Demand for food is growing with the swelling world population, while natural fish populations diminish and farmland disappears under the tread of development, making it necessary to adjust the way we grow our food. Milwaukee is the headquarters for several visionaries in today’s urban agricultural movement who are using a system of cultivation called aquaponics to raise fish and grow vegetables.
Step over the threshold of Sweet Water Organics in Bay View, and a massive manufacturing plant that once produced heavy machinery for Harnischfeger Industries reveals its new purpose as an experimental commercial urban fish and vegetable farm.
“If the Sweet Water experiment can prove commercially viable,” says James Godsil, who co-owns the business with Josh Fraundorf and Steve Lindner, “that would be cause for great hope for our Great Lakes Heartland cities of 10,000 under-used or unused vintage factory buildings.”
Aquaponics is an efficient, compact food production method that combines fish farming (aquaculture) with hydroponics, the cultivation of plants without soil, in one integrated system. In many ways, it mimics Earth’s natural ecosystems. Fish digest food and excrete waste in the water they’re living in. A beneficial form of bacteria converts the fish waste to nutrients used by plants growing in the same water. When they consume these nutrients, the plants purify the water, keeping the water healthy enough for the fish to live in. In this mini-ecosystem, both fish and plants thrive.
What makes aquaponics perfect for the empty industrial buildings littering America’s old manufacturing cities is that soil isn’t required. Aquaponics systems can be set up virtually anywhere fresh food is needed. In most climates, a greenhouse (or basement, garage or abandoned warehouse) is necessary to protect the delicate system from environmental factors like fluctuating temperatures, wind, snow, rain and insects. Since the dawn of agriculture, farmers have been at the mercy of the elements. Now the technology to control the environment within which their crops are being grown is a reality.
When Godsil, Fraundorf and Lindner began construction on their aquaponics system last February, they modeled it after MacArthur genius-grant-winner Will Allen’s pioneering three-tiered, biointensive fish-vegetable garden at Growing Power on Silver Spring Drive. The owners applied their skills—Lindner is a home builder and property owner (including the building Sweet Water Organics leases), and Godsil and Fraundorf run a roofing company—to the demolition and renovation needed to transform the 11,000 square feet of space into a suitable urban farm. They repaired the roof and replaced the grimy clerestory glass near the 50-foot ceiling with clear polycarbonate insulating windows. They cut 4 feet below the concrete floor to construct four parallel channels that will each hold an 11,000-gallon water raceway for the fish. Above the raceways, they built an impressive lumber structure to hold the plant beds.
When Sweet Water Organics was ready for fish, they looked to Fred Binkowski, a senior scientist at Great Lakes WATER Institute, a University of Wisconsin System research facility on the Milwaukee harbor. He coordinates outreach programs through WATER’s Aquaculture and Fisheries Research Center and the UW Sea Grant Advisory Services Program, and offered his research results from raising yellow perch in a commercially scaled recirculating aquaculture system (RAS). On July 8, 1,200 small yellow perch left the institute for their new home at Sweet Water. On July 22, another 1,200 perch were added, as well as 33,000 tilapia fingerlings from AmeriCulture Inc. in New Mexico.
As Jesse Hull, Sweet Water Organics’ lead horticulturist, explains it, water from each raceway is pumped up to two stacks of gravel. The water flows across the gravel, where bacteria breaks down the toxic ammonia from fish waste and converts it to nitrite and then to nitrogen, a key nutrient for plant development. In the middle bed, watercress is grown as a secondary means of water filtration. In the top bed, the water fertilizes hundreds of green plants, such as basil and lettuce, thriving beneath water-cooled grow lights. Finally, the filtered water flows from the growing beds back into the fish tanks. The “outside” inputs include oxygen from an aeration system, commercial fish food and swimming pool heaters that warm the water to 70 degrees for the perch and 85 degrees for the tilapia.
The nutrient-rich water of the fish tanks can support dense plant spacing, allowing urban growers like Sweet Water Organics to produce a substantial plant yield using a fraction of the water, machinery and labor required to cultivate crops on an open field. Because herbicides and pesticides aren’t needed in the controlled setting of an aquaponics system, consumers can enjoy their fish and vegetables knowing they haven’t been exposed to harmful chemicals.
Godsil says Sweet Water Organics will derive income from the sale of its fish, greens, cereal grains such as wheat grass, worms, worm castings and compost. They also hope to expand to include tours, training programs and installation of aquaculture systems. The owners plan to expand their operation in the coming months by adding three more fish tanks. Dec. 23 saw Sweet Water Organics’ first fish auction, and the lucky buyers will be picking up their newly purchased perch in February, when the fish are big enough to harvest.
Because Milwaukee is the headquarters for several visionaries in today’s urban agricultural movement, we, the residents, get to reap the rewards. Local urban agriculture, specifically aquaponics, reduces the use of fossil fuels for food production and transport; provides jobs for a ready workforce; produces fresh foods for underserved populations; and finds new uses for old buildings—preserving the memory of the heavy industry that Milwaukee was built on, and starting a new legacy on which to build its future.
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Care should be taken when asserting that consumers will not be exposed to harmful chemicals. The use of PVC pipe can lead to exposure to dangerous organotin compounds.
As Tom Watson has written in the Seattle Times: "All types of PVC products now face increased scrutiny, which means that consumer concerns about health and the environment are being taken seriously. And that's really better living." (Originally published Saturday, November 15, 2008 at 12:00 AM)
It should be noted that PVC pipe does not meet local building code for supplying drinking water it can only be used for waste water. Should we not be concerned about eating food produced in engineered systems using PVC?
Todd, it's one thing to try to create something with a vision for "greening the cities" like Sweet Water is trying to do, and it's entirely another for you to criticize them with hypothetical concerns about PVC pipes.
Where's your sense of the pioneering spirit?
If you are concerned about PVC exposure, then I suggest you avoid food wrappings, automotive upholsery, shower curtains, and urban drinking water that's traveled through PVC drains before being treated.
Yes there is scientific evidence that excessive PVC in our environment (among many other chemicals) is a potential endocrine disrupter, but your argument belongs in a wider consideration of chemicals, not a cheap shot at these guys who are trying hard to make something new work for our cities.
Suggest to sit this discussion out in your yurt.
PVC Phobic Todd is literally lurking beneath the bridge of every Sweet Water press event. I have written the world's aquaculture and aquaponics finest researchers and practitioners and cannot find anyone to support Todd's anxieties. I have asked Tom to spend $500 to set up a system using whatever his choice piping would be and then call in outside scientists to compare the health of our fish and plants with those his test station produced and he runs away. Oh well. :)
Todd, it's one thing to try to create something with a vision for "greening the cities" like Sweet Water is trying to do, and it's entirely another for you to criticize them with hypothetical concerns about PVC pipes. I respectfully disagree with your tone.
Where's your sense of the pioneering spirit?
If you are concerned about PVC exposure, then I suggest you avoid food wrappings, automotive upholsery, shower curtains, and urban drinking water that's traveled through PVC drain pipes before being re-treated.
Yes, there is scientific evidence that excessive PVC in our environment (among many other chemicals) can be a potential endocrine disrupter, but your argument belongs in a wider consideration of environmental chemicals in general, not a cheap shot at these guys who are trying hard to make something new work for our cities. PVC pipe is stiff and relatively intert chemically as is has much less of the plasticizers that make PVC flexible - these are the primary concerns for PVC in the medical industry that I work in.
I did not realize that you may have a competitive system, if you do it would be fair to disclose that.
KISS! Keep It Simple Stupid!
The re-circulating water in the Sweet Water Organic system is not for you or any human being to drink as potable water. Do you drink water from your toilet? Do you drink water from your swimming pool after your children been there? Do you drink water from the Lake where you go fishing? Do you drink water from the river or ditch nearest where you live? I THINK NOT.
Again, the water in the system is not for human consumption.
Cheers from the bayou of Ponchatoula, Louisiana!
Vinny
What is up with the illustration used for this article! I was sure that this article would be condemning aquaponics as unsanitary or something. Beach balls with band aids, oil slicks and hillbillies shoveling fish. I would not consider the illustration to be flattering to the aquaponics indstry at all, quite the contrary, if my business had been depicted in such a way I would probably be offended. With that said the article is very nice and I'm sure the artist did not mean it in a derogatory fashion. I don't know maybe I just don't get it...
GREAT IDEA, GREAT
great
Godsil's comments are unfortunate and not worth responding to.
Steve, I've been an advocate for aquaponics for close to 30 years. my only concern is that it produce an end product that is safe. Vinyl based plastics have been a concern for aquaponic pioneers for a long time. Another option, that I had strongly suggested to Sweet Water while they were developing their plans was HDPE pipe. This product is comparable in cost yet does not leach organotin compounds into water. It must be remembered that in an aquaponic system the water is recycled through the system. The dangerous organotin compounds can then bio-accumulate in both the fish and the vegetables. On small scale systems this may not be of concern, however when scaled up with the end product sold to the public it would seem that there should be some concern.
There is a clear record of those discussions on the Sweet Water discussion board with multiple references to the dangers of PVC from sources as diverse as the U.S. EPA, Canadian government, univerties across the country and many other sources. All of the references come from material that was published and has been subject to peer review.
It remains unclear why Sweet Water opted for PVC over HDPE. All I'm suggesting is that this may not have been the best choice if the primary concern is the safety of the food sold to the consumer. I'm not quite sure why we should place a value on a "pioneering spirit" if that spirit fails to value the people who will consume their product. We generally do not allow the ends to justify the means. And one has to wonder what ends are we seeking? Afterall the main concern should be for the consumer.
Todd,
Thanks for your comments - it is clear you have some kind of ax to grind with Sweetwater. From your posts, you are involved with aquaponics for 30 years and made recommendations to Sweetwater (formally or informally) during earlier development.
I can't strongly support or refute your technical positions on PVC, HDPE, etc. - but... my sense is that somewhere your advocacy for safety seems to cross a line towards something personal. Otherwise why keep sounding the alarm? PVC pipe is in our drinking water drains which carry it to the treatment plant and back to our faucets.
I think it would be fair to all reading these posts for you to disclose the exact nature of your business, be it industry consultant, or provider of a competitive system, qualifications, etc. thanks
Steve,
You ask "why keep sounding the alarm"? And you assume that I have an axe to grind. Sorry, no axe here. If you don't see why one should be concerned there's not much I can say. My only concern is that the public have access to safe food. Please note that I entered this forum with the following:"Care should be taken when asserting that consumers will not be exposed to harmful chemicals." Hardly alarmist rhetoric. I was simply referring to a statement made in the original article.
By the way, would you make the same assumption about the concern for BPA?
The only connection I have with Sweet Water was as a very informal participant in early discussions. I became involved because of my long time interest and a sincere hope that a safe system would be developed on a large scale here in Milwaukee. The one thing I insisted on when I was asked to participate was that all of the communication between me and Sweet Water be public and open to criticism.(Should you or anyone want to read those discussions they are on the google group for Urban Aquaculture and can be found here http://bit.ly/9gTq5G)
In anycase, this discussion should hardly be about me, unless one is attempting to divert attention from the key point, which I say again is: Care should be taken when asserting that consumers will not be exposed to harmful chemicals.
BTW Steve, just so there is no confusion, PVC pipe does not carry water to our faucets in Milwaukee, only away from it. That is if the plumbing meets code.
Todd,
Short question: do you have any stake or position in any business that offers another aquaponic system or alternative to Sweetwater's?
Your repeated criticisms should be viewed within the context of your business interests. That's central, not a distraction.
Disclosure is appropriate in critical public forums and it is a common ethical practice in journalism to disclose one's interests where they apply.
My own: co-founding a specialized wastewater treatment technology company that has nothing to do with aquaponics, only general interest in the technlogy. Current work with plastics in the medical industry.
Please honor this simple request for disclosure, thanks. I will be glad to let you have the last word. All the best.
Steve,
Fair question.
Answer: absolutely none whatsoever.
I am simply hoping to encourage safe aquaponics development as a potential consumer of fresh fish and organic vegetables.
My profession is a designer and maker of furniture.
Steve,
If you are interested you may review some of the links I've collected here http://delicious.com/twaukee/pvc (To tell you the truth, I'm not sure if you have to sign up for delicious or not to access this.) You may also add "organotin" to the search string and find more info I believe.