More Santa Clara County residents are another step closer to receiving higher-quality recycled water for irrigation. The cities of Mountain View and Palo Alto teamed up with the Santa Clara Valley Water District to study the best options for improving the quality of the recycled water produced at the Regional Water Quality Control Plant (RWQCP) in Palo Alto.
While the water currently produced by the RWQCP generally works well for irrigation, it tends to be saltier than regular drinking water. This doesn’t bother most plant life, but some plants and trees, such as redwoods, don’t tolerate it well. Blending the existing recycled water with advanced purified water results in a higher-quality water which is better for plants.
The Advanced Water Purification System Feasibility Study, which started in June 2016 and ended in December 2017, recommended incorporating a reverse osmosis system to improve the existing recycled water produced at the RWQCP. This would require construction of a new advanced water purification facility capable of treating about 1 to 2 million gallons per day and blending it with recycled water that’s already been treated up to three times. The water district is making smart investments in new and innovative technologies like water recycling to make sure our water supply meets future needs. The water district, Palo Alto and Mountain View funded the study, which cost $308,000.
Partners also evaluated a parcel of land next to the RWQCP that could be used for a future advanced water purification facility capable of producing 6 to 10 million gallons per day. A preliminary design report, which will be used as the basis for the facility’s construction, also resulted from the study.
This feasibility study and its recommendations are part of the larger Northwest County Recycled Water Strategic Plan. The plan includes developing strategies for the expansion of recycled water to south Palo Alto, in the Stanford Research Park area, and customers in Los Altos, Los Altos Hills, Mountain View, East Palo Alto, and Menlo Park.
The larger plan also includes a groundwater assessment in the northwest part of the county to better understand groundwater conditions and the potential for drinking water use in the future. Another critical component is determining how to pay for these improvement projects, whether through grants, low-interest loans or other partnerships. Water district and Palo Alto staff are continuing to work with consultants in the assessment stages and expect to finalize the strategic plan by March 2019.
The RWQCP helps protect the San Francisco Bay by cleaning and treating wastewater before it is discharged to the Bay. The plant cleans about 20 million gallons per day of wastewater, and can produce up to 4.5 million gallons per day of recycled water. Currently, about one million gallons of this cleaned wastewater irrigates parks and public spaces in the northeast areas of Palo Alto and Mountain View.