The Engineering Achievement award recognizes outstanding projects by an individual, group, or agency.
The City of Sunnyvale’s Headworks and Primary Treatment Project represents a transformative milestone in the City of Sunnyvale’s water resource management and environmental stewardship. The WPCP has served the community since 1956, providing essential wastewater treatment for a rapidly growing population. Over decades of operation, the original primary treatment facilities became outdated, structurally vulnerable to seismic events, and increasingly inefficient.
Lacking headworks facilities for screenings and grit removal, the WPCP allowed ground-up debris and other materials to pass into downstream processes, significantly reducing treatment capacity and compromising performance. Recognizing the need for modernization, the City launched the Cleanwater Program, a comprehensive, multi-phase capital improvement initiative designed to upgrade the WPCP to meet future regulatory requirements, accommodate population growth, and transition the facility into an automated, resilient, and energy-efficient resource recovery center. At $1.4 billion, this Program will be the largest investment in the City of Sunnyvale’s history. The Headworks and Primary Treatment Project marks the first major completed project of this ambitious and critical Program.
The Headworks and Primary Treatment Project incorporated a suite of innovative technologies and data-driven approaches selected to address site-specific challenges and project goals. At the core of the Project is a modern headworks facility equipped with advanced influent screening and grit removal systems. The City selected the Hydro International Eutek HeadCell and HUBER Coanda grit washers based on a comprehensive grit characterization study that revealed unusually fine, slow-settling grit with high organic content.
This tailored technology selection achieves efficient removal of both inorganic and organic materials, protecting downstream equipment and optimizing plant performance. To further refine the design and maximize treatment efficiency, the project team conducted extensive jar testing and employed computational fluid dynamic (CFD) modeling for the sedimentation tanks. These analyses informed the configuration and sizing of the tanks, ensuring optimal solids removal and hydraulic performance under a range of operating conditions. An integral influent distribution channel was incorporated to keep solids in suspension and promote partial flocculation, further enhancing the effectiveness of primary treatment.
Odor control was addressed by installing advanced dilution fans from Strobic Air Technologies. These high-efficiency and cost-effective fans provide robust odor mitigation by diluting and dispersing foul air, resulting in hydrogen sulfide emissions well below regulatory limits and significantly improving air quality for both plant staff and the surrounding community. The Project’s data-driven design approach and careful technology selection exemplify a commitment to innovation and operational resilience.
The Project’s state-of-the-art features are evident in its holistic, systems-based planning and execution. Hydraulic optimization, achieved through CFD modeling and jar testing, nearly doubled the sedimentation basin capacity compared to the legacy system, allowing the plant to accommodate higher flows and future population growth without compromising treatment quality.
Energy efficiency and automation are central to the Project’s resource recovery goals. The installation of premium-efficiency motors, optimized pump selection, and advanced process controls reduces energy consumption and operational costs, while supporting the City’s decarbonization and sustainability objectives. These features not only qualify the Project for Green Project Reserve funding but also position the WPCP for modern, sustainable utility operations.
The Headworks and Primary Treatment Project at the City of Sunnyvale Water Pollution Control Plant stands as a model of innovation, resilience, and community benefit. By replacing outdated, seismically vulnerable infrastructure with modern, energy-efficient systems, the Project has improved operational reliability, treatment capacity, and environmental compliance. The integration of state-of-the-art screening, grit removal, and odor control technologies ensures long-term sustainability and positions the facility to meet future regulatory and population demands.
Innovative research has the power to move the wastewater profession forward. Nominate a deserving individual or team for CWEA’s Engineering Achievement Award and recognize research that advances knowledge, addresses industry challenges, and contributes to the future of clean water.
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