“In a world where less than one percent of our water is available for human use, we must find new and innovative ways to extend the life of our finite water resources. By using our planet's water supplies effectively today, we can ensure that our world's water is safer, cleaner, and more sustainable —for our generation, and generations to come”. RainDance customers are helping to create a sustainable water future for our community, state, and planet. Our urban water use cycle.
Why is recycling water important?
By recycling water, residents and businesses can continue to irrigate landscaping, even during severe droughts. Every gallon of recycled water used on landscaping means a gallon of potable water is saved for drinking and other uses.  We believe we should use the right water for the right purpose.  Recycled water is for plants. Fresh water is for humans.

What is Recycled Water?  Where does it come from?

The recycled water brought to you by RainDance is highly treated wastewater from the Regional Water Quality Control Plant (RWQCP) in Palo Alto. This is “tertiary treated water”, meaning that it has been through three levels of treatment - physical, chemical and biological - so that it ends up looking and smelling much like drinking water.  These complex cleaning processes require careful maintenance and constant monitoring to make sure that the water can be discharged into San Francisco Bay without harm to the ecosystem, or be used for other purposes including landscape and agricultural irrigation, car washing, fish ponds, fire fighting, groundwater recharge and in fountains and recreational lakes where swimming is allowed.

Is it safe for people?

Yes it is. Tertiary-treated recycled water meets standards that allow it to be used for most non-drinking purposes. In California, the Regional Water Quality Control Board and California Department of Public Health have strict permitting and monitoring procedures to ensure the reliability of treatment processes and controlled use of recycled water. Disinfected tertiary-treated recycled water is virtually free from all pathogens, including viruses. Several long-term microbiological studies involving thousands of samples have confirmed that pathogens are reduced to non-detectable or insignificant levels in tertiary-treated recycled water.

  • What is "tertiary" recycled water?
    Tertiary recycled water is the highest quality recycled water.  It undergoes an extra process of UV exposure and chlorine treatment.  It is acceptable for human contact, but not suitable for drinking, swimming pools, or baths.
  • Is it safe for children and pets to play on grass irrigated by recycled water?
    Yes, the California Department of Health Services has very high treatment standards for recycled water. Palo Alto’s recycled water meets or exceeds all state standards for water used for irrigation and other uses with similar public exposure. According to Dr. Stanley Deresinski, Clinical Professor, Stanford School of Medicine, one would have to drink at least 12 gallons of reclaimed water, in a single sitting, in order to ingest an infectious dose of coliform bacteria. Recycled water is not certified for drinking, so to be completely safe, and avoid human ingestion, it should not be sprayed on people or left in ponds that children could play in.
  • Has anybody ever gotten sick from recycled water?
    No. Recycled water is commonly used throughout the country, and there are no reported cases of illness or allergies as a result of its use for the intended purpose of landscape irrigation.
  • What happens if a child falls down in a pool of recycled water and has an open cut? Will the cut get infected? No. The cut should be cleaned just as would be the case after any fall. Getting dirt into the cut would be more serious than the exposure to recycled water.
  • What happens if my dog or cat drinks from a recycled water puddle?
    Just the same thing that happens when they drink water running down a gutter in the street: no harmful effects. The water will be safer than if the pet drank from a ditch or pond.
  • What about contaminants that are not removed from the water?
    While small concentrations of pollutants are found in recycled water, there is no exposure route for these compounds to be ingested by humans when using recycled water for landscape and industrial purposes. Program staff at RWQCP monitor research regarding treatment technologies, mechanisms of human exposure, and health risk assessments to ensure that reuse practices protect human health.

Recycled water in the landscape

  • Is recycled water safe for gardens and landscaping?
    Yes, the State has approved this type of highly treated recycled water for use on all types of landscaping, turf, gardens and edible crops.
  • How good is the quality of recycled water?
    Palo Alto’s recycled water has been used on almost all plants and grasses successfully for many years.  Typically, our recycled water will have a slightly higher concentration of dissolved salts than drinking water. Water with high levels of salts can have adverse effects on plant health and appearance; however, our water does not have harmful levels of salts for most plants. As our water is slightly saltier than the drinking water supply, it is not recommended as the sole source of water for Redwood trees and some other salt-sensitive plant species.
  • Does recycled water give plants extra minerals?
    Yes. The higher nutrient content of nitrogen, phosphorous and potassium in recycled water is beneficial to turf grasses. In many cases, turf and other landscape plants will be able to obtain from recycled water all the phosphorous and potassium they require, and a large part of their nitrogen requirement.  Sufficient micro-nutrients are also supplied by recycled water.
  • Can this water hurt plants?
    Two studies done by University of California at Davis showed low occurrence of injury to many common landscape plants. In fact, one study showed health ratings were equal or higher using recycled water over potable water in all species tested. In some cases, nutrient rich recycled water can be beneficial to plant growth and might reduce the need for additional fertilizers. Summaries of these studies are found in the UCD Department of Environmental Horticulture newsletter “Growing Points” Fall 2001 and Fall/Winter 1996/97 issues.
  • What about salt?
    Plants sensitive to salts may be affected mostly by tip burning when recycled water with high saline content is applied by spray leaving salts behind when the water evaporates. Well-drained soils and periodic use of fresh water will mitigate potential salt accumulation effects.  RainDance recommends that recycled water should account for no more than 50% of the total water applied to landscapes.  Salt-sensitive grasses and some acid-loving plants should be irrigated using potable water at least every other watering to carry away any salts before they accumulate in the soil.

Is recycled water regulated?

Yes.  The California Department of Public Health (DPH) establishes and enforces the standards for recycled water. California laws regulating recycled water are located in the Health and Safety Code, the Water Code, and Titles 17 and 22 of the California Code of Regulations.

In Palo Alto, a permit process, training, signage and a number of restrictions apply to entities transporting and applying recycled water from the RWQCP. Residents or businesses accepting the recycled water must read and sign a statement to insure they are fully aware of the recycled water application and its restrictions.


We want to acknowledge the support of the city of Palo Alto Water Quality Control Plant. 


The water they provide has been processed at an advanced treatment facility that uses gravity settling, biological treatment with microorganisms and dual media filtration to remove organic materials and toxins.  

Learn more about Palo Alto's Reclaimed Water here: