United States
Environmental Protection
Agency
Hazardous Waste Engineering
Research Laboratory
Cincinnati OH 45268
Research and Development
EPA/600/S2-85/023 May 1985
-/I*
Project Summary
Optional Cost Models for
Landfill Disposal of Municipal
Solid Waste
James F. Hudson and Patricia L. Deese
Forty-five landfills and associated
transfer stations, balers, shredders,
and transportation networks were
analyzed to determine costs for
building and operating a landfill and
to identify the factors that have the
greatest impacts on those costs. The
landfills studied ranged in size from
under 100 to more than 5000 tons per
day and were located across the con-
tinental United States.
A primary concern of the study was
to determine whether baling or shred-
ding reduced landfill costs. Analysis
of the data indicates that any savings
incurred at the landfill, due to prior
baling or shredding, usually does not
compensate for the added cost of
these more sophisticated processing
facilities for the average case. On the
other hand, baling or shredding might
be feasible in a situation where com-
ponent costs for the entire landfilling
system are high.
Another important finding is that
landfilling is only a small portion of
total costs. On the average, both the
haul and the processing components
of the system are more expensive
than the landfilling component.
This Project Summary was devel-
oped by EPA's Hazardous Waste En-
gineering Research Laboratory, Cin-
cinnati, OH, to announce key findings
of the research project that is fully
documented in a separate report of
the same title (see Project Report
ordering information at back).
Introduction
All steps in solid waste management
cost money. An effective manager will try
to find the system that acceptably handles
wastes at minimum cost. But the number
of options is large, and .detailed engineer-
ing studies of every option are expensive.
Simple methods are needed to structure
the various options and estimate rough
costs for each step so that extravagant
options can be eliminated. The remaining
possibilities can then be analyzed in
depth.
This project was designed to determine
the average costs of each option. Cost
data were collected and analyzed from 45
operating solid waste management facil-
ities, and methods were developed to
relate these findings to other local com-
munity information. The methods make it
possible to compare the costs of systems
with direct haul, transfer stations, balers,
shredders, and various landfill locations
and characteristics. Incinerators and
systems with significant resource recovery
were not included in this study.
Waste is generated along various col-
lection routes and hauled in the collection
trucks to a processing facility or a landfill.
If the waste is processed, it is then
transported in large vehicles to the land-
fill. Three types of processing were
studied—transfer, bailing, and shredding.
The landfilling costs depend on the types
of processing as well as the landfill design.
(depth, number of lifts, etc.). Landfill
construction costs, including liners, leach-
ate control systems, excavation, and
other site-related costs, depend on site
conditions.
Site Selection
The original plan called for the collec-
tion of data from nine sites for each of
the following five solid waste manage-
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ment schemes, for a total of 45 sites:
• Direct haul systems
• Transfer stations
• Balers-untied
• Balers-tied
• Shredders
To meet the overall objectives of the
project, a set of criteria was developed for
the selection of solid waste management
facilities to be used in the data base:
• The waste from the processing facili-
ty had to be landfilled (minimal fer-
rous recovery was acceptable),
• Records of the weights of wastes
processed had to be available,
• The facility had to have been in
operation for at least 1 year before
January 1980, and
• Parties at the site had to be willing to
participate in the study.
The selection process consisted of con-
tacting persons knowledgeable in the field
and evaluating results of an extensive lit-
erature review. After a potential site was
identified, local officials were contacted to
verify site characteristics and data avail-
ability. Many potential sites were
eliminated because of the lack of scales.
After elimination of all sites that did not
meet the set criteria or did not have
records of the weights of waste proc-
essed, the final list of candidate sites in-
cluded 2 tied balers, 7 untied balers, and
14 shredders.
Because of the limited number of ac-
ceptable sites, a new selection strategy
was devised. First, all the balers were
grouped together. Second, every effort
was made to include all of the acceptable
shredder and baler facilities. Finally,
transfer stations and direct haul facilities
were selected to insure a reasonable sam-
ple distribution of the following param-
eters:
• size (with an effort to focus on
smaller facilities
• ownership (including private and
public facilities), and
• geographical location (selected to
permit reasonable logistics for field
work).
With this new selection process, the
final sample consisted of 12 balefills, 9
shredfills, 11 transfer stations, and 13
direct haul systems. Of these 45 sites
selected, 18 had some form of leachate
collection, and another 16 plan leachate
facilities in the future. Of the 18 sites with
leachate collection, 7 discharge leachate
to a sewer, 4 recycle leachate over the fill,
and 7 have onsite leachate treatment.
Over half of the sites have some sort of
liner. Eighteen sights use natural clay
liners and five sites use some form of
manmade liner. Table 1 shows the distri-
bution of facilities by type and size.
Data Collection
Substantial data were collected from
each of the solid waste management sys-
tems visited. Information fell into three
basic categories: background, operations,
and costs. The data were gathered during
a series of previsit telephone interviews, a
site visit, a review of documents, and
followup telephone calls. A detailed inter-
view guide was developed to insure that
the correct questions were asked and to
provide a mechanism for organizing the
information collected.
Collection of background data was
necessary to identify which parties actual-
ly incurred costs for the various com-
ponents of the solid waste management
systems. A special questionnaire was
developed for use during the previsit
telephone interviews to determine which
parties were responsible for which com-
ponents.
The hypothesis was that the main oper-
ational factors affecting cost are haul,
processing, transfer, landfill operations,
and landfill construction. For these com-
ponents, data were collected on the size
of the operation based on weights of
waste processed.
Haul operational data focused on the
factors that influenced the resources
dedicated to hauling wastes in collection
vehicles from the final pickup point to the
discharge point. The resources invested
include labor time, equipment time, and
fuel. Data were collected on the percent
of the work day dedicated to hauling
rather than to collection, the distance of
the haul, the average tons per load, and
the crew size.
Processing operational data were meant
to reflect the efficiency with which the
facilities are used. Data were collected on
the design capacity, the actual wastes
processed, days lost to down time, hours
of operation per day, and days per year.
Availability of storage capacity for both
processed and unprocessed waste was
determined. For shredders, the average
particle size and the existence of metal
separation were noted. For balers, the
type of facility (either tied or untied) and
the size and weight of the bales were
recorded.
Transfer operational data focused on
the resources used in transporting proc-
essed wastes to the landfill face. Data
gathered included vehicle type and capa-
city, crew size, transfer distance, and
round trip time.
Landfill operational factors that might
influence cost (other than size) included
the number and types of waste streams
handled, age of the facility, method used,
number and height of lifts, amount of dai-
ly cover, and source of cover.
Landfill construction data included type
of liner if any, type of leachate collection
and treatment if any, and landfill method
used. Another important factor was
whether the landfill construction was
phased with operations or whether the fill
was constructed all at one time.
The cost data collected for each com-
ponent of the solid waste management
system were divided into capital and
operational costs to assure costs were
comparable from site to site. The costs
were standardized for labor rates, infla-
tion, and discounting method. Thus the
labor and capital portions of each cost
had to be calculated.
Conclusions and
Recommendations
The cost data collected from the 45
case study sites were analyzed using sta-
tistical methods. Also developed was a
series of cost curves that illustrate the in-
fluence of various parameters on the cost
of different components.
For both haul in the collection vehicles
and haul in the larger transfer vehicles, in-
creasing vehicle capacity reduced costs. A
10-percent increase in vehicle size led to a
6- to 7-percent decrease in costs across
all sites.
Baling and shredding had little effect on
the cost of transportation in large ve-
hicles. As expected, shredders and balers
had higher capital and operating costs
than transfer stations which offset other
cost-reducing factors such as size.
Table 1. Number of Sites by Size and Type
Design Capacity (metric tons/
• Type of Site
Haul
Transfer
Shredder
Baler
Total
0-100
4
1
3
8
100-300
3
1
3
3
10
300-600
2
6
2
4
14
600 +
4
3
4
2
13
Total
13
11
9
12
45
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Large processing facilities did not ap-
pear to be much, if any, cheaper per ton
than small ones. The actual hours of
equipment operation did affect costs,
however.
Increases in landfilling capacity reduced
costs considerably. A 200-ton-per-day
facility was 27 percent less expensive per
ton than a 50-ton-per-day facility. Baling
and shredding also helped. A balefill was
43 percent less expensive per ton than a
conventional landfill, and an uncovered,
shredded waste fill was 70 percent less
expensive to run. Thus the extra process-
ing does lead to savings in landfilling, but
not enough to offset the extra processing
cost.
No model was developed for landfill
construction costs. These costs varied
greatly and were influenced by a large
number of site-specific characteristics.
Study results confirm that high-tech
processing is expensive and can be
justified only if it eliminates considerable
landfill construction costs or greatly in-
creases in-place density, thus spreading
landfill costs over a longer period. Since
the former is not likely to bring sufficient
savings, the latter may become the key
factor in decisionmaking.
Such analyses often require an estimate
of in-place density (the total amount of
solid waste that can be disposed of per
acre of landfill). Though there are many
theoretical or experimental estimates of
densities that can be achieved through
compaction, baling, or shredding, very
few actual operational data exist on in-
place densities. None of the 45 sites in
this study (which included most of the
major balers and shredders) kept records
of in-place density. Thus the collection of
operational in-place density data through
landfill surveys could greatly improve the
decisionmaking process.
James F. Hudson and Patricia L Deese are with Urban Systems Research and
Engineering, Inc., Cambridge, MA 02138.
Oscar W. Albrecht and Douglas C. Ammon were the EPA Project Officer (see
below).
The complete report, entitled "Optional Cost Models for Landfill Disposal of
Municipal Solid Waste," (Order No. PB 85-176 808/AS; Cost $ 13.00, subject
to change) will be available only from:
National Technical Information Service
5285 Port Royal Road
Springfield, VA 22161
Telephone: 703-487-4650
For further information, Douglas C. Ammon, can be contacted at:
Hazardous Waste Engineering Research Laboratory
U.S. Environmental Protection Agency
Cincinnati, OH 45268
ft U.S. GOVERNMENT PRINTING OFFICE: 1965-55M16/27048
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