Recycled water is wastewater that has been purified through a high level of treatment. This processed water is treated to strict standards set by the California Department of Health Services and is constantly monitored by local, state, and federal regulatory agencies to ensure it continuously meets those standards. Recycled water has been found safe for irrigation, industrial and agricultural uses.
Palo Alto Regional Water Quality Control Plant’s “tertiary” recycled water has been used on almost all plants and grasses successfully for many years. However, with total dissolved solids (TDS) levels in the 800ppm range, it is a bit saltier than the drinking water supply. It is not recommended in large quantities for Redwood Trees or other salt sensitive plants.
For more information on total dissolved solids (TDS), please see our resources page. If your property has a lot of salt sensitive plants and you’re concerned with water quality, you may prefer to have reclaimed groundwater delivered.
(Recaptured From Basement De-watering Sites)
Groundwater is Rainwater that has percolated into the ground and is contained underground in soil or in pores and crevices in rock, called aquifers.
Purple Pipe Water Services procures groundwater from basement de-watering sites in Palo Alto during the construction season. The groundwater generally has a lower salt content than recycled water, but it is not filtered or purified. The groundwater is tested for pH balance, turbidity, and conductivity (a measure of electrolyte levels) when the basement de-watering commences. Chemical analysis differs a bit at each basement site but in general, the water is very clear and okay for use on most plants.
Groundwater salinity tests are done by measuring the electrolyte composition of the water by examining its specific electrical conductance (SEC).
For more information on specific electrical (SEC), please see our resources page.
Our potable water is used for filling swimming pools, water tanks at ranches, special events and emergency situations. We procure this water from fire hydrants utilizing a water meter. This is the same water that comes from the tap in the City of Palo Alto.
The majority of Palo Alto’s tap water is sourced from the Tuolumne River and water system. The Tuolumne River drains from the glacial Hetch-Hetchy reservoir located in Yosemite National Park.
We try to use reclaimed water whenever possible, but in some situations, a higher quality of water is needed.
Enhanced Recycled Water
Palo Alto and other nearby cities have already completed projects that have substantially reduced salt levels (as measured by total dissolved solids or “TDS” and parts per million “PPM”), and will continue to plan and implement projects that will further reduce TDS levels. The Palo Alto Regional Water Quality Control Plant has plans to produce “enhanced recycled water.” This is “tertiary” recycled water which will undergo a 4th stage, reverse osmosis. This water is designed to be used for all landscaping, including redwood trees.
For more information, please refer to the following news articles: