Marsha SukardiProgram Manager for the Living MachineCivil Engineer, Wastewater EnterpriseSan Francisco Public Utilities Commission

Living Machineat SFPUC Headquarters

SFPUC HQ has two non-potable water reuse systems

1. Rainwater Harvesting System- Rainwater reused for irrigation

2. Living Machine System- Black- and greywater reused for toilet and urinal flushing

Reduces use from 12 gal/day/person5 gal/day/person

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Location of system components

How does it work?

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Living Machine Treatment Process

Primary Tank

Equalization and Recirculation Tanks Reclaimed Water Tank

Treatment Wetlands

Disinfection

Primary Tank

Primary Tank

Component Function Capacity Notes

Trash Chamber Receives sewage, settling and screening of larger solids

2,500 gal Excess sewagepumped to sewer

Settling Chamber Removal of settleableand suspended solids

7,500 gal Filtered WW flows to EQ Tank

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Living Machine Treatment Process

Primary TankEqualization and 

Recirculation TanksReclaimed Water Tank

Disinfection

Treatment Wetlands

Treatment Wetlands

Vegetation supports diverse micro-organism populationsContains Engineered Gravel = Lightweight Expanded Shale (LESA)

Tidal Flow Wetlands

Polishing Vertical Flow Wetlands

Equalization and Recirculation Tanks

Tidal Flow Wetland

• Alternates filling and draining

Tidal Flow Wetlands

Tidal Flow Wetland

NH4+ NO3

- NO2-

Organic matter CO2 (g)

Next Fill and Drain cycle NO2- N2 (g)

Soluble nutrients and organic matter move from solution to aggregate and biofilm

Tidal Flow Wetland

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Equalization and Recirculation Tanks

Vertical Flow Wetland

Polishing Vertical Flow Wetlands

Vertical Flow Wetland

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Vertical Flow Wetland

Living Machine Treatment Process

Primary TankEqualization and 

Recirculation TanksReclaimed Water Tank

DisinfectionTreatment Wetlands

Disinfection Equipment

2) 5μ Cartridge Filter3) Ultraviolet Disinfection

4) Tablet Chlorinator

1) 100μ Screen Filter

Living Machine Treatment

Primary TankEqualization and 

Recirculation TanksReclaimed Water Tank

Treatment Wetlands

Disinfection

Operating the Living Machine

Automated control panelMechanical components based on

operator settings and sensor signals.

Human-Machine Interface (HMI)Graphical interface for remote access.

Acheivements

• Saved over 3MG of potable water• Produces high quality non-potable water• Daily maintenance and monitoring is low• Most popular building tour feature with over 2,500 visitors

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Why did we install this?

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Buildings produce water

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Non-potable demands are significant

• Up to 50% of Multi-Family residential buildings’ water demands are non-potable

• Up to 95% of Commercial building’s water demands are non-potable

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Permitting: Collaborative effort

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On-Site Water Reuse Ordinance

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History lesson: “Living Machine”

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“Design outlaws on the Ecological Frontier,” by Chris Zelov. Retreieved from http://www.ratical.org/co-globalize/DO_JohnTodd.html

History lesson: “Living Machine”

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“Design outlaws on the Ecological Frontier,” by Chris Zelov. Retreieved from http://www.ratical.org/co-globalize/DO_JohnTodd.html

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Thank you!