
data only shows a mean LRV loss of 0.35 logs.
18
-------
Table 4-8. Retest Pressure Decay Results
Module
Module 1
Module 2
Module 3
Module 4
Module 5
Test
Intact Pre-Test
Intact Post-Test
Cut Fiber Pre-Test
Cut Fiber Post-Test
Intact Pre-Test
Intact Post-Test
Cut Fiber Pre-Test
Cut Fiber Post-Test
Intact Pre-Test
Intact Post-Test
Cut Fiber Pre-Test
Cut Fiber Post-Test
Intact Pre-Test
Intact Post-Test
Cut Fiber Pre-Test
Cut Fiber Post-Test
Intact Pre-Test
Intact Post-Test
Cut Fiber Pre-Test
Cut Fiber Post-Test
Date
05/18/2011
05/18/2011
05/11/2011
05/11/2011
05/18/2011
05/18/2011
05/12/2011
05/12/2011
05/19/2011
05/19/2011
05/12/2011
05/12/2011
05/19/2011
05/19/2011
05/12/2011
05/12/2011
05/19/2011
05/19/2011
05/13/2011
05/13/2011
Starting
Pressure
(psi)
30.90
31.55
30.60
30.60
31.10
31.42
30.90
30.85
30.24
30.38
31.50
31.00
30.64
30.60
30.50
30.50
31.88
30.33
31.00
30.60
Final
Pressure
(psi)
30.02
30.81
5.54
5.18
29.87
30.43
11.51
7.06
29.35
29.69
9.35
9.38
29.20
29.34
8.57
7.34
30.66
29.51
5.32
5.09
Elapsed
Time
(min)
20.00
20.00
20.00
20.00
20.00
20.00
20.00
20.00
20.00
20.00
20.00
20.00
20.00
20.00
20.00
20.00
20.00
20.00
20.00
20.00
Decay Rate
(psi/min)
0.044
0.037
1.253
1.271
0.062
0.050
0.970
1.190
0.044
0.034
1.108
1.081
0.072
0.063
1.097
1.158
0.061
0.041
1.284
1.276
Background
Decay Rate
(psi/min)
0.038
0.038
NM
NM
0.038
0.038
NM
NM
0.038
0.038
NM
NM
0.038
0.038
NM
NM
0.038
0.038
NM
NM
Corrected
Decay
Rate
(psi/min)
0.006
0.000
1.253
1.271
0.024
0.012
0.970
1.190
0.007
-0.003
1.108
1.081
0.035
0.026
1.097
1.158
0.023
0.003
1.284
1.276
The retest module operation data is presented in Table 4-9, and the water chemistry data is
presented in Table 4-10. As discussed in Section 4.2, the feed pressures for the retests were
lower than those for the first round of tests, which may have been due to the extra effort to purge
the modules of air left over from the pressure decay tests. The water chemistries for the retests
are different from those of the first round due to the switch from buffered, deionized water to
dechlorinated tap water. The alkalinities and pH are similar for the two water sources, but the
TDS and TOC are higher for the tap water, as expected. The turbidity of the tap water was in the
same range (0.1 to 0.2 NTU) as that for the deionized water, with the exception of two higher
measurements at 0.29 NTU.
19
-------
Table 4-9. Retest Module Operation Data
Challenge Test
Module 1 Intact
Module 2 Intact
Module 3 Intact
Module 4 Intact
Module 5 Intact
Module 1 Cut
Module 2 Cut
Module 3 Cut
Module 4 Cut
Module 5 Cut
Date
05/18/11
05/18/11
05/19/11
05/19/11
05/19/11
05/11/11
05/12/11
05/12/11
05/12/11
05/13/11
Filtrate Flow Rate
(gpm)
OMin.
40.5
40.4
40.6
40.3
40.4
40.2
40.5
40.5
40.9
40.3
30 Min.
40.3
40.5
39.9
40.3
40.3
40.7
40.4
39.9
40.3
40.1
Flux
(gfd)
OMin
70.3
70.2
70.5
70.0
70.2
69.8
70.3
70.3
71.0
70.0
30 Min
70.0
70.3
69.3
70.0
70.0
70.7
70.2
69.3
70.0
69.7
Feed Pressure
(psi)
OMin.
15.16
14.67
16.88
16.53
15.60
17.76
15.43
17.50
17.90
15.05
30 Min.
14.97
14.47
16.33
16.50
15.24
17.50
15.13
16.98
17.52
14.73
Filtrate Pressure
(psi)
OMin.
0.94
0.58
1.37
0.86
0.93
1.41
0.74
1.71
1.93
1.13
30 Min.
0.90
0.55
1.21
0.89
0.86
1.50
0.71
1.60
1.76
1.10
Table 4-10. Retest Feed Water Chemistry Data
Challenge Test
Module 1 Intact
Module 2 Intact
Module 3 Intact
Module 4 Intact
Module 5 Intact
Module 1 Cut
Module 2 Cut
Module 3 Cut
Module 4 Cut
Module 5 Cut
Alkalinity
(mg/L
CaCO3)
100
85
88
88
91
83
79
82
83
90
pH
8.03
7.56
7.52
7.44
7.22
7.61
7.28
7.23
7.51
7.35
Temp. (°C)
15.8
14.5
15.7
14.4
14.4
11.9
16.1
14.0
13.6
15.2
Total
Chlorine
(mg/L)
<0.05
O.05
<0.05
O.05
<0.05
O.05
<0.05
O.05
<0.05
O.05
TDS (mg/L)
410
390
400
400
420
390
390
400
390
390
TOC
(mg/L)
1.5
1.4
1.3
1.3
1.4
1.4
1.3
1.3
1.3
1.3
Turbidity
(NTU)
0.10
0.11
0.10
0.17
0.16
0.29
0.15
0.12
0.29
0.15
20
-------
Chapter 5
Quality Assurance/Quality Control
5.1 Introduction
An important aspect of verification testing is the QA/QC procedures and requirements. Careful
adherence to the procedures ensured that the data presented in this report was of sound quality,
defensible, and representative of the equipment performance. The primary areas of evaluation
were representativeness, accuracy, precision, and completeness.
Because this ETV was conducted at the NSF testing lab, all laboratory activities were conducted
in accordance with the provisions of the NSF International Laboratories Quality Assurance
Manual.
5.2 Test Procedure QA/QC
NSF testing laboratory staff conducted the tests by following a USEPA-approved test/QA plan
created specifically for this verification. NSF QA Department staff performed an audit during
testing to ensure the proper procedures were followed. The audit yielded no significant findings.
5.2.1 Test Negative Controls and Matrix Spikes
The results of the test negative control (module flush) samples are listed in the Results and
Discussion chapter along with the test data. The test negative control (module flush) and matrix
spike results are presented below in Table 5-1. The Microbiology Laboratory targeted spiking
the samples with an amount of the MS2 stock that would yield a PFU count that was similar to
the feed count. The volume spiked varied depending on the concentration of the stock solution.
There were some flush samples with MS2 detected at low levels, but only one filtrate sample had
detectible MS2. The retest Module 3 cut-fiber filtrate flush sample had 2 PFU/mL detected.
This low concentration of contamination, if still present during the test, would not have
significantly affected the results of the test, due to the high filtrate counts of approximately 3
logio.
21
-------
Table 5-1. Flush Sample and Matrix Spike Results
First
Round
of Tests
Retests
Intact
Module
Tests
Cut-
Fiber
Scenario
Tests
Intact
Module
Tests
Cut-
Fiber
Scenario
Tests
Sample Description
Module 1 Flush Samples
Module 1 Matrix Spikes
Module 2 Flush Samples
Module 2 Matrix Spikes
Module 3 Flush Samples
Module 3 Matrix Spikes
Module 4 Flush Samples
Module 4 Matrix Spikes
Module 5 Flush Samples
Module 5 Matrix Spikes
Module 1 Flush Samples
Module 1 Matrix Spikes
Module 2 Flush Samples
Module 2 Matrix Spikes
Module 3 Flush Samples
Module 3 Matrix Spikes
Module 4 Flush Samples
Module 4 Matrix Spikes
Module 5 Flush Samples
Module 5 Matrix Spikes
Module 1 Flush Samples
Module 1 Matrix Spikes
Module 2 Flush Samples
Module 2 Matrix Spikes
Module 3 Flush Samples
Module 3 Matrix Spikes
Module 4 Flush Samples
Module 4 Matrix Spikes
Module 5 Flush Samples
Module 5 Matrix Spikes
Module 1 Flush Samples
Module 1 Matrix Spikes
Module 2 Flush Samples
Module 2 Matrix Spikes
Module 3 Flush Samples
Module 3 Matrix Spikes
Module 4 Flush Samples
Module 4 Matrix Spikes
Module 5 Flush Samples
Module 5 Matrix Spikes
Feed
(geometric mean,
PFU/mL)
<1
l.lxlO6
<1
1.3x10"
2
7.6x10"
2
4.3x10"
<1
2.9x10"
<1
2.9x10"
<1
1.0x10"
<1
4.3x10"
<1
3.1x10"
<1
4.9xl04
<1
3.2x10"
2
2.6x10"
<1
2.5x10"
9
3.6x10"
2
5.0x10"
<1
6.1x10"
<1
1.7x10"
<1
7.0x10"
1
3.9x10"
<1
2.9x10"
Filtrate
(geometric mean,
PFU/mL)
<1
8.1x10"
<1
2.8x10"
<1
7.0x10"
<1
2.9x10"
<1
4.9x10"
<1
3.0x10"
<1
9.0xl04
<1
3.1x10"
<1
2.8x10"
<1
3.5xl04
<1
3.2x10"
<1
4.5x10"
<1
4.8x10"
<1
4.3x10"
<1
4.2x10"
<1
5.6x10"
<1
1.6x10"
2
8.0x10"
<1
5.6x10"
<1
2.0x10"
5.3 Sample Handling
All samples analyzed by the NSF Chemistry and Microbiology Laboratories were labeled with
unique identification numbers. All samples were analyzed within allowable holding times.
22
-------
5.4 Chemistry Laboratory QA/QC
The calibrations of all meters, gauges, and analytical instruments, and the analyses of all
parameters complied with the QA/QC provisions of the NSF International Laboratories Quality
Assurance Manual.
The NSF QA/QC requirements are all compliant with those given in the USEPA method or
Standard Method for the parameter. Also, every analytical method has an NSF standard
operating procedure.
5.5 Microbiology Laboratory QA/QC
5.5.1 Growth Media Positive Controls
All media were checked for sterility and positive growth response when prepared and when used
for microorganism enumeration. The media was discarded if growth occurred on the sterility
check media, or if there was an absence of growth in the positive response check.
5.5.2 Negative Controls
For each sample batch processed, an unused membrane filter and a blank with 100 mL of
buffered, sterilized dilution water was filtered through the membrane were also placed onto the
appropriate media and incubated with the samples as negative controls. No growth was observed
on any blanks.
5.5.3 Estimate of Analytical Uncertainty
Per the requirements of NSF's ISO 17025 accreditation, the Microbiology Laboratory was
required to estimate the uncertainty of its analytical methods. The laboratory calculated that the
uncertainty associated with the top-agar overlay method for enumerating MS2 was 29%.
5.6 Documentation
All laboratory activities were documented using specially prepared laboratory bench sheets and
NSF laboratory reports. Data from the bench sheets and laboratory reports were entered into
Microsoft™ Excel® spreadsheets. These spreadsheets were used to calculate the geometric
means and logic reductions. One hundred percent of the data entered into the spreadsheets was
checked by a reviewer to confirm all data and calculations were correct.
5.7 Data Review
NSF QA/QC staff reviewed the raw data records for compliance with QA/QC requirements. As
required in the ETV Quality Management Plan, NSF ETV staff checked at least 10% of the data
in the NSF laboratory reports against the lab bench sheets.
5.8 Data Quality Indicators
The quality of data generated for this ETV is established through four indicators of data quality:
representativeness, accuracy, precision, and completeness.
23
-------
5.8.1 Representativeness
Representativeness is a qualitative term that expresses "the degree to which data accurately and
precisely represent a characteristic of a population, parameter variations at a sampling point, a
process condition, or an environmental condition." Representativeness was ensured by
consistent execution of the test protocol for each challenge, including timing of sample
collection, sampling procedures, and sample preservation. Representativeness was also ensured
by using each analytical method at its optimum capability to provide results that represent the
most accurate and precise measurement it is capable of achieving.
5.8.2 Accuracy
Accuracy is a measure of the deviation of the analytical value from the true value. Since true
values for samples can never be known, accuracy measurements are made through analysis of
certified standards or QC samples of a known quantity.
Accuracy was maintained through the following items:
• Maintaining consistent sample collection procedures, including sample locations, timing
of sample collection, and sampling procedures;
• Calibrated instruments; and
• Laboratory control samples (e.g., method blanks, duplicates, matrix spikes, matrix spike
duplicates, and performance evaluation samples).
Recoveries for spiked samples were calculated in the following manner:
100*(SSR-SR)
Percent Recovery = —
xj^i
where: SSR = spiked sample result
SR = sample result
SA = spike amount added
Recoveries for laboratory control samples were calculated as follows:
100 * (Found Concentration)
Percent Recovery =
True Concentration
For acceptable analytical accuracy, the recoveries must be within control limits.
Accuracy of the benchtop chlorine, pH, and turbidity meters was checked daily during the
calibration procedures using certified check standards. Alkalinity and IDS were analyzed in
batches. Certified QC standards and/or matrix spikes were run with each batch.
The NSF Laboratory Quality Assurance Manual establishes the frequency of spike sample
analyses at 10% of the samples analyzed for chemical analyses. Laboratory control samples are
also run at a frequency of 10%. The recovery limits specified for the parameters in this
verification, excluding microbiological analyses, were 70-130% for laboratory-fortified samples
and 85-115% for laboratory control samples. The NSF QA department reviewed the laboratory
24
-------
records and found that all recoveries were within the prescribed QC requirements. Calibration
requirements were also achieved for all analyses.
5.8.3 Precision
Precision refers to the degree of mutual agreement among individual measurements and provides
an estimate of random error. One sample per batch was analyzed in duplicate for the TDS
measurements. At least one out of every ten samples for alkalinity was analyzed in duplicate.
Duplicate municipal drinking water samples were analyzed for pH, total chlorine, and turbidity
as part of the daily calibration process. Precision of duplicate analyses was measured by use of
the following equation to calculate RPD:
RPD =
:200
where:
Sl = sample analysis result; and
S2 = sample duplicate analysis result.
Acceptable analytical precision for the verification test was set at an RPD of 30%.
All RPD were within NSF's established allowable limits for each parameter. Please note that
samples from this evaluation for alkalinity and TDS were batched with other non-ETV samples.
The duplicate analysis requirements apply to the whole batch, not just the samples from this
ETV.
5.8.4 Completeness
Completeness is the proportion of valid, acceptable data generated using each method as
compared to the requirements of the test/QA plan. The completeness objective for data
generated during verification testing is based on the number of samples collected and analyzed
for each parameter and/or method, as presented in Table 5-2.
Table 5-2. Completeness Requirements
Number of Samples per Parameter and/or Method
0-10
11-50
>50
Percent Completeness
80%
90%
95%
25
-------
Completeness is defined as follows for all measurements:
%C = (V/T)x 100
where:
%C = percent completeness;
V = number of measurements judged valid; and
T = total number of measurements.
One hundred percent completeness was achieved for all aspects of this verification. All planned
testing activities were conducted as scheduled, and all planned samples were collected for
challenge organism and water chemistry analysis.
26
-------
Chapter 6
References
APHA, AWWA, and WEF (1999). Standard Methods for the Examination of Water and
Wastewater, 20th Edition.
NSF International (2007). NSF/ANSI Standard 55 - Ultraviolet Microbiological Water
Treatment Systems.
USEPA (2005). Membrane Filtration Guidance Manual (EPA 815-R-06-009).
USEPA and NSF International (2005). ETVProtocolfor Equipment Verification Testing for
Physical Removal of Microbiological and P articulate Contaminants.
USEPA and NSF International (2011). Environmental Technology Verification Report, Removal
ofMicrobial Contaminants in Drinking Water, Dow Chemical Company - Dow Water
Solutions SFD-2880 Ultrafiltration Module (EPA/600/R-11/004).
27
-------
Appendix A
Test/Quality Assurance Project Plan
Contact Mr. Bruce Bartley at 734-769-5148 or bartley@nsf.org for a copy of this document.
A-l
-------
Appendix B
Challenge Organism Triplicate Counts
Table B-l. First Round Intact Module MS2 Triplicate Counts
Module
Module
1
Module
2
Module
3
Module
4
Module
5
Sample
Flush
Matrix Spike
1 Minute
15 Minutes
30 Minutes
Flush
Matrix Spike
1 Minute
15 Minutes
30 Minutes
Flush
Matrix Spike
1 Minute
15 Minutes
30 Minutes
Flush
Matrix Spike
1 Minute
15 Minutes
30 Minutes
Flush
Matrix Spike
1 Minute
15 Minutes
30 Minutes
Feed (PFU/mL)
Count 1
<1
1.05xl06
1.52xl06
l.SlxlO6
1.41xl06
<1
1.20xl05
1.13x10"
2.6xl05
4.0xl05
2
7.3xl05
5.7xl05
3.7xl05
5.1xl05
3
5.0xl05
3.3x10"
3.6x10"
2.9x10"
<1
3.2x10"
7.7x10"
6.4x10"
1.26x10"
Count 2
<1
1.21xl06
1.26xl06
1.46xl06
1.21xl06
<1
1.45x10"
1.40x10"
2.9x10"
2.8x10"
1
7.4x10"
4.5x10"
3.4x10"
3.6x10"
2
4.2x10"
3.5x10"
4.5x10"
3.0x10"
<1
2.9x10"
7.0x10"
7.5x10"
1.30x10"
Count 3
<1
9.2x10"
1.45xl06
1.82xl06
1.42xl06
<1
1.32x10"
1.19x10"
2.5x10"
2.9x10"
2
8.1x10"
3.3x10"
4.0x10"
4.9x10"
2
3.9x10"
2.8x10"
3.4x10"
2.6x10"
<1
2.7x10"
7.4x10"
4.3x10"
1.34x10"
Filtrate (PFU/mL)
Count 1
<1
9.3x10"
1.71xl02
1.67xl02
1.88xl02
<1
1.13x10"
S.SxlO1
S.SxlO1
4.1X101
<1
7.5x10"
2
1.4X101
2.7X101
<1
3.0x10"
3.9x10'
8.7x10'
2.6x10'
<1
4.6x10"
3.6x10'
8.6x10'
3.1x10'
Count 2
<1
8.5x10"
1.41xl02
1.47xl02
1.75xl02
<1
1.40x10"
3.8x10'
2.3x10'
3.6x10'
<1
6.7x10"
<1
2.0X101
S.SxlO1
<1
3.1x10"
4.3x10'
1.12xl02
1.5x10'
<1
5.3x10"
6.2x10'
5.8x10'
4.5x10'
Count 3
<1
6.8x10"
1.99xl02
2.14xl02
2.23xl02
<1
1.19x10"
6.9x10'
6.5x10'
5.0x10'
<1
6.8x10"
8
1.2X101
4.6X101
<1
2.6x10"
5.8x10'
6.4x10'
7.2x10'
<1
4.9x10"
8.7x10'
8.2x10'
5.0x10'
B-l
-------
Table B-2. First Round Cut-Fiber Module MS2 Triplicate Counts
Module
Module
1
Module
2
Module
3
Module
4
Module
5
Sample
Flush
Matrix Spike
1 Minute
15 Minutes
30 Minutes
Flush
Matrix Spike
1 Minute
15 Minutes
30 Minutes
Flush
Matrix Spike
1 Minute
15 Minutes
30 Minutes
Flush
Matrix Spike
1 Minute
15 Minutes
30 Minutes
Flush
Matrix Spike
1 Minute
15 Minutes
30 Minutes
Feed (PFU/mL)
Count 1
<1
3.1x10"
1.11x10"
1.17x10"
8.8xl04
<1
9.7xl04
3.1x10"
3.2x10"
3.0x10"
<1
4.7x10"
5.5x10"
6.3x10"
5.1x10"
<1
2.7x10"
6.8x10"
3.3x10"
7.1x10"
<1
4.7xl04
6.2x10"
1.04xl06
8.9x10"
Count 2
<1
2.9x10"
1.08x10"
1.04x10"
1.03x10"
<1
8.8xl04
2.9x10"
3.3x10"
2.6x10"
<1
4.1x10"
6.0x10"
6.7x10"
5.3x10"
<1
3.2x10"
6.7x10"
3.8x10"
3.4x10"
<1
5.1xl04
8.7x10"
9.8x10"
7.6x10"
Count 3
<1
2.7x10"
1.22x10"
9.7xl04
1.19x10"
<1
1.04x10"
2.8x10"
2.7x10"
2.9x10"
<1
4.0x10"
5.1x10"
6.0x10"
5.7x10"
<1
3.6x10"
6.0x10"
5.2x10"
4.9x10"
<1
5.0xl04
9.3x10"
7.1x10"
5.6x10"
Filtrate (PFU/mL)
Count 1
<1
2.7x10"
8
6.9x10'
7.8x10'
<1
9.2xl04
6
8.3x10'
2.9xl02
<1
2.9x10"
<1
3.9x10'
3.2x10'
<1
2.9x10"
2
4
8
<1
3.9xl04
1.0x10'
3.3x10'
2.9x10'
Count 2
<1
2.9x10"
1.1x10'
6.8x10'
9.1x10'
<1
9.4xl04
8
8.2x10'
3.0xl02
<1
3.0x10"
1
4.2x10'
3.6x10'
<1
2.7x10"
5
6
9
<1
3.6xl04
9
5.4x10'
3.4x10'
Count 3
<1
3.3x10"
1.2x10'
9.3x10'
8.4x10'
<1
9.0xl04
6
9.6x10'
3.0xl02
<1
3.4x10"
<1
2.7x10'
3.7x10'
<1
2.8x10"
3
7
2.1x10'
<1
3.1xl04
1.7x10'
5.0x10'
3.3x10'
B-2
-------
Table B-3. Retest Intact Module MS2 Triplicate Counts
Module
Module
1
Module
2
Module
3
Module
4
Module
5
Sample
Flush
Matrix Spike
1 Minute
15 Minutes
30 Minutes
Flush
Matrix Spike
1 Minute
15 Minutes
30 Minutes
Flush
Matrix Spike
1 Minute
15 Minutes
30 Minutes
Flush
Matrix Spike
1 Minute
15 Minutes
30 Minutes
Flush
Matrix Spike
1 Minute
15 Minutes
30 Minutes
Feed (PFU/mL)
Count 1
<1
2.6x10"
2.6xl06
3.0xl06
3.5xl06
1
2.03xl05
5.6xl06
3.5xl06
4.9xl06
<1
2.5xl05
6.8xl06
7.2xl06
6.4xl06
13
4.1xl05
5.0xl06
4.1xl06
8.4xl06
4
4.5xl05
1.02xl07
7.3xl06
4.3xl06
Count 2
<1
3.4x10"
2.8xl06
2.8xl06
2.7xl06
5
2.7xl05
5.7xl06
3.6xl06
2.9xl06
<1
2.5xl05
7.4xl06
5.2xl06
5.8xl06
19
3.3xl05
5.6xl06
3.7xl06
3.6xl06
<1
3.9xl05
5.7xl06
5.3xl06
3.0xl06
Count 3
<1
3.7x10"
2.6xl06
2.7xl06
3.0xl06
3
3.1xl05
2.9xl06
4.8xl06
2.8xl06
<1
2.6xl05
4.5xl06
4.3xl06
4.0xl06
3
3.4xl05
4.6xl06
4.5xl06
4.2xl06
<1
7.2xl05
5.7xl06
3.6xl06
2.5xl06
Filtrate (PFU/mL)
Count 1
<1
3.3x10"
6.3xl02
1.30xlOj
1.85x10"
<1
4.3x10"
1.61x10"
4.9x10"
4.0x10"
<1
5.0x10"
1.88x10"
2.9x10"
3.9x10"
<1
4.0x10"
2.17x10"
2.7x10"
2.7x10"
<1
3.8x10"
1.31xl04
1.38xl04
1.45xl04
Count 2
<1
3.8x10"
7.7xl02
1.25x10"
1.95x10"
<1
5.0x10"
1.56x10"
4.2x10"
4.2x10"
<1
5.2x10"
1.24x10"
2.5x10"
4.3x10"
<1
4.8x10"
1.69x10"
3.8x10"
2.6x10"
<1
4.6x10"
1.26xl04
1.34xl04
1.22xl04
Count 3
<1
2.5x10"
6.7xl02
1.23x10"
1.59x10"
<1
4.1x10"
1.63x10"
4.3x10"
4.7x10"
<1
4.3x10"
1.38x10"
1.65x10"
4.8x10"
<1
4.2x10"
1.80x10"
4.8x10"
1.72x10"
<1
4.3x10"
1.17xl04
1.03xl04
1.27xl04
B-3
-------
Table B-4. Retest Cut-Fiber Module MS2 Triplicate Counts
Module
Module
1
Module
2
Module
3
Module
4
Module
5
Sample
Flush
Matrix Spike
1 Minute
15 Minutes
30 Minutes
Flush
Matrix Spike
1 Minute
15 Minutes
30 Minutes
Flush
Matrix Spike
1 Minute
15 Minutes
30 Minutes
Flush
Matrix Spike
1 Minute
15 Minutes
30 Minutes
Flush
Matrix Spike
1 Minute
15 Minutes
30 Minutes
Feed (PFU/mL)
Count 1
<1
4.6x10"
7.2xl06
6.4xl06
6.1xl06
<1
1.67xl05
8.7x10"
6.7x10"
9.1x10"
<1
7.2x10"
l.OOxlO6
8.6x10"
1.16xl06
1
4.1x10"
2.43xl06
3.8xl06
4.9xl06
<1
2.9x10"
2.7xl06
1.34xl06
1.22xl06
Count 2
<1
8.5x10"
5.5xl06
4.2xl06
4.2xl06
<1
1.74x10"
9.8x10"
8.1x10"
8.7x10"
<1
7.5x10"
9.2x10"
l.OlxlO6
1.05xl06
<1
4.1x10"
3.4xl06
3.8xl06
3.7xl06
<1
3.5x10"
1.49xl06
1.60xl06
1.32xl06
Count 3
<1
5.7x10"
5.6xl06
5.9xl06
4.8xl06
<1
1.77x10"
8.1x10"
9.0x10"
8.7x10"
<1
6.3x10"
8.3x10"
6.5x10"
9.0x10"
<1
3.6x10"
3.2xl06
3.0xl06
2.6xl06
<1
2.5x10"
1.66xl06
1.64xl06
l.llxlO6
Filtrate (PFU/mL)
Count 1
<1
5.1x10"
4.5x10"
3.7x10"
4.2x10"
<1
1.63x10"
2.06xlOj
1.90x10"
1.92x10"
1
8.1x10"
1.25x10"
1.14x10"
9.4xl02
<1
5.9x10"
5.4x10"
4.9x10"
1.45xl04
<1
2.0x10"
6.0x10"
6.7x10"
7.0x10"
Count 2
<1
6.6x10"
4.6x10"
4.3x10"
2.9x10"
<1
1.58x10"
1.73x10"
1.51x10"
1.81x10"
2
7.5x10"
1.16x10"
1.26x10"
9.1xl02
<1
4.9x10"
4.6x10"
4.8x10"
9.5x10"
<1
1.82x10"
4.8x10"
4.3x10"
5.0x10"
Count 3
<1
5.1x10"
4.4x10"
4.1x10"
4.5x10"
<1
1.68x10"
1.68x10"
1.76x10"
1.72x10"
3
8.5x10"
1.09x10"
1.00x10"
1.00x10"
<1
6.1x10"
3.3x10"
3.1x10"
8.9x10"
<1
2.34x10"
5.1x10"
5.1x10"
3.8x10"
B-4
------- |