Capital Improvement Projects

The Plant is a critical infrastructure facility located directly on the San Francisco Bay shoreline. This makes it vulnerable to sea level rise. The designs of current capital improvement projects have planned for future sea level rise. For example: 

• The Outfall Line Construction will address the discharge capacity to meet peak wet-weather flow, peak high tides and future sea level rise scenarios.  
• The 12 kV Loop Electrical Upgrades raised electrical equipment above ground level to anticipate increased flooding. 
• The Horizontal Levee Project pilots a nature-based solution to flood protection and sea level rise. As a pilot, it will answer questions that will inform future levee projects throughout the Bay Area.  

Sea Level Rise Planning in Palo Alto

Located just outside the Plant in the Baylands, the Horizontal Levee will pilot a new type of levee to protect against floods and predicted sea level rise. It will be the first of its kind on the San Francisco Bay and will inform planning for future levees.

A horizontal levee is a nature-based solution that provides many benefits over traditional levees. Their unique designs have a wide gentle slope which helps a marsh adapt as sea level rises. This one will also use treated wastewater to restore a native habitat on its slope. The process will further filter treated wastewater.

Palo Alto Horizontal Levee Pilot Project

The Plant replaced chlorine with ultraviolet (UV) light to disinfect treated wastewater that is discharged to the San Francisco Bay. The UV facility was built in 2010 (photo at left). Chlorine created harmful byproducts and is toxic to aquatic organisms. UV disinfection is both effective in destroying bacteria and viruses in the water and safe for the environment. Chlorine is still used in the production of the Plant’s recycled water.

The Plant’s recycled water program began in 2007 and generates approximately one million gallons of high quality recycled water each day. This water can be used for landscaping and industrial applications.

Learn more about recycled water

Most of the Plant’s treated wastewater is discharged into the Palo Alto Baylands, but approximately one million gallons each day is also released to a constructed pond in Renzel Wetlands. It takes the water about 12 days to pass through the pond before entering Matadero Creek, where it travels into the Bay.

 The pond east of the Bayshore Freeway was built in 1992. This project was a requirement of the Regional Water Quality Control Board, which regulates the Plant. The pond and wetlands connection provides a beneficial reuse for treated wastewater effluent. In 2018, the pond was drained and excavated to remove built up sediments, and a perimeter berm and trail was constructed.

Today the pond is an amazing viewing area for wildlife, like migratory birds.