The State of Food Waste Composting in Greater Milwaukee: An Illustrative Case Study ·...

THE STATE OF FOOD WASTE COMPOSTING IN GREATER MILWAUKEE:

AN ILLUSTRATIVE CASE STUDY

by

Timothy O. Allen Jr.

A thesis submitted in partial fulfillment of

the requirements for the degree of

Master of Science

(Environment and Resources)

at the

UNIVERSITY OF WISCONSIN-MADISON

2017

i

Abstract

This research carried out an illustrative case study of the food waste composting system of Greater

Milwaukee. Key questions asked include what is the quantity of food waste being diverted to com-

posting, what is the number of food waste composting sites, what is the size and location of these

sites, what is the capacity of the infrastructure to compost food residuals, and what is the amount of

compost produced by the system. The study has found that the infrastructure has the capacity to

compost 20,000 cubic yards of source separated compostable material which includes food waste.

This represents between 20% and 42% of the total quantity of food waste generated in the city of

Milwaukee, estimated at 47,000 tons. The volume of food waste currently diverted to composting is

12,176 cubic yards which represents between 9% and 20% of the total. Based on the increase in

food waste hauling, a trend toward increased food waste diversion was identified. It was found that

while there are eight sites composting food waste in the study area, most is being composted at one

site, Blue Ribbon Organics. The quantity of compost produced by food waste composting sites is

7,684 cubic yards, not all of which is sold commercially. The implications of this are not clear due to

further research needed to explore compost markets. This research concludes that greater invest-

ment in the food waste composting system is needed to support diversion rates, increase the sus-

tainability of the system, and to produce more compost.

ii

Acknowledgements

It is only fitting that I offer gratitude to those that supported and guided this master’s thesis.

First, I would like to thank my committee, Dr. Stephen J. Ventura, Dr. Alfonso Morales, Jo-

seph Van Rossum, MS, Greg Lawless, MS whose comments never fell on deaf ears. Second,

I would like to show gratitude for the funding sources that supported this research including

the ENVIROGRS Fellowship that supported the preparation of my research prospectus, the

USDA-AFRI grant 2011-68004-30044 Community and Regional Food Systems that sup-

ported my extent literature review and initial field work as well as USDA-SARE grant

NCR16-023 Systems Approach to Food Waste Composting for Urban Agriculture that made

possible the completion of this work.

Finally, I would like show gratitude to my family for their support during this journey which

has taken the greater part of my time and attention over the last three years.

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Table of Contents Abstract ...................................................................................................................................... i

Acknowledgements ................................................................................................................... ii

Table of Contents ..................................................................................................................... iii

List of Figures .......................................................................................................................... vi

List of Tables .......................................................................................................................... vii

I. Introduction ...................................................................................................................... 1

Background and Significance ............................................................................................... 2

Research Questions ............................................................................................................... 7

Approach and Limitations..................................................................................................... 7

II. Literature Review............................................................................................................. 9

The Abundance of Food Loss and Waste ............................................................................. 9

National and State Statistics.............................................................................................. 9

Reliance on Landfills for Food Waste Disposal ................................................................. 13

Alternative Food Waste Diversion Options ........................................................................ 18

Composting: A Solution for Abundant Food Waste with Environmental Benefits............ 20

Compost and Urban Soils ............................................................................................... 24

Composting to Scale ........................................................................................................... 26

Small Scale Composting ................................................................................................. 26

Medium and Large Scale Composting ............................................................................ 30

Food Waste Composting Policy & Regulation ................................................................... 32

III. Methodology .................................................................................................................. 37

Case Study Approach .......................................................................................................... 39

Assumptions and Limitations ............................................................................................. 42

IV. Case Study: State of Food Waste Composting in Greater Milwaukee .......................... 42

Food Waste Composting ..................................................................................................... 43

Blue Ribbon Organics ..................................................................................................... 44

Feedstock .................................................................................................................... 44

Size and Location ........................................................................................................ 45

Capacity ...................................................................................................................... 45

iv

Composting Method.................................................................................................... 46

Compost Produced ...................................................................................................... 47

Growing Power ............................................................................................................... 48

Food Scraps Collection ............................................................................................... 48


Capacity ...................................................................................................................... 50


Compost Production.................................................................................................... 52

Public Awareness and Education ................................................................................ 53

Kompost Kids ................................................................................................................. 54


Capacity ...................................................................................................................... 55



Orchard Ridge Composting Facility ............................................................................... 57

Feedstock .................................................................................................................... 58


Capacity ...................................................................................................................... 59



Composting at Community Gardens ............................................................................... 60


Capacity ...................................................................................................................... 61


Backyard Composting ..................................................................................................... 62

Purple Cow Organics-Genesee ....................................................................................... 63


Capacity ...................................................................................................................... 64



v

Non-food Waste (Yard Residuals) Composting ............................................................. 65

Anaerobic Digesters ............................................................................................................ 67

Forest County Potawatomi Anaerobic Biodigester......................................................... 67

Capacity ...................................................................................................................... 67

Milwaukee Metropolitan Sewerage District ................................................................... 68

Capacity ...................................................................................................................... 68

Food Waste Collection ........................................................................................................ 69

Compost Crusader ........................................................................................................... 69

Compost Express ............................................................................................................ 72

Sanimax........................................................................................................................... 73

Compost Distributor............................................................................................................ 74

Elyve Organics ................................................................................................................ 74

V. Discussion ...................................................................................................................... 76

Characteristics of the Food Waste Composting System ..................................................... 77

Composting Site Sizes and Spatial Distribution ............................................................. 78

Food Waste Composting System Capacity ..................................................................... 83

Composting Methods ...................................................................................................... 86

Compost Production........................................................................................................ 87

Yard Residuals Composting: Conversion potential of existing infrastructure ............... 90

Food Waste Collection and Compost Distribution ......................................................... 92

Sustainability and the Food Waste Composting System ................................................ 95

VI. Conclusion ................................................................................................................... 101

VII. References .................................................................................................................... 107

Appendix A. .......................................................................................................................... 113

Appendix B. .......................................................................................................................... 118

vi

List of Figures Figure 1. Total Municipal Solid Waste Landfilled ................................................................. 10

Figure 2. Food Waste Landfilling Greenhouse Gas Emission Factors ................................... 14

Figure 3. US EPA Food Recovery Hierarchy ......................................................................... 18

Figure 4. Food Waste Composting GHG Emissions Factors For Large Commercial Facility22

Figure 5. Aerial View of Blue Ribbon Organics Composting Site......................................... 45

Figure 6. Aerial View of Growing Power's 55th Street Farm ................................................ 50

Figure 7. Aerial View of Kompost Kids' Bay View Site (Prior To Occupancy) .................... 55

Figure 8. Close-Up View of Kompost Kids' Bay View Site (Prior To Occupancy) .............. 55

Figure 9. Kompost Kids Riverwest Multi-Bin Composting System ...................................... 57

Figure 10. Aerial View of Orchard Ridge Composting Facility ............................................. 58

Figure 11. Capacity of Greater Milwaukee Food Waste Composting Sites ........................... 60

Figure 12. Annual Compost Production For Food Waste Composting Sites ......................... 60

Figure 13. Purple Cow Organics Genesee Composting Site .................................................. 64

Figure 14. Greater Milwaukee Yard Residuals Composting Sites ......................................... 66

Figure 15. Volume of Food Waste Digested and Capacity of Anaerobic Digesters .............. 69

Figure 16. Compost Crusader’s Annual Organic Residuals Collection by Category (2015) . 70

Figure 17. Compost Crusader’s Organic Residuals Collection (2015) ................................... 71

Figure 18. Food Waste Collected by Business ....................................................................... 74

Figure 19. Spatial Distribution of Greater Milwaukee Food Waste Composting Site ........... 79

Figure 20. Proportion of Food Waste Composted at Greater Milwaukee Sites ...................... 81

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List of Tables

Table 1. Rate of Composting Based on Composition of Food Waste .................................... 12

Table 2. Food Waste Management Options and Impacts ....................................................... 16

Table 3. Environmental Impacts of Food Waste Management Options ................................. 16

Table 4. Environmental Benefits of Food Waste Composting ............................................... 23

Table 5. Potential Use of Compost From Organic Waste ....................................................... 25

Table 6. Community Composting Criteria.............................................................................. 27

Table 7. Composting Scales and Appropriate Methods.......................................................... 31

Table 8. Wisconsin Department of Natural Resources Food Waste Composting Regulations

......................................................................................................................................... 34

Table 9. City of Milwaukee Composting Regulations............................................................ 36

Table 10. Infrastructure Components and Characteristics ...................................................... 40

Table 11. Food Residuals Composting Stakeholders ............................................................. 41

Table 12. Summary of Food Waste Composting System Characteristics .............................. 83

Table 13. Distinction of Greater Milwaukee Compost Products ............................................ 89

Table 14. Urban Applications For Local Food Waste Compost ............................................. 90

Table 15. Food Waste Composting System Goals.................................................................. 97

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I. Introduction

In the last decade, there has been an increase in food waste composting across the

country at various scales including the community level and city-wide level. These increases

are due to several reasons. A major reason is an increase in public awareness of the amount

of food waste created and sent to landfills, which can be otherwise recovered. Another reason

is the increase in urban agriculture and green infrastructure activities, which have created a

demand for compost in urban environments including for gardens and on urban farms. Com-

plimenting these activities is a steady increase in yard waste composting facilities since the

1990s. The result is infrastructure that can and is being adapted for food waste composting.

Food waste composting in U.S. cities will undoubtedly continue to increase, and as such, pur-

poseful planning of the composting infrastructure is important to ensuring its sustainability.

Many instances of food waste composting have been documented, often focused on

large sources such as supermarkets and food processors. Just as well, there has been in-

creased attention to cities that have instituted residential composting programs (NatGeo,

2013; Yepson, 2012). To date, a system scale illustration of an entire metropolitan food

waste composting infrastructure, including commercial food waste diversion and residential

food waste diversion, has not been documented in the literature.

The food waste composting infrastructure serving Milwaukee, Wisconsin is at present

diverting food waste to composting, though the extent has not been documented. There are

over 30 licensed composting sites in Greater Milwaukee, but of them only two were licensed

to process food waste at the start of this study (WDNR, 2016). During this study three addi-

tional composting sites have become licensed to compost food waste. The remainder com-

post only yard residuals. As the City of Milwaukee has a set a solid waste diversion goal of

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40% by 2030, composting food waste can support this goal (Refresh, 2014). This research

presents an illustrative case study of the food waste composting system serving Greater Mil-

waukee and a potential pathway to meet this goal.

Background and Significance

As a society, we have realized the value of recycling paper, metals, and plastics, yet

organic materials—materials from products that were once living or derived from products

that were once living—have only recently been given serious attention as a recoverable mate-

rial (USEPA, 2002). Food waste—food produced for human consumption that goes uneaten

at the retail and consumer level—is a by-product of modern society that values convenience

and choices in what we eat. The term food waste is widely used but only refers to one aspect

of where food goes uneaten.

Nationally, about 40% of the food produced goes uneaten (Gunders, 2012). This esti-

mate includes food losses as well as food waste. Food loss is a term describing where food

produced for human consumption goes uneaten post-harvest along the food supply chain.

Food waste is a subset of food loss. A third term, food scraps, used as a euphemism for food

waste, will be employed here. A fourth term, food residuals, is used by the Wisconsin De-

partment of Natural Resources (WDNR) to classify types of materials allowable for compost-

ing. This term will be used where there is ambiguity over whether the material is food loss or

food waste.

Sources of composting feedstocks—organic material to be composted—may be the

result of food loss or food waste (Buzby & Hyman 2012). As defined here, included in food

loss and food waste are the inedible parts of food, which although they were not intended for

human consumption, can be diverted to composting (Food Loss + Waste Protocol, 2016). As

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discussed in the next section, this study will give greater emphasis to food waste as data on

the volume of food waste is more readily available which is important in planning for food

waste diversion.

Food waste is one of many organic materials, but one which contains proportionally

more plant macro- and micronutrients. These plant nutrients can be recycled back to the soil

through composting. In other words, food waste can be turned into a resource. As this study

has an underlying goal to assess whether appropriate compost can be made available for

community food production in the city of Milwaukee, food waste is the composting material

of most interest here. Other composting materials, or feedstock, are necessary for the com-

posting process, such as bulking materials i.e. yard residuals, but do not contain as many

plant nutrients. Furthermore, more yard residuals are currently composted than food residu-

als.

The United States Environmental Protection Agency (USEPA) reports that food

waste comprises 14.5% of municipal solid waste (MSW). Food waste, unlike other recycla-

ble materials, is typically co-mingled with MSW (USEPA, 2016). In terms of sustainability,

food waste results in negative impacts, including the squandering of resources (Buzby et al,

2014, FAO, 2011). There are, of course, many instances where food waste is avoidable, but

there will inevitably be some food waste. In cases where it is not prevented, or recovered by

other means, composting can serve to get higher uses from food waste than the status quo,

landfilling.

The need for an innovative approach to food waste has been given attention world-

wide (e.g., FAO, 2013). Emphasis has been placed on the perspective that food residuals not

be viewed as a problem of waste management, but as an opportunity for resource recovery

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(Nasr and Smit, 1997). This approach can alleviate the environmental impact of food residu-

als, most of which comes from their disposal in landfills (Brown, 2016).

Like other organic residuals, food waste decomposes. Because of the way in which it

decomposes in landfills, anaerobically, it produces methane. The methane not captured

through a landfill vapor recovery system becomes a greenhouse gas (GHG). As methane has

a global warming potential 25 times more potent than carbon dioxide, it is recognized as a

large contributor to climate change (USEPA, 2011).

The production of methane can be avoided by diverting food residuals, and other or-

ganic residuals, away from landfills to composting where aerobic decomposition occurs

(Cooperband, 2002). Under aerobic conditions, only carbon dioxide is produced, the result of

microbial respiration. While also a GHG, carbon dioxide released from composting food re-

siduals is considered a biogenic source and not included in GHG emissions quantification of

anthropogenic sources (USEPA, 2006).

The Institute for Local Self-Reliance produced the report The State of Composting in

the US: What, Why, Where, and How (Platt et al, 2014), which outlines assorted reasons why

composting should be prioritized. Environmental reasons include to protect the climate, to

improve soil and protect watersheds, and to reduce waste. Additionally, social and economic

reasons, not fully considered in this study, include increasing community awareness and cre-

ating jobs respectively.

While composting itself is an age-old agricultural practice, large-scale commercial

composting has grown since 1969 when there were fewer than 20 MSW composting facilities

in the U.S. (Breidenbach, 1971). These facilities took a mixed waste approach to composting,

e.g. the organic portion of MSW not separated out prior to reaching the composting site.

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Flash forward to 1988, there were just under 1,000 facilities composting only the yard waste

portion of MSW. In 1994, there were around 3,500-yard waste composting facilities as com-

pared to 17 MSW facilities with source separation of compostable materials from MSW be-

coming more widespread (Steuteville, 1995; Biocycle, 1994).

In recent years, the growth in the number of composting facilities has leveled off.

Many existing yard residuals composting facilities are incorporating food residuals into their

operations, a trend which has been increasing in frequency since the 1980s (Goldstein &

Steuteville, 1994). Best practices have recently been established which will help to facilitate

this transition for more facilities (Christensen, 2009).

In Wisconsin, yard residuals composting is required under administrative code

287.07(2) (WDNR, 2012). As of 2012, there were 239 composting facilities operating in

Wisconsin; of these, 10% accepted food residuals as a feedstock (Van Rossum, 2012). Mean-

while, food waste constitutes 10% of the MSW stream statewide, with large volumes gener-

ated in urban areas due to denser populations (Resource Connections Corporation, 2010). De-

spite the relative low incidence of food residuals composting facilities in Wisconsin, com-

posting to divert food residuals and other organic residuals, especially in urban areas, stands

to recover these resources.

To date, several studies have been undertaken to assess the potential for food residu-

als diversion in Wisconsin cities (WasteCap Resource Solutions, 2010; Organic Waste Sys-

tems, 2012; Pinero, 2009; Silva & Naik, 2005). These studies reveal there are opportunities

to institute food residuals diversion programs at a variety of scales and scopes. At the same

time, these studies typically only focus on either one of two aspects of food residuals: resi-

dential or commercial, not both. This is because municipalities typically institute residential

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composting programs while commercial composting operations often result from private

partnerships between composting facilitates and large volume food residuals generators.

Another feasibility study, on residential food waste collection in Milwaukee, found

there is composting infrastructure serving the city, but expanded diversion rates, like what

would result from a full-scale residential food waste composting program, cannot be sup-

ported without significant infrastructure investment and logistical planning (Meyers, 2015).

This finding warranted the need to determine the capacity of the composting infrastructure

serving the city.

While this research focused on one locale, it could apply to many cities due to the

context, subject and scope. Milwaukee is a medium sized city of just under 600,000 resi-

dents. It is the most populated city in Wisconsin, and the largest in size at 98.6 acres. While

many cities nationwide have already started municipal composting programs or are near

commercial composting facilities, the unique context of Milwaukee and the state at which the

food waste composting system is currently in can offer new insights.

At the national level, the Obama administration, in conjunction with the USEPA and

the United States Department of Agriculture (USDA), has set a specific food waste reduction

goal for the nation of 50% by 2030 (USDA, 2015). Implementation of this goal will drive

food waste diversion and may require the development of composting infrastructure where

needed. This too calls for the capacity of the food waste composting system to be deter-

mined. Additionally, an analysis of the context in which the composting infrastructure has

developed will elucidate the sustainability of the current system and aid in ensuring the sus-

tainability of future development.

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While food waste composting is occurring in Greater Milwaukee, a gap in the

knowledge surrounding exactly how much food waste can be composted existed. The amount

of food residuals generated within the city has been estimated, 47,000 tons/year, or 94,000 -

203,204 cubic yards (where food waste is 463 – 1,000 pounds / cubic yard) providing a

benchmark for the composting infrastructure’s capacity to meet (US EPA, 2016).

Research Questions

This research asked what the current state of food waste composting system is and

how it has come to be so. To illustrate the current state, this research found the capacity of

the current infrastructure to accept food waste and the current amount of food residuals di-

verted from landfills to composting. This research also asked what is the annual quantity of

food waste compost produced by the infrastructure.

This research proposed that while experiencing some growth, the food waste com-

posting infrastructure serving the city of Milwaukee will soon be incapable of supporting

rates of food waste diversion without significant investment in infrastructure as well as a

public awareness campaign. Furthermore, it was hypothesized that the current food waste

composting system is not poised for maximum efficiency or sustainability.

Approach and Limitations

The purpose of this research is to illustrate the current food residuals composting in-

frastructure in Greater Milwaukee. To do so, a mixed-methods approach was utilized consist-

ing of surveys, interviews and an audit of archival reports and other documents. Key findings

include the capacity of the composting infrastructure to compost food residuals and the

amount of compost produced annually. To get an accurate account of the food waste com-

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posting infrastructure, interviews of key persons in the study area were necessary. This in-

cluded composters, food waste collectors, public agency officials, as well as food waste gen-

erators and others involved in food waste diversion to composting.

The results of this methodology were both qualitative and quantitative data. Qualita-

tive data includes the names, locations, and sizes of the existing composting operations, com-

posting methods and how long they have been composting. Quantitative data includes the

amount of food residuals (and bulking materials) each operation composts and the amount of

compost produced annually. Local and state policies that influence or regulate composting

were reviewed, along with public programs and incentives for food waste composting.

These data were put into a spatial framework so the locations of food waste genera-

tors, composters, and compost users could be reconciled, leading to recommendations about

efficiency improvements. Taken together, these data revealed the state of the composting in-

frastructure serving Greater Milwaukee.

The quantitative data presented here, such as food waste diverted to composting oper-

ations and amount of compost produced, are correct as of the end of 2015, though some data

provided are from 2016. It is assumed that these data are true as reported by individual par-

ticipants or the reports from which they come. Some quantities on diverted food waste were

directly measured while others were approximated or inferred. In cases where data was ap-

proximated, as in the case of the small-scale composters, there was an inoperability to make

direct measurements.

Some data were not obtained due to the inability to interview key participants associ-

ated with said data. In addition, persons from compost sites licensed in the later stages of this

9

research were not contacted. Thus, it is recognized that this study does not represent the most

up to date state of the composting infrastructure in Greater Milwaukee.

II. Literature Review

The Abundance of Food Loss and Waste

Food waste in the U.S. is a problem of significant concern among many sectors. Food

waste identification and characterization studies have provided several categories of food

waste generators including industrial, commercial, institutional, and residential. Within these

categories, sources of food waste include schools and universities, hospitals, food and bever-

age manufacturers, corporate headquarters, and more. While most of the food waste gener-

ated from these sources can be considered part of MSW, this is not always the case. This

makes estimates based solely on MSW less than reliable. Sources of food waste have been

identified, and even though it is a recyclable material, it is less likely to be recovered.

National and State Statistics

Dana Gunders of the Natural Resources Defense Council (NRDC) makes the case

that food loss is a major issue considering the large amount of resources dedicated to food

production. Her report Wasted: How America Is Losing Up to 40 Percent of Its Food from

Farm to Fork to Landfill provides statistics on where in the food chain loss is occurring and

how much of each food group is lost. This study utilized previously published data, some of

which comes from studies described below.

One such study, conducted by the USDA Economic Research Service, estimated food

losses, or the difference between the amount of food produced and the amount of food con-

sumed (Buzby et al, 2014). This estimate includes retail and consumer-level food losses

(food waste) due to data limitations for losses earlier in the food supply chain. The study

10

found the total amount of food loss occurring nationwide is over 62 million tons annually.

The study also provides this volume in terms of calories which conveys the fact that this food

was originally intended for human consumption.

While there are ways to describe food waste other than in terms of weight, this means

of quantification is useful for the purposes of recovery from disposal. The USEPA annually

releases the report Advancing Sustainable Materials Management: 2014 Fact Sheet which

describes the quantity, in weight, of MSW produced over the course of a year in the U.S.

(USEPA, 2016). The report provides figures for several types of MSW; of interest for this

study are the organic waste streams which can be feedstock for composting.

Per the USEPA Fact

Sheet, in 2014, 258.5 million

tons of MSW were generated in

the U.S. Of this, 34.50 million

tons were yard trimmings, 68.61

million tons were paper and pa-

perboard, 16.12 million tons

were wood, and 38.40 million

tons were food waste (up from 37.06 in 2013), of which 1.94 million tons were recovered i.e.

not landfilled (up from 1.84 in 2012). These are all compostable materials. Nationally, after

recycling and composting, food waste comprises 21.6% of MSW, the largest category (Fig-

ure 1).

Figure 1. Total Municipal Solid Waste Landfilled

49%

21%

8%

14%

8%

Non-compostable

Food Waste

Wood

Paper & Paperboard

Yard Wastes

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Many states mandate paper be recycled and yard waste be composted, Wisconsin in-

cluded. Thus, the State has a considerable number of existing composting facilities pro-

cessing this material. Even so, most of these facilities do not incorporate food waste into their

composting operations (Van Rossum, 2012). While the ease of incorporation of food waste

into an existing composting operation is subject to the type of food waste, i.e. pre-consumer

or post-consumer waste, and other factors, best management practices have been compiled. It

is beyond the scope of this research to determine why, but it is clear food waste is recycled

disproportionately less often than yard trimmings, and paper or wood.

Another study conducted by Business for Social Responsibility (BSR), for the Gro-

cery Manufacturers Association and the Food Marketing Institute, puts food waste at 60.8

million tons (39.7 million tons after recycling and composting) (Food Waste Reduction Alli-

ance, 2013). This estimate includes food residuals from the food chain from farm gate sale to

manufacturing to consumers. It was reached from data compiled from several waste charac-

terization studies using direct sampling of MSW. One such study was commissioned by the

WDNR for Wisconsin’s MSW (Resource Connections Corporation, 2010).

Per the WDNR study, as of 2009, in Wisconsin, food waste is the most abundant cate-

gory of material being sent to landfills, rising to 455,259 tons annually and making up 10%

of the MSW stream. This estimate distinguishes between residential, 231,727 tons, (or

50.9%) and industrial/commercial/institutional (ICI), 220,801 tons, (or 48.5%) food waste

streams. This study is especially useful because it categorizes food waste generation which

improves the prospects for targeted food waste diversion efforts.

Expanding on this last point, the public sector typically takes an interest in residential

food waste while the private sector is more apt to take an interest in the latter. A population-

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based extrapolation of the statewide figure for food waste apportions 47,000 tons/year of

food waste to Milwaukee. While it is unknown what portion of the food waste in Milwaukee

is residential or ICI, the statewide breakdown can serve as a guideline indicating half the

MSW food waste is created by residents and half by ICI sources.

This is important considering that the City of Milwaukee is currently running a

curbside collection pilot for organic materials in two areas (Milwaukee Recycles for Good!,

2016). If the pilot is expanded to the entire city of Milwaukee, the capacity of the composting

infrastructure must be large enough to accept half the estimated amount of food waste. That

is, if none of the other half in this estimate is being composted. If the ICI food residuals are

being composted, there will be less capacity to accept residential food waste. Furthermore,

this does not include carbon (bulking) materials, such as leaves, that are needed in the com-

posting of food waste. This will also reduce the capacity of the composting system to accept

additional feedstocks.

In addition to identifying the source and quantity of food waste, the type of food

waste is also important for consideration as it can impact the composting rate with respect to

the composting system used. In general, the decomposition of organic matter will be faster

for carbohydrate rich foods and slower for more fibrous foods (Table 1).

Table 1. Rate of Composting based on Composition of Food Waste

Fast

Slow

Carbohydrates and Sugars Protein Fats Cellulose Bone

Adapted from Epstein (1997)

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Reliance on Landfills for Food Waste Disposal

The status quo for food waste disposal is to send it to a landfill. The problem with this

is landfilling food waste has lasting environmental effects. The modern sanitary landfill de-

veloped as a technological advancement that would solve the problem of waste management

such as foul odors, pathogens, and air pollution associated with opens dumps and incinera-

tors. Per Rathje and Murphy (1997), “The sanitary landfill started out in life as a solution to

the twin problem of garbage incinerators that befouled the air and the malodorous open

dumps that ringed American cities like vile garlands.” They go on to state:

“…the impetus was a concern for public health. Even before the role of bac-

teria and viruses in the onset of and spread of diseases was well understood,

people had made the connection between sickness in the community at large

and the open dumps nearby.”

The sanitary landfill was a great advance in waste management. Still, like the lack of

forethought given to waste management before the sanitary landfill, it also has resulted in un-

foreseen impacts. A major impact, and one receiving growing concern, is global warming

from the release of greenhouse gases (GHGs) such as carbon dioxide (CO2) and

methane (CH4), (Figure 2). Per the USEPA, landfills account for 18% of all U.S methane

emissions. These emissions are a significant contributor to atmospheric GHGs.

The USEPA’s Waste Reduction Model (WARM) was used to model the GHG emis-

sion factors from sending one ton of food waste to a landfill (USEPA, 2017).

The major food waste landfilling GHG emission factors are:

Transporting materials to landfill,

landfill CH4,

14

avoided CO2 emissions from energy recovery,

and landfill carbon storage.

While a variety of factors, such as temperature and moisture, will affect the produc-

tion of GHGs in landfills, internal landfill conditions lend themselves to an anaerobic

environment in which methanogenic bacteria will decompose food waste, thus, methane will

be produced. While the capture of methane from capped landfills has become a widespread

practice, at least for large landfills, the inefficiency of these systems allows the escape of me-

thane to the atmosphere (Brown, 2016). When a landfill is capped at the end of its life, it can

continue to emit GHGs and may also leach harmful chemical pollutants into the groundwater

(Laner et al, 2011).

Another critical issue surrounding landfills is their capacity and land use. In terms of

landfill space, one ton of food waste takes up 1.7 cubic yards. If the amount of food waste

generated in Milwaukee were diverted to composting, 799,000 cubic yards (47,000 tons food

waste/year x 1.7 cubic yards/1 ton of food waste) of landfill capacity could be conserved per

TransportingMaterial to

LandfillLandfill CH4

Avoided CO2Emissions from

Energy Recovery

Landfill CarbonStorage

Net Emissions

Food Waste 0.02 0.79 -0.04 -0.07 0.71

-0.3

-0.1

0.1

0.3

0.5

0.7

GH

G E

mis

sio

ns

in M

TCO

2 E

/To

n

Figure 2. Food Waste Landfilling Greenhouse Gas Emission Factors

15

year. In terms of land use, when a landfill closes, the site will be unusable for an indetermi-

nate duration.

The finite capacity of landfills near cities and issues about siting and licensing new

ones has been recognized (Epstein, 1997). In the late 1980s and early 1990s many states be-

gan to consider how to lengthen the life of landfills. At that time recycling programs were al-

ready underway. Like recycling programs, reducing the volume of material sent to landfills is

best accomplished by source separation. Yard waste represented a sizable proportion of ma-

terials sent to landfills. Thus, many states enacted landfill bans of yard waste to effectively

reduce the sum disposal of materials and therefore extending the life of landfills.

Several studies have been conducted that look at the environmental impacts of food

waste ‘management’ options, which point out several key points for why landfilling

food waste is still the status quo. One study, which focused only on food waste produced in

households, found that landfilling is the most cost effective of five food waste management

options (Diggleman, 1998).

The results of the study indicate why landfills are the most frequently chosen op-

tion for disposing of food waste (Table 1). For 220 pounds of food waste, a landfill has the

lowest cost. In terms of land dedicated to food waste management, landfills use 0.19 square

feet, the second lowest of all options. Composting is third at 0.8 square feet of land, though it

should be noted material at a composting site is not static as in landfills. Overtime, the

0.8 square feet of land will compost more than 220 pounds of food waste. Wastewater treat-

ment plants use the most land requiring 0.003 square feet for the sewer system plus 80 acres

for the facility.

16

Table 2. Food Waste Management Options and Impacts

Method Land Area (ft2) Cost (USD)

MSW – Landfills 0.19 $13.65

MSW – Composting 0.8 $16.60

MSW - Waste to Energy (Incineration) 0.01 $20.30

Food Waste Disposers On-site Wastewater Treatment Systems 20.0006 $67.20

Sewage Treatment System 0.003 + 80 acres $17.94

Based on Diggelman (1998), based on 220 pounds of food waste

In a more recent study, Lundie et al (2005) conducted an environmental impact as-

sessment of several food waste management options. The environmental indicators used in-

clude energy, GHG emissions, water usage, human toxicity potential, aquatic eco-toxicity

potential, terrestrial eco-toxicity potential, acidification potential, and eutrophication poten-

tial. Landfills had the highest value for the GHG emissions category when home composting

is properly managed to keep the pile aerobic. In fact, if managed properly, home composting

has the least environmental impact. Three indicators are shown below (Table 3).

Table 3. Environmental Impacts of Food Waste Management Options

Management Option Energy (MJ/fu) Greenhouse Gas Emissions (lbs CO2-eq./fu) Water Usage

(gal/fu)

Food Waste Disposer 146 29 616,842

Home Composting 40

0.66 (aerobic) 2,642

602 (anaerobic)

Centralized Composting 661 115 5,019

Landfill 218 181 12,680

*FU= 400.4 lbs. food waste

Per the EPA report “25 Years of RCRA: Building on Our Past to Protect Our Future”

in 1988, there were some 6,500 landfills in operation in the U.S. (USEPA, 2002). In 2002,

this number had dwindled down to 2,500, due to closures of substandard landfills and the

creation of larger ones. While there may be less wasted, new landfills will be unavoidable.

17

In Wisconsin, there are 63 landfills in operation, 35 of which accept MSW, or gar-

bage, as classified by the WDNR. Within Milwaukee County two landfills operate, Waste

Management WI- Metro Recycling and Disposal, which has a remaining life of five years as

of 2014 and Falk Landfill, which does not accept MSW. Landfills outside Milwaukee

County including Waste Management WI-Orchard Ridge Recycling & Disposal and Ad-

vanced Disposal Services Emerald Park Landfill, LLC both in Waukesha County, also serve

Milwaukee. These landfills have a five-year and seven-year estimated remaining life as of

2014. Currently, there are two closed landfill sites in Milwaukee County that require vapor

collection systems to mitigate future GHG emissions.

Historically, there have been 84 waste disposal sites within the Milwaukee city limits,

not all of which have been licensed landfills (WDNR, 2013). This fact illustrates that waste

disposal is inherently a community issue. The USEPA recognizes this and requires public

participation in the siting process of new landfills. Because landfills are “locally undesirable

land uses,” siting, and operation, of landfills often stirs up controversies due to the “not in my

backyard” approach taken by many communities.

Seeking a means to dispose of food residuals in a way that does the least amount of

harm to the communities that create it is necessary. Landfills developed as a necessary tech-

nology to manage the issue of waste, but the environmental impacts of landfill operation now

beckon new technological fixes. As cities across the U.S. move to increase their diversion

rates, and/or towards "zero waste" initiatives, composting is becoming more attractive (An-

derson et al, 2010).

18

Alternative Food Waste Diversion Options

The USEPA has established

the Food Recovery Hierarchy which

prioritizes actions that can be taken for

the reduction of food waste sent to

landfills (Figure 3). Other entities have

adopted similar hierarchies including

the WDNR. Topping the USEPA’s hi-

erarchy is source reduction of food loss

and waste. This is the obvious option to

improve the overall sustainability of our

food systems. As the nation is only now beginning to turn our attention to the problem of

food waste this option may not be achievable on a large scale soon.

Below source reduction, is food recovery for people followed by food recovery for

animals. These actions do succeed in saving a substantial portion of food from being wasted,

but due to the nature of the food supply chain, some foods are more readily available for re-

covery while others are less (Bloom, 2010). Notably, in some cases food residuals will not be

suitable for human (or animal) consumption (Kantor, 1997).

Barring such action, industrial uses of food waste, such as anaerobic digestion for en-

ergy creation should be considered. This is the third tier of the hierarchy. When in-sink dis-

posals are used, food waste enters the sewer system and ends up at wastewater treatment

plants (WWTP) where energy and nutrients may be recovered. Disposal through sanitary

sewer systems, and WWTP, has been considered as a viable option, though there continues to

Figure 3. US EPA Food Recovery Hierarchy

19

be uncertainty about the resulting increase in organic materials in the system (Marashlian &

El-Fadel, 2005).

Many municipal governments are in support of in-sink disposals such as the InSink-

Erator, a Racine, Wisconsin based company of the same name. The disposal grinds food

waste making more it acceptable for the sewer system. Milwaukee’s WWTP is conveniently

coupled with an anaerobic digestion (AD) system. The combined sewer sludge-food waste

undergoes AD after which the remaining solids are sent to the WWTP for further pro-

cessing.

This system succeeds in creating both natural gas as well as a pelletized fertilizer, Mi-

lorganite. While not all cities are equipped with this type of system, it does serve to divert a

portion of food waste from landfills in the Milwaukee Metropolitan Sewerage District

(MMSD). AD systems can be coupled with a WWTP to capture a portion of household food

waste. They may also accept food waste from food processing and manufacturing waste

streams and other streams.

Next on the hierarchy is composting. The premise for composting is food is recycled

back into the environment as a soil amendment—compost. Compost is a resource with nu-

merous applications. Composting already serves as a diversion strategy for non-food residu-

als i.e. yard residuals, and the result is existing technology and infrastructure that has poten-

tial to be utilized to compost food waste. The WDNR hierarchy of waste options, while not

specific to food, gives higher priority to composting (WDNR, 2015).

Sitting at the bottom of the hierarchy are landfills and incineration, which are consid-

ered the last resort for food residuals as previously discussed. These options, especially land-

fills, are typically the most convenient and least costly, and in the Midwest where land is

20

plentiful and population density relatively low, landfills are more abundant. In comparison,

on the East Coast where population density is higher, so are landfill tipping fees, which

makes landfills more expensive and therefore less attractive. While cost may not serve as a

deterrent in Wisconsin at present, considering urban sprawl, this may change, necessitating

an increase in the diversion rate of all materials.

Composting: A Solution for Abundant Food Waste with Environmental Benefits

To underscore the suitability of composting as a destination for food waste, the envi-

ronmental benefits of diversion to composting and the use of compost require atten-

tion. These are what make it a food recovery option worthy of consideration. The environ-

mental benefits of food waste composting can be divided into two broad categories.

The first benefits come from the diversion of food waste away from landfills to composting

operations and the second category comes for the use of compost.

Composting food waste serves waste reduction goals and conserves space in landfills

for other, non-recyclable, materials. The history of "waste management" shows that our ap-

proach to waste is constantly evolving, utilizing innovative technologies to improve the qual-

ity of life and health of humans. Recycling efforts, the primary means of waste reduction,

have historically been undertaken by individuals looking to make a profit from salvaging

thrown away materials that hold resell value. These instances led to the more organized recy-

cling industry we have today.

Similarly, composting in the U.S. began in the 1920s as a waste management option

towards the end of reducing removing the organic material from MSW before landfill (Brei-

denbach, 1971). Less notably, it has also occurred as an agricultural practice to improve soil

fertility for centuries. Presently composting has evolved into organized efforts though the

21

form it takes varies by scale and location. Composting today, has come to the point of serv-

ing as a waste reduction function and is increasingly becoming a resource recovery strategy.

As many other materials, such as construction debris and yard debris have already been sepa-

rated from MSW disposed of in landfills, the next step is to effectively reduce the amount of

organic waste.

Composting eliminates the GHG emissions that come from the anaerobic decomposi-

tion of food waste in landfills. While landfill gas capture systems are a useful means of re-

ducing GHG emissions, they are not as effective as diverting the materials from the landfill

(Brown, 2012). Studies have pointed out that GHGs are produced during the composting pro-

cess, particularly methane, which draws skepticism around the claim that diverting food

waste to composting is environmentally beneficial. Most recent studies have demonstrated

the net production is zero, when compost piles are managed properly (Brown, 2008).

An examination of the GHG emissions factors in composting can help elaborate on

the last point. If properly managed, the main source of GHGs in composting operations is the

use of electricity and petrol fuels to run equipment and machinery. Emissions from these

sources will vary by site depending on the type of energy generation, i.e. coal-fired power

plant or wind turbines which have obvious differences in emissions. Additionally, the type of

fuel and machinery will have different emission coefficients.

The method widely used for composting yard trimmings and food waste in large com-

mercial composting facilities, windrows, was used by the EPA to model GHG emissions

from food waste composting using WARM.

The major food waste composting GHG emission factors used are:

collection and transportation of materials to the compost site,

22

mechanical turning of the compost pile,

non-CO2 emissions during composting (CH4 and N2O),

and carbon sequestration after compost is applied to soil.

Transportation of the materials resulted in 0.04 MTCO2E/ton of food waste. Emis-

sions from the composting process which included CH4 and N2O were 0.05 MTCO2E/ton. As

illustrated, food waste composting results in net negative GHG emissions, when soil carbon

storage is considered. Here it was found to be 0.24 MTCO2E/ton.

Contrasting the food waste composting emissions factors (Figure 2) with the food

waste landfilling GHG emissions factors (Figure 4) provides perspective on the differences in

emissions in each disposal scheme. Both figures were derived from the USEPA’s WARM

data. Transportation of materials is necessary in both cases, assuming food waste is not gen-

erated at the site of disposal. This comparison shows that the landfill scheme had fewer emis-

sions, for purposes of comparison, if both sites are equidistant from the source of the food

TransportingMaterial toComposting

Compost CO2Compost CH4

and N20Soil Carbon

StorageNet Emissions

Food Waste 0.04 0 0.05 -0.24 -0.15

-0.3

-0.2

-0.1

1E-15

0.1

0.2

0.3

0.4

0.5

0.6

0.7

GH

G E

mis

sio

ns

in M

TCO

2 E

/To

n

Figure 4. Food Waste Composting GHG Emissions Factors for Large Commercial Facility

23

waste, these emissions would be equal. The category of most immediate importance for com-

parison is the emissions produced during the composting process and the emissions from

landfilling food residuals. In composting, 0.05 MTCO2 E/ton from CH4 and N2O are pro-

duced while in landfills 0.79 MTCO2 E/ton CH4 are produced.

In aerobic decomposition, the primary GHG, CO2, is biogenic, while anaerobic diges-

tion results in CH4, an anthropogenic GHG with a much more potent greenhouse effect in the

atmosphere. Furthermore, when compost is applied to soil an additional decrease in total

emissions occurs through the storage of carbon.

Composting food waste also serves materials recovery goals. Recycling has made a

significant impact on reducing the disposal rate of materials in landfills, e.g. their recovery,

which composting food waste can increase. Food waste contains plant macronutrients such as

nitrogen, carbon, and phosphorus, and are recovered in compost (Kort, 2016). The diversion

of food waste to composting, then, also produces a marketable resource that can be used in a

variety of applications. This resource is unique to composting as opposed to other approaches

to dispose of food residuals. While the immediate benefit here is an economic one for com-

post producers, benefits are extended to the users of compost and the ways in which it is ap-

plied.

Table 4. Environmental Benefits of Food Waste Composting

I. Diversion of Food Waste from Landfills to Composting II. Use of Finished Compost

Conserves landfill capacity Improves soil structure of urban soils: increases

soil water retention and reduces soil erosion Reduces greenhouse gas emissions (GHGs) Sequesters carbon in the form of organic mat-

ter Waste reduction & material recovery: plant nutrients and or-

ganic matter Contributes to soil fertility and plant growth

24

The use of finished compost is the second category of food residual composting bene-

fits. Here the benefits are realized in the many applications of compost. The improvement of

soil structure is a major benefit of compost use (USCC, 2008). The improvement of soil

structure results in several outcomes including greater water retention, reduced soil erosion,

and improved soil fertility for plant growth. This makes compost beneficial in a variety of ap-

plications.

Compost and Urban Soils

Of primary importance to this research, which focuses on the urban environment, is

the application of compost to urban soils to support food production and achieve green infra-

structure goals. There are numerous applications where compost can be used as a soil amend-

ment in urban areas. Green roofs, turf grass, and residential lawns are some examples. Com-

munity food production, a central principle of urban agriculture as reported by several schol-

ars (McClintock, 2013; Smith et al., 2012; Collasanti & Hamm, 2009), is another including

in Milwaukee where urban agriculture is a growing social movement.

Compost addition to soil improves the soil structure by the addition of organic matter.

This aids aggregation of soil particles and several subsequent benefits to the soil including

reduced bulk density, improved porosity and aeration, reduced erosion and runoff, and in-

creased hydrologic conductivity. With respect to urban soils, this addresses soil biophysical

challenges faced by urban agriculture: soil compaction, poor drainage, and degraded soils

with low biological activity (Beniston and Lal, 2012).

Increased water infiltration and retention in urban soils, optimizes the use of water

which can be a limiting factor in urban agriculture (Wortman and Lovell, 2014). Addition-

ally, compost can address issues such as soil contamination by diluting the contaminant,

25

binding the contaminant in less biologically available forms, or simply by replacing the con-

taminated soil (Heinegg et al, 2002).

Compost addition to soil improves the soil chemical properties as well. This happens

due to organic matter interactions with soil minerals and chemical characteristics of the com-

post, which will depend on the feedstocks and composting method. The primary benefit is

through an increase in the cation exchange capacity which allows the soil to retain nutrients.

Soil pH and electroconductivity are also optimized to create fertile soil.

Because nitrogen added to the soil in compost is in organic form, it is not soluble and

therefore much less subject to leaching. Over time organic nitrogen is mineralized by soil

bacteria into a form plants can take up. This provides a gradual supply of nitrogen, as op-

posed to it being available only after application when plants may not need it. These benefits

together contribute to the ultimate benefit to agriculture; improved soil fertility.

Over time, with the continued application of compost, soils will continue to accumu-

late carbon, effectively reducing atmospheric GHGs emissions (Lal, 2012). While different

composting methods and feedstock may result in various compost characteristics, in general,

compost from food waste will result in organic matter that is nutrient rich and biologically

active.

Table 5. Potential Use of Compost from Organic Waste

Per the report Pay

Dirt the organic waste cur-

rently sent to landfills could

generate 21 million tons of additional compost (Platt et al, 2013). When considering only ur-

ban applications of this compost, 208,264 acres of enhanced green space or urban farms can

Application Rate Enhanced Green Space Area

0.5” 208,264

1.0” 104,132

26

be amended at 0.5 inches a year. At a one-inch application rate, 104,132 acres of enhanced

green space or urban farms and gardens can be amended a year.

This finding points to the fact that the benefits of composting and compost can be re-

alized if the composting infrastructure is adequate to accept food waste. Discovering the

challenges preventing food waste composting is also important, which this research sought to

explore. In 2014, nationwide, 5.1% of food waste was composted. Nearly a quarter of yard

trimmings were recovered the same year. Incorporating food waste into existing yard residu-

als composting operations represents the low hanging fruit for food waste diversion. This is

already occurring in Greater Milwaukee but will require further development if diversion

rates increase.

Composting to Scale

It is argued in Pay Dirt that small-scale composting should be implemented before

large-scale composting facilities towards the goal of creating resilient communities. Cur-

rently, there are examples of these composting projects in effect both locally and nationally.

These activities take place on many scales and in a range of settings within which a variety of

composting methods, and equipment, are utilized. The versatility of composting is compli-

mentary to the goal of instituting a distributed composting infrastructure, from small back-

yard sites to large commercial composting facilities. What follows is an examination of the

various scales and forms of composting operations.

Small Scale Composting

The smallest scale and the most cost effective for both residents and municipalities is

backyard composting. Backyard composting reduces the need for transportation of food

waste to the processing site. Instead, residents carry out the composting process at home,

with the benefit of creating their own compost. Backyard composting is encouraged through

27

instructional classes, discounts on compost bins or bin materials, and additional support such

as a compost hotline or fact sheets and guides. Municipalities, community-based organiza-

tions, and/or the Cooperative Extension Service are among the entities that typically offer

these services.

Milwaukee's Department of Public Works & Sanitation (DPWS) and Keep Greater

Milwaukee Beautiful encourage backyard composting by offering discounted composting

bins. These efforts are also supported statewide through materials produced by the WDNR

and the University of Wisconsin-Extension's Master Composter program.

Table 6. Community Composting Criteria

The total amount of food waste di-

verted by backyard gardening is not great.

It has been estimated to be 646 lbs. per

household per year (Sherman-Huntoon,

1997). There are obvious limits to the total

amount of food waste that can be composted in backyards, i.e. not all residences have back-

yards. Though the most ideal approach to food waste composting, backyard composting can-

not be the only approach.

Community composting goes a step beyond backyard bins, and encourages neighbor-

hoods to compost together. It is worth mentioning that definitions of community vary (Firth

et al, 2011; Kurtz, 2001). Here it refers first to a geographic area, but also suggests coopera-

tion among residents in that area and shared resources i.e. tools and compost. Community

composting has been defined per several criteria as listed in Table 3 (Platt et al, 2014).

1. Resources recovered

2. Locally based and closed loop

3. Organic materials returned to soils

4. Community-scale and diverse

5. Community engaged, empowered, and educated

6. Community Supported.

28

A generic form of community composting is in community gardens. Kompost Kids, a

community-based nonprofit in Milwaukee, has helped establish a network of composting lo-

cations where food scraps can be dropped off by area residents. This provides a means for

community members to divert food waste without necessarily actively participating in the

composting process which is typically done by hand at this scale. Kompost Kids also collects

food waste from commercial businesses such as restaurants and cafés.

At the national level, examples of community composting are numerous and varied.

There is an exceptional number of community composting projects occurring in NYC, one of

which is the Lower Eastside Ecology Center (Biocycle, 2014). Sixteen one cubic yard aer-

ated plastic containers are used to compost food waste brought to the site, from residents as

well as commercial businesses. ECO City Farms in Edmonston, Maryland, which uses aer-

ated static piles for composting, is another example. Residential and restaurant food scraps

are used to compost, which used for food production or sold to the community.

Milwaukee boasts Growing Power which operates in a similar fashion to ECO City

Farms. One way Growing Power composts food waste, vermicomposting, has supported its

4.5-acre farm's intensive production of microgreens among other crops. Growing

Power's Chicago branch does food waste composting in a 20’ x 96’ hoop house (to circum-

vent city ordinances requiring in-vessel composting) using a static pile method

(Lauralyn Clawson, personal communication, 2016).

Like backyard and community composting, onsite composting is typically small-scale

and can be carried out at institutions such as schools, hospitals, grocery stores and even cor-

rectional facilities, again, reducing the need to transport food waste and keeping composting

local (Segal, 1994). This form of composting, though small-scale, does not usually involve

29

the surrounding community, but by its nature, it can occur at multiple locations throughout

the city. By occurring onsite, there is no reliance on food waste haulers, though it may be

necessary for maintenance of the composting system, depending on the system is used.

There are a variety of ways that onsite food waste composting can be carried out. In

some instances, in-vessel systems are used for onsite composting with capacities that range

from a few pounds a day to 60 tons a day. For example, Toyota Motor Manufacturing Ken-

tucky Inc. uses in-vessel Beer & Willis Organics (BWO) drums (32 cu yds. capacity) to pro-

cess food scraps from six of its cafeterias (Spencer, 2008). Findlay Market in Cincinnati,

Ohio uses two Earth Tubs, to compost most of the market’s unsold produce (Balz, 2012). In

San Diego County, vermicomposting is used to process the food scraps from Richard J. Do-

novan Correctional Facility (Flammer, 2014). Onsite composting can also be done using

windrows as is done by Davidson College in Davidson, NC (Goldstein, 2012).

Small-scale composting includes a spectrum of activities such as backyard compost-

ing, most community garden and school garden composting activities, urban farm compost-

ing, as well as onsite institutional composting activities (Table 2). Due, in part, to their small-

scale nature, these activities make up most urban composting activities.

Another form of community composting, food scraps drop-off sites have been effec-

tively implemented and proved successful in many localities. In these instances, programs

were established to pick up the food scrap receptacles; to some extent this is occurring in

Milwaukee with Kompost Kids’ compost site network though the food scraps are composted

on-site rather than picked-up. In Austin, TX, an entrepreneurial venture, Bootstrap Compost,

found transporting food scraps can be a sustainable venture.

30

Small-scale composting is important to a diverse composting infrastructure, though it

is only one part of the spectrum of composting scales. If the scale of a composting operation

is designated by the volume of organic wastes processed, then medium- to large-scale com-

posting operations are individually able to divert a larger portion of the food residuals pro-

duced by a city. This is good news, but by their very nature these facilities will be less com-

mon in cities. Nevertheless, these operations are important to the composting infrastructure

considering economies of scale.

Medium and Large Scale Composting

Medium-scale operations can be defined by the volume of materials they can accept.

A prime example, is on-farm operations. On-farm composting operations are not necessarily

planned to process food waste, but have lately taken on the challenge. One incentive for

farms to compost food waste is the use of the compost product as a soil amendment. On-farm

operations typically have greater capacity, in terms of space to compost and equipment i.e.

tractors or front-end loaders, to process food scraps than small-scale operations. It is im-

portant to note that farms may not be as production focused as large commercial facilities as

composting is not their primary operation.

Since the beginning of the yard waste bans in the 1980s and 1990s, many composting

operations have sprung up to process the leaves and other yard and garden residuals that

could no longer be sent to landfills. These facilities differ in respect to small-scale compost-

ing activities, as many of them compost as a waste management function. Like small- and

medium scale composting there are different methods that can be utilized by these facilities,

though they typically rely on more mechanical and technologically advanced equipment.

31

Table 7. Composting Scales and Appropriate Methods

Scale Description System

Small Scale

Backyard

Pile

Bin

Tumblers

Vermicomposting

Onsite Institutional

In-vessel

Vermicomposting

Community Composting

Community Gardens

Bin System

Aerated Static Pile

Passive aerated static pile

Windrow

Tumblers

In-vessel

Vermicomposting

Farms (Rural and Urban)

Schools

Drop-Off Networks

Collection Entrepreneurs

On-site Composters

Off-site Composters

Demonstration & Community Leader Training Sites

Worker-owned Cooperatives

Home-based or Homesteader Hubs

Mid-Scale On-farm Composting

Windrow

Passive aerated windrow

Aerated Static pile

Bin system

Tumblers

In-vessel

Vermicomposting

Large Scale Commercial Composting Facility

Windrow

Passive aerated windrow

Aerated Static pile

In-vessel (mechanical)

Vermicomposting Adapted from Platt el al (2014) State of Composting in the U.S.: Why, Where, and How

32

The ability to process large volumes of feedstocks is a defining characteristic for

many large-scale composting facilities. These facilities seek to process city organic waste ef-

ficiently. To do so, select equipment is necessary. Though equipment is utilized in some

small-scale composting operations, larger composting operations typically rely on it more.

Typical machinery will include front-end loaders, mixing equipment, screening equipment,

size-reduction equipment, and conveyor systems, all of which are available in several types

and specifications (Environment Canada, 2016).

The layout of a composting facility will conform to the composting method(s) uti-

lized, but most composting facilities will need to include spaces for receiving feedstocks,

storing amendments, blending and processing the materials, and storing finished products.

Thus, the availability of land large enough for the composting facility is needed. This typi-

cally precludes large scale composting sites in urban areas with dense residential populations.

Industrial zones are one option for large scale composting operations in urban areas but are

not common.

Food Waste Composting Policy & Regulation

Since the RCRA of 1976, cities have made considerable progress in creating recy-

cling programs and diverting a large part of their MSW from landfills. Nationwide, a 28 per-

cent recycling rate has been achieved (EPA, 2002). The rate of composting food waste, 5%

nationwide, or 2% of all materials recycled, trails way behind the recycling rate, though the

materials are equally recyclable. As the impetus for the recycling efforts made by the nation

has been driven, in part, by the RCRA, similar legislation may be necessary to see large scale

activity increases in this food waste composting.

33

In an effort to reduce their organic waste stream by 30%, Massachusetts has taken the

lead in organic waste diversion by instituting the first statewide commercial food waste ban

requiring entities that generate more than one ton per week to compost. Similarly, Vermont

and Connecticut require entities that generate more than two tons per week to compost. Ver-

mont’s Act 148 states that, starting in the year 2020, all yard debris and food waste will be

banned from landfills. On the West Coast, both Seattle and San Francisco have implemented

ordinances requiring both commercial and residential composting. San Francisco, in fact, is

diverting more than 80% of their MSW with the goal to eventually approach zero-waste (San

Francisco, 2002).

In addition to food waste diversion policies, policies that address the practices that

impact the ability to compost are also instrumental to increased activity. Many states, such

Illinois, Ohio, and Wisconsin have recently updated their composting regulations which

serve to support food waste diversion. Despite such changes, as Arroyo-Rodriguez (2012)

points out discrepancies between state and local composting policies can act as barriers to

composting practices. At the local level, there are clear ways localities can promote small-

scale food scraps composting (Suerth and Morales, 2014), but congruence between state and

local regulations will ensure such practices are easily established and/or continued.

The rules imposed by the WDNR which regulates solid waste handling facilities are

described in Table 4 (WDNR, 2012). The rules describe where composting can occur with

exemption, i.e. when the materials are less than 50 cubic yards, and where a license is re-

quired i.e. when the materials are between 50-5000 cubic yards. The materials limit refers to

how much material is allowed on the site at one time. Depending on the processing time of

34

Table 8. Wisconsin Department of Natural Resources Food Waste Composting Regulations

Type Site Size Requirements License Required?

Any Source-Separated

Compostable Material

(SSCM)

Up to 50 cubic yards NR 502.04(1)

NR 502.12(10)

Performance Standards

Minimum Operational Standards No

Any SSCM (including

food scraps) 50 to 5,000 cubic yards

NR 502.04(1)

NR 502.12(8)

NR 502.12(10)

NR 502.12(11)

NR 502.12(15) (a)1

NR 502.04(3)(a) and (b)


Locational Criteria

Minimum Operational Standards

Minimum Design Standards

Monitoring and Recordkeeping

Upon closing, meet requirements

Yes

Any SSCM (including

food scraps) More than 5,000 cubic yards

NR 502.04(1)

NR 502.12(8)

NR 502.12(10)

NR 502.12(11)

NR 502.12(12)

NR 502.12(15)

NR 502.12(3)


Locational Criteria


Additional Operational and Design Re-

quirements



Upon closing, meet requirement

Yes

On-farm 50 to 10,000 cubic yards

NR 502.12(8)

NR 502.12(10)

NR 502.12(11)

NR 502.12(15) (a)3 and 4

Locational Criteria




No

On-farm More than 10,000 cubic

yards

NR 502.04(1)

NR 502.12(8)

NR 502.12(10)

NR 502.12(11)

NR 502.12(12)

NR 502.12(15)

NR 502.04(3)


Locational Criteria



Additional Operational and Design Re-

quirements


Upon closing, meet requirements

Yes

Adapted from WDNR 2012

35

the site, the food waste that is composted on the site over the course of a year may exceed the

limit. Licensing requires an initial site inspection and locational criteria be met. These rules

were developed to take into consideration environmental impacts that may result from com-

posting such as run-off into nearby waters.

Other concerns addressed by the rules include human health and consumer protection,

though the latter is not mandatory. The WDNR incentivizes consumer protection by provid-

ing a compost quality standard, Class A. The standard requires that the composting process

provide maximum reduction of pathogens that may be present in feedstock. It also requires

compost test be carried out according to the standard and that heavy metals in the composts

be under prescribed limits. Class A designation is optional but has been particularly wel-

comed by municipal yard residuals composting sites that offer free compost to residents.

With or without legislation, public support will be needed if food waste diversion

rates are to match those of recycling. The environmental benefits of food waste composting

are an important part of obtaining public support of municipal composting programs (Suerth,

2014). They have been leveraged in sustainability initiatives in several cities. The New York

City (NYC) Council has imposed Local Law 77 (LL77) of 2013 which required the creation

of a voluntary residential curbside pilot and school organic waste collection pilot program as

part their sustainable waste management plan (Garcia, 2015).

As these programs are voluntary they do not require widespread public support,

though this is obviously favorable, but would if they were mandated. In response to LL77,

the NYC Department of Sanitation (DSNY) has established composting programs at various

levels including the citywide level, community level, and at home (or backyard) composting

which have successfully engaged the public.

36

With respect to composting practices in urban environments, local laws typically dic-

tate where composting can and cannot occur. These laws are more geared toward residential

concerns that may arise from a composting site such as odors and pests. The allowed size of a

composting pile or bin is also in accordance with residential concerns. In many cases food

scraps, or other organic materials, from off site are not allowed to be brought to the site and

composted.

In the city of Milwaukee, even if a composting site is allowed under the WDNR rules,

it may not be allowed by City Regulations (Table 9) for the reasons previously described. As

such the more likely scale of composting for many cities is small-scale.

Table 9. City of Milwaukee Composting Regulations

While only a part of the total potential composting infrastructure, small-scale com-

posting constitutes most composting activities that take place in urban areas. According to

Suerth (2104) there is an obvious need for "waste management" to completely undergo a par-

adigm shift in which it begins to move away from waste management to materials recovery.

To do this may entail finding a balance between centralized and decentralized composting

models. With greater public engagement in small-scale composting, an appreciation for com-

posting as resource recovery process may be realized.

Small-scale composting is defined as regulatory exempt operations. In Wisconsin,

this entails operations that process less than 50 cubic yards, but this will vary by state. Rhode

Method Prohibited Materials Size Location Other Requirements

Must be in a bin

constructed of

commercial

grade materials

i.e. treated lum-

ber, cinder block,

etc.

Oils, grease and lard, dairy or meat

products, feces - human, dog, cat,

or bird, diseased plant waste, poi-

sonous substances, treated lumber,

sawdust from treated lumber, ma-

terials that have been treated with

chemicals, inorganic material

Bin not taller

than 5 feet, cu-

mulative total

of all bins can-

not exceed 125

cubic feet

Side or

backyard,

not within

20 feet of

habitable

structure

Bin must have a hood

and allow gases to

vent. Must not allow

rodents to enter, com-

post pile must be

properly maintained

37

Island, recently revised its regulations on composting scales and defined small-, medium-,

and large-scale composting per the volume of materials being processed at any time (State of

Rhode Island, 2016). This is another approach to define the scale of composting, which is

also connected to regulation. In emphasizing the importance of a diverse composting infra-

structure, the policies which promote or deter small-scale composting should be under-

stood as discussed above.

As part of the City of Milwaukee's Sustainability plan, a solid waste reduction goal of

40%, by weight, by 2020 has been set (Refresh, 2014). Diverting food waste can go a long

way in supporting this goal. One way the City is already doing this is through a residential

organics collection pilot in two neighborhoods. The minimum number of households to run

the pilot was exceeded by 500%, indicating there is a measure of public engagement and the

City is making progress in meeting its waste reduction goal.

Greater progress can be made if the City decides to expand the program, but it has

been determined that a city wide residential curbside organics collection program could not

be supported by the existing composting infrastructure, though this study only took into con-

sideration licensed composting facilities (Meyers, 2015). Determining the exact capacity of

the infrastructure, including all scales of composting, as is the goal of this research, can help

the city to implement a plan to make additional progress towards its goal.

III. Methodology

This research carried out an illustrative case study of the current food residuals

composting system in Greater Milwaukee. Embedded within the system are components

from which both qualitative and quantitative units of analysis are derived. The composting

38

sites, which accept and compost food residuals, and produce compost are one of these com-

ponents. The units of analysis are complimentary of the research questions, or objectives,

which are discussed below.

A major objective of the case study was to identify the current capacity of the infra-

structure to accept and compost food waste. As such, the capacity of composting sites to ac-

cept this material is one unit of analysis. Another objective was to identify the quantity of

compost produced by all sites on an annual basis. As such, another unit of analysis is the rate

of production of each site. Together these units of analysis convey the potential of the current

system to divert food waste and provide compost for local food production and other mar-

kets.

Another objective of the study is to determine the ability of the system to remain sus-

tainable over time. This will be done, in part, by analysis of the qualitative aspects of the in-

frastructure. Several qualitative aspects have been identified as units of analysis such as size

and location of composting sites within the study area. Composting methods will also be the

basis for analysis. Lastly goals of compost site operators as well as sustainability initiatives

and local and state regulations will be basis for analysis.

Food residuals composting is being driven by several stakeholders including institu-

tions interested in diverting the food waste they generate from landfills. With these, and other

drivers, and with the realization that there must be a finite capacity to the current system, de-

termining what that capacity is, is integral to future growth. It was hypothesized the current

infrastructure does not have the capacity to compost the total volume of food residuals gener-

ated in Milwaukee.

39

While the nature of this case study is illustrative, it may also serve as an exploratory

case study of composting in Greater Milwaukee. This makes it useful for planners, decision

makers, etc. considering further investment in development of the food residuals composting

system.

Case Study Approach

Considering the current efforts to divert food residuals to composting are on a range

of scales and in separate locations, this research took a case study approach and employed

mixed-methods to effectively identify food residuals composting sites and their characteris-

tics. Of note, food residuals composting is distinguished from other composting operations

by the possession of a license to process food residuals or by their interest in composting

food residuals rather than yard residuals. Non-food waste composting sites were also in-

cluded in this study as they have potential to incorporate food waste into their operations.

In illustrating the current composting system two aspects can effectively organize the

methodology of this research. The first is the definite capacity of the infrastructure to com-

post food waste. This is in fact dictated by WDNR compost facility regulations. As such, ob-

taining descriptive data on the existing composting sites was the first step. In addition, ob-

taining descriptive data on the supporting businesses, such as haulers of food residuals, was

also carried out. The second aspect is the rate of compost production. Determining this infor-

mation entailed obtaining the production rates of all the composting sites and aggregating

them into a whole. Table 8 elaborates on the data obtained under each aspect.

The ability of composters to produce compost depends on their ability to receive the

starting materials, or feedstocks. As the State of Wisconsin Administrative Code NR 502.12

requires records be kept of all materials brought to a composting site (for licensed sites), it

40

was assumed compost site managers identified for this study would have records of the food

residuals they receive and compost.

Table 10. Infrastructure Components and Characteristics

Capacity to Accept Food Waste Compost Production

Capacity of Composting Sites Composting Supporting Infra-

structure

Annual Compost Production

Composting sites:

Size of each site, location, com-

posting methods, processing

time, and equipment

Food Waste Haulers:

Size of each company, i.e. num-

ber and capacity of vehicles

Compost produced:

Amount and characteristics: Class A,

OMRI listed, vermicompost, etc.

Capacity: permitted and operat-

ing (cubic yards)

Capacity of haulers to collect

food waste

Compost sales & how is it being sold

Thus, compost site managers were identified as key informants and a primary source

of data. To support this data, a record of existing composting licenses and annually reporting

data was obtained from the WDNR. While this provided the licensed capacity, it did not pro-

vide the operating capacity of each site which had to be obtained from the compost site man-

agers. Food waste haulers may also keep records of the materials they transport and were also

identified as key informants and a source of data.

The primary means of data collection was initially chosen to be a survey administered

to compost site managers and haulers. This was modified after greater familiarity with the

key informants was gained and their preferences, typically interviews, were sought. Compost

site managers and other key informants, or stakeholders, were known to this researcher, some

formally some informally thus of prior experience with several Milwaukee organiza-

tions centered on composting, urban agriculture and food systems work. As a part of a coor-

dinated effort to study the current state of the food residuals composting system, these stake-

holders where brought together and each individually agreed to participate in this research. In

41

addition to informing this thesis, this research also served to inform a USDA Sustainable Ag-

riculture Research and Education (SARE) grant funded two-year project (NCR16-023 Sys-

tems Approach to Food Waste Composting for Urban Agriculture).

In the spring of 2016 during a planning meeting for this project, stakeholders (key

informants) were notified of a forthcoming survey to characterize the current capacity of the

composting infrastructure. Stakeholders were later contacted to reaffirm their participation

and establish preferred methods of contact. After making initial contact, it was found that in-

person or phone interviews were the preferred format over surveys. Interviews were then

scheduled and carried out per the availability of individual stakeholders. The interviews were

semi-structured using the pre-designed survey as a loose guide.

Table 11. Food Residuals Composting Stakeholders

Stakeholder Name Organization Description

James Jutrzonka Blue Ribbon Organics Medium-sized Commercial Compost Facility

Sandy Syberg Purple Cow Organics Medium-sized Commercial Composting Facility

Will Allen & Joel Rissman Growing Power Urban Agriculture Non-profit

Marion Ecks Kompost Kids Community Compost Sites

Melissa Tashjian Compost Crusader Organics Residuals Hauler

Duane Dradzinski Compost Express Food Scraps Collection

Damian Coleman Elyve Organics Consultation and Distribution

To determine the production rate of compost, again composters were key sources of

information. There is one stakeholder who fills a unique position of distributing compost who

was also interviewed. All stakeholders interviewed are currently the most active (and visible)

in the composting infrastructure. Stakeholders identified after the preliminary stages of this

42

research were included as identified. Though stakeholder quantities compost produced were

obtained, this research ultimately relied on WDNR annual reporting data, for licensed sites,

as more standardized quantities. Site visits were also used to fill in gaps from interviews.

The range of organization types and the scales at which they operate is complimen-

tary of the goal to define the entire food residuals composting system in Greater Milwaukee.

The amount of food waste diverted by small-scale composting such as backyard composting

or community gardens was estimated to produce a more accurate representation of how much

of the total food scraps are diverted to composting and how much compost is being produced.

Assumptions and Limitations

It is important to acknowledge data limitations which resulted from a variety of fac-

tors. This research assumes that all data acquired from stakeholders is reported truthfully

and/or to the best of their knowledge. Some data were not obtainable due to their proprietary

nature i.e. Sanimax preferred to not divulge their customer’s identities. Other data were not

available as it was not being recorded by the respective organizations. Unless required, re-

cording data is required by regulation or integral to said operation it is not done. This data,

therefore, could not be obtained outside of conducting individual investigations which would

have unduly extended the scope and duration of this study.

IV. Case Study: State of Food Waste Composting in Greater Milwaukee

To present this case study in a manner conducive to understanding the extent of the

food residuals composting infrastructure, the following has been organized under distinct

headings. Each heading is a component of the food residuals composting infrastructure as

follows: food residuals composters, non-food residuals (yard residuals) composters, anaero-

43

bic digesters, food waste haulers, and compost distributor. Under each heading, the individ-

ual operations that make up that component are described. Operations are presented in alpha-

betical order and not in relation to importance to the infrastructure.

Each operation was described per the units of analysis as well as the unique context

each operation holds relative to the food residuals composting system. In as much, making

direct comparisons between operations that make up a component on a one to one basis is not

entirely possible, i.e. comparing Blue Ribbon Organics and Growing Power in terms compost

production. As will be revealed, operations have become a part of the current food waste

composting system in unique ways.

This section primarily aims to present the data collected in an informative manner.

Discussion of the implications of these results will be provided in the discussion section.

Contextual data, other than location, were not obtained for nonfood waste composting sites.

They were included to illustrate the extent to which composting sites are present in the study

area and their spatial distribution, as they hold potential for future development of the food

waste composting infrastructure as will be discussed in the next section.

Food Waste Composting

In Greater Milwaukee, there are currently eight food waste composting sites. Five of

these sites are licensed by the WDNR to compost SSCM. All five are large-scale and all are

located outside the city of Milwaukee. One, Wauwatosa Composting Facility is within Mil-

waukee County. Only two of the five, Blue Ribbon Organics and Orchard Ridge Composting

Facility were licensed at the start of this research and were included in the case study along

with Purple Cow Organics. Within the city, there are three small-scale composting sites that

are exempt from licensure. These sites were also included in the case study.

44

Blue Ribbon Organics

Formerly a landscaping business, Blue Ribbon Organics (BRO) is managed by James

Jurtzonka. Jurtzonka senior and two other employees, also keep the site, which has grown

since it began in 2008, in operation. Per Jurtzonka, the land the compost operation sits on is

now in its "6th generation of family ownership." Before it was Jurtzonka senior’s landscaping

business, the land was used for agriculture, changing from dairy to cash crops over time.

Feedstock

BRO is one of two large composting sites licensed to accept source separated com-

postable material (SSCM) which includes food waste. It is the only site that receives this ma-

terial from Milwaukee County. It also receives food waste from a variety of sources in

Greater Milwaukee. These sources include grocery stores, restaurants, residents, corpora-

tions, and hospitals among others. In total, last year BRO reported receiving 7,736 cubic

yards of SSCM and 16,000 cubic yards of yard residuals. Yard residuals are allowed by the

WDNR to be combined with the food waste as a bulking material. The yard residuals also

come from a variety of sources, including from residents who drop them off and from land-

scapers.

Of the total materials processed, 75% are bark/brush and yard residuals categories

and 25% in the SSCM. This includes pre- and post-consumer food waste. BRO does not ac-

cept meat as it can cause several issues such as attracting small animals and can be a vector

for pathogens. It also receives manure from the Milwaukee County Zoo’s herbivore animals.

Compost Crusaders and Sanimax are the main haulers that bring food residuals to the site. A

tipping fee of $30 is charged to haulers.

45

Size and Location

Located right outside of Milwaukee County, adjacent to Interstate-94, Blue Ribbon

Organics sits on 32 acres in the Town of Raymond, in Racine County. The compost opera-

tion now utilizes 14 acres of the total land owned by the family for composting. Also, occu-

pying the land are three structures: the family home, an office/shop building, and a barn. A

small tree nursery, remaining from the operations landscaping days, a market garden leased

to a third party, along with the vehicles and equipment utilized by the operation, also occupy

the land.

Capacity

The site holds two licenses from the WDNR. One is for composting up to 20,000 cu-

bic yards of bark/brush and/or yard residuals at one time. The other is for composting up to

5,000 cubic yards of SSCM at one time. Materials composted under each license are recorded

separately. Because the operation can process the material it receives in four to six months, it

is able to accept more than 5,000 cubic yards on a yearly basis while staying in compliance

with its license.

Figure 5. Aerial View of Blue Ribbon Organics Composting Site

46

Material brought to the site, food waste, landscaping debris, and other organics, is

typically weighed on a CAT™ scale at a nearby weigh station north of BRO adjacent to In-

terstate-94. The operation has a large receiving area where carbon materials are piled sepa-

rate from the nitrogen materials. Materials are received daily, especially during spring and

summer when landscapers are active. Peak operation time for the facility is from early spring

to late fall depending on the severity of the winter weather.

BRO currently operates a second site, a yard residuals composting operation, for Ad-

vanced Waste, located in Muskego WI, but no plans are being made for the facility to com-

post food waste. This site is licensed to process up to 20,000 cubic yards and is currently op-

erating at 50% capacity. The site does not compost any SSCM.

Composting Method

As do most large scale commercial composting operations, Blue Ribbon Organics re-

lies on heavy mechanized equipment to process the materials it receives. A large shredder is

utilized to reduce the particle size of the bulking materials before they are mixed with food

waste. Utilizing front end wheel loaders, the materials are mixed and are piled into windrows

(11’ x 6’) until the row extends 50 yards. Piles are covered with leaves to reduce odors. Be-

tween 12 and 15 windrows are actively composting at a time on the site. Rows are turned

every five days using an Aeromaster 11’ tractor pulled turner. This is done per Wisconsin

Department of Natural Resources (DNR) Class A compost production standards to kill patho-

gens and weed seeds. BRO uses this standard, which also includes guidelines for temperature

monitoring, though it does not market its compost as Class A.

47

Compost Produced

The material is processed in about six months and screened through a trommel to 3/8"

before it is matured. BRO annually produces at least 2,000 cubic yards of finished compost

from food waste. It also produced 2,500 cubic yards of finished compost from yard residuals

only. The finished compost is tested to the United States Composting Council’s (USCC) Seal

of Testing Assurance. Testing parameters include nutrient content, pH, moisture, maturity,

organic content, C:N ratio, soluble salts, bulk density, and heavy metals.

The compost produced is certified organic and Organic Materials Research Institute

(OMRI) listed. The production standards for organic compost are nearly identical to Class A

production standards. BRO also produces compost/soil blend products. The topsoil used in

the blend comes from a trusted vendor who has assured Jurtzonka there are not levels of

heavy metals in the topsoil of concern.

The operation has developed a reliable customer base because of the quality and

availability of its compost. Finished compost is largely sold in bulk with demand coming

mostly from urban markets such as home gardeners, along with many of the landscapers who

utilize the site to drop off their materials. The compost is also bagged and is currently sold by

one retailer, Outpost Natural Foods, a cooperatively-owned grocery store with four locations

in Milwaukee. A distributor, Elyve Organics rebrands and sells the compost as well.

Jurtzonka recognizes that Blue Ribbon Organics is a leader in food residuals com-

posting in Greater Milwaukee and even in southeastern Wisconsin where there are few other

licensed SSCM composting sites. James is actively seeking to expand his family’s business

and sees legislation that would ban organics from landfills as one way for the food scraps

composting to grow.

48

Growing Power

Growing Power is a Milwaukee based non-profit organization recognized nationally

for growing and advocating for fresh local foods as well as racial equality in the food system.

Growing Power grows healthy food, while addressing issues that impede communities' ac-

cess to healthy food. It does this is by educating individuals and community groups. Will Al-

len initially founded Growing Power on the last land parcel zoned for agriculture in the city

to engage local youth. This 4.5-acre site, on 55th and Silver Spring on Milwaukee’s North-

west side, started off with 5 greenhouses. The organization has since expanded to over 16

hoop houses. Growing Power now farms a total of 70 acres of cultivated land in Wisconsin.

It also has a branch in Chicago with urban agriculture and composting operations.

Growing Power began composting to provide its farm with a sufficient medium for

growing crops. While it does now operate a Growing Power Café and sells produce, fish, and

other value added products to support the organization, as it was initially, producing compost

continues to be a vital part of the operation, directly supporting its market crop production.

As Allen often says, “it all starts with the ‘soil’.”

Food Scraps Collection

Unlike larger scale composting operations, GP does not contract out food waste col-

lection. GP has developed relationships with several businesses for regular collections. The

amount collected has weekly variability. Per Joel Rissman, one staff member at the organiza-

tion that regularly carries out collection, the frequency of collection could be as often as

every weekday or only one day a week. Thursdays are typically the major collection day. On

this day, several generators are on the collection route from within the city of Milwaukee as

well as from outside the city. Collections are also done at the request of the customer.

49

There are several categories of food scraps generators Growing Power, Inc. services

including food manufacturing and processing i.e. breweries, as well as restaurants and cafes,

corporate headquarters, and hospitals. The amount of food scraps collected is estimated at

4,000 pounds per week, or 104 tons a year. With food waste 463 – 1,000 pounds per cubic

yard, then (104 ton / year) x (2,000 pounds / 1 ton) x (1 cubic yard / 463 -1000 pounds) = 208

– 449 cubic yards. Between 208 and 449 cubic yards of food waste are composted a year.

This material is combined with wood chips, used as a bulking material in the composting

piles, regularly brought to the site from several sources.

In addition to the use of food waste in composting at the 55th Street farm or added to

the worm depository, it may have another destination. Depending on the volume of feedstock

or the availability of space at the farm, the material may also be sent to a dairy farm outside

the city. The dairy farm uses it as feed for its cattle.

Size and Location

Much like the organization, composting at Growing Power has taken on many mani-

festations. At one point, Growing Power accepted large volumes of feedstock from all the lo-

cal Walmart stores and composted it near its Oak Creek farm. Nuisance complaints from

neighbors of the farm, which is on land leased from the Milwaukee Metropolitan Sewage

District, caused the discontinuance of composting. These feedstocks are now being sent to

Blue Ribbon Organics. The result is composting at Growing Power was temporarily reduced

to static piles (Figure 6, outlined in red, center) and pallet crates at its 55th Street farm. (The

brown box in Figure 6 outlines where wood chips rest at the site.)

50

Growing Power is well known in the urban agriculture community for its vermicom-

posting; using red wigglers to compost food scraps. It creates a compost product that is either

sold or mixed with other materials to create a growing medium for its microgreens. Two ac-

tive vermicomposting piles outside its greenhouses provide worms for vermicomposting

crates inside their greenhouses, (Figure 6, outlined in red on right). Worms are added to al-

ready composted material. When finished, the castings are screened, and the worms are re-

turned to the piles. Growing Power incorporates the vermicompost into its microgreens

growing mix as well as into its growing beds that are built with the static pile compost.

Capacity

Composting at GP has manifested in diverse ways over the course of its practice. This

is tightly linked to the fact that GP composts in a relatively urban environment with respect to

most composting sites in Greater Milwaukee. These challenges are also related to the scale of

composting carried out and the perception of the way composting is carried out. Both of these

aspects are subject to WDNR composting rules and regulations. The WDNR regulations state

that composting operations over 50 cubic yards are subject to regulation; operations under 50

Figure 6. Aerial View of Growing Power's 55th Street Farm

51

cubic yards are exempt. The WDNR also requires composting sites be operated in a nuisance

free manner.

Composting at Growing Power can be considered small scale in terms of size and reg-

ulatory status. One challenge at its 55th Street farm was in direct relation to scale. Now re-

ferred to as a worm husbandry pile, a large outdoor worm composting pile was redefined, fol-

lowing a visit from WDNR. As the pile was over this limit, at 66 cubic yards (60’ x 10’ x

3’), it was subject to regulation. The WDNR was satisfied by redefining the pile as ‘worm de-

pository’ as it poses no environmental risk or nuisance. This allowed GP to avoid disman-

tling the pile, or filing for a license.

Growing Power has also experienced problems with WDNR regulations at its former

composting site near its Oak Creek farm. Nuisance concerns from neighbors, specifically

odors, led to the sites discontinuance. Growing Power maintains the odors were coming from

the nearby wastewater treatment plant. These impediments, have led to the referral of its

large volume food waste generators, i.e. supermarkets to another composting site in Greater

Milwaukee. The result was a significant reduction in the volume of material received by GP

and in turn a reduction in the volume of compost it produces.

Growing Power is interested in composting within Milwaukee, where aside from reg-

ulations, the WDNR’s, as well as the City of Milwaukee’s, large enough land tracts to com-

post are scarce. An additional constraint on the composting capacity is the staff dedicated to

composting. This staff includes Allen, Joel Rissman, a soil scientist, and occasionally other

staff members though the composting operation is not their only role within the organization.

52

Composting Method

Composting at GP currently consists of an 1/8-acre (mostly) static pile, the ver-

micompost windrow, and several one-cubic yard wood pallet bins on the 55th Street farm.

Each of these composting systems requires a different albeit similar management approach.

The worms in the vermicompost windrow provide good aeration so turning is not required.

Turning is required for the bins and the static pile. Most turning of the piles is done manually

with shovels though the site does have a Bobcat® that is used to add material to the large

static pile and move the compost.

The time it takes to produce finished compost depends on the composting method.

Finished compost from the wood pallet bins takes four months (longer during the winter

months). The vermicompost windrow takes about the same amount of time or less as it has

the dual decomposition activity of both worms and microbes. The static pile, if not turned,

may take six months or longer for the feedstock to become finished compost. The compost

produced is not cured aside from its remaining in the respective pile until needed.

Compost Production

Growing Power is unique among other composters in this study as it composts food

waste to provide a growing medium and fertilizer for its own use in growing produce. GP

does not record the amount of compost it produces so a direct measurement of how much

compost it produces is unavailable. From the total amount of food scraps GP collects it can

be approximated that the amount of compost produced annually is 69 - 150 cubic yards. This

figure does not include bulking materials for which the quantity composted was unavailable.

53

Public Awareness and Education

Growing Power’s influence within the city of Milwaukee, and beyond, serves to pro-

mote the collective food waste composting effort. One way it does this is by offering com-

posting how-to workshops several times a year. In the workshop, participants gain an intro-

duction to composting using a one cubic yard bin, constructed with wood pallets; the smallest

volume for compost to reach adequate temperatures. The workshop covers general compost

recipe (feedstock), what to add and what not to add, carbon-to-nitrogen ratio, measuring bulk

density, and ensuring adequate moisture. Developing relationships with food scraps genera-

tors and securing a composting site are also topics of discussion.

Not all participants go off to start composting initiatives, but enough do so that these

efforts are not in vain. Several composting focused organizations in Milwaukee had their

start in GP workshops. Melissa Tashjian, formerly of Kompost Kids, and now CEO of Com-

post Crusaders, along with Marion Ecks of Kompost Kids adapted their training from GP to

use a three-bin system constructed from wooden pallets that are utilized at community com-

post sites throughout the city.

Similarly, Damian Coleman and Javon Taylor received training through Growing

Power’s Commercial Urban Agriculture program which incorporates the composting training

workshop. The two have gone on to start Elyve Organics, a compost focused entrepreneurial

venture. These organizations are part of the whole of the composting infrastructure within

Greater Milwaukee, and contribute to its capacity to divert food waste and produce compost.

As such, Growing Powers plays an instrumental role as part of the system.

54

Kompost Kids Kompost Kids (KK) is a nonprofit organization that organizes community compost-

ing sites within the City of Milwaukee. Founded in 2011 by Melissa Tashjian, now of Com-

post Crusader, KK now consists of several board members and a slew of volunteers. Kom-

post Kids started primarily as an education and advocacy group that sought to engage chil-

dren (Kids) and adults in composting. Working with several community gardens, the organi-

zation help set up composting sites to divert the food scraps of residents of the neighborhood

(including gardeners) as well as food scraps from local restaurants, breweries and cafes.

Size and Location

The primary site, also known as the demonstration site, is located on Milwaukee’s

south side in the Bay View neighborhood. This is its second location in the Bay View neigh-

borhood. The group lost its land tenure on the first site, behind former industrial buildings

close to the current site, after the landowner decided to sell the property for development.

Brian Williams-Van Klooster, the group’s treasurer, though roles get blurred, was successful

in securing its current site, on South Marina by negotiating a lease with the City’s Port Au-

thority. This site is also tentative, while future development plans for the area are being con-

sidered. The lease for this land is 16,000 square feet. In addition, to the composting opera-

tion, a raised bed garden also occupies the site.

Kompost Kids also actively manages a second site on Milwaukee’s eastside in the

Riverwest neighborhood. This site is part of an 11,000-square foot community garden on

Auer Avenue and Gordon Street. These two sites are unique among the network of sites es-

tablished by KK in that the organization actively manages them. Kompost Kids does help in-

stall composting systems at other sites though these sites are managed by the community gar-

deners or groups directly involved with them.

55

Figure 7. Aerial View of Kompost Kids' Bay View Site (Prior to occupancy)

Figure 8. Close-up View of Kompost Kids' Bay View Site (prior to occupancy)

Capacity

Both KK sites are considered small-scale, in terms of the volume of food waste composted,

and regulatory status. Per the WDNR composting sites under 50 cubic yards are exempt from

regulation. This means these sites do not have to meet locational requirements. The rationale

being that the volume of materials cannot lead to environments impacts.

56

As both sites are within the city of Milwaukee, they are also subject to city regulations.

Though not enforced, composting in the city is restricted to 125 cubic feet (just under 5 cubic

yards). If enforced this would put a constraint on the volume of food scraps composted by the

organization.

Another aspect of KKs’ capacity is its ability to recruit volunteers. In addition to rely-

ing on volunteers for food scraps collection, KK regularly holds “turnings” at each site where

volunteers are encouraged to help maintain the compost bins. This includes adding new ma-

terial to the bins, turning material already in the bins, and screening finished compost. Wash-

ing 5-gallon collection buckets is another task volunteers are encouraged to help with. The

volume of material collected and composted is limited by the extent of volunteerism.

Composting Method

Each KK composting site has a multi-bin composting system. The bins were con-

structed from pallets and are a cubic yard in volume. Attaching three or four of the bins to-

gether allows for compost to be processed in phases. The first bin receives incoming food

waste and carbon materials to begin composting. Sections of perforated PVC are placed in

the bins with the materials to provide aeration, this reduces the need for more regular turning.

After about a week, sometimes more sometimes less, the materials are moved into the next

bin to compost further. For a three-bin system, this process is done at least one more time to

transfer the material into another bin where it matures until more materials need to be turned

into the bin.

In addition to the multi bin system, KK has recently begun composting in a small

windrow at its Bay View site. The windrow is 20 feet long, 6 x 3 in width and height. One

volunteer brings his skid loader to the site to turn the windrow, on occasion. The windrow is

57

otherwise turned by hand. In addition to this equipment, the site also uses a small shredder to

reduce the size of materials, including wood chips, before adding them to bins or piles. This

reduces the time to mature compost.

Figure 9. Kompost Kids Riverwest Multi-Bin Composting System

Compost Production

Kompost Kids does not produce compost for sale. In its early years, the compost pro-

duced was given to a community garden selected through a vetting process. Now, the com-

post is used for gardening on-site. At the Riverwest site, gardeners from the adjacent commu-

nity garden are welcome to use the compost. At the Bay View site, KK uses the compost to

amend raised bed garden plots maintained by the organization. Plans to scale up compost

production at the Bay View site are being considered so that the community garden give

away can be continued.

Orchard Ridge Composting Facility

Waste Management (WM) is a national company specializing in doing exactly what

its name conveys. In addition to waste collection, WM also operates landfill facilities, some

of which include composting sites. This is the case at the Orchard Ridge Composting Facility

58

(ORCF). WM operated the compost site until recently citing customer costs as hampering the

operation's productivity. The composting operation has recently been contracted out to a

third-party, Purple Cow Organics, a composting business discussed below.

Feedstock

As a private company, it is not subject to keeping public records, and due to confiden-

tiality agreements with its customers, WM is unable to accommodate requests of information

such as its customers. It did however provide information on the volume of organics the fa-

cility processed which was affirmed by the WDNR (2016). ORCF, under WM, was compost-

ing 76,519 cubic yards of yard residuals annually, a significant amount. The amount of food

residuals was significantly less at 2,600 cubic yards annually. This quantity is only pre-con-

sumer food residuals; the site does not accept post-consumer. Of note, ORCF, under WM,

was not composting food waste from any generators within Milwaukee County.

Size and Location

ORCF, located in Washington County, located just north of Milwaukee County.

The ORCF is both a landfill and a composting site making it unique in context com-

pared to other composting sites in Greater Milwaukee. WM's interest in composting organic

Figure 10. Aerial View of Orchard Ridge Composting Facility

59

waste, was driven by the Wisconsin yard residuals landfill ban in 1993. Composting food

waste was initiated out of opportunity to compost additional materials while extending the

capacity of the landfill.

Capacity

Despite the change of management, ORCF will continue to accept and compost food

waste. Considering its location within Greater Milwaukee, it can contribute to the compost-

ing infrastructure, especially considering there are few commercial composters in the area.

ORCF was at one time permitted to process the largest volume of materials in the state,

50,000 cubic yards of yard residuals, but now is licensed to process 20,000 cubic yards at a

time. It is also licensed to process 5,000 cubic yards of SSCM. It is unknown whether the site

will seek to expand either license under its new management though there is sufficient land

surrounding the site to do so.

Composting Method

Like BRO, ORCF processes material using windrows. As depicted in the aerial image

(Figure 9), 25 windrows compost the material on 13 acres of land. The windrows are formed

using front-end loaders that are also used in the landfilling operation. Full details of the com-

posting process, including equipment used, were not obtained.

Compost Production

ORCF reported it produced 5,240 cubic yards of compost between October of 2015

and September of 2016. The material for this compost was mostly yard residuals, 4% were

from food residuals. The compost is sold on site and some of it was being used as landfill

cover under WM. The use and sale of the compost is likely to change under ORCF’s new

management by Purple Cow Organics.

60

Figure 11. Capacity of Greater Milwaukee Food Waste Composting Sites

Figure 12. Annual Compost Production for Food Waste Composting Sites

Composting at Community Gardens

Milwaukee Urban Gardens is a network of community gardens founded in the year

2000 as a means for community gardeners to ensure they had land tenure for their gardens.

The organization incorporated as a land trust and recently merged with the land trust organi-

zation Groundwork Milwaukee, an arm of the national Groundwork organization. Ground-

work helps to provide maintenance for the gardens in its network along with promotion for

5,000

10,000

50 50

5,000

50

7,736

449 155 12

2,970

854

0

1,000

2,000

3,000

4,000

5,000

6,000

7,000

8,000

9,000

10,000

Blue RibbonOrganics

Growing Power Kompost Kids(Bay View)

Kompost Kids(Riverwest)

Orchard RidgeComposting

Facility

Back Yard

cub

ic y

ard

s

SSCM Capacity (cy) Food Waste Composted (cy/yr)

2,000

150 5 5

5,240

284

0

1,000

2,000

3,000

4,000

5,000

6,000

Blue RibbonOrganics

Growing Power Kompost Kids(Bay View)

Kompost Kids(Riverwest)

Orchard RidgeComposting

Facility

Back Yard

cub

ic y

ard

s

Composting Site

61

the gardens. HOME GR/OWN Milwaukee, a City of Milwaukee program to revitalize vacant

lots into green spaces recently partnered with Groundwork to oversee 70 gardens that were

created through the HOME GR/OWN program.

There are also other community gardens overseen by other organizations like the Ur-

ban Ecology Center and agencies such as the UW-Extension some of which are composting

sites. The Urban Ecology Center composts mostly green waste from maintaining the parks

and forests at each branch. Its food scraps are picked up by Compost Crusaders. The UW-Ex-

tension has four other garden locations including the Kohl Farm Community Gardens which

includes small farms.

Two of these UW-Extension community gardens are composting sites while the oth-

ers are potential sites. The Green Corridor Community Garden has a multi-bin composting

system. Garden 19, as it is called, at Havenwoods State Forest, also has a multi bin sys-

tem. One garden location, Timmerman Garden is located next to an airport which may not be

appropriate for composting, at least on a large scale, as it can attract gulls that may cause se-

rious problems for airplanes.

Size and Location

As mentioned the composting occurring at community gardens is on a small-scale; a

step above backyard composting. While it is not known now exactly how many gardens are

composting sites, MUG has attempted to find out with its annual garden manager survey.

MUG is also interested in promoting composting to member gardens as well (Tom Welcen-

bach, personal communication, 2016).

Capacity

It is presumed that composting at these sites averages one cubic yard, but as de-

scribed, some may have a multi-bin system with each bin being a cubic yard. Most organic

62

materials will come from the gardens with some residential food scraps or yard waste

brought to the site by gardeners. It is unlikely that large sources of food waste are composted

at these sites given their small size.

Composting Method

It is assumed that most gardens have a compost pile or bin. Based on this scale the

method of composting will be a bin or a static pile. Aeration may be passive or the pile may

be regularly turned. As this compost is only produced for the gardens, attention to actively

managing compost piles may not be given great priority. Thus, the amount of compost pro-

duced will on average be five cubic yards though exceptions may exist.

Backyard Composting

While surveying residents of the Milwaukee area would have been a more accurate

means to determine the extent of backyard composting, a proxy was used instead. This was

done by determining the number of discounted compost bins sold by Keep Greater Milwau-

kee Beautiful (KGMB), an environmentally focused non-profit organization located in Mil-

waukee’s Menomonee Valley. In conjunction with KGMB, the City of Milwaukee's DPW

also sells these discounted compost bins once a year at a day-long event. By multiplying the

combined number of compost bins sold by the average amount of food scraps produced in a

U.S. household, a lower estimate of the extent of backyard composting was produced, 853

cubic yards. This of course assumes the composting bins become and remain operational. In

the coming year, it will be possible to validate and calibrate these estimates through the Mil-

waukee residential food waste curbside collection pilot project.

Composting in backyards is like that done in community gardens though homeowners

may invest more money, time, and/or effort in a backyard bin. There are a variety of compost

63

bins and in-vessel options available although compost piles are also likely options. The com-

post may be static, passively aerated, or regularly turned. As this compost is typically only

produced for the backyard use, there may not be a lot of compost produced but this will vary

by backyard.

Purple Cow Organics-Genesee

Purple Cow Organics (PCO) was one of the first composting operations not only in

the Greater Milwaukee area but in the state. Sandy Syberg, the founder and President of the

company, has been involved with the organics composting movement in Wisconsin since its

beginnings, helping to shape the landfill bans on yard residuals in the early 1990s. Sandy

Syberg is also an advocate for organic farming and sees composting as an integral part of

sustainable agriculture.

Purple Cow Organics has operated several composting operations in Wisconsin, one

of which was the Wauwatosa Composting Facility. Syberg was instrumental in helping Blue

Ribbon Organics successfully establish its composting operation. Purple Cow Organics is a

recognized brand and its soil amendments are marketed at numerous retailers in southeast

Wisconsin, the rest of the state, as well as across the U.S.

Size and Location

Currently, PCO has four licensed composting facilities and in addition now operates

the Orchard Ridge Composting Facility. Per the WDNR's register of licensed composting fa-

cilities, last year only one PCO site, Genesee, in Waukesha County, north of Milwaukee

County, was licensed to compost yard residuals. All sites are now licensed to process SSCM,

though it is unclear when these sites will begin to compost food residuals. PCO will continue

the food residuals composting at the ORCF.

64

Capacity

It is not known if any food residuals were composted prior to 2015 at the Genesee site

under the exemption limit, but per Sandy, the site was never intended to compost food resid-

uals. This site is now licensed to process up to 5,000 cubic yard of SSCM and as it continues

to be licensed to compost up to 20,000 cubic yards of yard materials and bark/brush.

Though none of the PCO sites were licensed to accept food waste in 2015, food resid-

uals were collected from within the study area, by Sanimax under contract by PCO, and was

sent to an anaerobic digester in Springfield over 100 miles from Milwaukee; outside the

study area. As discussed, the ORCF, which is in Greater Milwaukee, is now operated by

PCO, though, it also, did not have a license in 2015. PCO has been actively seeking a site

within Milwaukee and working with city officials to find a site meeting locational criteria set

by the WDNR.

Composting Method

Like the other large commercial composting sites, PCO uses windrows for compost-

ing at all its sites. The Genesee site, pictured above, can contain more than 11 windrows that

Figure 13. Purple Cow Organics Genesee Composting Site

65

extend 50 yards. Mechanized equipment is used to turn the windrows; the specific types of

equipment was not determined.

Compost Production

PCO produced 100,000 cubic yards of compost last year, with most feedstock being

yard residuals. The Genesee site alone produced 26,000 cubic yards of compost, again from

yard residuals. Compost produced by PCO is aggregated and sold in bulk and is also bagged

and sold in several retail locations in and out of state. Several compost products are sold in-

cluding only compost and compost blends. Composting food residuals at only one location

may require this compost to be bagged and sold separately from compost produced at other

sites to maintain its higher plant nutrient content.

Non-food Waste (Yard Residuals) Composting

Looking at Greater Milwaukee, there are 29 composting sites, not including sites in

the outlying counties of Sheboygan and Walworth. Of the 29, five are licensed to compost

food waste, under a SSCM license through the WDNR. Three of these sites were known

prior to this research. Two, were discovered in the late stages of this study; key informants

were not interviewed.

While modifications may be needed to the 24 yard residuals composting sites to com-

post food residuals, they have the potential to do so in the future. These composting sites are

in cities, towns and villages in Greater Milwaukee where the respective municipal govern-

ments may become interested in diverting food residuals from landfills. This was exemplified

by the Town of Wauwatosa's Wauwatosa Composting Facility which prior to the start of this

study was not licensed to compost food residuals. In this way, (non-food waste) yard residu-

als composting sites are potential components of the food waste composting infrastructure.

66

Figure 14. Greater Milwaukee Yard Residuals Composting Sites

67

Anaerobic Digesters

Anaerobic digesters (AD) are another destination for food waste in Greater Milwau-

kee. As provided by the US EPA’s food recovery hierarchy, AD is another way to get higher

uses from food waste than landfills. Food waste sent to AD will reduce the amount of feed-

stock available to produce compost. AD does produce a solid byproduct, digestate, which

could be composted. At present, neither of the two ADs in Milwaukee described below are

sending their digestate to a composting site.

Forest County Potawatomi Anaerobic Biodigester

Located in the center of the city of Milwaukee in the Menomonee Valley, the Forest

County Potawatomi Anaerobic Biodigester (FCPAB) was designed to support the Pota-

watomi Hotel and Casino located just feet from the facility. Its intent is to increase the sus-

tainability of the Hotel and Casino in keeping with the Potawatomi tribes' environmental val-

ues.

Capacity

The facility opened in October of 2013 and has a capacity of 2.6 million gallons. The

facility has yet to operate at full capacity. For the year 2016, the facility diverted 50 tons of

food waste, or 50,494 gallons. The facility is capable of processing all the food waste gener-

ated by the Hotel & Casino with extra capacity to accept food waste from elsewhere. It re-

ported that 30% of its food waste are from generators within the city of Milwaukee.

At present, the digestate produced by FCPAB, has been deemed hazardous by the

WDNR and as such is landfilled. Interested parties are currently exploring options to make

use of the digestate through composting or land spreading it.

68

Milwaukee Metropolitan Sewerage District

Milwaukee Metropolitan Sewage District (MMSD) operates the wastewater treatment

plant (WWTP) which serves the city of Milwaukee. The WWTP includes an anaerobic di-

gester at its south shore plant and a water reclamation facility at its Jones Island plant. Since

1927 MMSD has produced Milorganite, a pelletized nitrogen fertilizer as a byproduct of

wastewater treatment. As one of the nation's oldest recycling efforts, the sustainability of

Milwaukee’s WWTF is nationally renowned.

Capacity

The digester began operation in 1968, to process sludge so that methane can be recov-

ered for energy generation. MMSD has partnered with InSinkErator to encourage city resi-

dents to put their food scraps down in-sink disposals to end up at its anaerobic digester. It is

unknown how much food waste, sent through in-sink disposals, is processed by MMSD’s

AD system.

In addition to the food scraps that reach the facility through the sewer system, MMSD

also accepts food waste from commercial generators in Greater Milwaukee. MMSD has con-

tracts with two Grocery store chains: Pick 'n Save and Sendiks. Only one Pick 'n Save store is

diverting food waste to the MMSD digester, but 11 Sendiks stores, along with Sendiks’ dis-

tribution center, are diverting food waste to MMSD. In addition to grocery stores, several

other entities are diverting food waste to MMSD including one corporate headquarters and

one food manufacturer.

Like FCPAB, MMSD’s anaerobic digesters are operating under capacity and looking

to partner with more food waste generators to utilize the full potential of the six digesters at

its South Shore plant. In 2016, MMSD received 389,400 gallons of food residuals. All food

69

residuals are measured in gallons as they go into the digester which, as a closed vessel, has a

capacity measured by volume. How this volume is measured was not determined.

Figure 15. Volume of Food Waste Digested and Capacity of Anaerobic Digesters

Food Waste Collection

Compost Crusader

After founding Kompost Kids in 2011 and working to increase food waste diversion

through creating community composting sites over the next three years, Melissa realized the

diversion rate for most of the generators Kompost Kids was serving was less than ideal. Real-

izing Kompost Kids was not capable of composting large volumes of organics due to low

volunteerism, costs of materials, and weather disrupting composting, and unable to find will-

ing partners that were, Melissa decided to scale up her efforts.

This was made possible after she was awarded a $10,000 grant from Toms of Maine

for the express purpose to invest in a more sustainable composting system. Melissa pur-

chased a collection truck and in doing so Compost Crusader was born. Compost Crusader is a

food residuals and other organics residuals collection business. Leaving Kompost Kids in the

50,494

2,600,000

389,400

15,000,000

0

2,000,000

4,000,000

6,000,000

8,000,000

10,000,000

12,000,000

14,000,000

16,000,000

Food Waste Volume Digester Capacity

gallo

ns

Forest County Potawatomi Biodigester Milwaukee Metropolitan Sewage District

70

hands of its board members, Melissa has gone on to grow her business to a fleet of two col-

lection trucks.

At present, Compost Crusader is experiencing growth in its customer base. As of Au-

gust 2016, there were 61 customers. Compost Crusader began collecting food scraps from

restaurants and cafes, like Kompost Kids, and has been successful in developing a customer

base with these businesses. Through soliciting the organic residuals collection service, in ad-

dition to collecting from restaurants and cafes, Compost Crusader now also collects from cor-

porations, hospitals, and schools, (Figure 15).

Along with the increased customer base has come a gradual increase in the quantity

of organic residuals being diverted to composting. In 2015 Compost Crusader averaged col-

lecting 197,606 pounds of organic waste per month. It started the year with 85,422 pounds of

organics residuals per month and ended collecting 195,745 pounds. About half of this total is

388651

30495

77430

288285

900

69660

13050

50000

100000

150000

200000

250000

300000

350000

400000

po

un

ds

org

anic

res

idu

als

Restaurants Schools Food M&P Retail Hospitals Corporations Miscellaneous

Figure 16. Compost Crusader’s Annual Organic Residuals Collection by Category (2015)

71

food residuals; the rest is composed of other organic wastes such as used paper towels. Com-

post Crusader’s customer base has doubled in growth with each year of operation which is

promising for its continued success.

All organics collected by Compost Crusader are hauled to Blue Ribbon Organics in

Racine County. As Blue Ribbon Organics is the only large scale commercial composter near

Milwaukee accepting organics, her operation depends on the ability of the site to accept these

materials. While there are other compost sites within Milwaukee, these sites cannot process

all the materials she collects, decomposable bags and cutlery for example.

Beyond hauling, Tashjian of Compost Crusader is working with schools to prepare to

divert their organic wastes. This primarily takes the form of curriculum development around

diverting the organic residuals schools generate. While schools are a reliable source of food

residuals and other organics, preparing the staff and students to source separate out organics

from their waste stream requires an orientation to doing so which is the goal of the curricu-

lum (Melissa Tashjian, Personal communication). Additionally, Tashjian is working with

Figure 17. Compost Crusader’s Organic Residuals Collection (2015)

85,42275,380

90,496 95,530

124,650130,885

148,440

180,064187,020 187,270

211,245

195,745

50,000

70,000

90,000

110,000

130,000

150,000

170,000

190,000

210,000

Jan Feb Mar April May June July Aug Sept Oct Nov Dec

Monthly Totals

72

WDNR to help develop contract language for schools to use in negotiating their waste man-

agement contracts which, at present, do not include source separated organics collection.

Compost Crusader was recently awarded the contract for the recently begun residen-

tial curbside food scraps collection pilot in Milwaukee. The businesses continued success is

fueled by Tashjian’s passion to divert food residuals from landfills and the economic benefits

of doing so through her business.

Compost Express

Compost Express is a small business start-up that offers curbside food waste collec-

tion. Duane Drzadinski, the sole employee of Compost Express, began the business in 2014

after identifying a community need for food waste diversion and local compost. Drzadinski

grew up exposed to gardening as his father was a master gardener and thus has developed a

green thumb. Drzadinski himself recently became a master composter through the University

of Wisconsin-Extension Master Composter program and applies the skills he is acquired to

managing several compost piles that serve as drop-off locations for the food waste collected

by Compost Express.

Drzadinski collects food waste in five gallon buckets from 10 locations which are a

mix of residential and commercial customers. Compost Express relied on collection fees

from customers as its source of income. The compost produced by the drop-off sites is not

currently marketed and remains at the site. One of the largest drop-off and composting sites

is Drzadinski’s backyard in Franklin, WI where he manages three composting bins.

Drzadinski estimates his weekly collection averages 100 pounds. He has only recently

begun to weigh the food waste he collects; making this figure is an estimation of previous

year’s collection.

73

Sanimax

Sanimax is a for-profit organics recycling enterprise based in Montreal, Canada.

While Canada based, the company operates in WI, MN, IA, northern IL, and Upper MI. It

has had a presence in WI for over 100 years with its hide rendering plant in Green Bay. Ren-

dering organics residuals is Sanimax’ primary business, but it also provides collection of or-

ganics residuals for which it does not process itself.

In Southeastern WI, Sanimax collects from several large grocery store chains includ-

ing Walmart, Hyvee, and Festival Foods. By its ability to divert large volume of food waste

to composting, Sanimax represents a key component of the food waste composting system.

In total, the company collects about 40,000 pounds twice a week and transports it to Blue

Ribbon Organics in Racine to be composted. The company previously held collection con-

tracts with other food waste generators in Milwaukee other than grocery stores including

Marquette University.

Sanimax’ primary interest is in collecting large volumes of food waste per location.

The company has set a lower limit on the volume of food waste it will collect per stop, no

less than 600 pounds. The rationale behind this limit is the type of trucks it uses for collection

which are large straight trucks with an open trailer and rear lift. The company recently de-

clined the opportunity to bid for a Milwaukee residential collection pilot. This decision was

based on the investment in new trucks it would have required, $250,000 each, which was

prohibitive (Alan Ceschian, personal communication, 2016).

74

Figure 18. Food Waste Collected by Business

Compost Distributor

Elyve Organics

Elyve Organics is a startup entrepreneurial venture between Damian Coleman and

Javon Taylor. Both became interested in composting because of their completion of the Com-

mercial Urban Agriculture program offered by Growing Power. The business, started in

2012, was initially a food waste collection and composting operation. It has experienced

growing pains typical of both a small-business start-up and an urban agricultural operation.

The result is Elyve Organics now occupies an apparent niche in the Milwaukee food waste

composting system. Elyve currently offers only composting consulting and distribution ser-

vices.

These services are offered despite a series of events that twice led to the end of com-

posting operations. The first composting operation started out in a garage where equipment

was kept for collecting food scraps and composting them on-site. After running into prob-

lems with the local alderman, for nuisance concerns, the operation ended. Composting opera-

tions began again when Elyve secured a one-year lease at an abandoned industrial building.

856726

5200

960000

0

100000

200000

300000

400000

500000

600000

700000

800000

900000

1000000

Compost Crusader Compost Express Sanimax

PO

UN

DS

Food Waste Collected

75

Collected food scraps were composted in the buildings parking lot using the windrows. Due

to the property being sold for development, this lease ended as well.

When it was composting, Elyve’s customer base was small which fit its collection

method, by pick-up truck. Customers included, Outpost Natural Foods, the Juice bar, a res-

taurant, along with a pizzeria. Food scraps collected then were both pre- and post-consumer.

Though this experience caused Elyve Organics to change it business plan, it did make way

for its ability to provide its consulting service.

Since ending its own composting operation, Elyve has consulted on several projects

including the development of a vocational manual for Vincent High School students and oth-

ers, which informs on several ways to compost on a small-scale, while providing background

information on composting basics. Elyve Organics also consulted on a hoop house compost-

ing operation constructed on the campus of the University of Wisconsin-Milwaukee. The

hoop house contains several compost piles that are connected to on-going research. The piles

also serve as a source of heat for the growing vegetables in the winter months.

Elyve was also involved in another project which had the goal to compost the food

waste generated at the Milwaukee County House of Corrections (HOC), an adult correctional

facility. Though the project has not yet begun, due to problems securing a license from the

WDNR, both parties, and others including State Senator Lena Taylor, are interested in con-

tinuing the process to begin the composting operation. Per Damian, the HOC has begun ver-

micomposting its food scraps outside of its relationship with Elyve Organics.

While not currently collecting food waste or producing compost, Elyve does market

an organic compost product, produced by Blue Ribbon Organics, under the Elyve Organics

label. The compost is sold at several garden centers throughout Milwaukee.

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V. Discussion

Characterizing the current food waste composting system is possible using several

key aspects of it including compost site sizes and spatial distribution, capacity to compost

food waste, composting methods and the amount of compost produced. In the previous sec-

tion, the characteristics of individual composting sites, haulers and the one distributor were

described. Here, these characteristics will be collectively discussed to characterize the entire

infrastructure. Overall, two important characteristics were found: the food waste composting

system is centralized and it has insufficient capacity to compost the total available food

waste.

Using these and other overarching characteristics of the infrastructure, it was ana-

lyzed against three measures of sustainability: conservation of landfill capacity, reduction in

GHG emissions, and recovery of resources, i.e. food residuals. Two measures, landfill capac-

ity and recovery of resources were chosen because they are related to the sustainability plans

of two stakeholders in Milwaukee, the City of Milwaukee and MMSD respectively. Knowing

how the infrastructure fairs against these measures of sustainability can serve as a bench-

mark. The third measure of sustainability, reducing atmospheric GHG emissions, is an area

of interest nationally and internationally.

Aspects of the food scraps composting infrastructure that have an impact on

these measures include the size of individual composting sites and the spatial distribution of

the sites. The larger the individual composting sites, which equates to a greater system capac-

ity, the larger the potential offset of environmental impacts from landfilling food

77

scraps. Where composting sites are more spatially distributed within Greater Milwau-

kee, greater hauling distances are required and therein the consumption of fossil fuels, lead-

ing to greater GHG emissions.

It was found that the infrastructure is centralized because the largest composting site,

BRO, receives most of the food residuals with respect to the other sites. It was also found

that the capacity of the infrastructure is well under that necessary to divert the amount of

food residuals generated in Milwaukee. These and other findings were considered per the

measures of sustainability outlined in the literature review which have been restated here as

sustainability goals.

Characteristics of the Food Waste Composting System

This study revealed that there are currently eight sites in Greater Milwaukee capable

of composting food waste, with only five actively doing so. As described in the previous sec-

tion BRO, GP, KK (2 sites), and ORCF actively accept and compost food waste. Liesener’s

Soils, Inc., Purple Cow Organics, and Wauwatosa Composting Facility have recently become

licensed to compost food waste but have not begun doing so. Of the active composting sites,

BRO receives more food waste than all other sites combined leading to the determination that

the system is centralized with respect to composting activity.

Centralization of a composting system has a direct impact on its sustainability when,

as in this case, long hauling distances are required to take food scraps to the composting site.

A more sustainable composting system, with respect to GHG emissions, will consist of com-

posting sites around sources of food waste, minimizing hauling distances. A distributed infra-

structure, with multi-scalar sites, will result in sites in closer proximity to food waste genera-

tors with appropriate capacities to process the material received, and can successfully address

78

this issue of food waste collection. Heavy reliance on one composting site may impact the

sustainability of the infrastructure in other ways. Only one site, BRO, accepts post-consumer

material. If BRO were to close, most of the food waste being sent there could not be com-

posted elsewhere. There are currently no indications this will occur, but it has happened else-

where.

Composting Site Sizes and Spatial Distribution

As mentioned, most food waste collected is being hauled to a single composting

site, BRO. BRO is a large commercial composting facility in Racine County, south of Mil-

waukee County, Figure 19. Another large commercial composting site, ORCF, located in

Waukesha County, north of Milwaukee County, also composts food residuals but at the time

of inquiry was not receiving any from Milwaukee. There are other composting sites, that do

reduce the centralization, as illustrated in Figure 20, but their capacity is quite limited, such

that most collected food waste goes to BRO.

Three other sites within Greater Milwaukee are now licensed to process SSCM:

Liesener’s Soils, Inc., Purple Cow Organics, and Wauwatosa Compost Facility. Only Purple

Cow Organics had been identified prior to the start of this study: no representative from

Liesener's Soils, Inc. or Wauwatosa Compost Facility served as a key informant. Other sites

composting food waste included in this study are exempt from regulations due to the small

volume of food waste composted: Growing Power and Kompost Kids.

The food waste composting infrastructure was not designed as a centralized system. It

has evolved into this by some degree of chance due to the way the composting sites have de-

veloped. In some cities, centralized sites are designed to accommodate municipal curbside

79

Figure 19. Spatial Distribution of Greater Milwaukee Food Waste Composting Site

80

collection programs, but in this case, Milwaukee’s curbside collection pilot was made possi-

ble by the existence of BRO. The land BRO sits on, in Racine County, has been in the Jurt-

zonka family for six generations and has been utilized in several ways. BRO, as a family

owned business, evolved into a commercial composting site from a landscaping business

eight years ago. When BRO began composting, it only composted the landscaping materials

it was already receiving from landscapers to produce mulch.

By incorporating more of its 32 acres into the food waste composting operation,

which is separate from a yard residuals operation also on the site, BRO has adapted to com-

posting food waste over time. Due, in part, to efforts of Compost Crusader in developing a

customer base for food waste diversion, and its sole reliance on BRO as the destination for

this material, BRO has now come to the point of receiving a steady stream of this feedstock

for composting. Via Compost Crusader, BRO is the destination for the City of Milwaukee's

curbside organics collection pilot food scraps.

BRO’s acceptance of post-consumer food waste is another reason it receives the larg-

est volume of material. It is the reason the Greater Milwaukee food waste composting system

is diverting the current volume of material. Contamination from this post-consumer food

waste may lead to challenges for BRO, especially if its volume increases. In addition to being

the destination of Milwaukee’s curbside collection pilot, BRO also currently accepts residen-

tial food waste from the City of Madison's curbside collection program. BRO does have

a trommel screen to remove unwanted material from finished compost so, at present, the site,

and therein the system, has the capacity to process this material.

While details of ORCF may have provided a different picture of the infrastructure, it

will only be considered in brief as full details were not be obtained. It can be speculated that

81

Figure 20. Proportion of Food Waste Composted at Greater Milwaukee Sites

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the facility serves as a centralized site, at activity wise, for the areas of Waukesha County and

Washington County reducing the need to haul materials to BRO two counties over. It is

known that the site only accepts pre-consumer food waste from large commercial generators

to avoid contamination, so large-scale post-consumer food waste composting within the in-

frastructure is limited to BRO.

In addition to these two large composting sites, there are several other smaller com-

posting sites. Growing Power is one site located on the northwest side of Milwaukee. Kom-

post Kids is another with two sites in Milwaukee: one on the northeast side and one on the

southeast side. Neither organization has complete data on how much food waste they cur-

rently accept though Kompost Kids did record the food scraps it received in 2014. The figure

used in this study for Growing Power is based on an estimate by staff member, Joel Rissman,

who regularly collects food waste for the organization. Based on available data, these sites

receive a large volume of food waste relative to their size, but with respect to the amount re-

ceived by BRO, they do not, thus the characterization of a centralized system.

With BRO receiving more of the food residuals than other sites, it begs the question

of whether this is solely due to the characteristics of BRO or of the other composting sites. In

terms of size, and therefore capacity, it is true the size of BRO’s operation allows it to re-

ceive more feedstock. As discussed, each composting site has developed in its own way with

distinct goals and/or priorities. BRO has an interest in composting as much food residuals as

possible as a commercial enterprise. In comparison, GP is only focused on production in as

far as it needs the compost for it cash crop production. Kompost Kids, does have an interest

in diverting more food scraps from landfills but there are characteristics that prevent it from

83

doing so. Thus, the answer is yes. In as much, the capacity of the infrastructure was deter-

mined and will be discussed next.

Table 12. Summary of Food Waste Composting System Characteristics

Food Waste

Composting

Sites

Capacity (cy) Food Waste

Composted

(cy)

Food Waste

Collectors

Compost

Produced (cy)

Eight/Five Ac-

tive 20,150 12,176 Three 7,684

Food Waste Composting System Capacity

It is the relative activity of BRO that characterizes the system as centralized, and this

is directly correlated with BRO's capacity as well as that of other composting sites. BRO is

licensed to process up to 5,000 cubic yards of SSCM, which is the second to highest volume

for which composting sites in Wisconsin can be licensed. In addition, it can compost up to

20,000 cubic yards of yard residuals and bark/brush, or carbon materials, at a time. It is be-

cause BRO has this capacity, and due to the reasons previously mentioned, that BRO re-

ceives more food waste, and other SSCM, than any other site in the study area. With only 14

of its 32 acres of land utilized for composting, BRO could increase its license to process

greater than 5,000 cubic yards but would have to meet additional site criteria for the WDNR

to grant this license.

Growing Power and Kompost Kids also compost food waste, but a significantly

smaller volume with respect to BRO. Space at GP’s farm is fully occupied because of the in-

tensive farming practiced on the 4 ½ acres. Given greater space, GP would have greater ca-

pacity, and would compost more. One related point is important for discussion as it high-

lights distinctions between composting sites as well as the food recover hierarchy discussed

in the literature review. Not all the material collected by GP is taken to the 55th Street farm to

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be composted. Some days, the material is sent to a farm to be used as animal feed or sent to

BRO. GP is in the process of beginning composting at a new site, within Milwaukee, though

full details have not been revealed.

Kompost Kids does their composting at community gardens; one garden has a total

area of 16,000 square feet and the other 11,000 square feet. For composting, only, the capac-

ity for these sites is 500 square feet and 300 square feet respectively. Even without these con-

straints, composting would be restricted due to KK’s reliance on volunteers to manage the

composting process. Volunteers are also relied on to do "pick-ups" or collection of food

scraps from area businesses and to help aerate the compost piles. There is inconsistency in

volunteerism at the organization so capacity to compost remains a constraint.

As described in the previous section, community gardens that have composting bins

and backyard composting bins also add to the capacity of the infrastructure but this was not

quantified. Discussion of KK’s sites can be considered best case scenario for these sites. Sites

used as destinations for food scraps collected by Compost Express, which include school

compost bins as well as backyard compost bins also add additional capacity to the infrastruc-

ture. A common characteristic of these sites is they currently receive material based on their

overall capacity. Capacity, with respect to these smaller sites, encompasses space to compost,

as well as labor and equipment. These intricacies of capacity will not be discussed here.

As evidenced by the growing customer base of Compost Crusader (Figure 3), there is

a trend toward increased food waste diversion. Equally true, the infrastructure does not have

sufficient capacity to divert the total volume of food residuals generated in Milwaukee.

Though it is currently operating under capacity, increasing diversion rates may make the cur-

85

rent infrastructure inadequate. The exact percentage of the food waste generated in Milwau-

kee already diverted to higher uses other than composting, i.e. to feed livestock animals, is

unknown, but it can be assumed there is a sizable percentage available for composting.

Though food residuals from several grocery stores are being diverted to anaerobic digesters,

most residential food waste is not being diverted.

Assuming material can be processed in 6 months (2 times per year), based on a capac-

ity of 20,150 cubic yards of material onsite at any given time, and where 47,000 tons of food

waste are available, or 94,000 - 203,024 cubic yards of food waste, then the following equa-

tion provides the percentage of total food waste that can be composted by the system.

20,150 cubic yards / 94,000 – 203,024 cubic yards x 100 = 10 - 21 % x 2 = 20 - 42 %.

The capacity is sufficient to divert 20 - 42% of the total amount of food waste gener-

ated in Milwaukee. If 19,000 cubic yards of food waste is being diverted to composting

sites, the following equation provided the percentage akin to the volume of food waste avail-

able that is composted at present.

12,176 cubic yards / 94,000 – 203,024 cubic yards x 100 = 6 - 13%

The food waste composting system is diverting akin to 6 - 13% of the food waste pro-

duced in the city of Milwaukee. Not all the total diverted, comes from Milwaukee. Further

development of the system will be necessary if increasing rates of food residuals diversion

are to be composted.

It was found that composting sites are not the only destination for diverted food resid-

uals, i.e. there are two anaerobic digestion facilities that also process food residuals. These

two anaerobic digesters receive 1% of the food waste that is generated in Milwaukee, though

not all the material comes from Milwaukee. The food residuals reaching digesters are pre-

86

consumer and therefore less prone to contamination. This of course reduces the amount of

food residuals available for composting. If increasing rates of pre-consumer food residu-

als going to anaerobic digestion occur, composting sites may be left with no other option than

to accept more post-consumer food residuals, and may be forced to implement solutions to

the problems they present without adequate time to fully consider all options.

Composting Methods

This study revealed that composting methods within the infrastructure are tied to the

size of the composting site. The large commercial composting operations BRO, ORCF,

and PCO, all use the windrow composting method. These sites utilize different windrow

turners for aerating. Both KK sites use a multi-bin system for composting (Figure 8). How-

ever, KK has recently begun composting material in a windrow at its Bay View demonstra-

tion site, not having done so in the first five years operating at its previous demonstration

site. The windrow (10’ x 25') is being utilized in addition to its 3-bin system which has three

32" x 3' bins. Both methods are primarily for demonstration purposes; the sites are not man-

aged for maximum compost production. The Bay View site has more available space for

composting than the Riverwest site where only the multi-bin system is used.

Growing Power also uses bins for composting. Bins are set up as part of its compost-

ing workshops and the material is finished in about four months in warm weather, and longer

in wintry weather. It also has a large static pile which was not intentionally planned, but over

time turned into a compost pile from added food residuals and wood chips. This pile is the

largest on the site. GP has also recently begun composting using a windrow, though its wind-

row, tightly located between two of its hoop houses, contains worms unlike those at other

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sites. Similarly, GP's 66 cubic foot worm depository, in addition to breeding worms, also

produces vermicompost.

Compost Production

Considering all the composting sites collectively, including backyard bins, the food

residuals composting infrastructure is producing 7,684 cubic yards of compost annually. This

figure includes production of compost only and does not factor in what is done with the com-

post, i.e. does it reach markets. For example, while it does collect and compost food waste,

the compost GP produces is typically not sold. The compost is used for the organization's

farming operation. On the other hand, GP also produces, and sells, though not in copious

quantities, vermicompost, from its storefront at its 55th Street farm. GP's main contribution

to the composting infrastructure is therefore not in producing compost for markets. A greater

contribution to the system is from promoting food waste composting. It does this by collect-

ing food waste and by advocating for composting and training residents in Milwaukee and

beyond on how to compost food waste at the community level.

Like GP, Kompost Kids also does not sell the compost it produces. In its in-

fancy, Kompost Kids gifted the compost it produced annually to a community garden. This

has changed overtime as the volume of compost the organization produces has fluctuated.

Now, to operate within the Milwaukee ordinance that composting only be carried out as an

accessory use at a community garden, the compost KK produces at its Bay View site is

mostly used in its raised beds. Gardeners at the Riverwest site are also welcomed to use the

compost produced there in their garden plots.

Because of these practices, the amount of compost available for markets is not equal

to the amount of compost produced. Additionally, the compost produced by ORCF was only

88

being sold on-site. Based on this, the amount of compost from food waste available for mar-

kets is equal to that of BRO, 2,000 cubic yards. Considering the range of composting opera-

tions within the system, the compost produced can be expected to have distinct characteris-

tics. This is the result of the sources of composting feedstock and the composting methods

used and based on the intended applications of the compost. This results in distinctions of the

compost products, discussed below, which may affect the amount of compost available for

specific markets.

As depicted in Table 13, compost products, grouped per sales method: commercially,

not sold commercially, sold on-site, or sold commercially and on-site, produced by each site

have a wide range of distinctions, some of which were not obtained do to the constraints of

this research. Operations that are producing food waste compost are in black font, potential

food residuals composting operations are in gray font. Three products are not sold commer-

cially, that of GP, KK, and Wauwatosa Composting Facility. As mentioned, each has its own

intended uses for the compost product. Of the three, only this last operation, which produces

yard residuals only compost, has Class A designation certifying certain characteristics such

as the absence of prohibited levels of heavy metals.

Three operations sell compost commercially, one of these also sells compost on-site.

Based on the competitive nature of markets, it can be expected that the compost produced for

sale would exhibit exceptional characteristics. In fact, two of these operations produce Class

A compost. The third BRO, produces organic (OMRI listed) compost. It is unclear if markets

exist exclusively for Class A compost or the extent of demand for organic compost, but ap-

plications include organic farming and gardening. One operation sells compost on-site only,

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but it should be noted this was at the time of inquiry. Under its new management, the ORCF

compost will be marketed and sold commercially by PCO.

Table 13. Distinction of Greater Milwaukee Compost Products

Operation Class A Certified

organic Yard residuals

only Screen

size Tested

Not Sold Commercially

Growing Power

Not

screened Yes

Kompost Kids

3/8" No

Wauwatosa Composting Facility o

O unknown Yes

Sold Commercially

Liesener's Soils, Inc. o O unknown Yes

Purple Cow Organics o O O 3/8" Yes

Sold Commercially & On-site

Blue Ribbon Organics O 3/8" Yes

Sold On-site

Orchard Ridge Composting

Facility

unknown unknown

Based on the compost produced, the amount available for wide distribution through-

out Greater Milwaukee is equal to that of BRO. This is considering only compost produced

from food waste. One application of compost in the study area is to improve Milwaukee's

soil quality, most of which is currently happening through the growing practice of urban agri-

culture. In as much, two ways compost can be used in urban agriculture are in community

gardens and urban farms. It is assumed to food waste compost is of a quality better suitable

for growing fruits and vegetables due to higher plant nutrient content.

Using this total, the amount of land that can be amended with compost, at different

application rates, can be determined. At a rate of 0.5”, a typical application rate for turf, or

90

residential lawns, it would be possible to apply compost to 20 acres. At a rate of 1”, a con-

servative application rate for agricultural plots, it would be possible to apply compost to 15

acres.

Table 14. Urban Applications for Local Food Waste Compost

Compost Available Application Rate (inches) Area (acres)

2,000 cubic yards 0.5 30

1.0 15

6.0 2.5

For urban agriculture applications, it is probable that compost is applied at much

greater depths than one inch. For example, GP typically recommends at least 6" when start-

ing a new urban garden site. This may either be incorporated into existing soil or spread on

top of it. Under this scenario, much less land will be amended; only 2.5 acres.

All scenarios are hypothetical based on the current activities that could use the com-

post. Further research will be necessary to determine if the current quantity of compost pro-

duced is sufficient to meet demand. Alternatively, it is possible that there is more compost

than there is demand which should also be investigated.

Yard Residuals Composting: Conversion potential of existing infrastructure

In addition to the food residuals composting sites, there are yard residuals composting

sites in Greater Milwaukee. These sites can become food residuals composting sites, effec-

tively expanding the capacity of the infrastructure to compost food residuals and produce

compost. Given there are numerous sites, 24, within the study area, they have the potential to

create a distributed food residuals composting infrastructure. This distributed infrastructure

already exists for composting yard residuals, incentivized by the fact that this material is

banned from Wisconsin landfills.

91

It is likely more population dense municipalities will see a benefit to begin compost-

ing food residuals before their counterparts. Nevertheless, the sheer number of yard residuals

composting sites, could drastically increase the food residuals composting system's capacity

and increase the quantity of compost produced from food waste. That said, the impact of the

increase in food waste diversion would be realized by the individual municipalities. The large

residential and ICI food waste streams from Milwaukee would still need to be transported out

of the city.

To successfully make the transition from a yard residuals composting site to incorpo-

rating food residuals it will be necessary for these sites to obtain a license to compost SSCM.

Along with this license it may be necessary to make modifications to the site to ensure the

food residuals will be composted in a manner that ensures human and environmental health.

For example, leachate from food residuals need be prevented from reaching nearby water

sources. Additionally, the composting method may need to be changed to ensure minimal

odor and pest nuisances. A windbreak from residential areas would also be appropriate.

In addition to site considerations, the volume and sources of food residuals need to be

considered. If material will primarily be residential then educating residents on what can and

cannot be composted will be necessary to minimize contamination. Otherwise, investment in

screen equipment is required. Compost recipe should also be considered. Food residuals need

to be mixed with a bulking agent such as leaves, the available volume of which should be

known prior to accepting food residuals.

While PCO produced 26,000 cubic yards of compost at its Genesee site, food residu-

als were not feedstock for this compost so it was not included in the total production of com-

post given above. Other yard residuals composting sites also produced compost. Those in

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Milwaukee County, 7 total, produced 35,631 cubic yards of finished compost. In Greater

Milwaukee, there are 24 yard residuals composting sites, including BRO, which produced

84,336 cubic yards of compost. The applications of this compost are not known. It can be

presumed that at least some is utilized by the municipalities that produce it.

Food Waste Collection and Compost Distribution

Most of the compost produced by the system, not including yard residuals based com-

post, comes from BRO. As BRO does not collect the feedstock, i.e. food residuals (or bulk-

ing materials), its ability to produce compost depends on the efforts of food waste haulers.

Furthermore, while it does sell most of the compost it produces, in bulk and through retail, it

also relies on Elyve Organics to market and distribute a portion of its compost. As such, these

businesses are integral to materials coming to the site and moving off it. These components

will be discussed below with respect to the capacity to provide feedstock to food residuals

composting sites.

This study revealed four businesses that are involved in the food waste composting

infrastructure in a supportive role: Compost Crusader, Compost Express, Elyve Organics,

and Sanimax. Three of these businesses are involved in the collection and hauling of food

waste. Compost Crusader and Sanimax haul food waste to BRO on a regular basis. By doing

this, they ensure a continual supply of nitrogenous feedstocks for this site and therefore di-

rectly influence the amount of compost produced. Compost Express is a small food scraps

collection business that drops off the food scraps at school gardens, community gardens, and

backyard compost sites that it manages.

While Compost Express does not divert a large volume of food scraps or produce a

large volume of compost relative to other components of the infrastructure, the operation

93

could grow in the future; in one of several directions. One direction would be to scale up col-

lection and divert the material collected to BRO or another composting site. This would be

dependent on businesses diverting more food residuals. Alternatively, more emphasis

could be given to the composting side of the business where Compost Express could open a

new composting site for which it or another hauler would provide the food residuals.

Food waste haulers are experiencing increasing diversion rates at present but there are

several challenges to their ability to divert larger volumes of food waste to composting sites.

One challenge is the source of feedstocks. Compost Crusader relies on word of mouth adver-

tising to subscribe new customers. Most of these customers are interested in diverting post-

consumer food waste. The problem is that post-consumer food waste can be contaminated

with non-compostable materials. Contamination is a concern of BRO because contaminants

like plastic bags can get caught in machinery and litter the site. Other contaminants, may, in

rare cases include disease causing organisms.

The issue of contamination causes friction between Compost Crusader, which collects

some post-consumer material, and BRO. Consequently, there is also friction on the collection

end because Compost Crusader is held responsible for contamination on the part of food

waste generators. This compels Compost Crusader to admonish generators over contamina-

tion which can strain the relationship. Compost Express also collects post-consumer food

waste.

This is not the case for all food waste haulers in this study. Sanimax limits the food

waste it collects to being pre-consumer. This means that the likelihood of contamination is

lower. Remedies for contamination include educating food waste generators on how to effec-

94

tively separate food waste from the rest of their waste stream. Print materials have been de-

veloped to help train kitchen staff but training requires time on the part of the generator and

in some cases also requires employee buy in (Andrew Bryne, Harley-Davidson, interview,

2016).

Compost Crusader is not collecting some post-consumer food waste even though

there are food waste generators interested in diverting this material to composting. This is

preventing an increase in the diversion rate of food waste and the production of compost.

This is in part due to the While this is not a new issue in composting food waste, it is an

emerging issue for composters in this study. This could result in missed opportunities for

food waste haulers and composters, as well as food waste generators. Though several ways to

address this issue have been described in the literature, they have not been applied in the

study context. The ones that seems feasible in the Milwaukee context include educating food

waste generators on how to separate food residuals and other materials and composters add-

ing screening equipment to their operations.

Inherent in the Compost Crusader’s issue of not collecting post-consumer food waste

of uncertain quality is not having a destination for this material. Tashjian of Compost Cru-

sader and Jurtzonka of BRO are acquaintances and have been before Tashjian left Kompost

Kids to start Compost Crusader. Tashjian either has not established relationships with other

composting sites, or the sites are too far from Milwaukee, were most of the collection route

is, to haul the food waste there. New composting sites will, with the capacity to accept post-

consumer material would address this challenge.

Another challenge faced by Compost Crusader is maximizing the efficiency of collec-

tion routes. This has been addressed in other hauling industries, and may become less of an

95

issue as Compost Crusader gains more familiarity with existing technologies. Due to the cen-

tralization of the infrastructure, food waste must be hauled long distances to reach BRO

which in some cases means from Ozaukee County north of Milwaukee County to Racine

County, south of Milwaukee County.

Information was not obtained on the collection routes of Sanimax, but with large gen-

erators and less frequent stops, route efficiencies are less of an issue. It is known that Sani-

max runs a circuit from Green Bay to Milwaukee to Madison hauling food residuals to sev-

eral composting sites including BRO and PCO.

Another business, Elyve Organics, was at one time a food waste collector and com-

poster, like Compost Express, but now operates as a distributor of rebranded BRO compost.

Selling the compost ensures that bottlenecks do not occur at the compost site where space for

storing compost can become limited: as such, this is a vital component of the system. Elyve

Organics also does consulting with schools and other organizations interested in starting

small-scale composting sites.

Damian Coleman, of Elyve Organics, is a self-described entrepreneur and as

such Elyve Organics' function within the infrastructure may change over time. Elyve

Organics is in the process of seeking a new indoor composting site within the city of Milwau-

kee to begin composting again. Securing a necessary license to do so will be necessary once

a site is secured. It will be the first such site in Milwaukee so city zoning laws along with

WDNR regulations may need to be amended.

Sustainability and the Food Waste Composting System

Food waste composting has been increasing in Greater Milwaukee for several rea-

sons. Some driving force are landfill tipping fees, profit motives for composters and food

96

waste haulers, and more recently the City of Milwaukee’s sustainability agenda. Efforts to

produce quality compost are also being led by several stakeholders including community or-

ganizations and several universities, as is the case in the USDA-SARE project mentioned

above. This effort is directed at providing compost to create fertile soils for food production

in Milwaukee’s most food insecure neighborhoods and thereby addresses sustainability is-

sues.

Public and private support of food waste composting can be increased in intentional

ways. One is through adoption of sustainability initiatives, such as the City of Milwaukee’s

solid waste reduction goal, that improve the environment. Sustainability initiatives hold in-

centives for both public and private sectors. Articulating the environmental benefits of food

waste composting as goals provides a set of criteria from which the efficiency of the Greater

Milwaukee food waste composting system, and the efficacy of the drivers, in terms of envi-

ronmental sustainability, can be evaluated. As such, an evaluation of the environmental sus-

tainability of the current infrastructure can serve as a guide to where future development need

occur in seeking to reach sustainability goals and how the infrastructure currently stacks up.

The goals, like the environmental benefits, can be organized into two broad catego-

ries. Goals for food waste diversion and goals for the utilization of compost. The following

table illustrates these goals. It was beyond the scope of this research to explore the uses of

finished compost, so how and where these goals are met will not be discussed. Discussion of

the first set of goals follows.

In the first set of goals, Diversion of Food Waste to Composting, the current infra-

structure is succeeding to a limited extent, though goals in this category should be as specific

as possible with benchmarks to measure progress. For example, while food waste diversion

97

from landfills is occurring, the extent to which doing so has meaning should be defined by

the city or another governing or policy setting body with solid waste collection responsibili-

ties. The food waste composting system illustrated in this study will be evaluated per these

goals below.

Table 15. Food Waste Composting System Goals

Diversion of Food Waste to Composting Use of Finished Compost

Conserving landfill capacity Improve structure of urban soils: increase soil water

retention and reduce soil erosion

Reduce greenhouse gas emissions (GHGs) Sequester carbon in the form of organic matter

Waste reduction & material recovery: nutrients and or-

ganic matter in compost Improve soil fertility and increase plant growth

Goal 1: Conserving landfill capacity. The current composting efforts are succeeding in

conserving landfill capacity. Per the aggregated sum of the amount of food waste composted,

(including backyard composting in Milwaukee) the total amount of food waste diverted from

landfills is 12,176 cubic yards, or, 6,800 tons* (*1,000 pounds food waste = 1 cubic yard).

This amount is 15.5% of the 47,000 tons/year of food waste generated in Milwaukee. While

this number exclusive of the food waste diverted from the city of Milwaukee, it does repre-

sent progress, especially considering the relative youth of the food residuals composting in-

frastructure.

While this goal is being met broadly speaking, a specific objective could be to con-

serve 5% capacity a year, or more ambitiously still, to conserve enough capacity to allow a

landfill to remain open for five additional years, thereby extending the time until a new land-

fill will be needed. As there are three MSW landfills that serve the city of Milwaukee, it is

98

unknown which of them has experienced the greatest reduction in the disposal of food residu-

als because of composting. The Orchard Ridge Composting Facility has served to directly re-

duce the disposal of food residuals at the landfill there.

Goal 2: Reduce Greenhouse Gas Emissions. By diverting food waste from landfills,

a net reduction of GHG emissions is being achieved. Per the EPA WARM study, for every

ton of food waste composted, 0.71 MTCO2E are reduced compared to the same amount land-

filled. When the compost is used as a soil amendment, 0.15 MTCO2E are further reduced.

With the total amount of food waste composted by the current infrastructure, this amounts to

a reduction of 5,848 MTCO2E (0.86 MTCO2E / ton food waste x 6,880 tons food waste)

GHG emissions.

As evidenced by the WARM data, GHG emissions can also be further reduced by the

development of a distributed composting infrastructure with composting sites closer to

sources of food waste. In a distributed composting infrastructure, the collection routes are re-

duced and the total hauling distance is also. If more sites are located within greater Milwau-

kee, specifically where there is a greater density of food waste generators, there will be a

greater net reduction in CO2 emissions from fossil fuel combustion.

The methods used for composting determine whether the operation will emit GHGs,

as well as the final form of emissions. Large decentralized commercial composting facilities

are touted for their use of state-of-the-art equipment which maximizes efficiency and reduces

the likelihood of anaerobic conditions in compost piles. Yet, the use of this equipment re-

quires fossil fuels and/or electricity which cause GHG emissions. Though, these emissions

are not great, ways to reduce them will support this goal.

99

Smaller-scale composting operations, particularly those that rely on human labor will

have less or emissions from equipment. At the same time these sites are not always suffi-

ciently managed. Thus, anaerobic conditions can occur, resulting in the release of CH4 and

other GHGs from compost bins and piles. While individual compost sites on this scale do not

contribute many emissions on their own, the number of backyard and community garden

composting sites in a mid-size city could. Therefore, it would be appropriate for public edu-

cation about the problem of anaerobic compost piles and how to prevent it to accompany pro-

motion of backyard or community composting sites.

Considering there are several small-scale composting sites in the city of Milwaukee

located at community gardens, the system can become more decentralized if more food waste

were diverted to them. Yet, these sites are mostly for the management of garden waste, with

a small number of gardeners contributing food scraps. They were not originally intended, and

may not currently have the capacity, to accommodate large volumes of food waste. That said,

further development, and subsequent management of them could make them suitable food

waste composting sites.

Goal 3: Waste Reduction and Materials Recovery. The amount of plant nutrients in food

waste is quantifiable. In fact, a figure for the volume of plant nutrients contained in the

amount of food wasted generated by a city of one million has been calculated (Kort, 2016).

These nutrients have value as they can be utilized to grow fruits and vegetables. In many

cases, the compost can be used for food production in the same communities that generate

the food waste; making a closed loop system. This produces a local resource while reducing

100

transportation and associated GHG emissions previously discussed. In the case of food resid-

uals, these materials are a resource up until the point in which they are disposed of in a land-

fill.

In Greater Milwaukee, food waste is being turned into compost. Thus, this goal is be-

ing met. At present, there is no indication the supply is not meeting demand but this is not to

say further opportunities to utilize compost do not exist. Nevertheless, landfilling food waste

is still the status quo in Greater Milwaukee. Of the 47,000 tons of food waste generated in the

city of Milwaukee alone, only a fraction is being diverted as evidenced by what composters

and anaerobic digesters are receiving.

This is to say, while the creation of compost from food waste is enough to meet this

goal, the benefits of compost as a soil amendment for applications in urban environments can

lead to the achievement of additional goals. The use of compost in community food produc-

tion for one. For example, Cream City farm is located on Milwaukee's North side in the

30th Street Corridor. In its infancy, Cream City Farms needs compost to improve the fertility

of its soil to be able to increase production of fresh vegetables.

In the second category of goals for food waste composting, Use of Finished Compost,

the extent of the benefits from using compost can be described. It was beyond the scope of

this research to explore the markets the compost produced by the infrastructure reaches,

therefore an analysis of the extent to which the system meets these goals will not be done

here. Nevertheless, setting these goals can be invaluable to gaining public support of food

waste composting as well as meeting other sustainability goals.

101

VI. Conclusion

This case study has illustrated the extent of food residuals composting in Greater

Milwaukee. Major findings include the volume of food residuals being composted by the sys-

tem, the capacity of the system to accept and process these materials, and the amount of com-

post produced from food residuals on an annual basis. In carrying out this study, new com-

post sites have been discovered and/or licensed to process food residuals. Additionally, other

destinations for food waste were discovered. Due to time constraints, this case study only re-

ports on the compost sites initially identified as components of the food residuals composting

system.

This study has provided insights into the characteristics of the entire system in addi-

tion to insights into the individual components of the system such as composting sites and

food residuals haulers. At present the entire food residuals composting system is only com-

posting a volume akin to 6 - 13% of the annual amount of food waste generated in Milwau-

kee; not all this material comes from the city of Milwaukee.

The study revealed three businesses that collect food residuals which the composting

sites rely on. Compost Crusaders, Compost Express, and Sanimax all actively collect food

residuals for composting sites. At the time of this study Sanimax and Compost Crusaders

were collecting the most food residuals respectively. Maximizing route efficiencies and en-

suring contamination free food residuals were identified as challenges to increasing food

waste diversion to composting.

It was found that the largest food residuals composting site, Blue Ribbon Organics,

receives and composts the most food residuals of all sites. Based on this finding, the system

is characterized as centralized. This has implications for the resilience of the system (if this

102

site discontinues operations, it significantly reduces overall capacity). Other sites either do

not compost food residuals from Milwaukee, or their capacity is such that they do not com-

post very much food residuals, or produce very much compost, compared to Blue Ribbon Or-

ganics. As new food residuals composting sites emerge, this centralization may become re-

duced in time, the extent to which is not presently clear because not all plans are well

known.

In relation to the centralization, it was found that the long hauling distances required

to transport food residuals to Blue Ribbon Organics causes anthropogenic GHG emissions of

CO2 which offsets some of the reduction in GHG emissions that comes from diverting the

material from landfills. To maximize the reduction in GHG emissions a more distributed sys-

tem is necessary, one that minimizes the distance between sources of food waste and com-

posting sites. This will be possible with more neighborhood and community-scale sites

throughout the city, or if existing sites in the city of Milwaukee increase their capacity.

Though recently licensed sites could increase the distribution and capacity of the food waste

composting system, only one new site is within Milwaukee County, where it is presumed the

largest portion of food residuals are generated. Additional research is needed to determine the

most appropriate distribution of food waste composting sites.

Based on the processing volume capacities of the identified composting sites, the total

capacity of the food waste composting system remains well under that needed to compost all

food residuals generated in the city of Milwaukee, without even considering Greater Milwau-

kee. This finding was reached by determining the size and location of composting sites and

their individual capacity to accept and compost food waste, and thereby the sum capacity of

103

the system. The capacity of the system, including only the composting sites that were ini-

tially a part of this study, is sufficient to divert 20 – 42 % (9,400 – 19,740 tons) of the annual

amount of food waste generated in Milwaukee.

Further development of the system will be necessary if increasing diversion rates of

food residuals are to be composted. If further development of the system does not occur,

there will come a point where food waste diversion volumes will equal the capacity. Thus,

this is becoming yet another driving factor for new food residuals composting sites, or in-

creased capacity of existing sites.

It was also found that there is significant infrastructure for the composting of yard re-

siduals. This existing infrastructure may play a role in the future development of the food

waste composting system, though there are barriers to this occurring. One barrier would be

for these sites to become licensed to process food residuals, which would require site modifi-

cations in some instances. Another barrier is the identification of sources of food waste that

could provide an adequate supply of feedstock. The extent of interest in composting food re-

siduals by these composting sites is unknown and an area for further research.

To a limited extent, the types of food residuals (and other organics) collected, and

challenges to increased rates of diversion, have been revealed, though there is still more to be

learned about where, why, and what kind of food residuals are being disposed of or recov-

ered. One identified challenge is with the collection of post-consumer food waste which is

more likely to contain contamination presenting problems at the composting site. Existing so-

lutions to composting post-consumer food waste could reduce the likelihood of this becom-

ing a limiting factor for the system, but these solutions have yet to be widely implemented.

104

The food residuals composting system has experienced growth in the last decade.

More food waste generators are becoming interested in diverting their food waste from land-

fills, because of their interest in sustainability among other reasons. Half of the food residuals

generated in Milwaukee is post-consumer food waste but a city-wide residential curbside col-

lection program has not been put in place to compost this material. This is due to several rea-

sons, one of which is the perception, confirmed by this study, that the food residuals com-

posting system could not support such program. The continued growth of the food residuals

composting system depends on an increase in the food waste diversion rate. While an in-

creased diversion rate was found, it is not to the extent of what is possible or needed to sup-

port growth.

Another important finding is that the food residuals composting infrastructure is nas-

cent. Blue Ribbon Organics has operated on the current scale less than ten years. It has been

licensed to compost SSCM i.e. food waste since 2010 and yard residuals since 2008. Orchard

Ridge Composting Facility, the other large commercial composting site, has only been com-

posting food residuals for two years. Other sites have only become licensed to compost food

waste in the last two years but have not begun composting this material yet. This puts in per-

spective the current capacity of the system. This finding will prove useful for similar studies,

especially considering it was found that the system has the potential for significant growth.

In as much, small-scale composting sites in the city of Milwaukee play a part in di-

verting food waste as well as educating the public about issues of food waste, the benefits of

composting, and how to compost. These are necessary aspects of a successful food residuals

composting system. Still, these sites lack the capacity to compost on the scale of other sites

outside of the city like Blue Ribbon Organics. This lack of capacity is defined both by the

105

small size of the land available to compost on at each site and the small staff and volunteers

who operate the sites. Therefore, these are two issues these sites can address to increase their

capacity.

The sum compost production rate of the system was also determined. Annually, com-

post produced from food residuals in Greater Milwaukee amounts to 7,700 cubic yards. Of

this, only about 2,000 cubic yards, produced by Blue Ribbon Organics is sold commercially.

Orchard Ridge Composting Facility produces 2,700 cubic yards but this compost is only sold

on-site. This may change as this site has recently come under the management of Purple Cow

Organics. Implications of the quantity of food waste compost produced are not clear as a

study of composting markets and sales was not performed. Such is needed to fully under-

stand the economy for this compost.

While it was outside the bounds of this research to examine destinations for food

waste other than composting, anaerobic digesters and a livestock farm were identified. In ad-

dition to diverting food waste, anaerobic digesters can provide feedstock, digestate, for com-

posting sites. As does the livestock farm, anaerobic digesters rely on food waste haulers to

deliver food waste, though none of haulers identified in this study currently do. These alter-

native destinations can be considered as part of the system to divert food waste from land-

fills. Knowing how much food residuals are diverted to these destinations, or are otherwise

recovered by efforts provided by the US EPA’s food recovery hierarchy, will allow for a bet-

ter estimation of the amount of food waste available for composting. Determining this is thus

another area for further research.

106

This case study has illustrated the current state of the food waste composting system

in Greater Milwaukee. The systems approach to study the food waste composting infrastruc-

ture employed here will be useful in carrying out similar studies elsewhere. Depending on the

scope and scale of such a study, modifications can be made to focus on components of the

system. In doing so, as was achieved here, steps to be taken to support further development

of the system will be revealed.

107

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emption. (No. WA 1025). State of Wisconsin Department of Natural Resources.

80. Yepson, R. (2012). Residential food waste collection in the U.S. Biocycle, January, 23.

https://www.epa.gov/warm

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Appendix A.

Composter Survey

The purpose of this survey is to determine the state of the current composting infrastructure

in Metro Milwaukee. Please answer all questions to the best of your ability. Before entering

this survey, please indicate that you have read the consent form, you are age 18 or older and

that you voluntarily agree to participate in this research study.

* Required

1. Email address *

2. Do you agree to participate in this research? *

Here's a link to the consent form.

______Yes

______No

3. How long have you been composting? *

4. Please select the option below that best describes your organization? * Check all that

apply.

______Non-profit

______For profit

______Public

______Other

5. Is composting your organization's primary activity? If not what is?

6. In regard to receiving feedstocks, do you:

______Do your own hauling

______Charge tipping fees

______Both haul and charge tipping fees

______Neither haul nor charge tipping fees

7. Can you provide an average of the total quantity of feedstocks you take in monthly? *

https://docs.google.com/document/d/1Gn4zEe8PSYADdkH4To8Xra5NZjgeItnSnXoL1QcqosE

114

8. How much of your feedstocks are food waste? * What percentage?

9. Do you accept pre-consumer food waste, if yes how much? * What percentage or

weight?

10. Do you accept postconsumer food waste, if yes how much? * What percentage or

weight?

11. Which of the following food waste generator types do you accept from? *

Mark only one.

______Restaurants and/or cafes

______Grocery Stores

______Colleges, Universities, or Schools

______Corporations

______Food Processors or Manufacturers

______Convention or Sports Venues

______Other

12. Which methods do you use to compost? *

Check all that apply.

_______Windrows Static Pile

_______Aerated Static Pile

_______Passively aerated static pile

_______In-vessel

_______Bin (Hot Box)

_______Other:

13. Which of the following equipment do you use in your operation? * Check all that ap-

ply.

_______Skid Loader

_______Frontend Bucket Loader

_______Dump Trucks

_______Tracker

_______Windrow Turner

_______Screener

_______Shredder

_______Rototiller

_______None of the above

_______Other

14. How much compost (tonnage) do you produce per year? *

15. How much compost (cubic yards) do you produce per year? *

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16. What is the average bulk density of your compost?

17. Do you have a peak time of year for compost production? If yes, please describe.

18. Do you test your finished compost? Mark only one oval.

_______Yes

_______No

19. If you answered yes to the previous question, which parameters do you test for? Check

all that apply.

_______Nutrients

_______pH

_______Moisture

_______Maturity

_______Organic matter content

_______Soluble Salts

_______Bulk Density

_______Heavy Metals

_______Other

20. Do you intentionally produce unique compost products for different applications? If

yes, please explain.

21. What is the address of your composting operation(s)? * Please provide street address,

city, and zip code.

22. Do you have more than one site that serves metropolitan Milwaukee? Mark only one

oval.

_______Yes

_______No

23. What is the total acreage of the land your operation occupies? If multiple sites, please

describe each.

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24. How much of this land is dedicated solely to composting? * If multiple sites, please de-

scribe each.

25. Given your land and equipment, what percentage of your total capacity are you operat-

ing at? *

26. Do you have plans to expand your operation in the near future? * Mark only one oval.

_______Yes

_______No

_______Unsure

27. What is the number of employees supported by your composting operation?

28. How many volunteers, if any, do you rely on for your composting operation?

29. Where do you market and sell your compost? Check all that apply.

_______Milwaukee Area

_______Throughout Wisconsin

_______Throughout Midwest

_______Nationally

_______Other

30. How much of the compost you produce do you use on your own farm or for other ap-

plications? What percentage or weight?

31. How do you typically sell your compost? Check all that apply.

_______Bulk (cubic yard)

_______Bagged

_______Other:

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32. Are there state or local policies and/or regulations that present your operation(s) with

challenges? If yes, please explain.

33. Are there other significant challenges you perceive for your compost operation? * Such

as maintaining quality, consistent production, land, etc.

35. Why do you Compost? * i.e. environmental concerns, economic, social factors.

34. Please describe current opportunities you foresee for composters? *

Appendix B.

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