September 2006
NSF 06/23/EPADWCTR
EPA/600/R-06/101
Environmental Technology
Verification Report
Removal of Chemical and Microbial
Contaminants in Drinking Water
Watts Premier, Inc.
M-2400 Point-of-Entry Reverse Osmosis
Drinking Water Treatment System
Prepared by
NSF International
Under a Cooperative Agreement with
U.S. Environmental Protection Agency
-------
This page is intentionally blank
-------
THE ENVIRONMENTAL TECHNOLOGY VERIFICATION
PROGRAM
U.S. Environmental Protection Agency
NSF International
ETV Joint Verification Statement
TECHNOLOGY TYPE: POINT-OF-ENTRY DRINKING WATER TREATMENT
SYSTEM
APPLICATION: REMOVAL OF CHEMICAL AND MICROBIAL
CONTAMINANTS IN DRINKING WATER
PRODUCT NAME: M-2400 REVERSE OSMOSIS SYSTEM
VENDOR: WATTS PREMIER, INC.
ADDRESS: 1725 WEST WILLIAMS DRIVE, SUITE C-20
PHOENIX, AZ 85027
PHONE: 800-752-5582
INTERNET HTTP://WWW.WATTSPREMIER.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 Watts Premier, Inc. M-2400 Point-of-Entry (POE)
Reverse Osmosis (RO) Drinking Water Treatment System. NSF performed all of the testing activities and
also authored the verification report and this verification statement. The verification report contains a
comprehensive description of the testing activities.
The 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
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 06/23/EPADWCTR The accompanying notice is an integral part of this verification statement. September 2006
VS-i
-------
ABSTRACT
The Watts Premier M-2400 POE RO Drinking Water Treatment System was tested at the NSF Drinking
Water Treatment Systems Laboratory for removal of the viruses fir and MS2, the bacteria Brevundimonas
diminuta, and chemicals aldicarb, benzene, cadmium, carbofuran, cesium, chloroform, dichlorvos,
mercury, methomyl, mevinphos, oxamyl, paraquat, sodium fluoroacetate, strontium, and strychnine. The
microorganisms used in this study served as surrogates for pathogenic bacteria and viruses that may be
introduced into drinking water through accidental or intentional contamination. The target chemical
challenge concentration was 1 milligram per liter (mg/L). The target microorganism challenge
concentrations were IxlO6 colony forming units per 100 milliliters (CFU/100 mL) for B. diminuta, and
IxlO4 plaque forming units per milliliter (PFU/mL) for the viruses. NSF also separately tested an
optional post-membrane activated carbon filter that Watts Premier offers, the Flowmatic MAXVOC FF-
975. This filter was only tested with the chemicals not removed to 20 micrograms per liter (ng/L) or
lower by the RO membrane. One M-2400 system and one MAXVOC FF-975 carbon filter were tested.
Each challenge was 30 minutes in length. The M-2400 removed a minimum of 2.9 logio of the viruses,
and 2.5 logio of B. diminuta. The M-2400 removed all of the chemicals by 96% or more, except for
mercury, which was only removed by 38%. Based on the M-2400 chemical challenge results, the
MAXVOC FF-975 filter was challenged with chloroform, dichlorvos, mercury, and methomyl. The
MAXVOC FF-975 removed 96% or more of the four chemicals. The M-2400 and MAXVOC FF-975
together removed 99% or more of all chemicals but sodium flouroacetate, whose percent reduction was
limited by its high detection limit of 20 |o,g/L.
TECHNOLOGY DESCRIPTION
The following technology description was provided by the manufacturer and has not been verified.
The M-2400 is a skid-mounted RO system that utilizes one 4" x 40" RO membrane with a surface area of
82 square feet (ft2). The membrane is fed by a 330 gallons-per-hour booster pump. The system also
includes a pre-membrane sediment or activated carbon filter, an optional post-membrane activated carbon
filter, and an optional product water storage tank. The M-2400 has a control panel with pressure gauges
and flow meters to calibrate the system and monitor performance. The skid measures 27" wide, 32" deep,
and 57" high. The system as tested did not include any pre-membrane filters or a storage tank, but did
include a post-membrane carbon filter. Watts Premier uses the Flowmatic MAXVOC-FF975 activated
carbon filter as an optional post-membrane treatment step for organic chemical removal. The MAXVOC
FF-975 is a 4.625" x 9.75" block filter with a rated service flow rate of 2 gallons per minute (gpm).
Under normal operation, raw water entering the system first passes through the sediment or carbon pre-
filter to remove large particles. The pre-membrane filter effluent is then sent through the booster pump
and then on to the RO membrane. Water passing through the membrane is collected in a permeate line
that can be plumbed to a storage tank. A portion of the concentrate water from the membrane module can
be recycled back into the feed water line depending on the desired recovery for the system. The
remainder of the concentrate is sent to the drain. The recycle rate can be manually adjusted with a needle
control valve.
VERIFICATION TESTING DESCRIPTION
Test Site
The testing site was the Drinking Water Treatment Systems Laboratory at NSF in Ann Arbor, Michigan.
A description of the test apparatus can be found in the verification report. The testing was conducted in
January through April of 2006.
NSF 06/23/EPADWCTR The accompanying notice is an integral part of this verification statement. September 2006
VS-ii
-------
Methods and Procedures
The testing methods and procedures are detailed in the Test/QA Plan for Verification Testing of the Watts
Premier M-2400 Point-of-Entry Reverse Osmosis Drinking Water Treatment System for Removal of
Microbial and Chemical Contaminants. One M-2400 system and one MAXVOC FF-975 filter were
tested separately. The M-2400 was challenged with the chemicals, bacteria, and viruses listed in Table
VS-1. The MAXVOC filter was only challenged with the chemicals that the RO membrane did not
remove to 20 |o,g/L or below.
The challenge chemicals were chosen from a list of chemicals of interest supplied by the EPA. The
challenge bacteria and viruses were recommended by an advisory panel because they are smaller than
most other viruses and bacteria, and so provide a conservative estimate of performance. In addition to
using B. diminuta strain 19146 as obtained from American Type Culture Collection (ATCC), NSF also
used a genetically engineered strain of the organism. The NSF Microbiology Laboratory inserted into a
culture of B. diminuta a gene conferring resistance to the antibiotic kanamycin (KanR5. diminuta). This
allowed the Microbiology Laboratory to use a growth media amended with 50 |o,g/L of kanamycin to
prohibit heterotrophic plate count (HPC) bacteria in the treated water samples from growing along with
the kanamycin resistant B. diminuta.
Table VS-1. Challenge Chemicals and Microorganisms
Chemicals Bacteria Viruses
Aldicarb Brevundimonas diminuta fr
Benzene MS2
Cadmium Chloride
Carbofuran
Cesium Chloride (nonradioactive isotope)
Chloroform
Dichlorvos
Mercuric Chloride
Methomyl
Mevinphos
Oxamyl
Paraquat
Sodium Fluoroacetate
Strontium Chloride (nonradioactive isotope)
Strychnine
The target challenge concentrations were as follows:
Chemicals: 1 ± 0.5 mg/L;
B. diminuta: > IxlO6 CFU/100 mL; and
MS2 and fr: > IxlO4 PFU/mL.
The M-2400 was plumbed to a test rig in the NSF testing lab and was calibrated for operation according
to the instructions in the M-2400 operation manual.
The M-2400 was challenged with each organism or chemical individually, except for cadmium, cesium,
and strontium, which were combined into one challenge. Each challenge was 30 minutes in length. For
the microbial challenges, influent and permeate samples were collected for organism enumeration at start-
up, after 15 minutes of operation, and after 30 minutes of operation. For the chemical challenges, influent
and permeate samples were collected at start-up and 30 minutes. All samples were analyzed in triplicate.
NSF 06/23/EPADWCTR The accompanying notice is an integral part of this verification statement. September 2006
VS-iii
-------
The MAXVOC FF-975 was conditioned with water containing chloroform prior to being challenged. The
purpose of the conditioning was to load the carbon with chloroform to a degree that simulated
contaminant loading halfway through its effective lifespan. The MAXVOC FF-975 chemical challenges
were also 30 minutes in length. As described above, the filter was only challenged with the chemicals
that the RO membrane did not remove to 20 |o,g/L or below. Based on this criterion, the filter was
challenged with chloroform, dichlorvos, mercury, and methomyl. The target challenge concentrations
were the maximum permeate levels measured during the RO membrane challenges. The target flow rate
for the challenges was 1.85 gpm, which was the highest permeate flow rate measured during the RO
membrane challenges.
VERIFICATION OF PERFORMANCE
The results of the M-2400 microbial challenges are presented below in Tables VS-2 and VS-3. The
triplicate influent and permeate counts for each sample point were averaged by calculating geometric
means. The mean organism counts for each sample point were then averaged geometrically to give an
overall mean influent and permeate count for each challenge. The overall mean counts are presented
here. These counts were logio transformed, and logio reductions were calculated for each challenge.
Table VS-2. M-2400 Virus Challenge Results
Challenge
Mean Influent
(PFU/mL)
of
Influent
Mean Permeate
(PFU/mL)
Log of
Effluent
Log1?
Reduction
fr
MS2
9.4xl04
5.5xl04
5.0
4.7
121
49
2.1
1.7
2.9
3.1
Table VS-3. M-2400 Bacteria Challenge Results
Challenge
Mean Influent
(CFU/100 mL)
Log10 of
Influent
Mean Permeate
(CFU/100 mL)
Log10 of
Effluent
Log10
Reduction
IstB. diminuta
KanR B. diminuta
2nd 5. diminuta
2.0xl07
7.0xl06
6.9xl06
7.3
6.9
6.8
5.7xl04
2.8xl03
l.lxlO4
4.8
3.4
4.1
2.5
3.5
2.7
The results of the M-2400 chemical challenges are presented in Table VS-4. The triplicate influent and
permeate measurements were averaged by calculating the arithmetic mean. The means for each sample
point were then averaged to give an overall mean influent and permeate for each challenge. As with the
microbial challenge data, the overall means are presented here. Percent reductions were calculated from
the influent and permeate concentrations.
Note that there are two entries in Table VS-3 for B. diminuta. A second challenge was conducted after it
was noticed that the RO membrane operating pressure had risen above Watts Premier's recommended
maximum of 150 psig (pounds per square inch, gauge). The system inlet pressure did not rise, but the
membrane operating pressure created by the booster pump did rise after the system was initially
calibrated with the operating pressure set at 150 psig. The recorded RO membrane operating pressures
ranged from 160 to 172 psig for the microbial challenges and the cadmium/cesium/strontium, mercury,
strychnine, paraquat, and aldicarb challenges. To see if the higher operating pressures affected the
membrane's ability to filter out microorganisms, the B. diminuta challenge was conducted again. A
comparison of the data in Table VS-3 does not indicate that the higher pressure affected membrane
performance. The data from the chemical challenges at the higher pressures does not indicate that
chemical rejection performance was compromised. Therefore, no other challenges were conducted again
with a lower membrane operating pressure.
NSF 06/23/EPADWCTR
The accompanying notice is an integral part of this verification statement. September 2006
VS-iv
-------
Table VS-4. M-2400 Chemical Challenge Results
Mean Influent Mean Effluent Percent
Chemical (n.g/L) (u.g/L) Reduction
Aldicarb
Benzene
Cadmium
Carbofuran
Cesium
Chloroform
Dichlorvos
Mercury
Methomyl
Mevinphos
Oxamyl
Paraquat
Sodium
Fluoroacetate
Strontium
Strychnine
830
680
970
920
1100
790
1700
1200
990
920
1000
480
800
990
900
3
6.4
1.4
2.6
16
28
16
750
45
5.6
4
ND(1)
ND (20)
2
ND(5)
>99
>99
>99
>99
99
97
>99
38
96
>99
>99
>99
98
>99
>99
Based on the RO membrane permeate concentrations, the MAXVOC FF-975 filter was challenged with
chloroform, dichlorvos, mercury, and methomyl. The results for these challenges are presented in Table
VS-5. As with the RO membrane chemical challenge data, mean influents and effluents were calculated
for each challenge. Percent reductions were then calculated using the overall mean influents and
effluents.
Table VS-5. MAXVOC FF-975 Chemical Challenge Data
Target Measured
Influent Mean Influent Mean Effluent Percent
Chemical (u.g/L) (M-g/L) (ug/L) Reduction
Chloroform
Dichlorvos
Mercury
Methomyl
72
25
910
48
82
36
730
56
3.2
ND (0.2)
10
1
96
>99
99
98
The microbial challenges data shows that the M-2400 RO membrane alone can be expected to remove
more than 2 logs (>99%) of bacteria and viruses from contaminated water. The RO membrane alone also
removed greater than 96% of all challenge chemicals except mercury. The chemical challenges data in
Tables VS-4 and VS-5 shows that the M-2400 and MAXVOC FF-975 combined would remove 99% or
more of all challenge chemicals but sodium fluoroacetate, whose percent reduction was capped at 98%
because of the high detection limit of 20 |o,g/L for the chemical.
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 06/23/EPADWCTR The accompanying notice is an integral part of this verification statement. September 2006
VS-v
-------
Original signed by Sally Gutierrez 09/22/06 Original signed by Robert Ferguson 09/07/06
Sally Gutierrez Date Robert Ferguson 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 06/23/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/etv
EPA web site: http://www.epa.gov/etv
NSF 06/23/EPADWCTR The accompanying notice is an integral part of this verification statement. September 2006
VS-vi
-------
September 2006
Environmental Technology Verification Report
Removal of Chemical and Microbial Contaminants in Drinking
Water
Watts Premier Incorporated
M-2400 Point-of-Entry Reverse Osmosis
Drinking Water Treatment System
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
-------
Notice
The U.S. Environmental Protection Agency (USEPA), through its Office of Research and
Development (ORD), has financially supported and collaborated with NSF International (NSF)
under Cooperative Agreement No. R-82833301. This verification effort was supported by the
Drinking Water Systems (DWS) Center, operating under the Environmental Technology
Verification (ETV) Program. This document has been peer-reviewed, reviewed by NSF and
USEPA, and recommended for public release.
11
-------
Foreword
The U.S. Environmental Protection Agency (USEPA) is charged by Congress with protecting the
Nation's land, air, and water resources. Under a mandate of national environmental laws, the
Agency strives to formulate and implement actions leading to a compatible balance between
human activities and the ability of natural systems to support and nurture life. To meet this
mandate, USEPA's research program is providing data and technical support for solving
environmental problems today and building a science knowledge base necessary to manage our
ecological resources wisely, understand how pollutants affect our health, and prevent or reduce
environmental risks in the future.
The National Risk Management Research Laboratory (NRMRL) is the Agency's center for
investigation of technological and management approaches for preventing and reducing risks
from pollution that threaten human health and the environment. The focus of the Laboratory's
research program is on methods and their cost-effectiveness for prevention and control of
pollution to air, land, water, and subsurface resources; protection of water quality in public water
systems; remediation of contaminated sites, sediments and ground water; prevention and control
of indoor air pollution; and restoration of ecosystems. NRMRL collaborates with both public
and private sector partners to foster technologies that reduce the cost of compliance and to
anticipate emerging problems. NRMRL's research provides solutions to environmental problems
by: developing and promoting technologies that protect and improve the environment; advancing
scientific and engineering information to support regulatory and policy decisions; and providing
the technical support and information transfer to ensure implementation of environmental
regulations and strategies at the national, state, and community levels.
This publication has been produced as part of the Laboratory's strategic long-term research plan.
It is published and made available by USEPA's Office of Research and Development to assist
the user community and to link researchers with their clients.
Sally Gutierrez, Director
National Risk Management Research Laboratory
in
-------
Table of Contents
Verification Statement VS-i
Title Page i
Notice ii
Foreword iii
Table of Contents iv
List of Tables vi
List of Figures vi
Abbreviations and Acronyms vii
Acknowlegements ix
Chapter 1 Introduction 1
1.1 Environmental Technology Verification (ETV) Program Purpose and Operation 1
1.2 Purpose of Verification 1
1.3 Development of Test/Quality Assurance (QA)Plan 1
1.4 Challenge Chemicals and Microorganisms 2
1.5 Testing Participants and Responsibilities 3
1.5.1 NSF International 3
1.5.2 Watts Premier 3
1.5.3 U.S. Environmental Protection Agency 4
Chapter 2 Equipment Description 5
2.1 Activated Carbon Treatment Process 5
2.2 Reverse Osmosis Treatment Process 5
2.3 M-2400 Equipment Description 5
2.4 M-2400 Operation and Maintenance Requirements 8
2.5 Flowmatic MAXVOC-FF975 Activated Carbon Filter 9
Chapter 3 Methods and Procedures 11
3.1 Introduction 11
3.2 Challenge Substances 11
3.2.1 Bacteria and Virus Surrogates 11
3.2.2 Chemicals 12
3.3 Test Apparatus 12
3.4 Task 1: Test Unit Start-Up, Conditioning and RO Membrane Integrity Test 13
3.4.1 Test Unit Start-Up 13
3.4.2 RO Membrane Conditioning 14
3.4.3 MAXVOC Filter Conditioning 14
3.5 Task 2: System Operation Characterization 15
3.6 Task 3: Microbial Challenge Test Procedure 16
3.6.1 Test Water 16
3.6.2 Sanitizing the Test Apparatus 17
3.6.3 Challenge Test Procedure 17
3.7 Task 4: Chemical Challenge Tests 18
3.7.1 Test Water 18
iv
-------
3.7.1.1 RO Membrane Challenge Water 18
3.7.1.2 Carbon Filter Conditioning and Challenge Water 19
3.7.2 Challenge Test Procedures 19
3.7.2.1 RO Membrane Challenge Testing 19
3.7.2.2 MAXVOC Challenge Testing 20
3.8 Analytical Methods 20
3.8.1 Water Quality Analytical Methods 20
3.8.2 Microbiology Analytical Methods 21
3.8.2.1 Sample Processing, and Enumeration of Viruses 21
3.8.2.2 B. diminuta Cultivation and Challenge Suspension Preparation 21
3.8.2.3 Sample Processing and Enumeration of B. diminuta 22
3.8.3 Challenge Chemical Analytical Methods 21
Chapter 4 Results and Discussion 23
4.1 TDS Reduction Membrane Integrity Check 23
4.2 System Operation Characterization 23
4.3 RO Membrane Microbial Challenges 26
4.4 RO Membrane Chemical Challenges 27
4.5 MAXVOC Carbon Filter Chemical Challenges 28
Chapter 5 Quality Assurance/Quality Control 31
5.1 Introduction 31
5.2 Test Procedure QA/QC 31
5.3 Sample Handling 31
5.4 Chemistry Analytical Methods QA/QC 31
5.5 Microbiology Laboratory QA/QC 31
5.5.1 Growth Media Positive Controls 31
5.5.2 Negative Controls 32
5.6 Documentation 32
5.7 Data Review 32
5.8 Data Quality Indicators 32
5.8.1 Representativeness 32
5.8.2 Accuracy 33
5.8.3 Precision 33
5.8.4 Completeness 34
5.8.4.1 Parameters with less than 100% Completeness 34
5.9 Measurements Outside of the Test/QAPlan Specifications 35
Chapter 6 References 37
-------
Appendices
Appendix A Challenge Data
List of Tables
Table 1-1. Challenge Chemicals and Microorganisms 2
Table 2-1. M-2400 Equipment Specifications 7
Table 2-2. RO Membrane Specifications 8
Table 3-1. Challenge Chemicals 12
Table 4-1. M-2400 Microbial Challenges Operation and Water Chemistry Data 24
Table 4-2. M-2400 Chemical Challenges Operation and Water Chemistry Data 25
Table 4-3. M-2400 Microbial Challenges CPU or PFU Counts and Log Reductions 27
Table 4-4. M-2400 Chemical Challenge Data 28
Table 4-5. MAXVOC FF-975 Filter Conditioning Water Chemistry Data 28
Table 4-6. MAXVOC FF-975 Chemical Challenge Data 29
Table 5-1. Completeness Requirements 34
List of Figures
Figure 2-1. M-2400 RO system 6
Figure 3-1. Schematic diagram of "tank rig" test station 13
Figure 3-2. M-2400 plumbed to test rig in NSF testing laboratory 14
VI
-------
Abbreviations and Acronyms
ANSI
ASTM
ATCC
°C
CPU
cm
DWS
ETV
°F
ft2
GC/MS
gfd
gpd
gpm
HC1
HPC
HPLC
ICP-MS
KanR
L
Ibs
mL
nm
NaOH
NRMRL
NSF
NTU
ORD
PBDW
PFU
POE
POU
psi
psig
QA
QC
QA/QC
RO
RPD
SDI
SLB
SOP
IDS
IMP
American National Standards Institute
ASTM International (formerly American Society of Testing Materials)
American Type Culture Collection
degrees Celsius
colony forming unit
centimeter
Drinking Water Systems
Environmental Technology Verification
degrees Fahrenheit
square foot or feet
gas chromatography/mass spectrometry
gallons per square foot per day
gallons per day
gallons per minute
hydrochloric acid
heterotrophic plate count
high pressure liquid chromatography
inductively coupled plasma - mass spectrometry
kanamycin resistant
liter
pounds
milliliter
nanometer
Sodium Hydroxide
National Risk Management Research Laboratory
NSF International (formerly National Sanitation Foundation)
nephelometric turbidity units
Office of Research and Development
phosphate-buffered dilution water
plaque forming unit
point-of-entry
point-of-use
pounds per square inch
pounds per square inch, gauge
quality assurance
quality control
quality assurance/quality control
reverse osmosis
relative percent difference
silt density index
saline lactose broth
standard operating procedure
total dissolved solids
transmembrane pressure
vn
-------
Abbreviations and Acronyms, Cont'd.
TNTC too numerous to count
TOC total organic carbon
ISA tryptic soy agar
TSB tryptic soy broth
|o,g microgram
|oL microliter
jam micrometer
|o,S microSieman
USEPA U. S. Environmental Protection Agency
VOC volatile organic carbon
Vlll
-------
Acknowledgments
NSF International (NSF) 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.
The manufacturer of the equipment was:
Watts Premier Incorporated
1725 West Williams Drive
Suite C-20
Phoenix, AZ 85027
NSF wishes to thank the members of the expert technical panel for their assistance with
development of the test plan.
IX
-------
This page is intentionally blank
-------
Chapter 1
Introduction
1.1 Environmental Technology Verification (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; by
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 (DWS) 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 to evaluate treatment system performance under a simulated
intentional or accidental chemical or microbiological contamination event. Because any
contamination event would likely be short-lived, long-term performance of the treatment system
was not investigated. Each chemical or microbial challenge was only one half-hour long.
1.3 Development of Test/Quality Assurance (QA) Plan
USEPA's "Water Security Research and Technical Support Action Plan" (USEPA, 2004)
identifies the need to evaluate point-of-use (POU) and point-of-entry (POE) treatment system
capabilities for removing likely contaminants from drinking water. As part of the ETV Program,
NSF developed a test/QA plan for evaluating reverse osmosis (RO) drinking water treatment
systems for removal of chemical and microbial contaminants. To assist in this endeavor, NSF
assembled expert technical panels, which gave suggestions on a protocol design prior to
development of the test/QA plan. Panel members included experts from USEPA, United States
-------
Army, and United States Centers for Disease Control and Prevention, Division of Parasitic
Diseases, as well as a water utility microbiologist, a university professor, and an independent
consultant in the POU drinking water treatment systems industry.
The product-specific test/QA plan for evaluating the M-2400 was entitled Test/QA Plan for
Verification Testing of the Watts PremierM-2400 Point-of-Entry Drinking Water Treatment
System for Removal ofMicrobial and Chemical Contaminants. This test/QA plan calls for
challenge tests with actual chemicals of concern, but surrogate bacteria and viruses in place of
testing with the actual microorganisms of concern. Please note that this test plan does not cover
chemical contaminants derived from microorganisms, such as algal toxins, ricin or botulinum
toxin.
By participating in this ETV, Watts Premier has obtained USEPA- and NSF-verified
independent test data indicating potential user protection against intentional or accidental
chemical or microbiological contamination of drinking water. The M-2400 RO system is not
marketed as being effective at removing bacteria, viruses, nor all of the challenge chemicals.
This verification is a demonstration of possible performance. Verifications following a US
EPA approved test/QA plan serve to notify the public of the possible level of protection against
chemical or microbiological contaminants afforded to them by the use of the verified system.
Please note that in the event of system exposure to microbial contaminants, the user should
replace the RO membrane and all other pre- and post-membrane filters, and also sanitize
the system and its plumbing using bleach or another sanitizing agent. The removed RO
membrane and filter cartridges should be handled with extreme caution as biohazards.
1.4 Challenge Chemicals and Microorganisms
The challenge chemicals and surrogate microorganisms used for this verification are given below
in Table 1-1. See Section 3.2 for more discussion about the challenge substances.
Table 1-1. Challenge Chemicals and Microorganisms
Chemicals Bacteria Viruses
Aldicarb Brevundimonas diminuta fr
Benzene MS2
Cadmium
Carbofuran
Cesium
Chloroform
Dichlorvos
Mercury
Methomyl
Mevinphos
Oxamyl
Paraquat
Sodium Fluoroacetate
Strontium
Strychnine
-------
1.5 Testing Participants and Responsibilities
The ETV testing of the M-2400 was a cooperative effort between the following participants:
NSF
Watts Premier, Inc.
USEPA
The following is a brief description of each of the ETV participants and their roles and
responsibilities.
1.5.1 NSF International
NSF is a not-for-profit organization dedicated to public health and safety, and to 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. 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 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 Information: NSF International
789 N. Dixboro Road
Ann Arbor, MI 48105
Phone: 734-769-8010
Fax: 734-769-0109
Contact: Bruce Bartley, Project Manager
Email: bartley@nsf.org
1.5.2 Watts Premier
The verified system is manufactured by Watts Premier, a division of Watts Water Technologies.
Watts Premier manufactures industrial, food service, POE, and POU water treatment systems.
The manufacturer was responsible for supplying the test units and for providing logistical and
technical support as needed.
Contact Information: Watts Premier Incorporated
1725 West Williams Drive
Suite C-20
Phoenix, AZ 85027
Phone: 800-752-5582
Fax:623-931-0191
Contact Person: Mr. Shannon Murphy
Email: murphysp@wattsind.com
-------
1.5.3 U.S. Environmental Protection Agency
USEPA, through its Office of Research and Development, 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.
-------
Chapter 2
Equipment Description
2.1 Activated Carbon Treatment Process
Activated carbon removes organic chemicals from water through adsorption. The chemicals are
attracted to and attach to the surface of the carbon through electrostatic interactions. The
adsorbent properties of activated carbon are a function of the raw material used and the
activation process. Once the carbon is saturated with adsorbed molecules, it must be replaced.
2.2 Reverse Osmosis Treatment Process
Membrane technologies are among the most versatile water treatment processes because of their
ability to effectively remove a wide variety of contaminants. RO membranes operate by the
principal of cross-flow filtration. In this process, the influent water flows over and parallel to the
filter medium and exits the system as reject water. Under pressure, a portion of the water
diffuses through the membrane becoming "permeate." The membrane allows water molecules to
pass through its pores, but not most dissolved inorganic chemical molecules and larger molecular
weight organic chemical molecules. These molecules are concentrated in and washed away with
the reject water stream. RO membranes also remove suspended solids and microorganisms
through mechanical filtration.
Water passage through the RO membrane to generate permeate is known as "flux." It is a
function of applied pressure, water temperature, and the osmotic pressure of the solution under
treatment. Increasing the applied pressure will increase the permeate rate. However, a higher
flux will tend to promote more rapid fouling of the membrane. Membrane element
manufacturers usually provide limits with regard to the maximum applied pressures to be used as
a function of feed water quality and other factors.
Unlike activated carbon, which reaches an exhaustion point and needs to be replaced, the
reduction capabilities of RO membranes remain in effect until the membrane is compromised.
Monitoring of membrane performance can be conducted by measuring the total dissolved solids
(TDS) concentration of the permeate water.
2.3 M-2400 Equipment Description
The M-2400 is a skid-mounted RO system in a carbon steel frame with powder coating. The
system is 27" wide, 32" deep, and 57" high. A photograph of the system is shown in Figure 2-1.
The main system components are:
3/4 horsepower, 330 gallons per hour feed pump to increase the water pressure to the RO
membrane;
sediment and/or carbon pre-membrane filters;
-------
one 4" x 40" (10 centimeter [cm] x 102 cm) RO membrane module inside a stainless steel
pressure vessel;
control panel with permeate and concentrate flow meters, valves to adjust the
concentrated and recycle flows, and pressure gauges to measure the RO membrane
operating pressure, concentrate back-pressure, and storage tank pressure (for use with a
pressure tank); and
optional pressure tank or open-to-atmosphere tank for storage of treated water.
Figure 2-1. M-2400 RO system.
-------
Under normal operation, raw water entering the system first passes through a sediment or carbon
pre-filter to remove large particles. The pre-filter effluent is then sent through a booster pump
and then on to the RO membrane. Water passing through the membrane is collected in a
permeate line that can be plumbed to a storage tank. A portion of the concentrate water from the
membrane module can be recycled back into the feed water line depending on the desired
recovery for the system. The remainder of the concentrate is sent to the drain. The recycle rate
can be manually adjusted with a needle control valve.
The M-2400 has an automatic 12-second membrane flush using permeate water. The system can
be programmed so the rinse occurs when unit operation ceases, for operation on a short-duty
cycle, or on a certain frequency for operation on an extended-duty cycle.
The system as tested did not include a pre-membrane filter or a permeate storage tank. During
testing, a valve on the permeate line was slowly shut to increase the back-pressure on the
membrane to a point at which the automatic flush initiated. However, since there was no
permeate storage tank to supply the flush water, the flush only lasted a few seconds, until the
water in the permeate line was gone Please note that the observed operation and membrane
performance may not apply to a system operated with a pressurized storage tank, due to
back-pressure on the membrane from the tank.
The M-2400 operation specifications are presented in Table 2-1. The RO membrane
specifications are presented in Table 2-2.
Table 2-1. M-2400 Equipment Specifications
Parameter Specification
Dry Weight 350 pounds (Ibs.)
Wet Weight 1750 Ibs.
Feed Water:
Temperature 1.7° to 38°C (35° to 100° F)
Max. Feed Flow Rate 5.5 gallons per minute (gpm)
Feed Water Pressure 25 to 80 pounds per square inch, gauge (psig)
Membrane Operating Pressure 150 psig
PH 2 to 11
Hardness < 290 milligrams per liter (mg/L)
Iron < 0.1 mg/L
Manganese < 0.05 mg/L
Silica < 75 mg/L
TDS < 2500 mg/L
Turbidity < 1 Nephelometric turbidity units (NTU)
Permeate Flow Rate -1.67 gpm
Drain Connection: Floor drain within 10 feet of system, 1 1A inch connection
Electrical Requirements:
RO Processor 115 volts/11 amps
Delivery Pump 115 volts/12.4 amps
-------
Table 2-2. RO Membrane Specifications
Parameter
Specification
Membrane Manufacturer
Membrane Element Model Number
Size of Element
Active Membrane Surface Area per Element
Molecular Weight Cut-Off
Membrane Material Construction
Membrane Hydrophobicity
Reported Membrane Charge
Scroll Width
Design Pressure
Design Flux at Design Pressure
Variability of Design Flux
Design Specific Flux at 25°C
Standard Testing Recovery
Standard Testing pH
Standard Testing Temperature
Design Cross-Flow Velocity
Maximum Flow Rate to an Element
Minimum Flow Rate to an Element
Required Feed Flow to Permeate Flow Ratio
Maximum Element Recovery
Rejection of Reference Solute and Conditions of Test (e.;
Solute type and concentration)
Variability of Rejection of Reference Solute
Acceptable Range of Operating Pressures (psi, bar)
Acceptable Range of Operating pH Values
Typical Pressure Drop across a Single Element
Maximum Permissible Silt Density Index (SDI)
Maximum Permissible Turbidity
Chlorine/Oxidant Tolerance
Applied
M-T4040 ALE
4"X40"
82 square feet (ft2)
80-100 Daltons
Dow Filmtec
Hydrophobic
Negative
38 inches
150 psig
34 gallons per square foot per day (gfd)
± 15%
0.24 gfd/psig
50-75%
8
25°C
0.6 ft/s
16 gpm
4gpm
1:5
75%
80-99%
-0%, +1%
Dependent on Water Temperature
2-11
6 psi
4
1NTU
With Carbon Pre-Filter
2.4 M-2400 Operation and Maintenance Requirements
No maintenance was required during the test period. Under normal operation, periodic
replacement of the pre-membrane filter(s) and RO membrane is required. Pre-membrane filter
replacement is dependant upon inlet water quality; it is recommended that pre-membrane filters
be inspected after the first six months of operation to determine replacement need. Membranes
should be tested for TDS reduction after one month of use in order to establish initial reduction
capabilities. Following that, the system should be checked annually. In some cases, based upon
incoming water chemistry, antiscalants can be used to extend the life of the RO membrane.
Watts Premier estimates membrane life to be two years or longer.
The system does not require any manual backflush maintenance; it automatically flushes the RO
membrane for 12 seconds after every operation period.
There are no special licensing requirements to operate the M-2400.
-------
2.5 Flowmatic MAXVOC-FF975 Activated Carbon Filter
Watts Premier offers the Flowmatic MAXVOC-FF975 activated carbon filter as an optional
post-RO treatment step for the permeate water. This filter is designed to remove organic
chemicals, which may pass through the membrane. The addition of the MAXVOC-FF975 to the
M-2400 system offers a treatment system that can remove a wide variety of inorganic and
organic chemicals from drinking water, as well as microorganisms.
The MAXVOC-FF975 uses a 4.625" by 9.75" activated carbon block filter that can effectively
treat water at a flow rate of 2 gpm. This rated service flow works well with the M-2400, which
operates with a permeate flow rate of approximately 1.67 gpm.
-------
This page is intentionally blank
10
-------
Chapter 3
Methods and Procedures
3.1 Introduction
The challenge tests followed the procedures described in the Test/QA Plan for Verification
Testing of the Watts Premier M-2400 Point-of-Entry Reverse Osmosis Drinking Water Treatment
System for Removal ofMicrobial and Chemical Contaminants.
The microbial and chemical challenge protocols were adapted from the ETVProtocolfor
Equipment Verification Testing for Physical Removal of Microbiological and Paniculate
Contaminants.
The purpose of this verification was not to evaluate the production of drinking water from an
untreated source water, but rather, to evaluate the system's ability to remove chemicals and
microorganisms from drinking water. As such, this verification will not evaluate the cleaning
efficiency of the system, nor the flux recovery of the membrane after backwashing or cleaning.
One M-2400 system and one Flowmatic MAXVOC FF-975 filter were tested. No pre-membrane
filter or permeate water storage tank were included with the M-2400 test unit. The M-2400 was
challenged with both the microorganisms and chemicals, but the MAXVOC filter was only
challenged with chemicals. The MAXVOC filter has a nominal pore size rating of 0.5 microns
(|o,m), which is not small enough to retain the challenge organisms.
For the chemical challenge tests, the M-2400 was tested first. The MAXVOC carbon filter was
then tested separately for reduction of the chemicals that the RO membrane did not remove to 20
micrograms per liter (ng/L) or lower. Testing the carbon filter separately from the RO
membrane allowed an evaluation of the efficacy of each treatment step.
3.2 Challenge Substances
3.2.1 Bacteria and Virus Surrogates
The bacteria surrogate was the bacteria Brevundimonas diminuta (American Type Culture
Collection (ATCC) strain 19146). It was chosen based on its small size. It is the accepted
bacteria of choice for testing filters and membranes designed to retain bacteria and is used in the
ASTM International (ASTM) Standard Test Method for Determining Bacterial Retention of
Membrane Filters Utilized for Liquid Filtration. The smallest identified bacterium of concern is
Francisella tularensis., which can be as small as 0.2 jam in diameter. B. diminuta has a minimum
size of 0.2 to 0.3 jam in diameter.
The bacteria was used in its "normal" state, and also was genetically engineered to be resistant to
the antibiotic kanamycin. This allowed the use of growth media amended with kanamycin to
prohibit heterotrophic bacteria from also growing. The "normal" and kanamycin resistant
(KanR) strains were used in individual challenges.
11
-------
The virus surrogates were the coliphages fr and MS2. These phages were chosen as surrogates
based on their size and isoelectric points. Fr is 19 nanometers (nm) in diameter with an
isoelectric point at pH 8.9, and MS2 is 24 nm in diameter with an isoelectric point at pH 3.9.
The isoelectric point is the pH at which the virus is neutrally charged. The viruses have varying
isoelectric points, so they will have different surface charges, or different strengths of negative or
positive charge at the different pH values. In solutions above the isoelectric point, the virus is
negatively charged and below it, the virus is positively charged. Therefore, in the test water at
pH 7.5, MS2 should be negatively charged and fr should be positively charged. This approach
served to evaluate whether electrostatic forces play a role in virus retention in addition to
mechanical filtration.
The viruses were purchased from Biological Consulting Services of North Florida and the
bacteria were purchased from ATCC. The viruses were purchased in adequate volumes so that
volumes of the suspensions received were added directly to the test water. The bacteria were
cultivated at NSF to obtain the challenge suspensions. Section 3.8.2.2 describes the method used
to create the bacteria challenges.
3.2.2 Chemicals
The challenge chemicals used in this product verification are listed in Table 3-1. They were
chosen as chemicals of interest by the USEPA.
Table 3-1. Challenge Chemicals
Organic Chemicals Inorganic Chemicals
Aldicarb Cadmium Chloride
Benzene Cesium Chloride (nonradioactive isotope)
Carbofuran Mercuric Chloride
Chloroform Strontium Chloride (nonradioactive isotope)
Dichlorvos
Methomyl
Mevinphos
Oxamyl
Paraquat
Sodium Fluoroacetate
Strychnine
3.3 Test Apparatus
The M-2400 test unit was plumbed to a "tank rig" test station in the NSF testing laboratory. The
tank rig uses a 500-gallon stainless steel or a 500-gallon polyethylene tank to hold the influent
challenge water. See Figure 3-1 for a schematic diagram of the tank rig. Figure 3-2 shows the
M-2400 plumbed to a tank rig test station.
12
-------
Any suitable pressure or delivery system
w
ater supply
Tank
fill Mechanica
valve filter
Back flow preventer \_J
Mixer
CDi
(_3
1
1
i
7- Tank
Drain ine '
Pressure
gauge
9
_/- >
* ^ Diaphragm
Pump pressure
^^ Valves
Pressure
regulator
fi-
(J
Influent )
sampling
point _
L
C2H
C
Cycling <
solenoid A v.
C^
J Water meters 1
Pressure gauges
) Test units ^
J ^
o-
/
\
I
J
-0
.)
sol
cling
solenoid B
Product water
sampling points
Figure 3-1. Schematic diagram of "tank rig" test station.
The MAXVOC carbon filter was plumbed to an "injection rig" test station in the NSF testing
laboratory. The injection rigs use common tanks to hold the test water minus the challenge
chemical. Fresh water is periodically added to the tank as it is being used. Online monitors and
a computer system automatically control the water level and water chemistry. Downstream of the
feed water tank, a precisely controlled injection syringe is used to inject the challenge chemical
into the influent water. Immediately downstream of the injection point lies a motionless in-line
mixer to assure complete mixing of the challenge water. No schematic diagram of the injection
rig is available due to the proprietary nature of the design.
3.4 Task 1: Test Unit Start-Up, Conditioning and RO Membrane Integrity Test
3.4.1 Test Unit Start-Up
The test unit was calibrated for operation according to the instructions in the M-2400
Installation, Operation, & Maintenance Manual, so that the RO membrane operating pressure
was set at 150 psig. With an operating pressure of 150 psig, the influent flow rate was 3.72 gpm,
the permeate flow rate was 1.87 gpm, and the concentrate flow rate was 1.96 gpm.
13
-------
Figure 3-2. M-2400 plumbed to test rig in NSF testing laboratory.
3.4.2 RO Membrane Conditioning
The system was conditioned by operating it for one hour using the test water described in Section
3.7.1.1. After completion of the conditioning period, TDS reduction of the system was measured
(using conductivity) to verify that the system was operating properly.
3.4.3 MAXVOC Filter Conditioning
TheMAXVOC filter was operated using the test water described in Section 3.7.1.2 for 1,300
gallons. This is the volume equal to one-half of Watts Premier's claimed chemical reduction
capacity of 2,600 gallons for the filter. Chloroform was added to the test water to achieve an
average influent concentration of 300 ± 90 |J,g/L, which is the influent challenge concentration
for the volatile organic chemical (VOC) reduction test in NSF/ANSI Standard 53, Drinking water
treatment units - health effects (NSF International, 2005a) (chloroform is the surrogate chemical
for the Standard 53 VOC reduction claim). The chloroform served to load the carbon to a degree
that simulated contaminant loading in the middle of its effective lifespan.
14
-------
The filter was operated at a flow rate of 2 gpm, at an inlet water pressure of 60 + 3 psig, on a ten
minutes on, ten minutes off cycle. Influent samples were collected for analysis of chloroform,
pH, TDS, temperature, total organic carbon (TOC), and turbidity at start-up, 650 gallons, and at
the 1,300-gallon point. Effluent samples were also collected for chloroform analysis at the same
sample points.
Until the challenge tests began, the filter was stored with the conditioning water still in it, and the
inlet and outlets were closed off by valves or were plugged, so that the chloroform remained on
the carbon.
3.5 Task 2: System Operation Characterization
The following system parameters were measured and reported for each challenge test:
Influent, permeate, and concentrate flow rates;
Operating pressure of the RO membrane;
Concentrate line back pressure on the RO membrane; and
Permeate line pressure (the permeate discharge was to atmosphere - 0 to 1 psig; therefore,
the measurement was discontinued after the first few runs).
From these measurements, the following operational parameters were calculated:
Pressure drop across the RO membrane
Permeate Flux - The average permeate flux is the flow of permeate water divided by the
surface area of the membrane. Permeate flux was calculated according to the following
formula:
,
' S
where Jt = permeate flux at time t (gfd);
Qp = permeate flow (gpd [gallons per day]); and
S = membrane surface area (ft2).
Feedwater system recovery - The recovery of permeate from feed water is given as the ratio
of permeate flow to feed water flow:
% System Recovery =100- -
where Qp = permeate flow (gpd) and
Qf = feed flow to the membrane (gpd).
15
-------
Specific flux - The specific flux is the flux normalized for the transmembrane pressure
(TMP). Specific flux was calculated with the following equation:
J ~
IMP
where: Jtm = Specific flux at time t (gfd/psig);
TMP = Transmembrane pressure across the membrane (psig); and
Jt = permeate flux at time t (gfd). Temperature-corrected flux values
were employed.
Transmembrane pressure was calculated using the following equation:
IMP =
where: TMP = transmembrane pressure (psig);
Pf = feed pressure on the membrane (psig);
Pc = outlet pressure on the concentrate side of the membrane (psig); and
Pp = permeate pressure on the treated water side of the membrane (psig).
Note that the M-2400 permeate line was open to the atmosphere for this verification test, so
the permeate gauge pressure was essentially zero. Therefore, the transmembrane pressure
was just the average of the inlet pressure and outlet pressure.
The permeate flux, Jt, was corrected to 25°C to account for the variation of water viscosity
with temperature. The following empirically derived equation was used to provide
temperature corrections for specific flux calculations:
^-0.0239(1-25)
Jt(al25°C) = "
_ Qpxe'
where: Jt = permeate flux at time t (gfd);
Qp = permeate flow (gpd);
S = membrane surface area (ft2); and
T = temperature of the feed water (°C).
3.6 Task 3: Microbial Challenge Test Procedure
3.6.1 Test Water
Local tap water was treated by carbon filtration, RO, and deionization to make the base water for
the tests. The base water had the following characteristics:
conductivity < 2 microSiemans per centimeter (|j,S/cm) at 25°C;
TOC<100|ig/L;
total chlorine < 0.05 mg/L; and
heterotrophic plate count (HPC) bacteria < 100 colony forming units per milliliter
(CFU/mL).
16
-------
Only total chlorine was measured specifically for this verification. The other parameters are
measured periodically by NSF as part of the internal quality assurance/quality control (QA/QC)
program for test water quality.
The base water was adjusted to meet the following characteristics:
addition of sodium bicarbonate (NaHCOs) to achieve an alkalinity (as CaCOs) of 100 ±
10 mg/L prior to pH adjustment;
the pH was adjusted if necessary with hydrochloric acid (HC1) or sodium hydroxide
(NaOH) to reach a value of 7.5 ± 0.5.
temperature of 20 ± 2.5 °C.
The appropriate challenge organism, suspended in phosphate buffered dilution water (PBDW),
was added to the base water to create the challenge water. The target challenge concentration for
B. diminuta was > 1 X 106 CFU/100 mL. The target concentrations for MS2 and fr were > 1 X
104 plaque forming units per milliliter (PFU/mL).
Grab samples for analysis of total chlorine, alkalinity, TDS, and turbidity were collected prior to
the start of each challenge period, before addition of the challenge organism suspension.
Temperature and pH were measured at time 0. The pH was also measured at the end of each
challenge period.
3.6.2 Sanitizing the Test Apparatus
To keep the FIPC population to a minimum, the test apparatus was cleaned and sanitized prior to
the start of testing activities according to an NSF standard operating procedure (SOP). The
process is proprietary, and uses multiple chemicals as sanitizers. After sanitization, the test
apparatus was flushed until a less-than-detectable concentration of sanitizing agent was present.
3.6.3 Challenge Test Procedure
The M-2400 was challenged with each organism individually. The influent challenge holding
tank was mixed after addition of the challenge organism for a minimum of 30 minutes using a
recirculation pump prior to beginning the test.
The inlet water pressure was set to 60 + 3 psig and the test unit was operated continuously for 30
minutes. Influent and effluent samples for bacteria or virus analysis were collected at start-up, at
15 minutes, and at 30 minutes. The influent, permeate, and concentrate flow rates, and the RO
membrane operating and back pressures were recorded at start-up and at 30 minutes.
All samples for bacteria and virus analysis were analyzed in triplicate. For each sample point, an
appropriate volume was first collected into a sterile container, and then the triplicate aliquots
were drawn aseptically from this volume. Single samples were collected for the water chemistry
parameters.
17
-------
At the end of each challenge period, the RO membrane was backflushed with permeate water
using the system's automatic rinse cycle. The rinse was engaged by closing off a valve on the
permeate line, decreasing the pressure differential across the membrane (membrane feed side
pressure minus membrane permeate side pressure) to a certain set-point. As described in Section
2.3, under normal operation with a storage tank, the flush is 12 seconds. However, since the
system was operated without a storage tank for this verification, the flush lasted approximately
three seconds, since the only flush water available was the volume in the permeate line and on
the permeate side in the membrane vessel.
After the flush, the feed water supply was turned off. The unit was not operated between the
challenge periods. Prior to the next chemical challenge, the system was flushed for
approximately 15 minutes using the test water minus the challenge organism.
3.7 Task 4: Chemical Challenge Tests
As discussed in Section 3.1, the M-2400 RO membrane was challenged with all of the chemicals
in Table 3-1, but the MAXVOC carbon filter was challenged with only the chemicals that the
RO membrane did not remove to below 20 [ig/L. Separate challenges were conducted for each
chemical, except for cadmium chloride, cesium chloride, and strontium chloride, which were
combined into one challenge.
3.7.1 Test Water
3.7.1.1 RO Membrane Challenge Water
Local tap water was treated by carbon filtration, RO, and deionization to make the RO
membrane test water. Sodium chloride was added for TDS, and the pH was adjusted if necessary
with HC1 or NaOH for all challenges but sodium fluoroacetate. The NaCl interfered with
analysis for sodium fluoroacetate, so none was added to the challenge water, nor was the pH
adjusted for that challenge. The test water had the following characteristics prior to addition of
the challenge chemical(s):
pH-7.5 ±0.5;
TDS (by conductivity) - 750 + 75 mg/L;
temperature -25 + 1 °C;
total chlorine - < 0.05 mg/L; and
turbidity - < 1 NTU.
To this test water, the challenge chemical(s) were added at a concentration of 1 + 0.5 mg/L. The
allowable tolerance on the challenge concentrations was plus or minus 50%, because due to
analytical procedure lengths, the tests were conducted without waiting for confirmation of the
concentration from the chemistry laboratory.
Grab samples for analysis of total chlorine, alkalinity, TDS, and turbidity were collected prior to
the start of each challenge period, before addition of the challenge chemical to the test water.
After the challenge chemical was added to the test water tank, the water was mixed for a
minimum of 30 minutes using a recirculation pump prior to beginning test unit operation.
18
-------
Temperature and pH were measured at time zero. The pH was also measured at the end of each
challenge period.
3.7.1.2 Carbon Filter Conditioning and Challenge Water
The test water for carbon filter conditioning and testing was the "general test water" specified in
NSF/American National Standards Institute (ANSI) Standard 53. This water is Ann Arbor
municipal drinking water that is adjusted, if necessary, to have the following characteristics prior
to addition of the challenge chemical:
pH-7.5 ±0.5;
temperature - 20 ± 2.5 °C;
TDS - 200-500 mg/L;
TOC-> 1.0 mg/L; and
turbidity - < 1 NTU.
Note that the TOC parameter only has a minimum level specified, since it is the natural TOC in
the municipal water supply. The TOC level at the tap is usually in the range of 1.5 to 2.5 mg/L.
TDS, pH, and temperature were maintained in the appropriate range by the test rig's on-line
monitoring system with automatic delivery of chemicals and temperature adjustment capabilities.
Grab samples were analyzed for pH, temperature, TDS, TOC, total chlorine, and turbidity at the
start of each challenge period. The pH was also measured at 30 minutes. The samples were
collected upstream of the injection point for the challenge chemical.
The target challenge chemical concentrations for the MAXVOC tests were the maximum
effluent levels measured during the RO tests. The allowable tolerance on the challenge
concentrations was plus or minus 50%, because due to analytical procedure lengths, the tests
were conducted without waiting for confirmation of the concentration from the chemistry
laboratory.
3.7.2 Challenge Test Procedures
3.7.2.1 RO Membrane Challenge Testing
The M-2400 was challenged with each chemical individually, except for cadmium, cesium, and
strontium, which were combined into one challenge. The inlet water pressure was set to 60 + 3
psig, and the system was operated continuously for 30 minutes using the appropriate challenge
water. Influent and effluent samples for challenge chemical analysis were collected at start-up
and at 30 minutes. The influent, permeate, and concentrate flow rates, and the RO membrane
operating and back pressures were measured at start-up and at 30 minutes.
Following each challenge, the RO membrane was backflushed, as described in Section 3.6.3.
The unit was not operated between the challenge periods. Prior to the next chemical challenge,
the unit was flushed for five minutes using the test water in section 3.7.1.1 without any challenge
chemical present.
19
-------
All samples for challenge chemical analysis were collected in triplicate. Single samples were
collected for the water chemistry parameters.
3.7.2.2 MAXVOC Challenge Testing
As with the RO membrane challenges, each MAXVOC filter challenge was also 30 minutes.
The target flow rate was the maximum permeate flow rate measured during the RO membrane
challenges (1.85 gpm during the cadmium/cesium/strontium challenge). The inlet water pressure
was set to 60 + 3 psig. Influent and effluent samples for challenge chemical analysis were
collected at start-up and at 30 minutes. The influent flow rate and water pressure were recorded
at start-up.
All samples for challenge chemical analysis were collected in triplicate. Single samples were
collected for the water chemistry parameters.
3.8 Analytical Methods
3.8.1 Water Quality Analytical Methods
The following are the analytical methods used during verification testing. All analyses followed
procedures detailed in NSF SOP's.
Alkalinity was measured according to USEPA Method 310.2 with the SmartChem
Discrete Analyzer. Alkalinity was expressed as mg/L CaCOs.
pH measurements were made with a Beckman 350 pH meter. The meter was operated
according to the manufacturer's instructions, which are based on Standard Method 4500-
H+.
Water temperature was measured using an Omega model HH11 digital thermometer, or
equivalent.
TDS for the TDS reduction system check test was measured through conductivity
according to Standard Method 2510 using a Fisher Scientific Traceable Conductivity
Meter. This method has been validated for use with the test water; NSF uses this method
for analysis of samples from TDS reduction tests in NSF/ANSI58 - 2005, Reverse
osmosis drinking water treatment systems (NSF International, 2005b).
The TDS in the carbon filter conditioning and challenge water was measured
gravimetrically. The method used was an adaptation of USEPA Methods 160.3 and
160.4. An appropriate amount of sample was placed in a pre-weighed evaporating dish.
The sample was evaporated and dried at 103-105 °C to a constant weight. The dish was
then weighed again to determine the total solids weight.
Total chlorine was measured according to Standard Method 4500-C1 G with a Hach
Model DR/2010 spectrophotometer using AccuVac vials.
Total Hardness was measured according to USEPA Method 310.1 using a SmartChem
Discrete Analyzer.
TOC was measured according to Standard Method 53 IOC using a Teledyne Technologies
Company Tekmar Dohrmann Phoenix 8000 UV-Persulfate TOC analyzer.
20
-------
Turbidity was measured according to Standard Method 2130 using a Hach 2100N
turbidimeter.
3.8.2 Microbiology Analytical Methods
3.8.2.1 Sample Processing, and Enumeration of Viruses
The viruses were enumerated using a double agar layer method published in NSF/ANSI Standard
55 - Ultraviolet Microbiological Water Treatment Systems (NSF International 2005c) for
enumerating MS2. This method is similar to the double agar layer method in USEPA Method
1601.
Four to eighteen hours prior to sample processing, 100 microliters (|jL) of the appropriate host E.
coli suspension was pipetted into tubes containing 10 mL of fresh tryptic soy broth (TSB), and
incubated at 35 °C. After incubation, 100 |jL volumes of the resulting E. coli culture were
transferred to sterile, capped test tubes.
All samples were enumerated in triplicate. All samples were serially diluted for enumeration,
and the effluent samples were also enumerated directly. One-milliliter volumes of the sample or
dilution were pipetted into the E. coli suspension test tubes. The tubes were vortexed for a
minimum of 30 seconds to "mate" the bacteria and virus, and then 4 mL of molten, tempered
TSB plus 1% agar was added to each tube. These mixtures were then poured over tryptic soy
agar (TSA) plates and allowed to solidify. The plates were incubated at 35 °C for 18-24 hours.
Virus plaques were counted using a Quebec Colony Counter.
3.8.2.2 B. diminuta Cultivation and Challenge Suspension Preparation
The bacteria was purchased from ATCC and rehydrated with nutrient broth. After 48 hours of
incubation at 30°C, 5 mL of the nutrient broth culture was added to 50 mL of nutrient broth, and
the resultant cultures were incubated for 48 hours at 30°C. Freezer stocks were then obtained
from the nutrient broth culture, and these stocks were stored at -80°C until use.
To obtain the challenge suspensions, two 10 mL tubes of TSB were inoculated with 0.1 mL of
stock culture. These tubes were incubated at 35°C for 24 hours. Then 2 mL from either tube
was pipetted into eight flasks containing 1 L of Saline Lactose Broth (SLB). The eight flasks
were put on a shaker and incubated in a 35°C water bath for 24 hours. The contents of all eight
flasks were added to 200 gallons of base test water to create the challenge waters. The use of
SLB ensures that the cells are smaller in diameter. B. diminuta cells grown in nutrient broth can
have diameters greater than 0.5 |j,m. Cells grown in SLB have been measured by NSF to have
diameters ranging from 0.3 to 0.5 |j,m.
The challenge preparation procedure was identical for both the normal B. diminuta and the KanR
B. diminuta, the only difference was that for the KanR bacteria, the SLB was amended with 50
|j,g/L of kanamycin, and 10 |j,g/L of tetracycline.
21
-------
3.8.2.3 Sample Processing and Enumeration of B. diminuta
All samples were enumerated in triplicate using a membrane filtration method based on Standard
Method 9215 D. All samples were serially diluted for enumeration with sterile PBDW, and the
effluent samples were also enumerated directly. For the influent samples, 1 mL volumes of
either the straight sample or dilutions were pipetted into sterile glass vacuum filtration funnels,
and 25 mL of PBDW was also poured into the funnels. For the effluent samples, 100 mL of the
straight sample and the dilutions were pipetted into the funnels. The contents were then vacuum
filtered through sterile 0.1 jam membrane filters. The funnels were rinsed three times with
approximately 5 mL of PBDW, and the rinse water was also suctioned through the filters. The
membrane filters were aseptically removed from the apparatuses and placed onto R2A agar
plates. The plates were incubated at 30 °C for 48 hours. Characteristic B. diminuta colonies
were counted with a Quebec Colony Counter.
The sample processing and enumeration procedures were identical for both the normal B.
diminuta and the KanR B. diminuta, the only difference was that the R2A agar was amended
with 50 |J,g/L of kanamycin and 10 [ig/L of tetracycline for enumeration of the KanR bacteria.
3.8.3 Challenge Chemical Analytical Methods
Aldicarb, Carbofuran, Methomyl, and Oxamyl were measured by high pressure liquid
chromatography (HPLC) according to USEPA Method 531.1 or 531.2.
Dichlorvos and Mevinphos were measured by gas chromatography/mass spectrometry
(GC/MS) according to USEPA Method 525.2.
Cadmium, Cesium, Mercury, and Strontium were measured by Inductively Coupled
Plasma - Mass Spectrometry (ICP-MS) according to USEPA Method 200.8.
Benzene and Chloroform were measured by purge and trap capillary gas chromatography
according to USEPA Method 502.2.
There is no standard analytical method for strychnine. NSF developed a method to
measure it using reverse phase HPLC with ultraviolet lamp detection.
Paraquat was measured by FtPLC according to USEPA Method 549.1.
Sodium Fluoroacetate was measured by ion chromatography according to USEPA
Method 300.1.
22
-------
Chapter 4
Results and Discussion
4.1 TDS Reduction Membrane Integrity Check
Prior to the start of challenge testing, the TDS reduction capability of the M-2400 was evaluated
as a gross membrane integrity check. The system was challenged with 680 mg/L of NaCl. The
permeate TDS level was 11 mg/L, indicating that membrane integrity was intact.
4.2 System Operation Characterization
Tables 4-1 and 4-2 give the operation data and calculations for the microbial and chemical
challenges, respectively. The following system operation parameters were measured at the
beginning and end of each challenge test:
Influent flow rate;
Permeate flow rate;
Reject flow rate;
RO membrane operating pressure; and
RO membrane concentrate line back pressure.
The permeate pressure was recorded for the first few challenges, but was always around 1 psig
since the permeate line was open to atmosphere for this verification. Therefore, the lab
technicians stopped recording it, and it was treated as zero for the purpose of calculating the
transmembrane pressure (see Section 3.5 for equation).
The transmembrane pressure, permeate flux normalized to 25°C, and specific flux were
calculated for each challenge using the start-up operation data.
As discussed in Section 3.4.1, the M-2400 Installation, Operation, and Maintenance Manual
states that the RO membrane operating pressure should be set 150 psig. The manual also states
that the system should not be operated with the membrane operating pressure over 150 psig, so
that the membrane is not damaged. The membrane operating pressure was set at 150 psig for the
initial system calibration on January 26, 2006, but the system was not re-calibrated before each
challenge for the first three weeks of challenges. When the first B. diminuta and KanR B.
diminuta challenges were conducted on January 30, the recorded membrane operating pressures
were 155 psig and 158 psig, respectively. The data from these two challenges is not presented in
this report because the influent challenge concentrations were too low. The membrane operating
pressure was at 160 psig the next day, and rose to 172 psig by February 20. At this point, NSF
decided to recalibrate the system each day challenges were conducted, so that the membrane
operating pressure remained close to 150 psig. The challenges conducted at membrane operating
pressures above 150 psig were all microbial challenges, as well as the cadmium/cesium/
strontium, mercury, strychnine, paraquat, and aldicarb chemical challenges. To check whether
the higher membrane operating pressures adversely affected the performance of the membrane
for mechanical filtration of the viruses and bacteria, the B. diminuta challenge was conducted
again with a membrane operating pressure of 149 psig. The logio reductions from this challenge,
23
-------
discussed in Section 4.3, indicate that the higher pressure did not significantly impact the
mechanical reduction performance of the membrane. The system performed well against the
chemicals at higher pressure, so no chemical challenges were conducted again.
The data is organized by the date of each challenge in Tables 4-1 and 4-2 so that the potential
impact of the higher membrane operating pressures on the operation parameters can be more
easily discerned.
Table 4-1. M-2400 Microbial Challenges Operation and Water Chemistry Data
Sample
MS2
fr
First Kanamycin Second
B. diminuta Resistant B. diminuta
Challenge B. diminuta Challenge
Challenge Date
Start-up Operation Data
System Influent Flow Rate (gpm)
Permeate Flow Rate (gpm)
Reject Flow Rate (gpm)
Feed Water Recovery (%)
Membrane Operating Pressure (psig)
Concentrate Back-Pressure (psig)
Transmembrane Pressure (TMP) (psig)
Permeate Flux (normalized to 25°C) (gfd)
Specific Flux (gfd/psig)
30 Minute Operation Data
System Influent Flow Rate (gpm)
Permeate Flow Rate (gpm)
Reject Flow Rate (gpm)
Membrane Operating Pressure (psig)
Concentrate Back-Pressure (psig)
Transmembrane Pressure (TMP) (psig)
Permeate Flux (normalized to 25°C) (gfd)
Specific Flux (gfd/psig)
Start-up Influent
Alkalinity (mg/L CaCO3)
PH
Temperature (°C)
Total Chlorine (mg/L)
TDS (mg/L)
Turbidity (NTU)
30 Minute Influent
PH
01/31/06 02/02/06 02/14/06 02/14/06 03/08/06
3.63
1.69
2.00
46.6
160
157
159
35.1
0.22
3.63
1.81
1.90
49.9
162
160
161
35.8
0.22
3.61
1.72
1.89
162
159
161
35.7
0.22
3.58
1.81
1.88
162
160
161
35.8
0.22
92 68
7.6 7.8
18 20
ND (0.05) ND (0.05)
83 57
ND(O.l) 0.4
7.6
7.8
3.58
1.80
1.88
50.3
166
164
165
37.4
0.23
3.54
1.77
1.90
166
164
165
36.7
0.22
60
7.7
18
ND (0.05)
57
0.2
7.8
3.58
1.83
1.85
51.1
160
160
160
34.5
0.22
3.58
1.82
1.87
164
160
162
34.3
0.21
68
8.0
22
ND (0.05)
58
6.8
8.0
2.84
1.50
1.44
52.8
149
144
147
29.7
0.20
2.89
1.40
1.61
149
144
147
27.7
0.19
68
7.9
20
ND (0.05)
78
ND(O.l)
7.9
24
-------
Sample
Challenge Date
Start-up Operation Data
System Influent Flow Rate (gpm)
Permeate Flow Rate (gpm)
Reject Flow Rate (gpm)
Feed Water Recovery (%)
Membrane Operating Pressure (psig)
Concentrate Back-Pressure (psig)
Transmembrane Pressure (TMP) (psig)
Permeate Flux (normalized to 25°C) (gfd)
Specific Flux (gfd/psig)
30 Minute Operation Data
System Influent Flow Rate (gpm)
Permeate Flow Rate (gpm)
Reject Flow Rate (gpm)
Membrane Operating Pressure (psig)
RO Concentrate Back-Pressure (psig)
Transmembrane Pressure (TMP) (psig)
Permeate Flux (normalized to 25°C) (gfd)
Specific Flux (gfd/psig)
Start-up Influent
PH
Temperature (°C)
Total Chlorine (mg/L)
TDS (mg/L)
Turbidity (NTU)
Start-up Effluent TDS (mg/L)
30-Minute Influent
PH
TDS (mg/L)
30-Minute Effluent TDS (mg/L)
Table 4-2. M-2400 Chemical Challenges
Cadmium,
Cesium,
Strontium Mercury Strychnine Paraquat Aldicarb
02/01/06
3.58
1.85
1.81
51.7
160
156
158
32.5
0.21
3.58
1.83
1.82
159
154
157
32.1
0.21
7.8
25
ND (0.05)
800
ND(O.l)
13
7.8
800
15
02/16/06
3.57
1.78
1.83
49.9
170
169
170
31.3
0.18
3.57
1.78
1.83
166
164
165
31.3
0.19
7.6
25
ND (0.05)
740
0.1
11
7.6
740
11
02/17/06
3.53
1.80
1.80
51.0
168
166
167
32.4
0.19
3.53
1.75
1.81
168
166
167
31.5
0.19
7.4
24
ND (0.05)
710
0.1
9
7.3
700
9
02/20/06
3.39
1.74
1.78
51.3
171
169
170
30.6
0.18
3.44
1.75
1.75
170
168
169
30.7
0.18
7.5
25
ND (0.05)
770
0.2
12
7.5
770
12
02/20/06
3.57
1.75
1.79
49.0
172
170
171
31.5
0.18
3.53
1.76
1.77
172
170
171
31.7
0.19
7.4
24
ND (0.05)
810
0.1
10
7.5
790
10
Operation and Water Chemistry Data
Carbofuran Oxamyl Methomyl Dichlorvos Mevinphos
02/21/06
3.06
1.58
1.60
51.6
152
150
151
27.7
0.18
3.03
1.57
1.61
150
146
148
27.6
0.19
7.7
25
ND (0.05)
770
0.1
10
7.7
780
10
02/21/06
3.13
1.59
1.62
50.8
150
146
148
28.6
0.19
3.09
1.57
1.61
149
146
148
28.2
0.19
7.4
24
ND (0.05)
550
0.3
6
7.4
540
6
02/21/06
3.06
1.62
1.54
52.9
150
148
149
27.8
0.19
3.01
1.58
1.54
150
146
148
27.1
0.18
7.7
26
ND (0.05)
790
0.1
10
7.7
800
11
02/22/06
3.06
1.58
1.60
51.6
150
146
148
28.4
0.19
3.01
1.52
1.61
150
146
148
27.3
0.18
7.3
24
ND (0.05)
790
ND(O.l)
11
7.3
790
11
02/22/06
3.11
1.53
1.65
49.2
146
144
145
27.5
0.19
3.06
1.52
1.67
146
144
145
27.3
0.19
7.4
24
ND (0.05)
740
0.1
10
7.4
750
10
Chloroform
02/22/06
3.04
1.54
1.52
50.7
146
144
145
27.0
0.19
3.04
1.53
1.54
148
145
147
26.9
0.18
7.3
25
ND (0.05)
750
ND(O.l)
10
740
10
Benzene
02/23/06
2.87
1.50
1.47
52.3
150
146
148
26.3
0.18
2.87
1.52
1.48
148
144
146
26.7
0.18
7.2
25
0.05
810
ND(O.l)
10
7.3
800
11
Sodium
Fluoroacetate
04/07/06
3.05
1.50
1.55
49.2
144
140
142
29.0
0.20
3.05
1.49
1.56
143
139
141
28.8
0.20
4.9
21
ND (0.05)
ND(2)
ND(O.l)
ND(2)
4.8
ND(2)
ND(2)
25
-------
4.3 RO Membrane Microbial Challenges
The microbial challenges were conducted first, prior to the chemical challenges, to avoid any
possibility that any residual chemical on the membrane could kill a portion of the challenge
organisms, giving a positive bias to the performance of the membrane. However, bacteria
challenge retests were necessary after the first chemical challenge of cadmium, cesium, and
strontium had been conducted, because the measured influent concentrations for B. diminuta and
KanR B. diminuta during the first bacteria challenges were too low. The data for the first round
of bacteria challenges is not reported here.
Before the bacteria challenges were conducted a second time, the M-2400 was flushed with
approximately 500 gallons of water. Then the system was taken off-line, and the test rig
plumbing was sanitized with iodine.
Also, as discussed in the previous section, the B. diminuta challenge was conducted a third time
(second reported set of data) to evaluate whether system performance would be better at a lower
RO membrane operating pressure (149 psig versus 172 psig). The M-2400 was only flushed for
approximately five minutes immediately prior to this last bacteria challenge, but it was also
flushed for one hour immediately after the last chemical challenge.
The bacteria and virus challenge data is presented in Table 4-3. The water chemistry data for
each challenge was presented in Table 4-1. For each sample point, the geometric mean of the
triplicate CPU or PFU count is given. The CPU or PFU counts were logio transformed, and logio
reductions were calculated for each sample point. Geometric mean influents and effluents were
calculated for each challenge, and log reductions were also calculated from the means. The
individual triplicate CFU/PFU counts for each sample point and the water chemistry data for
each challenge can be found in Appendix A in Tables A-l through A-5.
The M-2400 achieved mean reductions of approximately 3 logs for the viruses. The minimum
log reduction was 2.5 for the fir challenge 15-minute sample point, and the maximum log
reduction was 3.3 for both challenges at the start-up sample point.
The bacteria reduction data varied more than the virus data. The minimum log reduction was 1.3
for the 02/14/06 B. diminuta challenge start-up sample point, while the maximum log reduction
was 3.5, achieved at both the 15-minute and 30-minute sample points for the KanR.8. diminuta
challenge. A comparison of the 02/14/06 B. diminuta challenge data to the 03/08/06 B. diminuta
challenge data shows that the decrease in the RO membrane operating pressure did not improve
the bacteria reduction performance of the system.
26
-------
Table 4-3. M-2400 Microbial
Challenge Date
Start-up Samples
Influent (CFU/100 mL orPFU/mL)
Logic of Influent
Permeate (CFU/100
Logic of Permeate
Logic Reduction
15 -Minute Samples
mL or PFU/mL)
Influent (CFU/100 mL orPFU/mL)
Logic of Influent
Permeate (CFU/100
Logic of Permeate
Logic Reduction
30-Minute Samples
mL or PFU/mL)
Influent (CFU/100 mL orPFU/mL)
Log! o of Influent
Permeate (CFU/100
Logic of Permeate
Logic Reduction
Means
Influent (CFU/100
Log10 of Influent
ml or PFU/mL)
mL or PFU/mL)
Permeate (CFU/100 mL or PFU/mL)
Log10 of Effluent
Log10 Reduction
Challenge CFU or PFU Counts and Log Reductions
2nd
1st KanR B. diminuta
MS2 fr B. diminuta B. diminuta Challenge
01/31/06
V.lxlO4
4.9
38
1.6
3.3
4.9xl04
4.7
46
1.7
3.0
4.9xl04
4.7
69
1.8
2.9
5.5xl04
4.7
49
1.7
3.1
02/02/06
1.28xl05
5.11
66
1.8
3.3
7.7xl04
4.9
233
2.4
2.5
8.5xl04
4.9
116
2.1
2.8
9.4xl04
5.0
121
2.1
2.9
02/14/06
3.0xl07
7.5
1.49xl06
6.17
1.3
2.5xl07
7.4
1.24xl04
4.09
3.3
l.OxlO7
7.0
9.8xl03
4.0
3.0
2.0xl07
7.3
5.7xl04
4.8
2.5
02/14/06
6.6xl06
6.8
2.7xl03
3.4
3.4
7.0xl06
6.9
2.8xl03
3.4
3.5
7.5xl06
6.9
2.8xl03
3.4
3.5
7.0xl06
6.9
2.8xl03
3.4
3.5
03/08/06
8.6xl06
6.9
3.2xl03
3.5
3.4
5.1xl06
6.7
2.55xl04
4.41
2.3
7.5xl06
6.9
1.78xl04
4.25
2.6
6.9xl06
6.8
l.lxlO4
4.1
2.7
4.4 RO Membrane Chemical Challenges
The RO membrane chemical challenge data is presented below in Table 4-4. The water
chemistry data for each challenge was presented in Table 4-2. The samples from each sample
point were analyzed in triplicate. The arithmetic means were calculated from the triplicate
analyses for each sample point. The overall mean influents and permeates were then calculated
for each challenge. Table 4-2 gives the overall mean influent and permeate for each challenge,
and the percent reductions calculated from these numbers. See Tables A-6 and A-7 in Appendix
A for the triplicate influent and effluent data for each sample point. Note that for non-detect
effluent samples, the detection limits were used for the purpose of calculating the means and
percent reductions.
As discussed in Section 4-2, the aldicarb, cadmium/cesium/strontium, paraquat, and strychnine
challenges were conducted with the RO membrane operating pressure above 150 psig. However,
in spite of this, the membrane performed well against all chemicals but mercury, which was
expected based on the results of previous RO membrane ETV tests with mercury. Excluding the
27
-------
mercury reduction data, the minimum percent reduction was 96%, for methomyl. Ten of the 15
chemicals were removed by greater than 99%.
Table 4-4. M-2400 Chemical Challenge Data
Mean Influent Mean Effluent Percent
Chemical (ng/L) (ng/L) Reduction
Aldicarb
Benzene
Cadmium
Carbofuran
Cesium
Chloroform
Dichlorvos
Mercury
Methomyl
Mevinphos
Oxamyl
Paraquat
Sodium Fluoroacetate
Strontium
Strychnine
830
680
970
920
1100
790
1700
1200
990
920
1000
480
800
990
900
3
6.4
1.4
2.6
16
28
16
750
45
5.6
4
ND(1)
ND(20)
2
ND(5)
>99
>99
>99
>99
99
97
>99
38
96
>99
>99
>99
98
>99
>99
4.5 MAXVOC Carbon Filter Chemical Challenges
As discussed in Section 3.4.3, prior to being challenged the MAXVOC carbon filter was
conditioned to one-half of the stated chemical reduction capacity using water containing
chloroform at a target concentration of 300 [ig/L. The water chemistry data for the conditioning
water is shown below in Table 4-5. Note that it appears that the influent and effluent chloroform
samples at 1,300 gallons may have been mislabeled, and if so, the influent chloroform
concentration was approximately twice what it should have been. However, if this is the case,
the extra chloroform loaded onto the carbon did not adversely affect the performance of the
filter, as evidenced by the carbon filter challenge data in Table 4-6.
Table 4-5. MAXVOC FF-975 Filter Conditioning Water Chemistry Data
Parameter Start-Up 650 Gal. 1,300 Gal.
Influent Water Chemistry
Chloroform (|J.g/L)
pH
Temperature (°C)
TDS (mg/L)
Total Chlorine (mg/L)
TOC* (mg/L)
TuAidity (MTU)
310
7.3
20
280
2.60
1.7
0.1
340
7.2
19
270
2.02
1.9
ND(O.l)
21
7.4
20
280
1.96
3.2
0.1
Effluent Chloroform (|ag/L) ND (0.5) 1.3 700
*Injection of chloroform into the influent stream was turned off when TOC samples were collected.
28
-------
The filter was challenged with chloroform, dichlorvos, mercury, and methomyl based on the
criteria that the MAXVOC carbon filter be challenged with the chemicals that the RO membrane
did not remove to 20 [ig/L or below at each sample point. The MAXVOC challenge data is
presented below in Table 4-6. As with the RO membrane challenges, mean influents and
effluents were calculated for each challenge. The individual triplicate influent and effluent data
for each sample point is presented in Table A-8 in Appendix A. Note that the total chlorine level
for the methomyl challenge water was only 0.32 mg/L. It was discovered that methomyl is
chlorine sensitive, so the challenge water specified in Section 3.7.1.2 was treated by activated
carbon filtration upstream of the challenge chemical injection point. Also, sodium thiosulfate
was added to all samples collected for methomyl analysis.
The MAXVOC filter removed all four chemicals to a degree that the carbon filter and the M-
2400 together as a treatment train would remove 99% or more of all of the challenge chemicals
at a 1 mg/L concentration, except for sodium fluoroacetate, whose percent reduction was limited
by the high detection limit.
Table 4-6. MAXVOC FF-975 Chemical Challenge Data
Chloroform Dichlorvos Mercury Methomyl
Sample (03/24/06) (03/24/06) (03/22/06) (04/04/06)
Target Influent (M-g/L)
Mean Influent (M-g/L)
Mean Effluent (M-g/L)
Percent Reduction
Flow Rate (gpm)
Inlet Pressure (psig)
Start-up Water Chemistry
pH
Temperature (°C)
TDS (mg/L)
Total Chlorine (mg/L)
TOC (mg/L)
Turbidity (NTU)
30-Minute pH
72
82
3.2
96
1.90
60.3
7.3
20
290
2.26
1.9
0.1
7.3
25
36
ND (0.2)
>99
1.89
60.3
7.2
21
270
1.96
2.1
ND(O.l)
7.2
910
730
10
99
1.89
60.3
7.3
20
260
2.44
1.9
0.2
7.3
48
56
1
98
1.88
60.9
7.2
21
290
0.32
1.8
ND(O.l)
7.2
29
-------
This page is intentionally blank
30
-------
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, precision, accuracy, and completeness.
Because the 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 (NSF 2004).
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 informal audit
during testing to ensure the proper procedures were followed. The audit yielded no findings.
5.3 Sample Handling
All samples analyzed by the NSF Chemistry and Microbiology Laboratories were labeled with
unique ID numbers. These ID numbers appear in the NSF laboratory reports for the tests. All
samples were analyzed within allowable holding times.
5.4 Chemistry Analytical Methods QA/QC
The calibrations of all 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, each analytical instrument has an NSF SOP governing
its use.
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. Both E. coli
hosts for the viruses were plated on TSA and incubated with the virus enumeration plates during
sample enumeration as a second positive growth control. B. diminuta from the stock cultures
was plated on R2A agar and incubated with the bacteria enumeration plates as a positive control.
-------
5.5.2 Negative Controls
All samples were enumerated in triplicate. For each sample batch processed, an unused
membrane filter and a blank with 100 mL of PBDW 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.
5.6 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
Excel spreadsheets. These spreadsheets were used to calculate average influents and effluents,
and logic reductions for each challenge. 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.
NSF ETV staff checked 100% 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.
5.8.1 Representativeness
Representativeness refers to the degree to which the data accurately and precisely represent the
expected performance of the RO system under normal use conditions. The test protocol was
designed to be a conservative evaluation of product performance. The test water was of very low
turbidity to minimize the potential for microbial adhesion to suspended particles, which could
enhance apparent log reduction. The surrogates were chosen because of their small size. The
virus surrogate challenges were carried out at pH 6, 7.5, and 9 to assess whether pH affects the
performance of the RO membrane.
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.
32
-------
5.8.2 Accuracy
Accuracy was quantified as the percent recovery of the parameter in a sample of known quantity.
Accuracy was measured through use of both matrix spikes of a known quantity, and certified
standards during calibration of an instrument. The following equation was used to calculate
percent recovery:
Percent ReCOVery = 100 X [(X^^ - XmeasurecD/Xknown]
where: X\^own = known concentration of the measured parameter
= measured concentration of parameter
Accuracy of the benchtop chlorine, pH, IDS, and turbidity meters was checked daily during the
calibration procedures using certified check standards. Alkalinity and total hardness were
analyzed in batches. Certified QC standards and/or matrix spikes were run with each batch.
The percent recoveries of all matrix spikes and standards were within the allowable limits for all
analytical methods.
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. Duplicate municipal drinking water samples were analyzed for pH, total
chlorine, and turbidity as part of the daily calibration process. One out of every ten samples for
alkalinity and total hardness was analyzed in duplicate. Precision of duplicate analyses was
measured by use of the following equation to calculate relative percent difference (RPD):
RPD=
:200
where:
Sl = sample analysis result; and
^2 = sample duplicate analysis result.
All RPDs were within NSF's established allowable limits for each parameter. Please note that
samples from this evaluation for alkalinity, TDS, and total hardness were batched with other
non-ETV samples when being analyzed by the NSF laboratory. The duplicate analysis
requirements apply to the whole batch, not just the samples from this ETV.
33
-------
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. Table 5-1 presents the completeness requirements.
Table 5-1. Completeness Requirements
Number of Samples per
Parameter and/or Method
0-10
11-50
>50
Percent
Completeness
80%
90%
95%
Completeness is defined as follows for all measurements:
%C = (V/T)X100
where:
%C = percent completeness;
V = number of measurements judged valid; and
T = total number of measurements.
5.8.4.1 Parameters with less than 100% Completeness
All parameters met the minimum completeness requirements presented in Table 5-1. However, a
few samples were missed or did not have reportable results. The following parameters had less
than 100% completeness:
15-Minute effluent samples for the fir challenge - One of the triplicate analyses was too
numerous to count (TNTC) in the un-diluted sample, but was <1 PFU/mL in the IxlO2
dilution. No IxlO1 dilution was analyzed. Seventeen of eighteen fir samples were
reported, giving a completeness of 94%.
RO membrane chloroform challenge - pH was not measured at 30 minutes. A total of 36
pH measurements were required by the test plan. The one missed measurement gives a
completeness of 97%.
RO membrane mevinphos challenge - Triplicate sample 3 for the 30-minute effluent
sample point was not reported due to low recovery of the internal standard for the sample.
There was not enough sample left to re-extract the mevinphos and reanalyze for it.
Eleven of twelve mevinphos samples had reportable data, giving a completeness of 92%.
34
-------
5.9 Measurements Outside of the Test/QA Plan Specifications
The RO membrane dichlorvos challenge influent samples were all above the maximum
target concentration of 1.5 mg/L. The high challenge concentration may have caused the
30-Minute effluent samples to be over 20 ng/L, requiring the MAXVOC carbon filter be
challenged with the chemical. However, the carbon filter removed the chemical to below
the detection limit, so the high challenge concentration for the RO membrane challenge
did not adversely affect the reported performance of the M-2400/MAXVOC filter
combination.
The influent sample concentrations for the RO membrane paraquat challenge were all
below the minimum target concentration of 0.5 mg/L. However, the effluent samples
were all below the detection limit of 1 |J,g/L. The challenge was not conducted again
because it is unlikely that doubling the influent challenge concentration would lead to an
increase in the effluent concentration to 20 |j,g/L or above.
The TDS of the RO membrane oxamyl challenge water was 550 mg/L at start-up, and
540 mg/L at 30 minutes. This is below the minimum target level of 675 mg/L. The low
TDS level is not a significant deviation from the test plan because the target TDS
concentration of 750 mg/L is mainly to provide an adequate TDS challenge to the
membrane along with the challenge chemical to serve as a membrane integrity check. An
influent TDS concentration of 550 mg/L was adequate to accomplish this goal.
Total chlorine is specified as less then the detection limit of 0.05 mg/L for the RO
membrane challenge water; exposure to chlorine can adversely affect the integrity of RO
membranes. For the benzene RO membrane challenge, total chlorine was measured at
the detection limit of 0.05 mg/L. This is not a significant deviation, because the chlorine
concentration was too low to be of a concern.
35
-------
This page is intentionally blank
36
-------
Chapter 6
References
ASTM International (2001). D 3862-80, Standard Test Method for Retention Characteristics of
0.2-|j,m Membrane Filters Used in Routine Filtration Procedures for the Evaluation of
Microbiological Water Quality.
NSF International (2004). NSF International Laboratories Quality Assurance Manual. Ann
Arbor, NSF International.
NSF International (2005a). NSF/ANSI Standard 53 - 2005, Drinking water treatment units -
health effects. Ann Arbor, NSF International.
NSF International (2005b). NSF/ANSI 58 - 2005, Reverse osmosis drinking water treatment
systems. Ann Arbor, NSF International.
NSF International (2005c). NSF/ANSI 55 - 2005, Ultraviolet microbiological water treatment
systems. Ann Arbor, NSF International.
USEPA (2004). Water Security Research and Technical Support Action Plan. EPA/600/R-
04/063.
37
-------
This page is intentionally blank
38
-------
Appendix A
Challenge Data
-------
This page is intentionally blank.
-------
Sample
Start-Up Influent
15 -Minute Influent
30-Minute Influent
Mean Influent
Start-Up Permeate
15 -Minute Permeate
30-Minute Permeate
Mean Permeate
Table A-l. First B. diminuta Challenge
Influent/Permeate Triplicate Influent/Permeate Geometric
Counts (CFU/lOOmL) Mean(CFU/100mL)
3.5xl07, 3.0xl07,2.6xl07
2.3xl07,2.7xl07,2.6xl07
1.76xl07,2.7xl07,2.15xl06
1.51xl06, 1.36xl06, 1.62xl06
1.35xl04, 1.20xl04, 1.17xl04
1.12xl04, 9.7xl03, 8.7xl03
3.0xl07
2.5xl07
l.OxlO7
2.0xl07
1.49xl06
1.24xl04
9.8xl03
5.7xl04
Log10
Influent/
Permeate
7.5
7.4
7.0
7.3
6.17
4.09
4.0
4.8
Log10
Reduction
1.3
3.3
3.0
2.5
Sample
Start-Up Influent
15 -Minute Influent
30-Minute Influent
Mean Influent
Start-Up Permeate
15 -Minute Permeate
30-Minute Permeate
Mean Permeate
Table A-2. Second
Influent/Permeate Triplicate
Counts (CFU/lOOmL)
8.7xl06, 7.9xl06, 9.2xl06
6.7xl06, 3.2xl06,6.1xl06
9.0xl06, 9.9xl06, 4.7xl06
9.9xl03,2.5xl03, 1.3xl03
3.15xl04, 2.48xl04, 2.12xl04
1.67xl04, 1.98xl04, 1.71xl04
B. diminuta Challenge
Influent/Permeate Geometric
Mean(CFU/100mL)
8.6xl06
5.1xl06
7.5xl06
6.9xl06
3.2xl03
2.55xl04
1.78xl04
l.lxlO4
Log10
Influent/
Permeate
6.9
6.7
6.9
6.8
3.5
4.41
4.25
4.1
Log10
Reduction
3.4
2.3
2.6
2.7
Sample
Start-Up Influent
15 -Minute Influent
30-Minute Influent
Mean Influent
Start-Up Permeate
15 -Minute Permeate
30-Minute Permeate
Mean Permeate
Table A-3. Kanamycin Resistant B. diminuta
Influent/Permeate Triplicate Influent/Permeate Geometric
Counts (CFU/lOOmL) Mean(CFU/100mL)
7.5xl06, 5.7xl06, 6.6xl06
7.7xl06, 8.5xl06, 5.3xl06
6.6xl06, 8.8xl06, 7.3xl06
2.8xl03,2.5xl03,2.8xl03
3.0xl03,2.5xl03,2.8xl03
2.7xl03, 3.3xl03,2.5xl03
6.6xl06
7.0xl06
7.5xl06
7.0xl06
2.7xl03
2.8xl03
2.8xl03
2.8xl03
Log10
Influent/
Permeate
6.8
6.9
6.9
6.9
3.4
3.4
3.4
3.4
Log10
Reduction
3.4
3.5
3.5
3.5
A-l
-------
Table A-4. fr Challenge
Influent/Permeate Triplicate Influent/Permeate
Counts (PFU/mL) Geometric Mean (PFU/mL)
Start-Up Influent
15 -Minute Influent
30-Minute Influent
Mean Influent
Start-Up Permeate
15 -Minute Permeate
30-Minute Permeate
Mean Permeate
1.52xl05, 1.38xl05, l.OlxlO5
7.1xl04, 6.7xl04, 9.6xl04
8.5xl04, 9.5xl04, 7.6xl04
63, 54, 85
245, 222, #
143,110,99
1.28xl05
7.7xl04
8.5xl04
9.4xl04
66
233
116
121
Log10
Influent/
Permeate
5.11
4.9
4.9
5.0
1.8
2.4
2.1
2.1
Log10
Reduction
3.3
2.5
2.8
2.9
Start-Up Influent
15 -Minute Influent
30-Minute Influent
Mean Influent
Start-Up Permeate
15 -Minute Permeate
30-Minute Permeate
Mean Permeate
Table A-5.
Influent/Permeate Triplicate
Counts (PFU/mL)
7.2xl04, 6.7xl04, 7.3xl04
4.6xl04, 5.2xl04, 5.0xl04
4.6xl04, 5.4xl04, 4.7xl04
37, 36, 40
47, 49, 42
80, 56, 72
MS2 Challenge
Influent/Permeate
Geometric Mean (PFU/mL)
7.1xl04
4.9xl04
4.9xl04
5.5xl04
38
46
69
49
Log10
Influent/
Permeate
4.9
4.7
4.7
4.7
1.6
1.7
1.8
1.7
Log10
Reduction
3.3
3.0
2.9
3.1
A-2
-------
Table A-6. Organic Chemical RO Membrane Challenges
Aldicarb Benzene Carbofuran Chloroform Dichlorvos Methomyl Mevinphos Oxamyl
Sample (H2/L) (H2/L) (ng/L) (ng/L) (H2/L) (H2/L) (H2/L) (H2/L)
Start-up Influent
Triplicate Sample 1
Triplicate Sample 1
Triplicate Sample 3
Mean
Start-up Permeate
Triplicate Sample 1
Triplicate Sample 1
Triplicate Sample 3
Mean
30-Minute Influent
Triplicate Sample 1
Triplicate Sample 1
Triplicate Sample 3
Mean
30-Minute Permeate
Triplicate Sample 1
Triplicate Sample 1
Triplicate Sample 3
Mean
Overall Mean Influent
Overall Mean Permeate
Percent Reduction
840
840
830
840
3
3
3
3
830
820
830
830
o
J
o
J
o
J
3
830
3
>99
750
690
660
700
ND (0.5)
ND (0.5)
ND (0.5)
ND(p.5)
670
640
650
650
12
13
12
12
680
6.4
>99
930
920
910
920
1.7
1.8
1.9
1.8
920
910
930
920
3.4
3.4
3.4
3.4
920
2.6
>99
800
830
800
810
1.3
1.7
1.5
1.5
740
750
830
770
43
46
72
54
790
28
97
1600
1600
1700
1600
5.1
7.4
11
7.8
2000
1700
1800
1800
25
23
24
24
1700
16
>99
950
1000
1000
980
40
42
42
41
1000
1000
1000
1000
48
48
48
48
990
45
96
830
870
950
880
5.2
5.5
4.5
5.1
950
1000
940
960
6.5
6.4
#
6.5
920
5.6
>99
1100
1000
1100
1100
3
4
4
4
1000
1000
1000
1000
4
4
4
4
1000
4
>99
Sodium
Paraquat Fluoroacetate
(H2/L) (H2/L)
540
450
470
490
ND(1)
ND(1)
ND(1)
ND(1)
470
460
470
470
ND(1)
ND(1)
ND(1)
ND(1)
480
ND(1)
>99
1400
660
680
910
ND(20)
ND(20)
ND(20)
ND(20)
680
680
670
680
ND(20)
ND(20)
ND(20)
ND (20)
800
ND (20)
98
Strychnine
(H2/L)
890
900
900
900
ND(5)
ND(5)
ND(5)
ND(5)
900
890
890
890
ND(5)
ND(5)
ND(5)
ND(5)
900
ND(5)
>99
A-2
-------
Table A-7. Inorganic Chemical RO Membrane Challenges
Cadmium Cesium Mercury Strontium
Sample (ng/L) (ng/L) (ng/L) (ng/L)
Start-up Influent
Triplicate Sample 1
Triplicate Sample 2
Triplicate Sample 3
Mean
Start-up Permeate
Triplicate Sample 1
Triplicate Sample 2
Triplicate Sample 3
Mean
30-Minute Influent
Triplicate Sample 1
Triplicate Sample 2
Triplicate Sample 3
Mean
30-Minute Permeate
Triplicate Sample 1
Triplicate Sample 2
Triplicate Sample 3
Mean
Overall Mean Influent
Overall Mean Permeate
Percent Reduction
1000
1000
990
1000
0.4
0.8
0.6
0.6
940
980
930
950
2.3
2.2
2.3
2.3
970
1.4
>99
1100
1100
1100
1100
20
14
13
16
1000
1100
1000
1000
16
16
16
16
1100
16
99
1100
1100
1100
1100
650
580
540
590
1200
1200
1200
1200
890
910
900
900
1200
750
38
1000
1000
1000
1000
1
1
1
1
970
1000
970
980
2
2
2
2
990
2
>99
Table A-8. MAXVOC Carbon Filter Challenges
Chloroform Dichlorvos Mercury Methomyl
Sample (ng/L) (ng/L) (ng/L) (ng/L)
Target Influent Cone.
Start-up Influent
Triplicate Sample 1
Triplicate Sample 2
Triplicate Sample 3
Mean
Start-up Effluent
Triplicate Sample 1
Triplicate Sample 2
Triplicate Sample 3
Mean
30-Minute Influent
Triplicate Sample 1
Triplicate Sample 2
Triplicate Sample 3
Mean
30-Minute Effluent
Triplicate Sample 1
Triplicate Sample 2
Triplicate Sample 3
Mean
Overall Mean Influent
Overall Mean Permeate
Percent Reduction
72
79
74
80
78
2.9
3.1
2.9
3.0
88
84
85
86
3.4
3.6
3.5
3.5
82
3.2
96
25
38
43
29
37
ND (0.2)
ND (0.2)
ND (0.2)
ND (0.2)
33
40
35
36
ND (0.2)
ND (0.2)
ND (0.2)
ND (0.2)
36
ND (0.2)
>99
910
790
830
750
790
7.6
7.1
6.5
7.1
580
720
690
660
13
12
12
12
730
10
99
48
55
56
57
56
ND(1)
ND(1)
ND(1)
ND(1)
57
56
56
56
ND(1)
ND(1)
2
1
56
1
98
A-4
------- |