Water Reuse

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How does water recycling work? (Source: UC Riverside)

Water recycling across Southern California keeps water flowing in every home.

In Los Angeles

Water Waste Systems

The City of Los Angeles’ wastewater system serves over four million people in Los Angeles and 27 cities that contract for this public works service. The system is comprised of more than 6,500 miles of sewer pipelines and four wastewater treatment and water reclamation plants that can process over 550 million gallons of flow each day citywide. The City of Los Angeles Bureau of Sanitation operates four treatment plants in the City of Los Angeles—Hyperion Treatment Plant, Donald C. Tillman Water Reclamation Plant, Los Angeles-Glendale Water Reclamation Plant, and the Terminal Island Water Reclamation Plant.

Laundromat. ©Ekaterina Belinskaya

Southern California Water Systems

The Treatment Process

The water treatment process is similar at various treatment plants, however treatment levels vary from plant to plant.

PRELIMINARY TREATMENT: This takes place as the sewage comes into the plant where the course debris and grit is removed through bars and rakes.
PRIMARY TREATMENT: 70% of organic and inorganic is removed from the raw wastewater. Solids are allowed to settle and oils and grease rise to the top. Both are collected and returned to the sewer.
SECONDARY TREATMENT: Biological treatment occurs here—living organisms are added to feed on the bio-solids. Aeration also occurs, helping the organisms to thrive. The fat organisms then settle to the bottom and are removed to be used again.
TERTIARY TREATMENT: Water passes through sand filters where the remaining solids are removed. From there it is disinfected and ready for use.
MICROFILTRATION and REVERSE OSMOSIS: At this time, the Terminal Island Water Reclamation Plant is the only plant in the city to produce advanced treated water.

Water Treatment Facility Chart

The following is a summary of the wastewater collection and treatment facilities currently operated by the Department of Public Works.

Wastewater Collection System – the Sewers

Over 6,500 miles of sewers ranging from eight inches to 12 feet in diameter
48 pumping plants lift wastewater from low-lying communities into larger sewers

Wastewater Treatment Plants

Hyperion Treatment Plant, the City’s largest facility, serves more than two-thirds of Los Angeles and has a capacity to process 450 million gallons per day (mgd); 100% secondary treatment
Terminal Island Treatment Plant in San Pedro, serves Los Angeles Harbor area communities and has a capacity of 30 mgd; 100% tertiary treatment with reverse osmosis treatment.

Water Reclamation Plants

Donald C. Tillman Water Reclamation Plant, serving San Fernando Valley communities, has the capacity to process 64 mgd, 100% tertiary treatment
Los Angeles-Glendale Water Reclamation Plant serves eastern San Fernando Valley communities; it has the capacity to process 15 mgd, 100% tertiary treatment
All wastewater treatment and water reclamation plants operate 24 hours a day, year round.

Caption

Waste Water Treatment - How It Works

Anaerobic Digesters handle solid waste for most of L.A. at Los Angeles Hyperion Wastewater Treatment Facility

Biosolids Handling

Hyperion and Terminal Island treatment plants have facilities on-site to process sewage sludge (solids removed during wastewater treatment) into biosolids.
Sewage sludge removed from wastewater at the Donald C. Tillman and Los Angeles-Glendale Water Reclamation Plants is returned to the sewer system and treated at Hyperion.
Stabilized and dewatered biosolids are used as soil nutrients primarily at the City of Los Angeles’ 4,700-acre farm in Kern County but this use does causes some heated controversy in Kern County.
The City’s 100% beneficial use program began in 1989 and is one of the largest in the country. The U.S. EPA has recognized the City’s program with two national awards for outstanding use of biosolids.
The Donald C. Tillman Water Reclamation Plant, near the Japanese Garden in the Sepulveda Basin, will be upgrading their facilities so they can become an advanced water purification facility. They will transfer this ultra-clean water by pipe to fill the aquifers at the different spreading grounds in the SF Valley. That water will be pumped up from the aquifers, treated again when needed for families and businesses.

Down the Drain

Grey Water Reuse

Put simply, grey water is wastewater generated by washing people and their clothes. It accounts for nearly half of the water used in a typical home and, while relatively clean, it accounts for about 70% of domestic wastewater. Grey water has the additional benefit of being warm and represents valuable water and heat resources being flushed away.

learn more about the connection between water, energy and food at Nexus

RECYCLING OPTIONS FOR TREATMENT AND USE OF RECYCLED WATER

There are four popular project alternatives that cities are considering:

1. Direct Potable Reuse

and Indirect Potable Reuse which includes:
2. Reservoir augmentation
3. Groundwater recharge via percolation ponds
4. Direct well injection into groundwater

Direct Potable Reuse (DPR)

Every drop of water on the planet has been recycled at one time or another, but when you talk about bringing wastewater back to potable standards, people get a little squeamish. That public perception factor is one of the biggest hurdles for communities considering direct potable reuse (DPR) as a means of generating a reliable source of clean water when other resources aren’t sufficient, said Wade Miller, executive director of the WateReuse Research Foundation (WRRF), a non-profit water reuse research organization that is leading efforts in applied research around direct potable reuse. DPR is the process of treating wastewater to drinkable standards and returning it to the raw water supply without the use of an environmental buffer. Rather than mixing the treated water into an aquifer or reservoir (as you would with an indirect potable reuse [IPR] system), with DPR, the treated water is distributed immediately upstream of a drinking water treatment plant or directly into the potable water distribution system. The technology exists today to return wastewater to drinking quality standards, Miller said.

A Recycling Option: Indirect Potable Reuse (IPR)

Indirect Potable Reuse

Tillman Reclamation Plant

Water Recycling in Los Angeles

Everyday our San Fernando Valley population uses a river of water that comes from faraway places like the Sierras; this imported water is used to wash dishes, shower, and more. San Fernando Valley has a very interesting way of handling bio/water waste. Much of the waste goes to the Tillman Waste Treatment Plant that is next to a Japanese Garden. The biosolid waste elements are transported to the Hyperion Plant but the separated water elements are processed to use for the Japanese Garden water areas, and the Sepulveda Wildlife Reserve, Lake Balboa and eventually to replenish the Los Angeles River, returning eventually to the Pacific Ocean.