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Reduce, Reuse, Recycle

Cal Poly Humboldt is striving to meet its sustainability goals through a series of campus wide projects. One of these goals is to reduce the amount of waste the campus generates. Currently a food waste diversion pilot study is being conducted in conjunction with the Humboldt Waste Management Authority (HWMA) to estimate feedstock for a proposed municipal anaerobic digester. This page outlines a current student project looking into the possibility of including bathroom paper towels to the food waste. A pilot study was conducted to determine: mass and volume of paper towels generated, behavior change through participation in project, and logistics for future study. Data from the study estimates an annual accumulation of 30,000 pounds or 15 tons of bathroom paper towels with a volume of 8,000 cubic feet. Through basic informational signing a 75% reduction in the amount of contamination. Even though these are rough estimates they support future investigation into paper towel waste diversion.

Introduction[edit | edit source]

In 2010 HSU disposed roughly 900 tons of waste a year, some of which can be diverted from the landfill to meet Assembly Bill 341's requirement of 75% diversion by 2020.[1] To meet that goal, the campus is aggressively looking for more ways to reduce, reuse, and recycle. This project is intended to create a possible solution for diverting additional waste from the landfill in order to meet this goal.

We have a unique situation as Humboldt County's, Cummings Road Landfill located in Eureka, CA was capped and closed in 2000.[2] Consequently, all waste generated is now trucked an average of 187 miles (380 miles round trip) out of the county to the Dry Creek Landfill in White City, Oregon or to the Anderson Landfill outside of Redding, CA.[3]

Humboldt County waste transportation routes.

The cost of transportation in diesel fuel and the external costs in greenhouse gases (GHG) are significant. Roughly 100,000 tons of waste is transported out of Humboldt County per year, generating 4,484 Metric Tons in GHG.[4] Landfills themselves are a source of Greenhouse Gas emissions, which include Carbon Dioxide (CO2), Methane (CH4), and Nitrous Oxide (N2O). Most of these GHG emissions are produced from organic material breaking down under anaerobic conditions, while other forms of solid waste do not produce GHG because they are not composed of carbon.[5] Paper towels are included as a type of "organic waste", making them a viable target for reducing GHG at the landfill and in transportation. As an early adopter to the HWMA pilot study the Department of Sustainability along with Waste Reduction and Resource Awareness Program (WRRAP) will be collecting food waste from two main cafeterias to determine the mass and volume generated on campus. The data will help as HWMA is preparing to bring a municipal anaerobic digester online as early as January 2012.[6]

Process Flow Diagram for a food waste digester. Green arrows are organic material flow, the black arrows follow contaminant flows, and the brown, blue and red arrows show end products
Anaerobic digestion process taking place in a synthetic bio-digester to create methane gas.

Anaerobic digestion is the decomposition of organic matter by microorganisms in an oxygen free (anaerobic) environment, creating biogas, residual solids and liquids[7] The biogas will be used to power the actual digesting plant, thereby reducing HWMA's dependence on electricity and their Greenhouse Gas Emissions (GHG). The residual solids and liquids are nutrient-rich and valuable soil amendments, with the possibility of providing an additional source of revenue for the facility.[8]

For more information see Anaerobic digestion wiki.

The following sections outline our initial Paper Towel Diversion Pilot Study, the results, analysis of findings, and a discussion on future projects.

Current Paper Waste Diversion Programs[edit | edit source]

There are many institutions such as schools, companies, and municipalities that have incorporated a paper towel diversion program. The following institutions reduce their solid waste by composting their paper towels:

One progressive UC campus that successfully reduced solid waste is UC Berkeley. Their paper towel composting program began as a Residential Sustainability student project in 2009. They conducted a bathroom paper towel-composting pilot study in two campus buildings, which resulted in a 90% diversion of paper towels, generating 325 pounds. The study involved a several weeks of social marketing, incorporating signs to promote awareness..[9] The success of the program prompted a full-scale operation though out the Unit 1 dormitories consisting of 4 high-rise buildings. This program utilized a short educational video that plays on a 30-second loop at the freshmen check in center and can be view on YouTube (Paper Towel Composting in Residence Halls at UC Berkeley!, 2010)[10] The student group Compost Alliance, housed under the Campus Recycling and Refuse Services, later initiated a continuation of the program in all dining facilities and cafes. The Cal Dining facilities along with several buildings on campus had already implemented a food waste composting program(UC Berkeley, 2010). With a pre-established food waste collection site, the addition of paper towels became a complementary addition.[11]

A truck offloads food waste to be processed in EBMUD's dome-shaped anaerobic digester. (Photo courtesy U.S. EPA)

Currently a third party private company called Recology collects the food and paper towel compost and transports it to East Bay Municipal Utility District (EBMUD). Their food waste pilot study began in 2007 and has been growing strong accepting food waste from neighboring restaurants.[12]

Project Goals[edit | edit source]

Our strategic goal is to simply reduce the amount of waste being generated on campus and transported long distances to the landfill. This reduce the GHG emissions associated with HSU and hopefully complement the future food waste-composting program being studied. Many stakeholders, including HSU, the campus Sustainability Department, WRAAP, and HWMA, share this goal.

In order to meet our strategic goal, we need to implement several programmatic goals or objectives. The following is a comprehensive list of what these goals are in chronological order:

  1. Develop and maintain relationships with all stakeholders.
  2. Research existing policy framework and determine if paper towels can be legally composted in the county.
  3. Research similar programs at other colleges.
  4. Research the type and brand of paper towels currently being used on campus and determine if they are an efficient feedstock for an anaerobic digester.
  5. Observe custodians during work and discuss issues and troubleshoot obstacles pertaining to collection methods.
  6. Perform a baseline study of current paper towel waste generation in a random sample of bathrooms on campus on campus to determine estimates of volume and weight.
  7. Perform a behavior change study to determine how well students are informed and can comply with a possible bathroom towel waste-composting program.
  8. Compile an organized planning document for future students to use to implement the actual paper towel waste composting program in the future

To gain support for our project we would like to prove that it could be successful by achieving a 70% decrease in contamination in our paper towel collection bins.

Implementation[edit | edit source]

Separating Paper Towels from Contamination
Measuring Mass of Paper Towels
Working Alongside the Custodial Staff.

This project was originally designed to be a three phase process, with each phase lasting one semester. The following outlines Phase one activities:

  1. Research existing paper towel diversion programs utilizing an anaerobic digester.
    1. U.C. Berkeley.
    2. Santa Clara State University.
  2. Schedule meetings to determine feasibility, legality, and logistics.
    1. Office of Sustainability.
    2. Humboldt Waste Management Authority.
    3. Humboldt County Environmental Health.
    4. Facilities Manager and Custodians.
  3. Begin Baseline Data Collection.
    1. Collect bathroom waste from 7 buildings in 4 days- 132 Bathrooms.
    2. Separate contamination from paper towels.
    3. Measure volume and mass of paper towels and contamination.
  4. Begin Behavioral Change Data Collection.
    1. Bin Sign.pdf
      Post instructional signs and bin signs indicating "paper towel only" bins along side "everything else" bins.
    2. Collect separated bathroom waste from 7 buildings-129.
    3. Separate paper towels from contamination.
    4. Measure volume and mass of paper towels and waste in everything else bin.
  5. Analyze Results.
    1. Calculate estimated total paper towel generation from Humboldt State.
    2. Determine effectiveness of signs.

Results[edit | edit source]

Baseline Data Collection

Baseline data consisted of a four-day collection period and 132 bathrooms from seven different buildings between the dates of November 7th and 10th. A total of 247.8 lbs of paper towels were collected. We measured 29.6 lbs of contamination mixed in with the paper towels, for a total waste mass of 277.4 pounds. Between the seven buildings, we collected 24.7 full bags of paper towels at 2.7 cubic feet per bag; that is 66.69 cubic feet of paper towels collected in the first week.

Behavior Change Data Collection

The behavior change data sampled a total of 129 bathrooms in seven buildings between the November 29th and December 2nd. A total of 168.1 pounds of paper towels were collected. We measured 6.7 pounds of contamination mixed in with the paper towels. Our bins marked "everything else" contained 26.3 pounds of waste. In total, 201.1 pounds were removed from the sample bathrooms. A total of 16 full bags at 2.7 cubic feet per bag for a total of 43.2 cubic feet of paper towels. Observations of contamination and "everything else" bins were noted.

Analysis[edit | edit source]

  • Mass and Behavior change

Over an eight-day period a total of 478.5 pounds of waste was removed from the sample bathrooms. Our baseline data averaged 1.9 pounds of paper towels and 0.2 pounds of contamination per bathroom. Behavior change sampling averaged 1.3 pounds of paper towels and 0.05 pounds per bathroom. This data shows a 120% difference or a 75% decrease in contamination between baseline data and behavior change data. Assuming there are 120 bathrooms on campus, we can extrapolate the average of 1.6 pounds of paper towel mass per bathroom for a total of 192 pounds generated in one day. This equates to 29,952 pounds or 15 tons of paper towels per semester.

  • Volume

We calculated an average of 10 pounds per full bag. This represents a total of 2,995 full bags of paper towels. A conservative estimate of 2.7 cubic feet of compressed paper towels per bag equates to a volume of 8,086.5 cubic feet. This volume of paper towels requires 2.7 waste hauling trucks.

  • GHG reductions

Using our data to calculate possible GHG offsets and reductions in disposal fees, we estimated a reduction of roughly 2,260 kg CO2/year and a savings of $2,250 a year. Current disposal costs of HSU are around $135,216 per year with a GHG equivalent of 37,725 kg CO2/year. These numbers are conservative because they do not account for the large amount of volume of uncompressed paper towels.

Discussion[edit | edit source]

Weakness in study

  • Time

Bathroom paper towel sampling requires two to four hours an evening.

  • Sample Size and Duration of Data Collection

A more robust sample over an entire semester including weekends, special events such as football games, and holidays are required to supply a more accurate representation for HSU's paper towel waste. Also an increase in sample size is recommended for a more complete statistical analysis. We were only able to acquire 32 out of the assumed 120 bathrooms located on HSU. This would require a larger work force with a longer time allowance than we were able to attain.

  • Mass Scale

The device we used to measure mass was a standard, inexpensive digital bathroom body weight scale. With contamination levels averaging a pound per building, it was nearly impossible to obtain accurate readings with this simple scale. We recommend using a hanging spring scale with accuracy up to one gram.

  • Social Marketing

The project was limited to signs posted in the bathrooms next to the waste bins. These signs were temporary, laminated, color coordinated pieces of paper held with strips of painters tape. This left the study vulnerable to sign removal and vandalism, which we experienced at multiple collection sites. Future signage needs be on a more permanent basis and should be harder to remove. The project was featured in the November 30th edition of the "Lumberjack". This may have boosted participation from students and faculty on campus. Although this was rather serendipitous, it could be employed as a social marketing tool in the future.

What we learned

  • Establishing communications and building relationships with employees and organizations are paramount. A good example of this would be that of the custodial staff; without their support and being allowed to conduct this study in their respective areas-of-responsibility, we would not have been able to pursue this experiment at all.
  • Accuracy and precision are important when measuring paper towels and especially contamination, given that large amounts of volume do not necessarily mean a high measurement of mass.
  • Effective signage is key to communicate your message. We used only temporary signs that were held up with painters tape, however we experienced a 120% difference in behavior change or 75% participation. With more permanent signs and education programs, higher results may be expected.
  • A large amount of time, labor, and commitment is required for this study. Two students spent an average of 2.5 hours each collection night, for eight nights.
  • There will always be those who initially will not agree with the proposed project or its methodologies. But we also found that brainstorming with them can help provide new, out-of-the-box ideas that were not originally included in the study.


  • Initiated pilot study allowing us to evaluate some of the issues necessary to continue this project in the future.
  • Created interest and support from different collaborators forming a project network. We feel that these relationships are very important and should be maintained to ensure future participation.
  • Supported by a strong volunteer group.
  • The study met our objective of reducing contamination in the paper towel bins by 70%. This shows that students can make a difference and support a paper towel waste diversion program.

Equipment used[edit | edit source]

  • 33 gallon plastic barrel w/ roller base
  • Plastic trash bags
  • Rubber Glove
  • Pen/paper
  • Standard digital bathroom scale
  • 28 Quart Plastic bins
  • Signs and tape
  • Camera
  • Volunteers

Next Steps[edit | edit source]

Phase Two: Re-Analysis and Adjustment

The planning document will serve as a guide for another group to continue next semester. The time sensitive nature of this project will require an additional semester for several reasons. Detailed transportation and collection logistics need to be thoroughly outlined during the second stage of progression in this project. A more robust sampling of the campus' paper towel waste may be needed to better estimate the volume of paper towels that will be sent to the proposed anaerobic digester. This will also impact the current transportation schedule and thusly, logistics on pickup schedules and coordination with 3rd party transportation will need to be squared away. More research must be done on social marketing measures to ensure behavioral change mechanisms are in place prior to the actual implementation of this composting program. In addition, HWMA expressed an interest in determining if the paper towels HSU currently uses are adequate for composting in an anaerobic digester. While we did learn that there are two types of paper towels used in campus bathrooms, one made of sugar cane (bagasse) and the other from 100% recycled paper fiber, further study into how these materials digest and break down will be needed to ensure they are fit for diversion (Meyer, J. 2011).

The second phase will continue to outline established resources, data collected, and additional work to complete. In addition, changes to methods will be outlined for future consideration. The second-phase group will be responsible for maintaining strong relationships with interested parties and collaborators. The idea is to build a seamless bridge between a student group and the office of Sustainability.

Phase Three: Project Roll Out

The last phase will be the transition from student group to the office of Sustainability. By this time there should be a good level of communication between all interested parties and a concrete commitment to the project.

The project will begin before the semester begins, roughly two weeks prior. Changes to waste transportation will be negotiated with Arcata Garbage using supporting data from phase two sampling. The custodial staff will be educated on the campus zero-waste commitment and given the empowerment to participate through incentive programs. All bathrooms will be fitted with smaller landfill wastebaskets and appropriate signage in preparation for incoming students.

The first week of school will focus on education through freshman orientation, tabling, articles in the lumberjack and PSA's on the radio. The main objective is to create social responsibility through community awareness.

Lastly there will be a monitoring program employed looking at the level of participation among students and collection strategies. A measure of the amount of contamination will indicate a level of behavioral change and allow for changes in social marketing strategies. Adjustments to collection schedules will also need to be made as participation changes along with troubleshooting of any other obstacles that come up.

The last step is to continually document and evaluate in preparation for institutionalization. Random waste characterization studies should be performed throughout the year and quarterly reports submitted to the Office of Sustainability and campus administration on the projects progress and success. Once institutionalized, the program should be promoted on a local and national scale so other student groups and universities can learn from this example.

Conclusions[edit | edit source]

Paper towels are an untapped component of HSUs waste stream that could be diverted to make energy. Our project narrowed in on this "low-hanging fruit", in order to aid HSU on its path towards sustainability. By reducing its waste, HSU meets state and local policy initiatives, and incurs the benefits of reduced disposal costs. It also can enjoy the opportunity to become apart of a larger picture towards reducing Humboldt Counties dependence on out-of-area landfills and in providing a new local energy source. There is much more work to be done for this project to come to fruition and this planning document is a first step towards attaining our final goal of an actual paper towel waste composting program.

Update and Link to Project Phase II[edit | edit source]

02/16/2012 The Paper Towel Waste Diversion Project was proposed and accepted as a class project to the Energy, Technology, and Society (ENGR370) at Cal Poly Humboldt Paper Towel Diversion Project Phase II. Click to follow progress on this project.

Full Document[edit | edit source]

You can view the whole document by clicking on this link

Paper Towel Diversion Project Document.pdf

Acknowledgments[edit | edit source]

We would like to extend special thanks to the following people, in particular order, for their help and assistance on this project. Dr. Richard Hansis, Tall Chief Comet, Morgan King, Ed Goodeyon, participating custodial staff, Carolyn Hawkins, Juliette Bohn, Sara Mosser, Norton Mitchell, Claire Evans, JoAnna Young, and all of personal friends who assisted in all the dirty work.

References[edit | edit source]

  1. Comet, Tall Chief. Interview. 15 Sep. 2011.
  2. Bohn, Juliette. "LMOP Project Expo 2010." Landfill Methane Outreach Program. 2010
  3. Bohn et al. 2010, Food Waste Diversion and Utilization in Humboldt County, Humboldt Waste Management Authority, See Figure 2.1 ,p.4
  4. Bohn, et al. 2010, Food Waste Diversion and Utilization in Humboldt County, Humboldt Waste Management Authority. pp. 4, 10
  5. (US EPA) U.S. Environmental Protection Agency (2009b). Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2007.EPA 430-R-09-004.
  6. Notes from HSU Food Waste Pilot Study Group Meeting. September 26, 2011.
  7. (Bohn, et al.2010, Food Waste Diversion and Utilization in Humboldt County, Humboldt Waste Management Authority. pp. 24, 51)
  8. (Bohn, et al. 2010, Food Waste Diversion and Utilization in Humboldt County, Humboldt Waste Management Authority. p. 52)
  9. Joanna Young, UC Berkeley Residential Sustainability, Program Volunteer. Telephone Interview, November 15, 2011
  10. Norton Mitchell, UC Berkeley Facilities Manager. Telephone Interview, November 3, 2011
  11. Claire Evans, UC Berkeley Cal Compost, Lead Coordinator. Telephone Interview, November 23,2011
  12. Claire Evans, UC Berkeley Cal Compost, Lead Coordinator. Telephone Interview, November 23,2011

Contact details[edit | edit source]

Discussion[View | Edit]

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