EPA/600/R-13/248
November 2013
THE ENVIRONMENTAL TECHNOLOGY VERIFICATION
PROGRAM
ET
V^lVl
V
U.S. Environmental Protection Agency
NSF International
ETV Joint Verification Statement
TECHNOLOGY TYPE: UV DISINFECTION IN DRINKING WATER
APPLICATION: REMOVAL OF MICROBIAL CONTAMINANTS
PRODUCT NAME: ETS UV SYSTEM ECP-113-5
VENDOR: ENGINEERED TREATMENT SYSTEMS LLC
ADDRESS: 9652 BEAVERLAND PARKWAY
BEAVER DAM, WISCONSIN
PHONE: 877-885-4628
WEBSITE: HTTP://ETS-UV.COM
EMAIL: INFO@ETS-UV.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 ETS UV System ECP-113-5 (Model ECP-113-5).
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 according to rigorous quality assurance protocols to ensure that data of known and adequate
quality are generated and that the results are defensible.
ABSTRACT
The ETS UV System Model ECP-113-5 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 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
NSF 13/39/EPADWCTR The accompanying notice is an integral part of this verification statement. November 2013
VS-i
-------
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 RED is achieved. The microorganism used for the validation was MS2 coliphage virus. ETS
selected flow rates for testing of 50, 75, and 100 gpm based on the unit design and preliminary screening
tests. The lowest irradiance tested was 82 W/m2 which occurred with full power to the unit and a feed
water ultraviolet transmittance (UVT) of 78%.
ETS also requested an additional set point be tested at a higher flow rate of 175 gpm. The purpose was to
demonstrate that a 3 log reduction of Cryptosporidium could be achieved at this higher flow rate based on
the validation factor and validated dose calculations specified in the USEPA Ultraviolet Design Guidance
Manual (UVDGM-2006). The goal was to use this additional set point in combination with the set points
at 50, 75 and 100 gpm to develop a setline for flow rate and irradiance combinations that would achieve a
3-log reduction of Cryptosporidium. A calculated 3 log reduction credit for Cryptosporidium was
achieved at all set points including the highest flow rate of 175 gpm at an intensity of 105 W/m2.
TECHNOLOGY DESCRIPTION
The Model ECP-113-5 uses one (1) medium pressure mercury amalgam lamp and one intensity sensor
mounted in a stainless steel flow chamber. The inlet pipe size is 3 inch diameter, the unit is designed for
an operating pressure of 60 psi, and operating power consumption is 1300 W. The medium pressure lamp
has a lamp life of 4000 hours. The sensor is a UV-Technik SUV20.1 A2Y2C unit with a measuring field
angle of 160 degrees and measuring range of 0 to 100 W/m2. The system has a control panel that
provides data on the lamp condition, operating hours, irradiance measured by the sensor, and operating
conditions such as temperature. 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 according to the ETS
installation and assembly instructions. Two 90 degree 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 + 2.7%
over the range of flow rates. A chemical feed pump (injector pump) was used to inject MS2 coliphage
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 factors 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.
NSF 13/39/EPADWCTR The accompanying notice is an integral part of this verification statement. November 2013
VS-ii
-------
Methods and Procedures
The tests followed the procedures described in the Test/Quality Assurance Plan for the ETS UV
Ultraviolet (UV) Reactor, Medium Pressure Lamps, June 2010 (TQAP). The TQAP was adapted from
Generic Protocol for Development of Test/Quality Assurance Plans for Validation of Ultraviolet (UV)
Reactors, 7/2010. 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 was based on biodosimetry which determines the log
inactivation of a challenge microorganism during full-scale reactor testing for specific operating
conditions of flow rate, UV transmittance (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
measured "Reduction Equivalent Dose (REDmeas)". The REDmeas 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 rates - irradiance set points (50 gpm - 80 W/m2; 75 gpm - 90 W/m2;
100 gpm - 105 W/m2) were tested for the set line with each condition being performed in duplicate. The
irradiance targets were based on expected irradiance at UVT's of 79%, 90%, and 94%. The fourth set
point for 3-log reduction of Cryptosporidium was run at 175 gpm and a target intensity of 105 W/m2,
which was expected to be the intensity for a UVT of 94%.
The main validation tests were run on two days, July 18 and July 19, 2012. Additional testing at the lower
flow rates (50 gpm, 75 gpm) was performed on September 11, 2012. The first day of testing was
dedicated to the test conditions and duplicate runs where the UVT of the feed water was lowered to the
target levels (<79%, <90%, and <94%) and the lamps were operated at full power. The second day of
testing was dedicated to the test conditions and duplicates where high UVT feed water (95%) was used
and the lamp power was reduced to achieve the target intensity level. On the third day of testing, both low
UVT water (<79%) with full power at a flow rate of 50 gpm and high UVT water with reduced power for
flow rates of 50 and 75 gpm were used. Collimated beam tests were run in duplicate on all three test days
and included minimum UVT water (79%) and maximum UVT water (97%). For this validation test, there
were four sets of duplicate collimated beam test data, two at low UVT and two at high UVT.
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 designed according to the DVGW guideline W 294 (June, 2006) and the ONORM M5873-2
standard (June 2002). Evidence of calibration of the sensors, traceable to a standard of the Physikalisch
NSF 13/39/EPADWCTR The accompanying notice is an integral part of this verification statement. November 2013
VS-iii
-------
Technische Bundesanstalt (PTB) in Braunschweig, was provided by ETS as provided to them by the
sensor manufacturer (uv-technik).
The same duty sensor was used for monitoring intensity (irradiance) for all test runs. The control panel
provided direct readings of intensity in W/m2. 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 3.5% to 7.3% of the average of the two reference sensors, which meets the QC goal of <10%.
The two reference sensors showed a variance of 0.0 to 1.0% at 100% power and 0.0 to 1.8% % at 64%
power.
Set Line for 40 m J/cm2 RED
The three set points selected for this validation all achieved a REDmeas of 40 mJ/cm2 based on MS2, 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 100 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 82 W/m2. A UV system cannot operate below the lowest validated
irradiance and claim a 40 mJ/cm2 REDmeas. The three set points used to develop at set line were:
Set Point 1 - 50 gpm; 82 W/m2
Set Point 2-75 gpm; 89 W/m2
Set Point 3-100 gpm; 105 W/m2
160
60
40
20
20
40 60 80
Flow Rate (gpm)
100
120
Figure 1. Set line for 40 mJ/cmz REDmeas for ETS UV Model ECP-113-5.
Deriving the Validation Factor and Log Credit for Cryptosporidium
NSF 13/39/EPADWCTR The accompanying notice is an integral part of this verification statement.
VS-iv
November 2013
-------
As described in UVDGM, several uncertainties and biases are involved in using experimental testing to
define a validated dose and validated operating conditions. The validation factor (VF) for
Cryptosporidium was determined quantitatively to account for key areas of uncertainty and variability.
The equation for the VF is:
VF = BRED x[l+(UVai/100)]
where:
VF = Validation Factor;
BRED = RED bias factor;
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 was 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 July UDR
results for low and high UVT waters (27.48% and 20.74%, respectively) are less than 30%, and therefore
UDR was not used in calculating UVai for the test runs corresponding to these days of testing. The
September UDR results for low and high UVT waters were 26.99% and 33.46%, respectively. Since the
UDR was >30% at the UV dose corresponding to 1-log inactivation of the challenge organism, the
uncertainty of the dose response (UDR) was included in the calculation of uncertainty (UVai) for the test
runs performed in September. The 75 gpm flow rate test with the power turned down included one test
run in July and one test run in September. The September test run had the highest UDR of 33.46%. The
highest Udr measured in September was applied to both test runs and was included in determining the
uncertainty (UVai) for both test runs.
The USp and UDR factors were used for calculating UVai perthe equation:
UVai = (USP2+UDR2)1/2 ifUDR>30%
UVai = USp if UDR <30%
After establishing the validation factor (VF), the validated dose was calculated as:
Validated dose = RED/VF
The three set points tested to demonstrate a minimum REDmeas of 40 mJ/cm2 and the additional set point
at the higher flow rate of 175 gpm and an intensity of 105 W/m2 met the objective of achieving a 3.0 log
reduction credit for Cryptosporidium. The set line for a 3.0 log reduction credit for Cryptosporidium is
shown in Figure 2. This set line was based on the following set points:
Set Point 1 - 50 gpm; 82 W/m2
Set Point 2- 75 gpm; 89 W/m2
Set Point 3-100 gpm; 105 W/m2
Set Point 4-175 gpm; 105 W/m2
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 13/39/EPADWCTR The accompanying notice is an integral part of this verification statement. November 2013
VS-v
-------
40
20
0 20 40 60 SO 100 120 140 160 180 200
Flow Rate (gpm)
Figure 2. Set Line for Minimum 3-log Cryptosporidium Inactivation for ETS UV Model ECP-113-5.
Original signed by Cynthia Sonich-Mullin on Original signed by David Purkiss on
01/23/2014 01/16/2014
Cynthia Sonich-Mullin Date
Director
National Risk Management Research
Laboratory
Office of Research and Development
United States Environmental Protection
Agency
Date
Vice President
Water Systems
NSF International
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
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
1. Electronic PDF copy
NSF web site: http://www.nsf.org/info/etv
EPA web site: http://www.epa.gov/etv
NSF 13/39/EPADWCTR
The accompanying notice is an integral part of this verification statement.
VS-vi
November 2013
------- |