THE ENVIRONMENTAL TECHNOLOGY VERIFICATION
PROGRAM
U.S. Environmental Protection Agency
NSF International
ETV Joint Verification Statement
TECHNOLOGY TYPE:
APPLICATION:
PRODUCT NAME:
COMPANY:
ADDRESS:
PHONE:
EMAIL:
POINT-OF-USE DRINKING WATER TREATMENT SYSTEM
REMOVAL OF CHEMICAL CONTAMINANTS IN DRINKING
WATER
ECOWATER SYSTEMS ERO-R450E
ECOWATER SYSTEMS, INC.
1890 WOODLANE DRIVE
WOODBURY,MN 55125
800-808-9899
INFO(%ECOWATERCOM
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 Eco Water Systems ERO-R450E 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.
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ABSTRACT
The EcoWater Systems ERO-R450E 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 ERO-R450E employs a reverse osmosis
(RO) membrane and activated carbon filters to treat drinking water. Treated water is stored in a 3.1-
gallon capacity storage tank. 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 organic chemical the RO membrane did not remove to below 30 |o,g/L. The carbon filter
was also challenged with cesium and mercury because the membranes did not remove these two
substances as well as total dissolved solids (TDS) in general. 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. Each pair of membranes was
tested with only one of the ten organic chemicals because of concern that a chemical could compromise
the integrity of the membrane or membrane seals. One pair of RO membrane components was also
challenged with the inorganic chemicals. 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 ERO-R450E as a whole, considering both the RO membrane challenge and post-membrane carbon
filter challenge results combined, reduced all of the challenge chemicals but cesium by 94% or more.
TECHNOLOGY DESCRIPTION
The following technology description was provided by the manufacturer, and has not been verified.
The ERO-R450E is a three-stage POU drinking water treatment system, employing an RO membrane,
and activated carbon filters both upstream and downstream of the membrane. The system includes a 3.1-
gallon maximum capacity pressurized bladder tank for storing the treated water, and a faucet to mount on
the kitchen sink. The influent water first passes through a carbon filter designed to remove chlorine and
particulate matter, such as rust and silt. The second stage of treatment is the reverse osmosis membrane,
which reduces a wide variety of contaminants. The permeate water is sent to the storage tank. When the
user opens the faucet, the partially treated water leaves the storage tank, passes through a second carbon
filter to remove organic chemicals and any taste and odor chemicals, and then exits the faucet.
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 activates an automatic shut-off
device, stopping the flow of water through the system. After a portion of the water is dispensed from the
storage tank, the shut-off device deactivates, allowing water to again flow into the system until the storage
tank is nearly full.
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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.
Methods and Procedures
Verification testing followed the procedures and methods detailed in the Test/QA Plan for Verification
Testing of the EcoWater Systems ERO-R450E 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. The complete ERO-R450E
system, including the storage tank, was used for the RO membrane challenges, but the carbon filters were
removed, leaving empty housings. 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. Each pair was tested with only one of the ten organic chemicals because of
concern that a chemical, especially benzene or chloroform, could compromise the integrity of the
membrane or membrane seals. One pair of RO membrane components was also challenged with the
inorganic chemicals. The inorganic chemical challenges were conducted prior to the organic chemical
challenges to eliminate the possibility of damage to the membranes that could bias the inorganic chemical
test results. 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
Prior to challenge testing, the RO membrane components were service-conditioned for seven days by
feeding the systems the test water without any chemical spikes. After completion of the conditioning
period, the membranes were subjected to a TDS reduction test using sodium chloride to verify that they
were operating properly.
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 the 5th tank fill, and the next morning after the
membranes rested under pressure overnight.
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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 carbon filter was also
challenged with cesium and mercury because the membranes did not remove these two substances as well
as total dissolved solids (TDS) in general. The filters were attached to a separate manifold that was of the
same design as the manifold in the full RO system. The pre-membrane carbon filter was not tested
because it is only designed to remove chlorine to protect the RO membrane. 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 target chloroform concentration was 300 ± 90 |o,g/L, which is the influent challenge concentration for
the VOC reduction test in NSF/ANSI Standard 53 (chloroform is the surrogate challenge chemical for the
test). The filters were operated at a flow rate of 0.5 gallons per minute (gpm) for 375 gallons (EcoWater
System's design capacity for the filter is 750 gallons).
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 on an "on/off operation cycle where the "on" portion was the time required to empty the system
storage tank when full, and the "off portion was the time required to fill the storage tank.
VERIFICATION OF PERFORMANCE
The results of the RO membrane challenges are presented in Table 2. The RO membrane treatment
process removed 94% or more of all challenge chemicals except cesium and mercury. The membrane
removed 82% of cesium, and only 9% of the mercury challenge.
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
960
930
1100
960
1000
980
1100
1100
1300
1100
930
1200
980
1100
33
170
1000
33
20
7.1
19
61
69
57
4
46
10
10
97
82
9
97
98
>99
98
94
95
95
>99
96
99
>99
The TDS reduction by each membrane component for all challenge tests was 87% or higher. The effluent
TDS levels for some of the chemical challenges rose from one sample point to the next over the challenge
period, but no TDS levels were significantly higher than the maximum TDS levels measured during TDS
reduction tests conducted on each unit after conditioning. Thus, the rising TDS levels likely do not
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indicate that the membrane components were becoming significantly compromised due to exposure to the
chemicals. The increase may have been due to the challenge protocol design. The challenges began with
empty storage tanks, so there was no back-pressure on the membranes when the start-up samples, which
all had the lowest observed TDS levels, were collected. Most of the challenge chemical levels were also
lowest in the start-up samples. The rest of the samples were collected after the membranes had been
operating facing back-pressure from the storage tanks. RO membranes perform better without back-
pressure, so the higher TDS levels are likely more indicative of the performance of the RO system under
normal operating conditions.
The post-membrane carbon filter components were challenged with chloroform, dichlorvos, dicrotophos,
and mevinphos based on the criteria that the RO membrane challenge effluents were above 30 |o,g/L. The
carbon filters were also challenged with cesium and mercury. The target challenge levels were the
maximum effluent levels measured during the RO membrane challenges. The carbon filters were
operated at 1.15 gpm on an operating cycle where the "on" portion was five minutes and eleven seconds,
and the "off portion was one hour and ten minutes.
The carbon challenge results are shown below in Table 3. Note that the percent reduction of dicrotophos
was limited by the detection limit for the chemical. The carbon filter removed 89% or more of all of the
challenge chemicals but cesium, which was effectively not removed at all by the carbon.
Table 3. Post-Membrane Carbon Filter Challenge Data
Mean Influent Mean Effluent Percent
Chemical (|ag/L) (|ag/L) Reduction (%)
Cesium
Mercury
Chloroform
Dichlorvos
Dicrotophos
Mevinphos
230
760
100
100
90
40
220
35
0.7
3.9
ND(10)
2.1
4.3
95
>99
96
89
95
The RO membrane and carbon challenge data combined shows that the two treatment technologies
working in concert within the ERO-R450E system removed 97% or more of all challenge chemicals but
cesium.
Complete descriptions of the verification testing results are included in the verification report.
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.
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Original signed by Andrew Avel, 10/25/05 Original signed by Robert Ferguson, 11/07/05
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
04/14b/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.nsf.org/etv/dws/dws_reports.html, and from
http://www.nsforg/etv/dws/dws_project_documents.html (electronic copy)
EPA web site: https://www.epa.gov/etv (electronic copy)
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