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Urban Agriculture: Can it Feed Our Cities?

Urban Agriculture: Can it Feed Our Cities?

by | Nov 1, 2017 | Feature, Issue 3, Stories

From rooftop gardens and indoor vertical farms to community plots and edible landscapes, urban agriculture is on the rise. As more of the world’s population resides in cities, city farming is touted as a sustainable solution. But are there enough rooftops to make it work?

New Jersey has been known since the late 19th century as the Garden State. But today its 12th largest city, Camden, is anything but lush and green. It is the country’s poorest city — an astonishing 42 percent of the population lives below the poverty line — and one of the country’s most dangerous. A recent Rolling Stone profile of the city began: “The first thing you notice about Camden, New Jersey, is that pretty much everyone you talk to has just gotten his or her ass kicked.”

And yet.

A small food economy is blossoming in Camden. AeroFarms, an indoor agriculture firm, plans to break ground as early as this year on a 78,000-square-foot vertical farm that would grow 12 stories of red-leaf lettuce, kale, bok choy and more.

Meanwhile, more than 100 of the city’s thousands of vacant lots have been transformed into community gardens. In 2009, at the dawn of enthusiasm for urban farming and during the last available year data were collected, gardeners at 44 sites harvested almost 31,000 pounds of vegetables. Had it not been an unusually wet and cold summer, it might have been more.

It’s all very inspiring: Whizz-bang technology that offers healthier food and much-needed jobs. Communities taking charge of their food destiny in a place that the almighty market has neglected. (Camden, population 77,000, has just one supermarket within its city limits.) But it’s not only struggling cities that see the promise of urban farming.

Urban agriculture — which by definition includes indoor farms, rooftop and backyard gardens, community plots and edible landscapes — is often hailed as a solution to daunting global challenges. It addresses climate change by allowing food to be grown close to home, rather than hauled thousands of miles. It could affect obesity and chronic disease by making healthy options more available. And urban farming could help feed a quickly growing world population, because many of the predicted 9 billion people on the planet (by 2050) are increasingly headed to cities.

SUSTAINABLE SOLUTION?

But can urban farming sustainably feed cities? A close look under the agri-hood suggests that it’s a lot more complicated than advertised.

For starters, let’s examine the history. The Industrial Revolution quickly and dramatically severed ties between consumers and the farmers who grew their food. Efficient train networks transported food more rapidly, from farther away, and more people moved away from rural areas to cities for work in factories. Since then, there have been regular waves of enthusiasm for urban gardening in the West, motivated by social reformers, who made a moral connection between the land and healthy living, or by the innate human desire for self-sufficiency.

To wit: One of the Salvation Army’s first initiatives in late 19th-century London was “farm colonies” designed to help city folks feed themselves. Beginning in the 20th century, Israel’s early Zionists created thousands of small urban farms. But the only examples of urban farming feeding substantial numbers of people occur when there is little other choice.

In Israel, urban farms soon gave way to rural kibbutzim (collectives based around agriculture). The United States saw Americans plant more than 5 million household plots during World War I and 20 million in World War II. Those 1940s victory gardens produced 9 million pounds of produce each year — what amounted to 44 percent of the U.S. harvest. (Read more about how people cope with food shortages during wartime in our story about rations.) But when the war ended, citizens largely abandoned their gardens and returned to the convenience of shopping at the supermarket.

World War II: Glass balls for forcing early cabbages are placed in position at a Salvation Army farming colony in Hadleigh, Essex, 1940. (Photo by Popperfoto/Getty Images)

HIGH-TECH FARMING

Proponents of urban farming say this time could be different. Besides the global challenges of climate change and population, there is wide consumer demand for locally grown food. Moreover, technology that makes urban farming more productive and more sustainable could tip the balance. The technologies include lightweight beds that can be stacked, efficient LED lights and hydroponics and aeroponics, by which plants grow without soil and fed a calculated diet of nutrients by water circulating beneath them.

“By some estimates, we will need 50 percent more food by 2050,” says David Rosenberg, CEO of AeroFarms. “We need transformational changes. Vertical farming does more with less.”

A decade ago, not even one of these so-called vertical farms existed. Today, there are dozens of them — one in Singapore, one in a former bomb shelter in London and one in Japan, built by researchers to provide safe food after the devastating Fukushima earthquake in 2011. That farm, formerly a semiconductor factory, now produces 10,000 heads of lettuce per day.

AeroFarms operates nine vertical farms. Its largest, in Newark, 90 miles northeast of Camden, produces 2 million pounds of leafy greens each year. The 70,000-square-foot complex is a poster child for futuristic farming. Inside, so-called grow tables are stacked 12 levels high and enveloped by a glow of pink LED light. (Plants, it turns out, require little from the yellow part of the light spectrum, which requires greater amounts of power to produce.)

Rosenberg sees AeroFarms less as an agricultural producer than as a data-science company, delving into the intersection of plant biology and engineering with the goal of controlling every aspect of growing and maximizing efficiency.

“We take data on plants and understand what makes them grow,” he explains. “You can’t do it this way in the field. There are too many unknowns.”

AeroFarms’ vertical gardens grow under energy-efficient LED lights and use up to 70 percent less water, compared with more traditional soil-based or horizontal farming. Its largest facility, in Newark, New Jersey, produces 2 million pounds of leafy greens each year, which don’t have to travel far to reach urban markets. Despite these efficiencies, critics of vertical farming say using electricity rather than renewable sunlight doesn’t add up for high-volume production. Photo courtesy Aerofarms.

RESOURCE CONSERVATION: PROS AND CONS

The biggest boon of vertical growing may be water conservation. Drive through California’s Salinas Valley, where the vast majority of America’s salad greens are grown, and you’ll see hundreds of sprinklers shooting great arcs of water across the fields. Some of that is used by the plants, but much is lost to evaporation and runoff.

In contrast, hydroponic and aeroponic systems give the plants only the water they need, and it is recirculated through the system. On average, indoor farms and greenhouses use at least 70 percent less water than traditionally farmed lettuce in California.

There are other benefits, too. The produce doesn’t have to travel — unlike the lettuces that journey as far as 2,800 miles if they are shipped from coast to coast. This all but eliminates the greenhouse-gas emissions associated with transport, though those are only a fraction of the total associated with producing food. (Read more about greenhouse gases tied to food waste in our feature on page 18.) And because they are fresher, the greens last longer in consumers’ refrigerators, which means less lettuce thrown away because it’s gone bad before it could be eaten.

No wonder vertical farms are catnip to technology investors looking for the next big disruptor. According to AgFunder, in 2016 funders poured $126 million into indoor agriculture- related startups (including things like lighting and software). But critics say that the environmental benefits of indoor farms don’t add up.

For one, to grow even a fraction of the fruits and vegetables needed to feed cities would take vast amounts of space. According to one analysis, it would require a 150-foot-by-150-foot, 37-story building to provide the vegetables for a city of just 15,000. This would cost $250 million to build and $7 million in electricity to run annually.

Indoor farms also fail to take advantage of a free and renewable source of energy: the sun. “If you’re not taking advantage of the sunlight, then the process will inherently involve excess energy consumption and carbon emissions,” says Stan Cox, a researcher at the Land Institute in Salinas, Kansas.

Substituting electricity for sunlight is costly. Using current technology, the equation just about works out for leafy greens, which are 90 to 95 percent water and don’t require as much light to grow. But do the math on denser fruits and vegetables or other crops — carrots, potatoes or wheat — and the amount of power required to grow them soars. According to Cox, it takes about 1,200 kilowatt-hours of electricity for each kilogram of edible matter (excluding the water stored inside). Or to put it another way: You need the same amount of electricity to grow one kilogram of tomatoes as you do to run your home refrigerator for an entire year.

“The claim of indoor farming is that we can spare the land by getting rid of industrial farming,” Cox says. “But of course, this vision uses more industrial inputs than anything done on the landscape.”

AeroFarms’ Rosenberg counters that lighting technology is getting ever more efficient. And though he concedes that indoor farming may look industrial, it addresses major challenges including the depletion of arable land, water pollution and conservation: “We don’t use soil. We don’t use pesticides. We use a fraction of the water that field farms do. We have a much softer footprint.”

In sunlit greenhouses on the outskirts of urban areas where land is more plentiful, BrightFarms raises greens and tomatoes using hydroponics — a system in which plants grow directly atop pools of fortified water. These and other crops like strawberries, cucumbers and peppers benefit from growing near where they’ll be consumed, a selling point for cities that have an urban-adjacent BrightFarms facility nearby. But hydroponic agriculture isn’t the right fit for all crops; apples, for instance, store well and travel more easily than delicate tomatoes, making traditional orchards a better option, for now. Photo by Chelsea Clough.

GREENHOUSE GROWING

An even softer footprint comes from other types of commercial urban and peri-urban farms that use greenhouses. Take BrightFarms, which operates three commercial greenhouses and sells directly to grocery stores in seven states and the District of Columbia.

BrightFarms uses hydroponics, which means that trays of greens grow atop vast ponds. But rather than place its farms in cities, where land is generally more limited (and much more expensive), it locates its greenhouses just outside of urban areas. With more space, it is not necessary to stack plants to turn a profit. The use of hydroponics also means that the farms can be, well, horizontal — and take advantage of (free) sunlight.

Today, the crops that make commercial sense for hydroponic farming are greens and tomatoes, says BrightFarms CEO Paul Lightfoot. Both crops travel long distances, unless you live on the West Coast. Both too are highly perishable and sell for a premium price. And, as anyone who has eaten a winter tomato knows, these crops benefit from being grown closer to home.

One day, Lightfoot hopes that BrightFarms will expand to other crops that meet the same criteria: strawberries, peppers and cucumbers. But there are limits to what he can produce. BrightFarms, he says, will never be able to compete on a crop like apples, which grow in many geographic areas, store well and travels easily. They will always be cheaper and more sustainably grown in the field.

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Hydroponics

A method of growing plants without soil, using mineral nutrient solutions in a water solvent. Nutrients may be delivered a variety of ways, including fish waste, duck manure or a fertilizer containing key macronutrients.

In a hydroponic set-up, plants get the nutrients they need through irrigation water. The process eliminates soil and increases yield. For this process to be successful, ventilation and temperature modulation are key. Solar panels provide renewable energy to power irrigation pumps and ventilation systems, and rainwater is captured in roof tanks for use as irrigation in dry periods. Water is constantly recirculated in a hydroponic system, wasting none. Illustration by Ellaphant in the Room.

CLOSING THE GAP

Commercial farms, of course, do not have to produce everything. Could community, rooftop and backyard gardens make up the difference? According to a 2016 report from the Johns Hopkins Center for a Livable Future, the answer is no. While a significant proportion of fresh produce needs could theoretically be met in some places, it would only work in those locations if urban farms are widely implemented and focus on intensive forms of production such as rooftop gardens.

To feed Cleveland, for example, 80 percent of every vacant lot (of which there are many), 62 percent of industrial and commercial rooftops, and 9 percent of every occupied residential lot would have to be put into food production. Those are daunting numbers before you even consider practical constraints such as property values, infrastructure limitations and zoning regulations.

Urban agriculture’s limits do not make it a failure. Community, rooftop and backyard gardens make significant impacts in the lives of the people who tend them, and give poor communities like Camden access to fresh, free food.

Dominic Vitiello, a professor of city planning and urban studies at the University of Pennsylvania who has studied urban farming in cities including Camden, concludes that in the United States, perhaps urban farming’s greatest potential is to effect “inside-out” community revitalization. Urban farming offers opportunities for social enterprise and supplemental income for low-income families. It also helps to build and sustain vital social networks that go unmeasured by traditional economic-development research.

In other words, urban farming may not feed a city like Camden. But its gardens can help rejuvenate the city and make it a worthy representative of the Garden State.

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Cutting Waste Across Cultures

Cutting Waste Across Cultures

by | Oct 31, 2017 | Feature, Issue 3, Stories

The United Nations has proposed a goal to cut global food waste in half by 2030. Liz Goodwin, a senior fellow and director of food loss and waste at the World Resources Institute (WRI), has taken that mandate to heart. Goodwin, of all people, would know what that entails. During her tenure as CEO of the U.K.-based Waste and Resources Action Programme, U.K. food waste fell by 21 percent. Now she seeks to take lessons learned from that effort and apply them to other countries that have very different challenges with regard to food waste.

The specific opportunities to prevent food waste vary from place to place, Goodwin explains, for reasons that are cultural, economic and tied to infrastructure.

In China, the world’s most populous nation, good hospitality would suggest that as much food remains on the table at the end of the meal as was there at the beginning. Otherwise, it sends the message that the host hasn’t provided enough to eat. However, Goodwin notes that it’s heartening to see that the Chinese government has been encouraging people not to waste food at banquets and events. Many Muslim countries have similar edicts that are in direct conflict with the goals of preventing food waste. Meanwhile, many modern industrialized societies such as Switzerland and Singapore impose unnecessarily cautious food expiration dates, which results in the disposal of perfectly edible food.

By contrast, poor countries have less waste in the home than in wealthy nations, Goodwin says. Leftovers don’t go bad in the fridge when hunger is an issue. Food scraps are more likely to be fed to animals or composted. But waste isn’t a non-issue. In developing nations there are gaping holes in the supply chain infrastructure through which large amounts of food are lost.

“With slow transport and unrefrigerated storage conditions, the food just doesn’t get through to the end user in time,” Goodwin says. “And then there are gluts of food, such as massive numbers of mangos that ripen at the same time, and no infrastructure in place to process it all.”

In the developed world, the biggest source of food waste is in private residences. It’s where 70 percent of food waste happens in the U.K., and there are a range of causes, including getting portion sizes wrong, not using leftovers and letting food expire or go bad before using it.

On the other hand, food waste is less of a problem in commercial or institutional settings. “Organizations can control what goes on within their operations,” explains Goodwin, referring to the large farms, processors, distributors, grocery stores, institutional kitchens and restaurants where food is flowing. Not only are these big players easier to work with, they can make big deliveries of salvageable food that could be diverted from the waste stream — or of food waste that can’t be eaten but which can be digested anaerobically and converted to energy and fertilizer.

The world’s two most populous nations, India and China, have both first-world and developing world conditions. “China and India have a mixture of developed-world problems and developing-world problems. Their populations are big, and they are producing a lot of food, so supply chain issues are really important.”

With such differences from country to country, Goodwin explains, the first thing to do when evaluating a nation’s food waste profile is to look at where the food waste is happening. Is it in restaurants, the household or at various points in the supply chain?

“Start measuring,” she says. “Because that will help to identify where their biggest issues lie.”

LIZ GOODWIN, SENIOR FELLOW AND DIRECTOR OF FOOD LOSS AND WASTE AT THE WORLD RESOURCES INSTITUTE (WRI)

From 2007 to 2016 she was CEO of Waste and Resources Action Program. During her tenure, recycling rates in the U.K. increased from 9 percent to 43 percent, and U.K. food waste was reduced by 21 percent. At WRI, her goal is to work with people and organizations around the world to cut global food waste in half by 2030, in line with UN sustainable development goals.

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The Hunt for Food Waste

The Hunt for Food Waste

by | Oct 31, 2017 | Feature, Issue 3, Stories

Not going to eat those carrots? Don’t throw them away. Once food reaches a landfill, its potential is lost. But unwanted food, captured before it’s tossed, can transform into energy, building materials — or even desirable food. Meet the new generation of hunters and gatherers.

Jake Milliner and Belinda Bonnen tend a towering vine of fresh malabar spinach at Joe’s Organics in Austin, Texas. Joe’s collects food waste from area restaurants and, with their composting partners, creates rich soil for their crops of baby greens.

Wherever there is food, there is food waste. Like water leaking from an aqueduct, food waste will find the gaps in the supply chain between field and plate, a journey filled with opportunities for loss.

A heartbreaking amount of produce rots in the field, unharvested. Some is culled for size, shape or another cosmetic factor. Even more food is thrown away or lost during cleaning, boxing, processing and distribution. It rots slowly in retail stores or commercial kitchens and in your fridge. Food is also tossed during meal preparation, at home or in restaurants or other commercial or institutional kitchens.

And then, far too often, the meal itself — or much of it — is thrown away. In the end, a third of the food we produce goes uneaten. Data from a new report issued by the Natural Resources Defense Council (NRDC) indicate that Americans throw out more 400 pounds of food per person per year. Sadly, in the shadow of this massive overproduction and loss of food, 10 percent of humanity still doesn’t have enough to eat.

But it’s not just about feeding the world: The environmental consequences are significant. The amount of cropland needed to produce the food that ends up as waste is roughly equivalent to the acreage of China and requires a fourth of the country’s irrigation water. Feeding people is the largest single contributor of greenhouse gases to the atmosphere of any human pursuit, and roughly 10 percent of greenhouse gases that humans release are in service of food that will not be eaten. When this wasted food rots in a landfill or is burned in an incinerator, the process releases even more greenhouse gases.

The holes in the food supply chain through which food slips away represent more than hunger and pollution. It’s wasted investment and fruitless effort that could have been channeled into something more useful. Entire cities could be built, or rebuilt, with the effort that goes into the food we throw away.

But there’s another side of the coin. The scale of this waste, and the problems it causes, have created opportunities. Wasted food is essentially money that’s being left on the table, available to whomever is crafty enough to grab it and put it to use. It has potential value as energy, soil fertility and calories — all of which can add up to dollars that can be earned from harvesting food from the waste stream, or intercepting food before it gets tossed.

Austin-based Joe’s Organic’s grows microgreens and produce with rich compost derived from their restaurant waste-collection program. Founder Joe Diffie stands with his fleet of compost carts.

Executive producer Anthony Bourdain takes a deep dive into this issue in “Wasted! The Story of Food Waste.”

Above, from top: uneaten restaurant meals contribute to the enormous amount of edible food discarded daily; byproducts from food preparation, such as this watermelon rind, can be composted or even pickled rather than chucked; food waste is a cause of greenhouse gases.

THE NEW HUNTERS AND GATHERERS

The highest good to which a piece of wasted food could aspire (if wasted food had aspirations) is to be rerouted to a hungry human mouth before being discarded. The next-best thing would be for it to be eaten by something else, like a chicken or a pig, or — in the case of food that can’t be routed to organisms with recognizable mouths — a bacteria. Today, most food waste diverted from landfills or incineration is digested by anaerobic bacteria to produce natural gas and fertilizer. Food scraps left over from food processing and retail food preparation are suited for this, as is the majority of household waste. The challenge is getting food out of the waste stream and sending it to a better place than the dump.

That best-case scenario, in which food is rescued from the edge of waste and routed to other human mouths, has been deeply explored in Europe in recent years, while the United States is playing catch-up. The players, increasingly, are for-profit waste hunters that are bringing high-tech solutions to the task of reducing food waste.

Sometimes that initiative comes from the (would-be) food wasters themselves. Campbell Soup Company has been an early corporate leader in reducing its share.

“Food that meets our rigorous safety standards is donated to local food banks in and around our manufacturing plants and distribution networks,” says Thomas Hushen, a Campbell spokesman. “In most cases, we partner with Feeding America and their network of food banks to make donations.”

While some corporations have been early and eager to embrace measures to curb food waste, other companies want to jump on the bandwagon but don’t know where to start.

Left: Malabar spinach stalk — the stalk and ugly leaves often get wasted, but they’re perfect for green juices. Right: Sorting sweet potatoes at Johnson’s Backyard Garden.

To see what kinds of value-add products are being made from uneaten food — from floor tiles made from coconut shells to plastic-like pellets made from blood meal, a byproduct of the meat industry — check out our gallery.

The French corporation Phenix (a 2017 Food+City Challenge Prize finalist) offers support services to businesses interested in diverting their food waste away from landfills and incinerators. The company has a solid track record in Europe, where the culture of food-waste recovery is more evolved than in the U.S.

But Sarah Lenoble, who heads Phenix’s push to set up shop in the States, is that rare French person who looks at America and sees a land of opportunity. The biggest reason food-waste recovery isn’t as advanced in the U.S., she says, is that the food-waste hunters are just getting started. “Even though it is happening, it’s not happening in a very structured way,” Lenoble says. To a veteran organization like Phenix, this youthful discombobulation amounts to low-hanging fruit.

Phenix uses a market-based approach that capitalizes on the fact that unused food has value even if it isn’t sold. American supermarkets, for example, must pay a waste disposal company to get rid of expired food, a fee they could forego if the food were collected by a charity. Last year, according to the NRDC, companies spent $1.3 billion disposing of food scraps, thanks largely to transport and disposal fees. Meanwhile, a surprisingly robust tax credit is available to companies that donate food: the Federal Enhanced Tax Deduction for Food Donation. It allows retailers to recover the higher retail price of their donations, even though they paid the lower wholesale price. Another law, passed in early 2017 with bipartisan support, amends the Good Samaritan Act to offer stronger liability protections to those who donate food. With laws like these in place, and companies eager to exploit them, Lenoble is optimistic about Phenix’s planned rollout into the U.S. food recovery space.

She notes that the U.S. charity scene is much stronger than in Europe, in part because in European governments often handle issues that in the States are left to charities. Even though it’s out to make a profit, Phenix won’t be competing with the food banks, churches and ugly-produce resellers. Instead, they’ll be partnering with them, providing logistical and strategic support to help these charities become more effective in their food-recovery efforts. A rising tide will lift all boats, Lenoble believes, and she likes what she sees. “We believe the market here is going in the right direction.”

In addition to its work with charities, Campbell recently doubled down on its corporate introspection, implementing its Food Loss and Waste Reporting Standard. It’s an effort to develop a benchmark of lost and wasted food, and to identify hotspots and opportunities for reduction and diversion. Like any other hunter, a food-waste hunter needs to know where the opportunities are. “We believe measurement improves management,” Hushen says.

Sarah Lenoble

After completing her MBA, Sarah worked in finance in the private sector before switching to microfinance and finally social business. Originally from France, Sarah has also lived and worked in Argentina and Italy. She is now based in Washington D.C., where she is launching the U.S. subsidiary of PHENIX, a French waste diversion social startup.

THE PERFECT FLAVOR OF IMPERFECT PRODUCE

The U.S. is so new at food recovery that one of the movement’s veteran waste hunters isn’t yet 30 years old. Fresh out of college in 2011, Claire Cummings started as a fellow at Bon Appétit Management Company (BAMCO), which runs more than 650 eateries on college and corporate campuses. A year later she became the company’s first food-waste specialist. She went on to create Imperfectly Delicious Produce (IDP), a BAMCO program that pursues ways to recover produce that usually goes to waste (mostly from farms and distributors) and serve it in the company’s many dining rooms.

Since it launched in 2014, IDP has recovered more than 3 million pounds of produce and served it as, for example, broccoli stem soup or cauliflower fritters made from small heads. While the figure sounds impressive, she admits it’s just a drop in the bucket.

“It’s a huge chunk of food that would have been wasted and was instead utilized in our operations, through purchasing and cooking it,” Cummings says. “But that is still such a small sliver of what actually is going to waste.”

She says many problems remain, but she believes they are solvable. “We’ve gone hunting for a lot of different products on farms. I’ve visited hundreds of farms at this point, large and small. I’ve seen all different types of operations: orchards, processing facilities, fields of produce,” she says. “There is so much product that is going to waste that could be rescued through purchasing if there were better systems for tackling those missed opportunities at harvest.”

WASTE ENERGY VERSUS WASTED ENERGY

Food contains energy, which powers life, makes the world go round — and happens to be worth money. The energy resides in the bonds between the carbon, oxygen, nitrogen and hydrogen atoms that make up the food molecules. When we eat, that energy is released into our bodies, where it fuels our daily escapades. Fed to animals, the energy transfers to other forms of edible potential energy, such as meat, milk and eggs, or some form of kinetic energy, such as chasing balls or pulling a plow.

Claire Cummings

Student activist turned garbage guru, Claire Cummings is the first-ever waste programs manager for Bon Appétit Management Company, the food service pioneer that operates more than 650 cafés in 33 states for universities, corporations and museums. Claire is one of Food Tank’s 30 Women Under 30 Changing Food, she’s a recipient of Saveur’s “Activist” Good Taste Award and her work has been featured in Bloomberg News, Sunset Magazine and The New York Times.

Keep up with the latest in food repurposing and follow Claire Cummings on Twitter @WasteAce.

But most food that isn’t eaten by humans is discarded, where, depending on the local trash disposal situation, it either gets buried or burned. Incineration releases carbon dioxide and other pollutants. And food in a landfill will break down anaerobically and release methane, which is even worse (about 18 percent of U.S. methane emissions comes from food scraps in landfills).

The best-case scenario is far from the most common, but it could be. The energy in that wasted food can be extracted as methane in an anaerobic digestor and captured. The resulting energy can be used to generate green electricity or heat houses.

Anaerobic digester operations are popping up wherever there is enough available food waste to make them feasible. Sewage treatment plants are the ideal places to build these operations because co-digesting allows the food-waste recovery process to piggyback on the existing infrastructure of the water-recovery process, rather than requiring a new facility.

Construction began in June 2017 on the Wasatch Resource Recovery Project (WRRP), Utah’s first anaerobic digester facility. A partnership between South Davis Sewer District in North Salt Lake City and the private Alpro Energy and Water, the WRRP is going up adjoining the county sewage treatment plant. Morgan Bowerman, sustainability manager for WRRP, is pleased with the arrangement.

“The South Davis Sewer District has been operating the most efficient wastewater treatment in the whole state for years,” Bowerman says. “The fact that we have these guys on board to run our digesters is huge. The other major advantage is that here in the West we are in a massive, 17-year drought. When we co-locate, we can use their wastewater, which is a huge boon to us and so much better for the environment.”

Step 1: Organic waste is separated into a designated container at a food business. Step 2: Waste is collected and delivered to Wasatch Resource Recovery facility. Step 3: Machines process the waste to remove contaminants or non-food. A. It goes into a grinder to be chopped into small pieces. B. Secondary (not potable) water is added to ground-up waste and mixed until it liquifies. C. The material passes through a screen where packaging or contaminants are washed free of remaining organic material, which is fed into the digester. Step 4: In the digester, waste is heated to aid growth of microbes, which break down organic matter without using oxygen. This produces biogas. Product 1: Biogas is captured and purified before being converted into biomethane (renewable natural gas), fed into nearby gas pipeline and sold as renewable “green” power. Product 2: The remaining product is a nutrient-rich, carbon-based fertilizer for crops.

Phase one of the project involves two 2.5-million-gallon digesters, to be operated, as mentioned, by the county sewer district. There will also be a “depackaging facility” to relieve expired edible goods of their containers. “It exponentially increases how much we can recycle. They can send it to us completely boxed and packaged, and we can do the depackaging and suddenly it’s viable,” Bowerman says.

They also have a F.O.G. (fats, oils and grease) receiving station and a depackaging station specifically for expired cans and bottles. “We can use the product inside to make energy and recycle the packaging.”

After the methane is recovered, what comes out is a nutrient-rich sludge, high in nitrogen, potassium, phosphate and organic matter — basically, fertilizer. Bowerman anticipates theirs will eventually be certified organic, once they determine its final form. Meanwhile, they’re also separating the ammonia and carbon gas from the methane for beneficial use. Wasatch plans to be operational in fall 2018.

Of the more than 1,000 sewage treatment plants in the U.S., about 216 are co-digesting food waste alongside sewage. That means 83 percent don’t yet have a food-waste digester, which amounts to a lot of money and energy being left on the table.

While pioneers like Wasatch are taking this plunge, the whole waste-to-energy industry is still coming of age. Groundbreaking advancements are frequent: Scientists at Cornell University have been playing with a process called hydrothermal liquefaction, which is a fancy way of saying “pressure-cook the food waste into oblivion.” It’s a process that recalls the way dinosaurs and their ecosystems were turned into oil under the ground. In the case of hydrothermal liquefaction, heat and pressure combine to turn food waste into an oily liquid that digests in days, rather than weeks, with more complete digestion and energy extraction.

Meanwhile, 97 percent of food waste is still getting away — for the moment anyway. But it’s only a matter of time before this low-hanging food waste will be plucked, because we can’t can afford not to.

“We wouldn’t take a barrel of oil and bury it,” Bowerman says. “And that is what we are doing with our food waste.”

COUNTERTOP COMBUSTION

The largest garbage disposal company in the world, Emerson, wants into the food-waste energy business. Any food industry player of a certain size that deals with large amounts of raw food can install Emerson’s subunit called Grind2Energy in a food disposal area. It includes a stainless steel work area, sink and a very powerful garbage disposal. Plumbing connects it to a special holding tank for the slurry, which features a sensor that notifies Grind2Energy when it’s time to be emptied. The free service saves the client in waste transport, disposal fees and kitchen labor.

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Edible Materials

Edible Materials

by | Oct 31, 2017 | Feature, Issue 3, Stories

Here’s some food for thought: The following products are derived from food system losses in agricultural and livestock production. These materials, currently used in buildings, apparel, consumer products and packaging, lead the way in replacing fossil-fuel derivatives and other strained natural resources with rapidly renewable food waste.

SORGHUM SURFACING The striking patterns of TorZo’s Tiikeri™ line come from post-harvest sorghum stalks. Acrylic resin combines with 50 percent agro-waste content to form a biocomposite material. Sorghum is a rapidly renewable crop grown worldwide, with many uses in food, alcoholic beverages, fodder, fuel and, of course, building materials. The panels are available in a variety of colors and are suitable for interior surfaces and furniture.

RICE HUSK CONCRETE Concrete is the most commonly used building material in the world, and it exerts enormous demand on natural resources. The production of Portland Cement, a critical ingredient in concrete, generates 5 percent of all CO₂ emissions. One agro-waste product that can be used as a partial substitute for cement is rice husk ash. Unburnt rice husk is also a promising aggregate in lightweight, insulative concrete.

PEANUT SHELL BOARD Another shell-based material used in buildings is Peanut Shell Board from Kokoboard, an alternative particleboard that flaunts its origins. The Thailand-based manufacturer purchases unwanted shells from local farmers and presses them into use. They also produce boards from post-harvest rice and coconut agro-waste. The boards, which are suitable for interior surfaces and furniture, are free of formaldehyde.

BIO-TREATED WOOD Some agro-waste materials are harder to spot. Kebony has the rich appearance and durability of tropical hardwood, but it’s manufactured through a patented process that uses bio-based liquid derived from byproducts of the sugarcane industry. This nontoxic process permanently enhances the cell structure of sustainably grown softwoods, producing an attractive alternative to lumber from old-growth forests.

FISH SKIN LEATHER Atlantic Leather uses animal-based byproducts of the fishing industry to produce an exotic leather alternative. The Icelandic tannery utilizes the skins of four species — salmon, cod, wolffish and perch — and recently introduced MIMOSA, a line of vegetable-tanned salmon leather processed with Mimosa bark.

CHOCOLATE PAPER Don’t be deceived by the somewhat unsavory term agro-waste. James Cropper, maker of luxury papers, offers Cocoa, which replaces 10 percent virgin fiber with cocoa shell powder. The line identifies a unique and higher use for this abundant byproduct of the chocolate industry. It was developed through a packaging collaboration with Barry Callebaut, maker of fine chocolates.

MUSHROOM MATERIALS Ecovative manufactures foam and wood substitutes from mushroom mycelium, which binds together agro-waste fibers such as flax, canola and hemp for a win-win. The material is molded or pressed into a variety of shapes and densities as packaging, acoustic and thermal insulation, and board material.

COCONUT SHELL TILES Indulge your fantasies of tropical escape with Coco Tiles from Kirei, made from coconut shells collected after harvest. The shells are an agricultural byproduct (agro-waste) otherwise subjected to open burning, a common practice that contributes to atmospheric pollution. Open burning is used in developing areas to quickly eliminate post-harvest waste and pests, and to prepare fields for planting. Converting coconut shells into building materials is a great example of transforming food-related waste into a higher-value use.

BLOODMEAL BIOPLASTIC Though you wouldn’t guess from its smooth, honey-colored appearance, Novatein from Aduro Biopolymers is made from blood meal, a byproduct of the meat industry. The bioplastic pellets have comparable capabilities to petroleum-based plastic and can be molded into a wide variety of products with different attributes, from pots and cutlery to softspun mats.

BARK CLOTH Harvested from the bark of the Mutuba fig tree, Bark Cloth is a non-woven textile with 600-year-old roots in Uganda. The trees are debarked annually and regenerate quickly, which qualifies the textile as a rapidly renewable material. Rapidly renewable content is defined by a short (less than 10-year) life or regeneration cycle. Bark cloth can be used for interior surfaces, furniture and apparel.

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