Construction at an operating water treatment plant

Robert Carty
Community Relations Specialist
City of San Diego Water Department
Capital Improvements Program

Construction in a perfect world would allow you to set your own hours, build whatever you want, wherever you want, and get the job done on time and under budget. But every construction project has challenges. In the City of San Diego, we have come up against significant challenges in completing necessary upgrades and expansions to our three water treatment plants.

In August 1998, the City issued an initial $385 million in bonds to fund a recently approved multi-million dollar water Capital Improvements Program (CIP). This eight-year capital program was in response to a growing recognition that the City's water infrastructure was in serious need of improvement in order to maintain service reliability as well as ensure adequate treatment, storage, and distribution facilities for current and future City needs.

The Water Department's capital program is now in its fourth execution year. Water infrastructure improvements have begun throughout the City's water system, including the three water treatment plants. These plants are being upgraded and in some cases expanded to meet a variety of needs, including obsolescence of plant equipment, population increases in service areas, and recent changes in state and federal drinking water quality regulations that require the plants meet new, stricter standards. In addition, by increasing treatment capacity, cost savings are anticipated by reducing the amount of treated water purchased from the regional water supplier, the San Diego County Water Authority (Water Authority).

Upgrading and expanding these facilities is no easy task, even in the best conditions. They are all older facilities, and two of the three are located in residential areas that were sparsely populated when they were built 40 to 50 years ago. Residential concerns are now much more important as these industrial facilities are undergoing massive years-long construction in these neighborhoods. Noise, dust and traffic impacts need to be addressed up front, and if they are not, residents can adversely impact a project's schedule and cost as they utilize the political process to see their needs are met.

In addition to community concerns and challenges, the treatment plants are operating facilities. They operate 24 hours a day, seven days a week providing 300 million gallons per day (mgd) of drinking water to the arid City of San Diego. Applying massive structural, architectural and engineering changes to a facility that needs to continue operating while it is being upgraded and expanded has posed many challenges to the designers, operators and contractors. The Alvarado Water Treatment Plant had never been off-line for more than 24 hours in its entire 50-year history until it underwent its expansion and improvement project. This process is similar to a surgeon operating on a patient—the patient needs to be alive while the doctor is operating, as well as when that surgeon is finished.

To accommodate these challenges, a task force was developed dubbed "Maintenance of Plant Operations" or MOPO. The MOPO Task Force is made up of the design engineers, project managers, contractors, operators and construction managers. They examine the design needs of the specific job relative to the needs of plant operations, they evaluate the schedule and water use requirements of the City, and what the contractor needs to get the job done on time. The MOPO operations are on a strict timeline, requiring 24-hour work for several days, with tight deadlines for finishing work and resuming normal water treatment operations. Room for error is minimal, as mistakes would impact project completion adding costs not only to construction, but also the water delivery. During longer shutdowns, water service cannot be supplied by water storage alone, and must be augmented by purchased treated water from the regional water purveyor. Those costs add up quickly, so any delay can significantly impact a project's budget.

Because the MOPO projects run into the night, construction noise can impact residents in the late or early hours for several days. To reduce community impacts, residents have been notified several weeks in advance of the pending work, and in the case of longer shutdowns are offered local hotel accommodations for the duration of the MOPO operation. To date the coordination work done by MOPO Task Force has been invaluable to ensuring a smooth project and led to transparent water distribution to ratepayers—all the MOPO operations have been completed successfully with no disruption in water service.

Working on operating facilities is not the only challenge that project team members have faced. All the treatment plant sites have a noticeable lack of onsite staging areas, and transporting large quantities of soil, rock and pipes through neighborhoods has not gone unnoticed. Streets seem to be constantly dirty, and construction deliveries often arrive between four and five o'clock in the morning disrupting residents' sleep. Additional street sweeping has become part of the project's budget, and locating alternative staging areas for deliveries arriving before 7 a.m. has been addressed.

The Alvarado Water Treatment Plant has also posed a unique improvement and expansion challenge that the other two plants do not. The San Diego Historical Site Board designated portions of the Alvarado property as historically significant on April 27, 1994, following an environmental impact report that initially indicated eligibility for designation.

"This treatment plant is an example of significant public architecture that went beyond the necessary and fulfilled a role greater than its utilitarian function," said Mike Tudury, senior planner of the City and former staff to the Historical Site Board during Alvarado's designation as a historic site. "The building addresses the human spirit, complements the environment and is an achievement that stands the test of time."

The operations building is the image of Spanish Colonial Revival architecture, a style which flourished during the 1920s. Both the interior and exterior feature elements typical of Streamline Moderne designs, similar to Art Deco. This blending of these two unrelated styles was common during the years that preceded World War II. Closely associated with federal government architecture, these styles were classical and formal, but added enough Moderne details to provide a contemporary feeling. In addition, the "Moorish" tower of the operations building is unique in its design and visible from many surrounding areas.

Features of Alvarado that particularly embrace the artistic and decorative elements of the structure include terrazzo floors in the operations building and photographic murals of San Diego's water history lining the foyer walls. Oil paintings of Hoover Dam's construction by artist Otto H. Schnieder are also featured. These features have been protected in place or removed from the area being renovated, to be returned when improvements are complete. These features make the Alvarado facility an architectural and artistic treasure for the City, as well as posing challenges to the designers and contractors who have to make sure to preserve the integrity of the plant while accomplishing the needed improvements and renovations.

When the upgrades and expansions are complete, these three plants will have an additional water treatment capacity of 155 mgd, increasing from approximately 300 mgd to 455 mgd, with modernized and safer facilities and equipment with the latest in water quality monitoring. After years of construction, the neighborhoods will be glad for some peace and quiet and plant operators can go about their daily activities without having to navigate through a milieu of contractors, material piles and construction equipment. And outside the immediate construction zone and some frequently used roads, a city of 1.2 million people will continue to receive their water. Many will not notice the quality, safety and security improvements implemented over years of planning, design and coordination to make their glass of water better and safer than before.

To reach Robert Carty, call (619) 533-6607 or send e-mail to