By Cora Kammeyer 

 

Water systems in most large urban areas like California’s Silicon Valley are linear and highly centralized. Water is cleaned at a central treatment plant, distributed to homes and businesses through a vast and decades-old system of pipes, used once, and then returned through another set of pipes to a wastewater treatment plant, before being discharged into a nearby waterway like the San Francisco Bay. This 20th-century approach to the urban water system is no longer sufficient to address 21st-century water challenges like climate change, growing populations and economies, and aging infrastructure.

The 20th-century approach to the urban water system is no longer sufficient to address 21st-century water challenges like climate change, growing populations and economies, and aging infrastructure.

There is a growing opportunity to build urban water systems that are distributed and circular, adding flexibility and providing back-up when integrated with centralized systems. This means capturing and treating water closer to the point of use and reusing that water multiple times before sending it back down the drain. Distributed, circular approaches like onsite water reuse have the potential to provide many benefits. They can, for example, provide alternative water supplies in the face of growing scarcity, add operational flexibility in the face of disruptions, provide opportunities for more green space, reduce greenhouse gas emissions, and more. But distributed water systems can also present challenges for water managers, and they require new strategies and new ways of thinking.

Distributed, circular approaches like onsite water reuse have the potential to provide many benefits.

The Pacific Institute report The Role of Onsite Water Systems in Advancing Water Resilience for Silicon Valley examines the opportunities and challenges of corporate investments in onsite non-potable water reuse in California’s Silicon Valley. In Silicon Valley, where commercial development is growing in the face of increasing water scarcity, sea level rise, and water quality challenges in the San Francisco Bay, a handful of leading companies are starting to invest in onsite water systems. Facebook installed California’s largest blackwater recycling system at its Menlo Park headquarters. Microsoft is capturing rainwater and treating wastewater onsite at its new Mountain View campus as part of the site’s Net Zero Water certification. Google has plans to implement onsite water reuse at its new Bay View campus at Moffett Field. These companies are making investments in onsite water systems to meet corporate sustainability goals, improve water security, and reduce their water impact on the surrounding region.

The Role of Onsite Water Systems in Advancing Water Resilience for Silicon Valley comprises three sections exploring the benefits and challenges of implementing onsite water systems in the region. First, the report provides a synthesis of the perspectives of Silicon Valley stakeholders — including water managers, regulators, technology companies, engineers, and academics — on onsite water systems. Second, it lays out a range of potential outcomes and impacts — both positive and negative — from onsite water systems. Third, a set of geospatial analyses in Silicon Valley assess the relative opportunities for onsite water systems to integrate with regional planning and contribute to regional water management strategies. These assessments incorporate key factors such as priority development areas, the reach of existing recycled water networks, expected sea level rise impacts, and more.

The report concludes that private sector investments in onsite water systems have the potential to provide numerous benefits to the region, but only if they are incorporated into the long-term regional water planning and decision-making. The report recommends:

1. Convening regional stakeholders to facilitate a constructive dialogue about the role of onsite water systems in Silicon Valley;
2. Conducting more detailed technical analyses to examine how best to integrate onsite water systems into existing centralized water and wastewater systems;
3. Evaluating policies and practices for effectively integrating onsite water systems into existing water and wastewater systems; and
4. Identifying opportunities to implement other distributed water strategies in concert with onsite water system implementation.

To read the full report, click here.