Urban Agriculturalist is a series on the ways city and suburb dwellers use their land as a food resource.
Struck by the high carbon cost of sending food to dense urban areas and communities in extreme climates, Andrew Bodlovich and Hogan Gleeson devised a highly efficient, waste-free aquaponic growing system in which vegetable crops and freshwater fish benefit from a symbiotic relationship. Each ecoCity Farm the size of one city block can sustainably feed up to 300 people with no waste, little water and minimal effort.
Barramundi, perch or other freshwater fish and crustaceans are raised in large tanks to harvest size. The wastewater generated from the population is filtered through a patented “bio-converter” which mineralizes any compound that could be dangerous to plant or fish health (e.g. bacterias, feces). The bio-converter works with vermiculture – colonies of waste-eating worms that turn undesirable compounds into plant-ready nutrients. After getting the worm treatment, the used water nourishes the vegetables. The veggies use up the minerals and nutrients from the fish water, effectively filtering it to its original, clean state. This newly plant-filtered water is sent back to the fish tanks.
This system of recycling allows for a zero-waste production plan. The system also conserves water at unprecedented levels – it uses only 5% of the amount of water used on a traditional farm of the same output. The co-founders attest that the only water lost is that which is drunk up by the plants themselves. This makes the system “drought proof.” And not a minute too soon for Australia, it seems.
The ecoCity Farm is also a highly scalable project because it is so easily and cheaply replicated anywhere in the world. The unique technology requires an IT team, but this seems to be the only major non-local operation cost. Anyone can purchase a modular ecoCity Farm kit to fit the available space. Because the crops are built in a shelf structure, even the smallest farms can produce a high yield. The farm can be assembled from the shipment and readily available local components.
The system works anywhere in the world because it uses no chemical or synthetic compounds and produces no waste. An eco-lodge on the edge of a protected forest or a scuba resort on a small island could both use this system to lessen their impact, for example.
So far, the only downside seems to be the use of energy, which is the same as a conventional aquaculture system. However, the prototype ecoCity Farm in Nimbin, Australia uses a solar panel to heat the fish tanks and gets its energy for automatic pumps and rotation devices from the alternative energy grid.
Another possible objection could be the ethical implications of raising fish in tanks. My feeling is that a fish in non-toxic tank water is fairing better than a fish in toxic river water, but food ethics is a personal line that every eater must draw for him/herself.
(Photo courtesy of Rivendell Organics)