Happy Water Quality Month!
Valley Water’s mission is to provide Santa Clara County with safe, clean water, so to us, every month is water quality month!
From the source
Our water resource specialists and laboratory staff collect samples and data at our reservoirs to check the water quality. Source water monitoring is important because it helps our treatment plants better understand the quality of the water coming into the facilities. In addition to our own source monitoring, we work with state and local partners to ensure our imported water quality is up to excellent standards.


At the plants
Before the water is delivered to your tap, it is treated at one of our three water treatment plants. These treatment facilities clean and disinfect imported water and water captured in four local reservoirs. Santa Teresa, Penitencia and Rinconada water treatment plants are in the foothills around the Santa Clara Valley and can produce as much as 220 million gallons of drinking water daily.
Significant upgrades were completed at Santa Teresa and Penitencia in 2006, and Rinconada is currently undergoing its upgrade project. Rinconada’s new equipment will improve the reliability and quality of the drinking water supply.
In addition to the drinking water treatment plants, Valley Water operates the Silicon Valley Advanced Water Purification Center. This state-of-the-art facility further treats wastewater that would be emptied into the San Francisco Bay. The center purifies water using three proven processes: microfiltration, reverse osmosis and ultraviolet light disinfection. This treatment process is so effective that it produces water with a quality so pure that it meets California drinking water standards.
Water produced by these advanced treatment technologies is only used for non-potable purposes, like irrigation. Valley Water is working on expanding the use of purified water to help replenish our groundwater basins and boost our drinking water supply through the Purified Water Project.
In the lab
Our state-of-the-art laboratory is here to help protect your water. The lab team tests water produced from each of our water treatment plants, our reservoirs and our groundwater basin. Each sample is carefully analyzed for nutrients, heavy metals, algal toxins, microbes and a variety of inorganic and organic compounds.
Our team works around the clock to ensure Santa Clara County’s water is of the highest quality. Our treated water consistently meets or exceeds all water quality regulatory standards. We thank our water resource specialists, treatment plant operators and laboratory staff for being dedicated to carrying out that mission. Thank you for all you do!
