Author: Gina Talt

Good evening,

This week’s ComPOSTer welcomes Princeton’s newest coffee shop, the Coffee Club, to our growing list of partnering venues!

Located in the taproom of Campus Club, the Coffee Club held its grand opening on April 14th and is run and staffed entirely by students.

With sustainability being one of its core values, collecting coffee grounds for composting at the S.C.R.A.P. lab  is now one of the Coffee Club’s initiatives to promote more environmental and socio-economic  practices. Additionally, the club also sources pastries and roasted coffee beans from local vendors, and is committed to maintaining affordable — if not the lowest — coffee prices both in and off campus to foster an inclusive environment.

In just under 2 days, the Coffee Club has produced 25 lbs. of coffee grounds, which will provide nitrogen-rich material to our feedstock, and a good source of energy for the microbes that convert the organic matter to compost.

Fun fact: Contrary to belief, coffee grounds will NOT lower pH and make compost more acidic.  While fresh coffee grounds may be acidic, once brewed, they are closer to pH neutral. Since acid is water-soluble, any acid in the beans would have already leached into your cup of Joe.

 

Weekly Data: 4/5 – 4/11

	Total Food	Campus Center/Cafes	Academic/Residential Buildings	Wood shavings (BA/CS)	% BA/CS	Compost Off-loaded	GHG Emissions Saved (MTCO2eq)
Week Totals (lbs.)	2,697	2,589	108	928	34%	2,000
CUMULATIVE (lbs)	68,072	67,545	527	21,062	31%	57,500	20

Hi all,

Last week we teamed up with Campus Dining to collect compostable material at our largest event to date – the Tiger Chef Challenge, which featured a Food Expo with complimentary food samples while student teams competed in an Iron Chef-like culinary challenge to see who could create the best plant-based entrée with the day’s secret ingredient (jackfruit).

Check out the photo essay below to learn about the process from collection to compost!

[At the event each compost bin had a sign picturing the acceptable items -food scraps, napkins, bamboo sampling plates]

[To prevent contamination, each resource recovery area was staffed by a student or staff member directing attendees on how to properly sort their items into either compost, landfill, recycling, or liquids]

[At the end of the event, Sanitation staff transported the 12 full totes to our facility. All together we recovered 154 lbs. of compostable material. Since the majority of the contents comprised of bamboo plates, we included this material as part of our weight total in the bulking agent/carbon source category because bamboo plates are essentially plant fibers just steam pressed together]

[Next we dumped the contents of the totes into the hopper via the lifter and the material was processed smoothly, needing only a few swings from the agitation arm to move material so that it could reach the cutting blades of the shredder. The shredded pieces then traveled up the auger via a screw conveyor and were emptied into the vessel]

[A few of the larger pieces that were not completely shredded by the cutting blades passed through after 4 days and ended in the compost that was off-loaded. We will continue to run these pieces back through the shredder so that they eventually break into smaller, more unidentifiable pieces. They will then finish biodegrading when applied to campus soils.]

Weekly Data: 3/29 – 4/4

We started to off-load compost again for the first time since before Spring Break. We are also starting to experience greater usage across the academic/residential building collection bins as campus awareness increases.

	Total Food	Campus Center/Cafes	Academic/Residential Buildings	Wood shavings (BA/CS)	% BA/CS	Compost Off-loaded	GHG Emissions Saved (MTCO2eq)
Week Totals (lbs.)	3,327	3,207	120	1,126	34%	2,000
CUMULATIVE (lbs)	65,375	64,956	419	20,134	31%	55,500	19

HI folks,

We have quite a few updates as we came back from Spring Break in full force. Check out the new partnerships, bioware testing, data metrics and Earth Month activities in the photo essay below:

1. We welcome the Geosciences and Ecology and Evolutionary Biology departments in Guyot Hall to our growing list of partnering venues thanks to the efforts of graduate students, Chris Crawford and Katja Luxem. Each of their department kitchens now has a 5-gal collection bin (shown above) similar to the ones in the McGraw Center (pictured below), the Mechanical & Aerospace Engineering department, and the Scully Co-op.

2. We continued testing more compostable food service ware after a departmental request to evaluate a caterer for future zero waste events. Items included a serving tray, bamboo tongs & serving picks, and birch utensils. The serving tray is likely to be too thick to break down inside of the composting system after 5 days, and it is likely that the picks may elude the cutting blades and pass through the shredder still intact, but the proof will be in the compost! Stay tuned for the results!

3. As part of this year’s Earth Month schedule of activities and events, the SCRAP Lab will be hosting drop-in hours every Tuesday in April (9:30 to 10:30am), as well as a guided tour on Friday, April 26th (11am – Noon).

Weekly Data: 3/22 – 3/28

We’ve updated our data chart slightly to include the break-down of the sources of the uneaten food (Campus Center/Cafes vs Academic/Residential Buildings) as well as a metric totaling the greenhouse gas emission savings from diverting the uneaten food from the landfill using the EPA’s Waste Reduction Model (WARM).

 

	Total Food	Campus Center/Cafes	Academic/Residential Buildings	Wood shavings (BA/CS)	% BA/CS	Compost Off-loaded	GHG Emissions Saved (MTCO2eq)
Week Totals (lbs.)	3,236	3,216	20	1,046	32%	6,000*
CUMULATIVE (lbs)	62,048	61,749	299	19,008	31%	53,500	18

*Compost off-loaded before Spring Break

Happy Spring!

After a short hiatus for Spring Break, the SCRAP Lab is back in operation! We thank Organic Diversion for assisting us and picking up the uneaten food from the University’s retail dinning venues while we were not in operation.

Since our composting system is demonstration-scale and has a limited capacity of 5,000 lbs. of uneaten food per week, we are unable to accept all that is generated and recovered across the University dining venues. As such, the University partners with Organic Diversion to pick-up both pre and post consumer uneaten food from all campus dining halls for transport to NJ farms where the feedstock is composted in windrows or used as animal feed.

See below for a visualization of the University’s food scraps diversion program:

[Data represents monthly totals. At full operational capacity, the SCRAP Lab would process about 1/5th of the total food scraps recovered from Campus Dining venues. However the SCRAP lab is only currently operating at 60% capacity. To reach full capacity we are gradually expanding into both academic and residential buildings, starting with the Scully Co-op and McGraw Center.]

Based in Marlton, NJ, Organic Diversion is in the process of building a regional organics recycling facility that combines anaerobic digestion with composting, but until that facility is operational, the company is only accepting food-based feedstocks versus other types of compostable material such as soiled paper products (e.g. napkins, paper towels, greasy pizza boxes) and plant-based food service ware. However these are all items that are readily acceptable in the FOR Solutions composting system and we have plans during the coming weeks to recover and test more of these items.

Stay tuned for more exciting initiatives as we approach Earth Month!

 

Hi all,

Our project has a new name!

As hinted at earlier, we decided to change the name of our project after learning that the term “biodigester” may refer to decomposition processes that create different forms of soil amendments other than the one produced by the FOR Solutions system (i.e. compost). Hence, to make the connection with composting clearer, we will be referring to the system as a composter or composting system, and will call the demonstration project:  “S.C.R.A.P.” Lab or Sustainable Composting Research at Princeton Lab. Our goal is to investigate the sustainability of repurposing uneaten campus food into a soil amendment using aerobic in-vessel rotary drum composting technology.

Note: The URL for this blog is now: https://scraplab.princeton.edu/ (although anyone who uses the old URL will automatically be re-directed).

We understand that there may be a negative association with the word “scrap,” but our intent is to change conventional thinking that [food] scraps are a form of “waste,” but rather nutrients that can be returned to the environment to enrich the soils that we all depend on for food and key ecosystem services. Help us spread the word!

In other news, we had a productive brainstorming session with staff and students on ideas for a new resource recovery station at the Frist Campus Center. Sarah Bavuso, Campus Dining Sustainability Manager, led us through a great session filled with colored sharpies and sticky notes.

Earlier today and over the rest of this week, we will be off-loading the composting system until it is nearly empty to prepare for a temporary shut-down of operations over Spring Break next week. But don’t worry – the uneaten food that we would normally process won’t go to the landfill. Organic Diversion, the University’s contracted hauler that picks up uneaten food at the campus dining halls, will be assisting us during this time. When we return from Spring Break we will provide more information about the differences between Organic Diversion and the S.C.R.A.P Lab.

See you in two weeks!

Weekly Data: 3/2 – 3/8

We again continued to load roughly 3,000 lbs. of food scraps and off-loaded a similar amount in compost. 

	Food	Wood shavings (BA/CS)	% BA/CS	Compost Off-loaded
Week Totals (lbs.)	3,029	995	33%	3,000
CUMULATIVE (lbs)	58,763	17,947	31%	47,500

Good evening compost subscribers,

We need your help!

If you are on campus or even following along from afar, we would love to hear any thoughts you might have for re-imaging the resource recovery station in the campus center where we receive some of our uneaten food.

Currently our system is only accepting pre-consumer kitchen scraps and leftover food from Frist Campus Center, but it would also be great if we can capture and divert post-consumer food scraps.

How should the new area and compost bin be designed so that they simultaneously limit contamination while educating the campus community and visitors about our food scraps composting project? Let us know your thoughts!

 

[The current layout and design of the Frist Gallery post-consumer compost bin contributes to contamination of the stream as shown above in which non-compostable materials such as a soda cup with a plastic lid and straw were thrown into the bin]

Weekly Data: 2/25 – 3/1

We continued to load roughly 3,000 lbs. of food scraps and off-loaded a similar amount in compost. 

[Besides these few pieces, most of the cardboard pizza boxes that we processed last week have composted successfully inside of the system.]

	Food	Wood shavings (BA/CS)	% BA/CS	Compost Off-loaded
Week Totals (lbs.)	3,098	1,013	33%	3,000
CUMULATIVE (lbs)	55,734	16,952	30%	44,500

In this week’s post, we highlight our effort at Friday night’s Tiger Sustainability Night double-header basketball game at which we partnered with Campus Dining and student EcoReps to recover food scraps at our first major event. Check out the below photo essay to learn more:

[EcoRep and Biodigester Operational Assistant, Wesley Wiggins ’21, staffs one of the five “Zero Waste Stations” stationed around the gym. Wesley and the other EcoReps instructed fans on how to properly sort their unwanted materials into either “Landfill,” “Recycling,” “Compost” or “Liquids”]

[About 15 gallons of compostable material was diverted from the landfill over the course of the night, consisting mostly of napkins, paper plates, popcorn, and…

[… 22 pizza boxes! Although cardboard from pizza boxes is technically a recyclable material, once it becomes saturated with pizza grease, it can no longer be recycled because the absorbed oil interferes with standard recycling processes. However, greasy cardboard pizza boxes can be shredded and composted at our facility. They will be gradually added over the course of this week and will act as a supplemental carbon source. ]

Weekly Data: 2/18 – 2/22

Unfortunately, we were unable to use our scale last week due to a temporary data transmission issue, so the data represented below are estimates. On the bright side, we were able to leverage several months of experience and data to assist in making informed estimates!

Although we received the same number of food scraps totes as the week prior in which we processed around 3,000 lbs., we estimated that we loaded a few hundred pounds over 3,000 lbs. because several of the totes were heavier than usual, most likely because of last Wednesday’s snow storm which led to an earlier closure time for our campus cafes. 

	Food	Wood shavings (BA/CS)	% BA/CS	Compost Off-loaded
Week Totals (lbs.)	3,334	1026	31%	3,000
CUMULATIVE (lbs)	52,636	15,939	30%	41,500

Hello fellow compost aficionados!

Apologizes for the overdue blog post! We’ve been busy preparing for several  new efforts in between continuing our compost operations. Check out the exciting new partnerships and initiatives that will start later this week:

• Compost Concierge Pilot : We’ve been working with grad students and departmental managers to begin a pilot food scraps collection program in three academic departments (Mechanical & Aerospace Engineering, Geosciences, Ecology & Evolutionary Biology). The food scraps, collected in 5-gal bins, will be picked up twice weekly by the operational team and dropped off at our composting facility.
• Composting at Tiger Sustainability Night (2/22): We will be partnering with Campus Dining and EcoReps Greening Athletics to recover food scraps at our first major event – double-header basketball games against Cornell at 5:30pm and 7:30pm at Jadwin Gym on Friday, February 22. Watch the promo video featuring Lexi Weger ’22 and Gabrielle Rush ’19

• Lastly, this week we will be finalizing a new name for the project to  better reflect that the biodigester is a composting system that decomposes food scraps into compost aerobically (with oxygen), not a digester,  which generally refers to systems that break down organic waste anaerobically (i.e. without oxygen) and produce digestate, which is similar to, but technically not the same as compost. We will unveil the new name next week!

Weekly Data: 2/4 – 2/15

Now that the spring semester is in full swing, our  weekly food scraps volume is starting to creep back up again, closer to the 3,000 lbs./week range. We are also experimenting with a higher percentage (by weight) of wood shavings to food scraps, increasing slightly from 30% to 33%.

	Food	Wood shavings (BA/CS)	% BA/CS	Compost Off-loaded
Week of 2/4 (lbs.)	2,679	875	33%	2,500
Week of 2/11 (lbs.)	2,997	985	33%	2,750
CUMULATIVE (lbs.)	49,302	14,913	30%	38,500

This week we welcome another project partner to our growing list of composting venues: the McGraw Center for Teaching & Learning!

Like the Scully Co-op, the McGraw Center will collect any food scraps generated in its office in a 5-gal bucket for weekly pick-ups.  The effort will be spearheaded by the McGraw Center’s Manager Sandra Moskovitz, a sustainability ambassador who has been composting herself for 30 years.

Almost five years ago, the Office of Sustainability interviewed Moskovitz for a staff profile. When asked, “How could the University become even more sustainable? she replied:

“My number one wish is for a campus wide composting program, it saddens me to see the waste around campus that could so easily be composted—miles of pizza boxes, tons of used paper towels and paper plates, not to mention the pounds of food scraps that are thrown away in offices and classrooms each day. I know that this is something that is being discussed, so I hope that a program will be in place soon. It will make a huge difference in reducing the amount of waste that the University’s population makes every day.”

Thanks to outspoken people like Moskovitz, the University now has an on-site composting system that will continue to support expanded food scraps diversion efforts while contributing to an ethos of sustainability where organics recycling will ultimately become the norm on campus.

To realize this goal, we plan to partner further with Moskovitz and the McGraw Center around green office strategies so that all of their events are zero-waste, and to share these best practices across campus.

Weekly Data: 1/28 – 2/1

The lower volume of weekly food scraps continued into the last week of January as finals wrapped up and led into Intersession (a 1-week break before the start of the spring semester).

	Food	Wood shavings (BA/CS)	% BA/CS	Compost Off-loaded
Week Totals (lbs.)	2,504	776	31%	2,000
CUMULATIVE (lbs)	43,626	13,053	30%	33,250

With campus cafes closed on Monday (1/21) in observance of Martin Luther King Jr. Day,  we only loaded  2,238 lbs. of food scraps into the composting system last week, or about 40% less than the average weekly amount.

We did not detect any visible pieces of recently tested bioware in the 2,000 lbs. of off-loaded compost. These results are promising, but we will wait for this week’s batch of compost to know for sure just in case the material didn’t fully migrate to the end of the vessel.

Weekly Data: 1/21 – 1/25

	Food	Wood shavings (BA/CS)	% BA/CS	Compost Off-loaded
Week Totals (lbs.)	2,238	706	32%	2,000
CUMULATIVE (lbs)	41,122	12,277	30%	31,250