Recycled water – part of the ‘new normal’
Marin County, along with much of California and the entire west, continues to experience more frequent and lengthier periods of significant drought conditions – what many are calling the ‘new normal.’ Water is already the most precious resource in the west, and recycled water plays an ever-more critical role in the water supply portfolios of many water providers. In fact, the California Legislature has declared that a substantial portion of the future water requirements of the state may be economically met by beneficial use of recycled water.
The Las Gallinas Valley Sanitary District (LGVSD) is proud to be an important part in helping to conserve the local supply of fresh drinking water, by producing high-quality, treated recycled water for non-potable uses – an increasingly valuable resource from its wastewater treatment facility.
In 2021, as part of LGVSD’s Secondary Treatment Plant Upgrade and Recycled Water Expansion Project, the wastewater treatment plant’s recycled water production facility was rebuilt and expanded, to effectively quadruple its production capacity to over 5 million gallons of recycled water per day (this replaces the Marin Municipal Water District facility that was in operation on the LGVSD site since 2012, and had reached the end of its useful life).
In an example of exceptional cooperation between neighboring public agencies, the expanded facility is providing much of this recycled water to the North Marin Water District and the Marin Municipal Water District, which then sell it for use in landscape irrigation, car washes, cooling towers, commercial laundries, toilet flushing, and other non-potable uses.
Some of the benefits of producing and using recycled water include:
- Converts wastewater into a valuable resource
- Provides a reliable and drought-proof water supply
- Every gallon of recycled water produced means a gallon of fresh water preserved for other critical uses
- Increases independence from limited outside water resources
What can recycled water be used for?
While commercial facilities most often use recycled water for landscape irrigation, a variety of other applications are also appropriate, including:
- Flushing toilets and urinals
- Soil compaction
- Dust control
- Aircraft washing
- Firefighting (installed fire control systems and/or fire hydrants)
- Priming drain traps
- Commercial laundry
- Water features (fountains, running streams, etc.)
- Mixing concrete
- Cooling and air conditioning
- Car washes
- Backfill consolidation
(source: WateReuse Association)
Is it safe? California’s Title 22 Standards
When used in compliance with the state’s Recycled Water Policy, the Uniform Statewide Recycling Criteria, and all applicable state and federal water quality laws, the State Water Resources Control Board finds that recycled water is safe for approved uses, and strongly supports recycled water as a safe alternative to raw and potable water supplies for approved uses.
LGVSD’s recycled water is treated to a level that meets or exceeds California’s Title 22 recycled water standards – some of the strictest water treatment standards in the world. The Recycled Water Treatment Facility is designed to receive treated wastewater from the Secondary Treatment Plant and to further treat the water to Title 22 standards. This additional level of treatment includes:
- Membrane supply pumps and membrane filtration
- High quality feedstock to the membrane ultrafiltration system is provided by a new activated sludge process
- Chlorine disinfection, water storage, and distribution pumps
The result of this process is recycled water that is suitable for the specified uses – uses that might otherwise be met with fresh drinking water. This beneficial reuse of treated effluent, turned into safe recycled water, is saving a remarkable amount of fresh water for more critical uses in the community.
Water In the Spotlight!
The Last Call at the Oasis and Downstream are two must-see videos explaining and exploring water ReUse. Please enjoy these exciting, sometimes humorous, and thought-provoking trailers.