Cost: $278 million
Location: San Bruno, Calif.
Size: 180 mgd
Owner: San Francisco Public Utilities Commission
Designers: San Francisco Public Utilities Commission, CDM Smith, Kennedy/Jenks Consultants
Contractor: Kiewit Infrastructure West Co.
In 2002, the San Francisco Public Utilities Commission (SFPUC) launched a $4.8 billion water system improvement program (WSIP) designed to provide reliable, affordable, high-quality water in a manner that complies with environmental and water quality regulations. The system also needed to improve seismic and delivery reliability, and achieve water supply level of service goals.
As part of the project, SFPUC’s 180-million-gal-per-day Harry Tracy Water Treatment Plant (HTWTP) underwent a major upgrade to improve its reliability after an earthquake. The $278 million upgrade limits damage to the existing plant and allows it to deliver a minimum of 140 mgd within 24 hours of a major earthquake on the San Andreas Fault. Seismic criteria were developed based on importance factors to either ensure restoration to a level of service consistent with adopted post-earthquake goals within 24 hours for primary disinfection, or experience damage but retain the capability to restore service within 30 days for secondary facilities.
The proximity of the San Andreas Fault posed design challenges due to the seismic forces, but additional challenges were found in the presence of two previously unidentified traces of the Serra Fault that cross the plant’s property. Design modifications were made to mitigate risks posed by these fault traces.
To meet the project’s goals, new and existing equipment was installed and retrofitted to withstand earthquakes, and redundancy was built into the plant process. The plant includes 15 filters, two parallel washwater systems, 6 MW of standby power, and an emergency chlorination system to chlorinate untreated San Andreas Reservoir water in the event of a major disaster.
To minimize impacts on plant operations, the project team partnered with the operations group to schedule a series of total-plant and process-specific shutdowns to support construction and startup activities. The group successfully worked together on this plan, and the project met all established deadlines for each shutdown.
Throughout construction, the public was kept informed via council meetings, open houses and written materials. The project was dedicated at a public ceremony in April 2015.
“The construction management team for the HTWTP project was presented with one of the most complex, multi-discipline and challenging projects of the WSIP,” said Alan Johanson, deputy director, construction WSIP, for SFPUC. “This complicated facility upgrade required multiple outages at the treatment plant, which were all successfully completed without impact to the system due to hard work by the contractor and construction management team. Through dedication, depth of experience and above all teamwork, they were able to complete the project to a high standard of quality, on time and within budget.”Project Year: 2015-12-09Contractor: Kiewit Infrastructure West Co.Designers: San Francisco Public Utilities Commission, CDM Smith, Kennedy/Jenks ConsultantsOwner: San Francisco Public Utilities CommissionLocation: San Bruno, Calif.Cost: $278 millionSize: 180 mgd