Alternative Management of Organic Waste in

Chatham-Kent, Ontario, Canada

Alexis Blair, Graeme Hollands, Kylee McIntosh, Adriana MacDonald, Bhumi Mehta, Honorio Umali, Sheree Pagsuyoin

University of Waterloo, acblair, gholland, k3mcintosh, anmacdon, bgmehta, hjumali, spagsuyoin@uwaterloo.ca

Abstract - The municipal solid waste collected from

Chatham-Kent is currently disposed to the Ridge

Landfill in Blenheim, Ontario. Although the

municipality implements recycling, the program does

not include separate collection and processing of organic

food waste. This paper presents an economic evaluation

of composting alternatives for the organic food waste

collected from households in Chatham-Kent. A cost-

benefit analysis was performed for three scenarios: (i)

continuing the current system of landfill disposal, (ii)

backyard composting in detached dwellings, and (iii)

centralized collection and off-site composting in London,

Ontario. Results indicate that backyard composting is an

economically feasible alternative to landfill disposal. The

cost of backyard composting is comparable to landfill

disposal (2% lower at a 25% participation rate and 8% lower at full uptake), suggesting that long-term benefits

offset the initial investments on backyard composters.

Centralized composting is twice more expensive than

landfill disposal at all uptake rates. Despite the lower

initial cost of the collection bins compared to backyard

composters, the cost of waste collection and transport is

significantly higher for centralized composting. In terms

of waste diversion at full uptake, the centralized

collection of source-separated organics results in a 6%

increase in overall diversion rates compared to a 5%

increase for backyard composting. Further, landfill life

is extended by 16 years for the centralized composting

and by 12 years for backyard composting. The analytical

method employed in this study can be applied to other

regions exploring similar decision options on

composting. The decision criteria presented in this paper

can be expanded and modified to accommodate regional variability such as access to facilities, materials costs,

and social acceptability.

Index Terms – Organic waste, Backyard composting,

Centralized waste collection, Cost analysis

INTRODUCTION

The municipality of Chatham-Kent is located in

Southwestern Ontario, Canada. It is bordered by Lake St. Clair to the west and by Lake Erie to the south and

southeast. The municipality is mostly rural; its largest

population centers are the districts of Chatham, Blenheim,

Wallaceburg, Ridgetown, Dresden, and Tilbury. The

municipality’s population in 2011 was 104,075 (42,840

households, of which 32,900 live in single-detached

dwellings) [1].

The municipal solid waste (MSW) collected from

Chatham-Kent consists of wastes from residential,

commercial, institutional, industrial, and construction

sectors. The collected waste is disposed to the Ridge

Landfill, a privately owned facility in Blenheim, Ontario. In

2013, 31,500 metric tonnes of MSW were landfilled. Waste

diversion is currently below the 60% target specified in the

Ontario Waste Diversion Goal, and is implemented only for

recyclables and seasonal yard waste. Although the

municipality hopes to achieve this target in the future, there

are no immediate plans for diverting residential source-

separated organics (SSO) [2].

This research evaluates the economic feasibility of

establishing a waste diversion program for residential food waste in Chatham-Kent. Two alternatives, backyard

composting and centralized composting, were compared

with the current practice of landfill disposal. Backyard

composting involves utilizing a composter purchased from

any major retail vendor. The resulting compost material is

intended for personal use and is considered an equivalent of

commercially available fertilizer. Due to waste volume

considerations, this alternative is assumed to be feasible

only for single-detached houses. Centralized composting

involves curbside waste collection where the household puts

organic wastes into a designated bin provided by the

municipality, and places the bin at the curb alongside other

household wastes and recyclables. Dual compaction trucks

will be used to collect both organic and residual solid waste

using the current collection routes. Organic waste will be

stored at the transfer facility at Ridge Landfill for no longer

than three days, and then be transported to the nearest composting facility in London, Ontario. This alternative is

available to all households, including single-detached

houses and apartments.

METHODOLOGY

The two composting alternatives were evaluated at three

levels of participation or uptake rates: 25%, 50%, and

100%. A 25% uptake represents an initial phase for a

composting program while a 50% uptake represents an

established composting program. A 100% uptake indicates

a very successful program, and more importantly for this

study, it allows a conservative cost estimate for cases where

transportation costs are critical to the overall waste

diversion costs.

978-1-4799-4836-9/14/$31.00 (c) 2014, IEEE 74

I. Base Case Scenario

Currently, the Ridge Landfill contractors collect wastes in

Chatham-Kent using rear-end packer trucks equipped with both manual and hydraulic loading only for curbside

collection. Households have a weekly limit of 3 bags. All

populated districts have waste collection twice a week with

the exception Chatham’s downtown area, which receives

collection service thrice each week. The annual costs of

residential waste collection and disposal are $1,809,100 and

$1,120,800, respectively [2].

Cost comparisons among the base and two alternative

scenarios were done on an annual cost basis using a 5%

interest rate and project life of 20 years.

II. Backyard Composting Program

Backyard composting bins can be purchased at any major

home improvement store such as Canadian Tire, Home

Depot, Home Hardware, and Rona. Based on an on-line

survey, a 310-L (11 cubic ft) backyard composter retails for

about $60 to $63. Bins are assumed to have a service life of

5 years; new bins will therefore be purchased every five

years within the 20-year study period.

Cost savings due to the compost product from the

composters were estimated based on a few assumptions.

Firstly, it was assumed that no households currently utilize a

backyard composter (i.e., 0% participation). Secondly, it

was assumed that the value of compost from the composter is equivalent to commercially available soil ($0.38/kg).

Finally, it was assumed that mass losses for the food waste

in the bin are negligible so that the mass of incoming food

waste equals the mass of compost product.

Promotional and advertising costs were also included

in the cost analysis. Expenses considered include newspaper

ads and promotional flyers. Website design and

maintenance costs were not considered because it was

assumed that existing government websites are available at

negligible cost. Promotional expenses were assumed to only

be required in the first year of program implementation;

thereafter, public awareness was considered sufficient to not

require promotion.

III. Centralized Composting Program

The closest composting facility to Chatham-Kent is located

in London, Ontario 110 km east of Chatham. Cost data for

collection bins, curbside collection, and waste disposal were

assumed to be equal to the values obtained from the Region

of Waterloo [3]. The Region of Waterloo transports its

organic waste to Guelph (located 40 km away). The

transportation cost for organic waste is $2.8/km per metric

tonne.

As per the certificate of approval for the Region of Waterloo’s organics program, organic waste can only be

stored in the transfer facility for a maximum of 3 days.

Since curbside collection takes place on Mondays through

Fridays, transporting the waste to the London facility twice

a week is the best available option for Chatham.

A slightly higher one-year advertising cost was

allocated for the centralized composting alternative to

account for additional promotion in multi-dwelling units.

IV. Benefits of Composting

Waste diversion strategies have several environmental and

social impacts and benefits that can potentially be converted

into equivalent dollars. For the purpose of this study, only

those impacts that directly affect the cost of managing a

composting program were included in the analysis. These

metrics are: extension of landfill life and reduction in the

cost of leachate treatment [4]. The extension of landfill life

was calculated based on the volume of waste diverted from

the site due to the composting (organics diversion)

programs. The remaining life of a landfill is determined

from its estimated remaining capacity and loading rate. The loading rate is calculated from (1)

L = G/ SW – S*C/ S (1)

where L is the loading rate, G is the solid waste

generation rate, SW is the specific weight of solid waste, S is the organics diversion rate, C is the organics compaction

ratio, and S is the specific weight of organics.

The remaining life of the landfill is determined from (2)

R = ERC* SW / G (2)

where R is the remaining landfill life and ERC is the

estimated remaining capacity of the landfill.

The decrease in loading rate due to the diversion of

organics determines the extension of landfill life, shown in

(3).

Ext = ERC / L – R (3)

where Ext is the extension of landfill life.

In this study, the Ridge Landfill has an estimated

remaining capacity of 12,417,000 cubic meters [4].

The reduction in the cost of leachate treatment is

determined based on the water content of the diverted food

waste. It is assumed that all of the moisture in landfilled food waste becomes leachate at some point, thus the

moisture content of diverted food waste represents cost

savings in leachate treatment. The water content of food

waste is assumed to be 65%. The cost of leachate treatment

is $10.00 per cubic meter [5] [6] [7].

RESULTS AND DISCUSSION

I. Cost of Composting

Figure 1 shows the annual costs of the current landfill

disposal program and the backyard and centralized

composting alternatives for 25%, 50%, and 100% uptake.

For most new composting programs, it is expected that

participation in the early years of implementation will be

75

closer to 25%. With increasing environmental awareness,

participation rates will be closer to 50%.

FIGURE 1

COST COMPARISON OF THE CURRENT (BASE CASE) AND COMPOSTING

ALTERNATIVES

The net annual cost of continuing the current waste

management (landfill) program is $2.93 million, of which

$1.80 million is collection cost and $1.13 million is disposal cost. The net annual cost of backyard composting is slightly

lower than the cost of landfilling: $2.87 million (2% lower)

at 25% uptake, $2.81 million (6% lower) at 50% uptake, and

$2.69 million (8% lower) at full uptake. The net annual cost

of backyard composting includes cost savings on organics

collection and transport, and cost benefits from compost

production and leachate reduction. Annual cost savings

range from $0.03 million for the 25% uptake to $0.14

million for the full uptake. Cost benefits range from $0.14

million to $0.56 million.

Although the cost of backyard composting is only

marginally better than the current practice of landfill

disposal, other environmental benefits, which were excluded

from this economic analysis, can make composting more

economically beneficial. These benefits can include: better

air quality from reduced particulate emission, reduced

greenhouse gas emissions, and soil enrichment. The relative cost of backyard composting also suggests that long-term

benefits offset the initial investments on backyard

composters.

The net annual cost of centralized composting is

significantly higher than the cost of either landfilling or

backyard composting: $6.6 million (2.2 times higher than

landfill disposal costs) at 25% uptake, $7 million (2.4 times

higher) for 50% uptake, and $7.9 million (2.7 times higher)

for full uptake. The bulk of this cost is associated with

higher collection and disposal cost for a new waste

collection/transportation system compared to the cost for the

current system. At a 25% program uptake, collection and

disposal represents 93% of the net cost; this goes down to

78% at full uptake as more economic benefits result from

reduced requirements for leachate treatment. Although

collection bins have a lower initial cost ($14) compared to

backyard composters ($60), this price difference cannot

offset collection and disposal costs regardless of uptake

rates.

II. Waste Diversion Due to Composting

Table 1 summarizes the increase in waste diversion

and landfill life due to backyard and centralized composting.

The difference in waste diversion between the two

composting alternatives is due to the assumption that

composters are only feasible in single detached dwellings.

At full uptake, centralized composting results in an annual

waste diversion of 1900 metric tons or a 6% increase in

overall residential waste diversion rate. In comparison,

annual waste diversion for backyard composting is 1450

metric tons, or a 5% increase in overall waste diversion rate.

These diversion rates are significant in the context of

Ontario’s waste diversion target of 60%. Despite the existence of a recycling program for metals, glass, paper and

plastics, Chatham-Kent’s waste diversion is still below

60%. Diverting organic waste, which represents between

60% and 75% of residential waste, can result in substantial

increase in diversion.

TABLE 1

WASTE DIVERSION AND LANDFILL LIFE EXTENSION

%

Participation

SSO

Diverted

New Landfill

Loading Rate

Landfill Life

Extension

(MT per

year) (m

3/year) (years)

Backyard

Composting

25% 363 51,981 2.8

50% 726 51,357 5.7

100% 1,452 50,108 11.8

Centralized

Composting

25% 473 51,793 3.7

50% 946 50,980 7.5

100% 1,891 49,353 15.6

Increased organics diversion lowers landfill loading

rates, which in turn extend the landfill life. At full uptake, landfill life is extended by 16 years for the centralized

composting and by 12 years for backyard composting,

representing 7% and 5%, respectively, of the remaining

landfill life.

CONCLUSIONS AND RECOMMENDATIONS

Although centralized collection is expensive at this point,

the overall costs of composting can be lowered if the

organic waste can be processed at closer facilities, for example, in Sarnia City (60-km distance). Constructing a

new anaerobic digester in or near Chatham-Kent and Sarnia

can also be considered. A cost-benefit analysis is needed to

determine the economic viability of building and operating a

dedicated composting facility over disposal at existing

facilities. Facilities can also be jointly managed with other

municipalities to reduce capital and operational costs.

This study focused solely on residential food waste;

other excluded cost factors may be more critical in waste

decision analysis. Although organics are a large component

of residential waste, on a wider perspective, waste quantities

0

1000

2000

3000

4000

5000

6000

7000

8000

9000

25 50 100

An

nu

al

Co

st, $

(x

10

00

)

Participation Rate (%)

Base Case Backyard Centralized

76

from other sectors of the society can be substantially greater

than residential waste streams. To achieve an overall 60%

diversion, waste management strategies may instead focus

on these sectors rather than on residential organic waste.

The analytical method presented in this paper can be

used to evaluate the economic feasibility waste of diversion

strategies in other locations. The findings of this study will

likely be comparable to findings for other nearby

municipalities in southern Ontario given the similar waste composition and unit costs for waste collection and

disposal. Where collection and disposal costs are

substantially different from the values adapted in this study,

results, and consequently the preferred waste diversion

system, can be different even for the same uptake rates. In

particular, when collection and disposal costs are similar for

centralized collection and landfill disposal, centralized

collection becomes a more economically feasible option to

landfill disposal.

REFERENCES

[1] Statistics Canada. (2012). “Focus on Geography Series, 2011

Census”. Statistics Canada Catalogue no. 98-310-XWE2011004.

Ottawa, ON: Analytical Products.

[2] R. Kucera. (2014, February 3). Waste Questions [Online]. Available

e-mail: CKwaste@chatham-kent.ca Message: Composting Questions

[3] Region of Waterloo, Kathleen Barsoum, Waste Management

Coordinator

[4] Environment Canada, “Technical Document on Municipal Solid

Waste Organics Processing”, pp. 2-4 to 2-5, En14-83/2013E, Ottawa,

ON: Environment Canada, 2013.

[5] L. M. Johannessen, “Guidance Note on Leachate Management for

MSW Landfills,” The International Bank for Reconstruction and

Development (Urban Development Division), Washington, DC: The

World Bank, 1999.

[6] Integrated Pollution Prevention and Control, “Guidance for the

Treatment of Landfill Leachate”, London: UK Environment Agency,

IPPC S5.03, February 2007.

[7] City of Willmar, “Cost Comparison MCES & WWTP Leachate

Transport and Treatment”, Willmar, MN: Town of Willmar, January

1, 2012.

AUTHOR INFORMATION

Alexis Blair, Honours Student, Bachelors of Applied

Science in Environmental Engineering, Department of Civil

and Environmental Engineering, University of Waterloo.

Graeme Hollands, Honours Student, Bachelors of Applied

Science in Civil Engineering, Department of Civil and

Environmental Engineering, University of Waterloo.

Adriana MacDonald, Honours Student, Bachelors of

Applied Science in Environmental Engineering, Department

of Civil and Environmental Engineering, University of

Waterloo.

Kylee McIntosh, Honours Student, Bachelors of Applied

Science in Environmental Engineering, Department of Civil

and Environmental Engineering, University of Waterloo.

Bhumi Mehta, Honours Student, Bachelors of Applied

Science in Environmental Engineering, Department of Civil

and Environmental Engineering, University of Waterloo.

Honorio Umali, Graduate Student, Department of Civil and

Environmental Engineering, University of Waterloo.

Sheree Pagsuyoin, Assistant Professor, Department of Civil

and Environmental Engineering, University of Waterloo.

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