Final Report: Sustainable aquaponic systems to end hunger and homelessness and provide employment in the inner cities of AmericaEPA Grant Number: SU836128
Title: Sustainable aquaponic systems to end hunger and homelessness and provide employment in the inner cities of America
Investigators: VanGinkel, Steven
Institution: Georgia Institute of Technology
EPA Project Officer: Page, Angela
Project Period: November 1, 2015 through October 31, 2016
Project Amount: $15,000
RFA: P3 Awards: A National Student Design Competition for Sustainability Focusing on People, Prosperity and the Planet (2015) RFA Text | Recipients Lists
Research Category: P3 Awards , Pollution Prevention/Sustainable Development , Sustainability , P3 Challenge Area - Built Environment
The topic of interest, aquaponics, is the combination of two well-developed agriculture techniques, aquaculture and hydroponics. In brief, aquaculture is the controlled cultivation of fish while hydroponics is a method of growing vegetables in nutrient rich solutions, with the use of inert substrates or open water instead of soil. Like the term, aquaponics is a combination of these two techniques, with the goal of achieving more for less by designing the two systems to benefit one another. Aquaponics can be more productive than traditional agriculture because seedlings are grown at super high densities before being put into hydroponics tanks where some vegetables can grow to maturity in just a few weeks. The produce never suffers water stress, always has adequate nutrients, and the roots are well aerated. The greatest advantage in an aquaponics system is the reduction in resources (water, energy, nutrients, space, labor) needed to yield the same products. Fish waste laden water is used to fertilize vegetables which clean the water for the fish in a closed loop recirculating system, allowing the same amount of fish to be grown in tanks a fraction of the size of pond production while vegetables are grown without synthetic fertilizers or pesticides; all with reduced water consumption. In separated systems, such as hydroponic or aquaculture systems, water has to be periodically wasted to prevent the buildup of nutrient salts and ammonia, respectively. In hydroponic systems where the nutrients are supplied as inorganic fertilizers, the water gets saltier over time and needs to be periodically purged. However, in aquaponics systems where the fertilizer is supplied in organic form in the fish feed, the salinity does not increase as much. The advantages of aquaponics have been noticed from hobbyists to commercial farmers, giving momentum to the field and eventually leading to different techniques. We think we can make aquaponics more sustainable by incorporating it into urban centers that have ready access to waste water, nutrient, and energy sources to provide the inputs to the aquaponics system. In our CEE 4699 - “Urban Algae-Fueled Aquaponics: the food, energy, water nexus in Atlanta, GA” we are comparing the food, energy and water (FEW) systems of California-grown produce to growing the same produce locally. Our hypothesis is that we can educate and train a workforce to grow vegetables using more resilient and sustainable, high-tech and high areal productivity urban aquaponic systems, due to synergistic benefits from reducing energy, nutrient and water use, rather than shipping these vegetables from California. Our prototype is called Sustainable Aquaponic Systems (SAS). We have compared several designs from commercialscale growers and believe we have found a design that has the lowest capital and operating costs while having the same amount of vegetable production. In the Phase I, we performed a detailed economic analysis of the capital and operating costs and the revenues. We think we are in an even better position to make SAS financially sustainable. We plan on doing energy, water, and material mass balances on SAS and make SAS netzero in these respects by using renewable solar energy technologies, rainwater harvesting, and using waste nutrient resources to produce algal meal as the fish feed. While making SAS socially, environmentally, and financially sustainable such that communities in food deserts can have access to healthy food, we plan on educating and training K-University students, military veterans, and community members to construct and operate the system. We have acquired the greenhouse to house SAS and will soon begin workshops while continuing to invite all interested parties to help with the design and construction. It is our hope that the K-University students get educated in sustainable urban farming practices and will continue to bring good food into their communities. We are also partnering with Rising Above 3 Poverty (RAP) Farms, a group of retired military veterans, who are developing RAP Academy to train unemployed and homeless veterans to construct and operate aquaponic systems. Since the Phase I proposal was written, we have received a lot of input from faculty and students campus-wide. Our EPA P3 project is now part of Georgia Tech’s Serve-Learn-Sustain Initiative which is part of our 10 year Quality Enhancement Plan and will also become a Vertically Integrated Project (VIP) where student teams can follow SAS over multiple semesters for credit. Dr. Van Ginkel has also become part of Atlanta’s Urban Farming Taskforce members and is working with the Mayor’s office to see how best to use vacant land and warehouses to implement SAS.
Our results include understanding the U.S. FEW system and what vegetables to target for local production in order to increase overall FEW system efficiency and resiliency. We have also refined our aquaponic design and arrived on a system that has reduced capital and operating costs while having the same amount of vegetable production compared to previous designs. We have also received a lot of input from Georgia Tech faculty and students, Atlanta’s Urban Farming Taskforce, and Atlanta Public Schools to increase the efficiency of SAS. We have had two setbacks as well. Our first two spots to implement SAS have been changed and we are now working with Atlanta Public Schools to house SAS at one of two schools. We have acquired a greenhouse to house SAS and are ready to implement SAS.
SAS is in a good position to move forward. We have developed the expertise, knowledge, and team to really make a difference – helping children living in food desert communities and employing, feeding, and housing homeless veterans.