October 2002
Environmental Technology
Veri fication Protocol
Water Quality Protection Center
Verification Protocol for Secondary Effluent
and Water Reuse Disinfection Applications
Prepared by
NSF International
Under a Cooperative Agreement with
U.S. Environmental Protection Agency
ElVElVElV
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Environmental Technology Verification
Water Quality Protection Center
Verification Protocol for Secondary Effluent and
Water Reuse Disinfection Applications
VERIFICATION PROTOCOL FOR SECONDARY EFFLUENT
AND WATER REUSE DISINFECTION APPLICATIONS
Prepared by:
O. Karl Scheible
Edward J. Mignone
HydroQual, Inc.
Mahwah, NJ
and
NSF International
P. O. Box 130140
Ann Arbor, MI 48113-0140
734-769-8010
800-673-6275
with support from the
U.S. Environmental Protection Agency
Copyright 2002 NSF International 40CFR35.6450.
Permission is hereby granted to reproduce all or part of this work, subject to the limitation that users
may not sell all or any part of the work and may not create any derivative work therefrom. Contact an
ETV Water Quality Protection Center Manager at (800) NSF-MARK with any questions regarding
authorized or unauthorized uses of this work.
Issued January 11, 2002
Revised October 2002
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Environmental Technology Verification
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Water Reuse Disinfection Applications
FOREWORD
In 1995, the U.S. Environmental Protection Agency (EPA) instituted the Environmental Technology
Verification Program (ETV) to verify the performance characteristics of commercial-ready
environmental technologies through the evaluation of objective and quality-assured data. Managed by
EPA's Office of Research and Development, ETV was created to substantially accelerate the entrance
of innovative environmental technologies into the domestic and international marketplaces. The
independent technology verifications generated through the ETV Program provide purchasers and
permitters of technologies with an independent and credible assessment of the technology they are
purchasing or permitting. Participation on the part of technology manufacturers is strictly voluntary.
The goal of the ETV Water Quality Protection Center, one of six ETV Centers that were established to
address each of the major environmental media and various categories of environmental technologies, is
to verify the performance of technologies used to protect ground and surface waters from
contamination. The Center is guided by the expertise of several stakeholder groups. Stakeholder
groups consist of representatives of key customer groups for the particular technology sector, including
buyers and users of technology, developers and vendors, state and federal regulatory personnel, and
consulting engineers. All technology verification activities are based on testing and quality assurance
protocols that have been developed with input from the major stakeholder/customer groups.
NSF is the verification partner organization for two centers under EPA's ETV Program: the Drinking
Water Systems Center and the Water Quality Protection Center. NSF International is an independent,
not-for-profit organization dedicated to public health, safety, and protection of the environment. NSF
develops standards, provides educational services, and offers superior third-party conformity
assessment services, while representing the interests of all stakeholders. In addition to well-established
standards-development and certification programs, NSF specifically responds to and manages research
projects, one-time evaluations and special studies.
This Verification Protocol for Secondary Effluent and Water Reuse Disinfection Applications was
developed under the Source Water Protection Pilot, which merged with the Wet Weather Flow
Technologies Pilot in 2002 to form the Water Quality Protection Center. Testing conducted under the
ETV program using this protocol does not constitute an NSF or EPA certification of the product tested.
Rather, it recognizes that the performance of the equipment has been determined and verified by these
organizations.
Verification differs from certification in that it employs a broad, public distribution of test reports and
does not use pass/fail criteria. In addition, there are differences in policy issues relative to certification
versus verification. Certification, unlike verification, requires auditing of manufacturing facilities, periodic
retesting, mandatory review of product changes, and use of the NSF Mark. Both processes are similar,
however, in regard to having standardized test methods and independent performance evaluations and
test result preparation. This protocol is subject to revision; please contact NSF to confirm this revision
is current.
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ACKNOWLEDGEMENTS
EPA and NSF acknowledge and thank those persons who participated in the preparation and review of
this Verification Protocol for Secondary Effluent and Water Reuse Disinfection Applications.
Without their hard work and dedication to the project, this document would not have been approved
through the process that has been set forth for this ETV project.
Protocol Writers
Karl Scheible
Edward Mignone
NSF Staff
Thomas Stevens
Maren Roush
Carol Becker
Robert Donofrio
Bruce DeMaine
HydroQual, Inc.
HydroQual, Inc.
Project Manager, ETV Water Quality Protection Center
Project Coordinator, ETV Water Quality Protection Center
Project Coordinator, ETV Drinking Water Systems Center
Manager, Microbiology Laboratory
Manager, QA & Safety
EPA Staff
Raymond Frederick EPA ETV Water Quality Protection Center Manager
Dr. Izabela Wojtenko ORD-NRMRL, Urban Watershed Management Branch
ETV Water Quality Protection Center — Technolosv Panel Participants
Parviz Amirhor
Dr. Raul Cardenas
Dr. Andreas Kolch
Dr. Victor Moreland
Dr. Didier Penin
Dr. Rick Sakaji
Ken Smith
Dr. George Tchobanoglous
Dr. Elliott Whitby
Faye, Spofford and Thorndike
Environmental Consultant
Wedeco AG
University of Hawaii
Degremont North America
California Department of Health Services
Camp, Dresser & McKee
University of California - Davis
SUNTEC Environmental
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TABLE OF CONTENTS
FOREWORD ii
ACKNOWLEDGEMENTS iii
LIST OF TABLES viii
LIST OF FIGURES ix
1 INTRODUCTION 1
1.1 ETV OBJECTIVES 1
1.1.1 Purpose of this Protocol 2
1.1.2 Verification Process 2
1.2 UV TECHNOLOGY DESCRIPTION 3
1.3 TECHNICAL APPROACH 4
1.3.1 Dose-Delivery 5
1.3.2 Dose-Delivery Reliability 6
1.3.2.1 Quartz Surface Maintenance 7
1.3.2.2 System Response or Impact from Failures/Interrupts/Upsets/Maintenance 7
1.3.2.3 Process Control 8
1.3.3 UV Design Factor Verification 8
1.3.3.1 Quartz Sleeve Fouling Factor Verification 8
1.3.3.2 Lamp Age Factor Verification 9
2 DEVELOPMENT OF A VERIFICATION TEST PLAN 10
2.1 OBJECTIVES 10
2.2 PROJECT ORGANIZATION 11
2.2.1 NSF International 11
2.2.2 U.S. Environmental Protection Agency (EPA) 11
2.2.3 Testing Organization (TO) 12
2.2.4 UV Technology Vendor 12
2.2.5 Support Organizations 13
2.2.6 Technology Panel on Disinfection 13
2.3 CAPABILITIES AND DESCRIPTION OF THE SYSTEM 13
2.3.1 System Description 13
2.3.2 System Capabilities 14
2.4 EXPERIMENTAL DESIGN 15
2.5 HEALTH AND SAFETY PLAN (HASP) 15
2.6 QUALITY ASSURANCE PROJECT PLAN (QAPP) 15
3 TEST ELEMENT 1: DOSE-DELIVERY VERIFICATION 16
3.1 DOSE-RESPONSE CALIBRATION 16
3.1.1 Selection, Culturing and Harvesting of Test Organism 16
3.1.2 Dose-Response Calibration of the MS2 Phage 23
3.1.2.1 Collimated Beam Apparatus 23
3.1.2.2 Intensity Probe and Radiometer Calibration 26
3.1.2.3 Dose-Response Test with the Collimated Beam Apparatus 26
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3.1.3 Dose-Response Data Analysis 29
3.2 UV TEST UNIT SPECIFICATIONS 31
3.2.1 Size and Component Considerations 31
3.2.2 Lamp Output 34
3.2.3 Reactor Configuration 34
3.3 TEST FACILITY 34
3.3.1 Test Facility Equipment 34
3.4 DOSE-FLOW ASSAY 37
3.4.1 Test Batch Preparation 37
3.4.2 Test Conditions 41
3.4.2.1 Quartz Surface Condition 41
3.4.2.2 UV Transmittance of the Test Water 41
3.4.2.3 Turbidity 41
3.4.2.4 MS2 Phage Densities 42
3.4.2.5 Lamp Output 42
3.4.2.6 Reduced Lamp Output 42
3.4.2.7 Temperature 43
3.4.2.8 Hydraulic Loading Rates 44
3.4.2.9 Headloss Measurement 44
3.4.2.10 Power Utilization 44
3.4.3 Test Procedures, Sampling, System Monitoring 45
3.4.3.1 Test Procedure 45
3.4.3.2 System Monitoring 47
3.4.3.3 Hydraulic Testing 47
3.4.3.3.1 Residence Time Distribution 48
3.4.3.3.2 Velocity Profiles 48
3.4.3.3.3 Headlosses 49
3.5 DATA COMPILATION AM) ANALYSIS 49
3.5.1 Dose-Response Calibration 49
3.5.2 Dose-Flow Relationships 49
3.5.3 Hydraulic Characterization Results 51
4 TEST ELEMENT 2: DOSE-DELIVERY RELIABILITY VERIFICATIONS 52
4.1 TEST ELEMENT 2A: UV QUARTZ SURFACE MAINTENANCE 52
4.1.1 Test System Specifications 52
4.1.1.1 Size and Component Considerations 52
4.1.1.2 Test Facility Setup 54
4.1.1.2.1 Feed Formulation/Characterization 54
4.1.1.2.2 Test Facility Equipment/Assembly 55
4.1.2 Fouling/Cleaning Evaluation 57
4.1.2.1 Operating Conditions 57
4.1.2.2 Quartz Transparency Measurement 58
4.1.2.3 Operating Sequence and Procedures 60
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4.1.3 Data Compilation and Analysis 62
4.2 TEST ELEMENT 2B: GENERAL SYSTEM RELIABILITY 62
4.2.1 System Monitoring 62
4.2.2 Additional Reliability Claims 63
4.2.2.1 Monitor Alarms and/or Indicators Verification 63
4.2.2.2 Example Conditions 63
4.2.3 General Test Protocol 65
4.2.4 Data Compilation and Analysis 65
4.3 TEST ELEMENT 2C: PROCESS SYSTEM CONTROL VERIFICATION 65
4.3.1 UV Test Unit Specifications 67
4.3.2 TestFacility 67
4.3.3 Dose-Flow Assay 67
4.3.4 Data Compilation and Analysis 67
5 TEST ELEMENT 3: UV DESIGN FACTORS VERIFICATIONS 68
5.1 TEST ELEMENT 3 A: FOULING FACTOR DETERMINATION 68
5.1.1 Test System Specifications 68
5.1.2 Test Facility Setup 71
5.1.2.1 Source Water and Characterization 71
5.1.2.2 Test F acility Equipment/Assembly 72
5.1.3 Fouling/Cleaning Evaluation 72
5.1.4 Operating Conditions 72
5.1.5 Quartz Transparency Measurement 74
5.1.6 Fouling and Cleaning Procedures 74
5.1.7 Data Compilation and Analysis 75
5.2 TEST ELEMENT 3B: LAMP AGE FACTOR VERIFICATION 75
5.2.1 Minimum System Requirements 75
5.2.2 TestFacility 76
5.2.3 Test Facility Equipment 76
5.2.3.1 Test Reactor(s) 76
5.2.3.2 Lamp Output Measurement Reactor 77
5.2.3.3 Electrical Source 77
5.2.3.4 Water Source 77
5.2.3.5 Water Temperature Variability 77
5.2.3.6 UV Output Monitoring 77
5.2.4 General Test Protocol 78
5.2.5 Data Compilation and Analysis 81
6 DOCUMENTATION AND REPORTING 82
6.1 DATA MANAGEMENT AND DOCUMENTATION 82
6.2 VERIFICATION REPORT 82
7 QUALITY ASSURANCE AND QUALITY CONTROL 84
7.1 PROJECT DESCRIPTIONS, OBJECTIVES and ORGANIZATION 84
7.2 EXPERIMENTAL APPROACH 84
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7.3 SAMPLING PROCEDURES 85
7.4 TESTING AND MEASUREMENT PROTOCOLS 85
7.5 QA/QC CHECKS 86
7.5.1 Data Quality Indicators 86
7.5.1.1 Representativeness 86
7.5.1.2 Accuracy 86
7.5.1.3 Precision 87
7.6 DATA REPORTING, DATA REDUCTION, AND DATA VALIDATION 88
7.7 ASSESSMENTS 89
7.8 REFERENCES 89
8 GLOSSARY 90
9 REFERENCES 92
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LIST OF TABLES
3-1 SUMMARY OF THE EXPERIMENTAL EFFORT FOR TEST ELEMENT 1: DOSE
DELIVERY VERIFICATION 18
4-1 SUMMARY OF THE EXPERIMENTAL EFFORT FOR TEST ELEMENT 2A: UV
QUARTZ CLEANING DEVICE VERIFICATION 53
4-2 SUMMARY OF THE EXPERIMENTAL EFFORT FOR TEST ELEMENT 2B: GENERAL
SYSTEM RELIABILITY VERIFICATION 64
4-3 ADDITIONAL TASKS REQUIRED FOR TEST ELEMENT 2C: PROCESS CONTROL
SYSTEM VERIFICATION 66
5-1 COMPARISON OF TEST ELEMENT 2A AND TEST ELEMENT 3 A 69
5-2 SUMMARY OF THE EXPERIMENTAL EFFORT FOR TEST ELEMENT 3A: FOULING
FACTOR DETERMINATION 70
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LIST OF FIGURES
3-1 EXAMPLE COLLIMATOR APPARATUS FOR DOSE-RESPONSE TEST 24
3-2 EXAMPLE DOSE-RESPONSE CALIBRATION FOR MS2 COLIPHAGE 30
3-3 EXAMPLE TEST FACILITY LAYOUT FOR PHAGE DOSE-DELIVERY ASSAYS 36
3-4 EXAMPLE CORRELATION OF TRANSMITTANCE WITH COFFEE ADDITION 39
3-5 EXAMPLE RELATIONSHIP OF DOSE (mW-s/cm2) AS A FUNCTION OF
HYDRAULIC LOADING (I.pm/I.amp) 50
4-1 SCHEMATIC LAYOUT OF CLEANING EVALUATION TEST FACILITY 56
4-2 QUARTZ TRANSPARENCY TEST UNIT 59
5-1 SCHEMATIC LAYOUT OF FOULING FACTOR VERIFICATION TEST FACILITY 73
5-2 TEST SET-UP SCHEMATIC 80
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1 INTRODUCTION
This introductory section presents the objectives of the ETV program, a general description of UV
disinfection technologies, and the technical approach to be used in the verification of UV equipment and
related systems.
1.1 ETV OBJECTIVES
The Environmental Technology Verification (ETV) program was created by the United States
Environmental Protection Agency to accelerate the development and commercialization of improved
environmental technologies through third-party verification and reporting of performance. The goal of
the ETV Program is to verify performance characteristics of commercial-ready environmental
technologies through the evaluation of objective and quality assured data so that potential buyers and
permitting authorities are provided with an independent and credible assessment of the technology that
they are buying or permitting.
There are six "centers" in the ETV Program, one of which is the Water Quality Protection (WQP)
Center being administered by NSF International. The goal of the WQP Center is to verify technologies
that protect the quality of ground and surface waters by preventing or reducing contamination. The
WQP Center addresses several areas of environmental technologies, one of which is disinfection
technologies, including UV radiation. A Technology Panel formed through NSF International advises
on the design of the protocol and its subsequent implementation.
A generic protocol is being developed through the WQP Center for the verification of disinfection
equipment used for treated wastewater from small (less than 0.01 mgd) on-site, or similar systems.
These include UV and chemical disinfectants:
"Verification Protocol for Wastewater Disinfection Technologies for Small Systems"
Draft 1.0, prepared by HydroQual, Inc. for USEPA and NSF International, December
2000.
With respect to the use of UV, other protocols have been used and/or proposed in the industry that
have very similar objectives to that of the ETV Program. These include a protocol that has been a
"standard" for assaying dose-delivery in a secondary effluent application, testing the equipment at 55
and/or 65%T (at 254 nm) and at lamp output in the vicinity of 65 to 75 percent nominal. The National
Water Research Institute (NWRI) recently published a second protocol, appended to its document:
"Ultraviolet Disinfection Guidelines for Drinking Water and Water Reuse" NWRI and
American Water Works Association Research Foundation, December 2000.
This addressed water reuse applications where the treated wastewaters received final treatment by
granular or other media filtration, membrane filtration, or reverse osmosis varying the transmittance
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accordingly to 55, 65 and 90 percent (at 254 nm), respectively. It required a default power attenuation
factor of 0.5 and that test conditions mimic a quartz-fouling factor (default) of 0.8. Protocols are
suggested in the same guidance document for verifying alternate quartz-fouling and/or lamp-power
attenuation factors.
In addition to the cited protocols, a verification protocol was also prepared under the ETV Wet-
Weather Flow Technologies Pilot to address high-rate disinfection of wet-weather flows with UV
radiation:
"Generic Verification Protocol for High-Rate, Wet-Weather Flow Disinfection
Applications" Version 4.1, Prepared by HydroQual, Inc., for USEPA and NSF
International, July 2000.
Given the UV disinfection applications that are already covered by the ETV Program, incorporating the
secondary effluents and wastewater reuse applications, and related testing, results in comprehensive
coverage of the broad spectrum of opportunities available to the UV industry in wastewater treatment.
It also brings this myriad of protocols and testing requirements under the single umbrella of the ETV
program, a benefit to the industry, allowing prospective owners a single resource from which to gain UV
technology information.
The ETV Program and its associated Technology Panel recommended the preparation of this generic
protocol for testing UV technologies, as applied to secondary effluents and wastewater reuse. It
specifies the objectives and technical approach of the ETV center and the general procedures that shall
be followed to meet the specific technology verification objectives. Subsequently reviewed by the
Stakeholder Advisory Group (SAG) and approved by the EPA, it is then offered to technology vendors
who elect to participate in the testing program. A project or technology-specific Test Plan shall be
prepared in which the protocols are refined to meet the technology's configuration and vendor claims,
while staying within the framework and objectives of the generic protocol.
1.1.1 Purpose of this Protocol
This Verification Protocol describes the steps that must be followed to ensure that an UV technology
verification is carried out in a consistent and objective manner, with appropriate quality control to ensure
the integrity of the data.
1.1.2 Verification Process
The verification process under the ETV program consists of three major steps:
1. Planning. The planning phase establishes the procedures to be followed for verification of
a specific technology, the testing firm, and the verification program's organization with
respect to personnel and oversight. A Verification Test Plan is developed by the
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designated testing organization and is submitted for approval to the NSF and EPA. It
will include detailed site and equipment specifications, procedures for testing (including
documentation for conformity to the generic protocol), and a quality assurance project
plan for assuring valid data. Guidelines for this phase of the program are provided in
Section 2.
2. Verification Testing. This phase of the project involves the actual assembly, installation, and
operation of the test facility, collection of the targeted samples, and completion of all
analyses required under the Verification Test Plan. Sections 3, 4 and 5 present the
protocols for this testing phase of the UV Disinfection ETV for secondary wastewater
and water reuse applications.
3. Data Assessment and Reporting. The final phase of the verification program includes analysis of
the data generated during testing, and preparation of a final Verification Report and
Verification Statement. Guidelines for this phase of the project are given in Section 6.
1.2 UV TECHNOLOGY DESCRIPTION
Ultraviolet (UV) light radiation is a widely accepted method for accomplishing disinfection of treated
wastewaters. Its germicidal effectiveness is generally attributed to its ability to damage links in the DNA
molecule of a cell, resulting in the cells' inability to replicate. UV is most effective in the far UV region
of the electromagnetic spectrum, between 230 and 290 nm (generally referred to as the UVC range),
generally corresponding to the absorbance spectrum of nucleic acids. The optimum germicidal
wavelengths appear to be in the vicinity of 255 to 265 nm.
The dominant commercial source of UV light for germicidal applications is the mercury vapor, electric
discharge lamp. These are commercially available in "low-pressure" and "medium-pressure"
configurations. The conventional low-pressure lamp operates at 0.007 mm Hg, and is typically supplied
in long lengths (0.75 to 1.5 m) and with diameters between 1.5 and 2 cm. The major advantages of the
low-pressure lamp are that its UV output is nearly monochromatic at a wavelength of 254 nm and it is
energy efficient, converting approximately one-third of its input energy to UV light. The overall output
of a conventional low-pressure lamp is relatively low, typically about 25 W at 254 nm for a 70 to 75 W,
1.47-m long lamp. More recent developments have produced higher output low-pressure lamps,
generally by using an amalgam and/or a higher current discharge and pressures between 0.01 to 0.001
mm of Hg. These are very similar in appearance to the conventional low-pressure lamps, but with
outputs 1.5 to 5 times higher, thus reducing the required number of lamps for an application.
The medium-pressure lamps operate at 100 mm of Hg, and can have many times the total UVC output
of the conventional low-pressure lamp, depending on the input energy to the lamp. The light is
polychromatic in this case, with a conversion of approximately 7 percent of its input energy to germicidal
light in the vicinity of 254 nm. However, the sum of all the spectral lines in the UVC region can total
three to four times the output at 254 nm. Because of the very high output rates, fewer medium-pressure
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lamps are needed, when compared to conventional low-pressure lamps, although they are substantially
lower in efficiency.
Other UV sources are being developed and commercialized, including pulsed power lamps and lasers.
These are emerging in the disinfection market, and may find a commercial niche in the future. This
protocol can be used in large part for such systems, modified as needed in the Verification Test Plan.
The low- and medium-pressure germicidal lamps are sheathed in quartz sleeves and placed
directly in the wastewater stream, configured in a geometric array, and oriented horizontally or vertically.
The lamp systems are typically modular in design, and assembled in single or multiple channels and/or
reactors. Key considerations in the design of the system are directed to efficient delivery of the energy
to the wastewater and to the organisms. This is quantified as the "dose," or the product of the intensity
of the radiation (I, watts/cm2) and the time (t, seconds) to which an organism is exposed to the
radiation. The intensity of the radiation is a function of the output of the lamps, and of the factors that
attenuate the energy as it moves to and through the water. These include simple dilution of the energy as
it moves from the source, absorbance of the energy by the quartz sleeve separating the lamp from the
liquid, and the chemical absorbance, or demand, of the energy by constituents in the wastewater.
Exposure time is a function of the hydraulic and physical design of the reactor. Ideally, all
elements entering the reactor should be exposed to all levels of radiation for the same amount of time; a
condition described as turbulent, ideal plug flow. In fact, non-ideal conditions exist; there is a
distribution of residence times in the reactor due to advective dispersion and mixing in the reactor. The
degree to which the reactor strays from ideal plug flow will directly impact the efficiency of dose-
delivery in the system.
1.3 TECHNICAL APPROACH
There are three major UV system operation and performance elements addressed in this
Protocol, comprising up to eleven individual verifications. A vendor may choose to conduct
verifications covering any one or combination of these test elements:
Dose-Delivery Verification
Quantitative assessment of the ability of the UV equipment to deliver dose at liquid UV
transmittances (at 254 nm) that are representative of the desired application(s)
a. Secondary Effluent
• 55% Transmittance
• 65% Transmittance
• 75%) Transmittance
b. Reuse Applications (Based on NWRI/AwwaRF Guidelines, December 2000)
• Granular or Fabric Media Filtered Effluent - 55% Transmittance
• Membrane Filtered Effluent - 65% Transmittance
• Reverse Osmosis Effluent - 90% Transmittance
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Dose-Delivery Reliability Verification
a. Quartz Surface Maintenance
Assessment of the efficacy of an UV system's automatic cleaning device to
consistently maintain the quartz surfaces in a clean state, efficiently transmitting
the UV energy to the liquid
b. System Reliability
System response control and a qualitative assessment of UV system monitors,
alarms and/or indicators
c. Process Control
The ability of the UV system to automatically monitor and/or adjust UV doses
to changing conditions
UV Design Factor Verification
a. Quartz-Fouling Factor Determination
Quantitative determination of the long-term attenuation factor for quartz
transmittance losses
b. Lamp-Age Factor Testing
Quantitative (termination of the relative UV output after continuous normal
operation for the vendor-prescribed effective life
1.3.1 Dose-Delivery
By its nature, UV disinfection performance is dependent on the upstream processes used for
pretreatment, particularly for particle removal or reduction, and for oil/grease and organics removal.
These conditions are variable, particularly as they apply to alternative levels of treatment provided
upstream and from site to site. The design basis typically developed for a specific UV system
application incorporates the characteristics of the wastewater to be disinfected, including particulates,
the nature and size distributions of the particulates, bacterial levels to be disinfected, flow rates, and the
UV transmissibility (or, conversely, the absorbency) of the wastewaters. These are all established to
reflect a planned level of treatment, and the expected variability in quality and quantity. Finally, the dose
required to meet specific target levels is typically established from direct testing (e.g., collimated-beam,
dose-response methods) of the wastewaters or similar wastewaters. Once this "design basis" is
established, independent of the UV equipment, the next step is to select equipment that can meet these
specific dose requirements under the expected wastewater conditions.
Demonstrating, or verifying, the ability of a specific system to deliver an effective dose meets the
ETV's technical objective. This is described as the "delivered dose," which is defined
(NWRI/AwwaRF, December 2000) as the dose equivalent to that measured with the collimated beam
apparatus for the same degree of inactivation of the target pathogen. Although recent research has been
directed to modeling the delivered dose, particularly methods utilizing computational fluid dynamics in
conjunction with computed intensity fields, (NWRI/AwwaRF, December 2000), direct biological assay
procedures have generally been used to estimate the delivered dose for specific reactor configurations,
typically as a function of the hydraulic loading rate. It is a viable and accepted method and has been
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used successfully for many years. The results are often applied to qualification requirements in bid
documents for wastewater treatment plant applications.
The bioassay procedure uses a known microorganism, which is cultured and harvested in the
laboratory and then subjected to a range of discrete UV doses. These doses are provided by a
laboratory-scale, collimated-beam apparatus, which can deliver a known accurately measured dose
(measured intensity, I, times a controlled time, t). By measuring the response (log survival ratio) to these
doses, a dose-response relationship, or calibration curve, is developed for the specific organism. Once
calibrated, this same batch of microorganisms is then injected into the field-scale UV test unit, which is
operated over a range of hydraulic loadings (thus yielding a range of exposure times). The response of
the organism can then be used to infer, from the laboratory-based dose-response relationship, the dose
that was delivered by the UV unit. These tests are typically run in a "clean" water matrix (i.e. a particle-
free potable water supply), which has been adjusted by chemical means to mimic the transmittances
encountered with secondary wastewaters or wastewater reuse applications.
Effective dose delivery is also predicated on the assumption that the hydraulic behavior results in
full dose distribution throughout the reactor. This is achieved by approximating plug-flow conditions
with low axial dispersion. Methods to assess the hydraulic characteristics of reactors include the
development of residence time distributions (RTD) and the measurement of velocities across a
representative cross-sectional plane in the up- and down-stream vicinities of the lamp batteries.
The velocity profiles are typically measured with appropriate meters at a pre-set minimum
number of points in a cross-section, sufficient to be representative of the entire cross-section. The intent
is to determine if there is a constant, or near-constant velocity across the entire cross-section. The RTD
tests require continuously injecting a conservative tracer into the wastewater until a new steady-state
condition is achieved over background conditions. Once steady state is achieved, the tracer feed is
discontinued and the die-off is recorded. The tracer data are analyzed for conformance to industry-
accepted guidelines for acceptable plug-flow characteristics. It is acknowledged that for some closed-
shell systems, minimal hydraulic detention times preclude the use of these methods. In these cases, the
vendor shall propose an alternative test methodology in the final Verification Test Plan.
1.3.2 Dose-Delivery Reliability
While dose delivery is critical in assessing the performance and capacity of a given disinfection
system, the ability of the system to reliably maintain delivery of the dose is equally important. Does the
system respond adequately to changing conditions to maintain a minimum applied disinfectant dose?
This addresses process control (automatic or manual adjustment to dosing), system response to
component failures, power interruptions, upstream treatment upsets, intermittent flows, and depletion of
disinfectant. Additionally, with respect to UV systems, such operational considerations must address
maintenance devices available for cleaning the quartz surfaces.
Certainly, all integral components for any system need to be structurally and functionally reliable,
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Verification Protocol for Secondary Effluent and
Water Reuse Disinfection Applications
such as mixers, diffusers, pumps, lamps, ballasts, and controls, etc.; however, individual assessment of
such items is not considered under this protocol. Also, ancillary equipment or systems whose express
functions are with operator or public health and safety concerns or issues are not covered. The intent of
the protocol is not to optimize a particular design; it is to assess the system's overall capability with
respect to dose-delivery reliability.
1.3.2.1 Quartz Surface Maintenance
This protocol incorporates an evaluation of the cleaning device provided with a particular
commercial UV system. The approach is to operate a unit with a "typical" feed, comprising simulated
or actual wastewaters, and to monitor the transparency of the quartz sleeves. The Verification Test Plan
for this aspect of a specific ETV will need to address a performance benchmark (i.e., quantify fouling).
This will include controlling the wastewater characteristics imposed on the system (with respect to
"fouling" agents), establishing the period of operation and assessing the system's ability to "restore" the
quartz surface relative to operation without such a device. It is appropriate to conduct this part of the
evaluation on small-scale systems, as long as the cleaning device and operating conditions are
representative of the lull-scale application.
1.3.2.2 System Response or Impact from Failures/Interrupts/Upsets/Maintenance
It is not realistic to expect uninterrupted dose-delivery reliability under all possible
circumstances. Upstream process upsets may result in temporary conditions where disinfection
efficiency is severely compromised. It must also be recognized that individual system components or
part of the overall disinfection system may fail unilaterally. Issues such as impact from power
interruptions or atypical "upset conditions" should be addressed in the final installation design.
What generally is important from a dose-delivery reliability standpoint is the capability of a
system to either self-adjust or somehow indicate conditions which need attention under "normal"
operations. UV systems either have to be equipped with an automatic cleaning system or have the
ability to indicate when cleaning is required or when lamps fail.
To verify specific applicable claims under this section, the vendor must provide an Operations
and Maintenance Manual for the given application. The O&M manual should include recommended or
required maintenance schedules for each piece of operating equipment or subsystem. The manual
should also provide recommended procedures for proper operation of all components and modules
comprising the entire disinfection system.
The protocol provides generic guidance for assessing operational status indicators or alarms. In
the case of automatic lamp shutoffs in cases of no flow, the system will be operated under both
conditions and the response assessed qualitatively (e.g. did the lamps shut off). It is not the intent of the
protocol to determine long-term reliability or verify the life span of individual components, but simply
confirm a vendor's claimed response(s) to a given situation or set of conditions.
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1.3.2.3 Process Control
Process control ensures that there is constant disinfection performance despite fluctuations in
wastewater quality and/or flow. Process control may be a pretreatment design consideration, such as
flow equalization prior to disinfection. In some cases, it would then be possible to maintain the dose at
some constant minimum. This is very often the case with UV in that "overdosing" is of no real concern.
In some cases, process control relies on either manual or automatic adjustments to the UV dose
in response to some predetermined, quantifiable change in conditions. The NWRI Guidance
(NWRI/AwwaRF, December 2000) requires the inclusion and reporting of the "operational dose" on a
continuous basis, defined as an operating algorithm that uses water quality and equipment conditions to
estimate real-time dose. This must be calibrated to performance data, such as might be obtained from
the dose-delivery assays. The verification of this algorithm can be a component of this test element.
Based on the stated vendors' claims, process control reliability can be verified by confirming
expected specific system responses to changes in conditions, using prescribed microbial inactivation
rates as performance indicators. Testing is conducted in batch mode using an appropriate wastewater
matrix (secondary effluent or reuse water). A series of bioassay test runs are undertaken where the
transmittance of the water matrix is changed for each test. Between run sets, the system will be
manually adjusted (as prescribed by the vendor) or the system will be allowed to change automatically
as test conditions change. Samples will be collected to measure microbial inactivation and inferred
delivered dose. Qualitative observations will also be recorded, such as status of alarms, flags or other
indicators.
1.3.3 UV Design Factor Verification
Two fundamental design factors used for sizing UV systems are the quartz sleeve fouling factor
and the end-of-lamp life, or aging factor. While empirical data exist that allow designers to choose
appropriate factors, they may sometimes be too conservative for some applications. The previously
cited "Ultraviolet Disinfection Guidelines for Drinking Water and Water Reuse" by NWRI/AWWARF
suggests general protocols to allow vendors to demonstrate design factors that may be ultimately less
conservative than those used as default values in the general guidelines.
1.3.3.1 Quartz Sleeve Fouling Factor Verification
To verify a quartz-sleeve fouling factor, the protocol requires that a vendor-supplied UV system
be equipped with an automatic cleaning device. The UV equipment, with the cleaning mechanism in
operation, will be continuously subjected to a typical secondary effluent for a period of at least six
months. Transmittance of the quartz sleeves will be measured every two months and these
measurements will be compared to the transmittance of a clean, new quartz sleeve. This evaluation
does not have to be conducted on a full-scale module; however, at least four sleeves shall be monitored
for the duration of the test. Polychromatic lamps may be used; however, this protocol only provides
generic guidelines with respect to the peak wavelengths at which quartz transmittance should be
monitored.
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Verification Protocol for Secondary Effluent and
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1.3.3.2 Lamp Age Factor Verification
To verify a lamp age factor, the protocol requires that a set number of lamps be operated in an
environment typical of full-scale operation, covering a specified range of operating water temperatures.
Testing may be conducted remotely or in the laboratory. Lamps must also be operated with a
prescribed number of on/off cycles and their output shall be measured at intervals of not less than 20
percent of the vendor-prescribed lamp life. The output at the end of the test period will be compared to
those measured immediately after the initial 100-hour burn-in period. Polychromatic lamps may also be
used; however, this protocol only provides generic guidelines with respect to the peak wavelengths at
which lamp output should be monitored.
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2 DEVELOPMENT OF A VERIFICATION TEST PLAN
Prior to the start of verification testing of a UV system under the ETV Program, the testing
organization (TO) shall prepare a Verification Test Plan that clearly describes how, where, and by
whom testing is to be conducted. An adequate Verification Test Plan will help to ensure that testing is
conducted and that the results are reported in a manner consistent with the requirements specified in this
Protocol. A good Verification Test Plan also ensures that information about a vendor's equipment is
available for incorporation into a Verification Report upon the completion of testing. An individual
Verification Test Plan shall be developed for each UV System undergoing verification testing.
At a minimum a Verification Test Plan for the verification of a UV System shall include:
• An introduction that briefly describes the objectives of verification testing and an
overview of the approach taken to accomplish the verification;
• Roles and responsibilities of participants in the verification testing;
• A complete description of the technology and its intended functions and capabilities;
• A description of the site(s) where verification testing is to take place;
• A description of the experimental design, that includes the specific test procedures to be
followed and identifies any necessary deviations from the requirements established in
this Protocol;
• A description of the Quality Assurance/Quality Control procedures to be employed to
ensure data quality objectives are met;
• A description of how data is to be analyzed, managed, and reported; and
• Health and safety procedures.
Subsections 2.1 through 2.8 of this protocol establish guidelines and requirements for the content and
scope of each section required in a Verification Test Plan.
2.1 OBJECTIVES
The objectives of the verification test shall be clearly explained, including those identified by the
ETV program itself and those claims identified by the Vendor.
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2.2 PROJECT ORGANIZATION
The organization of the project shall be explained, including the management and oversight
activities of the effort. Organizations and individuals assigned to the project shall be described, including
their specific roles. Key individuals must be presented, including a brief description of their relevant
experience. General guidelines on the roles and responsibilities for the major parties are summarized in
the following discussions.
2.2.1 NSF International
NSF International is the USEPA's verification partner on the Water Quality Protection Center.
NSF's responsibilities include:
• Review and approval of the Verification Test Plan;
• Oversight of Quality Assurance, including the performance of technical system and data
quality audits, as prescribed in the Quality Management Plan for the ETV Water Quality
Protection Center;
• Oversight and audit of the Testing Organization;
• Coordination of Verification Report peer reviews;
• Review and approval of the Verification Report; and
• Preparation and dissemination of the Verification Statement.
2.2.2 U.S. Environmental Protection Agency (EPA)
The EPA will have review and approval responsibilities through the various phases of a
Verification project:
• Verification Test Plan;
• Verification Report;
• Verification Statement; and
• Posting the Verification Report and Verification Statement on the EPA Website.
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2.2.3 Testing Organization (TO)
The Testing Organization shall have experience in the operation and evaluation of UV systems,
the performance of the various procedures comprising the protocol, and the design and performance of
pilot studies. In addition, key individuals must have direct relevant experience and training in the
operation, investigation and sampling tasks associated with each test element. One of these key
individuals in a supervisory or managerial role must also be a registered professional engineer. The TO
will serve as the primary consultant for developing, implementing and reporting the verification. The
responsibilities of the TO will include, but not be limited to, the following:
• Developing the Verification Test Plan in conformance with the generic protocol,
including its revisions in response to comments made during the review period;
• Coordinating the Verification Test Plan with the Vendor and NSF, including
documentation of equipment and facility information and specifications for the
Verification Test Plan;
• Contracting with sub-consultants and general contractors, as needed, to implement the
Test Plan;
• Coordinating and contracting, as needed, with the Host of the test facility, and arranging
the necessary logistics for activities at the plant site;
• Managing the communications, documentation, staffing and scheduling activities
necessary to successfully and efficiently complete the verification;
• Overseeing and/or performing the verification testing per the approved Verification Test
Plan;
• Managing, evaluating, interpreting and reporting the data generated during the
verification testing; and
• Preparing and reviewing the Draft Verification Report.
2.2.4 UV Technology Vendor
The Vendor's responsibilities may include, but shall not be limited to the following:
• Provide the test unit for verification, with all ancillary equipment, instrumentation,
materials and supplies necessary to operate, monitor, maintain and repair the system;
• Provide documentation and calculations necessary to demonstrate the system's
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conformity to commercial systems, hydraulic scalability, and to the requirements of the
protocol;
• Provide descriptive details of the system, its operation and maintenance, its capabilities
and intended function in the targeted applications;
• Provide technical support for the installation and operation of the UV system, including
designation of a staff technical support person and of an on-site technician for training;
• Review and approval of the Verification Test Plan; and
• Review and comment on the Verification Report and Verification Statement.
2.2.5 Support Organizations
The Verification Test Plan may require the support of other organizations, if such activities
cannot be provided from the NSF, EPA, TO or Vendor. This may include laboratory microbiological
and chemical analyses, instrumentation calibrations, mechanical/construction, and operations. Any
contractors brought into the project will be subordinate to the TO and shall be identified as part of the
Verification Test Plan, along with their roles and responsibilities.
2.2.6 Technology Panel on Disinfection
Some or all of the WQP Center UV Disinfection Technology Panel will serve as a technical and
professional resource during all phases of the verification, including the review of Verification Test Plans
and the issuance of verification reports.
2.3 CAPABILITIES AND DESCRIPTION OF THE SYSTEM
2.3.1 System Description
The Verification Test Plan shall provide details of all components comprising the disinfection
system to be verified including the purpose of each component, its intended applications and the scale of
the test equipment. This must also address the test unit's conformity with full-scale commercial systems
offered by the vendor.
A process flow diagram illustrating the testing facility system components should be provided.
The diagram should show all components of the test facility, including support equipment, location of
sampling points and flow metering. The facility description should clearly delineate the equipment
components that are being verified and those that are being provided through the vendor and others to
support the test facility. In addition, the following information should be included:
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• Detailed dimensional drawings of the equipment showing all components, including;
Vendor name, address and telephone number
Equipment name, model number and serial number
Electrical requirements (voltage, amperage, frequency)
Warning and caution statements, as applicable
Capacity and output rate, as applicable
• A detailed description of physical characteristics of the equipment including its weight
and size;
• A detailed drawing of the equipment layout;
• Utility requirements such as water and electricity;
• Identification of any special permitting requirements associated with the operation of the
equipment, if appropriate; and
• The method for effluent disposal and verification that it is a permitted practice for the
site.
The vendor must also provide any ancillary equipment necessary for the health and safety of the
operator in compliance with Occupational Safety and Health Administration (OSHA) standards (e.g.
face shields, emergency shut off switches, etc.).
2.3.2 System Capabilities
The Verification Test Han shall address the application of the equipment, its limitations and its
potential advantages. Statements of capabilities that are too easily met may not be of interest to the
potential user, while statements of capabilities that are overstated may not be achievable and may
diminish the value of the verification. The statement of capabilities forms the basis of the equipment
verification testing and should be chosen carefully. The statement of capabilities should include, but not
necessarily be limited to:
• Regulated microbial species or microbial indicators that can be removed or reduced by
the tested technology;
• The anticipated dose - delivery levels as a function of the targeted water quality;
• The operating limits in terms of hydraulic loading range;
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• The operating envelope in terms of wastewater quality, specifically wastewater
transmittance for UV systems;
• Instrumentation and control requirements;
• Equipment installation requirements; and
• Operation and maintenance requirements.
2.4 EXPERIMENTAL DESIGN
The Verification Test Plan shall describe how the objectives and technical approach will be
implemented, and shall include the procedures that will be followed for each of the Test Elements
chosen for the Verification. Within this framework, a Sampling, Analysis and Monitoring Plan must
be provided, in support of the Experimental Design. This must address the procedures that will be
followed for sampling, and references for all analytical methods. All monitoring equipment and
instrumentation shall be described.
2.5 HEALTH AND SAFETY PLAN (HASP)
The Verification Test Plan shall have a HASP, which addresses safety considerations that are
appropriate to the test site and the equipment being tested, and the storage, handling, transport and
disposal of chemical constituents or wastewaters. If testing is to be conducted at a site covered by a
separate HASP, the Verification Test Plan HASP shall conform with and incorporate any other
requirements under that facility's general plan.
2.6 QUALITY ASSURANCE PROJECT PLAN (QAPP)
The Verification Test Plan shall include a QAPP that specifies procedures to be used to ensure
data quality and integrity. This shall follow the generic outline presented separately in Section 7.
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3 TEST ELEMENT 1: DOSE-DELIVERY VERIFICATION
The dose-delivery capabilities of the system, for application to secondary or reuse waters, shall
be verified by an MS2 coliphage assay. The challenge MS2 phage shall be calibrated in the laboratory
via a collimated-beam apparatus, and then added to a prepared batch of either granular or cloth media-
filtered effluent or potable water, which has been adjusted to a targeted transmittance at 254 nm. The
seeded water shall be passed through the UV reactor over a targeted range of flows and sampled for
influent and effluent phage analysis. This shall yield a dose-hydraulic loading relationship for the
particular system configuration. Table 3-1 provides a summary of the laboratory and field tasks in this
Test Element.
3.1 DOSE-RESPONSE CALIBRATION
Key elements of the bioassay process are the selection and harvesting of a test organism, and
the accurate calibration of its response to UV exposure.
3.1.1 Selection, Culturing and Harvesting of Test Organism
The test organism shall be the F-specific RNA bacteriophage MS2. For a number of reasons,
this organism is widely used to assay delivered UV germicidal dose (NWRI/AwaaRF, December
2000):
• The MS2 phage has a relatively high tolerance to ultraviolet light and exhibits dose
requirements that are typically higher than what is required by most bacterial and viral
organisms to exhibit measurable levels of inactivation. This allows development of a
dose-response relationship that encompasses dose levels required for most disinfection
applications.
• The response of the bacteriophage is fairly consistent over repeated applications.
• The MS2 phage can be cultivated up to densities of 1012 pfu/mL, This permits its
practical use for preparing and inoculating the relatively large volumes of water needed
to test large-scale reactors.
• This phage is not pathogenic to humans, and is harmless in the aquatic environment. No
special safety precautions are required.
• The attachment site is only expressed at temperatures exceeding 35°C. This
temperature is much higher than would be present in secondary effluent or reuse
applications. Because the attachment site is not present at the applicable temperature,
there is no risk of confounding results by infection and subsequent multiplication in the
natural environment.
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Standard procedures are available for cultivating and enumerating F-specific RNA
bacteriophage.
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Table 3-1. Summary of the Experimental Effort for Test Element 1: Dose-Delivery Verification
TASK
SUBTASK
REF
DESCRIPTION
FREQUENCY
ANALYSES TO BE DONE
A. Prepare
1. Harvesting.
3.1.1
Prepare a sufficient quantity of
Prepare one stock for
Periodic titers of the MS2 Phage
MS2 Phage
phage in one stock for the full
verification.
a full verification of a
vendor's system.
to estimate density. Once per
month.
B. Dose
1. Intensity Probe
3.1.2.2
In accordance with the
Once per 4 months of
No analytical.
Calibration
and radiometer
calibration.
vendor's specification.
active use.
2. Measure
3.1.2.3
Map the intensities across the
Once for each stock
No analytical.
intensity field
sample surface plane. This is
dose-response
across sample
to assure uniformity.
calibration. Verify
surface plane in
once every four
collimator.
weeks.
3. Verify
3.4.1
Check dechlorination of the
Once for each stock.
UV transmittance of the control
Dechlorination and
stock water. Test each new
and test samples (approximately
the Effect of
stock phage with exposure to
10).
Coffee and
coffee and thiosulfate to
Phage titers of each sample
Thiosulfate on
assure that the phage are
(approximately 10).
Phage.
unaffected.
Residual Chlorines (as needed).
4a. Dose-
3.1.2.3
Conduct a collimated beam
Mnimum of four runs
1. Five doses plus a minimum of
Response
and 3.1.3
dose run on the phage to
for each stock phage
two controls in each run, at a
Calibration Runs
calibrate its response to UV.
conducted within 3
single transmittance. Do this at
(Secondary
Each run is comprised of
weeks before field
least four times.
Effluent
exposure to a minimum of five
testing and during the
2. Approximately 12
Applications
doses.
field test period.
transmittances (each control).
Only).
Seed water shall be the same
water source that will be used
for the field challenge tests.
3. Approximately 70 phage
analyses (controls, test dose
samples, in duplicate).
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Table 3-1. Summary of the Experimental Effort for Test Element 1: Dose-Delivery Verification
TASK
SUBTASK
REF
DESCRIPTION
FREQUENCY
ANALYSES TO BE DONE
4b. Dose-
Response
Calibration Runs
(Reuse
Applications Only)
3.1.2.3
and 3.1.3
Conduct a collimated beam
dose run on the phage to
calibrate its response to UV.
Each run is comprised of
exposure to a minimum of five
doses. Seed water shall be
the seeded feed water
adjusted to the test
transmittance used for the field
challenge tests.
Each run must be
carried out within 24
hours of the field
challenge tests.
1. Five doses plus a minimum of
two controls in each run, at a
single transmittance. Do this four
times.
2. Approximately 15
transmittances (each control).
3. Approximately 70 phage
analyses (controls and test dose
samples, in duplicate).
CI. Test Unit
Assay
(Secondary
Effluent)
Application
Only
1. System
Monitoring
3.4.3.1
3.4.3.2
Monitor the test system for
operating variables and test
unit conditions
At each hydraulic
loading sampling
event.
1. Temperature of ambient
(influent) water and, at each flow
condition sampled. If the test unit
uses low-pressure, low-output
lamps, measure lamp temperature
(2 lamps).
2. Intensity at 100% and test %
output.
3. Voltage/Amperage at each
Intensity setting, or alternative
method to verily lamp operation.
4. Flow rate at every sampling
5. Headloss (via elevation or
pressure differentials) at each flow
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Table 3-1. Summary of the Experimental Effort for Test Element 1: Dose-Delivery Verification
TASK
SUBTASK
REF
DESCRIPTION
FREQUENCY
ANALYSES TO BE DONE
sampled.
2. Conduct Dose-
Flow Assays
3.4.3.1
and
3.4.2.1
Conduct runs with prepared
phage batches. Each run shall
comprise five different flow
rates (equivalent to five
doses).
Quartz sleeves are cleaned
manually each day or with
each run.
Minimum of four runs
at each selected target
test transmittance.
1. Conduct Influent and Effluent
sampling in triplicate at each flow
event at the test transmittances
[55, 65 and/or 75% at 254nm]
2. Conduct a duplicate flow event
at each 10th flow event.
3. Yields a total 30 samples (5
flow events with 3 inf/eff samples
each) for phage analyses and 15
transmittances (influents only) for
each flow-series run.
3. Residence Time
Distribution (RTD)
3.4.3.3.1
Determine fundamental
hydraulic information about
the reactor using tracer
techniques.
Minimum three runs at
the lowest, highest and
mid-point of the test
flow range.
No analyses unless methodology
requires discrete collection of
samples and analysis for tracer
concentration
C2. Test Unit
Assay
(Reuse)
Application
Only
1. Minimum
Sensor Level
Determination
3.4.2.6
Determine the most
conservative means for
achieving the combined effect
of end-of-lamp life, and
minimum water transmittance,
loss through sleeve and a
fouling factor. The results will
be the basis for the dose-flow
assays.
(1) Combined effect by
transmittance altering only.
Minimum of three runs
at a single flow rate
before the start of
dose-flow assay
testing.
1. Conduct influent and effluent
sampling in triplicate for each test
condition.
2. Yields 6 samples for phage
analysis for each separate test run.
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Table 3-1. Summary of the Experimental Effort for Test Element 1: Dose-Delivery Verification
TASK
SUBTASK
REF
DESCRIPTION
FREQUENCY
ANALYSES TO BE DONE
(2) Combined effluent by
direct reduction of lamp
output at the minimum
water transmittance
depending on the
application.
This comparison shall be done
only if the commercial system
itself offers power turndown,
and only to the extent that this
turndown can be applied.
2. System
3.4.3.1
Monitor the test system for
At each hydraulic
1. Power at every dose.
Monitoring
3.4.3.2
operating variables and test
loading sampling
2. Temperature of ambient water
3.4.3.3
unit conditions.
event.
and air, at each flow condition
sampled. If low-pressure, low-
output lamps are used, also
measure the lamp temperature (2
lamps).
3. Intensity at 100-percent and
50-percent output.
4. Voltage/Amperage at each
Intensity setting.
5. Flow rate at every sampling.
6. Headloss (via elevation or
pressure differentials) at each flow
sampled.
3. Conduct Dose-
3.4.3.1
Conduct runs with prepared
Mnimum of four runs
1. Conduct Influent and Effluent
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Table 3-1. Summary of the Experimental Effort for Test Element 1: Dose-Delivery Verification
TASK
SUBTASK
REF
DESCRIPTION
FREQUENCY
ANALYSES TO BE DONE
Flow Assays
and
3.4.2.1
phage batches. Each run shall
comprise five different flow
rates (equivalent to five
doses).
Quartz sleeves are manually
cleaned each day or with each
run.
at each minimum
sensor level.
sampling in triplicate at each flow
event, at each minimum sensor
level.
2. Conduct a duplicate flow event
at each 10th flow event.
3. Yields a total of approximately
30 samples for phage analyses
and 15 transmittances for each
test run (see C2).
4. Velocity Profile
Measurements
3.4.3.3.2
Establish velocity profile
before first reactor and after
final reactor.
Minimum of three runs
at each hydraulic
loading.
No Analytical.
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F-specific RNA bacteriophage are bacterial viruses which can infect a specific host strain with
F- or sex-pili, producing clear areas, or plaques, within a confluent lawn of grown host strain. The
methodology for detection and enumeration of F-specific RNA bacteriophage (ATTC 15597 - Bl) is
presented in ISO DIS 10705 (Havelaar): Water Quality - Detection and Enumeration of Bacteriophage
(see References). Briefly, a sample infected with MS2 phage is mixed with a small volume of semi-solid
nutrient medium. A culture of host-strain is added to the sample. The sample is then plated on a solid
nutrient medium and then incubated for a period of 16 to 20 hours. After the incubation period, the
number of visible plaques is counted on the plate. The results are expressed as the number of plaque
forming units (Cp&) per unit volume. The required host strain is Escherichia coli (E. coli) ATTC
23631. Alternate methods, as outlined in NWRI/AwwaRF (December 2000), can also be used.
A large enough stock of MS2 shall be cultured and harvested by the methods outlined in
Havelaar (ISO, 1995) or NWRI/AwwaRF (December 2000) to meet the needs for a complete field
assay of a specific piece of equipment. The amount required shall be demonstrated as part of the
Verification Test Plan. The entire stock shall be filtered through a 0.45-micron membrane filter as the
final cleanup. This stock shall be stored under refrigerated conditions (or under deep-freeze, if facilities
are available), and used to develop a dose-response relationship. Stocks shall be kept separate and
calibrated separately. Although evidence suggests that variations from stock to stock are relatively
small, greater precision can be obtained for a dose-response calibration within a stock. If the stock is
held for a period of months, the response of the phage to UV shall be checked at least once per month
to assure that the culture is viable and unchanged.
3.1.2 Dose-Response Calibration of the MS2 Phage
3.1.2.1 Collimated Beam Apparatus
The dose-response calibration assay is conducted using a collimated beam apparatus that
consists of a lamp housing and a collimating tube. Figure 3-1 presents an example of a collimating
apparatus. The lamp housing is a horizontal tube, constructed of an opaque and a non-reflective
material and ventilated continuously via a blower or other device. The collimating tube, also constructed
of an opaque non-reflective material, extends downward and perpendicular to the center of the lamp.
The purpose of the tube is to select and direct those photons emitted from the lamp into a uniform, or
collimated path, perpendicular to the surface of the sample being irradiated. This radiation is imposed
on the surface of a mixed sample held in a container immediately below the collimator, which may be
suspended by an adjustable drive, as shown, or with a lab jack. The lower, open workspace must be
treated as a microbiological work area with respect to cleanup and disinfection procedures. The use of
the collimator requires the use of an accurate timing device and radiometer (not shown).
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FIGURE 3-1. Example Collimator Apparatus for Dose-Response Test.
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Collimators can be constructed rather simply, and the Verification Test Plan shall provide a
detailed description of the apparatus, including dimensional drawings. Certain specifications will need to
be met:
• The lamp shall be a conventional, monochromatic G64T5 lamp, or equivalent low-
pressure lamp. Multiple lamps and lamps of varying length may be used. The
collimator shall be equipped with a lamp temperature monitor and shall be designed to
minimize lamp temperature fluctuations.
• The ratio of the length of the collimating tube to its diameter shall be at least 4:1 in order
to assure a uniform emission from the bottom of the tube.
• The irradiance across the cross-sectional plane at the bottom of the collimating tube
shall be relatively uniform. The irradiance across the surface plane of the sample dish
shall be mapped over the entire plane at sectors of equal area (minimum of 20 cells); the
average irradiance shall be determined via numerical integration. Ninety percent of the
data points shall have a ratio of single value to the average between 0.9 and 1.1. The
mapping procedure, which shall be described in the Verification Test Plan, must ensure
minimal variation of intensity across the surface of the sample, and the Verification Test
Plan must describe what measures will be taken to restore a collimator not meeting
specifications. This mapping procedure should be done at least once every two months
for the same setup (sample container is always the same and is always in the exact same
position relative to the collimator), and immediately if any change is made to the
apparatus.
• The diameter of the sample container shall be less than the diameter of the collimating
tube. The outer perimeter of the sample container shall never be outside the diameter of
the collimator. The container shall be a petri-type dish, with straight sides and a flat
bottom.
• The sample container to be irradiated shall be located immediately below the collimating
tube. The distance between the sample surface and the bottom of the collimating tube
shall be less than 2.5 cm in order to minimize dispersion of radiation once it leaves the
collimator. The sample container must be in the same fixed position relative to the
collimator whenever a test is being conducted.
• The depth of the sample shall be such that the calculated intensity at the bottom of the
container is greater than 25 percent of the intensity at the surface of the sample (refer to
Section 3.1.2.3).
• The sample in the dish must be continuously stirred via a small spinbar and magnetic
stirrer. The spinbar size and speed shall be sufficient to maintain a stirred sample, but
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shall not cause surface turbulence. Once a workable stirring speed is identified, this
speed shall be left undisturbed for the remainder of the assay and the stirrer shall be
turned on and off at the preset speed. The magnetic stirrer shall be insulated such that
there is no significant (e.g., no more than 2 degrees C) rise in the sample temperature
during exposure.
• The apparatus shall allow for positioning a radiometer detector at the exact elevation of
the sample surface.
• The venting provided for maintaining a reasonably constant lamp temperature should not
be excessive and should be designed to minimize contamination of the air in the vicinity
of the collimator. A filter on the intake air is suggested, as shown on Figure 3-1.
3.1.2.2 Intensity Probe and Radiometer Calibration
The UV intensity emitted from the collimating tube is measured with a radiometer (IL 1700,
SED 240 detector, International Light, Newburyport, Massachusetts, or equivalent), calibrated using
standards traceable to the National Institute of Standards and Technology. Calibrations of the detector
and meter shall be certified and performed within six weeks before an ETV test is conducted, and then
after completion of the test program, if it occurs more than four months after startup. It is advisable to
have two detectors available as checks against one another. Additionally, the detectors may be
checked experimentally, via a previously standardized actinometric procedure, to assure consistency
and accuracy of the dose imposed as part of the collimated beam dose-response test (Bolton, 1997).
Similarly, a reference sensor can be maintained and checked by an actinometric procedure, and factory
calibrations. Refer to Section 3.2.1 regarding the general specifications expected for the UV sensors.
During the actual collimated-beam dosing activities, a minimum of three UV intensity readings shall be
taken, generally at the beginning, middle and end of a dose-response assay run at a single reference
point. The readings shall be within 5 percent of their average. If variations occur beyond these limits,
the tests shall be repeated. The Verification Test Plan shall detail the readings to be taken.
3.1.2.3 Dose-Response Test with the Collimated Beam Apparatus
A collimated beam dose-response assay shall be performed for each MS2 phage stock. The
assay requires exposing a known concentration of MS2 phage to a known UV intensity from the
collimating apparatus over various time intervals and then measuring phage survival. Dose is determined
by irultiplying the intensity (averaged to account for deviations across the exposure plane and depth-
corrected for the given transmittance) and exposure time. A dose-response relationship is then
developed, expressed as log survival (N/N0) as a function of the applied dose.
The laboratory assay shall be conducted under controlled, constant conditions. All waters used
for dilution (of the phage stock) shall be the same as used for the field tests. For secondary effluent
verifications, the tests can be conducted at the ambient source-water transmittance. For reuse
verifications, the dose-response test water must be from the field-seeded and transmittance-adjusted
waters being directly used for the challenge test. If the field test shall be conducted with a reactor using
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an alternate lamp (medium-pressure, or low-pressure/high-output lamps), the dose-response calibration
shall still be conducted with the conventional low-pressure, monochromatic G64T5 lamp. The overall
intent is to normalize the bioassay results to an equivalent dose at 254 nm.
To develop a dose-response relationship, the measurement of responses at a minimum of five
different doses is required, covering and bracketing the expected operating range of UV doses of the
UV test unit. At least four runs should be conducted, resulting in at least 20 points to develop a dose-
response relationship. Extrapolations shall not be made beyond the minimum and maximum dose levels
actually tested. The collimating apparatus shall be set up and adjusted as needed to yield the desired
intensity from the collimator to the sample surface. This is typically on the order of 0.1 to 0.5 mW/cra2,
and is generally a function of the setup of the apparatus and the need to have exposure times that are
long enough to be practically applied and measured. Generally, exposure times shall be greater than 30
seconds. The intensity can be altered by having one, two or more lamps in operation, or by adjusting
the collimator length. The collimator must still stay within the specifications discussed in Section 3.1.2.1.
Before starting the dose-response runs, the intensity mapping must be completed across the surface of
the sample container. Mapping shall be conducted at least once every four weeks of active testing. If
exposure times of less than 10 seconds are needed, an automatic shutter arrangement is recommended
for the collimating apparatus.
The Verification Test Plan shall present the methods and materials to be used to conduct the
collimated beam dose-response analyses. The following is a general procedure to be followed, unless
otherwise specified and approved in the Verification Test Plan:
1. Warm the collimator UV lamp(s) and radiometer for a minimum period of 0.5 hour.
Record the intensity periodically (e.g., every 5 minutes) at the exact height of the sample
surface until a stable reading is obtained. Begin testing only when there is a variance of
5 percent or less for the last three readings.
2. Place a known volume of MS2 phage solution in the irradiation container and add a
sterile spinbar (UV sterilization is adequate). The targeted density should be at least
106pfu/mL, reflecting the intent to achieve up to a five-log reduction at the higher dose
levels. The volume that is added shall be determined from a calculation/direct
measurement, such that the depth is accurately known. This should be on the order of 1
to 2 cm. If low transmittance samples are being tested, the depth shall be adjusted such
that the estimated intensity at the bottom of the container is still more than 25 percent of
the surface intensity, based on the attenuation of the intensity at the given transmittance:
M0=e"kd (3-1)
Where:
I0 = the incident intensity at the surface of the sample (mW/cm2)
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3
4.
5.
6.
7.
8.
I = the intensity at the bottom of the sample (mW/cm2)
k = the absorbance coefficient (base e) (cm"1)
d = the depth of the sample (cm)
The depth should be constant over the entire area of the sample. Place the vessel onto
the magnetic stirrer and allow the sample to thoroughly mix. The sample should be
mixed for about 30 seconds before the sample is exposed.
Simultaneously remove the shield and start the timer.
After the desired time has elapsed, cover the irradiation vessel with the shield and turn
off the stirrer. This sample shall be plated immediately. Samples shall be plated in
triplicate at three dilutions, according to the requirements of the bacterial or phage
enumeration protocol, which shall be included in the verification test plan.
Repeat Steps 2 through 4 for different time intervals.
Control samples shall be generated following the same procedure for each 5-dose run.
Controls are run in the same manner as each test dose sample, except that the lamps are
off (or shielded) and there is no exposure to the UV light. As a minimum, control
samples are analyzed at time zero and the maximum exposure time for the dosed
samples, yielding at least 2 controls for each dose series. Intermediate controls may be
generated, depending on the overall number of samples being generated in a given run; if
five or more dose levels are run, at least one intermediate control should be sampled.
During the middle and end of the dose-response runs (e.g. after the third and fifth dose
applications), measure and record the intensity at the elevation of the sample surface.
These readings shall not vary by more than 5 percent from the initial reading. Checks
are required at intermediate points to assure consistency of the reading; if desired, the
intensity may be measured before and after each dose delivery. The Verification Test
Plan shall define this.
The concentration of the phage solution used for the dosing assays shall be greater than
1 xlO6 pfli/mL, and shall be sufficient to yield no less than 20 pfli/mL after exposure
(this is relevant at the very high doses, where one can expect nearly 5-logs reduction).
The transmittance of the diluted phage stock used for the assays shall be measured with
each preparation.
Compute the dose as follows:
D = Iot[(l - e kd)/ kd
(3-2)
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Where:
D = UV Dose at 253.7 nm (mW-s/cm2)
t = Exposure time (seconds)
I0= Incident intensity at the surface of the sample (mW/cm2)
k = absorbance coefficient (cm"1) (note that this is base e)
d = Depth of the sample (cm)
The incident intensity shall be corrected for reflectance at the surface of the sample. This is
approximately 2.5 percent of the measured incident intensity (Reference 5). Thus the value of I0 should
be approximately 0.975 times the measured intensity at the surface of the sample. With respect to the
absorbance coefficient, note that this is base e, with units cm"1. Spectrophotometers can report
absorbance and/or transmittance. Absorbance units per centimeter (a.u./cm) can be converted to the
absorbance coefficient:
Absorbance Coefficient, k = 2.3(a.u./cm) (3-3)
Transmittance measurements can also be converted by the relationship:
%T= 100 * 10"(a u /cm) (3-4)
3.1.3 Dose-Response Data Analysis
The theoretical UV disinfection model follows first order kinetics according to the following
equation:
N = N0 e Ht (3-5)
Where:
N = the organism density remaining after exposure to UV, pfu/mL
N0 = the initial organism density, pfu/mL
K = the inactivation rate constant, cm2/W-s
I = the intensity of UV radiation, W/cm2
t = the exposure time, seconds
The product (It) is the applied UV dose. The above equation can be expressed as a linear
relationship by graphing the logarithm of N/N0 as a function of the applied UV dose. The resulting slope
of a linear regression analysis is equal to the inactivation rate constant, K. Note that the intensity in this
case is the depth-averaged intensity, as described in equation 3-2, accounting for the transmittance of
the sample being tested.
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The data generated by a dose-response analysis are N, N0 and the applied UV doses. An
example of a dose-response curve is presented on Figure 3-2, displaying data generated from several
MS2 stocks. Under ideal conditions, the data from a dose-response analysis should be expected to
intercept the origin, and should be linear throughout the full dose range. This is generally not the case.
The observed data do not yield a y-intercept at zero, and there is evidence of tailing at the higher dose
levels. The deviation of the observed data from the theoretical model results from the non-ideal
conditions under which the tests are performed. For the purposes of developing a dose-response
curve, it is more appropriate to apply a model that better represents the observed data. Figure 3-2
presents an example of a non-linear regression of dose-response data. Non-linear regression analyses
of the dose response data are suggested for the ETV, unless otherwise proposed and approved in the
Verification Test Plan.
Dose (mWs/cm2)
Figure 3-2. Example Dose-Response Calibration for MS2 Coliphage
Dose response data for the MS2 coliphage must be generated in the range of 10 to 100 mJ/cm2
and these data must fall in the area bounded by the following equations:
-logio(N/N0) = 0.036*( UV Dose, mJ/cm2) + 0.134
-logio(N/N0) = 0.044*(UV Dose, mJ/cm2) + 0.700
If the verification test plan requires operating conditions outside the 10 to 100 mJ/cm2 dose range, data
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in this range must still be gpnerated to determine QA compliance of the MS2 coliphage. However, the
data and linear relationship developed within this range of 10 to 100 mJ/cm2 cannot be extrapolated to
doses outside this range. If the field tests are to assess doses outside this range, then dose-response
data outside this range must also be generated. These additional data shall not be held to the QA
defined by the above lines, but must represent an uninterrupted continuation of those data. If, as
expected, the outer range are non-linear, then a non-linear regression analysis shall be performed to
develop a representative relationship of dose and survival outside the linear range of 10 to 100 mJ/cm2.
The Verification Test Plan shall present a discussion of the methods that will be used to estimate dose
delivery if the intent is to verify performance levels outside of the range 10 to 100 mJ/cm2.
In addition, at least 80 percent of the data points shall lie inside the area defined above; if not,
the run is discarded. The remaining data can lie in the region outside the area, but all data points in the
appropriate dose range shall be included in the regression analysis. Conformance with this requirement
forms the primary QA control for the collimating apparatus and the growth, harvesting and calibration of
the MS2 phage.
For secondary effluent applications, a minimum of four dose-response runs, each run comprising
5 doses (two of which bracket the operating range of the proposed test unit), are required for the dose-
response calibration of the MS2 stock culture. These can be conducted before the field testing is
initiated, or conducted through the term of the field tests. For reuse applications, each dose-response
run must be conducted concurrently or within 24 hours of a field challenge test using the same seeded,
transmittance- altered waters.
3.2 UV TEST UNIT SPECIFICATIONS
The test unit submitted for evaluation by the ETV protocol must be equivalent in configuration
and operation to the commercial unit offered by the vendor. It will be critical to clearly describe both
the commercial unit and the test unit as part of the Verification Test Plan.
3.2.1 Size and Component Considerations
The system that is tested shall be a hydraulically scaleable unit. In some cases, given the
modular nature of UV systems, the test unit may be a commercially available full-scale module. Note
that for secondary effluent verifications, only one reactor (pilot or full scale) is required. A minimum of
two independent reactors in series is required for reuse application verifications. A reactor is defined as
an independent combination of single or multiple bank(s) in series with a common mode of failure (e.g.,
electrical, cooling, cleaning system, etc.) (NWRI/AwwaRF, December 2000). The maximum scale-up
from the unit used for the verification test shall be 10:1. There shall be no scale-down from the test unit
size. The minimum size for scale-up shall be 4 lamps per reactor. Hydraulically scaleable means that
the hydraulic behavior and characteristics of the test system are sufficiently similar to that of the full-scale
unit, such that direct design sizing assumptions can be made on the basis of the test unit results.
Examples for assessing hydraulic similarity include the ratios of flow rate to number of lamps; equivalent
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cross-sectional velocities; equivalent ratios of width to depth and length to cross-sectional dimension
(e.g. aspect ratio), ratio of wetted perimeter to total quartz perimeter, etc. These would need to be
selected on the basis of the type of system (e.g., open channel, closed reactor, etc.). This is best done
as part of the Verification Test Plan and serves to justify/qualify a test unit selected for verification. The
vendor is required to submit such calculations of hydraulic comparisons between the test unit and the
equivalent full-scale, commercial unit. The Verification Organization and Field Test Organization shall be
responsible for reviewing and accepting the hydraulic claims provided by the vendor. The information on
the hydraulic scaling calculations shall become part of the final Verification Report.
With respect to system components, there are key elements of the test unit that should be
identical to that of the full-scale commercial unit. The vendor must provide the following documentation
for each UV reactor tested;
• A technical description of the UV reactor that includes dimensions, maximum pressure
rating, working flow range, head loss, internal fixtures, spare part specifications, circuit
diagram, power consumption, ballast information, and the number and type of UV
lamps and sleeves.
• Assembly and installation instructions (with all the necessary information on electrical
and mechanical installation).
• An operation and maintenance manual.
• Cleaning procedures and instructions (including any special cleaning equipment).
If they are a part of a commercial system, intensity meters, temperature probes for the lamp and
the liquid, voltage and amperage readouts, power meters, lamp indicator lights, ambient air temps and
exhaust air temps (in systems that may have cooling or temperature control devices) shall also be
provided. The use, calibration and recording of these monitoring and control devices shall be detailed
as part of the Verification Test Plan.
UV sensors in the reactor can be useful to the test program to denote operation of the lamps
(although these are generally noted by pilot lights on the individual lamps). In addition to the sensors
provided with the commercial unit, at least one reference sensor (IL1700 NBS 254, SUD, or
equivalent) shall be installed within the reactor in a fixed, non-movable position. Fiber-optic extensions
for such sensors are acceptable. The consistency of output on a day-to-day basis shall be monitored
during the test period. Readings should not vary significantly (+/- 5% of mean) under both clean water
and adjusted water conditions.
The UV reactor must have UV sensors that continuously monitor UV intensity within the
reactor. The vendor must specify the number and location of UV sensors within the reactor and must
provide the methodology used for selecting the sensor location and monitoring positions in the
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Verification Test Plan. The sensors must be set to monitor the UV lamp output away from the lamp
electrodes and must account for the UV intensity field geometry, the possible scaling of the lamp sleeve,
and the influence of water UV absorbance.
The vendor must provide reference sensors that can be used to verily the accuracy of the
reactor sensors. The UV reactor shall be designed with a sensor(s) position that allows reproducible
determination of the UV intensity by reference and system sensors. The Verification Test Plan shall
describe the sensors and their fixed location setups, and how these conform to commercial system
design. During testing, the reactor sensors must be checked by comparison with the reference sensors.
If the reading of a reactor sensor deviates from the reference sensor by more than the measurement
uncertainty, as specified below, then the cause of the deviation must be identified or the reactor sensors
must be recalibrated or replaced.
Documentation must be provided to verily that UV reactor sensors and reference sensors
conform to the performance standards as described in "Ultraviolet Disinfection Guidelines for Drinking
Water and Water Reuse," (NWRI/AwwaRF, December 2000):
• The working range of sensors must correspond to the UV intensity expected at the
monitoring position(s) in the UV reactor.
• The measurement uncertainty of reactor sensors must be less than 10 percent of the
working range. Uncertainty of reference sensors must be less than 5 percent of the
working range.
• The selectivity of the reactor sensors must be greater than 90 percent for the germicidal
range (i.e., wavelengths between 200 and 300 nm). The selectivity of reference sensors
must be greater than 95 percent.
• The linearity of reactor and reference sensors in the working range must be within 5
percent.
• The stability of sensors must be such that sensitivity does not deviate by more than 5
percent within the specified working temperature range and over a specified operating
period of at least 5,000 hours.
• The acceptance angle of all reactor and reference sensors must be uniform.
Temperature probes shall be installed on at least two lamps in the conventional low-pressure,
low-output lamp systems. Changes in temperature, if any, shall be reported as a function of flow.
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3.2.2 Lamp Output
The vendor must specify the type and manufacturer of the lamps used in the UV reactor. The
UV lamps must be subject to a burn-in period (e.g., 100 hours) sufficient to produce nearly constant
emission during the test period. For UV lamp sleeves and sensor monitoring windows, the vendor must
specify the dimensions, transmission spectrum, and pressure rating. For medium-pressure lamps, the
reactor must be equipped against overheating with a safety cut-off switch. Instrumentation must be
provided to monitor ballast power. The vendor must also supply all necessary facilities to allow testing
at reduced UV output. The reduced UV output testing is intended to simulate old and fouled lamp
conditions.
Data on lamp output and the anticipated effects of temperature shall be included in the
Verification Test Plan. The lamps that are used in the test unit, and the ballasts used to drive them, must
be the same that are used in the commercial systems. This is a critical factor in establishing the
acceptability of the test unit as representative of the full-scale commercial systems. The vendor shall
verify this information, which shall be incorporated into the Verification Test Plan.
3.2.3 Reactor Configuration
The Verification Test Plan submitted for a specific equipment dose-delivery assay shall be
explicit with respect to the layout of the lamp reactors, and conformity with the full-scale design of the
system. This shall include the number of lamps, modules and banks; channel design; stilling plates in the
case of open-channel gravity flow systems; level control; and inlet and outlet structures. Engineering
drawings and equipment specifications will be provided as support documentation for the test unit
design. The ETV Verification Organization and Testing Organization must approve the design and
conformity to full-scale design practice.
3.3 TEST FACILITY
The ETV protocol anticipates a fairly large-scale equipment configuration, requiring a site
capable of supplying sufficient wastewater or potable water and, in the case of the granular, synthetic or
cloth-media filtration application for reuse, filtered effluent, on a continuous basis, and with capacity to
dispose of the material once it has passed through the system. The protocol assumes that the
appropriate location will be a secondary wastewater treatment plant with access to a potable water
supply and filtered final effluent.
3.3.1 Test Facility Equipment
This protocol gives direction to the setup at a test site. Figure 3-3 presents an example test
facility layout for conducting a large-scale dose-delivery bioassay. The Verification Test Plan shall
provide more detail in its layout of the test facility. This protocol is based on a batch-testing approach,
drawing from a batch of test water that has been adjusted to specified characteristics. The batch
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approach offers good control and consistency and is established as the default method within this
protocol. Alternate methods, such as those that may use a continuous flow stream with direct injection
may be proposed in the Verification Test Plan. In the case of tests that are conducted by continuous
injection of seed and transmittance-adjustment chemicals, the facility should be equipped with
continuous transmittance monitors, or semi-continuous sampling shall be conducted to assure that a
consistent %T adjustment is made throughout the exposure period (influent/effluent sampling event). At
a minimum the Test Plans shall describe the following site equipment, as suggested in Figure 3-3:
• Batch Tank. One or more sufficiently large tanks will be needed for preparation of the
batch water to feed the UV system. The size of the tank(s) required will depend on the
system requirements. These should have access ladders and sufficiently sized ports for
intake and discharge. If they are steel tanks, they should be lined to avoid metal
corrosion in an aggressive water condition.
• Pump. One or two pumps are suggested. Hereto, the size of the pump or pumps will
be dependent on the system needs. It is important that the piping and intakes are well
sealed to avoid air induction and discharge to the UV system. Fine bubbles dispersed
in the water can affect the transfer of energy to the liquid and will impact the
performance of the UV system. This same observation applies to pumps that may be
used for batch water mixing or recirculation. Pump specifications and curves shall be
submitted with the Verification Test Plan, demonstrating how the five equivalent dose
flows will be accomplished.
• Electrical Source. Experience has shown that different systems require different
service with respect to power. A diesel-powered generator may be appropriate to run
the system or direct feed may be used depending on local power availability and
conditioning.
• Flow meter. A magnetic flow meter is recommended, with a digital readout. The
calibration and flow ranges shall be verified.
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/"
/-
Secondary
Clarifiers
Clarifier Effluent
C~lParie.f
TL
UV Reactor
it
Generator
Flow
Meter1
Clean Water Line
Pump ^
Potable Water
q Hydrant
Batch Tank
Recirculation Line
October 2002
FIGURE 3-3. Example Test Facility Layout for Phage Dose-Delivery Assays.
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• Discharge. The discharge during this Test Element is relatively clean, consisting of
potable water that has had an absorber and phage seed added. It does not require
treatment. The discharge from larger systems, however, can be significant and can
affect the receiver. Depending on the size of the test system, a location that can accept
short-term, high-volume inputs is required. An appropriate location would be a large
capacity wastewater treatment plant.
• Piping. Generally, Schedule 40 PVC s sufficient. However, in higher-pressure
systems, such as closed-vessel reactors, Schedule 80 PVC shall be used.
• Water Source. Clean, potable quality water is recommended for the dose-delivery
bioassays for the Secondary Effluents and the Reuse applications with pretreatment by
microfiltration and RO Treatment. This may be conveniently tapped off an existing
hydrant at a candidate treatment plant location. In this case, backflow preventers will
be required. A water meter is generally placed in-line to monitor water use. For reuse
verifications for granular, synthetic or cloth-filtered water, a granular media filtered
reclaimed water (1 ntu minimum turbidity) is required.
The TO will be required to prepare and submit with the Verification Test Plan appropriate
Piping and Instrumentation Diagrams, equipment layouts, and schematics of the test facility, showing all
components of the test equipment and accessory installations, and all sampling and monitoring locations.
3.4 DOSE-FLOW ASSAY
3.4.1 Test Batch Preparation
Batch preparation is an effective method for preparing test water of consistent quality with
respect to UV transmittance, dechlorination and phage seeding. In this method, a sufficient volume of
test water to conduct a number of dose-flow assay samplings is prepared in a large vessel. The tank is
equipped with a mixing or recirculation system to adequately and efficiently mix the tank contents. Once
the batch is prepared, the test water can be delivered to the UV system under controlled conditions.
The UV transmittance of the test water shall be adjusted to the transmittances required for this
test, as specified in 3.4.2.2. The transmittance of the test water shall be adjusted by adding a substance
that will absorb the UV energy at 253.7 nm, but will not interfere with the test (e.g., cause toxicity to the
phage). Instant coffee has been found to be very effective at reducing the UV transmittance at 253.7
nm and testing has shown that it does not have an effect on MS2 phage at the levels routinely used for
adjustment of the transmittance. It also exhibits a relatively flat spectral line across the UVC wavelength
range. To determine the amount of coffee needed to adjust the transmittance to the target level, a
relationship of percent UV transmittance at 253.7 nm, versus the amount of coffee added to the test
water shall be developed. This can be accomplished in the laboratory and then scaled-up to determine
quantities needed for the test batch preparation. An example of this relationship developed for a
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potable water source where the UV transmittance was targeted between 50 and 80 percent is shown in
Figure 3-4. The relationship was found to be linear, with a correlation coefficient of 0.941. This
relationship can be used as a guidance tool for estimating the amount of coffee needed, although a
similar relationship should be generated using the specific test water, since both the UV transmittance of
the test water and the particular brand/type of instant coffee used will effect the results. If polychromatic
lamp systems are being tested, full UVC spectral scans shall be performed in order to determine the
impact of the UV absorbent.
If the test water contains chlorine, such as the residual in a potable water supply, the water shall
be dechlorinated before it is used in the assay. Dechlorination may be accomplished by adding sodium
thiosulfate directly into the batching vessel. The stoichiometry between sodium thiosulfate and free
chlorine (as HOC1) is such that one mole of sodium thiosulfate reacts with 4 moles of free chlorine. To
remove 1 mg/L of residual chlorine (as CI), approximately 1.1 mg/L of sodium thiosulfate is needed.
An excess of sodium thiosulfate is generally added to assure quick removal of the chlorine. This should
be 4-times the stoichiometric amount. This is a critical step in the preparation of a test batch; even
modest chlorine residuals (0.5 to 1.0 mg/L) can affect the phage. The Verification Test Plan shall
describe the procedure for measuring and recording the chlorine residual before and after
dechlorination. The use of the batch water shall proceed only after it is confirmed that there is non-
detectable residual chlorine. If an on-site chlorine test kit is used, it shall have a minimum detection limit
of 0.05 mg/L. The impact of the thiosulfate on polychromatic absorbance shall be measured and
documented at this point.
The addition of thiosulfate for dechlorination may affect the pH in poorly buffered waters. The
pH should be measured after the addition cf thiosulfate and dechlorination is complete. If the pH is
within 0.5 s.u. of the initial pH, the batch is acceptable. Consider buffering the water if the pH falls
outside these acceptable limits. The Verification Test Plan shall discuss and present reagents that will be
use for buffering.
The stock MS2 phage suspension shall be added directly into the batching vessel in sufficient
quantity to achieve a density between 106 and 107 pfli/mL. As an example, if the MS2 phage stock has
a concentration of 1011 pfu/mL and the batch size is 10,000 gallons, approximately 400 mL of stock
phage solution would be required. The phage shall be added after the test water is dechlorinated and
after the UV transmittance has been adjusted to the target level. The transmittance of the batch shall be
checked again once the phage has been added, and adjusted, if necessary. The phage stock solution
shall be kept on ice and out of direct sunlight until it is needed. Temperatures shall not exceed 10
degrees C, and the stock shall be stored under such temporary conditions for no more than 8 hours.
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Water Quality Protection Center
Verification Protocol for Secondary Effluent and
Water Reuse Disinfection Applications
The following is a default protocol to prepare batches of test water for field testing. The
Verification Test Plan shall detail the proposed procedure (or alternate, non-batch, continuous
procedure) for preparing the test water:
1. Fill the batching tank with the source water.
2. Check the residual chlorine in the waters and compute the amount of thiosulfate to be
added.
3. When the batching vessel is approximately half full, add the appropriate amounts of both
sodium thiosulfate and instant coffee. The recirculation pump or tank mixers shall be
operating at this time.
4. After the batching vessel reaches capacity, the contents shall continue to be mixed for
an additional amount of time sufficient to achieve a homogenous solution. Sampling and
analyzing the transmittance of the sample can verify this. Mixing is complete once there
is minimal variation in the reading (less than 2 percent change).
5. Collect a sample and measure the residual chlorine. The residual chlorine shall be non-
detect. If not, add sufficient thiosulfate to exceed the measured residual's stoichiometric
requirement by a factor of three. Allow the contents to continue mixing and resample to
confirm complete dechlorination.
6. Once the tank contents have been dechlorinated, collect a sample and measure the UV
transmittance at 253.7nm. The percent transmittance shall be within +/- 2 percentage
units of the target level. If the measured percent transmittance is below the target level,
replace some of the test water with clean water until the target transmittance is achieved
(confirm dechlorination once again). If the measured percent transmittance is above the
target level, add an additional amount of coffee (as determined from the relationship of
transmittance versus coffee addition) until the target level is achieved.
7. Add the appropriate volume of MS2 phage stock solution to the test water, making
certain to rinse the container with a small amount of chlorine-free water. Add the rinse
waters to the test water to assure that all organisms are added to the test water.
8. Mix the contents of the batching vessel. While mixing, take a sample for final percent
transmittance reading before testing begins. If necessary, adjust accordingly by the
procedure in (6).
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3.4.2 Test Conditions
A dose-flow assay is conducted to establish a relationship between delivered UV dose and flow
rate through a scaleable UV test reactor under specific test conditions. To develop this relationship, a
minimum of five flow rates shall be tested at conditions best simulating actual full-scale conditions. Test
conditions that need to be defined are the condition of the quartz surfaces, UV transmittance of the test
water, indicator organism densities, lamp output, temperature, flow rates and headloss:
3.4.2.1 Quartz Surface Condition
The objective of the assay portion of this test is to assess the performance of the system with
respect to dose delivery, when the quartz surfaces are clean. It is recommended that the test unit's
quartz sleeves be manually cleaned before each "batch run" or, at a minimum, once each day before
startup of the unit. This is done by physically removing each lamp module from the unit, spraying/wiping
the quartz with a cleaner (e.g. Lime-Away), rinsing the surface with clean water and then reinserting the
module in the reactor. The vendor can offer alternative methods.
3.4.2.2 UV Transmittance of the Test Water
For verifications under secondary effluent applications, dose-flow assays shall be conducted at
75%, 65% and/or 55% transmittances. For verification under reuse applications, the dose-flow assays
shall be conducted at the following transmittances:
The transmittance of the test water shall be adjusted as described in Section 3.4.1. Note that the
vendor may choose to have different distances between the lamps in the unit as a function of the
targeted transmittance. This is acceptable as long as this option is offered commercially, and it is fully
described and justified in the Verification Test Plan. Transmittance shall be measured using a UV
spectrophotometer or photometer. In the case of polychromatic lamp applications, a transmittance scan
of the prepared water shall be made over the operating UVC spectra of the lamp, and specifically
between 230 and 280 nm. The distance of the light path and cuvette used shall be reported. This
information shall be included in the final Verification Report. In all cases, deionized water shall be used
as a reference and matched quartz cuvettes shall be used to hold the samples and reference water. A
photometer uses only a single cuvette, which must be properly cleaned.
3.4.2.3 Turbidity
The finished, or potable, waters used for preparation of the coliphage challenge batches shall
conform to local drinking water regulations with respect to turbidity levels. In the case of the test
condition for granular, synthetic or cloth-filtered reuse waters, a filtered secondary effluent shall be used,
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Upstream Process
Application
Media Filtration
Membrane Filtration
Reverse Osmosis (R/O)
Test Transmittance
55%
65%
90%
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which has a turbidity of at least 1 NTU. This conforms to NWRI/AwwaRF guidance (December
2000).
3.4.2.4 MS2 Phage Densities
The density of the MS2 phage in the test water shall be high enough to yield a
density after treatment at the highest applied dose. The target initial (influent) density shall
106 to 107 pfu/mL. The minimum exposed effluent density shall be 50 pfu/mL.
3.4.2.5 Lamp Output
With operating time, both low- and medium-pressure lamps will diminish in their output of UVC
light. The low-pressure lamp's rating, or nominal output, is generally cited as that output after 100 hrs
of operation, while output near the end of a lamp's operating life is cited as 50 to 75 percent of nominal
(this varies among different lamp types and manufacturers). In the case of medium pressure lamps,
there is no need to burn-in the lamps, but, to be consistent, the burn-in shall be done, regardless of the
lamp type. The end-of-life factor of a medium-pressure lamp is variable, depending on the watt density
(watt/cm of bulb), the power level during operation of the lamp, the hours of operation and the number
of on/off cycles. The end-of-life output of a medium-pressure lamp is suggested to be between 50 and
80 percent of nominal, depending on the above factors.
Standard practice for assays is to adjust the output of the lamps to reflect the end of their
guaranteed UV output, since design sizing would necessarily have to account for the actual output of the
lamps over the course of their operation.
The lamps that are installed in the Test Unit shall be new and shall then be "burned-in" for a
period of 100 hours. This shall occur regardless cf the type of lamp and ballast configuration, and
should be accomplished as part of the test set-up.
3.4.2.6 Reduced Lamp Output
The assays shall be conducted under conditions that simulate a prescribed lamp-aging factor.
This can be done by turning down the input power to the lamps or by further reducing the transmittance
of the water. The testing shall be conducted at 75 percent of the UV intensity of the submerged lamps
for secondary effluent applications, and at 50 percent of the nominal intensity for reuse applications. If
the vendor chooses an alternate equivalent lamp-aging factor, it must be explained fully and technically
justified in the final Verification Test Plan. The Verification Test Plan shall describe how both the 100
percent (of nominal) and reduced (75 percent output or 50 percent output) electrical conditions are
verified (e.g., direct voltage and amperage readings). Installing a UV sensor in a fixed position in the
water and measuring a reduction in intensity equivalent to the target percent of the intensity observed
when the lamps are at 100 percent output shall verify the intensity reduction. Note, for reuse
applications, a reduction factor higher than 50 percent may be used if an alternate lamp-age factor has
been established through an appropriate verification (see Section 5.2). The Verification Test Plan shall
describe how the stability of the lamp output shall be verified. For example, a determination must be
made of the time for lamps to warm up and to respond to adjustments in power changes. The
measurable
be between
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verification test plan shall also describe how the output stability of the system is verified during test runs;
power or intensity measurements may be used to verily that there are no major excursions in unit
performance during flow tests. Continuous recordings are recommended to monitor the selected
variable, such as intensity, which shall not vary more than +/- 5% of the mean reading.
Note that for certain commercial systems the lamp-ballast configuration precludes direct
electrical manipulation to achieve a reduced UV output. Recognizing this, an alternate method for
simulating end-of-life output via UV transmittance adjustment may be used:
1. Using an approved point-source summation algorithm (USEPA/HydroQual UVDIS
3.1, or equivalent), the theoretical nominal intensity is calculated for water
transmittances between 15% and 90% (every 0.5%). Note that this calculation
must be consistent in its treatment of boundary conditions in the calculation of the
average reactor intensity.
2. Starting with the targeted flow-dose test water transmittance (e.g. 65%), calculate
the target test intensity level by direct ratio of the test water transmittance and the
prescribed test output reduction factor (e.g. 0.50), loss through sleeve factor 0.9,
and fouling factor, 0.8. From the theoretical intensity vs. transmittance relationship
developed in step 1, determine the transmittance necessary to achieve the "new"
reduced intensity (+/- 5%). This is the actual transmittance that will be used for the
flow-dose runs.
Note that the default values for the test output reduction factor and fouling factor
can be changed if alternate values are verified previously (refer to Section 5).
For the secondary effluent application, either direct electrical turn down or transmittance
adjustment is acceptable. For reuse applications, screening challenge runs must be conducted to first
determine which method (electrical turndown or transmittance altering) provides the most conservative
approach. This value is referred to as the "minimum sensor level" as described in the NWRI/AwwaRF
guidance (NWRI/AwwaRF, December 2000). This shall comprise influent/effluent phage analyses in
triplicate at a single flow under each turndown method. Whichever method yields the lower dose shall
be used for the verification testing. Other methodologies may be suggested by the vendor and must be
technically justified in the final Verification Test Plan.
3.4.2.7 Temperature
Lamp output will vary with temperature in the conventional, low-pressure lamp systems.
Testing on different systems at different locations could lead to some bias in the results if the operating
temperatures are significantly different. As stated earlier, the anticipated impact of liquid temperature on
lamp output shall be addressed in the Verification Test Plan. The impact of liquid temperature on lamp
output shall be specified by the vendor. This will allow an estimation of the intensity reduction occurring
at less-than-optimum temperatures. Tests shall be performed within a liquid temperature range of 10°C
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to 30°C for most applications. A significant deviation outside this temperature range must be justified in
the VTP; for example, stormwater runoff disinfection in cold climates may involve lower operating
temperatures.
3.4.2.8 Hydraulic Loading Rates
A minimum of five hydraulic loading rates shall be tested in quadruplicate. The hydraulic loading
rate (HLR) shall be defined as the flow (Lpm) divided by the number of lamps. Alternatively, the HLR
can be defined as the flow per total input watts (Lpm/W). One can express the rate in terms of nominal
UV Watts in the system, but this can only be a secondary expression, since there is no direct verification
of UV output. In either case the flow is the primary variable. These flow rates should represent the
expected operating condition for the targeted application and should bracket the peak design flow rate
of the test unit.
Flow rate shall be measured accurately. An in-line magnetic flow meter is recommended. The
flow meter calibration should be verified at the beginning and end of the hydraulic tests by comparing
the flow meter reading to flows that are computed using the change in volume (in the preparation vessel)
over a given time or by inferring flow in an open-channel by collecting velocity profile measurements.
Specific procedures for flow meter calibration shall be included in the Quality Assurance Project Plan.
The flow meter shall have the same operating range as the proposed testing, and shall have a precision
at least within 5 percent of the actual flow.
3.4.2.9 Headloss Measurement
Although not a direct factor in the performance of a system, as defined by its dose delivery,
headloss is a key factor in determining a system's design application. Headloss measurements through
the lamped portion of open channel, gravity flow reactors, shall be recorded for each test flow rate.
This can be done by measuring depth differentials (from a constant elevation datum) between the
approach and exit ends of the reactors. In closed reactors, pressure differential measurements shall be
taken at the inlet and outlets of the reactor at each test flow rate. The Verification Test Plan shall
specify the method and instrumentation used to measure headlosses, and include appropriate
specifications and calibrations.
3.4.2.10 Power Utilization
Power Utilization must be determined as part of all test plans. The purpose of power
measurements is to 1) Determine the power requirements of the system; and 2) Monitor the electrical
stability of the system during the flow tests. Some of these measurements (for 100% intensity) need to
be made before and/or after the actual flow tests if lower lamp output intensity is achieved by reducing
power to the unit. On-going measurement of power (voltage, amperage) or lamp intensity is needed
during the actual flow tests in order to verify that power fluctuations are not inducing changes during the
actual flow test.
A recording wattmeter shall be installed on the power input to the UV system, inclusive of the
power panel and the lamp banks, but exclusive of any major device that is solely related to the test and
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is not part of the normally installed system. This recording unit will allow for monitoring the total power
draw for the system under various conditions (e.g. warm-up, full lamp intensity, lower lamp intensity
during flow tests). Data collected during periods of 100% intensity will show power draw during
"normal system operation." Data collected during flow tests under "turn down" conditions (lower lamp
intensity) will provide information on conditions during the actual test. Power data collected during warm
up and "turn down/up" periods can be used to show the relationship of lamp intensity to power draw or
panel current. The Verification Test Plan will specify the wattmeter (5 percent accuracy) and the method
for calibration and measuring total power draw for the system and estimating the draw per lamp.
The Verification Test Plan shall also describe how power measurements to each lamp unit (e. g.
ballast control or lamp group) exclusive of other power consuming components will be achieved. These
measurements must be made for a system that is operating under 100% lamp output. This direct
measurement of power draw by lamp group will provide data for scaling 1he power requirements for
systems with different numbers of lamps and/or different control panel configurations.
3.4.3 Test Procedures, Sampling, System Monitoring
3.4.3.1 Test Procedure
Each dose-flow assay shall be conducted using the same batch preparation procedure, thereby
insuring similar test water characteristics with respect to organism density and UV transmittance. A
minimum of four runs shall be conducted, each comprising five different doses. The following presents
the general procedure for conducting a dose-flow assay. It is provided as the default protocol and can
be modified to meet the needs of the specific test set-up. The Verification Test Plan must clearly define
the procedures to be used for a particular ETV, and shall include sample sizes, sample collection sites,
sampling procedures, handling and storage as well as inclusion of or reference to microbiological
protocols:
1. The UV system shall be turned on and allowed to operate for at least one hour prior to
testing to ensure a stable output from the lamps. This is determined by monitoring the
lamp intensity. The stable lamp intensity shall be established as the 100 percent output
(nominal) operating condition for the system with respect to current and voltage. This
warm-up and stabilization period must be done with a continuous flow of water,
independent of the batch tank, which is likely being prepared at the same time. This
flow can be set to an arbitrary baseline rate whereby the initial (100 percent) settings
can be checked. The water shall be from a clean source, (i.e., potable water) and the
flow rate should be low to conserve water. However, it must be sufficient to avoid any
water temperature change (greater than 0.5 degrees C) due to the heat from the lamps.
The Verification Test Plan shall detail this operation, including the minimum flow rate.
All sensors and recording meters shall be checked for stable and accurate operation at
this time.
2. While the lamp battery is stabilizing, a batch of test water shall be prepared in the
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batching vessel, as outlined in Section 3.4.1, Test Batch Preparation.
3. After the lamp intensity has stabilized, the UV intensity shall be measured and recorded
using a radiometer detector that is set in a fixed position within the lamp battery (e.g., on
the downstream side of the end bank, pointing into the lamp battery). It shall be
separate and independent from any sensor device supplied with the system. The
detector shall be kept in this fixed position throughout the test period in order to obtain
consistent and comparable results. The system shall then be turned-downed
electronically, if possible, or the batch shall be prepared at an alternate transmittance as
described in Section 3.4.1.
4. Once the system is stabilized and the batch test water has been prepared and checked,
the water source to the test unit is changed from the clean source to the prepared test
water, still maintaining a relatively low flow. Lamp intensity is again monitored and
recorded until a stable reading is obtained. The flow through the system is then changed
from the baseline flow rate to a desired flow rate. The flow rate is monitored via the
magnetic flow meter until a stable reading is obtained.
5. The system shall be operated under these conditions for a time interval sufficient to
accomplish a minimum of five volume changes in the entire UV system, inclusive of the
approach and exit reactor, thereby ensuring steady-state conditions. The lamp intensity
shall be recorded. At this time, additional parameters, as defined by the vendor, shall
also be recorded, specific to the test unit.
Note that the time required to achieve steady-state conditions shall be determined by
direct calculation of the total void volume between the tank outlet and the channel
effluent point and at the flows to be tested. These data should then be used to establish
the minimum number of volume changes that should be incurred before sampling. As
stated earlier, at least five volumes shall pass before sampling can proceed. The
Verification Test Plan shall describe the procedure used to establish this or an alternate
approach, if desired.
6. Sampling locations are equipment specific and shall be clearly defined in the Verification
Test Plan. Samples shall be collected in pre-labeled sterile sampling containers.
7. Influent and effluent samples shall be collected in triplicate. Note that this comprises a
sampling event.
8. After a sample is collected, it shall be capped, placed in a cooler and the cooler lid
closed to prevent any exposure to sunlight. Samples shall be held under refrigerated
storage for no more than 48 hours. If possible the samples should be plated within 6
hours after collection, although time studies have shown that the samples can be held
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under refrigerated conditions fir an extended period of time (up to 48 hours). At a
minimum, three replicates of each sample shall be plated. Each replicate shall be plated
at two dilutions with each dilution plated in triplicate.
9. One duplicate sampling event shall be conducted (a second set of triplicate influent and
effluent samples at the given flow condition) with every 10th sampling event collected.
10. A separate sample of the influent shall also be collected to measure UV transmittance.
Samples collected for the determination of percent transmittance samples shall be kept
at 4°C and analyzed within 96 hours of collection.
11. The influent and effluent samples shall be collected in an alternating sequence, and at
times that approximate the time of travel. The influent sample may be taken directly
from the batch tank, from a continuously flowing tap off the feed pipe or directly from
the channel. The effluent sample shall be taken from the reactor outflow, directly in
channel over an effluent weir or from a continuously flowing sample tap. In all cases,
the influent and effluent samples must be representative of the total water stream.
12. Once sampling is completed, the flow rate shall be adjusted to the next target flow rate.
Steps 5 and 6 are repeated.
13. After all flow rates have been tested for a single batch run (i.e., the contents of the batch
tank have been depleted), the feed shall be switched to the alternate water source and
the flow rate shall be adjusted to the baseline flow rate, as in Step 1 (note that the
Verification Test Plan should define this). The intensity shall be recorded. The water
source shall be changed to clean water at the baseline flow rate. A stable intensity (+/-
5% of mean) shall be obtained and recorded.
3.4.3.2 System Monitoring
Several operating parameters may provide information about how an UV system is operating.
The Verification Test Plan shall identify parameters that are important to the performance of a specific
UV system to be tested. These parameters shall include, but are not limited to lamp output, lamp
amperage/voltage (to verify operation), power conditioning, ambient air temperature, and water
temperature. The selected parameters should be monitored under the different flow conditions, at the
beginning and ending of each flow test. The Verification Test Plan shall describe how the parameters
are to be monitored.
3.4.3.3 Hydraulic Testing
Depending on the verification undertaken, additional hydraulic characterization of the system will
be required.
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3.4.3.3.1 Residence Time Distribution
For verifications conducted for secondary effluent applications, residence time distributions will
be developed at a minimum of three flow conditions, equivalent to the lowest, highest and mid-
point of the dose-flow series. Protocols are established for the step-response method in the
U.S. EPA Design Manual for Municipal Wastewater Disinfection (EPA/625/1-86-921, 1986).
The procedure is summarized as follows:
1. A concentrated coffee solution is continuously injected at a constant rate into the
upstream end of the reactor.
2. Coffee injection is continued until a new "steady-state" UV intensity is reached from
background.
3. The coffee solution is shut-off and the return of UV intensity to background conditions is
traced on a chart recorder.
4. Chart recordings are then digitized and used to develop residence time distribution
curves.
Alternate protocols are acceptable but must be described in the final Verification Test Plan.
Note that for some reactors, the step-response method may not be appropriate. In that case
the vendor and TO may prescribe an alternate methodology, which must be fully described and
technically justified in the final Verification Test Plan.
3.4.3.3.2 Velocity Profiles
Velocity profiles shall be established for system verification for reuse applications. The profile
shall be measured at a cross-section within 0.3 m (11.8 inch) upstream of the first reactor and
0.3 m (11.8 inch) downstream of the final reactor. The velocity measurement shall be
conducted at equally spaced points in a grid layout covering the entire cross-section of the UV
reactor. The velocity measurement points shall be 6 to 12 centimeters (cm) (2.4 to 4.7 inches)
apart. For reactors smaller than 25-cm (9.8-inch) wide or 25-cm (9.8-inch) in diameter,
velocity measurements shall be conducted at a minimum of four points (two-by-two grid). For
larger reactors, a minimum of nine points (three-by-three grid) shall be used for establishing the
velocity profile. For widths less than 100 cm, the spacing between the velocity measurement
points shall not exceed 12 cm (4.7 inch). For widths greater than 100 cm, the velocity
measurement points shall not exceed 15 cm. The grid layout shall be specified in the
Verification Test Plan.
For each flow rate used in the reactor validation test, three velocity measurements shall be
conducted at each point using sonic, vector oriented meters, or similar. The Verification Test
Plan shall specify the velocity meters that will be used for testing, including calibration methods.
For the reactor tested, the mean measured velocity at any measured cross-sectional point
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(excluding momentum boundaries [i.e., stationary surfaces such as reactor wall]) shall not vary
by more than 20 percent from the theoretical average velocity (i.e., flow divided by the cross-
sectional area), unless an alternate velocity field can be measured and demonstrated to provide
satisfactory performance.
Note that for closed-shell or pressure reactors, the vendor or TO must propose a test
methodology and protocol for assessing the hydraulic behavior of the unit. This may or may not
be based on velocity profiles; however, the approach and considerations must be fully explained
and technically justified in the final Verification Test Plan.
3.4.3.3.3 Headlosses
The headloss through the lamp reactor portions of the system shall be measured at each of the
flow rates tested under the dose-flow studies. The Verification Test Plan shall describe the
method to be used for such measurements.
3.5 DATA COMPILATION AND ANALYSIS
All data generated from the ETV dose-delivery test element will be compiled, analyzed and
presented in the Verification Report. These data specifically address the components related to dose-
response calibration and the dose-flow evaluation of the test unit.
3.5.1 Dose-Response Calibration
The dose-response calibration method was described in Section 3.1.2, and the analysis of the
data in Section 3.1.3. The Verification Test Plan should include the design of the collimator used,
calibration of the intensity probe, as well as contingency planning in the event a stock fails to meet the
required acceptance criteria (e.g., preparation of a new stock, repeating the dose-response tests, and/or
acceptance of the stock after verifying its dose-response by the repeated tests).
3.5.2 Dose-Flow Relationships
The influent and effluent phage data from the test unit evaluation shall be compiled, along with
the associated flow and transmittance data. The log survival ratio, or response, shall be used to
determine the delivered dose, by comparing it to the dose-response relationship developed by the
collimated beam method. This equivalent dose is then computed and plotted against the flow rate for
each of the transmittances tested. For reuse applications, the 75-percent confidence interval for
inactivation results shall be established using the two-tail Students-t distribution. This is also the default
statistical procedure to be applied for secondary effluent applications unless another method is detailed
in the Verification Test Plan.
A non-linear regression analysis shall be conducted to develop a dose-flow relationship. This
should relate the dose as a function of the inverse flow.
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The flow shall be expressed as a hydraulic loading as follows:
1. Flow per lamp (Lpm/Lamp)
2. Flow per Total Watt Input (Lpm/W)
A graphical representation of the log survival ratio as a function of hydraulic loading shall also be
included.
Note that if similar dose data are collected at reduced power levels, as discussed in Section
3.4.2.5, relationships shall be developed for dose as a function of the equivalent Lpm/Total Watt Input
for the given flow and transmittance. Figure 3-5 presents an example of a dose-hydraulic loading
(expressed as Lpm/Lamp) relationship.
Other relevant data collected as part of the test program shall be compiled and presented,
including:
• Power consumed per unit lamp
• Intensity readings at the different flow settings and calibration steps
• Temperatures recorded for ambient air and water, and relevant system temperatures
• Other measurements and relevant to the specific ETV.
Hydraulic Loading (Lpm/Lamp)
FIGURE 3-5. Example Relationship of Dose (mW-s/cm2) as a Function of Hydraulic Loading
(Lpm/Lamp)
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3.5.3 Hydraulic Characterization Results
RTD curves developed for the test unit shall be presented in the verification report. There shall
be a digitized tracer recording for each test. The first derivative of the tracing will be calculated showing
the slope of the curve as a function of time. Lastly, the cumulative area under the residence time curve
as a function of time, effectively showing the distribution of residence times in the system, will be
generated.
Key quantitative parameters derived from these RTD analyses shall be tabulated. The flow
rates and equivalent velocities through the lamp battery shall be given. The theoretical detention time
shall be computed as the volume (less the quartz/lamp assembly) divided by flow (V/Q), while the mean
residence time (9) is computed as the first moment of the residence time curve.
Several dimensionless ratios will be derived from the RTD analysis, which are useful in
evaluating hydraulic characteristics. Guidance is also given as to expected values for such indices,
although an acceptable unit does not have to conform to these indices:
0/T The ratio of the mean residence time to the theoretical residence time. This should fall
between 0.8 and 1.2.
tp/9 The ratio of the time at which the peak tracer level occurs to the mean residence time.
This should be greater than 0.9, indicating absence of any skew in the residence time
due to back mixing, dead spaces or eddying effects.
t5o/0 The ratio of the time for 50 percent of the tracer to pass to the mean residence time is
also a measure of the skew and should be greater than 0.9 for effective plug flow.
ti/9 The ratio of the time the tracer first appears to the mean residence time is a measure of
short-circuiting, and should be greater than 0.5.
t9o/tio The ratio of the time for 90 percent of the tracer to pass to the time for 10 percent of
the tracer to pass. Also known as the Morrill Dispersion Index, it is a measure of the
spread of the residence time distribution curve; a value of 1.0 would indicate ideal plug
flow, and 21.9 for ideal complete mix. A value of 2.0 or less is generally required for
UV systems.
The dispersion coefficient, E, shall also be computed from the RTD analysis. E can vary from
zero to infinity, approaching zero under ideal plug flow conditions. An E less than 100 cm2/sec is
generally targeted for UV disinfection reactors. An additional parameter, the dimensionless dispersion
number, d, is derived from this testing and should fall below 0.05 for plug-flow conditions.
Headloss and velocity data shall be presented as tabular summaries.
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4 TEST ELEMENT 2: DOSE-DELIVERY RELIABILITY
VERIFICATIONS
This test element includes protocols for verifying dose-delivery reliability through three means:
quartz surface maintenance, general system reliability and/or process controls. Not all sub-elements
may be appropriate for a given technology. The Verification Test Plan shall describe in detail which of
the test sub-elements will be verified.
4.1 TEST ELEMENT 2A: UV QUARTZ SURFACE MAINTENANCE
This section presents the methods and materials associated with evaluating the UV device for
cleaning the quartz sleeves. Maintenance of the quartz surfaces is a critical operation for an UV system
to ensure continued effective performance. The protocol calls for operating two parallel units, each with
a Hill-scale equivalent of the cleaning mechanism. Both units receive the source effluent on an
intermittent basis; one unit has the cleaning device activated while the second does not. The testing
focuses on the condition of the quartz, and compares the rates at which the surfaces foul and lose their
required UV transmissibility.
Table 4-1 provides a summary of the Tasks in Test Element 2A.
4.1.1 Test System Specifications
4.1.1.1 Size and Component Considerations
The objective of this test element is to evaluate the effectiveness of a full-scale cleaning device
that is commercially offered as a component of a UV disinfection system. Typically, these are
comprised of devices that wipe the surface of the quartz, with mechanical or pneumatic drives. In some
cases, a cleaning solution such as acid is a component of the wiping device. Operating variables tend to
be limited to the number of strokes that the device makes over the quartz surface. Other cleaning
mechanisms may include ultrasonic and/or in-situ chemical scouring. Note that this protocol is limited to
in-situ devices.
From a practical verification standpoint, the vendor shall provide a system size, based on
fabrication requirements, that reflects the modularization of the cleaning mechanism. Thus, a multiple
lamp unit shall be provided if it represents the smallest commercial module for a full-scale cleaning
device. In the Verification Test Plan, the vendor shall clearly state the specifications of the test units and
their conformity to full-scale specifications. The reactor enclosure itself does not necessarily have to
mimic a full- scale configuration; thus one can provide a closed shell, pressure vessel, even if the normal
design is open channel, gravity flow. In all cases, the units shall be provided with ports to quickly drain
the wastewaters when they are shutdown.
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Table 4-1. Summary of the Experimental Effort for Test Element 2A: UV Quartz Cleaning Device Verification
TASK
SUBTASK
REF
DESCRIPTION
FREQUENCY
ANALYSES TO BE DONE
A. Initial
Analysis
1. Sampling and
Analysis of WW
4.1.1.2.1
The wastewater to be used
as the matrix for
challenging the wiper is
sampled and analyzed for a
target list of compounds.
Two samples
collected from the
proposed feed water.
Analyze each for TSS, Turbidity, Grease and
Oil (G/O), COD, BOD5, Fe, Hardness, TDS,
Calcium, Magnesium, Total Phosphates, pH,
Settleable solids, %T at 254nm (T and F),*
and Langlier Index.
B.
Cleaning
Evaluatio
n
1. Wastewater
sampling
4.1.2.3
(Step 3)
During operations, collect
samples of the feed to the
units, characterize the
wastewater quality.
Once per 3-day
operating period
(three consecutive
test days)
1. Sample the common influent. These will
comprise time-composites, and single grabs,
depending on the analytical need.
2. Analyze each sample for %T (T and F),
COD, G/O, Fe, Hardness, TSS, Temperature,
pH, Ca, Mg, Total Phosphates, Langlier
Index, BOD5.
2. Monitor and
Test Quartz
Transparency
4.1.2
The quartz sleeves from
each test unit shall be
measured for their
transparency at the end of
every third test day. The
quartz will be cleaned if
their transparency falls
below a pre-set level.
The evaluation shall
proceed until the
measured quartz
transmittance reaches
50% of its initial
transmittance, at
which point the quartz
sleeves will be
cleaned. Run for
three cycles or 21
days, whichever is
longer.
1. Each quartz sleeve is tested at the end of
every third test day.
2. If one considers 4 quartz per unit(or 8 test
quartz) and 3 control quartz sleeves, eleven
sleeves will require transparency testing
every three test days.
3. If the quartz sleeves are cleaned, their
transparency has to be measured before re-
installing in the test unit. This represents a
"cycle."
3. Monitor the
operation and
condition of the
test units.
4.1.2.3
(Steps 4,6
and 10)
Throughout the testing
period, observe the unit
with respect to fouling of
surfaces, accumulation of
debris, etc.
Every test day.
1. Observations shall be recorded with
respect to flow rates, cumulative volumes
treated, intensity (if test unit is equipped with
monitors), cleaning mechanism stroke rate,
and appearance of the quartz surfaces and of
the cleaning mechanism.
T = unfiltered, F= filtered
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The two units provided to the test shall be identical. All components, including the lamps,
ballasts, quartz sleeves, cleaning devices, cleaning device drives, should be the same as used on a full-
scale system. If differences between the test unit and a full-scale system are unavoidable, then the
differences shall be fully explained and justified in the Verification Test Plan. The reactor design should
be such that there is easy access to the quartz sleeve assemblies. The protocol calls for repeated
removal, testing, and reinstallation of the lamp/quartz assemblies, and any design consideration that
allows for efficient handling of these elements (without compromising conformity to the full-scale design)
is a benefit to the test.
The transparency of the quartz will be the primary indicator of cleaning effectiveness. As such,
UV intensity detectors may be installed in the two test systems. These may be fiber-optic strands,
feeding back to the radiometer. These are optional and are not meant to be the direct measures of
quartz-cleanliness; rather, they will provide a qualitative indication of the quartz surface condition
between the times that the quartz will be removed for direct bench-scale measurements. The
Verification Test Plan shall include drawings and sensor specifications, including details on the positions
of the sensors in the reactors. The Verification Test Plan may offer alternative strategies to monitor the
output through the quartz sleeves with detectors that are themselves non-fouling.
4.1.1.2 Test Facility Setup
Important components of the field setup include the wastewater source, pumps, UV units and
meters. The discharge should be routed back to the wastewater plant.
4.1.1.2.1 Feed Formulation/Characterization
Depending on the application, the vendor can recommend the type of wastewater for use in
these cleaning device efficacy tests. As an example, a primary effluent is used for the same purpose for
verification under the ETV Wet-Weather program. Similarly, a secondary effluent can be used as the
challenge water for these verifications. The key is to use water that has the ability to foul a quartz
surface under normal operating conditions. If one uses water that does not even foul the surfaces of the
quartz without the cleaning device, then the verification has little meaning. One can consider using an
altered wastewater; for example a blend of secondary and primary effluents, or a secondary effluent that
is spiked with known fouling agents (examples might include hardness, iron, calcium and magnesium,
oils, fats and greases). This approach is recommended and used as the default method within the
context of this protocol.
The wastewater shall be biologically active. Pretreated wastewater (e.g., secondary effluent or
filtered secondary effluent) that can be spiked with specific components should be considered if the
vendor determines that the system offered is commercially available only for the secondary effluent
and/or reuse applications. At minimum, the feedwater shall be characteristic of the application, and shall
have a positive Langlier Index. In developing a Verification Test Plan for the verification, the analyses
listed in Section 4.1.2.3 shall be conducted and reported for the wastewater or mix of wastewaters to
be used for the evaluation. This should be done for two, separately collected samples, at minimum.
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The Verification Test Plan shall define the methods to be used for feed-water sampling and
analysis. Standard Methods (20th Ed.) and/or USEPA approved methods, if available shall be used for
analyses of the feed water. Primary effluent from a wastewater treatment plant may be diluted with the
same plant's secondary effluent, if necessary. Addition of known fouling agents such as iron and/or
magnesium is acceptable, assuming proper quantification and tracking. The characteristics of the feed
shall be monitored weekly in order to document wastewater conditions during operation of the units.
The Verification Test Plan shall provide characterization data from the proposed test site and shall detail
any anticipated adjustments to the wastewater. The Verification Test Plan shall also specify the
methods to be used to dose the wastewaters with chemical additives, how they will be mixed and the
procedures for monitoring the specific constituents.
4.1.1.2.2 Test Facility Equipment/Assembly
Figure 4-1 presents a schematic process flow diagram for an example test setup. This is used
as the default setup for this protocol. In the example test setup, wastewater in this case is pumped from
the effluent of a plant's secondary or filtered secondary discharge trough and discharged to a constant
head tank. Additives, including chemical and/or process water for dilution may be added to the
constant head tank equipped with a low-speed mixer. The Verification Test Plan may propose
alternative configurations provided they conform to the requirements of the Protocol.
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Discharge Back to
Treatment Plant
Primary Effluent
Channel Pump Q
5 3
uv
I
Units
I
Ed
&
Flow Meters
-£¦
Overflow
Mixer
O Potable
Water Supply
Chemical Additions
¦ Process Water
{Dilution)
FIGURE 4-1. Schematic Layout of Cleaning Evaluation Test Facility.
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In-line valves should be used to set the flow rates, which should be measured by in-line
magnetic flow meters for each unit. Discharge from the UV units is back to the WWTP. A separate,
clean-water line should be available for rinsing the units with clean water in accordance with the
vendor's recommended cleaning procedures.
The Verification Test Plan shall include detailed drawings of the facility setup, including all piping
and tankage, and specifications on the UV test units and all accessory instrumentation, electrical and
mechanical elements of the test assembly.
4.1.2 Fouling/Cleaning Evaluation
The objective of this test element is to determine the efficacy of a system's cleaning mechanism
in maintaining the quartz surfaces while the system is operated intermittently. This will be assessed
relative to an identical system that does not activate its cleaning mechanism, and will be quantified by the
loss in transparency of the quartz sleeves.
4.1.2.1 Operating Conditions
The fouling studies shall be conducted at a single, constant flow rate over a sufficient time period
as described below. There shall be intermittent down periods when the units are not receiving flow and
the lamps are off. The selected flow rate to each unit shall be equivalent to a dose and average
hydraulic loading per lamp prescribed by the vendor and technically justified in the final Verification Test
Plan. The cleaning device shall always be activated on one unit, while the second unit's device will be
inactivated for the entire test period. The lamps will be operated at full power in both units when there is
flow.
The test period shall encompass a minimum of three "cycles," wherein a cycle is defined as the
period between manual quartz cleanings for the unit without the cleaning device, or for a minimum of 21
days, if more than three cycles are experienced during the 21 days. The quartz in this case is cleaned
when the average quartz transparency falls below a prescribed set point relative to clean quartz. Within
the context of this protocol, a set point of 50% is established, unless otherwise proposed and explained
in the Verification Test Plan.
The two units shall have an intermittent operation to simulate down times. Unless otherwise
proposed in the Verification Test Plan, the units shall be operated for a period of 20 hours on and 4
hours off. When off, the units shall be in a drained condition, unless the vendor states that the
commercial systems are held in effluent during dormant periods. Additionally, the vendor shall state if
the unit cleaning devices are operated during shut down and draining. At the end of every third 20-hour
on period, the transparency of the quartz from both units shall be measured.
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4.1.2.2 Quartz Transparency Measurement
The effectiveness of the cleaning mechanism shall be determined by its relative effect on the
transparency of the quartz sleeves to light at 253.7 nm. A standard, monochromatic low-pressure lamp
with a standard electronic ballast shall be used as the UV source. Figure 4-2 provides a schematic of
an example bench-top testing apparatus.
The quartz sleeves being tested shall be slipped over the standard UV lamp. The quartz/lamp
assembly shall be placed in a ventilated housing similar to the collimating apparatus discussed in Section
3 (Figure 4-2). Care shall be taken to assure that the lamp is positioned along the center axis of the
quartz, and does not touch the quartz at any point along its arc length Teflon spacers may be used for
this purpose.
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Platform
October 2002
FIGURE 4-2. Quartz Transparency Test Unit.
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Collimator sections shall be positioned at the one-third, one-half and two-thirds points along the
length of the quartz. The lamp shall be turned on and a stable reading established. Using a narrow-
band 254 UV detector, record the intensity at the bottom of each collimator from a fixed position run-
to-run. The intensity shall be recorded at quarter-points around the perimeter of the quartz sleeve. In
this manner, 12 readings are taken for each quartz sleeve, which are then averaged to give an "average
transparency at 253.7 nm." This procedure shall be conducted for each quartz sleeve from the two test
units.
In addition, three quartz sleeves, identical to ones used in the test units, but kept in a dean,
unused condition, should be tested in the same manner. This should be done at least 20 percent of the
number of times the procedure is followed for the test unit quartz sleeves. These will serve as the
controls for the test units' fouling evaluations. The QAPP shall address the generation of these data and
their analysis.
Note that the apparatus shown on Figure 4-2 is provided as an example. Given the variations
of quartz sleeves, there is flexibility with respect to the test apparatus. The Verification Test Plan shall
describe the apparatus proposed for such testing and clearly indicate the type of data that will be
generated. The Verification Test Plan should, at minimum, measure transparency along the length of the
sleeve and about its circumference.
4.1.2.3 Operating Sequence and Procedures
The following procedures shall be used when evaluating UV systems that use a wiping
mechanism to clean the quartz surfaces. Planned deviations shall be fully described and justified in the
Verification Test Plan.
1. At time zero, the two units shall be thoroughly cleaned. The Verification Test Plan shall identify
and describe the composition of the cleaning fluid. The quartz from each will be removed
(note that each quartz must be properly and permanently labeled) and tested for
transparency to UV at 254 nm, as described in Section 4.1.2.2. The quartz sleeves shall
then be returned to the units.
2. Begin flow to both units at the prescribed rate. The wastewater feed shall be from the head
tank, adjusted by chemical addition and dilution, as needed, and as defined by the
Verification Test Plan. The wiper shall be activated at a prescribed operating rate in one
unit, and left dormant in the second.
3. A composite sample shall be taken from the common influent (e.g., the equalization tank) over a
minimum 6-hour period once each operating week. This can be a time-composite of grabs
taken every 30 minutes manually or via an automatic sampler. Grab samples shall also be
taken at the end of the compositing period for 1hose analytes requiring grab samples only.
The weekly samples shall be analyzed for the following:
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Transmittance at 254nm (filtered and unfiltered)
COD (filtered and unfiltered)
BOD5 (filtered and unfiltered)
G/O
Iron
Hardness
Total Dissolved Solids (TDS)
Temperature
pH
Calcium
Magnesium
Phosphates
Turbidity
Langlier Index
Total Suspended Solids (TSS)
4. If the units are equipped with intensity sensors, record the intensities periodically (at a minimum,
daily). Record the following daily: (1) the flows to the two units (2) the chemical metering
inputs; and (3) the process dilution water flows, if applicable.
5. After approximately 20 hours continuous operation, shutdown and, if required by the vendor for
its commercial systems, drain both units. This draining step should be quick and thorough.
The wiper operation should be maintained in accordance with vendor's operating
procedures during the draining step. The lamps should be turned off before the units are
drained. The quartz shall not be rinsed.
6. At the end of every third 20-hour operating period, turn off the lamps and wipers and drain the
units. Once drained and fully shut down, the quartz shall be removed. The condition of the
quartz sleeves diall be observed visually and recorded. Each quartz sleeve shall then be
tested for transparency at 254 nm in accordance with Section 4.1.2.2. The quartz shall be
exposed to air and allowed to drain any excess water. They shall not be wiped in any way
nor handled such that the surface condition is disturbed before testing for transparency.
7. If the average transparency of the quartz in either unit has been reduced to less than 50 percent
of the average "clean" quartz transparency (an alternate level can be proposed), then the
quartz sleeves for that unit should be cleaned manually in accordance with the vendor's
operating instructions. After manual cleaning, the transparency of each quartz sleeve shall
be measured again. The operation from one manual cleaning to the next of either unit is
considered one "cycle". If the transparency is greater than 50 percent, the quartz will not
be manually cleaned, and will be returned to its respective unit. Once installed, the flow will
be initiated.
8. The units shall be run through 21 days, or through a minimum of three cleaning cycles for the
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system without the cleaning device. Throughout this period, the flow to the units shall be
kept constant. The wiper (or other cleaning device) operation can be modified, if
appropriate, only after three cleaning cycles have been experienced for the non-operating
unit during this period. The Verification Test Plan shall discuss this and justify alternate
operating conditions within the prescribed period.
9. The Verification Test Han shall describe any additional testing that is to be conducted on the
cleaning devices (such as with different stroke rates for a wiper) as part of this verification,
beyond the minimum default program described in steps 1 through 6.
10. Throughout the testing, observations shall be made on the condition of the wiping mechanism.
Required maintenance, repair and operational procedures shall be recorded. The nature of
material accumulating on the quartz and on the wiping mechanism itself should also be
observed and recorded (e.g., organic, inorganic or biological, debris, algal fibers). The
materials best suited to chemically remove it shall be noted.
4.1.3 Data Compilation and Analysis
The data and field observations generated during the evaluation of the cleaning device shall be
compiled and presented in tabular and graphical formats. To show the effectiveness of the cleaning
device the average transparency of the quartz sleeves shall be plotted as a function of operating time and
cumulative volume of water treated. This should be done for both systems to allow for comparison
between the units with and without the cleaning device in operation. Thus, one should expect relatively
frequent manual cleanings of the unit without the device, and extended periods between manual
cleanings for the unit with the device (the unit with the cleaning device may not have required manual
cleaning within the selected period).
The water quality data (suspended solids, UV transmittance, iron, etc.) should be reported and
evaluated with respect to the quality of the wastewater during testing and the impact that specific
constituents may have on fouling.
4.2 TEST ELEMENT 2B: GENERAL SYSTEM RELIABILITY
The operational data and observations recorded under Verification test runs for dose delivery
capability will be used as a qualitative indicator of the system's overall operational reliability.
Table 4-2 provides a summary of the tasks in Test Element 2B.
4.2.1 System Monitoring
During each day of Verification Testing, operating parameters will be monitored and recorded
on a routine basis on Standardized Field forms. This shall include UV irradiance as measured by the
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vendor's UV irradiance sensor, lamp hours, cleaning mechanism cycles, and electrical energy consumed
by the UV equipment and parts replacement, if necessary. Other parameters may be monitored and
must be described in the final Verification Test Plan.
An automatic device for monitoring UV irradiance is strongly suggested with any UV system
and is mandatory for systems uidergoing verification for reuse applications. The Verification Test Plan
should include a determination of the minimum irradiance below which the flow and equipment shutoff
should occur to assure adequate disinfection at all times. When the irradiance drops below this value,
flow can be shut off or a signal given to the operator indicating the need for cleaning or lamp
replacement. The functionality will be assessed qualitatively.
4.2.2 Additional Reliability Claims
The final Verification Test Plan shall include vendors' claims with respect to how the tested
system can consistently deliver a verified dose under changing conditions and/or with time. Therefore
the TO shall obtain the vendor-supplied O & M manual to evaluate the instructions, procedures,
recommendations and/or claims for their applicability under this verification.
4.2.2.1 Monitor Alarms and/or Indicators Verification
Only alarms/indicators that relate to overall system operability, and which react through audible
or visual means to situations where disinfection effectiveness may be compromised will be subject to
verification claims under this protocol. Those that deal with internal mechanism/component protection
or for health and safety alerts are not considered.
4.2.2.2 Example Conditions
At a minimum, the system should have an audible or visual alarm to indicate the following
conditions:
(a) Shut off UV lamps if the flow of water to the reactor is stopped or drops below a
minimum required level, or if a reactor is physically removed from channel.
(b) Lamp/Ballast Failure Indicator
(c) Startup times from cold start, or delays from shutoff to new start.
Other conditions can be included, based on the vendor's O & M Manual, and can be incorporated into
the Verification Test Plan.
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Table 4-2. Summary of the Experimental Effort for Test Element 2B: General System Reliability Verification
TASK
SUBTASK
REF
DESCRIPTION
FREQUENCY
ANALYSES TO BE DONE
A. Initial
Analysis
1. System
Monitoring
4.2.1
Record and review
operating data/parameters
from Test Element 1
Verification
Refer to Section
3.4.3.1, 3.4.3.2 Test
Element 1.
No Analytical
B.
Monitors,
Alarms
and/or
Indicators
Verificatio
IIS
1. Identify critical
monitors, alarms
and/or indicators
and mechanisms.
4.2.2.1
-4.2.3
Qualitatively check
response of each monitor,
alarm and/or indicator
when trip mechanism
activated.
Three times for each
condition
No Analytical
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4.2.3 General Test Protocol
(1) Determine the mechanism that triggers a shutdown response (e.g. flow sensor, level
monitor)
(2) Artificially create an upset condition (e.g. stop flow to contactor, interrupt power
supply)
(3) Verify expected system response (e.g. visual or audible alarm)
(4) Repeat three times for each alarm/indicator test.
4.2.4 Data Compilation and Analysis
The data and field observations generated during this test element shall be compiled and
presented in tabular format. A qualitative assessment shall be made regarding the consistency of
operational and monitoring data compared to field calibration tests or observations. Qualitative
statements shall be included with aspect to the basic functionality and response of monitors, alarms
and/or indicators
4.3 TEST ELEMENT 2C: PROCESS SYSTEM CONTROL VERIFICATION
This section presents the general test protocol for conducting a verification of an UV system's
process control system. A process control system's primary objective is to automatically adjust
operating variables to respond to changes in ambient conditions. For most cases, systems are designed
for worst-case conditions. This may result in a significant amount of time where the system's deliverable
UV dose is much higher than would be necessary for average conditions. Some systems are equipped
with automatic lamp controls that can vary the UV output to optimize dose delivery, minimize operating
costs and minimize electrical consumption. This test protocol allows a vendor to verify claims for such
operations. The objective is not to verify that lamps are capable of being dimmed or that changes
encountered by a UV or flow sensor will affect the lamp output (these types of PLC qualitative
verifications would be considered under Test Element 2B). The objective of this Test Element would be
to demonstrate that a minimum dose could be delivered and maintained under differing hydraulic
conditions.
Verification under this test element shall be demonstrated through the use of a dose-delivery
assay conducted at different test conditions while allowing the UV system to automatically adjust as
needed to meet the vendor's dose-delivery claims. The assay shall be conducted in a clean-water
matrix with MS2 phage (same as for Test Element 1).
It is strongly recommended that if a vendor intends to verify process control claims, it is best
that the testing be completed concurrently with the standard dose delivery capability verification(s) as
described in Section 3. The additional tests required under this test element are summarized in Table 4-
3.
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Table 4-3. Additional Tasks Required for r
"est Element 2C: Process Control System Verification
TASK
SUBTASK
REF
DESCRIPTION
FREQUENCY
ANALYSES TO BE COND
A. Test
Unit Assay
1. System
Monitoring
3.4.3.1
3.4.3.2
Monitor the test system
for operating variables and
test unit conditions
At each hydraulic
loading sampling
event.
1. Temperature of water, air and lamp (2
lamps), at each flow condition sampled.
2. Intensity at 100 and test output. (Set
automatically by P.L.C. or manually at
set points prescribed by the vendor)
3. Voltage/Amperage at each Intensity
setting.
2. Conduct Dose-
Flow Assays
3.4.3.1
Conduct runs with
prepared phage batches.
Each run shall comprise
four different flow rates.
Quartz are cleaned
manually each day or with
each run.
Minimum of three
runs.
1. Conduct Influent and Effluent sampling
in triplicate at each flow event at the two
test transmittances [55 and 65]
2. Conduct a duplicate flow event at each
10th flow event.
3. Yields a total 24 samples for phage
analyses and 12 transmittances (influent
only) for each run at each transmittance.
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4.3.1 UV Test Unit Specifications
The test unit submitted for evaluation by the ETV protocol must be equivalent to the commercial
unit offered by the vendor. It will be critical to clearly describe both the commercial unit and the test
unit as part of the Verification Test Plan. This should be in conformance with Section 3.2 et seq.
4.3.2 Test Facility
The test facility for verification under this protocol shall be in conformance with Section 3.3 et
seq.
4.3.3 Dose-Flow Assay
Under this verification protocol, flow-dose assays are conducted at different hydraulic loadings
and water transmittances to demonstrate the capability of UV systems to automatically respond to
changing conditions and maintain a targeted delivered dose. Test conditions set for the dose-delivery
assays (Section 3) such as quartz sleeve surface conditions, indicator organism densities and
temperature shall be the same as for dose-delivery verifications (refer to Sections 3.4.2.1, 3.4.2.3,
3.4.2.6). The Verification Test Plan shall specifically describe the challenges imposed on the test unit
with respect to changes in transmittance, flow and operating power.
4.3.4 Data Compilation and Analysis
All data generated from the ETV process control system verification will be compiled, analyzed
and presented in a Verification Report. These data specifically address the components related to
dose-response calibration and the dose-flow evaluation on the test unit. The specific analyses and
relationships shall be in accordance with Section 3.5.1 et seq.
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5 TEST ELEMENT 3: UV DESIGN FACTORS VERIFICATIONS
This section presents test methods and protocols to verify two key design factors: quartz sleeve
fouling factor and lamp age factor. Default values for these factors are commonly used in design and
often form the basis for test conditions for performance tests (i.e., bioassays). In the case of the
secondary effluent UV performance test, the lamp age factor has typically been set at between 0.65 and
0.75, and the quartz sleeves were maintained in a clean state for the tests, equivalent to a fouling factor
of 1.0. The NWRI/AWWARF guidance requires a fouling factor of 0.8 and a lamp age factor of 0.5
for design, and as test conditions when verifying dose delivery via biodosimetry. If a vendor wishes to
claim a different factor(s), the guidance further states that direct testing must be conducted to verify such
alternate factors. The verifications conducted under this protocol will allow a vendor to demonstrate
alternative factors. This will then allow for these factors to be used for design/life cycle estimates, as well
as conduct dose verification for reuse applications at the alternate verified factors.
5.1 TEST ELEMENT 3A: FOULING FACTOR DETERMINATION
This section presents the general test protocol for conducting an ETV verification of a vendor-
prescribed fouling factor. The fouling factor represents the minimum quartz sleeve transmittance
achievable in a fouling-inducing matrix in conjunction with a continuously operating cleaning mechanism.
The fouling factor can be used as a design criterion for the vendor or other interested parties. In
addition, verification under this protocol will allow a vendor to use the derived fouling factor to set the
test conditions for dose-delivery verification for reuse applications in lieu of the default values.
While seemingly similar to Test Element 2A, Quartz Cleaning Device Verification, this test
element differs in its objective and final product. The goal is to establish an estimate of the long-term
deterioration in quartz transmittance due to continuous operation in a fouling environment and with the
continuous operation of a cleaning device integral to the commercial system. As such, the test period is
longer, and one is not concerned with a comparison to quartz conditions without the cleaning device in
operation. A comparison of the two verification protocols is presented on Table 5-1.
Table 5-2 presents a summary of tasks in Test Element 3 A.
5.1.1 Test System Specifications
One test unit shall be setup at the test facility. From a verification standpoint, it is necessary only
to simulate a minimum of four quartz sleeves or the smallest cleaning mechanism assembly, whichever is
greater. In the Verification Test Plan, the vendor shall clearly state the specifications of the test unit and
their conformity to full-scale specifications. In all cases, the unit shall be provided with ports to quickly
drain the wastewaters when they are shutdown.
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Table 5-1. Comparison of Test Element 2A and Test Element 3A
Quartz Surface Maintenance
Fouling Factor Verification
Objective
Quantitative comparison of fouling with
cleaning mechanism vs. no cleaning.
Test periods are discrete and not
necessarily continuous.
Quantitative determination of relative
fouling of system at the end of a
continuous six-month (minimum) test
period.
No. Units
¦ 2 identical reactors.
¦ 1 with cleaning mechanism on-line
¦ 1 with cleaning mechanism off-line
or;
¦ 1 unit with 2 separate lamp banks.
1 reactor with minimum 4 sleeves or
smallest mechanism assembly.
Feed Waters
Can vary depending on vendor claims.
Non-disinfected filtered (non-
membrane) effluent with a positive
Langlier saturation index.
Operating
Condition
¦ Single flow rate.
¦ Quartz transparency measurement
after approximately 3 days continuous
operation.
¦ Short Shutdown period every day
¦ Continue test until transparency is 50%
¦ Single flow rate.
¦ Continuous 6-month operation
(minimum).
¦ Quartz transparency measurement
every 2 months.
¦ Wiper rate and assembly cannot be
modified during the test period.
Monitoring
¦ Influent characterization 1 time per
week of continuous operation.
¦ Daily record of system operation
conditions.
¦ Lamp power continuous
¦ Daily record of mechanism cycle
¦ Weekly influent characterization
Polychromatic
Systems
Considerations
Transparency of different wavelengths
depends on vendor claims.
Monitor at least 5 wavelengths in the
UVC band.
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Table 5-2. Summary of the Experimental Effort for Test Element 3A: Fouling Factor Determination
TASK
SUBTASK
REF
DESCRIPTION
FREQUENCY
ANALYSES TO BE DONE
A. Initial
Analysis
1. Sampling and
Analysis of feed
water.
5.1.2.1
The feed water to be used
is sampled and analyzed
for a target list of
compounds.
Two samples
collected from the
filtered effluent one to
two days apart.
Analyze each for Turbidity, Fe, Hardness,
IDS, Calcium, Magnesium, pH,
Temperature, %T at 254nm (T and F),
Alkalinity, Langlier Index
B. Fouling
Factor
Determinatio
n
1. Feed water
sampling
5.1.6
(Step
3)
Collect samples of the
feed to the units,
characterize the water
quality
Once each week.
1. Sample the influent. These will comprise
time-composites, and single grabs,
depending on the analytical need.
2. Analyze each sample for %T (T and F),
Fe, Hardness, Temperature, pH, Ca, Mg,
Langlier Index, Alkalinity, IDS.
2. Monitor and
Test Quartz
Transparency
5.1.3
to
5.1.7
and
(4.1.2.
2)
The quartz sleeves from
the test unit shall be
measured for their
transparency every 2
months.
The evaluation shall
proceed for at least
six months.
1. Each quartz sleeve is tested at the end of
each 2-month period.
2. Assuming 4 quartz per unit, 4 test quartz
and 3 control quartz will require
transparency testing.
3. Monitor the
operation and
condition of the test
unit.
5.1.6
(Steps
3 and
7)
Throughout the testing
period, observe the unit
with respect to fouling of
surfaces, accumulation of
debris, etc.
This is done at least
weekly.
1. Observations shall be recorded with
respect to flow rates, intensity (if the test unit
is equipped with monitors), cleaning
mechanism stroke rate, appearance of the
quartz surfaces and of the cleaning
mechanism, and lamp input/output power.
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All components, including the lamps, ballasts, quartz sleeves, cleaning devices, and cleaning
device drives, shall be the same as used on a full-scale system. The vendor shall prescribe in detail, the
operating conditions including number passes/stroke intervals, etc. that will be recommended for a full-
scale commercial system.
As in test element 2A, the transparency of the quartz will be the primary indicator of fouling. As
such, one or more UV intensity detectors may be installed in the test system, but are not meant to be the
direct measures of quartz-cleanliness; rather, they will provide a qualitative indication of the quartz
surface condition between the times that the quartz will be removed for direct bench-scale
measurements. The Verification Test Plan shall include drawings and sensor specifications, including
details on the positions of the sensors in the reactors. The Verification Test Plan may offer alternative
strategies to monitor the output through the quartz sleeves with detectors that are themselves non-
fouling.
5.1.2 Test Facility Setup
Important components of the field setup include the wastewater source, pumps, UV units and
meters. The discharge should be routed back to the wastewater plant.
5.1.2.1 Source Water and Characterization
The source water used for this evaluation shall be a non-disinfected filtered (non-membrane)
secondary effluent with a positive Langlier saturation index. Additionally, the effluent fed to the unit shall
have an average iron concentration of at least 1 mg/L, and a minimum hardness of 100 mg/L as CaC03.
Direct chemical addition can be made in order to meet these minimum targets.
In addition, the source water shall also be characterized for the following parameters:
Turbidity
Iron
Hardness
Calcium
Magnesium
Total Dissolved Solids
Transmittance @ 254 nm (filtered and unfiltered), and other wavelengths desired.
Temperature
Alkalinity
Langlier Index
The initial characterization should be conducted on 3 discrete samples collected one to two
days apart within 2 weeks of anticipated startup. The characteristics of the feed water shall be
pH
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monitored periodically (at least once per week) throughout the duration of the test. The final
Verification Test Plan shall define the methods to be used for feed water sampling and analysis
(Standard Methods, 20th Ed. and/or USEPA approved methods.)
5.1.2.2 Test Facility Equipment/Assembly
Figure 5-1 presents a schematic process flow diagram for an example test setup. This is used as
the default setup for this protocol. In the example test setup, wastewater is pumped from the effluent of
a plant's filtered secondary discharge trough directly through the test reactor. The Verification Test Plan
may propose alternative configurations provided they conform to the requirements of Protocol.
In-line valves should be used to set the flow rate, which should be measured by in-line magnetic
flow meters. Discharge from the UV unit is back to the WWTP. The Verification Test Plan shall
include detailed drawings of the facility setup, including all piping and tankage, and specifications on the
UV test units and all accessory instrumentation, electrical and mechanical elements of the test assembly.
5.1.3 Fouling/Cleaning Evaluation
The objective of this test element is to quantitatively determine the transmittance of a system's
quartz sleeve, relative to new quartz, after being subjected to the long-term (6 months) conditions in a
representative flowing effluent and with the system's cleaning device in continuous operation.
5.1.4 Operating Conditions
The fouling studies shall be conducted at a single, constant flow rate for at least 6 months, as
described below. The selected flow rate shall be that needed to achieve an equivalent theoretical
average dose level of 50 mWs/cm2 with the lamps fully powered and the quartz in a clean state, or as
otherwise prescribed by the vendor. This must be technically justified in the Verification Test Plan.
The unit shall be operated continuously and the lamps shall be operated at full power or at its
highest power set point for a minimum of six months. The cleaning device shall be activated
continuously. The mechanism's operating cycle, cleaning solution change-out frequency and/or cleaning
sleeve replacement interval (if appropriate) shall conform to the vendors' recommendation for a full-
scale commercially available system.
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Discharge Back to
Treatment Plant
Filtered Effluent
Channel Pump Q
t 4
uv
Units
L-G-
Pump
Flow
Meter
O Potable
Water Supply
(for cleaning)
FIGURE 5-1, Schematic Layout of Fouling Factor Verification Test Facility,
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5.1.5 Quartz Transparency Measurement
The condition of the quartz sleeve surface shall be quantified by the measured transparency of
the quartz sleeves to light at 253.7 nm. This procedure is the same as described for Test Element 2A
(refer to Section 4.1.2.2).
5.1.6 Fouling and Cleaning Procedures
The Verification Test Plan shall describe the procedures for the determination of the system-
fouling factor. The following procedures shall be used when evaluating UV systems that use a wiping
mechanism to clean the quartz surfaces. Planned deviations from these procedures shall be fully
described and justified in the Verification Test Plan.
1. At time zero, the unit shall be thoroughly cleaned. The Verification Test Plan shall identify
and describe the composition of the cleaning fluid. The quartz from each shall be removed
(note that each quartz must be properly and permanently labeled) and tested for
transparency to UV at 254 nm or in the case of polychromatic lamps, alternate wavelengths
if desired. The quartz sleeves are then returned to the unit.
2. Begin flow to the unit at the prescribed rate. The feed shall be from the filtered (non-
membrane) secondary effluent, and the wiper shall be activated at a prescribed operating
rate, which shall be recorded, and the lamps operated on full power or at the highest power
set point.
3. Operate the unit at the constant flow rate continuously. If the unit is equipped with an
intensity sensor, record the intensity and flow rate periodically (minimum of once per
business day). Lamp input/output power and water temperature should also be monitored
daily. The feed water shall be sampled at least once per week (Section 5.1.2.1). Lamp
temperature should be monitored, if the unit uses conventional low-pressure lamps.
4. At the end of two months of continuous operation, shutdown and drain the unit. This
draining step should be quick and thorough. The wiper operation should be maintained in
accordance with vendor's operating procedures during the draining step. The lamps should
be turned off before the unit is drained. The quartz shall not be rinsed.
5. Once the unit has been drained and fully shut down, the quartz shall be removed. The
condition of the quartz sleeves shall be observed visually and recorded. Each quartz sleeve
shall then be tested for transparency at 254 nm or other wavelength in accordance with
Section 5.1.5. The quartz sleeves shall be exposed to air and allowed to drain any excess
water. They shall not be wiped in any way nor handled such that the surface condition is
disturbed before testing for transparency. The three control quartz sleeves, which are
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separate from the four test sleeves, shall also be measured.
6. The quartz sleeves shall then be returned to the unit and the system returned to its prior
operating conditions. Quartz transparency measurements shall be conducted at least every
two months, for a minimum elapsed period of six months.
7. Throughout the testing, observations shall be made on the condition of the wiping
mechanism. Required maintenance, repair and operational procedures shall be recorded.
The nature of material accumulating on the quartz and on the wiping mechanism itself should
also be observed and recorded (e.g., organic, inorganic or biological, debris, algal fibers).
5.1.7 Data Compilation and Analysis
The data and field observations generated during the six-month operating period shall be
compiled and presented in tabular and graphical formats. The ratio of the transparency of the quartz
sleeves at each two-month "measurement event" interval to the average transparency of the control
quartz sleeve shall be plotted as a function of operating time and cumulative volume of water treated. A
trend line through the data set will be used to determine the decay function over the test interval. The
lowest ratio observed over the test interval will be the verified "fouling factor" for the commercial
system.
The water quality data (e.g. Langlier saturation index, temperature, transmittance, etc) should be
reported and evaluated with respect to the quality of the wastewaters during testing. A statement of
verification regarding the cleaning mechanism operation and confirmation of full lamp output operation
during the test period shall also be included.
5.2 TEST ELEMENT 3B: LAMP AGE FACTOR VERIFICATION
This section presents the general test protocol for conducting an ETV verification of a vendor
prescribed lamp age factor. The lamp-age factor can be used as a design criterion for the vendor or
other interested parties. In addition, verification under this protocol allows use of the derived lamp-age
factor to set the test conditions for dose delivery verification for reuse applications in lieu of the default
values.
5.2.1 Minimum System Requirements
Lamp age factor testing must be conducted using a minimum of 10 lamps selected from two
different lamp batches for conventional low-pressure lamps and low-pressure, high output lamps. A
minimum of ten lamps from two batches is also the default requirement for polychromatic lamp
verifications. Note that these quantities represent those that shall have been successfully carried through
the entire period. It is recommended that additional lamps be included to allow for breakage.
A vendor may propose testing fewer lamps than the default requirement of ten lamps from two
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batches if sufficient historical QA/QC documentation, and previous lamp aging or similar data, is
provided by the vendor and/or hmp vendor. The vendor, before the start of a testing program using
less than the default number of lamps, should review the supporting documentation and Verification Test
Plan with the appropriate regulating authorities).
The lamps do not have to be housed in a commercial reactor, but the identical quartz sleeve,
lamp and ballast configuration as a commercial system must be used. The vendor claims must include a
statement as to the expected lamp life or minimum replacement interval.
The test system shall have the ability to cycle the lamps on/off. The vendor claims must specify
the maximum number of on/off cycles and intervals that the lamps shall be operated. There shall be at
least four on/off cycles per day for low-pressure systems. For polychromatic systems, lamps are
generally not on/off cycled as often, but rather, operated at different power set points. In this case, the
vendor claims must address how the minimum power set point is determined and specify the
methodology used to adjust set points over the course of the test period. The vendor must address the
power and on/off cycling to be imposed for the test period and explain how this conforms to the
commercial system.
5.2.2 Test Facility
The only requirements for a test facility are the ability to provide a source of water covering a
temperature range of 10 to 25 degrees (as stated by the NWRI/AwwaRF guidance) centigrade and a
suitable setup to measure lamp output. As such, testing under this protocol can be conducted at a water
or wastewater treatment plant or in a laboratory setting, provided all the basic test requirements are met.
Note that the NWRI/AwwaRF (December 2000) guidance states the range as 10 to 25 degrees C.
This may not be practical, possibly requiring testing at both a warm and cold climate plant to capture the
full temperature range. The modified range required by this protocol is responsive to the intent of the
test, and is one that can be found in a single facility.
5.2.3 Test Facility Equipment
This protocol gves general direction to the setup of a test site. The Verification Test Plan shall
provide details of the test facility.
5.2.3.1 Test Reactorf s)
Test reactors are the housing in which the lamps will be held as they age. A reactor may hold a
single hmp or multiple lamps. The reactor shall be designed so that heat transfer conditions (between
the lamps and surrounding water) are similar to full-scale operation. In lieu of constructed reactors, a
commercial UV reactor can be used. In this case, the reactors may be placed in a temporary or full-
scale channel under appropriate flow conditions.
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5.2.3.2 Lamp Output Measurement Reactor
The lamp output measurement reactor is a separate reactor designed to allow for the
measurement of output from a single lamp. A series of such reactors can also serve as the aging
reactors.
5.2.3.3 Electrical Source
An uninterruptible power supply should power the lamps during testing. This may be from an
existing feed line or from a portable generator conditioned to meet the vendor's specifications for their
control panel.
5.2.3.4 Water Source
The water source selected for the verification shall be discussed in detail in the final Verification
Test Plan. In laboratory test facilities, potable tap or deionized water may be used. Secondary,
process, tertiary or potable waters may be used at a treatment plant setup for aging. However, it is also
recommended that potable water or DI water be used in the lamp output measurement reactor when
recording irradiance. The e£fect(s), if any, the water source may have on the overall test program shall
be discussed in the Verification Test Plan.
5.2.3.5 Water Temperature Variability
The lamps shall be subjected to water temperature variations between 10 and 25 degrees
centigrade. If a plant effluent is to be used, historical temperature data shall be included in the
Verification Test Plan, if available. Potable sources will not likely be subject to the required variation.
Therefore, artificial means for heating and/or chilling the water must be provided. The equipment and
methodology to adjust source water temperature during the test period shall be discussed in detail in the
Verification Test Plan.
The Verification Test Plan must also address how the temperature variation will be distributed
over the course of testing. This distribution should mimic seasonal variations in water temperature.
5.2.3.6 UV Output Monitoring
UV output monitoring during the test period can be measured in-situ, if provided for in the
design of the reactor and approved by the TO. A separate test reactor can also be used and is
preferred. The minimum requirements for either condition are that UV output readings are not
influenced from adjacent lamps and that all readings are conducted under heat transfer conditions
representative of full-scale operation.
For low-pressure systems, all UV output measurements shall be at a wavelength of 254 nm.
For polychromatic lamps, a minimum of six wavelengths shall be monitored; such as it is 240, 250, 254,
260, 280 and 300 nm. The selection of wavelengths and the methodology/instrumentation for
measurement shall be fully described in the Verification Test Plan.
For all measurements, an appropriate UV sensor with necessary diffusers and/or narrow band
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filters and radiometer shall be used. The UV sensor assembly shall be calibrated no more than one
month before the start of the testing according to the vendor's recommendations. An independent party
shall check the calibration at least once every six months of continuous testing.
The TO will be required to prepare and submit with the Verification Test Plan appropriate
Piping and Instrumentation Diagrams, equipment layouts, and schematics of the test facility, showing all
components of the test equipment and accessory installations and all monitoring locations. A schematic
of an example laboratory-based installation using a re-circulation flow loop is presented in Figure 5-2.
5.2.4 General Test Protocol
The following general protocol is provided as a default for testing the output for the individual test lamps
with time. It assumes that the full set of lamps are aged in a separate "aging" reactor, and that the
individual lamps are then removed and installed in a "measurement" reactor for actual output/irradiance
measurements.
1. The lamps shall be burned-in for a minimum of 100 hours before the baseline UV output
measurements are taken.
2. All quartz surfaces in the lamp output measurement reactor shall be cleaned according
to the vendor's recommendations; this includes the sleeves as well as any quartz
windows associated with monitoring ports. The test lamp is then installed in the
measurement reactor.
3. Water shall be continuously circulated through the measurement reactor and its
temperature adjusted, as necessary, to average ambient conditions (i.e. 20 degrees
centigrade +/- 1 degree). Once the water temperature is set, UV output at the selected
wavelength(s) shall be measured using an International Light radiometer with the
appropriate UV sensors/diffuser/filters (or equivalent). Readings will be taken through
water. Water temperature and electrical readings shall be recorded at the time of each
measurement. A sample of the source water shall also be collected and measured for
UV absorbance at the wavelength(s) measured. The Verification Test Plan should
describe in detail how system stabilization/equalization (lamp output with regard to
water temperature and flow through) shall be determined and verified.
4. After baseline conditions are established, the lamps are returned to the aging reactor
and operated at full power under continuous flow conditions and at the temperature
variations prescribed by the Verification Test Plan. The system shall be monitored for
flow, lamp-hours elapsed, ballast and lamp power (as appropriate to the specific lamp),
and on/off cycling events. Monitoring may be continuous or at discrete time intervals
(e.g., daily). The Verification Test Plan shall provide details of the monitoring protocols
during the lamp aging periods, and shall describe and justify how continuous operation
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of the lamps at full power will be verified.
5. This monitoring and measurement period shall extend for the period claimed by the
vendor.
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Flow Meter
AT^sre-
Ti
Reactor •
housing
Quartz sleeve ¦
1/3L
/nfertsjfyl
n
±n HTgn Li
^-Qwarfz windo^^
V
Lamp
<¦
////////
.feed wafer
Tefrp [10 - 25 C]
Pump
Heater Chiller
Power
T
'e
Timer
7t
Ballast
*' Record
V: /, /> Hz, etc.
FIGURE 5-2. Test set-up schematic.
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UV output measurements shall be repeated following the same methodology at intervals of no
more than 20 percent of the specified lamp life or change-out interval. Note, all subsequent UV output
measurements must be taken at the same source water temperature at which the baseline conditions
were established. Monitoring is necessary only for the water temperature. It is recommended that the
lamp temperature be monitored for low-pressure, low-output lamps.
The Verification Test Plan shall provide a plan to ensure that the required water temperature
fluctuation is achieved over the course of the test period. The temperature profile does not have to
necessarily follow seasonally. At a minimum, 80 percent of the operating period shall be conducted at a
source water temperature between 15 and 20 degrees centigrade. Ten percent of the interval shall be
conducted with the temperature varying between 10 and 15 degrees and the remaining ten percent shall
be conducted at water temperatures between 20 and 25 degrees. Other temperature profiles may be
considered, but must be fully described and technically justified in the Verification Test Plan.
There may be some instances where a vendor may choose to conduct the lamp aging and
associated measurements at its facility, remote from the TO's location. This is an appropriate set-up;
however, the Verification Test Plan must include a detailed plan to ensure that the TO can confidently
and independently verify that all conditions regarding lamp-aging conditions are met. This may include
continuous data loggers; control panel lockouts or other means.
5.2.5 Data Compilation and Analysis
All data generated from the ETV lamp age factor verification element shall be compiled and
presented in the verification report.
Monitoring data shall be tabulated chronologically and all instrumentation calibration certificates
and/or in-field checks shall be included in the report. A summary of operational history, including lamp
output measurement events, field observations and deviations from the test protocol shall be fully
described.
A lamp age factor shall be calculated for each lamp tested by plotting each lamp's output,
relative to its baseline, as a function of elapsed lamp-hours. A trend line through the aggregate data set
will be used to determine an average UV output decay function over the test interval. The average ratio
from the aggregate data set at the end of the test interval shall be reported as the "lamp age factor,"
unless an alternate approach is discussed in the final Verification Test Plan.
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6 DOCUMENTATION AND REPORTING
Documentation and compilation of data generated by the verification testing will be critical tasks.
Several documents will also be generated as part of the ETV, including the Verification Test Plan and
the final report. A summary Verification Statement will also be prepared, presenting the important
results of the ETV.
6.1 DATA MANAGEMENT AND DOCUMENTATION
A variety of data will be generated during the verification testing. All data identified for
collection in the verification test should be included in the Verification Report. The data handling section
of the Verification Test Plan shall describe the types of data that are to be collected and managed and
how they will be subsequently reported. The use of field notebooks, photographs, slides and
videotapes, and compiled observations from field tests shall be described. All data shall be available in
hard copy and in electronic format.
6.2 VERIFICATION REPORT
The ETV report will follow an establish format, based on NSF and EPA protocols for report
preparation. A key element will be the presentation of the results of the ETV. This must be done in a
manner that is consistent with the objectives of the ETV, and clearly articulates verification of the
capabilities and performance of the UV system to the appropriate applications. This should specifically
encompass whichever of the three Test Elements that were performed separately and then summarize
the overall effectiveness and application of the system, within the bounds set by the ETV.
The Verification Report shall include the following items:
• Executive Summary
• Introduction and Background
• Description and Identification of the System Tested
• Experimental Design
• Procedures and Materials Used in Testing
• Results and Discussion
• References
• Appendices, which may include Verification Test Plan, O and M Manual(s), QA/QC
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Procedures and Test Data
The data shall be compiled, analyzed and presented in the Verification Report in a manner that
clearly addresses the objectives of the verification and the individual test elements. The Verification Test
Plan should describe how the results of the verification tests would be presented in the Verification
Report.
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7 QUALITY ASSURANCE AND QUALITY CONTROL
A Quality Assurance Project Plan (QAPP) shall be prepared as part of the Verification Test
Plan for evaluating UV disinfection technologies for secondary effluent and water reuse applications.
The generic format for such QAPPs is outlined in this section.
7.1 PROJECT DESCRIPTIONS, OBJECTIVES AND ORGANIZATION
7.1.1 The purpose of the study shall be clearly stated.
7.1.2 The processes to be evaluated will be described.
7.1.3 The facility, apparatus and pilot-plant set-up will be fully described.
7.1.4 Project objectives shall be clearly stated and identified as being primary or non-primary.
7.1.5 Responsibilities of all project participants shall be identified. Key personnel and their
organizations shall be identified, along with the designation of responsibilities for planning,
coordination, sample collection, measurements (i.e., analytical, physical, and process), data
reduction, data validation (independent of data generation), data analysis, report preparation,
and quality assurance.
7.2 EXPERIMENTAL APPROACH
7.2.1 Pilot-plant installation and shakedown procedures will be identified.
7.2.2 Pilot-plant startup procedures will be identified. Startup will comprise a number of tasks to
implement and check operating and sampling protocols. Tasks will include establishing feed
makeup and performing flow meter calibration checks, identifying sampling and monitoring
points and identifying the types of samples to be collected.
7.2.3 The Verification Test Plan will be outlined for each test unit. This will include developing dose-
response curves in the laboratory, performing hydraulic checks on the pilot unit and performing
dose-flow bioassays on pilot unit.
7.2.4 Physical, analytical or chemical measurements to be taken during the study will be provided.
Examples include total suspended solids, transmittance, grease and oil, pH, temperature, flow,
pressure, headloss, relative intensity, lamp hours, particle size distribution, etc.
7.2.5 Sampling and monitoring points for each test unit and the type of sample to be collected (grab
or composite) will be identified.
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7.2.6 The frequency of sampling and monitoring as well as the number of samples required will be
provided. This includes the number of samples needed to meet QA/QC objectives.
7.2.7 Planned approach for evaluation objectives (data analysis). This will include formulas, units, and
definition of terms and statistical analyses to be performed in the analysis of the data. Example
graphical relationships will be provided.
7.2.8 Demobilization of the pilot units, including scheduling and site restoration requirements, will be
described.
7.3 SAMPLING PROCEDURES
7.3.1 Whenever applicable or necessary to achieve project objectives, the method used to establish
steady-state conditions shall be described.
7.3.2 Each sampling/monitoring procedure to be used shall be described in detail or referenced. If
compositing or splitting samples, those procedures shall be described.
7.3.3 Sampling/monitoring procedures shall be appropriate for the matrix/analyte being tested.
7.3.4 If sampling/monitoring equipment is used to collect critical measurement data (e.g., used to
calculate the final concentration of a critical parameter), the QAPP shall describe how the
sampling equipment is calibrated.
7.3.5 If sampling/monitoring equipment is used to collect critical measurement data, the QAPP shall
describe how cross-contamination between samples is avoided.
7.3.6 When representativeness is essential for meeting a primary project objective, the QAPP shall
include a discussion of the procedures to be used to assure fiat representative samples are
collected.
7.3.7 A list of sample quantities to be collected, and the sample amount required for each analysis,
including QC sample analysis, shall be specified in the QAPP.
7.3.8 Containers used for sample collection for each sample type shall be described in the QAPP.
7.3.9 Sample preservation methods (e.g., refrigeration, acidification, etc.) and holding times shall be
described in the QAPP.
7.4 TESTING AND MEASUREMENT PROTOCOLS
7.4.1 Each measurement method to be used shall be described in detail or referenced in the QAPP.
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Modifications to EPA-approved or similarly validated methods shall be specified.
7.4.2 For unproven methods, the QAPP shall provide evidence that the proposed method is capable
of achieving the desired performance.
7.4.3 For measurements that require a calibrated system, the QAPP shall include specific calibration
procedures, and the procedures for verifying both initial and continuing calibrations (including
frequency and acceptance criteria, and corrective actions to be performed if acceptance criteria
are not met).
7.5 QA/QC CHECKS
7.5.1 Data Quality Indicators
Statistical analyses shall be carried out on data obtained for all performance measurements. As
part of the assessment of data quality, six data quality indicators (DQIs) can be used to interpret the
degree of acceptability or utility of the data. At a minimum, the QAPP shall include a protocol for
assessing the following DQIs, and acceptable limits and criteria for each of these indicators:
representativeness, accuracy, precision, bias, comparability, and completeness.
The TO shall determine acceptable values or qualitative descriptors for all DQIs in advance of
verification testing as part of the experimental design. The assessment of data quality will require
specific field and laboratory procedures to determine the data quality indicators. All details of DQI
selection and values shall be documented in the QAPP.
7.5.1.1 Representativeness
Representativeness refers to the degree to which the data accurately and precisely represent the
conditions or characteristics of the parameter represented by the data. In this testing, representativeness
will be ensured by executing consistent verification procedures. Representativeness will also be ensured
by using each method at its optimum capability to provide results that represent the most accurate and
precise measurement it is capable of achieving. For equipment operating data, representativeness
entails collecting a sufficient quantity of data during operation to be able to detect a change in
operations.
7.5.1.2 Accuracy
For water quality analyses, accuracy refers to the difference between a sample result and the
reference or true value for the sample. Loss of accuracy can be caused by such processes as errors in
standards preparation, equipment calibrations, loss of target analyte in the extraction process,
interferences, and systematic or carryover contamination from one sample to the next. Loss of accuracy
for microbial species can be caused by such factors as error in dilution or concentration of
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microbiological organisms, systematic or carryover contamination from one sample to the next,
improper enumeration techniques, etc. The TO shall discuss the applicable ways of determining the
accuracy of the chemical and microbiological sampling and analytical techniques in the Verification Test
Plan.
For equipment operating parameters, accuracy refers to the difference between the reported
operating condition and the actual operating condition. For water flow, accuracy may be the difference
between the reported flow indicated by a flow meter and the flow as actually measured on the basis of
known volumes of water and carefully defined times. Meters and gauges must be checked periodically
for accuracy, and when proven dependable over time, the time interval between accuracy checks can
be increased. In the Verification Test Plan, the TO shall discuss the applicable ways of determining the
accuracy of the operational conditions and procedures.
From an analytical perspective, accuracy represents the deviation of the analytical value from the known
value. Since true values are never known in the field, accuracy measurements are made on the analysis
of QC samples analyzed with field samples. QC samples for analysis shall be prepared with laboratory
control samples, matrix spikes and spike duplicates. It is recommended for verification testing that the
Verification Test Plan include laboratory performance of one matrix spike for determination of sample
recoveries. Recoveries for spiked samples are calculated in the following manner:
% Recovery = 100(SSR~SR) (7.!)
where: SSR = spiked sample result
SR = sample result
S A = spike amount added
Recoveries for laboratory control samples are calculated as follows:
„ 100( foundconcentration)
% Recovery = — -
trueconcentration
For acceptable analytical accuracy under the verification testing program, the recoveries
reported during analysis of the verification testing samples must be within control limits, where control
limits are defined as the mean recovery plus or minus three times the standard deviation.
7.5.1.3 Precision
Precision refers to the degree of mutual agreement among individual measurements and provides
an estimate of random error. Analytical precision is a measure of how far an individual measurement
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may be from the mean of replicate measurements. The standard deviation and the relative standard
deviation recorded from sample analyses may be reported as a means to quantify sample precision.
The percent relative standard deviation may be calculated in the following manner:
5(100)
% Relative Standard Deviation = (7-3)
^average
where: S = standard deviation
Xaverage = the arithmetic mean of the recovery values
Standard Deviation is calculated as follows:
I (X — X)2
Standard Deviation = J—! (7-4)
V n-1
where: Xi = the individual recovery values
X = the arithmetic mean of the recovery values
n = the number of determinations
For acceptable analytical precision under the verification testing program, the percent relative
standard deviation for drinking water samples must be less than 30%.
7.5.2 The QAPP shall list and define all other QC checks and/or procedures (e.g., detection limits
determination, blanks, surrogates, controls, etc.) used for the project.
7.5.3 For each specified QC check or procedure, required frequencies, associated acceptance
criteria, and corrective actions to be performed if acceptance criteria are not met shall be included in the
QAPP.
7.6 DATA REPORTING, DATA REDUCTION, AND DATA VALIDATION
7.6.1 The reporting requirements (e.g., units) for each measurement and matrix shall be identified in
the QAPP.
7.6.2 Data reduction procedures specific to the project shall be described, including calculations and
equations.
7.6.3 The data validation procedures used to ensure the reporting of accurate project data to internal
and external clients should be described.
7.6.4 The expected product document that will be prepared shall be specified.
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7.7 ASSESSMENTS
7.7.1 Whenever applicable, the QAPP shall identify all audits (i.e., both technical system audits
[TSAs] and performance evaluations [PEs]) to be performed, who will perform these audits, and who
will receive the audit reports.
7.8 REFERENCES
7.8.1 References shall be provided in the QAPP in the body of the text as appropriate.
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8 GLOSSARY
Terms and acronyms used in this Protocol that have special meaning are defined here:
Accuracy - A measure of the closeness of an individual measurement or the average of a number of
measurements to the true value and includes random error and systematic error.
Bias - the systematic or persistent distortion of a measurement process that causes errors in one
direction.
Comparability - a qualitative term that expresses confidence that two data sets can contribute to a
common analysis and interpolation.
Completeness - a qualitative term that expresses confidence that all necessary data have been
included.
EPA - The United States Environmental Protection Agency, its staff or authorized representatives.
Generic Verification Protocol - A written document that clearly states the objectives, goals, and
scope of the testing under the ETV Program and that establishes the minimum requirements for
verification testing and for the development of a verification test plan. A protocol shall be used for
reference during vendor participation in the verification testing program.
NSF - NSF International, its staff, or other authorized representatives.
Precision - A measure of the agreement between replicate measurements of the same property made
under similar conditions.
Quality Assurance Project Plan (QAPP) - A written document that describes the implementation
of quality assurance and quality control activities during the life cycle of the project. The QAPP is a
required component of a Verification Test Plan.
Representativeness - A measure of the degree to which data accurately and precisely represent a
characteristic of a population parameter at a sampling point or for a process condition or environmental
condition.
Standard Operating Procedure - A written document containing specific procedures and protocols to
ensure that quality assurance requirements are maintained.
Testing Organization - An organization qualified to conduct studies and testing of UV disinfection
equipment in accordance with the Verification Protocol.
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Vendor - A business that assembles or sells UV Disinfection Technology.
Verification - To establish the evidence on the range of performance of equipment and/or device
under specific conditions following an established protocol(s) and verification test plan(s).
Verification Test Plan (VTP) - A written document that establishes the detailed test procedures for
verifying the performance of a specific technology. It also defines the roles of the specific parties
involved in the testing and contains instructions for sample and data collection, sample handling and
preservation, and quality assurance and quality control requirements relevant to a given test site.
Verification Report - A written document that summarizes a final report reviewed and approved by
NSF on behalf of EPA or directly by EPA.
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9 REFERENCES
American Public Health Association (APHA), American Water Works Association (AWWA), Water
Environment Federation (WEF). 1988. Standard Method for the Examination of Water
and Wastewater, 20th ed. Washington, D.C.: American Public Health Association.
Bolton, J.R., trans. "UV-Desinfektionsanlagen fur die Trinkwasserversorgung - Anforderungen und
Priifung," 1997, (UV Systems for Disinfection in Drinking Water Supplies - Requirements and
Testing). Bonn, Germany: Deutsche Vereinigung des Gas - und Wasserfaches e.V. (DVGW)
(German Association on Gas and Water).
HydroQual, Inc., July 2000. Generic Verification Protocol for High-Rate, Wet-Weather Flow
Disinfection Applications - Prepared for NSF International and the U.S. Environmental
Protection Agency under the Environmental Technology Verification Program Wet-Weather
Flow Technologies Pilot.
HydroQual, Inc., December 2000, Generic Verification Protocol for Wastewater Disinfection
Technologies for Small Systems, Draft 1.0 - Prepared for NSF International and the U.S.
Environmental Protection Agency under the Environmental Technology Verification Program
Source Water Protection Pilot.
HydroQual, Inc., Test Plan for Conducting Secondary Effluent Bioassays (numerous confidential
clients).
HydroQual, Inc., 1993, UVDIS Ver 3.1 software for Design and Analysis of UV Disinfection Systems.
International Standards Organization (ISO). 1995, Water Quality - Detection and Enumeration of
Bacteriophage, Part I: Enumeration of F-Specific RNA Bacteriophage." Switzerland:
International Standards Organization, ISO 10705-1.
National Water Research Institute/American Water Works Association Research Foundation,
(NWRI/AwwaRF) December, 2000, "Ultraviolet Disinfection Guidelines for Drinking
Water and Water Reuse" December, 2000.
United States Environmental Protection Agency, 1986, Design Manual, Municipal Wastewater
Disinfection - EPA/625/1-86/021.
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