university of wisconsin system solid waste research … · estimated monthly generation of...

Accessing the Feasibility of Composting Pre-Consumer

Food Waste at the University of Wisconsin-Green Bay

May 2010

Student Investigators: Molly Collard and Shaun Raganyi

Faculty Advisor: John Katers

University of Wisconsin-Green Bay

UNIVERSITY OF WISCONSIN SYSTEM

SOLID WASTE RESEARCH PROGRAM

Undergraduate Project Report

of 62

ABSTRACT

Pre-consumer food waste is a valuable product and is often underutilized. If pre-consumer food

wastes are mixed with high carbon wastes like leaves or shredded paper, the system will yield high

quality compost when properly maintained. There is the potential to create a composting system at the

University of Wisconsin – Green Bay (UWGB), but a thorough technical and economic analysis has yet to

be preformed. This study evaluated the amount and type of pre-consumer food waste generated at

UWGB, and then explored four composting options for this specific waste stream. Composting using

windrows, aerated static piles, in-vessel, and vermicomposting systems were each evaluated for their

technical feasibility on campus. It was determined that in-vessel composting was the most feasible

option based on the Wisconsin climate and logistical issues on campus. It was shown that in-vessel

composting is a solid project – environmentally, economically, and educationally. A thorough cost

benefit analysis was performed for a commonly used in-vessel composter (Earth Tub), where future

potential changes in electricity costs and the waste hauling contract were factored in. Changes in the

cost of electricity do not significantly alter the payback and even if the conservative scenario where

waste hauling costs remain the same, the Earth Tub offers a 6 year payback. It is recommended that an

Earth Tub be operational before 2012 and prior to 2011, the University Union and A’viands use this

study to formulate a more detailed plan regarding pre-consumer food waste generation collection,

paper collection, and other logistics associated with operating and maintaining an Earth Tub.

of 62

TABLE OF CONTENTS

ABSTRACT ..................................................................................................................................................... 2

LIST OF FIGURES ............................................................................................................................................ 4

LIST OF TABLES .............................................................................................................................................. 5

INTRODUCTION ............................................................................................................................................. 6

WASTE CHARACTERIZATION STUDY ............................................................................................................. 7

Pre-Consumer Food Waste ....................................................................................................................... 7

Bulking Agents......................................................................................................................................... 10

EVALUATING COMPOSTING OPTIONS ........................................................................................................ 13

Methods of Composting ......................................................................................................................... 13

Windrows ............................................................................................................................................ 13

Aerated Static Piles ............................................................................................................................. 18

In-Vessel .............................................................................................................................................. 21

Vermicomposting ................................................................................................................................ 23

COMPARISON OF COMPOSTING METHODS ............................................................................................... 26

COST BENEFIT ANALYSIS (EARTH TUB)........................................................................................................ 27

END USE OPTIONS AND EDUCATION VALUE .............................................................................................. 33

CONCLUSIONS ............................................................................................................................................. 34

REFERENCES ................................................................................................................................................ 35

APPENDIX .................................................................................................................................................... 37

Background Information – Properties of Compost ................................................................................. 37

Potential Sites for Various Composting Options at UWGB ..................................................................... 39

Tables and Figures .................................................................................................................................. 50

of 62

LIST OF FIGURES

Figure 1. Pre-Consumer Food Waste Generation ......................................................................................... 8

Figure 2. Characterization of Pre-Consumer Food Waste ............................................................................ 9

Figure 3. Estimated Monthly Generation of Pre-Consumer Food Waste ................................................... 10

Figure 4. Example of windrow compost piles (Bear Path Farm, 2009). ...................................................... 14

Figure 5. Example of an aerated static pile compost system (Large Scale Composting, 1999) .................. 18

Figure 6. Earth Tub (Earth Tub, 2009). ........................................................................................................ 21

Figure 7. Institutional Size Vermicomposting Systems. Model 5-6 ............................................................ 24

Figure 8. Ten Year Cost Outlook ($25 Monthly Contract Cost Increase Per Year) ...................................... 51

Figure 9. 10 Year Cost Outlook ($10 Monthly Contract Cost Increase Per Year)........................................ 51

Figure 10. Differential Monthly Contract Cost Increases............................................................................ 52

Figure 11. 10 Year Monthly Contract Cost Comparison ............................................................................. 52

Figure 12. Total Profit/Debt (0/0) ............................................................................................................... 53

Figure 13. Total Profit/Debt of 10 years (0/0) ............................................................................................ 54

Figure 14. Total Profit/Debt (0/1) ............................................................................................................... 55

Figure 15. Total Profit/Debt (0/E1) ............................................................................................................ 56

Figure 16. Total Profit/Debt (10/0) ............................................................................................................. 57


Figure 18. Total Profit/Debt (10/E1) ........................................................................................................... 59


Figure 20. Total Profit/Debt (25/1) ............................................................................................................ 61

Figure 21. Total Profit/Debt (25/E1) ........................................................................................................... 62

of 62

LIST OF TABLES

Table 1. Pounds of Pre-Consumer Food Waste ............................................................................................ 8

Table 2. Annual Weight and Volume Estimates of Pre-Consumer Food Waste ........................................ 15

Table 3. Feedstock, Bulking Agent, and Information on the Corresponding Parameters ......................... 15

Table 4. Annual Mass Balance Calculations ............................................................................................... 16

Table 5. Windrow Pad Size: For Active Composting, Raw Materials Storage, Curing, Cured Storage ....... 16

Table 6. Total Cost of Windrow Composting By Operation and Per Unit for Three Types of Pads ........... 17

Table 7. Land area needed for Aerated Static Pile ..................................................................................... 19

Table 8. Total Cost of Aerated Static Pile Composting By Operation and Per Unit .................................... 20

Table 9. Comparison of Composting Methods. .......................................................................................... 26

Table 10. $0.00 Monthly Contract Cost Increase Comparison Chart ......................................................... 29

Table 11. $10.00 Monthly Contract Cost Increase Comparison Chart ....................................................... 30

Table 12. $25.00 Monthly Contract Cost Increase Comparison Chart ....................................................... 31

Table 13. Temperature stages that occur during composting (Shah, 2000). ............................................. 38

Table 14. Tipping Fee Increases Over 10 Years ........................................................................................... 50

Table 15. Waste Hauling Contract Cost Increases Over 10 Years ............................................................... 50

of 62

INTRODUCTION

Food waste has value and college campuses across the nation are utilizing it. The Association for

the Advancement of Sustainability in Higher Education (AASHE) lists over 80 campuses that currently

have a composting program. Composting food waste frees up landfill space and reduces the costs of

transporting wastes off campus and disposing in the landfill. Besides offering a cost savings in some

areas, composting is also environmentally responsible because the waste is recycled into a valuable

product.

The idea of composting at the University of Wisconsin – Green Bay (UWGB) has long been

discussed by faculty and students, but a thorough feasibility study and implementation plan has yet to

be completed. Some recent changes at UWGB may increase the feasibility of composting on campus.

In 2009, a student garden, a hoop house, and a green roof project were implemented on campus. All

three projects would be enthusiastic consumers of campus-made compost. Also as of August 2009,

UWGB has a new food vendor, A’viands. The director of A’viands, Pat Niles, previously headed the food

service at Lawrence University (Appleton, WI) where he worked with students to start a composting

project. Niles is more than willing to share his knowledge and work with UWGB students on a similar

project.

To assess the feasibility of composting pre-consumer food waste on campus, this study will

meet the following objectives:

1. Waste Characterization Study: Determine the amount and composition of pre-consumer waste

generated in the University Union over a temporal scale.

of 62

2. Evaluating Composting Options: Evaluate potential composting options based on the amount of

waste produced and when it’s produced. During the evaluation of each feasible composting

method we will:

a. Perform a short-term and long-term cost benefit analysis using projections of campus

growth and cost of waste disposal.

b. Evaluate options for beneficial reuse of the finished product and incorporate them into

the cost benefit analysis.

WASTE CHARACTERIZATION STUDY

Pre-Consumer Food Waste

This study is looking only at pre-consumer food waste, defined as the food waste generated in

the kitchen before it is served to customers. Post-consumer food waste, defined as the food thrown

away by the customer, must be dealt with differently as it requires education efforts to capture the

compostable waste stream. Pre-consumer food waste that is considered compostable typically includes

fruit and vegetable scraps, egg shells, and coffee grounds (DeBell, Erlich, Mirza, & Runyon Sr., 2002).

From initial conversations with campus staff and from Biedermann’s study (2004), it was determined

that approximately 95% of the pre-consumer waste is generated in the Kitchen in the University Union

(Union). A’viands agreed to set aside the pre-consumer food waste generated in the Union for three

days. Data was collected on 3 different days to get a more accurate estimate of the composition and

amount of pre-consumer waste generated in the Union Kitchen. Those days included one Monday, one

Wednesday, and one Friday. The amount and composition of pre-consumer food waste generation is

expected to vary on each of these days. On Mondays, students return from the weekend and A’viands

starts preparing for the rest of the week. Wednesday is a middle of the week estimate (a normal day

load). On Fridays, A’viands prepares food for the weekend. On each of these days the Union Kitchen

of 62

staff used the four trash cans set aside for pre-consumer food waste and the trash containers were

specially labeled (fruit, vegetables, egg shells, coffee grounds). Visual inspection of the food waste

containers and the regular containers confirmed that they were utilized appropriately. A large scale

from Laboratory Sciences was utilized for weighing the waste. The results are shown in Table 1, Figure

1, and Figure 2.

Table 1. Pounds of Pre-Consumer Food Waste

Fruit Vegetables Egg Shells Coffee Grounds Totals

Wednesday (12/2) 43.25 20.70 0.55 16.25* 80.75

Friday (12/4) 57.15 24.60 0.60 17.05* 99.40

Monday (12/7) 62.05 16.25 0.50 18.35 97.15

Average 54.15 20.52 0.55 17.22 92.43

*Estimates, full collection was not available.

Figure 1. Pre-Consumer Food Waste Generation

of 62

Figure 2. Characterization of Pre-Consumer Food Waste

Figure 3 contains estimates of pre-consumer food waste generation throughout the year. These

estimates are based on the school calendar and conversations with Union employees regarding the

quantity and type of food service throughout the year. Through these conversations, it was determined

that there is very little pre-consumer waste production during Summer Break and Winter Break. During

all other times of the year, the estimates made during this study were very accurate and correctly

represent pre-consumer food waste production at UWGB. There are only certain times of the year

(during major programs and/or events) that pre-consumer food waste production would be higher, but

these occasions would not have a significant impact on the estimates made.

of 62

Figure 3. Estimated Monthly Generation of Pre-Consumer Food Waste

The C:N of pre-consumer food waste is typically between 15:1 and 20:1, with higher end

estimates often including more carbohydrates and some paper waste (Confesor et al, 2008 and DeBell et

al, 2002). Based on the 15:1 carbon to nitrogen ratio for food waste, DeBell et al (2002) recommends a

starting formula for mixing food waste and bulking materials of 2-3 parts bulking materials to 1 part food

waste, by volume.

Bulking Agents

Leaves are one potential bulking agent and there are certainly a plethora of supplies. As

aforementioned, UWGB is seated perfectly on the outskirts of Green Bay and is surrounded by

numerous trees, open fields, and areas covered with grass. Paul Pinkston, Interim Director of Facilities

Planning and Management, stated that currently this waste is brought to the nearby city composting

operation and he had no off-hand estimate as to the monthly or annual amount (Pinkston, 2009).

Leaves, however, are not often collected exclusively, as the grass is often mowed at the same time. The

of 62

grass clippings, leaves, and other organic matters are then often put through a chipper. This presents

various issues. The general campus grass is treated with chemicals and the grass at the golf course on

campus (Shorewood Golf Course) is treated with a lot of chemicals. Although the composition of

pesticides and herbicides vary greatly, in general these substances are not broken down within the time

span of a composting operation (Confesor et al, 2008). These chemicals, if present in the compost, can

exhibit the same traits as desired during their original application. For example, some herbicides inhibit

seed germination. If these chemicals were present in the compost, they could inhibit seed germination

(of non-weed seeds) in the campus garden or wherever the compost is utilized (Confesor et al, 2008).

This would obviously be counterproductive. If grass clippings (along with leaves) were used for bulking

materials, it would be necessary to ensure that no grass clippings are used from the Shorewood Golf

Course. The only problem with making sure this is followed is that it greatly complicates the process of

collecting grass clippings. However, this is not the only problem with using grass clippings and leaves as

bulking agents.

Storage options for the bulking materials of grass clippings and leaves are also a problem. All

storage options are analyzed in depth and available in the Appendix. The most common problems with

any of the storage options include transportation of the materials when needed, the likelihood of any

“storage piles” becoming a home for vectors (most likely mice) that find it inhabitable, the possibility of

mixing grass clippings from Shorewood Golf Course with grass clippings from other areas (which may

result in “contamination”), accessing the storage piles in the middle of winter, and there are potential

odor issues when decomposition processes have started. These common problems and the

aforementioned issue of “contamination” are more than enough to eliminate this bulking material

option or place it as a last resort.

of 62

The other option for a bulking material is to use paper. Throughout the University Union (and

across the UWGB Campus if it was needed) there is a vast quantity of paper available for use. Also,

within the University Union is DigiCopy (a service that offers various copying, printing, and numerous

other services) and this particular service uses plenty of paper. Outside of the University Union

(specifically located on the Loading Dock) is a large paper compactor that is used on a daily basis. Using

paper as a bulking agent not only eases the process of collecting and storing bulking materials, but it

also improves environmental sustainability, environmental friendliness, and may even lower costs that

the University Union accumulates in its recycling of paper. Further research may be needed to ensure

that all paper that leaves University Union is not a profitable commodity. Before the paper could be

used as a bulking material, it would have to be shredded and then stored until needed.

Storage options for the shredded paper were analyzed in depth and available in the Appendix.

There are multiple options possible, but the best one is to have multiple shredders located throughout

the University Union and have one main collection area (most likely located in World Unity Room A).

This would simply require that once “satellite” collection baskets are filled that they would have to be

transported to the main collection site. This would be a very simple process and once any small

problems are solved the entire process would be able to run very smoothly, effectively, and efficiently.

Using shredded paper as a bulking material is the best option available, but if it could not be used then

using grass clippings and leaves as bulking materials could be considered with a bit more effort.

of 62

EVALUATING COMPOSTING OPTIONS

Methods of Composting

The four composting methods discussed below were chosen based on recommendations from

DeBell et al (2002) and Project Compost (2004). Both studies looked at typical composting methods at

campuses or other institutions.

Windrows

Windrows are heaps of elongated and dome shaped compost piles, shaped to shed rain or snow

and shown in Figure 4. The windrows can be anywhere from 4 to 8 feet high with a base width of 8 to

17 feet, respectively (Shah, 2000 and Project Compost, 2004). DeBell et al (2002) recommend a pile size

that is 5 to 6 feet high and 10 to 12 feet wide at the base, stating that this size pile is suited well for

winter climates. Even when temperatures drop below freezing, the center of this size pile will be

insulated enough to continue composting. At times, it may be necessary to stop turning the pile until air

temperatures increase.

Windrows are typically agitated once or twice per week with a front-end loader or specially

designed equipment. The agitation provides air to the microbes and decreases particle size, creating

more surface area for microbes to colonize. This leads to faster decomposition rates and a more

homogenous end product (DeBell et al, 2002). Shah estimates that after 5 to 6 weeks of turning, the

compost is ready for the 4 week curing or stabilization process.

of 62

Figure 4. Example of windrow compost piles (Bear Path Farm, 2009).

A windrow system typically takes up a lot of land space, with the general rule of thumb stating

that 1 acre of land is required for every 3000 to 3500 yd3 of leaves collected (Shah, 2000). It is unclear

whether this standard can be applied to organic waste in general or whether this estimate was using

leaves for the bulking agent. Most outdoor composting operations are on paved surfaces to assure that

the turning equipment can access the pile year round (DeBell et al, 2002).

To get estimates on the amount of space needed for a windrow operation, this study is utilizing

a spreadsheet tool called Co-Composter, developed by the Cornell Waste Management Institute

(available at http://compost.css.cornell.edu/CoComposter.xls). Co-Composter requires the user to enter

information about the potential composting operation, including the type and volume of the feedstock

and bulking agents, the type of composting system, and estimated pile size. This information is used to

calculate the final volume of compost, determine the appropriate pad size, and estimate the overall

cost/profits.

http://compost.css.cornell.edu/CoComposter.xls

of 62

From the waste characterization study, it was determined that the campus generates about

16,963 lbs of pre-consumer food waste per year. That weight converts to a volume of 305 ft3 or 11.3

yd3, by using a well known weight-to-volume conversion of 1500 lbs/yd3 (RecycleMania). This

information is summarized in Table 2.

Table 2. Annual Weight and Volume Estimates of Pre-Consumer Food Waste

Weight – lbs 16,964

Weight – tons 8.48 Volume - ft3 305 Volume - yd3 11.3

After entering the 305 ft3 for the annual volume of food waste, the volume of shredded paper to

add was adjusted until the optimum balance of C:N, moisture, and bulk density was achieved. The

information is summarized in Table 3. Shredded paper was chosen as the bulking agent because of the

limited storage option for leaves and grass clippings, along with the potential unwanted chemical

residues associated with the grass clippings.

Table 3. Feedstock, Bulking Agent, and Information on the Corresponding Parameters

Parameter Value Recommended

Food Waste (ft3/yr) 305 n/a

Paper (shredded) (ft3/yr) 225 n/a

Moisture Content (%): 48.8 40 to 65%

C/N Ratio: 34.7 20 to 40

Bulk Density (lb/ft3): 18 less than 40 lb/ft3

A pile size of with a height of 6 ft tall and a width of 12 ft was chosen based on

recommendations within the spreadsheet and DeBell et al (2002). Space was also allocated for raw

materials storage and a curing pile.

of 62

Table 4. Annual Mass Balance Calculations

Total Annual Compost Production = 265 ft3 / yr

10 yd3 / yr

2 ton / yr

Table 5. Windrow Pad Size: For Active Composting, Raw Materials Storage, Curing, Cured Storage

Total Pad Area (ft2) = 13,560

Total Pad Area (ac) = 0.3

To determine the overall cost of the operation, several assumptions had to be made about cost

of pad construction, machine rental for turning, labor hours, and life of the project. The total costs are

summarized in Table 6. A 5 year project life was used to annualize capital costs and three different pad

types were chosen. The estimated profits come from savings to the campus. These savings come from

reduced contract fees from Waste Management that result from removing pre-consumer food waste

from what is hauled off campus and the savings from purchasing compost for the campus gardens.

of 62

Table 6. Total Cost of Windrow Composting By Operation and Per Unit for Three Types of Pads

Costs with variable pad types

Remove vegetation and top

soil only

Concrete Pad Recycled Asphalt

Loader Option: Rented Rented Rented

Handling Cost $230 $230 $230

Turning Cost $555 $555 $555

Pad Cost $285 $9,120 $1,851

Materials:

Input:

Monthly Contract Costs* ($3,360.00) ($3,360.00) ($3,360.00)

Costs $0 $0 $0

Output:

Value of Final Product ($482) ($482) ($482)

Total Annual Cost** ($2,767) $6,069 ($1,201)

Input

Cost per Ton input ($580.31) $1,277.56 ($251.12)

Cost per Yd3 input ($140.71) $309.96 ($61.01)

Output

Cost per Ton output ($1,159.82) $2,551.25 ($502.24)

Cost per Yd3 output ($281.87) $619.93 ($122.00)

*The cost to remove pre-consumer food waste (using current methods) was calculated based on a monthly contract cost that is established with Waste Management. ** If profit exists, results will appear in parenthesis to represent profits from tipping fees, total annual profit, or profit per Input/Output.

The use of a concrete pad is highly cost prohibitive over five years. The other pads are more

affordable, but present issues for machinery access if the ground becomes too wet. The feasibility of

year-round composting is not figured into the model. The majority of compostable waste is generated

in the winter months when school is in session. Simon Bollin, Special Projects Manager at a local

composting company – Soil Solutions, was consulted in regards to composting in this climate (Bollin,

2010). Bollin stated that their operation in De Pere, WI struggled with keeping pile temperatures up last

of 62

winter. Their pile sizes were even larger than estimated for the potential UWGB operation. The major

problem was snow and snow melt reducing pile temperature and increasing moisture. Their operation

is less than 30 miles from campus, so a very similar climate can be assumed. Low temperatures and

excess moisture can increase the management time, risk of odors, and total compost processing time.

The risks and benefits of windrow composting are summarized in Table 9.

Aerated Static Piles

The static method includes no mechanical agitation, but instead uses pipes to blow or pull air

through the pile (see Figure 5). Flexible drainage pipes are ran through a porous base such as wood

chips or compost and the pipes are connected to a fan or blower that can exert a negative or positive

pressure throughout the pile (Shah, 2000).

Figure 5. Example of an aerated static pile compost system (Large Scale Composting, 1999)

If a negative pressure is generated, where air is being drawn through the pile, the exhaust must

be run through an odor biopile which is typically screened compost. This method, of drawing air

through the pile versus blowing it through, is usually preferred because it offers increased odor control.

of 62

Typical pile heights for this method are 7-8 feet. Since the compost pile is never turned, the initial

feedstocks should be mixed well before piled. The pile is usually covered with a layer of finished

compost to insulate and reduce odors (Shah, 2000). This method can be more expensive than windrows

because of the additional equipment and electricity costs, but aerated static piles can offer faster

composting rates (DeBell et al, 2002).

The Co-Composter spreadsheet was also utilized to make calculation for space requirements

and costs of operation. All parameters were kept the same as the windrow operation, except the

project life was increased to 10 years since the capital investment is higher. Therefore the information in

Table 3 and Table 4 also apply to this method. The only additional information needed for calculating

costs was the cost of the electricity ($0.11/kWh used). The amount of space needed is shown in Table 7

and total cost results are show in Table 8.

Table 7. Land area needed for Aerated Static Pile

Total land requirement

Total Area (ft2) = 9150

Total Area (ac) = 0.21

of 62

Table 8. Total Cost of Aerated Static Pile Composting By Operation and Per Unit

Annual Costs

Loader Option: none

Handling Cost $230

Turning Cost No Turning

Screening Cost No screening

Pad Cost $712

Materials:

Input:

Monthly Contract Costs* ($3,360.00)

Costs $0

Output:

Value of Final Product ($477)

Bldg. Constr. Cost $4,081

Aeration Cost $927

Total Annual Cost** $2,118

Input

Cost per Ton input $445.03

Cost per Yd3 input $108.07

Output

Cost per Ton output $889.59

Cost per Yd3 output $216.22

*The cost to remove pre-consumer food waste (using current methods) was calculated based on a monthly contract cost that is established with Waste Management. ** If profit exists, results will appear in parenthesis to represent profits from tipping fees, total annual profit, or profit per Input/Output.

This method of composting, although it could offer faster processing times, is more costly than

windrows and faces the same climatic issues. The advantages and disadvantages are summarized in

Table 9.

of 62

In-Vessel

In-vessel composting offers the fastest processing times of methods discussed in this study. In-

vessel composting can take many forms, but generally involves a highly mechanical composting system

inside of a container. The organic wastes are put into the container and then agitated with an auger

and/or air is forced through the system. In-vessel systems come with high capital and O&M costs, but

offer essentially odor-free composting with a small physical footprint. These characteristics make

composting more feasible in urban areas or where space is limited. Depending on the amount of

organic waste to be composted, the startup costs of these systems vary between $20,000 and $100,000

(DeBell et al, 2002).

Figure 6. Earth Tub (Earth Tub, 2009).

In-vessel composting, more specifically the Earth Tub is the one of the best options, if not the

best option for composting pre-consumer food waste at UWGB. There are numerous positives to this

composting option that include its multiple location possibilities (as described in the Appendix), its

ability to have an exterior location that is contained, literally no “smell” accompanied with the

of 62

composting process, no concern with local animals (specifically mice) invading the process in pursuit of

an inhabitable location, and allows for easy transportation of compost when it is fully ready. The Earth

Tub would allow a quick, easy, and effective process for composting that would greatly increase the

environmental sustainability and environmental friendliness of UWGB.

The Earth Tub could be operated only at times that there is good availability of pre-consumer

food waste available and either operated still at full potential (if resources are available), at half

potential, or not at all during times that pre-consumer food waste is not readily available. Compared to

other composting options, the Earth Tub is one of the only ones, if not the only one that can be used less

or not at all if pre-consumer food waste is not available during Summer Break and Winter Break. This

flexibility makes this composting option extremely feasible.

Transportation ease is another reason as to why the Earth Tub is an extremely feasible

composting option. With locations available directly next to the University Union (specifically right

outside of the 1965 Room), transportation of materials to be composted, bulking materials, and

materials that are ready to be used would be simplistic and easy. Compared to other composting

options, there are no great difficulties with the transportation of materials.

There are only small concerns with the Earth Tub option that include an increase with electricity

usage (it is a very minimal increase that will cost at the most $100.00-$200.00 yearly) which could be

classified as a decrease in the sustainability and friendliness of UWGB, but the benefits certainly

outweigh the costs. Another small concern is the initial starting costs that are over $14,000.00 (most

details are displayed in the cost benefit analysis concerning the Earth Tub), the need for a concrete pad

to be installed, and the need for other materials (i.e. security fence, shovels, wheelbarrow, etc.), but a

payback can be shown in approximately six years. The last small concern with the Earth Tub option is

the fact that it cannot be operated in extremely cold temperatures. Fortunately, the coldest times of

of 62

the year do fall during the majority of Winter Break, but there are times that extremely cold

temperatures can occur in late January and even possibly throughout February. Despite these small

concerns, the Earth Tub is still an extremely feasible composting option.

Vermicomposting

Vermicomposting is the process of using worms to convert organic matter into a quality soil

amendment known as castings. The worms eat the food waste and bulking materials and microbes are

also involved in the process (DeBell et al, 2002). The worms also provide natural aeration, so small piles

do not need to be turned or ventilated. Red wiggler worms are most commonly used in this process

because they efficiently convert the organic matter and they feed vertically. If fresh organic matter is

added to the top of the pile, the worms will move up through the pile, leaving worm- free castings and

compost on the bottom (Project Compost, 2004). Commercial worm composting containers are often

designed to easily harvest the worm-free compost on the bottom (Figure 7). DeBell et al (2002) stated

that startup costs for vermicomposting can range from $600-$80,000 based feedstocks of 20 -1,200

lbs/day, respectively. These systems are often indoors because the worms function best between

temperatures of 55-77 degrees Fahrenheit and cannot tolerate temperatures below 33 degrees or

higher than 96 degrees Fahrenheit. Since the temperature of the pile never reaches thermophilic

conditions, it is recommended that the compost be finished further after it leaves the container.

of 62

Figure 7. Institutional Size Vermicomposting Systems. Model 5-6

Vermicomposting is not a feasible composting option for composting pre-consumer food waste

at UWGB. The largest problem with vermicomposting is where to locate the composting mechanism.

The only possible location for this composting option would be within the University Union. Currently,

the only room that is available and has enough space is World Unity A. The problem with this is that

rooms constantly go “online” and “offline” at the University Union as the needs of the students and its

customers are constantly changing, so a guarantee could not be made to ensure that this room would

always be available. Also, temperature management would have to be separately handled for World

Unity A than it is for the rest of the University Union to ensure that the worms are stored in the optimal

temperature of 55-77 degrees Fahrenheit. This problem is enough to eliminate this composting option

completely at UWGB.

Another major problem with vermicomposting is the question of what the worms will eat when

there are periods of little or no pre-consumer food waste production at UWGB. This occurs during

Summer Break and during Winter Break. With other composting options, the decrease or no availability

of pre-consumer food waste production would not severely inhibit the composting process as it would

of 62

with vermicomposting. These two problems between finding a food source for the worms during

periods of little or no pre-consumer waste production and the fact that the worms need specific

conditions are enough to prove that this is an unfeasible composting option.

Overall, vermicomposting is a great option for composting. Unfortunately, it does not meet the

needs to compost pre-consumer food waste at UWGB. The complications that go along with starting

this composting option such as selecting a location that is indoors and has a temperature that can be

controlled, figuring out a food source for the worms during times of little or no pre-consumer food

waste production, the residual “smell” that may result from composting inside, and other reasons (all

that are described in detail in the Appendix) support the aforementioned statement that this particular

type of composting is unfeasible at UWGB.

of 62

COMPARISON OF COMPOSTING METHODS

Table 9 shows the main advantages and disadvantages of each composting method. The text in

red can be deemed as the “deal-breakers”, the main reason why that method of composting is ill-suited

for UWGB.

Table 9. Comparison of Composting Methods.

Method Advantages Disadvantages

Windrow Low tech

High educational value

Visible demonstration of UWGB’s environmental efforts

Front end loader/special equipment required to turn pile

Could not compost year round due to climate and pile size

Aerated Static Pile No turning required

Faster processing times

Easier control over moisture/temperature

Visible demonstration of UWGB’s environmental efforts

High capital and O&M costs

Could not compost year round due to climate and pile size

Vermicomposting No turning required

Low tech

Must be indoors due to climate

Not Visible

No food source for worms in the summer

In-vessel High degree of process control

Fastest method of composting

Less sensitive to climatic factors

High capital and O&M costs

Not visible

Low educational value

of 62

COST BENEFIT ANALYSIS (EARTH TUB)

After a preliminary analysis was conducted on all of the possible composting methods for

composting pre-consumer food waste at UWGB, it was concluded that the most feasible composting

method was in-vessel and more specifically the Earth Tub. Since the Earth Tub was selected as the most

feasible composting method, a detailed cost benefit analysis was conducted using numerous variables.

It was discovered that if the Earth Tub was purchased and implemented at UWGB, it would save the

University Union approximately $280.00 per month ($3,360.00 annually) on waste removal costs.

Currently, all pre-consumer food waste is deposited directly in the dumpsters for removal from UWGB.

By simply diverting this amount of waste, the number of current trash pick-ups per week (3) can be

reduced (2). Certainly, some other methods of properly using all of the dumpster space available would

have to be figured out, but this simply includes filling from the back first, ensuring that a garbage bag

certainly needs to be taken out, and combining less filled bags in order to also save space.

Variables that were taken into account during this cost benefit analysis were the

aforementioned monthly contract costs and kilowatt hour usage (kWh). All other costs were estimated

to remain the same yearly, but it must be kept in mind that slight increases may occur (for example the

cost of operating the unit in terms of labor may increase slightly on a yearly basis). Cost benefit analyses

were ran with the variables of monthly contract costs increasing $0 per year, $10 per year, and $25 per

year, along with kWh costs increasing $0 per year, $0.01 per year, and $0.01 every other year. Each cost

benefit analysis was conducted on a scale of 5 years and a separate cost benefit analysis was conducted

on the current monthly contract costs ($3,360.00 per year) and kWh costs ($0.01 per kWh) on a scale of

10 years to show when an actual payback would occur.

The startup costs for the Earth Tub were estimated to be at $14,323.15 for the first year, which

included the estimated yearly kWh cost ($118.80 for 1,080 kWh per year), miscellaneous

of 62

supplies/maintenance ($600.00), and the cost for a student intern ($850.00 at $8.50 per hour for an

estimated 100 hours). As was previously aforementioned, labor costs may increase slightly and the

University Union and/or A’viands may be asked to operate the Earth Tub with compensation included

for labor around the same amount that was estimated for a student intern. All three of these costs were

included in each of the following years in each of the cost benefit analyses.

Purchasing the Earth Tub itself carries an estimated cost of ($11,475.00) that includes

accessories, shipping & handling, etc. (Price Calculator, 2009). It was also estimated that the Earth Tub

would need a concrete pad to sit on that would have to be 12’ x 12’ x 5” and would run an estimated

cost of $291.55 that includes the concrete and framing boards (this estimate was received from

Menards back in January 2010). A chain-linked fence for security purposes would also be required for

an estimated cost of $354.52 that includes all accessories and an access point (this estimate was

received from Menards back in January 2010). Also, additional tools (these prices were estimates from

Wal-Mart that were received back in January 2010) such as a wheelbarrow ($117.24), steel shovel

($16.04), and any other additional materials needed to start the composting process ($500.00). All of

these estimated costs add up to equal the total estimated start-up cost of $14,323.15 for the first year

that composting with the Earth Tub would take place.

In each of the following years, an estimated profit of $3,360.00 per year was made based on

savings from the monthly contract costs and this number increased accordingly with other cost benefit

analyses (the amount increased either $10.00 per month for each year or $25.00 per month for each

year). Also, an estimated $400.00 was saved yearly for compost that would not have to be purchased

for the hoop or the organic garden (from compost purchases made last year, it was estimated that

compost cost $40.00 per cubic yard and it is estimated that from the pre-consumer food waste that is

produced per year that approximately 10 cubic yards of compost could be made).

of 62

Below are numerous comparison charts (see Table 10, Table 11, and Table 12) comparing the

results of numerous cost benefit analyses conducted. There is a chart for a monthly contract cost

increase of $0.00 per month for each year, $10.00 per month for each year, and $25.00 per month for

each year. Along with each of these charts, there are analyses conducted for a $0.00 kWh cost increase

per year, a $0.01 kWh cost increase per year, and a $0.01 kWh cost increase every other year.

Table 10. $0.00 Monthly Contract Cost Increase Comparison Chart

Earth Tub

Year

2011 2012 2013 2014 2015

Monthly Contract

Cost (M.C.C.)

And Purchased Compost

With Differing

kWh Increases

$0 M.C.C. With $0.00 Yearly

kWh Increase

$3,760.00 $3,760.00 $3,760.00 $3,760.00 $3,760.00

$0 M.C.C. With $0.01 Yearly

kWh Increase

$3,760.00 $3,760.00 $3,760.00 $3,760.00 $3,760.00

$0 M.C.C. With $0.01 Yearly (Every Other) kWh Increase

$3,760.00 $3,760.00 $3,760.00 $3,760.00 $3,760.00

Total Expenditures $14,323.15 $1,568.80 $1,568.80 $1,568.80 $1,568.80

$14,323.15 $1,579.60 $1,590.40 $1,601.20 $1,612.00

$14,323.15 $1,579.60 $1,579.60 $1,590.40 $1,590.40 Total Cost Saved On

M.C.C./Purchased Compost $3,760.00 $3,760.00 $3,760.00 $3,760.00 $3,760.00

$3,760.00 $3,760.00 $3,760.00 $3,760.00 $3,760.00

$3,760.00 $3,760.00 $3,760.00 $3,760.00 $3,760.00 Total Profit/Debt (Yearly) -$10,563.15 $2,191.20 $2,191.20 $2,191.20 $2,191.20

-$10,563.15 $2,180.40 $2,169.60 $2,158.80 $2,148.00

-$10,563.15 $2,180.40 $2,180.40 $2,169.60 $2,169.60 Total Profit/Debt (Total) -$10,563.15 -$8,371.95 -$6,180.75 -$3,989.55 -$1,798.35

-$10,563.15 -$8,382.75 -$6,213.15 -$4,054.35 -$1,906.35

-$10,563.15 -$8,382.75 -$6,202.35 -$4,032.75 -$1,863.15 Total Profit/Debt (Total

Excluding Start-Up Costs) N/A $3,291.20 $4,382.40 $6,573.60 $8,764.80

N/A $3,280.40 $4,350.00 $6,508.80 $8,656.80

N/A $3,280.40 $4,360.80 $6,530.40 $8,700.00

of 62

Table 11. $10.00 Monthly Contract Cost Increase Comparison Chart Earth Tub

Year 2011 2012 2013 2014 2015

Monthly Contract

Cost (M.C.C.)


With Differing

kWh Increases

$10 M.C.C. With $0.00

Yearly kWh

Increase

$3,880.00 $4,000.00 $4,120.00 $4,240.00 $4,360.00

$10 M.C.C. With $0.01

Yearly kWh

Increase

$3,880.00 $4,000.00 $4,120.00 $4,240.00 $4,360.00

$10 M.C.C. With $0.01

Yearly (Every Other) kWh

Increase

$3,880.00 $4,000.00 $4,120.00 $4,240.00 $4,360.00


$14,323.15 $1,579.60 $1,590.40 $1,601.20 $1,612.00

$14,323.15 $1,579.60 $1,579.60 $1,590.40 $1,590.40 Total Cost Saved On M.C.C./Purchased

Compost

$3,880.00 $4,000.00 $4,120.00 $4,240.00 $4,360.00

$3,880.00 $4,000.00 $4,120.00 $4,240.00 $4,360.00


-$10,443.15 $2,420.40 $2,529.60 $2,638.80 $2,748.00

-$10,443.15 $2,420.40 $2,540.40 $2,649.60 $2,769.60 Total Profit/Debt (Total) -$10,443.15 -$8,011.95 -$5,460.75 -$2,789.55 $1.65

-$10,443.15 -$8,022.75 -$5,493.15 -$2,854.35 -$106.35

-$10,443.15 -$8,022.75 -$5,482.35 -$2,832.75 -$63.15 Total Profit/Debt (Total


N/A $2,420.40 $4,950.00 $7,588.80 $10,336.80

N/A $2,420.40 $4,960.80 $7,610.40 $10,380.00

of 62

Table 12. $25.00 Monthly Contract Cost Increase Comparison Chart

Earth Tub

Year

2011 2012 2013 2014 2015

Monthly Contract

Cost (M.C.C.)


With Differing

kWh Increases

$25 M.C.C. With $0.00 Yearly kWh

Increase

$4,060.00 $4,360.00 $4,660.00 $4,960.00 $5,260.00

$25 M.C.C. With $0.01 Yearly kWh

Increase

$4,060.00 $4,360.00 $4,660.00 $4,960.00 $5,260.00

$25 M.C.C. With $0.01

Yearly (Every Other) kWh

Increase

$4,060.00 $4,360.00 $4,660.00 $4,960.00 $5,260.00


$14,323.15 $1,579.60 $1,590.40 $1,601.20 $1,612.00

$14,323.15 $1,579.60 $1,579.60 $1,590.40 $1,590.40 Total Cost Saved On

M.C.C./Purchased Compost $4,060.00 $4,360.00 $4,660.00 $4,960.00 $5,260.00

$4,060.00 $4,360.00 $4,660.00 $4,960.00 $5,260.00


-$10,263.15 $2,780.40 $3,069.60 $3,358.80 $3,648.00

-$10,263.15 $2,780.40 $3,080.40 $3,369.60 $3,669.60 Total Profit/Debt (Total) -$10,263.15 -$7,471.95 -$4,380.75 -$989.55 $2,701.65

-$10,263.15 -$7,482.75 -$4,413.15 -$1,054.35 $2,593.65

-$10,263.15 -$8,282.75 -$4,402.35 -$1,032.75 $2,636.85 Total Profit/Debt (Total


N/A $2,780.40 $5,850.00 $9,208.80 $12,856.80

N/A $2,780.40 $5,860.80 $9,230.40 $12,900.00

of 62

Numerous additional graphs for each cost benefit analysis that was conducted are available in

the Appendix. Each of these graphs displays the results for each cost benefit analysis more in depth to

provide a wider look at the numerous possible scenarios that could result and still show the benefit of

composting pre-consumer food waste at UWGB.

After an initial 5 year cost benefit analysis was completed with a monthly contract cost increase

of $0.00 per year and a $0.00 kWh cost increase per year, it was determined that after 5 years the entire

process would have a profit/cost total of -$1,798.35. If the first year startup costs are removed (the

costs and possible profits of the entire first year are removed), then it was determined that after 5 years

the entire process would have a profit/cost of $2,191.20 per year and a total of $8,764.80. Within this

specific cost benefit analysis it was determined that if startup costs were not covered, then a profit

would not be seen after 5 years.

Another cost benefit analysis was completed using the same aforementioned variables, but this

one was completed over a span of 10 years. It was determined that after 10 years the entire process

would have a profit/cost total of $9,157.65 and averaged out to be a profit of about $915.77 per year if

the startup costs were included. If the first year startup costs are removed (the costs and possible

profits of the entire first year removed), then it was determined that after 10 years the entire process

would have a profit/cost of $2,191.20 per year and a total of $19,720.80. A payback or point of time in

which a profit would be made if the startup costs and possible profits of the entire first year were both

still included would end up being 6 years during which a total profit/cost of $392.85 would have

resulted.

This specific cost benefit analysis and all of the other cost benefit analyses that were conducted

conclude that the in-vessel composting option, more specifically the Earth Tub, is a very feasible method

in which UWGB could effectively and efficiently compost pre-consumer food waste. If funding could be

provided by the students to try to at least offset the startup costs and/or the entire first year of the

of 62

process, then a profit would be seen even more quickly. This all proves that composting pre-consumer

food waste at UWGB by using the Earth Tub is not only a way to vastly improve environmental

sustainability, help start returning UWGB towards being recognized as a leading eco-friendly campus,

and result in an economically smart move.

END USE OPTIONS AND EDUCATION VALUE

A student organization, SLO Food Alliance, established vegetable gardens on campus and they

are committed to using organic growing methods. They will have an annual need for compost, which

could be partially met through utilizing compost made on campus. Supplying their gardens with

compost will translate into a cost savings to UWGB students because the any costs associated with

maintaining the garden are currently funded through student Segregated Fees. There would also be a

need for compost in the hoop house on campus. Another option could be to coordinate with the annual

Heirloom Plant Sale and have compost available for purchase during the sale. The proceeds could go

towards O&M of the composting operation.

The composting operation would offer research opportunities within various existing courses

(Waste Management and Resource Recovery and The Soil Environment are two examples) or as an

independent project. Students could monitor the technology’s performance, experiment with various

bulking agents, determine the C:N at various stages of the process, or track the mass balance over time.

UWGB could highlight it as part of their environmental efforts and use it to encourage environmental

stewardship. One downside to using an in-vessel composter is its lack of visibility. This study

recommends that a small demonstration compost pile be started near Lab Sciences, but more

specifically by the hoop house. The pile would only be functional seasonally (not be added to/turned in

the winter months), but would serve as a visual and hands-on learning tool of composting. It would be

unfortunate if people thought they needed some high tech equipment (like the Earth Tub) to compost.

of 62

UWGB’s composting operation should strive to highlight the benefits of composting and show that

anyone can start a compost pile.

CONCLUSIONS

The purpose of this study was to assess the feasibility of composting pre-consumer food waste

at UWGB. To assess the feasibility, a complete waste characterization study was done, providing daily

data and monthly estimates of food waste generation. Then four common composting options were

sized out and evaluated based on the amount of waste generated over the year. It was determined that

in-vessel composting was the most feasible option based on the Wisconsin climate and logistical issues

on campus. It was shown that in-vessel composting is a solid project – environmentally, economically,

and educationally. A thorough cost benefit analysis was performed for the Earth Tub, where potential

changes in electricity costs and the waste hauling contract were factored in. Changes in the cost of

electricity do not significantly alter the payback and even if the conservative scenario where waste

hauling costs remain the same, the Earth Tub offers a 6 year payback. It is recommended that

management in the University Union and A’viands use this study to formulate a more detailed plan

regarding pre-consumer food waste generation collection, paper collection, and other logistics

associated with operating and maintaining an Earth Tub. If there is an issue with the initial funding

coming solely out of the University Union budget, there is the option to approach the students (for

funding out of Segregated Fees), the campus’ Sustainability Committee, or seek support from alumni.

UWGB would benefit from on-campus composting by reducing waste disposal costs, providing an on-

campus source of fertilizer for growers on campus, utilizing the system as learning tool for students, and

by having a visible effort that showcases the campus’ environmental stewardship.

of 62

REFERENCES

(n.d.). Retrieved October 20, 2009, from Bear Path Farm:

http://www.bearpathfarm.com/how_BPF_makes_compost.html >

AASHE. (n.d.). Campus Composting Programs. Retrieved February 2, 2010, from Association for

Advancing Sustainability in Higher Education: http://www.aashe.org/resources/campus-composting-

programs.php

Agnew, J., & Leonard, J. (2003). The Physical Properties of Compost. Compost Science & Utilization , 11:

238-264.

Biedermann, K. (2004). Composting at the University of Wisconsin-Green Bay: A Feasibility Study. .

University of Wisconsin System. Solid Waste Research Program.

Bollin, S. (2010, February 2). Special Projects Consultant, Soil Solutions Co. (M. Collard, Interviewer)

Confesor, R., Hamlet, J., Shannon, R., & Graves, R. (2008). Potential Pollutants from Farm, Food and Yard

Waste Composts at Differing Ages: Part I. Physical and Chemical Properties. Compost Science &

Utilization , 16: 228-238.

DeBell, J., Erlich, O., Mirza, A., & Runyon Sr., A. (2002). Colorado Institutional Food Waste Composting

Guide. http://ecenter.colorado.edu/files/77342c92dbad96e181e5ea3805db9a1dbf39441d.pdf:

University of Colorado Recycling Services.

Large Scale Composting. (1999). Retrieved October 10, 2009, from Food and Agriculture Organization of

the United Nations: http://www.fao.org/docrep/007/y5104e/y5104e07.htm

Niles, P. (2009, September). Food Service Director, A'viands. (M. Collard, Interviewer)

Pinkston, P. (2009, November 5). Interim Facilities Manager and Campus Planner. (M. Collard,

Interviewer)

Price Calculator. Earth Tub Package 1. (2009). Retrieved October 10, 2009, from Earth Tubs:

http://www.compostingtechnology.com/invesselsystems/earthtub/pricing

Project Compost. (2004). College Guide to Campus Wide Composting.

http://projectcompost.ucdavis.edu/files/Compost_Guide.pdf: University of California, Davis.

RecycleMania. (n.d.). WasteWise Volume-to-Weight Conversion Factors . Retrieved March 24, 2010,

from RecycleMania: http://www.recyclemaniacs.org/doc/measurement-tracking/conversions.pdf

of 62

Rosinski, A. (1997). A Feasibility Study for Expanding An On-Campus Compost Program to Include Post –

Consumer Food Waste. University of Wisconsin System. Solid Waste Research Program.

Shah, K. (2000). Basics of Solid and Hazardous Waste Management Technologies. Upper Saddle River,

New Jersey: Prentice Hall.

of 62

APPENDIX

Background Information – Properties of Compost

Composting is defined as controlled decomposition using aerobic microorganisms to break

down food, leaves, paper, and other organic materials into a soil amendment that is virtually seed and

pathogen free. The composting conditions are controlled to maximize the efficiency of the aerobic

microorganisms (Agnew & Leonard, 2003). The aerobic composting organisms include bacteria, fungi,

and protozoa. They compost organic waste as follows (Shah, 2000):

organic matter + O2 new cells + CO2 +H2O + NH3 + SO4

To optimize this process, several parameters are often considered and controlled for, including

moisture, temperature, oxygen, carbon to nitrogen ratio, and pH. The optimum moisture content is

between 50 and 60 percent. Below 50 percent moisture content, microorganisms will be significantly

less active. If the moisture content is higher than 60 percent, water displaces too much of the air space,

leading to anaerobic conditions (Agnew & Leonard, 2003).

Composting is a heat-producing or exothermic process. As the microbes process the organic

matter, they release heat as a byproduct. Table 13 outlines the three temperature stages that occur

throughout the decomposition process. For efficient composting, the thermophilic stage should be

reached within three weeks and maintained during the initial processing. At temperatures greater than

thermophilic, biological activity decreases but higher rates of pathogen destruction occur (Shah, 2000).

of 62

Table 13. Temperature stages that occur during composting (Shah, 2000).

Stage Temperature Range (F)

Psychrophilic 59-68

Mesophilic 77-95

Thermophilic 122-140

Assuring proper aeration, or oxygen levels, also improves the composting process. Without

oxygen, the process switches to anaerobic decomposition which is much slower than aerobic

decomposition and produces more odors. Proper aeration is a function of moisture content, the

frequency of turning or ventilation, and the particle size of the compost feedstock (Agnew & Leonard,

2003). The particle size should be small to increase the surface area available to microbes, but if the

material is too fine, compaction and low pore space could be an issue. Organic bulking agents, like

wood chips often offer larger particle sizing and an increase in overall bulk density, increasing the

proportion of free air space within the pile.

Achieving the optimal carbon to nitrogen ratio (C:N) in the mixture of compost feedstock is

crucial to the success of the system. Shah (2000) lists the optimal range to be between 20:1 and 40:1,

with many systems striving for numbers between 30:1 and 35:1 (DeBell et al, 2002 and Confesor et al,

2008). The C:N for food waste ranges from 12:1 to 18:1, with the latter representing a wetter food

waste (Rosinski, 1997). A C:N of 15:1 is often estimated for pre-consumer food waste (DeBell et al,

2002). Organic matter with a low C:N is often called “greens”, while organic wastes with higher C:N are

often called “browns” and these are typically the bulking agents. Leaves, a “brown”, have a C:N of about

60:1, while grass clippings, are closer to 19:1 (Rosinski, 1997). If the C:N is less than 20:1, there is not

of 62

enough carbon in the feedstock for efficient microbial decomposition. Similarly, if the C:N is greater

than 40:1, the microbes will not have enough nitrogen for efficient decomposition (Shah, 2000).

The pH of the combined compost materials should also be considered. The optimum range for

microbial activity is between 6 and 8. The pH will be lower in the initial days of composting, as organic

acids are formed, but these acids will decompose later in the thermophilic stage (Shah, 2000).

Potential Sites for Various Composting Options at UWGB

Windrows

Outside Housing Entrance of the University Union:

Convenient location directly next to the UWGB Student Garden Allow for easy transport of the compost after it has “fully matured” Paved paths to allow for the use of a front-end loader to agitate the windrows 1-2 times per

week Good visibility for all students and visitors to see what steps UWGB is taking to improve

sustainability Space concern with the construction of new Housing complex(es) Possibility of large exposure of “smell” that may accompany the composting process The attraction of small creatures that find the compost an “inhabitable” location (especially

mice) Possibly “decrease” the appearance of the University Union with a “pile of natural junk” right

out front Mediocre distance from Facilities and Grounds that would create more travel and possibly

increase costs

Outside Main Entrance of Laboratory Sciences:

Convenient location directly next to the UWGB Hoop House Allow for easy transport of the compost after it has “fully matured” Concrete paths to allow for the use of a front-end loader to agitate the windrows 1-2 times per

week Mediocre visibility for all students and visitors to see what steps UWGB is taking to improve

sustainability Limited space concern due to the location and no “known” plans for expansion in that area Extremely close to Facilities and Grounds to allow for minimal travel and quick composting

services Possibly “decrease” the appearance of Laboratory Sciences with a “pile of natural junk” right out

front The attraction of small creatures that find the compost an “inhabitable” location (especially

mice)

of 62

Possibility of mediocre exposure of “smell” that may accompany the composting process Possibly a logistical concern with moving material that is ready to be composted from the

University Union to this location

Outside Greenhouse Attached to Laboratory Sciences:

Convenient location very close to the UWGB Hoop House Allow for easy transport of the compost after it has “fully matured” Concrete paths to allow for the use of a front-end loader to agitate the windrows 1-2 times per

week Mediocre visibility for all students and visitors to see what steps UWGB is taking to improve

sustainability Limited space concern due to the location and no “known” plans for expansion in that area Extremely close to Facilities and Grounds to allow for minimal travel and quick composting

services Possibly “decrease” the appearance of Laboratory Sciences with a “pile of natural junk” near the

front The attraction of small creatures that find the compost an “inhabitable” location (especially

mice) Possibility of mediocre exposure of “smell” that may accompany the composting process Possibly a logistical concern with moving material that is ready to be composted from the


Near the Old Language House:

Attraction of small creatures that find the compost an “inhabitable” location (especially mice) not a concern

Will not “decrease” the appearance of the Old Language House due to its secluded location No exposure of “smell” that may accompany the composting process Minimal (if any) visibility for all students and visitors to see what steps UWGB is taking to

improve sustainability Create a more difficult process for the transport of compost after it has “fully matured” Not really a convenient location at all (for transportation, care, etc.) No paved or concrete paths to allow for the use of a front-end loader to agitate the windrows 1-

2 times per week Possibly space concern due to the amount of trees in the area (may need to clear trees to make

room) Extended distance from Facilities and Grounds that would require greater travel and most likely

increase costs Possibly a logistical concern with moving material that is ready to be composted from the


Aerated Static Piles

Outside Housing Entrance of the University Union:

Convenient location directly next to the UWGB Student Garden

of 62

Allow for easy transport of the compost after it has “fully matured” Relatively close to electrical access that is needed to power aeration process Good visibility for all students and visitors to see what steps UWGB is taking to improve

sustainability Possibly “decrease” the appearance of the University Union with a “pile of natural junk” right

out front (despite covering) Space concern with the construction of new Housing complex(es) The attraction of small creatures that find the compost an “inhabitable” location (especially

mice) Logistical concern for power (despite being very close to electrical access) that could

substantially increase starting costs Possibility of exposure of “smell” (despite covering) that may accompany the composting

process


Convenient location very close to the UWGB Hoop House Allow for easy transport of the compost after it has “fully matured” Mediocre visibility for all students and visitors to see what steps UWGB is taking to improve

sustainability Limited space concern due to the location and no “known” plans for expansion in that area Relatively close to electrical access that is needed to power aeration process Possibly “decrease” the appearance of Laboratory Sciences with a “pile of natural junk” near the

front (despite covering) The attraction of small creatures that find the compost an “inhabitable” location (especially

mice) Possibility of mediocre exposure of “smell” (despite covering) that may accompany the

composting process Logistical concern for power (despite being close to electrical access) that could substantially

increase starting costs Possibly a logistical concern with moving material that is ready to be composted from the



Convenient location directly next to the UWGB Hoop House Allow for easy transport of the compost after it has “fully matured” Mediocre visibility for all students and visitors to see what steps UWGB is taking to improve

sustainability Limited space concern due to the location and no “known” plans for expansion in that area Relatively close to electrical access that is needed to power aeration process Possibly “decrease” the appearance of Laboratory Sciences with a “pile of natural junk” right out

front (despite covering) The attraction of small creatures that find the compost an “inhabitable” location (especially

mice) Possibility of mediocre exposure of “smell” (despite covering) that may accompany the

composting process

of 62

Logistical concern for power (despite being close to electrical access) that could substantially increase starting costs

Possibly a logistical concern with moving material that is ready to be composted from the University Union to this location


Attraction of small creatures that find the compost an “inhabitable” location (especially mice) not a concern

Will not “decrease” the appearance of the Old Language House due to its secluded location (despite covering)

No exposure of “smell” (despite covering) that may accompany the composting process Minimal (if any) visibility for all students and visitors to see what steps UWGB is taking to

improve sustainability Create a more difficult process for the transport of compost after it has “fully matured” Not really a convenient location at all (for transportation, care, etc.) Possibly a logistical problem for the location of piles (not so much in terms of space, but more in

terms of placement) Major logistical concern for power (only “local” electrical access is possibly the Old Language

House) The likely need for development of a new and centralized access for electricity would

substantially increase starting costs Possibly a logistical concern with moving material that is ready to be composted from the


In-Vessel

Inside of the University Union:

Allow for easy transport of the compost after it has “fully matured” Literally right next to electrical access that is needed for power The entire composting process is literally contained in one single area and eliminates the

logistics of moving materials Could easily be maintained and run by the University Union and A’viands (with compensation

for costs) Minimal odor from the composting process and there are effective and efficient methods

available to completely eliminate it World Unity A could be converted for placement (currently is used as a temporary storage room

and is unattractive as a room) Minimal (if any) visibility for all students and visitors to see what steps UWGB is taking to

improve sustainability Possibly complicate the process for the transport of compost after it has “fully matured” Conversion of World Unity A would require additional materials (tarps, air filters to eliminate

residual odor, etc.) Direct access to a sewer line to handle “run-off” is a logistical problem (holding tank could

create additional problems)

of 62

Size of the machine (Earth Tub is 7’ 5” x 7’ 5” x 6’ and weighs approximately 750 pounds) could complicate logistics

Placement and logistics may “plague” this option to the point that the feasibility of it may be reduced to nothing

Outside 1965 Room Emergency Exit Area of the University Union:

Allow for easy transport of the compost after it has “fully matured” The entire composting process is literally contained in one single area and simplifies the logistics

of moving materials Could easily be maintained and run by the University Union and A’viands (with compensation

for costs) Minimal possibility of “smell” (odor is almost completely contained) that may accompany the

composting process Good visibility for all students and visitors to see what steps UWGB is taking to improve

sustainability Would not “decrease” the appearance of the University Union (within a container that has an

attractive appearance) Relatively close to electrical access that is needed Despite being outside the container is able to withstand the cold climate that occurs in

Wisconsin Convenient location that is very close to the UWGB Student Garden Centralized location makes it the most qualified area for placement and most feasible option to

start composting at UWGB Accessing the container during the winter months could cause problems (path must be

maintained and the area cleared) Despite the fact that students and visitors can see the container it is not the most visible

composting option Logistical concern for power (despite being close to electrical access) that could substantially

increase starting costs Despite the minimal possibility of “smell” there could still be some residual odor from the

composting process Additional materials would be required (fencing, possibly a concrete pad, security, etc.) to begin

the composting process


Convenient location directly next to the UWGB Hoop House Allow for easy transport of the compost after it has “fully matured” Minimal possibility of “smell” (odor is almost completely contained) that may accompany the

composting process Mediocre visibility for all students and visitors to see what steps UWGB is taking to improve

sustainability Relatively close to electrical access that is needed Despite being outside the container is able to withstand the cold climate that occurs in

Wisconsin

of 62

Could easily be maintained and run by a paid internship that is “housed” within Laboratory Sciences


Accessing the container during the winter months could cause problems (path must be maintained and the area cleared)

Despite the fact that students and visitors can see the container it is not the most visible composting option

Logistical concern for power (despite being close to electrical access) that could substantially increase starting costs

Despite the minimal possibility of “smell” there could still be some residual odor from the composting process

Additional materials would be required (fencing, possibly a concrete pad, security, etc.) to begin the composting process


Convenient location directly very close to the UWGB Hoop House Allow for easy transport of the compost after it has “fully matured” Minimal possibility of “smell” (odor is almost completely contained) that may accompany the

composting process Mediocre visibility for all students and visitors to see what steps UWGB is taking to improve

sustainability Relatively close to electrical access that is needed power aeration process Despite being outside the container is able to withstand the cold climate that occurs in

Wisconsin Could easily be maintained and run by a paid internship that is “housed” within Laboratory

Sciences Possibly a logistical concern with moving material that is ready to be composted from the

University Union to this location Accessing the container during the winter months could cause problems (path must be

maintained and the area cleared) Despite the fact that students and visitors can see the container it is not the most visible

composting option Logistical concern for power (despite being close to electrical access) that could substantially

increase starting costs Despite the minimal possibility of “smell” there could still be some residual odor from the

composting process Additional materials would be required (fencing, possibly a concrete pad, security, etc.) to begin

the composting process


Virtually the only benefit of this particular location is the assurance that any residual odor will not impact anyone


of 62

Accessing the container during the winter months could cause major problems (clearing a path and always maintaining it)

Additional materials would be required (fencing, possibly a concrete pad, security, etc.) to begin the composting process

Minimal (if any) visibility for all students and visitors to see what steps UWGB is taking to improve sustainability

Create a more difficult process for the transport of compost after it has “fully matured” Not really a convenient location at all (for transportation, care, etc.) Major logistical concern for power (only “local” electrical access is possibly the Old Language

House) The likely need for development of a new and centralized access for electricity would

substantially increase starting costs

Vermicomposting

Inside of the University Union:

Allow for easy transport of the compost after it has “fully matured” The entire composting process is literally contained in one single area and eliminates the

logistics of moving materials Could easily be maintained and run by the University Union and A’viands (with compensation

for costs) Minimal odor from the composting process and there are effective and efficient methods

available to completely eliminate it World Unity A could be converted for placement (currently is used as a temporary storage room

and is unattractive as a room) Literally the only location possible for this particular composting option Possibility of having difficulty with the DNR over the introduction of species (despite the fact it

would be indoors) The temperature sensitivity of the worms makes this the only feasible location (very poor and

limited option) Minimal (if any) visibility for all students and visitors to see what steps UWGB is taking to

improve sustainability Possibly complicate the process for the transport of compost after it has “fully matured” Conversion of World Unity A would require additional materials (tarps, air filters to eliminate

residual odor, etc.) The size of the container that is needed and building it inside is enough to completely eliminate

this location and option Basically a logistical and operational “nightmare” in which the costs would most certainly

outweigh the benefits

of 62

Potential Sites for Storage of Bulking Materials

Any potential sites for the storage of bulking materials near any possible location where the Earth Tub

might be placed (most likely near the University Union for the simplification of transportation) have

been eliminated for the following reasons:

Having a “pile of natural junk” directly outside of the building may “decrease” its appearance The storage of bulking materials (grass clippings and leaves) would attract certain animals

(mice) The “smell” that most likely would be associated with the storage of these bulking materials

would be unattractive Despite the fact that transportation would be relatively easy the aforementioned “cons”

eliminate all of these options

If the Earth Tub is determined to be the most feasible composting option and is selected as the one

that UWGB will use, shredded paper will most likely be used instead of grass clippings and leaves for

the following reasons:

The possibility of mixing grass clippings from Shorewood with others could bring dangerous chemicals with them

The type of fertilizer that is used on grass across UWGB carries certain chemicals with it that are undesirable

The compost is to be used to grow food to be eaten and risking contamination is unwanted and unnecessary

Leaves are only available during the Fall and being able to effectively store them year round could be a major problem

Using shredded paper would surely ease the issues with storage and transportation of other bulking material options

Since all potential sites for the storage of bulking materials near any possible location where the Earth

Tub might be placed (most likely near the University Union for the simplification of transportation)

have been eliminated there are only two other potential storage sites:


The “smell” that most likely would be associated with the storage of these bulking materials would not be a concern

The storage of bulking materials (grass clippings and leaves) attracting certain animals (mice) would not be a concern

A large amount of bulking materials could easily be stored in this area without a space concern The storage of bulking materials would be hidden from all individuals and would not be

considered an “eyesore” The transportation of bulking materials to be stored and delivered could be complicated and

increase costs Large tarps would have to be purchased to cover the bulking materials from weather conditions

of 62

Accessing the bulking materials (if they are needed) during the Winter months could be a serious problem

Unsure of how to handle the differing moisture conditions that could result and contaminate the bulking materials

Possible difficulty of having transportation vehicles even be able to have access to deliver bulking materials

The feasibility of this potential site for storage of bulking materials is very unlikely and could complicate things

Behind Laboratory Sciences (Hidden Location:

The “smell” that most likely would be associated with the storage of these bulking materials would not be a concern

The storage of bulking materials (grass clippings and leaves) attracting certain animals (mice) would not be a concern

A large amount of bulking materials could easily be stored in this area without a space concern The storage of bulking materials would be hidden from all individuals and would not be

considered an “eyesore” The transportation of bulking materials to be stored and delivered could be complicated and

increase costs Large tarps would have to be purchased to cover the bulking materials from weather conditions Accessing the bulking materials (if they are needed) during the Winter months could be a

serious problem Unsure of how to handle the differing moisture conditions that could result and contaminate

the bulking materials Possible difficulty of having transportation vehicles even be able to have access to deliver

bulking materials Most the area behind Laboratory Sciences is used for field experiments and use for storage

could hinder these Accessing the area even in months other than Winter could be a logistical “nightmare” and

unfeasible The feasibility of this potential site for storage of bulking materials is very unlikely and could

complicate things Potential Sites for Storage of Shredded Paper (Bulking Material for Earth Tub Option)

On the Loading Dock (Specifically Inside of the Compactor Room) Inside the University Union:

Extremely convenient site directly next to the compactor Directly next to the area where all paper to be recycled within the University Union ends up No concern with extra transport of paper since it is located directly next to the final destination Possible problem with the storage of shredded paper due to space concerns Logistical problem with electrical access directly next to the compactor Most likely would get in the way when trying to empty carts that are full of cardboard Due to already mounting concerns with proper usage of bins the shredded paper could be easily

“contaminated”

of 62

Unsure if people will even try to use the shredder since the compactor is right next to it and it is considered “easier”

The space concern of this specific location will most likely be the determining factor of why it is not feasible

Inside of DigiCopy Located Within the University Union:

One of the largest collection sites of paper that cannot be used and/or to be recycled within the University Union

Could easily be shredded and would actually ease logistics of disposing unused paper from DigiCopy

Already have mounting stacks of “scrap paper” that DigiCopy encourages others to take and are usually unused

Consistent source of paper to be shredded and could have entire building deliver paper to be recycled to DigiCopy

Very likely problem with the storage of shredded paper due to space concerns Compensation might be needed to have DigiCopy “operate” the paper shredding process Movement of shredded paper could be a problem and could “hinder” business Possible logistical problem with electrical access since almost all power sources are already in

use for machines Unsure if the paper to be recycled would even make it to DigiCopy to be shredded The space and transportation concerns of this specific location make it a logistical “nightmare”

and unfeasible

Inside of World Unity A Room Located Within the University Union:

Currently an “unattractive” room that is used for only storage Could still be used for storage since only a small amount of room would be needed for a

shredder and collection bin Easily accessible electrical access in multiple spots throughout the room When paper recycling is collected in the morning it could simply be dropped off to be shredded

later Would not get in the way of any business being conducted Really no logistical problem with a limited amount of space Can be considered a very feasible option Slight concern with individuals actually dropping paper to be recycled off instead of throwing it

into the compactor Deciding on who would be in charge of shredding paper in order to make bulking material could

cause problems Compensation might be needed to have the University Union “operate” the paper shredding

process If World Unity A is ever decided to be used (instead of just a storage room) then a change in

locations would occur Getting the University Union to ensure that World Unity A will be a permanent place for

shredding may be difficult

of 62

The changing usage of rooms and changes within the University Union may decrease feasibility of this location

Somewhere on Third Floor of the University Union:

Located within the vicinity of where the majority of paper recycling bins for office usage are kept Located within the same area that the most used printer/copier is located within the University

Union All office paper recycling bins could be easily emptied and shredded on a daily basis No real concern with the “competitive usage” of the compactor since it is located so far away Unsure of where to even place a shredder and collection bin A major space concern due to the fact that there is really no area large enough to hold a large

collection bin Unsure of who the responsibility will fall on to ensure that the paper is actually shredded Transportation concern of shredded paper when it is needed for bulking material Logistical concerns of location and space could make this a very unfeasible location Just too small of an area to hold a large shredding and collection operation

Numerous Locations throughout the University Union:

A shredder would be located within the vicinity of all locations that collect large amounts of paper to be recycled

Eliminate all logistical concerns associated with space Questions of where to place shredders would be eliminated by simply placing them within a

“community” location Concerns with individuals taking the “easy” option by using the compactor completely

eliminated Multiple locations would ensure that the majority of paper to be recycled is actually shredded A larger collection bin could be placed in multiple areas to “dump” shredded paper when

shredder is full Simplifies the entire operation of shredding paper to be recycled for bulking material Can be considered the most feasible option Costs might increase by having to purchase multiple shredders instead of one large one Placement of responsibility of emptying “satellite” collection bins into one large collection bin

could be a problem Location of one large collection bin with shredded paper could cause some concerns Some major problems may result in the beginning of the transportation and collection process

of 62

Tables and Figures

Table 14 and Table 15, and Figure 8 through Figure 11 all summarize data regarding potential future

changes in tipping fees and monthly waste hauling contract costs.

Table 14. Tipping Fee Increases Over 10 Years

Table 15. Waste Hauling Contract Cost Increases Over 10 Years

Year Monthly Contract Cost Increase

$0.00 $10.00 $25.00

2010 $3,360.00 $3,360.00 $3,360.00

2011 $3,360.00 $3,480.00 $3,660.00

2012 $3,360.00 $3,600.00 $3,960.00

2013 $3,360.00 $3,720.00 $4,260.00

2014 $3,360.00 $3,840.00 $4,560.00

2015 $3,360.00 $3,960.00 $4,860.00

2016 $3,360.00 $4,080.00 $5,160.00

2017 $3,360.00 $4,200.00 $5,460.00

2018 $3,360.00 $4,320.00 $5,760.00

2019 $3,360.00 $4,440.00 $6,060.00

Total Cost

$33,600.00 $39,000.00 $47,100.00

Year Tipping Fee Increase

$0.00 $5.00 $10.00

2010 $325.04 $325.04 $325.04

2011 $325.04 $367.44 $409.84

2012 $325.04 $409.84 $494.64

2013 $325.04 $452.24 $579.44

2014 $325.04 $494.64 $664.24

2015 $325.04 $537.04 $749.04

2016 $325.04 $579.44 $833.84

2017 $325.04 $621.84 $918.64

2018 $325.04 $664.24 $1,003.44

2019 $325.04 $706.64 $1,088.24

Total Cost

$3,250.40 $5,158.40 $7,066.40

of 62

Figure 8. Ten Year Cost Outlook ($25 Monthly Contract Cost Increase Per Year)

Figure 9. 10 Year Cost Outlook ($10 Monthly Contract Cost Increase Per Year)

of 62

Figure 10. Differential Monthly Contract Cost Increases

Figure 11. 10 Year Monthly Contract Cost Comparison

of 62

Figure 12 shows the 5 year Earth Tub analysis of contract increases of $0/month and kWh increases of

$0.00/year. This scenario is signified by “0/0”. Figure 13 shows the same scenario over 10 years.

Figure 12. Total Profit/Debt (0/0)

of 62

Figure 13. Total Profit/Debt of 10 years (0/0)

of 62

Figure 14 shows the Earth Tub analysis of contract increases of $0/month and kWh increases of

$0.01/year. This scenario is signified by “0/1”.


of 62


$0.01/every other year. This scenario is signified by “0/E1”.

Figure 15. Total Profit/Debt (0/E1)

of 62




university of wisconsin system solid waste research … · estimated monthly generation of...

Documents