THE ENVIRONMENTAL TECHNOLOGY VERIFICATION
PROGRAM
&EPA
U.S. Environmental Protection Agency
NSF International
ETV Joint Verification Statement
TECHNOLOGY TYPE: POINT-OF-ENTRY DRINKING WATER TREATMENT
SYSTEM
APPLICATION: REMOVAL OF CHEMICAL AND MICROBIAL
CONTAMINANTS IN DRINKING WATER
PRODUCT NAME: M-2400 REVERSE OSMOSIS SYSTEM
VENDOR: WATTS PREMIER, INC.
ADDRESS: 1725 WEST WILLIAMS DRIVE, SUITE C-20
PHOENIX, AZ 85027
PHONE: 800-752-5582
INTERNET HTTP://WWW.WATTSPREMIER.COM
NSF International (NSF) manages the Drinking Water Systems (DWS) Center under the U.S.
Environmental Protection Agency's (EPA) Environmental Technology Verification (ETV) Program. The
DWS Center recently evaluated the performance of the Watts Premier, Inc. M-2400 Point-of-Entry (POE)
Reverse Osmosis (RO) Drinking Water Treatment System. NSF performed all of the testing activities and
also authored the verification report and this verification statement. The verification report contains a
comprehensive description of the testing activities.
The EPA created the ETV Program to facilitate the deployment of innovative or improved environmental
technologies through performance verification and dissemination of information. The goal of the ETV
Program is to further environmental protection by accelerating the acceptance and use of improved and
more cost-effective technologies. ETV seeks to achieve this goal by providing high-quality, peer-
reviewed data on technology performance to those involved in the design, distribution, permitting,
purchase, and use of environmental technologies.
ETV works in partnership with recognized standards and testing organizations, stakeholder groups
(consisting of buyers, vendor organizations, and permitters), and with the full participation of individual
technology developers. The program evaluates the performance of innovative technologies by developing
test plans that are responsive to the needs of stakeholders, conducting field or laboratory tests (as
appropriate), collecting and analyzing data, and preparing peer-reviewed reports. All evaluations are
conducted in accordance with rigorous quality assurance protocols to ensure that data of known and
adequate quality are generated and that the results are defensible.
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ABSTRACT
The Watts Premier M-2400 POE RO Drinking Water Treatment System was tested at the NSF Drinking
Water Treatment Systems Laboratory for removal of the viruses fir and MS2, the bacteria Brevundimonas
diminuta, and chemicals aldicarb, benzene, cadmium, carbofuran, cesium, chloroform, dichlorvos,
mercury, methomyl, mevinphos, oxamyl, paraquat, sodium fluoroacetate, strontium, and strychnine. The
microorganisms used in this study served as surrogates for pathogenic bacteria and viruses that may be
introduced into drinking water through accidental or intentional contamination. The target chemical
challenge concentration was 1 milligram per liter (mg/L). The target microorganism challenge
concentrations were IxlO6 colony forming units per 100 milliliters (CFU/100 mL) for B. diminuta, and
IxlO4 plaque forming units per milliliter (PFU/mL) for the viruses. NSF also separately tested an
optional post-membrane activated carbon filter that Watts Premier offers, the Flowmatic MAXVOC FF-
975. This filter was only tested with the chemicals not removed to 20 micrograms per liter (ng/L) or
lower by the RO membrane. One M-2400 system and one MAXVOC FF-975 carbon filter were tested.
Each challenge was 30 minutes in length. The M-2400 removed a minimum of 2.9 logio of the viruses,
and 2.5 logio of B. diminuta. The M-2400 removed all of the chemicals by 96% or more, except for
mercury, which was only removed by 38%. Based on the M-2400 chemical challenge results, the
MAXVOC FF-975 filter was challenged with chloroform, dichlorvos, mercury, and methomyl. The
MAXVOC FF-975 removed 96% or more of the four chemicals. The M-2400 and MAXVOC FF-975
together removed 99% or more of all chemicals but sodium flouroacetate, whose percent reduction was
limited by its high detection limit of 20 |o,g/L.
TECHNOLOGY DESCRIPTION
The following technology description was provided by the manufacturer and has not been verified.
The M-2400 is a skid-mounted RO system that utilizes one 4" x 40" RO membrane with a surface area of
82 square feet (ft2). The membrane is fed by a 330 gallons-per-hour booster pump. The system also
includes a pre-membrane sediment or activated carbon filter, an optional post-membrane activated carbon
filter, and an optional product water storage tank. The M-2400 has a control panel with pressure gauges
and flow meters to calibrate the system and monitor performance. The skid measures 27" wide, 32" deep,
and 57" high. The system as tested did not include any pre-membrane filters or a storage tank, but did
include a post-membrane carbon filter. Watts Premier uses the Flowmatic MAXVOC-FF975 activated
carbon filter as an optional post-membrane treatment step for organic chemical removal. The MAXVOC
FF-975 is a 4.625" x 9.75" block filter with a rated service flow rate of 2 gallons per minute (gpm).
Under normal operation, raw water entering the system first passes through the sediment or carbon pre-
filter to remove large particles. The pre-membrane filter effluent is then sent through the booster pump
and then on to the RO membrane. Water passing through the membrane is collected in a permeate line
that can be plumbed to a storage tank. A portion of the concentrate water from the membrane module can
be recycled back into the feed water line depending on the desired recovery for the system. The
remainder of the concentrate is sent to the drain. The recycle rate can be manually adjusted with a needle
control valve.
VERIFICATION TESTING DESCRIPTION
Test Site
The testing site was the Drinking Water Treatment Systems Laboratory at NSF in Ann Arbor, Michigan.
A description of the test apparatus can be found in the verification report. The testing was conducted in
January through April of 2006.
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Methods and Procedures
The testing methods and procedures are detailed in the Test/QA Plan for Verification Testing of the Watts
Premier M-2400 Point-of-Entry Reverse Osmosis Drinking Water Treatment System for Removal of
Microbial and Chemical Contaminants. One M-2400 system and one MAXVOC FF-975 filter were
tested separately. The M-2400 was challenged with the chemicals, bacteria, and viruses listed in Table
VS-1. The MAXVOC filter was only challenged with the chemicals that the RO membrane did not
remove to 20 |o,g/L or below.
The challenge chemicals were chosen from a list of chemicals of interest supplied by the EPA. The
challenge bacteria and viruses were recommended by an advisory panel because they are smaller than
most other viruses and bacteria, and so provide a conservative estimate of performance. In addition to
using B. diminuta strain 19146 as obtained from American Type Culture Collection (ATCC), NSF also
used a genetically engineered strain of the organism. The NSF Microbiology Laboratory inserted into a
culture of B. diminuta a gene conferring resistance to the antibiotic kanamycin (KanR5. diminuta). This
allowed the Microbiology Laboratory to use a growth media amended with 50 |o,g/L of kanamycin to
prohibit heterotrophic plate count (HPC) bacteria in the treated water samples from growing along with
the kanamycin resistant B. diminuta.
Table VS-1. Challenge Chemicals and Microorganisms
Chemicals Bacteria Viruses
Aldicarb Brevundimonas diminuta fr
Benzene MS2
Cadmium Chloride
Carbofuran
Cesium Chloride (nonradioactive isotope)
Chloroform
Dichlorvos
Mercuric Chloride
Methomyl
Mevinphos
Oxamyl
Paraquat
Sodium Fluoroacetate
Strontium Chloride (nonradioactive isotope)
Strychnine
The target challenge concentrations were as follows:
• Chemicals: 1 ± 0.5 mg/L;
• B. diminuta: > IxlO6 CFU/100 mL; and
• MS2 and fr: > IxlO4 PFU/mL.
The M-2400 was plumbed to a test rig in the NSF testing lab and was calibrated for operation according
to the instructions in the M-2400 operation manual.
The M-2400 was challenged with each organism or chemical individually, except for cadmium, cesium,
and strontium, which were combined into one challenge. Each challenge was 30 minutes in length. For
the microbial challenges, influent and permeate samples were collected for organism enumeration at start-
up, after 15 minutes of operation, and after 30 minutes of operation. For the chemical challenges, influent
and permeate samples were collected at start-up and 30 minutes. All samples were analyzed in triplicate.
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The MAXVOC FF-975 was conditioned with water containing chloroform prior to being challenged. The
purpose of the conditioning was to load the carbon with chloroform to a degree that simulated
contaminant loading halfway through its effective lifespan. The MAXVOC FF-975 chemical challenges
were also 30 minutes in length. As described above, the filter was only challenged with the chemicals
that the RO membrane did not remove to 20 |o,g/L or below. Based on this criterion, the filter was
challenged with chloroform, dichlorvos, mercury, and methomyl. The target challenge concentrations
were the maximum permeate levels measured during the RO membrane challenges. The target flow rate
for the challenges was 1.85 gpm, which was the highest permeate flow rate measured during the RO
membrane challenges.
VERIFICATION OF PERFORMANCE
The results of the M-2400 microbial challenges are presented below in Tables VS-2 and VS-3. The
triplicate influent and permeate counts for each sample point were averaged by calculating geometric
means. The mean organism counts for each sample point were then averaged geometrically to give an
overall mean influent and permeate count for each challenge. The overall mean counts are presented
here. These counts were logio transformed, and logio reductions were calculated for each challenge.
Table VS-2. M-2400 Virus Challenge Results
Challenge
Mean Influent
(PFU/mL)
of
Influent
Mean Permeate
(PFU/mL)
Log™ of
Effluent
Log1?
Reduction
fr
MS2
9.4xl04
5.5xl04
5.0
4.7
121
49
2.1
1.7
2.9
3.1
Table VS-3. M-2400 Bacteria Challenge Results
Challenge
Mean Influent
(CFU/100 mL)
Log10 of
Influent
Mean Permeate
(CFU/100 mL)
Log10 of
Effluent
Log10
Reduction
IstB. diminuta
KanR B. diminuta
2nd 5. diminuta
2.0xl07
7.0xl06
6.9xl06
7.3
6.9
6.8
5.7xl04
2.8xl03
l.lxlO4
4.8
3.4
4.1
2.5
3.5
2.7
The results of the M-2400 chemical challenges are presented in Table VS-4. The triplicate influent and
permeate measurements were averaged by calculating the arithmetic mean. The means for each sample
point were then averaged to give an overall mean influent and permeate for each challenge. As with the
microbial challenge data, the overall means are presented here. Percent reductions were calculated from
the influent and permeate concentrations.
Note that there are two entries in Table VS-3 for B. diminuta. A second challenge was conducted after it
was noticed that the RO membrane operating pressure had risen above Watts Premier's recommended
maximum of 150 psig (pounds per square inch, gauge). The system inlet pressure did not rise, but the
membrane operating pressure created by the booster pump did rise after the system was initially
calibrated with the operating pressure set at 150 psig. The recorded RO membrane operating pressures
ranged from 160 to 172 psig for the microbial challenges and the cadmium/cesium/strontium, mercury,
strychnine, paraquat, and aldicarb challenges. To see if the higher operating pressures affected the
membrane's ability to filter out microorganisms, the B. diminuta challenge was conducted again. A
comparison of the data in Table VS-3 does not indicate that the higher pressure affected membrane
performance. The data from the chemical challenges at the higher pressures does not indicate that
chemical rejection performance was compromised. Therefore, no other challenges were conducted again
with a lower membrane operating pressure.
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Table VS-4. M-2400 Chemical Challenge Results
Mean Influent Mean Effluent Percent
Chemical (n.g/L) (u.g/L) Reduction
Aldicarb
Benzene
Cadmium
Carbofuran
Cesium
Chloroform
Dichlorvos
Mercury
Methomyl
Mevinphos
Oxamyl
Paraquat
Sodium
Fluoroacetate
Strontium
Strychnine
830
680
970
920
1100
790
1700
1200
990
920
1000
480
800
990
900
3
6.4
1.4
2.6
16
28
16
750
45
5.6
4
ND(1)
ND (20)
2
ND(5)
>99
>99
>99
>99
99
97
>99
38
96
>99
>99
>99
98
>99
>99
Based on the RO membrane permeate concentrations, the MAXVOC FF-975 filter was challenged with
chloroform, dichlorvos, mercury, and methomyl. The results for these challenges are presented in Table
VS-5. As with the RO membrane chemical challenge data, mean influents and effluents were calculated
for each challenge. Percent reductions were then calculated using the overall mean influents and
effluents.
Table VS-5. MAXVOC FF-975 Chemical Challenge Data
Target Measured
Influent Mean Influent Mean Effluent Percent
Chemical (u.g/L) (M-g/L) (ug/L) Reduction
Chloroform
Dichlorvos
Mercury
Methomyl
72
25
910
48
82
36
730
56
3.2
ND (0.2)
10
1
96
>99
99
98
The microbial challenges data shows that the M-2400 RO membrane alone can be expected to remove
more than 2 logs (>99%) of bacteria and viruses from contaminated water. The RO membrane alone also
removed greater than 96% of all challenge chemicals except mercury. The chemical challenges data in
Tables VS-4 and VS-5 shows that the M-2400 and MAXVOC FF-975 combined would remove 99% or
more of all challenge chemicals but sodium fluoroacetate, whose percent reduction was capped at 98%
because of the high detection limit of 20 |o,g/L for the chemical.
QUALITY ASSURANCE/QUALITY CONTROL (QA/QC)
NSF provided technical and quality assurance oversight of the verification testing as described in the
verification report, including a review of 100% of the data. NSF QA personnel also conducted a technical
systems audit during testing to ensure the testing was in compliance with the test plan. A complete
description of the QA/QC procedures is provided in the verification report.
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Original signed by Sally Gutierrez 09/22/06 Original signed by Robert Ferguson 09/07/06
Sally Gutierrez Date Robert Ferguson Date
Director Vice President
National Risk Management Research Water Systems
Laboratory NSF International
Office of Research and Development
United States Environmental Protection
Agency
NOTICE: Verifications are based on an evaluation of technology performance under specific,
predetermined criteria and the appropriate quality assurance procedures. EPA and NSF make no
expressed or implied warranties as to the performance of the technology and do not certify that a
technology will always operate as verified. The end-user is solely responsible for complying with
any and all applicable federal, state, and local requirements. Mention of corporate names, trade
names, or commercial products does not constitute endorsement or recommendation for use of
specific products. This report is not an NSF Certification of the specific product mentioned
herein.
Availability of Supporting Documents
Copies of the test protocol, the verification statement, and the verification report (NSF
report # NSF 06/23/EPADWCTR) are available from the following sources:
1. ETV Drinking Water Systems Center Manager (order hard copy)
NSF International
P.O. Box 130140
Ann Arbor, Michigan 48113-0140
2. Electronic PDF copy
NSF web site: http://www.nsf.org/etv
EPA web site: http://www.epa.gov/etv
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