Residuals Management Project upgrades
Every day, Valley Water treats and delivers clean, safe drinking water. It's a responsibility we don't take lightly and the number one goal of the Penitencia Water Treatment Plant. In 2025, the Penitencia Water Treatment Plant will have critical components that clean and treat your drinking water upgraded. Known as the Penitencia Water Treatment Plant Residuals Management Project, the project will replace the plant's existing residuals management system (RMS). The RMS are the components that process, handle, and treat recovered washwater, and dispose of the sludge produced by the primary water treatment process.
The upgrades will improve the plant's operations and abilities to achieve water quality goals, address aging infrastructure and maintenance issues, and improve capacity, efficiency, and reliability. The completed project will extend the life of the RMS and increase the plant's reliability in treating and providing you with safe, clean drinking water.
RMS components and how do they clean your water
The components of the RMS that will be upgraded include:
1. Sedimentation basin sludge withdrawal equipment: The water treatment process begins in these containers made of concrete that hold the water to be treated for drinking. Water gently mixes in the basins, allowing particles to settle as they separate from the water. As the particles settle, they become sludge, which we remove. Sludge is removed with manually operated equipment and then pumped to sludge holding basins
2. Sludge holding and dewatering facilities: Sludge from the sedimentation basins is removed with manually operated equipment and pumped into sludge holding basins. The sludge then goes through a treatment process that utilizes a belt press method that squeezes the sludge. This process results in the production of dewatered solids and filtrate. Dewatered solids are taken to a landfill for disposal. The filtrate, which is turbid water, is pumped to the wash water recovery basins.
3. Washwater recovery basins: in addition to receiving the filtrate, these basins collect the discharged water when the plant washes its filtration system. Through gravity, the heavier particles settle to the bottom, becoming sludge. The recovered water is pumped back to the sedimentation basin to go through the primary water treatment process. The remaining sludge is sent back to the sludge holding basins, which goes through the belt press method, squeezing the water out of the sludge.
Through this process, all water is saved and cleaned.
Work activities and timeline
The upgraded RMS requires demolishing outdated process basins, mixing tanks, pump stations, equipment, electrical and instrumentation control rooms, and buildings that will be replaced with more efficient, automated, and modern facilities to support the current treatment plant capacity. The service road inside the plant will be extended, and new vegetation will be planted inside the treatment plant after all the construction work. The map shows the areas of the plant where work will occur.
Once construction starts in the spring of 2025, it will take approximately 5 years to complete the project. All work will occur inside the Penitencia Water Treatment Plant and construction staging areas located along Whitman Way. Some nearby neighbors may hear the construction activity during the scheduled work hours, which will be identified before the start of construction.
Public Input
The environmental review process for the Penitencia Water Treatment Plant Residuals Management Project starts with releasing a Notice of Intent to adopt a Mitigated Negative Declaration (MND). A review of the project's environmental impacts resulted in the MND finding no significant environmental impacts that can be mitigated through measures implemented during the project's construction. Valley Water welcomes input on issues for consideration during the public review period from Thursday, September 27, 2024, through Monday, October 28, 2024.
Additional information on the environmental review process and the Draft MND is available at https://www.valleywater.org/public-review-documents
The 17-acre Penitencia facility opened in 1974 as the second of Valley Water's treatment plants. Penitencia treats and delivers up to 42 million gallons of water each day for the cities of San José and Milpitas and local water providers such as the San Jose Water Company, a private company that serves most of San José. Our plant neighbors all receive their water from the Penitencia Water Treatment Plan. This plant is the smallest of the three water treatment plants that serve Santa Clara County.
Please contact Public Information Representative Jose Villarreal with project questions at [email protected] or 408-630-2879.