IN THE NEAR FUTURE, whenever a resident flushes their toilet on Treasure Island’s west side, the wastewater will travel to the east side, to an innovative treatment facility, where it will be made clean enough to send back to the resident’s building and used to flush another toilet, clean laundry or hydrate the hydrangeas.
And it will all be done without emitting any odor or discharging pollutants into the Bay.
That’s how Treasure Island’s Water Resource Recovery Facility won the prestigious 2025 Envision Platinum Award from the Institute for Sustainable Infrastructure, a nonprofit that represents associations of public works agencies and civil engineers. The facility is on track for completion in 2026.
“We originally applied for gold designation, but then they looked at all the features and they gave us platinum,” said Jignesh Desai, senior project manager for the water treatment plant. The award is ranked on performance, and the $165 million wastewater treatment facility is expected to perform well above standard and well above sea level.
“We’re raising the footprint throughout the development to account for 36 inches of sea level rise,” said Robert Beck, director of the Treasure Island Development Authority, the agency in charge of the island’s full transformation. Beck said the land beneath the new treatment facility was raised 30 inches, as well as the land beneath several new apartment buildings on the east side. The elevation process will be done zone by zone. In fact, there is a 5-foot retaining wall between the new apartment buildings and the rest of the island. The ground has subsided since its creation by the New Deal’s Works Progress Administration in 1936, with areas of the north end sinking nearly 8 to 10 feet.
Has the necessity for sea level rise adaptation contributed to the ability to treat the island like a clean slate?
“That’s part of it, but a big part of it also is the Navy decided to close this space in 1993, which means there’s been very little investment in historical infrastructure since then,” Beck said.
“Every infrastructure has a life span in terms of mechanical and electrical systems, right?” said Desai, referring to the old water treatment plant built when the island was owned by the U.S. Navy in the 1970s.
“The old treatment plant is running on Band-Aids right now,” he said. “It’s been in operation beyond its useful life.”
400,000 gallons of recycled water per day
The state of California has a standard called “Title 22” for recycled water. It sets requirements for treated wastewater to be clean enough for reuse. The water from this plant will meet those requirements and be pumped through a dual-pipe system to be used by future residents.
“We’ll be providing up to 400,000 gallons per day average,” Dasai said. “We’ve got 300 acres of parks and open space, and all the open space on Treasure Island will be irrigated using this water. Then all the new development on Treasure Island, all toilet flushing, will be off this system. All laundry facilities will be off this system.”
New innovations at the facility include the use of organic biological compounds and ultraviolet light to clean the water, rather than chemicals.
There is also a man-made wetland for treated water that is not reused. Native grasses and plants will clean additional fertilizers and other pollutants from the water before it is discharged into the Bay.
“You heard in 2022 and 2023, we had a major algal bloom in the Bay?” Dasai said. “The water was clear, which encourages the algae growth. When the algae die it takes dissolved oxygen from the water, away from the fish, and that creates the fish kill. By removing nutrients through the wetland process, the effluent that leaves the facility has a very minimal amount of inorganic nitrogen.”
“The old treatment plant is running on Band-Aids right now. It’s been in operation beyond its useful life.”
Jignesh Desai, senior project manager
The design for the plant will include a public Bay trail with public art around the perimeter of the facility.
“We have a two stage or a control system with a biological trickling filter,” said Dasai. “The first stage takes away 90% of the odors. The second stage is a carbon unit. There will be no odors beyond the fence line.”
The solid waste, the part that smells the most, will be trucked to San Francisco’s Oceanside plant to be converted to gas that can generate electricity. Dasai sees a future where the solids will be processed on the island and used as fertilizer.
“This is a once in a lifetime opportunity in my career as a public servant,” Dasai said. “On a personal note, it is very special to be involved in a plant that’s going to rebuild or change a place over 30 or 40 years.”
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