Visalia Water Conservation Plant Upgrades And Expansion — Visalia, CA
Client
- City of Visalia
Project Value 
$70 Million
Market
Water And Wastewater
Services
Design, Engineering
We provided design and engineering services during construction to upgrade and expand Visalia’s Water Conservation Plant (WCP). The project increased treatment capacity to 22 mgd with nitrogen removal. The city’s 2010 service area population was expected to nearly double by 2030. The plant had a permitted capacity of 20 mgd and treated the influent and sludge processes.
Regulatory Drivers And Technology Evaluation
While the main driver for this project involved increasing the permitted capacity to 22 mgd, the City of Visalia also needed reliable biochemical oxygen demand and nitrogen removal, as well as tertiary treatment processes that comply with California Title 22.
These regulations govern indirect potable and potable reuse in California. Sustainability, pollution-free energy recovery, groundwater recharge, and extensive water recycling also guided the project. We performed a technology evaluation and a life‑cycle cost analysis and compared conventional tertiary treatment systems, such as tertiary filters and chlorine disinfection, with advanced systems that use MBR and UV disinfection. We then assisted the City with selecting and pre‑purchasing a 22‑mgd MBR. GE (Zenon) supplied the selected MBR system. The MBR system produces high quality recycled water for landscape irrigation, agricultural irrigation, and groundwater recharge. For wastewater disinfection, the City chose UV light.
Treatment, Energy, And Equipment Upgrades
We assisted the City in preselecting the UV equipment. Infilco Degremont’s Ozonia vertical lamp system became the selected system. Parsons also helped the City preselect a renewable power generation system (RPGS) and related equipment. The RPGS will use an internal combustion engine sized to maximize utilization of digester gas for power generation and heat recovery. The heat recovery system maximizes heat recovery from exhaust. The hot water produced will heat the anaerobic digesters at the WCP. We also assisted the City in evaluating and preselecting turbo blowers and fine bubble diffusers for aeration. In addition, we evaluated sludge disintegration to improve digester performance and supported selection of sludge dewatering equipment.
Funding Assistance And Financial Support
We assisted the City with applying for and securing $500,000 in grant funding from Southern California Edison. We also supported the City in preparing its State Revolving Fund application. Furthermore, we helped evaluate other available grants for potential use on the project.
Controls Integration And SCADA Modernization
We led and participated in extensive consultations with plant operators and the City’s system integrator, Telstar. During these meetings, we developed instrumentation and controls (I&C) design criteria and maintained compatibility with the plant’s existing programmable logic controllers (PLCs). We also ensured integration with the existing Supervisory Control and Data Acquisition (SCADA) system. At the same time, we addressed a key I&C challenge. The project upgraded the entire plant SCADA system with the latest state‑of‑the‑industry technologies.
