Toolkit for Urban Regenerative Environments

Editor's Notes

1. Hello, my name is EleniKatrini.Through my thesis I have studied different systems of of urban agriculture, water management and treatment, as well as energy production from waste in order to create a toolkit for urban regenerative environments.
2. Today I am going to talk to you about the motivation of the study, present you some of the case studies I have studied and incorporated in the toolkit, and finally I will demonstrate how the toolkit works through an application in a neighborhood in Philadelphia
3. So, why did I want to study this kind of infrastructures? Our cities are built dependent on centralized systems of water and waste management, food and energy production. That practice may have been efficient for quite some time, but as our cities expand with immense speed and population increases, severe issues of food access, waste accumulation, floods, water contamination and increased energy demand are starting to show the inefficiency of those systems.We spend 10.25 quadrilllionBtus just for the production and distribution of our food and 14% of that is consumed in transportation. Probably the food you just ate travelled for 1500 miles, which is equal to the distance between Denver and Philly. We produce food far away from the cities, disconnecting the actual demand from the supply. And after all that energy consumed to produce and transport food, there are more than 23 million people who live in low-income neighborhoods that are more than a mile away from a supermarket with fresh produce, the so called food deserts.
4. The disconnection between the food production and the actual demand leads to increased production of food waste. It is estimated that in US almost 1/3 of the food produced is thrown away before it even gets eaten. Each one of us produces about 1 pound of waste every day, making food waste the second largest source of waste to end up to our landfills. Speaking of which, they keep becoming less and less, because, who wants a landfill next to him? That means we have to load again our food waste and sent it somewhere far away to be treated. After the closure of Freshkills in Staten Island, NY is sending all her waste to be treated in Pennsylvania!
5. The way we build and expand our cities also affects the hydrological cycle. The increased impervious surfaces in a dense urban environment can lead up to 60% of the precipitation turn into runoff. That leads to large flood events, which keep increasing. Only in 2004 there were more than 80 flood events in the US. The aftermath of those floods is the overflow of our sewer systems, which in the case of approximately 772 cities in the US which have combined sewer systems can lead to the contamination of our watershed.
6. Finally, something that is really well known in this workplace is that we are energy inefficient. The building sector consumes 42% of the total energy we produce. In order to cover those demands we produce electricity mostly by burning coal or natural gas, leading to enormous amounts of Greenhouse Gases, and we finally throw away heat and use only a third of the initial energy.
7. After looking at all these, I couldn’t help it but wonder if addressing food, water, waste and energy locally yields in urban regenerative environments. And if it does, how could designers and people in the building industry be informed about those decentralized systems.­­­
8. The process of my work was to gather information through literature and investigate several mostly ongoing case studies for food production, stormwater management, wastewater treatment and energy from waste systems in urban environments. Afterwards, I filed the case studies focusing on the systems dimensions and quantitative benefits in order to create the Toolkit for Urban Regenerative Environments. Finally I used the toolkit in an area in Philadelphia as a proof of concept.
9. The following case studies are filed based on the system, their location in the urban context and their scale. In each case study you will find these same keys that will help you understand the type of the systemSo what are the possibilities? What can we do?
10. Food can be grown traditionally on the ground, using conventional methods of gardening. Here we see, the Added Value farm which was set up in an old baseball field in Brooklyn. It started as an initiative of the Red Hook Community in order to create educational opportunities for the young people. Currently they provide 115 job opportunities, they produce 12 tons of fruits and vegetables each year, and they distribute it through a farmer’s market on site, their CSA program and six local restaurants.
11. Moreover, the same geoponic system can be used along with a layer of root barrier and drainage mats in order to grow food on rooftops too. This is one of the biggest rooftop farms, Brooklyn Grange on top of an old warehouse in Queens, which is a little bit less than an acre. They produce 7 tons of fruits and vegetables and they are supplying it to restaurants and markets within 5 miles radius. Even though the building was old, they managed to create their green roof with a special lightweight soil from compost and porous stones that is 25% lighter than normal topsoil.
12. Another good idea is to grow fruits and vegetables on top of restaurants or grocery stores. In the case of restaurants the fresh produce never sees the refrigerator; it goes straight from roof to table. Such an example is the rooftop of the Bell Book and Candle restaurant in NY. Within only 1500 square feet the chef has installed 60 aeroponic towers which are 6 feet tall and can carry 28 plants each. In that way they are able to cover 60% of the restaurant’s needs. Aeroponic towers are actually a version of a hydroponic system. Which means that the growing medium is not soil, but water. Hydroponic system can use as less as 10% of the water needed for typical gardening and can yield up to 100 times more.
13. There are not only vertical but also in horizontal hydroponic systems such as that of the Gotham Greens farm. They are using hydroponic trays in a 12,000 square feet greenhouse which provides a totally controlled environment so that they are growing greens year round. Due to the increased energy demand they have installed a 56 kW PV array on the roof which provides a good amount of their energy demand.
14. There are people who are trying to achieve vertical farming and growing great quantities of food in large facilities. Here is a system from Plantlab in Netherlands.Theyuse hydroponic trays, LED technology and a totally controlled system. Computers capture over 160,000 reports per second to determine the conditions of the environment and the plants. Even though I am not keen in food to be grown without natural lighting, the robotic technology of the system’s harvesting and maintaining the plants can be combined with daylight for very great yields.
15. Moving on to stormwater, the most important practice is to reduce it by minimizing the impervious surfaces. As this is not always possible in urban environments, stormwater can be managed by points of infiltration such as parking lot bio-swales or sidewalk stormwater planters. In that way water is retained and used to recharge our aquifers. Portland is known for its stormwater practices. Here we see a system of four sidewalk planters that manage to infiltrate water from a 7,500 sqft area in a rate of 4 in per hour.
16. Rainwater can also be harvested to be reused with slight treatment for toilet flushing and landscape irrigation. In the case of StataCennter in MIT, because of their underground tunnels it was impossible to drain the 7 acres roof of the center, hence this bioswale was created which can manage a 100-year flood event, cleans the water with sand filtration and UV sterilization and uses it for toilet flushing and irrigation.
17. However harvesting rainwater for non-potable uses is not that important as using it to recharge our aquifers. In order to satisfy our demands for non-potable water, wastewater treatment facilities have developed a lot, and can produce water of really high quality. For example the living machine in Omega Center can clean 52,000 gallons of wastewater per day to drinkable levels using natural processes. However, what they do is that they treat the water recharge the aquifer and then draw water with wells to cover their water needs, closing like this the natural water loop. Water from a living machine can also be used directly for non potable uses.
18. Another way of treating wastewater is through chemical procedures, such as that of a Membrane Bioreactor, which is used in both OHSU Center in Portland and in Dockside Green. This system can treat large amounts of wastewater; in the case of Dockside green it has a capacity of 100,000 gallons per day. The water again can be used for toilet flushing, irrigation as well as for HVAC demands, such as cooling towers. A really important point in wastewater treatment and reuse is the education of the residents, in order to avoid throwing chemicals or pharmaceutical products down the drain that cannot be treated. Proper signage and hand out information should be given to the residents, just like in the case of Oregon Health and Science University Center
19. Sewage can also be used for energy production through anaerobic digesters. For example in the case of Hammarby Neighborhood, the wastewater treatment plant which as you can see is next to the residential areas, has installed anaerobic digester which can treat up to 600,000 tons of sewage annually mixed with food waste and fats in order to produce more than 200,000MMBtusof upgraded gas. A pipeline takes the biogas to a bus depot to be used in buses as fuel. Additionally it is supplied to 11 gas filling stations.
20. It must be noted that the yield per tonne of waste can vary significantly between 20-800 m3 of biogas based on the waste quality and the digester design. Food waste is a more efficient source of waste in order to produce biogas, compared to manure and sewage. In the case of The Plant in Chicago, which is a project with a holistic approach to food production, they are planning to install an anaerobic digester on their 3 acre site. The project which is focused on reusing an old meatpacking factory to house food production and processing businesses. The anaerobic digester is going to treat annually 5,000 tons of organic waste from the building’s and the neighboring businesses in the first phase.From the process press-cake for composting and liquid soil amendment for fertilizer are produced. The generated heat will be used in the absorption chiller and in the brewery they will have in the building.
21. However, in order to proceed in such design and infrastructure actions such as installing a digester or a wastewater treatment facility within an urban area, we have to be more forward thinking and try to find ways of avoiding a Not In My Backyard situation. Plants cannot look like this anymore, but something more like this. This is an example in Copenhagen, a waste incinerator that treats 550,000 tons of waste and alsouses its roof as a ski slope. It is being built right now and will be delivered by 2015. We can see that plants do not have to be ugly and far away from the city, but can be beautiful and maybe have social impact to the community
22. So how do all this come together? The idea of the toolkit is to present these different systems through current case studies and practices. Due to the ongoing technology advance the intent is not to showcase best practices but present current practices and make them easy to understand. The toolkit is meant to help incorporate such systems during the preliminary study. To aid this, spatial demands along with quantitative benefits of each case study are presented. Each card provides a plan of the system which can be introduced as a stamp on the potential development plan.
23. As a proof of concept of the toolkit a design exercise was developed in Philadelphia. The selected neighborhood is located in the general area of Northern Liberties and even though it is close to downtown it is considered a food desert. It has 2171 residents out of which 100% have low access to a grocery store or a supermarket. Below you can see their annual needs in fresh produce, the amount of waste they produce and the energy demands
24. From the available case studies of the toolkit, the ones that matched the sizing of the area and the available spaces of action were selected. And here we can also see the stamps of those case studies.
25. From the available case studies of the toolkit, the ones that matched the sizing of the area and the available spaces of action were selected. And here we can also see the stamps of those case studies.
26. From the available case studies of the toolkit, the ones that matched the sizing of the area and the available spaces of action were selected. And here we can also see the stamps of those case studies.
27. For food production, commercial and industrial rooftops of the area were identified
28. I used 62% of these rooftops for food production which adds up to an area of 8.5 acres. Firstly the large rooftops were selected, where the greenhouse from Gotham Greens Case study could be implemented because it has the maximum yield. There were 6 roofs were that was possible to be done. For the rest, green roofs with growing beds of the Brooklyn Grange case study are being used. The above design actions, lead to an annual fresh produce of 296.7 tons.
29. Afterwards the vacant lots of the area were identified, and I used 80% of their area for food production.
30. The system applied here is from the Added Value Farm. Based on this design action 62.4 tons can be added to the annual fresh produce. In the neighborhood there is a great undeveloped area which has the potential to be used for a park with food production.
31. Here we can see a view of the Fresh park (before and after)
32. As far as wastewater is concerned a Membrane Bioreactor as the one of Dockside Green is selected, as it can meet the capacity of the neighborhood. A pond with crayfish can be added for further purification and algae removal.
33. The neighborhood will accommodate also an anaerobic digester which will treat 5,000 tons of food waste per year. That adds up to the food waste of up to 12 neighborhoods. The digester is placed in a park and includes an informational center about how waste is digested and produces methane gas. The tank that captures methane can look like a balloon filled with air in order to make it attractive to the neighborhood.
34. This is a street view of before and after of the biogas tank
35. Based on the above design actions, food can be produced on site to satisfy 50% of the neighborhood’s needs. That means that the daily fruits and vegetables’ needs of 1085 residents can be addressed.100% of the wastewater is treated on site. The reclaimed water is used for green roof and landscape irrigation as well as toilet flushing.The neighborhood will host the anaerobic digester which will treat the food waste from up to 12 neighborhoods of the same size.The biogas produced can satisfy 7% of the neighborhood’s residential gas demand.Finally, through this process it was realized that stormwater calculations are more complicated for such a large area and there is a limitation of the toolkit to address it.
36. Apart from the quantitative benefits, the design actions create educational and professional opportunities in the neighborhood and community is brought together through urban agriculture activities. The miles travelled for food supply and waste treatment are being reducedFinally waste is diverted from the landfills and more than 70 million square feet ofmethane is captured instead of being emitted into the air
37. From the above exercise and work we realize that the toolkit has a lot of assets and could become a really helpful guide during the design process. Its main purpose is to help people understand complicated systems, like an “Infrastructure for Dummies” book per say and it filters the case studies providing the basic information. It can be used during the preliminary study and in charettes to get designers and people excited about different systems. It can also be of help on the process of achieving LEED ND or Building Living Challenge accreditations, as they both address issues of urban agriculture, stormwater and wastewater management and onsite renewable energy resources
38. In the future, a better incorporation of stormwater should be addressed, especially for larger areasThe main focus of this work in the future is to create an online database that is kept up to date and will be available to everybody. The process of gathering information and convincing people to share information was really difficult. Hence, I believe that the most important thing is to be able to share the current knowledge in order to move forward.A key factor to be incorporated in the database is the economic factor and the connection to actual manufacturers.