One of the ultimate goals of green building is the application ecological design to the greatest extent possible, including a synergistic relationship between natural systems, buildings, and human inhabitants.
The use of wetlands to treat wastewater effects of buildings is well known and is becoming mainstream – most of us are familiar with the use of landscaping bioswales to filter storm water effluent before discharging it back into the aquifer.
A more exotic and robust use of ecosystems to treat building effluent is the so-called Living Machine, in which nature is brought directly into a built structure in order to break down the effluent – both greywater and blackwater – as part of the wastewater treatment system. Several approaches are in use, although the best known is said to be that pioneered by John Todd, an early exponent of the development of natural wastewater processing systems.
Contrasted with conventional wastewater treatment plants, a Living Machine is different in four major ways:
- A Living Machine fundamentally relies on living organisms, rather than mechanical parts, to produce work. These “cogs” in the machine can include hundreds of species of bacteria, plants, invertebrates, and even vertebrates including fish and reptiles.
- A Living Machine regulates its own internal ecology in relationship to the energy and nutrient streams feeding it.
- Should it be stressed by toxic substances or by interruption of its energy or nutrient streams, the Living machine is self-healing and self-regulating.
- A Living Machine is capable of self-replication through the propagation of its constituent organisms.
Among the most famous examples of Living Machine is that at the Lewis Center for Environmental Studies at Oberlin College in Oberlin OH. Local, regional examples occur at San Francisco Public Utilities Commission (SFPUC) Headquarters, San Francisco and at Esalen Institute in Big Sur.