EPA/600/R-13/096S
May 2013
THE ENVIRONMENTAL TECHNOLOGY VERIFICATION
PROGRAM
U.S. Environmental Protection Agency
NSF International
ETV Verification Statement
TECHNOLOGY TYPE: UV DISINFECTION IN DRINKING WATER
APPLICATION: INACTIVATION OF MICROBIOLOGICAL
CONTAMINANTS
PRODUCT NAME: NEOTECH D438™ UV WATER TREATMENT SYSTEM
VENDOR: NEOTECH AQUA SOLUTIONS INC.
ADDRESS: 5893 OBERLIN DRIVE, SUITE 104
SAN DIEGO, CALIFORNIA 92121
PHONE: 1-888-718-5040 OR 1-858-571-6590
WEBSITE: HTTP://NEOTECHAQUA.COM
EMAIL: INFO@NEOTECHAQUA.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 NeoTech Aqua Solutions, Inc. D438™ UV water
Treatment System (Model 438™). NSF performed all verification testing activities at its Ann Arbor, MI
location.
EPA created the ETV Program to facilitate the deployment of innovative or improved environmental
technologies through performance verification and dissemination of information. The ETV Program's
goal 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 13/38/EPADWCTR The accompanying notice is an integral part of this verification statement. May 2013
VS-i
-------
ABSTRACT
The NeoTech Aqua Solutions, Inc. D438™ UV Water Treatment System was tested to validate the UV
dose delivered by the system using biodosimetry and a set line approach. The set line for 40 mJ/cm2
measured Reduction Equivalent Dose (RED) was based on validation testing at three (3) set points. A set
point is defined at a single flow rate and irradiance output that delivers the targeted UV dose. The results
of the three set point tests were used to develop the setline that defined the maximum flow rate and
minimum irradiance output required to ensure that a 40 mJ/cm2 measured RED is achieved. The
microorganism used for the validation was MS2 coliphage virus. NeoTech Aqua Solutions selected flow
rates for testing of 150, 250, and 435 gpm based on the unit design and preliminary screening tests. The
lowest irradiance tested was 7.9 mW/cm2 which occurred with full power to the unit, at a flow rate of 151
gpm, and a feed water ultraviolet transmissionUltraviolet Transmission (UVT) of 91 %.
The measured RED was adjusted for RED bias and uncertainty to determine the validation factor for
calculating log inactivation of Cryptosporidium. The validation factor (VF) and validated dose
calculations were performed as specified in the USEPA Ultraviolet Design Guidance Manual (UVDGM-
2006). Based on the results of these tests and the calculated validation factor, the NeoTech D438™
achieved a minimum of 3.5-log reduction credit for Cryptosporidium at the test flow rates and
corresponding irradiance levels. The validation factors for log inactivation credit for Giardia were also
calculated and the NeoTech D438™ also achieved a minimum of 3.5-log reduction credit for Giardia at
the test conditions.
TECHNOLOGY DESCRIPTION
The vendor provided the following description, which was not verified. The Model D438™ uses two (2)
low pressure mercury amalgam lamps and one intensity sensor mounted in a stainless steel flow chamber.
The inside of the flow chamber is coated with a highly reflective material that according to NeoTech
reduces the amount of light energy required to achieve a targeted dose. The inlet pipe size is 3 inch
diameter, the unit is designed for an operating pressure of up to 145 psi, and operating power
consumption is 300 W. The low pressure lamps have an expected lamp life of 9000 hours. The sensor is a
UVIM 3-1660-002 unit with a measuring field angle of 180° and measuring range of 0 to 160 mW/m2.
The system has a control panel that provides data on the lamp condition, operating hours, and irradiance
measured by the sensor. The operating manual provides schematics and tables with parts, dimensions and
other specifications for the reactor, the sensors, the lamps and the quartz sleeves.
VERIFICATION TESTING DESCRIPTION
Test Site and Equipment
The verification test was conducted using a full scale unit installed at the NSF Engineering Laboratory in
Ann Arbor Michigan. The water source for this test was City of Ann Arbor Michigan municipal drinking
water that was de-chlorinated using activated carbon. Lignosulfonic Acid (LSA) was used to lower the
UV transmittance (UVT) for the full power low UVT test runs. UVT was measured continuously using an
in-line UVT meter (calibrated daily) to confirm that proper UVT was attained.
NSF used a test rig and system setup that is designed to conform to the specifications described in the
UVDGM-2006. The UV reactor inlet and outlet connections were installed in accordance with the
NeoTech installation and assembly instructions. Two 90° elbows were attached directly to the inlet and
outlet of the system to eliminate stray UV light. The feed water pump was a variable speed pump. Flow
rate was controlled by adjusting the power supplied to the pump and by a control valve. A turbine water
flow meter was used to monitor flow rate. The meter was calibrated and achieved an accuracy of ± 2%
over the range of flow rates. A chemical feed pump (injector pump) was used to inject MS2 coliphage
NSF 13/38/EPADWCTR The accompanying notice is an integral part of this verification statement. May 2013
VS-ii
-------
upstream of an inline static mixer. The inline mixer ensured sufficient mixing of the microorganism prior
to the influent sampling port, which was located upstream of the 90° elbow at the inlet to the unit. The
effluent sampling port was located downstream of the 90° elbow and a second inline static mixer. The
sampling location met the UVDGM-2006 requirement to ensure good mixing of the treated water prior to
the effluent sampling port. A power platform that measures amperage, volts, watts, and power factor was
used to monitor power use by the test unit. The unit was wired into the platform and power consumption
was recorded for each test run.
Methods and Procedures
The tests followed the procedures described in the Test/Quality Assurance Plan for The NeoTech UV
Ultraviolet Water Purification System Model D438™, August 2010 (TQAP). The TQAP was adapted
from the Generic Protocol for Development of Test/Quality Assurance Plans for Validation of Ultraviolet
(UV) Reactors, July 2010 (GP). This generic protocol is based on the USEPA's UVDGM-2006. The
TQAP was updated based on the GP of August 2011 prior to the start of the validation test.
The approach used to validate UV reactors is based on biodosimetry which determines the log
inactivation of a challenge microorganism during full-scale reactor testing for specific operating
conditions of flow rate, UVT, and UV intensity (measured by the duty sensor). MS2 coliphage ATCC
15597-B1 was used in collimated beam bench scale testing and for the full-scale reactor dose validation
tests. A dose-response equation for the challenge microorganism (MS2 coliphage for this test) was
determined using a collimated beam bench-scale test. The observed log-inactivation values from full-
scale testing were input into the collimated beam derived UV dose-response equations to estimate a RED.
The RED value was adjusted for uncertainties and biases to produce the validated dose of the reactor for
the specific operating conditions tested.
The UV lamp was new and therefore the system was operated for 100 hours with the lamps turned on at
full power prior to the start of the test.
VERIFICATION OF PERFORMANCE
System Operation
Each set point represented a given flow rate - irradiance pair with testing under two conditions: (1)
lowered UVT-max power, and (2) high UVT-reduced power. The first test condition involved reducing
the UVT while operating the UV system at full power, until the UV intensity measured by the unit UV
sensor equaled the target UV intensity set point. The second test condition was run with high UVT and
with the power reduced until the unit UV intensity measured by the sensor was equal to the target UV
intensity set point. Three target flow rate - irradiance set points (150 gpm - 7.5 mW/cm2; 250 gpm - 10
mW/cm2; 435 gpm - 13 mW/cm2) were tested for the set line with each condition being performed in
duplicate. The irradiance targets were based on expected irradiance at UVTs of 91%, 94%, and 97%.
The validation tests were run on two days, August 2 and 3, 2012. The first day of testing was dedicated to
the test condition with the UVT lowered to the target levels (91%, 94%, and 97%) and the lamps
operating at full power. The second day of testing was dedicated to the test condition where high UVT
feed water (98%) was used and the lamp power was reduced to achieve the target irradiance level.
Collimated beam tests were run in duplicate on both test days with minimum UVT water (91%) on Day 1
and with maximum UVT water (98%) on Day 2. Thus, for this validation test, there are two sets of
duplicate collimated beam test data, one set at low UVT and one set at high UVT.
NSF 13/38/EPADWCTR The accompanying notice is an integral part of this verification statement. May 2013
VS-iii
-------
Test Results
Sensor Assessment
The test unit duty sensor was evaluated according to the UV sensor requirements in the UVDGM-2006
prior to the verification testing. All UV intensity sensors (the duty and two reference sensors) were new
sensors provided by NeoTech. Evidence of calibration of the sensors traceable to NIST standards was
provided by NeoTech.
The same duty sensor was used for monitoring intensity (irradiance) for all test runs. The control panel
provided direct readings of intensity in mW/cm2. The duty sensor was compared against two reference
sensors before and after the validation test runs. These data demonstrate that the duty sensor was within
the range of 5.1% to 8.8% of the average of the two reference sensors. The two reference sensors showed
avariance of 2.9% at 100% power and 1.3% to 6.8% at the reduced power level.
Set Line for 40 mJ/cm2 REDmeas
The three set point conditions selected for this validation all achieved a minimum REDmeas of 40 mJ/cm2,
which was the target minimum REDmeas for developing the set line. Figure 1 shows the set line. The unit
is validated for a minimum REDmeas of 40 mJ/cm2 for any flow rate and intensity combination above and
to the left of the set line. The maximum flow rate demonstrated was 434 gpm. A UV system cannot
operate above the highest validated flow rate and claim a 40 mJ/cm2 REDmeas. The lowest intensity
demonstrating a REDmeas of 40 mJ/cm2 was 7.9 mW/cm2. A UV system cannot operate below the lowest
validated irradiance and claim a 40 mJ/cm2 REDmeas.
Set Point 1-151 gpm, 7.9 mW/cm2; Set Point 2-251 gpm, 10.4 mW/cm2; Set Point 3 - 434 gpm, 13.2
mW/cm2.
50 100 150 200 250 300 350 400 450 500
Flow Rate (gpm)
Figure 1. Set Line for 40 m J/cmz REDmeas.
NSF 13/38/EPADWCTR The accompanying notice is an integral part of this verification statement.
VS-iv
May 2013
-------
Deriving the Validation Factor and Log Credit for Cryptosporidium
As described in UVDGM, several uncertainties and biases are involved in using experimental testing to
define a validated dose and validated operating conditions. The VF for Cryptosporidium was determined
quantitatively to account for key areas of uncertainty and variability.
The equation for the VF is:
VF = BREDx[l+(UVal/100)]
where:
VF = Validation Factor;
BRED = RED bias factor; and
Uvai = Uncertainty of validation expressed as a percentage.
The highest BRED value found among the replicates at a given set point was selected for the BRED value for
use in the VF calculation per the UVDGM-2006. UVai is calculated based on the Us (uncertainty of sensor
value), UDR (uncertainty of the fit of the dose-response curve and USp (uncertainty of set-point). The QC
requirement that the duty sensor measurements should be within 10% of the average of two or more
reference sensors eliminates the need to calculate the Us factor per the UVDGM-2006. The UDR factor
calculation was greater than 30% for one set of collimated beam tests (UDR of 32.58%), so UDR is included
in the calculation of uncertainty. The USP and UDR factors are used for calculating UVai per the equation:
l = (U
SP
The highest UDR at 1.0-log inactivation for all collimated beam tests is selected for use in calculating the
uncertainty (UVAL)- In this case the highest UDR is 32.58% from the Day 1 set of collimated beam data.
After establishing the VF, the validated dose is calculated as:
Validated dose = RED /VF
The NeoTech D438™ achieved a minimum of 3. 5 -log reduction credit for the low power runs at 251 gpm
at 10.4 mW/cm2 and a 4.0-log reduction credit for all of the test runs at the set points at 151 gpm - 7.9
mW/cm2 and 434 gpm - 13.2 mW/cm2. The set line for a minimum 3.0-log reduction credit for
Cryptosporidium is shown in Figure 2.
NSF 13/38/EPADWCTR The accompanying notice is an integral part of this verification statement. May 2013
VS-v
-------
4
0 50 100 150 200 250 300 350 400 450 500
Flow Rate (gpm)
Figure 2. Set Line for Minimum 3.0-log Cryptosporidium Reduction Credit.
Deriving the Validation Factor and Log Credit for Giardia
The VF for Giardia was determined quantitatively to account for key areas of uncertainty and variability,
using the same procedures and equations described above. The RED bias factor for Giardia was obtained
from Appendix G of the UVDGM-2006. The UDR and USP uncertainties were the same as those used for
the Cryptosporidium calculations.
The NeoTech D438™ achieved a minimum of 3.5-log reduction credit for the low power runs at 251 gpm
at 10.4 mW/cm2 and a 4.0-log reduction credit for all of the test runs at the set points of 151 gpm - 7.9
mW/cm2 and 434 gpm - 13.2 mW/cm2. The set line for a minimum 3.0-log reduction credit for Giardia is
the same as the set line for a minimum 3.0-log reduction credit for Cryptosporidium, as shown in Figure
2.
QUALITY ASSURANCE/QUALITY CONTROL
The NSF QA Department performed a QA review of the analytical data. A complete description of the
QA/QC procedures is provided in the verification report.
NSF 13/38/EPADWCTR
The accompanying notice is an integral part of this verification statement.
VS-vi
May 2013
-------
Original signed by Cynthia Sonich-Mullin on
06/05/2013
Original signed
06/17/2013
by David Purkiss on
Cynthia Sonich-Mullin
Director
Date
David Purkiss
Water Systems General Manager
Date
National Risk Management Research
Laboratory
Office of Research and Development
United States Environmental Protection
Agency
NSF International
NOTICE: Verifications are based on an evaluation of technology performance under specific,
predetermined criteria and the appropriate quality assurance procedures. EPA makes 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 10/33/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 13/38/EPADWCTR
The accompanying notice is an integral part of this verification statement.
VS-vii
May 2013
------- |