Construction is quickly proceeded by a contract of about $ 165 million to build a new wastewater treatment plant on the San Francisco Treasure Island, an artificial island originally built by the United States Army Engineers in the 1930’s. Millions of dollars, a ten -year capital program to improve resilience and housing options for residents in the bay area.
It is expected that about 20,000 new residents will occupy the Treasure Island for 2036, eight times the current population. The new plant, located in a 50,000 square meter place on the northeastern tip of the island, is a critical component of a Long-term sustainability plan, ensuring that recovered water can be reused effectively and providing Expected green spaces, hotels, restaurants, shops and entertainment places. It will provide about 1.3 million daily gallons for the Treasure Island and the island of Yerba Buena and an annual capacity for the treatment of average recycled water of 400,000 daily gallons for treasure Island.
The design design team led by PCL Construction and Statec began working in January 2023, with a tight three -year schedule. “I have never seen a three -year project this complex,” says Jignesh Desai, responsible for the SFPUC project. “It is a unique opportunity as a public server: to build a sustainable plant.” The installation aims at a forecast gold rating.
The treatment installation includes a solid liquid and solid stream consisting of thick screens, grain removal, fine screens, biological nutrient feeding, a membrane bioreactor and ultraviolet disinfection. The additional features include recycled water pumping, wetlands, rainy water pipes, aerated solid solid deposit, solid thickness, recycled water dispenser and administration and maintenance building.
These represent the change of the wastewater industry towards methods of “resource recovery”, he emphasizes. Treasure Island, once owned by the United States Navy, is now owned by the city of San Francisco, with a development agency that serves as a teacher builder for new planned residential developments. SFPUC issued RFQS and RFP in 2019, but the pandemic delayed the concession until 2023.
The Stantec and PCL design design team began to wine the project even before signing the contract, says Baird Kerr, PCL Senior Projects Engineer. “They provided a conceptual plan and we made an offer for this, then they incorporated our ideas.”
These included compression of the site to reduce the necessary amounts of pipes and pavement, postpone the orders of the equipment that was not immediately needed and put the deep foundation packages, he says. The crews will install more than 6,000 concrete cuts and about 17,500 linear feet of pipes.
“During the tender phase, one thing we agreed to was that we do not need batteries for foundations; it is the entire slab of mattress,” says Khaled Ammari, PCL project manager. “We have eliminated the need to disappear the project.” The team also suggested the use of crushed rock to achieve compaction for the structure of the membrane bioreactor and the Shotcrete concrete versus the casting concrete for five buildings.
“It is a massive structure, along with a pumping station of influence,” adds Billy Wong, the main engineer of Stanec. The team moved a detention basin so that the structure could be built above the ground, requiring only 6 feet of excavation to 27 feet and “creating a more favorable situation for operations” during operations and maintenance. In addition, the original concept had two screening processes to eliminate materials, but “we found equipment that can do both stages in one package,” he says. Value engineering saved $ 5 million, according to project officials.
The construction is 70% of complete construction, says Desai, with buildings topped and installed solar panels. “The plan is to introduce clean water for evidence and instrumentation in the spring,” he says. “Currently, all the main teams are on the site, including a long lead element, a transformer that took 18 months to get there.” A key challenge will be to learn how to operate and maintain a nutrient removal installation that is among the first of this type for the bay area.
The installation replaces the old plant of the 70’s, which did not meet the evolutionary requirements of the region. “Usually a plant has a primary and secondary treatment,” says Ammari. “Secondary treatment usually involves clarifiers. For this project, we use bioreactors of the elimination of biputrients and the membrane. Mix the sludge introduced in the secondary phase and break organic pollutants, aerobic bacteria and nutrients. They are installed, so you can separate them and proceed to tertiary treatment. “”
Future planning
SFPUC $ 11.8 million plan, the ten -year plan includes sewer improvements, rolling capital projects and an installation infrastructure program included in the installation of Treasure Island, says Bessie Tamie, director of the capital program. The main projects currently include $ 3 billion on updates at the South -East treatment plant, where there is a project of digester biosolid installations and the biogas use system. PCL and Statec received the $ 121 million design design contract for the biogas system in January.
MHW/Webcor is building biosolid facilities of $ 2.3 billion, 400,000 square meters, with most concrete and steel work in completed disappearance buildings and a planned completion of 2026.
SFPUC has also committed more than $ 1 billion for a main nutrient reduction project scheduled for the south -south floor, adds Tam.
The installation of the island of the Treasure is underway to achieve the Golden State and the objectives of more than 4,000 hours of volunteering, a goal of 17.9% for the design contracts of local companies and 15.8% of LBE construction contracts. SFPUC and the team also coordinated with numerous stakeholders in the city and the state, ranging from the Public Health Department to the Arts Commission to other water agencies.
The city’s development authority is developing infrastructure outside the perimeter of the installation, says Wong. “There was a lot of external coordination of interest to ensure that the installation works before the developer is ready to build his own pipes and force the main network.”
