The Food Waste Disposer as a
Municipal Tool for Waste Diversion

An Evaluation in Five Cities
Project Overview by InSinkErator

This publication is based on an InSinkErator-sponsored review of 432 households over a three year
period and is provided for general informational and promotional purposes.
Municipalities that are considering alternative waste diversion
solutions are encouraged to consult with a qualified waste professional
to analyze and consider all potential options.

© 2016 InSinkErator, InSinkErator® is a business unit of Emerson Electric Co. All Rights Reserved.

The Food Waste Disposer as a Municipal Tool for Waste Diversion

Introduction
The results from fivecities conclude that foodwaste disposer use
reduced the amount of
discarded food waste bymore than 30%, or about
one-third. At that rate,
after a 3-year period
of disposer use, nearly afull year’s worth of foodwaste would be kept
out of landfills.

From 2012 to 2015, InSinkErator® initiated partnerships with five major cities acrossthe United States in order to assess the viability of using food waste disposers
as a municipal tool to manage food waste and accomplish what is known as“resource recovery.”
These initiatives were launched to determine the impact of food waste disposers on
reducing the volume of food waste discarded into the trash by a household. The five-city
initiatives also sought to assess quality of life impacts on households and to measuremunicipal cost savings as a result of diverting a portion of food waste from landfills.
In short, the results were significant.
Experts examining data collected during the InSinkErator initiatives estimate that in thecourse of a week, discarded food waste decreased by about 30% in the areas measured.
At that rate, after a 3-year period of disposer use, about a full year’s worth of food waste
would be kept out of landfills.
This report provides a wide-range view of the results from initiatives in Philadelphia,
Chicago, Tacoma, Milwaukee and Boston, which affected 432 households and thelives and behaviors of the residents living in them. It presents results that provethe value of food waste disposers extending beyond the home, to surrounding
neighborhoods, greater metro areas and regions as a whole.
InSinkErator is proud of the initiatives summarized in this report. This undertaking —a unique public-private partnership of dedicated, creative and hard-working people —was made successful by the efforts of citizens and officials ranging from municipal
executives and policy makers to staff and block captains, from community
development groups and volunteers to plumbers.
Not to mention, the participants who opened their homes and kitchens to us.

2

An Evaluation in Five Cities

Project Overview by InSinkErator© 2016 InSinkErator, InSinkErator® is a business unit of Emerson Electric Co. All Rights Reserved.

The Food Waste Disposer as a Municipal Tool for Waste Diversion

Background
According to the United States Environmental Protection Agency (USEPA) food waste
is the largest percentage of municipal solid waste after recycling, with 35 million tons
discarded each year. But with a disposer present in about half of all U.S. homes, there
is an opportunity for local governments to leverage the installed base of food waste
disposers to help reduce the volume of solid waste collected, hauled and disposed.

In areas served bycapable treatment
plants, disposers may
be an aid to resource
recovery resulting in
renewable energy andfertilizer recycledfrom food waste.

Because disposers convert food scraps into liquid slurry for transport via sewers to
local wastewater treatment plants or septic systems, they may also serve as an aid toresource recovery of clean water, renewable energy and fertilizer at capable plants.

2013 Composition of Municipal Solid Waste
Discarded in the U.S. (EPA 2015)*

yard
trimmings
8%

wood
8%

metals
9%

glass
5%

other
4%

food 21%

rubber,leather &textiles12%

paper &
paperboard
15%

plastics
18%*After recycling
and composting2

3

An Evaluation in Five Cities

Project Overview by InSinkErator© 2016 InSinkErator, InSinkErator® is a business unit of Emerson Electric Co. All Rights Reserved.

The Food Waste Disposer as a Municipal Tool for Waste Diversion

Project Description
To gauge the effect disposers can make on discarded waste, InSinkErator® measured
the reduction in food waste after installation of a disposer in homes previously withoutone. Each of the five cities was chosen because it shared the goal of organics diversion
from the solid waste stream and increasing resource recovery at their wastewater
treatment plant.

The Project Steps:
Philadelphia’s mayor
helped kick off the media
campaign to encourage
and educate residents on
the use of disposers.

1

2

city
selectionneighborhood
selection

8

summaryreport3 pre-

installation
waste study

7

participant
survey6

Mayor Michael Nutter

4

4

disposerinstallations

postinstallation
waste study

An Evaluation in Five Cities

5

education& outreach

Project Overview by InSinkErator© 2016 InSinkErator, InSinkErator® is a business unit of Emerson Electric Co. All Rights Reserved.

The Food Waste Disposer as a Municipal Tool for Waste Diversion

Participants & Timeline
InSinkErator® representatives met with city officials in each city to select theneighborhoods in which to conduct the study. For statistical reliability, a goal ofninety (90) participants in each neighborhood was set, the minimum was set at 70.
Both goals proved to be a challenge given the widespread adoption of disposers in
the U.S. In Philadelphia, two neighborhoods in close proximity were chosen as one
large sample. In Boston, even though a smaller sample size was settled upon, every
unit of the apartment complex received a disposer. In Tacoma, 90 homes agreed toget disposers, but fewer (63) eventually received them due to typical neighborhood
turnover. In Chicago, while two areas were originally selected, one neighborhood
was dropped due to low participation. Each participating household received acomplimentary disposer and installation.

Neighborhood Participation by City
City

Neighborhood

Participating Households

Philadelphia, Pennsylvania

Point Breeze & West Oak Lane

173

Tacoma, Washington

Wapato Lake

63

Milwaukee, Wisconsin

Burnham Park

96

Boston, Massachusetts

Thomas Atkins Apartments

48

Chicago, Illinois

Maple Park

52

Timeline of Municipal Projects
2012

2013

2014

2015

Philadelphia (April 2012 to September 2014)
Tacoma (September 2012 to November 2014)
Milwaukee (July 2013 to Dec 2014)
Boston (April 2013 to May 2015)
Chicago (August 2012 to June 2015)

5

An Evaluation in Five Cities

Project Overview by InSinkErator© 2016 InSinkErator, InSinkErator® is a business unit of Emerson Electric Co. All Rights Reserved.

The Food Waste Disposer as a Municipal Tool for Waste Diversion

Waste Diversion – Results and Impacts
Generation rates of municipal solid waste vary greatly from region to region,and even within a given location due to culture, diet, economics and other factors.
Consultants specializing in waste characterization were hired for the project evaluation,
which included a series of waste measurements before and after the installation of disposers.

Professional Waste Consultants Utilized
Philadelphia, Pennsylvania

Mid Atlantic Solid Waste Consultants

Tacoma, Washington

Cascadia Consulting Group

Milwaukee, Wisconsin

Mid Atlantic Solid Waste Consultants

Boston, Massachusetts

Mid Atlantic Solid Waste Consultants

Chicago, Illinois

CDM Smith

Project Results Weekly Household Waste Generation
Waste consultants
concluded that on
average, after the use of
disposers, food waste in
the trash was reduced
by about 30%.*
The estimated amount offood waste processed bydisposers was 1.4 to 4.1
pounds per household
per week.

Total Garbage (baseline)

Food Waste (before disposers)

Food Waste (after disposers)
21.9 lbs.

Philadelphia
4.1 lbs.

1.4 pounds REDUCTION
per household per week

2.7 lbs.

Tacoma25.7 lbs.
7.6 lbs.

1.9 pounds REDUCTION
per household per week

5.7 lbs.

Milwaukee

43.8 lbs.
12.1 lbs.

3.3 pounds REDUCTION
per household per week

8.8 lbs.

Boston38.5 lbs.
11.9 lbs.

4.1 pounds REDUCTION
per household per week
Chicago neighborhood notincluded – insufficient data

7.8 lbs.

0

10

20

30

40

*Reductions were calculated by measuring the food waste in the garbage.
The actual amount of food waste processed by disposers not available.

6

An Evaluation in Five Cities

Project Overview by InSinkErator© 2016 InSinkErator, InSinkErator® is a business unit of Emerson Electric Co. All Rights Reserved.

The Food Waste Disposer as a Municipal Tool for Waste Diversion
Th

The potential anticipated environmental implications of city-wide disposer use are shown
below. By projecting the waste characterization data from each neighborhood to thebelowhole city for a year, the total potential diversion was calculated for illustration purposes.
who
Then, using a proprietary tool developed for InSinkErator® the potential reduction ofThegreenhousegree
gas emissions due to food waste diversion was calculated. The potential
increaseincr
in methane production at the wastewater treatment plant was also estimated.
Each
Eac of the cities employed anaerobic digestion when the project was initiated.

Potential Environmental Implications
Total
Current
Food waste
number of disposer
diverted perhouseholds adoption
householdrate(pounds/week) citywide

Potential
mass of foodwaste diverted(tons) per year

Current
Reduction of
Additional
solid waste
greenhousemethanemanagement
gas emissions
production(MT of CO2e per year) (ML per year)
systemPhiladelphia, Pennsylvania

1.4

580,01749%

21,113waste-to energy

290

2,332

Tacoma, Washington

1.9

78,44767%

3,875

landfill

4,770

428

Milwaukee, Wisconsin

3.2

440,000

52%

36,608

landfill

10,6004,040

Boston, Massachusetts

4.1

890,000

55%

94,87433% landfill& 67% WTE

11,90010,479Chicago, Illinois

NA

1,028,746

34%

NA

landfill

NA

NA

InSinkErator has not determined if citywide use is feasible; potential adoption rates should beconsidered when reviewing this report.

Results – Social & Quality of Life Impacts
Assessments were madevia surveys, phone calls
and focus groups, inaddition to conversations
with community leaders,volunteers andblock captains.

7

For disposers to be considered a valid “tool” for cities to use in managing food waste,
the residents must accept using them and be willing to incorporate them into daily
behaviors. We questioned participants – each of which receiving a complimentary
disposer and installation – about their satisfaction with disposers and any changes within
the household and neighborhood about waste and reduction in pests, rodents andsmells. Participants were also asked if they would recommend a disposer to a friend or
relative and how likely they were to replace it at the end of its useful life.
These assessments were taken via surveys, phone interviews and focus groups,
in addition to conversations with community leaders, volunteers and block captains.

An Evaluation in Five Cities

Project Overview by InSinkErator© 2016 InSinkErator, InSinkErator® is a business unit of Emerson Electric Co. All Rights Reserved.

The Food Waste Disposer as a Municipal Tool for Waste Diversion

Outreach & Education

Outreach ran the gamut
from letters to flyers togarbage truck wraps.

Residents needed to be informed how to use disposers and what to grind. The
installing plumber initiated this education at the time of install. All residents
were later sent educational materials a minimum of eight times over the course of
the months following installation. InSinkErator® Customer Service also phoned theresidents. Materials were delivered via U.S. mail or face-to-face via door-knocking or atneighborhood parties and get-togethers. In Philadelphia, a media campaign followed
the initial announcement of the program at a press conference sponsored by themayor’s office, generating numerous news stories. Radio ads, and robo-calls fromthe mayor’s office were other forms of outreach employed.

In their surveys, residents said that, after the plumber, the most effective educational
outreach came through neighborhood groups and volunteers.

8

An Evaluation in Five Cities

Project Overview by InSinkErator© 2016 InSinkErator, InSinkErator® is a business unit of Emerson Electric Co. All Rights Reserved.

The Food Waste
W
Disposer as a Municipal Tool for Waste Diversion

Methodology
M
ethod
To
o establish
esta
stab
ablilish a baseline, participants completed a survey assessing food waste
habits
h
ha
bits
bi
ts a
att tthehe b
beginning of the project, before disposer installation. A second survey
was
wa
as co
ccompletedom
mp
pleted at the end of the study, a few months after installation. This timing
wasw
wa
as set
set ttoseo give residents opportunity to become familiar with the appliance andputtingpu
utttining food
food wastew
down the drain.

ResidentResiden Populations Measuredof populations were included in the study, ranging from a 48-unit
A variety oapartment building of diverse, moderate income families in Boston to an urban,
apartme
Hispanic neighborhood in Milwaukee.
HispanTwo focus group sessions were conducted in Philadelphia among project
participants which provided additional insights beyond those revealed byparthe surveys.
thSurvey Response Rates
A variety of
populations were
included. The
neighborhoods wereselected with theassistance of thecity teams.

Households Surveyed & Response Rates

Sent Survey

Returned Survey

Response Rate

Philadelphia, Pennsylvania

173

75

39%

Tacoma, Washington

63

41

68%

Milwaukee, Wisconsin

96

27

28%

Chicago, Illinois

52

19

37%

Boston not included due to insufficient data

9

An Evaluation in Five Cities

Project Overview by InSinkErator© 2016 InSinkErator, InSinkErator® is a business unit of Emerson Electric Co. All Rights Reserved.

The Food Waste Disposer as a Municipal Tool for Waste Diversion

Disposer Installation
In order to facilitate confidence and satisfaction and to encourage participants togrind all their food waste, InSinkErator® installed advanced performing Evolution
PRO Compact® models. The project was put out for bid through local chapters of
Plumbing Heating Cooling Contractors (PHCC) national association, which ultimately
referred plumbers to InSinkErator. In Philadelphia and Boston, two of the plumbers
hired were referred by the community development organizations.

Participant Satisfaction and Quality of Life

Evolution PRO Compact®

Participants were overwhelmingly happy with the use of their complimentary
disposers, reporting they reduced trash disposed, made kitchen clean up easier,reduced odors and smells in the house and neighborhood, and limited vectors andpests. Participants reported that disposer use had a very positive impact on their lives.
Comments made about the program included, “It was a blessing to me” and “Once you
have a disposer you can’t live without one.”

Satisfaction of Project Participants,“Are you satisfied with how the disposer works?”*“Once you have a disposer
you can’t live without one.”- Project Participant

Responses by City

Philadelphia,
Pennsylvania

Tacoma,Washington

Chicago,Illinois

Milwaukee,
Wisconsin

Very Satisfied

92%

90%

79%

93%

Somewhat Satisfied

7%

10%

16%

4%

Somewhat Dissatisfied

1%

0%

11%

4%

Very Dissatisfied

0%

0%

5%

0%

*Participants received a free disposer and installation.

10

An Evaluation in Five Cities

Project Overview by InSinkErator© 2016 InSinkErator, InSinkErator® is a business unit of Emerson Electric Co. All Rights Reserved.

The Food Waste Disposer as a Municipal Tool for Waste Diversion

The disposer also provided benefits beyond reduced trash: other benefits included
cleaner streets, less rodents and other animals going through trash, fewer bugs andpests and healthier kitchens. Residents also reported no longer needing to freeze
their garbage until trash day, a common practice.

Benefits of Disposer Use:
“What was the best part of having a disposer?”*
Responses by City

Philadelphia,
Pennsylvania

Tacoma,Washington

Chicago,Illinois

Less trash

68%

68%

68%

Cleaner kitchen

55%

65%

21%

Less smells in kitchen

62%

60%

47%

Fewer bugs or pests

42%

38%

5%

Got me to recycle more

30%

25%

42%

Improved value of my home

27%

35%

16%

None

0%

0%

5%

Other

4%

3%

0%

After their complimentary disposer was installed by InSinkErator, most participants
reported using the disposer for all or nearly all of the food scraps that werepreviously disposed of in the trash. The majority of respondents reported that theyalmost always use the disposer when preparing meals or cleaning up after them.

Overall Disposer Impacts on Food Disposal:“How do you manage food waste at home?”*Most food scraps were now
going down the disposer.

Change in Food Scrap Diversion

Philadelphia,
Pennsylvania

Tacoma,Washington

Milwaukee,
Wisconsin

Put pretty much all food scraps in the disposer

74%

74%

33%

Put about half the food scraps in the disposer

14%

15%

56%

Put a little of the food scraps in the disposer

7%

5%

4%

(%of Total)*Participants received a free disposer and installation.

11

An Evaluation in Five Cities

Project Overview by InSinkErator© 2016 InSinkErator, InSinkErator® is a business unit of Emerson Electric Co. All Rights Reserved.

The Food Waste Disposer as a Municipal Tool for Waste Diversion

Decrease in Trash Disposal:“After you started using your disposer, which of the following applies?”*30%

Approximate reduction
in trash disposed.

Responses by City

Philadelphia,
Pennsylvania

Tacoma,Washington

Milwaukee,
Wisconsin

Trash decreased a lot

58%

46%

56%

Trash decreased a little

29%

36%

33%

No difference in trash

12%

18%

4%

Trash increased a little

1%

0%

4%

Trash increased a lot

0%

0%

0%

Average number of bags set out Pre- vs. Post-Installation
Weekly Household Waste
Philadelphia Average Bags

Pre-Disposer

Post-Disposer

Tacoma Average Bags

Pre-Disposer

Post-Disposer*Participants received a free disposer and installation.

12

An Evaluation in Five Cities

Project Overview by InSinkErator© 2016 InSinkErator, InSinkErator® is a business unit of Emerson Electric Co. All Rights Reserved.

The Food Waste Disposer as a Municipal Tool for Waste Diversion

80%

Approximate number ofparticipants who would
recommend a disposer to afriend or family member.

Perhaps the most significant measure of satisfaction with disposers as a kitchen
tool was summed up by the willingness of participants to recommend one.

Willingness to make personal recommendation
to friend or family member*Philadelphia,
Pennsylvania

Tacoma,Washington

Yes, definitely would recommend to friend / family

80%

76%

Yes, probably would recommend to friend / family

18%

50%

No, would not recommend to friend / family

3%

22%

Additional Information Gathered
Participants reported that they now put all or nearly all of the acceptable food scraps
down the disposer on a regular basis. They said they use the disposer for items suchas peelings, fruits, vegetables, egg shells, grains, dairy and even for small bones,(fish and chicken) and seafood shells (shrimp and crab).
Structural barriers and property ownership present challenges. Focus group
participants reported that one of the barriers faced by neighbors who wanted toparticipate in the study was the need for major plumbing work in order to installa disposal. Not being the property owner was cited as another barrier.

*Participants received a free disposer and installation.

13

An Evaluation in Five Cities

Project Overview by InSinkErator© 2016 InSinkErator, InSinkErator® is a business unit of Emerson Electric Co. All Rights Reserved.

The Food Waste Disposer as a Municipal Tool for Waste Diversion

Conclusions and Outlook
As a result of the municipal partnerships described in this report, resident behavior wasaffected in ways resembling acceptance and compliance with recycling and composting
programs.2 But we believe disposers are capable of much greater diversion, and even“experienced” users tend to under-utilize them.
A city may be able to realize significant potential savings when its residents use a disposer
to manage organic waste. These savings include – but are not limited to – transport andtipping fees and the potential for increased biogas generation at treatment plants.
Potential non-monetary benefits include cleaner, more pleasant cities largely free ofodorous, rotting organic waste and the pests it attracts to neighborhoods. There is also
potential for decreased greenhouse gases due to less transported waste in landfills.
Many – if not most – of these savings can be estimated. As an example, in Milwaukee, theuse of food waste disposers to divert 36,600 tons of food scraps to a wastewater plantwith anaerobic digestion could result in the reduction of approximately 10,600 MT of CO2eof greenhouse gas emissions and would be equivalent to removing 2,200 cars from theroad for one year. The biogas produced from the anaerobic digestion of those food scraps
could produce enough electricity to power 1,290 homes per year using GHG equivalencies
by the USEPA.
The cost of first-time disposer installation in existing housing, some of which is electrical,
prompted InSinkErator® to cover installation costs. To overcome the first-time installation
challenges, discussions continue regarding building code changes to mandate disposer
installation in new residential construction and city-owned housing. Following the project’s
conclusion in Philadelphia, disposers were included in a building code as one option forproperty owners to comply with solid waste management.3

1
Skumatz and Freeman. 2011. “Best Management Practices in Food Scraps Programs.” U.S. EPA.
http://www.foodscrapsrecovery.com/epa_foodwastereport_ei_region5_v11_final.pdf
2

U.S. EPA. 2015. “Advancing Sustainable Materials Management: 2013 Fact Sheet.
http://www.epa.gov/osw/nonhaz/municipal/pubs/2013_advncng_smm_fs.pdf

3City of Philadelphia. 2015. The Philadelphia Code - PM-308.3.1 Garbage facilities. American Legal
Publishing Corporation. http://www.amlegal.com/nxt/gateway.dll/Pennsylvania/philadelphia_pa/
title4thephiladelphiabuildingconstructio/subcodepmthephiladelphiapropertymaintena/chapter3generalr
equirements0?f= templates$fn=default.htm$3.0$vid= amlegal:philadelphia_pa$anc=JD_PM-308.3.1

14

An Evaluation in Five Cities

Project Overview by InSinkErator© 20152016 InSinkErator, InSinkErator® is a business unit of Emerson Electric Co. All Rights Reserved.

clean kitchen
green community
RECYCLE YOUR FOOD WASTE • USE A DISPOSER

This publication is based on an InSinkErator-sponsored review of 432 households
over a three year period and is provided for general informational andpromotional purposes. Municipalities that are considering alternative waste diversion
solutions are encouraged to consult with a qualified waste professional
to analyze and consider all potential options.

Food waste disposers can provide an environmentally responsible alternative totransporting food waste to landfills. And they can help reduce greenhouse gas emissions.
At capable wastewater treatment plants, food waste can be recycled into renewable energy.
Additionally, capable wastewater treatment plants can process food waste into fertilizer.
(Check the plant in your area.)

The Emerson logo is a trademark and service mark of Emerson Electric Co.
The mounting collar configuration is a trademark of Emerson Electric Co.

1.800.558.5700
www.insinkerator.com

InSinkErator may make improvements and/or changes in the specificationsat any time, in its sole discretion, without notice or obligation andfurther reserves the right to change or discontinue models.
© 2016 InSinkErator, InSinkErator® is a business unit of Emerson Electric Co. All Rights Reserved.