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TRANSCRIPT
Composting Feasibility and Implementation Analysis
for the University of Wisconsin-Whitewater
May 2010
Student Investigator: Alyssa Peschke
Faculty Supervisor: Dr. Eric Compas
University of Wisconsin-Whitewater
UNIVERSITY OF WISCONSIN SYSTEM SOLID WASTE RESEARCH PROGRAM Undergraduate Project Report
Composting Feasibility Study May 2010
2
Composting Feasibility and Implementation Analysis
for the University of Wisconsin-Whitewater
Alyssa Peschke, Student Researcher
Dr. Eric Compas, Faculty Researcher
University of Wisconsin—Whitewater
Composting Feasibility Study May 2010
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Introduction
Campuses are a vital site of future innovations, including researching and
developing sustainable plans and practices. An important advancement many
universities have been making is changing to more sustainable food waste disposal
and utilizing the waste‘s nutrients through composting.
Waste collection and removal is an increasing concern for campuses across
the country with social pressure to work toward more sustainable practices.
Capturing the nutrients and value in food waste can continue long-standing
cultivation to soil and surrounding nature. In a university setting, this can offer an
educational benefit for university students, faculty, and visitors in an increasingly
environmentally and sustainability-focused world. Furthermore, capturing the
nutrients and value in food waste can also create potential for cost savings or
avoidance through reducing fertilizer purchases and paying tipping fees for waste
removal and transportation (Bertagnolli).
Within the eight largest University of Wisconsin (UW) System universities, six
are currently composting their food waste. These universities are (listed from largest
to smallest student population) UW-Madison, UW-Milwaukee, UW-Eau Claire, UW-La
Crosse, UW-Stevens Point, and UW-Stout (―Fact‖). The second largest UW-System
university, UW-Oshkosh, has been formulating a plan to purchase a digester to
compost waste from the university and within the city of Oshkosh (Norby). Now is the
appropriate time for University of Wisconsin-Whitewater, the system‘s fifth largest
university, to analyze its own food waste removal and assess composting options.
UW-Whitewater has taken multiple steps and commitments toward becoming
a more sustainable campus. In 1997, UW-Whitewater‘s Chancellor signed The
American College and University Presidents‘ Climate Commitment pledging to work
toward becoming climate neutral (―Signatory‖). For the last two years, the campus
has participated in RecycleMania, a ten-week recycling competition (―RecycleMania‖).
With a growing campus, plans to decrease waste for UW-Whitewater students are
able to expand and produce an escalating impact through time. The university has
created a ―Sustainability Council,‖ co-chaired by Dr. Eric Compas and Greg Swanson,
to review various sustainability issues on campus (Compas). Chartwells has recently
switched away from having any polystyrene (‗Styrofoam‘) cups and went ―tray-less,‖
decreasing the necessary amounts of water and costs associated with washing and
maintaining trays in the University Center ―student union‖ (UC) and dining halls on
campus. Chartwells also gave each student living on campus a reusable BPA-free
bottle to be used in place of disposable cups to decrease waste as well (Wick).
Through involvement in sustainable efforts, the goal of responsible waste removal
has emerged as a priority of the campus.
The purpose of this report is to 1) assess current practices, 2) survey campus
alternatives, and 3) give a recommendation of the best alternative. This report offers
an outline of analyzing food waste starting by describing the current food waste
disposal practices and analyzing specific criteria. The analyses will also propose
basic steps for implementing each alternative, referencing needed agreements,
resources, labor, and planning. Concluding the report is an analysis section,
contrasting each alternative‘s strengths and shortcomings while discussing possible
variations. Additionally, this report offers contacts for local resources.
Composting Feasibility Study May 2010
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The criteria used to analyze each option are the following (in no particular order):
Initial costs
Regulations: including Department of Natural Resources (DNR)
regulations and safety requirements
Ongoing costs
Feasibility through Wisconsin winters
Potential for educational benefits
Degree to which each option could be expanded
Applicability to the UW-Whitewater campus
Pre-consumer / Post-consumer Waste
This study will primarily focus on the trail of pre-consumer food waste. Pre-
consumer food waste entails kitchen preparatory waste. This typically will include
food waste such as peels, rinds, potato skins, crusts, or trimmings. Outside the scope
of this study, termed post-consumer food waste, is food which has been served or
left by a customer. Post-consumer food waste includes all material after food
preparation, whether the food had been served or not, including items in a buffet line.
Post-consumer waste may be mixed with other materials or have sauces or spreads,
making it not compostable.1
Overall, pre-consumer waste is a much more straightforward first step to
composting. Post-consumer waste separation can add increased difficulty, being
especially problematic through summer months during camps and conferences
where many visitors are on campus for three days or fewer (Wick). Focusing on pre-
consumer waste for this study enables focusing on the procedures of composting
and staff needed to transport materials and monitor the compost first without the
additional complications added when food is not separated correctly. Teaching
student Chartwells workers to properly separate food waste, as discussed through
this study, can ease the transition to future customer separation of waste from
establishing a knowledgeable base of students who are aware of correct separation
when the university decides to expand. Consequently, focusing on pre-consumer
waste will allow for the most initial progress; however, it is valuable to keep
expansion plans in mind and incorporate collecting post-consumer waste in future
planning.
Composting has a variety of distinct advantages as well as a few distinct
disadvantages that need to be noted.
Advantages of correctly composted materials:
- Can act as a pH buffer for both alkaline and acidic soils
- Returns valuable nutrients to the soil when used as a fertilizer or mulch
- Saves money otherwise spent on fertilizers
- Acts as a sponge, helping the soil absorb more water
- Improves soil structure, loosening up heavy clay soils for plant roots
- Can help break down and minimize the effects of toxic chemicals remaining in the
soil from past chemical applications
1 The University Center currently only collects post-consumer waste for breakfast and Drumlin dining
hall does not have a turn-style to collect dishes to easily collect post-consumer waste, further
complicating the collection of post-consumer waste. See footnote 9 for additional information.
Composting Feasibility Study May 2010
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- Compost has lots of beneficial microorganisms that help reduce plant disease
- Compost stays in the soil and releases plant nutrients slowly over time
- Finished compost has no risk of burning plants, as can happen with synthetic
fertilizers (―About‖)
Appropriate compost materials: Non-compostable materials: 2
It is also important to note that while composting can be very beneficial for
the environment, if a compost pile is not maintained and turned regularly, compost
piles can become anaerobic (a result from not having enough oxygen gas), releasing
methane gas, a gas 22 times stronger than carbon dioxide, damaging our
atmosphere (―Environmental‖). Compost piles can also have excess runoff, lechate,
released into soil and surrounding areas, potentially creating negative odors, etc.
Potential Solutions
From research on other campus‘ practices and on-campus interviews, the following
top solutions were analyzed for improving food disposal at UW-Whitewater:
1A) Windrow composting on the UW-Whitewater campus
1B) Windrow composting at the City of Whitewater composting site
2) Promoting additional use of garbage disposals
3) Using an in-vessel compost system
3A) Using a dehydrator
3B) Using an Earth Tub
Of these, we are recommending option 1A: windrow composting at the
university as our most feasible option for food waste handling at the University of
Wisconsin-Whitewater.
Methodology Through the course of this study, information was primarily gathered from
several semi-structured interviews and multiple site visits with local waste
management systems, city composting sites, and representatives of prospective
organizations (See Table 1). This project has utilized models of other colleges in the
2 Many non-compostable materials are not decomposable due to excess grease or a wax
coating. If workers responsible for composting choose, meat scraps, bones, and dairy products may
be added in small proportions. To minimize potential vermin through collecting meat and dairy items,
a suggestion is to collect these materials initially only on days waste is picked up.
Milk, soy milk, or ice cream
cartons
Used pizza containers
Food wrappers
Coffee creamers, stirrers
Plastic bags, plastic wrap
Polystyrene (‗Styrofoam‘)
Recyclables (plastic, glass)
Dishes, silverware
Fruits, vegetables: peels, prep
waste
Coffee grounds, tea bags
Breads, cereals, grains
Noodles, pasta
Salads with limited dressing or
cheese
Paper napkins, paper towel: if un-
used
Composting Feasibility Study May 2010
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University of Wisconsin-System, specifically UW-Madison‘s composting system.
Literature reviews have also been used to collect information on current practices at
other similarly-sized campuses. Institutional Review Board approval was acquired to
conduct this study.
Table 1 - Interviews
Contact Interviewed Organization Position
Bob Barry UW-Whitewater Director of Student Union
Steve Bertagnolli UW-Whitewater Buildings/Grounds Supervisor
Michael Keleman InSinkerator Disposals Environmental Engineer
Chuck Nass City of Whitewater Streets and Parks Superintendent
Eileen Norby University of Wisconsin System
Administration
Waste Minimization Manager
Tim Reel City of Whitewater
Wastewater Treatment Facility
Superintendent
Greg Swanson UW-Whitewater Facilities
Planning and Management
Director
Ann Wick Chartwells Dining Service Marketing Director
Thomas Wright UW-Madison W. Agricultural
Research Station
Superintendent
Status Quo Currently, Chartwells, the university dining service, disposes of 90-95% of the
university pre-consumer waste through garbage disposals. This includes waste from
the three primary dining locations on campus: the University Center (UC), Esker, and
Drumlin. At the UC‘s Ike Schaffer Commons for breakfast and at Esker for all meals,
the post-consumer waste is also discarded in garbage disposals. This totals 47.96
quarts of waste in wet weight per day, excluding university breaks or closings.3
Current waste removed through garbage disposals,
separated by area, is as follows (Wick):
University Center: 12.32 quarts per day
Esker Dining Hall: 14.58 quarts per day
Drumlin Market: + 11.06 quarts per day
Total for campus: 47.96 quarts per day
Using the wet waste as a basis of our anticipated total waste to be used for
composting and using RecycleMania‘s estimate that mixed food waste is equivalent
to 1.33 cubic yards per ton, the total collected food waste would be 14.51 tons of
mixed food waste (See Table 2).
Table 2 – Total Waste
47.96 x 325 = 15,587 x 0.25 = 3,897
3 In addition, the coffee shops, on average create 755 ounces of dry weight per weekday from coffee
grounds. This includes the Center of the Arts Café, Deloitte Cafe at Hyland Hall, and Food for Thought
at Andersen Library, but excludes hours the Beans coffee shop is open Saturdays and Sundays (Wick).
0
2
4
6
8
10
12
14
16
Quarts per day
Esker
Drumlin
UC
Composting Feasibility Study May 2010
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Quarts of
mixed food
waste per
day
Days UW-W
is open per
year
Quarts per
year
1
quart=0.25
gallons
Gallons per
year
3,897 / 201.974 = 19.29 x 1.33 = 14.51
Gallons per
year
1 cubic
yard=201.97
4
Cubic yards
of mixed
food waste
Cubic yards
per ton of
mixed food
waste
Tons of
mixed food
waste per
year
Current disposal waste from UW-Whitewater flows to the Whitewater
Wastewater Treatment Facility. From there, the course material is caught in multiple
screens of varying sizes. This material (screening and grit) is disposed of in a landfill.
The end solid product or ―biosolids‖ are treated and land applied on local agricultural
fields as it has nutrient value. The water is then filtered and disinfected (seasonally)
prior to discharge in the Whitewater Creek. The solid product is offered to farmers in
the community to use as fertilizer for their fields. When farmers chose to take
Whitewater‘s biosolids, it is land injected, termed knifing, using ‗chisels‘ to inject the
effluent underground into the farmer‘s fields.4
With the large amount of treated wastewater being recycled onto farm fields
or discharged into the Whitewater Creek after being appropriately treated the effects
can be very similar to composting. However, similarly to how when carrots are cooked
and drained, much of the nutrients are lost into the water, all of the nutrients may not
be fully maintained in garbage disposal sludge. The nutrients may go to a pond or be
lost through the pipes and tanks rather than fully staying in the material as with
compost (Reel).
Since a majority of UW-Whitewater‘s pre-consumer waste is disposed of
through garbage disposals, the potential for cost savings for UW-Whitewater is not as
sizeable as it may be in other campuses. Understanding these costs demonstrates
the future investment of utilizing composting or
garbage disposals for our campus‘ post-
consumer waste.
Options:
1) Windrow Composting The first option, windrow composting, will
be explained in general, analyzing the criteria
then further discussed in detail for two specific
options on campus compared to the local city
composting site.
4 In some areas, this process is billed for, but Whitewater‘s wastewater treatment plant offers this at
no cost. This is due to the negative stigma associated with wastewater and its associated odors (Reel).
Fig. 1 – City of Whitewater Composting Site
Composting Feasibility Study May 2010
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Windrow composting is a process where food scraps are collected to break
down into usable nutrient-filled compost which can be used for landscaping. It offers
many benefits to the soil and offers a potential cost savings.
The central task in food waste removal of correctly separating food material
has been set in motion and may be soon underway. The food service contract, active
for the next seven years, includes an agreement for Chartwells to work with the
university in improving waste management efforts. The Request for Proposals (RFP)
food service contract, becoming effective June 1, 2010, states that the new food
service contractor, Chartwells, ―will be required to collaborate with the University and
City of Whitewater to develop a food separation process no later than six months into
the first year of the contract (Barry).‖ Through Chartwells agreement in staff
cooperation and upcoming planning, this offers the potential significantly ease the
process of initiating composting at Whitewater.
Initial Costs
To implement windrow composting at UW-Whitewater
for pre-consumer waste, university staff would be
needed in various stages, as outlined below (Harrod):
6 hours oversight/other
2 hours composting with machinery (See Fig. 2)
+ 2 hours picking up the material
10 hours per week
In order to allow for the best follow through with the dining service, an
employee would need to oversee the collection process. This employee could be a
university limited-time employee (LTE) or potentially a work-study student. This
position‘s duties would primarily involve communication with Chartwells to train
managers and potentially student workers on appropriate food separation. Contact
between the student employees will include initial training of the dining service
managers and/or staff as well as follow-up e-mails with updates or feedback on
which materials may need additional separation instructions. This communication
would start through in-person communication with managers and other Chartwells
staff and, through a semester; decrease to once or twice per week. With all needed
oversight and preparation, this position would be, on average, six hours per week.
Additional costs will include the cost of new machinery, bins for collection,
transportation funds and equipment as follows:
Five 35-gallon containers: may be donated or sold at a low cost by UW-
Madison contacts (Harrod)
Seven 5-gallon garbage containers: UW-Whitewater may have pre-
existing or saved containers
A dump truck, golf-cart, or other vehicle for collection of food waste
Potentially a lift for 35-gallon containers
Machinery to turn the compost
pH monitoring devices
Fig. 2 – Mechanical Mixer
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Fig. 3 - UW-Madison‘s Composting Pick-up Machine
Fig. 4 - Lift for Compost Pick-Up
If the UC chooses to start separating materials at select areas first, collection
at the UC joint kitchen (for Ike Schaffer Commons, Graham Street Café, and Down
Under), Esker, and Drumlin are preferable starting locations. At these locations, it is
recommended that compostables be collected in a 35-gallon container (See Fig. 5).
Through expansion, the café areas: Beans, Center of the Arts Café, Deloitte Cafe at
Hyland Hall, and Food for Thought at Andersen Library, will also collect primarily
coffee grounds, as the majority of food preparation for these areas is done elsewhere.
Each of these locations will have a 5-gallon bucket (see Fig. 6) which can be emptied
into a larger bucket in a trash collection area when it is full and kept until the next
pick-up day. Through the new food service contract, Chartwells‘ previously flavoring-
based smoothies sold in Beans will soon use real fruit, possibly resulting in banana
peels and/or other food preparation waste being collected in these areas (Wick).
Fig. 6– 5-gallon bucket for collection
Fig. 5 - 35-gallon bins for larger kitchens
Composting Feasibility Study May 2010
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A consistent schedule would be determined to collect compostable material
from the kitchen each week and bring the materials to the chosen composting site. It
is recommended that collection days are no more than three days apart (Ex. each
week on Tuesdays and Fridays) and, if necessary, would allow for best compatibility
with the pre-existing systems. For instance, at Madison the same crew of workers
picks up the compost as the remainder of the waste, resulting in pick up of
compostable materials on a day opposite general waste to allow for similar shifts
each day (Harrod). Staff needed to transport materials may vary depending on the
location of the composting site and employees available.
We recommend that staff in charge of monitoring the composting procedures
go to the Midwest Composting School, which offers in-depth instructions on the
composting process during a three-day composting workshop.5Throughout their
training, staff will learn about monitoring compost through regulating pH, moisture,
and aeration. Appropriate regulation allows for the most efficient composting
operation with limited odor (to ensure that ammonia gas is not being released into
the air) and limited pests. The most typical compost options, all of which could be
appropriate to UW-Whitewater, are windrows (with or without temperature control
and aeration); piles and tunnels; bays, beds, and tunnels; and vermi-composting
(incorporating worms to increase the breakdown of material) (Compost).
Finding labor for these positions may be difficult, as both the landscaping
department on campus and the city compost site employees are under-staffed;
however, workers at the University Center may have more staff time available.
Regulations
DNR regulations can be very specific to a particular area, requiring
appropriate distancing from floodplains, private water wells, navigable lakes, ponds,
flowage, rivers, or streams and other requirements. DNR regulations may be minimal
if we compost only our anticipated pre-consumer waste at the university site due to of
anticipating less than 50 tons of waste per year. At the city composting site, adding
food waste may require additional permits than their current permits and the site will
have over 50 tons of food waste per year, also adding a potential increase in
requirements. Conversely, some permits may overlap, decreasing permits needed.
Requirements will be covered broadly at the previously mentioned Midwest
Composting School (See footnote 4).
Ongoing Costs
The longer the project has been enacted, the easier trainings, pick-ups, and
oversight will become and the investments will more likely pay off or be invested into
additional expansion of the project. Monitoring hours required for the compost
overseer will sink to only one or two hours per week in later semesters, possibly being
combined with another position‘s hours. Pick up of materials may increase slightly
with additional food, but once all of the locations are included, the amount of time to
pick up material will generally not change depending out how much is collected, as
5 This training is presented through collaboration between the University of Wisconsin Extension, the
University of Minnesota, and Iowa State University. This year (2010), the composting school will be
held in Madison, WI June 8- June 10. For more information, contact UW Extension Recycling Specialist
Joe Van Rossum at [email protected] or (608) 262-0936 (―Solid‖).
Composting Feasibility Study May 2010
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the waste will continue to be picked up regardless of the amount. Compost
monitoring will maintain its two hours per week as well, with only slight increases
from additional food waste.
Feasibility through Wisconsin winters
Through colder temperatures, if compostable bags are chosen to be used,
bags are potentially less likely to break down, as there is a very narrow range from
the typical 135ºF of an internal composting temperature and the 130ºF required for
compostable bags to break decompose. 6
Educational Benefits
Composting can offer significantly more of an impact on education at a
university location. This can include offering training associated with composting in
knowing how to separate materials As a result of separating compostable materials,
the estimated 200-300 Chartwells workers that are university students would learn
more about composting (Wick). Again, having university students knowledgeable
about compost separation can ease the process of post-consumer waste separating
in the future. This can also create positive impacts through awareness of
sustainability in student‘s own futures or promoting implementing future projects
both throughout and after attending UW-Whitewater. Creating a position for a
―Compost monitor‖ or potentially additional positions involved in monitoring total
waste can offer additional employment, with a positive impact on the economy, and
provide applicable work experience, especially for geology/science students or recent
graduates. With each system, student organizations, including our student
environmental association (SAGE), could also learn a lot through involvement in the
project, especially through incorporating available volunteer hours or through
promoting independent studies to further advance the project.
Ability to be Scaled
An advantage of windrow composting is its ability to be scaled easily. Despite
the amount of waste, the process is still the same. With large increases in the
amount of waste, changes would only require small and gradual additions such as
additional collection buckets. Time needed to pick up the material will also be a
gradual process and an increase in material will contribute minimal additional labor.
Further, the same site could be used throughout and there would not need to be any
additional large purchases. As with any system, through long-term usage, machinery
may wear down or have opportunities for upgrades.
Applicability to the UW-Whitewater campus
1 A) At UW-Whitewater
If composting were to be done on the UW-Whitewater campus, material
from Chartwells kitchens would be picked up and potentially be taken behind
6Through winters, compost piles generally maintain their average internal temperature of
130ºF, and the composting process consequently is not affected from the outside temperatures
(―BioBag‖). As discussed earlier, bags not composting create additional labor to separate pieces of
bags that had not degraded (Wright).
Composting Feasibility Study May 2010
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the Facilities Planning and Management Building on campus, about 1 mile
from the UC (Swanson). A large benefit a site on the university offers is the
encouragement towards students and faculty to be aware of the projects and
advancements of the university. Being on campus may offer additional
educational opportunities to advertise the progress of the university with
effectively utilizing its food waste. Researching composting may be more-
easily promoted if the site was at the university as well, where researching
about our composting effort would have to be much more planned if the
compost were located at the city site. If volunteering were considered as a
means of monitoring the pile, the university may offer a more conducive
location for this as well.
1 B) At the City
If composting were to be at the city location, a pertinent difference is
that the city site is currently only open to city residents from April to November.
During these operating times, the site is open twice per week: on Wednesdays
and Saturdays. During this time, the piles are turned once per week and once
per month during the winter (Nass).
Currently the city has four rows of compost, at varying levels of
readiness. The collection site is available for residents and city commercial
businesses to drop off their yard waste and materials and advertised through
a link from the city website. It collects leaves and offers BioBags to its
residents to bag their yard waste in (Nass).
A service that the city site offers, in part by themselves and in part
through an outside company, is wood-chipping. This is offered both at the site
and at resident‘s homes. With these woodchips, this could allow for less
transportation costs if woodchips were needed as a buffer in the compost.
The city site may offer additional permits for composting that would be easier
to obtain due to already composting at the site. The city will likely only have to
add an additional permit specifically for food waste, which they had not used
before.
Surprisingly, the change in transportation between the on-campus site and
the city composting site is less than ½ of a mile difference, with only 1 mile to nearby
agricultural buildings on campus from the UC compared to approximately 1.4 miles to
city composting site. Some campuses such as UW-Stout, have implemented plans
incorporating transporting their waste or further distances to be collected at a waste
recycling site (Norby). However, with a site on campus, classes or campus
presentations could more easily visit the site, as it can be within walking distance,
where even that ½ mile could require transportation and liability associated with this.
2) Garbage disposals
With such a majority of our current pre-consumer waste being disposed
through garbage disposals, it was pertinent to analyze the effects of this. With
positive effects, this could be promoted further, incorporating more post-consumer
waste.
Composting Feasibility Study May 2010
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A pertinent difference between composting
and garbage disposals is that garbage disposal
sludge is mixed with all other sewer systems
including biosolids and anything from household or
business toilets, sinks, showers, or other sewage
materials. This includes if any users were to dispose
of chemicals or other products down a drain,
potentially decreasing the quality of the sludge (Reel).
However, the Whitewater Wastewater treatment
facility also ―has an exceptional track record of
quality effluent (―Wastewater‖).‖
I
Initial Costs
The initial cost for garbage disposals is low due to
how garbage disposal usage is already largely enacted.
Regulations
There are only general safety requirements associated with garbage disposals
and there have been no significant injuries or difficulties associated with this (Wick).
Ongoing Costs
The ongoing costs on a day-to-day basis are minimal, as disposals are only on
while being used (Wick). The usage of water may increase in cost through time as
water is becoming an increasingly valuable resource. Garbage disposals typically do
not break down due to over-usage, but, rather, from the wrong materials being put
down the garbage disposal. Currently, all waste collected with the exceptions of
napkins is disposed of through garbage disposals (Wick). However, as our university
continues to utilize these disposals, it should consider limiting the types of materials
that are disposed of through garbage disposals. Stringy materials such as banana
peels do not break down as other food may, leaving large particles to be screened
out and potentially damage the piping to the wastewater treatment facility through
contributing to blockages in the collection system. With correct usage, clogging is
rare. However, one of the most frequent difficulties is from clogging, due to the
buildup of oil in pipes. When these clogs occur, this can be an extremely costly
process as much of the piping is underground and very difficult to access.7
Feasibility through Wisconsin winters
Through Wisconsin winters, pipes are unlikely to freeze, the only expected
difficulty with a cold climate (Reel).
7 Grease build-up is a decreased concern due to state plumbing codes requiring grease interceptors
(or grease traps). When grease interceptors are maintained correctly, grease traps are now infrequent
(Reel).
Fig. 7 – Wastewater Treatment Facility collection final
stage of processing
Composting Feasibility Study May 2010
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Educational Benefits
There is only very minimal information on the environmental effects of
garbage disposals, although there has been growing curiosity on a research basis
about the impacts of the effects on farmer‘s fields from garbage disposal effects
compared to composting. As with much new research, some research states that
garbage disposals are a simple way to dispose of waste and give back to the
environment, where others advise avoiding it. In part, this is due to differences in
treatment plants and methods (Keleman).
Key parts to the environmental impact are whether or not the
treatment plant uses anaerobic digestion and captures methane, both
which can be very beneficial (Keleman). Through capturing methane,
this can offer a potential cost-avoidance to the Whitewater Wastewater
Treatment Facility from using this to heat their buildings. Currently, the
Whitewater facility also has anaerobic digestion and is nearing
completion of a study on biogas use. It previously collected methane
while a nearby dairy was open, but since stopped collecting this (Reel).
Ability to be Scaled
UW-Whitewater garbage disposals have not had any difficulty in the past with
having too large of an amount of waste disposed in the garbage disposals and it is
not predicted to have any additional complications in the near future if they are is
continued to be used correctly, however disposals are typically engineered differently
depending on the expected amount of use of the disposals.8
Applicability to the UW-Whitewater campus
This solution fits well with UW-Whitewater due to so much already being
largely implemented already. With an excellent history of quality effluent, passing
each year ―with flying colors,‖ the Whitewater Wastewater Treatment Plant
specifically would offer one of the safest sludge mixtures (Reel).
3) In-Vessel Composting System In an in-vessel system, compost is generated from the
system/machine which grinds, dehydrates, or in some way
composts the materials. An in-vessel system would still require
separation of materials.
3A) Dehydrator
Upon begin presented to campus administrators, the Somat
model ET-1000w dehydrator initially appeared to be a ―clean and easy way to
compost without having to have the city or campus develop a compost site (Barry).‖
Being a dehydrator indicates that the system would only decrease the weight of the
total waste through dehydrating the material. This does not, however, result in a
8 In communities with varying garbage disposal usage, engineers use different design standards (.22
lbs of BOD/person/day in communities with significant garbage disposal usage compared to .17 lbs of
BOD/person/day with less usage). This is not overly significant; however, it does indicate that an
increase in usage of garbage disposals, there may be a need for varying design standards (Reel).
Fig. 8 – Methane Collection Tank
Fig. 9 – Somat Dehydrator
Composting Feasibility Study May 2010
15
compostable product (Norby). In fact, if this were used as compost, it would re-
hydrate ―essentially giving the appearance that food scraps have been strewn about
(Barry).‖ Similarly, once this material is placed in a landfill, it would re-hydrate with
natural rain and runoff (Norby). Furthermore, because food waste is 70% water,
dehydration can be a costly and energy-inefficient procedure (―Environmental‖).
Some campuses have chosen this option to decrease tipping costs, as this fee
is generally paid by ton and a dehydrator would decrease the weight of the material.9
Through disposing of our garbage in garbage disposals, we have already avoided this
fee for our garbage disposal waste (pre-consumer waste and post-consumer waste at
Esker). Collection of post-consumer waste at Drumlin dining hall has added difficulty
from not having any type of system for post-consumer waste collection such as a
turn-style (See footnote 10).
Through not creating a compostable product, its energy inefficiency, and not
saving a significant disposal cost, the dehydrator is not a recommended food waste
removal system for the UW-Whitewater campus.
3B) Earth Tub
An Earth Tub was also considered. This is a smaller-
scale option very similar to an in-vessel composting system.
This would use a lot of electricity, and would still require
transportation to gather food. The option, from Green Mountain
Technologies, offers an option of a self-enclosed unit ―specifically
designed for food waste.‖ It contains a power auger for mixing; a
biofilter to control odors; and separate loading and discharging hatches.
Its manufacturers pledge a user can simply add cut food waste; a
bulking agent, such as woodchips; and turn the rotating, powered auger
for approximately ten minutes a few times per week. Then, once the compost is full,
workers need to only continue mixing for two weeks and a final composting product
would result (―Earth‖).
Initial Costs
The initial cost, optimal for operation with 40 to 150 pounds of organic
material each day, would cost $9,975 for the smallest system (―Earth‖). In addition,
installation, transportation of the 750 pound machine, permits, and training quickly
add up (Donahue).
Regulations
A significant part of installation of an Earth Tub is the variety of permits that
may be needed. In Eugene, Oregon a study was conducted analyzing Earth Tubs.
Here, local codes and regulations required fencing, electrical and plumbing permits,
and analysis by city planners, land use analysts, and electrical and plumbing
supervisors. Installation for two Earth Tubs had cost approximately $4,700 in
addition to the Earth Tubs themselves. Additionally, supervision for the first year
9 This could range from a land-filling fee of approximately $40 per ton or a fee of $136 per ton
incorporating all labor, transportation, and including the landfill fee (Janesville, Mallard, Swanson).
See implementation study for additional information.
Fig. 10 – Earth Tub
Composting Feasibility Study May 2010
16
totaled 250 hours, and at $15 per hour, this totaled $3,750 for the first year:
significantly more than the $2,000 estimated cost savings (Donahue).
Ongoing Costs
After the initial year, routine labor is expected to consist of 20 minutes to mix,
5 days per week with an additional 11 hours of yearly maintenance and discharge,
accounting for around 100 hours per year. Through one year, electricity cost
approximately $100. With only one Earth Tub, these costs would be cut in half.
Feasibility through Wisconsin winters
The Earth Tub manufacturer states ―The Earth Tubs have been installed in
some very cold locations,‖ but that ―It may need supplemental heat if the
temperature remains below 10ºF for more than 7 days. The aerations system should
be shut down during cold weather (―Earth‖).‖ Wisconsin‘s average temperature for
the month of January is 13.2ºF and December and February average 19ºF. In the
Whitewater area, the average amount of days with temperatures even lower than
zero degrees Fahrenheit is around 20-25 days per year (―Statewide‖). The power
auger may also have difficulty working in an excessively cold climate. With this, an
Earth Tub may either not be used during winter months or require supplemental
heating and additional safety instructions, permits, electricity, or monitoring
associated with this, increasing costs (―Earth‖).
Educational Benefits
Students may have increased interest in the Earth Tub, especially if in a
visible, on-campus location. The Earth Tub could fit in well with the marketing and
business aspects of UW-Whitewater in its visually appealing design (―Earth‖). The
Earth Tub would also have the potential for less lechate than a compost pile. Workers
or possible volunteers may be more interested in a clean, enclosed system with
simple operations than a windrow compost system.
Ability to be Scaled
The Earth Tub website claims to be scaled ―easily,‖ yet collecting more than
150 pounds of food waste requires purchasing an additional Earth Tub (―Earth‖). This
may also require changes in space, electricity, and permits.
Campuses have not been satisfied with their Earth Tubs because it created
excessive odor and did not result in a high-quality compostable material. The
decreased daily monitoring only seemed to create a decrease in quality product.
Some campuses have even given away their Earth Tubs or sold them at a very low
cost due to their disappointment (Harrod). Thus, using an Earth Tub has not proven
to be a recommendable system.
Analysis
A key component to food waste removal is what impact it has on the
environment. This is important to follow through with our campus‘ sustainability
efforts and to give back to the environment. In composting, the nutrients are put
directly into the soil and through re-using the material as compost, the soil is
Composting Feasibility Study May 2010
17
strengthened. Composting also can result in saved costs from purchasing fertilizer or
soil amendments (Bertagnolli). In addition, when compost is high quality, it could
potentially even be sold to offset further costs as well (Compost).
The impact of waste from garbage disposals is still uncertain overall, requiring
additional research beyond the scope of this study. Although food‘s nutrients are
potentially saved and diverted into the soil of farmer‘s field, the potentially toxic
material added to septic system may be a legitimate concern.
With dehydrators, there is as much actual waste material disposed of in a
landfill, with the entirety of the nutrient being wasted; only initially taking up less
weight and space in transportation. Furthermore, the material available to collect on
campus is primarily pre-consumer waste that is already being disposed of through
garbage disposals, therefore there would not be a significant decrease tipping fees
until additional post-consumer waste is collected10.
Even though an Earth tub may require fewer instructions, this only decreases
the quality of the compost and many labor costs will still apply with collection of
material.
At this point in time, composting appears to be the most environmentally-
friendly option, but further research on garbage disposals may provide added results.
Cost
Both our university Landscaping and Grounds Department and city
composting site have few staff to offer. The UC may have additional workers available
to assist with a waste removal system and, as needed, funding and labor may be
able to be spread through a variety of departments. Thankfully, collecting materials
will be eased with the food service contract implying cooperation from Chartwells.
From a cost perspective, garbage disposals are the least expensive solution.
Suggested Future Implementation
Once pre-consumer composting is established, it is recommended the
university expand the project to include first post-consumer at Esker, at the UC, and
expanding to other cafés and Drumlin dining hall.11
Conclusion
10
Within the next three years, the Drumlin food service area will have a Heating, Ventilation,
and Air Conditioning (HVAC) re-model where a turn-style for dish collection could very likely be installed.
With a turn-style this could allow for an increased ability to collect post-consumer waste. This could
also include transitioning from using disposable containers to purchasing additional reusable
serviceware and having a traditional resident dining buffet-style eatery (Wick). 11
Another university has offered an opportunity for their student to be involved by having
clean yogurt containers labeled ―compost tubs‖ offered for students who wanted to collect their own
food waste and combine it with the university‘s compost pile ("Composting‖). These could be available
at the residence halls, the UC, or at SAGE (our campus environmental organization) meetings.
Also, with any improvement it is important to advertise to consumers the impacts the
business through signage around campus or around the dining areas. This could also include posting
information or videos on the campus website in addition to Chartwells own dining service website,
Royal Purple (the school newspaper) or other local newspapers‘ articles.
Composting Feasibility Study May 2010
18
Through this analysis, we believe that windrow composting best meets the
criteria laid out and is consequently the best option for the University of Wisconsin-
Whitewater.
With each sustainable project students, faculty, staff and campus visitors who
hear about positive improvements on the campus can be inspired to make their own
positive impact on the environment. This could be through home composting,
discussing options of sustainability on their own campus, being more conscious of
their waste, or inspired to clean up litter. Positive improvements also result in
promoting UW-Whitewater as an environmentally-aware campus. Collaboration with
the city or vendors may encourage similar environmentally-sustainable improvements.
Overall, composting can create a sustainable, feasible option for the campus, adding
another step to create a positive impact on the world.
If there are any additional ideas, findings, questions or comments regarding
this research proposal, please contact us at UW-Whitewater professor Eric Compas at
(262) 472-5126 or [email protected] or Alyssa Peschke at (920) 627-2597 or
Throughout the study, there are many additional goals recommended to
improve the sustainability of universities, some of the best of which I would like to
include here:
1) Setting up a collection of old furniture, electronics, posters, un-opened, non-
perishable food, and other items that would be otherwise thrown out at the end of
the year. This would be through having a designated collection area for these items
while students move out of dorms for other students or community members to be
welcome to re-use on their own at no cost. The items could be separated by area or
simply collected. This would be advertised throughout the end of the school year
throughout campus.
2) Have an Earth Day event on your campus with information about sustainability
on campus and throughout the world.
3) Have your food service label which items are locally grown to allow student to
see how their own food items are making an impact on the community
4) Have ―exchange racks‖ for magazines or used items that may be
5) Increase advertising for collection areas on campus of items such as used
electronics, empty ink cartridges, or old cell phones or batteries.
6) Encourage your campus to do a ―Clean Plate‖ project encouraging students to
take less food so they are able to decrease waste, but ALSO to donate money from
saved food to the local food pantry!
Composting Feasibility Study May 2010
19
Table 4 - Contacts throughout the study:
Contact Position E-mail Ph. #
Bob Barry UW-W UC Executive Director [email protected] (262) 472-6223
Steve Bertagnolli UW-W Buildings/Grounds
Supervisor
(262) 472-6721
Eric Compas UW-W Faculty Researcher and
Professor
[email protected] (262) 472-5126
Amanda Dent UW-Stevens Point Graduate [email protected] (920) 296-1114
Brent Flickema Johns Disposal Service, Inc.
Commercial Service
Representative
[email protected] (262) 473-4700
Wes Enterline UW-W Sustainability
Coordinator
(262) 472-6709
James Harrod UW-Madison Graduate [email protected] (608) 516-7632
Tom Hinspater Resident District Manager,
Chartwells
[email protected] (262) 472-5795
Michael
Keleman
Environmental Engineer for
InSinkerator Disposals
Michael.Keleman@emerso
n.com
(262) 598-5219
Chuck Nass City of Whitewater Streets
Superintendent
[email protected] (262) 473-0542
Eileen Norby University of Wisconsin System
Administration Waste
Minimization Manager
[email protected] (608) 262-8252
Tim Reel City of Whitewater
Wastewater Superintendent
[email protected] (262) 473-5920
Greg Swanson UW-W Facilities Planning and
Management Director
(262) 472-6703
Ann Wick Chartwells Campus Dining
Services Marketing Director
[email protected] (262) 472-4943
Thomas Wright UW-Madison W. Agricultural
Research Station
Superintendent
[email protected] (608) 262-2257
Composting Feasibility Study May 2010
20
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Composting Feasibility Study May 2010
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