THE ENVIRONMENTAL TECHNOLOGY VERIFICATION
PROGRAM
oEPA
ET
V^lVl
V
U.S. Environmental Protection Agency
NSF International
ETV Joint Verification Statement
TECHNOLOGY TYPE: ULTRAFILTRATION AND REVERSE OSMOSIS
APPLICATION: REMOVAL OF CHEMICAL AND MICROBIAL
CONTAMINANTS FROM A SURFACE DRINKING WATER
SOURCE
PRODUCT NAME: EXPEDITIONARY UNIT WATER PURIFIER (EUWP),
GENERATION 1
VENDOR: VILLAGE MARINE TEC.
ADDRESS: 2000 W. 135TH ST.
GARDENA, CA 90249
PHONE: 310-516-9911
EMAIL: SALES@VILLAGEMARINE.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 evaluated the performance of the Village Marine Tec. Generation 1 Expeditionary Unit
Water Purifier (EUWP). The EUWP, designed under U.S. Military specifications for civilian use,
employs ultrafiltration (UF) and reverse osmosis (RO) to produce drinking water from a variety of
sources. This document provides the verification test results for the EUWP system evaluated at a fresh
surface water site at Selfridge Air National Guard Base in Michigan.
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 voluntary 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 09/28/EPADWCTR The accompanying notice is an integral part of this verification statement. October 2009
VS-i
-------
PRODUCT DESCRIPTION
The following technology description was provided by the manufacturer and has not been verified.
The EUWP was developed to treat challenging water sources with variable turbidity, chemical
contamination, and very high total dissolved solids (TDS) including seawater, during emergency
situations when other water treatment facilities are incapacitated. The EUWP components include feed
pumps, a UF pretreatment system, a one or two pass RO desalination system with an energy recovery
device, storage tanks, and product pumps. It has chemical feed systems for optional pretreatment
coagulation and post treatment chlorination. Clean-in-place systems (CIP) are included with the UF and
RO skids. During this verification test, coagulation pretreatment was employed, but chlorination was not
evaluated.
Design specifications indicate that the UF system alone has a production capacity up to 250,000 gallons
per day (gpd) from a fresh water source with up to 500 mg/L TDS and a temperature of 25°C. The
combined UF and RO system is designed to produce from 98,000 gpd up to 162,000 gpd, depending on
the TDS of the source water and the recovery settings of the RO process.
VERIFICATION TEST DESCRIPTION
Test Site
The testing site was Lake St. Clair at Selfridge Air National Guard Base in Michigan. The source water
for testing was raw lake water. Initial characterization samples of raw lake water were collected in August
2006, and again in May 2007 for the second round of testing. Highlights of the source water
characterization are presented in Table VS-i. The measured concentrations of regulated metals,
phosphorus, nitrite, and nitrate are not shown here, but are presented in the final report, because they are
either below the laboratory reporting limit or below the limit in the EPA National Primary Drinking
Water Regulations (NPDWR) limit.
Table VS-i. Lake St. Clair Raw Water Characterization Data
Sample Date
Parameter 08/16/06 05/31/07
Total Organic Carbon (TOC, mg/L) 2.9 NM1
UV Light Absorbance at 254 nanometers (UV254, Abs) 0.0668 NM
Total Suspended Solids (TSS, mg/L) <5 <2
TDS (mg/L) 130 140
Alkalinity (mg/L as CaCO3) 70 86
Total Hardness (mg/L as CaCO3) 95 110
Total Silica (mg/L as SiO2) 1.1 1.1
Specific Conductance (nmhos/cm) NM 250
Cryptosporidium (oocysts/L) <1 NM
Giardia (cysts/L) <1 NM
Heterotrophic Plate Count (HPC, CFU/mL) 500 NM
Total Coliforms (CFU/100 mL) 291 NM
Bacillus Endospores (CFU/100 mL) NM 689
(1) NM = not measured
Methods and Procedures
Initial testing of the EUWP was conducted in September and October of 2006 by the U.S Army Tank-
Automotive Research, Development, and Engineering Center (TARDEC), with assistance from the U.S.
Bureau of Reclamation (USER). Immediately prior to the ETV test, the initial UF pressure decay tests
indicated that pressure was being lost at a higher than desirable rate. The problem was investigated, and
NSF 09/28/EPADWCTR The accompanying notice is an integral part of this verification statement. October 2009
VS-ii
-------
was found to be the o-ring seals between the membrane modules and filtrate collection tubes. As a
temporary fix, polytetrafluoroethylene (Teflon®) thread sealing tape was wrapped around the o-rings to
increase the seal surface between the o-rings and membrane cartridges, and the test proceeded. After
testing was complete, the UF performance data indicated that the temporary fix did not maintain sufficient
membrane integrity. Therefore, a second test employing only the UF system was conducted in July and
August of 2007 after permanent repairs were made. Issues concerning the seal problems and subsequent
repairs are discussed in the ETV verification report.
The testing activities followed a test/quality assurance plan (TQAP) prepared specifically for the project.
The TQAP was developed in accordance with the ETV Protocols EPA/NSF Protocol for Equipment
Verification Testing for Removal of Inorganic Constituents - April 2002, and the EPA/NSF Protocol for
Equipment Verification Testing for Physical Removal of Microbiological and Paniculate Contaminants -
September 2005.
The 2006 verification test began on September 25, and ran for the planned 30 day test period, ending on
October 25. The UF system was operated each day on semi-continuous basis, automatically shutting
down when the RO feed tank was full. A typical operating day for the UF system was 15-17 hours (h) in
duration. The RO system was setup to operate continuously, and typically ran 22 to 24 h per day. The RO
system was shutdown periodically for various maintenance activities, or when alarms occurred and shut
the system down. When alarms and shutdown occurred during unattended operation at night, the entire
system would remain shutdown until an operator arrived in the morning.
The 2007 UF system retest was conducted from July 30 to August 24. The retest was stopped short of 30
days because the intent of the test as stated in the ETV test protocol - operation until a membrane
cleaning was needed - was met. During the retest, the UF system was in operation an average of 14 h per
day, not including down time for backwashes, cleanings, and other maintenance activities.
Flow, pressure, conductivity, and temperature recordings were collected twice per day when possible to
quantify membrane flux, specific flux, flux decline, and recovery. Turbidity and pH readings were also
recorded twice per day. The UF skid included in-line particle counters which recorded particle counts
every five minutes. Pressure decay tests were conducted daily on the UF system to verify membrane
integrity. Once per week samples were collected from the UF and RO process streams for analysis of
alkalinity, hardness, total silica, TDS, TOC, TSS, UV254, HPC (2006 test only), and total coliforms (2006
test only). For the 2007 test, Bacillus endospores were substituted for HPC and total coliforms.
VERIFICATION OF PERFORMANCE - 2006 TEST
Finished Water Quality
The UF system reduced the turbidity from a mean of 4.77 Nephelometric Turbidity Units (NTU) in the
feed water to a mean of 0.14 NTU in the UF filtrate. The UF system reduced the turbidity of the feed
water by a mean value of 95.9%. All filtrate turbidity measurements were below the NPDWR of 1 NTU.
The second NPDWR criterion for turbidity is that 95% of the daily samples in any month must be <0.3
NTU. Only one filtrate turbidity measurement out of 58 was above 0.3 NTU: 0.47 NTU on October 5.
Therefore, the EUWP UF system met the second NPDWR turbidity requirement, as 98% of the turbidity
measurements were <0.3 NTU.
The RO membranes provided additional turbidity removal, resulting in a mean turbidity of 0.09 NTU
from the permeate grab samples. The maximum measured RO permeate turbidity was 0.18 NTU. In
general, the RO system provided an additional turbidity reduction in the range of 40% to 66%.
NSF 09/28/EPADWCTR The accompanying notice is an integral part of this verification statement. October 2009
VS-iii
-------
The UF system showed only a minor reduction in organic material as measured by the TOC data. The UF
feed TOC concentrations ranged from 2.1 to 2.7 mg/L, and the UF filtrate levels were typically only 0.1
to 0.4 mg/L lower. These data indicate that most of the organic material, as measured by TOC, was
dissolved in the feed water. The RO system reduced the permeate TOC to below the detection limit of 0.1
mg/L.
The RO system also reduced the dissolved ions in the water, as measured by conductivity, with a mean
percent reduction of 99.4%. The mean conductivity of the RO permeate was 1.8 microSiemens per
centimeter ((iS/cm) compared to a mean RO feed conductivity of 287 (iS/cm. The maximum measured
permeate conductivity was 4.9 (iS/cm. Hardness, alkalinity, TDS, and total silica were all removed to
below the detection limit in the RO permeate.
UF andRO Membrane Integrity
Daily pressure decay tests were used to document UF membrane integrity, and HPC and total coliforms
were measured in the UF feed and filtrate as a microbial membrane integrity indicator. The in-line
particle counters provided an additional measurement of membrane integrity, and the capability of the
system to remove particulate and microbial contaminants.
As discussed in the Methods and Procedures section, prior to the 2006 test TARDEC and USER
discovered that the seals between the UF elements and membrane module housings were not as tight as
desired. After the problem was temporarily fixed, the pressure decay rate was measured as 0.37 pounds
per square inch, gauge (psig) per minute (min). While this was higher than desired, there was no critical
pressure decay rate to achieve, so the test proceeded. The mean daily pressure decay rate for the test was
0.29 psig/min, with a maximum observed decay rate of 0.43 psig/min.
While the turbidity data indicated that the UF system performed satisfactorily, the microbiological data
showed higher than expected UF filtrate counts. The UF feed geometric mean HPC count was 2810
CFU/mL, and the filtrate geometric mean HPC count was 1670 CFU/mL. Mean total coliform counts
were not calculated because only five sets of samples were collected. The UF feed total coliform counts
ranged from 41 to 532 CFU/100 mL, while the filtrate counts ranged from 11 to 94 CFU/100 mL. High
numbers of HPC and total coliforms were also found in the RO permeate. The mean RO permeate HPC
count was 247 CFU/mL and the RO permeate total coliform counts ranged from <1 to 95 CFU/100 mL.
This phenomenon has been observed in other published membrane studies, but it was beyond the scope of
this study to determine whether the observed HPC and total coliform levels were breaching the
membrane, or were a result of microbial contamination and growth downstream of the UF and RO
membranes from previous field tests of the EUWP.
There is no reportable particle count data for the 2006 test because after the test was completed it was
discovered that the particle counters had been improperly calibrated.
Direct integrity measurements of the RO system were performed prior to the start of the verification test,
and again at the end of the test. A dye marker test was conducted, where a food-grade dye was added to
the RO feed water, and UV absorbance levels were compared among the feed, permeate, and concentrate
streams over a ten minute period. For the pre-verification test, the dye rejection rate was 99.6%, while
that for the post-verification dye test was 99.8%. As with the UF pressure decay tests, there was no
critical rejection level.
UF System Operation
UF process operations data for the 2006 test are presented in Table VS-ii. The intake flow is defined as
the source water pumped into the UF feed water tank. The mean UF feed water flow rate of 246 gallons
NSF 09/28/EPADWCTR The accompanying notice is an integral part of this verification statement. October 2009
VS-iv
-------
per minute (gpm) was below the design feed flow rate of 259 gpm specified for the system. The UF water
recovery was 89.5% based on the mean feed water and filtrate flow rates. The UF system only operated
15 h per day, on average, but the 220 gpm mean filtrate flow corresponds to a 24-h production rate of
316,800 gallons (gal). The UF system target production rate was 250,000 gpd (not including backwash
water). The backwash process used about 900 gal of UF filtrate per event, and a backwash was conducted
every 30 minutes. For 24 h of operation, a total of 43,200 gal of UF filtrate would be used for
backwashes. Subtracting the backwash water from the calculated daily UF filtrate production results in
273,600 gpd of UF product water, which was above the performance goal of 250,000 gpd.
Table VS-ii. 2006 Test UF Operations Productivity Data
Parameter
Standard
Count Mean Median Minimum Maximum Deviation
95%
Confidence
Interval
UF Operation per day (h)
Intake Flow (gpm)
Feed Flow (gpm)
Filtrate Flow (gpm)
Retentate Flow (gpm)
Backwash Flow (gpm)
Feed Pressure (psig)
Retentate Pressure (psig)
Filtrate Temperature (0F:)
31
58
59
59
59
59
59
59
15.0
298
246
220
26
21
19
52
17.2
299
248
222
26
Estimated
21
19
52
3.4
278
175
149
21
at 900 :
12
10
43
21.5
302
268
243
31
4.85
3.34
16.0
16.1
1.81
±1.71
±0.86
±4.07
±4.10
±0.46
gal per backwash cycle
33
31
60
4.26
4.20
5.16
±1.09
±1.07
±1.32
(1) °F = degrees Fahrenheit
A chemical coagulant (ferric chloride) was not used at the beginning of the verification test. At the start of
the test on September 25, the trans-membrane pressure (TMP) was 11 psig. However, it quickly rose to
26 psig on September 29. As the TMP rose, the specific flux declined from 3.56 gallons per square foot
per day (gfd)/psig on September 25 to 1.38 gfd/psig on September 29. It was evident that a coagulant
should be used to attempt to lengthen the time between UF cleanings. The UF system was shut down on
September 30 and cleaned. The CIP was successful as the specific flux rose to 3.52 gfd/psig. Ferric
chloride was injected to the feed water upstream of the UF feed tank from September 29 through the end
of the test. The addition of the coagulant improved performance, and the system was able to maintain
filtrate production with the TMP below 20 psig until the last two days of the test. The specific flux varied
between 3.0 and 4.5 gfd/psig from September 29 to October 18, and then it dropped down to 2.46
gfd/psig on October 19. From October 19 to the end of the test on October 25, it ranged from
approximately 1.5 to 3.0 gfd/psig.
RO System Operation
The RO process operations data for the 2006 test are presented in Table VS-iii. The mean RO permeate
flows of 53 gpm for Array 1 and 21 gpm for Array 2 yield a mean total permeate production of 74 gpm.
The mean feed water flow of 107 gpm for Array 1 and 53 gpm for Array 2 were below the target feed
rates of 116 gpm and 58 gpm, respectively. The recovery for Array 1 was 49.5%, (design target 50%) and
the recovery for Array 2 was 39.6% (design target 48%).
Over the 30-day verification test, the RO feed water totalizer showed 5,382,670 gal of water fed to the
RO unit. At an average recovery of 47% (prorated between Array 1 at 49.5% and Array 2 at 39.6%), the
total volume of permeate produced was approximately 2,530,000 gal or an average of 84,330 gpd over the
entire test period. The target flowrate fell short of the goal of producing 100,000 gpd of finished water.
The RO system maintained a steady permeate flow rate for both arrays throughout the verification test.
The feed pressure was increased over the duration of the test to maintain feed water flow rates. The Array
NSF 09/28/EPADWCTR
The accompanying notice is an integral part of this verification statement.
VS-v
October 2009
-------
1 feed pressure increased from 387 psig on September 25 to a maximum of 539 psig on October 24. The
concentrate pressure from Array 1 was used by the energy recovery device to increase feed water pressure
for Array 2. Based on the small pressure loss from the transfer of pressure between the Array 1
concentrate and the Array 2 feed water, the energy recovery device worked properly during the test.
Table VS-iii. RO System Operations Productivity Data for 2006 Test
95%
Standard Confidence
Parameter Count Mean Median Minimum Maximum Deviation Interval
Array 1 Feed Flow (gpm) 59 107 107 104 110 1.38 ±0.35
Array 1 Permeate Flow (gpm) 59 53 53 44 56 2.0 ± 0.50
Array 1 Concentrate Flow (gpm) 59 54 54 48 62 2.4 ±0.61
Array 2 Feed Flow (gpm) 59 53 52 49 59 2.3 ±0.60
Array 2 Permeate Flow (gpm) 59 21 21 19 24 1.1 ±0.27
Array 2 Concentrate Flow (gpm) 59 32 31 27 37 2.3 ±0.58
Array 1 Feed Pressure (psig) 59 444 428 374 539 45.9 ±11.7
Array 1 Concentrate Pressure (psig) 59 346 330 286 419 40.5 ±10.3
Array 2 Feed Pressure (psig) 59 345 327 284 436 42.5 ±10.8
Array 2 Concentrate Pressure (psig) 59 255 238 204 325 35.2 ± 8.98
Array 1 and 2 Combined Permeate 59 28 27 15 39 4.6 ±1.2
Pressure (psig)
The specific flux calculations show that the RO membranes were slowly being fouled during operation.
Over the 30-day test, the specific flux dropped by approximately 31% for Array 1, from 0.050 to 0.035
gfd/psig and 26% for Array 2, from 0.054 to 0.040 gfd/psig. The RO system was chemically cleaned on
October 6 using a citric acid low pH solution. The specific flux just before the start of the cleaning was
0.043 gfd/psig, and the cleaning increased the specific flux to 0.047 gfd/psig. Given the slow but steady
trend of decreasing specific flux, an anti-sealant was fed to the RO system beginning on October 12. This
chemical feed continued through the end of the verification test.
VERIFICATION OF PERFORMANCE - 2007 UF SYSTEM RETEST
The 2007 retest was conducted from July 31 to August 24. Prior to starting the retest, each membrane
cartridge was individually integrity tested, and several were found to have broken fibers that required
plugging. This is a typical practice prior to installation of hollow-fiber membrane modules. After
plugging these fibers, each cartridge was again pressure tested. The results showed that 15 of the 16
modules were acceptable, so TARDEC and USER decided to operate the UF system with only 15
membranes. After completion of the individual module pressure decay tests and repairs, the full system
pressure decay rate was 0.025 psig/min. This value was more than ten times lower than the mean value of
0.29 psig/min obtained during the 2006 verification test. This indicated that the repairs made to the UF
system following the 2006 test were providing better membrane module pressure-hold capability.
Finished Water Quality
For the 2007 retest, the UF system reduced the turbidity from a mean of 2.3 NTU in the feed water to a
mean of 0.14 NTU in the UF filtrate. Despite the UF system integrity issues during the 2006 test, the
2006 mean filtrate turbidity was the same as for the 2007 test. Turbidity in the feed water was reduced by
a mean value of 92.5%. There were two spikes in the feed water turbidity - on August 6, and from August
20 to 22. Both spikes were likely caused by rain events on these days. These feed water turbidity spikes
did cause small increases in the filtrate turbidity, but only one measurement - 0.51 NTU on August 22 -
was above 0.3 NTU. Therefore, the UF system also met the NPDWR turbidity requirements during the
2007 test.
NSF 09/28/EPADWCTR The accompanying notice is an integral part of this verification statement. October 2009
VS-vi
-------
UF Membrane Integrity
Pressure decay tests were again conducted daily for the 2007 UF system retest. The observed pressure
decay rates were 5-10 times lower than those from the 2006 test, with a mean value of 0.025 psig/min.
These direct integrity test results were indicative of membrane modules with no significant observable
breaches.
The mean 2 to 3 (im particle count for the feed water was 13,376/10 mL. The range of 2 to 3 um particle
counts for the feed water was 1 to 39,418/10 mL. The filtrate had a mean particle count in the 2 to 3 um
size of 112/10 mL with a median of 55/10 mL and a range of 0 to 13,908/10 mL. However, the maximum
particle count of 13,908 may not be indicative of typical performance. The UF system went through a
backflush cycle every half-hour, and during these backflushes the particle counts were still being
recorded. Consequently, the filtrate particle count data included numerous spikes. The backflushes were
not time-stamped, so the spikes due to backflushes could not be identified with certainty and removed
from the data set. As evidenced by the low mean and median filtrate counts, most of the counts were less
than 200/10 mL. The UF system reduced the 2 to 3 um particles by a mean value of 2.21 log 10.
The mean 3 to 5 um particle count for the feed water was 24,634/10 mL. The range of 3 to 5 um particle
counts for the feed water was 0 to 91,595/10 mL. The filtrate had a mean 3 to 5 um particle count of
157/10 mL with a median of 77/10 mL and a range of 0 to 14,059/10 mL. As with the 2 to 3 um
maximum count, the 3 to 5 um maximum count of 14,059 may not be indicative of UF performance due
to particle count data being collected during the backflushes. The UF system reduced the 3 to 5 um
particles by a mean value of 2.33 Iogi0.
The geometric mean UF feed Bacillus endospore count was 1,562 CFU/100 mL, with range of 862 to
7,420 CFU/100 mL. The mean filtrate endospore count was 203 CFU/100 mL, with a range of 78 to 996
CFU/100 mL. The mean log reduction was 0.88 logic with a range of 0.07 to 1.74 logic for the feed and
filtrate sample pairs. This was a lower reduction than predicted based on the observed pressure decay
rates and the particle count data. To explore the concern of membrane module integrity further, additional
studies were conducted on selected modules from this UF skid. Results from these additional studies
conducted at the NSF testing facility in Ann Arbor, MI, are not presented in this verification report. The
following reference report provides separate ETV verification testing results for the laboratory challenge
study of selected EUWP UF modules: "Removal of Microbial Contaminants in Drinking Water: Koch
Membrane Systems, Inc. Targa® 10-48-35-PMC™ Ultrafiltration Membrane, as Used in the Village
Marine Tec. Expeditionary Unit Water Purifier", EPA/600/R-09/075, http://www.epa.gov/etv.
UF System Operation
The 2007 UF system retest operations data are presented in Table VS-iv. With only 15 modules in
operation, the mean feed and filtrate flow rates of 232 gpm and 206 gpm, respectively, were lower than
those for the 2006 test. Based on the mean flow rates, the mean water recovery for the UF system was
88.8%. The 206 gpm mean filtrate flow corresponds to a 24-h production rate of 296,640 gpd. Subtracting
the backwash water from the calculated daily filtrate production results in 253,440 gpd of UF product
water, which is still above the design UF production of 250,000 gpd, despite being short one module.
Actual UF filtrate production was tracked using the RO feed totalizer. The total filtrate produced (not
including backwash water) was 3,551,000 gal over 350.1 h of operation. This yields a mean useable UF
filtrate production of 242,500 gpd. If the filtrate water used for backwashing the system is added (595,730
gal) to this production volume, then the mean total filtrate production is 283,200 gpd.
NSF 09/28/EPADWCTR The accompanying notice is an integral part of this verification statement. October 2009
VS-vii
-------
Table VS-iv. UF System Operations Productivity Data for 2007 Test
95%
Standard Confidence
Parameter Count Mean Median Minimum Maximum Deviation Interval
UF Operation per day (h)
Intake Flow (gpm)
Feed Flow (gpm)
Filtrate Flow (gpm)
Retentate Flow (gpm)
Backwash Flow (gpm)
Feed Pressure (psig)
Retentate Pressure (psig)
Filtrate Temperature (°F)
25
44
45
45
44
45
45
45
13.8
288
232
206
26
Not
24
22
74
14.3
296
237
212
26
measured
25
23
75
4.0
235
174
148
25
- approximately
13
11
62
21.5
303
271
245
28
900 gal
32
31
84
4.
16
19
19
0.
6
.2
.7
.6
7
±1
±4.
.8
.8
±5.7
5.7
±0.
.2
per backwash
5.
5.
5.
9
8
3
±1
±1
±1.
.7
.7
.6
From August 2 through 7, the feed water pressure needed to be increased every day to maintain the target
filtrate flow rate. During this time, TMP increased from 7 to 17 psig. On August 7, the UF system was
shutdown for a chemical cleaning, and put back into service on August 9. The TMP did not drop as a
result of the cleaning, but instead further increased up to 22 psig on August 12. Therefore, the feed
pressure was increased to 30 psig in order to maintain water flow rates. The UF system was again
shutdown and a second chemical cleaning performed on August 13. This cleaning dropped the TMP down
to 16 psig. The feed water pressure was increased again to over 30 psig on August 14 and TMP increased
accordingly. A decision was made to operate the UF system at the higher feed water pressure and TMP,
since these pressures were still within the design specification and operating specification for the unit.
The UF feed pressure remained steady for several days and was actually lower during the last week of the
test. TMP remained fairly steady at around 20 psig for the duration of the test.
As the TMP increased, the specific flux declined. The CIP was successful in stabilizing the drop in
specific flux, but did not result in returning the membrane to the specific flux attained at the beginning of
the test. The specific flux at the start of the test on July 30 was 4.62 gfd/psig. The specific flux dropped to
1.78 gfd/psig on August 7, then remained between 1.12 and 2.18 gfd/psig for the remainder of the test.
Ferric chloride was also used as a coagulant during the retest. During the initial test runs for the retest, jar
tests showed a ferric chloride dose of 1 mg/L as Fe should be the target feed rate. This feed rate was
maintained until the rapid increase in TMP and drop in specific flux occurred. After the chemical cleaning
on August 7 and 8, the ferric chloride feed rate was increased to 2 mg/L as Fe. Subsequent jar tests
suggested that with the low source water turbidity, the ferric chloride feed should actually be decreased.
The ferric chloride feed was shut off on August 10 and remained off until the CIP was required on August
13. The rapid loss of flux and rise in TMP indicated that the coagulant should be used in the system, but
at a lower dose than used at the start of the test. The ferric chloride feed was set at 0.2 mL/min (0.02 mg/L
as Fe) and continued at that rate for the remainder of the test.
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. One important
finding was that the particle count data from the 2006 test was incorrect due to improper calibration of the
particle counters. The particle counters were calibrated properly for the 2007 retest, so only the particle
count data from the 2007 test is reported.
A complete description of the QA/QC procedures is provided in the verification report.
NSF 09/28/EPADWCTR The accompanying notice is an integral part of this verification statement. October 2009
VS-viii
-------
Original signed by Sally Gutierrez 11/24/09 Original signed by Robert Ferguson 12/14/09
Sally Gutierrez Date Robert Ferguson Date
Director Vice President
National Risk Management Research Laboratory Water Systems
Office of Research and Development NSF International
United States Environmental Protection Agency
NOTICE: Verifications are based on 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 09/28/EPADWCTR) are available from the following sources:
1. ETV Drinking Water Systems Center Manager (order hard copy)
NSF International
P.O. Box 130140
Ann Arbor, Michigan 48113-0140
2. Electronic PDF copy
NSF web site: http://www.nsf.org/info/etv
EPA web site: http://www.epa.gov/etv
NSF 09/28/EPADWCTR The accompanying notice is an integral part of this verification statement. October 2009
VS-ix
------- |