Outdoor shot of a water treatment tank at sunrise

What is Recycled Water?

When you think of recycling, you probably think of newspapers, pop cans, glass and plastic bottles, but water can be recycled, too.

Did you know that more than half of Santa Clara County’s water supply comes from rain or snow that originates in the Sierra Nevada Mountains and goes through the Sacramento-San Joaquin Delta? Environmental stresses on the Delta are threatening this important source of water. As a result, many water utilities are searching for other sources that will provide a reliable, sustainable and drought-proof water supply. One source is recycled water, which can meet a surprising number of water demands.

Let’s take a closer look at recycled water, and the role it’s playing in our water supply today.

What is recycled water, and where does it come from?

Simply put, recycled water is wastewater that’s purified through multiple levels of disinfection and treatment. Wastewater is created when we use showers, toilets, sinks, dishwashers and washing machines.

Recycled water is safe

The recycled water in Santa Clara County is treated to California Department of Health Services standards and is monitored by state, local and federal agencies. The result is clean, safe and clear, non-potable (not for drinking) water that can be used for irrigation, industry and agriculture.  

It’s natural

Water has been recycled naturally through the earth’s water cycle for millions of years. Water recycling can be either "unplanned" or "planned."  Unplanned recycling happens when cities discharge their treated wastewater to a river or other waterway to cities that are downstream. For example, the Mississippi River gets treated wastewater and that water is  a source for a large number of cities and towns.3

What is gray water?

Gray water is really just another kind of recycled water. It’s reusable wastewater that comes from bathroom sinks, showers and washing machine drains. Gray water systems can meet up to 50% of a property's water needs by supplying water for landscaping.

Tip: Be sure to use nontoxic and low-sodium soap and personal care products to protect vegetation when reusing gray water for irrigation.   

Recycled water saves money

Wastewater treatment can be adjusted to meet water quality requirements for planned reuse. For example, recycled water for landscape irrigation needs less treatment than recycled water for drinking water. Plus, recycling gray water saves fresh, potable water for other uses.

Water recycling is green

In addition to offering a dependable, locally controlled water supply, water recycling has huge environmental benefits, like decreasing the diversion of water from ecosystems. It can help reduce wastewater discharge and prevent pollution. Recycled water can also be used for developing wetlands supporting natural habitats that occur in areas surrounding bodies of water like rivers or streams.

Recycling water saves energy

When water quality is matched to a water use, it reduces the energy needed to treat it. The water quality need for flushing a toilet is less than the water quality required for drinking water, so it takes less energy. Using recycled water for specific applications like landscaping or toilet water saves energy and helps ensure highly treated water remains available for other applications like drinking water.

What are some innovative ways that water agencies recycle water?

Water agencies are using advanced water treatment techniques like microfiltration, reverse osmosis, and UV disinfection to produce highly purified (near-distilled quality) recycled water for a variety of uses, including indirect potable reuse.

Growing use of recycled water in Santa Clara County

About 4% percent of the Santa Clara County’s total water use is made up of recycled water. To make sure there is an adequate and reliable supply of high-quality water, the water district has partnered with cities and water retailers in the county to develop recycled water supplies.

The Silicon Valley Advanced Water Purification Center is an advanced water treatment facility, producing up to 8 million gallons a day of highly purified recycled water. This purified water is added to recycled water from the nearby Santa Clara/San Jose Water Pollution Control Plant. The result is an improvement to the recycled water quality and water that can be used for industry and irrigation.

Looking to learn more about recycled water and how it’s currently being utilized and proposals for future use in the greater San Jose region? Check out a study conducted by San Jose Water.