Valley Water works hard to ensure that our infrastructure is in good condition so we can provide safe, clean water to Santa Clara County. We recently completed the $20.6 million Santa Teresa Water Treatment Filter Media Replacement Project to replace important water-cleaning equipment at the plant. These upgrades are important for maintaining reliable, high-quality service.
Valley Water replaced 12 large filters essential for cleaning water by removing particles, contaminants and impurities. Each filter is 16 feet deep and measures 30 feet by 32 feet, covering 960 square feet. These filters are essential for treating water by capturing materials too small to see.
Workers remove sand from the old filter media at the Santa Teresa plant. 
Workers install new domes and underdrain nozzles within the filter. 
A look at one of the 12 old media filters at the Santa Teresa Water Treatment Plant . 
A before-and-after view of one of the 12 media filters at the Santa Teresa Water Treatment Plant.
As part of the upgrade, Valley Water installed new valves and actuators for water intake and backwashing, along with other worn-out parts. We also replaced the old filter media, which is the material inside the filters, with modern sand and granular activated carbon (GAC). These materials work together to remove harmful substances and improve water quality. GAC is especially good for filtering out organic chemicals and improving taste and odor.
Each filter can process a large amount of water and gets cleaned regularly through backwashing, which flushes out trapped impurities. Valley Water also replaced over 28,000 underdrain nozzles inside the filters to ensure they work reliably for their life cycle.
Filter media is the material used in a water treatment filter to remove unwanted substances from the water. As water passes through the filter, the media act as a barrier, trapping sediment, microorganisms, and other particles. This process is a vital step in producing safe drinking water. Over time, filter media wears out and loses its effectiveness. Replacing it ensures the treatment process remains efficient and reliable.
The Santa Teresa Water Treatment Filter Media Replacement Project is part of Valley Water’s Capital Improvement Program (CIP) Five-Year Plan for Fiscal Years 2025–2029. This plan outlines funding for planning, designing and building water infrastructure projects across the county.
Much of Santa Clara County’s water infrastructure is 50 to 60 years old. The CIP focuses on replacing or upgrading aging systems to ensure continued delivery of clean, reliable water. It includes investments in water supply, flood protection, environmental stewardship, facilities, and technology.
Valley Water is also working on similar upgrade projects at its other two plants, Penitencia and Rinconada. These improvements are part of a long-term plan to maintain and modernize the county’s water treatment infrastructure.