Did you know that Ohio University is home to the largest in-vessel composting system at any college or university in the nation?

Compost Facility

Facts about composting at Ohio University:

  • Ohio University currently produces Class II Compost and Class IV Compost.
  • In 2009, Ohio University became the university with the largest in-vessel compost facility in the nation thanks, in great part, to a $350,000 grant from Division of Recycling and Litter Prevention within the Ohio Department of Natural Resources that allowed the institution to purchase a 2 ton in-vessel composting system from Wright Environmental Management Inc. (a Canadian company).
    • An additional $35,105 for the solar array was awarded from the Department of Development's Energy Loan Fund grant program.
    • The remaining funding was provided through the operational budgets of two Ohio University departments: Facilities Management
      and Auxiliaries.
  • The original system (Wright Environmental Management, Inc. WEMI-4000) that was installed in 2009 cost $355,370.00. However, the total start-up costs associated with the project were more than twice that, or about $800,000.00. Some of the costs included a road upgrade, a cement pad, and a heated pole barn. The total cost also included bringing utilities to the site, creating a leach field, installing a 10 kWh solar array and installing a rainwater harvesting system.
  • The facility was expanded in 2012 thanks to an American Recovery and Reinvestment Act grant in the amount of $1,088,571. The expansion included the addition of: a 4-ton expandable in-vessel system (WEMI-8000EX), enabling the university to compost 100% of its pre- and post-consumer dining waste; a 31.1 kilowatt solar array to completely power the current site and expansion; a 1.4 gallon solar thermal water heating system to improve the ability of workers to clean the collection bins with harvested rainwater; a windrow turner; and a waste-oil burner to heat the pole barn during the winter.
  • The ARRA funds do not encompass all of the costs for this project. Ohio University has committed to $579,646 of matching funds for
    successful implementation of the compost expansion. That does not include annual operational costs (staffing, truck maintenance, utilities, training, etc.).
  • Waste pick-up and facility management is handled by two full-time staff members and approximately 5 part-time student staff
    members. That is an increase in staffing in FY12 due to the facility's expansion.
  • Collection/Process: Food is collected from Central Foods Facility and all Athens campus dining halls six days per week. Both pre- and post- consumer waste is collected.
    • It should be noted that OU's kitchen preparation process is quite streamlined. Therefore, a significant portion of the weight collected comes from post-consumer waste. This is one area that our office is currently working to rectify through behavior change programming.
  • The organic waste is combined with bulking agents (wood chips from landscape waste are commonly used) and then processed in the in-vessel system for approximately 14 days.

About the In-Vessel Composting Machine:

  • Ohio University elected to employ this type of in-vessel composting system for management of all its food waste for several reasons: the system features a highly efficient contained system, which has the capacity to manage all forms of organic waste (including meat, dairy, biodegradable service-ware and landscape waste); it speeds the processing of waste into usable soil; it controls odors, vectors and leachates; and minimizes staff time needed for operation.
  • The tunnel optimizes the natural composting process by controlling airflow, moisture levels and temperatures thereby accelerating the decomposition cycle of organic wastes. Composting material is moved in a plug flow fashion through the tunnel in the designated number of retention days. Material is supported on a series of stainless steel perforated trays that form the tunnel floor.The trays are pushed forward as a continuous unit by an external hydraulic ram. When the ram is moving an empty tray into the tunnel, all trays within the tunnel are moving forward. As an empty tray is being inserted, compost from a single tray is being unloaded at the tunnel discharge end using a series of vertical breaker bars and a discharge auger. The auger discharges the compost from the unloading tray onto a conveyor and the empty tray emerges from the tunnel ready for inspection and re-use.
  • Surges of waste quantities or changes in composition can be accommodated by inserting and filling more trays than the number required on a typical loading day.
  • The tunnel is controlled for air supply and temperature using dedicated control probes, a supply and exhaust fan and an air circulation system with associated air plenums. Composting material then moves through a set of spinners that act to invert, homogenize, agitate and stack the material into the next zone. Water is added during material cross-mixing (if needed) to re-establish proper moisture levels. Material remains in the second zone for an additional number of days equivalent to the retention time in Zone 1 (e.g. 7 days in Zone 1 and 7 days in Zone 2 equals 14 retention days) while significant stabilization occurs through control of air supply, water and temperature.
  • The tunnel is equipped with a series of probes that monitor temperatures. These temperatures, in relation to control panel set points, are used to operate supply fans. The optimum temperature range for composting organic waste is 50 degrees Celsius to 65 degrees Celsius. The temperature set point in the first composting zone is typically set between 58 degrees Celsius and 60 degrees Celsius for greater than three days to ensure pathogen reduction. A set point between 52 degrees Celsius and 54 degrees Celsius is used in the second zone to maximize conversion of putrescible materials. Any moisture that drains out of the composting material flows into the plenums that run along the base of the tunnel and from the plenums to sump boxes through pipes located at the sides of the tunnel. Leachate is pumped back onto the composting materials from the sump boxes through pipes located at each sump box. Some leachate is released to the on-site septic system when the overall water balance is positive inside the machine.
  • Once removed from the system, the compost needs to cure for at least 90 days.The windrows are turned regularly to offer a more homogenous mix to the compost. The 2012 expansion project included the purchase of a Windrow Turner which is expected to streamline this turning process.
  • The resulting nutrient-rich soil is used on-campus (intramural athletic fields, gardens used by Plant Biology students, Ecohouse community garden, etc.).
  • The University has spent several years testing out a variety of biodegradable/compostable service-ware (plates, cups, forks, etc.).
    It was discovered that certain products, particularly those that are potato starch-based, do not break down quickly enough to be used with our system. We have had recent success in PLA (polylactic acid) service-ware. During our transition from a 2-ton daily load to 6+-ton
    daily loads, the use of service-ware as a bulking agent slowed. Now that our new system is running (as of Fall 2012), we are hopeful that we can reintroduce service-ware as a primary bulking agent in the compost recipe.
  • Note: Details regarding the "compost recipe" are not provided here since it can be a temperamental process depending on individual
    batches of organic matter, among other things. This is a learning process that can only be mastered by experiencing it first-hand. Typically, we strive for 60% food waste and 40% bulking agents.
  • The compost staff was trained by Wright Environmental following the installation of each facility.
  • Additionally, various other staff members at the institution have completed trainings for successful operation of the facilities.

While composting is an excellent way to divert waste from the landfill, Ohio University is also excited to be able to use this project as a way to promote student engagement and academic programs while improving the efficacy and sustainability of our program.The opportunities for research studies and programming surrounding soil analysis, PLA testing, sociological impacts, behavior change, etc. is at the heart of what we hope to offer.Students are encouraged to contact the Office of Sustainability with research requests as they relate to the Compost Facility.

The waste generated on the Athens campus is managed in multiple ways internally by the Office of Recycling and Zero Waste, the Compost Facility and Moving & Surplus. Recycling, compost, landfilled waste and surplus items generated on campus are carefully and separately processed to allow the University to perform responsibly in regards to our waste management practices. Ohio University has a contract with Athens Hocking Recycling Centers to haul recycling and landfill waste from the Athens campus. Compost and surplus items are processed internally.


Compost Facility:

Ohio University currently produces Class II Compost and Class IV Compost. The Class II compost facility is the largest known in-vessel composting system at any college or university in the nation. Food waste generated in the dining halls on campus is taken to this facility where it is processed into nutrient-rich soil amendment and then used on campus grounds and sold to the public.

Community members are encouraged to utilize the nutrient-rich soil amendment generated at the Class IV compost facility. Learn how to purchase soil amendment from the compost facility.

Do you know what happens to your food waste when you dine in the dining halls on campus? Are you an office or department interested in creating your own office compost program? Learn more about composting on campus.

Compost Facility Tours
Are you a faculty member interested in bringing your class up to the compost facility? Are you a staff member at another institution looking to develop a compost facility? Or, are you a student club interested in learning more about organics recycling? The staff in the Office of Sustainability would be happy to support your goals by offering a tour of the facility for groups of 6 or more. Schedule a tour of the facility by contacting 740-593-2911.


How To Compost On Campus

Ohio University is home to the largest in-vessel composting system at any college or university in the nation.

Any individual who dines on-campus is encouraged to only take as much food as they can eat. The absence of waste is the most important step in managing organic materials. Though, we understand that, sometimes, there are food items which cannot be consumed.

In situations when food waste does exist, the process for participating in the composting efforts on campus is quite simple!

In most dining facilities, the diner merely places his/her tray of leftover food on the conveyor belt.
The conveyor belt takes the tray to a trained Culinary Services employee who separates the tray's contents into three categories: food waste, landfilled waste and recyclable waste.
The wasted items are separated into bins and the filled bins are then taken to a loading dock where appropriate entities pick-up and process the contents of the bins.
In the case of compost, the food waste is taken to the compost facility located at The Ridges, mixed with a bulking agent (mostly woodchips) and then processed in the in-vessel system.
It takes approximately 2 weeks for items to pass through the system and then it "cures" in windrows for an additional 90 days.
After that time, the nutrient rich soil amendment that is created is used on campus grounds, reducing our need to purchase petroleum-based fertilizers.

While we are able to collect 100% of the organic materials disposed of in the dining halls and Central Food Facility, we do not currently have the infrastructure available to locate compost bins in every building or campus space. Though, members of an academic or administrative unit, office or department are encouraged to capture organic materials (such as food waste) and deposit it for organics recycling (composting). There are a few simple steps involved with setting up an office-wide composting program:

Office Composting Program

There are requests campus-wide from offices which wish to engage in composting efforts. We're thrilled to hear that so many people are excited to compost. Though, there are many logistics about such an effort that will require research and infrastructure upgrades. So, Ohio University is currently in the pilot phase of being able to encourage inidividual offices to compost their food waste. The Office of Global Opportunities is currently serving as a test office to determine if individual offices can collect and drop-off their food waste at central campus locations.

In the meantime, other offices can choose to collect food waste and elect an employee to take the organic material to their home composting system. If your office wishes to pursue this avenue, here are some tips for getting started:

1.) During a team meeting, communicate the desire to implement an office-wide composting program. Allow all individuals to weigh in with questions or concerns. If there are questions you cannot answer, be sure to write them down and email them to We'll do our best to help you navigate this step in the process.

2.) If the group votes to implement a composting program, create guidelines and disposal schedules. Be sure to create answers to the following questions:

What types of materials are you willing to accept? The individual taking the food waste home should weigh in on this question. Many home systems cannot accept dairy and meat products.

How will materials be collected in the office (what bin will you use and where will it be located)? Consider finding a bin with a tight fitting lid. If you have extra fridge space, perhaps your team will agree to leave the container there or on a kitchen counter, space permitting.

What is your disposal schedule? Plan out how often the designated employee will empty the small bin and who is responsible for cleaning the returned bing. Consider developing a schedule of responsibility to share the load.

3.) Check back to this website often to see if an on-campus departmental composting program is adopted.

Thank you for your interest in supporting sustainable behaviors at Ohio University!