uv webcast 5 17 13 - water research · pdf fileuv is the most scrutinized water technology...
TRANSCRIPT
5/16/2013
1
© 2013 Water Research Foundation. ALL RIGHTS RESERVED.© 2013 Water Research Foundation. ALL RIGHTS RESERVED.
UV DisinfectionGreater Cincinnati Water Works
© 2013 Water Research Foundation. ALL RIGHTS RESERVED.
Richard Miller Treatment Plant
* chemical fed as needed
Clearwells GACAdsorption
SandFiltration
SecondarySedimentation
(Clarification Basins)
PrimarySedimentation
(Lamella)
Reservoirs(Settled)
AlumPolymerPAC *
LimeFerric Sulfate*KMnO4 *PAC *
PAC *
NaOHChlorine
OhioRiverSupply
ToDistributionSystem
SludgeDischarge
WashwaterRecovery
UV-MP
Na HexFluoride
5/16/2013
2
© 2013 Water Research Foundation. ALL RIGHTS RESERVED.
Why UV • Vulnerability of the Ohio
River water• Upstream wastewater
plants• Multiple inactivation
barrier Cl2 + UV• >7-log removal plus
inactivation of Cryptosporidium and giardia
• Several logs of virus inactivation
© 2013 Water Research Foundation. ALL RIGHTS RESERVED.
UV System• Designed and
approved for 4-log Giardia and Cryptosporidium
• Validation— 3 to 52 mgd/reactor— 75-98.2% UVT— MS2, T1UV, and T7
5/16/2013
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© 2013 Water Research Foundation. ALL RIGHTS RESERVED.
Ongoing activities
• Field Testing—Operational readiness – hardware—Functional demonstration – performance—Site acceptance – 30-days of continuous
operation
• Training • Fully functional – late summer
UV Disinfection Technologies:gWhat Are the Issues?
Paul Swaim, P.E.Paul Swaim, P.E.
Vice President, CH2M HILL Denver
President, IUVA (www.iuva.org)
Vice President, CH2M HILL Denver
President, IUVA (www.iuva.org)
May 17 2013May 17 2013
, ( g), ( g)
May 17, 2013May 17, 2013
Presentation Outline
� UV disinfection regulations and grequirements
� Introduction to current key issues� Introduction to current key issues
� UV disinfection systems� How are they different?� What do they mean?� PLC programs� PLC programs� Cleaning systems
� Start-up, testing, and optimizationStart up, testing, and optimization
UV Disinfection RegulationsUV Disinfection Regulationsand Requirementsq
Availability and Feasibility of UV Disinfection Was a Premise of USEPA’s LT2ESWTR
EPA recognized that UV disinfection was a newEPA recognized that UV disinfection was a newtechnology to the water industry. EPA developed the UVDGM including:
UV dose tablesValidationprotocolOff-specoperationMonitoringReporting
UVDGM Published in November 2006
Many years of y yeffort
S ti fScrutiny frommultiplestakeholdersand reviewersand reviewerswith disparate
http://www.epa.gov/safewater/disinfection/lt2/compliance.htmlinterests
UV: a New Technology for Water Treatment?Treatment?
• Can you guess the year? “It is a matter of common k l d d th t th lt i l t hknowledge nowadays that the ultraviolet rays have a strong bactericidal power.”
� 1887 � 1955� 1914
Source: AWWA Conference Proceedings, 1914
� 2001
• 1991 SWTR GM: 4-page appendix allows UV for virus inactivation
• As of 2012, more than 300 UV disinfection installations being implemented across North America (Wright et al.,g p ( g ,WaterRF 3117, 2012)
UV Is the Most Scrutinized Water Technology EverTechnology Ever
• Technology-Specific EPA Guidance for Drinking Water Treatment
• SWTR Compliance Guidance Manual: �580 pages addressing unfiltered systems, filtration,
disinfection, residual monitoring, etc.�Appendix O: Guidance to Evaluate Ozone�Appendix O: Guidance to Evaluate Ozone
Disinfection (80 pages)• LT2ESWTR:LT2ESWTR:
�Membrane Filtration Guidance Manual (332 pages)�UVDGM (436 pages)
Typical UV Disinfection Design Criteria
� Target Pathogen and Inactivation (Dose) � Design Flowrate� UV Transmittance � Sleeve Fouling and Lamp Aging Factor:
� Tie lamp aging to lamp life guaranteep g g p g� Tie sleeve fouling to water quality, cleaning
method, and frequency� Level of redundancy� Future considerations (expansion, new
applications)
Regulatory Approval of UV Disinfection Projects Encompasses More than Validationj p
� Water quality data and design criteria� Elements of UV design� Hydraulic configuration for UV reactor� Consideration of potential off-spec operation� I&C approach� Plan for commissioning� Monitoring and reportingg p g
EPA Requirements for “Off-Spec Operation”Operation
• Continuously monitor dose-monitoring parameters (i.e., at least every 5 minutes) for each reactor
• Record values at least once every 4 hours• Record off-spec at minimum of 5-minute intervals until
condition is corrected
Introduction to CurrentIntroduction to CurrentKey Issuesy
What Are the Issues? Critical Issues for Successful UV Implementationp
1. Collect UV transmittance data as soon as possible if you are considering UV
2. Once the project begins, talk to your State regulator early and often
3. Understand seasonal issues that impactpwater quality or water demands
4. There is no EPA requirement for a UV dose4. There is no EPA requirement for a UV doseof 40 mJ/cm2 – select the appropriate UV dose for your facility
What Are the Issues? Critical Issues for Successful UV Implementationp
5. Procure equipment early in design for5. Procure equipment early in design forefficiency and optimized O&M
6 Select the best reactor for your operations6. Select the best reactor for your operations,considering validated operation of the UV reactor and turndown optimizationp
7. UV reactor’s validation window should extend well beyond your design criteriaextend well beyond your design criteria
8. Hydraulic configuration at the WTP must be equivalent or better to the validationequivalent or better to the validationconfiguration
What Are the Issues? Critical Issues for Successful UV Implementationp
9. Consider off-specification operation during design, but remember that off-spec of zero is analogous to an MCLG
10. Validation testing is not the only testing needed for smooth startup
11. Specify the performance of intensity sensors, UVT analyzer, cleaning system
12. Develop emergency operatingplans/emergency response plans before UV equipment arrives on site
2011: MP Low-Wavelength Issue Emerges
9
10 • Slide courtesy of WaterRF
7
8
9MS2�Action�Spectrum
Cryptosporidium�Action�Spectrum
of WaterRF4371 and Dr. Karl Linden
5
6
e�Actio
n
Karl Linden• Issue applies
to MP UV only
3
4
Relativ
e to MP UV only
1
2
0200 220 240 260 280 300
Wavelength,�nm
UV Disinfection SystemsUV Disinfection Systems
UV Lamp Types for Large Commercial Drinking Water ApplicationsDrinking Water Applications
Lo Press re/Lo Press re Medi m Press re*• Low Pressure/Low PressureHigh Output (LPHO)
Monochromatic light
• Medium Pressure*Lamps
Polychromatic lightMonochromatic lightLower kW lampsLarger footprint
Polychromatic lightHigher kW lampsSmaller footprintg p p
* Indicates the vapor pressure within the lamp
UV Lamp Output (EPA UVDGM)
tive
toRa
nge
DNA MP tive
ton
Rang
e
1 0 1 0tive
toRa
nge
DNA MP tive
ton
Rang
e
1 0 1 0
tput
Rel
atO
utpu
t in
R Absorbance Output �
ance
Rel
arb
ance
in
0.6
0.8
1.0
0.6
0.8
1.0
tput
Rel
atO
utpu
t in
R Absorbance Output �
ance
Rel
arb
ance
in
0.6
0.8
1.0
0.6
0.8
1.0
Lam
p O
utax
imum
O
LP Output�
A Ab
sorb
am
um A
bso
00.0
0.2
0.4
0.0
0.2
0.4
Lam
p O
utax
imum
O
LP Output�
A Ab
sorb
am
um A
bso
00.0
0.2
0.4
0.0
0.2
0.4
200 250 300Wavelength (nm)
LM
a
DNA
Max
im
200 250 300Wavelength (nm)
LM
a
DNA
Max
im
UVDGM (EPA, 2006)
UV Reactor Considerations
• Manufacturers design UV reactors, which vary in size, shape geometry components and lamp configurationshape, geometry, components, and lamp configuration
• Flow through reactors is turbulent with residence times of seconds or less
• Some reactors incorporate baffles to improve hydrodynamics and dose deliveryInlet and outlet conditions influence reactor hydrodynamics• Inlet and outlet conditions influence reactor hydrodynamicsand UV dose delivery
Evaluate Potential UV Systems
LPHO vs. MP lamps: reactor configuration and size p gValidation hydraulic conditionsFootprint and power requirementsp p qControl strategiesPower modulation capabilitiespO&M requirements:
Lamp aging, lamp life, and lamp replacementSleeve fouling and cleaning
Key Design Issues – I&C
• Programmed with validated dose equationC di t I&C d i ith it i d ti• Coordinate I&C design with monitoring and reportingguidance from UVDGM and input from regulator
• Think through alarms and resulting actions and UV reactorThink through alarms and resulting actions and UV reactorstart-up and shut-down sequences
• Intertie with controls for upstream pumps or filters• Safety controls and avoiding high flowrates
UV Sleeve Cleaning Systems
Startup Testing andStartup, Testing, andOptimizationp
Functional Testing Verifies Functionality
• First testing step following installationinstallation
• Verification of: � Operation of each system
componentcomponent� I&C systems � Signals and scaling
Alarms and responses� Alarms and responses� Ancillary items (e.g., flowmeters,
valves)Responsibilit ill t picall reside• Responsibility will typically residewith Contractor and UV manufacturer to certify functionalityO E i R l t• Owner, Engineer, Regulator may want to witness
Some Typical Alarm Conditions for UV ReactorsReactors
Low UV validated dose
Low UV intensity
Low UVT
High flowrate
Lamp/Ballast failure
Low liquid levelLow liquid level
High temperature
Mechanical cleaning failureMechanical cleaning failure
Lamp life exceeded
Calibration check of UV intensity sensor due
UV System Performance Testing
• Performance Testing:A ti f f th UV f ilit� Assess operating performance of the UV facility
� Demonstrate performance under extended period at actual operating conditions during early stages of operation
� Verify manufacturer guarantees and claims
• Performance Testing may be as little as 48 hrs to as much as weeks or months in durationweeks or months in duration
• May require UV manufacturer and/or contractor involvement
Performance Testing May Include:
• Observation of operation including typical operation, alarm diti ff ifi ti ticonditions, off-specification operation
• Monitor dose control using input signalsM t f l t i l i ti• Measurement of electrical service, power consumption,harmonics, power factor
• Test performance of UV intensity sensors with frequent• Test performance of UV intensity sensors with frequentcalibration checks
• Test performance of UVT analyzer with frequent calibration• Test performance of UVT analyzer with frequent calibrationchecks
• Headloss verificationHeadloss verification
Conclusions: UV Disinfection System Testing and Commissioning IssuesTesting and Commissioning Issues
• Validation testing is not the only necessaryg y ytesting for UV systems
• Functional Testing and PerformanceFunctional Testing and PerformanceTesting are critical to successful startup and operationp
Where Can I Turn for Help?
IUVA vision:…to advance the science,…to advance the science,engineering and applications ofultraviolet technologies to enhanceultraviolet technologies to enhancethe quality of human life and toprotect the environment.protect the environment.
About the IUVA
• IUVA is a non-profit educational association founded in 1999• 600+ members from 35 countries including leading utilities• 600+ members from 35 countries including leading utilities,
regulators, academicians, consulting engineers, manufacturers, and more
• Our website: www iuva org• Our website: www.iuva.org• See you in Las Vegas in September?
UV Disinfection Technologies:gWhat Are the Issues?
Paul Swaim, P.E.Paul Swaim, P.E.
Vice President, CH2M HILL Denver
President, IUVA (www.iuva.org)
Vice President, CH2M HILL Denver
President, IUVA (www.iuva.org)
May 17 2013May 17 2013
, ( g), ( g)
May 17, 2013May 17, 2013
5/16/2013
1
Uniting the World of WaterJune 9 – 13, 2013 | Denver, Colorado
Regulatory Compliance Concerns and ChallengesWhat type of information do regulators expect and need?
Christine Cotton, P.E.
Associate Vice President
213-327-1615
Imagine the result
James Collins, P.E.
Project Manager
Acknowledgements and Disclaimer
• Thank you to regulators
• Regulatory requirements are state and can be district dependent
5/16/2013
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Regulatory Coordination is Critical
Drives design requirements
Sets required timelines
Establishes long-term reports
Issues permit
Monitors reports
Example Regulator Involvement
Rel
ativ
e R
egul
ator
Coo
rdin
atio
n
Conceptual Design
Detailed Design
Construction Start-up & Commissioning
Operations
5/16/2013
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Regulatory Coordination Can Drive UV Projects
Regulators
OffSpecifi-cation
Design
Validation
Operations
Reporting
Regulatory Coordination Can Drive UV Projects
Regulators
OffSpecifi-cation
Design
Validation
Operations
Reporting
5/16/2013
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Off-Specification Operation Can Occur
Flowrate
UVT
Calculated dose
UV sensor and UVT analyzer calibration
Installed UV equipment different from validated
Validation Conditions
LT2ESWTR Allows a Maximum of 5% Off-spec Each Month
May be challenging
Increased operational
flexibility
Min
imal
5%
Target driven by the utility or regulator
5/16/2013
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Off-Spec Requirements
Off-Spec Requirements
DesignDesignValidationValidation
Off-Specification Affects all Project Elements
Design values chosen to reduce off-spec
Validation must include design conditions
The reactor is operated to minimize off-specification
Regulatory Coordination Can Drive UV Projects
Regulators
OffSpecifi-cation
Design
Validation
Operations
Reporting
5/16/2013
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Design Elements Typically Discussed
Design Criteria
Hydraulics
Off-Specification Management
Regulators Focus on Design Criteria
Target Pathogen and
Log InactivationFlow Rate
Design UVT Power Supply
5/16/2013
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UV Facility Inlet Piping Configuration
Five pipe diameters upstream • 90-deg bend
directly upstream during validation
UV facility inlet piping• Includes any
additional piping downstream of 90-deg bend during validation
Custom-validated hydraulics
CFD modeling of
different conditions
Off-Spec Requirements Affect Design
Preventable Conditions
• Conservative design
• Power supply
• Conservative design
• Power supply
Unpreventable Conditions
• Equipment failure• Lamp/ballast• UV sensor
• Equipment failure• Lamp/ballast• UV sensor
5/16/2013
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Regulatory Coordination Can Drive UV Projects
Regulators
OffSpecifi-cation
Design
Validation
Operations
Reporting
Review Validation Results
Validation ConditionsValidation Conditions
Flow
UVT
Include Fouling/Aging
Any UVDGM Exceptions
Any UVDGM Exceptions
Upstream piping
QA/QC
Validation calculations
ChecklistsChecklists
UV Reactor Documentation
Validation Test Plan
Validation Report Review
QA/QC
5/16/2013
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Regulatory Coordination Can Drive UV Projects
Regulators
OffSpecifi-cation
Design
Validation
Operations
Reporting
Start-up and Operations
Start-up• Verify validation
equations in programming
Commissioning • Verify and tweak overall operation
Operations • Routine O&M
5/16/2013
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O&M Supporting Documents
• Overall UV facility operation• UV integration with other facilities• Backup plans• Required procedures
• Overall UV facility operation• UV integration with other facilities• Backup plans• Required procedures
Operations and
Maintenance Plan
• Manufacturer supplied• Detailed procedures• Manufacturer supplied• Detailed proceduresO&M Manual
Items may have been developed earlier in project
Required Maintenance Activities
Required Tasks Recommended Frequency
Duty UV sensor calibration check
Monthly
UVT analyzer calibration check
Weekly
5/16/2013
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Regulatory Coordination Can Drive UV Projects
Regulators
OffSpecifi-cation
Design
Validation
Operations
Reporting
UV Disinfection Reporting Critical
USEPA UVDGM provides example forms
Most states have adopted UVDGM forms
Coordination for state specific requirements
5/16/2013
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Operation and Key Maintenance Reports
Daily treatment performance per unit
Percentage of off-specification water by volume
UV sensor calibration monitoring
UVT analyzer calibration monitoring
Off-specification Volume Key Compliance Measure
• Other communication may be necessary• Other communication may be necessary
Compliance is based on monthly totals
• Select alarms to document reason for off-spec events• Coordination between UV manufacturer and controls• Capturing information for each off-spec event
• Select alarms to document reason for off-spec events• Coordination between UV manufacturer and controls• Capturing information for each off-spec event
UV reactor and SCADA programming is key
5/16/2013
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Regulatory Coordination Can Drive UV Projects
Regulators
OffSpecifi-cation
Design
Validation
Operations
Reporting
Regulatory Coordination is Critical
Regulatory input can change design elements
Saves time/money to coordinate periodically
Less surprises through project
Clear expectations to obtain permit
5/16/2013
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Uniting the World of WaterJune 9 – 13, 2013 | Denver, Colorado
Regulatory Compliance Concerns and ChallengesWhat type of information do regulators expect and need?
Christine Cotton, P.E.
Associate Vice President
213-327-1615
Imagine the result
1
WaterRF UV Knowledge Base Documents UV Disinfection in
North America
Water Research Foundation Webinar, May 17, 2013
Harold WrightCarollo Engineers
12592 West Explorer, Suite 200, Boise, Idaho [email protected]
Drinking Water UV Has Evolved Over Last Ten Years
Regulations Validation
Portland Validation Facility2006 UVDGM
2
Drinking Water UV Has Evolved Over Last Ten Years
Technology Science
Impacts of Wall ReflectionsUV AOP Reactor
How much lamp aging and fouling occurs? Are UV systems properly sized? How reliable are UV systems? How much do they cost? Is mercury release an issue? How do they comply with Guidance and
Regulations? What are the lessons learned?
Utilities, Engineers and Regulators Have Questions
3
WaterRF UV Knowledge base Project Documents UV
DataBase Includes Geographic Info on Who’s Implementing UV
4
Including Canada, eh!
Data Shows Top States and Provinces Implementing UV United States
• New York• Massachusetts• Colorado• California• Arizona• Georgia
Canada• Ontario• British Columbia• Alberta
5
DataBase Shows Market Share by UV System Manufacturer
0 10 20 30 40 50 60
Sunlight Systems
Severn Trent Services
Hanovia
Aquionics
Ondeo Degremont
R-Can
Siemans
WEDECO UV Technologies
Calgon Carbon Corporation
Trojan Technologies
Percentage of UV Systems
USA
Canada
And Where Those Systems are Being Installed
6
0 10 20 30 40 50 60 70
K3000
B Series
BX3200
K143
IH-20L
UVSw ift 30
UVSw ift SC
NYC LPHO
UVSw ift 24
UVSw ift
UVSw ift 12
SUVAM
36" Sentinel
24" Sentinel
48" Sentinel
18" Sentinel
12" Sentinel
Aquaray H2O
CrossFlow
Frontline
UVP200M
PMD200D1
PAP503L8
sun series
Number of Systems
Calgon
Trojan
WEDECO/ITT
R-CAN
Ozonia
Aquionics, Hanovia, Berson
Sunlight
And What They Are …
Survey Requested Photos and Drawings of Installed Systems
Lethbridge, Alberta
7
Photos Provide Ideas for Installation Alternatives
UV is Treating Waters from Various Sources
0 5 10 15 20 25 30 35 40
Surface water
River/Reservoir
River/Lake
River
Reservoir
Lake
GWUI
Groundwater
Number of Systems
USA
Canada
8
Top Locations: Combined Filter Effluent, Post Pumps, Each Filter
0 10 20 30 40 50 60
Other
Wash Water Return
Post Ozone
Finished Storage Reservoir Outlet
Incoming Transmission Line
Pre filter
Pre-High Lift Pumps
Post Clearwell
Well Discharge
Each filter
Post High/Low Lift Pumps
Combined Filter Effluent
Percentage of Systems
Many Plants Have Multiple UV Treatment Objectives
0
1
2
3
4
5
6
7
8
0 20 40 60 80 100
Percentile Ranking (%)
Nu
mb
er
of
UV
Tre
atm
en
t O
bje
cti
ve
s
9
0 10 20 30 40 50 60
Contact time
Taste
Advanced Oxidation for T&O
GWUDI
Regs Require UV for Wells
Government Gudielines
Disinfection
Sulphur & Iron Bacteria
Bacteria
Heterotroph Inactivation
DBP Reduction
Virus Credit
Reduce Chemical CT
Multibarrier Disinfection
Giardia Credit
Crypto Credit
Number of Systems
Surface Water
Groundwater
Database Obtained Info on Target Microbes
0 5 10 15 20 25 30 35
Total Coliform
Bacteria
Heterotrophs
Virus
Giardia
Crypto & Giardia
Cryptosporidium
Percentage of UV Systems
10
Target Pathogen Log Inactivation Criteria
Number of Responses
0.5 log 1.0 log 2.0 log 2.5 log 3.0 log 4.0 log
Cryptosporidium 0 1 6 1 7 6Crypto & Giardia 0 0 1 0 7 1Giardia 2 1 0 0 0 3Virus 0 0 1 0 0 5Heterotrophs 0 0 0 1 1 1Total Coliform 0 0 0 0 0 1
Most UV Systems are Small Systems < 5 mgd
0
20
40
60
80
100
120
140
160
180
0.5 to 5 mgd 5 to 50 mgd 50 to 500 mgd > 500
Design Flowrate (mgd)
Nu
mb
er o
f U
V S
yste
ms
11
Total Installed Capacity Driven by Large Utilities and 3 Vendors
0 500 1000 1500 2000 2500 3000 3500
Sunlight Systems
Severn Trent Services
Hanovia
Aquionics
Ondeo Degremont
R-Can
Siemans
WEDECO UV Technologies
Calgon Carbon Corporation
Trojan Technologies
Total Flowrate (mgd)
New York City
Vancouver
Washington Suburban Sanitary Commission
Design UVT Being Defaulted to 75, 80, 85, 90 or 95%
0
10
20
30
40
50
60
70
80
90
70 72 74 76 78 80 82 84 86 88 90 92 94 96 98
Design UVT (%)
Nu
mb
er o
f U
V S
yste
ms
12
Headloss Ranges from 1 to 34”, Lower with MP
0
5
10
15
20
25
30
35
0 20 40 60 80 100
Percentile Ranking (%)
Hea
dlo
ss (
inch
es)
All
MP
LPHO/Amalgam
UV Knowledge Base Includes UV System Component Data Lamps, sleeves, ballasts, wipers, UV sensors Lifetime, replacements labor, replacement
costs
13
LPHO Replacement Costs Typically $140 to $200
0
50
100
150
200
250
300
350
400
0 20 40 60 80 100
Percentile Ranking (%)
UV
Lam
p R
epla
cem
ent
Co
sts
($)
LPHO All
LPHO Canada
LPHO USA
MP Replacement Costs Range from $250 to $1500
0
500
1000
1500
2000
2500
0 20 40 60 80 100
Percentile Ranking (%)
UV
Lam
p R
epla
cem
ent
Co
sts
($)
MP All
MP Canada
MP USA
14
Auto Cleaning Frequencies Range from 1 to 24 hrs
0
5
10
15
20
25
30
0 20 40 60 80 100
Percentile Ranking (%)
Au
toC
lea
nin
gP
eri
od
(h
rs)
MP
LPHO
Off Line Cleaning Frequencies Range from 1 to 6 Months
0
2
4
6
8
10
12
14
0 20 40 60 80 100
Percentile Ranking (%)
Off
lin
e C
lea
nin
g P
eri
od
(m
on
ths
)
MP
LPHO
15
35 Percent of Systems not Using On-Line or Bench UVT Monitors, 50% Not Checking Monitors
0%
10%
20%
30%
40%
50%60%
70%
80%
90%
100%
UVT Monitor Lab Spec UVT Monitorchecks
Nu
mb
er o
f S
yste
ms
No
Yes
Data Collected on Reporting
USA
0% 25% 50% 75% 100%
UVT Monitor Checks
UV Sensor Checks
Off spec
UV Sensor
UVT
Flow rate
UV Dose
Percentage of UV Systems
Yes
No
16
Data Collected on UV System Labor
0
5
10
15
20
25
30
35
0 20 40 60 80 100
Percentile Ranking (%)
UV
La
bo
r H
ou
rs P
er
Mo
nth MP
LPHO
UV Knowledgebase Project Documents Drinking Water UV Experience in North America Database includes information on:
• Who is implementing UV • UV system design criteria• Locations and installation configurations• Performance and replacements costs for UV
systems components• UV system operation and maintenance• Lessons learned and recommendations
17
WaterRF UV Knowledge Base Documents UV Disinfection in
North America
Water Research Foundation Webinar, May 17, 2013
Harold WrightCarollo Engineers
12592 West Explorer, Suite 200, Boise, Idaho [email protected]
1
Start-up of San Francisco’s UV Disinfection Facility
Enio Sebastiani, P.E.SFPUC Water Quality Division
Operated by the San Francisco Public Utilities Commission
Water Research Foundation Webcast May 17, 2013
2
Overview
• SFPUC System Background
• Tesla Treatment Facility Design Criteria
• Start-up Tests and Facility Permitting
• Fouling Condensation in sensor wells
Biofilm in reactor piping
• Flow Split and Valve Position
• Lessons Learned
2
3
SFPUC System Background
• Hetch Hetchy is 85% of the water supply for San Francisco and its wholesale customers (about 2.6 million total customers).
• Unfiltered Hetch Hetchy supply requires 2-log Cryptosporidium inactivation and two disinfectants per the LT2ESWTR.
• Added 315 mgd UV disinfection system to complement sodium hypochlorite system. Lime added for pH adjustment.
4
Raw Water Quality
Parameter Units Average Range
Turbidity NTU 0.56 0.23 - 2.6
TDS mg/L 12.1 5 - 23
pH 6.8 6.3 - 7.6
Total Hardness mg/L CaCO3 5.5 2 - 20
Alkalinity mg/L CaCO3 6 4 - 20
TOC mg/L 1.7 0.6 - 2.7
UVT 89% 83.5 - 93.8
Color (apparent) CU 11 9 - 15
Iron μg/L 58 35.3 - 116
Manganese μg/L 4.4 2.8 - 7.3
3
5
SFPUC Regional System
6
Key UV Design & Operating Criteria
• Design 3.4 log Cryptosporidium using MS2 82.5% UVT (reactor validated off-site down to 75% UVT) Fouling Factor of 0.8 End of lamp life (EOLL) factor of 0.9 for a Combined Aging and
Fouling (CAF) factor of 0.72 315 mgd (nominal max) 10 Duty and 2 Standby reactors at max flow
• Operation 2.3 log Cryptosporidium using MS2 (includes 20% dose safety
factor) 89% UVT annual average (83.5% to 94% range) 45 mgd max flow per reactor (validated up to 51.3 mgd)
4
7
Additional Design Criteria
• Provide storage and chemical feed facilities for upgraded NaOCl, new fluoride (H2SiF6), and new CO2 system to lower pH.
• Maximum headloss of 6.5 feet over entire facility (achieved 4.74 ft).
• Reduce inlet flow velocities to 2.2 fps for sand/grit settling with large diameter header. Include grit removal system along header invert.
• UPS and Diesel Generators 3 – 1200 kVA/960 kW Flywheel UPS for UV system Battery UPS for chemical pumps (4 hours) 2 – 1875 kVA/1500 kW Diesel generators for entire plant (72
hour fuel storage)
8
Tesla Layout
5
9
Sentinel 48-inch Chevron 9 lamps (20 kW ea)
• Validated Off-site in 2010
• 108 UV Intensity Sensors One germicidal sensor/lamp
in dry well
Mechanical cleaning of sensor window
• Lamp Sleeves Suprasil synthetic quartz
Mechanical cleaning with stainless steel brush
• Ballasts Electromagnetic
One lamp per ballast
(Courtesy of Calgon Carbon Corporation)
10
Off-site Validation and Hydraulics
• Reactors validated off-site Feb-Mar 2010.
• Minimum of 5 pipe diameters of straight pipe upstream of the UV reactors to ensure dose delivery per UVDGM.
31.3 ft or 7.8 diam.
6
Velocity Profile Measurement
11
• Velocity Measurements
6 traverses for first, middle, and last reactor on each train (4 for others)
Measure 5 cm apart
At 10, 25, and 45 mgd
1 ft upstream
Must be within 20% of the theoretical velocity
• Upstream for 12 reactors
• Downstream for 6 reactors
First, middle, and last reactor on each train
12
Velocity Profile Measurement
• Velocity profile measurements were as good or better than those from Validation.
7
13
Start-up Tests
• Velocity Profile Measurements
• 7-day Operational Test prior to substantial completion Wiper travel alarms and drive system repairs
Low Irradiance Alarms
• Power Guarantee at typical seasonal UVTs and flows and combined aging and fouling allowance (CAF).
• Maximum Power Consumption
• Harmonics
• Final Acceptance (30-day) Tests (two by contract) First test from January 12 to February 12, 2012
Second test from April 12 to May 17, 2012
Third test from July 13 to August 13, 2012 for valve position and flow variation follow-up
14
CDPH Permitting Documents
• Permit Application on January 6, 2011
• Design Drawings and Workshops
• Validation Protocol WTC for off-site approval
• Validation Report
• Velocity Profile Test Plan and Test Report
• Validation Control Sheet
• UV Control Narrative
• Operations Plan (three inspections)
• Action Spectra Correction Factor Modeling Memo
• Permit received February 28, 2012
9
Sensor Well Interior Window Fouling
• Include desiccant packs in the PVC insertion tube housing the sensor.
• Add slots in insertion tube and on sensor rim to allow air circulation to desiccant.
• Desiccant packs checked during monthly sensor calibrations.
17
Biofilm Growth
• Biofilm growth was observed in areas removed from UV light but exposed to some incidental visible light.
• Pre-chlorination practice initiated in January 2013. Objective is to just meet demand with minimal residual in the
reactors.
Observed about 0.5% increase in UVT during test in Fall 2012.
• Reactors chlorinated and flushed in February 2013 during aqueduct shutdown.
• Pre-chlorination has continued.18
10
Biofilm Growth
19
20
Sleeve Fouling
• Quartz sleeves (type 214A) replaced in September 2011
• Suprasil 300 synthetic quartz installed to match those used in validation.
• Old sleeves were in reactors since January 2010
• Lamps operating since May 2011
• Wipers operate every 6 hours
• Sleeve fouling will be continue to be examined especially with pre-chlorination practice or any future pH adjustments.
11
Flow Split and Valve Position
• Initial goal was to operate reactors with effluent valves 100% open based on favorable flow split from CFD modeling.
• Lower system headloss resulted in uneven flow split requiring modulating effluent valves.
• Difficulties experienced with valve position feedback resulted in Mechanical Dial Position Indicator gear replacement for valve actuator on four reactors.
• Periodic effluent valve hunting also evident.
• Investigating alternative control strategy not as reliant on valve position feedback. Goal is to remain safely below 45 mgd hydraulic limit per reactor
without negative impact on power consumption.21
Flow Split and Valve Position
Reactor Flow % Open Flow % Open
1 0 0 33.9 100
2 36.8 69 30.4 100
3 36.9 75 26.5 100
4 0 0 23.7 100
5 37 80 22.9 100
6 36.7 100 20.8 100
7 0 0 0 0
8 37.1 82 31 100
9 37.1 83 28.3 100
10 35.8 100 25.6 100
11 0 0 25 100
12 33.1 100 22.3 100
Total 290.5 290.4 22
12
23
Key Lessons Learned
• Start Early
Crypto and on-line UVT data collection began in 2004.
Design-Build contract substantially complete in 32 months (November 10, 2008 start design; March 31, 2009 start construction; June 24, 2011 Substantial Completion).
• 9-month commissioning period prior to April 1, 2012 was invaluable to verify systems, make corrections, and gain operational familiarity.
• Conservative design criteria (3.4-log, 82.5% UVT, 0.72 CAF) have already paid dividends in addressing start-up issues.
• Coordination and communication with CDPH in all project phases facilitated securing plant’s permit.
24
Thank You
26 December 2012
PowerPoint Sample 1
17 M
ay 2013
UV PROCESS SPECIALISTB&V WATER TECHNOLOGY GROUPBRYAN TOWNSEND
P L C B L A C K B O X4
IMPLEMENTATION OF VALIDATED MODELS FOR THE MONITORING AND OPERATION OF UV SYSTEMS
• UV Dose = Intensity x Time
• All UV reactors have a dose distribution
• Non‐uniform distribution of irradiance field and velocity profile
• Avg. LogI of a microbial population is a function of:
• Flow path through the reactor UV intensity & exposure time
• UV sensitivity (i.e. dose‐response) of the microbe @ 254nm
• Microbial action spectra @ 200‐300nm for MP systems
NEED FOR VALIDATION
2
Ideal (plug flow)1
0
Probability
Wider Distribution (less efficient)
Narrow Distribution (more efficient)
UV Dose (mJ/cm2)
17 May 2013WaterRF Webcast: UV System Start‐Up, Operations and Avoidance of Off‐Spec Water
26 December 2012
PowerPoint Sample 2
• Testing of full‐scale reactor with identical wetted dimensions to vessel installed at a WTP
• Conducted at validation facility by independent 3rd party
• UV Disinfection Guidance Manual (UVDGM)
• Released in November 2006
• Primary guidelines for validation, sizing and operation of UV systems in the U.S.
• Increasing interest and applications world wide
• Established a long awaited standard for UV disinfection of potable water
• Allows for flexibility / advancement in techniques
UV REACTOR VALIDATION TESTING
17 May 2013
3
WaterRF Webcast: UV System Start‐Up, Operations and Avoidance of Off‐Spec Water
• Functional Testing• Head loss
• UV Intensity
• Biodosimetry• Reactor challenges – measure logi of a microbial surrogate(s) under various operating conditions
• UV254 Transmittance (UVT), Flow (Q), UV intensity (S)
• Collimated beam testing – measure microbial dose‐response
• Equate the measured logi through reactor to a “Reduction Equivalent Dose” (RED)
• Development of dose monitoring algorithm
VALIDATION TESTING COMPONENTS
17 May 2013
4
WaterRF Webcast: UV System Start‐Up, Operations and Avoidance of Off‐Spec Water
2
10
UVAEUVADC
oUVABA
Q
SS
UVARED
0
20
40
60
80
100
0 1 2 3 4
Dos
e (
mJ/
cm2 )
MS2 logi
• Power (kW)
26 December 2012
PowerPoint Sample 3
• Validated Dose (DVal)
• Validation Factor accounts for:
• Polychromatic bias (BPoly) ‐MP systems only
• RED bias (BRED)
• Validation testing uncertainty (UVal)
• Uncertainty of Interpolation (UIN) of dose monitoring algorithm
• Uncertainty of surrogate microbe(s) dose‐response (UDR) from collimated beam testing
• UV sensor measurement uncertainty (US)
VALIDATION FACTOR & VALIDATED DOSE
17 May 2013
5
WaterRF Webcast: UV System Start‐Up, Operations and Avoidance of Off‐Spec Water
VF
REDDVal
1001 Val
REDPoly
UBBVF
222SDRINVal UUUU
• Provided in LT2ESWTR
• Validated dose (DVal) ≥ the required dose (DReq) to receive inactivation credits for target pathogen
DOSE REQUIREMENTS
17 May 2013
6
WaterRF Webcast: UV System Start‐Up, Operations and Avoidance of Off‐Spec Water
qVal DD Re
UV Dose Requirements (mJ/cm2)
TargetPathogen
Log Inactivation
0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0
Crypto 1.6 2.5 3.9 5.8 8.5 12 15 22
Giardia 1.5 2.1 3.0 5.2 7.7 11 15 22
Virus 39 58 79 100 121 143 163 186
26 December 2012
PowerPoint Sample 4
• Accounts for bias in dose monitoring algorithm resulting from differences in UV sensitivity between target pathogen and microbial surrogate used for validation
• Surrogates having a higher resistance to UV disinfection will tend to overestimate the dose received by target pathogen
• Reactor‐specific dose distribution
• UV sensitivity of pathogen and surrogate
• RED bias values in UVDGM based on CFD modeling of UV reactor with “worst case” dose distribution
• Typically results in conservative calculation of VF and DVAL
• Selection of proper surrogate microbe (or microbes) with is key
• Major focal point of recent validation advancements to develop more accurate dose monitoring algorithms
• Reduce or eliminate RED bias from VF calculation
RED BIAS
17 May 2013WaterRF Webcast: UV System Start‐Up, Operations and Avoidance of Off‐Spec Water
7
• Developed from testing with a single phage
• RED bias can be reduced using a surrogate with similar UV254 dose response as pathogen (such as T1UV)
CALCULATED DOSE (RED) ALGORITHM
17 May 2013WaterRF Webcast: UV System Start‐Up, Operations and Avoidance of Off‐Spec Water
2
10
UVAEUVADC
oUVABA
Q
SS
UVARED
8
0
20
40
60
80
100
0 1 2 3 4
UV
Do
se (
mJ/
cm2 )
Log Inactivation
T1UV Giardia Crypto
26 December 2012
PowerPoint Sample 5
2
10log
UVAEUVADC
L
oUVABA
DQ
SS
UVAi
• Developed from testing with multiple (2 to 3) phage having UV254
dose‐responses bracketing the target pathogen
• Direct calc of pathogen log inactivation (logi) or RED based on interpolation of UV sensitivity (DL) = eliminate RED bias
LOG INACTIVATION (logi) ALGORITHM
17 May 2013WaterRF Webcast: UV System Start‐Up, Operations and Avoidance of Off‐Spec Water
LDiRED log
9
0
20
40
60
80
100
0 1 2 3 4
UV
Do
se (
mJ/
cm2 )
Log Inactivation
MS2 T1UV T7 Giardia Crypto
• Incorporates equations developed from reactor validation
• Algorithms for UV reactor monitoring and control
• Generation of warnings, alarms, and critical alarms
• Two levels of system control/monitoring
• Local Control Panel (LCP)
• Monitoring / control individual reactor
• Master Control Panel (MCP)
• Supervision of entire UV facility
• Coordination of UV reactor operation
PLC BLACKBOX
17 May 2013
10
WaterRF Webcast: UV System Start‐Up, Operations and Avoidance of Off‐Spec Water
26 December 2012
PowerPoint Sample 6
MONITORING ALGORITHMS
17 May 2013
11
WaterRF Webcast: UV System Start‐Up, Operations and Avoidance of Off‐Spec Water
logi & RED
1a
1b
• Target logi is entered in PLC (fixed)• UVA calc by PLC (Eq. 2)• Intensity (S) measured by UV sensors• S0 calc by PLC (Eq. 3)• Flow (Q) from flow meter• UV sensitivity (DL) calc by PLC‐ Pathogens: LT2 dose requirements‐ Surrogate: Validated dose‐response
UV254 Absorbance (UVA)
2• UV254 Transmittance (UVT) from on‐line monitor (via MCP)
Max UV Intensity (S0)
3• UVT from on‐line monitor (via MCP)• Lamp power (PL) set to 100% for S0
2
10log
UVAEUVADC
L
oUVABA
DQ
SS
UVAi
2
10 UVTDUVTCL
BUVTA PUVTS
100log UVTUVA
LDiRED log
MONITORING ALGORITHMS
17 May 2013
12
WaterRF Webcast: UV System Start‐Up, Operations and Avoidance of Off‐Spec Water
Validated Dose
4• RED calc by PLC (Eq. 1b)• VF calc by PLC (Eq. 5)
Validation Factor
5• BRED derived from UVDGM (App. G)• BPoly fixed value or calc by PLC• UVal calc by PLC (Eq. 6)
Validation Uncertainty
6
• UIN calc by PLC f(RED)• UDR calc by PLC f(RED); or fixed value‐ omit if < 15%
• US fixed value (typ. 0)‐ omit if < 10%
1001 Val
PolyREDUBBVF
222SDRINVal UUUU
VFREDDVal
26 December 2012
PowerPoint Sample 7
• Two dose set points
• Compliance set point (DReq): DVal required to provide logi required for compliance with regulations
• PLC generates off‐spec alarm is DVal < DReq
• Target dose (DTar): Normal operating target typ. set above DReq
• Provide an operating buffer to account for process fluctuations
• PLC generates warning if DVal < DTar
• Response to process fluctuations (normal operation)
• PLC will adjust operating parameters to maintain target dose
• ↓UVT or ↑Flow = decrease in UV dose provided by reactor
• PLC: ↑lamp power (intensity), ↑lamps or ↑reactors
• ↑UVT or ↓Flow = increase in UV dose
• PLC : ↓ lamp power (intensity), ↓lamps or ↓reactors
MAINTAINING DOSE
17 May 2013
13
WaterRF Webcast: UV System Start‐Up, Operations and Avoidance of Off‐Spec Water
*Not universally applied for all UV disinfection applications : Depends on interpretation of LT2ESWTR (not specifically recommended by UVDGM)
OFF‐SPEC OPERATION
17 May 2013
14
WaterRF Webcast: UV System Start‐Up, Operations and Avoidance of Off‐Spec Water
• DVal < DReq
• Operating outside of validated limits
• Flow rate > maximum validated flow
• UVT < minimum validated UVT
• S/S0 < minimum validated S/S0*
• PLC calculated logi < minimum validated logi (or REDCALC < REDValMin)
• Calibration of monitors not properly maintained
• UV Sensors (monthly) & UV Sensor (weekly)
• Meter (or signal) failure
• May include flow meter and UVT monitor
• LT2ESWTR allowance of ≤ 5% off‐spec (monthly production vol.)
26 December 2012
PowerPoint Sample 8
• In some circumstances operation outside of the validated range is acceptable
• Values used in monitoring algorithms must result in conservative estimate of logi or RED
• If Q < validated range, lower limit used in logi calc
• If UVT > validated range, upper limit used in logi calc
• Actual UVT should be used to calculate S0• If S/S0 > validated range, upper limit used in logi calc*
• If PLC calc logi > validated range, value capped at upper limit
or If PLC calc RED > validated range, upper limit used in DVal calc
DEFAULT VALUES USED FOR CONSERVATIVE SYSTEM CONTROL
17 May 2013
15
WaterRF Webcast: UV System Start‐Up, Operations and Avoidance of Off‐Spec Water
*Not universally applied for all UV disinfection applications : Depends on interpretation of LT2ESWTR (not specifically recommended by UVDGM)
2D evaluation of validated limits, typically as a f(flow & UVT)
VALIDATION “ENVELOPE”
17 May 2013
16
WaterRF Webcast: UV System Start‐Up, Operations and Avoidance of Off‐Spec Water
50
60
70
80
90
100
0 10 20 30 40 50
UV
T (
%)
Q (mgd)
Validation Conditions Validation Envelope
26 December 2012
PowerPoint Sample 9
RESPONSE TO COMPONENTOR SIGNAL FAILURE
17 May 2013
17
WaterRF Webcast: UV System Start‐Up, Operations and Avoidance of Off‐Spec Water
Component Response
Lamp or Sensor
LCP• Lamp or Sensor failure alarm • Lamp or assoc. bank removed from logi (or RED) calc ‐ if DVal < DReq = off‐spec alarm, record vol.‐ if DVal < DTar = warning
• Calc. available reactor capacity (send to MCP)‐ if capacity > Q: ↑power, ac vate req. lamps /banks‐ if capacity < Q: ↑power of on‐line lamps
MCP• if capacity < Q: Activate backup reactor, remove faulted reactor from service
RESPONSE TO COMPONENT OR SIGNAL FAILURE
17 May 2013
18
WaterRF Webcast: UV System Start‐Up, Operations and Avoidance of Off‐Spec Water
Component Response
Flow meter LCP• Flow meter failure alarm (send to MCP)• if alt. signal* not provided by MCP = off‐spec alarm, record vol.‐ ↑power of on‐line lamps
MCP• Provide alt. signal* (if avail.) for temporary operation ‐ Avoidance of off‐spec operation
• Activate backup reactor, remove faulted reactor from service
UVT monitor MCP• UVT monitor failure alarm • Default or manually entered UVT sent to LCP of each reactor for logi or REC calc‐ Avoidance of off‐spec operation
*Site‐specific – alternate approaches may be available to determine flow through a reactor in the event of a single flow meter failure
5/16/2013
1
© 2013 Water Research Foundation. ALL RIGHTS RESERVED.© 2013 Water Research Foundation. ALL RIGHTS RESERVED.
Performance of Installed UV Systems
WaterRF Webcast, May 17, 2013
Mark HeathCarollo Engineers
720 SW Washington St., Suite 550, Portland, OR 97205 [email protected]
© 2013 Water Research Foundation. ALL RIGHTS RESERVED.
Presentation Overview
UV Disinfection Knowledge Base Dose Monitoring Algorithms Lamp Ageing Sleeve Fouling
Combined Aging and Fouling
5/16/2013
2
© 2013 Water Research Foundation. ALL RIGHTS RESERVED.
Database Supported by Detailed On-site Investigations
Poughkeepsie, N.Y.Victoria, B.C.Lethbridge, Alta.Edmonton, Alta.Lake Havasu, Ariz.Tempe, Ariz.Weber Basin, Layton, UTNeenah, Wis.
© 2013 Water Research Foundation. ALL RIGHTS RESERVED.
Online UV Dose Monitoring is the Basis for Compliance
UVIntensity
UVT
Flowrate
UV Dose
LampStatus
5/16/2013
3
© 2013 Water Research Foundation. ALL RIGHTS RESERVED.
UV Monitoring Algorithms Evaluations
Simulate a range of flows, UVTs, lamp power settings
Compare displayed RED to UV validation report Excellent agreement with more recent UV
systems (post 2003 UVDGM) Early systems (pre 2003) have undocumented
UV dose algorithms Not UVDGM compliant Recommend UV system upgrades
© 2013 Water Research Foundation. ALL RIGHTS RESERVED.
Many UV Systems Overdosing by a Factor of 2 or More
0
10
20
30
40
50
60
70
80
90
100
1/3/07 4/13/07 7/22/07 10/30/07 2/7/08 5/17/08 8/25/08 12/3/08
Ca
lcu
late
d R
ED
(m
J/c
m2 )
Date
MS2 RED Sliding Average Required MS2 RED
5/16/2013
4
© 2013 Water Research Foundation. ALL RIGHTS RESERVED.
MP UV Lamps Met Lamp Aging Criteria
• Design: 0.80 lamp output after 5,000 hrs• Observed: 0.92 lamp output after 14,000 hrs
0.880.900.920.940.960.981.001.021.041.061.08
0 2000 4000 6000 8000 10000 12000 14000
Rel
ativ
e U
V S
enso
r R
ead
ing
Lamp Age (Hours)
100% 80% 60%
© 2013 Water Research Foundation. ALL RIGHTS RESERVED.
LPHO UV Lamps Also Met Lamp Aging Criteria
• Design: 0.87 lamp output after 12,000 hrs• Observed: 0.88 to 1.08 lamp output after
6,000 hrs, average output 0.99
5/16/2013
5
© 2013 Water Research Foundation. ALL RIGHTS RESERVED.
With Wipers Disabled, No Fouling Observed at Two MP Locations
y = -0.0002x + 1
0.8
0.9
1.0
1.1
1.2
0 50 100 150 200
CA
F
Run Time (days)
Wipers Disabled to Reduce Maintenance
0.97 factor after 175 days
© 2013 Water Research Foundation. ALL RIGHTS RESERVED.
MP Wipers are Doing Their Job
5/16/2013
6
© 2013 Water Research Foundation. ALL RIGHTS RESERVED.
But Internal Fouling Can Be an Issue With MP Systems
Internal Fouling Sometimes Can be Removed Using Acid Cleaning
© 2013 Water Research Foundation. ALL RIGHTS RESERVED.
Significant Fouling Observed with Unwiped LPHO Systems
0.00
0.10
0.20
0.30
0.40
0.50
0.60
0.70
1 2 3 4 5 6Sle
eve/
UV
Sen
sor
Po
rt F
ou
lin
g
Fac
tor
UV Sensor Port ID
Reactor 1 Reactor 2
Direction of Water Flow
5/16/2013
7
© 2013 Water Research Foundation. ALL RIGHTS RESERVED.
Foulant Removed by Offline Acid Cleaning
0
0.2
0.4
0.6
0.8
1
1.2
2-1 3-4 3-7 3-10
Sleeve ID
Sle
eve
Fo
uli
ng
Fa
cto
r
Viewed Top to Bottom Viewed Side to Side
© 2013 Water Research Foundation. ALL RIGHTS RESERVED.
But Manual Cleaning May Be Required
0.000.100.200.300.400.500.600.700.800.901.00
After Chemical Cleaning After Spray with Water Only
Sleeve ID
Sle
eve
Fo
uli
ng
Fa
cto
r
Viewed Top to Bottom Viewed Side to Side
1
2
3
4
5
6
7
8
9
10
11
12
1
2
3
4
5
6
7
8
9
10
11
12
Spray Wand Location
Lamp Rows Lamp
5/16/2013
8
© 2013 Water Research Foundation. ALL RIGHTS RESERVED.
Fouling: Out of Sight, Out of Mind
Utility operators do not have tools to quantify lamp aging and fouling
So if UV dose meets target dose, operators assume all is OK
But fouling significantly increases UV system O&M costs
© 2013 Water Research Foundation. ALL RIGHTS RESERVED.
CAF Index Uses UV Sensors to Monitor Lamp Aging/Fouling
CAFS
Sp
Measured UV Sensor Reading
Predicted UV Sensor Reading
5/16/2013
9
© 2013 Water Research Foundation. ALL RIGHTS RESERVED.
What is Sp
CAP PUVTBS exp10
UVT Lamp PowerSensor Reading
with New Lamp and Clean Sleeve
© 2013 Water Research Foundation. ALL RIGHTS RESERVED.
How Do We Determine Sp
The Easy way: Obtain Equation from Validation Report
The Hard Way: Determine Directly
5/16/2013
10
© 2013 Water Research Foundation. ALL RIGHTS RESERVED.
What Can The CAF Index tell Us?
Provides Real-Time Status on Lamp Output Indicates When Fouling is Occurring Monitor Wiper Performance Trigger Manual Cleaning May Identify a Failing Sensor May Identify Problems with On-Line UVT Monitor
© 2013 Water Research Foundation. ALL RIGHTS RESERVED.
Monitor CAF Index Over Time to Identify Important Trends
0.0
0.2
0.4
0.6
0.8
1.0
1.2
CA
F I
nd
ex B
ased
on
Lab
UV
T
Date
Reactor 1 Reactor 2 Reactor 3 Reactor 4 Average
5/16/2013
11
© 2013 Water Research Foundation. ALL RIGHTS RESERVED.
Bad News
Sensor Equations from Validation Reports can be Complex, Requiring Calculations Run in SCADA or External Spreadsheets.
Normal Variations in Lamp Output, Sleeve Transmittance and Water Quality during Validation may Cause Inaccuracies at Installation.
© 2013 Water Research Foundation. ALL RIGHTS RESERVED.
Good News
Many UV Vendors are Incorporating CAF Index Calculations into System Control Software Displaying Real Time Data on System HMI.
On-Site Fine Tuning is possible to Account for Variability in Lamp Output and Sleeve Transmittance for LP and MP Systems, and Spectral Differences in Water, for MP Systems to improve CAF Accuracy.
5/16/2013
12
© 2013 Water Research Foundation. ALL RIGHTS RESERVED.
Conclusions Dose monitoring algorithms in good agreement with
validation reports written post 2003. Many systems providing significant overdosing. Lamp aging criteria generally met or exceeded. Wipers for MP system generally effective. Significant fouling observed in some un-wiped systems. Operators do not have sufficient tools to monitor sleeve
fouling. CAF index provides operators a real-time troubleshooting
tool to understand system performance.
© 2013 Water Research Foundation. ALL RIGHTS RESERVED.© 2013 Water Research Foundation. ALL RIGHTS RESERVED.
Performance of Installed UV Systems
WaterRF Webcast, May 17, 2013
Mark HeathCarollo Engineers
720 SW Washington St., Suite 550, Portland, OR 97205 [email protected]
5/16/2013
1
UV Disinfection
Tools, Tips, and Techniques for Operations and Maintenance
Presenters:
• Marilyn Towill, Superintendent SCFP and Systems Control
• Kevin Brown, Assistant Water Treatment Operations Supervisor
Co‐Authors:
• Willyam Dragon, Operations Supervisor SCFP
• Karen Tully, Senior Project Engineer
5/16/2013
2
Three Source Lakes
Multiple Protection Barriers• Closed Watersheds
• Water Treatment
• Water Distribution integrity
• Certified Operators
• Monitoring
5/16/2013
3
Seymour Capilano Filtration Plant
Clearwells
Post‐Treatment using Chlorine & pH adjustment
Filtration
Flocculation
Pre‐Treatment
UV Disinfection
5/16/2013
4
UV Reactors
• WEDECO model K143 12/4 (5)
• 24 UV reactors , each located directly downstream of a filter
• Each UVR has 4 rows of 12‐low pressure high output (LPHO) lamps, 1 additional row for future use, 350 Watts per lamp
• Online UV transmittance monitors, 2 for each process train
• UV design > 2‐log Cryptosporidium and Giardiainactivation
UV Performance Parameters
• SCFP Individual Filter/UV operations:
‐ 40 to 80 MLD (11 to 21 MGD)
‐ 95 to 98% UVT
• Normally 2 rows operating at 70% power, dose over30 mJ/cm2
‐ UV operating at or above target dose ≥ 99% time
‐ US EPA guideline > 95% on a monthly basis
‐ UV default startup was 4 rows of lamps on for 8 hours prior to modulation. Reset to 1 hour saving 23% energy per filter run
• UV uses < 8% of total SCFP energy use
5/16/2013
5
Tips and Tricks
Training and Procedures
– Web based training developed for SCFP prior to start up, with knowledge assessment
– Field assessment
– Continuously updated as operations change
– Consistency of operations and knowledge
Web based Training
5/16/2013
6
Web based Training
Tips and Tricks
• Daily coordination meeting (Monday ‐ Friday )
– Operations, Maintenance, Quality Control, Software Specialists, Utility System Control
– Coordinate work activities:
• Next month, next week, and today
• Including contractors, preventative maintenance
• Safety
• Equipment or process issues
5/16/2013
7
Tips and Tricks
Alarm management ‐ Today
– 20,000 alarm points
– Multiple nuisance alarms
– Need to review, rationalize and prioritize alarms
Tips and Tricks
Alarm management ‐ Tomorrow
– Alarms reduced to less than 15,000
– Eradication of nuisance alarms
– Alarms prioritized to appropriate level based on:
• Safety Consequences
• Environmental Consequences
• Process Interruptions and Upsets
• Time Response for Operator intervention
5/16/2013
8
Tips and Tricks
• Alarm Optimization
Filter Water Level
UVR Level
Filter in Service
Level Switch Low
Tips and Tricks
• Alarm Optimization
Filter Water Level
UVR Level
Filter Drain down
Level Switch Low
5/16/2013
9
Tips and Tricks
• Alarm Optimization
– UV lamp row start alarm
• Lamp warranty based on no more than 4 starts per day
• Lamps occasionally starting multiple times per day
• Added alarm to alert Operator if this condition occurs
Tips and Tricks
• Alarm Optimization
– UV dose auto increase
• When filter turbidity is >0.1 NTU and particle count is >90 counts/100ml the UV dose doubles for that reactor
• Dose increase ensures effective UV disinfection with abnormal water quality from an individual filter
5/16/2013
10
Tools and Techniques
UVR Excel spreadsheet
• Almost realtimeinformation
• Easily select and view UVR 1 to 24
• Choose start date and span
• Observe long‐term trends
• Remotely accessible via secure network
SCFP UV Intensity Filter Number 14, from 31-Mar-2013 23:20 to 02-Apr-2013 02:40
5/16/2013
11
SCFP UV Intensity Filter Number 14, from 31-Mar-2013 23:45 to 01-Apr-2013 02:45
UVT Measure (%)
SCFP UV Intensity Filter Number 14, from 31-Mar-2013 23:45 to 01-Apr-2013 02:45
Power (W)
5/16/2013
12
SCFP UV Intensity Filter Number 14, from 31-Mar-2013 23:45 to 01-Apr-2013 02:45
Rows 1, 2, 3, 4Sensor Intensity (mW/cm2)
SCFP UV Intensity Filter Number 14, from 31-Mar-2013 23:45 to 01-Apr-2013 02:45
Flow (MLD)
5/16/2013
13
SCFP UV Intensity Filter Number 14, from 31-Mar-2013 23:45 to 01-Apr-2013 02:45
Calculated UV Dose (mJ/cm2)
Target Dose (21 mJ/cm2)
Tools and Techniques
Monthly Sensor Checks• Compare to reference sensor, replace if % Error is too great
5/16/2013
14
Tools and Techniques
• UV Manual Cleaning Frequency
– Every 6 months clean sensor sleeves
– Every 12 months clean reactors
– Timed prior to organic seasons
– Benefits:
• More accurate performance information
• Power savings
• Mitigate low intensity alarms on older lamps
Tools and TechniquesManual Cleaning
• 5% phosphoric acid made from 85% food grade
• Use one batch solution for 12 reactors
• Reactor isolated from filter and clearwell during cleaning
• After cleaning neutralize acid solution with sodium bicarbonate
5/16/2013
15
Tools and Techniques
UV Cleaning Results
• Deposits primarily aluminum and iron
• Overall 7 to 15% improvement in sensor readings
• Virtually full recovery to initial cleanliness
before
after
Tools and Techniques
UV Cleaning Results
• Results kept as records
• Compare initial, pre, and post data
• Helps identify end of life for UV lamps
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Overall Results
• UV Reactors are more reliable with less downtime
• Reduction in staff time associated with maintaining UV Reactors
• Reduced energy costs
• Improved alarms and focused troubleshooting
Before optimization
After optimization with 3 years operating experience
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What’s next at SCFP
• Lamp replacements (upgrade)
– Ecoray® Lamps and ballasts are next generation
• Less mercury in lamps
• Lower power consumption when dimmed
• More reliable startup / operation
• Parts same cost, longer warranty on lamps
– Project to replace all 24 units over 4 years
• Normalizes Maintenance replacement cost and labourover time
What’s next at SCFP
• Investigating revalidation based on available data
– UV reactors validated had limited data points above 96% UVT
– Actual filtered UVT is up to 98%
– Expected to reduce amount of energy consumed
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Coming Soon
Complement existing ozone treatment
By adding ultraviolet treatment
Coquitlam Source Treatment
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CWTP UV Reactors• Trojan UVTorrent ®
• 8 Reactors (7 duty, 1 standby)
• 5 rows of 8 Lamps
• Higher intensity (1 kW) LPHO Lamps
• 200 MLD (53 MGD) per unit
• Chemical/mechanical wipers
• On demand to distribution system
Lessons Learned
• Training and Procedure development prior to start up helped transition from theory to operation.
• Clear communication between all work groups on a daily basis ensures work is done efficiently and effectively.
• Alarm management and optimization helps Operators focus on key issues, problems, and opportunities for further optimization.