Final Report for CNE13-104
The following is the 2014 Final Report Summary of the Brooklyn Grange Compost Project – awarded by a SARE grant in 2013. The project is a pilot of a closed loop composting program inside of the New York City’s largest Industrial Park – the Brooklyn Navy Yard.
The grant award period began promptly in the spring of 2013, and ended a year later in the spring of 2014. During the duration of the grant, the Brooklyn Grange composted well over 150,000 pounds of organic waste. This composted waste is still being cured, harvested, and sifted, but will yield over 60 cubic yards of usable finished compost. A new project was successfully implemented, and members of the community were actively engaged.
The objectives of the grant were to launch the program, compost and divert a significant amount of organic product as possible in the Navy Yard, produce a high quality, fertile compost for the rooftop farm, and to develop positive social momentum and awareness for composting.
David Buckel, one of the most experienced community composting experts in New York City, agreed to join the project for the first three months of the grant to the launch the program, establish the basic layout of the composting operation, establish basic systems, create signage, and begin establishing relationships with companies which produce compostable materials across the Navy Yard. During those three months from April to June of 2013, the project was launched very efficiently.
- The exact location of the compost project was negotiated and solidified
- Friendly, informative signage was printed and setup at the compost site – including labels such as “feeder row”, “active compost pile”, and “curing pile”. The physical setup of the operation has been important, in dealing with flow issues, keep space free to large loads of wood chips, etc.
- Feeder pile system was setup for drop-offs which occur when our personnel are not on site.
- Relationships were developed with largest vendors – Agger Fish, King’s County Distillery, Florishop, Brooklyn Roasting Company.
- 64 gallon toters were researched, tested, chosen, purchased, and distributed to businesses.
- Other tools and materials were identified, priced, sourced, and purchased: shovels, wide pitch forks, tarps, large wheel barrows, 3-ft thermometer, wheeled tote bins, hoses
- Three valuable items were sourced from the community, which did not have to paid for: bicycle powered compost sifter (see photo), a scale, and a cargo bicycle.
- A significant amount of woodchips was sourced on multiple occasions from a neighboring tree service, which has provided ongoing drop-offs through the project. The chip was a valuable addition, provided materials for the base of the composting project, and also and important source of carbon and texture to aerate the pile.
The Brooklyn Grange is a rooftop farm operation based in New York City. On two roofs which total 2.5 acres, it grow a variety of different market vegetables which are sold fresh to the community. One of the Brooklyn Grange roof locations is atop Building #3, an anchor building with a 65,000 square foot footprint in the Brooklyn Navy Yard. Compost is the most critical form of nutrient added to the soil at the rooftop farm.
The Navy Yard is home to over 200 businesses, and it was a perfect location to launch a pilot composting project. Space for composting was acquired in the back of a neighboring tenant’s leased lot – called the King’s County Distillery. The distillery is a small business with eithics and environmental vision similar to our farm, which made it a good partner. The space worked well because the distillery produces a significant amount of spent grains from its distilling work, and has also been in the process of building up the soil in its property for vegetable, corn, and other grain growth during summers.
Composting was done using an aerobic process – a system which requires turning the compost to expose microorganisms in the center of the piles to air and oxygen at regular time intervals. Organic materials for the compost pile were sourced from neighboring tenants including the King's County distillery, cafes, a coffee roaster, a chocolate roaster, a fish processing company, and dropoffs from NYC Farmer's Markets. Finished product was brought up to Brooklyn Grange's rooftop farm, and also shared with King's County Distillery's small grains plot.
The sources of materials evolved over the course of the summer. We quickly realized that the smaller businesses and dropoff locations were not going to add up to a significant enough quantity of material to hit our projection of 12,500 lbs per month, so we focused on the larger sources – which are the main businesses mentioned above. We setup the system and layout in the spring, and quickly received about 80 cubic yards of wood chip from a local tree service. This dropoff was mutually beneficial for both parties, as we were able to stock up considerably on our carbon based materials, or “browns”, and the tree service was able to avoid many miles of transportation, fuel, tolls, and “tipping fees”. A few weeks later, a large load of farmer’s market scraps consolidated from neighboring markets was delivered on June 1st, which totaled 6,748lbs of mostly green material. The messy but beautiful and colorful mix of vegetables scraps, peel, rinds, coffee grounds, etc served to kickstart the piles, and start getting them hot and biologically active.
The grains from the distillery comprised a lesser portion of our total greens materials than predicted at the onset, however the grains volume increased significantly in the fall. The production from the cafe in the Navy Yard was also significantly lower than expected. However a new relationship emerged with a neighboring cafe and coffee roaster which warehouses coffee in the Brooklyn Navy Yard. In July, we approached the owners to see if they would like to compost their waste. The roasters agreed without hesitation, and began dropping off daily loads of up to 100-150 lbs of coffee grounds and chaff from the roasting process. This provided a significant amount of nitrogen, or “greens” for the piles, (although the grounds are brown, they are high in nitrogen which qualifies them as "green" in typical composting terminology) which was mixed in with the organic materials from other businesses. We also began testing the decomposition of fish scraps from a neighboring fish vendor. The fish is heavy, can have bad smells, etc, but is very rich in nutrient, and worked well in the piles once buried sufficiently and introduced into a healthy, active, pile.
The majority of the “harvest” of finished compost is stored in a curing pile for several months. We have used a couple of different sifting techniques, including a borrowed bicycle powered sifter. Sifting is important to remove the larger pieces of wood chip, and other material which does not break down to a small size during the process. On the farm, particularly in our greens beds, we use a seeding tool which requires generally small and consistent soil texture.
Other streams of compost product were also discovered and found from other sources. A summary is as follows:
- Mast Brothers Chocolate Company – chocolate husk from chocolate making process
- Brooklyn Roasting Company – Spent coffee grounds and chaff from the roasting process
- Blue Bottle Coffee - chaff from roasting process
- Florishop – A florist which provides us with compostable materials from flower and plant scraps.
- Ted and Honey – A café with catering kitchen in the Navy Yard.
- Brooklyn Grange (Mushroom Substrate / Hay)
- Straw from Red Hook Crit Road Bicycle Race
- Tenants from Building (Food scraps)
- Various Wood shops in the Navy Yard – contributed wood shavings (coarse sawdust), however some policing and awareness issues arose because the farm only should be using pure wood – not any plywood, treated, painted, or glued.
- GrowNYC – Farmer’s market collection program
- Global Enviro – A local onsite food waste solutions business which starts the decomposition process onsite, and then provides us with nutrient rich materials from nearby restaurants.
- Leaf Collections in fall
- Wood chip deliveries from local tree service
- Horse Manure – generated at stables in Prospect Park in Brooklyn, and easily hauled to the compost pile, especially when some extra nitrogen and heat is needed in the piles.
Throughout the winter of 2014, the compost project received a very large amount of coffee grounds as mentioned above. After we started receiving a heavy amount of the coffee grounds, we needed to conduct some research and learn more about how to best handle the materials. Research was done, and we sent emails around the community and as far as the West Coast to a composting expert who we’ve worked with in the past. We quickly learned that despite our assumption that coffee grounds are “wet” and would give the pile a high moisture content, they actually dry out very quickly, and also lose moisture in the process of being blended with wood chip, wood shavings, and other products in the pile. They are very porous and fluffy, which contributes to their drying out rapidly.
It is important for our piles to steadily hit high temperatures – we aim for at least 140-160 Fahrenheit to ensure that all weed seeds are broken down before being taken to the farm. As farmers, we work hard to keep our weed populations under control, thus it is important to not spread/inocculate our growing beds with any unnecessary invasive weeds.
Temperatues in the mid-150s Fahrenheit are also optimal for ensuring a high amount of biological activity, and thus a very healthy finished product. Soon after incorporating the coffee grounds, we commonly experienced conditions where the piles were only at around 120 F, which was not as high as desired. But after being watered heavily, they typically rose to over 150 F. Blending with other nitrogen based materials was also beneficial to the process. We were also assuming that the coffee grounds were fairly acidic, however also quickly learned from research that most of the acidity is pulled out into the coffee, and that the grounds are actually closer to neutral. New York City produces a large amount of coffee grounds which are laden with water weight, and then trucked long distances, mostly to landfills. There seems to be potential in focusing on a specific system to help recover some of this organic waste amongst the community.
We were not able to consistently practice a single specific recipe or formula because the quantity and availability of different product tended to fluctuate. We did learn quite quickly, however which recipes and blends worked the best. We could test the temperature and moisture, and also rely on personal observation. We continually aimed for a C:N ratio of 25:1 - 30:1. Adding a substantial amount of chip and wood shavings quickly pushes the carbon ratio well above 30:1, so in general we tried not to use too much carbon, although we did err on the side of caution at times, to ensure that vegetable scraps would have plenty of aeration, and low risk of odor. When possible to use low amounts of carbon we found that the lower the carbon, the hotter and quicker the process went, plus we ended up with less chip to sift out, and thus a higher final yield. We would typically turn a pile every 30-60 days during the winter, and more frequently in the summer. Sometimes the first flip would be necessary in as little as 2 weeks after a pile was built. The breakdown reaction occurs much more rapidly in the summer with the warmer temperatures. We wouldn't physically move a pile as it evolved through the decomposition stage, and into the final curing stage, because it was too much work. The high temperature breakdown period would often last about 2-3 months, and then the curing period typically would often require several more months, with a substantially reduced temperature, but still often warmer than room temperature.
The quality of imputs is another important consideration. The large loads of vegetable scraps were generally high quality. Inevitably there are some rubber bands, bits of plastic, and the occasional plastic bag which must be removed. Other pure sources are perfect - such as chocolate husk, coffee grounds, and spent grain. Vegetable scraps from the dropoff location and cafes/restaurants were the worst - with the occasional rubber gloves, plastic twisties, etc. The task of removing small bits of contamination becomes an expected task, and was never an extreme distraction or challenge in the project.
The compost project has generated a considerable amount of energy and awareness amongst our community. An important aspect is that it has demonstrated to the Brooklyn Navy Yard Development Corporation that composting and organic waste recovery can be done in a clean, efficient way which is not detrimental to relationships with businesses, neighbors, tenants, etc. As we began to pursue this project, we encountered some political headwinds, due to BNYDC's logical concern of odors, smells, pests, and associated headache and backlash from other tenants. We’ve now demonstrated that such a project can be run successfully, and management has begun discussions regarding other ways to continue composting beyond our project. Numerous meetings and sales pitches have been held regarding in-vessel gasification system, and other ideas are on the table to develop a modern organic waste management system in the Brooklyn Navy Yard.
Odors and potential conflicts were avoided largely by using proper compost procedures. Nitrogen heavy (green) waste should not sit for an extended period of time in the feeder row before blended with browns and a modest amount of chip. This blending balances the blend, and also allow for more oxygenation, thus alleviate buildup and ammonia and related strong odors. If left to sit unblended, a pile of weeds and food scrap will generate odors. Large vegeatable scrap loads were blended immediately, and never allowed to sit, even for a day. Containers were also rinsed quickly, especially in the warmer summer days.
The compost project also created social bonds and relationships. Businesses that contributed organic materials were enthusiastic about the idea of a community based compost system, and similarly, it has been a positive experience exposing other employees and members of the community to the system. We’ve hosted group volunteer days where we turned the compost piles and incorporated large loads. These volunteers have the ability to learn important lessons on nature's systems, recipes for a compost build out, and the chemistry of composting.
The Brooklyn Grange has also integrated further into the community via the project, as we’ve borrowed the bicycle powered sifter, accepted farmer's market loads, and joined compost forums and discussions. Compost has also been shared with the site host, King's County Distillery. As the grant sunsets, we plan to continue to manage the compost program, educate others, and generate positive social opinions of composting in the community. This education is particularly well-timed as the city of New York is launching other trial municipal composting programs.
Dozens of yards of finished compost material have been were produced during the 1-year grant period. As of the date of this report, there remain dozens of yards of curing and in-process material in the system, and we will continue to sift and harvest more needed materials as the summer passes. Well over a hundred thousand pounds of organic material was processed in the past 12 months, which will yield at least 75 cubic yards of finished compost.
Fresh high quality compost typically costs us around $70/yd delivered in New York City when purchased from local and regional sources, and the material has been beneficial towards maintaining proper nutrients in Brooklyn Grange's soil.
Some of the grant's funds contributed towards startup and materials, and other funds went towards operations to process the compost pile. The cost per cubic yard was close to $150/cy in the first year, however in future years, now that the system is setup and materials have been purchased, it should be possible to reduce the cost (mainly labor) to produce additional compost well below $100/cubic yard.
To continue the project, we will be able to rely on most of the equipment already purchased. Additional expenses will occur, particularly for replacements and repairs. Labor will be an ongoing expense. We do not yet have the exact calculation of time per lb or time per cubic yard, but will hope to figure out this metric in the future. Please see the discussion of future
Compost is a heavy business. Organic materials can be very heavy, especially when wet with water weight. During the process we've frequently been reminded of the often arduous tasks involved in the process, especially when done with manual labor. Such tasks include:
- Transporting materials to the site
- Building out piles with specific recipes and blends
- Turning and maintaining the piles
- Sifting cured compost
- Transporting finished compost to its final location
Technology can be very important in reducing the effort that goes into all of these tasks. We would recommend for even small scale composting to think about ways to allow for expansion, especially when working in large cities where the amount of potential materials is nearly unlimited. Front end loaders can be very beneficial for moving and turning piles. The vast majority of our labor budget went towards the physically arduous tasks of buildouts and turning. Simple inexpensive forced air systems can mechanically aerate the center of a pile and significantly reduce the amount of labor involved in turning the piles, and still maintaining a healthy aerobic environment.
Lastly, the sifting process, which can be very time-consuming, can be streamlined with larger, professional equipment. Professional sifting equipment is very expensive. Even modest sized Trommel spinning machines can cost in excess of $10,000. Brooklyn Grange is working with a local cooperative called DB Co-op to design a new, affordable design for a sifter. A photo is attached here of the existing machine designed by DB Co-op which is essentially a miniature Trommel machine, and powered by bicycle. Efforts should continue to be put towards designing affordable, small/medium scale sifting equipment. Also community partnerships should continue to be forged between groups to share the use and cost burden of such machines, with the goal of reaching a high utilization of the machines. Sharing and community partnerships will also be beneficial for transport and distribution of finished compost.
Cities and communities should also continue to research and support other composting technologies, and monitor developments as they evolve and become realistic. New technology, seemingly futuristic only a few decades ago, is becoming more and more accessible, and certain concepts such as anaerobic digestors and vessels can process substantially larger amounts of materials.