ASCE Los Angeles Section

Sylmar, CA

The Los Angeles Department of Water and Power (LADWP) is the largest municipal water and power utility in the United States serving over 4 million residents with a service area that encompasses 465 square miles between the San Fernando Valley and the Los Angeles Harbor. LADWP is committed to providing excellent water quality and reliability to its customers.  To this end, LADWP owns and operates the Los Angeles Aqueduct Filtration Plant (LAAFP) that has been operating since 1986. LADWP has recently completed construction of an ultraviolet (UV) disinfection plant at the LAAFP that was built as part of a two pronged approach to comply with the United States Environmental Protection Agency (USEPA) Stage 1 and Stage 2 Disinfectants/Disinfection Byproduct Rules (DBPR).  The UV disinfection plant provides a multi-barrier disinfection approach and additional operational flexibility to adjust chlorine and ozone doses to meet the Stage 2 DBPR requirements.  The distribution system disinfectant is also being converted to chloramines disinfection and is the second key change to reduce DBP levels.  The LADWP UV disinfection plant is the largest UV facility in California and the second largest in the United States.
One the project’s complex challenges was the need to meet regulations by designing and completing construction of the projected $110 million UV facility in less than four years.  To meet the schedule, the project was constructed by LADWP’s internal construction forces, which allowed for construction to begin prior to completion of the facility’s 30% design.  Despite the aggressive schedule, the project is expected to come in under budget and has successfully met all regulatory required deadlines.

One of this project’s complex challenges was the need to meet regulations by designing and constructing a $110 million UV facility in less than four years.  It was identified that there was not sufficient time to utilize the traditional design, bid, build project delivery approach. Given LADWP’s extensive internal construction capabilities, it was decided that construction would be done with in-house crews.  This was a large undertaking considering the facility included 144” steel piping and large concrete channels, which were constructed from approximately 5,000 cubic yards of concrete.  It was also identified that the only way to meet the regulatory deadline would be to start construction of the facility in early 2011 before the UV facility design was completed. Therefore, it was necessary to prepare some “early-out” design packages to get construction crews working on site preparation and the construction of the concrete structure for the facility, while the remainder of the design was completed.  Within three months of starting the detailed design phase, excavation equipment was mobilized to the site to perform the extensive excavation required for fault mitigation at the site. 

This project was also very unique from the design production aspect.  LADWP has engineering staff that is capable of designing large water projects of this nature but had never designed a UV facility and thus reached out to the consultant team to partner with them for the design.  The project team response was to pull together the best resources from within LADWP’s engineering staff and from within the consultant team’s staff to deliver the fast track design project.  In some situations, staff from both the consultant and LADWP were working on different portions of the same discipline.  This required close collaboration between the design management staff within LADWP and the consultant team to maintain the project schedule and avoid unnecessary delays.

In-house construction of a facility this size is rare in the municipal market, especially at this scale.  However, this approach allowed for added flexibility in construction, which was required in order to meet the schedule requirements. For example, procurement of electrical equipment was identified as a critical path item due to equipment delivery delays. LADWPs in-house design and construction staff were able to proactively design and construct temporary power supplies to power the complete UV facility for several months until the main switchgear was installed. 
The hydraulic capacity of the LAAFP UV facility necessitated either 144”diameter piping or concrete channels.  The procurement timeline needed for new 144” pipes would delay the project; therefore, concrete inlet and outlet channels were designed and constructed.  Despite utilizing concrete headers, 144” pipe was still required to tie into the existing finished water pipeline.  To accomplish this, the LADWP construction crew was able to refurbish 144” pipe that was left over from the original construction of the LAAFP in the early 1980s. The work also included in-house fabrication of two 144” elbows to divert flow through the facility.
For most facilities, the UV reactor is selected prior to final design.  For this project, the design had to be completed and construction had to commence prior to the selection of the UV reactor.  This presented unique challenges for design and procurement.  The design had to allow for multiple reactor configurations and required a full dual design for the reactor specific electrical requirements.  This also complicated procurement as specifications had to ensure the selected reactor would fit within the design while allowing for multiple bidders to maximize price competition. 

To keep the project on schedule, a detailed 1,000+ activity schedule was developed to organize and monitor construction progress.  Scheduling activities consisted of the development of the detailed design and construction baseline schedule with weekly updates working with the DWP construction team to optimize schedule and sequencing of activities. The schedule was also used in the development of the 4D (NavisWorks) model, which provided a visual model of the project construction plan, design clash detection, and schedule optimization.
Another example of the unique measures required to maintain the project schedule is the approach taken to starting up the facility.  The excavation and concrete channels were one of the first activities completed for the project in early 2011.  The UV reactors did not arrive until June 2013 with staggered deliveries through August 2013. The UV reactor first shipments arrived as the metal building was being constructed and the UV reactor floor space was required for the lifts needed to construct the building.  As a result, the UV reactor installation was coordinated with the building installation such that when a bay of the building was completed, a set of reactors was installed.  As soon as the UV reactors were installed, functional and performance testing of the UV reactors commenced.  This resulted in building construction, UV reactor installation, and functional/performance testing all occurring simultaneously within one building.  Water started flowing through the first UV reactor with piping and installation only completed on the first three of the fourteen UV trains.

The main driver for the project is to improve the water quality provided to the over 4 million residents. In order for the project to be successful, the facility must be able to reliably deliver disinfected drinking water, which requires reliable power as well as an easy to operate facility. Reliable power is a key component for any UV facilities.  To this end, the design included several reliability features to provide robust power supply including fully redundant power feeds as well as back-up uninterruptible power supplies (UPS) and generator.
The success of the facility also depends on the ability of the water treatment plant operators to be able to easily and reliably operate the facility.  The design team conducted workshops on the design to the LADWP operators, design staff, and management at the 30%, 60%, and 90% design milestones to obtain design feedback from the end users to ensure that the completed facility is something that will be reliable and easy to operate.  The feedback from these workshops provided important recommendations to aid in the access and operation of the facility. In addition to the design reviews, LADWP staff was also able to visit UV facilities across the country to evaluate lessons learned and apply them to this facility.  The tours and design feedback were an integral part to the overall success of the project. 

The in-house construction also provided the additional benefit of easing the transition from construction to operation.  With the construction crews and operations staff being from the same organization, the operations staff became an important part of the facility start-up activities.  The experience gained during the start-up activities provided critical on the job training for LADWP operators and instrument mechanics, such that once it came time for commissioning the facility, the staff was already very facility with the design and operation of the facility. 

The Los Angeles Department of Water and Power’s (LADWP) Dr. Pankaj Parekh UV Disinfection Facility was an ambitious project designed to assist LADWP with providing the highest quality water to its customers. One the project’s challenges was the need to meet regulations by designing and completing construction of the project in less than four years.  Despite the aggressive schedule, the project is expected to come in under budget and has successfully met all regulatory required deadlines.

The Los Angeles Department of Water and Power (LADWP) is the largest municipal water and power utility in the United States serving over 4 million residents with a service area that encompasses 465 square miles between the San Fernando Valley and the Los Angeles Harbor. LADWP is committed to providing excellent water quality and reliability to its customers.  To this end, LADWP owns and operates the Los Angeles Aqueduct Filtration Plant (LAAFP) that has been operating since 1986. LADWP has recently completed construction of an ultraviolet (UV) disinfection plant at the LAAFP that was built as part of a two pronged approach to comply with the United States Environmental Protection Agency (USEPA) Stage 1 and Stage 2 Disinfectants/Disinfection Byproduct Rules (DBPR).  The UV disinfection plant provides a multi-barrier disinfection approach and additional operational flexibility to adjust chlorine and ozone doses to meet the Stage 2 DBPR requirements.  The distribution system disinfectant is also being converted to chloramines disinfection and is the second key change to reduce DBP levels.  The LADWP UV disinfection plant is the largest UV facility in California and the second largest in the United States.
One the project’s complex challenges was the need to meet regulations by designing and completing construction of the projected $110 million UV facility in less than four years.  To meet the schedule, the project was constructed by LADWP’s internal construction forces, which allowed for construction to begin prior to completion of the facility’s 30% design.  Despite the aggressive schedule, the project is expected to come in under budget and has successfully met all regulatory required deadlines.