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LADWP AND UV DISINFECTION:Comparing the World’s Second and Third Largest UV Disinfection Facilities
Authors: Christine Cotton, Richard Chang, Kurt Wells, Michael Maxwell, Ben Kuhnel
© Arcadis 2017
Largest Municipal Water and Power Utility
LADWP facts• Area served 465 mi2
(1,024 km2)• 4.1 million residents• 716,531 water service
connections• Fiscal year budget of
$1 billion US for water• 114 tanks and
reservoirs• 7,238 miles (11,648 km)
of distribution pipe
© Arcadis 2017
Two Surface Water Sources
Los Angeles Aqueduct (LAA)
State Water Project (SWP) West Branch
SWP East Branch will be available in 2018 State
Water Project
1st Los Angeles Aqueduct (1913)
2nd Los Angeles Aqueduct (1970)
SWP West Branch
SWP East Branch
© Arcadis 2017
Los Angeles Bearings
Treatment is in Van Norman Complex (Sylmar)• 40 miles
DWP main office downtown
• 18 miles
© Arcadis 2017
Van Norman Complex
© Arcadis 2017
LAAFP and LAR TreatmentLos Angeles Aqueduct Filtration Plant
Ozone FlocculationDirect Filtration
Chlorine
Distribution System
AmmoniaChlorine
LA Res
© Arcadis 2017
Dr. Pankaj Parekh UV Disinfection FacilityDesign Criteria ValueRegulatory Driver Stage 2 DBPTarget Pathogen GiardiaLog Inactivation 2-logUVT 90%Flow Rate 600 MGD
© Arcadis 2017
LAAFP Construction
April 26, 2011August 26, 2012October 31, 2012December 10, 2013August 27, 2014
© Arcadis 2017
© Arcadis 2017
LAAFP UV Meets Disinfection Goals
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3‐Dec‐13 2‐Jan‐14 1‐Feb‐14 3‐Mar‐14 2‐Apr‐14 2‐May‐14 1‐Jun‐14
Daily Average Giardia Log
Inactiv
ation
Log Giardia Inactivation
Target Log Inactivation
Required Log
Inactivation
© Arcadis 2017
Off-specification Water Has Been Well Below Regulatory Requirements
0.177% 0.020% 0.000% 0.003% 0.004% 0.004%0%
1%
2%
3%
4%
5%
6%
Dec‐13 Jan‐14 Feb‐14 Mar‐14 Apr‐14 May‐14
% Off‐spe
c Water
RegulatoryRequirement
© Arcadis 2017
LAAFP UV ChallengesBiogrowth
in UVT Analyzers
Chemical feed
Algae growth
Low Cl2upstream of
UV
Low UVT from wet
2017
Met regs(low flows)
Y215 Switchgear
Vendor coordination
Operates well and meets UVDGM and CA requirements
© Arcadis 2017
Van Norman Complex
© Arcadis 2017
LAR UV Disinfection
Design Criteria ValueRegulatory Driver LT2ESWTRTarget Pathogen CryptoLog Inactivation 3-logUVT 90%Flow Rate 650 MGD
© Arcadis 2017
LAR UV Construction
LAAFP and LAR Comparison
© Arcadis 2017
Design Criteria ComparisonDesign Criteria LAAFP LAR
Regulatory Driver Stage 2 DBP LT2ESWTR
Target Pathogen Giardia Giardia
Log Inactivation 2-log 3-log
UVT 90% 90%Flow Rate 600 MGD 650 MGD
© Arcadis 2017
Hydraulics Differences
LAAFP
LAR
Plant Flow
Block flow
Floats
Hydraulics constraints
Box conduits/ 2 levels
Common headers /
Single level
Control
Weir Setting for
LAAFP UV
Flow Control Station
© Arcadis 2017
Construction
LAAFP UV
DWP design-build
approach
LAR UV
Design-Bid-Build
Contractor build
© Arcadis 2017
Early out Civil package
Integrated Design Team
Creativity with UV reactor procurement
LADWP in-house construction
Closely managed procurement
LAAFP UV Built in less than 4 years
© Arcadis 2017
LADWP construction
Design/Build
LADWP engineering
Purchasing equipment
LADWP Steel shop
Fabrication of
components
LAAFP UV Design Build Approach
© Arcadis 2017
Design
Hybrid LADWP and consultant design team
Construction
LADWP construction of
trunklineconnections
DBB with Contractor (Steve
P. Rados)
Equipment Procurement
LADWP purchase of UV reactors
and main pipeline and valves
LAR UV Construction Approach
© Arcadis 2017
Keys to Success for Both UV Facilities
Identify goals early
Fast track design decisions
Early buy-in with management
Involve regulators early and often
Construct method to meet schedule