Silicon Valley’s Watershed Moment

The region’s ambitious plan to recycle wastewater and restore the environment

Image © Hargreaves Associates

March 22nd is World Water Day, organized by the United Nations to promote the importance of freshwater resources. This year’s event focuses on wastewater, and how it can be responsibly managed to safeguard health and support sustainable development. In San José, California, the largest advanced wastewater treatment facility in the western United States is at the forefront of meeting these challenges. But, wastewater is just the beginning. The city has a vision not only to serve the region’s future water needs, but also to revitalize the natural environment.

California residents, having recently suffered a five-year drought, are keenly aware that water is a finite resource. But water that goes down the drain is not all lost. Increasingly, wastewater is having a second life. Water treatment infrastructure allows the water supply to be replenished, in part, with recycled water. In a drought-prone region, this has a major impact — and the possibilities for recycled water are just beginning to be realized.

Every day, an average of more than 100 million gallons of wastewater reaches the San José-Santa Clara Regional Wastewater Facility, a sprawling complex on the southern edge of San Francisco Bay. After a thorough treatment process, most of the cleaned water is safely released into the bay. However, millions of gallons of treated water are also returned to the water supply for uses such as irrigating lawns and flushing toilets. Now, the wastewater facility is upgrading its infrastructure, investing in new technology, and also working with the Santa Clara Valley Water District to demonstrate how treated wastewater can eventually become a source of drinking water.

The San José-Santa Clara Regional Wastewater Facility is the largest operation of its kind in the western United States.

Not by coincidence, these progressive wastewater treatment practices are being developed at an epicenter for high-tech research. “It’s certainly the mindset that you would expect — for the governmental agencies in Silicon Valley to reflect our community,” says Kerrie Romanow, director of the San José Environmental Services Department. “Most of us live here, so we’re in that entrepreneurial mode as well. We want to see the local economy do well. And if there’s a better way to do our work and to use our natural resources, then we’re also personally invested in that.”

The investments being made now are based on the Regional Wastewater Facility Master Plan, a comprehensive study completed in 2013. Crucially, this plan looks not only toward how the facility will serve its community in the future, but also how it can contribute to restoring the sensitive watershed ecosystem of the San Francisco Bay.

“This aging infrastructure is really what keeps Silicon Valley going. Our businesses and our residents can’t grow and move forward if wastewater isn’t treated.”

When the wastewater facility first opened, in 1956, the Santa Clara Valley was a sparsely developed, largely agricultural area. Today, the wastewater facility serves 1.4 million people and 17,000 businesses across eight cities — including San José, the most populated city in northern California — and portions of Santa Clara County. The master plan was developed in response to a dire need to upgrade the facility’s technology to keep pace with the region. “This aging infrastructure is really what keeps Silicon Valley going,” Romanow says. “Our businesses and our residents can’t grow and move forward if wastewater isn’t treated.”

SOM and Hargreaves Associates developed the master plan as part of a project team led by Carollo Engineers for the San José Environmental Services Department. Ellen Lou, an urban design and planning director at SOM, explains that one of the most significant opportunities for the wastewater facility is the land that it sits on: 2,600 acres fronting the bay. “A wastewater facility isn’t a project that SOM would typically work on,” Lou says. “But we got involved because of the incredible opportunity here to reuse the land.”

The site is larger than both San Francisco’s Golden Gate Park and New York City’s Central Park.

The facility is surrounded by hundreds of open acres — known as the “bufferlands” — that constitute one of the largest undeveloped parcels in the Bay Area. This territory was acquired decades ago to protect the surrounding community from some of the formerly unpleasant aspects of the treatment process, including odors and chemicals. In recent years, however, the facility has phased out the use of substances such as chlorine in favor of greener methods. And advanced odor treatment strategies have made noxious smells less of an issue than in the past.

Over the next 30 years, upgrades in wastewater treatment technology will also allow the facility to use its land more efficiently. Eventually, it will be able to reduce its operational footprint by more than 70 percent — opening up thousands of acres to new potential uses. Romanow notes that the site is larger than both San Francisco’s Golden Gate Park and New York City’s Central Park. “When you think of it in that context, you can really appreciate how much land it is,” she says.

Above: Site area plan (left) and existing wastewater facility area (right)
While reducing the wastewater facility’s footprint, the master plan dedicates more than 1,800 acres to the restoration of natural habitats. Image © SOM

To determine how best to use the land, the project team worked with several advisory groups, including community members, stakeholders, and technical experts. The master plan was developed through three years of intensive community engagement, with thousands of local residents participating in public meetings, surveys, and tours. As a result, Romanow says, “The plan adjusted and evolved to be something that the community wanted.” The final document adopted by San José outlines a number of goals — among these, to support the region’s economy, to provide the community with new recreation spaces and access to the bayfront, and to restore the environment.

Photos © SOM

The environmental issues facing the bay have a long history. Like many urban waterfronts developed in the 19th century, the bay became a place for industry. In particular, the natural salt ponds along the southern bayfront were used for salt production — an industrial-scale operation that transformed the coastline, and also decimated the wetlands habitat. Sixty years ago, when the wastewater facility was built, the bayfront was still considered an appropriate place for industrial uses. “There was landfill around the bay. This land wasn’t seen as valuable, but now, that’s changed,” Lou says. “We realize how important our natural ecosystems are.”

The master plan puts forward a bold vision to restore these natural systems. “The extra land presented the opportunity to open up the historic watershed and resuscitate the bay,” says Alan Lewis, who worked on the project with Hargreaves Associates, and is now an associate director at SOM. Central to this effort is restoring natural habitats. At this place where saltwater and freshwater mix, the estuary ecosystem is particularly fertile, and especially sensitive. “The amphibious zone is a nutrient-rich fertile ground that fosters wildlife,” Lewis says. “The industry of the salt ponds obliterated the marshland and the mudflat lands. We saw an opportunity to use the territory to help to revive that vital piece of ecology.”

“We’re providing places for nature to flourish again.”

The planning team found that during the rainy season, the wastewater facility would provide more recycled water than the cities of San José and Santa Clara could use. The water could then be used to revitalize the former salt ponds along the bay edge. This, along with other environmental remediation strategies, will help to restore the area’s rich biodiversity. “We’re providing places for nature to flourish again,” Lewis says.

The master plan also envisions how to guard the coastline against the effects of climate change. The wastewater facility is located at one of the lowest points along the bay, making it vulnerable to sea level rise. In response to this, the team is coordinating with partners in the South Bay Shoreline Project to construct a levee that will protect the wastewater facility, residences, and businesses in the area. The shoreline levee will feature an innovative sloped design that will allow natural habitats to gradually move upward over time. Designed to address the 100-year expectation for sea level rise, the levee will provide a resilient landscape that adapts to the changing characteristics of the bay.

Image © Hargreaves Associates

In its sweeping scope and vision, the master plan’s single defining quality is the way it resolves multiple, interconnected priorities to equip the region for the future. With other urban areas taking note of the comprehensive strategies being used in San José, the project could serve as a model for communities dealing with similar challenges. “If we’re able to integrate nature into our way of thinking about solving problems,” says Lewis, “we’ll have the highest rate of return across all of the issues we’re facing.”

Image © Hargreaves Associates