The ComPOSTer: ICAW Recap

Hi everyone,

Thanks for celebrating International Compost Awareness Week (virtually) with us!

In case you missed some of our featured content, here were some of our favorites from last week:



The ComPOSTer – International Compost Awareness Week!

Good evening everyone,

Did you know that the first full week in May is International Compost Awareness Week (ICAW)! This year celebrates the 25th anniversary of the event which aims to increase public awareness on the benefits of compost and organics recycling.

To celebrate ICAW, we’ve made a few updates to the blog. You’ll find:

  1. A new “Resources” section that provides readers with information on how to compost at home
  2. The background story behind the S.C.R.A.P. Lab which can be found in the “About” section

Additionally, be sure to follow the Office of Sustainability’s social media accounts (tigersgogreen) this week for learning and engagement opportunities including fun videos from our staff and student EcoReps:




Happy composting!

The ComPOSTer: New Video, Gov. Signs Food Waste Bill, How to Plant a Victory Garden

Happy Friday everyone!

Today the ComPOSTer presents a few highlights and resources to bring some positivity to your day, as well as inspiration for sustainable action as we head into the weekend and Earth Week! In this post, you’ll get a virtual behind the scenes look into S.C.R.A.P. Lab operations, read an update about the NJ food waste recycling bill, and learn about a “toolshed” of resources to start your own Victory Garden (using compost, of course).


Follow the journey of campus food scraps as they travel from the kitchen in Frist Campus Center to the University’s onsite S.C.R.A.P. Lab for conversion into compost that is used to support plant growth and health on campus:


After passing in the Senate, New Jersey’s food waste recycling bill was signed into law by Governor Murphy earlier this week. Starting in 18 months, establishments in the state that generate 52 or more tons of food waste annually must arrange for separate recycling if an authorized facility is located within 25 road miles. On-site recycling is an allowable option as well. Additionally, a Food Waste Recycling Market Development Council will be established and tasked with developing recommendations for stimulating market demand for the soil amendments and energy products produced by recycling facilities. New Jersey is now the 9th US state to have some form of an organics recycling policy.


As a result of the COVID-19 pandemic, food waste losses across the country have increased significantly as US producers and growers can’t find buyers for their vegetables and dairy products. Approximately half the food grown in the US usually goes to restaurants, schools, stadiums, theme parks and cruise ships. Now that these food service operations are temporarily “closed,” vegetables are rotting in farm fields, and milk is being washed down drains. Growers are making efforts to fix the mismatch in supply and demand by donating surplus food to food banks and charities, but until more resources and partnerships are established, they are not enough to absorb the current surplus.

On the flip side, millions of Americans are now turning to “victory” gardening as a fun and productive outdoor activity to do while stuck at home.

Have you started your garden yet? If so, let us know and send some pictures by emailing

If not, you’ll gain the satisfaction of growing something yourself without having to go to the grocery store.

Here are some tips for getting started and maintaining your garden, adapted from resources provided by the U.S. Composting Council:

STEP 1: Prepare your “garden” whether that is a container garden on your balcony or patio, or a raised bed in your backyard. And remember to add compost! The foundation of growing healthy and nutritious food is healthy soil. By adding compost to your garden beds, you’ll build organic matter and provide your plants with key nutrients for healthy growth.

The difference in plant growth and health between soil with compost (right) and without compost (left)

STEP 2: Choose your seeds and plants!

STEP 3: Plant your seeds and nurture your plants through weeding, watering, and controlling pests.

STEP 4: Enjoy the harvest!

Have a question about your garden?

Contact your county’s Master Gardener representative or your state’s agriculture extension office. Link to Rutgers Master Gardener Helpline (NJ residents only).

The ComPOSTer: Status update amid COVID-19

Good afternoon everyone,

I hope this blog post finds you and those around you doing well during this difficult time.

As with many activities and events at the University, the S.C.R.A.P. Lab has closed for the remainder of the semester due to the COVID-19 restrictions. In the meantime, any food waste generated at Frist Campus Center will be picked up by our third-party organics recycler, Organic Diversion.

When S.C.R.A.P. Lab operations resume, the composting facility will no longer reside at the current location on FitzRandolph Road, but at a new site on campus. Due to Capital Planning efforts, we will be moving to a permanent location along Washington Road in May/June. Over the next weeks and months, the ComPOSTer will chronicle this journey, and will continue to provide research updates and information about all things composting and compost, so please keep reading along!

A big thank you to all of the students who assisted with composting during the ’19-’20 academic year! Pictured here: TOP from left to right: Wesley Wiggins ’21, Stanley Cho ’23, Joe Kawalec ’21; BOTTOM from left to right: Gina Talt (project manager) ’15, Reese Knopp ’23, Kiley Coates ’20

On that note and in better news – earlier this month, the NJ food waste bill that was referenced in the last blog post was passed by the Senate and currently waits to be signed by Gov. Murphy.

Under the bill, large food waste generators (e.g. establishments like prisons, hospitals, higher education institutions) will be required to source separate and recycle their food waste if they generate an average projected volume of 52 or more tons of food waste per year (i.e. 1 ton or more of food waste per week), and are located within 25 miles of an authorized food waste recycling facility.

The bill will advance the organics recycling industry in New Jersey by incentivizing the construction of either composting or food waste-to-energy facilities in the state, as well as the use of the associated soil amendments like compost for landscaping and construction projects. Read more here.


We end the academic year having composted a cumulative 91 tons of food waste since the start of the project. We look forward to continuing our journey in a few months!

The ComPOSTer: How much can composting help in solving the climate challenge? [UPDATED]

According to Project Drawdown’s updated list of the most effective solutions to “draw down” or reverse the build-up of carbon in the atmosphere, reducing food waste ranks within the top 3 solutions while composting ranks between #57 and #62 out of the 76 solutions (the exact rank differs depending on the climate goal achieved).

Given that one third of food produced in the world is wasted (along with the associated resources and carbon emissions), it is clear why reducing food waste ranks so high, but why is the ranking for composting relatively low on the list?

The study found that composting organic waste versus landfilling it can reduce more than 50% of carbon dioxide-equivalent greenhouse gas emissions, for a total of 2.1 gigatons between now (2020) and 2050 if climate change is curbed to a 2 degree Celsius rise in the average global temperature. However the emission savings from landfill diversion is only one benefit of composting.

What is not as talked about nor accounted for in the analysis on composting by Project Drawdown, is the benefit of applying compost to soil. When the end-use of compost is considered, composting is indirectly tied to a dozen or more solutions presented in Project Drawdown from green roofs and conservation agriculture, to plant-based diets.

Compost is a natural way to provide nutrients to plants to enhance productivity while storing carbon in soils. As such, compost not only reduces carbon emissions by the aforementioned amount, but shares emissions savings through many of the other climate solutions in Project Drawdown by acting as a carbon sink or “sponge” that can soak up emissions currently in the atmosphere and limit the impacts of climate change which is already causing devastating wildfires, flooding, and droughts to name a few.

However, Project Drawdown sends an optimistic message – the reversal of global warming is both environmentally and economically achievable by mid-century if we act now and scale up already practical climate solutions like composting.

In New Jersey, the next steps around composting will be decided tomorrow as the state senate will be voting on legislation that would require large food waste generators (e.g. institutions like colleges and universities) to source separate and recycle food waste. If passed, the bill would be a significant step forward in advancing organics recycling and compost utilization in the state. Stay tuned for updates!

Data: 2/14 – 2/28

Meanwhile….with the Spring semester in full swing, the amount of food composted at the S.C.R.A.P. Lab has risen to over 3,000 lbs/week in the last two weeks.

The ComPOSTer: Meet the New Team Members!

In 2020 we are excited to welcome three new student assistants to our team. Get to know them below!

Name: Milan Eldridge ’20
Major:  Art & Archaeology 
Hometown:  Dayton, Ohio / Louisville, Kentucky 
Why I was interested in assisting: I have really enjoyed being involved in Pink House [Forbes College’s residential social sustainability living community] what I could do to personally be more sustainable. Among many things, this led me to become more interested in composting on a larger scale and I wanted to help convert our campus’s food waste into a useful material. I am excited to help make our university more environmentally friendly while meeting like-minded peers!

Name: Roy Kim ’22
Major: Anthropology
Hometown: New York City
Why I was interested in assisting: I wanted to help steward the incredible resource of food scraps that we have on campus by turning it to beautiful compost. 

Name  Reese Knopp ’23
Major:  Mechanical Engineering
Hometown:  Northport, NY
Why I was interested in assisting: I’ve always been interested in environmentalism and sustainability, so the S.C.R.A.P. lab has provided me with a great opportunity to participate in practical efforts that make a difference on campus, while also learning a lot about food waste mitigation and composting practices. 

Data: 1/31 – 2/13

The data table now includes a column for POST-CONSUMER material as we continue our effort to collect and compost consumer plate scrapings and compostable serviceware from the food gallery in Frist Campus Center.

The ComPOSTer: PFAS and Volunteer Project

Happy Friday everyone,

This week’s update is a recap from Intersession week. The S.C.R.A.P. Lab was closed and the composting system remained in its auto-digest cycle while Gina attended the U.S. Composting Council’s (U.S.C.C.)’s Annual Conference, COMPOST 2020, where she presented a case study on the S.C.R.A.P. Lab as part of a panel discussing the composting experience on a large(r) college campus. In between her session, Gina also attended other sessions and participated in a volunteer compost bin making project. Read the highlights below:


One of the biggest topics at the conference was a change in the certification standards for compostable serviceware. Starting this year, the Biodegradable Products Institute (BPI) – North America’s leading certifier of compostable products and packaging – will no longer certify compostable serviceware containing intentionally added fluorinated chemicals such as PFAS .

Why does this matter?

PFAS are a group of long-lived chemicals that are used ubiquitously in everyday products for their stain/grease resistant properties. They are found in our clothes, carpets, food packaging, and even Post-It Notes! Because PFAS are water soluble, they enter our waterways and soils, and as a result can accumulate in our bloodstream. In excess amounts, these chemicals may have toxic implications and adverse effects on human health.

What is the impact of the new rule?

About 2,000 or 20% of BPI’s certified products have since lost certification and compostable product vendors are researching and testing new alternatives.

Here at the University, our Campus Dining team will be asking for updated certifications from vendors to limit our procurement of food serviceware and packaging containing PFAS.

Compost Bin Volunteer Project

Several other young compost professionals and I participated in a compost bin-making volunteer project with Charleston (SC)’s Green Heart Project – a non-profit that builds garden-based experiential learning projects and school garden programs to educate students, connect people, and cultivate community through growing, eating, and celebrating food.

We built several 8 cubic feet bins and dropped one off at the recipient school in its urban garden as shown below:

These bins aren’t necessarily large enough to generate hot composting conditions for accelerated organic decomposition, but are small enough to enable school children to engage with them.
The urban school farm incorporates composting into its crop rotation plan.

Data: End of January

With the S.C.R.A.P. Lab closed last week, this week’s data comes from the week prior and represents the to-date statistics at the close of January.

The ComPOSTer: Back at it with baseline post-consumer measurements

Hi all,

The S.C.R.A.P. Lab has been back up and running as of Jan. 6th when students arrived back to campus for Reading Week. In addition to resuming regular loading activities, we have started one of our 2020 action items to expand compostable ware collection in the retail food gallery of Frist Campus Center.

As with all data collection efforts, our first step is to obtain a baseline of current quantity and quality of the items that are placed in the S.C.R.A.P. Lab bin by diners for composting. Under the current procurement practices, these include all food scraps, napkins, burrito bowls and molded fiber (paper) plates as indicated by the signage on the temporary bin:

To limit contamination of non-acceptable items, the S.C.R.A.P. Lab bin has a lid and is placed at the end of the line so only the most well-intended consumers use the bin. We find that many people just discard their items in the first bin that they see without even looking at the signage. So we might not capture the greatest amount of viable material, but the risk of contamination is lower.

The S.C.R.AP. Lab bin is placed at the far end of the materials sorting line to limit contamination.

Over the last 6 days of measurement, we’ve noticed the following trends:

  • The amount of post-consumer material collected is about 30 lbs/day
  • Contamination levels hover around 15% (by volume), you can think of that as a B to B+ which is good but not great
  • The most common contaminants have been polymer-based materials such as cups and utensils made with PLA (see below) which can only be composted in facilities that keep these materials at a high temperature for an extended (or repeated) number of times unlike our composting system which has a short residency period of 5-7 days.
PLA-based cup and utensils that were incorrectly placed in the S.C.R.A.P. Lab bin

Next Steps:

  • We will continue to collect and monitor the “front of house” bin this week to confirm the above trends
  • We will test a “Report Card” sign to bring awareness to the level of contamination and the most common culprits
  • Meanwhile, our Campus Dining team is hard at work at reviewing their disposable product line and trying to replace certain items with ‘SCRAPPY-friendly” items

Weekly Data: 1/3 – 1/16

Over the last two weeks, we resumed loading activities. This week when the composting vessel reaches capacity (about 75% full), we will resume off-loading.

Looking back on 2019

Dear composting friends,

Thank you for being loyal followers and supporters of the S.C.R.A.P. lab in its first full calendar year of composting operations! With the New Year (and Decade) just a few hours away, the ComPOSTer takes a moment to look back on the highlights of 2019 as well as the next steps to look forward to in 2020. See you in the New Year!


Over the last year, the S.C.R.A.P. Lab…

  • Converted 62 tons of food scraps into nutrient-rich compost that is now being tested on the campus grounds in a variety of forms
  • Avoided 37 metric tons of CO2-equivalent emissions
  • Engaged 18 students as operational assistants
  • Expanded food scraps collection partnerships with the Coffee Club and 4 campus departments (McGraw Center, Geosciences, Ecology & Evolutionary Biology, Psychology)
  • Partnered with several major campus events to divert both food scraps and serviceware for compostability testing
  • Featured in and engaged many more people in 30 presentations and tours
  • Contributed to Campus as Lab projects:
    • Student course projects: 3
    • Faculty-sponsored research projects: 3 active
    • Junior papers/senior theses: 2 active


  • Expanded compostables collection in the food gallery of Frist Campus Center
  • Integration of research efforts with operational testing of different carbon feedstocks, beginning with wood pellets
  • Testing of different food scraps collection and drop-off systems to expand reach across campus
  • Begin the study of compost applications on campus farmland
  • A new video highlighting the behind the scenes processes and the people involved in the journey from food scrap to compost
  • Facility Relocation: “SCRAPPY” will be moved to a permanent home on campus in spring 2020.

The ComPOSTer: Meet this semester’s new assistants

Good evening all,

As we head into Thanksgiving, I just wanted to convey my gratitude to the team of student assistants who make the daily to weekly cross-campus trek to participate in the food scraps composting demonstration project.

Composting can be a very labor intensive process, so having a hardworking and dedicated team is key to success! This semester we are lucky to have 8 regular student assistants, 3 of whom are new to the project.

Hear in their own words why each wanted to join the S.C.R.A.P. Lab team:

Name and Class Year: Christian Hernandez ’22
Concentration: Molecular Biology
Hometown: Manvel, TX
Why you decided to join the team: As a small farmer and composter myself, I want to participate in how composting can work at a larger scale as well as just maintain some fitness through physical labor.
Name and Class Year: Julia Herrle, ’19*23
Concentration: MPA, International Relations
Hometown: Wexford, PA
Why you decided to join the team: I’m passionate about improving food security and sustainability of food systems. Reducing food waste is an important part of this, and I’m excited to learn more about composting at Princeton!
Name and Class Year: Chloé Vettier, GS
Concentration: French Literature
Hometown: Paris, France
Why you decided to join the team: because I want to support sustainable initiatives on campus – and I really miss my composter in Paris!

Weekly Data: 11/8 – 11/21

Happy Thanksgiving!