November 2005
NSF05/12C/EPADWCTR
EPA/600/R-06/005
Environmental Technology
Verification Report
Removal of Chemical Contaminants in
Drinking Water
Watts Premier Incorporated
WP-4V Drinking Water Treatment System
Prepared by
NSF International
Under a Cooperative Agreement with
U.S. Environmental Protection Agency
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THE ENVIRONMENTAL TECHNOLOGY VERIFICATION
PROGRAM
oEPA
U.S. Environmental Protection Agency
ET
V^lVl
V
NSF International
ETV Joint Verification Statement
TECHNOLOGY TYPE:
APPLICATION:
PRODUCT NAME:
COMPANY:
ADDRESS:
PHONE:
POINT-OF-USE DRINKING WATER TREATMENT SYSTEM
REMOVAL OF CHEMICAL CONTAMINANTS IN DRINKING
WATER
WATTS PREMIER WP-4V
WATTS PREMIER, INC.
1725 WEST WILLIAMS DR.
SUITE C-20
PHOENIX, AZ 85027
800-752-5582
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 WP-4V point-of-use (POU)
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 test.
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 05/12c/EPADWCTR
The accompanying notice is an integral part of this verification statement.
VS-i
November 2005
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ABSTRACT
The Watts Premier WP-4V POU drinking water treatment system was tested for removal of aldicarb,
benzene, cadmium, carbofuran, cesium, chloroform, dichlorvos, dicrotophos, fenamiphos, mercury,
mevinphos, oxamyl, strontium, and strychnine. The WP-4V employs a reverse osmosis (RO) membrane,
a sediment filter, and activated carbon filters to treat drinking water. The system was first tested with
only the RO membrane component in place. The target challenge concentration for each chemical for the
RO membrane tests was 1 mg/L. Following the RO membrane challenges, the post-membrane carbon
filter component was challenged alone with each chemical the RO membrane did not remove to below 30
Hg/L. Based on this criterion, the carbon filter was challenged with benzene, chloroform and mercury.
The target challenge concentration for the carbon filter tests was the maximum effluent level measured
during the RO membrane tests.
A total of 20 RO membrane components were tested, divided into ten pairs. Only one pair of membranes
was tested for removal of each chemical. Each RO membrane chemical challenge was conducted over a
one-day period. Influent and effluent samples were collected during the operation period, and also the
next morning. The post-membrane carbon filter challenges were conducted over a 15-hour duration.
Two filters were tested for each chemical challenge, and each pair was only used for one challenge.
Influent and effluent samples were collected at the beginning, middle, and end of the challenge period.
The WP-4V as a whole, considering both the RO membrane challenge and post-membrane carbon filter
challenge results combined, reduced all of the challenge chemicals 98% or more.
TECHNOLOGY DESCRIPTION
The following technology description was provided by the manufacturer and has not been verified.
The WP-4V is a four-stage POU drinking water treatment system, using sediment filtration, activated
carbon filtration, and reverse osmosis. Treated water is stored in a three-gallon storage tank. The WP-4V
is certified by NSF to NSF/ANSI Standard 58 - Reverse Osmosis Drinking Water Treatment Systems. It
has a certified production rate of 9.06 gallons per day.
Incoming water first passes through a sediment filter to remove particulate matter, such as rust and silt,
and then through a carbon filter to remove chlorine or other contaminants. The third stage of treatment is
the reverse osmosis membrane, which removes a wide variety of inorganic and larger molecular weight
organic contaminants, and also protozoan cysts such as cryptosporidium and Giardia. The permeate water
is sent to a 3-gallon maximum capacity storage tank. Upon leaving the storage tank, the water passes
through a second carbon filter to remove organic chemicals and other taste and odor causing substances
before dispensing through the faucet. The pre-membrane carbon and sediment filters were not tested,
because they are only designed to remove chlorine and particulate matter to protect the RO membrane.
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 test/QA plan and verification report. The testing
was conducted November 2004 through March 2005.
NSF 05/12c/EPADWCTR The accompanying notice is an integral part of this verification statement. November 2005
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Methods and Procedures
Verification testing followed the procedures and methods detailed in the Test/QA Plan for Verification
Testing of the Watts Premier WP-4V Point-of-Use Drinking Water Treatment System for Removal of
Chemical Contamination Agents. Because any contamination event would likely be short-lived, the
challenge period for each chemical lasted only one day. Long-term performance over the life of the
membrane was not evaluated.
The system was first tested with only the RO membrane component in place. A total of 20 RO
membranes were challenged with the chemicals in Table 1. The target challenge concentration for each
chemical was 1 mg/L. The 20 membrane test units were divided into ten pairs. One pair of systems was
tested for removal of each chemical. The reduction of TDS was also measured during the challenges to
evaluate whether any organic chemicals damaged the membrane material or membrane seals.
Table 1. Challenge Chemicals
Organic Chemicals Inorganic Chemicals
Aldicarb Cadmium Chloride
Benzene Cesium Chloride (nonradioactive isotope)
Carbofuran Mercuric Chloride
Chloroform Strontium Chloride (nonradioactive isotope)
Dicrotophos
Dichlorvos
Fenamiphos
Mevinphos
Oxamyl
Strychnine
Each RO membrane chemical challenge was conducted over a one-day period. The systems were
operated for six tank-fill periods, and then were allowed to rest overnight. Influent and effluent samples
were collected at start-up, after the 3rd tank fill, after 15 hours of operation, and the next morning after
the membranes rested under pressure overnight. During the chloroform, dichlorvos, and fenamiphos
challenges, the systems were still in operation for the 3rd tank fill at 15 hours, so the 3rd tank-fill samples
were not collected.
Following the RO membrane challenges, the post-membrane carbon filters were challenged with the
chemicals that the RO membranes did not remove to below 30 |o,g/L. The filters were attached to a
separate manifold that was of the same design as the manifold in the full RO system. Two carbon filters
were tested for each chemical challenge, and each filter was only used for one challenge. The target
challenge concentrations were the maximum effluent levels measured during the RO membrane tests.
Prior to testing, each carbon filter was service-conditioned by feeding water containing chloroform to
simulate the possible contaminant loading on the carbon halfway through the filter's effective lifespan.
The post-membrane carbon filter challenges were 15 hours in duration. Influent and effluent samples
were collected at the beginning, middle, and end of the challenge period. The carbon filters were
operated at 0.3 gallons per minute on an operating cycle where the "on" portion was 19 minutes (the time
required to empty the system storage tank when full), and the "off portion was 3 hours and 45 minutes
(the time required to fill the storage tank).
NSF 05/12c/EPADWCTR The accompanying notice is an integral part of this verification statement. November 2005
VS-iii
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VERIFICATION OF PERFORMANCE
The results of the RO membrane challenges are presented in Table 2. The RO membrane treatment
process removed 98% or more of all challenge chemicals but mercury, benzene, and chloroform. The
membranes removed 44% of mercury, 85% of benzene, and 84% of the chloroform challenge.
The TDS reduction by each membrane component for all challenge tests was 95% or higher. The TDS
reduction data does not indicate that any of the membranes or membrane seals were adversely affected by
exposure to the challenge chemicals.
The post-membrane carbon filter components were challenged with benzene, chloroform, and mercury.
Table 2. RO Membrane Challenge Data
Mean Influent Mean Effluent Percent
Chemical Qg/L) (|ag/L) Reduction (%)
Cadmium
Cesium
Mercury
Strontium
Aldicarb
Benzene
Carbofuran
Chloroform
Dichlorvos
Dicrotophos
Fenamiphos
Mevinphos
Oxamyl
Strychnine
910
660
1200
920
1100
1100
1100
1100
560
840
1200
1200
1100
1000
0.4
11
670
1
10
160
5
180
10
10
11
16
4
6
>99
99
44
>99
>99
85
>99
84
98
99
>99
99
>99
>99
The carbon challenge results are shown below in Table 3. The carbon filter removed 98% or more of all
three substances. The RO membrane and carbon challenge data combined shows that the two treatment
technologies working in concert within the WP-4V system removed 98% or more of all challenge
chemicals.
Complete descriptions of the verification testing results are included in the verification report.
Table 3. Post-Membrane Carbon Filter Challenge Data
Target Measured
Influent0} Mean Influent Mean Effluent Percent
Chemical (|ag/L) (|ag/L) (|ag/L) Reduction (%)
Benzene 290 300 O5 ^99
Chloroform 300 300 ND (0.5) > 99
Mercury 740 760 12 98
(1) Target influent level set at maximum single effluent level from RO challenge.
NSF 05/12c/EPADWCTR The accompanying notice is an integral part of this verification statement. November 2005
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QUALITY ASSURANCE/QUALITY CONTROL (QA/QC)
NSF ETV and QA staff monitored the testing activities to ensure that the testing was in compliance with
the test plan. NSF also conducted a data quality audit of 100% of the data. Please see the verification
report referenced below for more QA/QC information.
Original signed by Andrew Avel 01/18/06 Original signed by Robert Ferguson 01/24/06
Andrew P. Avel Date Robert Ferguson Date
Acting Director Vice President
National Homeland Security Research Center Water Systems
United States Environmental Protection NSF International
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
04/12c/EPADWCTR) are available from the following sources:
(NOTE: Not all of the appendices are included in the verification report. The appendices are available
from NSF upon request.)
1. ETV Drinking Water Systems Center Manager (order hard copy)
NSF International
P.O. Box 130140
Ann Arbor, Michigan 48113-0140
2. NSF web site: http://www.nsforg/etv/dws/dws_reports.html, and from
http://www.nsforg/etv/dws/dws_project_documents.html (electronic copy)
EPA web site: http://www.epa.gov/etv (electronic copy)
NSF 05/12c/EPADWCTR The accompanying notice is an integral part of this verification statement. November 2005
VS-v
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November 2005
Environmental Technology Verification Report
Removal of Chemical Contaminants in Drinking Water
Watts Premier Incorporated
WP-4V 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
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Notice
The U.S. Environmental Protection Agency (USEPA) through its Office of Research and
Development has financially supported and collaborated with NSF International (NSF) under
Cooperative Assistance 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
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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
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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 viii
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 2
1.5 Testing Participants and Responsibilities 2
1.5.1 NSF International 2
1.5.2 Watts Premier Inc 3
1.5.3 U.S. Environmental Protection Agency 3
Chapter 2 Equipment Description 4
2.1 Principals of Operation 4
2.1.1 Activated Carbon 4
2.1.2 RO Membrane 4
2.2 Equipment Capabilities 4
2.3 System Components 4
2.4 System Operation 5
2.5 Rate of Waste Product!on 7
2.6 Equipment Operation Limitations 7
2.7 Operation and Maintenance Requirements 7
Chapter 3 Methods and Procedures 8
3.1 Introduction 8
3.1.1 RO Membrane Challenges 8
3.1.2 Post-Membrane Carbon Filter Challenges 9
3.1.3 System Operation Scenarios 9
3.2 Verification Test Procedure 10
3.2.1 Challenge Protocol Tasks 10
3.2.2 Test Rig 10
3.2.3 Test Water 11
3.2.3.1 RO Membrane Conditioning and Challenge Test Water 11
3.2.3.2 Post-Membrane Carbon Filter Conditioning and Test Water 11
iv
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3.2.3.3 Chemical Challenges 12
3.2.4 Test System Installation and Conditioning 12
3.2.4.1 RO Membrane Test Units 12
3.2.4.2 Post-Membrane Carbon Filter Test Units 13
3.2.5 Challenge Protocols and Sampling Plans 13
3.2.5.1 TDS Reduction System Performance Check 13
3.2.5.2 RO Membrane Challenge Testing 14
3.2.5.3 Post-Membrane Carbon Filter Challenge Testing 16
3.3 Analytical Methods 18
3.3.1 Water Quality Analytical Methods 18
3.3.2 Challenge Chemical Analytical Methods 19
Chapter 4 Results and Discussion 20
4.1 RO membrane Conditioning 20
4.1.1 RO Membrane System Operation Data 20
4.2 Post-Membrane Carbon Filter Conditioning 20
4.3 TDS Reduction System Performance Check 20
4.4 RO Membrane Chemical Challenges 21
4.4.1 Inorganic Chemicals Challenges 21
4.4.2 Organic Chemical Challenges 22
4.5 Post-Membrane Carbon Filter Challenges 24
Chapters QA/QC 26
5.1 Introduction 26
5.2 Test Procedure QA/QC 26
5.3 Sample Handling 26
5.4 Analytical Methods QA/QC 27
5.5 Documentation 27
5.6 Data Review 27
5.7 Data Quality Indicators 27
5.7.1 Representativeness 27
5.7.2 Accuracy 27
5.7.3 Precision 28
5.7.4 Completeness 29
5.7.4.1 Number of Systems Tested 29
5.7.4.2 Water Chemistry Measurements 29
5.7.4.3 Challenge Chemicals 30
Chapter 6 References 31
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Appendix
Appendix A Conditioning and Chemical Challenges Data Tables
List of Tables
Table 1-1. Challenge Chemicals 2
Table 3-1. Challenge Chemicals 9
Table 3-2. Summary of the Sampling Plan for RO Membrane Challenges 16
Table 3-3. Summary of the Sampling Plan for Post-Membrane Carbon Filter Challenges 17
Table 3-4. QC Limits and Method Reporting Limits for Analyses 18
Table 4-1. RO Membrane Inorganic Chemical Reduction Data 21
Table 4-2. RO Membrane Organic Chemical Challenge Data 22
Table 4-3. TDS Reduction Data for Organic Chemical Challenges 23
Table 4-4. Organic Chemical Challenges Reject Water Data 23
Table 4-5. Post-Membrane Carbon Filter Challenge Data 25
Table 5-1. Completeness Requirements 29
List of Figures
Figure 2-1. Photograph of the WP-4V 5
Figure 2-2. Schematic Diagram of the WP-4V 6
Figure 3-1. RO Membrane Test Units Installed at Test Station 14
Figure 3-2. Post-Membrane Carbon Filter Test Units Installed at Test Station 17
VI
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Abbreviations and Acronyms
ANSI
°C
DWS
DWTS
ETV
°F
GC/MS
gpd
gpm
HC1
HPLC
ICP/MS
L
LFB
LFM
mg
mL
NaOH
ND
NRMRL
NSF
NTU
POE
POU
psi
QA
QC
QA/QC
RO
RPD
RSD
SOP
IDS
TOC
Hg
USEPA
VOC
American National Standards Institute
Degrees Celsius
Drinking Water Systems
Drinking Water Treatment Systems
Environmental Technology Verification
Degrees Fahrenheit
Gas Chromatography/Mass Spectrometry
Gallons Per Day
Gallons Per Minute
Hydrochloric Acid
High Pressure Liquid Chromatography
Inductively Coupled Plasma - Mass Spectrometry
Liter
Laboratory Fortified Blank
Laboratory Fortified Matrix
Milligram
Milliliter
Sodium Hydroxide
Non-detect
National Risk Management Research Laboratory
NSF International (formerly known as National Sanitation Foundation)
Nephelometric Turbidity Unit
Point-of-Entry
Point-of-Use
Pounds per Square Inch
Quality Assurance
Quality Control
Quality Assurance/Quality Control
Reverse Osmosis
Relative Percent Difference
Relative Standard Deviation
Standard Operating Procedure
Total Dissolved Solids
Total Organic Carbon
Microgram
U. S. Environmental Protection Agency
Volatile Organic Chemical
vn
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Acknowledgments
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.
Vlll
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Chapter 1
Introduction
1.1 Environmental Technology Verification (ETV) Program Purpose and Operation
The U.S. Environmental Protection Agency (USEPA) has 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; 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 non-intentional chemical contamination event. Because any contamination event
would likely be short-lived, the challenge period for each chemical lasted only one day. Long-
term performance over the life of the membrane was not investigated.
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 POU reverse osmosis (RO) drinking water
treatment systems for removal of chemical contaminants. To assist in this endeavor, NSF
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assembled an expert technical panel, which gave suggestions on a protocol design prior to
development of the test/QA plan.
The product-specific test/QA plan for evaluating the WP-4V was entitled Test/QA Plan for
Verification Testing of the Watts Premier WP-4V Point-of-Use Drinking Water Treatment
System for Removal of Chemical Contamination Agents.
By participating in this ETV evaluation, the vendor obtains USEPA and NSF verified
independent test data indicating potential user protection against intentional or non-intentional
chemical contamination of drinking water. Verifications following an approved test/QA plan
serve to notify the public of the possible level of protection against chemical contamination
agents afforded to them by the use of a verified system.
1.4 Challenge Chemicals
The challenge chemicals for this verification are listed in Table 1-1.
Table 1-1. Challenge Chemicals
Organic Chemicals Inorganic Chemicals
Aldicarb Cadmium Chloride
Benzene Cesium Chloride (nonradioactive isotope)
Carbofuran Mercuric Chloride
Chloroform Strontium Chloride (nonradioactive isotope)
Dicrotophos
Dichlorvos
Fenamiphos
Mevinphos
Oxamyl
Strychnine
1.5 Testing Participants and Responsibilities
The ETV testing of the WP-4V 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
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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, ETV Program Manager
Email: bartley@nsf.org
1.5.2 Watts Premier Inc.
The verified system is manufactured by Watts Premier, a division of Watts Water Technologies.
Watts Premier manufactures industrial, food service, point-of-entry, and point-of-use 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@watts.com
1.5.3 U.S. Environmental Protection Agency
The 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 the USEPA, and recommended for public release.
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Chapter 2
Equipment Description
2.1 Principals of Operation
2.1.1 Activated Carbon
Activated carbon removes organic chemicals from water through the process of 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.
2.1.2 RO Membrane
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.
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 TDS of the permeate
water with a TDS monitor.
2.2 Equipment Capabilities
The WP-4V is certified by NSF to NSF/ANSI Standard 58 - Reverse Osmosis Drinking Water
Treatment Systems. The post-membrane carbon filter in the system is certified to NSF/ANSI
Standard 53 - Drinking Water Treatment Units - Health Effects. The WP-4V has a certified
production rate of 9.06 gallons per day. This measurement is based on system operation at 50
pounds per square inch, gauge (psig) inlet pressure, a water temperature of 25 °C, and a total
dissolved solids (TDS) level of 750 + 40 mg/L. The amount and quality of treated water
produced varies depending on the inlet pressure, water temperature, and level of TDS. These
measurements were not subject to verification during this study.
2.3 System Components
The WP-4V is a four-stage treatment system. Incoming water first passes through a sediment
filter to remove particulate matter, such as rust and silt, and then through a carbon filter to
remove chlorine or other contaminants. The third stage of treatment is the reverse osmosis
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membrane, which removes a wide variety of inorganic and larger molecular weight organic
contaminants, and also protozoan cysts such as cryptosporidium and Giardia. The permeate
water is sent to a 3-gallon maximum capacity storage tank. Upon leaving the storage tank, the
water passes through a second carbon filter to remove organic chemicals and other taste and odor
causing substances before dispensing through the faucet. A photograph of the system is shown
in Figure 2.1, and a schematic diagram shown in Figure 2.2. Please note that this description,
and the system operation description in Section 2.4 are given for informational purposes only.
This information was not subject to verification.
Figure 2-1. Photograph of the WP-4V
2.4 System Operation
When the flow of water into the system is started, treated water will be continually produced
until the storage tank is nearly full. At that time, the water pressure in the tank causes an
automatic shut-off valve to stop the flow of water through the system. After a portion of the
water is dispensed from the tank, the shut-off valve deactivates, allowing water to once again
flow through the RO membrane into the storage tank.
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Figure 2-2. Schematic Diagram of the WP-4V
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The operational storage tank capacity will vary slightly from system to system, and may also be
affected by the inlet water pressure. The storage tank capacity was measured to be 2.64 gallons
when the system was tested for NSF/ANSI Standard 58 cerification.
2.5 Rate of Waste Production
The rate of reject water production was measured during the certification process for NSF/ANSI
Standard 58 certification. The efficiency rating, as defined by Standard 58 is the percentage
measure of the amount of influent water delivered as permeate under a closed permeate
discharge set of actual use conditions. The efficiency rating of the WP-4V is 8.4%, which means
the system produces approximately 11 gallons of reject water for each gallon of product water
produced. The efficiency rating was not verified as part of this evaluation.
2.6 Equipment Operation Limitations
Watts Premier gives the following limitations for the drinking water to be treated by the system:
• temperature of 40 - 100 °F;
• pressure of 40 - 100 psi;
• pHof3-ll;
• maximum TDS level of 1,800 mg/L;
• maximum water hardness of 10 grains per gallon (1 grain per gallon equals 17.1 mg/L of
hardness, expressed as calcium carbonate equivalent); elevated hardness levels may
reduce membrane life; and
• maximum iron level of 0.2 ppm.
2.7 Operation and Maintenance Requirements
The following are the operation and maintenance requirements specified in the product owner's
manual:
• Replacement of the pre-membrane sediment and pre-membrane carbon filter every 12
months;
• Replacement of the RO membrane every 2 to 5 years (Watts Premier offers free treated
water TDS analysis for monitoring membrane operation, or the user can purchase a TDS
monitor);
• Replacement of the post-membrane carbon filter every 12 months or 600 gallons treated;
• Annual sanitization of the system with hydrogen peroxide or bleach is recommended; and
• The flow restrictor plug must be cleaned each time the RO membrane is replaced.
The WP-4V system relies on the user to determine when the filters and RO membrane need to be
replaced. There are no on-line monitors or indicators built into the system to track the volume of
water treated. However, to compensate for this, for NSF/ANSI Standard 58 certification the
post-membrane carbon filter was tested out to 200% of the claimed capacity, as opposed to 120%
of capacity for systems with volume-based monitors.
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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 WP-4V Point-of-Use Drinking Water Treatment System for
Removal of Chemical Contamination Agents.
As described in Section 2.3, the WP-4V employs an RO membrane, a sediment filter, and carbon
filters to treat drinking water. The system was first tested with only the RO membrane
component in place. After the RO membrane challenges were complete, the post-membrane
carbon filter was challenged alone. This approach allowed an evaluation of the individual
performance of each component, and also served to simulate a worst-case scenario where the
carbon filters are at or past the end of their useful life. This approach also allowed each
treatment component to be challenged using a challenge water that presented more of a worse-
case scenario for that component. The pre-membrane carbon and sediment filters were not
tested, because they are only designed to remove chlorine and particulate matter to protect the
RO membrane.
3.1.1 RO Membrane Challenges
The RO membranes were challenged with each chemical in Table 3-1. The target challenge
concentration for each chemical was 1 mg/L, which is much higher than most challenge levels in
the NSF/ANSI Standards for POU devices. Of the chemicals in Table 3-1 included in the POU
device standards, the highest challenge is chloroform at 450 (ig/L for the total trihalomethanes
reduction test.
Only two membranes were challenged with each chemical. The organic chemical challenges and
the mercury challenge were conducted individually, but cadmium, cesium, and strontium were
combined into one challenge. The test/QA plan called for each membrane to be tested with only
one of the ten organic chemicals, because of concern that some of them, especially benzene and
chloroform, could damage the membranes or membrane seals at the high challenge levels.
However, two units had to be tested with three of the organic chemicals. See Sections 4.4.2 and
5.7.4.1 for further discussion.
TDS reduction was also measured during the challenges, to serve as a membrane performance
benchmark, and also to evaluate whether any organic chemicals damaged the membrane or
integrity of the membrane seals.
A total of twenty RO membranes were tested, divided into ten pairs. The inorganic chemical
challenges were conducted first. The two systems used for with the inorganic chemicals were
used again for an organic chemical challenge. As discussed in Section 1.2, each challenge period
was only one day. The membranes were operated for five tank-fill periods or fifteen hours,
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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)
Dicrotophos
Dichlorvos
Fenamiphos
Mevinphos
Oxamyl
Strychnine
whichever came first. Influent and effluent samples were collected during the operation period
at start-up, after the third tank-fill, and after the fifth tank-fill, or end of fifteen hours of
operation. After the last samples were collected, the systems were operated again for a sixth tank
fill, then rested overnight. Post-rest effluent samples were collected from the storage tank the
next morning. In addition to influent and effluent samples, reject water samples were also
collected during the organic chemical challenges in an attempt to determine whether any of the
chemicals adsorbed onto or absorbed into the membrane material in significant amounts. See
Section 3.2.5.2 for RO membrane challenge protocol details.
3.1.2 Post-Membrane Carbon Filter Challenges
The post-membrane carbon filter was tested alone for reduction of some of the chemicals. The
carbon filter was challenged with the organic chemicals the RO membrane did not remove to a
level of 30 |j,g/L or less. The inorganic chemicals were considered on a case-by-case basis, since
USEPA does not consider carbon to be the best available technology for removing cadmium,
cesium, or strontium. As with the membranes, the carbon filters were challenged in pairs, and
each pair was only tested once. Each challenge was 15 hours. The target challenge
concentrations for the carbon filter tests were the maximum effluent levels measured during the
RO tests. See Section 3.2.5.3 for the post-membrane carbon filter test protocol details.
3.1.3 System Operation Scenarios
The challenge protocol was designed to evaluate system performance under two different
operation scenarios. The first is operation with the product water storage tank over half full,
giving high back-pressure. This is how the system is likely to operate in the home, as the user
will usually dispense small volumes of water until the shut-off valve deactivates, allowing the
storage tank to fill again. RO membrane performance is affected by the net driving pressure on
the membrane. The net driving pressure is the feed water pressure minus the osmotic pressure
minus the back-pressure from the storage tank. As the storage tank fills up and the tank bladder
expands, the back-pressure increases, reducing the net driving pressure. As the net driving
pressure drops, the ion rejection performance of the membrane can also drop (Slovak, 2000).
-------
This test protocol was designed so that the membranes operate for multiple tank fills under
conditions where the net driving pressure was as low as possible. After the first tank fill, the lab
technician dispensed the product water to the drain until the shut-off valve deactivated, allowing
the RO membrane to again produce treated water. This cycle was repeated for a total of five
storage tank fill periods.
The second operation scenario is continued contaminant rejection while the system is at rest.
The NSF/ANSI Standard 58 testing protocols call for a two-day stagnation period to check
whether the membrane can maintain rejection of the contaminants. NSF has observed that RO
systems can give higher contaminant concentrations after the rest period than before. This
phenomenon is due to the membrane's difficulty maintaining the osmotic differential across the
membrane, and perhaps also imperfections in the membrane material. At the end of each
challenge, the membranes were allowed to rest under pressure overnight, and product water
samples were collected for analysis the next morning.
3.2 Verification Test Procedure
3.2.1 Challenge Protocol Tasks
The following are the tasks in the challenge protocol, and the order in which they were
conducted:
1. Installation of the RO membrane devices on the test rig, and seven days of
conditioning (Section 3.2.4.1);
2. One-day TDS challenge test to evaluate system integrity (Section 3.2.5.1);
3. Conditioning of the post-membrane carbon filters while the RO membrane tests are
being conducted (Section 3.2.4.2); and
4. Chemical challenge tests
a. RO inorganic chemical challenges (Section 3.2.5.2)
b. RO organic chemical challenges (Section 3.2.5.2)
c. Post-membrane carbon filter challenges (Section 3.2.5.3).
3.2.2 Test Rig
All test units were plumbed to "injection rig" test stations in the NSF Drinking Water Treatment
Systems (DWTS) Laboratory. The injection rigs have a common 90-gallon tank to hold the test
water without the challenge chemicals. 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 feedwater tank, a precisely controlled pump is used to
inject the challenge chemical(s) at the proper concentrations. Immediately downstream of the
pump lies a motionless in-line mixer to assure complete mixing of the challenge water. An
influent sample port is downstream of the in-line mixer. No schematic diagram of the injection
rig is available, due to the proprietary nature of the design.
10
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3.2.3 Test Water
3.2.3.1 RO Membrane Conditioning and Challenge Test Water
The test water for the RO membrane conditioning and challenges was a synthetic water
constructed from deionized municipal drinking water. The municipal water was first filtered
through activated carbon to remove chlorine, then it was deionized and treated with reverse
osmosis. Sodium chloride was added for TDS, and the pH was adjusted with hydrochloric acid
(HC1) or sodium hydroxide (NaOH), if necessary, to achieve the following characteristics prior
to addition of the challenge chemical(s):
• pH - 7.5 ± 0.5 for the TDS reduction test, conditioning, and organic chemical challenges,
6.0-6.5 for the inorganic chemicals challenges;
• total chlorine - < 0.05 mg/L;
• temperature - 25 ± 1 °C;
• TDS - 750 ± 75 mg/L; and
• turbidity - < 1 Nephelometric Turbidity Unit (NTU).
TDS, pH, temperature, and turbidity were maintained within the appropriate range by a computer
system with on-line monitors. In addition, grab samples were collected and analyzed for all
parameters according to the sampling plans described in Sections 3.2.4.1, 3.2.5.1, and 3.2.5.2.
Note that the pH specification for the inorganic chemicals challenges was 6.0 to 6.5, to ensure
that the metals were present as dissolved free ions in the challenge water. This ensured that the
metals challenges were testing the ability of the RO membrane to reject the ions instead of
physically removing suspended particles of the metals.
3.2.3.2 Post-Membrane Carbon Filter Conditioning and Test Water
The test water for post-membrane carbon filter conditioning and testing was the "general test
water" specified in NSF/ANSI Standard 53, Drinking water treatment units - health effects (NSF
International, 2002). This water is the 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;
• TDS - 200-500 mg/L
• temperature - 20 ± 2.5 °C;
• total organic carbon (TOC) - > 1.0 mg/L; and
• turbidity - < 1 NTU.
Please note that the TOC parameter only has a minimum level specified, since it is the natural
TOC in the municipal water supply. The natural TOC in the water supply usually ranges from
approximately 2 to 3 mg/L. The TOC levels in the organic chemical challenge waters were
much higher due to the methanol used as the carrier solution for the chemicals.
TDS, pH, and temperature were maintained within the appropriate range by a computer system
with on-line monitors. The pH of the Ann Arbor drinking water was above 7.5 during the test
period, so the pH was adjusted with HC1. The TDS level was within the allowable range, so no
adjustments were needed. The water was not dechlorinated prior to use.
11
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Grab samples were collected and analyzed for all parameters according to the sampling plans
described in Sections 3.2.4.2 and 3.2.5.3. Total chlorine was also measured, although there is no
specification given for it as there is in Section 3.2.3.1 for the RO membrane test water.
3.2.3.3 Chemical Challenges
The appropriate chemical(s) were added to the base test waters given in Sections 3.2.3.1 and
3.2.3.2 to make the challenge waters. The RO membrane challenge target concentration for each
chemical was 1 + 0.5 mg/L. The target challenge concentrations for the carbon filter tests were
the maximum effluent levels measured during the RO tests. For each challenge, a concentrated
solution of the chemical(s) was made, and this mixture injected into the influent water stream at
an appropriate rate. Due to analytical procedure lengths, the amount of chemical to add to the
test water to achieve the proper challenge concentration was calculated based on the known
concentration in the feed solution. The tests were conducted without waiting for confirmation of
the influent level from the chemistry laboratory.
3.2.4 Test System Installation and Conditioning
3.2.4.1 RO Membrane Test Units
The RO membrane test units were installed on the test rigs by an NSF DWTS Laboratory
technician according to the instructions in the WP-4V owner's manual. Watts Premier's
recommended conditioning procedure of operation for three tank-fill periods was not conducted,
instead the membranes underwent a seven-day, seven tank-fills conditioning period. Previous
POU RO system ETV tests for microbial agents indicated that perhaps membrane performance
does not stabilize until after four or five days (four or five tank fills) of conditioning. A seven-
day conditioning period ensured that the membranes were performing optimally prior to the
chemical challenges.
For the first six days, the membranes were operated at 60 + 3 psi inlet pressure for one storage
tank fill period per day using the water described in Section 3.2.3.1. Influent water samples were
collected each day at the beginning of the operation period for analysis of pH, TDS, temperature,
total chlorine, and turbidity. The membranes rested under pressure overnight, and the storage
tanks were emptied the next morning prior to beginning that day's operation period.
On the seventh day, the membranes were instead operated at 80 + 3 psi inlet pressure. Influent
water samples were collected at the beginning of the operation period for analysis of pH, TDS,
temperature, total chlorine, and turbidity. The times required to fill the storage tanks were
measured and recorded for the three test units whose tanks filled the fastest. On the morning of
the eighth day, the times to dispense the first liter of water and to empty the storage tanks with
the faucet fully open were measured and recorded for the three test units whose operation times
were recorded the previous day. The tank fill times, times to empty the storage tank, and first
liter flow rates were used to determine the operating parameters for the post-membrane carbon
filters during the carbon filter challenge tests. The longest time to empty the storage tank was
used for the "on" time portion of the operating cycle. The shortest tank fill time was used for the
"off portion of the cycle. The flow rates during the carbon filter challenges were set at the
fastest first liter flow rate. Operation at 80 psi instead of 60 psi caused the tank fill time to be
12
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shorter, which gave a worse case testing scenario for the carbon filters. See Section 3.2.5.3 for
further discussion about the post-membrane carbon filter challenge tests.
3.2.4.2 Post-Membrane Carbon Filter Test Units
The carbon filters were plumbed to a test station and operated using the water described in
Section 3.2.3.2 amended with 300 + 90 |o,g/L of chloroform until 300 gallons passed through
each filter. This is the volume equal to one-half of Watts Premier's stated capacity of 600
gallons for the filter. The filters were operated at an inlet water pressure of 60 + 3 psi and a
maximum flow rate of approximately 0.4 gallons per minute (gpm), on a ten minutes on, ten
minutes off cycle. Chloroform at 300 |o,g/L is the influent challenge concentration for the VOC
(volatile organic chemical) reduction test in NSF/ANSI Standard 53 (chloroform is the surrogate
challenge chemical). The chloroform served to load the carbon filters to a degree that simulated
contaminant loading in the middle of their effective lifespan. Influent samples were collected for
analysis of chloroform, pH, temperature, TOC, and turbidity at start-up, approximately 25% of
capacity, and approximately 50% of capacity. Effluent samples were collected at the same three
points for chloroform analysis.
If the filters were not immediately used for a challenge test, they were stored with the
conditioning water still in them. The manifold inlets and outlets were closed off by valves to
ensure that the chloroform remained on the carbon.
3.2.5 Challenge Protocols and Sampling Plans
3.2.5.1 TDS Reduction System Performance Check
After the RO membrane conditioning period was complete, they underwent a short-term TDS
reduction test to verify that they were operating properly. The challenge was conducted as
follows:
1. The product water storage tanks were drained, and membrane operation was started at 50 ± 3
psig inlet pressure using the water described in Section 3.2.3.1 without any challenge
chemicals added.
2. Immediately after the membranes began operation, influent samples were collected for
analysis of pH, temperature, total chlorine, turbidity, and TDS.
3. The systems were allowed to operate until the automatic shut-off mechanisms activated.
4. The entire contents of the storage tanks were emptied into separate containers, and three 250
mL samples were collected from each container for TDS analysis.
Removal of 75% or more of the TDS was required for the use of each membrane for the
chemical challenges.
13
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3.2.5.2 RO Membrane Challenge Testing
As discussed in Section 3.1.1, the RO membrane test units were divided into ten pairs. The
inorganic chemical challenges were conducted first, followed by the organic chemicals. Figure
3-1 shows a pair of test devices plumbed to the test rig.
Figure 3-1. RO Membrane Test Units Installed at Test Station
14
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The challenge tests were conducted as follows:
1. At the start of each challenge period, the test system storage tanks were emptied.
2. The initial dynamic inlet water pressure was set at 50 + 3 psi, and test system operation was
started using the test water described in Section 3.2.3.1 with the proper challenge chemical(s)
added.
3. Influent and effluent water samples were collected for analysis of the challenge chemical(s)
and TDS immediately after the units began operation. Influent samples were also collected
for analysis of pH, temperature, total chlorine, and turbidity. All influent and effluent
samples for challenge chemical analysis were collected and analyzed in triplicate, except
where indicated below. To collect the triplicate samples, the volumes necessary to obtain the
triplicate samples were first collected into a polyethylene container, and then the triplicate
samples were collected from that volume. Due to the volatility of benzene and chloroform,
true triplicate samples were not collected for these chemicals. Instead, three consecutive
replicate samples were collected directly into the sample bottles that were delivered to the
NSF Chemistry Laboratory. TDS samples were collected as single samples.
4. During first tank-fill period of the organic chemical challenges, duplicate samples were
collected from the reject water line of one of the systems for challenge chemical(s) analysis.
Samples were collected at start-up, approximately halfway through, and approximately three-
fourths of the way through the period.
5. The systems were operated continuously until the shut-off valves activated. The faucets were
then fully opened, and a minimum of one liter, the volume required for sample analysis, or
the amount needed to fully deactivate the shut-off valve, was dispensed to drain from each
system. Full deactivation was estimated by monitoring resumption of the flow of reject water
as the product water is dispensed. The shut-off valve was considered fully deactivated when
the flow of reject water appeared to have fully resumed.
6. Step 5 was repeated until five storage tank fill periods were complete, or 15 hours of
operation had passed. After the third storage tank fill period ended, influent and effluent
samples were collected for analysis of the challenge chemical(s) and TDS.
7. Approximately halfway through the last tank fill period for the organic chemical challenges,
duplicate reject water samples were again collected for challenge chemical(s) analysis. The
samples were collected from the same system from which the reject water samples were
collected in step 4. This sample served to check whether any chemical adsorption/absorption
observed during the first storage tank fill period was still occurring, or the membrane became
saturated with the chemical.
8. After the fifth storage tank fill, or after 15 hours of operation, effluent samples were collected
from each system for challenge chemical(s) and TDS analysis. Influent samples were
collected for analysis of the challenge chemical(s), TDS, pH, temperature, total chlorine, and
turbidity. If a system did not resume operation after sample collection, the additional volume
necessary to resume operation was dispensed from each system.
9. The units were then allowed to operate until the shut-off valves activated, and then rest under
pressure for at least eight hours. After the rest period, the faucets were fully opened, and the
first draw out of each faucet was collected for single challenge chemical and TDS analysis.
After collection of the first draw water, the rest of the contents of each storage tank were
15
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collected into suitable containers, and three samples were collected from each volume for
triplicate challenge chemical analysis. Table 3-2 gives a summary of the sampling plan.
Table 3-2. Summary of the Sampling Plan for RO Membrane Challenges
T „ + „ , , T , Effluent Sample Numbers
Influent Sample Numbers , t ,
r (per system)
Water Chemistry Challenge Challenge
Sample Point Parameters Chemical TDS Chemical TDS
„. ^TT 1 sample for ,
Startup , F . 3
each parameter
1
3 1
1st Tank Reject Water Samples
Startup
Half Tank
Three-fourths Tank
3rd Tank Fill
2 (from one system)
2 (from one system)
2 (from one system)
3
5th Tank Fill
Reject Water - Halfway Through
5th Tank Fill
Post-Rest - First Draw
Post-Rest - Rest of Tank
1 sample for
each parameter
1 3
2 (from one system)
1
3
1
1
3.2.5.3 Post-Membrane Carbon Filter Challenge Testing
The post-membrane carbon filter in the WP-4V is downstream from the storage tank, so it was
tested at the flow rate measured at the faucet outlet during the RO membrane conditioning step.
Each challenge was 15 hours. The filters were operated on an "on/off operation cycle where the
"on" portion was the time required to empty the storage tank when full, and the "off portion of
the cycle was the time required to fill the storage tank at 80 psi inlet pressure, as measured
during the RO membrane conditioning period. Figure 3-2 shows a pair of carbon filters being
tested for dichlorvos removal.
The challenge tests were conducted as follows:
1. The proper "on/off cycle parameters were entered into the test station computer.
2. The initial dynamic inlet water pressure was set at 60 + 3 psi, and filter operation was started
using the water described in Section 3.2.3.2 with the proper challenge chemical added. The
flow rate was adjusted as necessary using a valve downstream of each filter on the effluent
line.
3. Influent and effluent samples were collected for challenge chemical analysis immediately
after operation began. All effluent samples were collected during the last half of the "on"
portion of the operation cycle, so that the dwell water was flushed out prior to sample
collection. All challenge chemical samples were collected and analyzed in triplicate. The
sample volumes were those required to obtain the triplicate samples.
4. Single influent samples were also collected for analysis of pH, TDS, temperature, TOC, total
chlorine, and turbidity whenever challenge chemical samples were collected.
16
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5. After 7.5 and 15 hours of operation, second and third sets of influent and effluent samples
were collected for challenge chemical analysis. The flow of challenge water through the
filters was started manually if they were not in the "on" portion of the operation cycle. Table
3-3 gives a summary of the sampling schedule.
Figure 3-2. Post-Membrane Carbon Filters Installed at Test Station
Table 3-3. Summary of the Sampling Plan for Post-Membrane Carbon Filter Challenges
Influent Water Chemistry Challenge Chemical Challenge Chemical
Sample Point Sample Numbers Influent Sample Numbers Effluent Sample Numbers
Startup
7.5 Hours
15 Hours
1 for each parameter
1 for each parameter
1 for each parameter
3
3
3
17
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3.3 Analytical Methods
3.3.1 Water Quality Analytical Methods
The following are the analytical methods used during verification testing. All analyses followed
procedures detailed in NSF's Standard Operating Procedures (SOPs). The reporting limits, and
the acceptable precision and accuracy for each parameter are shown in Table 3-4.
Table
Parameter
pH
TDS (conductivity)
TDS (gravimetric)
TOC
Total Chlorine
Turbidity
Aldicarb
Benzene
Cadmium
Carbofuran
Cesium
Chloroform
Dicrotophos
Dichlorvos
Fenamiphos
Mercury
Mevinphos
Oxamyl
Strontium
Strychnine
3-4. QC Limits
Reporting Limit
NA
2 mg/L
5 mg/L
0.1 mg/L
0.05 mg/L
0.1 NTU
1.0 |J.g/L
0.5 ^g/L
0.3 |J.g/L
1 |J-g/L
1 |J-g/L
0.5 |J.g/L
10 ^g/L
0.2 (o,g/L
4|ag/L
0.2 (o,g/L
0.2 ^g/L
1.0 |J.g/L
2 ng/L
5 ug/L
and Method Reporting
Acceptable Precision
(RPD or RSD)
RPD < 10%
RPD < 10%
RPD < 10%
RPD < 10%
RPD < 10%
RPD < 10%
RSD < 20%
RSD < 20%
RSD < 20%
RSD < 20%
RSD < 20%
RSD < 20%
RSD < 30%
RSD < 30%
RSD < 30%
RSD < 20%
RSD < 30%
RSD < 20%
RSD < 20%
RSD < 20%
Limits for Analyses
Acceptable Accuracy (% recovery)
90-110%
80-120%
90-110%
80-120%
90-110%
95-105%
LFB
80-120%
80-120%
85-115%
80-120%
85-115%
80-120%
70-130%
70-130%
70-130%
85-115%
70-130%
80-120%
85-115%
LFM
65-135%
NA
70-130%
65-135%
70-130%
NA
70-130%
70-130%
70-130%
70-130%
70-130%
65-135%
70-130%
70-130%
LFB = Laboratory Fortified Blank
LFM = Laboratory Fortified Matrix
RPD = Relative Percent Deviation
RSD = Relative Standard Deviation
• pH - All pH measurements were made with an Orion Model SA 720 meter. The meter
was operated according to the manufacturer's instructions, which are based on Standard
Method 4500-H+.
• Temperature - Water temperature was measured using an Omega model HH11 digital
thermometer.
• TDS (by conductivity) - 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 under
Standard 58.
18
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• TDS (gravimetrically) - 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 - Total chlorine was measured according to Standard Method 4500-C1 G
with a Hach Model DR/2010 spectrophotometer using AccuVac vials.
3.3.2 Challenge Chemical Analytical Methods
The following are the analytical methods used during verification testing. All analyses followed
procedures detailed in NSF SOPs. The reporting limits, and the acceptable precision and
accuracy for each parameter are shown in Table 3-4.
• Aldicarb, Carbofuran, and Oxamyl were measured by high pressure liquid
chromatography (HPLC) according to USEPA Method 531.1 or 531.2.
• Dichlorvos, Dicrotophos, Fenamiphos, and Mevinphos were measured by gas
chromatography/mass spectrometry (GC/MS) according to USEPA Method 525.2.
• Cadmium, Chromium, 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.
19
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Chapter 4
Results and Discussion
4.1 RO membrane Conditioning
As discussed in Section 3.2.4.1, the RO membranes were conditioned for seven days prior to the
chemical challenges. All of the influent water quality parameters in Section 3.2.3.1 were
maintained within the allowable ranges. The individual data values for these parameters can be
found in Table A-l of Appendix A
4.1.1 RO Membrane System Operation Data
As described in Section 3.2.4.1, the storage tank fill times, first liter dispense times, and times to
dispense the entire tanks were measured and recorded for the three systems whose tanks filled
the fastest. These parameters were to be used for the post-membrane carbon filter challenges.
The shortest tank fill time measured was 3 hours, 45 minutes, and the fastest first liter flow rate
was 1.22 gpm. However, the flow rates were measured without the post-membrane carbon filter
in place. When the carbon filters were plumbed to the test rigs, 1.22 gpm could not be achieved.
Watts Premier informed NSF that the filter has an integral flow controller that limits the flow
rate through the carbon to approximately 0.3 gpm. A carbon filter was installed into an RO unit
to confirm this. NSF measured a first liter flow rate of 0.29 gpm and a storage tank dispense
time of 19 minutes, 4 seconds. These parameters, along with the tank-fill time of 3 hours, 45
minutes, were used for the carbon filter challenges.
4.2 Post-Membrane Carbon Filter Conditioning
As described in Section 3.2.4.2, the post-membrane carbon filters were to be conditioned with
water containing 300 + 90 ug/L of chloroform until 300 gallons had passed through them.
However, the measured influent chloroform levels were higher, ranging from 430 to 520 ng/L.
This loaded the carbon filters with more chloroform than was planned, but the carbon filter
challenge data in Table 4-8 does not indicate that the excess chloroform loading adversely
affected the performance of the carbon.
The carbon filter conditioning effluent samples were all below the detection limit of 0.5 ng/L,
except for the unit 6 25% effluent sample, which was 160 ng/L. The 160 |o,g/L is likely due to a
sampling or analytical error, since the start-up and 50% effluent samples for unit 6 were non-
detects. The chloroform and water chemistry data are presented in Table A-3 of Appendix A.
4.3 TDS Reduction System Performance Check
After the RO membranes were conditioned, all underwent the TDS reduction test described in
Section 3.2.5.1. The maximum effluent TDS level measured was 23 mg/L, corresponding to a
minimum 97% reduction of TDS. The average TDS reduction was 98%. Watts Premier's
reported TDS reduction is 97%, so the tested systems were representative of expected membrane
20
-------
performance. The IDS reduction data for each RO membrane system can be found in Table A-2
of Appendix A.
4.4 RO Membrane Chemical Challenges
The RO membrane challenges were conducted according to the procedure in Section 3.2.5.2.
The systems operated too slowly in all challenges but that for mercury to complete five tank-fills
within the 15-hour operation period. Note that the challenge period likely ended while the
systems were in operation, so the 15-hour samples may have been collected from partially filled
tanks. The numbers of tank-fills completed are given in the challenge data tables that follow.
4.4.1 Inorganic Chemicals Challenges
The inorganic chemicals challenge data are shown in Table 4-1. Each challenge chemical data
point is the arithmetic mean of the triplicate sample analyses, except for the post-rest first liter
draws, which were only single samples. All individual challenge chemical sample values
constituting the triplicate analyses are presented in Table A-4 of Appendix A. The challenge
water chemistry data are presented in Table A-6 of Appendix A.
Table 4-1. RO Membrane
Cadmium
Sample (H-g/L)
Start-up Influent
Start-up Effluent, Unit 1
Start-up Effluent, Unit 2
3rd Tank Influent
3rd Tank Effluent, Unit 1
3rd Tank Effluent, Unit 2
5th Tank/1 5 Hr. Influent
5th Tank/15 Hr. Effluent, Unit 1
5th Tank/15 Hr. Effluent, Unit 2
Post-Rest 1st Liter Draw, Unit 1
Post-Rest 1st Liter Draw, Unit 2
Post-Rest 2nd Sample, Unit 1
Post-Rest 2nd Sample, Unit 2
Mean Influent
Mean Effluent, Unit 1
Mean Effluent, Unit 2
Percent Reduction, Unit 1
Percent Reduction, Unit 2
Overall Mean Effluent
Overall Percent Reduction
Units Tested (Unit #'s)
Number of Tank-Fills Completed
1000
ND (0.3)
0.3
890
0.4
0.3
830
0.5
ND (0.3)
0.6
ND (0.3)
0.6
ND (0.3)
910
0.5
0.3
>99
>99
0.4
>99
5,6
4
Inorganic Chemicals Reduction Data
Cd, Cs, Sr Mercury
Cesium Mercury Strontium Challenge Challenge
(HB/L) (nfi/L) (HB/L) TDS (mg/L) TDS (mg/L)
640
8
7
700
12
10
650
13
11
13
11
13
11
660
12
10
99
99
11
99
5,6
4
1200
470
520
1300
670
670
1200
710
720
720
740
710
740
1200
650
680
46
44
670
44
1,2
5
940
1
ND(1)
950
ND(1)
ND(1)
860
ND(1)
ND(1)
ND(1)
ND(1)
ND(1)
ND(1)
920
1
ND(1)
>99
>99
1
>99
5,6
4
740
19
16
750
14
12
750
15
13
15
14
NA
NA
750
16
14
98
98
—
—
—
—
660
16
12
650
15
14
420
14
11
11
12
NA
NA
580
14
12
98
98
—
—
—
—
21
-------
The RO membrane removed 99% or more of the cadmium, cesium, and strontium. The
membrane removed less than 50% of the mercury challenge, but this was not a surprising result.
There are no POU RO systems certified by NSF for mercury reduction because mercury is not
well removed by RO membranes using the test water specified in NSF/ANSI Standard 58.
4.4.2 Organic Chemical Challenges
The organic chemical challenge data are shown below in Table 4-2. Each data point is the
arithmetic mean of the triplicate sample analyses, except where indicated, and for the post-rest
first draw samples, which were only single samples. All individual sample values constituting
the triplicate analyses are presented in Table A-5 in Appendix A. The challenge water chemistry
data are presented in Table A-6 of Appendix A.
As discussed in Section 3.1.1, the challenge water also contained TDS to serve as a membrane
integrity check. The TDS reduction data are presented in Table 4-3.
The reject water data are shown in Table 4-4. The values presented are the arithmetic means of
the duplicate sample analyses. The individual sample results are presented in Table A-7 of
Appendix A.
Sample
Table 4-2. RO Membrane Organic Chemical Challenge Data
Aldicarb Benzene Carbofuran Chloroform Dichlorvos Dicrotophos Fenamiphos Mevinphos Oxamyl Strychnine
Start-up Influent
Start-up Effluent, Unit 1
Start-up Effluent, Unit 2
3rd Tank Influent
3rd Tank Effluent, Unit 1
3rd Tank Effluent, Unit 2
15 hr. Influent
15 hr. Effluent, Unit 1
15hr. Effluent, Unit 2
Post- Rest 1st Draw, Unit 1
Post- Rest 1st Draw, Unit 2
Post-Rest 2nd Sample, Unit 1
Post-Rest 2nd Sample, Unit 2
Mean Influent
Mean Effluent, Unit 1
Mean Effluent, Unit 2
Percent Reduction, Unit 1
Percent Reduction, Unit 2
Overall Mean Effluent
Overall Percent Reduction
Units Tested (Unit #'s)
Number of Tank-Fills Completed
1100
10
4
~TToo~
12
7
1200""
12
8
12
8
12
8
1100
12
7
99
>99
10
>99
7,8
4
900
ND(0.5)
0.5
1100
140
99
1200
220
150
270
190
290
190
1100
190
120
83
88
160
85
3,4
4
1000
3
3
1100
4
5
1100
4
5
4
5
4
5
1100
4
5
>99
>99
5
>99
11, 12
4
1100
0.8
0.8
X
X
X
1200
120
160
290
270
300
280
1100
180
180
84
84
180
84
1,2
3
560
7.0
12
X
X
X
ND~(8)il;r
16
23
15
24
15
23
560(2)
7.0(2)
12(2)
99
98
10
98
4, 5
3
900
10
20
800
ND(10)
20
860
ND (10)
10
ND(10)
10
10
10
840
10
10
99
98
10
99
13, 14
4
1300
7
ND(4)
X
X
X
990
16
4
22
7
22
6
1200
17
5
99
>99
11
>99
4,5
3
1200
12
10
1200
17
22
1100
18
18
19
12
18
15
1200
17
15
99
99
16
99
17, 18
4
1200
2
1
1200
6
5
1000
6
5
4
3
4
3
1100
4
3
>99
>99
4
>99
5,6
4
1000
ND(5)
_JNDj(5_)_
1000
ND(5)
5
1000
5
6
6
6
5
7
1000
5
6
>99
>99
6
>99
19,20
4
Note: The detection limit values were used for calculating the mean effluents and percent reductions.
X - Samples not collected
(1) Influent sample was non-detect for the challenge chemical, likely due to sampling error (sampling from the wrong
tap).
(2) The mean influent and effluents are only the start-up sample means. The other influent and effluent data were not
included because of the lack of 3rd tank and 15-hour influent data.
22
-------
Table 4-3. TDS Reduction Data for Organic Chemical Challenges
Aldicarb Benzene Carbofuran Chloroform Dichlorvos Dicrotophos Fenamiphos Mevinphos Oxamyl
TDS TDS TDS TDS TDS TDS TDS TDS TDS
Sample (mg/L) (mg/L) (mg/L) (mg/L) (mg/L) (mg/L) (mg/L) (mg/L) (mg/L)
Start-up Influent
Start-up Effluent, Unit 1
Start-up Effluent, Unit 2
3rd Tank Influent
3rd Tank Effluent, Unit 1
3rd Tank Effluent, Unit 2
15hr. Influent
15hr. Effluent, Unit 1
15hr. Effluent, Unit 2
Post-Rest 1st Draw, Unit 1
Post-Rest 1st Draw, Unit 2
Mean Influent
Mean Effluent, Unit 1
Mean Effluent, Unit 2
Percent Reduction, Unit 1
Percent Reduction, Unit 2
750
30
24
740
14
12
740
15
12
15
12
740
19
15
98
98
830
18
19
790
19
14
790
19
14
19
14
800
19
15
98
98
740
34
46
740
14
14
750
12
12
12
13
740
18
21
98
97
860
20
22
x
X
X
840
24
24
25
25
850
23
24
97
97
830
39
37
x
X
X
840
27
45
28
43
840
31
42
96
95
730
12
13
630
11
13
640
14
11
11
13
670
12
13
98
98
1200
74
55
x
X
X
iioo
59
44
56
39
1200
63
46
95
96
450
15
16
620
13
12
590
13
13
13
12
550
14
13
98
98
750
17
20
750
13
12
740
13
12
13
12
750
14
14
98
98
Strychnine
TDS
(mg/L)
780
18
24
770
12
12
760
12
12
13
13
770
14
15
98
98
Table 4-4. Organic Chemical Challenge Reject Water Data
Aldicarb Benzene Carbofuran Chloroform Dichlorvos Dicrotophos Fenamiphos Mevinphos Oxamyl Strychnine
Sample (Hg/L) (HS/L) (ng/L) (ng/L) (ng/L) (Hg/L) (HS/L) (Hg/L) (HS/L) (Hg/L)
Start-up
1/2 through 1st Tank
3/4 through 1st tank
1/2 through Last Tank
Unit Sampled
2900
1300
1300
1300
7
890
990
1000
1300
3
1100
1300
1300
1100
11
940
1100
1100
1200
1
300*
580
570
510
4
1000
1200
1000
1000
13
680
1600
1600
980
4
810
1300
1300
1200
17
1100
1400
1300
1300
5
260
1200
1100
1100
19
* Reported number is one of the duplicate analyses, there was an analytical error with the second sample, so average not calculated
The RO membrane removed all chemicals but benzene and chloroform by 98% or more.
However, please note that the dichlorvos mean influent, effluents and percent reductions are only
from the start-up samples. Third tank samples were not collected, because the two systems
tested had not yet completed their third tank-fills at the 15-hour point. The 15-hour and post-rest
sample data was not used because the challenge chemical was not detected in the 15-hour
influent samples. It is likely that the influent samples were collected from the wrong sample
port, and the proper challenge water was being fed into the test units since the 15-hour effluent
and post-rest effluent samples all had detectible levels of dichlorvos.
At start-up, the membranes removed greater than 99% of both benzene and chloroform, but the
effluent levels rose after that from sample point to sample point. The maximum effluents were
290 |o,g/L for benzene, and 300 |o,g/L for chloroform. These effluents correspond to percent
reductions of 74% and 73%, respectively, using the overall mean influents for the percent
reduction calculations. Both of these substances are volatile, so perhaps volatility played a role
in their passage through the membrane. They may have absorbed into and diffused through the
membrane material. It is not apparent that benzene or chloroform began to degrade the integrity
of the RO membrane, because the membranes maintained rejection of TDS as detailed in Table
4-3.There is also no evidence in Table 4-3 that any other chemicals adversely affected membrane
TDS rejection.
23
-------
Another possible factor in the lower rejection of benzene and chloroform is the low molecular
weight of the compounds (78.1 and 119.4, respectively). RO membranes are known to be most
effective at removing by size exclusion organic compounds with molecular weights over 200.
However, this does not explain the greater than 99% removal at start-up.
The test plan called for each RO membrane to be challenged with only one of the organic
chemicals. However, units 4 and 5 were used for both the dichlorvos and fenamiphos challenges
after they were already used in other challenges. Unit 4 was first challenged with benzene, and
unit 5 was first challenged with oxamyl. The dichlorvos and fenamiphos challenge data
presented in Table 4-2 are from retests. The influent challenge levels from the first tests were
below the allowable minimum level of 0.5 mg/L. By the time the influent samples had been
analyzed, and then reanalyzed to confirm the low numbers, the test units had been discarded.
Therefore, the retests had to be conducted with units already used for another challenge. The
dichlorvos and fenamiphos data in Table 4-2 does not indicate that the membranes were
compromised at all by exposure to benzene or oxamyl during the first challenges.
4.5 Post-Membrane Carbon Filter Challenges
Based on the RO membrane challenge results, and the criteria discussed in Section 3.1.2, the
post-membrane carbon filter was challenged with benzene, chloroform, and mercury. The target
challenge levels were the maximum effluent levels measured during the RO membrane
challenges. Using the data from Section 4.1.1, the filters were operated at 0.3 gpm on an
operation cycle where the "on" portion was 19 minutes, and the "off portion was 3 hours and 45
minutes.
The carbon challenge results are shown below in Table 4-5. Each data point is the arithmetic
mean of the triplicate sample analyses. All individual sample values constituting the triplicate
analyses are presented in Table A-8 in Appendix A. The water chemistry data for these
challenges can be found in Table A-9 of Appendix A.
The post-membrane carbon filters removed 98% of the mercury challenge, and greater than 99%
of the benzene and chloroform challenges.
An examination of the data in Tables 4-1, 4-2 and 4-5 shows that the full WP-4V system with the
RO membrane and post-membrane carbon filter working in concert removed all of the challenge
chemicals by 98% or more.
24
-------
Table 4-5. Post-Membrane Carbon Filter Challenge Data
Benzene Chloroform Mercury
Sample (H-g/L) (H-g/L) (H-g/L)
Target Influent Level
Start-up Influent
Start-up Effluent, Unit 1
Start-up Effluent, Unit 2
290
280
ND (0.5)
ND (0.5)
300
300
ND (0.5)
740
820
22
28
7.5 Hours Effluent, Unit 1 ND (0.5) ND (0.5) 1.3
7.5 Hours Effluent, Unit 2 ND (0.5) ND (0.5) 1.3
15"Hours Influent 290 300 570
15 Hours Effluent, Unit 1 0.5 ND (0.5) 5.4
15 Hours Effluent, Unit 2 ND (0.5) ND (0.5) 1.3
Mean Influent 300 300 800
Mean Effluent, Unit 1 0.5 ND (0.5) 9.6
Mean Effluent, Unit 2 ND (0.5) ND (0.5) 10
Percent Reduction, Unit 1 > 99 > 99 99
Percent Reduction, Unit 2 >99 >99 99
Overall Mean Effluent 0.5 ND (0.5) 9.8
Overall Percent Reduction >99 > 99 99
Units Tested (Unit #'s) 3,4 5,6 7,8
Note: The detection limit values were used for calculating the mean effluents and percent reductions.
25
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Chapter 5
QA/QC
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.
5.2 Test Procedure QA/QC
NSF testing laboratory staff conducted the tests by following an NSF SOP created specifically
for the tests. NSF QA Department Staff performed an informal audit during testing to ensure the
proper procedures were followed.
All water chemistry measurements were within the specifications in Sections 3.2.3.1 and 3.2.3.2,
except for the challenge water pH for the cadmium, cesium, and strontium challenge. The
test/QA plan called for the pH to be between 6.0 and 6.5 to ensure that the metals remained
dissolved. However, the lab technician responsible for the challenge instead adjusted the pH to
7.5 + 0.5, as was done for the organic chemical challenges. The substances' solubilities in water
are all much higher than 1 mg/L, so it is unlikely that any significant amounts precipitated out of
solution during the challenges, thus being mechanically filtered instead of being ionically
rejected by the membrane.
All chemical challenge levels for the RO membranes were within the allowable range of 1.0 +
0.5 mg/L, except for dichlorvos at the 15-hour sample point. As discussed in Section 4.4.2, the
challenge chemical was not detected in the 15-hour influent samples. The samples were
analyzed three times, each time no dichlorvos was detected. The laboratory fortified blanks and
laboratory fortified blank duplicates showed acceptable recovery of the surrogates, internal
standards, and dichlorvos. It is likely that the influent samples were collected from the wrong
sample port, and the proper challenge water was being fed into the test units since the 15-hour
effluent and post-rest effluent samples all had detectible levels of dichlorvos.
5.3 Sample Handling
All samples analyzed by the NSF Chemistry Laboratory were labeled with unique ID numbers.
These ID numbers appear on the NSF laboratory reports for the tests. All samples were analyzed
within allowable holding times.
26
-------
5.4 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, every analytical instrument has an NSF SOP
governing its use.
5.5 Documentation
All laboratory activities were documented using specially prepared laboratory bench sheets and
NSF laboratory reports. Data from the bench sheets and laboratory reports were entered into
Microsoft Excel spreadsheets. These spreadsheets were used to calculate average influents and
effluents, and percent reductions for each challenge chemical. One hundred percent of the data
entered into the spreadsheets was checked by a reviewer to confirm all data and calculations
were correct.
5.6 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.
5.7 Data Quality Indicators
The quality of data generated for this ETV is established through four indicators of data quality:
representativeness, accuracy, precision, and completeness.
5.7.1 Representativeness
Representativeness refers to the degree to which the data accurately and precisely represent the
conditions or characteristics of the parameter represented by the data, or the expected
performance of the RO system under normal use conditions. Representativeness was ensured by
consistent execution of the test protocol for each challenge chemical, including timing of sample
collection, sampling procedures, and sample preservation. Representativeness was also ensured
by using each analytical method at its optimum capability to provide results that represent the
most accurate and precise measurement it is capable of achieving.
5.7.2 Accuracy
Accuracy was quantified as the percent recovery of the parameter in a sample of known quantity.
Accuracy was measured through use of LFB and/or LFM samples of a known quantity, and
certified standards during calibration of the instrument. The following equation was used to
calculate percent recovery:
27
-------
Percent ReCOVery = 100 X [(Xknown - XmeasurecD/Xknown]
where: Xkn0wn = known concentration of the measured parameter
= measured concentration of parameter
The accuracy of the benchtop chlorine, pH, TDS, and turbidity meters were checked daily during
the calibration procedures using certified check standards. For samples analyzed in batches
(gravimetric TDS, TOC, all challenge chemicals), certified QC standards, and LFB and/or LFM
samples were run with each batch.
The percent recoveries of all fortified samples and standards were within the allowable limits for
all analytical methods.
5.7.3 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 gravimetric
TDS and TOC analyses. LFB and/or LFM samples were analyzed to measure precision for the
challenge chemical analyses. Duplicate drinking water samples were analyzed as part of the
daily calibration process for the benchtop chlorine, pH, TDS, and turbidity meters.
Precision of the duplicate analyses was measured by use of the following equation to calculate
relative percent deviation (RPD):
RPD =
x200
where:
Sl = sample analysis result; and
S2 = sample duplicate analysis result.
Precision of the LFB and LFM sample analyses was measured through calculation of the RSD as
follows:
%RSD = S(100)/Xaverage
where: S = standard deviation and
Xaverage = the arithmetic mean of the recovery values.
Standard Deviation is calculated as follows:
Standard Deviation = 1|
n-\
28
-------
Where: X; = the individual recovery values;
X = the arithmetic mean of then recovery values; and
n = the number of determinations.
All RPDs were within NSF's established allowable limits for each parameter.
5.7.4 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. Completeness Requirements
Number of Samples per Parameter
and/or Method Percent Completeness
(MO 80%
11-50 90%
> 50 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.
5.7.4.1 Number of Systems Tested
Twenty systems were tested, as called for in the test/QA plan. However the reported results did
not come from twenty systems. As discussed in Section 4.4.2, the results from the first
dichlorvos and fenamiphos challenges were not reported, and the systems used for those tests
were discarded before it was known that the tests would have to be conducted over again.
Therefore, the reported results came from only 16 systems. This gives a completeness of 80%
for the number of systems tested.
5.7.4.2 Water Chemistry Measurements
All of the planned samples were collected, and acceptable results were reported for all water
chemistry measurements.
29
-------
5.7.4.3 Challenge Chemicals
All planned samples were collected, but results for four dichlorvos challenge samples were
deemed unacceptable due to analytical or sampling error. The samples in question are the three
15-hour influent triplicate samples, and one of the start-up reject water duplicate samples.
Discarding these sample results gives acceptable results from 30 of the 34 dichlorvos samples
collected, for a completeness of 88%.
30
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Chapter 6
References
APHA, AWWA and WEF (1998). Standard Methods for Examination of Water and
Wastewater. 20th ed. Washington, D.C. APHA.
NSF International (2005). NSF/ANSI53-2005, Drinking water treatment units - health effects.
Ann Arbor, MI, NSF International.
NSF International (2005). NSF/ANSI 58 - 2005, Reverse osmosis drinking water treatment
systems. Ann Arbor, MI, NSF International.
Slovak, Robert (2000). A Practical Application Manual for Residential, Point of Use Reverse
Osmosis Systems. Lisle, IL, Water Quality Association
USEPA (2004). Water Security Research and Technical Support Action Plan. EPA/600/R-
04/063.
31
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Appendix A
Conditioning and Chemical Challenges Data Tables
-------
Table A-l. RO Membrane Conditioning Water Chemistry Data
Sample
Day 1
Day 2
Day 3
Day 4
Day 5
Day 6
Day?
Group A, Units 1-11
PH
Temperature (°C)
Total Chlorine (mg/L)
TDS (mg/L)
Turbidity (NTU)
Group B, Units 12-20
PH
Temperature (°C)
Total Chlorine (mg/L)
TDS (mg/L)
Turbidity (NTU)
7.9
26
ND (0.05)
760
ND(O.l)
7.3
26
ND (0.05)
750
ND(O.l)
7.2
26
ND (0.05)
780
ND(O.l)
7.2
25
ND (0.05)
740
ND(O.l)
7.1
26
ND (0.05)
750
ND(O.l)
7.7
26
ND (0.05)
780
0.1
7.9
26
ND (0.05)
740
0.1
7.6
25
ND (0.05)
780
ND(O.l)
7.2
26
ND (0.05)
780
ND(O.l)
7.7
26
ND (0.05)
780
0.1
7.0
24
0.06
780
ND(O.l)
7.9
26
ND (0.05)
740
ND(O.l)
7.5
26
ND (0.05)
750
0.2
7.9
24
ND (0.05)
740
0.1
Table A-2. RO Membrane TDS Reduction System Check Data
Sample
PH
Xotal Influent Effluent
Temperature Chlorine Turbidity TDS TDS Percent
(°C) (mg/L) (NTU) (mg/L) (mg/L) Reduction
Group 1 Influent
Unit 1
Unit 2
Unit3
Unit 4
UnitS
Unite
Unit?
Unit 8
Unit 9
Unit 10
Unit 11
Group 2 Influent
Unit 12
Unit 13
Unit 14
Unit 15
Unit 16
Unit 17
Unit 18
Unit 19
Unit 20
7.4
26
ND(0.05) ND(O.l)
780
7.4
25
ND (0.05)
0.1
750
17
18
23
19
18
16
19
17
19
22
19
19
19
18
16
17
18
17
15
17
98
98
97
98
98
98
98
98
98
97
98
97
97
98
98
98
98
98
98
98
A-l
-------
Table A-3. Carbon Filter Conditioning Influent Water Chemistry
Sample Point
Chloroform Temperature Total Organic Turbidity
Qg/L) pH (°C) Carbon (mg/L) (NTU)
Unit 1, Start-Up
Unit 1, 25% of Capacity
Unit 1,50% of Capacity
Unit 2, Start-Up
Unit 2, 25% of Capacity
Unit 2, 50% of Capacity
Unit 3, Start-Up
Unit 3, 25% of Capacity
Unit 3, 50% of Capacity
Unit 4, Start-Up
Unit 4, 25% of Capacity
Unit 4, 50% of Capacity
Unit 5, Start-Up
Unit 5, 25% of Capacity
UnitS, 50% of Capacity
Unit 6, Start-Up
Unit 6, 25% of Capacity
Unit 6, 50% of Capacity
Unit 7, Start-Up
Unit 7, 25% of Capacity
Unit 7, 50% of Capacity
Unit 8, Start-Up
UnitS, 25% of Capacity
Unit 8, 50% of Capacity
Influent
Effluent
Influent
Effluent
Influent
Effluent
Influent
Effluent
Influent
Effluent
Influent
Effluent
Influent
Effluent
Influent
Effluent
Influent
Effluent
Influent
Effluent
Influent
Effluent
Influent
Effluent
Influent
Effluent
Influent
Effluent
Influent
Effluent
Influent
Effluent
Influent
Effluent
Influent
Effluent
Influent
Effluent
Influent
Effluent
Influent
Effluent
Influent
Effluent
Influent
Effluent
Influent
Effluent
430
ND(0.5)
460
ND(0.5)
480
ND(0.5)
430
ND(0.5)
470
ND(0.5)
500
ND(0.5)
430
ND(0.5)
490
ND(0.5)
470
ND(0.5)
430
ND(0.5)
490
ND(0.5)
520
ND(0.5)
430
ND(0.5)
490
ND(0.5)
470
ND(0.5)
430
ND(0.5)
470
160
480
ND(0.5)
430
ND(0.5)
470
ND(0.5)
480
ND(0.5)
430
ND(0.5)
470
ND(0.5)
500
ND(0.5)
7.3
7.4
7.4
7.3
7.4
7.4
7.3
7.4
7.4
7.3
7.4
7.4
7.4
7.4
7.3
7.4
7.4
7.3
7.4
7.4
7.3
7.4
7.4
7.3
21
22
21
21
22
21
21
21
21
21
21
21
22
22
22
22
22
22
22
21
21
22
21
21
* TOC measured after addition of chloroform, which was in a methanol solution.
due to the methanol.
20*
2.9
2.9
20*
2.9
2.9
20*
2.9
2.9
20*
2.9
3.0
20*
2.9
2.9
20*
2.9
2.9
20*
2.9
2.9
20*
2.9
2.9
High TOC
0.2
0.1
ND(O.l)
0.2
0.1
ND(O.l)
0.2
ND(O.l)
0.8
0.2
ND(O.l)
0.8
ND(O.l)
0.1
ND(O.l)
ND(O.l)
0.1
ND(O.l)
ND(O.l)
ND(O.l)
ND(O.l)
ND(O.l)
ND(O.l)
ND(O.l)
readings were
A-2
-------
Table A-4. RO Membrane Inorganic Chemicals Challenge Data
Sample
Start-up Influent
Triplicate Sample 1
Triplicate Sample 2
Triplicate Sample 3
Mean
Start-up Effluent, Unit 1
Triplicate Sample 1
Triplicate Sample 2
Triplicate Sample 3
Mean
Start-up Effluent, Unit 2
Triplicate Sample 1
Triplicate Sample 2
Triplicate Sample 3
Mean
3rd Tank Influent
Triplicate Sample 1
Triplicate Sample 2
Triplicate Sample 3
Mean
3rd Tank Effluent, Unit 1
Triplicate Sample 1
Triplicate Sample 2
Triplicate Sample 3
Mean
3rd Tank Effluent, Unit 2
Triplicate Sample 1
Triplicate Sample 2
Triplicate Sample 3
Mean
1 5-Hour Influent
Triplicate Sample 1
Triplicate Sample 2
Triplicate Sample 3
Mean
15-Hour Effluent, Unit 1
Triplicate Sample 1
Triplicate Sample 2
Triplicate Sample 3
Mean
15-Hour Effluent, Unit 2
Triplicate Sample 1
Triplicate Sample 2
Triplicate Sample 3
Mean
Post-Rest 1st Draw, Unit 1
Post-Rest 1st Draw, Unit 2
Post-Rest 2nd Sample, Unit 1
Triplicate Sample 1
Triplicate Sample 2
Triplicate Sample 3
Mean
Post-Rest 2nd Sample, Unit 2
Triplicate Sample 1
Triplicate Sample 2
Triplicate Sample 3
Mean
Cadmium
(Hg/L)
1000
1000
1000
1000
ND (0.3)
ND (0.3)
ND (0.3)
ND (0.3)
ND (0.3)
ND (0.3)
0.3
0.3
910
890
880
890
0.5
0.4
0.4
0.4
ND (0.3)
ND (0.3)
0.3
0.3
840
810
830
830
0.6
0.4
0.5
0.5
ND (0.3)
ND (0.3)
ND (0.3)
ND (0.3)
0.6
ND (0.3)
0.6
0.6
0.6
0.6
ND (0.3)
ND (0.3)
ND (0.3)
ND (0.3)
Cesium
(re/L)
640
640
640
640
8
7
8
8
6
7
7
7
710
700
690
700
12
11
12
12
10
10
10
10
650
630
660
650
13
12
13
13
11
11
11
11
13
11
13
14
13
13
11
12
11
11
Mercury
(MS/L)
1200
1200
1200
1200
430
460
510
470
480
550
530
520
1300
1200
1300
1300
670
670
660
670
670
660
670
670
1100
1100
1300
1200
710
700
710
710
730
720
720
720
720
740
710
700
720
710
740
740
740
740
Strontium
(re/L)
940
950
920
940
ND(1)
1
ND(1)
1
ND(1)
ND(1)
ND(1)
ND.C1)
960
960
930
950
ND(1)
ND(1)
ND(1)
ND(1)
ND(1)
ND(1)
ND(1)
ND(1)
870
850
860
860
ND(1)
ND(1)
ND(1)
ND(1)
ND(1)
ND(1)
ND(1)
ND(1)
ND('i)
ND(1)
ND(1)
ND(1)
ND(1)
ND(1)
ND(1)
ND(1)
ND(1)
ND(1)
A-3
-------
Table A-5. RO Membrane Organic Chemical Challenge Data
Aldicarb Benzene Carbofuran Chloroform Dichlorvos Dicrotophos Fenamiphos Mevinphos Oxamyl Strychnine
Sample
Start-up Influent
Triplicate Sample 1
Triplicate Sample 2
Triplicate Sample 3
Mean
Start-up Effluent, Unit 1
Triplicate Sample 1
Triplicate Sample 2
Triplicate Sample 3
Mean
Start-up Effluent, Unit 2
Triplicate Sample 1
Triplicate Sample 2
Triplicate Sample 3
Mean
3rd Tank Influent
Triplicate Sample 1
Triplicate Sample 2
Triplicate Sample 3
Mean
3rd Tank Effluent, Unit 1
Triplicate Sample 1
Triplicate Sample 2
Triplicate Sample 3
Mean
3rd Tank Effluent, Unit 2
Triplicate Sample 1
Triplicate Sample 2
Triplicate Sample 3
Mean
15-Hour Influent
Triplicate Sample 1
Triplicate Sample 2
Triplicate Sample 3
Mean
1 5-Hour Effluent, Unit 1
Triplicate Sample 1
Triplicate Sample 2
Triplicate Sample 3
Mean
15-Hour Effluent, Unit 2
Triplicate Sample 1
Triplicate Sample 2
Triplicate Sample 3
Mean
Post-Rest 1st Draw, Unit 1
Post-Rest 1st Draw, Unit 2
Post-Rest 2nd Sample, Unit 1
Triplicate Sample 1
Triplicate Sample 2
Triplicate Sample 3
Mean
Post-Rest 2nd Sample, Unit 2
Triplicate Sample 1
Triplicate Sample 2
Triplicate Sample 3
Mean
(Hg/L)
1100
1100
1100
1100
3
10
16
10
ND(1)
4
8
4
1100
1100
1100
1100
12
12
12
12
7
8
7
7
1200
1200
1100
1200
12
12
12
12
8
8
8
8
12
8
12
12
12
12
8
8
8
8
(|xg/L)
910
900
880
900
ND(0.5)
ND(0.5)
ND(0.5)
ND (0.5)
ND(0.5)
0.5
ND(0.5)
0.5
1000
1300
1000
1100
120
160
140
140
96
100
100
99
1300
1100
1300
1200
230
220
220
220
140
160
140
150
270
190
290
280
310
290
190
180
190
190
(|xg/L)
1000
1000
1000
1000
3
3
3
3
3
3
3
3
1100
1100
1100
1100
4
4
4
4
5
5
5
5
1100
1100
1100
1100
4
4
4
4
5
5
5
5
4
5
4
4
4
4
5
5
5
5
(|xg/L)
1100
1000
1100
1100
0.6
0.6
1.3
0.8
0.7
0.8
1.0
0.8
X
X
X
X
X
X
X
X
X
1200
1200
1200
1200
110
140
120
120
150
170
170
160
290
270
300
290
310
300
280
280
280
280
(|xg/L)
590
550
540
560
1.7
8.4
11
7.0
3.9
15
18
12
X
X
X
X
X
X
X
X
X
ND (8.0)
ND (8.0)
ND (8.0)
ND (8.0)
15
16
16
16
24
23
23
23
15
24
15
15
15
15
23
23
23
23
(|xg/L)
800
1000
900
900
10
ND(10)
10
10
10
20
20
20
800
700
800
770
ND (10)
ND (10)
ND (10)
ND (10)
20
20
10
20
1000
870
700
860
ND (10)
ND(10)
ND(10)
ND (10)
10
20
10
10
ND"(10)
10
ND(10)
10
ND(10)
10
ND(10)
10
10
10
(|xg/L)
1400
1400
1200
1300
ND(4)
8
10
7
ND(4)
ND(4)
ND(4)
ND (4)
X
X
X
X
X
X
X
X
X
1000
990
980
990
18
14
15
16
4
4
4
4
22
7
23
19
23
22
7
6
6
6
(re/L)
1200
1200
1100
1200
7.1
14
15
12
6.2
12
13
10
1400
1200
1000
1200
16
17
17
17
27
18
20
22
1200
1100
1100
1100
17
19
18
18
18
17
18
18
19
12
18
18
17
18
13
16
16
15
(|xg/L)
1200
1200
1200
1200
ND(1)
1
3
2
ND(1)
2
1
1
1200
1200
1200
1200
6
6
6
6
4
5
5
5
1000
1100
1000
1000
6
6
6
6
5
5
5
5
4
3
4
4
4
4
3
3
3
3
(|xg/L)
1000
1000
1000
1000
ND(5)
ND(5)
ND(5)
ND(5)
ND(5)
ND(5)
ND(5)
ND(5)
1000
1000
1000
1000
ND(5)
ND(5)
ND(5)
ND(5)
5
5
5
5
1000
1000
1000
1000
ND(5)
5
5
5
6
6
6
6
6
6
5
5
5
5
7
7
7
7
A-4
-------
Table A-6. RO Membrane Challenges Water Chemistry Data
Sample
Start-up Influent
PH
Temperature (°C)
Total Chlorine (mg/L)
Turbidity (NTU)
15-Hour Influent
PH
Temperature (°C)
Total Chlorine (mg/L)
Turbidity (NTU)
Cd, Cs, Sr
Challenge
7.6
24
ND (0.05)
0.3
7.3
24
ND (0.05)
ND(O.l)
Mercury
Challenge
6.5
25
ND (0.05)
0.1
6.1
24
ND (0.05)
ND(O.l)
Aldicarb Benzene
Challenge Challenge
7.4 7.3
24 24
ND (0.05) ND (0.05)
ND(O.l) 0.2
7.3 7.2
24 24
ND (0.05) ND (0.05)
ND(O.l) ND(O.l)
Carbofuran Chloroform
Challenge Challenge
7.5
24
ND (0.05)
ND(O.l)
7.3
24
ND (0.05)
ND(O.l)
7.5
24
ND (0.05)
0.1
7.1
24
ND (0.05)
0.5
Dichlorvos
Challenge
7.7
25
ND (0.05)
ND(O.l)
7.3
22
ND (0.05)
ND(O.l)
Dicrotophos
Challenge
7.4
26
ND (0.05)
ND(O.l)
7.4
26
ND (0.05)
0.5
Fenamiphos
Challenge
7.4
25
ND (0.05)
ND(O.l)
7.3
25
ND (0.05)
0.2
Mevinphos
Challenge
7.4
25
ND (0.05)
0.1
7.5
25
ND (0.05)
ND(O.l)
Oxamyl
Challenge
7.4
24
ND (0.05)
ND(O.l)
7.3
24
ND (0.05)
ND(O.l)
Strychnine
Challenge
7.6
25
ND (0.05)
ND(O.l)
7.3
24
ND (0.05)
ND(O.l)
Table A-7. RO Membrane Organic Chemical Challenges Reject Water Data
Sample
Aldicarb
(Mg/L)
Benzene
(Mg/L)
Carbofuran
(Mg/L)
Chloroform
(Mg/L)
Dichlorvos
(Mg/L)
Dicrotophos
(Mg/L)
Fenamiphos Mevinphos
(Mg/L) (Mg/L)
Oxamyl Strychnine
(Mg/L) (Mg/L)
Start-up
Duplicate Sample 1 2900 860 1100 930 30(1) 1000 810 680 1100 180
Duplicate Sample 2 2900 910 1100 940 300 900 540 940 1100 330
Mean 2900 890 1100 940 300 950 680 810 1100 260
1/2 Through First Tank
Duplicate Sample 1 1300 1000 1300 1100 590 1100 1500 1300 1400 1200
Duplicate Sample 2 1300 980 1300 1100 570 1200 1600 1200 1400 1200
Mean 1300 990 1300 1100 580 1200 1600 1300 1400 1200
3/4 Through First Tank
Duplicate Sample 1 1200 920 1300 1100 570 900 1500 1200 1300 1100
Duplicate Sample 2 1300 1100 1200 1100 570 1000 1600 1300 1300 1100
Mean 1300 1000 1300 1100 570 970 1600 1300 1300 1100
1/2 Through Last Tank
Duplicate Sample 1 1200 1300 1100 1200 500 900 950 1200 1200 1100
Duplicate Sample 2 1300 1300 1100 1200 520 1000 1000 1200 1300 1100
Mean 1300 1300 1100 1200 510 970 980 1200 1300 1100
(1) Result not used for mean calculation, due to a likely dilution error.
A-5
-------
Table A-8. Post-Membrane Carbon Filter Challenges Data
Sample
Target Influent Level
Start-up Influent
Triplicate Sample 1
Triplicate Sample 2
Triplicate Sample 3
Mean
Start-up Effluent, Unit 1
Triplicate Sample 1
Triplicate Sample 2
Triplicate Sample 3
Mean
Start-up Effluent, Unit 2
Triplicate Sample 1
Triplicate Sample 2
Triplicate Sample 3
Mean
7.5 Hours Influent
Triplicate Sample 1
Triplicate Sample 2
Triplicate Sample 3
Mean
7.5 Hours Effluent, Unit 1
Triplicate Sample 1
Triplicate Sample 2
Triplicate Sample 3
Mean
7.5 Hours Effluent, Unit 2
Triplicate Sample 1
Triplicate Sample 2
Triplicate Sample 3
Mean
1 5 Hours Influent
Triplicate Sample 1
Triplicate Sample 2
Triplicate Sample 3
Mean
15 Hours Effluent, Unit 1
Triplicate Sample 1
Triplicate Sample 2
Triplicate Sample 3
Mean
15 Hours Effluent, Unit 2
Triplicate Sample 1
Triplicate Sample 2
Triplicate Sample 3
Mean
Mercury
(re/L)
740
810
810
840
820
8.9
17
39
22
40
37
7.4
28
1000
1000
1000
1000
1.3
1.3
1.4
1.3
1.3
1.2
1.4
1.3
590
570
550
570
5.6
5.3
5.3
5.4
1.5
1.0
1.3
1.3
Benzene
(re/L)
290
280
280
280
280
ND(0.5)
ND(0.5)
ND(0.5)
ND (0.5)
ND(0.5)
ND(0.5)
ND(0.5)
ND (0.5)
300
340
350
330
ND(0.5)
ND(0.5)
ND(0.5)
ND (0.5)
ND(0.5)
ND(0.5)
ND(0.5)
_JNDJO.SL
290
290
290
290
0.5
0.5
0.5
0.5
ND(0.5)
ND(0.5)
ND(0.5)
ND (0.5)
Chloroform
(re/L)
300
300
300
300
300
ND(0.5)
ND(0.5)
ND(0.5)
ND (0.5)
ND(0.5)
ND(0.5)
ND(0.5)
ND(0.5)
310
310
310
310
ND(0.5)
ND(0.5)
ND(0.5)
ND (0.5)
ND(0.5)
ND(0.5)
ND(0.5)
ND (0.5)
300
300
300
300
ND(0.5)
ND(0.5)
ND(0.5)
ND (0.5)
ND(0.5)
ND(0.5)
ND(0.5)
ND (0.5)
A-6
-------
Table A-9. Post-Membrane Carbon Filter Challenges Water Chemistry Data
Sample
Mercury
Challenge
Benzene
Challenge
Chloroform
Challenge
Start-up Influent
pH 7.3 7.3 7.3
Temperature (°C) 22 21 22
Total Chlorine (mg/L) 0.83 0.57 0.79
TOC(mg/L) 3.0 57 50
TDS(mg/L) 300 330 350
Turbidity (NTU) 0.2 ND(O.l) ND(O.l)
7.5 Hour Influent
pH 7.2 7.3 7.4
Temperature (°C) 22 22 22
Total Chlorine (mg/L) 0.96 1.5 1.5
TOC (mg/L) 2.8 53 50
TDS (mg/L) 330 320 340
Turbidity (NTU) 0.2 0.1 0.1
15 Hour Influent
pH 7.2 7.1 7.3
Temperature (°C) 20 22 22
Total Chlorine (mg/L) 1.2 0.68 1.8
TOC (mg/L) 3.2 53 50
TDS (mg/L) 320 320 350
Turbidity (NTU) O5 O2 ND(O.l)
A-7
------- |